feat: integrate RTL-TCP server support

.gitattributes

@@ -0,0 +1 @@
+assets/* linguist-vendored

.vscode/settings.json

@@ -0,0 +1,83 @@
+{
+    "java.configuration.updateBuildConfiguration": "interactive",
+    "files.associations": {
+        "xstring": "cpp",
+        "algorithm": "cpp",
+        "any": "cpp",
+        "array": "cpp",
+        "atomic": "cpp",
+        "bit": "cpp",
+        "bitset": "cpp",
+        "cctype": "cpp",
+        "charconv": "cpp",
+        "chrono": "cpp",
+        "clocale": "cpp",
+        "cmath": "cpp",
+        "compare": "cpp",
+        "complex": "cpp",
+        "concepts": "cpp",
+        "coroutine": "cpp",
+        "cstddef": "cpp",
+        "cstdint": "cpp",
+        "cstdio": "cpp",
+        "cstdlib": "cpp",
+        "cstring": "cpp",
+        "ctime": "cpp",
+        "cwchar": "cpp",
+        "exception": "cpp",
+        "format": "cpp",
+        "forward_list": "cpp",
+        "fstream": "cpp",
+        "functional": "cpp",
+        "initializer_list": "cpp",
+        "iomanip": "cpp",
+        "ios": "cpp",
+        "iosfwd": "cpp",
+        "iostream": "cpp",
+        "istream": "cpp",
+        "iterator": "cpp",
+        "limits": "cpp",
+        "list": "cpp",
+        "locale": "cpp",
+        "map": "cpp",
+        "memory": "cpp",
+        "mutex": "cpp",
+        "new": "cpp",
+        "numeric": "cpp",
+        "optional": "cpp",
+        "ostream": "cpp",
+        "ratio": "cpp",
+        "regex": "cpp",
+        "set": "cpp",
+        "sstream": "cpp",
+        "stdexcept": "cpp",
+        "stop_token": "cpp",
+        "streambuf": "cpp",
+        "string": "cpp",
+        "system_error": "cpp",
+        "thread": "cpp",
+        "tuple": "cpp",
+        "type_traits": "cpp",
+        "typeindex": "cpp",
+        "typeinfo": "cpp",
+        "unordered_map": "cpp",
+        "utility": "cpp",
+        "variant": "cpp",
+        "vector": "cpp",
+        "xfacet": "cpp",
+        "xhash": "cpp",
+        "xiosbase": "cpp",
+        "xlocale": "cpp",
+        "xlocbuf": "cpp",
+        "xlocinfo": "cpp",
+        "xlocmes": "cpp",
+        "xlocmon": "cpp",
+        "xlocnum": "cpp",
+        "xloctime": "cpp",
+        "xmemory": "cpp",
+        "xtr1common": "cpp",
+        "xtree": "cpp",
+        "xutility": "cpp",
+        "codecvt": "cpp"
+    }
+}

README.md

@@ -3,21 +3,36 @@
 LBJ Console 是一款应用程序，用于通过 BLE 从 [SX1276_Receive_LBJ](https://github.com/undef-i/SX1276_Receive_LBJ) 设备接收并显示列车预警消息，功能包括：
 
 - 接收列车预警消息，支持可选的手机推送通知。
+- 监控指定列车的轨迹，在地图上显示。
 - 在地图上显示预警消息的 GPS 信息。
 - 基于内置数据文件显示机车配属，机车类型和车次类型。
+- [WIP] 从 RTL-TCP 获取数据。
 
 [android](https://github.com/undef-i/LBJ_Console/tree/android) 分支包含项目早期基于 Android 平台的实现代码，已实现基本功能，现已停止开发。
 
-
 ## 数据文件
 
 LBJ Console 依赖以下数据文件，位于 `assets` 目录，用于支持机车配属和车次信息的展示：
+
 - `loco_info.csv`：包含机车配属信息，格式为 `机车型号,机车编号起始值,机车编号结束值,所属铁路局及机务段,备注`。
 - `loco_type_info.csv`：包含机车类型编码信息，格式为 `机车类型编码前缀,机车类型`。
 - `train_info.csv`：包含车次类型信息，格式为 `正则表达式,车次类型`。
 
 数据来源于网络，可能存在错误或不完整，欢迎通过提交 Pull Request 共同完善数据准确性。
 
+# 计划实现的功能
+
+- 集成 ESP-Touch 协议，实现设备 WiFi 凭证的配置。
+- 从设备端拉取历史数据记录。
+
+# 致谢
+
+本项目的 RTL-TCP 解析功能以 [RailwayPagerDemod](https://github.com/Arch-Jason/RailwayPagerDemod) 为基础，并移植了 [SX1276_Receive_LBJ](https://github.com/FLN1021/SX1276_Receive_LBJ) 的部分解析逻辑。
+
+感谢以上项目作者的贡献。
+
+
 # 许可证
 
 该项目采用 GNU 通用公共许可证 v3.0（GPLv3）授权。
+

android/app/build.gradle

@@ -26,7 +26,7 @@ if (flutterVersionName == null) {
 android {
     namespace = "org.noxylva.lbjconsole.flutter"
     compileSdk = 36
-    ndkVersion = "26.1.10909125"
+    ndkVersion = "28.1.13356709"
 
     compileOptions {
         sourceCompatibility = JavaVersion.VERSION_11
@@ -72,6 +72,12 @@ android {
             universalApk true
         }
     }
+    externalNativeBuild {
+        cmake {
+            path "src/main/cpp/CMakeLists.txt"
+            version "3.22.1"
+        }
+    }
 }
 
 dependencies {

android/app/src/main/AndroidManifest.xml

@@ -1,4 +1,5 @@
-<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools">
     <uses-permission android:name="android.permission.BLUETOOTH"/>
     <uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>
     <uses-permission android:name="android.permission.BLUETOOTH_CONNECT" android:usesPermissionFlags="neverForLocation"/>
@@ -14,10 +15,11 @@
     <uses-permission android:name="android.permission.WAKE_LOCK"/>
     <uses-permission android:name="android.permission.POST_NOTIFICATIONS"/>
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE_DATA_SYNC"/>
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE_CONNECTED_DEVICE"/>
     
     <uses-feature android:name="android.hardware.bluetooth_le" android:required="true"/>
     <application
-        android:label="lbjconsole"
+        android:label="LBJ Console"
         android:name="${applicationName}"
         android:icon="@mipmap/ic_launcher">
         <activity
@@ -47,6 +49,15 @@
         <meta-data
             android:name="flutterEmbedding"
             android:value="2" />
+            
+        <!-- 前台服务配置 -->
+        <service
+            android:name="id.flutter.flutter_background_service.BackgroundService"
+            android:foregroundServiceType="connectedDevice|dataSync"
+            android:exported="false"
+            android:stopWithTask="false"
+            android:enabled="true"
+            tools:replace="android:exported"/>
     </application>
     <!-- Required to query activities that can process text, see:
          https://developer.android.com/training/package-visibility and

android/app/src/main/cpp/CMakeLists.txt

@@ -0,0 +1,22 @@
+# android/app/src/main/cpp/CMakeLists.txt
+
+cmake_minimum_required(VERSION 3.22.1)
+project("railwaypagerdemod")
+
+add_library(${CMAKE_PROJECT_NAME} SHARED
+        demod.cpp
+        demod.h
+        native-lib.cpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/dsp/firfilter.cpp
+        )
+
+target_link_libraries(${CMAKE_PROJECT_NAME}
+        android
+        log
+        m)
+
+add_definitions(-DSDRBASE_API=)
+include_directories(
+        ${CMAKE_CURRENT_SOURCE_DIR}
+        ${CMAKE_CURRENT_SOURCE_DIR}/fcdlib
+)

android/app/src/main/cpp/demod.cpp

@@ -0,0 +1,410 @@
+#include "demod.h"
+
+bool is_message_ready = false;
+
+PhaseDiscriminators phaseDiscri;
+Lowpass<double> lowpassBaud;
+MovingAverageUtil<double, double, 2048> preambleMovingAverage;
+
+bool got_SC = false;
+double dc_offset = 0.0;
+bool prev_data, bit_inverted, data_bit;
+int sync_cnt, bit_cnt = 0, word_cnt = 0;
+uint32_t bits;
+uint32_t code_words[PAGERDEMOD_BATCH_WORDS];
+bool code_words_bch_error[PAGERDEMOD_BATCH_WORDS];
+
+std::string numeric_msg, alpha_msg;
+int function_bits;
+uint32_t address;
+uint32_t alpha_bit_buffer; // Bit buffer to 7-bit chars spread across codewords
+int alpha_bit_buffer_bits; // Count of bits in alpha_bit_buffer
+int parity_errors;         // Count of parity errors in current message
+int bch_errors;            // Count of BCH errors in current message
+int batch_num;             // Count of batches in current transmission
+
+double magsqRaw;
+
+int pop_cnt(uint32_t cw)
+{
+    int cnt = 0;
+    for (int i = 0; i < 32; i++)
+    {
+        cnt += cw & 1;
+        cw = cw >> 1;
+    }
+    return cnt;
+}
+
+uint32_t bchEncode(const uint32_t cw)
+{
+    uint32_t bit = 0;
+    uint32_t localCW = cw & 0xFFFFF800; // Mask off BCH parity and even parity bits
+    uint32_t cwE = localCW;
+
+    // Calculate BCH bits
+    for (bit = 1; bit <= 21; bit++)
+    {
+        if (cwE & 0x80000000)
+        {
+            cwE ^= 0xED200000;
+        }
+        cwE <<= 1;
+    }
+    localCW |= (cwE >> 21);
+
+    return localCW;
+}
+
+// Use BCH decoding to try to fix any bit errors
+// Returns true if able to be decode/repair successful
+// See: https://www.eevblog.com/forum/microcontrollers/practical-guides-to-bch-fec/
+bool bchDecode(const uint32_t cw, uint32_t &correctedCW)
+{
+    // Calculate syndrome
+    // We do this by recalculating the BCH parity bits and XORing them against the received ones
+    uint32_t syndrome = ((bchEncode(cw) ^ cw) >> 1) & 0x3FF;
+
+    if (syndrome == 0)
+    {
+        // Syndrome of zero indicates no repair required
+        correctedCW = cw;
+        return true;
+    }
+
+    // Meggitt decoder
+
+    uint32_t result = 0;
+    uint32_t damagedCW = cw;
+
+    // Calculate BCH bits
+    for (uint32_t xbit = 0; xbit < 31; xbit++)
+    {
+        // Produce the next corrected bit in the high bit of the result
+        result <<= 1;
+        if ((syndrome == 0x3B4) || // 0x3B4: Syndrome when a single error is detected in the MSB
+            (syndrome == 0x26E) || // 0x26E: Two adjacent errors
+            (syndrome == 0x359) || // 0x359: Two errors, one OK bit between
+            (syndrome == 0x076) || // 0x076: Two errors, two OK bits between
+            (syndrome == 0x255) || // 0x255: Two errors, three OK bits between
+            (syndrome == 0x0F0) || // 0x0F0: Two errors, four OK bits between
+            (syndrome == 0x216) ||
+            (syndrome == 0x365) ||
+            (syndrome == 0x068) ||
+            (syndrome == 0x25A) ||
+            (syndrome == 0x343) ||
+            (syndrome == 0x07B) ||
+            (syndrome == 0x1E7) ||
+            (syndrome == 0x129) ||
+            (syndrome == 0x14E) ||
+            (syndrome == 0x2C9) ||
+            (syndrome == 0x0BE) ||
+            (syndrome == 0x231) ||
+            (syndrome == 0x0C2) ||
+            (syndrome == 0x20F) ||
+            (syndrome == 0x0DD) ||
+            (syndrome == 0x1B4) ||
+            (syndrome == 0x2B4) ||
+            (syndrome == 0x334) ||
+            (syndrome == 0x3F4) ||
+            (syndrome == 0x394) ||
+            (syndrome == 0x3A4) ||
+            (syndrome == 0x3BC) ||
+            (syndrome == 0x3B0) ||
+            (syndrome == 0x3B6) ||
+            (syndrome == 0x3B5))
+        {
+            // Syndrome matches an error in the MSB
+            // Correct that error and adjust the syndrome to account for it
+            syndrome ^= 0x3B4;
+            result |= (~damagedCW & 0x80000000) >> 30;
+        }
+        else
+        {
+            // No error
+            result |= (damagedCW & 0x80000000) >> 30;
+        }
+        damagedCW <<= 1;
+
+        // Handle syndrome shift register feedback
+        if (syndrome & 0x200)
+        {
+            syndrome <<= 1;
+            syndrome ^= 0x769; // 0x769 = POCSAG generator polynomial -- x^10 + x^9 + x^8 + x^6 + x^5 + x^3 + 1
+        }
+        else
+        {
+            syndrome <<= 1;
+        }
+        // Mask off bits which fall off the end of the syndrome shift register
+        syndrome &= 0x3FF;
+    }
+
+    // Check if error correction was successful
+    if (syndrome != 0)
+    {
+        // Syndrome nonzero at end indicates uncorrectable errors
+        correctedCW = cw;
+        return false;
+    }
+
+    correctedCW = result;
+    return true;
+}
+
+int xorBits(uint32_t word, int firstBit, int lastBit)
+{
+    int x = 0;
+    for (int i = firstBit; i <= lastBit; i++)
+    {
+        x ^= (word >> i) & 1;
+    }
+    return x;
+}
+
+// Check for even parity
+bool evenParity(uint32_t word, int firstBit, int lastBit, int parityBit)
+{
+    return xorBits(word, firstBit, lastBit) == parityBit;
+}
+
+// Reverse order of bits
+uint32_t reverse(uint32_t x)
+{
+    x = (((x & 0xaaaaaaaa) >> 1) | ((x & 0x55555555) << 1));
+    x = (((x & 0xcccccccc) >> 2) | ((x & 0x33333333) << 2));
+    x = (((x & 0xf0f0f0f0) >> 4) | ((x & 0x0f0f0f0f) << 4));
+    x = (((x & 0xff00ff00) >> 8) | ((x & 0x00ff00ff) << 8));
+    return ((x >> 16) | (x << 16));
+}
+
+// Decode a batch of codewords to addresses and messages
+// Messages may be spreadout over multiple batches
+// https://www.itu.int/dms_pubrec/itu-r/rec/m/R-REC-M.584-1-198607-S!!PDF-E.pdf
+// https://www.itu.int/dms_pubrec/itu-r/rec/m/R-REC-M.584-2-199711-I!!PDF-E.pdf
+void decodeBatch()
+{
+    int i = 1;
+    for (int frame = 0; frame < PAGERDEMOD_FRAMES_PER_BATCH; frame++)
+    {
+        for (int word = 0; word < PAGERDEMOD_CODEWORDS_PER_FRAME; word++)
+        {
+            bool addressCodeWord = ((code_words[i] >> 31) & 1) == 0;
+
+            // Check parity bit
+            bool parityError = !evenParity(code_words[i], 1, 31, code_words[i] & 0x1);
+
+            if (code_words[i] == PAGERDEMOD_POCSAG_IDLECODE)
+            {
+                // Idle
+            }
+            else if (addressCodeWord)
+            {
+                // Address
+                function_bits = (code_words[i] >> 11) & 0x3;
+                int addressBits = (code_words[i] >> 13) & 0x3ffff;
+                address = (addressBits << 3) | frame;
+                numeric_msg = "";
+                alpha_msg = "";
+                alpha_bit_buffer_bits = 0;
+                alpha_bit_buffer = 0;
+                parity_errors = parityError ? 1 : 0;
+                bch_errors = code_words_bch_error[i] ? 1 : 0;
+            }
+            else
+            {
+                // Message - decode as both numeric and ASCII - not all operators use functionBits to indidcate encoding
+                int messageBits = (code_words[i] >> 11) & 0xfffff;
+                if (parityError)
+                {
+                    parity_errors++;
+                }
+                if (code_words_bch_error[i])
+                {
+                    bch_errors++;
+                }
+
+                // Numeric format
+                for (int j = 16; j >= 0; j -= 4)
+                {
+                    uint32_t numericBits = (messageBits >> j) & 0xf;
+                    numericBits = reverse(numericBits) >> (32 - 4);
+                    // Spec has 0xa as 'spare', but other decoders treat is as .
+                    const char numericChars[] = {
+                        '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '.', 'U', ' ', '-', ')', '('};
+                    char numericChar = numericChars[numericBits];
+                    numeric_msg.push_back(numericChar);
+                }
+
+                // 7-bit ASCII alpnanumeric format
+                alpha_bit_buffer = (alpha_bit_buffer << 20) | messageBits;
+                alpha_bit_buffer_bits += 20;
+                while (alpha_bit_buffer_bits >= 7)
+                {
+                    // Extract next 7-bit character from bit buffer
+                    char c = (alpha_bit_buffer >> (alpha_bit_buffer_bits - 7)) & 0x7f;
+                    // Reverse bit ordering
+                    c = reverse(c) >> (32 - 7);
+                    // Add to received message string (excluding, null, end of text, end ot transmission)
+                    if (c != 0 && c != 0x3 && c != 0x4)
+                    {
+                        alpha_msg.push_back(c);
+                    }
+                    // Remove from bit buffer
+                    alpha_bit_buffer_bits -= 7;
+                    if (alpha_bit_buffer_bits == 0)
+                    {
+                        alpha_bit_buffer = 0;
+                    }
+                    else
+                    {
+                        alpha_bit_buffer &= (1 << alpha_bit_buffer_bits) - 1;
+                    }
+                }
+            }
+
+            // Move to next codeword
+            i++;
+        }
+    }
+}
+
+void processOneSample(int8_t i, int8_t q)
+{
+    float fi = ((float)i) / 128.0f;
+    float fq = ((float)q) / 128.0f;
+
+    std::complex<float> iq(fi, fq);
+
+    float deviation;
+    double fmDemod = phaseDiscri.phaseDiscriminatorDelta(iq, magsqRaw, deviation);
+    // printf("fmDemod: %.3f\n", fmDemod);
+
+    double filt = lowpassBaud.filter(fmDemod);
+
+    if (!got_SC)
+    {
+        preambleMovingAverage(filt);
+        dc_offset = preambleMovingAverage.asDouble();
+    }
+
+    bool data = (filt - dc_offset) >= 0.0;
+    // printf("filt - dc: %.3f\n", filt - dc_offset);
+
+    if (data != prev_data)
+    {
+        sync_cnt = SAMPLES_PER_SYMBOL / 2; // reset
+    }
+    else
+    {
+        sync_cnt--; // wait until next bit's midpoint
+
+        if (sync_cnt <= 0)
+        {
+            if (bit_inverted)
+            {
+                data_bit = data;
+            }
+            else
+            {
+                data_bit = !data;
+            }
+
+            // printf("%d", data_bit);
+
+            bits = (bits << 1) | data_bit;
+            bit_cnt++;
+
+            if (bit_cnt > 32)
+            {
+                bit_cnt = 32;
+            }
+
+            if (bit_cnt == 32 && !got_SC)
+            {
+                // printf("pop count:     %d\n", pop_cnt(bits ^ POCSAG_SYNCCODE));
+                // printf("pop count inv: %d\n", pop_cnt(bits ^ POCSAG_SYNCCODE_INV));
+
+                if (bits == POCSAG_SYNCCODE)
+                {
+                    got_SC = true;
+                    bit_inverted = false;
+                    printf("\nSync code found\n");
+                }
+                else if (bits == POCSAG_SYNCCODE_INV)
+                {
+                    got_SC = true;
+                    bit_inverted = true;
+                    printf("\nSync code found\n");
+                }
+                else if (pop_cnt(bits ^ POCSAG_SYNCCODE) <= 3)
+                {
+                    uint32_t corrected_cw;
+                    if (bchDecode(bits, corrected_cw) && corrected_cw == POCSAG_SYNCCODE)
+                    {
+                        got_SC = true;
+                        bit_inverted = false;
+                        printf("\nSync code found\n");
+                    }
+                    // else printf("\nSync code not found\n");
+                }
+                else if (pop_cnt(bits ^ POCSAG_SYNCCODE_INV) <= 3)
+                {
+                    uint32_t corrected_cw;
+                    if (bchDecode(~bits, corrected_cw) && corrected_cw == POCSAG_SYNCCODE)
+                    {
+                        got_SC = true;
+                        bit_inverted = true;
+                        printf("\nSync code found\n");
+                    }
+                    // else printf("\nSync code not found\n");
+                }
+
+                if (got_SC)
+                {
+                    bits = 0;
+                    bit_cnt = 0;
+                    code_words[0] = POCSAG_SYNCCODE;
+                    word_cnt = 1;
+                }
+            }
+            else if (bit_cnt == 32 && got_SC)
+            {
+                uint32_t corrected_cw;
+                code_words_bch_error[word_cnt] = !bchDecode(bits, corrected_cw);
+                code_words[word_cnt] = corrected_cw;
+                word_cnt++;
+
+                if (word_cnt == 1 && corrected_cw != POCSAG_SYNCCODE)
+                {
+                    got_SC = false;
+                    bit_inverted = false;
+                }
+
+                if (word_cnt == PAGERDEMOD_BATCH_WORDS)
+                {
+                    decodeBatch();
+                    batch_num++;
+                    word_cnt = 0;
+                }
+
+                bits = 0;
+                bit_cnt = 0;
+
+                if (address > 0 && !numeric_msg.empty())
+                {
+                    is_message_ready = true;
+                    printf("Addr: %d | Numeric: %s | Alpha: %s\n", address, numeric_msg.c_str(), alpha_msg.c_str());
+                }
+                else
+                {
+                    is_message_ready = false;
+                }
+            }
+
+            sync_cnt = SAMPLES_PER_SYMBOL;
+        }
+    }
+
+    prev_data = data;
+}

android/app/src/main/cpp/demod.h

@@ -0,0 +1,39 @@
+#ifndef DEMOD_H
+#define DEMOD_H
+
+#include <complex>
+#include <stdbool.h>
+#include <stdint.h>
+#include <string>
+#include <iostream>
+
+#include "dsp/phasediscri.h"
+#include "dsp/firfilter.h"
+#include "util/movingaverage.h"
+
+#define SDR_RX_SCALED 32768.0
+#define SAMPLE_RATE 48000.0
+#define BAUD_RATE 1200.0
+#define DEVIATION 4500.0
+#define SAMPLES_PER_SYMBOL (SAMPLE_RATE / BAUD_RATE)
+#define POCSAG_SYNCCODE 0x7CD215D8
+#define POCSAG_SYNCCODE_INV ~0x7CD215D8
+#define PAGERDEMOD_POCSAG_IDLECODE 0x7A89C197
+#define PAGERDEMOD_BATCH_WORDS 17
+#define PAGERDEMOD_FRAMES_PER_BATCH 8
+#define PAGERDEMOD_CODEWORDS_PER_FRAME 2
+
+extern bool is_message_ready;
+extern std::string numeric_msg;
+extern std::string alpha_msg;
+extern uint32_t address;
+extern int function_bits;
+
+extern PhaseDiscriminators phaseDiscri;
+extern Lowpass<double> lowpassBaud;
+extern MovingAverageUtil<double, double, 2048> preambleMovingAverage;
+extern double magsqRaw;
+
+void processOneSample(int8_t i, int8_t q);
+
+#endif

android/app/src/main/cpp/dsp/afsquelch.cpp

@@ -0,0 +1,278 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2015-2019 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+// Copyright (C) 2020 Kacper Michajłow <kasper93@gmail.com>                      //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include <cmath>
+
+#include <QDebug>
+
+#include "dsp/afsquelch.h"
+
+
+AFSquelch::AFSquelch() :
+            m_nbAvg(128),
+			m_N(24),
+			m_sampleRate(48000),
+			m_samplesProcessed(0),
+            m_samplesAvgProcessed(0),
+			m_maxPowerIndex(0),
+			m_nTones(2),
+			m_samplesAttack(0),
+			m_attackCount(0),
+			m_samplesDecay(0),
+			m_decayCount(0),
+			m_squelchCount(0),
+			m_isOpen(false),
+			m_threshold(0.0)
+{
+	m_k = new double[m_nTones];
+	m_coef = new double[m_nTones];
+	m_toneSet = new double[m_nTones];
+	m_u0 = new double[m_nTones];
+	m_u1 = new double[m_nTones];
+	m_power = new double[m_nTones];
+    m_movingAverages.resize(m_nTones, MovingAverage<double>(m_nbAvg, 0.0f));
+
+    for (unsigned int j = 0; j < m_nTones; ++j)
+	{
+		m_toneSet[j] = j == 0 ? 1000.0 : 6000.0;
+        m_k[j] = ((double)m_N * m_toneSet[j]) / (double) m_sampleRate;
+        m_coef[j] = 2.0 * cos((2.0 * M_PI * m_toneSet[j])/(double) m_sampleRate);
+        m_u0[j] = 0.0;
+        m_u1[j] = 0.0;
+        m_power[j] = 0.0;
+        m_movingAverages[j].fill(0.0);
+	}
+}
+
+
+AFSquelch::~AFSquelch()
+{
+	delete[] m_k;
+	delete[] m_coef;
+	delete[] m_toneSet;
+	delete[] m_u0;
+	delete[] m_u1;
+	delete[] m_power;
+}
+
+void AFSquelch::setCoefficients(
+        unsigned int N,
+        unsigned int nbAvg,
+        unsigned int sampleRate,
+        unsigned int samplesAttack,
+        unsigned int samplesDecay,
+        const double *tones)
+{
+	m_N = N;                   // save the basic parameters for use during analysis
+	m_nbAvg = nbAvg;
+	m_sampleRate = sampleRate;
+	m_samplesAttack = samplesAttack;
+	m_samplesDecay = samplesDecay;
+	m_movingAverages.resize(m_nTones, MovingAverage<double>(m_nbAvg, 0.0));
+	m_samplesProcessed = 0;
+    m_samplesAvgProcessed = 0;
+	m_maxPowerIndex = 0;
+	m_attackCount = 0;
+	m_decayCount = 0;
+	m_squelchCount = 0;
+	m_isOpen = false;
+	m_threshold = 0.0;
+
+	// for each of the frequencies (tones) of interest calculate
+	// k and the associated filter coefficient as per the Goertzel
+	// algorithm. Note: we are using a real value (as opposed to
+	// an integer as described in some references. k is retained
+	// for later display. The tone set is specified in the
+	// constructor. Notice that the resulting coefficients are
+	// independent of N.
+
+    for (unsigned int j = 0; j < m_nTones; ++j)
+	{
+        m_toneSet[j] = tones[j] < ((double) m_sampleRate) * 0.4 ? tones[j] : ((double) m_sampleRate) * 0.4; // guarantee 80% Nyquist rate
+		m_k[j] = ((double)m_N * m_toneSet[j]) / (double)m_sampleRate;
+		m_coef[j] = 2.0 * cos((2.0 * M_PI * m_toneSet[j])/(double)m_sampleRate);
+		m_u0[j] = 0.0;
+		m_u1[j] = 0.0;
+        m_power[j] = 0.0;
+        m_movingAverages[j].fill(0.0);
+	}
+}
+
+
+// Analyze an input signal
+bool AFSquelch::analyze(double sample)
+{
+
+	feedback(sample); // Goertzel feedback
+
+	if (m_samplesProcessed < m_N) // completed a block of N
+	{
+	    m_samplesProcessed++;
+        return false;
+	}
+	else
+	{
+        feedForward(); // calculate the power at each tone
+        m_samplesProcessed = 0;
+
+        if (m_samplesAvgProcessed < m_nbAvg)
+        {
+            m_samplesAvgProcessed++;
+            return false;
+        }
+        else
+        {
+            return true; // have a result
+        }
+	}
+}
+
+
+void AFSquelch::feedback(double in)
+{
+	double t;
+
+	// feedback for each tone
+    for (unsigned int j = 0; j < m_nTones; ++j)
+	{
+		t = m_u0[j];
+		m_u0[j] = in + (m_coef[j] * m_u0[j]) - m_u1[j];
+		m_u1[j] = t;
+	}
+}
+
+
+void AFSquelch::feedForward()
+{
+    for (unsigned int j = 0; j < m_nTones; ++j)
+	{
+		m_power[j] = (m_u0[j] * m_u0[j]) + (m_u1[j] * m_u1[j]) - (m_coef[j] * m_u0[j] * m_u1[j]);
+		m_movingAverages[j].feed(m_power[j]);
+		m_u0[j] = 0.0;
+		m_u1[j] = 0.0; // reset for next block.
+	}
+
+	evaluate();
+}
+
+
+void AFSquelch::reset()
+{
+    for (unsigned int j = 0; j < m_nTones; ++j)
+	{
+        m_u0[j] = 0.0;
+        m_u1[j] = 0.0;
+        m_power[j] = 0.0;
+        m_movingAverages[j].fill(0.0);
+	}
+
+	m_samplesProcessed = 0;
+	m_maxPowerIndex = 0;
+	m_isOpen = false;
+}
+
+
+bool AFSquelch::evaluate()
+{
+	double maxPower = 0.0;
+	double minPower;
+	int minIndex = 0, maxIndex = 0;
+
+    for (unsigned int j = 0; j < m_nTones; ++j)
+	{
+		if (m_movingAverages[j].sum() > maxPower)
+		{
+			maxPower = m_movingAverages[j].sum();
+			maxIndex = j;
+		}
+	}
+
+    if (maxPower == 0.0)
+    {
+        return m_isOpen;
+    }
+
+	minPower = maxPower;
+
+    for (unsigned int j = 0; j < m_nTones; ++j)
+	{
+		if (m_movingAverages[j].sum() < minPower) {
+			minPower = m_movingAverages[j].sum();
+			minIndex = j;
+		}
+	}
+
+//    m_isOpen = ((minPower/maxPower < m_threshold) && (minIndex > maxIndex));
+    if ((minPower/maxPower < m_threshold) && (minIndex > maxIndex)) // open condition
+    {
+
+        if (m_squelchCount < m_samplesAttack + m_samplesDecay)
+        {
+            m_squelchCount++;
+        }
+    }
+    else
+    {
+        if (m_squelchCount > m_samplesAttack)
+        {
+            m_squelchCount--;
+        }
+        else
+        {
+            m_squelchCount = 0;
+        }
+    }
+
+    m_isOpen = (m_squelchCount >= m_samplesAttack) ;
+
+//	if ((minPower/maxPower < m_threshold) && (minIndex > maxIndex)) // open condition
+//	{
+//		if ((m_samplesAttack > 0) && (m_attackCount < m_samplesAttack))
+//		{
+//			m_isOpen = false;
+//			m_attackCount++;
+//		}
+//		else
+//		{
+//			m_isOpen = true;
+//			m_decayCount = 0;
+//		}
+//	}
+//	else
+//	{
+//		if ((m_samplesDecay > 0) && (m_decayCount < m_samplesDecay))
+//		{
+//			m_isOpen = true;
+//			m_decayCount++;
+//		}
+//		else
+//		{
+//			m_isOpen = false;
+//			m_attackCount = 0;
+//		}
+//	}
+
+	return m_isOpen;
+}
+
+void AFSquelch::setThreshold(double threshold)
+{
+	qDebug("AFSquelch::setThreshold: threshold: %f", threshold);
+	m_threshold = threshold;
+	reset();
+}

android/app/src/main/cpp/dsp/afsquelch.h

@@ -0,0 +1,91 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2015-2019 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef INCLUDE_GPL_DSP_AFSQUELCH_H_
+#define INCLUDE_GPL_DSP_AFSQUELCH_H_
+
+#include "dsp/movingaverage.h"
+#include "export.h"
+
+/** AFSquelch: AF squelch class based on the Modified Goertzel
+ * algorithm.
+ */
+class SDRBASE_API AFSquelch {
+public:
+    // constructor with default values
+	AFSquelch();
+    virtual ~AFSquelch();
+
+    // setup the basic parameters and coefficients
+    void setCoefficients(
+            unsigned int N,              //!< the algorithm "block"  size
+			unsigned int nbAvg,          //!< averaging size
+			unsigned int sampleRate,     //!< input signal sample rate
+			unsigned int samplesAttack,  //!< number of results before squelch opens
+			unsigned int samplesDecay,   //!< number of results keeping squelch open
+			const double *tones);        //!< center frequency of tones tested
+
+    // set the detection threshold
+    void setThreshold(double _threshold);
+
+    // analyze a sample set and optionally filter
+    // the tone frequencies.
+    bool analyze(double sample); // input signal sample
+    bool evaluate(); // evaluate result
+
+    // get the tone set
+    const double *getToneSet() const
+    {
+    	return m_toneSet;
+    }
+
+    bool open() const {
+    	return m_isOpen;
+    }
+
+    void reset();                       // reset the analysis algorithm
+
+protected:
+    void feedback(double sample);
+    void feedForward();
+
+private:
+    unsigned int m_nbAvg; //!< number of power samples taken for moving average
+    unsigned int m_N;
+    unsigned int m_sampleRate;
+    unsigned int m_samplesProcessed;
+    unsigned int m_samplesAvgProcessed;
+    unsigned int m_maxPowerIndex;
+    unsigned int m_nTones;
+    unsigned int m_samplesAttack;
+    unsigned int m_attackCount;
+    unsigned int m_samplesDecay;
+    unsigned int m_decayCount;
+    unsigned int m_squelchCount;
+    bool m_isOpen;
+    double m_threshold;
+    double *m_k;
+    double *m_coef;
+    double *m_toneSet;
+    double *m_u0;
+    double *m_u1;
+    double *m_power;
+    std::vector<MovingAverage<double> > m_movingAverages;
+};
+
+
+#endif /* INCLUDE_GPL_DSP_CTCSSDETECTOR_H_ */

android/app/src/main/cpp/dsp/agc.cpp

@@ -0,0 +1,191 @@
+///////////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2015-2019 Edouard Griffiths, F4EXB <f4exb06@gmail.com>              //
+//                                                                                   //
+// This program is free software; you can redistribute it and/or modify              //
+// it under the terms of the GNU General Public License as published by              //
+// the Free Software Foundation as version 3 of the License, or                      //
+// (at your option) any later version.                                               //
+//                                                                                   //
+// This program is distributed in the hope that it will be useful,                   //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                    //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                      //
+// GNU General Public License V3 for more details.                                   //
+//                                                                                   //
+// You should have received a copy of the GNU General Public License                 //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.              //
+///////////////////////////////////////////////////////////////////////////////////////
+
+#include <algorithm>
+#include "dsp/agc.h"
+
+#include "util/stepfunctions.h"
+
+AGC::AGC(int historySize, double R) :
+	m_u0(1.0),
+	m_R(R),
+	m_moving_average(historySize, m_R),
+	m_historySize(historySize),
+	m_count(0)
+{}
+
+AGC::~AGC()
+{}
+
+void AGC::resize(int historySize, double R)
+{
+	m_R = R;
+	m_moving_average.resize(historySize, R);
+	m_historySize = historySize;
+	m_count = 0;
+}
+
+Real AGC::getValue()
+{
+	return m_u0;
+}
+
+Real AGC::getAverage()
+{
+	return m_moving_average.average();
+}
+
+
+MagAGC::MagAGC(int historySize, double R, double threshold) :
+	AGC(historySize, R),
+	m_squared(false),
+	m_magsq(0.0),
+	m_threshold(threshold),
+	m_thresholdEnable(true),
+	m_gate(0),
+	m_stepLength(std::min(2400, historySize/2)), // max 50 ms (at 48 kHz)
+    m_stepDelta(1.0/m_stepLength),
+	m_stepUpCounter(0),
+    m_stepDownCounter(0),
+	m_gateCounter(0),
+	m_stepDownDelay(historySize),
+    m_hardLimiting(false)
+{}
+
+MagAGC::~MagAGC()
+{}
+
+void MagAGC::resize(int historySize, int stepLength, Real R)
+{
+    m_stepLength = stepLength;
+    m_stepDelta = 1.0 / m_stepLength;
+    m_stepUpCounter = 0;
+    m_stepDownCounter = 0;
+    AGC::resize(historySize, R);
+    m_moving_average.fill(m_squared ? R : R*R);
+}
+
+void MagAGC::setOrder(double R)
+{
+    AGC::setOrder(R);
+    m_moving_average.fill(m_squared ? R : R*R);
+}
+
+void MagAGC::setThresholdEnable(bool enable)
+{
+    if (m_thresholdEnable != enable)
+    {
+        m_stepUpCounter = 0;
+        m_stepDownCounter = 0;
+    }
+
+    m_thresholdEnable = enable;
+}
+
+void MagAGC::feed(Complex& ci)
+{
+	ci *= feedAndGetValue(ci);
+}
+
+double MagAGC::hardLimiter(double multiplier, double magsq)
+{
+    if ((m_hardLimiting) && (multiplier*multiplier*magsq > 1.0)) {
+        return 1.0 / (multiplier*sqrt(magsq));
+    } else {
+        return multiplier;
+    }
+}
+
+double MagAGC::feedAndGetValue(const Complex& ci)
+{
+    m_magsq = ci.real()*ci.real() + ci.imag()*ci.imag();
+    m_moving_average.feed(m_magsq);
+    m_u0 = m_R / (m_squared ? m_moving_average.average() : sqrt(m_moving_average.average()));
+
+    if (m_thresholdEnable)
+    {
+        bool open = false;
+
+        if (m_magsq > m_threshold)
+        {
+            if (m_gateCounter < m_gate) {
+                m_gateCounter++;
+            } else {
+                open = true;
+            }
+        }
+        else
+        {
+            m_gateCounter = 0;
+        }
+
+        if (open)
+        {
+            m_count = m_stepDownDelay; // delay before step down (grace delay)
+        }
+        else
+        {
+            m_count--;
+            m_gateCounter = m_gate; // keep gate open during grace
+        }
+
+        if (m_count > 0) // up phase
+        {
+            m_stepDownCounter = m_stepUpCounter; // prepare for step down
+
+            if (m_stepUpCounter < m_stepLength) // step up
+            {
+                m_stepUpCounter++;
+                return hardLimiter(m_u0 * StepFunctions::smootherstep(m_stepUpCounter * m_stepDelta), m_magsq);
+            }
+            else // steady open
+            {
+                return hardLimiter(m_u0, m_magsq);
+            }
+        }
+        else // down phase
+        {
+            m_stepUpCounter = m_stepDownCounter; // prepare for step up
+
+            if (m_stepDownCounter > 0) // step down
+            {
+                m_stepDownCounter--;
+                return hardLimiter(m_u0 * StepFunctions::smootherstep(m_stepDownCounter * m_stepDelta), m_magsq);
+            }
+            else // steady closed
+            {
+                return 0.0;
+            }
+        }
+    }
+    else
+    {
+        return hardLimiter(m_u0, m_magsq);
+    }
+}
+
+float MagAGC::getStepValue() const
+{
+    if (m_count > 0) // up phase
+    {
+        return StepFunctions::smootherstep(m_stepUpCounter * m_stepDelta); // step up
+    }
+    else // down phase
+    {
+        return StepFunctions::smootherstep(m_stepDownCounter * m_stepDelta); // step down
+    }
+}

android/app/src/main/cpp/dsp/agc.h

@@ -0,0 +1,137 @@
+///////////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2015-2019 Edouard Griffiths, F4EXB <f4exb06@gmail.com>              //
+//                                                                                   //
+// This program is free software; you can redistribute it and/or modify              //
+// it under the terms of the GNU General Public License as published by              //
+// the Free Software Foundation as version 3 of the License, or                      //
+// (at your option) any later version.                                               //
+//                                                                                   //
+// This program is distributed in the hope that it will be useful,                   //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                    //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                      //
+// GNU General Public License V3 for more details.                                   //
+//                                                                                   //
+// You should have received a copy of the GNU General Public License                 //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.              //
+///////////////////////////////////////////////////////////////////////////////////////
+
+#ifndef INCLUDE_GPL_DSP_AGC_H_
+#define INCLUDE_GPL_DSP_AGC_H_
+
+#include "dsp/dsptypes.h"
+#include "movingaverage.h"
+#include "export.h"
+
+class SDRBASE_API AGC
+{
+public:
+	AGC(int historySize, double R);
+	virtual ~AGC();
+
+	void resize(int historySize, double R);
+	void setOrder(double R) { m_R = R; }
+	Real getValue();
+	Real getAverage();
+    void reset(double R) { m_moving_average.fill(R); }
+	virtual void feed(Complex& ci) = 0;
+
+protected:
+	double m_u0;                            //!< AGC factor
+	double m_R;                             //!< ordered magnitude
+	MovingAverage<double> m_moving_average; //!< Averaging engine. The stack length conditions the smoothness of AGC.
+	int m_historySize;                      //!< Averaging length (the longer the slower the AGC)
+	int m_count;                            //!< Samples counter
+};
+
+
+class SDRBASE_API MagAGC : public AGC
+{
+public:
+	MagAGC(int historySize, double R, double threshold);
+	virtual ~MagAGC();
+	void setSquared(bool squared) { m_squared = squared; }
+	void resize(int historySize, int stepLength, Real R);
+	void setOrder(double R);
+	virtual void feed(Complex& ci);
+    double feedAndGetValue(const Complex& ci);
+    double getMagSq() const { return m_magsq; }
+    void setThreshold(double threshold) { m_threshold = threshold; }
+    void setThresholdEnable(bool enable);
+    void setGate(int gate) { m_gate = gate; m_gateCounter = 0; m_count = 0; }
+    void setStepDownDelay(int stepDownDelay) { m_stepDownDelay = stepDownDelay; m_gateCounter = 0; m_count = 0; }
+    int getStepDownDelay() const { return m_stepDownDelay; }
+    float getStepValue() const;
+    void setHardLimiting(bool hardLimiting) { m_hardLimiting = hardLimiting; }
+    void resetStepCounters() { m_stepUpCounter = 0; m_stepDownCounter = 0; }
+
+private:
+    bool m_squared;        //!< use squared magnitude (power) to compute AGC value
+	double m_magsq;        //!< current squared magnitude (power)
+    double m_threshold;    //!< squelch on magsq average
+    bool m_thresholdEnable; //!< enable squelch on power threshold
+    int m_gate;            //!< power threshold gate in number of samples
+    int m_stepLength;      //!< transition step length in number of samples
+    double m_stepDelta;    //!< transition step unit by sample
+    int m_stepUpCounter;   //!< step up transition samples counter
+    int m_stepDownCounter; //!< step down transition samples counter
+    int m_gateCounter;     //!< threshold gate samples counter
+    int m_stepDownDelay;   //!< delay in samples before cutoff (release)
+    bool m_hardLimiting;   //!< hard limit multiplier so that resulting sample magnitude does not exceed 1.0
+
+    double hardLimiter(double multiplier, double magsq);
+};
+
+template<uint32_t AvgSize>
+class SimpleAGC
+{
+public:
+	SimpleAGC(Real initial, Real cutoff=0, Real clip=0) :
+        m_cutoff(cutoff),
+        m_clip(clip),
+        m_moving_average(AvgSize, initial)
+	{
+	}
+
+	void resize(Real initial, Real cutoff=0, Real clip=0)
+	{
+        m_cutoff = cutoff;
+        m_clip = clip;
+        m_moving_average.resize(AvgSize, initial);
+	}
+
+    void resizeNew(uint32_t newSize, Real initial, Real cutoff=0, Real clip=0)
+    {
+        m_cutoff = cutoff;
+        m_clip = clip;
+        m_moving_average.resize(newSize, initial);
+    }
+
+    void fill(double value)
+    {
+        m_moving_average.fill(value);
+    }
+
+	Real getValue()
+	{
+        if ((Real) m_moving_average.average() > m_clip) {
+            return (Real) m_moving_average.average();
+        } else {
+            return m_clip;
+        }
+	}
+
+    void feed(Real value)
+    {
+        if (value > m_cutoff) {
+            m_moving_average.feed(value);
+        }
+    }
+
+private:
+    Real m_cutoff;  // consider samples only above this level
+    Real m_clip;    // never go below this level
+    MovingAverage<double> m_moving_average; // Averaging engine. The stack length conditions the smoothness of AGC.
+    //MovingAverageUtil<Real, double, AvgSize> m_moving_average;
+};
+
+#endif /* INCLUDE_GPL_DSP_AGC_H_ */

android/app/src/main/cpp/dsp/autocorrector.h

@@ -0,0 +1,106 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2018-2019 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef SDRBASE_DSP_AUTOCORRECTOR_H_
+#define SDRBASE_DSP_AUTOCORRECTOR_H_
+
+#include "util/movingaverage.h"
+
+template<typename T>
+class AutoCorrector
+{
+public:
+    AutoCorrector(qint32 intBits);
+    void process(const T& inreal, const T& inimag, qint32& outreal, qint32& outimag);
+    void process(qint32& xreal, qint32& ximag);
+    void setIQCorrection(bool iqCorrection) { m_iqCorrection = iqCorrection; }
+private:
+    bool m_iqCorrection;
+    float m_scalef;
+    MovingAverageUtil<int32_t, int64_t, 1024> m_iBeta;
+    MovingAverageUtil<int32_t, int64_t, 1024> m_qBeta;
+    MovingAverageUtil<float, double, 128> m_avgII;
+    MovingAverageUtil<float, double, 128> m_avgIQ;
+    MovingAverageUtil<float, double, 128> m_avgII2;
+    MovingAverageUtil<float, double, 128> m_avgQQ2;
+    MovingAverageUtil<double, double, 128> m_avgPhi;
+    MovingAverageUtil<double, double, 128> m_avgAmp;
+};
+
+template<typename T>
+AutoCorrector<T>::AutoCorrector(qint32 intBits) :
+    m_iqCorrection(false),
+    m_scalef((float) (1<<(intBits-1)))
+{
+}
+
+template<typename T>
+void AutoCorrector<T>::process(const T& inreal, const T& inimag, qint32& outreal, qint32& outimag)
+{
+    outreal = inreal;
+    outimag = inimag;
+    process(outreal, outimag);
+}
+
+template<typename T>
+void AutoCorrector<T>::process(qint32& xreal, qint32& ximag)
+{
+    m_iBeta(xreal);
+    m_qBeta(ximag);
+
+    if (m_iqCorrection)
+    {
+        // DC correction and conversion
+        float xi = (xreal - (int32_t) m_iBeta) / m_scalef;
+        float xq = (ximag - (int32_t) m_qBeta) / m_scalef;
+
+        // phase imbalance
+        m_avgII(xi*xi); // <I", I">
+        m_avgIQ(xi*xq); // <I", Q">
+
+
+        if (m_avgII.asDouble() != 0) {
+            m_avgPhi(m_avgIQ.asDouble()/m_avgII.asDouble());
+        }
+
+        float yi = xi - m_avgPhi.asDouble()*xq;
+        float yq = xq;
+
+        // amplitude I/Q imbalance
+        m_avgII2(yi*yi); // <I, I>
+        m_avgQQ2(yq*yq); // <Q, Q>
+
+        if (m_avgQQ2.asDouble() != 0) {
+            m_avgAmp(sqrt(m_avgII2.asDouble() / m_avgQQ2.asDouble()));
+        }
+
+        // final correction
+        float zi = yi;
+        float zq = m_avgAmp.asDouble() * yq;
+
+        // convert and store
+        xreal = zi * m_scalef;
+        ximag = zq * m_scalef;
+    }
+    else
+    {
+        xreal -= (int32_t) m_iBeta;
+        ximag -= (int32_t) m_qBeta;
+    }
+}
+
+#endif /* SDRBASE_DSP_AUTOCORRECTOR_H_ */

android/app/src/main/cpp/dsp/basebandsamplesink.cpp

@@ -0,0 +1,28 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2018, 2020-2022 Edouard Griffiths, F4EXB <f4exb06@gmail.com> //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include "basebandsamplesink.h"
+
+BasebandSampleSink::BasebandSampleSink()
+{
+}
+
+BasebandSampleSink::~BasebandSampleSink()
+{
+}

android/app/src/main/cpp/dsp/basebandsamplesink.h

@@ -0,0 +1,44 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2022 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef INCLUDE_SAMPLESINK_H
+#define INCLUDE_SAMPLESINK_H
+
+#include <string>
+
+#include "dsp/dsptypes.h"
+#include "export.h"
+
+class Message;
+
+class SDRBASE_API BasebandSampleSink {
+public:
+	BasebandSampleSink();
+	virtual ~BasebandSampleSink();
+
+	virtual void start() = 0;
+	virtual void stop() = 0;
+	virtual void feed(const SampleVector::const_iterator& begin, const SampleVector::const_iterator& end, bool positiveOnly) = 0;
+    virtual void feed(const Complex*, unsigned int) { //!< Special feed directly with complex array
+    }
+	virtual void pushMessage(Message *msg) = 0;
+	virtual std::string getSinkName() = 0;
+};
+
+#endif // INCLUDE_SAMPLESINK_H

android/app/src/main/cpp/dsp/basebandsamplesource.cpp

@@ -0,0 +1,28 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2016-2019, 2021-2022 Edouard Griffiths, F4EXB <f4exb06@gmail.com> //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include "dsp/basebandsamplesource.h"
+
+BasebandSampleSource::BasebandSampleSource()
+{
+}
+
+BasebandSampleSource::~BasebandSampleSource()
+{
+}

android/app/src/main/cpp/dsp/basebandsamplesource.h

@@ -0,0 +1,40 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2019, 2021-2022 Edouard Griffiths, F4EXB <f4exb06@gmail.com> //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef SDRBASE_DSP_BASEBANDSAMPLESOURCE_H_
+#define SDRBASE_DSP_BASEBANDSAMPLESOURCE_H_
+
+#include "dsp/dsptypes.h"
+#include "export.h"
+
+class Message;
+
+class SDRBASE_API BasebandSampleSource {
+public:
+	BasebandSampleSource();
+	virtual ~BasebandSampleSource();
+
+	virtual void start() = 0;
+	virtual void stop() = 0;
+	virtual void pull(SampleVector::iterator& begin, unsigned int nbSamples) = 0;
+	virtual void pushMessage(Message *msg) = 0;
+	virtual QString getSourceName() = 0;
+};
+
+#endif /* SDRBASE_DSP_BASEBANDSAMPLESOURCE_H_ */

