Simplify the LSF processing to allow changed META field data changed

through.

M17Control.cpp

@@ -76,9 +76,12 @@ m_rfFrames(0U),
 m_netFrames(0U),
 m_rfErrs(0U),
 m_rfBits(1U),
-m_rfLSF(),
+m_rfLSF1(),
+m_rfLSF2(),
+m_rfLSF3(),
 m_rfLSFn(0U),
 m_netLSF(),
+m_netLSFn(0U),
 m_rssiMapper(rssiMapper),
 m_rssi(0U),
 m_maxRSSI(0U),
@@ -106,8 +109,8 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
 	unsigned char type = data[0U];
 
 	if (type == TAG_LOST && (m_rfState == RS_RF_AUDIO || m_rfState == RS_RF_DATA_AUDIO)) {
-		std::string source = m_rfLSF.getSource();
+		std::string source = m_rfLSF1.getSource();
-		std::string dest   = m_rfLSF.getDest();
+		std::string dest   = m_rfLSF1.getDest();
 
 		if (m_rssi != 0U)
 			LogMessage("M17, transmission lost from %s to %s, %.1f seconds, BER: %.1f%%, RSSI: -%u/-%u/-%u dBm", source.c_str(), dest.c_str(), float(m_rfFrames) / 25.0F, float(m_rfErrs * 100U) / float(m_rfBits), m_minRSSI, m_maxRSSI, m_aveRSSI / m_rssiCount);
@@ -160,7 +163,7 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
 	interleaver(temp, data + 2U);
 
 	if (m_rfState == RS_RF_LISTENING && data[0U] == TAG_HEADER) {
-		m_rfLSF.reset();
+		m_rfLSF1.reset();
 
 		CM17Convolution conv;
 		unsigned char frame[M17_LSF_LENGTH_BYTES];
@@ -168,11 +171,11 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
 
 		bool valid = CM17CRC::checkCRC16(frame, M17_LSF_LENGTH_BYTES);
 		if (valid) {
-			m_rfLSF.setLinkSetup(frame);
+			m_rfLSF1.setLinkSetup(frame);
 
 			bool ret = processRFHeader(false);
 			if (!ret) {
-				m_rfLSF.reset();
+				m_rfLSF1.reset();
 				return false;
 			}
 
@@ -181,6 +184,8 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
 			m_rfFrames  = 0U;
 			m_rfErrs    = ber;
 			m_rfBits    = 368U;
+			m_rfLSF2.reset();
+			m_rfLSF3.reset();
 			m_rfTimeoutTimer.start();
 			m_minRSSI   = m_rssi;
 			m_maxRSSI   = m_rssi;
@@ -188,9 +193,6 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
 			m_rssiCount = 1U;
 			m_rfLSFn    = 0U;
 
-			if (m_network != NULL)
-				m_network->writeHeader(m_rfLSF.getSource(), m_rfLSF.getDest(), frame);
-
 #if defined(DUMP_M17)
 			openFile();
 #endif
@@ -203,7 +205,7 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
 
 	if (m_rfState == RS_RF_LISTENING && data[0U] == TAG_DATA) {
 		m_rfState = RS_RF_LATE_ENTRY;
-		m_rfLSF.reset();
+		m_rfLSF1.reset();
 	}
 
 	if (m_rfState == RS_RF_LATE_ENTRY && data[0U] == TAG_DATA) {
@@ -220,31 +222,27 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
 		CM17Utils::combineFragmentLICH(lich1, lich2, lich3, lich4, lich);
 
 		m_rfLSFn = (lich4 >> 5) & 0x07U;
-		m_rfLSF.setFragment(lich, m_rfLSFn);
+		m_rfLSF1.setFragment(lich, m_rfLSFn);
 
-		bool valid = m_rfLSF.isValid();
+		bool valid = m_rfLSF1.isValid();
 		if (valid) {
 			bool ret = processRFHeader(true);
 			if (!ret) {
-				m_rfLSF.reset();
+				m_rfLSF1.reset();
 				return false;
 			}
 
 			m_rfFrames  = 0U;
 			m_rfErrs    = 0U;
 			m_rfBits    = 1U;
+			m_rfLSF2.reset();
+			m_rfLSF3.reset();
 			m_rfTimeoutTimer.start();
 			m_minRSSI   = m_rssi;
 			m_maxRSSI   = m_rssi;
 			m_aveRSSI   = m_rssi;
 			m_rssiCount = 1U;
 
