feat: enhance message handling and logging in demodulation and TCP channel

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

@@ -1,4 +1,5 @@
 #include "demod.h"
+#include <android/log.h>
 
 bool is_message_ready = false;
 
@@ -188,6 +189,10 @@ void decodeBatch()
                 function_bits = (code_words[i] >> 11) & 0x3;
                 int addressBits = (code_words[i] >> 13) & 0x3ffff;
                 address = (addressBits << 3) | frame;
+                
+                __android_log_print(ANDROID_LOG_DEBUG, "DEMOD", "addr_cw: raw=0x%08X addr=%u func=%d frame=%d bch_err=%d parity_err=%d",
+                    code_words[i], address, function_bits, frame, code_words_bch_error[i] ? 1 : 0, parityError ? 1 : 0);
+                
                 numeric_msg = "";
                 alpha_msg = "";
                 alpha_bit_buffer_bits = 0;
@@ -201,6 +206,9 @@ void decodeBatch()
                 if (parityError) parity_errors++;
                 if (code_words_bch_error[i]) bch_errors++;
                 
+                __android_log_print(ANDROID_LOG_DEBUG, "DEMOD", "msg_cw: raw=0x%08X msgbits=0x%05X bch_err=%d parity_err=%d",
+                    code_words[i], messageBits, code_words_bch_error[i] ? 1 : 0, parityError ? 1 : 0);
+
                 for (int j = 16; j >= 0; j -= 4)
                 {
                     uint32_t numericBits = (messageBits >> j) & 0xf;
@@ -325,6 +333,7 @@ void processBasebandSample(double sample)
 
                 if (got_SC)
                 {
+                    __android_log_print(ANDROID_LOG_DEBUG, "DEMOD", "sync_found: inverted=%d bits=0x%08X", bit_inverted ? 1 : 0, bits);
                     bits = 0;
                     bit_cnt = 0;
                     code_words[0] = POCSAG_SYNCCODE;
@@ -381,5 +390,90 @@ void processOneSample(int8_t i, int8_t q)
     float deviation;
     double fmDemod = phaseDiscri.phaseDiscriminatorDelta(iq, magsqRaw, deviation);
     
-    processBasebandSample(fmDemod);
+    double filt = lowpassBaud.filter(fmDemod);
+
+    if (!got_SC) {
+        preambleMovingAverage(filt);
+        dc_offset = preambleMovingAverage.asDouble();
+    }
+
+    bool data = (filt - dc_offset) >= 0.0;
+
+    if (data != prev_data) {
+        sync_cnt = SAMPLES_PER_SYMBOL / 2;
+    } else {
+        sync_cnt--;
+        
+        if (sync_cnt <= 0) {
+            if (bit_inverted) {
+                data_bit = data;
+            } else {
+                data_bit = !data;
+            }
+
+            bits = (bits << 1) | data_bit;
+            bit_cnt++;
+
+            if (bit_cnt > 32) {
+                bit_cnt = 32;
+            }
+
+            if (bit_cnt == 32 && !got_SC) {
+                if (bits == POCSAG_SYNCCODE) {
+                    got_SC = true;
+                    bit_inverted = false;
+                } else if (bits == POCSAG_SYNCCODE_INV) {
+                    got_SC = true;
+                    bit_inverted = true;
+                } 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;
+                    }
+                } 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;
+                    }
+                }
+
+                if (got_SC) {
+                    __android_log_print(ANDROID_LOG_DEBUG, "DEMOD", "sync_found: inverted=%d bits=0x%08X", bit_inverted ? 1 : 0, bits);
+                    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;
+                }
+            }
+
+            sync_cnt = SAMPLES_PER_SYMBOL;
+        }
+    }
+
+    prev_data = data;
 }

android/app/src/main/cpp/native-lib.cpp

@@ -255,27 +255,33 @@ void clientThread(std::string host, int port)
                 std::lock_guard<std::mutex> demodLock(demodDataMutex);
                 processOneSample(i_ds, q_ds);
 
+                if (is_message_ready)
+                {
+                    std::ostringstream ss;
+                    std::lock_guard<std::mutex> msgLock(msgMutex);
+
+                    std::string message_content;
+                    if (function_bits == 3) {
+                        message_content = alpha_msg;
+                    } else {
+                        message_content = numeric_msg;
+                    }
+                    if (message_content.empty()) {
+                        message_content = alpha_msg.empty() ? numeric_msg : alpha_msg;
+                    }
+
+                    ss << "[MSG]" << address << "|" << function_bits << "|" << message_content;
+                    messageBuffer.push_back(ss.str());
+
+                    is_message_ready = false;
+                    numeric_msg.clear();
+                    alpha_msg.clear();
+                }
+
                 acc_i = acc_q = 0;
                 decim_counter = 0;
             }
         }
-
-        if (is_message_ready)
-        {
-            std::ostringstream ss;
-
-            std::lock_guard<std::mutex> demodLock(demodDataMutex);
-            std::lock_guard<std::mutex> msgLock(msgMutex);
-
-            std::string message_content = alpha_msg.empty() ? numeric_msg : alpha_msg;
-            ss << "[MSG]" << address << "|" << function_bits << "|" << message_content;
-            messageBuffer.push_back(ss.str());
-
-            is_message_ready = false;
-
-            numeric_msg.clear();
-            alpha_msg.clear();
-        }
     }
 