android/app/src/main/cpp/dsp/channelmarker.cpp

@@ -0,0 +1,260 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015, 2017-2019, 2021 Edouard Griffiths, F4EXB <f4exb06@gmail.com> //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include "SWGChannelMarker.h"
+#include "dsp/channelmarker.h"
+#include "util/simpleserializer.h"
+
+QRgb ChannelMarker::m_colorTable[] = {
+	qRgb(0xc0, 0x00, 0x00),
+	qRgb(0x00, 0xc0, 0x00),
+	qRgb(0x00, 0x00, 0xc0),
+
+	qRgb(0xc0, 0xc0, 0x00),
+	qRgb(0xc0, 0x00, 0xc0),
+	qRgb(0x00, 0xc0, 0xc0),
+
+	qRgb(0xc0, 0x60, 0x00),
+	qRgb(0xc0, 0x00, 0x60),
+	qRgb(0x60, 0x00, 0xc0),
+
+	qRgb(0x60, 0x00, 0x00),
+	qRgb(0x00, 0x60, 0x00),
+	qRgb(0x00, 0x00, 0x60),
+
+	qRgb(0x60, 0x60, 0x00),
+	qRgb(0x60, 0x00, 0x60),
+	qRgb(0x00, 0x60, 0x60),
+
+	0
+};
+int ChannelMarker::m_nextColor = 0;
+
+ChannelMarker::ChannelMarker(QObject* parent) :
+	QObject(parent),
+	m_centerFrequency(0),
+	m_bandwidth(0),
+    m_oppositeBandwidth(0),
+	m_lowCutoff(0),
+    m_shift(0),
+	m_sidebands(dsb),
+	m_visible(false),
+	m_highlighted(false),
+	m_color(m_colorTable[m_nextColor]),
+	m_movable(true),
+	m_fScaleDisplayType(FScaleDisplay_freq),
+    m_sourceOrSinkStream(true),
+    m_enabledStreamsBits(1)
+{
+	++m_nextColor;
+	if(m_colorTable[m_nextColor] == 0)
+		m_nextColor = 0;
+}
+
+void ChannelMarker::emitChangedByAPI()
+{
+    emit changedByAPI();
+}
+
+void ChannelMarker::setTitle(const QString& title)
+{
+	m_title = title;
+	emit changedByAPI();
+}
+
+void ChannelMarker::setCenterFrequency(int centerFrequency)
+{
+	m_centerFrequency = centerFrequency;
+	emit changedByAPI();
+}
+
+void ChannelMarker::setCenterFrequencyByCursor(int centerFrequency)
+{
+    m_centerFrequency = centerFrequency;
+    emit changedByCursor();
+}
+
+void ChannelMarker::setBandwidth(int bandwidth)
+{
+	m_bandwidth = bandwidth;
+	emit changedByAPI();
+}
+
+void ChannelMarker::setOppositeBandwidth(int bandwidth)
+{
+    m_oppositeBandwidth = bandwidth;
+    emit changedByAPI();
+}
+
+void ChannelMarker::setLowCutoff(int lowCutoff)
+{
+	m_lowCutoff = lowCutoff;
+	emit changedByAPI();
+}
+
+void ChannelMarker::setShift(int shift)
+{
+	m_shift = shift;
+	emit changedByAPI();
+}
+
+void ChannelMarker::setSidebands(sidebands_t sidebands)
+{
+	m_sidebands = sidebands;
+	emit changedByAPI();
+}
+
+void ChannelMarker::setVisible(bool visible)
+{
+	m_visible = visible;
+	emit changedByAPI();
+}
+
+void ChannelMarker::setHighlighted(bool highlighted)
+{
+	m_highlighted = highlighted;
+	emit changedByAPI();
+}
+
+void ChannelMarker::setHighlightedByCursor(bool highlighted)
+{
+    m_highlighted = highlighted;
+    emit highlightedByCursor();
+}
+
+void ChannelMarker::setColor(const QColor& color)
+{
+	m_color = color;
+	emit changedByAPI();
+}
+
+void ChannelMarker::resetToDefaults()
+{
+    setTitle("Channel");
+    setCenterFrequency(0);
+    setColor(Qt::white);
+    setFrequencyScaleDisplayType(FScaleDisplay_freq);
+}
+
+QByteArray ChannelMarker::serialize() const
+{
+    SimpleSerializer s(1);
+    s.writeS32(1, getCenterFrequency());
+    s.writeU32(2, getColor().rgb());
+    s.writeString(3, getTitle());
+    s.writeS32(7, (int) getFrequencyScaleDisplayType());
+    return s.final();
+}
+
+bool ChannelMarker::deserialize(const QByteArray& data)
+{
+    SimpleDeserializer d(data);
+
+    if(!d.isValid())
+    {
+        resetToDefaults();
+        return false;
+    }
+
+    if(d.getVersion() == 1)
+    {
+        quint32 u32tmp;
+        qint32 tmp;
+        QString strtmp;
+
+        blockSignals(true);
+
+        d.readS32(1, &tmp, 0);
+        setCenterFrequency(tmp);
+        if(d.readU32(2, &u32tmp)) {
+            setColor(u32tmp);
+        }
+        d.readString(3, &strtmp, "Channel");
+        setTitle(strtmp);
+        d.readS32(7, &tmp, 0);
+        if ((tmp >= 0) && (tmp < FScaleDisplay_none)) {
+            setFrequencyScaleDisplayType((frequencyScaleDisplay_t) tmp);
+        } else {
+            setFrequencyScaleDisplayType(FScaleDisplay_freq);
+        }
+
+        blockSignals(false);
+
+        return true;
+    }
+    else
+    {
+        resetToDefaults();
+        return false;
+    }
+}
+
+void ChannelMarker::formatTo(SWGSDRangel::SWGObject *swgObject) const
+{
+    SWGSDRangel::SWGChannelMarker *swgChannelMarker = static_cast<SWGSDRangel::SWGChannelMarker *>(swgObject);
+
+    swgChannelMarker->setCenterFrequency(getCenterFrequency());
+    swgChannelMarker->setColor(getColor().rgb());
+    swgChannelMarker->setFrequencyScaleDisplayType((int) getFrequencyScaleDisplayType());
+
+    if (swgChannelMarker->getTitle()) {
+        *swgChannelMarker->getTitle() = getTitle();
+    } else {
+        swgChannelMarker->setTitle(new QString(getTitle()));
+    }
+}
+
+void ChannelMarker::updateFrom(const QStringList& keys, const SWGSDRangel::SWGObject *swgObject)
+{
+    SWGSDRangel::SWGChannelMarker *swgChannelMarker =
+        static_cast<SWGSDRangel::SWGChannelMarker *>(const_cast<SWGSDRangel::SWGObject *>(swgObject));
+
+    if (keys.contains("channelMarker.centerFrequency")) {
+        setCenterFrequency(swgChannelMarker->getCenterFrequency());
+    }
+    if (keys.contains("channelMarker.color")) {
+        setColor(swgChannelMarker->getColor());
+    }
+    if (keys.contains("channelMarker.frequencyScaleDisplayType")) {
+        setFrequencyScaleDisplayType((frequencyScaleDisplay_t) swgChannelMarker->getFrequencyScaleDisplayType());
+    }
+    if (keys.contains("channelMarker.title")) {
+        setTitle(*swgChannelMarker->getTitle());
+    }
+}
+
+void ChannelMarker::updateSettings(const ChannelMarker *channelMarker)
+{
+    m_fScaleDisplayType = channelMarker->m_fScaleDisplayType;
+}
+
+void ChannelMarker::addStreamIndex(int streamIndex)
+{
+    m_enabledStreamsBits |= (1<<streamIndex);
+}
+
+void ChannelMarker::removeStreamIndex(int streamIndex)
+{
+    m_enabledStreamsBits &= ~(1<<streamIndex);
+}
+
+void ChannelMarker::clearStreamIndexes()
+{
+    m_enabledStreamsBits = 0;
+}

android/app/src/main/cpp/dsp/channelmarker.h

@@ -0,0 +1,142 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2019, 2021 Edouard Griffiths, F4EXB <f4exb06@gmail.com>    //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef INCLUDE_CHANNELMARKER_H
+#define INCLUDE_CHANNELMARKER_H
+
+#include <QObject>
+#include <QColor>
+#include <QByteArray>
+
+#include "settings/serializable.h"
+#include "export.h"
+
+class SDRBASE_API ChannelMarker : public QObject, public Serializable {
+	Q_OBJECT
+
+public:
+	typedef enum sidebands_e
+	{
+		dsb,
+		lsb,
+		usb,
+		vusb, //!< USB with vestigial LSB
+		vlsb  //!< LSB with vestigial USB
+	} sidebands_t;
+
+	typedef enum frequencyScaleDisplay_e
+	{
+        FScaleDisplay_freq,
+        FScaleDisplay_title,
+        FScaleDisplay_addressSend,
+        FScaleDisplay_addressReceive,
+        FScaleDisplay_none
+	} frequencyScaleDisplay_t;
+
+	ChannelMarker(QObject* parent = NULL);
+
+	void emitChangedByAPI();
+
+	void setTitle(const QString& title);
+	const QString& getTitle() const { return m_title; }
+
+	void setCenterFrequency(int centerFrequency);
+    void setCenterFrequencyByCursor(int centerFrequency);
+	int getCenterFrequency() const { return m_centerFrequency; }
+
+	void setBandwidth(int bandwidth);
+	int getBandwidth() const { return m_bandwidth; }
+
+    void setOppositeBandwidth(int bandwidth);
+    int getOppositeBandwidth() const { return m_oppositeBandwidth; }
+
+	void setLowCutoff(int lowCutoff);
+	int getLowCutoff() const { return m_lowCutoff; }
+
+    void setShift(int shift);
+    int getShift() const { return m_shift; }
+
+	void setSidebands(sidebands_t sidebands);
+	sidebands_t getSidebands() const { return m_sidebands; }
+
+	void setVisible(bool visible);
+	bool getVisible() const { return m_visible; }
+
+	void setHighlighted(bool highlighted);
+    void setHighlightedByCursor(bool highlighted);
+	bool getHighlighted() const { return m_highlighted; }
+
+	void setColor(const QColor& color);
+	const QColor& getColor() const { return m_color; }
+
+	void setMovable(bool movable) { m_movable = movable; }
+	bool getMovable() const { return m_movable; }
+
+    void setFrequencyScaleDisplayType(frequencyScaleDisplay_t type) { m_fScaleDisplayType = type; }
+    frequencyScaleDisplay_t getFrequencyScaleDisplayType() const { return m_fScaleDisplayType; }
+
+    const QString& getDisplayAddressSend() const { return m_displayAddressSend; }
+    const QString& getDisplayAddressReceive() const { return m_displayAddressReceive; }
+
+    void setSourceOrSinkStream(bool sourceOrSinkStream) { m_sourceOrSinkStream = sourceOrSinkStream; }
+    bool getSourceOrSinkStream() const { return m_sourceOrSinkStream; }
+    void addStreamIndex(int streamIndex);
+    void removeStreamIndex(int streamIndex);
+    void clearStreamIndexes();
+
+    bool streamIndexApplies(int streamIndex) const {
+        return m_enabledStreamsBits & (1<<streamIndex);
+    }
+
+    virtual QByteArray serialize() const;
+    virtual bool deserialize(const QByteArray& data);
+    virtual void formatTo(SWGSDRangel::SWGObject *swgObject) const;
+    virtual void updateFrom(const QStringList& keys, const SWGSDRangel::SWGObject *swgObject);
+	void updateSettings(const ChannelMarker *channelMarker);
+
+protected:
+	static QRgb m_colorTable[];
+	static int m_nextColor;
+
+	QString m_title;
+	QString m_displayAddressSend;
+    QString m_displayAddressReceive;
+	int m_centerFrequency;
+	int m_bandwidth;
+    int m_oppositeBandwidth;
+	int m_lowCutoff;
+    int m_shift;
+	sidebands_t m_sidebands;
+	bool m_visible;
+	bool m_highlighted;
+	QColor m_color;
+	bool m_movable;
+    frequencyScaleDisplay_t m_fScaleDisplayType;
+    bool m_sourceOrSinkStream;
+    uint32_t m_enabledStreamsBits;
+
+    void resetToDefaults();
+
+signals:
+	void changedByAPI();
+    void changedByCursor();
+    void highlightedByCursor();
+};
+
+#endif // INCLUDE_CHANNELMARKER_H

android/app/src/main/cpp/dsp/channelsamplesink.cpp

@@ -0,0 +1,26 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2019 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include "channelsamplesink.h"
+
+ChannelSampleSink::ChannelSampleSink()
+{}
+
+ChannelSampleSink::~ChannelSampleSink()
+{}

android/app/src/main/cpp/dsp/channelsamplesink.h

@@ -0,0 +1,38 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2019 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+// This is a lightweight channel sample source interface
+
+#ifndef SDRBASE_DSP_CHANNELSAMPLESINK_H_
+#define SDRBASE_DSP_CHANNELSAMPLESINK_H_
+
+#include "export.h"
+#include "dsp/dsptypes.h"
+
+class Message;
+
+class SDRBASE_API ChannelSampleSink {
+public:
+	ChannelSampleSink();
+	virtual ~ChannelSampleSink();
+
+    virtual void feed(const SampleVector::const_iterator& begin, const SampleVector::const_iterator& end) = 0;
+};
+
+#endif // SDRBASE_DSP_CHANNELSAMPLESINK_H_

android/app/src/main/cpp/dsp/channelsamplesource.cpp

@@ -0,0 +1,26 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2019 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include "channelsamplesource.h"
+
+ChannelSampleSource::ChannelSampleSource()
+{}
+
+ChannelSampleSource::~ChannelSampleSource()
+{}

android/app/src/main/cpp/dsp/channelsamplesource.h

@@ -0,0 +1,38 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2019 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+// This is a lightweight channel sample source interface
+
+#ifndef SDRBASE_DSP_CHANNELSAMPLESOURCE_H_
+#define SDRBASE_DSP_CHANNELSAMPLESOURCE_H_
+
+#include "export.h"
+#include "dsp/dsptypes.h"
+
+class SDRBASE_API ChannelSampleSource {
+public:
+	ChannelSampleSource();
+	virtual ~ChannelSampleSource();
+
+	virtual void pull(SampleVector::iterator begin, unsigned int nbSamples) = 0; //!< pull nbSamples from the source and write them starting at begin
+    virtual void pullOne(Sample& sample) = 0; //!< pull a single sample from the source
+	virtual void prefetch(unsigned int nbSamples) = 0; //!< Do operation(s) before pulling nbSamples
+};
+
+#endif // SDRBASE_DSP_CHANNELSAMPLESOURCE_H_

android/app/src/main/cpp/dsp/complex.h

@@ -0,0 +1,61 @@
+///////////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany     //
+// written by Christian Daniel                                                       //
+// Copyright (C) 2015-2016 Edouard Griffiths, F4EXB <f4exb06@gmail.com>              //
+//                                                                                   //
+// This program is free software; you can redistribute it and/or modify              //
+// it under the terms of the GNU General Public License as published by              //
+// the Free Software Foundation as version 3 of the License, or                      //
+// (at your option) any later version.                                               //
+//                                                                                   //
+// This program is distributed in the hope that it will be useful,                   //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                    //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                      //
+// GNU General Public License V3 for more details.                                   //
+//                                                                                   //
+// You should have received a copy of the GNU General Public License                 //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.              //
+///////////////////////////////////////////////////////////////////////////////////////
+// ----------------------------------------------------------------------------
+// complex.h  --  Complex arithmetic
+//
+// Copyright (C) 2006-2008
+//		Dave Freese, W1HKJ
+// Copyright (C) 2008
+//		Stelios Bounanos, M0GLD
+//
+// This file is part of fldigi.
+//
+// Fldigi is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Fldigi is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with fldigi.  If not, see <http://www.gnu.org/licenses/>.
+// ----------------------------------------------------------------------------
+
+#ifndef _COMPLEX_H
+#define _COMPLEX_H
+
+#include <cmath>
+#include <complex>
+
+typedef std::complex<float> cmplx;
+
+inline cmplx cmac (const cmplx *a, const cmplx *b, int ptr, int len) {
+	cmplx z;
+	ptr %= len;
+	for (int i = 0; i < len; i++) {
+		z += a[i] * b[ptr];
+		ptr = (ptr + 1) % len;
+		}
+	return z;
+}
+
+#endif

android/app/src/main/cpp/dsp/costasloop.cpp

@@ -0,0 +1,112 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2021 Jon Beniston, M7RCE <jon@beniston.com>                     //
+// Copyright 2006-2021 Free Software Foundation, Inc.                            //
+// Copyright (C) 2018 Edouard Griffiths, F4EXB                                   //
+//                                                                               //
+// Based on the Costas Loop from GNU Radio                                       //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include "costasloop.h"
+#include <cmath>
+
+// Loop bandwidth supposedly ~ 2pi/100 rads/sample
+// pskOrder 2, 4 or 8
+CostasLoop::CostasLoop(float loopBW, unsigned int pskOrder) :
+    m_maxFreq(1.0f),
+    m_minFreq(-1.0f),
+    m_pskOrder(pskOrder)
+{
+    computeCoefficients(loopBW);
+    reset();
+}
+
+CostasLoop::~CostasLoop()
+{
+}
+
+void CostasLoop::reset()
+{
+    m_y.real(1.0f);
+    m_y.imag(0.0f);
+    m_freq = 0.0f;
+    m_phase = 0.0f;
+    m_freq = 0.0f;
+    m_error = 0.0f;
+}
+
+// 2nd order loop with critical damping
+void CostasLoop::computeCoefficients(float loopBW)
+{
+    float damping = sqrtf(2.0f) / 2.0f;
+    float denom = (1.0 + 2.0 * damping * loopBW + loopBW * loopBW);
+    m_alpha = (4 * damping * loopBW) / denom;
+    m_beta = (4 * loopBW * loopBW) / denom;
+}
+
+void CostasLoop::setSampleRate(unsigned int sampleRate)
+{
+    (void) sampleRate;
+
+    reset();
+}
+
+static float branchlessClip(float x, float clip)
+{
+    return 0.5f * (std::abs(x + clip) - std::abs(x - clip));
+}
+
+// Don't use built-in complex.h multiply to avoid NaN/INF checking
+static void fastComplexMultiply(std::complex<float> &out, const std::complex<float> cc1, const std::complex<float> cc2)
+{
+    float o_r, o_i;
+
+    o_r = (cc1.real() * cc2.real()) - (cc1.imag() * cc2.imag());
+    o_i = (cc1.real() * cc2.imag()) + (cc1.imag() * cc2.real());
+
+    out.real(o_r);
+    out.imag(o_i);
+}
+
+void CostasLoop::feed(float re, float im)
+{
+    std::complex<float> nco(::cosf(-m_phase), ::sinf(-m_phase));
+
+    std::complex<float> in, out;
+    in.real(re);
+    in.imag(im);
+    fastComplexMultiply(out, in, nco);
+
+    switch (m_pskOrder)
+    {
+    case 2:
+        m_error = phaseDetector2(out);
+        break;
+    case 4:
+        m_error = phaseDetector4(out);
+        break;
+    case 8:
+        m_error = phaseDetector8(out);
+        break;
+    }
+    m_error = branchlessClip(m_error, 1.0f);
+
+    advanceLoop(m_error);
+    phaseWrap();
+    frequencyLimit();
+
+    m_y.real(-nco.real());
+    m_y.imag(nco.imag());
+}

android/app/src/main/cpp/dsp/costasloop.h

@@ -0,0 +1,122 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2021 Jon Beniston, M7RCE <jon@beniston.com>                     //
+// Copyright 2006-2021 Free Software Foundation, Inc.                            //
+// Copyright (C) 2018 Edouard Griffiths, F4EXB                                   //
+//                                                                               //
+// Based on the Costas Loop from GNU Radio                                       //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef SDRBASE_DSP_COSTASLOOP_H_
+#define SDRBASE_DSP_COSTASLOOP_H_
+
+#include <QDebug>
+
+#include "dsp/dsptypes.h"
+#include "export.h"
+
+/** Costas Loop for phase and frequency tracking. */
+class SDRBASE_API CostasLoop
+{
+public:
+    CostasLoop(float loopBW, unsigned int pskOrder);
+    ~CostasLoop();
+
+    void computeCoefficients(float loopBW);
+    void setPskOrder(unsigned int pskOrder) { m_pskOrder = pskOrder; }
+    void reset();
+    void setSampleRate(unsigned int sampleRate);
+    void feed(float re, float im);
+    const std::complex<float>& getComplex() const { return m_y; }
+    float getReal() const { return m_y.real(); }
+    float getImag() const { return m_y.imag(); }
+    float getFreq() const { return m_freq; }
+    float getPhiHat() const { return m_phase; }
+
+private:
+
+    std::complex<float> m_y;
+    float m_phase;
+    float m_freq;
+    float m_error;
+    float m_maxFreq;
+    float m_minFreq;
+    float m_alpha;
+    float m_beta;
+    unsigned int m_pskOrder;
+
+    void advanceLoop(float error)
+    {
+        m_freq = m_freq + m_beta * error;
+        m_phase = m_phase + m_freq + m_alpha * error;
+    }
+
+    void phaseWrap()
+    {
+        const float two_pi = (float)(2.0 * M_PI);
+
+        while (m_phase > two_pi)
+            m_phase -= two_pi;
+        while (m_phase < -two_pi)
+            m_phase += two_pi;
+    }
+
+    void frequencyLimit()
+    {
+        if (m_freq > m_maxFreq)
+            m_freq = m_maxFreq;
+        else if (m_freq < m_minFreq)
+            m_freq = m_minFreq;
+    }
+
+    void setMaxFreq(float freq)
+    {
+        m_maxFreq = freq;
+    }
+
+    void setMinFreq(float freq)
+    {
+        m_minFreq = freq;
+    }
+
+    float phaseDetector2(std::complex<float> sample) const // for BPSK
+    {
+        return (sample.real() * sample.imag());
+    }
+
+    float phaseDetector4(std::complex<float> sample) const // for QPSK
+    {
+        return ((sample.real() > 0.0f ? 1.0f : -1.0f) * sample.imag() -
+                (sample.imag() > 0.0f ? 1.0f : -1.0f) * sample.real());
+    };
+
+    float phaseDetector8(std::complex<float> sample) const // for 8PSK
+    {
+        const float K = (sqrtf(2.0) - 1);
+        if (fabsf(sample.real()) >= fabsf(sample.imag()))
+        {
+            return ((sample.real() > 0.0f ? 1.0f : -1.0f) * sample.imag() -
+                    (sample.imag() > 0.0f ? 1.0f : -1.0f) * sample.real() * K);
+        }
+        else
+        {
+            return ((sample.real() > 0.0f ? 1.0f : -1.0f) * sample.imag() * K -
+                    (sample.imag() > 0.0f ? 1.0f : -1.0f) * sample.real());
+        }
+    };
+
+};
+
+#endif /* SDRBASE_DSP_COSTASLOOP_H_ */

android/app/src/main/cpp/dsp/ctcssdetector.cpp

@@ -0,0 +1,159 @@
+//////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2015-2017, 2020 Edouard Griffiths, F4EXB <f4exb06@gmail.com>                               //
+// Copyright (C) 2020 Kacper Michajłow <kasper93@gmail.com>                                                 //
+//                                                                                                          //
+// See: http://www.embedded.com/design/connectivity/4025660/Detecting-CTCSS-tones-with-Goertzel-s-algorithm //
+//                                                                                                          //
+// This program is free software; you can redistribute it and/or modify                                     //
+// it under the terms of the GNU General Public License as published by                                     //
+// the Free Software Foundation as version 3 of the License, or                                             //
+// (at your option) any later version.                                                                      //
+//                                                                                                          //
+// This program is distributed in the hope that it will be useful,                                          //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                                           //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                                             //
+// GNU General Public License V3 for more details.                                                          //
+//                                                                                                          //
+// You should have received a copy of the GNU General Public License                                        //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.                                     //
+//////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+#include <cmath>
+
+#include "dsp/ctcssdetector.h"
+
+CTCSSDetector::CTCSSDetector() :
+			m_N(0),
+			m_sampleRate(0),
+			m_samplesProcessed(0),
+			m_maxPowerIndex(0),
+			m_toneDetected(false),
+			m_maxPower(0.0)
+{
+	m_k = new Real[CTCSSFrequencies::m_nbFreqs];
+	m_coef = new Real[CTCSSFrequencies::m_nbFreqs];
+	m_u0 = new Real[CTCSSFrequencies::m_nbFreqs];
+	m_u1 = new Real[CTCSSFrequencies::m_nbFreqs];
+	m_power = new Real[CTCSSFrequencies::m_nbFreqs];
+}
+
+CTCSSDetector::~CTCSSDetector()
+{
+	delete[] m_k;
+	delete[] m_coef;
+	delete[] m_u0;
+	delete[] m_u1;
+	delete[] m_power;
+}
+
+
+void CTCSSDetector::setCoefficients(int N, int sampleRate)
+{
+	m_N = N;                   // save the basic parameters for use during analysis
+	m_sampleRate = sampleRate;
+
+	// for each of the frequencies (tones) of interest calculate
+	// k and the associated filter coefficient as per the Goertzel
+	// algorithm. Note: we are using a real value (as apposed to
+	// an integer as described in some references. k is retained
+	// for later display. The tone set is specified in the
+	// constructor. Notice that the resulting coefficients are
+	// independent of N.
+	for (int j = 0; j < CTCSSFrequencies::m_nbFreqs; ++j)
+	{
+		m_k[j] = ((double) m_N * CTCSSFrequencies::m_Freqs[j]) / (double)m_sampleRate;
+		m_coef[j] = 2.0 * cos((2.0 * M_PI * CTCSSFrequencies::m_Freqs[j])/(double)m_sampleRate);
+	}
+}
+
+
+// Analyze an input signal for the presence of CTCSS tones.
+bool CTCSSDetector::analyze(Real *sample)
+{
+
+	feedback(*sample); // Goertzel feedback
+	m_samplesProcessed += 1;
+
+	if (m_samplesProcessed == m_N) // completed a block of N
+	{
+		feedForward(); // calculate the m_power at each tone
+		m_samplesProcessed = 0;
+		return true; // have a result
+	}
+	else
+	{
+		return false;
+	}
+}
+
+
+void CTCSSDetector::feedback(Real in)
+{
+	Real t;
+
+	// feedback for each tone
+	for (int j = 0; j < CTCSSFrequencies::m_nbFreqs; ++j)
+	{
+		t = m_u0[j];
+		m_u0[j] = in + (m_coef[j] * m_u0[j]) - m_u1[j];
+		m_u1[j] = t;
+	}
+}
+
+
+void CTCSSDetector::feedForward()
+{
+	initializePower();
+
+	for (int j = 0; j < CTCSSFrequencies::m_nbFreqs; ++j)
+	{
+		m_power[j] = (m_u0[j] * m_u0[j]) + (m_u1[j] * m_u1[j]) - (m_coef[j] * m_u0[j] * m_u1[j]);
+		m_u0[j] = m_u1[j] = 0.0; // reset for next block.
+	}
+
+	evaluatePower();
+}
+
+
+void CTCSSDetector::reset()
+{
+	for (int j = 0; j < CTCSSFrequencies::m_nbFreqs; ++j)
+	{
+		m_power[j] = m_u0[j] = m_u1[j] = 0.0; // reset
+	}
+
+	m_samplesProcessed = 0;
+	m_maxPower = 0.0;
+	m_maxPowerIndex = 0;
+	m_toneDetected = false;
+}
+
+
+void CTCSSDetector::initializePower()
+{
+	for (int j = 0; j < CTCSSFrequencies::m_nbFreqs; ++j)
+	{
+		m_power[j] = 0.0; // reset
+	}
+}
+
+
+void CTCSSDetector::evaluatePower()
+{
+	Real sumPower = 0.0;
+	Real aboveAvg = 2.0; // Arbitrary max m_power above average threshold
+	m_maxPower = 0.0;
+
+	for (int j = 0; j < CTCSSFrequencies::m_nbFreqs; ++j)
+	{
+		sumPower += m_power[j];
+
+		if (m_power[j] > m_maxPower)
+		{
+			m_maxPower = m_power[j];
+			m_maxPowerIndex = j;
+		}
+	}
+
+	m_toneDetected = (m_maxPower > (sumPower/CTCSSFrequencies::m_nbFreqs) + aboveAvg);
+}

android/app/src/main/cpp/dsp/ctcssdetector.h

@@ -0,0 +1,94 @@
+//////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2015-2016, 2018, 2020 Edouard Griffiths, F4EXB <f4exb06@gmail.com>                         //
+//                                                                                                          //
+// See: http://www.embedded.com/design/connectivity/4025660/Detecting-CTCSS-tones-with-Goertzel-s-algorithm //
+//                                                                                                          //
+// This program is free software; you can redistribute it and/or modify                                     //
+// it under the terms of the GNU General Public License as published by                                     //
+// the Free Software Foundation as version 3 of the License, or                                             //
+// (at your option) any later version.                                                                      //
+//                                                                                                          //
+// This program is distributed in the hope that it will be useful,                                          //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                                           //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                                             //
+// GNU General Public License V3 for more details.                                                          //
+//                                                                                                          //
+// You should have received a copy of the GNU General Public License                                        //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.                                     //
+//////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+#ifndef INCLUDE_GPL_DSP_CTCSSDETECTOR_H_
+#define INCLUDE_GPL_DSP_CTCSSDETECTOR_H_
+
+#include "dsp/dsptypes.h"
+#include "export.h"
+#include "ctcssfrequencies.h"
+
+/** CTCSSDetector: Continuous Tone Coded Squelch System
+ * tone detector class based on the Modified Goertzel
+ * algorithm.
+ */
+class SDRBASE_API CTCSSDetector {
+public:
+    CTCSSDetector();
+    virtual ~CTCSSDetector();
+
+    // setup the basic parameters and coefficients
+    void setCoefficients(
+    		int N,          // the algorithm "block"  size
+			int sampleRate  // input signal sample rate
+    );
+
+    // set the detection threshold
+    void setThreshold(double thold);
+
+    // analyze a sample set and optionally filter the tone frequencies.
+    bool analyze(Real *sample); // input signal sample
+
+    // get the number of defined tones.
+    static int getNTones() {
+    	return CTCSSFrequencies::m_nbFreqs;
+    }
+
+    // get the tone set
+    static const Real *getToneSet() {
+    	return CTCSSFrequencies::m_Freqs;
+    }
+
+    // get the currently detected tone, if any
+    bool getDetectedTone(int &maxTone) const
+    {
+    	maxTone = m_maxPowerIndex;
+    	return m_toneDetected;
+    }
+
+    // Get the max m_power at the detected tone.
+    Real getMaxPower() const {
+    	return m_maxPower;
+    }
+
+    void reset(); // reset the analysis algorithm
+
+protected:
+    // Override these to change behavior of the detector
+    virtual void initializePower();
+    virtual void evaluatePower();
+    void feedback(Real sample);
+    void feedForward();
+
+private:
+    int m_N;
+    int m_sampleRate;
+    int m_samplesProcessed;
+    int m_maxPowerIndex;
+    bool m_toneDetected;
+    Real m_maxPower;
+    Real *m_k;
+    Real *m_coef;
+    Real *m_u0;
+    Real *m_u1;
+    Real *m_power;
+};
+
+
+#endif /* INCLUDE_GPL_DSP_CTCSSDETECTOR_H_ */

android/app/src/main/cpp/dsp/ctcssfrequencies.cpp

@@ -0,0 +1,77 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2020 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+//                                                                               //
+// This program is free software, you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY, without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include "ctcssfrequencies.h"
+
+// The 51 tones from various standards (https://en.wikipedia.org/wiki/Continuous_Tone-Coded_Squelch_System)
+const float CTCSSFrequencies::m_Freqs[] = {
+   67.0, // 0
+   69.3,
+   71.9,
+   74.4,
+   77.0,
+   79.7,
+   82.5,
+   85.4,
+   88.5,
+   91.5,
+   94.8, // 10
+   97.4,
+   100.0,
+   103.5,
+   107.2,
+   110.9,
+   114.8,
+   118.8,
+   123.0,
+   127.3,
+   131.8, // 20
+   136.5,
+   141.3,
+   146.2,
+   150.0,
+   151.4,
+   156.7,
+   159.8,
+   162.2,
+   165.5,
+   167.9, // 30
+   171.3,
+   173.8,
+   177.3,
+   179.9,
+   183.5,
+   186.2,
+   189.9,
+   192.8,
+   196.6,
+   199.5, // 40
+   203.5,
+   206.5,
+   210.7,
+   218.1,
+   225.7,
+   229.1,
+   233.6,
+   241.8,
+   250.3,
+   254.1, // 50
+};
+
+const int CTCSSFrequencies::m_nbFreqs = 51;

android/app/src/main/cpp/dsp/ctcssfrequencies.h

@@ -0,0 +1,25 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2020 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include "export.h"
+
+struct SDRBASE_API CTCSSFrequencies {
+    static const int m_nbFreqs;
+    static const float m_Freqs[];
+};

android/app/src/main/cpp/dsp/cudavkfftengine.cpp

@@ -0,0 +1,155 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2023 Jon Beniston, M7RCE <jon@beniston.com>                     //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include <QDebug>
+
+#include "dsp/cudavkfftengine.h"
+#include "util/profiler.h"
+
+CUDAvkFFTEngine::CUDAvkFFTEngine()
+{
+    VkFFTResult resFFT;
+    resFFT = gpuInit();
+    if (resFFT != VKFFT_SUCCESS)
+    {
+        qDebug() << "CUDAvkFFTEngine::CUDAvkFFTEngine: Failed to initialise GPU" << getVkFFTErrorString(resFFT);
+        delete vkGPU;
+        vkGPU = nullptr;
+    }
+}
+
+CUDAvkFFTEngine::~CUDAvkFFTEngine()
+{
+    if (vkGPU)
+    {
+        freeAll();
+        cuCtxDestroy(vkGPU->context);
+    }
+}
+
+const QString CUDAvkFFTEngine::m_name = "vkFFT (CUDA)";
+
+QString CUDAvkFFTEngine::getName() const
+{
+    return m_name;
+}
+
+VkFFTResult CUDAvkFFTEngine::gpuInit()
+{
+    CUresult res = CUDA_SUCCESS;
+    cudaError_t res2 = cudaSuccess;
+    res = cuInit(0);
+    if (res != CUDA_SUCCESS) {
+        return VKFFT_ERROR_FAILED_TO_INITIALIZE;
+    }
+    res2 = cudaSetDevice((int)vkGPU->device_id);
+    if (res2 != cudaSuccess) {
+        return VKFFT_ERROR_FAILED_TO_SET_DEVICE_ID;
+    }
+    res = cuDeviceGet(&vkGPU->device, (int)vkGPU->device_id);
+    if (res != CUDA_SUCCESS) {
+        return VKFFT_ERROR_FAILED_TO_GET_DEVICE;
+    }
+    res = cuDevicePrimaryCtxRetain(&vkGPU->context, (int)vkGPU->device);
+    if (res != CUDA_SUCCESS) {
+        return VKFFT_ERROR_FAILED_TO_CREATE_CONTEXT;
+    }
+    return VKFFT_SUCCESS;
+}
+
+VkFFTResult CUDAvkFFTEngine::gpuAllocateBuffers()
+{
+    cudaError_t res;
+    CUDAPlan *plan = reinterpret_cast<CUDAPlan *>(m_currentPlan);
+
+    // Allocate DMA accessible pinned memory, which may be faster than malloc'ed memory
+    res = cudaHostAlloc(&plan->m_in, sizeof(Complex) * plan->n, cudaHostAllocMapped);
+    if (res != cudaSuccess) {
+        return VKFFT_ERROR_FAILED_TO_ALLOCATE;
+    }
+    res = cudaHostAlloc(&plan->m_out, sizeof(Complex) * plan->n, cudaHostAllocMapped);
+    if (res != cudaSuccess) {
+        return VKFFT_ERROR_FAILED_TO_ALLOCATE;
+    }
+
+    // Allocate GPU memory
+    res = cudaMalloc((void**)&plan->m_buffer, sizeof(cuFloatComplex) * plan->n * 2);
+    if (res != cudaSuccess) {
+        return VKFFT_ERROR_FAILED_TO_ALLOCATE;
+    }
+
+    plan->m_configuration->buffer = (void**)&plan->m_buffer;
+
+    return VKFFT_SUCCESS;
+}
+
+VkFFTResult CUDAvkFFTEngine::gpuConfigure()
+{
+    return VKFFT_SUCCESS;
+}
+
+void CUDAvkFFTEngine::transform()
+{
+    if (m_currentPlan)
+    {
+        CUDAPlan *plan = reinterpret_cast<CUDAPlan *>(m_currentPlan);
+        cudaError_t res = cudaSuccess;
+        void* buffer = ((void**)&plan->m_buffer)[0];
+
+        // Transfer input from CPU to GPU memory
+        PROFILER_START()
+        res = cudaMemcpy(buffer, plan->m_in, plan->m_bufferSize, cudaMemcpyHostToDevice);
+        PROFILER_STOP(QString("%1 TX %2").arg(getName()).arg(m_currentPlan->n))
+        if (res != cudaSuccess) {
+            qDebug() << "CUDAvkFFTEngine::transform: cudaMemcpy host to device failed";
+        }
+
+        // Perform FFT
+        PROFILER_RESTART()
+        VkFFTLaunchParams launchParams = {};
+        VkFFTResult resFFT = VkFFTAppend(plan->m_app, plan->m_inverse ? 1 : -1, &launchParams);
+        PROFILER_STOP(QString("%1 FFT %2").arg(getName()).arg(m_currentPlan->n))
+        if (resFFT != VKFFT_SUCCESS) {
+            qDebug() << "CUDAvkFFTEngine::transform: VkFFTAppend failed:" << getVkFFTErrorString(resFFT);
+        }
+
+        // Transfer result from GPU to CPU memory
+        PROFILER_RESTART()
+        res = cudaMemcpy(plan->m_out, buffer, plan->m_bufferSize, cudaMemcpyDeviceToHost);
+        PROFILER_STOP(QString("%1 RX %2").arg(getName()).arg(m_currentPlan->n))
+        if (res != cudaSuccess) {
+            qDebug() << "CUDAvkFFTEngine::transform: cudaMemcpy device to host failed";
+        }
+    }
+
+}
+
+vkFFTEngine::Plan *CUDAvkFFTEngine::gpuAllocatePlan()
+{
+    return new CUDAPlan();
+}
+
+void CUDAvkFFTEngine::gpuDeallocatePlan(Plan *p)
+{
+    CUDAPlan *plan = reinterpret_cast<CUDAPlan *>(p);
+
+    cudaFree(plan->m_in);
+    plan->m_in = nullptr;
+    cudaFree(plan->m_out);
+    plan->m_out = nullptr;
+    cudaFree(plan->m_buffer);
+}

android/app/src/main/cpp/dsp/cudavkfftengine.h

@@ -0,0 +1,55 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2019 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+// Copyright (C) 2021, 2023 Jon Beniston, M7RCE <jon@beniston.com>               //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef INCLUDE_CUDAVKFFTENGINE_H
+#define INCLUDE_CUDAVKFFTENGINE_H
+
+#include "vkfftengine.h"
+
+#include <cuda.h>
+#include <cuda_runtime.h>
+#include <nvrtc.h>
+#include <cuda_runtime_api.h>
+#include <cuComplex.h>
+
+class SDRBASE_API CUDAvkFFTEngine : public vkFFTEngine {
+public:
+	CUDAvkFFTEngine();
+	virtual ~CUDAvkFFTEngine();
+
+	void transform() override;
+    QString getName() const override;
+    static const QString m_name;
+
+protected:
+
+    struct CUDAPlan : Plan {
+		cuFloatComplex* m_buffer;    // GPU memory
+    };
+
+    VkFFTResult gpuInit() override;
+    VkFFTResult gpuAllocateBuffers() override;
+    VkFFTResult gpuConfigure() override;
+    Plan *gpuAllocatePlan() override;
+    void gpuDeallocatePlan(Plan *) override;
+
+};
+
+#endif // INCLUDE_CUDAVKFFTENGINE_H

android/app/src/main/cpp/dsp/cwkeyer.cpp

@@ -0,0 +1,625 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2016-2019, 2021 Edouard Griffiths, F4EXB <f4exb06@gmail.com>    //
+// Copyright (C) 2022 Jiří Pinkava <jiri.pinkava@rossum.ai>                      //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include <stdint.h>
+#include <QChar>
+#include <QDebug>
+#include "cwkeyer.h"
+#include "util/stepfunctions.h"
+
+MESSAGE_CLASS_DEFINITION(CWKeyer::MsgConfigureCWKeyer, Message)
+
+/**
+ * 0:  dot
+ * 1:  dash
+ * -1: end of sequence
+ */
+const signed char CWKeyer::m_asciiToMorse[128][7] = {
+        {-1,0,0,0,0,0,0}, // 0
+        {-1,0,0,0,0,0,0}, // 1
+        {-1,0,0,0,0,0,0}, // 2
+        {-1,0,0,0,0,0,0}, // 3
+        {-1,0,0,0,0,0,0}, // 4
+        {-1,0,0,0,0,0,0}, // 5
+        {-1,0,0,0,0,0,0}, // 6
+        {-1,0,0,0,0,0,0}, // 7
+        {-1,0,0,0,0,0,0}, // 8
+        {-1,0,0,0,0,0,0}, // 9
+        {-1,0,0,0,0,0,0}, // 10
+        {-1,0,0,0,0,0,0}, // 11
+        {-1,0,0,0,0,0,0}, // 12
+        {-1,0,0,0,0,0,0}, // 13
+        {-1,0,0,0,0,0,0}, // 14
+        {-1,0,0,0,0,0,0}, // 15
+        {-1,0,0,0,0,0,0}, // 16
+        {-1,0,0,0,0,0,0}, // 17
+        {-1,0,0,0,0,0,0}, // 18
+        {-1,0,0,0,0,0,0}, // 19
+        {-1,0,0,0,0,0,0}, // 20
+        {-1,0,0,0,0,0,0}, // 21
+        {-1,0,0,0,0,0,0}, // 22
+        {-1,0,0,0,0,0,0}, // 23
+        {-1,0,0,0,0,0,0}, // 24
+        {-1,0,0,0,0,0,0}, // 25
+        {-1,0,0,0,0,0,0}, // 26
+        {-1,0,0,0,0,0,0}, // 27
+        {-1,0,0,0,0,0,0}, // 28
+        {-1,0,0,0,0,0,0}, // 29
+        {-1,0,0,0,0,0,0}, // 30
+        {-1,0,0,0,0,0,0}, // 31
+        {-1,0,0,0,0,0,0}, // 32 space is treated as word separator
+        {1,0,1,0,1,1,-1}, // 33 !
+        {0,1,0,0,1,0,-1}, // 34 "
+        {-1,0,0,0,0,0,0}, // 35
+        {-1,0,0,0,0,0,0}, // 36
+        {-1,0,0,0,0,0,0}, // 37
+        {-1,0,0,0,0,0,0}, // 38
+        {0,1,1,1,1,0,-1}, // 39 '
+        {1,0,1,1,0,1,-1}, // 40 (
+        {1,0,1,1,0,1,-1}, // 41 )
+        {-1,0,0,0,0,0,0}, // 42
+        {0,1,0,1,0,-1,0}, // 43 +
+        {1,1,0,0,1,1,-1}, // 44 ,
+        {1,0,0,0,0,1,-1}, // 45 -
+        {0,1,0,1,0,1,-1}, // 46 .
+        {1,0,0,1,0,-1,0}, // 47 /
+        {1,1,1,1,1,-1,0}, // 48 0
+        {0,1,1,1,1,-1,0}, // 49 1
+        {0,0,1,1,1,-1,0}, // 50 2
+        {0,0,0,1,1,-1,0}, // 51 3
+        {0,0,0,0,1,-1,0}, // 52 4
+        {0,0,0,0,0,-1,0}, // 53 5
+        {1,0,0,0,0,-1,0}, // 54 6
+        {1,1,0,0,0,-1,0}, // 55 7
+        {1,1,1,0,0,-1,0}, // 56 8
+        {1,1,1,1,0,-1,0}, // 57 9
+        {1,1,1,0,0,0,-1}, // 58 :
+        {1,0,1,0,1,0,-1}, // 59 ;
+        {-1,0,0,0,0,0,0}, // 60 <
+        {1,0,0,0,1,-1,0}, // 61 =
+        {-1,0,0,0,0,0,0}, // 62 >
+        {0,0,1,1,0,0,-1}, // 63 ?
+        {0,1,1,0,1,0,-1}, // 64 @
+        {0,1,-1,0,0,0,0}, // 65 A
+        {1,0,0,0,-1,0,0}, // 66 B
+        {1,0,1,0,-1,0,0}, // 67 C
+        {1,0,0,-1,0,0,0}, // 68 D
+        {0,-1,0,0,0,0,0}, // 69 E
+        {0,0,1,0,-1,0,0}, // 70 F
+        {1,1,0,-1,0,0,0}, // 71 G
+        {0,0,0,0,-1,0,0}, // 72 H
+        {0,0,-1,0,0,0,0}, // 73 I
+        {0,1,1,1,-1,0,0}, // 74 J
+        {1,0,1,-1,0,0,0}, // 75 K
+        {0,1,0,0,-1,0,0}, // 76 L
+        {1,1,-1,0,0,0,0}, // 77 M
+        {1,0,-1,0,0,0,0}, // 78 N
+        {1,1,1,-1,0,0,0}, // 79 O
+        {0,1,1,0,-1,0,0}, // 80 P
+        {1,1,0,1,-1,0,0}, // 81 Q
+        {0,1,0,-1,0,0,0}, // 82 R
+        {0,0,0,-1,0,0,0}, // 83 S
+        {1,-1,0,0,0,0,0}, // 84 T
+        {0,0,1,-1,0,0,0}, // 85 U
+        {0,0,0,1,-1,0,0}, // 86 V
+        {0,1,1,-1,0,0,0}, // 87 W
+        {1,0,0,1,-1,0,0}, // 88 X
+        {1,0,1,1,-1,0,0}, // 89 Y
+        {1,1,0,0,-1,0,0}, // 90 Z
+        {-1,0,0,0,0,0,0}, // 91 [
+        {-1,0,0,0,0,0,0}, // 92 back /
+        {-1,0,0,0,0,0,0}, // 93 ]
+        {-1,0,0,0,0,0,0}, // 94 ^
+        {-1,0,0,0,0,0,0}, // 95 _
+        {-1,0,0,0,0,0,0}, // 96 `
+        {0,1,-1,0,0,0,0}, // 97 A lowercase same as uppercase
+        {1,0,0,0,-1,0,0}, // 98 B
+        {1,0,1,0,-1,0,0}, // 99 C
+        {1,0,0,-1,0,0,0}, // 100 D
+        {0,-1,0,0,0,0,0}, // 101 E
+        {0,0,1,0,-1,0,0}, // 102 F
+        {1,1,0,-1,0,0,0}, // 103 G
+        {0,0,0,0,-1,0,0}, // 104 H
+        {0,0,-1,0,0,0,0}, // 105 I
+        {0,1,1,1,-1,0,0}, // 106 J
+        {1,0,1,-1,0,0,0}, // 107 K
+        {0,1,0,0,-1,0,0}, // 108 L
+        {1,1,-1,0,0,0,0}, // 109 M
+        {1,0,-1,0,0,0,0}, // 110 N
+        {1,1,1,-1,0,0,0}, // 111 O
+        {0,1,1,0,-1,0,0}, // 112 P
+        {1,1,0,1,-1,0,0}, // 113 Q
+        {0,1,0,-1,0,0,0}, // 114 R
+        {0,0,0,-1,0,0,0}, // 115 S
+        {1,-1,0,0,0,0,0}, // 116 T
+        {0,0,1,-1,0,0,0}, // 117 U
+        {0,0,0,1,-1,0,0}, // 118 V
+        {0,1,1,-1,0,0,0}, // 119 W
+        {1,0,0,1,-1,0,0}, // 120 X
+        {1,0,1,1,-1,0,0}, // 121 Y
+        {1,1,0,0,-1,0,0}, // 122 Z
+        {-1,0,0,0,0,0,0}, // 123 {
+        {-1,0,0,0,0,0,0}, // 124 |
+        {-1,0,0,0,0,0,0}, // 125 }
+        {-1,0,0,0,0,0,0}, // 126 ~
+        {-1,0,0,0,0,0,0}, // 127 DEL
+};
+
+CWKeyer::CWKeyer() :
+    m_textPointer(0),
+	m_elementPointer(0),
+    m_samplePointer(0),
+    m_elementSpace(false),
+    m_characterSpace(false),
+    m_key(false),
+    m_dot(false),
+    m_dash(false),
+    m_elementOn(false),
+	m_asciiChar('\0'),
+    m_keyIambicState(KeySilent),
+	m_textState(TextStart)
+{
+    connect(&m_inputMessageQueue, SIGNAL(messageEnqueued()), this, SLOT(handleInputMessages()));
+    applySettings(m_settings, true);
+}
+
+CWKeyer::~CWKeyer()
+{
+}
+
+void CWKeyer::setSampleRate(int sampleRate)
+{
+    CWKeyerSettings settings = m_settings;
+    settings.m_sampleRate = sampleRate;
+    MsgConfigureCWKeyer *msg = MsgConfigureCWKeyer::create(settings, false);
+    m_inputMessageQueue.push(msg);
+}
+
+int CWKeyer::getSample()
+{
+    QMutexLocker mutexLocker(&m_mutex);
+
+    if (m_settings.m_mode == CWKeyerSettings::CWText)
+    {
+    	nextStateText();
+        return m_key ? 1 : 0;
+    }
+    else if ((m_settings.m_mode == CWKeyerSettings::CWDots) || (m_settings.m_mode == CWKeyerSettings::CWDashes))
+    {
+        nextStateIambic();
+        return m_key ? 1 : 0;
+    }
+    else if (m_settings.m_mode == CWKeyerSettings::CWKeyboard)
+    {
+        if (m_settings.m_keyboardIambic)
+        {
+            nextStateIambic();
+            return m_key ? 1 : 0;
+        }
+        else
+        {
+            return (m_dot || m_dash) ? 1 : 0;
+        }
+    }
+    else
+    {
+    	return 0;
+    }
+}
+
+void CWKeyer::nextStateIambic()
+{
+    switch (m_keyIambicState)
+    {
+    case KeySilent:
+        if (m_dot)
+        {
+            m_keyIambicState = KeyDot;
+            m_samplePointer = 0;
+        }
+        else if (m_dash)
+        {
+            m_keyIambicState = KeyDash;
+            m_samplePointer = 0;
+        }
+
+        m_key = false;
+        break;
+    case KeyDot:
+        if (m_samplePointer < m_dotLength) // dot key
+        {
+            m_key = true;
+            m_samplePointer++;
+        }
+        else if (m_samplePointer < 2*m_dotLength) // dot silence (+1 dot length)
+        {
+            m_key = false;
+            m_samplePointer++;
+        }
+        else // end
+        {
+            if (m_dash)
+            {
+                m_keyIambicState = KeyDash;
+            }
+            else if (!m_dot)
+            {
+                m_keyIambicState = KeySilent;
+            }
+
+            m_samplePointer = 0;
+            m_key = false;
+        }
+        break;
+    case KeyDash:
+        if (m_samplePointer < 3*m_dotLength) // dash key
+        {
+            m_key = true;
+            m_samplePointer++;
+        }
+        else if (m_samplePointer < 4*m_dotLength) // dash silence (+1 dot length)
+        {
+            m_key = false;
+            m_samplePointer++;
+        }
+        else // end
+        {
+            if (m_dot)
+            {
+                m_keyIambicState = KeyDot;
+            }
+            else if (!m_dash)
+            {
+                m_keyIambicState = KeySilent;
+            }
+
+            m_samplePointer = 0;
+            m_key = false;
+        }
+        break;
+    default:
+        m_samplePointer = 0;
+        m_key = false;
+        break;
+    }
+}
+
+void CWKeyer::nextStateText()
+{
+	switch (m_textState)
+	{
+	case TextStart:
+		m_samplePointer = 0;
+		m_elementPointer = 0;
+		m_textPointer = 0;
+		m_textState = TextStartChar;
+		m_key = false;
+		m_dot = false;
+		m_dash = false;
+		break;
+	case TextStartChar:
+		m_samplePointer = 0;
+		m_elementPointer = 0;
+		if (m_textPointer < m_settings.m_text.length())
+		{
+            m_asciiChar = (m_settings.m_text.at(m_textPointer)).toLatin1();
+//            qDebug() << "CWKeyer::nextStateText: TextStartChar: " << m_asciiChar;
+
+            if (m_asciiChar < 0) { // non ASCII
+                m_asciiChar = 0;
+            }
+
+            if (m_asciiChar == ' ')
+            {
+                m_textState = TextWordSpace;
+            }
+            else
+            {
+                m_textState = TextStartElement;
+            }
+            m_textPointer++;
+		}
+		else // end of text
+		{
+		    m_textState = TextEnd;
+		}
+		break;
+	case TextStartElement:
+		m_samplePointer = 0;
+//        qDebug() << "CWKeyer::nextStateText: TextStartElement: " << (int) m_asciiToMorse[m_asciiChar][m_elementPointer];
+		if (m_asciiToMorse[(uint8_t)(m_asciiChar&0x7F)][m_elementPointer] == -1) // end of morse character
+		{
+		    m_elementPointer = 0;
+		    m_textState = TextCharSpace;
+		}
+		else
+		{
+            if (m_asciiToMorse[(uint8_t)(m_asciiChar&0x7F)][m_elementPointer] == 0) // dot
+            {
+                m_dot = true;
+                m_dash = false;
+            }
+            else // dash
+            {
+                m_dot = false;
+                m_dash = true;
+            }
+	        m_keyIambicState = KeySilent; // reset iambic state
+	        nextStateIambic(); // init dash or dot
+            m_dot = false; // release keys
+            m_dash = false;
+            m_textState = TextElement;
+            m_elementPointer++;
+		}
+		break;
+	case TextElement:
+		nextStateIambic(); // dash or dot
+		if (m_keyIambicState == KeySilent) // done
+		{
+			m_textState = TextStartElement; // next element
+		}
+		break;
+	case TextCharSpace:
+		if (m_samplePointer < 2*m_dotLength) // - 1 dot length space from element
+		{
+			m_samplePointer++;
+			m_key = false;
+		}
+		else
+		{
+			m_textState = TextStartChar;
+		}
+		break;
+	case TextWordSpace:
+		if (m_samplePointer < 4*m_dotLength) // - 3 dot length space from character
+		{
+			m_samplePointer++;
+			m_key = false;
+		}
+		else
+		{
+			m_textState = TextStartChar;
+		}
+		break;
+	case TextEnd:
+	    if (m_settings.m_loop)
+	    {
+	        m_textState = TextStart;
+	    }
+        m_key = false;
+        m_dot = false;
+        m_dash = false;
+	    break;
+	case TextStop:
+	default:
+		m_key = false;
+        m_dot = false;
+        m_dash = false;
+		break;
+	}
+}
+
+bool CWKeyer::eom()
+{
+    return !(m_textPointer < m_settings.m_text.length());
+}
+
+void CWKeyer::setKeyboardDots()
+{
+    m_dot = true;
+    m_dash = false;
+    m_keyIambicState = KeySilent;
+}
+
+void CWKeyer::setKeyboardDashes()
+{
+    m_dot = false;
+    m_dash = true;
+    m_keyIambicState = KeySilent;
+}
+
+void CWKeyer::setKeyboardSilence()
+{
+    m_dot = false;
+    m_dash = false;
+}
+
+CWSmoother::CWSmoother() :
+        m_fadeInCounter(0),
+        m_fadeOutCounter(0),
+        m_nbFadeSamples(0),
+        m_fadeInSamples(0),
+        m_fadeOutSamples(0)
+{
+    setNbFadeSamples(192); // default is 4 ms at 48 kHz sample rate
+}
+
+CWSmoother::~CWSmoother()
+{
+    delete[] m_fadeInSamples;
+    delete[] m_fadeOutSamples;
+}
+
+void CWSmoother::setNbFadeSamples(unsigned int nbFadeSamples)
+{
+    if (nbFadeSamples != m_nbFadeSamples)
+    {
+        QMutexLocker mutexLocker(&m_mutex);
+
+        m_nbFadeSamples = nbFadeSamples;
+
+        if (m_fadeInSamples) delete[] m_fadeInSamples;
+        if (m_fadeOutSamples) delete[] m_fadeOutSamples;
+
+        m_fadeInSamples = new float[m_nbFadeSamples];
+        m_fadeOutSamples = new float[m_nbFadeSamples];
+
+        for (unsigned int i = 0; i < m_nbFadeSamples; i++)
+        {
+            float x = i/ (float) m_nbFadeSamples;
+            float y = 1.0f -x;
+
+            m_fadeInSamples[i] = StepFunctions::smootherstep(x);
+            m_fadeOutSamples[i] = StepFunctions::smootherstep(y);
+        }
+
+        m_fadeInCounter = 0;
+        m_fadeOutCounter = 0;
+    }
+}
+
+bool CWSmoother::getFadeSample(bool on, float& sample)
+{
+    QMutexLocker mutexLocker(&m_mutex);
+
+    if (on)
+    {
+        m_fadeOutCounter = 0;
+
+        if (m_fadeInCounter < m_nbFadeSamples)
+        {
+            sample = m_fadeInSamples[m_fadeInCounter];
+            m_fadeInCounter++;
+            return true;
+        }
+        else
+        {
+            sample = 1.0f;
+            return false;
+        }
+    }
+    else
+    {
+        m_fadeInCounter = 0;
+
+        if (m_fadeOutCounter < m_nbFadeSamples)
+        {
+            sample = m_fadeOutSamples[m_fadeOutCounter];
+            m_fadeOutCounter++;
+            return true;
+        }
+        else
+        {
+            sample = 0.0f;
+            return false;
+        }
+    }
+}
+
+bool CWKeyer::handleMessage(const Message& cmd)
+{
+    if (MsgConfigureCWKeyer::match(cmd))
+    {
+        MsgConfigureCWKeyer& cfg = (MsgConfigureCWKeyer&) cmd;
+        qDebug() << "CWKeyer::handleMessage: MsgConfigureCWKeyer";
+
+        applySettings(cfg.getSettings(), cfg.getForce());
+
+        return true;
+    }
+
+    return true;
+}
+
+void CWKeyer::handleInputMessages()
+{
+	Message* message;
+
+	while ((message = m_inputMessageQueue.pop()) != 0)
+	{
+		if (handleMessage(*message)) {
+			delete message;
+		}
+	}
+}
+
+void CWKeyer::applySettings(const CWKeyerSettings& settings, bool force)
+{
+    qDebug() << "CWKeyer::applySettings: "
+        << " m_dashKey: " << settings.m_dashKey
+        << " m_dashKeyModifiers: " << settings.m_dashKeyModifiers
+        << " m_dotKey: " << settings.m_dotKey
+        << " m_dotKeyModifiers: " << settings.m_dotKeyModifiers
+        << " m_keyboardIambic: " << settings.m_keyboardIambic
+        << " m_loop: " << settings.m_loop
+        << " m_mode: " << settings.m_mode
+        << " m_sampleRate: " << settings.m_sampleRate
+        << " m_text: " << settings.m_text
+        << " m_wpm: " << settings.m_wpm;
+
+    if ((m_settings.m_wpm != settings.m_wpm)
+     || (m_settings.m_sampleRate != settings.m_sampleRate) || force)
+    {
+        QMutexLocker mutexLocker(&m_mutex);
+        m_dotLength = (int) ((1.2f / settings.m_wpm) * settings.m_sampleRate);
+        m_cwSmoother.setNbFadeSamples(m_dotLength/10); // 10% the dot time
+    }
+
+    if ((m_settings.m_mode != settings.m_mode) || force)
+    {
+        QMutexLocker mutexLocker(&m_mutex);
+
+        if (settings.m_mode == CWKeyerSettings::CWText)
+        {
+            m_textState = TextStart;
+        }
+        else if (settings.m_mode == CWKeyerSettings::CWDots)
+        {
+            m_dot = true;
+            m_dash = false;
+            m_keyIambicState = KeySilent;
+        }
+        else if (settings.m_mode == CWKeyerSettings::CWDashes)
+        {
+            m_dot = false;
+            m_dash = true;
+            m_keyIambicState = KeySilent;
+        }
+        else if (settings.m_mode == CWKeyerSettings::CWKeyboard)
+        {
+            m_dot = false;
+            m_dash = false;
+            m_keyIambicState = KeySilent;
+        }
+    }
+
+    if ((m_settings.m_text != settings.m_text) || force)
+    {
+        QMutexLocker mutexLocker(&m_mutex);
+        m_textState = TextStart;
+    }
+
+    m_settings = settings;
+}
+
+void CWKeyer::webapiSettingsPutPatch(
+    const QStringList& channelSettingsKeys,
+    CWKeyerSettings& cwKeyerSettings,
+    SWGSDRangel::SWGCWKeyerSettings *apiCwKeyerSettings
+)
+{
+    cwKeyerSettings.updateFrom(channelSettingsKeys, apiCwKeyerSettings);
+}
+
+void CWKeyer::webapiFormatChannelSettings(
+    SWGSDRangel::SWGCWKeyerSettings *apiCwKeyerSettings,
+    const CWKeyerSettings& cwKeyerSettings
+)
+{
+    cwKeyerSettings.formatTo(apiCwKeyerSettings);
+}