-			if (m_network != NULL) {
-				unsigned char lsf[M17_LSF_LENGTH_BYTES];
-				m_rfLSF.getNetwork(lsf);
-				m_network->writeHeader(m_rfLSF.getSource(), m_rfLSF.getDest(), lsf);
-			}
-
 #if defined(DUMP_M17)
 			openFile();
 #endif
@@ -258,6 +256,37 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
 #if defined(DUMP_M17)
 		writeFile(data + 2U);
 #endif
+		// Keep looking at the running LSF in case of changed META field data
+		unsigned int lich1, lich2, lich3, lich4;
+		bool valid1 = CGolay24128::decode24128(data + 2U + M17_SYNC_LENGTH_BYTES + 0U, lich1);
+		bool valid2 = CGolay24128::decode24128(data + 2U + M17_SYNC_LENGTH_BYTES + 3U, lich2);
+		bool valid3 = CGolay24128::decode24128(data + 2U + M17_SYNC_LENGTH_BYTES + 6U, lich3);
+		bool valid4 = CGolay24128::decode24128(data + 2U + M17_SYNC_LENGTH_BYTES + 9U, lich4);
+
+		if (valid1 && valid2 && valid3 && valid4) {
+			unsigned char lich[M17_LICH_FRAGMENT_LENGTH_BYTES];
+			CM17Utils::combineFragmentLICH(lich1, lich2, lich3, lich4, lich);
+
+			unsigned int n = (lich4 >> 5) & 0x07U;
+			m_rfLSF2.setFragment(lich, n);
+
+			// If the latest LSF is valid, save it and start collecting the next one
+			bool valid = m_rfLSF2.isValid();
+			if (valid) {
+				m_rfLSF3 = m_rfLSF2;
+				m_rfLSF2.reset();
+			}
+		}
+
+		// Update the currently transmitted LSF when the fragement number is zero
+		if (m_rfLSFn == 0U) {
+			bool valid = m_rfLSF3.isValid();
+			if (valid) {
+				m_rfLSF1 = m_rfLSF3;
+				m_rfLSF3.reset();
+			}
+		}
+
 		CM17Convolution conv;
 		unsigned char frame[M17_FN_LENGTH_BYTES + M17_PAYLOAD_LENGTH_BYTES];
 		unsigned int errors = conv.decodeData(data + 2U + M17_SYNC_LENGTH_BYTES + M17_LICH_FRAGMENT_FEC_LENGTH_BYTES, frame);
@@ -282,7 +311,7 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
 			CSync::addM17StreamSync(rfData + 2U);
 
 			unsigned char lich[M17_LICH_FRAGMENT_LENGTH_BYTES];
-			m_rfLSF.getFragment(lich, m_rfLSFn);
+			m_rfLSF1.getFragment(lich, m_rfLSFn);
 
 			// Add the fragment number
 			lich[5U] = (m_rfLSFn & 0x07U) << 5;
@@ -309,13 +338,16 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
 		}
 
 		if (m_network != NULL && m_rfTimeoutTimer.isRunning() && !m_rfTimeoutTimer.hasExpired()) {
-			unsigned char lich[M17_LICH_FRAGMENT_LENGTH_BYTES];
+			unsigned char netData[M17_LSF_LENGTH_BYTES + M17_FN_LENGTH_BYTES + M17_PAYLOAD_LENGTH_BYTES + M17_CRC_LENGTH_BYTES];
-			m_rfLSF.getFragment(lich, m_rfLSFn);
 
-			// Add the fragment number
+			m_rfLSF1.getNetwork(netData + 0U);
-			lich[5U] = (m_rfLSFn & 0x07U) << 5;
 
-			m_network->writeData(m_rfLSF.getSource(), m_rfLSF.getDest(), lich, frame);
+			// Copy the FN and payload from the frame
+			::memcpy(netData + M17_LSF_LENGTH_BYTES - M17_CRC_LENGTH_BYTES, frame, M17_FN_LENGTH_BYTES + M17_PAYLOAD_LENGTH_BYTES);
+
+			// The CRC is added in the networking code
+
+			m_network->write(netData);
 		}
 
 		m_rfFrames++;
@@ -328,8 +360,8 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
 		bool bEnd   = (fn & 0x8000U) == 0x8000U;
 
 		if (bValid && bEnd) {
-			std::string source = m_rfLSF.getSource();
+			std::string source = m_rfLSF1.getSource();
-			std::string dest   = m_rfLSF.getDest();
+			std::string dest   = m_rfLSF1.getDest();
 
 			if (m_rssi != 0U)
 				LogMessage("M17, received RF end of transmission from %s to %s, %.1f seconds, BER: %.1f%%, RSSI: -%u/-%u/-%u dBm", source.c_str(), dest.c_str(), float(m_rfFrames) / 25.0F, float(m_rfErrs * 100U) / float(m_rfBits), m_minRSSI, m_maxRSSI, m_aveRSSI / m_rssiCount);
@@ -365,7 +397,9 @@ void CM17Control::writeEndRF()
 
 	m_rfTimeoutTimer.stop();
 