     if (n < 0 && running)

android/app/src/main/kotlin/org/noxylva/lbjconsole/flutter/RtlTcpChannelHandler.kt

@@ -61,6 +61,7 @@ class RtlTcpChannelHandler : EventChannel.StreamHandler {
     override fun onListen(arguments: Any?, events: EventChannel.EventSink?) {
         android.util.Log.d("RTL-TCP", "evt_listen")
         this.eventSink = events
+        lastConnectedState = true
         startPolling() 
     }
 
@@ -77,34 +78,76 @@ class RtlTcpChannelHandler : EventChannel.StreamHandler {
                     android.util.Log.w("RTL-TCP", "evt_null");
                     return;
                 }
+                val connected = try {
+                    isConnected()
+                } catch (e: Exception) {
+                    android.util.Log.e("RTL-TCP", "isConnected() failed", e)
+                    false
+                }
+
+                val strength = try {
+                    getSignalStrength()
+                } catch (e: Exception) {
+                    android.util.Log.e("RTL-TCP", "getSignalStrength() failed", e)
+                    0.0
+                }
+
+                val logs = try {
+                    pollMessages()
+                } catch (e: Exception) {
+                    android.util.Log.e("RTL-TCP", "pollMessages() failed", e)
+                    ""
+                }
 
-                val connected = isConnected()
-                val strength = getSignalStrength() 
-                val logs = pollMessages()
                 val regex = "\\[MSG\\]\\s*(\\d+)\\|(-?\\d+)\\|(.*)".toRegex()
 
-                if (connected != lastConnectedState || connected) {
+                android.util.Log.d("RTL-TCP", "poll: connected=$connected magsqRaw=$strength logsLen=${logs.length}")
+                if (logs.isNotEmpty()) {
+                    val preview = if (logs.length > 1000) logs.substring(0, 1000) + "..." else logs
+                    android.util.Log.d("RTL-TCP", "pollLogs: $preview")
+                }
+
+                if (connected != lastConnectedState) {
                     val statusMap = mutableMapOf<String, Any?>()
                     statusMap["connected"] = connected
                     statusMap["magsqRaw"] = strength
-                    eventSink?.success(statusMap)
+                    try {
+                        eventSink?.success(statusMap)
+                    } catch (e: Exception) {
+                        android.util.Log.e("RTL-TCP", "eventSink status send failed", e)
+                    }
                     lastConnectedState = connected
                 }
 
                 if (logs.isNotEmpty()) {
                     regex.findAll(logs).forEach { match ->
                         try {
+                            val addr = match.groupValues[1]
+                            val func = match.groupValues[2]
+                            val raw = match.groupValues[3]
+                            android.util.Log.d("RTL-TCP", "msg_match: addr=$addr func=$func raw_len=${raw.length}")
+
+                            val gbkBytes = raw.toByteArray(Charsets.ISO_8859_1)
+                            val utf8String = try {
+                                String(gbkBytes, Charset.forName("GBK"))
+                            } catch (e: Exception) {
+                                android.util.Log.e("RTL-TCP", "GBK decode failed", e)
+                                raw
+                            }
+
+                            android.util.Log.d("RTL-TCP", "msg_decoded: addr=$addr func=$func numeric=$utf8String")
+
                             val dataMap = mutableMapOf<String, Any?>()
-                            dataMap["address"] = match.groupValues[1]
+                            dataMap["address"] = addr
-                            dataMap["func"] = match.groupValues[2]
+                            dataMap["func"] = func
-                            
-                            val gbkBytes = match.groupValues[3].toByteArray(Charsets.ISO_8859_1)
-                            val utf8String = String(gbkBytes, Charset.forName("GBK"))
                             dataMap["numeric"] = utf8String
-                            
                             dataMap["magsqRaw"] = strength
 
-                            eventSink?.success(dataMap)
+                            try {
+                                eventSink?.success(dataMap)
+                            } catch (e: Exception) {
+                                android.util.Log.e("RTL-TCP", "eventSink data send failed", e)
+                            }
                         } catch (e: Exception) {
                             android.util.Log.e("RTL-TCP", "decode_fail", e)
                         }