android/app/src/main/cpp/dsp/cwkeyer.h

@@ -0,0 +1,163 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2019 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+// Copyright (C) 2022 Jiří Pinkava <jiri.pinkava@rossum.ai>                      //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef SDRBASE_DSP_CWKEYER_H_
+#define SDRBASE_DSP_CWKEYER_H_
+
+#include <QObject>
+#include <QRecursiveMutex>
+
+#include "export.h"
+#include "util/message.h"
+#include "util/messagequeue.h"
+#include "cwkeyersettings.h"
+#include "SWGChannelSettings.h"
+
+/**
+ * Ancillary class to smooth out CW transitions with a sine shape
+ */
+class SDRBASE_API CWSmoother
+{
+public:
+    CWSmoother();
+    ~CWSmoother();
+
+    void setNbFadeSamples(unsigned int nbFadeSamples);
+    bool getFadeSample(bool on, float& sample);
+
+private:
+    QRecursiveMutex m_mutex;
+    unsigned int m_fadeInCounter;
+    unsigned int m_fadeOutCounter;
+    unsigned int m_nbFadeSamples;
+    float *m_fadeInSamples;
+    float *m_fadeOutSamples;
+};
+
+class SDRBASE_API CWKeyer : public QObject {
+    Q_OBJECT
+
+public:
+    class SDRBASE_API MsgConfigureCWKeyer : public Message {
+        MESSAGE_CLASS_DECLARATION
+
+    public:
+        const CWKeyerSettings& getSettings() const { return m_settings; }
+        bool getForce() const { return m_force; }
+
+        static MsgConfigureCWKeyer* create(const CWKeyerSettings& settings, bool force)
+        {
+            return new MsgConfigureCWKeyer(settings, force);
+        }
+
+    private:
+        CWKeyerSettings m_settings;
+        bool m_force;
+
+        MsgConfigureCWKeyer(const CWKeyerSettings& settings, bool force) :
+            Message(),
+            m_settings(settings),
+            m_force(force)
+        { }
+    };
+
+    enum CWKeyIambicState
+    {
+        KeySilent,
+        KeyDot,
+        KeyDash
+    };
+
+    enum CWTextState
+    {
+    	TextStart,
+		TextStartChar,
+		TextStartElement,
+		TextElement,
+		TextCharSpace,
+		TextWordSpace,
+		TextEnd,
+		TextStop
+    };
+
+    CWKeyer();
+    ~CWKeyer();
+
+    void resetToDefaults();
+    QByteArray serialize() const;
+    bool deserialize(const QByteArray& data);
+    MessageQueue *getInputMessageQueue() { return &m_inputMessageQueue; } //!< Get the queue for asynchronous inbound communication
+
+    void setSampleRate(int sampleRate);
+    const CWKeyerSettings& getSettings() const { return m_settings; }
+
+    void reset() { m_keyIambicState = KeySilent; }
+
+    CWSmoother& getCWSmoother() { return m_cwSmoother; }
+    int getSample();
+    bool eom();
+    void resetText() { m_textState = TextStart; }
+    void stopText() { m_textState = TextStop; }
+    void setKeyboardDots();
+    void setKeyboardDashes();
+    void setKeyboardSilence();
+
+    static void webapiSettingsPutPatch(
+        const QStringList& channelSettingsKeys,
+        CWKeyerSettings& cwKeyerSettings,
+        SWGSDRangel::SWGCWKeyerSettings *apiCwKeyerSettings
+    );
+
+    static void webapiFormatChannelSettings(
+        SWGSDRangel::SWGCWKeyerSettings *apiCwKeyerSettings,
+        const CWKeyerSettings& cwKeyerSettings
+    );
+
+private:
+    QRecursiveMutex m_mutex;
+    CWKeyerSettings m_settings;
+    MessageQueue m_inputMessageQueue;
+    int m_dotLength;   //!< dot length in samples
+    int m_textPointer;
+    int m_elementPointer;
+    int m_samplePointer;
+    bool m_elementSpace;
+    bool m_characterSpace;
+    bool m_key;
+    bool m_dot;
+    bool m_dash;
+    bool m_elementOn;
+    signed char m_asciiChar;
+    CWKeyIambicState m_keyIambicState;
+    CWTextState m_textState;
+    CWSmoother m_cwSmoother;
+
+    static const signed char m_asciiToMorse[128][7];
+
+    void applySettings(const CWKeyerSettings& settings, bool force = false);
+    bool handleMessage(const Message& cmd);
+    void nextStateIambic();
+    void nextStateText();
+
+private slots:
+    void handleInputMessages();
+};
+
+#endif /* SDRBASE_DSP_CWKEYER_H_ */

android/app/src/main/cpp/dsp/cwkeyersettings.cpp

@@ -0,0 +1,158 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2017, 2019, 2021 Edouard Griffiths, F4EXB <f4exb06@gmail.com> //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include "SWGCWKeyerSettings.h"
+#include "util/simpleserializer.h"
+#include "cwkeyersettings.h"
+
+CWKeyerSettings::CWKeyerSettings()
+{
+    resetToDefaults();
+}
+
+void CWKeyerSettings::resetToDefaults()
+{
+    m_loop = false;
+    m_mode = CWNone;
+    m_sampleRate = 48000;
+    m_text = "";
+    m_wpm = 13;
+    m_keyboardIambic = true;
+    m_dotKey = Qt::Key_Period;
+    m_dotKeyModifiers = Qt::NoModifier;
+    m_dashKey = Qt::Key_Minus;
+    m_dashKeyModifiers = Qt::NoModifier;
+}
+
+QByteArray CWKeyerSettings::serialize() const
+{
+    SimpleSerializer s(1);
+
+    s.writeBool(2, m_loop);
+    s.writeS32(3, (int) m_mode);
+    s.writeS32(4, m_sampleRate);
+    s.writeString(5, m_text);
+    s.writeS32(6, m_wpm);
+    s.writeS32(7, (int) m_dotKey);
+    s.writeU32(8, (unsigned int) m_dotKeyModifiers);
+    s.writeS32(9, (int) m_dashKey);
+    s.writeU32(10, (unsigned int) m_dashKeyModifiers);
+    s.writeBool(11, m_keyboardIambic);
+
+    return s.final();
+}
+
+bool CWKeyerSettings::deserialize(const QByteArray& data)
+{
+    SimpleDeserializer d(data);
+
+    if (!d.isValid())
+    {
+        resetToDefaults();
+        return false;
+    }
+
+    if (d.getVersion() == 1)
+    {
+        int intval;
+        unsigned int uintval;
+
+        d.readBool(2, &m_loop, false);
+        d.readS32(3, &intval, 0);
+        m_mode = (CWMode) intval;
+        d.readS32(4, &m_sampleRate, 48000);
+        d.readString(5, &m_text, "");
+        d.readS32(6, &m_wpm, 13);
+        d.readS32(7, &intval, (int) Qt::Key_Period);
+        m_dotKey = (Qt::Key) (intval < 0 ? 0 : intval);
+        d.readU32(8, &uintval, 0);
+        m_dotKeyModifiers = (Qt::KeyboardModifiers) uintval;
+        d.readS32(9, &intval, (int) Qt::Key_Minus);
+        m_dashKey = (Qt::Key) (intval < 0 ? 0 : intval);
+        d.readU32(10, &uintval, 0);
+        m_dashKeyModifiers = (Qt::KeyboardModifiers) uintval;
+        d.readBool(11, &m_keyboardIambic, true);
+
+        return true;
+    }
+    else
+    {
+        resetToDefaults();
+        return false;
+    }
+}
+
+void CWKeyerSettings::formatTo(SWGSDRangel::SWGObject *swgObject) const
+{
+    SWGSDRangel::SWGCWKeyerSettings *apiCwKeyerSettings = static_cast<SWGSDRangel::SWGCWKeyerSettings *>(swgObject);
+
+    apiCwKeyerSettings->setLoop(m_loop ? 1 : 0);
+    apiCwKeyerSettings->setMode((int) m_mode);
+    apiCwKeyerSettings->setSampleRate(m_sampleRate);
+
+    if (apiCwKeyerSettings->getText()) {
+        *apiCwKeyerSettings->getText() = m_text;
+    } else {
+        apiCwKeyerSettings->setText(new QString(m_text));
+    }
+
+    apiCwKeyerSettings->setWpm(m_wpm);
+    apiCwKeyerSettings->setKeyboardIambic(m_keyboardIambic ? 1 : 0);
+    apiCwKeyerSettings->setDotKey((int) m_dotKey);
+    apiCwKeyerSettings->setDotKeyModifiers((unsigned int) m_dotKeyModifiers);
+    apiCwKeyerSettings->setDashKey((int) m_dashKey);
+    apiCwKeyerSettings->setDashKeyModifiers((unsigned int) m_dashKeyModifiers);
+}
+
+void CWKeyerSettings::updateFrom(const QStringList& keys, const SWGSDRangel::SWGObject *swgObject)
+{
+    SWGSDRangel::SWGCWKeyerSettings *apiCwKeyerSettings =
+        static_cast<SWGSDRangel::SWGCWKeyerSettings *>(const_cast<SWGSDRangel::SWGObject *>(swgObject));
+
+    if (keys.contains("cwKeyer.loop")) {
+        m_loop = apiCwKeyerSettings->getLoop() != 0;
+    }
+    if (keys.contains("cwKeyer.mode")) {
+        m_mode = (CWKeyerSettings::CWMode) apiCwKeyerSettings->getMode();
+    }
+    if (keys.contains("cwKeyer.text")) {
+        m_text = *apiCwKeyerSettings->getText();
+    }
+    if (keys.contains("cwKeyer.sampleRate")) {
+        m_sampleRate = apiCwKeyerSettings->getSampleRate();
+    }
+    if (keys.contains("cwKeyer.wpm")) {
+        m_wpm = apiCwKeyerSettings->getWpm();
+    }
+    if (keys.contains("cwKeyer.keyboardIambic")) {
+        m_keyboardIambic = apiCwKeyerSettings->getKeyboardIambic() != 0;
+    }
+    if (keys.contains("cwKeyer.dotKey")) {
+        m_dotKey = (Qt::Key) apiCwKeyerSettings->getDotKey();
+    }
+    if (keys.contains("cwKeyer.dotKeyModifiers")) {
+        m_dotKeyModifiers = (Qt::KeyboardModifiers) apiCwKeyerSettings->getDotKeyModifiers();
+    }
+    if (keys.contains("cwKeyer.dashKey")) {
+        m_dashKey = (Qt::Key) apiCwKeyerSettings->getDashKey();
+    }
+    if (keys.contains("cwKeyer.dashKeyModifiers")) {
+        m_dashKeyModifiers = (Qt::KeyboardModifiers) apiCwKeyerSettings->getDashKeyModifiers();
+    }
+}

android/app/src/main/cpp/dsp/cwkeyersettings.h

@@ -0,0 +1,63 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2016-2019, 2021 Edouard Griffiths, F4EXB <f4exb06@gmail.com>    //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef SDRBASE_DSP_CWKEYERSETTINGS_H_
+#define SDRBASE_DSP_CWKEYERSETTINGS_H_
+
+#include <QString>
+#include <QByteArray>
+
+#include "export.h"
+#include "settings/serializable.h"
+
+class SDRBASE_API CWKeyerSettings: public Serializable
+{
+public:
+    typedef enum
+    {
+        CWNone,
+        CWText,
+        CWDots,
+        CWDashes,
+        CWKeyboard
+    } CWMode;
+
+    bool m_loop;
+    CWMode m_mode;
+    int m_sampleRate;
+    QString m_text;
+    int m_wpm;
+    bool m_keyboardIambic;
+    Qt::Key m_dotKey;
+    Qt::KeyboardModifiers m_dotKeyModifiers;
+    Qt::Key m_dashKey;
+    Qt::KeyboardModifiers m_dashKeyModifiers;
+
+    CWKeyerSettings();
+    void resetToDefaults();
+
+    QByteArray serialize() const;
+    bool deserialize(const QByteArray& data);
+    virtual void formatTo(SWGSDRangel::SWGObject *swgObject) const;
+    virtual void updateFrom(const QStringList& keys, const SWGSDRangel::SWGObject *swgObject);
+};
+
+
+
+#endif /* SDRBASE_DSP_CWKEYERSETTINGS_H_ */

android/app/src/main/cpp/dsp/datafifo.cpp

@@ -0,0 +1,314 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2016, 2018-2022 Edouard Griffiths, F4EXB <f4exb06@gmail.com>    //
+// Copyright (C) 2022 Jiří Pinkava <jiri.pinkava@rossum.ai>                      //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include "datafifo.h"
+
+void DataFifo::create(unsigned int s)
+{
+	m_size = 0;
+	m_fill = 0;
+	m_head = 0;
+	m_tail = 0;
+
+	m_data.resize(s);
+	m_size = m_data.size();
+}
+
+void DataFifo::reset()
+{
+	QMutexLocker mutexLocker(&m_mutex);
+	m_suppressed = -1;
+	m_fill = 0;
+	m_head = 0;
+	m_tail = 0;
+}
+
+DataFifo::DataFifo(QObject* parent) :
+	QObject(parent),
+	m_data(),
+	m_currentDataType(DataTypeI16)
+{
+	setObjectName("DataFifo");
+	m_suppressed = -1;
+	m_size = 0;
+	m_fill = 0;
+	m_head = 0;
+	m_tail = 0;
+}
+
+DataFifo::DataFifo(int size, QObject* parent) :
+	QObject(parent),
+	m_data(),
+	m_currentDataType(DataTypeI16)
+{
+	setObjectName("DataFifo");
+	m_suppressed = -1;
+	create(size);
+}
+
+DataFifo::DataFifo(const DataFifo& other) :
+    QObject(other.parent()),
+    m_data(other.m_data),
+	m_currentDataType(DataTypeI16)
+{
+	setObjectName("DataFifo");
+  	m_suppressed = -1;
+	m_size = m_data.size();
+	m_fill = 0;
+	m_head = 0;
+	m_tail = 0;
+}
+
+DataFifo::~DataFifo()
+{
+	QMutexLocker mutexLocker(&m_mutex);
+	m_size = 0;
+}
+
+bool DataFifo::setSize(int size)
+{
+	QMutexLocker mutexLocker(&m_mutex);
+	create(size);
+	return m_data.size() == size;
+}
+
+unsigned int DataFifo::write(const quint8* data, unsigned int count, DataType dataType)
+{
+	QMutexLocker mutexLocker(&m_mutex);
+
+	if (dataType != m_currentDataType)
+	{
+		m_suppressed = -1;
+		m_fill = 0;
+		m_head = 0;
+		m_tail = 0;
+		m_currentDataType = dataType;
+	}
+
+	unsigned int total;
+	unsigned int remaining;
+	unsigned int len;
+	const quint8* begin = (const quint8*) data;
+	//count /= sizeof(Sample);
+
+	total = std::min(count, m_size - m_fill);
+
+    if (total < count)
+    {
+		if (m_suppressed < 0)
+        {
+			m_suppressed = 0;
+			m_msgRateTimer.start();
+			qCritical("DataFifo::write: overflow - dropping %u samples (size=%u)", count - total, m_size);
+		}
+        else
+        {
+			if (m_msgRateTimer.elapsed() > 2500)
+            {
+				qCritical("DataFifo::write: %u messages dropped", m_suppressed);
+				qCritical("DataFifo::write: overflow - dropping %u samples (size=%u)", count - total, m_size);
+				m_suppressed = -1;
+			}
+            else
+            {
+				m_suppressed++;
+			}
+		}
+	}
+
+	remaining = total;
+
+    while (remaining > 0)
+    {
+		len = std::min(remaining, m_size - m_tail);
+		std::copy(begin, begin + len, m_data.begin() + m_tail);
+		m_tail += len;
+		m_tail %= m_size;
+		m_fill += len;
+		begin += len;
+		remaining -= len;
+	}
+
+	if (m_fill > 0) {
+		emit dataReady();
+    }
+
+	return total;
+}
+
+unsigned int DataFifo::write(QByteArray::const_iterator begin, QByteArray::const_iterator end, DataType dataType)
+{
+	QMutexLocker mutexLocker(&m_mutex);
+
+	if (dataType != m_currentDataType)
+	{
+		m_suppressed = -1;
+		m_fill = 0;
+		m_head = 0;
+		m_tail = 0;
+		m_currentDataType = dataType;
+	}
+
+	unsigned int count = end - begin;
+	unsigned int total;
+	unsigned int remaining;
+	unsigned int len;
+
+	total = std::min(count, m_size - m_fill);
+
+    if (total < count)
+    {
+		if (m_suppressed < 0)
+        {
+			m_suppressed = 0;
+			m_msgRateTimer.start();
+			qCritical("DataFifo::write: overflow - dropping %u samples", count - total);
+		}
+        else
+        {
+			if (m_msgRateTimer.elapsed() > 2500)
+            {
+				qCritical("DataFifo::write: %u messages dropped", m_suppressed);
+				qCritical("DataFifo::write: overflow - dropping %u samples", count - total);
+				m_suppressed = -1;
+			}
+            else
+            {
+				m_suppressed++;
+			}
+		}
+	}
+
+	remaining = total;
+
+    while (remaining > 0)
+    {
+		len = std::min(remaining, m_size - m_tail);
+		std::copy(begin, begin + len, m_data.begin() + m_tail);
+		m_tail += len;
+		m_tail %= m_size;
+		m_fill += len;
+		begin += len;
+		remaining -= len;
+	}
+
+	if (m_fill > 0) {
+		emit dataReady();
+    }
+
+	return total;
+}
+
+unsigned int DataFifo::read(QByteArray::iterator begin, QByteArray::iterator end, DataType& dataType)
+{
+	QMutexLocker mutexLocker(&m_mutex);
+	dataType = m_currentDataType;
+	unsigned int count = end - begin;
+	unsigned int total;
+	unsigned int remaining;
+	unsigned int len;
+
+	total = std::min(count, m_fill);
+
+    if (total < count) {
+		qCritical("DataFifo::read: underflow - missing %u samples", count - total);
+    }
+
+	remaining = total;
+
+    while (remaining > 0)
+    {
+		len = std::min(remaining, m_size - m_head);
+		std::copy(m_data.begin() + m_head, m_data.begin() + m_head + len, begin);
+		m_head += len;
+		m_head %= m_size;
+		m_fill -= len;
+		begin += len;
+		remaining -= len;
+	}
+
+	return total;
+}
+
+unsigned int DataFifo::readBegin(unsigned int count,
+	QByteArray::iterator* part1Begin, QByteArray::iterator* part1End,
+	QByteArray::iterator* part2Begin, QByteArray::iterator* part2End,
+	DataType& dataType)
+{
+	QMutexLocker mutexLocker(&m_mutex);
+	dataType = m_currentDataType;
+	unsigned int total;
+	unsigned int remaining;
+	unsigned int len;
+	unsigned int head = m_head;
+
+	total = std::min(count, m_fill);
+
+    if (total < count) {
+		qCritical("DataFifo::readBegin: underflow - missing %u samples", count - total);
+    }
+
+	remaining = total;
+
+    if (remaining > 0)
+    {
+		len = std::min(remaining, m_size - head);
+		*part1Begin = m_data.begin() + head;
+		*part1End = m_data.begin() + head + len;
+		head += len;
+		head %= m_size;
+		remaining -= len;
+	}
+    else
+    {
+		*part1Begin = m_data.end();
+		*part1End = m_data.end();
+	}
+
+    if (remaining > 0)
+    {
+		len = std::min(remaining, m_size - head);
+		*part2Begin = m_data.begin() + head;
+		*part2End = m_data.begin() + head + len;
+	}
+    else
+    {
+		*part2Begin = m_data.end();
+		*part2End = m_data.end();
+	}
+
+	return total;
+}
+
+unsigned int DataFifo::readCommit(unsigned int count)
+{
+	QMutexLocker mutexLocker(&m_mutex);
+
+	if (count > m_fill)
+    {
+		qCritical("DataFifo::readCommit: cannot commit more than available samples");
+		count = m_fill;
+	}
+
+    m_head = (m_head + count) % m_size;
+	m_fill -= count;
+
+	return count;
+}

android/app/src/main/cpp/dsp/datafifo.h

@@ -0,0 +1,79 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2016, 2018-2021 Edouard Griffiths, F4EXB <f4exb06@gmail.com> //
+// Copyright (C) 2022 Jiří Pinkava <jiri.pinkava@rossum.ai>                      //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef INCLUDE_DATAFIFO_H
+#define INCLUDE_DATAFIFO_H
+
+#include <QObject>
+#include <QRecursiveMutex>
+#include <QElapsedTimer>
+#include <QByteArray>
+
+#include "export.h"
+
+class SDRBASE_API DataFifo : public QObject {
+	Q_OBJECT
+public:
+	enum DataType
+	{
+		DataTypeI16,  //!< 16 bit signed integer
+		DataTypeCI16  //!< Complex (i.e. Re, Im pair of) 16 bit signed integer
+	};
+
+	DataFifo(QObject* parent = nullptr);
+	DataFifo(int size, QObject* parent = nullptr);
+    DataFifo(const DataFifo& other);
+	~DataFifo();
+
+	bool setSize(int size);
+    void reset();
+	inline unsigned int size() const { return m_size; }
+	inline unsigned int fill() { QMutexLocker mutexLocker(&m_mutex); unsigned int fill = m_fill; return fill; }
+
+	unsigned int write(const quint8* data, unsigned int count, DataType dataType);
+	unsigned int write(QByteArray::const_iterator begin, QByteArray::const_iterator end, DataType dataType);
+
+	unsigned int read(QByteArray::iterator begin, QByteArray::iterator end, DataType& dataType);
+
+	unsigned int readBegin(unsigned int count,
+		QByteArray::iterator* part1Begin, QByteArray::iterator* part1End,
+		QByteArray::iterator* part2Begin, QByteArray::iterator* part2End,
+		DataType& daaType);
+	unsigned int readCommit(unsigned int count);
+
+signals:
+	void dataReady();
+
+private:
+	QElapsedTimer m_msgRateTimer;
+	int m_suppressed;
+	QByteArray m_data;
+	DataType m_currentDataType;
+	QRecursiveMutex m_mutex;
+
+	unsigned int m_size;
+	unsigned int m_fill;
+	unsigned int m_head;
+	unsigned int m_tail;
+
+	void create(unsigned int s);
+};
+
+#endif // INCLUDE_DATAFIFO_H

android/app/src/main/cpp/dsp/dcscodes.cpp

@@ -0,0 +1,465 @@
+//////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2021 Edouard Griffiths, F4EXB <f4exb06@gmail.com>                                          //
+//                                                                                                          //
+// This program is free software; you can redistribute it and/or modify                                     //
+// it under the terms of the GNU General Public License as published by                                     //
+// the Free Software Foundation as version 3 of the License, or                                             //
+// (at your option) any later version.                                                                      //
+//                                                                                                          //
+// This program is distributed in the hope that it will be useful,                                          //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                                           //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                                             //
+// GNU General Public License V3 for more details.                                                          //
+//                                                                                                          //
+// You should have received a copy of the GNU General Public License                                        //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.                                     //
+//                                                                                                          //
+// Source: http://onfreq.com/syntorx/dcs.html                                                               //
+//                                                                                                          //
+//////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+#include "dcscodes.h"
+
+const QMap<unsigned int, unsigned int> DCSCodes::m_toCanonicalCode {
+    {0023, 0023},
+    {0340, 0023},
+    {0766, 0023},
+    {0025, 0025},
+    {0026, 0026},
+    {0566, 0026},
+    {0031, 0031},
+    {0374, 0031},
+    {0643, 0031},
+    {0032, 0032},
+    {0036, 0036},
+    {0137, 0036},
+    {0043, 0043},
+    {0355, 0043},
+    {0047, 0047},
+    {0375, 0047},
+    {0707, 0047},
+    {0051, 0051},
+    {0771, 0051},
+    {0520, 0051},
+    {0053, 0053},
+    {0054, 0054},
+    {0405, 0054},
+    {0675, 0054},
+    {0065, 0065},
+    {0301, 0065},
+    {0071, 0071},
+    {0603, 0071},
+    {0717, 0071},
+    {0746, 0071},
+    {0072, 0072},
+    {0470, 0072},
+    {0701, 0072},
+    {0073, 0073},
+    {0640, 0073},
+    {0074, 0074},
+    {0360, 0074},
+    {0721, 0074},
+    {0112, 0112},
+    {0250, 0112},
+    {0505, 0112},
+    {0512, 0112},
+    {0114, 0114},
+    {0327, 0114},
+    {0615, 0114},
+    {0115, 0115},
+    {0534, 0115},
+    {0674, 0115},
+    {0116, 0116},
+    {0060, 0116},
+    {0737, 0116},
+    {0122, 0122},
+    {0535, 0125},
+    {0125, 0125},
+    {0173, 0125},
+    {0131, 0131},
+    {0572, 0131},
+    {0702, 0131},
+    {0132, 0132},
+    {0605, 0132},
+    {0634, 0132},
+    {0714, 0132},
+    {0134, 0134},
+    {0273, 0134},
+    {0143, 0143},
+    {0333, 0143},
+    {0145, 0145},
+    {0525, 0145},
+    {0152, 0152},
+    {0366, 0152},
+    {0415, 0152},
+    {0155, 0155},
+    {0233, 0155},
+    {0660, 0155},
+    {0156, 0156},
+    {0517, 0156},
+    {0741, 0156},
+    {0162, 0162},
+    {0416, 0162},
+    {0553, 0162},
+    {0165, 0165},
+    {0354, 0165},
+    {0172, 0172},
+    {0057, 0172},
+    {0174, 0174},
+    {0142, 0174},
+    {0270, 0174},
+    {0205, 0205},
+    {0135, 0205},
+    {0610, 0205},
+    {0212, 0212},
+    {0253, 0212},
+    {0223, 0223},
+    {0350, 0223},
+    {0475, 0223},
+    {0750, 0223},
+    {0225, 0225},
+    {0536, 0225},
+    {0226, 0226},
+    {0104, 0226},
+    {0557, 0226},
+    {0243, 0243},
+    {0267, 0243},
+    {0342, 0243},
+    {0244, 0244},
+    {0176, 0244},
+    {0417, 0244},
+    {0245, 0245},
+    {0370, 0245},
+    {0246, 0246},
+    {0542, 0246},
+    {0653, 0246},
+    {0554, 0245},
+    {0251, 0251},
+    {0236, 0251},
+    {0704, 0251},
+    {0742, 0251},
+    {0252, 0252},
+    {0661, 0252},
+    {0255, 0255},
+    {0425, 0255},
+    {0261, 0261},
+    {0227, 0261},
+    {0567, 0261},
+    {0263, 0263},
+    {0213, 0263},
+    {0736, 0263},
+    {0265, 0265},
+    {0171, 0265},
+    {0426, 0265},
+    {0266, 0266},
+    {0655, 0266},
+    {0271, 0271},
+    {0427, 0271},
+    {0510, 0271},
+    {0762, 0271},
+    {0274, 0274},
+    {0652, 0274},
+    {0306, 0306},
+    {0147, 0306},
+    {0303, 0306},
+    {0761, 0306},
+    {0311, 0311},
+    {0330, 0311},
+    {0456, 0311},
+    {0561, 0311},
+    {0315, 0315},
+    {0321, 0315},
+    {0673, 0315},
+    {0325, 0325},
+    {0550, 0325},
+    {0626, 0325},
+    {0331, 0331},
+    {0372, 0331},
+    {0507, 0331},
+    {0332, 0332},
+    {0433, 0332},
+    {0552, 0332},
+    {0343, 0343},
+    {0324, 0343},
+    {0570, 0343},
+    {0346, 0346},
+    {0616, 0346},
+    {0635, 0346},
+    {0724, 0346},
+    {0351, 0351},
+    {0353, 0351},
+    {0435, 0351},
+    {0356, 0356},
+    {0521, 0356},
+    {0364, 0364},
+    {0130, 0364},
+    {0641, 0364},
+    {0365, 0365},
+    {0107, 0365},
+    {0371, 0371},
+    {0217, 0371},
+    {0453, 0371},
+    {0530, 0371},
+    {0411, 0411},
+    {0117, 0411},
+    {0756, 0411},
+    {0412, 0412},
+    {0127, 0412},
+    {0441, 0412},
+    {0711, 0412},
+    {0413, 0413},
+    {0133, 0413},
+    {0620, 0413},
+    {0423, 0423},
+    {0234, 0423},
+    {0563, 0423},
+    {0621, 0423},
+    {0713, 0423},
+    {0431, 0431},
+    {0262, 0431},
+    {0316, 0431},
+    {0730, 0431},
+    {0432, 0432},
+    {0432, 0432},
+    {0276, 0432},
+    {0326, 0432},
+    {0445, 0445},
+    {0222, 0445},
+    {0457, 0445},
+    {0575, 0445},
+    {0446, 0446},
+    {0467, 0446},
+    {0511, 0446},
+    {0672, 0446},
+    {0452, 0452},
+    {0524, 0452},
+    {0765, 0452},
+    {0454, 0454},
+    {0545, 0454},
+    {0513, 0454},
+    {0564, 0454},
+    {0455, 0455},
+    {0533, 0455},
+    {0551, 0455},
+    {0462, 0462},
+    {0462, 0462},
+    {0472, 0462},
+    {0623, 0462},
+    {0725, 0462},
+    {0464, 0464},
+    {0237, 0464},
+    {0642, 0464},
+    {0772, 0464},
+    {0465, 0465},
+    {0056, 0465},
+    {0656, 0465},
+    {0466, 0466},
+    {0144, 0466},
+    {0666, 0466},
+    {0503, 0503},
+    {0157, 0503},
+    {0322, 0503},
+    {0506, 0506},
+    {0224, 0506},
+    {0313, 0506},
+    {0574, 0506},
+    {0516, 0516},
+    {0067, 0516},
+    {0720, 0516},
+    {0523, 0523},
+    {0647, 0523},
+    {0726, 0523},
+    {0526, 0526},
+    {0562, 0526},
+    {0645, 0526},
+    {0532, 0532},
+    {0161, 0532},
+    {0345, 0532},
+    {0546, 0546},
+    {0317, 0546},
+    {0614, 0546},
+    {0751, 0546},
+    {0565, 0565},
+    {0307, 0565},
+    {0362, 0565},
+    {0606, 0606},
+    {0153, 0606},
+    {0630, 0606},
+    {0612, 0612},
+    {0254, 0612},
+    {0314, 0612},
+    {0706, 0612},
+    {0624, 0624},
+    {0075, 0624},
+    {0501, 0624},
+    {0627, 0627},
+    {0037, 0627},
+    {0560, 0627},
+    {0631, 0631},
+    {0231, 0631},
+    {0504, 0631},
+    {0636, 0631},
+    {0745, 0631},
+    {0632, 0632},
+    {0123, 0632},
+    {0657, 0632},
+    {0654, 0654},
+    {0163, 0654},
+    {0460, 0654},
+    {0607, 0654},
+    {0662, 0662},
+    {0363, 0662},
+    {0436, 0662},
+    {0443, 0662},
+    {0444, 0662},
+    {0664, 0664},
+    {0344, 0664},
+    {0471, 0664},
+    {0715, 0664},
+    {0703, 0703},
+    {0150, 0703},
+    {0256, 0703},
+    {0712, 0712},
+    {0136, 0712},
+    {0502, 0712},
+    {0723, 0723},
+    {0235, 0723},
+    {0671, 0723},
+    {0611, 0723},
+    {0731, 0731},
+    {0447, 0731},
+    {0473, 0731},
+    {0474, 0731},
+    {0744, 0731},
+    {0732, 0732},
+    {0164, 0732},
+    {0207, 0732},
+    {0734, 0734},
+    {0066, 0734},
+    {0743, 0743},
+    {0312, 0743},
+    {0515, 0743},
+    {0663, 0743},
+    {0754, 0754},
+    {0076, 0754},
+    {0203, 0754},
+};
+
+const QMap<unsigned int, unsigned int> DCSCodes::m_signFlip = {
+    {0023, 0047},
+    {0025, 0244},
+    {0026, 0464},
+    {0031, 0627},
+    {0032, 0051},
+    {0043, 0445},
+    {0047, 0023},
+    {0051, 0032},
+    {0053, 0452},
+    {0054, 0413},
+    {0065, 0271},
+    {0071, 0306},
+    {0072, 0245},
+    {0073, 0506},
+    {0074, 0174},
+    {0114, 0712},
+    {0115, 0152},
+    {0116, 0754},
+    {0122, 0225},
+    {0125, 0365},
+    {0131, 0364},
+    {0132, 0546},
+    {0134, 0223},
+    {0143, 0412},
+    {0145, 0274},
+    {0152, 0115},
+    {0155, 0731},
+    {0156, 0265},
+    {0162, 0503},
+    {0165, 0251},
+    {0172, 0036},
+    {0174, 0074},
+    {0205, 0263},
+    {0212, 0356},
+    {0223, 0134},
+    {0225, 0122},
+    {0226, 0411},
+    {0243, 0351},
+    {0244, 0025},
+    {0245, 0072},
+    {0246, 0523},
+    {0251, 0165},
+    {0252, 0462},
+    {0255, 0511},
+    {0261, 0732},
+    {0263, 0205},
+    {0265, 0156},
+    {0266, 0454},
+    {0271, 0065},
+    {0274, 0145},
+    {0306, 0071},
+    {0311, 0664},
+    {0315, 0423},
+    {0325, 0526},
+    {0331, 0465},
+    {0332, 0455},
+    {0343, 0532},
+    {0346, 0612},
+    {0351, 0243},
+    {0356, 0212},
+    {0364, 0131},
+    {0365, 0125},
+    {0371, 0734},
+    {0411, 0226},
+    {0412, 0143},
+    {0413, 0054},
+    {0423, 0315},
+    {0431, 0723},
+    {0432, 0516},
+    {0445, 0043},
+    {0446, 0255},
+    {0452, 0053},
+    {0454, 0655},
+    {0455, 0332},
+    {0462, 0252},
+    {0464, 0026},
+    {0465, 0331},
+    {0466, 0662},
+    {0503, 0162},
+    {0506, 0073},
+    {0516, 0432},
+    {0523, 0246},
+    {0526, 0325},
+    {0532, 0343},
+    {0546, 0132},
+    {0565, 0703},
+    {0606, 0631},
+    {0612, 0346},
+    {0624, 0632},
+    {0627, 0031},
+    {0631, 0606},
+    {0632, 0624},
+    {0654, 0743},
+    {0662, 0466},
+    {0664, 0311},
+    {0703, 0565},
+    {0712, 0114},
+    {0723, 0431},
+    {0731, 0155},
+    {0732, 0261},
+    {0734, 0371},
+    {0743, 0654},
+    {0754, 0116},
+};
+
+
+void DCSCodes::getCanonicalCodes(QList<unsigned int>& codes)
+{
+    codes.clear();
+
+    for (auto code : m_toCanonicalCode.keys())
+    {
+        if (code == m_toCanonicalCode.value(code)) {
+            codes.append(code);
+        }
+    }
+}

android/app/src/main/cpp/dsp/dcscodes.h

@@ -0,0 +1,35 @@
+//////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2021 Edouard Griffiths, F4EXB <f4exb06@gmail.com>                                          //
+//                                                                                                          //
+// This program is free software; you can redistribute it and/or modify                                     //
+// it under the terms of the GNU General Public License as published by                                     //
+// the Free Software Foundation as version 3 of the License, or                                             //
+// (at your option) any later version.                                                                      //
+//                                                                                                          //
+// This program is distributed in the hope that it will be useful,                                          //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                                           //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                                             //
+// GNU General Public License V3 for more details.                                                          //
+//                                                                                                          //
+// You should have received a copy of the GNU General Public License                                        //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.                                     //
+//////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+#ifndef INCLUDE_DSP_DCSCODES_H_
+#define INCLUDE_DSP_DCSCODES_H_
+
+#include <QList>
+#include <QMap>
+
+#include "export.h"
+
+class SDRBASE_API DCSCodes
+{
+public:
+    static void getCanonicalCodes(QList<unsigned int>& codes);
+    static const int m_nbCodes;
+    static const QMap<unsigned int, unsigned int> m_toCanonicalCode;
+    static const QMap<unsigned int, unsigned int> m_signFlip;
+};
+
+#endif // INCLUDE_DSP_DCSCODES_H_

android/app/src/main/cpp/dsp/decimatorc.cpp

@@ -0,0 +1,223 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2020 Edouard Griffiths, F4EXB <f4exb06@gmail.com>               //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include "decimatorc.h"
+
+DecimatorC::DecimatorC() :
+    m_log2Decim(0),
+    m_decim(1)
+{}
+
+void DecimatorC::setLog2Decim(unsigned int log2Decim)
+{
+    m_log2Decim = log2Decim;
+    m_decim = 1 << log2Decim;
+}
+
+bool DecimatorC::decimate(Complex c, Complex& cd)
+{
+    if (m_log2Decim == 0) { // no decimation hence no translation possible
+        return true;
+    }
+
+    if (m_log2Decim == 1) {
+        return decimate2(c, cd);
+    } else if (m_log2Decim == 2) {
+        return decimate4(c, cd);
+    } else if (m_log2Decim == 3) {
+        return decimate8(c, cd);
+    } else if (m_log2Decim == 4) {
+        return decimate16(c, cd);
+    } else if (m_log2Decim == 5) {
+        return decimate32(c, cd);
+    } else if (m_log2Decim == 6) {
+        return decimate64(c, cd);
+    } else {
+        return true; // no decimation
+    }
+}
+
+bool DecimatorC::decimate2(Complex c, Complex& cd)
+{
+    float x = c.real();
+    float y = c.imag();
+    bool done2 = m_decimator2.workDecimateCenter(&x, &y);
+
+    if (done2)
+    {
+        cd.real(x);
+        cd.imag(y);
+    }
+
+    return done2;
+}
+
+bool DecimatorC::decimate4(Complex c, Complex& cd)
+{
+    float x = c.real();
+    float y = c.imag();
+    bool done2 = m_decimator2.workDecimateCenter(&x, &y);
+
+    if (done2)
+    {
+        bool done4 = m_decimator4.workDecimateCenter(&x, &y);
+
+        if (done4)
+        {
+            cd.real(x);
+            cd.imag(y);
+            return true;
+        }
+    }
+
+    return false;
+}
+
+bool DecimatorC::decimate8(Complex c, Complex& cd)
+{
+    float x = c.real();
+    float y = c.imag();
+    bool done2 = m_decimator2.workDecimateCenter(&x, &y);
+
+    if (done2)
+    {
+        bool done4 = m_decimator4.workDecimateCenter(&x, &y);
+
+        if (done4)
+        {
+            bool done8 = m_decimator8.workDecimateCenter(&x, &y);
+
+            if (done8)
+            {
+                cd.real(x);
+                cd.imag(y);
+                return true;
+            }
+        }
+    }
+
+    return false;
+}
+
+bool DecimatorC::decimate16(Complex c, Complex& cd)
+{
+    float x = c.real();
+    float y = c.imag();
+    bool done2 = m_decimator2.workDecimateCenter(&x, &y);
+
+    if (done2)
+    {
+        bool done4 = m_decimator4.workDecimateCenter(&x, &y);
+
+        if (done4)
+        {
+            bool done8 = m_decimator8.workDecimateCenter(&x, &y);
+
+            if (done8)
+            {
+                bool done16 = m_decimator16.workDecimateCenter(&x, &y);
+
+                if (done16)
+                {
+                    cd.real(x);
+                    cd.imag(y);
+                    return true;
+                }
+            }
+        }
+    }
+
+    return false;
+}
+
+
+bool DecimatorC::decimate32(Complex c, Complex& cd)
+{
+    float x = c.real();
+    float y = c.imag();
+    bool done2 = m_decimator2.workDecimateCenter(&x, &y);
+
+    if (done2)
+    {
+        bool done4 = m_decimator4.workDecimateCenter(&x, &y);
+
+        if (done4)
+        {
+            bool done8 = m_decimator8.workDecimateCenter(&x, &y);
+
+            if (done8)
+            {
+                bool done16 = m_decimator16.workDecimateCenter(&x, &y);
+
+                if (done16)
+                {
+                    bool done32 = m_decimator32.workDecimateCenter(&x, &y);
+
+                    if (done32)
+                    {
+                        cd.real(x);
+                        cd.imag(y);
+                        return true;
+                    }
+                }
+            }
+        }
+    }
+
+    return false;
+}
+
+bool DecimatorC::decimate64(Complex c, Complex& cd)
+{
+    float x = c.real();
+    float y = c.imag();
+    bool done2 = m_decimator2.workDecimateCenter(&x, &y);
+
+    if (done2)
+    {
+        bool done4 = m_decimator4.workDecimateCenter(&x, &y);
+
+        if (done4)
+        {
+            bool done8 = m_decimator8.workDecimateCenter(&x, &y);
+
+            if (done8)
+            {
+                bool done16 = m_decimator16.workDecimateCenter(&x, &y);
+
+                if (done16)
+                {
+                    bool done32 = m_decimator32.workDecimateCenter(&x, &y);
+
+                    if (done32)
+                    {
+                        bool done64 = m_decimator32.workDecimateCenter(&x, &y);
+
+                        if (done64)
+                        {
+                            cd.real(x);
+                            cd.imag(y);
+                            return true;
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    return false;
+}

android/app/src/main/cpp/dsp/decimatorc.h

@@ -0,0 +1,58 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2016-2020 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+// Half-band centered decimators with Complex (i.e. omplex<float>) input/output
+// Decimates by a power of two using centered half-band filters
+
+#ifndef INCLUDE_DSP_DECIMATORC_H_
+#define INCLUDE_DSP_DECIMATORC_H_
+
+#include "dsp/dsptypes.h"
+#include "dsp/inthalfbandfiltereof.h"
+#include "export.h"
+
+#define DECIMATORSXS_HB_FILTER_ORDER 64
+
+class SDRBASE_API DecimatorC
+{
+public:
+    DecimatorC();
+    void setLog2Decim(unsigned int log2Decim);
+    bool decimate(Complex c, Complex& cd);
+    unsigned int getDecim() const { return m_decim; }
+
+private:
+    IntHalfbandFilterEOF<DECIMATORSXS_HB_FILTER_ORDER, true> m_decimator2; // 1st stages
+    IntHalfbandFilterEOF<DECIMATORSXS_HB_FILTER_ORDER, true> m_decimator4; // 2nd stages
+    IntHalfbandFilterEOF<DECIMATORSXS_HB_FILTER_ORDER, true> m_decimator8; // 3rd stages
+    IntHalfbandFilterEOF<DECIMATORSXS_HB_FILTER_ORDER, true> m_decimator16; // 4th stages
+    IntHalfbandFilterEOF<DECIMATORSXS_HB_FILTER_ORDER, true> m_decimator32; // 5th stages
+    IntHalfbandFilterEOF<DECIMATORSXS_HB_FILTER_ORDER, true> m_decimator64; // 6th stages
+    unsigned int m_log2Decim;
+    unsigned int m_decim;
+
+    bool decimate2(Complex c, Complex& cd);
+    bool decimate4(Complex c, Complex& cd);
+    bool decimate8(Complex c, Complex& cd);
+    bool decimate16(Complex c, Complex& cd);
+    bool decimate32(Complex c, Complex& cd);
+    bool decimate64(Complex c, Complex& cd);
+};
+
+#endif // INCLUDE_DSP_DECIMATORC_H_

android/app/src/main/cpp/dsp/decimatorsff.cpp

@@ -0,0 +1,213 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2018-2020 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+// Copyright (C) 2020 Kacper Michajłow <kasper93@gmail.com>                      //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include "decimatorsff.h"
+
+template<>
+SDRBASE_API void DecimatorsFF<true>::decimate1(FSampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
+{
+    float xreal, yimag;
+
+    for (int pos = 0; pos < nbIAndQ - 1; pos += 2)
+    {
+        xreal = buf[pos+0];
+        yimag = buf[pos+1];
+        (**it).setReal(xreal);
+        (**it).setImag(yimag);
+        ++(*it); // Valgrind optim (comment not repeated)
+    }
+}
+
+template<>
+SDRBASE_API void DecimatorsFF<false>::decimate1(FSampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
+{
+    float xreal, yimag;
+
+    for (int pos = 0; pos < nbIAndQ - 1; pos += 2)
+    {
+        xreal = buf[pos+1];
+        yimag = buf[pos+0];
+        (**it).setReal(xreal);
+        (**it).setImag(yimag);
+        ++(*it); // Valgrind optim (comment not repeated)
+    }
+}
+
+template<>
+void DecimatorsFF<true>::decimate2_inf(FSampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
+{
+    float xreal, yimag;
+
+    for (int pos = 0; pos < nbIAndQ - 7; pos += 8)
+    {
+        xreal = (buf[pos+0] - buf[pos+3]);
+        yimag = (buf[pos+1] + buf[pos+2]);
+        (**it).setReal(xreal);
+        (**it).setImag(yimag);
+        ++(*it);
+
+        xreal = (buf[pos+7] - buf[pos+4]);
+        yimag = (- buf[pos+5] - buf[pos+6]);
+        (**it).setReal(xreal);
+        (**it).setImag(yimag);
+        ++(*it);
+    }
+}
+
+template<>
+void DecimatorsFF<false>::decimate2_inf(FSampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
+{
+    float xreal, yimag;
+
+    for (int pos = 0; pos < nbIAndQ - 7; pos += 8)
+    {
+        xreal = (buf[pos+1] + buf[pos+2]);
+        yimag = (buf[pos+0] - buf[pos+3]);
+        (**it).setReal(xreal);
+        (**it).setImag(yimag);
+        ++(*it);
+
+        xreal = (- buf[pos+5] - buf[pos+6]);
+        yimag = (buf[pos+7] - buf[pos+4]);
+        (**it).setReal(xreal);
+        (**it).setImag(yimag);
+        ++(*it);
+    }
+}
+
+template<>
+void DecimatorsFF<true>::decimate2_sup(FSampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
+{
+    float xreal, yimag;
+
+    for (int pos = 0; pos < nbIAndQ - 7; pos += 8)
+    {
+        xreal = (buf[pos+1] - buf[pos+2]);
+        yimag = (- buf[pos+0] - buf[pos+3]);
+        (**it).setReal(xreal);
+        (**it).setImag(yimag);
+        ++(*it);
+
+        xreal = (buf[pos+6] - buf[pos+5]);
+        yimag = (buf[pos+4] + buf[pos+7]);
+        (**it).setReal(xreal);
+        (**it).setImag(yimag);
+        ++(*it);
+    }
+}
+
+template<>
+void DecimatorsFF<false>::decimate2_sup(FSampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
+{
+    float xreal, yimag;
+
+    for (int pos = 0; pos < nbIAndQ - 7; pos += 8)
+    {
+        xreal = (- buf[pos+0] - buf[pos+3]);
+        yimag = (buf[pos+1] - buf[pos+2]);
+        (**it).setReal(xreal);
+        (**it).setImag(yimag);
+        ++(*it);
+
+        xreal = (buf[pos+4] + buf[pos+7]);
+        yimag = (buf[pos+6] - buf[pos+5]);
+        (**it).setReal(xreal);
+        (**it).setImag(yimag);
+        ++(*it);
+    }
+}
+
+template<>
+void DecimatorsFF<true>::decimate4_inf(FSampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
+{
+    float xreal, yimag;
+
+    for (int pos = 0; pos < nbIAndQ - 7; pos += 8)
+    {
+        xreal = (buf[pos+0] - buf[pos+3] + buf[pos+7] - buf[pos+4]);
+        yimag = (buf[pos+1] - buf[pos+5] + buf[pos+2] - buf[pos+6]);
+
+        (**it).setReal(xreal);
+        (**it).setImag(yimag);
+
+        ++(*it);
+    }
+}
+
+template<>
+void DecimatorsFF<false>::decimate4_inf(FSampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
+{
+    float xreal, yimag;
+
+    for (int pos = 0; pos < nbIAndQ - 7; pos += 8)
+    {
+        xreal = (buf[pos+1] - buf[pos+5] + buf[pos+2] - buf[pos+6]);
+        yimag = (buf[pos+0] - buf[pos+3] + buf[pos+7] - buf[pos+4]);
+
+        (**it).setReal(xreal);
+        (**it).setImag(yimag);
+
+        ++(*it);
+    }
+}
+
+template<>
+void DecimatorsFF<true>::decimate4_sup(FSampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
+{
+    // Sup (USB):
+    //            x  y   x  y   x   y  x   y  / x -> 1,-2,-5,6 / y -> -0,-3,4,7
+    // [ rotate:  1, 0, -2, 3, -5, -4, 6, -7]
+    // Inf (LSB):
+    //            x  y   x  y   x   y  x   y  / x -> 0,-3,-4,7 / y -> 1,2,-5,-6
+    // [ rotate:  0, 1, -3, 2, -4, -5, 7, -6]
+    float xreal, yimag;
+
+    for (int pos = 0; pos < nbIAndQ - 7; pos += 8)
+    {
+        xreal = (buf[pos+1] - buf[pos+2] - buf[pos+5] + buf[pos+6]);
+        yimag = (- buf[pos+0] - buf[pos+3] + buf[pos+4] + buf[pos+7]);
+
+        (**it).setReal(xreal);
+        (**it).setImag(yimag);
+
+        ++(*it);
+    }
+}
+
+template<>
+void DecimatorsFF<false>::decimate4_sup(FSampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
+{
+    // Sup (USB):
+    //            x  y   x  y   x   y  x   y  / x -> 1,-2,-5,6 / y -> -0,-3,4,7
+    // [ rotate:  1, 0, -2, 3, -5, -4, 6, -7]
+    // Inf (LSB):
+    //            x  y   x  y   x   y  x   y  / x -> 0,-3,-4,7 / y -> 1,2,-5,-6
+    // [ rotate:  0, 1, -3, 2, -4, -5, 7, -6]
+    float xreal, yimag;
+
+    for (int pos = 0; pos < nbIAndQ - 7; pos += 8)
+    {
+        xreal = (- buf[pos+0] - buf[pos+3] + buf[pos+4] + buf[pos+7]);
+        yimag = (buf[pos+1] - buf[pos+2] - buf[pos+5] + buf[pos+6]);
+
+        (**it).setReal(xreal);
+        (**it).setImag(yimag);
+
+        ++(*it);
+    }
+}

android/app/src/main/cpp/dsp/decimatorsfi.cpp

@@ -0,0 +1,214 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2018-2020 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+// Copyright (C) 2020 Kacper Michajłow <kasper93@gmail.com>                      //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include "decimatorsfi.h"
+
+template<>
+SDRBASE_API void DecimatorsFI<true>::decimate1(SampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
+{
+    float xreal, yimag;
+
+    for (int pos = 0; pos < nbIAndQ - 1; pos += 2)
+    {
+        xreal = buf[pos+0];
+        yimag = buf[pos+1];
+        (**it).setReal(xreal * SDR_RX_SCALEF);
+        (**it).setImag(yimag * SDR_RX_SCALEF);
+        ++(*it); // Valgrind optim (comment not repeated)
+    }
+}
+
+template<>
+SDRBASE_API void DecimatorsFI<false>::decimate1(SampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
+{
+    float xreal, yimag;
+
+    for (int pos = 0; pos < nbIAndQ - 1; pos += 2)
+    {
+        xreal = buf[pos+1];
+        yimag = buf[pos+0];
+        (**it).setReal(xreal * SDR_RX_SCALEF);
+        (**it).setImag(yimag * SDR_RX_SCALEF);
+        ++(*it); // Valgrind optim (comment not repeated)
+    }
+}
+
+template<>
+SDRBASE_API void DecimatorsFI<true>::decimate2_inf(SampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
+{
+    float xreal, yimag;
+
+    for (int pos = 0; pos < nbIAndQ - 7; pos += 8)
+    {
+        xreal = (buf[pos+0] - buf[pos+3]);
+        yimag = (buf[pos+1] + buf[pos+2]);
+        (**it).setReal(xreal * SDR_RX_SCALED);
+        (**it).setImag(yimag * SDR_RX_SCALED);
+        ++(*it);
+
+        xreal = (buf[pos+7] - buf[pos+4]);
+        yimag = (- buf[pos+5] - buf[pos+6]);
+        (**it).setReal(xreal * SDR_RX_SCALED);
+        (**it).setImag(yimag * SDR_RX_SCALED);
+        ++(*it);
+    }
+}
+
+template<>
+SDRBASE_API void DecimatorsFI<false>::decimate2_inf(SampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
+{
+    float xreal, yimag;
+
+    for (int pos = 0; pos < nbIAndQ - 7; pos += 8)
+    {
+        xreal = (buf[pos+1] + buf[pos+2]);
+        yimag = (buf[pos+0] - buf[pos+3]);
+        (**it).setReal(xreal * SDR_RX_SCALED);
+        (**it).setImag(yimag * SDR_RX_SCALED);
+        ++(*it);
+
+        xreal = (- buf[pos+5] - buf[pos+6]);
+        yimag = (buf[pos+7] - buf[pos+4]);
+        (**it).setReal(xreal * SDR_RX_SCALED);
+        (**it).setImag(yimag * SDR_RX_SCALED);
+        ++(*it);
+    }
+}
+
+template<>
+SDRBASE_API void DecimatorsFI<true>::decimate2_sup(SampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
+{
+    float xreal, yimag;
+
+    for (int pos = 0; pos < nbIAndQ - 7; pos += 8)
+    {
+        xreal = (buf[pos+1] - buf[pos+2]);
+        yimag = (- buf[pos+0] - buf[pos+3]);
+        (**it).setReal(xreal * SDR_RX_SCALED);
+        (**it).setImag(yimag * SDR_RX_SCALED);
+        ++(*it);
+
+        xreal = (buf[pos+6] - buf[pos+5]);
+        yimag = (buf[pos+4] + buf[pos+7]);
+        (**it).setReal(xreal * SDR_RX_SCALED);
+        (**it).setImag(yimag * SDR_RX_SCALED);
+        ++(*it);
+    }
+}
+
+template<>
+SDRBASE_API void DecimatorsFI<false>::decimate2_sup(SampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
+{
+    float xreal, yimag;
+
+    for (int pos = 0; pos < nbIAndQ - 7; pos += 8)
+    {
+        xreal = (- buf[pos+0] - buf[pos+3]);
+        yimag = (buf[pos+1] - buf[pos+2]);
+        (**it).setReal(xreal * SDR_RX_SCALED);
+        (**it).setImag(yimag * SDR_RX_SCALED);
+        ++(*it);
+
+        xreal = (buf[pos+4] + buf[pos+7]);
+        yimag = (buf[pos+6] - buf[pos+5]);
+        (**it).setReal(xreal * SDR_RX_SCALED);
+        (**it).setImag(yimag * SDR_RX_SCALED);
+        ++(*it);
+    }
+}
+
+template<>
+SDRBASE_API void DecimatorsFI<true>::decimate4_inf(SampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
+{
+    float xreal, yimag;
+
+    for (int pos = 0; pos < nbIAndQ - 7; pos += 8)
+    {
+        xreal = (buf[pos+0] - buf[pos+3] + buf[pos+7] - buf[pos+4]);
+        yimag = (buf[pos+1] - buf[pos+5] + buf[pos+2] - buf[pos+6]);
+
+        (**it).setReal(xreal * SDR_RX_SCALED);
+        (**it).setImag(yimag * SDR_RX_SCALED);
+
+        ++(*it);
+    }
+}
+
+template<>
+SDRBASE_API void DecimatorsFI<false>::decimate4_inf(SampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
+{
+    float xreal, yimag;
+
+    for (int pos = 0; pos < nbIAndQ - 7; pos += 8)
+    {
+        xreal = (buf[pos+1] - buf[pos+5] + buf[pos+2] - buf[pos+6]);
+        yimag = (buf[pos+0] - buf[pos+3] + buf[pos+7] - buf[pos+4]);
+
+        (**it).setReal(xreal * SDR_RX_SCALED);
+        (**it).setImag(yimag * SDR_RX_SCALED);
+
+        ++(*it);
+    }
+}
+
+template<>
+SDRBASE_API void DecimatorsFI<true>::decimate4_sup(SampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
+{
+    // Sup (USB):
+    //            x  y   x  y   x   y  x   y  / x -> 1,-2,-5,6 / y -> -0,-3,4,7
+    // [ rotate:  1, 0, -2, 3, -5, -4, 6, -7]
+    // Inf (LSB):
+    //            x  y   x  y   x   y  x   y  / x -> 0,-3,-4,7 / y -> 1,2,-5,-6
+    // [ rotate:  0, 1, -3, 2, -4, -5, 7, -6]
+    float xreal, yimag;
+
+    for (int pos = 0; pos < nbIAndQ - 7; pos += 8)
+    {
+        xreal = (buf[pos+1] - buf[pos+2] - buf[pos+5] + buf[pos+6]);
+        yimag = (- buf[pos+0] - buf[pos+3] + buf[pos+4] + buf[pos+7]);
+
+        (**it).setReal(xreal * SDR_RX_SCALED);
+        (**it).setImag(yimag * SDR_RX_SCALED);
+
+        ++(*it);
+    }
+}
+
+template<>
+SDRBASE_API void DecimatorsFI<false>::decimate4_sup(SampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
+{
+    // Sup (USB):
+    //            x  y   x  y   x   y  x   y  / x -> 1,-2,-5,6 / y -> -0,-3,4,7
+    // [ rotate:  1, 0, -2, 3, -5, -4, 6, -7]
+    // Inf (LSB):
+    //            x  y   x  y   x   y  x   y  / x -> 0,-3,-4,7 / y -> 1,2,-5,-6
+    // [ rotate:  0, 1, -3, 2, -4, -5, 7, -6]
+    float xreal, yimag;
+
+    for (int pos = 0; pos < nbIAndQ - 7; pos += 8)
+    {
+        xreal = (- buf[pos+0] - buf[pos+3] + buf[pos+4] + buf[pos+7]);
+        yimag = (buf[pos+1] - buf[pos+2] - buf[pos+5] + buf[pos+6]);
+
+        (**it).setReal(xreal * SDR_RX_SCALED);
+        (**it).setImag(yimag * SDR_RX_SCALED);
+
+        ++(*it);
+    }
+}
+

android/app/src/main/cpp/dsp/devicesamplemimo.cpp

@@ -0,0 +1,41 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2019 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include "devicesamplemimo.h"
+
+DeviceSampleMIMO::DeviceSampleMIMO() :
+    m_guiMessageQueue(nullptr)
+{
+	connect(&m_inputMessageQueue, SIGNAL(messageEnqueued()), this, SLOT(handleInputMessages()));
+}
+
+DeviceSampleMIMO::~DeviceSampleMIMO() = default;
+
+void DeviceSampleMIMO::handleInputMessages()
+{
+	Message* message;
+
+	while ((message = m_inputMessageQueue.pop()) != nullptr)
+	{
+		if (handleMessage(*message))
+		{
+			delete message;
+		}
+	}
+}

android/app/src/main/cpp/dsp/devicesamplemimo.h

@@ -0,0 +1,176 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2021 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef SDRBASE_DSP_DEVICESAMPLEMIMO_H_
+#define SDRBASE_DSP_DEVICESAMPLEMIMO_H_
+
+#include <vector>
+
+#include "samplemififo.h"
+#include "samplemofifo.h"
+#include "util/message.h"
+#include "util/messagequeue.h"
+#include "export.h"
+
+namespace SWGSDRangel
+{
+    class SWGDeviceSettings;
+    class SWGDeviceState;
+    class SWGDeviceReport;
+    class SWGDeviceActions;
+}
+
+class SDRBASE_API DeviceSampleMIMO : public QObject {
+	Q_OBJECT
+public:
+    enum MIMOType //!< Type of MIMO
+    {
+        MIMOAsynchronous,    //!< All streams are asynchronous (false MIMO)
+        MIMOHalfSynchronous, //!< MI + MO (synchronous inputs on one side and synchronous outputs on the other side)
+        MIMOFullSynchronous, //!< True MIMO (all streams synchronous)
+    };
+
+    typedef enum {
+        FC_POS_INFRA = 0,
+        FC_POS_SUPRA,
+        FC_POS_CENTER
+    } fcPos_t;
+
+	DeviceSampleMIMO();
+	virtual ~DeviceSampleMIMO();
+	virtual void destroy() = 0;
+
+    virtual void init() = 0;  //!< initializations to be done when all collaborating objects are created and possibly connected
+	virtual bool startRx() = 0;
+	virtual void stopRx() = 0;
+	virtual bool startTx() = 0;
+	virtual void stopTx() = 0;
+
+    virtual QByteArray serialize() const = 0;
+    virtual bool deserialize(const QByteArray& data) = 0;
+
+	virtual const QString& getDeviceDescription() const = 0;
+
+	virtual int getSinkSampleRate(int index) const = 0;                     //!< Sample rate exposed by the sink at index
+    virtual void setSinkSampleRate(int sampleRate, int index) = 0;          //!< For when the sink sample rate is set externally
+	virtual quint64 getSinkCenterFrequency(int index) const = 0;            //!< Center frequency exposed by the sink at index
+    virtual void setSinkCenterFrequency(qint64 centerFrequency, int index) = 0;
+
+	virtual int getSourceSampleRate(int index) const = 0;                   //!< Sample rate exposed by the source at index
+    virtual void setSourceSampleRate(int sampleRate, int index) = 0;        //!< For when the source sample rate is set externally
+	virtual quint64 getSourceCenterFrequency(int index) const = 0;          //!< Center frequency exposed by the source at index
+    virtual void setSourceCenterFrequency(qint64 centerFrequency, int index) = 0;
+
+    virtual quint64 getMIMOCenterFrequency() const = 0; //!< Unique center frequency for preset identification or any unique reference
+    virtual unsigned int getMIMOSampleRate() const = 0; //!< Unique sample rate for any unique reference
+
+	virtual bool handleMessage(const Message& message) = 0;
+
+    virtual int webapiSettingsGet(
+            SWGSDRangel::SWGDeviceSettings& response,
+            QString& errorMessage)
+    {
+        (void) response;
+        errorMessage = "Not implemented";
+        return 501;
+    }
+
+    virtual int webapiSettingsPutPatch(
+            bool force, //!< true to force settings = put
+            const QStringList& deviceSettingsKeys,
+            SWGSDRangel::SWGDeviceSettings& response,
+            QString& errorMessage)
+    {
+        (void) force;
+        (void) deviceSettingsKeys;
+        (void) response;
+        errorMessage = "Not implemented";
+        return 501;
+    }
+
+    virtual int webapiRunGet(
+            int subsystemIndex,
+            SWGSDRangel::SWGDeviceState& response,
+            QString& errorMessage)
+    {
+        (void) response;
+        (void) subsystemIndex;
+        errorMessage = "Not implemented";
+        return 501;
+    }
+
+    virtual int webapiRun(bool run,
+            int subsystemIndex,
+            SWGSDRangel::SWGDeviceState& response,
+            QString& errorMessage)
+    {
+        (void) run;
+        (void) subsystemIndex;
+        (void) response;
+        errorMessage = "Not implemented";
+        return 501;
+    }
+
+    virtual int webapiReportGet(
+            SWGSDRangel::SWGDeviceReport& response,
+            QString& errorMessage)
+    {
+        (void) response;
+        errorMessage = "Not implemented";
+        return 501;
+    }
+
+    virtual int webapiActionsPost(
+            const QStringList& deviceActionsKeys,
+            SWGSDRangel::SWGDeviceActions& actions,
+            QString& errorMessage)
+    {
+        (void) deviceActionsKeys;
+        (void) actions;
+        errorMessage = "Not implemented";
+        return 501;
+    }
+
+    MIMOType getMIMOType() const { return m_mimoType; }
+	MessageQueue *getInputMessageQueue() { return &m_inputMessageQueue; }
+    virtual void setMessageQueueToGUI(MessageQueue *queue) = 0; // pure virtual so that child classes must have to deal with this
+    MessageQueue *getMessageQueueToGUI() { return m_guiMessageQueue; }
+
+    unsigned int getNbSourceFifos() const { return m_sampleMOFifo.getNbStreams(); } //!< Get the number of Tx FIFOs
+    unsigned int getNbSinkFifos() const { return m_sampleMIFifo.getNbStreams(); }   //!< Get the number of Rx FIFOs
+    SampleMIFifo* getSampleMIFifo() { return &m_sampleMIFifo; }
+    SampleMOFifo* getSampleMOFifo() { return &m_sampleMOFifo; }
+    // Streams and FIFOs are in opposed source/sink type whick makes it confusing when stream direction is involved:
+    //   Rx: source stream -> sink FIFO    -> channel sinks
+    //   Tx: sink stream   <- source FIFO  <- channel sources
+    unsigned int getNbSourceStreams() const { return m_sampleMIFifo.getNbStreams(); } //!< Commodity function same as getNbSinkFifos (Rx or source streams)
+    unsigned int getNbSinkStreams() const { return m_sampleMOFifo.getNbStreams(); }   //!< Commodity function same as getNbSourceFifos (Tx or sink streams)
+
+protected slots:
+	void handleInputMessages();
+
+protected:
+    MIMOType m_mimoType;
+    SampleMIFifo m_sampleMIFifo;      //!< Multiple Input FIFO
+    SampleMOFifo m_sampleMOFifo;      //!< Multiple Output FIFO
+	MessageQueue m_inputMessageQueue; //!< Input queue to the sink
+    MessageQueue *m_guiMessageQueue;  //!< Input message queue to the GUI
+};
+
+#endif // SDRBASE_DSP_DEVICESAMPLEMIMO_H_

android/app/src/main/cpp/dsp/devicesamplesink.cpp

@@ -0,0 +1,113 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2016-2017, 2019 Edouard Griffiths, F4EXB <f4exb06@gmail.com>    //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include <QDebug>
+
+#include "dsp/devicesamplestatic.h"
+#include "dsp/devicesamplesink.h"
+
+DeviceSampleSink::DeviceSampleSink() :
+    m_sampleSourceFifo(1<<19),
+    m_guiMessageQueue(0)
+{
+	connect(&m_inputMessageQueue, SIGNAL(messageEnqueued()), this, SLOT(handleInputMessages()));
+}
+
+DeviceSampleSink::~DeviceSampleSink()
+{
+}
+
+void DeviceSampleSink::handleInputMessages()
+{
+	Message* message;
+
+	while ((message = m_inputMessageQueue.pop()) != 0)
+	{
+		if (handleMessage(*message))
+		{
+			delete message;
+		}
+	}
+}
+
+qint64 DeviceSampleSink::calculateDeviceCenterFrequency(
+            quint64 centerFrequency,
+            qint64 transverterDeltaFrequency,
+            int log2Interp,
+            fcPos_t fcPos,
+            quint32 devSampleRate,
+            bool transverterMode)
+{
+    return DeviceSampleStatic::calculateSinkDeviceCenterFrequency(
+        centerFrequency,
+        transverterDeltaFrequency,
+        log2Interp,
+        (DeviceSampleStatic::fcPos_t) fcPos,
+        devSampleRate,
+        transverterMode
+    );
+}
+
+qint64 DeviceSampleSink::calculateCenterFrequency(
+            quint64 deviceCenterFrequency,
+            qint64 transverterDeltaFrequency,
+            int log2Interp,
+            fcPos_t fcPos,
+            quint32 devSampleRate,
+            bool transverterMode)
+{
+    return DeviceSampleStatic::calculateSinkCenterFrequency(
+        deviceCenterFrequency,
+        transverterDeltaFrequency,
+        log2Interp,
+        (DeviceSampleStatic::fcPos_t) fcPos,
+        devSampleRate,
+        transverterMode
+    );
+}
+
+/**
+ * log2Interp = 0:  no shift
+ *
+ * log2Interp = 1:  middle of side band (inf or sup: 1/2)
+ *        ^     |     ^
+ *  | inf | inf | sup | sup |
+ *
+ * log2Interp = 2:  middle of far side half side band (inf, inf or sup, sup: 1/2 + 1/4)
+ *     ^        |        ^
+ *  | inf | inf | sup | sup |
+ *
+ * log2Interp = 3:  inf, inf, sup or sup, sup, inf: 1/2 + 1/4 - 1/8 = 5/8
+ * log2Interp = 4:  inf, inf, sup, inf or sup, sup, inf, sup: 1/2 + 1/4 - 1/8 + 1/16 = 11/16
+ * log2Interp = 5:  inf, inf, sup, inf, sup or sup, sup, inf, sup, inf: 1/2 + 1/4 - 1/8 + 1/16 - 1/32 = 21/32
+ * log2Interp = 6:  inf, sup, inf, sup, inf, sup or sup, inf, sup, inf, sup, inf: 1/2 - 1/4 + 1/8 -1/16 + 1/32 - 1/64 = 21/64
+ *
+ */
+qint32 DeviceSampleSink::calculateFrequencyShift(
+            int log2Interp,
+            fcPos_t fcPos,
+            quint32 devSampleRate)
+{
+    return DeviceSampleStatic::calculateSinkFrequencyShift(
+        log2Interp,
+        (DeviceSampleStatic::fcPos_t) fcPos,
+        devSampleRate
+    );
+}
+

android/app/src/main/cpp/dsp/devicesamplesink.h

@@ -0,0 +1,162 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2021 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef SDRBASE_DSP_DEVICESAMPLESINK_H_
+#define SDRBASE_DSP_DEVICESAMPLESINK_H_
+
+#include <QtGlobal>
+
+#include "samplesourcefifo.h"
+#include "util/message.h"
+#include "util/messagequeue.h"
+#include "export.h"
+
+namespace SWGSDRangel
+{
+    class SWGDeviceSettings;
+    class SWGDeviceState;
+    class SWGDeviceReport;
+    class SWGDeviceActions;
+}
+
+class SDRBASE_API DeviceSampleSink : public QObject {
+	Q_OBJECT
+public:
+    typedef enum {
+        FC_POS_INFRA = 0,
+        FC_POS_SUPRA,
+        FC_POS_CENTER
+    } fcPos_t;
+
+	DeviceSampleSink();
+	virtual ~DeviceSampleSink();
+	virtual void destroy() = 0;
+
+    virtual void init() = 0;  //!< initializations to be done when all collaborating objects are created and possibly connected
+	virtual bool start() = 0;
+	virtual void stop() = 0;
+
+    virtual QByteArray serialize() const = 0;
+    virtual bool deserialize(const QByteArray& data) = 0;
+
+	virtual const QString& getDeviceDescription() const = 0;
+	virtual int getSampleRate() const = 0; //!< Sample rate exposed by the sink
+    virtual void setSampleRate(int sampleRate) = 0; //!< For when the sink sample rate is set externally
+	virtual quint64 getCenterFrequency() const = 0; //!< Center frequency exposed by the sink
+    virtual void setCenterFrequency(qint64 centerFrequency) = 0;
+
+	virtual bool handleMessage(const Message& message) = 0;
+
+    virtual int webapiSettingsGet(
+            SWGSDRangel::SWGDeviceSettings& response,
+            QString& errorMessage)
+    {
+        (void) response;
+        errorMessage = "Not implemented";
+        return 501;
+    }
+
+    virtual int webapiSettingsPutPatch(
+            bool force, //!< true to force settings = put
+            const QStringList& deviceSettingsKeys,
+            SWGSDRangel::SWGDeviceSettings& response,
+            QString& errorMessage)
+    {
+        (void) force;
+        (void) deviceSettingsKeys;
+        (void) response;
+        errorMessage = "Not implemented";
+        return 501;
+    }
+
+    virtual int webapiRunGet(
+            SWGSDRangel::SWGDeviceState& response,
+            QString& errorMessage)
+    {
+        (void) response;
+        errorMessage = "Not implemented";
+        return 501;
+    }
+
+    virtual int webapiRun(bool run,
+            SWGSDRangel::SWGDeviceState& response,
+            QString& errorMessage)
+    {
+        (void) run;
+        (void) response;
+        errorMessage = "Not implemented";
+        return 501;
+    }
+
+    virtual int webapiReportGet(
+            SWGSDRangel::SWGDeviceReport& response,
+            QString& errorMessage)
+    {
+        (void) response;
+        errorMessage = "Not implemented";
+        return 501;
+    }
+
+    virtual int webapiActionsPost(
+            const QStringList& deviceActionsKeys,
+            SWGSDRangel::SWGDeviceActions& actions,
+            QString& errorMessage)
+    {
+        (void) deviceActionsKeys;
+        (void) actions;
+        errorMessage = "Not implemented";
+        return 501;
+    }
+
+	MessageQueue *getInputMessageQueue() { return &m_inputMessageQueue; }
+    virtual void setMessageQueueToGUI(MessageQueue *queue) = 0; // pure virtual so that child classes must have to deal with this
+    MessageQueue *getMessageQueueToGUI() { return m_guiMessageQueue; }
+	SampleSourceFifo* getSampleFifo() { return &m_sampleSourceFifo; }
+
+    static qint64 calculateDeviceCenterFrequency(
+            quint64 centerFrequency,
+            qint64 transverterDeltaFrequency,
+            int log2Interp,
+            fcPos_t fcPos,
+            quint32 devSampleRate,
+            bool transverterMode = false);
+
+    static qint64 calculateCenterFrequency(
+            quint64 deviceCenterFrequency,
+            qint64 transverterDeltaFrequency,
+            int log2Interp,
+            fcPos_t fcPos,
+            quint32 devSampleRate,
+            bool transverterMode = false);
+
+    static qint32 calculateFrequencyShift(
+            int log2Interp,
+            fcPos_t fcPos,
+            quint32 devSampleRate);
+
+protected slots:
+	void handleInputMessages();
+
+protected:
+    SampleSourceFifo m_sampleSourceFifo;
+	MessageQueue m_inputMessageQueue; //!< Input queue to the sink
+    MessageQueue *m_guiMessageQueue;  //!< Input message queue to the GUI
+};
+
+#endif /* SDRBASE_DSP_DEVICESAMPLESINK_H_ */

android/app/src/main/cpp/dsp/devicesamplesource.cpp

@@ -0,0 +1,115 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2016-2019 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include <QDebug>
+
+#include "dsp/devicesamplestatic.h"
+#include "dsp/devicesamplesource.h"
+
+DeviceSampleSource::DeviceSampleSource() :
+    m_guiMessageQueue(0)
+{
+	connect(&m_inputMessageQueue, SIGNAL(messageEnqueued()), this, SLOT(handleInputMessages()));
+}
+
+DeviceSampleSource::~DeviceSampleSource()
+{
+}
+
+void DeviceSampleSource::handleInputMessages()
+{
+	Message* message;
+
+	while ((message = m_inputMessageQueue.pop()) != 0)
+	{
+		if (handleMessage(*message))
+		{
+			delete message;
+		}
+	}
+}
+
+qint64 DeviceSampleSource::calculateDeviceCenterFrequency(
+            quint64 centerFrequency,
+            qint64 transverterDeltaFrequency,
+            int log2Decim,
+            fcPos_t fcPos,
+            quint32 devSampleRate,
+            FrequencyShiftScheme frequencyShiftScheme,
+            bool transverterMode)
+{
+    return DeviceSampleStatic::calculateSourceDeviceCenterFrequency(
+        centerFrequency,
+        transverterDeltaFrequency,
+        log2Decim,
+        (DeviceSampleStatic::fcPos_t) fcPos,
+        devSampleRate,
+        (DeviceSampleStatic::FrequencyShiftScheme) frequencyShiftScheme,
+        transverterMode
+    );
+}
+
+qint64 DeviceSampleSource::calculateCenterFrequency(
+            quint64 deviceCenterFrequency,
+            qint64 transverterDeltaFrequency,
+            int log2Decim,
+            fcPos_t fcPos,
+            quint32 devSampleRate,
+            FrequencyShiftScheme frequencyShiftScheme,
+            bool transverterMode)
+{
+    return DeviceSampleStatic::calculateSourceCenterFrequency(
+        deviceCenterFrequency,
+        transverterDeltaFrequency,
+        log2Decim,
+        (DeviceSampleStatic::fcPos_t) fcPos,
+        devSampleRate,
+        (DeviceSampleStatic::FrequencyShiftScheme) frequencyShiftScheme,
+        transverterMode
+    );
+}
+
+/**
+ * log2Decim = 0:  no shift
+ *
+ * n = log2Decim <= 2: fc = +/- 1/2^(n-1)
+ *      center
+ *  |     ^     |
+ *  | inf | sup |
+ *     ^     ^
+ *
+ * n = log2Decim > 2: fc = +/- 1/2^n
+ *         center
+ *  |         ^         |
+ *  |  |inf|  |  |sup|  |
+ *       ^         ^
+ */
+qint32 DeviceSampleSource::calculateFrequencyShift(
+            int log2Decim,
+            fcPos_t fcPos,
+            quint32 devSampleRate,
+            FrequencyShiftScheme frequencyShiftScheme)
+{
+    return DeviceSampleStatic::calculateSourceFrequencyShift(
+        log2Decim,
+        (DeviceSampleStatic::fcPos_t) fcPos,
+        devSampleRate,
+        (DeviceSampleStatic::FrequencyShiftScheme) frequencyShiftScheme
+    );
+}

android/app/src/main/cpp/dsp/devicesamplesource.h

@@ -0,0 +1,178 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2020 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef INCLUDE_SAMPLESOURCE_H
+#define INCLUDE_SAMPLESOURCE_H
+
+#include <QtGlobal>
+#include <QByteArray>
+
+#include "samplesinkfifo.h"
+#include "util/message.h"
+#include "util/messagequeue.h"
+#include "export.h"
+
+namespace SWGSDRangel
+{
+    class SWGDeviceSettings;
+    class SWGDeviceState;
+    class SWGDeviceReport;
+    class SWGDeviceActions;
+}
+
+class SDRBASE_API DeviceSampleSource : public QObject {
+	Q_OBJECT
+public:
+    typedef enum {
+        FC_POS_INFRA = 0,
+        FC_POS_SUPRA,
+        FC_POS_CENTER
+    } fcPos_t;
+
+    typedef enum {
+        FSHIFT_STD = 0, // Standard Rx independent
+        FSHIFT_TXSYNC   // Follows same scheme as Tx
+    } FrequencyShiftScheme;
+
+	DeviceSampleSource();
+	virtual ~DeviceSampleSource();
+	virtual void destroy() = 0;
+
+	virtual void init() = 0;  //!< initializations to be done when all collaborating objects are created and possibly connected
+	virtual bool start() = 0;
+	virtual void stop() = 0;
+
+    virtual QByteArray serialize() const = 0;
+    virtual bool deserialize(const QByteArray& data) = 0;
+
+	virtual const QString& getDeviceDescription() const = 0;
+	virtual int getSampleRate() const = 0; //!< Sample rate exposed by the source
+    virtual void setSampleRate(int sampleRate) = 0; //!< For when the source sample rate is set externally
+	virtual quint64 getCenterFrequency() const = 0; //!< Center frequency exposed by the source
+    virtual void setCenterFrequency(qint64 centerFrequency) = 0;
+
+	virtual bool handleMessage(const Message& message) = 0;
+
+	virtual int webapiSettingsGet(
+            SWGSDRangel::SWGDeviceSettings& response,
+	        QString& errorMessage)
+    {
+        (void) response;
+        errorMessage = "Not implemented";
+        return 501;
+    }
+
+    virtual int webapiSettingsPutPatch(
+            bool force, //!< true to force settings = put
+            const QStringList& deviceSettingsKeys,
+            SWGSDRangel::SWGDeviceSettings& response,
+            QString& errorMessage)
+    {
+        (void) force;
+        (void) deviceSettingsKeys;
+        (void) response;
+        errorMessage = "Not implemented";
+        return 501;
+    }
+
+    virtual int webapiRunGet(
+            SWGSDRangel::SWGDeviceState& response,
+            QString& errorMessage)
+    {
+        (void) response;
+        errorMessage = "Not implemented";
+        return 501;
+    }
+
+    virtual int webapiRun(bool run,
+            SWGSDRangel::SWGDeviceState& response,
+            QString& errorMessage)
+    {
+        (void) run;
+        (void) response;
+        errorMessage = "Not implemented";
+        return 501;
+    }
+
+    virtual int webapiReportGet(
+            SWGSDRangel::SWGDeviceReport& response,
+            QString& errorMessage)
+    {
+        (void) response;
+        errorMessage = "Not implemented";
+        return 501;
+    }
+
+    virtual int webapiActionsPost(
+            const QStringList& deviceSettingsKeys,
+            SWGSDRangel::SWGDeviceActions& actions,
+            QString& errorMessage)
+    {
+        (void) deviceSettingsKeys;
+        (void) actions;
+        errorMessage = "Not implemented";
+        return 501;
+    }
+
+	MessageQueue *getInputMessageQueue() { return &m_inputMessageQueue; }
+	virtual void setMessageQueueToGUI(MessageQueue *queue) = 0; // pure virtual so that child classes must have to deal with this
+	MessageQueue *getMessageQueueToGUI() { return m_guiMessageQueue; }
+    SampleSinkFifo* getSampleFifo() { return &m_sampleFifo; }
+
+    static qint64 calculateDeviceCenterFrequency(
+            quint64 centerFrequency,
+            qint64 transverterDeltaFrequency,
+            int log2Decim,
+            fcPos_t fcPos,
+            quint32 devSampleRate,
+            FrequencyShiftScheme frequencyShiftScheme,
+            bool transverterMode = false
+    );
+
+    static qint64 calculateCenterFrequency(
+            quint64 deviceCenterFrequency,
+            qint64 transverterDeltaFrequency,
+            int log2Decim,
+            fcPos_t fcPos,
+            quint32 devSampleRate,
+            FrequencyShiftScheme frequencyShiftScheme,
+            bool transverterMode = false
+    );
+
+    static qint32 calculateFrequencyShift(
+            int log2Decim,
+            fcPos_t fcPos,
+            quint32 devSampleRate,
+            FrequencyShiftScheme frequencyShiftScheme
+    );
+
+protected slots:
+	void handleInputMessages();
+
+signals:
+    void positionChanged(float latitude, float longitude, float altitude);
+    void directionChanged(bool isotropic, float azimuth, float elevation);
+
+protected:
+    SampleSinkFifo m_sampleFifo;
+	MessageQueue m_inputMessageQueue; //!< Input queue to the source
+	MessageQueue *m_guiMessageQueue;  //!< Input message queue to the GUI
+};
+
+#endif // INCLUDE_SAMPLESOURCE_H

android/app/src/main/cpp/dsp/devicesamplestatic.cpp

@@ -0,0 +1,247 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2016-2019 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include <QDebug>
+
+#include "devicesamplestatic.h"
+
+int64_t DeviceSampleStatic::calculateSourceDeviceCenterFrequency(
+            uint64_t centerFrequency,
+            int64_t transverterDeltaFrequency,
+            int log2Decim,
+            fcPos_t fcPos,
+            uint32_t devSampleRate,
+            FrequencyShiftScheme frequencyShiftScheme,
+            bool transverterMode)
+{
+    int64_t deviceCenterFrequency = centerFrequency;
+    deviceCenterFrequency -= transverterMode ? transverterDeltaFrequency : 0;
+    deviceCenterFrequency = deviceCenterFrequency < 0 ? 0 : deviceCenterFrequency;
+    int64_t f_img = deviceCenterFrequency;
+
+    deviceCenterFrequency -= calculateSourceFrequencyShift(log2Decim, fcPos, devSampleRate, frequencyShiftScheme);
+    f_img -= 2*calculateSourceFrequencyShift(log2Decim, fcPos, devSampleRate, frequencyShiftScheme);
+
+    qDebug() << "DeviceSampleStatic::calculateSourceDeviceCenterFrequency:"
+            << " frequencyShiftScheme: " << frequencyShiftScheme
+            << " desired center freq: " << centerFrequency << " Hz"
+            << " device center freq: " << deviceCenterFrequency << " Hz"
+            << " device sample rate: " << devSampleRate << "S/s"
+            << " Actual sample rate: " << devSampleRate/(1<<log2Decim) << "S/s"
+            << " center freq position code: " << fcPos
+            << " image frequency: " << f_img << "Hz";
+
+    return deviceCenterFrequency;
+}
+
+int64_t DeviceSampleStatic::calculateSourceCenterFrequency(
+            uint64_t deviceCenterFrequency,
+            int64_t transverterDeltaFrequency,
+            int log2Decim,
+            fcPos_t fcPos,
+            uint32_t devSampleRate,
+            FrequencyShiftScheme frequencyShiftScheme,
+            bool transverterMode)
+{
+    qint64 centerFrequency = deviceCenterFrequency;
+    centerFrequency += calculateSourceFrequencyShift(log2Decim, fcPos, devSampleRate, frequencyShiftScheme);
+    centerFrequency += transverterMode ? transverterDeltaFrequency : 0;
+    centerFrequency = centerFrequency < 0 ? 0 : centerFrequency;
+
+    qDebug() << "DeviceSampleStatic::calculateSourceCenterFrequency:"
+            << " frequencyShiftScheme: " << frequencyShiftScheme
+            << " desired center freq: " << centerFrequency << " Hz"
+            << " device center freq: " << deviceCenterFrequency << " Hz"
+            << " device sample rate: " << devSampleRate << "S/s"
+            << " Actual sample rate: " << devSampleRate/(1<<log2Decim) << "S/s"
+            << " center freq position code: " << fcPos;
+
+    return centerFrequency;
+}
+
+/**
+ * log2Decim = 0:  no shift
+ *
+ * n = log2Decim <= 2: fc = +/- 1/2^(n-1)
+ *      center
+ *  |     ^     |
+ *  | inf | sup |
+ *     ^     ^
+ *
+ * n = log2Decim > 2: fc = +/- 1/2^n
+ *         center
+ *  |         ^         |
+ *  |  |inf|  |  |sup|  |
+ *       ^         ^
+ */
+int DeviceSampleStatic::calculateSourceFrequencyShift(
+            int log2Decim,
+            fcPos_t fcPos,
+            uint32_t devSampleRate,
+            FrequencyShiftScheme frequencyShiftScheme)
+{
+    if (frequencyShiftScheme == FSHIFT_STD)
+    {
+        if (log2Decim == 0) { // no shift at all
+            return 0;
+        } else if (log2Decim < 3) {
+            if (fcPos == FC_POS_INFRA) { // shift in the square next to center frequency
+                return -(devSampleRate / (1<<(log2Decim+1)));
+            } else if (fcPos == FC_POS_SUPRA) {
+                return devSampleRate / (1<<(log2Decim+1));
+            } else {
+                return 0;
+            }
+        } else {
+            if (fcPos == FC_POS_INFRA) { // shift centered in the square next to center frequency
+                return -(devSampleRate / (1<<(log2Decim)));
+            } else if (fcPos == FC_POS_SUPRA) {
+                return devSampleRate / (1<<(log2Decim));
+            } else {
+                return 0;
+            }
+        }
+    }
+    else // frequencyShiftScheme == FSHIFT_TXSYNC
+    {
+        if (fcPos == FC_POS_CENTER) {
+            return 0;
+        }
+
+        int sign = fcPos == FC_POS_INFRA ? -1 : 1;
+        int halfSampleRate = devSampleRate / 2; // fractions are relative to sideband thus based on half the sample rate
+
+        if (log2Decim == 0) {
+            return 0;
+        } else if (log2Decim == 1) {
+            return sign * (halfSampleRate / 2);         // inf or sup: 1/2
+        } else if (log2Decim == 2) {
+            return sign * ((halfSampleRate * 3) / 4);   // inf, inf or sup, sup: 1/2 + 1/4
+        } else if (log2Decim == 3) {
+            return sign * ((halfSampleRate * 5) / 8);   // inf, inf, sup or sup, sup, inf: 1/2 + 1/4 - 1/8 = 5/8
+        } else if (log2Decim == 4) {
+            return sign * ((halfSampleRate * 11) / 16); // inf, inf, sup, inf or sup, sup, inf, sup: 1/2 + 1/4 - 1/8 + 1/16 = 11/16
+        } else if (log2Decim == 5) {
+            return sign * ((halfSampleRate * 21) / 32); // inf, inf, sup, inf, sup or sup, sup, inf, sup, inf: 1/2 + 1/4 - 1/8 + 1/16 - 1/32 = 21/32
+        } else if (log2Decim == 6) {
+            return sign * ((halfSampleRate * 21) / 64); // inf, sup, inf, sup, inf, sup or sup, inf, sup, inf, sup, inf: 1/2 - 1/4 + 1/8 -1/16 + 1/32 - 1/64 = 21/64
+        } else {
+            return 0;
+        }
+    }
+}
+
+int64_t DeviceSampleStatic::calculateSinkDeviceCenterFrequency(
+            uint64_t centerFrequency,
+            int64_t transverterDeltaFrequency,
+            int log2Interp,
+            fcPos_t fcPos,
+            uint32_t devSampleRate,
+            bool transverterMode)
+{
+    int64_t deviceCenterFrequency = centerFrequency;
+    deviceCenterFrequency -= transverterMode ? transverterDeltaFrequency : 0;
+    deviceCenterFrequency = deviceCenterFrequency < 0 ? 0 : deviceCenterFrequency;
+    int64_t f_img = deviceCenterFrequency;
+
+    deviceCenterFrequency -= calculateSinkFrequencyShift(log2Interp, fcPos, devSampleRate);
+    f_img -= 2*calculateSinkFrequencyShift(log2Interp, fcPos, devSampleRate);
+
+    qDebug() << "DeviceSampleStatic::calculateSinkDeviceCenterFrequency:"
+            << " desired center freq: " << centerFrequency << " Hz"
+            << " device center freq: " << deviceCenterFrequency << " Hz"
+            << " device sample rate: " << devSampleRate << "S/s"
+            << " Actual sample rate: " << devSampleRate/(1<<log2Interp) << "S/s"
+            << " center freq position code: " << fcPos
+            << " image frequency: " << f_img << "Hz";
+
+    return deviceCenterFrequency;
+}
+
+int64_t DeviceSampleStatic::calculateSinkCenterFrequency(
+            uint64_t deviceCenterFrequency,
+            int64_t transverterDeltaFrequency,
+            int log2Interp,
+            fcPos_t fcPos,
+            uint32_t devSampleRate,
+            bool transverterMode)
+{
+    int64_t centerFrequency = deviceCenterFrequency;
+    centerFrequency += calculateSinkFrequencyShift(log2Interp, fcPos, devSampleRate);
+    centerFrequency += transverterMode ? transverterDeltaFrequency : 0;
+    centerFrequency = centerFrequency < 0 ? 0 : centerFrequency;
+
+    qDebug() << "DeviceSampleStatic::calculateSinkCenterFrequency:"
+            << " desired center freq: " << centerFrequency << " Hz"
+            << " device center freq: " << deviceCenterFrequency << " Hz"
+            << " device sample rate: " << devSampleRate << "S/s"
+            << " Actual sample rate: " << devSampleRate/(1<<log2Interp) << "S/s"
+            << " center freq position code: " << fcPos;
+
+    return centerFrequency;
+}
+
+/**
+ * log2Interp = 0:  no shift
+ *
+ * log2Interp = 1:  middle of side band (inf or sup: 1/2)
+ *        ^     |     ^
+ *  | inf | inf | sup | sup |
+ *
+ * log2Interp = 2:  middle of far side half side band (inf, inf or sup, sup: 1/2 + 1/4)
+ *     ^        |        ^
+ *  | inf | inf | sup | sup |
+ *
+ * log2Interp = 3:  inf, inf, sup or sup, sup, inf: 1/2 + 1/4 - 1/8 = 5/8
+ * log2Interp = 4:  inf, inf, sup, inf or sup, sup, inf, sup: 1/2 + 1/4 - 1/8 + 1/16 = 11/16
+ * log2Interp = 5:  inf, inf, sup, inf, sup or sup, sup, inf, sup, inf: 1/2 + 1/4 - 1/8 + 1/16 - 1/32 = 21/32
+ * log2Interp = 6:  inf, sup, inf, sup, inf, sup or sup, inf, sup, inf, sup, inf: 1/2 - 1/4 + 1/8 -1/16 + 1/32 - 1/64 = 21/64
+ *
+ */
+int DeviceSampleStatic::calculateSinkFrequencyShift(
+            int log2Interp,
+            fcPos_t fcPos,
+            uint32_t devSampleRate)
+{
+    if (fcPos == FC_POS_CENTER) {
+        return 0;
+    }
+
+    int sign = fcPos == FC_POS_INFRA ? -1 : 1;
+    int halfSampleRate = devSampleRate / 2; // fractions are relative to sideband thus based on half the sample rate
+
+    if (log2Interp == 0) {
+        return 0;
+    } else if (log2Interp == 1) {
+        return sign * (halfSampleRate / 2);
+    } else if (log2Interp == 2) {
+        return sign * ((halfSampleRate * 3) / 4);
+    } else if (log2Interp == 3) {
+        return sign * ((halfSampleRate * 5) / 8);
+    } else if (log2Interp == 4) {
+        return sign * ((halfSampleRate * 11) / 16);
+    } else if (log2Interp == 5) {
+        return sign * ((halfSampleRate * 21) / 32);
+    } else if (log2Interp == 6) {
+        return sign * ((halfSampleRate * 21) / 64);
+    } else {
+        return 0;
+    }
+}
+

android/app/src/main/cpp/dsp/devicesamplestatic.h

@@ -0,0 +1,83 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2019-2020 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include <stdint.h>
+
+#include "export.h"
+
+class SDRBASE_API DeviceSampleStatic
+{
+public:
+    typedef enum {
+        FC_POS_INFRA = 0,
+        FC_POS_SUPRA,
+        FC_POS_CENTER
+    } fcPos_t;
+
+    typedef enum {
+        FSHIFT_STD = 0, // Standard Rx independent
+        FSHIFT_TXSYNC   // Follows same scheme as Tx
+    } FrequencyShiftScheme;
+
+    static int64_t calculateSourceDeviceCenterFrequency(
+            uint64_t centerFrequency,
+            int64_t transverterDeltaFrequency,
+            int log2Decim,
+            fcPos_t fcPos,
+            uint32_t devSampleRate,
+            FrequencyShiftScheme frequencyShiftScheme,
+            bool transverterMode = false
+    );
+
+    static int64_t calculateSourceCenterFrequency(
+            uint64_t deviceCenterFrequency,
+            int64_t transverterDeltaFrequency,
+            int log2Decim,
+            fcPos_t fcPos,
+            uint32_t devSampleRate,
+            FrequencyShiftScheme frequencyShiftScheme,
+            bool transverterMode = false
+    );
+
+    static int calculateSourceFrequencyShift(
+            int log2Decim,
+            fcPos_t fcPos,
+            uint32_t devSampleRate,
+            FrequencyShiftScheme frequencyShiftScheme
+    );
+
+    static int64_t calculateSinkDeviceCenterFrequency(
+            uint64_t centerFrequency,
+            int64_t transverterDeltaFrequency,
+            int log2Interp,
+            fcPos_t fcPos,
+            uint32_t devSampleRate,
+            bool transverterMode = false);
+
+    static int64_t calculateSinkCenterFrequency(
+            uint64_t deviceCenterFrequency,
+            int64_t transverterDeltaFrequency,
+            int log2Interp,
+            fcPos_t fcPos,
+            uint32_t devSampleRate,
+            bool transverterMode = false);
+
+    static int calculateSinkFrequencyShift(
+            int log2Interp,
+            fcPos_t fcPos,
+            uint32_t devSampleRate);
+};

android/app/src/main/cpp/dsp/downchannelizer.cpp

@@ -0,0 +1,336 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2020, 2023 Edouard Griffiths, F4EXB <f4exb06@gmail.com>    //
+// Copyright (C) 2023 Jon Beniston, M7RCE <jon@beniston.com>                     //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include <array>
+
+#include <QString>
+#include <QDebug>
+
+#include "dsp/hbfilterchainconverter.h"
+#include "downchannelizer.h"
+
+DownChannelizer::DownChannelizer(ChannelSampleSink* sampleSink) :
+    m_filterChainSetMode(false),
+	m_sampleSink(sampleSink),
+	m_basebandSampleRate(0),
+	m_requestedOutputSampleRate(0),
+	m_requestedCenterFrequency(0),
+    m_channelSampleRate(0),
+	m_channelFrequencyOffset(0),
+    m_log2Decim(0),
+    m_filterChainHash(0)
+{
+}
+
+DownChannelizer::~DownChannelizer()
+{
+	freeFilterChain();
+}
+
+void DownChannelizer::feed(const SampleVector::const_iterator& begin, const SampleVector::const_iterator& end)
+{
+	if (m_sampleSink == 0)
+    {
+		m_sampleBuffer.clear();
+		return;
+	}
+
+	if (m_filterStages.size() == 0) // optimization when no downsampling is done anyway
+	{
+		m_sampleSink->feed(begin, end);
+	}
+	else
+	{
+		for (SampleVector::const_iterator sample = begin; sample != end; ++sample)
+		{
+			Sample s(*sample);
+			FilterStages::iterator stage = m_filterStages.begin();
+
+			for (; stage != m_filterStages.end(); ++stage)
+			{
+#ifndef SDR_RX_SAMPLE_24BIT
+                s.m_real /= 2; // avoid saturation on 16 bit samples
+                s.m_imag /= 2;
+#endif
+				if (!(*stage)->work(&s)) {
+					break;
+				}
+			}
+
+			if(stage == m_filterStages.end())
+			{
+#ifdef SDR_RX_SAMPLE_24BIT
+			    s.m_real /= (1<<(m_filterStages.size())); // on 32 bit samples there is enough headroom to just divide the final result
+			    s.m_imag /= (1<<(m_filterStages.size()));
+#endif
+				m_sampleBuffer.push_back(s);
+			}
+		}
+
+		m_sampleSink->feed(m_sampleBuffer.begin(), m_sampleBuffer.end());
+		m_sampleBuffer.clear();
+	}
+}
+
+void DownChannelizer::setChannelization(int requestedSampleRate, qint64 requestedCenterFrequency)
+{
+    if (requestedSampleRate < 0)
+    {
+        qWarning("DownChannelizer::setChannelization: wrong sample rate requested: %d", requestedSampleRate);
+        return;
+    }
+
+    m_requestedOutputSampleRate = requestedSampleRate;
+    m_requestedCenterFrequency = requestedCenterFrequency;
+    applyChannelization();
+}
+
+void DownChannelizer::setBasebandSampleRate(int basebandSampleRate, bool decim)
+{
+    m_basebandSampleRate = basebandSampleRate;
+
+    if (decim) {
+        applyDecimation();
+    } else {
+        applyChannelization();
+    }
+}
+
+void DownChannelizer::applyChannelization()
+{
+    m_filterChainSetMode = false;
+
+	if (m_basebandSampleRate == 0)
+	{
+		qDebug() << "DownChannelizer::applyChannelization: aborting (in=0)"
+            << " in (baseband):" << m_basebandSampleRate
+            << " req:" << m_requestedOutputSampleRate
+            << " out (channel):" << m_channelSampleRate
+            << " fc:" << m_channelFrequencyOffset;
+        return;
+	}
+
+	freeFilterChain();
+
+	m_channelFrequencyOffset = createFilterChain(
+		m_basebandSampleRate / -2, m_basebandSampleRate / 2,
+		m_requestedCenterFrequency - m_requestedOutputSampleRate / 2, m_requestedCenterFrequency + m_requestedOutputSampleRate / 2);
+
+	m_channelSampleRate = m_basebandSampleRate / (1 << m_filterStages.size());
+
+	qDebug() << "DownChannelizer::applyChannelization done:"
+        << " nb stages:" << m_filterStages.size()
+        << " in (baseband):" << m_basebandSampleRate
+		<< " req:" << m_requestedOutputSampleRate
+		<< " out (channel):" << m_channelSampleRate
+		<< " fc:" << m_channelFrequencyOffset;
+}
+
+void DownChannelizer::setDecimation(unsigned int log2Decim, unsigned int filterChainHash)
+{
+    m_log2Decim = log2Decim;
+    m_filterChainHash = filterChainHash;
+    applyDecimation();
+}
+
+void DownChannelizer::applyDecimation()
+{
+    m_filterChainSetMode = true;
+    std::vector<unsigned int> stageIndexes;
+    m_channelFrequencyOffset = m_basebandSampleRate * HBFilterChainConverter::convertToIndexes(m_log2Decim, m_filterChainHash, stageIndexes);
+    m_requestedCenterFrequency = m_channelFrequencyOffset;
+
+    freeFilterChain();
+
+    m_channelFrequencyOffset = m_basebandSampleRate * setFilterChain(stageIndexes);
+    m_channelSampleRate = m_basebandSampleRate / (1 << m_filterStages.size());
+    m_requestedOutputSampleRate = m_channelSampleRate;
+
+	qDebug() << "DownChannelizer::applyDecimation:"
+            << " m_log2Decim:" << m_log2Decim
+            << " m_filterChainHash:" << m_filterChainHash
+            << " out:" << m_basebandSampleRate
+			<< " in:" << m_channelSampleRate
+			<< " fc:" << m_channelFrequencyOffset;
+}
+
+#ifdef SDR_RX_SAMPLE_24BIT
+DownChannelizer::FilterStage::FilterStage(Mode mode) :
+    m_filter(new IntHalfbandFilterEO<qint64, qint64, DOWNCHANNELIZER_HB_FILTER_ORDER, true>),
+    m_workFunction(0),
+    m_mode(mode),
+    m_sse(true)
+{
+    switch(mode) {
+        case ModeCenter:
+            m_workFunction = &IntHalfbandFilterEO<qint64, qint64, DOWNCHANNELIZER_HB_FILTER_ORDER, true>::workDecimateCenter;
+            break;
+
+        case ModeLowerHalf:
+            m_workFunction = &IntHalfbandFilterEO<qint64, qint64, DOWNCHANNELIZER_HB_FILTER_ORDER, true>::workDecimateLowerHalf;
+            break;
+
+        case ModeUpperHalf:
+            m_workFunction = &IntHalfbandFilterEO<qint64, qint64, DOWNCHANNELIZER_HB_FILTER_ORDER, true>::workDecimateUpperHalf;
+            break;
+    }
+}
+#else
+DownChannelizer::FilterStage::FilterStage(Mode mode) :
+    m_filter(new IntHalfbandFilterEO<qint32, qint32, DOWNCHANNELIZER_HB_FILTER_ORDER, true>),
+    m_workFunction(0),
+    m_mode(mode),
+    m_sse(true)
+{
+    switch(mode) {
+        case ModeCenter:
+            m_workFunction = &IntHalfbandFilterEO<qint32, qint32, DOWNCHANNELIZER_HB_FILTER_ORDER, true>::workDecimateCenter;
+            break;
+
+        case ModeLowerHalf:
+            m_workFunction = &IntHalfbandFilterEO<qint32, qint32, DOWNCHANNELIZER_HB_FILTER_ORDER, true>::workDecimateLowerHalf;
+            break;
+
+        case ModeUpperHalf:
+            m_workFunction = &IntHalfbandFilterEO<qint32, qint32, DOWNCHANNELIZER_HB_FILTER_ORDER, true>::workDecimateUpperHalf;
+            break;
+    }
+}
+#endif
+
+DownChannelizer::FilterStage::~FilterStage()
+{
+	delete m_filter;
+}
+
+Real DownChannelizer::channelMinSpace(Real sigStart, Real sigEnd, Real chanStart, Real chanEnd)
+{
+    Real leftSpace = chanStart - sigStart;
+    Real rightSpace = sigEnd - chanEnd;
+    return std::min(leftSpace, rightSpace);
+}
+
+Real DownChannelizer::createFilterChain(Real sigStart, Real sigEnd, Real chanStart, Real chanEnd)
+{
+	Real sigBw = sigEnd - sigStart;
+    Real chanBw = chanEnd - chanStart;
+	Real rot = sigBw / 4;
+
+
+    std::array<Real, 3> filterMinSpaces; // Array of left, center and right filter min spaces respectively
+    filterMinSpaces[0] = channelMinSpace(sigStart, sigStart + sigBw / 2.0, chanStart, chanEnd);
+    filterMinSpaces[1] = channelMinSpace(sigStart + rot, sigEnd - rot, chanStart, chanEnd);
+    filterMinSpaces[2] = channelMinSpace(sigEnd - sigBw / 2.0f, sigEnd, chanStart, chanEnd);
+    auto maxIt = std::max_element(filterMinSpaces.begin(), filterMinSpaces.end());
+    int maxIndex = maxIt - filterMinSpaces.begin();
+    Real maxValue = *maxIt;
+
+	qDebug("DownChannelizer::createFilterChain: Signal [%.1f, %.1f] (BW %.1f) Channel [%.1f, %.1f] (BW %.1f) Selected: %d (fit %.1f)",
+        sigStart, sigEnd, sigBw, chanStart, chanEnd, chanBw, maxIndex, maxValue);
+
+    if ((sigStart < sigEnd) && (chanStart < chanEnd) && (maxValue >= chanBw/8.0))
+    {
+        if (maxIndex == 0)
+        {
+            m_filterStages.push_back(new FilterStage(FilterStage::ModeLowerHalf));
+            return createFilterChain(sigStart, sigStart + sigBw / 2.0, chanStart, chanEnd);
+        }
+
+        if (maxIndex == 1)
+        {
+            m_filterStages.push_back(new FilterStage(FilterStage::ModeCenter));
+            return createFilterChain(sigStart + rot, sigEnd - rot, chanStart, chanEnd);
+        }
+
+        if (maxIndex == 2)
+        {
+            m_filterStages.push_back(new FilterStage(FilterStage::ModeUpperHalf));
+            return createFilterChain(sigEnd - sigBw / 2.0f, sigEnd, chanStart, chanEnd);
+        }
+    }
+
+	Real ofs = ((chanEnd - chanStart) / 2.0 + chanStart) - ((sigEnd - sigStart) / 2.0 + sigStart);
+	qDebug("DownChannelizer::createFilterChain: -> complete (final BW %.1f, frequency offset %.1f)", sigBw, ofs);
+	return ofs;
+}
+
+double DownChannelizer::setFilterChain(const std::vector<unsigned int>& stageIndexes)
+{
+    // filters are described from lower to upper level but the chain is constructed the other way round
+    std::vector<unsigned int>::const_reverse_iterator rit = stageIndexes.rbegin();
+    double ofs = 0.0, ofs_stage = 0.25;
+
+    // Each index is a base 3 number with 0 = low, 1 = center, 2 = high
+    // Functions at upper level will convert a number to base 3 to describe the filter chain. Common converting
+    // algorithms will go from LSD to MSD. This explains the reverse order.
+    for (; rit != stageIndexes.rend(); ++rit)
+    {
+        if (*rit == 0)
+        {
+            m_filterStages.push_back(new FilterStage(FilterStage::ModeLowerHalf));
+            ofs -= ofs_stage;
+            qDebug("DownChannelizer::setFilterChain: lower half: ofs: %f", ofs);
+        }
+        else if (*rit == 1)
+        {
+            m_filterStages.push_back(new FilterStage(FilterStage::ModeCenter));
+            qDebug("DownChannelizer::setFilterChain: center: ofs: %f", ofs);
+        }
+        else if (*rit == 2)
+        {
+            m_filterStages.push_back(new FilterStage(FilterStage::ModeUpperHalf));
+            ofs += ofs_stage;
+            qDebug("DownChannelizer::setFilterChain: upper half: ofs: %f", ofs);
+        }
+    }
+
+    return ofs;
+}
+
+void DownChannelizer::freeFilterChain()
+{
+	for(FilterStages::iterator it = m_filterStages.begin(); it != m_filterStages.end(); ++it)
+		delete *it;
+	m_filterStages.clear();
+}
+
+void DownChannelizer::debugFilterChain()
+{
+    qDebug("DownChannelizer::debugFilterChain: %lu stages", m_filterStages.size());
+
+    for(FilterStages::iterator it = m_filterStages.begin(); it != m_filterStages.end(); ++it)
+    {
+        switch ((*it)->m_mode)
+        {
+        case FilterStage::ModeCenter:
+            qDebug("DownChannelizer::debugFilterChain: center %s", (*it)->m_sse ? "sse" : "no_sse");
+            break;
+        case FilterStage::ModeLowerHalf:
+            qDebug("DownChannelizer::debugFilterChain: lower %s", (*it)->m_sse ? "sse" : "no_sse");
+            break;
+        case FilterStage::ModeUpperHalf:
+            qDebug("DownChannelizer::debugFilterChain: upper %s", (*it)->m_sse ? "sse" : "no_sse");
+            break;
+        default:
+            qDebug("DownChannelizer::debugFilterChain: none %s", (*it)->m_sse ? "sse" : "no_sse");
+            break;
+        }
+    }
+}

android/app/src/main/cpp/dsp/downchannelizer.h

@@ -0,0 +1,97 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2020, 2023 Edouard Griffiths, F4EXB <f4exb06@gmail.com>    //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef SDRBASE_DSP_DOWNCHANNELIZER_H
+#define SDRBASE_DSP_DOWNCHANNELIZER_H
+
+#include <list>
+#include <vector>
+
+#include "export.h"
+#include "dsp/inthalfbandfiltereo.h"
+
+#include "channelsamplesink.h"
+
+#define DOWNCHANNELIZER_HB_FILTER_ORDER 48
+
+class SDRBASE_API DownChannelizer : public ChannelSampleSink {
+public:
+	DownChannelizer(ChannelSampleSink* sampleSink);
+	virtual ~DownChannelizer();
+
+	virtual void feed(const SampleVector::const_iterator& begin, const SampleVector::const_iterator& end);
+
+    void setDecimation(unsigned int log2Decim, unsigned int filterChainHash);         //!< Define channelizer with decimation factor and filter chain definition
+    void setChannelization(int requestedSampleRate, qint64 requestedCenterFrequency); //!< Define channelizer with requested sample rate and center frequency (shift in the baseband)
+    void setBasebandSampleRate(int basebandSampleRate, bool decim = false);           //!< decim: true => use direct decimation false => use channel configuration
+	int getBasebandSampleRate() const { return m_basebandSampleRate; }
+    int getChannelSampleRate() const { return m_channelSampleRate; }
+	int getChannelFrequencyOffset() const { return m_channelFrequencyOffset; }
+
+protected:
+	struct FilterStage {
+		enum Mode {
+			ModeCenter,
+			ModeLowerHalf,
+			ModeUpperHalf
+		};
+
+#ifdef SDR_RX_SAMPLE_24BIT
+        typedef bool (IntHalfbandFilterEO<qint64, qint64, DOWNCHANNELIZER_HB_FILTER_ORDER, true>::*WorkFunction)(Sample* s);
+        IntHalfbandFilterEO<qint64, qint64, DOWNCHANNELIZER_HB_FILTER_ORDER, true>* m_filter;
+#else
+        typedef bool (IntHalfbandFilterEO<qint32, qint32, DOWNCHANNELIZER_HB_FILTER_ORDER, true>::*WorkFunction)(Sample* s);
+        IntHalfbandFilterEO<qint32, qint32, DOWNCHANNELIZER_HB_FILTER_ORDER, true>* m_filter;
+#endif
+
+		WorkFunction m_workFunction;
+		Mode m_mode;
+		bool m_sse;
+
+		FilterStage(Mode mode);
+		~FilterStage();
+
+		bool work(Sample* sample)
+		{
+			return (m_filter->*m_workFunction)(sample);
+		}
+	};
+	typedef std::list<FilterStage*> FilterStages;
+	FilterStages m_filterStages;
+    bool m_filterChainSetMode;
+	ChannelSampleSink* m_sampleSink; //!< Demodulator
+    int m_basebandSampleRate;
+	int m_requestedOutputSampleRate;
+	int m_requestedCenterFrequency;
+	int m_channelSampleRate;
+    int m_channelFrequencyOffset;
+    unsigned int m_log2Decim;
+    unsigned int m_filterChainHash;
+	SampleVector m_sampleBuffer;
+
+	void applyChannelization();
+    void applyDecimation();
+    static Real channelMinSpace(Real sigStart, Real sigEnd, Real chanStart, Real chanEnd);
+	Real createFilterChain(Real sigStart, Real sigEnd, Real chanStart, Real chanEnd);
+    double setFilterChain(const std::vector<unsigned int>& stageIndexes);
+	void freeFilterChain();
+	void debugFilterChain();
+};
+
+#endif // SDRBASE_DSP_DOWNCHANNELIZER_H

android/app/src/main/cpp/dsp/dspcommands.cpp

@@ -0,0 +1,48 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2016, 2018-2019, 2022 Edouard Griffiths, F4EXB <f4exb06@gmail.com> //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include "dsp/dspcommands.h"
+
+MESSAGE_CLASS_DEFINITION(DSPAcquisitionInit, Message)
+MESSAGE_CLASS_DEFINITION(DSPAcquisitionStart, Message)
+MESSAGE_CLASS_DEFINITION(DSPAcquisitionStop, Message)
+MESSAGE_CLASS_DEFINITION(DSPGenerationInit, Message)
+MESSAGE_CLASS_DEFINITION(DSPGenerationStart, Message)
+MESSAGE_CLASS_DEFINITION(DSPGenerationStop, Message)
+MESSAGE_CLASS_DEFINITION(DSPGetSourceDeviceDescription, Message)
+MESSAGE_CLASS_DEFINITION(DSPGetSinkDeviceDescription, Message)
+MESSAGE_CLASS_DEFINITION(DSPGetErrorMessage, Message)
+MESSAGE_CLASS_DEFINITION(DSPSetSource, Message)
+MESSAGE_CLASS_DEFINITION(DSPSetSink, Message)
+MESSAGE_CLASS_DEFINITION(DSPAddBasebandSampleSink, Message)
+MESSAGE_CLASS_DEFINITION(DSPAddSpectrumSink, Message)
+MESSAGE_CLASS_DEFINITION(DSPAddBasebandSampleSource, Message)
+MESSAGE_CLASS_DEFINITION(DSPRemoveBasebandSampleSink, Message)
+MESSAGE_CLASS_DEFINITION(DSPRemoveSpectrumSink, Message)
+MESSAGE_CLASS_DEFINITION(DSPRemoveBasebandSampleSource, Message)
+MESSAGE_CLASS_DEFINITION(DSPAddAudioSink, Message)
+MESSAGE_CLASS_DEFINITION(DSPRemoveAudioSink, Message)
+MESSAGE_CLASS_DEFINITION(DSPConfigureCorrection, Message)
+MESSAGE_CLASS_DEFINITION(DSPEngineReport, Message)
+MESSAGE_CLASS_DEFINITION(DSPConfigureScopeVis, Message)
+MESSAGE_CLASS_DEFINITION(DSPSignalNotification, Message)
+MESSAGE_CLASS_DEFINITION(DSPMIMOSignalNotification, Message)
+MESSAGE_CLASS_DEFINITION(DSPConfigureChannelizer, Message)
+MESSAGE_CLASS_DEFINITION(DSPConfigureAudio, Message)
+MESSAGE_CLASS_DEFINITION(DSPPushMbeFrame, Message)

android/app/src/main/cpp/dsp/dspcommands.h

@@ -0,0 +1,400 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2016, 2018-2019, 2022-2023 Edouard Griffiths, F4EXB <f4exb06@gmail.com> //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef INCLUDE_DSPCOMMANDS_H
+#define INCLUDE_DSPCOMMANDS_H
+
+#include <QString>
+#include "dsp/dsptypes.h"
+#include "util/message.h"
+#include "export.h"
+
+class DeviceSampleSource;
+class BasebandSampleSink;
+class DeviceSampleSink;
+class BasebandSampleSource;
+class AudioFifo;
+
+class SDRBASE_API DSPAcquisitionInit : public Message {
+	MESSAGE_CLASS_DECLARATION
+};
+
+class SDRBASE_API DSPAcquisitionStart : public Message {
+	MESSAGE_CLASS_DECLARATION
+};
+
+class SDRBASE_API DSPAcquisitionStop : public Message {
+	MESSAGE_CLASS_DECLARATION
+};
+
+class SDRBASE_API DSPGenerationInit : public Message {
+	MESSAGE_CLASS_DECLARATION
+};
+
+class SDRBASE_API DSPGenerationStart : public Message {
+	MESSAGE_CLASS_DECLARATION
+};
+
+class SDRBASE_API DSPGenerationStop : public Message {
+	MESSAGE_CLASS_DECLARATION
+};
+
+class SDRBASE_API DSPGetSourceDeviceDescription : public Message {
+	MESSAGE_CLASS_DECLARATION
+
+public:
+	void setDeviceDescription(const QString& text) { m_deviceDescription = text; }
+	const QString& getDeviceDescription() const { return m_deviceDescription; }
+
+private:
+	QString m_deviceDescription;
+};
+
+class SDRBASE_API DSPGetSinkDeviceDescription : public Message {
+	MESSAGE_CLASS_DECLARATION
+
+public:
+	void setDeviceDescription(const QString& text) { m_deviceDescription = text; }
+	const QString& getDeviceDescription() const { return m_deviceDescription; }
+
+private:
+	QString m_deviceDescription;
+};
+
+class SDRBASE_API DSPGetErrorMessage : public Message {
+	MESSAGE_CLASS_DECLARATION
+
+public:
+	void setErrorMessage(const QString& text) { m_errorMessage = text; }
+	const QString& getErrorMessage() const { return m_errorMessage; }
+
+private:
+	QString m_errorMessage;
+};
+
+class SDRBASE_API DSPSetSource : public Message {
+	MESSAGE_CLASS_DECLARATION
+
+public:
+	DSPSetSource(DeviceSampleSource* sampleSource) : Message(), m_sampleSource(sampleSource) { }
+
+	DeviceSampleSource* getSampleSource() const { return m_sampleSource; }
+
+private:
+	DeviceSampleSource* m_sampleSource;
+};
+
+class SDRBASE_API DSPSetSink : public Message {
+	MESSAGE_CLASS_DECLARATION
+
+public:
+	DSPSetSink(DeviceSampleSink* sampleSink) : Message(), m_sampleSink(sampleSink) { }
+
+	DeviceSampleSink* getSampleSink() const { return m_sampleSink; }
+
+private:
+	DeviceSampleSink* m_sampleSink;
+};
+
+class SDRBASE_API DSPAddBasebandSampleSink : public Message {
+	MESSAGE_CLASS_DECLARATION
+
+public:
+	DSPAddBasebandSampleSink(BasebandSampleSink* sampleSink) : Message(), m_sampleSink(sampleSink) { }
+
+	BasebandSampleSink* getSampleSink() const { return m_sampleSink; }
+
+private:
+	BasebandSampleSink* m_sampleSink;
+};
+
+class SDRBASE_API DSPAddSpectrumSink : public Message {
+	MESSAGE_CLASS_DECLARATION
+
+public:
+	DSPAddSpectrumSink(BasebandSampleSink* sampleSink) : Message(), m_sampleSink(sampleSink) { }
+
+	BasebandSampleSink* getSampleSink() const { return m_sampleSink; }
+
+private:
+	BasebandSampleSink* m_sampleSink;
+};
+
+class SDRBASE_API DSPAddBasebandSampleSource : public Message {
+	MESSAGE_CLASS_DECLARATION
+
+public:
+	DSPAddBasebandSampleSource(BasebandSampleSource* sampleSource) : Message(), m_sampleSource(sampleSource) { }
+
+	BasebandSampleSource* getSampleSource() const { return m_sampleSource; }
+
+private:
+	BasebandSampleSource* m_sampleSource;
+};
+
+class SDRBASE_API DSPRemoveBasebandSampleSink : public Message {
+	MESSAGE_CLASS_DECLARATION
+
+public:
+	DSPRemoveBasebandSampleSink(BasebandSampleSink* sampleSink, bool deleting) : Message(), m_sampleSink(sampleSink), m_deleting(deleting) { }
+
+	BasebandSampleSink* getSampleSink() const { return m_sampleSink; }
+	bool getDeleting() const { return m_deleting; }
+
+private:
+	BasebandSampleSink* m_sampleSink;
+	bool m_deleting;
+};
+
+class SDRBASE_API DSPRemoveSpectrumSink : public Message {
+	MESSAGE_CLASS_DECLARATION
+
+public:
+	DSPRemoveSpectrumSink(BasebandSampleSink* sampleSink) : Message(), m_sampleSink(sampleSink) { }
+
+	BasebandSampleSink* getSampleSink() const { return m_sampleSink; }
+
+private:
+	BasebandSampleSink* m_sampleSink;
+};
+
+class SDRBASE_API DSPRemoveBasebandSampleSource : public Message {
+	MESSAGE_CLASS_DECLARATION
+
+public:
+	DSPRemoveBasebandSampleSource(BasebandSampleSource* sampleSource, bool deleting) : Message(), m_sampleSource(sampleSource), m_deleting(deleting) { }
+
+	BasebandSampleSource* getSampleSource() const { return m_sampleSource; }
+	bool getDeleting() const { return m_deleting; }
+
+private:
+	BasebandSampleSource* m_sampleSource;
+	bool m_deleting;
+};
+
+class SDRBASE_API DSPAddAudioSink : public Message {
+	MESSAGE_CLASS_DECLARATION
+
+public:
+	DSPAddAudioSink(AudioFifo* audioFifo) : Message(), m_audioFifo(audioFifo) { }
+
+	AudioFifo* getAudioFifo() const { return m_audioFifo; }
+
+private:
+	AudioFifo* m_audioFifo;
+};
+
+class SDRBASE_API DSPRemoveAudioSink : public Message {
+	MESSAGE_CLASS_DECLARATION
+
+public:
+	DSPRemoveAudioSink(AudioFifo* audioFifo) : Message(), m_audioFifo(audioFifo) { }
+
+	AudioFifo* getAudioFifo() const { return m_audioFifo; }
+
+private:
+	AudioFifo* m_audioFifo;
+};
+
+class SDRBASE_API DSPConfigureCorrection : public Message {
+	MESSAGE_CLASS_DECLARATION
+
+public:
+	DSPConfigureCorrection(bool dcOffsetCorrection, bool iqImbalanceCorrection) :
+		Message(),
+		m_dcOffsetCorrection(dcOffsetCorrection),
+		m_iqImbalanceCorrection(iqImbalanceCorrection)
+	{ }
+
+	bool getDCOffsetCorrection() const { return m_dcOffsetCorrection; }
+	bool getIQImbalanceCorrection() const { return m_iqImbalanceCorrection; }
+
+private:
+	bool m_dcOffsetCorrection;
+	bool m_iqImbalanceCorrection;
+
+};
+
+class SDRBASE_API DSPEngineReport : public Message {
+	MESSAGE_CLASS_DECLARATION
+
+public:
+	DSPEngineReport(int sampleRate, quint64 centerFrequency) :
+		Message(),
+		m_sampleRate(sampleRate),
+		m_centerFrequency(centerFrequency)
+	{ }
+
+	int getSampleRate() const { return m_sampleRate; }
+	quint64 getCenterFrequency() const { return m_centerFrequency; }
+
+private:
+	int m_sampleRate;
+	quint64 m_centerFrequency;
+};
+
+class SDRBASE_API DSPConfigureScopeVis : public Message {
+	MESSAGE_CLASS_DECLARATION
+
+public:
+	DSPConfigureScopeVis(int triggerChannel, Real triggerLevelHigh, Real triggerLevelLow) :
+		Message(),
+		m_triggerChannel(triggerChannel),
+		m_triggerLevelHigh(triggerLevelHigh),
+		m_triggerLevelLow(triggerLevelLow)
+	{ }
+
+	int getTriggerChannel() const { return m_triggerChannel; }
+	Real getTriggerLevelHigh() const { return m_triggerLevelHigh; }
+	Real getTriggerLevelLow() const { return m_triggerLevelLow; }
+
+private:
+	int m_triggerChannel;
+	Real m_triggerLevelHigh;
+	Real m_triggerLevelLow;
+};
+
+class SDRBASE_API DSPSignalNotification : public Message {
+	MESSAGE_CLASS_DECLARATION
+
+public:
+	DSPSignalNotification(int samplerate, qint64 centerFrequency, bool realElseComplex = false) :
+		Message(),
+		m_sampleRate(samplerate),
+		m_centerFrequency(centerFrequency),
+        m_realElseComplex(realElseComplex)
+	{ }
+
+	int getSampleRate() const { return m_sampleRate; }
+	qint64 getCenterFrequency() const { return m_centerFrequency; }
+    bool getRealElseComplex() const { return m_realElseComplex; }
+
+private:
+	int m_sampleRate;
+	qint64 m_centerFrequency;
+    bool m_realElseComplex;
+};
+
+class SDRBASE_API DSPMIMOSignalNotification : public Message {
+	MESSAGE_CLASS_DECLARATION
+public:
+	DSPMIMOSignalNotification(int samplerate, qint64 centerFrequency, bool sourceOrSink, unsigned int index, bool realElseComplex = false) :
+		Message(),
+		m_sampleRate(samplerate),
+		m_centerFrequency(centerFrequency),
+        m_realElseComplex(realElseComplex),
+		m_sourceOrSink(sourceOrSink),
+		m_index(index)
+	{ }
+	int getSampleRate() const { return m_sampleRate; }
+	qint64 getCenterFrequency() const { return m_centerFrequency; }
+    bool getRealElseComplex() const { return m_realElseComplex; }
+	bool getSourceOrSink() const { return m_sourceOrSink; }
+	unsigned int getIndex() const { return m_index; }
+private:
+	int m_sampleRate;
+	qint64 m_centerFrequency;
+    bool m_realElseComplex;
+	bool m_sourceOrSink;
+	unsigned int m_index;
+};
+
+class SDRBASE_API DSPConfigureChannelizer : public Message {
+	MESSAGE_CLASS_DECLARATION
+
+public:
+	DSPConfigureChannelizer(int sampleRate, int centerFrequency) :
+		Message(),
+		m_sampleRate(sampleRate),
+		m_centerFrequency(centerFrequency)
+	{ }
+
+	int getSampleRate() const { return m_sampleRate; }
+	int getCenterFrequency() const { return m_centerFrequency; }
+
+private:
+	int m_sampleRate;
+	int m_centerFrequency;
+};
+
+class SDRBASE_API DSPConfigureAudio : public Message {
+    MESSAGE_CLASS_DECLARATION
+
+public:
+    enum AudioType
+    {
+        AudioInput,
+        AudioOutput
+    };
+
+    DSPConfigureAudio(int sampleRate, AudioType audioType) :
+        m_sampleRate(sampleRate),
+        m_autioType(audioType)
+    { }
+
+    int getSampleRate() const { return m_sampleRate; }
+    AudioType getAudioType() const { return m_autioType; }
+
+private:
+    int m_sampleRate;
+    AudioType m_autioType;
+};
+
+class SDRBASE_API DSPPushMbeFrame : public Message {
+	MESSAGE_CLASS_DECLARATION
+
+public:
+	DSPPushMbeFrame(
+        const unsigned char *mbeFrame,
+        int mbeRateIndex,
+        int mbeVolumeIndex,
+        unsigned char channels,
+        bool useHP,
+        int upsampling,
+        AudioFifo *audioFifo
+    ) :
+		Message(),
+		m_mbeFrame(mbeFrame),
+		m_mbeRateIndex(mbeRateIndex),
+        m_mbeVolumeIndex(mbeVolumeIndex),
+        m_channels(channels),
+        m_useHP(useHP),
+        m_upsampling(upsampling),
+        m_audioFifo(audioFifo)
+	{ }
+
+	const unsigned char * getMbeFrame() const { return m_mbeFrame; }
+	int getMbeRateIndex() const { return m_mbeRateIndex; }
+    int getMbeVolumeIndex() const { return m_mbeVolumeIndex; }
+    unsigned char getChannels() const { return m_channels; }
+    bool getUseHP() const { return m_useHP; }
+    int getUpsampling() const { return m_upsampling; }
+    AudioFifo *getAudioFifo() const { return m_audioFifo; }
+
+private:
+    const unsigned char *m_mbeFrame;
+    int m_mbeRateIndex;
+    int m_mbeVolumeIndex;
+    unsigned char m_channels;
+    bool m_useHP;
+    int m_upsampling;
+    AudioFifo *m_audioFifo;
+};
+
+#endif // INCLUDE_DSPCOMMANDS_H

android/app/src/main/cpp/dsp/dspdevicemimoengine.h

@@ -0,0 +1,369 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2019-2020, 2023 Edouard Griffiths, F4EXB <f4exb06@gmail.com>    //
+// Copyright (C) 2022 Jon Beniston, M7RCE <jon@beniston.com>                     //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef SDRBASE_DSP_DSPDEVICEMIMOENGINE_H_
+#define SDRBASE_DSP_DSPDEVICEMIMOENGINE_H_
+
+#include <QObject>
+
+#include "dsp/dsptypes.h"
+#include "util/message.h"
+#include "util/messagequeue.h"
+#include "util/movingaverage.h"
+#include "util/incrementalvector.h"
+#include "export.h"
+
+class DeviceSampleMIMO;
+class BasebandSampleSink;
+class BasebandSampleSource;
+class MIMOChannel;
+
+class SDRBASE_API DSPDeviceMIMOEngine : public QObject {
+	Q_OBJECT
+
+public:
+    class SetSampleMIMO : public Message {
+        MESSAGE_CLASS_DECLARATION
+    public:
+        explicit SetSampleMIMO(DeviceSampleMIMO* sampleMIMO) : Message(), m_sampleMIMO(sampleMIMO) { }
+        DeviceSampleMIMO* getSampleMIMO() const { return m_sampleMIMO; }
+    private:
+        DeviceSampleMIMO* m_sampleMIMO;
+    };
+
+    class AddBasebandSampleSource : public Message {
+        MESSAGE_CLASS_DECLARATION
+    public:
+        AddBasebandSampleSource(BasebandSampleSource* sampleSource, unsigned int index) :
+            Message(),
+            m_sampleSource(sampleSource),
+            m_index(index)
+        { }
+        BasebandSampleSource* getSampleSource() const { return m_sampleSource; }
+        unsigned int getIndex() const { return m_index; }
+    private:
+        BasebandSampleSource* m_sampleSource;
+        unsigned int m_index;
+    };
+
+    class RemoveBasebandSampleSource : public Message {
+	    MESSAGE_CLASS_DECLARATION
+
+    public:
+        RemoveBasebandSampleSource(BasebandSampleSource* sampleSource, unsigned int index, bool deleting) :
+            Message(),
+            m_sampleSource(sampleSource),
+            m_index(index),
+            m_deleting(deleting)
+        { }
+        BasebandSampleSource* getSampleSource() const { return m_sampleSource; }
+        unsigned int getIndex() const { return m_index; }
+        bool getDeleting() const { return m_deleting; }
+    private:
+        BasebandSampleSource* m_sampleSource;
+        unsigned int m_index;
+        bool m_deleting;
+    };
+
+    class AddMIMOChannel : public Message {
+        MESSAGE_CLASS_DECLARATION
+    public:
+        explicit AddMIMOChannel(MIMOChannel* channel) :
+            Message(),
+            m_channel(channel)
+        { }
+        MIMOChannel* getChannel() const { return m_channel; }
+    private:
+        MIMOChannel* m_channel;
+    };
+
+    class RemoveMIMOChannel : public Message {
+        MESSAGE_CLASS_DECLARATION
+    public:
+        explicit RemoveMIMOChannel(MIMOChannel* channel) :
+            Message(),
+            m_channel(channel)
+        { }
+        MIMOChannel* getChannel() const { return m_channel; }
+    private:
+        MIMOChannel* m_channel;
+    };
+
+    class AddBasebandSampleSink : public Message {
+        MESSAGE_CLASS_DECLARATION
+    public:
+        AddBasebandSampleSink(BasebandSampleSink* sampleSink, unsigned int index) :
+            Message(),
+            m_sampleSink(sampleSink),
+            m_index(index)
+        { }
+        BasebandSampleSink* getSampleSink() const { return m_sampleSink; }
+        unsigned int getIndex() const { return m_index; }
+    private:
+        BasebandSampleSink* m_sampleSink;
+        unsigned int m_index;
+    };
+
+    class RemoveBasebandSampleSink : public Message {
+        MESSAGE_CLASS_DECLARATION
+    public:
+        RemoveBasebandSampleSink(BasebandSampleSink* sampleSink, unsigned int index) :
+            Message(),
+            m_sampleSink(sampleSink),
+            m_index(index)
+        { }
+        BasebandSampleSink* getSampleSink() const { return m_sampleSink; }
+        unsigned int getIndex() const { return m_index; }
+    private:
+        BasebandSampleSink* m_sampleSink;
+        unsigned int m_index;
+    };
+
+    class AddSpectrumSink : public Message {
+        MESSAGE_CLASS_DECLARATION
+    public:
+        explicit AddSpectrumSink(BasebandSampleSink* sampleSink) : Message(), m_sampleSink(sampleSink) { }
+        BasebandSampleSink* getSampleSink() const { return m_sampleSink; }
+    private:
+        BasebandSampleSink* m_sampleSink;
+    };
+
+    class RemoveSpectrumSink : public Message {
+        MESSAGE_CLASS_DECLARATION
+    public:
+        explicit RemoveSpectrumSink(BasebandSampleSink* sampleSink) : Message(), m_sampleSink(sampleSink) { }
+        BasebandSampleSink* getSampleSink() const { return m_sampleSink; }
+    private:
+        BasebandSampleSink* m_sampleSink;
+    };
+
+    class GetErrorMessage : public Message {
+        MESSAGE_CLASS_DECLARATION
+    public:
+        explicit GetErrorMessage(unsigned int subsystemIndex) :
+            m_subsystemIndex(subsystemIndex)
+        {}
+        void setErrorMessage(const QString& text) { m_errorMessage = text; }
+        int getSubsystemIndex() const { return m_subsystemIndex; }
+        const QString& getErrorMessage() const { return m_errorMessage; }
+    private:
+        int m_subsystemIndex;
+        QString m_errorMessage;
+    };
+
+    class GetMIMODeviceDescription : public Message {
+        MESSAGE_CLASS_DECLARATION
+    public:
+        void setDeviceDescription(const QString& text) { m_deviceDescription = text; }
+        const QString& getDeviceDescription() const { return m_deviceDescription; }
+    private:
+        QString m_deviceDescription;
+    };
+
+    class ConfigureCorrection : public Message {
+        MESSAGE_CLASS_DECLARATION
+    public:
+        ConfigureCorrection(bool dcOffsetCorrection, bool iqImbalanceCorrection, unsigned int index) :
+            Message(),
+            m_dcOffsetCorrection(dcOffsetCorrection),
+            m_iqImbalanceCorrection(iqImbalanceCorrection),
+            m_index(index)
+        { }
+        bool getDCOffsetCorrection() const { return m_dcOffsetCorrection; }
+        bool getIQImbalanceCorrection() const { return m_iqImbalanceCorrection; }
+        unsigned int getIndex() const { return m_index; }
+    private:
+        bool m_dcOffsetCorrection;
+        bool m_iqImbalanceCorrection;
+        unsigned int m_index;
+    };
+
+    class SetSpectrumSinkInput : public Message {
+        MESSAGE_CLASS_DECLARATION
+    public:
+        SetSpectrumSinkInput(bool sourceElseSink, int index) :
+            m_sourceElseSink(sourceElseSink),
+            m_index(index)
+        { }
+        bool getSourceElseSink() const { return m_sourceElseSink; }
+        int getIndex() const { return m_index; }
+    private:
+        bool m_sourceElseSink;
+        int m_index;
+    };
+
+	enum class State {
+		StNotStarted,  //!< engine is before initialization
+		StIdle,        //!< engine is idle
+		StReady,       //!< engine is ready to run
+		StRunning,     //!< engine is running
+		StError        //!< engine is in error
+	};
+
+	DSPDeviceMIMOEngine(uint32_t uid, QObject* parent = nullptr);
+	~DSPDeviceMIMOEngine() override;
+
+	MessageQueue* getInputMessageQueue() { return &m_inputMessageQueue; }
+
+	bool initProcess(int subsystemIndex);  //!< Initialize process sequence
+	bool startProcess(int subsystemIndex); //!< Start process sequence
+	void stopProcess(int subsystemIndex);  //!< Stop process sequence
+
+	void setMIMO(DeviceSampleMIMO* mimo); //!< Set the sample MIMO type
+	DeviceSampleMIMO *getMIMO() { return m_deviceSampleMIMO; }
+	void setMIMOSequence(int sequence); //!< Set the sample MIMO sequence in type
+    uint getUID() const { return m_uid; }
+
+	void addChannelSource(BasebandSampleSource* source, int index = 0);            //!< Add a channel source
+	void removeChannelSource(BasebandSampleSource* source, bool deleting, int index = 0); //!< Remove a channel source
+	void addChannelSink(BasebandSampleSink* sink, int index = 0);                  //!< Add a channel sink
+	void removeChannelSink(BasebandSampleSink* sink, int index = 0);               //!< Remove a channel sink
+    void addMIMOChannel(MIMOChannel *channel);                                     //!< Add a MIMO channel
+    void removeMIMOChannel(MIMOChannel *channel);                                  //!< Remove a MIMO channel
+
+	void addSpectrumSink(BasebandSampleSink* spectrumSink);    //!< Add a spectrum vis baseband sample sink
+	void removeSpectrumSink(BasebandSampleSink* spectrumSink); //!< Add a spectrum vis baseband sample sink
+    void setSpectrumSinkInput(bool sourceElseSink, int index);
+
+	State state(int subsystemIndex) const //!< Return DSP engine current state
+    {
+        if (subsystemIndex == 0) {
+            return m_stateRx;
+        } else if (subsystemIndex == 1) {
+            return m_stateTx;
+        } else {
+            return State::StNotStarted;
+        }
+    }
+
+	QString errorMessage(int subsystemIndex) const; //!< Return the current error message
+	QString deviceDescription() const; //!< Return the device description
+
+   	void configureCorrections(bool dcOffsetCorrection, bool iqImbalanceCorrection, int isource); //!< Configure source DSP corrections
+
+private:
+    struct SourceCorrection
+    {
+        bool m_dcOffsetCorrection = false;
+        bool m_iqImbalanceCorrection = false;
+        double m_iOffset = 0;
+        double m_qOffset = 0;
+        int m_iRange = 1 << 16;
+        int m_qRange = 1 << 16;
+        int m_imbalance = 65536;
+        MovingAverageUtil<int32_t, int64_t, 1024> m_iBeta;
+        MovingAverageUtil<int32_t, int64_t, 1024> m_qBeta;
+#if IMBALANCE_INT
+        // Fixed point DC + IQ corrections
+        MovingAverageUtil<int64_t, int64_t, 128> m_avgII;
+        MovingAverageUtil<int64_t, int64_t, 128> m_avgIQ;
+        MovingAverageUtil<int64_t, int64_t, 128> m_avgPhi;
+        MovingAverageUtil<int64_t, int64_t, 128> m_avgII2;
+        MovingAverageUtil<int64_t, int64_t, 128> m_avgQQ2;
+        MovingAverageUtil<int64_t, int64_t, 128> m_avgAmp;
+#else
+        // Floating point DC + IQ corrections
+        MovingAverageUtil<float, double, 128> m_avgII;
+        MovingAverageUtil<float, double, 128> m_avgIQ;
+        MovingAverageUtil<float, double, 128> m_avgII2;
+        MovingAverageUtil<float, double, 128> m_avgQQ2;
+        MovingAverageUtil<double, double, 128> m_avgPhi;
+        MovingAverageUtil<double, double, 128> m_avgAmp;
+#endif
+        SourceCorrection()
+        {
+            m_iBeta.reset();
+            m_qBeta.reset();
+            m_avgAmp.reset();
+            m_avgII.reset();
+            m_avgII2.reset();
+            m_avgIQ.reset();
+            m_avgPhi.reset();
+            m_avgQQ2.reset();
+            m_iBeta.reset();
+            m_qBeta.reset();
+        }
+    };
+
+	uint32_t m_uid; //!< unique ID
+    State m_stateRx;
+    State m_stateTx;
+
+    QString m_errorMessageRx;
+    QString m_errorMessageTx;
+	QString m_deviceDescription;
+
+	DeviceSampleMIMO* m_deviceSampleMIMO;
+	int m_sampleMIMOSequence;
+
+    MessageQueue m_inputMessageQueue;  //<! Input message queue. Post here.
+
+	using BasebandSampleSinks = std::list<BasebandSampleSink *>;
+	std::vector<BasebandSampleSinks> m_basebandSampleSinks; //!< ancillary sample sinks on main thread (per input stream)
+    std::map<int, bool> m_rxRealElseComplex; //!< map of real else complex indicators for device sources (by input stream)
+	using BasebandSampleSources = std::list<BasebandSampleSource *>;
+	std::vector<BasebandSampleSources> m_basebandSampleSources; //!< channel sample sources (per output stream)
+    std::map<int, bool> m_txRealElseComplex; //!< map of real else complex indicators for device sinks (by input stream)
+    std::vector<IncrementalVector<Sample>> m_sourceSampleBuffers;
+    std::vector<IncrementalVector<Sample>> m_sourceZeroBuffers;
+    unsigned int m_sumIndex;            //!< channel index when summing channels
+
+    using MIMOChannels = std::list<MIMOChannel *>;
+    MIMOChannels m_mimoChannels; //!< MIMO channels
+
+    std::vector<SourceCorrection> m_sourcesCorrections;
+
+    BasebandSampleSink *m_spectrumSink; //!< The spectrum sink
+    bool m_spectrumInputSourceElseSink; //!< Source else sink stream to be used as spectrum sink input
+    unsigned int m_spectrumInputIndex;  //!< Index of the stream to be used as spectrum sink input
+
+    void workSampleSinkFifos(); //!< transfer samples of all sink streams (sync mode)
+    void workSampleSinkFifo(unsigned int streamIndex); //!< transfer samples of one sink stream (async mode)
+    void workSamplesSink(const SampleVector::const_iterator& vbegin, const SampleVector::const_iterator& vend, unsigned int streamIndex);
+    void workSampleSourceFifos(); //!< transfer samples of all source streams (sync mode)
+    void workSampleSourceFifo(unsigned int streamIndex); //!< transfer samples of one source stream (async mode)
+    void workSamplesSource(SampleVector& data, unsigned int iBegin, unsigned int iEnd, unsigned int streamIndex);
+
+	State gotoIdle(int subsystemIndex);     //!< Go to the idle state
+	State gotoInit(int subsystemIndex);     //!< Go to the acquisition init state from idle
+	State gotoRunning(int subsystemIndex);  //!< Go to the running state from ready state
+	State gotoError(int subsystemIndex, const QString& errorMsg); //!< Go to an error state
+	void setStateRx(State state);
+	void setStateTx(State state);
+
+    void handleSetMIMO(DeviceSampleMIMO* mimo); //!< Manage MIMO device setting
+    void iqCorrections(SampleVector::iterator begin, SampleVector::iterator end, int isource, bool imbalanceCorrection);
+    bool handleMessage(const Message& cmd);
+
+private slots:
+	void handleDataRxSync();           //!< Handle data when Rx samples have to be processed synchronously
+	void handleDataRxAsync(int streamIndex); //!< Handle data when Rx samples have to be processed asynchronously
+	void handleDataTxSync();           //!< Handle data when Tx samples have to be processed synchronously
+	void handleDataTxAsync(int streamIndex); //!< Handle data when Tx samples have to be processed asynchronously
+	void handleInputMessages();        //!< Handle input message queue
+
+signals:
+	void stateChanged();
+
+    void acquisitionStopped();
+    void sampleSet();
+    void generationStopped();
+    void spectrumSinkRemoved();
+};
+
+#endif // SDRBASE_DSP_DSPDEVICEMIMOENGINE_H_

android/app/src/main/cpp/dsp/dspdevicesinkengine.cpp

@@ -0,0 +1,526 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2016-2023 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+// Copyright (C) 2022 Jon Beniston, M7RCE <jon@beniston.com>                     //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include <stdio.h>
+#include <QDebug>
+#include <QThread>
+
+#include "dspdevicesinkengine.h"
+
+#include "dsp/basebandsamplesource.h"
+#include "dsp/basebandsamplesink.h"
+#include "dsp/devicesamplesink.h"
+#include "dsp/dspcommands.h"
+
+DSPDeviceSinkEngine::DSPDeviceSinkEngine(uint32_t uid, QObject* parent) :
+	QObject(parent),
+    m_uid(uid),
+	m_state(State::StNotStarted),
+	m_deviceSampleSink(nullptr),
+	m_sampleSinkSequence(0),
+	m_basebandSampleSources(),
+	m_spectrumSink(nullptr),
+	m_sampleRate(0),
+	m_centerFrequency(0),
+    m_realElseComplex(false)
+{
+    setState(State::StIdle);
+	connect(&m_inputMessageQueue, SIGNAL(messageEnqueued()), this, SLOT(handleInputMessages()), Qt::QueuedConnection);
+}
+
+DSPDeviceSinkEngine::~DSPDeviceSinkEngine()
+{
+    qDebug("DSPDeviceSinkEngine::~DSPDeviceSinkEngine");
+}
+
+void DSPDeviceSinkEngine::setState(State state)
+{
+    if (m_state != state)
+    {
+        m_state = state;
+        emit stateChanged();
+    }
+}
+
+bool DSPDeviceSinkEngine::initGeneration()
+{
+	qDebug() << "DSPDeviceSinkEngine::initGeneration";
+	auto *cmd = new DSPGenerationInit();
+    getInputMessageQueue()->push(cmd);
+	return true;
+}
+
+bool DSPDeviceSinkEngine::startGeneration()
+{
+	qDebug() << "DSPDeviceSinkEngine::startGeneration";
+	auto *cmd = new DSPGenerationStart();
+    getInputMessageQueue()->push(cmd);
+	return true;
+}
+
+void DSPDeviceSinkEngine::stopGeneration()
+{
+	qDebug() << "DSPDeviceSinkEngine::stopGeneration";
+	auto *cmd = new DSPGenerationStop();
+    getInputMessageQueue()->push(cmd);
+}
+
+void DSPDeviceSinkEngine::setSink(DeviceSampleSink* sink)
+{
+	qDebug() << "DSPDeviceSinkEngine::setSink";
+    m_deviceSampleSink = sink;
+	auto *cmd = new DSPSetSink(sink);
+    getInputMessageQueue()->push(cmd);
+}
+
+void DSPDeviceSinkEngine::setSinkSequence(int sequence)
+{
+	qDebug("DSPDeviceSinkEngine::setSinkSequence: seq: %d", sequence);
+	m_sampleSinkSequence = sequence;
+}
+
+void DSPDeviceSinkEngine::addChannelSource(BasebandSampleSource* source)
+{
+	qDebug() << "DSPDeviceSinkEngine::addChannelSource: " << source->getSourceName().toStdString().c_str();
+	auto *cmd = new DSPAddBasebandSampleSource(source);
+    getInputMessageQueue()->push(cmd);
+}
+
+void DSPDeviceSinkEngine::removeChannelSource(BasebandSampleSource* source, bool deleting)
+{
+	qDebug() << "DSPDeviceSinkEngine::removeChannelSource: " << source->getSourceName().toStdString().c_str();
+	auto *cmd = new DSPRemoveBasebandSampleSource(source, deleting);
+    getInputMessageQueue()->push(cmd);
+}
+
+void DSPDeviceSinkEngine::addSpectrumSink(BasebandSampleSink* spectrumSink)
+{
+	qDebug() << "DSPDeviceSinkEngine::addSpectrumSink: " << spectrumSink->getSinkName().toStdString().c_str();
+    m_spectrumSink = spectrumSink;
+}
+
+void DSPDeviceSinkEngine::removeSpectrumSink(BasebandSampleSink* spectrumSink)
+{
+	qDebug() << "DSPDeviceSinkEngine::removeSpectrumSink: " << spectrumSink->getSinkName().toStdString().c_str();
+	auto *cmd = new DSPRemoveSpectrumSink(spectrumSink);
+	getInputMessageQueue()->push(cmd);
+}
+
+QString DSPDeviceSinkEngine::errorMessage() const
+{
+	qDebug() << "DSPDeviceSinkEngine::errorMessage";
+    return m_errorMessage;
+}
+
+QString DSPDeviceSinkEngine::sinkDeviceDescription() const
+{
+	qDebug() << "DSPDeviceSinkEngine::sinkDeviceDescription";
+    return m_deviceDescription;
+}
+
+void DSPDeviceSinkEngine::workSampleFifo()
+{
+    SampleSourceFifo *sourceFifo = m_deviceSampleSink->getSampleFifo();
+
+    if (!sourceFifo) {
+        return;
+    }
+
+    SampleVector& data = sourceFifo->getData();
+    unsigned int iPart1Begin;
+    unsigned int iPart1End;
+    unsigned int iPart2Begin;
+    unsigned int iPart2End;
+    unsigned int remainder = sourceFifo->remainder();
+
+    while ((remainder > 0) && (m_inputMessageQueue.size() == 0))
+    {
+        sourceFifo->write(remainder, iPart1Begin, iPart1End, iPart2Begin, iPart2End);
+
+        if (iPart1Begin != iPart1End) {
+            workSamples(data, iPart1Begin, iPart1End);
+        }
+
+        if (iPart2Begin != iPart2End) {
+            workSamples(data, iPart2Begin, iPart2End);
+        }
+
+        remainder = sourceFifo->remainder();
+    }
+}
+
+void DSPDeviceSinkEngine::workSamples(SampleVector& data, unsigned int iBegin, unsigned int iEnd)
+{
+    unsigned int nbSamples = iEnd - iBegin;
+    SampleVector::iterator begin = data.begin() + iBegin;
+
+    if (m_basebandSampleSources.size() == 0)
+    {
+        m_sourceZeroBuffer.allocate(nbSamples, Sample{0,0});
+        std::copy(
+            m_sourceZeroBuffer.m_vector.begin(),
+            m_sourceZeroBuffer.m_vector.begin() + nbSamples,
+            data.begin() + iBegin
+        );
+    }
+    else if (m_basebandSampleSources.size() == 1)
+    {
+        BasebandSampleSource *source = m_basebandSampleSources.front();
+        source->pull(begin, nbSamples);
+    }
+    else
+    {
+        m_sourceSampleBuffer.allocate(nbSamples);
+        auto sBegin = m_sourceSampleBuffer.m_vector.begin();
+        BasebandSampleSources::const_iterator srcIt = m_basebandSampleSources.begin();
+        BasebandSampleSource *source = *srcIt;
+        source->pull(begin, nbSamples);
+        srcIt++;
+        m_sumIndex = 1;
+
+        for (; srcIt != m_basebandSampleSources.end(); ++srcIt, m_sumIndex++)
+        {
+            source = *srcIt;
+            source->pull(sBegin, nbSamples);
+            std::transform(
+                sBegin,
+                sBegin + nbSamples,
+                data.begin() + iBegin,
+                data.begin() + iBegin,
+                [this](const Sample& a, const Sample& b) -> Sample {
+                    FixReal den = m_sumIndex + 1; // at each stage scale sum by n/n+1 and input by 1/n+1
+                    FixReal nom = m_sumIndex;     // so that final sum is scaled by N (number of channels)
+					FixReal x = a.real()/den + nom*(b.real()/den);
+					FixReal y = a.imag()/den + nom*(b.imag()/den);
+                    return Sample{x, y};
+                }
+            );
+        }
+    }
+
+    // possibly feed data to spectrum sink
+    if (m_spectrumSink) {
+        m_spectrumSink->feed(data.begin() + iBegin, data.begin() + iEnd, m_realElseComplex);
+    }
+}
+
+// notStarted -> idle -> init -> running -+
+//                ^                       |
+//                +-----------------------+
+
+DSPDeviceSinkEngine::State DSPDeviceSinkEngine::gotoIdle()
+{
+	qDebug() << "DSPDeviceSinkEngine::gotoIdle";
+
+	switch(m_state) {
+		case State::StNotStarted:
+			return State::StNotStarted;
+
+		case State::StIdle:
+		case State::StError:
+			return State::StIdle;
+
+		case State::StReady:
+		case State::StRunning:
+			break;
+	}
+
+	if (!m_deviceSampleSink) {
+		return State::StIdle;
+	}
+
+	// stop everything
+	m_deviceSampleSink->stop();
+
+	for(BasebandSampleSources::const_iterator it = m_basebandSampleSources.begin(); it != m_basebandSampleSources.end(); it++)
+	{
+        qDebug() << "DSPDeviceSinkEngine::gotoIdle: stopping " << (*it)->getSourceName().toStdString().c_str();
+		(*it)->stop();
+	}
+
+	m_deviceDescription.clear();
+	m_sampleRate = 0;
+
+	return State::StIdle;
+}
+
+DSPDeviceSinkEngine::State DSPDeviceSinkEngine::gotoInit()
+{
+	switch(m_state) {
+		case State::StNotStarted:
+			return State::StNotStarted;
+
+		case State::StRunning:
+			return State::StRunning;
+
+		case State::StReady:
+			return State::StReady;
+
+		case State::StIdle:
+		case State::StError:
+			break;
+	}
+
+	if (!m_deviceSampleSink) {
+		return gotoError("DSPDeviceSinkEngine::gotoInit: No sample source configured");
+	}
+
+	// init: pass sample rate and center frequency to all sample rate and/or center frequency dependent sinks and wait for completion
+
+	m_deviceDescription = m_deviceSampleSink->getDeviceDescription();
+	m_centerFrequency = m_deviceSampleSink->getCenterFrequency();
+	m_sampleRate = m_deviceSampleSink->getSampleRate();
+
+	qDebug() << "DSPDeviceSinkEngine::gotoInit: "
+            << " m_deviceDescription: " << m_deviceDescription.toStdString().c_str()
+			<< " sampleRate: " << m_sampleRate
+			<< " centerFrequency: " << m_centerFrequency;
+
+	DSPSignalNotification notif(m_sampleRate, m_centerFrequency);
+
+	for (BasebandSampleSources::const_iterator it = m_basebandSampleSources.begin(); it != m_basebandSampleSources.end(); ++it)
+	{
+		qDebug() << "DSPDeviceSinkEngine::gotoInit: initializing " << (*it)->getSourceName().toStdString().c_str();
+		(*it)->pushMessage(new DSPSignalNotification(notif));
+	}
+
+	if (m_spectrumSink) {
+        m_spectrumSink->pushMessage(new DSPSignalNotification(notif));
+	}
+
+	// pass data to listeners
+	if (m_deviceSampleSink->getMessageQueueToGUI())
+	{
+        auto* rep = new DSPSignalNotification(notif); // make a copy for the output queue
+        m_deviceSampleSink->getMessageQueueToGUI()->push(rep);
+	}
+
+	return State::StReady;
+}
+
+DSPDeviceSinkEngine::State DSPDeviceSinkEngine::gotoRunning()
+{
+	qDebug() << "DSPDeviceSinkEngine::gotoRunning";
+
+	switch(m_state)
+    {
+		case State::StNotStarted:
+			return State::StNotStarted;
+
+		case State::StIdle:
+			return State::StIdle;
+
+		case State::StRunning:
+			return State::StRunning;
+
+		case State::StReady:
+		case State::StError:
+			break;
+	}
+
+	if (!m_deviceSampleSink) {
+		return gotoError("DSPDeviceSinkEngine::gotoRunning: No sample source configured");
+	}
+
+	qDebug() << "DSPDeviceSinkEngine::gotoRunning: " << m_deviceDescription.toStdString().c_str() << " started";
+
+	// Start everything
+
+	if (!m_deviceSampleSink->start()) {
+		return gotoError("DSPDeviceSinkEngine::gotoRunning: Could not start sample sink");
+	}
+
+	for(BasebandSampleSources::const_iterator it = m_basebandSampleSources.begin(); it != m_basebandSampleSources.end(); it++)
+	{
+        qDebug() << "DSPDeviceSinkEngine::gotoRunning: starting " << (*it)->getSourceName().toStdString().c_str();
+		(*it)->start();
+	}
+
+	if (m_spectrumSink)
+	{
+        m_spectrumSink->start();
+	}
+
+	qDebug() << "DSPDeviceSinkEngine::gotoRunning: input message queue pending: " << m_inputMessageQueue.size();
+
+	return State::StRunning;
+}
+
+DSPDeviceSinkEngine::State DSPDeviceSinkEngine::gotoError(const QString& errorMessage)
+{
+	qDebug() << "DSPDeviceSinkEngine::gotoError";
+
+	m_errorMessage = errorMessage;
+	m_deviceDescription.clear();
+	setState(State::StError);
+	return State::StError;
+}
+
+void DSPDeviceSinkEngine::handleSetSink(const DeviceSampleSink*)
+{
+    if (!m_deviceSampleSink) { // Early leave
+        return;
+    }
+
+    qDebug("DSPDeviceSinkEngine::handleSetSink: set %s", qPrintable(m_deviceSampleSink->getDeviceDescription()));
+
+    QObject::connect(
+        m_deviceSampleSink->getSampleFifo(),
+        &SampleSourceFifo::dataRead,
+        this,
+        &DSPDeviceSinkEngine::handleData,
+        Qt::QueuedConnection
+    );
+}
+
+void DSPDeviceSinkEngine::handleData()
+{
+	if (m_state == State::StRunning) {
+		workSampleFifo();
+	}
+}
+
+bool DSPDeviceSinkEngine::handleMessage(const Message& message)
+{
+    if (DSPSignalNotification::match(message))
+    {
+        auto& notif = (const DSPSignalNotification&) message;
+
+        // update DSP values
+
+        m_sampleRate = notif.getSampleRate();
+        m_centerFrequency = notif.getCenterFrequency();
+        m_realElseComplex = notif.getRealElseComplex();
+
+        qDebug() << "DSPDeviceSinkEngine::handleInputMessages: DSPSignalNotification:"
+            << " m_sampleRate: " << m_sampleRate
+            << " m_centerFrequency: " << m_centerFrequency
+            << " m_realElseComplex" << m_realElseComplex;
+
+        // forward source changes to sources with immediate execution
+
+        for(BasebandSampleSources::const_iterator it = m_basebandSampleSources.begin(); it != m_basebandSampleSources.end(); it++)
+        {
+            auto *rep = new DSPSignalNotification(notif); // make a copy
+            qDebug() << "DSPDeviceSinkEngine::handleInputMessages: forward message to " << (*it)->getSourceName().toStdString().c_str();
+            (*it)->pushMessage(rep);
+        }
+
+        // forward changes to listeners on DSP output queue
+        if (m_deviceSampleSink)
+        {
+            MessageQueue *guiMessageQueue = m_deviceSampleSink->getMessageQueueToGUI();
+            qDebug("DSPDeviceSinkEngine::handleInputMessages: DSPSignalNotification: guiMessageQueue: %p", guiMessageQueue);
+
+            if (guiMessageQueue)
+            {
+                auto *rep = new DSPSignalNotification(notif); // make a copy for the output queue
+                guiMessageQueue->push(rep);
+            }
+        }
+
+        return true;
+    }
+    // From synchronous messages
+	if (DSPGenerationInit::match(message))
+	{
+		setState(gotoIdle());
+
+		if(m_state == State::StIdle) {
+			setState(gotoInit()); // State goes ready if init is performed
+		}
+
+        return true;
+	}
+	else if (DSPGenerationStart::match(message))
+	{
+		if(m_state == State::StReady) {
+			setState(gotoRunning());
+		}
+
+        return true;
+	}
+	else if (DSPGenerationStop::match(message))
+	{
+		setState(gotoIdle());
+		emit generationStopped();
+        return true;
+	}
+	else if (DSPSetSink::match(message))
+    {
+        const auto& cmd = (const DSPSetSink&) message;
+		handleSetSink(cmd.getSampleSink());
+		emit sampleSet();
+        return true;
+	}
+	else if (DSPRemoveSpectrumSink::match(message))
+	{
+        auto& cmd = (const DSPRemoveSpectrumSink&) message;
+		BasebandSampleSink* spectrumSink = cmd.getSampleSink();
+
+		if(m_state == State::StRunning) {
+			spectrumSink->stop();
+		}
+
+		m_spectrumSink = nullptr;
+		emit spectrumSinkRemoved();
+        return true;
+	}
+	else if (DSPAddBasebandSampleSource::match(message))
+	{
+        auto& cmd = (const DSPAddBasebandSampleSource&) message;
+		BasebandSampleSource* source = cmd.getSampleSource();
+		m_basebandSampleSources.push_back(source);
+        auto *notif = new DSPSignalNotification(m_sampleRate, m_centerFrequency);
+        source->pushMessage(notif);
+
+        if (m_state == State::StRunning) {
+            source->start();
+        }
+
+        return true;
+	}
+	else if (DSPRemoveBasebandSampleSource::match(message))
+	{
+        auto& cmd = (const DSPRemoveBasebandSampleSource&) message;
+		BasebandSampleSource* source = cmd.getSampleSource();
+		bool deleting = cmd.getDeleting();
+
+		if (!deleting && (m_state == State::StRunning)) {
+			source->stop();
+		}
+
+		m_basebandSampleSources.remove(source);
+        return true;
+	}
+
+    return false;
+}
+
+void DSPDeviceSinkEngine::handleInputMessages()
+{
+	Message* message;
+
+	while ((message = m_inputMessageQueue.pop()) != nullptr)
+	{
+		qDebug("DSPDeviceSinkEngine::handleInputMessages: message: %s", message->getIdentifier());
+        if (handleMessage(*message)) {
+            delete message;
+        }
+	}
+}

android/app/src/main/cpp/dsp/dspdevicesinkengine.h

@@ -0,0 +1,134 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2014 John Greb <hexameron@spam.no>                              //
+// Copyright (C) 2015-2019, 2023 Edouard Griffiths, F4EXB <f4exb06@gmail.com>    //
+// Copyright (C) 2022 Jon Beniston, M7RCE <jon@beniston.com>                     //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef SDRBASE_DSP_DSPDEVICESINKENGINE_H_
+#define SDRBASE_DSP_DSPDEVICESINKENGINE_H_
+
+#include <QObject>
+#include <QTimer>
+#include <QMutex>
+#include <QWaitCondition>
+
+#include <stdint.h>
+#include <list>
+#include <map>
+
+#include "dsp/dsptypes.h"
+#include "util/messagequeue.h"
+#include "util/incrementalvector.h"
+#include "export.h"
+
+class DeviceSampleSink;
+class BasebandSampleSource;
+class BasebandSampleSink;
+
+class SDRBASE_API DSPDeviceSinkEngine : public QObject {
+	Q_OBJECT
+
+public:
+	enum class State {
+		StNotStarted,  //!< engine is before initialization
+		StIdle,        //!< engine is idle
+		StReady,       //!< engine is ready to run
+		StRunning,     //!< engine is running
+		StError        //!< engine is in error
+	};
+
+	DSPDeviceSinkEngine(uint32_t uid, QObject* parent = nullptr);
+	~DSPDeviceSinkEngine() final;
+
+	uint32_t getUID() const { return m_uid; }
+
+	MessageQueue* getInputMessageQueue() { return &m_inputMessageQueue; }
+
+	bool initGeneration(); //!< Initialize generation sequence
+	bool startGeneration(); //!< Start generation sequence
+	void stopGeneration();   //!< Stop generation sequence
+
+	void setSink(DeviceSampleSink* sink); //!< Set the sample sink type
+	DeviceSampleSink *getSink() { return m_deviceSampleSink; }
+	void setSinkSequence(int sequence); //!< Set the sample sink sequence in type
+
+	void addChannelSource(BasebandSampleSource* source);       //!< Add a baseband sample source
+	void removeChannelSource(BasebandSampleSource* source, bool deleting);    //!< Remove a baseband sample source
+
+	void addSpectrumSink(BasebandSampleSink* spectrumSink);    //!< Add a spectrum vis baseband sample sink
+	void removeSpectrumSink(BasebandSampleSink* spectrumSink); //!< Add a spectrum vis baseband sample sink
+
+	State state() const { return m_state; } //!< Return DSP engine current state
+
+	QString errorMessage() const; //!< Return the current error message
+	QString sinkDeviceDescription() const; //!< Return the sink device description
+
+private:
+	uint32_t m_uid; //!< unique ID
+
+	MessageQueue m_inputMessageQueue;  //<! Input message queue. Post here.
+
+	State m_state;
+
+	QString m_errorMessage;
+	QString m_deviceDescription;
+
+	DeviceSampleSink* m_deviceSampleSink;
+	int m_sampleSinkSequence;
+
+	using BasebandSampleSources = std::list<BasebandSampleSource *>;
+	BasebandSampleSources m_basebandSampleSources; //!< baseband sample sources within main thread (usually file input)
+
+	BasebandSampleSink *m_spectrumSink;
+    IncrementalVector<Sample> m_sourceSampleBuffer;
+    IncrementalVector<Sample> m_sourceZeroBuffer;
+
+	uint32_t m_sampleRate;
+	quint64 m_centerFrequency;
+    bool m_realElseComplex;
+    unsigned int m_sumIndex; //!< channel index when summing channels
+
+	void workSampleFifo(); //!< transfer samples from baseband sources to sink if in running state
+    void workSamples(SampleVector& data, unsigned int iBegin, unsigned int iEnd);
+
+	State gotoIdle();     //!< Go to the idle state
+	State gotoInit();     //!< Go to the acquisition init state from idle
+	State gotoRunning();  //!< Go to the running state from ready state
+	State gotoError(const QString& errorMsg); //!< Go to an error state
+	void setState(State state);
+
+	void handleSetSink(const DeviceSampleSink* sink); //!< Manage sink setting
+    bool handleMessage(const Message& cmd);
+
+private slots:
+	void handleData(); //!< Handle data when samples have to be written to the sample FIFO
+	void handleInputMessages(); //!< Handle input message queue
+
+signals:
+	void stateChanged();
+
+	void generationStopped();
+	void sampleSet();
+	void spectrumSinkRemoved();
+};
+
+
+
+
+
+#endif /* SDRBASE_DSP_DSPDEVICESINKENGINE_H_ */

android/app/src/main/cpp/dsp/dspdevicesourceengine.cpp

@@ -0,0 +1,659 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2014 John Greb <hexameron@spam.no>                              //
+// Copyright (C) 2015-2019, 2022-2023 Edouard Griffiths, F4EXB <f4exb06@gmail.com> //
+// Copyright (C) 2022 Jon Beniston, M7RCE <jon@beniston.com>                     //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include "dspdevicesourceengine.h"
+
+#include <dsp/basebandsamplesink.h>
+#include <dsp/devicesamplesource.h>
+#include <stdio.h>
+#include <QDebug>
+#include "dsp/dspcommands.h"
+#include "samplesinkfifo.h"
+
+DSPDeviceSourceEngine::DSPDeviceSourceEngine(uint uid, QObject* parent) :
+	QObject(parent),
+    m_uid(uid),
+	m_state(State::StNotStarted),
+	m_deviceSampleSource(nullptr),
+	m_sampleSourceSequence(0),
+	m_basebandSampleSinks(),
+	m_sampleRate(0),
+	m_centerFrequency(0),
+    m_realElseComplex(false),
+	m_dcOffsetCorrection(false),
+	m_iqImbalanceCorrection(false),
+	m_iOffset(0),
+	m_qOffset(0),
+	m_iRange(1 << 16),
+	m_qRange(1 << 16),
+	m_imbalance(65536)
+{
+    setState(State::StIdle);
+	connect(&m_inputMessageQueue, SIGNAL(messageEnqueued()), this, SLOT(handleInputMessages()), Qt::QueuedConnection);
+}
+
+DSPDeviceSourceEngine::~DSPDeviceSourceEngine()
+{
+	qDebug("DSPDeviceSourceEngine::~DSPDeviceSourceEngine");
+}
+
+void DSPDeviceSourceEngine::setState(State state)
+{
+    if (m_state != state)
+    {
+        m_state = state;
+        emit stateChanged();
+    }
+}
+
+bool DSPDeviceSourceEngine::initAcquisition() const
+{
+	qDebug("DSPDeviceSourceEngine::initAcquisition (dummy)");
+	return true;
+}
+
+bool DSPDeviceSourceEngine::startAcquisition()
+{
+	qDebug("DSPDeviceSourceEngine::startAcquisition");
+	auto *cmd = new DSPAcquisitionStart();
+    getInputMessageQueue()->push(cmd);
+    return true;
+}
+
+void DSPDeviceSourceEngine::stopAcquistion()
+{
+	qDebug("DSPDeviceSourceEngine::stopAcquistion");
+	auto *cmd = new DSPAcquisitionStop();
+    getInputMessageQueue()->push(cmd);
+
+	if (m_dcOffsetCorrection) {
+		qDebug("DC offset:%f,%f", m_iOffset, m_qOffset);
+	}
+}
+
+void DSPDeviceSourceEngine::setSource(DeviceSampleSource* source)
+{
+	qDebug("DSPDeviceSourceEngine::setSource");
+	auto *cmd = new DSPSetSource(source);
+    getInputMessageQueue()->push(cmd);
+}
+
+void DSPDeviceSourceEngine::setSourceSequence(int sequence)
+{
+	qDebug("DSPDeviceSourceEngine::setSourceSequence: seq: %d", sequence);
+	m_sampleSourceSequence = sequence;
+}
+
+void DSPDeviceSourceEngine::addSink(BasebandSampleSink* sink)
+{
+	qDebug() << "DSPDeviceSourceEngine::addSink: " << sink->getSinkName().toStdString().c_str();
+	auto *cmd = new DSPAddBasebandSampleSink(sink);
+    getInputMessageQueue()->push(cmd);
+}
+
+void DSPDeviceSourceEngine::removeSink(BasebandSampleSink* sink, bool deleting)
+{
+	qDebug() << "DSPDeviceSourceEngine::removeSink: " << sink->getSinkName().toStdString().c_str();
+	auto *cmd = new DSPRemoveBasebandSampleSink(sink, deleting);
+    getInputMessageQueue()->push(cmd);
+}
+
+void DSPDeviceSourceEngine::configureCorrections(bool dcOffsetCorrection, bool iqImbalanceCorrection)
+{
+	qDebug("DSPDeviceSourceEngine::configureCorrections");
+	auto *cmd = new DSPConfigureCorrection(dcOffsetCorrection, iqImbalanceCorrection);
+	getInputMessageQueue()->push(cmd);
+}
+
+QString DSPDeviceSourceEngine::errorMessage() const
+{
+	qDebug("DSPDeviceSourceEngine::errorMessage");
+    return m_errorMessage;
+}
+
+QString DSPDeviceSourceEngine::sourceDeviceDescription() const
+{
+	qDebug("DSPDeviceSourceEngine::sourceDeviceDescription");
+    return m_deviceDescription;
+}
+
+void DSPDeviceSourceEngine::iqCorrections(SampleVector::iterator begin, SampleVector::iterator end, bool imbalanceCorrection)
+{
+    for(SampleVector::iterator it = begin; it < end; it++)
+    {
+        m_iBeta(it->real());
+        m_qBeta(it->imag());
+
+        if (imbalanceCorrection)
+        {
+#if IMBALANCE_INT
+            // acquisition
+            int64_t xi = (it->m_real - (int32_t) m_iBeta) << 5;
+            int64_t xq = (it->m_imag - (int32_t) m_qBeta) << 5;
+
+            // phase imbalance
+            m_avgII((xi*xi)>>28); // <I", I">
+            m_avgIQ((xi*xq)>>28); // <I", Q">
+
+            if ((int64_t) m_avgII != 0)
+            {
+                int64_t phi = (((int64_t) m_avgIQ)<<28) / (int64_t) m_avgII;
+                m_avgPhi(phi);
+            }
+
+            int64_t corrPhi = (((int64_t) m_avgPhi) * xq) >> 28;  //(m_avgPhi.asDouble()/16777216.0) * ((double) xq);
+
+            int64_t yi = xi - corrPhi;
+            int64_t yq = xq;
+
+            // amplitude I/Q imbalance
+            m_avgII2((yi*yi)>>28); // <I, I>
+            m_avgQQ2((yq*yq)>>28); // <Q, Q>
+
+            if ((int64_t) m_avgQQ2 != 0)
+            {
+                int64_t a = (((int64_t) m_avgII2)<<28) / (int64_t) m_avgQQ2;
+                Fixed<int64_t, 28> fA(Fixed<int64_t, 28>::internal(), a);
+                Fixed<int64_t, 28> sqrtA = sqrt((Fixed<int64_t, 28>) fA);
+                m_avgAmp(sqrtA.as_internal());
+            }
+
+            int64_t zq = (((int64_t) m_avgAmp) * yq) >> 28;
+
+            it->m_real = yi >> 5;
+            it->m_imag = zq >> 5;
+
+#else
+            // DC correction and conversion
+            float xi = (float) (it->m_real - (int32_t) m_iBeta) / SDR_RX_SCALEF;
+            float xq = (float) (it->m_imag - (int32_t) m_qBeta) / SDR_RX_SCALEF;
+
+            // phase imbalance
+            m_avgII(xi*xi); // <I", I">
+            m_avgIQ(xi*xq); // <I", Q">
+
+
+            if (m_avgII.asDouble() != 0) {
+                m_avgPhi(m_avgIQ.asDouble()/m_avgII.asDouble());
+            }
+
+            const float& yi = xi; // the in phase remains the reference
+            float yq = xq - (float) m_avgPhi.asDouble()*xi;
+
+            // amplitude I/Q imbalance
+            m_avgII2(yi*yi); // <I, I>
+            m_avgQQ2(yq*yq); // <Q, Q>
+
+            if (m_avgQQ2.asDouble() != 0) {
+                m_avgAmp(sqrt(m_avgII2.asDouble() / m_avgQQ2.asDouble()));
+            }
+
+            // final correction
+            const float& zi = yi; // the in phase remains the reference
+            auto zq = (float) (m_avgAmp.asDouble() * yq);
+
+            // convert and store
+            it->m_real = (FixReal) (zi * SDR_RX_SCALEF);
+            it->m_imag = (FixReal) (zq * SDR_RX_SCALEF);
+#endif
+        }
+        else
+        {
+            // DC correction only
+            it->m_real -= (int32_t) m_iBeta;
+            it->m_imag -= (int32_t) m_qBeta;
+        }
+    }
+}
+
+void DSPDeviceSourceEngine::dcOffset(SampleVector::iterator begin, SampleVector::iterator end)
+{
+	// sum and correct in one pass
+	for(SampleVector::iterator it = begin; it < end; it++)
+	{
+        m_iBeta(it->real());
+        m_qBeta(it->imag());
+        it->m_real -= (int32_t) m_iBeta;
+        it->m_imag -= (int32_t) m_qBeta;
+	}
+}
+
+void DSPDeviceSourceEngine::imbalance(SampleVector::iterator begin, SampleVector::iterator end)
+{
+	int iMin = 0;
+	int iMax = 0;
+	int qMin = 0;
+	int qMax = 0;
+
+	// find value ranges for both I and Q
+	// both intervals should be same same size (for a perfect circle)
+	for (SampleVector::iterator it = begin; it < end; it++)
+	{
+		if (it != begin)
+		{
+			if (it->real() < iMin) {
+				iMin = it->real();
+			} else if (it->real() > iMax) {
+				iMax = it->real();
+			}
+
+			if (it->imag() < qMin) {
+				qMin = it->imag();
+			} else if (it->imag() > qMax) {
+				qMax = it->imag();
+			}
+		}
+		else
+		{
+			iMin = it->real();
+			iMax = it->real();
+			qMin = it->imag();
+			qMax = it->imag();
+		}
+	}
+
+	// sliding average (el cheapo again)
+	m_iRange = (m_iRange * 15 + (iMax - iMin)) >> 4;
+	m_qRange = (m_qRange * 15 + (qMax - qMin)) >> 4;
+
+	// calculate imbalance on 32 bit full scale
+	if(m_qRange != 0) {
+		m_imbalance = ((uint)m_iRange << (32-SDR_RX_SAMP_SZ)) / (uint)m_qRange;
+	}
+
+	// correct imbalance and convert back to sample size
+	for(SampleVector::iterator it = begin; it < end; it++) {
+		it->m_imag = (it->m_imag * m_imbalance) >> (32-SDR_RX_SAMP_SZ);
+	}
+}
+
+void DSPDeviceSourceEngine::work()
+{
+	SampleSinkFifo* sampleFifo = m_deviceSampleSource->getSampleFifo();
+	std::size_t samplesDone = 0;
+	bool positiveOnly = m_realElseComplex;
+
+	while ((sampleFifo->fill() > 0) && (m_inputMessageQueue.size() == 0) && (samplesDone < m_sampleRate))
+	{
+		SampleVector::iterator part1begin;
+		SampleVector::iterator part1end;
+		SampleVector::iterator part2begin;
+		SampleVector::iterator part2end;
+
+		std::size_t count = sampleFifo->readBegin(sampleFifo->fill(), &part1begin, &part1end, &part2begin, &part2end);
+
+		// first part of FIFO data
+		if (part1begin != part1end)
+		{
+			// correct stuff
+            if (m_dcOffsetCorrection) {
+                iqCorrections(part1begin, part1end, m_iqImbalanceCorrection);
+            }
+
+			// feed data to direct sinks
+			for (BasebandSampleSinks::const_iterator it = m_basebandSampleSinks.begin(); it != m_basebandSampleSinks.end(); ++it) {
+				(*it)->feed(part1begin, part1end, positiveOnly);
+			}
+
+		}
+
+		// second part of FIFO data (used when block wraps around)
+		if(part2begin != part2end)
+		{
+			// correct stuff
+            if (m_dcOffsetCorrection) {
+                iqCorrections(part2begin, part2end, m_iqImbalanceCorrection);
+            }
+
+			// feed data to direct sinks
+			for (BasebandSampleSinks::const_iterator it = m_basebandSampleSinks.begin(); it != m_basebandSampleSinks.end(); it++) {
+				(*it)->feed(part2begin, part2end, positiveOnly);
+			}
+
+		}
+
+		// adjust FIFO pointers
+		sampleFifo->readCommit((unsigned int) count);
+		samplesDone += count;
+	}
+}
+
+// notStarted -> idle -> init -> running -+
+//                ^                       |
+//                +-----------------------+
+
+DSPDeviceSourceEngine::State DSPDeviceSourceEngine::gotoIdle()
+{
+	qDebug("DSPDeviceSourceEngine::gotoIdle");
+
+	switch(m_state) {
+		case State::StNotStarted:
+			return State::StNotStarted;
+
+		case State::StIdle:
+		case State::StError:
+			return State::StIdle;
+
+		case State::StReady:
+		case State::StRunning:
+			break;
+	}
+
+	if (!m_deviceSampleSource) {
+		return State::StIdle;
+	}
+
+	// stop everything
+	m_deviceSampleSource->stop();
+
+	for(BasebandSampleSinks::const_iterator it = m_basebandSampleSinks.begin(); it != m_basebandSampleSinks.end(); it++)
+	{
+		(*it)->stop();
+	}
+
+	m_deviceDescription.clear();
+	m_sampleRate = 0;
+
+	return State::StIdle;
+}
+
+DSPDeviceSourceEngine::State DSPDeviceSourceEngine::gotoInit()
+{
+	switch(m_state) {
+		case State::StNotStarted:
+			return State::StNotStarted;
+
+		case State::StRunning:
+			return State::StRunning;
+
+		case State::StReady:
+			return State::StReady;
+
+		case State::StIdle:
+		case State::StError:
+			break;
+	}
+
+	if (!m_deviceSampleSource) {
+		return gotoError("No sample source configured");
+	}
+
+	// init: pass sample rate and center frequency to all sample rate and/or center frequency dependent sinks and wait for completion
+
+	m_iOffset = 0;
+	m_qOffset = 0;
+	m_iRange = 1 << 16;
+	m_qRange = 1 << 16;
+
+	m_deviceDescription = m_deviceSampleSource->getDeviceDescription();
+	m_centerFrequency = m_deviceSampleSource->getCenterFrequency();
+	m_sampleRate = m_deviceSampleSource->getSampleRate();
+
+	qDebug() << "DSPDeviceSourceEngine::gotoInit: "
+            << " m_deviceDescription: " << m_deviceDescription.toStdString().c_str()
+			<< " sampleRate: " << m_sampleRate
+			<< " centerFrequency: " << m_centerFrequency;
+
+
+	for (BasebandSampleSinks::const_iterator it = m_basebandSampleSinks.begin(); it != m_basebandSampleSinks.end(); ++it)
+	{
+		auto *notif = new DSPSignalNotification(m_sampleRate, m_centerFrequency);
+		qDebug() << "DSPDeviceSourceEngine::gotoInit: initializing " << (*it)->getSinkName().toStdString().c_str();
+		(*it)->pushMessage(notif);
+	}
+
+	// pass data to listeners
+	if (m_deviceSampleSource->getMessageQueueToGUI())
+	{
+        auto *rep = new DSPSignalNotification(m_sampleRate, m_centerFrequency);
+        m_deviceSampleSource->getMessageQueueToGUI()->push(rep);
+	}
+
+	return State::StReady;
+}
+
+DSPDeviceSourceEngine::State DSPDeviceSourceEngine::gotoRunning()
+{
+	qDebug("DSPDeviceSourceEngine::gotoRunning");
+
+	switch(m_state)
+    {
+		case State::StNotStarted:
+			return State::StNotStarted;
+
+		case State::StIdle:
+			return State::StIdle;
+
+		case State::StRunning:
+			return State::StRunning;
+
+		case State::StReady:
+		case State::StError:
+			break;
+	}
+
+	if (!m_deviceSampleSource) {
+		return gotoError("DSPDeviceSourceEngine::gotoRunning: No sample source configured");
+	}
+
+	qDebug() << "DSPDeviceSourceEngine::gotoRunning: " << m_deviceDescription.toStdString().c_str() << " started";
+
+	// Start everything
+
+	if (!m_deviceSampleSource->start()) {
+		return gotoError("Could not start sample source");
+	}
+
+	for(BasebandSampleSinks::const_iterator it = m_basebandSampleSinks.begin(); it != m_basebandSampleSinks.end(); it++)
+	{
+        qDebug() << "DSPDeviceSourceEngine::gotoRunning: starting " << (*it)->getSinkName().toStdString().c_str();
+		(*it)->start();
+	}
+
+	qDebug() << "DSPDeviceSourceEngine::gotoRunning:input message queue pending: " << m_inputMessageQueue.size();
+
+	return State::StRunning;
+}
+
+DSPDeviceSourceEngine::State DSPDeviceSourceEngine::gotoError(const QString& errorMessage)
+{
+	qDebug() << "DSPDeviceSourceEngine::gotoError: " << errorMessage;
+
+	m_errorMessage = errorMessage;
+	m_deviceDescription.clear();
+	setState(State::StError);
+	return State::StError;
+}
+
+void DSPDeviceSourceEngine::handleSetSource(DeviceSampleSource* source)
+{
+	gotoIdle();
+
+	m_deviceSampleSource = source;
+
+	if (m_deviceSampleSource)
+	{
+		qDebug("DSPDeviceSourceEngine::handleSetSource: set %s", qPrintable(source->getDeviceDescription()));
+		connect(m_deviceSampleSource->getSampleFifo(), SIGNAL(dataReady()), this, SLOT(handleData()), Qt::QueuedConnection);
+	}
+	else
+	{
+		qDebug("DSPDeviceSourceEngine::handleSetSource: set none");
+	}
+}
+
+void DSPDeviceSourceEngine::handleData()
+{
+	if(m_state == State::StRunning)
+	{
+		work();
+	}
+}
+
+bool DSPDeviceSourceEngine::handleMessage(const Message& message)
+{
+    if (DSPConfigureCorrection::match(message))
+    {
+        auto& conf = (const DSPConfigureCorrection&) message;
+        m_iqImbalanceCorrection = conf.getIQImbalanceCorrection();
+
+        if (m_dcOffsetCorrection != conf.getDCOffsetCorrection())
+        {
+            m_dcOffsetCorrection = conf.getDCOffsetCorrection();
+            m_iOffset = 0;
+            m_qOffset = 0;
+        }
+
+        if (m_iqImbalanceCorrection != conf.getIQImbalanceCorrection())
+        {
+            m_iqImbalanceCorrection = conf.getIQImbalanceCorrection();
+            m_iRange = 1 << 16;
+            m_qRange = 1 << 16;
+            m_imbalance = 65536;
+        }
+
+        m_avgAmp.reset();
+        m_avgII.reset();
+        m_avgII2.reset();
+        m_avgIQ.reset();
+        m_avgPhi.reset();
+        m_avgQQ2.reset();
+        m_iBeta.reset();
+        m_qBeta.reset();
+
+        return true;
+    }
+    else if (DSPSignalNotification::match(message))
+    {
+        auto& notif = (const DSPSignalNotification&) message;
+
+        // update DSP values
+
+        m_sampleRate = notif.getSampleRate();
+        m_centerFrequency = notif.getCenterFrequency();
+        m_realElseComplex = notif.getRealElseComplex();
+
+        qDebug() << "DSPDeviceSourceEngine::handleInputMessages: DSPSignalNotification:"
+            << " m_sampleRate: " << m_sampleRate
+            << " m_centerFrequency: " << m_centerFrequency;
+
+        // forward source changes to channel sinks with immediate execution (no queuing)
+
+        for(BasebandSampleSinks::const_iterator it = m_basebandSampleSinks.begin(); it != m_basebandSampleSinks.end(); it++)
+        {
+            auto* rep = new DSPSignalNotification(notif); // make a copy
+            qDebug() << "DSPDeviceSourceEngine::handleInputMessages: forward message to " << (*it)->getSinkName().toStdString().c_str();
+            (*it)->pushMessage(rep);
+        }
+
+        // forward changes to source GUI input queue
+        if (m_deviceSampleSource)
+        {
+            MessageQueue *guiMessageQueue = m_deviceSampleSource->getMessageQueueToGUI();
+            qDebug("DSPDeviceSourceEngine::handleInputMessages: DSPSignalNotification: guiMessageQueue: %p", guiMessageQueue);
+
+            if (guiMessageQueue)
+            {
+                auto* rep = new DSPSignalNotification(notif); // make a copy for the source GUI
+                guiMessageQueue->push(rep);
+            }
+        }
+
+        return true;
+    }
+    // was in handleSynchronousMessages:
+	else if (DSPAcquisitionInit::match(message))
+	{
+        return true; // discard
+	}
+	else if (DSPAcquisitionStart::match(message))
+	{
+		setState(gotoIdle());
+
+		if(m_state == State::StIdle) {
+			setState(gotoInit()); // State goes ready if init is performed
+		}
+
+		if(m_state == State::StReady) {
+			setState(gotoRunning());
+		}
+
+        return true;
+	}
+	else if (DSPAcquisitionStop::match(message))
+	{
+		setState(gotoIdle());
+		emit acquistionStopped();
+        return true;
+	}
+	else if (DSPSetSource::match(message))
+    {
+        auto cmd = (const DSPSetSource&) message;
+		handleSetSource(cmd.getSampleSource());
+		emit sampleSet();
+		return true;
+	}
+	else if (DSPAddBasebandSampleSink::match(message))
+	{
+        auto cmd = (const DSPAddBasebandSampleSink&) message;
+		BasebandSampleSink* sink = cmd.getSampleSink();
+		m_basebandSampleSinks.push_back(sink);
+        // initialize sample rate and center frequency in the sink:
+        auto *msg = new DSPSignalNotification(m_sampleRate, m_centerFrequency);
+        sink->pushMessage(msg);
+        // start the sink:
+        if(m_state == State::StRunning) {
+            sink->start();
+        }
+		return true;
+	}
+	else if (DSPRemoveBasebandSampleSink::match(message))
+	{
+        auto cmd = (const DSPRemoveBasebandSampleSink&) message;
+		BasebandSampleSink* sink = cmd.getSampleSink();
+		bool deleting = cmd.getDeleting();
+
+		// Don't dereference sink if deleting, as it may have already been deleted
+		if (!deleting && (m_state == State::StRunning)) {
+			sink->stop();
+		}
+
+		m_basebandSampleSinks.remove(sink);
+		emit sinkRemoved();
+		return true;
+	}
+
+    return false;
+}
+
+void DSPDeviceSourceEngine::handleInputMessages()
+{
+	Message* message;
+
+	while ((message = m_inputMessageQueue.pop()) != nullptr)
+	{
+		qDebug("DSPDeviceSourceEngine::handleInputMessages: message: %s", message->getIdentifier());
+
+        if (handleMessage(*message)) {
+            delete message;
+        }
+	}
+}

android/app/src/main/cpp/dsp/dspdevicesourceengine.h

@@ -0,0 +1,151 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2014 John Greb <hexameron@spam.no>                              //
+// Copyright (C) 2015-2019, 2023 Edouard Griffiths, F4EXB <f4exb06@gmail.com>    //
+// Copyright (C) 2022 Jon Beniston, M7RCE <jon@beniston.com>                     //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef INCLUDE_DSPDEVICEENGINE_H
+#define INCLUDE_DSPDEVICEENGINE_H
+
+#include <QObject>
+#include <QTimer>
+#include <QMutex>
+#include <QWaitCondition>
+#include "dsp/dsptypes.h"
+#include "util/messagequeue.h"
+#include "export.h"
+#include "util/movingaverage.h"
+
+class DeviceSampleSource;
+class BasebandSampleSink;
+
+class SDRBASE_API DSPDeviceSourceEngine : public QObject {
+	Q_OBJECT
+
+public:
+	enum class State {
+		StNotStarted,  //!< engine is before initialization
+		StIdle,        //!< engine is idle
+		StReady,       //!< engine is ready to run
+		StRunning,     //!< engine is running
+		StError        //!< engine is in error
+	};
+
+	DSPDeviceSourceEngine(uint uid, QObject* parent = nullptr);
+	~DSPDeviceSourceEngine() final;
+
+	uint getUID() const { return m_uid; }
+
+	MessageQueue* getInputMessageQueue() { return &m_inputMessageQueue; }
+
+	bool initAcquisition() const; //!< Initialize acquisition sequence
+	bool startAcquisition(); //!< Start acquisition sequence
+	void stopAcquistion();   //!< Stop acquisition sequence
+
+	void setSource(DeviceSampleSource* source); //!< Set the sample source type
+	void setSourceSequence(int sequence); //!< Set the sample source sequence in type
+	DeviceSampleSource *getSource() { return m_deviceSampleSource; }
+
+	void addSink(BasebandSampleSink* sink); //!< Add a sample sink
+	void removeSink(BasebandSampleSink* sink, bool deleting); //!< Remove a sample sink
+
+	void configureCorrections(bool dcOffsetCorrection, bool iqImbalanceCorrection); //!< Configure DSP corrections
+
+	State state() const { return m_state; } //!< Return DSP engine current state
+
+	QString errorMessage() const; //!< Return the current error message
+	QString sourceDeviceDescription() const; //!< Return the source device description
+
+private:
+	uint m_uid; //!< unique ID
+
+	MessageQueue m_inputMessageQueue;  //<! Input message queue. Post here.
+
+	State m_state;
+
+	QString m_errorMessage;
+	QString m_deviceDescription;
+
+	DeviceSampleSource* m_deviceSampleSource;
+	int m_sampleSourceSequence;
+
+	using BasebandSampleSinks = std::list<BasebandSampleSink *>;
+	BasebandSampleSinks m_basebandSampleSinks; //!< sample sinks within main thread (usually spectrum, file output)
+
+	uint m_sampleRate;
+	quint64 m_centerFrequency;
+    bool m_realElseComplex;
+
+	bool m_dcOffsetCorrection;
+	bool m_iqImbalanceCorrection;
+	double m_iOffset;
+	double m_qOffset;
+
+	MovingAverageUtil<int32_t, int64_t, 1024> m_iBeta;
+    MovingAverageUtil<int32_t, int64_t, 1024> m_qBeta;
+
+#if IMBALANCE_INT
+    // Fixed point DC + IQ corrections
+    MovingAverageUtil<int64_t, int64_t, 128> m_avgII;
+    MovingAverageUtil<int64_t, int64_t, 128> m_avgIQ;
+    MovingAverageUtil<int64_t, int64_t, 128> m_avgPhi;
+    MovingAverageUtil<int64_t, int64_t, 128> m_avgII2;
+    MovingAverageUtil<int64_t, int64_t, 128> m_avgQQ2;
+    MovingAverageUtil<int64_t, int64_t, 128> m_avgAmp;
+
+#else
+    // Floating point DC + IQ corrections
+    MovingAverageUtil<float, double, 128> m_avgII;
+    MovingAverageUtil<float, double, 128> m_avgIQ;
+    MovingAverageUtil<float, double, 128> m_avgII2;
+    MovingAverageUtil<float, double, 128> m_avgQQ2;
+    MovingAverageUtil<double, double, 128> m_avgPhi;
+    MovingAverageUtil<double, double, 128> m_avgAmp;
+#endif
+
+    qint32 m_iRange;
+	qint32 m_qRange;
+	qint32 m_imbalance;
+
+	void iqCorrections(SampleVector::iterator begin, SampleVector::iterator end, bool imbalanceCorrection);
+	void dcOffset(SampleVector::iterator begin, SampleVector::iterator end);
+	void imbalance(SampleVector::iterator begin, SampleVector::iterator end);
+	void work(); //!< transfer samples from source to sinks if in running state
+
+	State gotoIdle();     //!< Go to the idle state
+	State gotoInit();     //!< Go to the acquisition init state from idle
+	State gotoRunning();  //!< Go to the running state from ready state
+	State gotoError(const QString& errorMsg); //!< Go to an error state
+	void setState(State state);
+
+	void handleSetSource(DeviceSampleSource* source); //!< Manage source setting
+    bool handleMessage(const Message& cmd);
+
+private slots:
+	void handleData(); //!< Handle data when samples from source FIFO are ready to be processed
+	void handleInputMessages(); //!< Handle input message queue
+
+signals:
+	void stateChanged();
+
+	void acquistionStopped();
+	void sampleSet();
+	void sinkRemoved();
+};
+
+#endif // INCLUDE_DSPDEVICEENGINE_H

android/app/src/main/cpp/dsp/dspengine.cpp

@@ -0,0 +1,235 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2014 John Greb <hexameron@spam.no>                              //
+// Copyright (C) 2015-2020, 2022 Edouard Griffiths, F4EXB <f4exb06@gmail.com>    //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include <QGlobalStatic>
+#include <QThread>
+
+#include "dsp/dspengine.h"
+#include "dsp/dspdevicesourceengine.h"
+#include "dsp/dspdevicesinkengine.h"
+#include "dsp/dspdevicemimoengine.h"
+#include "dsp/fftfactory.h"
+
+DSPEngine::DSPEngine() :
+    m_deviceSourceEnginesUIDSequence(0),
+    m_deviceSinkEnginesUIDSequence(0),
+    m_deviceMIMOEnginesUIDSequence(0),
+    m_audioInputDeviceIndex(-1),    // default device
+    m_audioOutputDeviceIndex(-1),   // default device
+    m_fftFactory(nullptr)
+{
+	m_dvSerialSupport = false;
+    m_mimoSupport = false;
+    m_masterTimer.start(50);
+}
+
+DSPEngine::~DSPEngine()
+{
+    auto it = m_deviceSourceEngines.begin();
+
+    while (it != m_deviceSourceEngines.end())
+    {
+        delete *it;
+        ++it;
+    }
+
+    if (m_fftFactory) {
+        delete m_fftFactory;
+    }
+}
+
+Q_GLOBAL_STATIC(DSPEngine, dspEngine)
+DSPEngine *DSPEngine::instance()
+{
+	return dspEngine;
+}
+
+DSPDeviceSourceEngine *DSPEngine::addDeviceSourceEngine()
+{
+    auto *deviceSourceEngine = new DSPDeviceSourceEngine(m_deviceSourceEnginesUIDSequence);
+    auto *deviceThread = new QThread();
+    m_deviceSourceEnginesUIDSequence++;
+    m_deviceSourceEngines.push_back(deviceSourceEngine);
+    m_deviceEngineReferences.push_back(DeviceEngineReference{0, m_deviceSourceEngines.back(), nullptr, nullptr, deviceThread});
+    deviceSourceEngine->moveToThread(deviceThread);
+
+    QObject::connect(
+        deviceThread,
+        &QThread::finished,
+        deviceThread,
+        &QThread::deleteLater
+    );
+
+    deviceThread->start();
+
+    return deviceSourceEngine;
+}
+
+void DSPEngine::removeLastDeviceSourceEngine()
+{
+    if (!m_deviceSourceEngines.empty())
+    {
+        const DSPDeviceSourceEngine *lastDeviceEngine = m_deviceSourceEngines.back();
+        m_deviceSourceEngines.pop_back();
+
+        for (int i = 0; i < m_deviceEngineReferences.size(); i++)
+        {
+            if (m_deviceEngineReferences[i].m_deviceSourceEngine == lastDeviceEngine)
+            {
+                QThread* deviceThread = m_deviceEngineReferences[i].m_thread;
+                deviceThread->exit();
+                deviceThread->wait();
+                m_deviceEngineReferences.removeAt(i);
+                break;
+            }
+        }
+    }
+}
+
+DSPDeviceSinkEngine *DSPEngine::addDeviceSinkEngine()
+{
+    auto *deviceSinkEngine = new DSPDeviceSinkEngine(m_deviceSinkEnginesUIDSequence);
+    auto *deviceThread = new QThread();
+    m_deviceSinkEnginesUIDSequence++;
+    m_deviceSinkEngines.push_back(deviceSinkEngine);
+    m_deviceEngineReferences.push_back(DeviceEngineReference{1, nullptr, m_deviceSinkEngines.back(), nullptr, deviceThread});
+    deviceSinkEngine->moveToThread(deviceThread);
+
+    QObject::connect(
+        deviceThread,
+        &QThread::finished,
+        deviceThread,
+        &QThread::deleteLater
+    );
+
+    deviceThread->start();
+
+    return deviceSinkEngine;
+}
+
+void DSPEngine::removeLastDeviceSinkEngine()
+{
+    if (!m_deviceSinkEngines.empty())
+    {
+        const DSPDeviceSinkEngine *lastDeviceEngine = m_deviceSinkEngines.back();
+        m_deviceSinkEngines.pop_back();
+
+        for (int i = 0; i < m_deviceEngineReferences.size(); i++)
+        {
+            if (m_deviceEngineReferences[i].m_deviceSinkEngine == lastDeviceEngine)
+            {
+                QThread* deviceThread = m_deviceEngineReferences[i].m_thread;
+                deviceThread->exit();
+                deviceThread->wait();
+                m_deviceEngineReferences.removeAt(i);
+                break;
+            }
+        }
+    }
+}
+
+DSPDeviceMIMOEngine *DSPEngine::addDeviceMIMOEngine()
+{
+    auto *deviceMIMOEngine = new DSPDeviceMIMOEngine(m_deviceMIMOEnginesUIDSequence);
+    auto *deviceThread = new QThread();
+    m_deviceMIMOEnginesUIDSequence++;
+    m_deviceMIMOEngines.push_back(deviceMIMOEngine);
+    m_deviceEngineReferences.push_back(DeviceEngineReference{2, nullptr, nullptr, m_deviceMIMOEngines.back(), deviceThread});
+    deviceMIMOEngine->moveToThread(deviceThread);
+
+    QObject::connect(
+        deviceThread,
+        &QThread::finished,
+        deviceThread,
+        &QThread::deleteLater
+    );
+
+    deviceThread->start();
+
+    return deviceMIMOEngine;
+}
+
+void DSPEngine::removeLastDeviceMIMOEngine()
+{
+    if (!m_deviceMIMOEngines.empty())
+    {
+        const DSPDeviceMIMOEngine *lastDeviceEngine = m_deviceMIMOEngines.back();
+        m_deviceMIMOEngines.pop_back();
+
+        for (int i = 0; i < m_deviceEngineReferences.size(); i++)
+        {
+            if (m_deviceEngineReferences[i].m_deviceMIMOEngine == lastDeviceEngine)
+            {
+                QThread* deviceThread = m_deviceEngineReferences[i].m_thread;
+                deviceThread->exit();
+                deviceThread->wait();
+                m_deviceEngineReferences.removeAt(i);
+                break;
+            }
+        }
+    }
+}
+
+QThread *DSPEngine::getDeviceEngineThread(int deviceIndex)
+{
+    if (deviceIndex >= m_deviceEngineReferences.size()) {
+        return nullptr;
+    } else {
+        return m_deviceEngineReferences[deviceIndex].m_thread;
+    }
+}
+
+void DSPEngine::removeDeviceEngineAt(int deviceIndex)
+{
+    if (deviceIndex >= m_deviceEngineReferences.size()) {
+        return;
+    }
+
+    if (m_deviceEngineReferences[deviceIndex].m_deviceEngineType == 0) // source
+    {
+        DSPDeviceSourceEngine *deviceEngine = m_deviceEngineReferences[deviceIndex].m_deviceSourceEngine;
+        m_deviceEngineReferences[deviceIndex].m_thread->exit();
+        m_deviceSourceEngines.removeAll(deviceEngine);
+    }
+    else if (m_deviceEngineReferences[deviceIndex].m_deviceEngineType == 1) // sink
+    {
+        DSPDeviceSinkEngine *deviceEngine = m_deviceEngineReferences[deviceIndex].m_deviceSinkEngine;
+        m_deviceEngineReferences[deviceIndex].m_thread->exit();
+        m_deviceSinkEngines.removeAll(deviceEngine);
+    }
+    else if (m_deviceEngineReferences[deviceIndex].m_deviceEngineType == 2) // MIMO
+    {
+        DSPDeviceMIMOEngine *deviceEngine = m_deviceEngineReferences[deviceIndex].m_deviceMIMOEngine;
+        m_deviceEngineReferences[deviceIndex].m_thread->exit();
+        m_deviceMIMOEngines.removeAll(deviceEngine);
+    }
+
+    m_deviceEngineReferences.removeAt(deviceIndex);
+}
+
+void DSPEngine::createFFTFactory(const QString& fftWisdomFileName)
+{
+    m_fftFactory = new FFTFactory(fftWisdomFileName);
+}
+
+void DSPEngine::preAllocateFFTs()
+{
+    m_fftFactory->preallocate(7, 10, 1, 0); // pre-acllocate forward FFT only 1 per size from 128 to 1024
+}

android/app/src/main/cpp/dsp/dspengine.h

@@ -0,0 +1,103 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2014 John Greb <hexameron@spam.no>                              //
+// Copyright (C) 2015-2020, 2022 Edouard Griffiths, F4EXB <f4exb06@gmail.com>    //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef INCLUDE_DSPENGINE_H
+#define INCLUDE_DSPENGINE_H
+
+#include <QObject>
+#include <QTimer>
+#include <vector>
+
+#include "audio/audiodevicemanager.h"
+#include "export.h"
+
+class DSPDeviceSourceEngine;
+class DSPDeviceSinkEngine;
+class DSPDeviceMIMOEngine;
+class FFTFactory;
+class QThread;
+
+class SDRBASE_API DSPEngine : public QObject {
+	Q_OBJECT
+public:
+	DSPEngine();
+	~DSPEngine();
+
+	static DSPEngine *instance();
+
+	unsigned int getDefaultAudioSampleRate() const { return AudioDeviceManager::m_defaultAudioSampleRate; }
+
+	DSPDeviceSourceEngine *addDeviceSourceEngine();
+	void removeLastDeviceSourceEngine();
+
+	DSPDeviceSinkEngine *addDeviceSinkEngine();
+	void removeLastDeviceSinkEngine();
+
+	DSPDeviceMIMOEngine *addDeviceMIMOEngine();
+	void removeLastDeviceMIMOEngine();
+
+    QThread *getDeviceEngineThread(int deviceIndex);
+    void removeDeviceEngineAt(int deviceIndex);
+
+	AudioDeviceManager *getAudioDeviceManager() { return &m_audioDeviceManager; }
+
+    uint32_t getDeviceSourceEnginesNumber() const { return m_deviceSourceEngines.size(); }
+    DSPDeviceSourceEngine *getDeviceSourceEngineByIndex(unsigned int deviceIndex) { return m_deviceSourceEngines[deviceIndex]; }
+
+    uint32_t getDeviceSinkEnginesNumber() const { return m_deviceSinkEngines.size(); }
+    DSPDeviceSinkEngine *getDeviceSinkEngineByIndex(unsigned int deviceIndex) { return m_deviceSinkEngines[deviceIndex]; }
+
+    uint32_t getDeviceMIMOEnginesNumber() const { return m_deviceMIMOEngines.size(); }
+    DSPDeviceMIMOEngine *getDeviceMIMOEngineByIndex(unsigned int deviceIndex) { return m_deviceMIMOEngines[deviceIndex]; }
+
+    const QTimer& getMasterTimer() const { return m_masterTimer; }
+    void setMIMOSupport(bool mimoSupport) { m_mimoSupport = mimoSupport; }
+    bool getMIMOSupport() const { return m_mimoSupport; }
+    void createFFTFactory(const QString& fftWisdomFileName);
+    void preAllocateFFTs();
+    FFTFactory *getFFTFactory() { return m_fftFactory; }
+
+private:
+    struct DeviceEngineReference
+    {
+        int m_deviceEngineType; //!< 0: Rx, 1: Tx, 2: MIMO
+        DSPDeviceSourceEngine *m_deviceSourceEngine;
+        DSPDeviceSinkEngine *m_deviceSinkEngine;
+        DSPDeviceMIMOEngine *m_deviceMIMOEngine;
+        QThread *m_thread;
+    };
+
+	QList<DSPDeviceSourceEngine*> m_deviceSourceEngines;
+	unsigned int m_deviceSourceEnginesUIDSequence;
+	QList<DSPDeviceSinkEngine*> m_deviceSinkEngines;
+	unsigned int m_deviceSinkEnginesUIDSequence;
+	QList<DSPDeviceMIMOEngine*> m_deviceMIMOEngines;
+	unsigned int m_deviceMIMOEnginesUIDSequence;
+    QList<DeviceEngineReference> m_deviceEngineReferences;
+    AudioDeviceManager m_audioDeviceManager;
+    int m_audioInputDeviceIndex;
+    int m_audioOutputDeviceIndex;
+    QTimer m_masterTimer;
+	bool m_dvSerialSupport;
+    bool m_mimoSupport;
+    FFTFactory *m_fftFactory;
+};
+
+#endif // INCLUDE_DSPENGINE_H

android/app/src/main/cpp/dsp/dsptypes.h

@@ -0,0 +1,102 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2019, 2021 Edouard Griffiths, F4EXB <f4exb06@gmail.com>    //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef INCLUDE_DSPTYPES_H
+#define INCLUDE_DSPTYPES_H
+
+#include <complex>
+#include <vector>
+#include <stdint.h>
+
+#ifdef SDR_RX_SAMPLE_24BIT
+#define SDR_RX_SAMP_SZ 24 // internal fixed arithmetic sample size
+#define SDR_RX_SCALEF 8388608.0f
+#define SDR_RX_SCALED 8388608.0
+typedef qint32 FixReal;
+#else
+#define SDR_RX_SAMP_SZ 16 // internal fixed arithmetic sample size
+#define SDR_RX_SCALEF 32768.0f
+#define SDR_RX_SCALED 32768.0
+typedef int16_t FixReal;
+#endif
+
+#define SDR_TX_SAMP_SZ 16
+#define SDR_TX_SCALEF 32768.0f
+#define SDR_TX_SCALED 32768.0
+
+typedef float Real;
+typedef std::complex<Real> Complex;
+typedef std::vector<Complex> ComplexVector;
+
+#pragma pack(push, 1)
+struct Sample
+{
+	Sample() : m_real(0), m_imag(0) {}
+	Sample(FixReal real) : m_real(real), m_imag(0) {}
+	Sample(FixReal real, FixReal imag) : m_real(real), m_imag(imag) {}
+	Sample(const Sample& other) : m_real(other.m_real), m_imag(other.m_imag) {}
+	inline Sample& operator=(const Sample& other) { m_real = other.m_real; m_imag = other.m_imag; return *this; }
+
+	inline Sample& operator+=(const Sample& other) { m_real += other.m_real; m_imag += other.m_imag; return *this; }
+	inline Sample& operator-=(const Sample& other) { m_real -= other.m_real; m_imag -= other.m_imag; return *this; }
+	inline Sample& operator/=(const unsigned int& divisor) { m_real /= divisor; m_imag /= divisor; return *this; }
+
+	inline void setReal(FixReal v) { m_real = v; }
+	inline void setImag(FixReal v) { m_imag = v; }
+
+	inline FixReal real() const { return m_real; }
+	inline FixReal imag() const { return m_imag; }
+
+	FixReal m_real;
+	FixReal m_imag;
+};
+
+struct FSample
+{
+	FSample() : m_real(0), m_imag(0) {}
+	FSample(Real real) : m_real(real), m_imag(0) {}
+	FSample(Real real, Real imag) : m_real(real), m_imag(imag) {}
+	FSample(const FSample& other) : m_real(other.m_real), m_imag(other.m_imag) {}
+	inline FSample& operator=(const FSample& other) { m_real = other.m_real; m_imag = other.m_imag; return *this; }
+
+	inline FSample& operator+=(const FSample& other) { m_real += other.m_real; m_imag += other.m_imag; return *this; }
+	inline FSample& operator-=(const FSample& other) { m_real -= other.m_real; m_imag -= other.m_imag; return *this; }
+	inline FSample& operator/=(const Real& divisor) { m_real /= divisor; m_imag /= divisor; return *this; }
+
+	inline void setReal(Real v) { m_real = v; }
+	inline void setImag(Real v) { m_imag = v; }
+
+	inline Real real() const { return m_real; }
+	inline Real imag() const { return m_imag; }
+
+	Real m_real;
+	Real m_imag;
+};
+
+struct AudioSample {
+    int16_t l;
+    int16_t r;
+};
+#pragma pack(pop)
+
+typedef std::vector<Sample> SampleVector;
+typedef std::vector<FSample> FSampleVector;
+typedef std::vector<AudioSample> AudioVector;
+
+#endif // INCLUDE_DSPTYPES_H

android/app/src/main/cpp/dsp/fftcorr.cpp

@@ -0,0 +1,128 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2018-2020 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+//                                                                               //
+// FFT based cross correlation. Uses FFTW/Kiss engine.                           //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include <algorithm>
+
+#include "dsp/dspengine.h"
+#include "dsp/fftfactory.h"
+#include "dsp/fftengine.h"
+#include "fftcorr.h"
+
+void fftcorr::init_fft()
+{
+    FFTFactory *fftFactory = DSPEngine::instance()->getFFTFactory();
+    fftASequence = fftFactory->getEngine(flen, false, &fftA);
+    fftBSequence = fftFactory->getEngine(flen, false, &fftB);
+    fftInvASequence = fftFactory->getEngine(flen, true, &fftInvA);
+
+    m_window.create(FFTWindow::Hanning, flen);
+
+    dataA    = new cmplx[flen];
+    dataB    = new cmplx[flen];
+    dataBj   = new cmplx[flen];
+    dataP    = new cmplx[flen];
+
+    std::fill(dataA, dataA+flen, 0);
+    std::fill(dataB, dataB+flen, 0);
+
+    inptrA = 0;
+    inptrB = 0;
+    outptr = 0;
+}
+
+fftcorr::fftcorr(int len) :
+    flen(len),
+    flen2(len>>1),
+    fftA(nullptr),
+    fftB(nullptr),
+    fftInvA(nullptr),
+    fftASequence(0),
+    fftBSequence(0),
+    fftInvASequence(0)
+{
+    init_fft();
+}
+
+fftcorr::~fftcorr()
+{
+    FFTFactory *fftFactory = DSPEngine::instance()->getFFTFactory();
+    fftFactory->releaseEngine(flen, false, fftASequence);
+    fftFactory->releaseEngine(flen, false, fftBSequence);
+    fftFactory->releaseEngine(flen, true, fftInvASequence);
+    delete[] dataA;
+    delete[] dataB;
+    delete[] dataBj;
+    delete[] dataP;
+}
+
+int fftcorr::run(const cmplx& inA, const cmplx* inB, cmplx **out)
+{
+    dataA[inptrA++] = inA;
+
+    if (inB) {
+        dataB[inptrB++] = *inB;
+    }
+
+    if (inptrA < flen2) {
+        return 0;
+    }
+
+    m_window.apply(dataA, fftA->in());
+    fftA->transform();
+
+    if (inB)
+    {
+        m_window.apply(dataB, fftB->in());
+        fftB->transform();
+    }
+
+    if (inB) {
+        std::transform(fftB->out(), fftB->out()+flen, dataBj, [](const cmplx& c) -> cmplx { return std::conj(c); });
+    } else {
+        std::transform(fftA->out(), fftA->out()+flen, dataBj, [](const cmplx& c) -> cmplx { return std::conj(c); });
+    }
+
+    std::transform(fftA->out(), fftA->out()+flen, dataBj, fftInvA->in(), [](const cmplx& a, const cmplx& b) -> cmplx { return a*b; });
+
+    fftInvA->transform();
+    std::copy(fftInvA->out(), fftInvA->out()+flen, dataP);
+
+    std::fill(dataA, dataA+flen, 0);
+    inptrA = 0;
+
+    if (inB)
+    {
+        std::fill(dataB, dataB+flen, 0);
+        inptrB = 0;
+    }
+
+    *out = dataP;
+    return flen2;
+}
+
+const fftcorr::cmplx& fftcorr::run(const cmplx& inA, const cmplx* inB)
+{
+    cmplx *dummy;
+
+    if (run(inA, inB, &dummy)) {
+        outptr = 0;
+    }
+
+    return dataP[outptr++];
+}

android/app/src/main/cpp/dsp/fftcorr.h

@@ -0,0 +1,60 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2018-2020 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+//                                                                               //
+// FFT based cross correlation. Uses FFTW/Kiss engine.                           //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef SDRBASE_DSP_FFTCORR2_H_
+#define SDRBASE_DSP_FFTCORR2_H_
+
+#include <complex>
+
+#include "dsp/fftwindow.h"
+#include "export.h"
+
+class FFTEngine;
+
+class SDRBASE_API fftcorr {
+public:
+    typedef std::complex<float> cmplx;
+    fftcorr(int len);
+    ~fftcorr();
+
+    int run(const cmplx& inA, const cmplx* inB, cmplx **out); //!< if inB = 0 then run auto-correlation
+    const cmplx& run(const cmplx& inA, const cmplx* inB);
+
+private:
+    void init_fft();
+    int flen;  //!< FFT length
+    int flen2; //!< half FFT length
+    FFTEngine *fftA;
+    FFTEngine *fftB;
+    FFTEngine *fftInvA;
+    unsigned int fftASequence;
+    unsigned int fftBSequence;
+    unsigned int fftInvASequence;
+    FFTWindow m_window;
+    cmplx *dataA;  // from A input
+    cmplx *dataB;  // from B input
+    cmplx *dataBj; // conjugate of B
+    cmplx *dataP;  // product of A with conjugate of B
+    int inptrA;
+    int inptrB;
+    int outptr;
+};
+
+
+#endif /* SDRBASE_DSP_FFTCORR2_H_ */

android/app/src/main/cpp/dsp/fftengine.cpp

@@ -0,0 +1,118 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2017-2018, 2020 Edouard Griffiths, F4EXB <f4exb06@gmail.com>    //
+// Copyright (C) 2023 Jon Beniston, M7RCE <jon@beniston.com>                     //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include <QDebug>
+
+#include "dsp/fftengine.h"
+#ifdef USE_KISSFFT
+#include "dsp/kissengine.h"
+#endif
+#ifdef USE_FFTW
+#include "dsp/fftwengine.h"
+#endif
+#ifdef VKFFT_BACKEND
+#if VKFFT_BACKEND==0
+#include "dsp/vulkanvkfftengine.h"
+#elif VKFFT_BACKEND==1
+#include "dsp/cudavkfftengine.h"
+#endif
+#endif
+
+QStringList FFTEngine::m_allAvailableEngines;
+
+FFTEngine::~FFTEngine()
+{
+}
+
+FFTEngine* FFTEngine::create(const QString& fftWisdomFileName, const QString& preferredEngine)
+{
+    QStringList allNames = getAllNames();
+    QString engine;
+
+    if (allNames.size() == 0)
+    {
+        // No engines available
+	   qCritical("FFTEngine::create: no engine built");
+	   return nullptr;
+    }
+    else if (!preferredEngine.isEmpty() && allNames.contains(preferredEngine))
+    {
+        // Use the preferred engine
+        engine = preferredEngine;
+    }
+    else
+    {
+        // Use first available
+        engine = allNames[0];
+    }
+
+	qDebug("FFTEngine::create: using %s engine", qPrintable(engine));
+
+#ifdef VKFFT_BACKEND
+#if VKFFT_BACKEND==0
+    if (engine == VulkanvkFFTEngine::m_name) {
+	    return new VulkanvkFFTEngine();
+    }
+#endif
+#if VKFFT_BACKEND==1
+    if (engine == CUDAvkFFTEngine::m_name) {
+	    return new CUDAvkFFTEngine();
+    }
+#endif
+#endif
+#ifdef USE_FFTW
+	if (engine == FFTWEngine::m_name) {
+	    return new FFTWEngine(fftWisdomFileName);
+    }
+#endif
+#ifdef USE_KISSFFT
+    if (engine == KissEngine::m_name) {
+	    return new KissEngine;
+    }
+#endif
+    return nullptr;
+}
+
+QStringList FFTEngine::getAllNames()
+{
+    if (m_allAvailableEngines.size() == 0)
+    {
+#ifdef USE_FFTW
+        m_allAvailableEngines.append(FFTWEngine::m_name);
+#endif
+#ifdef USE_KISSFFT
+        m_allAvailableEngines.append(KissEngine::m_name);
+#endif
+#ifdef VKFFT_BACKEND
+#if VKFFT_BACKEND==0
+        VulkanvkFFTEngine vulkanvkFFT;
+        if (vulkanvkFFT.isAvailable()) {
+            m_allAvailableEngines.append(vulkanvkFFT.getName());
+        }
+#elif VKFFT_BACKEND==1
+        CUDAvkFFTEngine cudavkFFT;
+        if (cudavkFFT.isAvailable()) {
+            m_allAvailableEngines.append(cudavkFFT.getName());
+        }
+#endif
+#endif
+    }
+    return m_allAvailableEngines;
+}

android/app/src/main/cpp/dsp/fftengine.h

@@ -0,0 +1,53 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2016, 2018, 2020 Edouard Griffiths, F4EXB <f4exb06@gmail.com> //
+// Copyright (C) 2023 Jon Beniston, M7RCE <jon@beniston.com>                     //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef INCLUDE_FFTENGINE_H
+#define INCLUDE_FFTENGINE_H
+
+#include <QString>
+
+#include "dsp/dsptypes.h"
+#include "export.h"
+
+class SDRBASE_API FFTEngine {
+public:
+	virtual ~FFTEngine();
+
+	virtual void configure(int n, bool inverse) = 0;
+	virtual void transform() = 0;
+
+	virtual Complex* in() = 0;
+	virtual Complex* out() = 0;
+
+    virtual void setReuse(bool reuse) = 0;
+
+	static FFTEngine* create(const QString& fftWisdomFileName, const QString& preferredEngine="");
+
+    virtual bool isAvailable() { return true; } // Is this FFT engine available to be used?
+    virtual QString getName() const = 0;        // Get the name of this FFT engine
+
+    static QStringList getAllNames();           // Get names of all available FFT engines
+
+private:
+    static QStringList m_allAvailableEngines;
+
+};
+
+#endif // INCLUDE_FFTENGINE_H

android/app/src/main/cpp/dsp/fftfactory.cpp

@@ -0,0 +1,153 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2020 Edouard Griffiths, F4EXB <f4exb06@gmail.com>               //
+// Copyright (C) 2022 Jiří Pinkava <jiri.pinkava@rossum.ai>                      //
+// Copyright (C) 2023 Jon Beniston, M7RCE <jon@beniston.com>                     //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include <QMutexLocker>
+#include "fftfactory.h"
+#include "maincore.h"
+
+FFTFactory::FFTFactory(const QString& fftwWisdomFileName) :
+    m_fftwWisdomFileName(fftwWisdomFileName)
+{}
+
+FFTFactory::~FFTFactory()
+{
+    qDebug("FFTFactory::~FFTFactory: deleting FFTs");
+
+    for (auto mIt = m_fftEngineBySize.begin(); mIt != m_fftEngineBySize.end(); ++mIt)
+    {
+        for (auto eIt = mIt->second.begin(); eIt != mIt->second.end(); ++eIt) {
+            delete eIt->m_engine;
+        }
+    }
+}
+
+void FFTFactory::preallocate(
+    unsigned int minLog2Size,
+    unsigned int maxLog2Size,
+    unsigned int numberFFT,
+    unsigned int numberInvFFT)
+{
+    if (minLog2Size <= maxLog2Size)
+    {
+        for (unsigned int log2Size = minLog2Size; log2Size <= maxLog2Size; log2Size++)
+        {
+            unsigned int fftSize = 1<<log2Size;
+            m_fftEngineBySize.insert(std::pair<unsigned int, std::vector<AllocatedEngine>>(fftSize, std::vector<AllocatedEngine>()));
+            m_invFFTEngineBySize.insert(std::pair<unsigned int, std::vector<AllocatedEngine>>(fftSize, std::vector<AllocatedEngine>()));
+            std::vector<AllocatedEngine>& fftEngines = m_fftEngineBySize[fftSize];
+            std::vector<AllocatedEngine>& invFFTEngines = m_invFFTEngineBySize[fftSize];
+
+            for (unsigned int i = 0; i < numberFFT; i++)
+            {
+                fftEngines.push_back(AllocatedEngine());
+                fftEngines.back().m_engine = FFTEngine::create(m_fftwWisdomFileName);
+                fftEngines.back().m_engine->setReuse(false);
+                fftEngines.back().m_engine->configure(fftSize, false);
+            }
+
+            for (unsigned int i = 0; i < numberInvFFT; i++)
+            {
+                invFFTEngines.push_back(AllocatedEngine());
+                invFFTEngines.back().m_engine = FFTEngine::create(m_fftwWisdomFileName);
+                fftEngines.back().m_engine->setReuse(false);
+                invFFTEngines.back().m_engine->configure(fftSize, true);
+            }
+        }
+    }
+}
+
+unsigned int FFTFactory::getEngine(unsigned int fftSize, bool inverse, FFTEngine **engine, const QString& preferredEngine)
+{
+    QMutexLocker mutexLocker(&m_mutex);
+    std::map<unsigned int, std::vector<AllocatedEngine>>& enginesBySize = inverse ?
+        m_invFFTEngineBySize : m_fftEngineBySize;
+
+    // If no preferred engine requested, use user preference
+    QString requestedEngine = preferredEngine;
+    if (requestedEngine.isEmpty())
+    {
+        const MainSettings& mainSettings = MainCore::instance()->getSettings();
+        requestedEngine = mainSettings.getFFTEngine();
+    }
+
+    if (enginesBySize.find(fftSize) == enginesBySize.end())
+    {
+        qDebug("FFTFactory::getEngine: new FFT %s size: %u", (inverse ? "inv" : "fwd"), fftSize);
+        enginesBySize.insert(std::pair<unsigned int, std::vector<AllocatedEngine>>(fftSize, std::vector<AllocatedEngine>()));
+        std::vector<AllocatedEngine>& engines = enginesBySize[fftSize];
+        engines.push_back(AllocatedEngine());
+        engines.back().m_inUse = true;
+        engines.back().m_engine = FFTEngine::create(m_fftwWisdomFileName, requestedEngine);
+        engines.back().m_engine->setReuse(false);
+        engines.back().m_engine->configure(fftSize, inverse);
+        *engine = engines.back().m_engine;
+        return 0;
+    }
+    else
+    {
+        unsigned int i = 0;
+
+        // Look for existing engine of requested size and type not currently in use
+        for (; i < enginesBySize[fftSize].size(); i++)
+        {
+            if (!enginesBySize[fftSize][i].m_inUse && (enginesBySize[fftSize][i].m_engine->getName() == requestedEngine)) {
+                break;
+            }
+        }
+
+        if (i < enginesBySize[fftSize].size())
+        {
+            qDebug("FFTFactory::getEngine: reuse engine: %u FFT %s size: %u", i, (inverse ? "inv" : "fwd"), fftSize);
+            enginesBySize[fftSize][i].m_inUse = true;
+            *engine = enginesBySize[fftSize][i].m_engine;
+            return i;
+        }
+        else
+        {
+            std::vector<AllocatedEngine>& engines = enginesBySize[fftSize];
+            qDebug("FFTFactory::getEngine: create engine: %lu FFT %s size: %u", engines.size(), (inverse ? "inv" : "fwd"), fftSize);
+            engines.push_back(AllocatedEngine());
+            engines.back().m_inUse = true;
+            engines.back().m_engine = FFTEngine::create(m_fftwWisdomFileName, requestedEngine);
+            engines.back().m_engine->setReuse(false);
+            engines.back().m_engine->configure(fftSize, inverse);
+            *engine = engines.back().m_engine;
+            return engines.size() - 1;
+        }
+    }
+}
+
+void FFTFactory::releaseEngine(unsigned int fftSize, bool inverse, unsigned int engineSequence)
+{
+    QMutexLocker mutexLocker(&m_mutex);
+    std::map<unsigned int, std::vector<AllocatedEngine>>& enginesBySize = inverse ?
+        m_invFFTEngineBySize : m_fftEngineBySize;
+
+    if (enginesBySize.find(fftSize) != enginesBySize.end())
+    {
+        std::vector<AllocatedEngine>& engines = enginesBySize[fftSize];
+
+        if (engineSequence < engines.size())
+        {
+            qDebug("FFTFactory::releaseEngine: engineSequence: %u FFT %s size: %u",
+                engineSequence, (inverse ? "inv" : "fwd"), fftSize);
+            engines[engineSequence].m_inUse = false;
+        }
+    }
+}

android/app/src/main/cpp/dsp/fftfactory.h

@@ -0,0 +1,61 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2016-2020 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+// Copyright (C) 2022 Jiří Pinkava <jiri.pinkava@rossum.ai>                      //
+// Copyright (C) 2023 Jon Beniston, M7RCE <jon@beniston.com>                     //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef _SDRBASE_FFTWFACTORY_H
+#define _SDRBASE_FFTWFACTORY_H
+
+#include <map>
+#include <vector>
+
+#include <QRecursiveMutex>
+#include <QString>
+
+#include "export.h"
+#include "fftengine.h"
+
+class SDRBASE_API FFTFactory {
+public:
+	FFTFactory(const QString& fftwWisdomFileName);
+	~FFTFactory();
+
+    void preallocate(unsigned int minLog2Size, unsigned int maxLog2Size, unsigned int numberFFT, unsigned int numberInvFFT);
+    unsigned int getEngine(unsigned int fftSize, bool inverse, FFTEngine **engine, const QString& preferredEngine=""); //!< returns an engine sequence
+    void releaseEngine(unsigned int fftSize, bool inverse, unsigned int engineSequence);
+
+private:
+    struct AllocatedEngine
+    {
+        FFTEngine *m_engine;
+        bool m_inUse;
+
+        AllocatedEngine() :
+            m_engine(nullptr),
+            m_inUse(false)
+        {}
+    };
+
+    QString m_fftwWisdomFileName;
+    std::map<unsigned int, std::vector<AllocatedEngine>> m_fftEngineBySize;
+    std::map<unsigned int, std::vector<AllocatedEngine>> m_invFFTEngineBySize;
+    QRecursiveMutex m_mutex;
+};
+
+#endif // _SDRBASE_FFTWFACTORY_H

android/app/src/main/cpp/dsp/fftfilt.cpp

@@ -0,0 +1,690 @@
+///////////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany     //
+// written by Christian Daniel                                                       //
+// Copyright (C) 2014-2015 John Greb <hexameron@spam.no>                             //
+// Copyright (C) 2015, 2017-2018, 2020, 2022-2023 Edouard Griffiths, F4EXB <f4exb06@gmail.com> //
+// Copyright (C) 2020 Kacper Michajłow <kasper93@gmail.com>                          //
+//                                                                                   //
+// This program is free software; you can redistribute it and/or modify              //
+// it under the terms of the GNU General Public License as published by              //
+// the Free Software Foundation as version 3 of the License, or                      //
+// (at your option) any later version.                                               //
+//                                                                                   //
+// This program is distributed in the hope that it will be useful,                   //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                    //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                      //
+// GNU General Public License V3 for more details.                                   //
+//                                                                                   //
+// You should have received a copy of the GNU General Public License                 //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.              //
+///////////////////////////////////////////////////////////////////////////////////////
+// ----------------------------------------------------------------------------
+//	fftfilt.cxx  --  Fast convolution Overlap-Add filter
+//
+// Filter implemented using overlap-add FFT convolution method
+// h(t) characterized by Windowed-Sinc impulse response
+//
+// Reference:
+//	 "The Scientist and Engineer's Guide to Digital Signal Processing"
+//	 by Dr. Steven W. Smith, http://www.dspguide.com
+//	 Chapters 16, 18 and 21
+//
+// Copyright (C) 2006-2008 Dave Freese, W1HKJ
+//
+// This file is part of fldigi.
+//
+// Fldigi is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Fldigi is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with fldigi.  If not, see <http://www.gnu.org/licenses/>.
+//
+// Augmented with more filter types
+// Copyright (C) 2015-2022 Edouard Griffiths, F4EXB
+// ----------------------------------------------------------------------------
+
+#include <memory.h>
+#include <algorithm>
+#include <iostream>
+#include <fstream>
+#include <cstdlib>
+#include <cmath>
+#include <typeinfo>
+#include <array>
+
+#include <stdio.h>
+#include <sys/types.h>
+
+#include <dsp/misc.h>
+#include <dsp/fftfilt.h>
+
+//------------------------------------------------------------------------------
+// initialize the filter
+// create forward and reverse FFTs
+//------------------------------------------------------------------------------
+
+// Only need a single instance of g_fft, used for both forward and reverse
+void fftfilt::init_filter()
+{
+	flen2	= flen >> 1;
+	fft	= new g_fft<float>(flen);
+
+	filter		= new cmplx[flen];
+    filterOpp   = new cmplx[flen];
+	data		= new cmplx[flen];
+	output		= new cmplx[flen2];
+	ovlbuf		= new cmplx[flen2];
+
+	std::fill(filter, filter + flen, cmplx{0, 0});
+    std::fill(filterOpp, filterOpp + flen, cmplx{0, 0});
+	std::fill(data, data + flen , cmplx{0, 0});
+	std::fill(output, output + flen2, cmplx{0, 0});
+	std::fill(ovlbuf, ovlbuf + flen2, cmplx{0, 0});
+
+	inptr = 0;
+}
+
+//------------------------------------------------------------------------------
+// fft filter
+// f1 < f2 ==> band pass filter
+// f1 > f2 ==> band reject filter
+// f1 == 0 ==> low pass filter
+// f2 == 0 ==> high pass filter
+//------------------------------------------------------------------------------
+fftfilt::fftfilt(int len) :
+    m_noiseReduction(len)
+{
+	flen	= len;
+	pass    = 0;
+	window  = 0;
+    m_dnr   = false;
+	init_filter();
+}
+
+fftfilt::fftfilt(float f1, float f2, int len) :
+    m_noiseReduction(len)
+{
+	flen	= len;
+	pass    = 0;
+	window  = 0;
+    m_dnr   = false;
+	init_filter();
+	create_filter(f1, f2);
+}
+
+fftfilt::fftfilt(float f2, int len) :
+    m_noiseReduction(len)
+{
+	flen	= len;
+    pass    = 0;
+    window  = 0;
+    m_dnr   = false;
+	init_filter();
+	create_dsb_filter(f2);
+}
+
+fftfilt::~fftfilt()
+{
+	if (fft) delete fft;
+
+	if (filter) delete [] filter;
+    if (filterOpp) delete [] filterOpp;
+	if (data) delete [] data;
+	if (output) delete [] output;
+	if (ovlbuf) delete [] ovlbuf;
+}
+
+void fftfilt::create_filter(float f1, float f2, FFTWindow::Function wf)
+{
+	// initialize the filter to zero
+	std::fill(filter, filter + flen, cmplx{0, 0});
+
+	// create the filter shape coefficients by fft
+	bool b_lowpass, b_highpass;
+	b_lowpass = (f2 != 0);
+	b_highpass = (f1 != 0);
+
+	for (int i = 0; i < flen2; i++) {
+		filter[i] = 0;
+	// lowpass @ f2
+		if (b_lowpass)
+			filter[i] += fsinc(f2, i, flen2);
+	// highighpass @ f1
+		if (b_highpass)
+			filter[i] -= fsinc(f1, i, flen2);
+	}
+	// highpass is delta[flen2/2] - h(t)
+	if (b_highpass && f2 < f1)
+		filter[flen2 / 2] += 1;
+
+    FFTWindow fwin;
+    fwin.create(wf, flen2);
+    fwin.apply(filter);
+
+	// for (int i = 0; i < flen2; i++)
+	// 	filter[i] *= _blackman(i, flen2);
+
+	fft->ComplexFFT(filter); // filter was expressed in the time domain (impulse response)
+
+	// normalize the output filter for unity gain
+	float scale = 0, mag;
+	for (int i = 0; i < flen2; i++) {
+		mag = abs(filter[i]);
+		if (mag > scale) scale = mag;
+	}
+	if (scale != 0) {
+		for (int i = 0; i < flen; i++)
+			filter[i] /= scale;
+	}
+}
+
+void fftfilt::create_filter(const std::vector<std::pair<float, float>>& limits, bool pass, FFTWindow::Function wf)
+{
+    std::vector<int> canvasNeg(flen2, pass ? 0 : 1); // initialize the negative frequencies filter canvas
+    std::vector<int> canvasPos(flen2, pass ? 0 : 1); // initialize the positive frequencies filter canvas
+	std::fill(filter, filter + flen, cmplx{0, 0}); // initialize the positive filter to zero
+    std::fill(filterOpp, filterOpp + flen, cmplx{0, 0}); // initialize the negative filter to zero
+
+    for (const auto& fs : limits)
+    {
+        const float& f1 = fs.first + 0.5;
+        const float& w = fs.second > 0.0 ? fs.second : 0.0;
+        const float& f2 = f1 + w;
+
+        for (int i = 0; i < flen; i++)
+        {
+            if (pass) // pass
+            {
+                if ((i >= f1*flen) && (i <= f2*flen))
+                {
+                    if (i < flen2) {
+                        canvasNeg[flen2-1-i] = 1;
+                    } else {
+                        canvasPos[i-flen2] = 1;
+                    }
+                }
+            }
+            else // reject
+            {
+                if ((i >= f1*flen) && (i <= f2*flen))
+                {
+                    if (i < flen2) {
+                        canvasNeg[flen2-1-i] = 0;
+                    } else {
+                        canvasPos[i-flen2] = 0;
+                    }
+                }
+            }
+        }
+    }
+
+    std::vector<std::pair<int,int>> indexesNegList;
+    std::vector<std::pair<int,int>> indexesPosList;
+    int cn = 0;
+    int cp = 0;
+    int defaultSecond = pass ? 0 : flen2 - 1;
+
+    for (int i = 0; i < flen2; i++)
+    {
+        if ((canvasNeg[i] == 1) && (cn == 0)) {
+            indexesNegList.push_back(std::pair<int,int>{i, defaultSecond});
+        }
+
+        if ((canvasNeg[i] == 0) && (cn == 1)) {
+            indexesNegList.back().second = i;
+        }
+
+        if ((canvasPos[i] == 1) && (cp == 0)) {
+            indexesPosList.push_back(std::pair<int,int>{i, defaultSecond});
+        }
+
+        if ((canvasPos[i] == 0) && (cp == 1)) {
+            indexesPosList.back().second = i;
+        }
+
+        cn = canvasNeg[i];
+        cp = canvasPos[i];
+    }
+
+    for (const auto& indexes : indexesPosList)
+    {
+        const float f1 = indexes.first / (float) flen;
+        const float f2 = indexes.second / (float) flen;
+
+        for (int i = 0; i < flen2; i++)
+        {
+            if (f2 != 0) {
+                filter[i] += fsinc(f2, i, flen2);
+            }
+            if (f1 != 0) {
+                filter[i] -= fsinc(f1, i, flen2);
+            }
+        }
+
+        if (f2 == 0 && f1 != 0) {
+            filter[flen2 / 2] += 1;
+        }
+    }
+
+    for (const auto& indexes : indexesNegList)
+    {
+        const float f1 = indexes.first / (float) flen;
+        const float f2 = indexes.second / (float) flen;
+
+        for (int i = 0; i < flen2; i++)
+        {
+            if (f2 != 0) {
+                filterOpp[i] += fsinc(f2, i, flen2);
+            }
+            if (f1 != 0) {
+                filterOpp[i] -= fsinc(f1, i, flen2);
+            }
+        }
+
+        if (f2 == 0 && f1 != 0) {
+            filterOpp[flen2 / 2] += 1;
+        }
+    }
+
+    FFTWindow fwin;
+    fwin.create(wf, flen2);
+    fwin.apply(filter);
+    fwin.apply(filterOpp);
+
+	fft->ComplexFFT(filter); // filter was expressed in the time domain (impulse response)
+    fft->ComplexFFT(filterOpp); // filter was expressed in the time domain (impulse response)
+
+    float scalen = 0, scalep = 0, magn, magp; // normalize the output filter for unity gain
+
+	for (int i = 0; i < flen2; i++)
+    {
+		magp = abs(filter[i]);
+
+        if (magp > scalep) {
+            scalep = magp;
+        }
+
+        magn = abs(filterOpp[i]);
+
+        if (magn > scalen) {
+            scalen = magn;
+        }
+	}
+
+    if (scalep != 0)
+    {
+        std::for_each(
+            filter,
+            filter + flen,
+            [scalep](fftfilt::cmplx& s) { s /= scalep; }
+        );
+	}
+
+    if (scalen != 0)
+    {
+        std::for_each(
+            filterOpp,
+            filterOpp + flen,
+            [scalen](fftfilt::cmplx& s) { s /= scalen; }
+        );
+	}
+}
+
+// Double the size of FFT used for equivalent SSB filter or assume FFT is half the size of the one used for SSB
+void fftfilt::create_dsb_filter(float f2, FFTWindow::Function wf)
+{
+	// initialize the filter to zero
+	std::fill(filter, filter + flen, cmplx{0, 0});
+
+	for (int i = 0; i < flen2; i++) {
+		filter[i] = fsinc(f2, i, flen2);
+		// filter[i] *= _blackman(i, flen2);
+	}
+
+    FFTWindow fwin;
+    fwin.create(wf, flen2);
+    fwin.apply(filter);
+
+	fft->ComplexFFT(filter); // filter was expressed in the time domain (impulse response)
+
+	// normalize the output filter for unity gain
+	float scale = 0, mag;
+	for (int i = 0; i < flen2; i++) {
+		mag = abs(filter[i]);
+		if (mag > scale) scale = mag;
+	}
+	if (scale != 0) {
+		for (int i = 0; i < flen; i++)
+			filter[i] /= scale;
+	}
+}
+
+// Double the size of FFT used for equivalent SSB filter or assume FFT is half the size of the one used for SSB
+// used with runAsym for in band / opposite band asymmetrical filtering. Can be used for vestigial sideband modulation.
+void fftfilt::create_asym_filter(float fopp, float fin, FFTWindow::Function wf)
+{
+    // in band
+    // initialize the filter to zero
+    std::fill(filter, filter + flen, cmplx{0, 0});
+
+    for (int i = 0; i < flen2; i++) {
+        filter[i] = fsinc(fin, i, flen2);
+        // filter[i] *= _blackman(i, flen2);
+    }
+
+    FFTWindow fwin;
+    fwin.create(wf, flen2);
+    fwin.apply(filter);
+
+    fft->ComplexFFT(filter); // filter was expressed in the time domain (impulse response)
+
+    // normalize the output filter for unity gain
+    float scale = 0, mag;
+    for (int i = 0; i < flen2; i++) {
+        mag = abs(filter[i]);
+        if (mag > scale) scale = mag;
+    }
+    if (scale != 0) {
+        for (int i = 0; i < flen; i++)
+            filter[i] /= scale;
+    }
+
+    // opposite band
+    // initialize the filter to zero
+    std::fill(filterOpp, filterOpp + flen, cmplx{0, 0});
+
+    for (int i = 0; i < flen2; i++) {
+        filterOpp[i] = fsinc(fopp, i, flen2);
+        // filterOpp[i] *= _blackman(i, flen2);
+    }
+
+    fwin.apply(filterOpp);
+    fft->ComplexFFT(filterOpp); // filter was expressed in the time domain (impulse response)
+
+    // normalize the output filter for unity gain
+    scale = 0;
+    for (int i = 0; i < flen2; i++) {
+        mag = abs(filterOpp[i]);
+        if (mag > scale) scale = mag;
+    }
+    if (scale != 0) {
+        for (int i = 0; i < flen; i++)
+            filterOpp[i] /= scale;
+    }
+}
+
+// This filter is constructed directly from frequency domain response. Run with runFilt.
+void fftfilt::create_rrc_filter(float fb, float a)
+{
+    std::fill(filter, filter+flen, 0);
+
+    for (int i = 0; i < flen; i++) {
+        filter[i] = frrc(fb, a, i, flen);
+    }
+
+    // normalize the output filter for unity gain
+    float scale = 0, mag;
+    for (int i = 0; i < flen; i++)
+    {
+        mag = abs(filter[i]);
+        if (mag > scale) {
+            scale = mag;
+        }
+    }
+    if (scale != 0)
+    {
+        for (int i = 0; i < flen; i++) {
+            filter[i] /= scale;
+        }
+    }
+}
+
+// test bypass
+int fftfilt::noFilt(const cmplx & in, cmplx **out)
+{
+	data[inptr++] = in;
+	if (inptr < flen2)
+		return 0;
+	inptr = 0;
+
+	*out = data;
+	return flen2;
+}
+
+// Filter with fast convolution (overlap-add algorithm).
+int fftfilt::runFilt(const cmplx & in, cmplx **out)
+{
+	data[inptr++] = in;
+	if (inptr < flen2)
+		return 0;
+	inptr = 0;
+
+	fft->ComplexFFT(data);
+	for (int i = 0; i < flen; i++)
+		data[i] *= filter[i];
+
+	fft->InverseComplexFFT(data);
+
+	for (int i = 0; i < flen2; i++) {
+		output[i] = ovlbuf[i] + data[i];
+		ovlbuf[i] = data[flen2 + i];
+	}
+	std::fill(data, data + flen , cmplx{0, 0});
+
+	*out = output;
+	return flen2;
+}
+
+// Second version for single sideband
+int fftfilt::runSSB(const cmplx & in, cmplx **out, bool usb, bool getDC)
+{
+	data[inptr++] = in;
+	if (inptr < flen2)
+		return 0;
+	inptr = 0;
+
+	fft->ComplexFFT(data);
+
+	// get or reject DC component
+	data[0] = getDC ? data[0]*filter[0] : 0;
+    m_noiseReduction.setScheme(m_dnrScheme);
+    m_noiseReduction.init();
+
+	// Discard frequencies for ssb
+	if (usb)
+	{
+		for (int i = 1; i < flen2; i++)
+        {
+			data[i] *= filter[i];
+			data[flen2 + i] = 0;
+
+            if (m_dnr)
+            {
+                m_noiseReduction.push(data[i], i);
+                m_noiseReduction.push(data[flen2 + i], flen2 + i);
+            }
+		}
+	}
+	else
+	{
+		for (int i = 1; i < flen2; i++)
+        {
+			data[i] = 0;
+			data[flen2 + i] *= filter[flen2 + i];
+
+            if (m_dnr)
+            {
+                m_noiseReduction.push(data[i], i);
+                m_noiseReduction.push(data[flen2 + i], flen2 + i);
+            }
+		}
+	}
+
+    if (m_dnr)
+    {
+        m_noiseReduction.m_aboveAvgFactor = m_dnrAboveAvgFactor;
+        m_noiseReduction.m_sigmaFactor = m_dnrSigmaFactor;
+        m_noiseReduction.m_nbPeaks = m_dnrNbPeaks;
+        m_noiseReduction.calc();
+
+        for (int i = 0; i < flen; i++)
+        {
+            if (m_noiseReduction.cut(i)) {
+                data[i] = 0;
+            }
+        }
+    }
+
+	// in-place FFT: freqdata overwritten with filtered timedata
+	fft->InverseComplexFFT(data);
+
+	// overlap and add
+	for (int i = 0; i < flen2; i++) {
+		output[i] = ovlbuf[i] + data[i];
+		ovlbuf[i] = data[i+flen2];
+	}
+	std::fill(data, data + flen , cmplx{0, 0});
+
+	*out = output;
+	return flen2;
+}
+
+// Version for double sideband. You have to double the FFT size used for SSB.
+int fftfilt::runDSB(const cmplx & in, cmplx **out, bool getDC)
+{
+	data[inptr++] = in;
+	if (inptr < flen2)
+		return 0;
+	inptr = 0;
+
+	fft->ComplexFFT(data);
+
+	for (int i = 0; i < flen2; i++) {
+		data[i] *= filter[i];
+		data[flen2 + i] *= filter[flen2 + i];
+	}
+
+    // get or reject DC component
+    data[0] = getDC ? data[0] : 0;
+
+	// in-place FFT: freqdata overwritten with filtered timedata
+	fft->InverseComplexFFT(data);
+
+	// overlap and add
+	for (int i = 0; i < flen2; i++) {
+		output[i] = ovlbuf[i] + data[i];
+		ovlbuf[i] = data[i+flen2];
+	}
+
+	std::fill(data, data + flen , cmplx{0, 0});
+
+	*out = output;
+	return flen2;
+}
+
+// Version for asymmetrical sidebands. You have to double the FFT size used for SSB.
+int fftfilt::runAsym(const cmplx & in, cmplx **out, bool usb)
+{
+    data[inptr++] = in;
+    if (inptr < flen2)
+        return 0;
+    inptr = 0;
+
+    fft->ComplexFFT(data);
+
+    data[0] *= filter[0]; // always keep DC
+
+    if (usb)
+    {
+        for (int i = 1; i < flen2; i++)
+        {
+            data[i] *= filter[i]; // usb
+            data[flen2 + i] *= filterOpp[flen2 + i]; // lsb is the opposite
+        }
+    }
+    else
+    {
+        for (int i = 1; i < flen2; i++)
+        {
+            data[i] *= filterOpp[i]; // usb is the opposite
+            data[flen2 + i] *= filter[flen2 + i]; // lsb
+        }
+    }
+
+    // in-place FFT: freqdata overwritten with filtered timedata
+    fft->InverseComplexFFT(data);
+
+    // overlap and add
+    for (int i = 0; i < flen2; i++) {
+        output[i] = ovlbuf[i] + data[i];
+        ovlbuf[i] = data[i+flen2];
+    }
+
+    std::fill(data, data + flen , cmplx{0, 0});
+
+    *out = output;
+    return flen2;
+}
+
+/* Sliding FFT from Fldigi */
+
+struct sfft::vrot_bins_pair {
+	cmplx vrot;
+	cmplx bins;
+} ;
+
+sfft::sfft(int len)
+{
+	vrot_bins = new vrot_bins_pair[len];
+	delay  = new cmplx[len];
+	fftlen = len;
+	first = 0;
+	last = len - 1;
+	ptr = 0;
+	double phi = 0.0, tau = 2.0 * M_PI/ len;
+	k2 = 1.0;
+	for (int i = 0; i < len; i++) {
+		vrot_bins[i].vrot = cmplx( K1 * cos (phi), K1 * sin (phi) );
+		phi += tau;
+		delay[i] = vrot_bins[i].bins = 0.0;
+		k2 *= K1;
+	}
+}
+
+sfft::~sfft()
+{
+	delete [] vrot_bins;
+	delete [] delay;
+}
+
+// Sliding FFT, cmplx input, cmplx output
+// FFT is computed for each value from first to last
+// Values are not stable until more than "len" samples have been processed.
+void sfft::run(const cmplx& input)
+{
+	cmplx & de = delay[ptr];
+	const cmplx z( input.real() - k2 * de.real(), input.imag() - k2 * de.imag());
+	de = input;
+
+	if (++ptr >= fftlen)
+		ptr = 0;
+
+	for (vrot_bins_pair *itr = vrot_bins + first, *end = vrot_bins + last; itr != end ; ++itr)
+		itr->bins = (itr->bins + z) * itr->vrot;
+}
+
+// Copies the frequencies to a pointer.
+void sfft::fetch(float *result)
+{
+	for (vrot_bins_pair *itr = vrot_bins, *end = vrot_bins + last;  itr != end; ++itr, ++result)
+		*result = itr->bins.real() * itr->bins.real()
+                        + itr->bins.imag() * itr->bins.imag();
+}
+

android/app/src/main/cpp/dsp/fftfilt.h

@@ -0,0 +1,153 @@
+///////////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany     //
+// written by Christian Daniel                                                       //
+// Copyright (C) 2014-2015 John Greb <hexameron@spam.no>                             //
+// Copyright (C) 2015-2018, 2022-2023 Edouard Griffiths, F4EXB <f4exb06@gmail.com>   //
+// Copyright (C) 2020 Kacper Michajłow <kasper93@gmail.com>                          //
+//                                                                                   //
+// This program is free software; you can redistribute it and/or modify              //
+// it under the terms of the GNU General Public License as published by              //
+// the Free Software Foundation as version 3 of the License, or                      //
+// (at your option) any later version.                                               //
+//                                                                                   //
+// This program is distributed in the hope that it will be useful,                   //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                    //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                      //
+// GNU General Public License V3 for more details.                                   //
+//                                                                                   //
+// You should have received a copy of the GNU General Public License                 //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.              //
+///////////////////////////////////////////////////////////////////////////////////////
+/*
+ * Filters from Fldigi.
+*/
+
+#ifndef	_FFTFILT_H
+#define	_FFTFILT_H
+
+#include <complex>
+#include <cmath>
+
+#include "gfft.h"
+#include "fftwindow.h"
+#include "fftnr.h"
+#include "export.h"
+
+//----------------------------------------------------------------------
+
+class SDRBASE_API fftfilt {
+enum {NONE, BLACKMAN, HAMMING, HANNING};
+
+public:
+	typedef std::complex<float> cmplx;
+
+	fftfilt(int len);
+	fftfilt(float f1, float f2, int len);
+	fftfilt(float f2, int len);
+	~fftfilt();
+// f1 < f2 ==> bandpass
+// f1 > f2 ==> band reject
+	void create_filter(float f1, float f2, FFTWindow::Function wf = FFTWindow::Blackman);
+    void create_filter(const std::vector<std::pair<float, float>>& limits, bool pass = true, FFTWindow::Function wf = FFTWindow::Blackman);
+    void create_filter(const std::vector<std::pair<float, float>>& limits, bool pass = true); //!< Windowless version
+	void create_dsb_filter(float f2, FFTWindow::Function wf = FFTWindow::Blackman);
+    void create_asym_filter(float fopp, float fin, FFTWindow::Function wf = FFTWindow::Blackman); //!< two different filters for in band and opposite band
+    void create_rrc_filter(float fb, float a); //!< root raised cosine. fb is half the band pass
+
+	int noFilt(const cmplx& in, cmplx **out);
+	int runFilt(const cmplx& in, cmplx **out);
+	int runSSB(const cmplx& in, cmplx **out, bool usb, bool getDC = true);
+	int runDSB(const cmplx& in, cmplx **out, bool getDC = true);
+	int runAsym(const cmplx & in, cmplx **out, bool usb); //!< Asymmetrical filtering can be used for vestigial sideband
+
+    void setDNR(bool dnr) { m_dnr = dnr; }
+    void setDNRScheme(FFTNoiseReduction::Scheme scheme) { m_dnrScheme = scheme; }
+    void setDNRAboveAvgFactor(float aboveAvgFactor) { m_dnrAboveAvgFactor = aboveAvgFactor; }
+    void setDNRSigmaFactor(float sigmaFactor) { m_dnrSigmaFactor = sigmaFactor; }
+    void setDNRNbPeaks(int nbPeaks) { m_dnrNbPeaks = nbPeaks; }
+    void setDNRAlpha(float alpha) { m_noiseReduction.setAlpha(alpha); }
+
+protected:
+    // helper class for FFT based noise reduction
+	int flen;
+	int flen2;
+	g_fft<float> *fft;
+	cmplx *filter;
+    cmplx *filterOpp;
+	cmplx *data;
+	cmplx *ovlbuf;
+	cmplx *output;
+	int inptr;
+	int pass;
+	int window;
+    bool m_dnr;
+    FFTNoiseReduction::Scheme m_dnrScheme;
+    float m_dnrAboveAvgFactor; //!< above average factor
+    float m_dnrSigmaFactor; //!< sigma multiplicator for average + std deviation
+    int m_dnrNbPeaks; //!< number of peaks (peaks scheme)
+    FFTNoiseReduction m_noiseReduction;
+
+	inline float fsinc(float fc, int i, int len)
+	{
+	    int len2 = len/2;
+		return (i == len2) ? 2.0 * fc:
+				sin(2 * M_PI * fc * (i - len2)) / (M_PI * (i - len2));
+	}
+
+	inline float _blackman(int i, int len)
+	{
+		return (0.42 -
+				 0.50 * cos(2.0 * M_PI * i / len) +
+				 0.08 * cos(4.0 * M_PI * i / len));
+	}
+
+	/** RRC function in the frequency domain. Zero frequency is on the sides with first half in positive frequencies
+	 * and second half in negative frequencies */
+	inline cmplx frrc(float fb, float a, int i, int len)
+	{
+        float x = i/(float)len; // normalize to [0..1]
+        x = 0.5-fabs(x-0.5); // apply symmetry: now both halves overlap near 0
+        float tr = fb*a; // half the transition zone
+
+        if (x < fb-tr)
+        {
+            return 1.0; // in band
+        }
+        else if (x < fb+tr) // transition
+        {
+            float y = ((x-(fb-tr)) / (2.0*tr))*M_PI;
+            return (cos(y) + 1.0f)/2.0f;
+        }
+        else
+        {
+            return 0.0; // out of band
+        }
+	}
+
+	void init_filter();
+	void init_dsb_filter();
+};
+
+
+
+/* Sliding FFT filter from Fldigi */
+class SDRBASE_API sfft {
+#define K1 0.99999
+public:
+	typedef std::complex<float> cmplx;
+	sfft(int len);
+	~sfft();
+	void run(const cmplx& input);
+	void fetch(float *result);
+private:
+	int fftlen;
+	int first;
+	int last;
+	int ptr;
+	struct vrot_bins_pair;
+	vrot_bins_pair *vrot_bins;
+	cmplx *delay;
+	float k2;
+};
+
+#endif

android/app/src/main/cpp/dsp/fftnr.cpp

@@ -0,0 +1,148 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2023 Edouard Griffiths, F4EXB <f4exb06@gmail.com>               //
+//                                                                               //
+// Helper class for noise reduction                                              //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include <algorithm>
+#include <numeric>
+
+#include <QDebug>
+
+#include "fftnr.h"
+
+FFTNoiseReduction::FFTNoiseReduction(int len) :
+    m_flen(len)
+{
+    m_scheme = SchemeAverage;
+    m_mags = new float[m_flen];
+    m_tmp = new float[m_flen];
+    m_aboveAvgFactor = 1.0;
+    m_sigmaFactor = 1.0;
+    m_nbPeaks = m_flen;
+}
+
+FFTNoiseReduction::~FFTNoiseReduction()
+{
+    delete[] m_mags;
+    delete[] m_tmp;
+}
+
+void FFTNoiseReduction::init()
+{
+    std::fill(m_mags, m_mags + m_flen, 0);
+    std::fill(m_tmp, m_tmp + m_flen, 0);
+    m_magAvg = 0;
+}
+
+void FFTNoiseReduction::push(cmplx data, int index)
+{
+    m_mags[index] = std::abs(data);
+
+    if ((m_scheme == SchemeAverage) || (m_scheme == SchemeAvgStdDev)) {
+        m_magAvg += m_mags[index];
+    }
+}
+
+void FFTNoiseReduction::calc()
+{
+    if (m_scheme == SchemeAverage)
+    {
+        m_magAvg /= m_flen;
+        m_magAvg = m_expFilter.push(m_magAvg);
+    }
+    if (m_scheme == SchemeAvgStdDev)
+    {
+        m_magAvg /= m_flen;
+
+        auto variance_func = [this](float accumulator, const float& val) {
+            return accumulator + ((val - m_magAvg)*(val - m_magAvg) / (m_flen - 1));
+        };
+
+        float var = std::accumulate(m_mags, m_mags + m_flen, 0.0, variance_func);
+        m_magThr = (m_sigmaFactor/2.0)*std::sqrt(var) + m_magAvg;
+        m_magThr = m_expFilter.push(m_magThr);
+    }
+    else if (m_scheme == SchemePeaks)
+    {
+        std::copy(m_mags, m_mags + m_flen, m_tmp);
+        std::sort(m_tmp, m_tmp + m_flen);
+        m_magThr = m_tmp[m_flen - m_nbPeaks];
+    }
+}
+
+bool FFTNoiseReduction::cut(int index)
+{
+    if (m_scheme == SchemeAverage)
+    {
+        return m_mags[index] < m_aboveAvgFactor * m_magAvg;
+    }
+    else if ((m_scheme == SchemePeaks) || (m_scheme == SchemeAvgStdDev))
+    {
+        return m_mags[index] < m_magThr;
+    }
+
+    return false;
+}
+
+void FFTNoiseReduction::setScheme(Scheme scheme)
+{
+    if (m_scheme != scheme) {
+        m_expFilter.reset();
+    }
+
+    m_scheme = scheme;
+}
+
+FFTNoiseReduction::ExponentialFilter::ExponentialFilter()
+{
+    m_alpha = 1.0;
+    m_init = true;
+}
+
+float FFTNoiseReduction::ExponentialFilter::push(float newValue)
+{
+    if (m_init)
+    {
+        m_prev = newValue;
+        m_init = false;
+    }
+
+    if (m_alpha == 1.0)
+    {
+        m_prev = newValue;
+        return newValue;
+    }
+    else
+    {
+        float result = m_alpha*m_prev + (1.0 - m_alpha)*newValue;
+        m_prev = result;
+        return result;
+    }
+}
+
+void FFTNoiseReduction::ExponentialFilter::reset()
+{
+    m_init = true;
+}
+
+void FFTNoiseReduction::ExponentialFilter::setAlpha(float alpha)
+{
+    m_alpha = alpha < 0.0f ? 0.0f : alpha > 1.0f ? 1.0f : alpha;
+    qDebug("FFTNoiseReduction::ExponentialFilter::setAlpha: %f", m_alpha);
+    m_init = true;
+}
+

android/app/src/main/cpp/dsp/fftnr.h

@@ -0,0 +1,72 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2023 Edouard Griffiths, F4EXB <f4exb06@gmail.com>               //
+//                                                                               //
+// Helper class for noise reduction                                              //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef	_FFTNR_H
+#define	_FFTNR_H
+
+#include <complex>
+
+#include "export.h"
+
+class SDRBASE_API FFTNoiseReduction {
+public:
+    typedef std::complex<float> cmplx;
+    enum Scheme {
+        SchemeAverage,
+        SchemeAvgStdDev,
+        SchemePeaks
+    };
+
+    FFTNoiseReduction(int len);
+    ~FFTNoiseReduction();
+
+    void init(); //!< call before start of initial FFT scan
+    void push(cmplx data, int index); //!< Push FFT bin during initial FFT scan
+    void calc(); //!< calculate after initial FFT scan
+    bool cut(int index); //!< true if bin is to be zeroed else false (during second FFT scan)
+    void setAlpha(float alpha) { m_expFilter.setAlpha(alpha); }
+    void setScheme(Scheme scheme);
+
+    float m_aboveAvgFactor; //!< above average factor
+    float m_sigmaFactor; //!< sigma multiplicator for average + std deviation
+    int m_nbPeaks; //!< number of peaks (peaks scheme)
+
+private:
+    class ExponentialFilter {
+        public:
+            ExponentialFilter();
+            float push(float newValue);
+            void reset();
+            void setAlpha(float alpha);
+        private:
+            bool m_init;
+            float m_alpha;
+            float m_prev;
+    };
+
+    Scheme m_scheme;
+    int m_flen; //!< FFT length
+    float *m_mags; //!< magnitudes (PSD)
+    float *m_tmp; //!< temporary buffer
+    float m_magAvg; //!< average of magnitudes
+    float m_magThr; //!< magnitude threshold (peaks scheme)
+    ExponentialFilter m_expFilter; //!< exponential filter for parameter smoothing
+};
+
+#endif

android/app/src/main/cpp/dsp/fftwengine.cpp

@@ -0,0 +1,127 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2020 Edouard Griffiths, F4EXB <f4exb06@gmail.com>               //
+// Copyright (C) 2023 Jon Beniston, M7RCE <jon@beniston.com>                     //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include <QDebug>
+#include <QElapsedTimer>
+
+#include "dsp/fftwengine.h"
+#include "util/profiler.h"
+
+FFTWEngine::FFTWEngine(const QString& fftWisdomFileName) :
+    m_fftWisdomFileName(fftWisdomFileName),
+	m_plans(),
+	m_currentPlan(nullptr),
+    m_reuse(true)
+{
+}
+
+FFTWEngine::~FFTWEngine()
+{
+	freeAll();
+}
+
+const QString FFTWEngine::m_name = "FFTW";
+
+QString FFTWEngine::getName() const
+{
+    return m_name;
+}
+
+void FFTWEngine::configure(int n, bool inverse)
+{
+    if (m_reuse)
+    {
+        for (Plans::const_iterator it = m_plans.begin(); it != m_plans.end(); ++it)
+        {
+            if (((*it)->n == n) && ((*it)->inverse == inverse))
+            {
+                m_currentPlan = *it;
+                return;
+            }
+        }
+    }
+
+	m_currentPlan = new Plan;
+	m_currentPlan->n = n;
+	m_currentPlan->inverse = inverse;
+	m_currentPlan->in = (fftwf_complex*)fftwf_malloc(sizeof(fftwf_complex) * n);
+	m_currentPlan->out = (fftwf_complex*)fftwf_malloc(sizeof(fftwf_complex) * n);
+	QElapsedTimer t;
+	t.start();
+    m_globalPlanMutex.lock();
+
+    if (m_fftWisdomFileName.size() > 0)
+    {
+        int rc = fftwf_import_wisdom_from_filename(m_fftWisdomFileName.toStdString().c_str());
+
+        if (rc == 0) { // that's an error (undocumented)
+            qInfo("FFTWEngine::configure: importing from FFTW wisdom file: '%s' failed", qPrintable(m_fftWisdomFileName));
+        } else {
+            qDebug("FFTWEngine::configure: successfully imported from FFTW wisdom file: '%s'", qPrintable(m_fftWisdomFileName));
+        }
+    }
+    else
+    {
+        qDebug("FFTWEngine::configure: no FFTW wisdom file");
+    }
+
+	m_currentPlan->plan = fftwf_plan_dft_1d(n, m_currentPlan->in, m_currentPlan->out, inverse ? FFTW_BACKWARD : FFTW_FORWARD, FFTW_PATIENT);
+    m_globalPlanMutex.unlock();
+
+    qDebug("FFT: creating FFTW plan (n=%d,%s) took %lld ms", n, inverse ? "inverse" : "forward", t.elapsed());
+	m_plans.push_back(m_currentPlan);
+}
+
+void FFTWEngine::transform()
+{
+    PROFILER_START()
+
+	if(m_currentPlan != NULL)
+		fftwf_execute(m_currentPlan->plan);
+
+    PROFILER_STOP(QString("%1 %2").arg(getName()).arg(m_currentPlan->n))
+}
+
+Complex* FFTWEngine::in()
+{
+	if(m_currentPlan != NULL)
+		return reinterpret_cast<Complex*>(m_currentPlan->in);
+	else return NULL;
+}
+
+Complex* FFTWEngine::out()
+{
+	if(m_currentPlan != NULL)
+		return reinterpret_cast<Complex*>(m_currentPlan->out);
+	else return NULL;
+}
+
+QMutex FFTWEngine::m_globalPlanMutex;
+
+void FFTWEngine::freeAll()
+{
+	for(Plans::iterator it = m_plans.begin(); it != m_plans.end(); ++it) {
+		fftwf_destroy_plan((*it)->plan);
+		fftwf_free((*it)->in);
+		fftwf_free((*it)->out);
+		delete *it;
+	}
+	m_plans.clear();
+}

android/app/src/main/cpp/dsp/fftwengine.h

@@ -0,0 +1,66 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2016, 2018, 2020 Edouard Griffiths, F4EXB <f4exb06@gmail.com> //
+// Copyright (C) 2023 Jon Beniston, M7RCE <jon@beniston.com>                     //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef INCLUDE_FFTWENGINE_H
+#define INCLUDE_FFTWENGINE_H
+
+#include <QMutex>
+#include <QString>
+
+#include <fftw3.h>
+#include <list>
+#include "dsp/fftengine.h"
+#include "export.h"
+
+class SDRBASE_API FFTWEngine : public FFTEngine {
+public:
+	FFTWEngine(const QString& fftWisdomFileName);
+	virtual ~FFTWEngine();
+
+	virtual void configure(int n, bool inverse);
+	virtual void transform();
+
+	virtual Complex* in();
+	virtual Complex* out();
+
+    virtual void setReuse(bool reuse) { m_reuse = reuse; }
+    QString getName() const override;
+    static const QString m_name;
+
+protected:
+	static QMutex m_globalPlanMutex;
+    QString m_fftWisdomFileName;
+
+	struct Plan {
+		int n;
+		bool inverse;
+		fftwf_plan plan;
+		fftwf_complex* in;
+		fftwf_complex* out;
+	};
+	typedef std::list<Plan*> Plans;
+	Plans m_plans;
+	Plan* m_currentPlan;
+    bool m_reuse;
+
+	void freeAll();
+};
+
+#endif // INCLUDE_FFTWENGINE_H

android/app/src/main/cpp/dsp/fftwindow.cpp

@@ -0,0 +1,129 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2019-2020, 2022 Edouard Griffiths, F4EXB <f4exb06@gmail.com>    //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include "dsp/fftwindow.h"
+
+FFTWindow::FFTWindow() :
+	m_kaiserAlpha(M_PI) // first sidelobe at < -70dB
+{
+	m_kaiserI0Alpha = zeroethOrderBessel(m_kaiserAlpha);
+}
+
+void FFTWindow::setKaiserAlpha(Real alpha)
+{
+	m_kaiserAlpha = alpha;
+	m_kaiserI0Alpha = zeroethOrderBessel(m_kaiserAlpha);
+}
+
+void FFTWindow::setKaiserBeta(Real beta)
+{
+	m_kaiserAlpha = beta / M_PI;
+	m_kaiserI0Alpha = zeroethOrderBessel(m_kaiserAlpha);
+}
+
+void FFTWindow::create(Function function, int n)
+{
+	Real (*wFunc)(Real n, Real i);
+
+	m_window.clear();
+
+	if (function == Kaiser) // Kaiser special case
+	{
+		for(int i = 0; i < n; i++) {
+			m_window.push_back(kaiser(n, i));
+		}
+
+		return;
+	}
+
+	switch (function) {
+		case Flattop:
+			wFunc = flatTop;
+			break;
+
+		case Bartlett:
+			wFunc = bartlett;
+			break;
+
+		case BlackmanHarris:
+			wFunc = blackmanHarris;
+			break;
+
+		case Hamming:
+			wFunc = hamming;
+			break;
+
+		case Hanning:
+			wFunc = hanning;
+			break;
+
+        case Blackman:
+            wFunc = blackman;
+            break;
+
+        case BlackmanHarris7:
+            wFunc = blackmanHarris7;
+            break;
+
+		case Rectangle:
+		default:
+			wFunc = rectangle;
+			break;
+	}
+
+	for(int i = 0; i < n; i++) {
+		m_window.push_back(wFunc(n, i));
+	}
+}
+
+void FFTWindow::apply(const std::vector<Real>& in, std::vector<Real>* out)
+{
+	for(size_t i = 0; i < m_window.size(); i++) {
+		(*out)[i] = in[i] * m_window[i];
+    }
+}
+
+void FFTWindow::apply(const std::vector<Complex>& in, std::vector<Complex>* out)
+{
+	for(size_t i = 0; i < m_window.size(); i++) {
+		(*out)[i] = in[i] * m_window[i];
+    }
+}
+
+void FFTWindow::apply(std::vector<Complex>& in)
+{
+	for(size_t i = 0; i < m_window.size(); i++) {
+		in[i] *= m_window[i];
+    }
+}
+
+void FFTWindow::apply(const Complex* in, Complex* out)
+{
+	for(size_t i = 0; i < m_window.size(); i++) {
+		out[i] = in[i] * m_window[i];
+    }
+}
+
+void FFTWindow::apply(Complex* in)
+{
+	for(size_t i = 0; i < m_window.size(); i++) {
+		in[i] *= m_window[i];
+    }
+}
+

android/app/src/main/cpp/dsp/fftwindow.h

@@ -0,0 +1,146 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2020, 2022 Edouard Griffiths, F4EXB <f4exb06@gmail.com>    //
+// Copyright (C) 2020 Kacper Michajłow <kasper93@gmail.com>                      //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef INCLUDE_FFTWINDOW_H
+#define INCLUDE_FFTWINDOW_H
+
+#include <vector>
+#include <cmath>
+#include "dsp/dsptypes.h"
+#include "export.h"
+
+class SDRBASE_API FFTWindow {
+public:
+	enum Function {
+		Bartlett,
+		BlackmanHarris,
+		Flattop,
+		Hamming,
+		Hanning,
+		Rectangle,
+		Kaiser,
+        Blackman,
+        BlackmanHarris7
+	};
+
+	FFTWindow();
+
+	void create(Function function, int n);
+	void apply(const std::vector<Real>& in, std::vector<Real>* out);
+	void apply(const std::vector<Complex>& in, std::vector<Complex>* out);
+    void apply(std::vector<Complex>& in);
+	void apply(const Complex* in, Complex* out);
+    void apply(Complex* in);
+	void setKaiserAlpha(Real alpha); //!< set the Kaiser window alpha factor (default 2.15)
+	void setKaiserBeta(Real beta);   //!< set the Kaiser window beta factor = pi * alpha
+
+private:
+	std::vector<float> m_window;
+	Real m_kaiserAlpha;    //!< alpha factor for Kaiser window
+	Real m_kaiserI0Alpha;  //!< zeroethOrderBessel of alpha above
+
+	static inline Real flatTop(Real n, Real i)
+	{
+		// correction ?
+		return 1.0 - 1.93 * cos((2.0 * M_PI * i) / n) + 1.29 * cos((4.0 * M_PI * i) / n) - 0.388 * cos((6.0 * M_PI * i) / n) + 0.03222 * cos((8.0 * M_PI * i) / n);
+	}
+
+	static inline Real bartlett(Real n, Real i)
+	{
+		// amplitude correction = 2.0
+		return (2.0 / (n - 1.0)) * ( (n - 1.0) / 2.0 - fabs(i - (n - 1.0) / 2.0)) * 2.0;
+	}
+
+	static inline Real blackmanHarris(Real n, Real i) // 4 term Blackman-Harris
+	{
+		// amplitude correction = 2.79
+		return (0.35875
+            - 0.48829 * cos((2.0 * M_PI * i) / n)
+            + 0.14128 * cos((4.0 * M_PI * i) / n)
+            - 0.01168 * cos((6.0 * M_PI * i) / n)) * 2.79;
+	}
+
+	static inline Real blackmanHarris7(Real n, Real i) // 7 term Blackman-Harris
+	{
+		return (0.27105
+            - 0.43330 * cos((2.0 * M_PI * i) / n)
+            + 0.21812 * cos((4.0 * M_PI * i) / n)
+            - 0.065925 * cos((6.0 * M_PI * i) / n)
+            + 0.010812 * cos((8.0 * M_PI * i) / n)
+            - 0.00077658 * cos((10.0 * M_PI * i) / n)
+            + 0.000013887 * cos((12.0 * M_PI * i) / n)) * 3.72;
+	}
+
+    static inline Real blackman(Real n, Real i) // 3 term Blackman
+    {
+        return (0.42438
+            - 0.49734 * cos(2.0 * M_PI * i / n)
+            + 0.078279 * cos(4.0 * M_PI * i / n)) * 2.37;
+    }
+
+	static inline Real hamming(Real n, Real i)
+	{
+		// amplitude correction = 1.855, energy correction = 1.586
+		return (0.54 - 0.46 * cos((2.0 * M_PI * i) / n)) * 1.855;
+	}
+
+	static inline Real hanning(Real n, Real i)
+	{
+		// amplitude correction = 2.0, energy correction = 1.633
+		return (0.5 - 0.5 * cos((2.0 * M_PI * i) / n)) * 2.0;
+	}
+
+	static inline Real rectangle(Real, Real)
+	{
+		return 1.0;
+	}
+
+	// https://raw.githubusercontent.com/johnglover/simpl/master/src/loris/KaiserWindow.C
+	inline Real kaiser(Real n, Real i)
+	{
+		Real K = ((2.0*i) / n) - 1.0;
+		Real arg = sqrt(1.0 - (K*K));
+		return zeroethOrderBessel(m_kaiserAlpha*arg) / m_kaiserI0Alpha;
+	}
+
+	static inline Real zeroethOrderBessel( Real x )
+	{
+		const Real eps = 0.000001;
+
+		//  initialize the series term for m=0 and the result
+		Real besselValue = 0;
+		Real term = 1;
+		Real m = 0;
+
+		//  accumulate terms as long as they are significant
+		while(term  > eps * besselValue)
+		{
+			besselValue += term;
+
+			//  update the term
+			++m;
+			term *= (x*x) / (4*m*m);
+		}
+
+		return besselValue;
+	}
+};
+
+#endif // INCLUDE_FFTWINDOWS_H

android/app/src/main/cpp/dsp/filerecord.cpp

@@ -0,0 +1,250 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2015-2021 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+// Copyright (C) 2018 beta-tester <alpha-beta-release@gmx.net>                   //
+// Copyright (C) 2020 Felix Schneider <felix@fx-schneider.de>                    //
+// Copyright (C) 2021, 2023 Jon Beniston, M7RCE <jon@beniston.com>               //
+// Copyright (C) 2021 Andreas Baulig <free.geronimo@hotmail.de>                  //
+// Copyright (C) 2021 Christoph Berg <myon@debian.org>                           //
+// Copyright (C) 2022 CRD716 <crd716@gmail.com>                                  //
+// Copyright (C) 2022 Jiří Pinkava <jiri.pinkava@rossum.ai>                      //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include <boost/crc.hpp>
+#include <boost/cstdint.hpp>
+
+#include <QDebug>
+#include <QDateTime>
+
+#include "dsp/dspcommands.h"
+#include "util/message.h"
+
+#include "filerecord.h"
+
+FileRecord::FileRecord(quint32 sampleRate, quint64 centerFrequency) :
+	FileRecordInterface(),
+    m_fileBase("test"),
+    m_sampleRate(sampleRate),
+    m_centerFrequency(centerFrequency),
+	m_recordOn(false),
+    m_recordStart(false),
+    m_byteCount(0),
+    m_msShift(0)
+{
+	setObjectName("FileRecord");
+}
+
+FileRecord::FileRecord(const QString& fileBase) :
+    FileRecordInterface(),
+    m_fileBase(fileBase),
+    m_sampleRate(0),
+    m_centerFrequency(0),
+    m_recordOn(false),
+    m_recordStart(false),
+    m_byteCount(0)
+{
+    setObjectName("FileRecord");
+}
+
+FileRecord::~FileRecord()
+{
+    stopRecording();
+}
+
+void FileRecord::setFileName(const QString& fileBase)
+{
+    if (!m_recordOn)
+    {
+        m_fileBase = fileBase;
+    }
+}
+
+void FileRecord::genUniqueFileName(uint deviceUID, int istream)
+{
+    if (istream < 0) {
+        setFileName(QString("rec%1_%2.sdriq").arg(deviceUID).arg(QDateTime::currentDateTimeUtc().toString("yyyy-MM-ddTHH_mm_ss_zzz")));
+    } else {
+        setFileName(QString("rec%1_%2_%3.sdriq").arg(deviceUID).arg(istream).arg(QDateTime::currentDateTimeUtc().toString("yyyy-MM-ddTHH_mm_ss_zzz")));
+    }
+}
+
+void FileRecord::feed(const SampleVector::const_iterator& begin, const SampleVector::const_iterator& end, bool positiveOnly)
+{
+    QMutexLocker mutexLocker(&m_mutex);
+
+    (void) positiveOnly;
+
+    // if no recording is active, send the samples to /dev/null
+    if(!m_recordOn)
+        return;
+
+    if (begin < end) // if there is something to put out
+    {
+        if (m_recordStart)
+        {
+            writeHeader();
+            m_recordStart = false;
+        }
+
+        m_sampleFile.write(reinterpret_cast<const char*>(&*(begin)), (end - begin)*sizeof(Sample));
+        m_byteCount += end - begin;
+    }
+}
+
+void FileRecord::start()
+{
+}
+
+void FileRecord::stop()
+{
+    stopRecording();
+}
+
+bool FileRecord::startRecording()
+{
+    QMutexLocker mutexLocker(&m_mutex);
+
+    if (m_recordOn) {
+        stopRecording();
+    }
+
+#ifdef ANDROID
+    if (!m_sampleFile.isOpen())
+#else
+    if (!m_sampleFile.is_open())
+#endif
+    {
+    	qDebug() << "FileRecord::startRecording";
+#ifdef ANDROID
+        // FIXME: No idea how to write to a file where the filename doesn't come from the file picker
+        m_currentFileName = m_fileBase + ".sdriq";
+        m_sampleFile.setFileName(m_currentFileName);
+        if (!m_sampleFile.open(QIODevice::ReadWrite))
+        {
+            qWarning() << "FileRecord::startRecording: failed to open file: " << m_currentFileName << " error " << m_sampleFile.error();
+            return false;
+        }
+#else
+        m_currentFileName = m_fileBase + "." + QDateTime::currentDateTimeUtc().toString("yyyy-MM-ddTHH_mm_ss_zzz") + ".sdriq"; // Don't use QString::arg on Android, as filename can contain %2
+        m_sampleFile.open(m_currentFileName.toStdString().c_str(), std::ios::binary);
+        if (!m_sampleFile.is_open())
+        {
+            qWarning() << "FileRecord::startRecording: failed to open file: " << m_currentFileName;
+            return false;
+        }
+#endif
+        m_recordOn = true;
+        m_recordStart = true;
+        m_byteCount = 0;
+    }
+    return true;
+}
+
+bool FileRecord::stopRecording()
+{
+    QMutexLocker mutexLocker(&m_mutex);
+
+#ifdef ANDROID
+    if (m_sampleFile.isOpen())
+#else
+    if (m_sampleFile.is_open())
+#endif
+    {
+    	qDebug() << "FileRecord::stopRecording";
+        m_sampleFile.close();
+        m_recordOn = false;
+        m_recordStart = false;
+#ifdef ANDROID
+#else
+        if (m_sampleFile.bad())
+        {
+            qWarning() << "FileRecord::stopRecording: an error occurred while writing to " << m_currentFileName;
+            return false;
+        }
+#endif
+    }
+    return true;
+}
+
+bool FileRecord::handleMessage(const Message& message)
+{
+	if (DSPSignalNotification::match(message))
+	{
+        QMutexLocker mutexLocker(&m_mutex);
+		DSPSignalNotification& notif = (DSPSignalNotification&) message;
+		quint32 sampleRate = notif.getSampleRate();
+		qint64 centerFrequency = notif.getCenterFrequency();
+		qDebug() << "FileRecord::handleMessage: DSPSignalNotification: inputSampleRate: " << sampleRate
+				<< " centerFrequency: " << centerFrequency;
+
+        if (m_recordOn && (m_sampleRate != sampleRate)) {
+            startRecording();
+        }
+
+        m_sampleRate = sampleRate;
+        m_centerFrequency = centerFrequency;
+
+        return true;
+	}
+    else
+    {
+        return false;
+    }
+}
+
+void FileRecord::writeHeader()
+{
+    Header header;
+    header.sampleRate = m_sampleRate;
+    header.centerFrequency = m_centerFrequency;
+    qint64 ts = QDateTime::currentMSecsSinceEpoch();
+    header.startTimeStamp = (quint64)(ts + m_msShift);
+    header.sampleSize = SDR_RX_SAMP_SZ;
+    header.filler = 0;
+
+    writeHeader(m_sampleFile, header);
+}
+
+bool FileRecord::readHeader(std::ifstream& sampleFile, Header& header)
+{
+    sampleFile.read((char *) &header, sizeof(Header));
+    boost::crc_32_type crc32;
+    crc32.process_bytes(&header, 28);
+    return header.crc32 == crc32.checksum();
+}
+
+bool FileRecord::readHeader(QFile& sampleFile, Header& header)
+{
+    sampleFile.read((char *) &header, sizeof(Header));
+    boost::crc_32_type crc32;
+    crc32.process_bytes(&header, 28);
+    return header.crc32 == crc32.checksum();
+}
+
+void FileRecord::writeHeader(std::ofstream& sampleFile, Header& header)
+{
+    boost::crc_32_type crc32;
+    crc32.process_bytes(&header, 28);
+    header.crc32 = crc32.checksum();
+    sampleFile.write((const char *) &header, sizeof(Header));
+}
+
+void FileRecord::writeHeader(QFile& sampleFile, Header& header)
+{
+    boost::crc_32_type crc32;
+    crc32.process_bytes(&header, 28);
+    header.crc32 = crc32.checksum();
+    sampleFile.write((const char *) &header, sizeof(Header));
+}

android/app/src/main/cpp/dsp/filerecord.h

@@ -0,0 +1,97 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2015-2016, 2018-2020 Edouard Griffiths, F4EXB <f4exb06@gmail.com> //
+// Copyright (C) 2018 beta-tester <alpha-beta-release@gmx.net>                   //
+// Copyright (C) 2021, 2023 Jon Beniston, M7RCE <jon@beniston.com>               //
+// Copyright (C) 2022 CRD716 <crd716@gmail.com>                                  //
+// Copyright (C) 2022 Jiří Pinkava <jiri.pinkava@rossum.ai>                      //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef INCLUDE_FILERECORD_H
+#define INCLUDE_FILERECORD_H
+
+#include <QFile>
+
+#include <dsp/basebandsamplesink.h>
+#include <string>
+#include <iostream>
+#include <fstream>
+#include <ctime>
+
+#include "dsp/filerecordinterface.h"
+#include "export.h"
+
+class Message;
+
+class SDRBASE_API FileRecord : public FileRecordInterface {
+public:
+
+#pragma pack(push, 1)
+    struct Header
+    {
+    	quint32 sampleRate;
+        quint64 centerFrequency;
+        quint64 startTimeStamp;
+        quint32 sampleSize;
+        quint32 filler;
+        quint32 crc32;
+    };
+#pragma pack(pop)
+
+	FileRecord(quint32 sampleRate=0, quint64 centerFrequency=0);
+    FileRecord(const QString& fileBase);
+	virtual ~FileRecord();
+
+    quint64 getByteCount() const { return m_byteCount; }
+    void setMsShift(qint64 shift) { m_msShift = shift; }
+    const QString& getCurrentFileName() { return m_currentFileName; }
+
+    void genUniqueFileName(uint deviceUID, int istream = -1);
+
+	virtual void feed(const SampleVector::const_iterator& begin, const SampleVector::const_iterator& end, bool positiveOnly);
+	virtual void start();
+	virtual void stop();
+	virtual bool handleMessage(const Message& message);
+
+    virtual void setFileName(const QString& fileBase);
+    virtual bool startRecording();
+    virtual bool stopRecording();
+    virtual bool isRecording() const { return m_recordOn; }
+
+    static bool readHeader(std::ifstream& samplefile, Header& header); //!< returns true if CRC checksum is correct else false
+    static bool readHeader(QFile& samplefile, Header& header); //!< returns true if CRC checksum is correct else false
+    static void writeHeader(std::ofstream& samplefile, Header& header);
+    static void writeHeader(QFile& samplefile, Header& header);
+
+private:
+	QString m_fileBase;
+	quint32 m_sampleRate;
+	quint64 m_centerFrequency;
+	bool m_recordOn;
+    bool m_recordStart;
+#ifdef ANDROID
+    QFile m_sampleFile;
+#else
+    std::ofstream m_sampleFile;
+#endif
+    QString m_currentFileName;
+    quint64 m_byteCount;
+    qint64 m_msShift;
+    QRecursiveMutex m_mutex;
+
+    void writeHeader();
+};
+
+#endif // INCLUDE_FILERECORD_H

android/app/src/main/cpp/dsp/filerecordinterface.cpp

@@ -0,0 +1,88 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2020 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+// Copyright (C) 2021, 2023 Jon Beniston, M7RCE <jon@beniston.com>               //
+//                                                                               //
+// File recorder in SigMF format single channel for SI plugins                   //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include <QDateTime>
+#include <QFileInfo>
+
+#include "filerecordinterface.h"
+
+FileRecordInterface::FileRecordInterface()
+{
+    connect(&m_inputMessageQueue, SIGNAL(messageEnqueued()), this, SLOT(handleInputMessages()));
+}
+
+FileRecordInterface::~FileRecordInterface()
+{}
+
+QString FileRecordInterface::genUniqueFileName(unsigned int deviceUID, int istream)
+{
+    if (istream < 0) {
+        return QString("rec%1.%2.sdriq").arg(deviceUID).arg(QDateTime::currentDateTimeUtc().toString("yyyy-MM-ddTHH_mm_ss_zzz"));
+    } else {
+        return QString("rec%1_%2.%3.sdriq").arg(deviceUID).arg(istream).arg(QDateTime::currentDateTimeUtc().toString("yyyy-MM-ddTHH_mm_ss_zzz"));
+    }
+}
+
+FileRecordInterface::RecordType FileRecordInterface::guessTypeFromFileName(const QString& fileName, QString& fileBase)
+{
+    QFileInfo fileInfo(fileName);
+    QString extension = fileInfo.suffix();
+
+    fileBase = fileName;
+    if (!extension.isEmpty())
+    {
+        fileBase.chop(extension.size() + 1);
+        if (extension == "sdriq")
+        {
+            return RecordTypeSdrIQ;
+        }
+        else if (extension == "sigmf-meta")
+        {
+            return RecordTypeSigMF;
+        }
+        else if (extension == "wav")
+        {
+            return RecordTypeWav;
+        }
+        else
+        {
+            return RecordTypeUndefined;
+        }
+    }
+    else
+    {
+        return RecordTypeUndefined;
+    }
+}
+
+void FileRecordInterface::handleInputMessages()
+{
+	Message* message;
+
+	while ((message = m_inputMessageQueue.pop()) != 0)
+	{
+		if (handleMessage(*message))
+		{
+			delete message;
+		}
+	}
+}

android/app/src/main/cpp/dsp/filerecordinterface.h

@@ -0,0 +1,79 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2020 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+// Copyright (C) 2021 Jon Beniston, M7RCE <jon@beniston.com>                     //
+//                                                                               //
+// File recorder in SigMF format single channel for SI plugins                   //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef INCLUDE_FILERECORD_INTERFACE_H
+#define INCLUDE_FILERECORD_INTERFACE_H
+
+#include <QString>
+#include <QObject>
+
+#include "dsp/dsptypes.h"
+#include "util/message.h"
+#include "util/messagequeue.h"
+#include "export.h"
+
+class SDRBASE_API FileRecordInterface : public QObject {
+    Q_OBJECT
+public:
+    enum RecordType
+    {
+        RecordTypeUndefined = 0,
+        RecordTypeSdrIQ,
+        RecordTypeSigMF,
+        RecordTypeWav
+    };
+
+    FileRecordInterface();
+    virtual ~FileRecordInterface();
+
+	virtual void start() = 0;
+	virtual void stop() = 0;
+	virtual void feed(const SampleVector::const_iterator& begin, const SampleVector::const_iterator& end, bool positiveOnly) = 0;
+	virtual bool handleMessage(const Message& cmd) = 0; //!< Processing of a message. Returns true if message has actually been processed
+
+	MessageQueue *getInputMessageQueue() { return &m_inputMessageQueue; } //!< Get the queue for asynchronous inbound communication
+    virtual void setMessageQueueToGUI(MessageQueue *queue) { m_guiMessageQueue = queue; }
+    MessageQueue *getMessageQueueToGUI() { return m_guiMessageQueue; }
+
+    virtual void setFileName(const QString &filename) = 0;
+    virtual const QString& getCurrentFileName() = 0;
+    virtual bool startRecording() = 0;
+    virtual bool stopRecording() = 0;
+    virtual bool isRecording() const = 0;
+
+    virtual void setMsShift(qint64 msShift) = 0;
+    virtual int getBytesPerSample() { return sizeof(Sample); };
+
+    static QString genUniqueFileName(unsigned int deviceUID, int istream = -1);
+    static RecordType guessTypeFromFileName(const QString& fileName, QString& fileBase);
+
+protected:
+	MessageQueue m_inputMessageQueue; //!< Queue for asynchronous inbound communication
+    MessageQueue *m_guiMessageQueue;  //!< Input message queue to the GUI
+
+protected slots:
+	void handleInputMessages();
+
+};
+
+
+#endif // INCLUDE_FILERECORD_INTERFACE_H

android/app/src/main/cpp/dsp/filtermbe.cpp

@@ -0,0 +1,52 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2019 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+// Copyright (C) 2015 John Greb <hexameron@spam.no>                              //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include "filtermbe.h"
+
+const float MBEAudioInterpolatorFilter::m_lpa[3] = {1.0,           1.392667E+00, -5.474446E-01};
+const float MBEAudioInterpolatorFilter::m_lpb[3] = {3.869430E-02,  7.738860E-02,  3.869430E-02};
+
+const float MBEAudioInterpolatorFilter::m_hpa[3] = {1.000000e+00,  1.667871e+00, -7.156964e-01};
+const float MBEAudioInterpolatorFilter::m_hpb[3] = {8.459039e-01, -1.691760e+00,  8.459039e-01};
+
+MBEAudioInterpolatorFilter::MBEAudioInterpolatorFilter() :
+        m_filterLP(m_lpa, m_lpb),
+        m_filterHP(m_hpa, m_hpb),
+        m_useHP(false)
+{
+}
+
+MBEAudioInterpolatorFilter::~MBEAudioInterpolatorFilter()
+{}
+
+float MBEAudioInterpolatorFilter::run(const float& sample)
+{
+    return m_useHP ? m_filterLP.run(m_filterHP.run(sample)) : m_filterLP.run(sample);
+}
+
+float MBEAudioInterpolatorFilter::runHP(const float& sample)
+{
+    return m_filterHP.run(sample);
+}
+
+float MBEAudioInterpolatorFilter::runLP(const float& sample)
+{
+    return m_filterLP.run(sample);
+}

android/app/src/main/cpp/dsp/filtermbe.h

@@ -0,0 +1,91 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2019 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+// Copyright (C) 2015 John Greb <hexameron@spam.no>                              //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef SDRBASE_DSP_FILTERMBE_H_
+#define SDRBASE_DSP_FILTERMBE_H_
+
+/**
+ * Uses the generic IIR filter internally
+ *
+ * Low pass / High pass:
+ *
+ * This is a 2 pole Chebyshev (recursive) filter using coefficients found in table 20-1 (low pass)
+ * or table 20-2 (high pass) of http://www.analog.com/media/en/technical-documentation/dsp-book/dsp_book_Ch20.pdf
+ *
+ * For low pass fc = 0.075
+ * For high oass fc = 0.01
+ *
+ * Convention taken here exchanges A and B coefficients as shown in this image:
+ * https://cdn.mikroe.com/ebooks/img/8/2016/02/digital-filter-design-chapter-03-image-2-9.gif
+ * So A applies to Y and B to X
+ *
+ * At the interpolated sampling frequency of 48 kHz the -3 dB corner is at 48 * .075 = 3.6 kHz which is perfect for voice
+ * The high pass has a 3 dB corner of 48 * 0.01 = 0.48 kHz
+ *
+ * Low pass:
+ *
+ * b0 = 3.869430E-02 (a0 = 1.0)
+ * b1 = 7.738860E-02 a1 =  1.392667E+00
+ * b2 = 3.869430E-02 a2 = -5.474446E-01
+ *
+ * High pass:
+ *
+ * b0 =  9.567529E-01 (a0 = 1.0)
+ * b1 = -1.913506E+00  a1 =  1.911437E+00
+ * b2 =  9.567529E-01  a2 = -9.155749E-01
+ *
+ * given x[n] is the new input sample and y[n] the returned output sample:
+ *
+ * y[n] = b0*x[n] + b1*x[n] + b2*x[n] + a1*y[n-1] + a2*y[n-2]
+ *
+ * This one works directly with floats
+ *
+ *
+ */
+
+#include "iirfilter.h"
+#include "export.h"
+
+class SDRBASE_API MBEAudioInterpolatorFilter
+{
+public:
+    MBEAudioInterpolatorFilter();
+    ~MBEAudioInterpolatorFilter();
+
+    void useHP(bool useHP) { m_useHP = useHP; }
+    bool usesHP() const { return m_useHP; }
+    float run(const float& sample);
+    float runHP(const float& sample);
+    float runLP(const float& sample);
+
+private:
+    IIRFilter<float, 2> m_filterLP;
+    IIRFilter<float, 2> m_filterHP;
+    bool m_useHP;
+    // low pass coefficients
+    static const float m_lpa[3];
+    static const float m_lpb[3];
+    // band pass coefficients
+    static const float m_hpa[3];
+    static const float m_hpb[3];
+};
+
+
+#endif /* SDRBASE_DSP_FILTERMBE_H_ */

android/app/src/main/cpp/dsp/filterrc.cpp

@@ -0,0 +1,88 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2014 John Greb <hexameron@spam.no>                              //
+// Copyright (C) 2015, 2019 Edouard Griffiths, F4EXB <f4exb06@gmail.com>         //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include <QDebug>
+#include "dsp/filterrc.h"
+
+// Construct 1st order low-pass IIR filter.
+LowPassFilterRC::LowPassFilterRC(Real timeconst) :
+    m_timeconst(timeconst),
+	m_y1(0)
+{
+	m_a1 = - exp(-1/m_timeconst);
+	m_b0 = 1 + m_a1;
+}
+
+// Reconfigure
+void LowPassFilterRC::configure(Real timeconst)
+{
+	m_timeconst = timeconst;
+	m_y1 = 0;
+	m_a1 = - exp(-1/m_timeconst);
+	m_b0 = 1 + m_a1;
+
+	qDebug() << "LowPassFilterRC::configure: t: " << m_timeconst
+			<< " a1: " << m_a1
+			<< " b0: " << m_b0;
+}
+
+// Process samples.
+void LowPassFilterRC::process(const Real& sample_in, Real& sample_out)
+{
+    /*
+     * Continuous domain:
+     *   H(s) = 1 / (1 - s * timeconst)
+     *
+     * Discrete domain:
+     *   H(z) = (1 - exp(-1/timeconst)) / (1 - exp(-1/timeconst) / z)
+     */
+
+	m_y1 = (sample_in * m_b0) - (m_y1 * m_a1);
+	sample_out = m_y1;
+}
+
+// Construct 1st order high-pass IIR filter.
+HighPassFilterRC::HighPassFilterRC(Real timeconst) :
+     m_timeconst(timeconst),
+     m_y1(0)
+{
+	m_a1 = 1 - exp(-1/m_timeconst);
+	m_b0 = 1 + m_a1;
+}
+
+// Reconfigure
+void HighPassFilterRC::configure(Real timeconst)
+{
+	m_timeconst = timeconst;
+	m_y1 = 0;
+	m_a1 = 1 - exp(-1/m_timeconst);
+	m_b0 = 1 + m_a1;
+
+	qDebug() << "HighPassFilterRC::configure: t: " << m_timeconst
+			<< " a1: " << m_a1
+			<< " b0: " << m_b0;
+}
+
+// Process samples.
+void HighPassFilterRC::process(const Real& sample_in, Real& sample_out)
+{
+	m_y1 = (sample_in * m_b0) - (m_y1 * m_a1);
+	sample_out = m_y1;
+}

android/app/src/main/cpp/dsp/filterrc.h

@@ -0,0 +1,80 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2016, 2018-2019 Edouard Griffiths, F4EXB <f4exb06@gmail.com> //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef INCLUDE_DSP_FILTERRC_H_
+#define INCLUDE_DSP_FILTERRC_H_
+
+#include "dsp/dsptypes.h"
+#include "export.h"
+
+/** First order low-pass IIR filter for real-valued signals. */
+class SDRBASE_API LowPassFilterRC
+{
+public:
+
+    /**
+     * Construct 1st order low-pass IIR filter.
+     *
+     * timeconst :: RC time constant in seconds (1 / (2 * PI * cutoff_freq)
+     */
+    LowPassFilterRC(Real timeconst);
+
+    /**
+     * Reconfigure filter with new time constant
+     */
+    void configure(Real timeconst);
+
+    /** Process samples. */
+    void process(const Real& sample_in, Real& sample_out);
+
+private:
+    Real m_timeconst;
+    Real m_y1;
+    Real m_a1;
+    Real m_b0;
+};
+
+/** First order high-pass IIR filter for real-valued signals. */
+class SDRBASE_API HighPassFilterRC
+{
+public:
+
+    /**
+     * Construct 1st order high-pass IIR filter.
+     *
+     * timeconst :: RC time constant in seconds (1 / (2 * PI * cutoff_freq)
+     */
+    HighPassFilterRC(Real timeconst);
+
+    /**
+     * Reconfigure filter with new time constant
+     */
+    void configure(Real timeconst);
+
+    /** Process samples. */
+    void process(const Real& sample_in, Real& sample_out);
+
+private:
+    Real m_timeconst;
+    Real m_y1;
+    Real m_a1;
+    Real m_b0;
+};
+
+#endif /* INCLUDE_DSP_FILTERRC_H_ */

android/app/src/main/cpp/dsp/firfilter.cpp

@@ -0,0 +1,73 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2017, 2019-2020 Edouard Griffiths, F4EXB <f4exb06@gmail.com> //
+// Copyright (C) 2020 Kacper Michajłow <kasper93@gmail.com>                      //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include "firfilter.h"
+#include <stdio.h>
+
+namespace FirFilterGenerators
+{
+
+void generateLowPassFilter(int nTaps, double sampleRate, double cutoff, std::vector<Real> &taps)
+{
+    if (!(nTaps & 1))
+    {
+        printf("Filter has to have an odd number of taps\n");
+        nTaps++;
+    }
+
+    double Wc = (2.0 * M_PI * cutoff) / sampleRate;
+    int halfTaps = nTaps / 2 + 1;
+    taps.resize(halfTaps);
+
+    for (int i = 0; i < halfTaps; ++i)
+    {
+        if (i == halfTaps - 1)
+        {
+            taps[i] = Wc / M_PI;
+        }
+        else
+        {
+            int n = i - (nTaps - 1) / 2;
+            taps[i] = sin(n * Wc) / (n * M_PI);
+        }
+    }
+
+    // Blackman window
+    for (int i = 0; i < halfTaps; i++)
+    {
+        int n = i - (nTaps - 1) / 2;
+        taps[i] *= 0.42 + 0.5 * cos((2.0 * M_PI * n) / nTaps) + 0.08 * cos((4.0 * M_PI * n) / nTaps);
+    }
+
+    Real sum = 0;
+    size_t i;
+
+    for (i = 0; i < taps.size() - 1; ++i) {
+        sum += taps[i] * 2.0;
+    }
+
+    sum += taps[i];
+
+    for (i = 0; i < taps.size(); ++i) {
+        taps[i] /= sum;
+    }
+}
+
+}

android/app/src/main/cpp/dsp/firfilter.h

@@ -0,0 +1,144 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2020 Edouard Griffiths, F4EXB <f4exb06@gmail.com>               //
+// Copyright (C) 2020 Kacper Michajłow <kasper93@gmail.com>                      //
+// Copyright (C) 2021, 2023 Jon Beniston, M7RCE <jon@beniston.com>               //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#pragma once
+
+#include <cmath>
+#include <cstdio>
+#include "dsp/dsptypes.h"
+#include "dsp/basebandsamplesink.h"
+#include "export.h"
+
+namespace FirFilterGenerators
+{
+    SDRBASE_API void generateLowPassFilter(int nTaps, double sampleRate, double cutoff, std::vector<Real> &taps);
+};
+
+template <class Type>
+class FirFilter
+{
+public:
+    Type filter(Type sample)
+    {
+        Type acc = 0;
+        unsigned int n_samples = m_samples.size();
+        unsigned int n_taps = m_taps.size() - 1;
+        unsigned int a = m_ptr;
+        unsigned int b = a == n_samples - 1 ? 0 : a + 1;
+
+        m_samples[m_ptr] = sample;
+
+        for (unsigned int i = 0; i < n_taps; ++i)
+        {
+            acc += (m_samples[a] + m_samples[b]) * m_taps[i];
+
+            a = (a == 0)             ? n_samples - 1 : a - 1;
+            b = (b == n_samples - 1) ? 0             : b + 1;
+        }
+
+        acc += m_samples[a] * m_taps[n_taps];
+
+        m_ptr = (m_ptr == n_samples - 1) ? 0 : m_ptr + 1;
+
+        return acc;
+    }
+
+    // Print taps as a Matlab vector
+    // To view:
+    //   h=fvtool(filter);
+    //   h.Fs=...
+    void printTaps(const char *name)
+    {
+        printf("%s = [", name);
+        for (int i = 0; i <= m_taps.size() - 1; ++i) {
+            printf("%g ", m_taps[i]);
+        }
+        for (int i = m_taps.size() - 2; i >= 0; --i) {
+            printf("%g ", m_taps[i]);
+        }
+        printf("];\n");
+    }
+
+protected:
+    void init(int nTaps)
+    {
+        m_ptr = 0;
+        m_samples.resize(nTaps);
+
+        for (int i = 0; i < nTaps; i++) {
+            m_samples[i] = 0;
+        }
+    }
+
+protected:
+    std::vector<Real> m_taps;
+    std::vector<Type> m_samples;
+    size_t m_ptr;
+};
+
+template <class T>
+struct Lowpass : public FirFilter<T>
+{
+public:
+    void create(int nTaps, double sampleRate, double cutoff)
+    {
+        this->init(nTaps);
+        FirFilterGenerators::generateLowPassFilter(nTaps, sampleRate, cutoff, this->m_taps);
+    }
+};
+
+template <class T>
+struct Bandpass : public FirFilter<T>
+{
+    void create(int nTaps, double sampleRate, double lowCutoff, double highCutoff)
+    {
+        this->init(nTaps);
+        FirFilterGenerators::generateLowPassFilter(nTaps, sampleRate, highCutoff, this->m_taps);
+        std::vector<Real> highPass;
+        FirFilterGenerators::generateLowPassFilter(nTaps, sampleRate, lowCutoff, highPass);
+
+        for (size_t i = 0; i < highPass.size(); ++i) {
+            highPass[i] = -highPass[i];
+        }
+
+        highPass[highPass.size() - 1] += 1;
+
+        for (size_t i = 0; i < this->m_taps.size(); ++i) {
+            this->m_taps[i] = -(this->m_taps[i] + highPass[i]);
+        }
+
+        this->m_taps[this->m_taps.size() - 1] += 1;
+    }
+};
+
+template <class T>
+struct Highpass : public FirFilter<T>
+{
+    void create(int nTaps, double sampleRate, double cutoff)
+    {
+        this->init(nTaps);
+        FirFilterGenerators::generateLowPassFilter(nTaps, sampleRate, cutoff, this->m_taps);
+
+        for (size_t i = 0; i < this->m_taps.size(); ++i) {
+            this->m_taps[i] = -this->m_taps[i];
+        }
+
+        this->m_taps[this->m_taps.size() - 1] += 1;
+    }
+};

android/app/src/main/cpp/dsp/fmpreemphasis.cpp

@@ -0,0 +1,80 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2020 Kacper Michajłow <kasper93@gmail.com>                      //
+// Copyright (C) 2020 Jon Beniston, M7RCE <jon@beniston.com>                     //
+// Copyright (C) 2005,2007,2012 Free Software Foundation, Inc.
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include <cmath>
+#include <QDebug>
+#include "dsp/fmpreemphasis.h"
+
+FMPreemphasis::FMPreemphasis(int sampleRate, Real tau, Real highFreq)
+{
+    configure(sampleRate, tau, highFreq);
+}
+
+void FMPreemphasis::configure(int sampleRate, Real tau, Real highFreq)
+{
+    // Based on: https://github.com/gnuradio/gnuradio/blob/master/gr-analog/python/analog/fm_emph.py
+    // Compare to freq response in https://www.mathworks.com/help/comm/ref/comm.fmbroadcastmodulator-system-object.html
+
+    // High frequency corner at which to flatten the gain
+    double fh = std::min((double)highFreq, 0.925 * sampleRate/2.0);
+
+    // Digital corner frequencies
+    double w_cl = 1.0 / tau;
+    double w_ch = 2.0 * M_PI * fh;
+
+    // Prewarped analog corner frequencies
+    double w_cla = 2.0 * sampleRate * std::tan(w_cl / (2.0 * sampleRate));
+    double w_cha = 2.0 * sampleRate * std::tan(w_ch / (2.0 * sampleRate));
+
+    // Resulting digital pole, zero, and gain term from the bilinear
+    // transformation of H(s) = (s + w_cla) / (s + w_cha) to
+    // H(z) = b0 (1 - z1 z^-1)/(1 - p1 z^-1)
+    double kl = -w_cla / (2.0 * sampleRate);
+    double kh = -w_cha / (2.0 * sampleRate);
+    double z1 = (1.0 + kl) / (1.0 - kl);
+    double p1 = (1.0 + kh) / (1.0 - kh);
+    double b0 = (1.0 - kl) / (1.0 - kh);
+
+    // Adjust with a gain, g, so 0 dB gain at DC
+    double g = std::abs(1.0 - p1) / (b0 * std::abs(1.0 - z1));
+
+    // Calculate IIR taps
+    m_b0 = (Real)(g * b0 * 1.0);
+    m_b1 = (Real)(g * b0 * -z1);
+    m_a1 = (Real)-p1;
+    // Zero delay line so we get reproducible results
+    m_z = 0;
+
+    qDebug() << "FMPreemphasis::configure: tau: " << tau
+                << " sampleRate: " << sampleRate
+                << " b0: " << m_b0
+                << " b1: " << m_b1
+                << " a1: " << m_a1;
+}
+
+Real FMPreemphasis::filter(const Real sampleIn)
+{
+    Real sampleOut;
+
+    // See Transposed Direct form 2 - https://en.wikipedia.org/wiki/Digital_biquad_filter
+    sampleOut = sampleIn * m_b0 + m_z;
+    m_z = sampleIn * m_b1 + sampleOut * -m_a1;
+
+    return sampleOut;
+}

android/app/src/main/cpp/dsp/fmpreemphasis.h

@@ -0,0 +1,58 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
+// written by Christian Daniel                                                   //
+// Copyright (C) 2015-2020 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+// Copyright (C) 2020 Jon Beniston, M7RCE <jon@beniston.com>                     //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef INCLUDE_DSP_FMPREEMPHASIS_H_
+#define INCLUDE_DSP_FMPREEMPHASIS_H_
+
+#include "dsp/dsptypes.h"
+#include "export.h"
+
+#define FMPREEMPHASIS_TAU_EU     50e-6f
+#define FMPREEMPHASIS_TAU_US     75e-6f
+
+/** FM preemphasis filter.
+ * Amplifies frequencies above ~3.2k (tau=50e-6 in EU) or ~2.1k (tau=75e-6 in US)
+ * at ~6dB per octave, and then flattens at 12k (highFreq).
+ * Frequency response:
+ *       highFreq
+ *           -------
+ *          /
+ *         /
+ * -------/
+ *   1/(2*pi*tau)
+ */
+class SDRBASE_API FMPreemphasis
+{
+public:
+
+    FMPreemphasis(int sampleRate, Real tau = FMPREEMPHASIS_TAU_EU, Real highFreq = 12000.0);
+
+    void configure(int sampleRate, Real tau = FMPREEMPHASIS_TAU_EU, Real highFreq = 12000.0);
+
+    Real filter(Real sampleIn);
+
+private:
+    Real m_z;                   // Delay element
+    Real m_b0;                  // IIR numerator taps
+    Real m_b1;
+    Real m_a1;                  // IIR denominator taps
+};
+
+#endif /* INCLUDE_DSP_FMPREEMPHASIS_H_ */

android/app/src/main/cpp/dsp/freqlockcomplex.cpp

@@ -0,0 +1,93 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2018-2019 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+// Copyright (C) 2020 Kacper Michajłow <kasper93@gmail.com>                      //
+//                                                                               //
+// See: http://liquidsdr.org/blog/pll-howto/                                     //
+// Fixed filter registers saturation                                             //
+// Added order for PSK locking. This brilliant idea actually comes from this     //
+// post: https://www.dsprelated.com/showthread/comp.dsp/36356-1.php              //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include "freqlockcomplex.h"
+#include <cmath>
+
+FreqLockComplex::FreqLockComplex() :
+    m_a0(0.998),
+    m_a1(0.002),
+    m_y(1.0, 0.0),
+    m_yRe(1.0),
+    m_yIm(0.0),
+    m_freq(0.0),
+    m_phi(0.0),
+    m_phiX0(0.0),
+    m_phiX1(0.0),
+    m_y1(0.0f)
+{
+}
+
+FreqLockComplex::~FreqLockComplex()
+{
+}
+
+void FreqLockComplex::reset()
+{
+    m_y.real(1.0);
+    m_y.imag(0.0);
+    m_yRe = 1.0f;
+    m_yIm = 0.0f;
+    m_freq = 0.0f;
+    m_phi = 0.0f;
+    m_phiX0 = 0.0f;
+    m_phiX1 = 0.0f;
+    m_y1 = 0.0f;
+}
+
+void FreqLockComplex::setSampleRate(unsigned int sampleRate)
+{
+    m_a1 = 10.0f / sampleRate; // 1 - alpha
+    m_a0 = 1.0f - m_a1; // alpha
+    reset();
+}
+
+void FreqLockComplex::feed(float re, float im)
+{
+    m_yRe = cos(m_phi);
+    m_yIm = sin(m_phi);
+    m_y.real(m_yRe);
+    m_y.imag(m_yIm);
+    std::complex<float> x(re, im);
+    m_phiX0 = std::arg(x);
+
+    float eF = normalizeAngle(m_phiX0 - m_phiX1);
+    float fHat = m_a1*eF + m_a0*m_y1;
+    m_y1 = fHat;
+
+    m_freq = fHat; // correct instantaneous frequency
+    m_phi += fHat; // advance phase with instantaneous frequency
+    m_phiX1 = m_phiX0;
+}
+
+float FreqLockComplex::normalizeAngle(float angle)
+{
+    while (angle <= -M_PI) {
+        angle += 2.0*M_PI;
+    }
+    while (angle > M_PI) {
+        angle -= 2.0*M_PI;
+    }
+    return angle;
+}
+

android/app/src/main/cpp/dsp/freqlockcomplex.h

@@ -0,0 +1,62 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2018-2019 Edouard Griffiths, F4EXB <f4exb06@gmail.com>          //
+//                                                                               //
+// See: http://liquidsdr.org/blog/pll-howto/                                     //
+// Fixed filter registers saturation                                             //
+// Added order for PSK locking. This brilliant idea actually comes from this     //
+// post: https://www.dsprelated.com/showthread/comp.dsp/36356-1.php              //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef SDRBASE_DSP_FREQLOCKCOMPLEX_H_
+#define SDRBASE_DSP_FREQLOCKCOMPLEX_H_
+
+#include "dsp/dsptypes.h"
+#include "export.h"
+
+/** General purpose Phase-locked loop using complex analytic signal input. */
+class SDRBASE_API FreqLockComplex
+{
+public:
+    FreqLockComplex();
+    ~FreqLockComplex();
+
+    void reset();
+    void setSampleRate(unsigned int sampleRate);
+    /** Feed PLL with a new signa sample */
+    void feed(float re, float im);
+    const std::complex<float>& getComplex() const { return m_y; }
+    float getReal() const { return m_yRe; }
+    float getImag() const { return m_yIm; }
+    float getFreq() const { return m_freq; }
+
+private:
+    /** Normalize angle in radians into the [-pi,+pi] region */
+    static float normalizeAngle(float angle);
+
+    float m_a0;
+    float m_a1;
+    std::complex<float> m_y;
+    float m_yRe;
+    float m_yIm;
+    float m_freq;
+    float m_phi;
+    float m_phiX0;
+    float m_phiX1;
+    float m_y1;
+};
+
+
+#endif /* SDRBASE_DSP_FREQLOCKCOMPLEX_H_ */

android/app/src/main/cpp/dsp/gaussian.h

@@ -0,0 +1,122 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2020-2021 Jon Beniston, M7RCE <jon@beniston.com>                //
+// Copyright (C) 2020 Kacper Michajłow <kasper93@gmail.com>                      //
+// Copyright (C) 2015 Edouard Griffiths, F4EXB                                   //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef INCLUDE_GAUSSIAN_H
+#define INCLUDE_GAUSSIAN_H
+
+#include <math.h>
+#include "dsp/dsptypes.h"
+
+// Standard values for bt
+#define GAUSSIAN_BT_BLUETOOTH   0.5
+#define GAUSSIAN_BT_GSM         0.3
+#define GAUSSIAN_BT_CCSDS       0.25
+#define GAUSSIAN_BT_802_15_4    0.5
+#define GAUSSIAN_BT_AIS         0.5
+
+// Gaussian low-pass filter for pulse shaping
+// https://onlinelibrary.wiley.com/doi/pdf/10.1002/9780470041956.app2
+// Unlike raisedcosine.h, this should be feed NRZ values rather than impulse stream, as described here:
+// https://www.mathworks.com/matlabcentral/answers/107231-why-does-the-pulse-shape-generated-by-gaussdesign-differ-from-that-used-in-the-comm-gmskmodulator-ob
+template <class Type> class Gaussian {
+public:
+    Gaussian() : m_ptr(0) { }
+
+    // bt - 3dB bandwidth symbol time product
+    // symbolSpan - number of symbols over which the filter is spread
+    // samplesPerSymbol - number of samples per symbol
+    void create(double bt, int symbolSpan, int samplesPerSymbol)
+    {
+        int nTaps = symbolSpan * samplesPerSymbol + 1;
+        int i;
+
+        // check constraints
+        if(!(nTaps & 1)) {
+            qDebug("Gaussian filter has to have an odd number of taps");
+            nTaps++;
+        }
+
+        // make room
+        m_samples.resize(nTaps);
+        for(int i = 0; i < nTaps; i++)
+            m_samples[i] = 0;
+        m_ptr = 0;
+        m_taps.resize(nTaps / 2 + 1);
+
+        // See eq B.2 - this is alpha over Ts
+        double alpha_t = std::sqrt(std::log(2.0) / 2.0) / (bt);
+        double sqrt_pi_alpha_t = std::sqrt(M_PI) / alpha_t;
+
+        // calculate filter taps
+        for(i = 0; i < nTaps / 2 + 1; i++)
+        {
+            double t = (i - (nTaps / 2)) / (double)samplesPerSymbol;
+
+            // See eq B.5
+            m_taps[i] = sqrt_pi_alpha_t * std::exp(-std::pow(t * M_PI / alpha_t, 2.0));
+        }
+
+        // normalize
+        double sum = 0;
+        for(i = 0; i < (int)m_taps.size() - 1; i++)
+            sum += m_taps[i] * 2;
+        sum += m_taps[i];
+        for(i = 0; i < (int)m_taps.size(); i++)
+            m_taps[i] /= sum;
+    }
+
+    Type filter(Type sample)
+    {
+        Type acc = 0;
+        unsigned int n_samples = m_samples.size();
+        unsigned int n_taps = m_taps.size() - 1;
+        unsigned int a = m_ptr;
+        unsigned int b = a == n_samples - 1 ? 0 : a + 1;
+
+        m_samples[m_ptr] = sample;
+
+        for (unsigned int i = 0; i < n_taps; ++i)
+        {
+            acc += (m_samples[a] + m_samples[b]) * m_taps[i];
+
+            a = (a == 0)             ? n_samples - 1 : a - 1;
+            b = (b == n_samples - 1) ? 0             : b + 1;
+        }
+
+        acc += m_samples[a] * m_taps[n_taps];
+
+        m_ptr = (m_ptr == n_samples - 1) ? 0 : m_ptr + 1;
+
+        return acc;
+    }
+/*
+    void printTaps()
+    {
+        for (int i = 0; i < m_taps.size(); i++)
+            printf("%.4f ", m_taps[i]);
+        printf("\n");
+    }
+*/
+private:
+    std::vector<Real> m_taps;
+    std::vector<Type> m_samples;
+    unsigned int m_ptr;
+};
+
+#endif // INCLUDE_GAUSSIAN_H