-	m_rfLSF.reset();
+	m_rfLSF1.reset();
+	m_rfLSF2.reset();
+	m_rfLSF3.reset();
 
 	if (m_netState == RS_NET_IDLE) {
 		m_display->clearM17();
@@ -409,10 +443,6 @@ void CM17Control::writeNetwork()
 
 	m_networkWatchdog.start();
 
-	if (netData[0U] == TAG_HEADER) {
-		m_netLSF.setNetwork(netData + 19U);
-		m_netLSF.setCAN(m_can);
-
 	if (!m_allowEncryption) {
 		unsigned char type = m_netLSF.getEncryptionType();
 		if (type != M17_ENCRYPTION_TYPE_NONE) {
@@ -421,6 +451,10 @@ void CM17Control::writeNetwork()
 		}
 	}
 
+	if (m_netState == RS_NET_IDLE) {
+		m_netLSF.setNetwork(netData);
+		m_netLSF.setCAN(m_can);
+
 		std::string source = m_netLSF.getSource();
 		std::string dest   = m_netLSF.getDest();
 
@@ -439,7 +473,7 @@ void CM17Control::writeNetwork()
 			m_netState = RS_NET_DATA_AUDIO;
 			break;
 		default:
-			LogMessage("M17, received unknown network transmission from %s to %s", source.c_str(), dest.c_str());
+			LogMessage("M17, received network unknown transmission from %s to %s", source.c_str(), dest.c_str());
 			m_network->reset();
 			break;
 		}
@@ -449,6 +483,7 @@ void CM17Control::writeNetwork()
 		m_netTimeoutTimer.start();
 		m_elapsed.start();
 		m_netFrames = 0U;
+		m_netLSFn   = 0U;
 
 		// Create a dummy start message
 		unsigned char start[M17_FRAME_LENGTH_BYTES + 2U];
@@ -473,7 +508,13 @@ void CM17Control::writeNetwork()
 		writeQueueNet(start);
 	}
 
-	if (netData[0U] == TAG_DATA) {
+	if (m_netState == RS_NET_AUDIO || m_netState == RS_NET_DATA_AUDIO) {
+		// Refresh the LSF every six frames in case the META field changes
+		if (m_netLSFn == 0U) {
+			m_netLSF.setNetwork(netData);
+			m_netLSF.setCAN(m_can);
+		}
+
 		unsigned char data[M17_FRAME_LENGTH_BYTES + 2U];
 
 		data[0U] = TAG_DATA;
@@ -484,8 +525,15 @@ void CM17Control::writeNetwork()
 
 		m_netFrames++;
 
+		// Add the fragment LICH
+		unsigned char lich[M17_LICH_FRAGMENT_LENGTH_BYTES];
+		m_netLSF.getFragment(lich, m_netLSFn);
+
+		// Add the fragment number
+		lich[5U] = (m_netLSFn & 0x07U) << 5;
+
 		unsigned int frag1, frag2, frag3, frag4;
-		CM17Utils::splitFragmentLICH(netData + 19U, frag1, frag2, frag3, frag4);
+		CM17Utils::splitFragmentLICH(lich, frag1, frag2, frag3, frag4);
 
 		// Add Golay to the LICH fragment here
 		unsigned int lich1 = CGolay24128::encode24128(frag1);
@@ -495,9 +543,13 @@ void CM17Control::writeNetwork()
 
 		CM17Utils::combineFragmentLICHFEC(lich1, lich2, lich3, lich4, data + 2U + M17_SYNC_LENGTH_BYTES);
 
+		// Add the FN and the data/audio
+		unsigned char payload[M17_FN_LENGTH_BYTES + M17_PAYLOAD_LENGTH_BYTES];
+		::memcpy(payload, netData + 28U, M17_FN_LENGTH_BYTES + M17_PAYLOAD_LENGTH_BYTES);
+
 		// Add the Convolution FEC
 		CM17Convolution conv;
-		conv.encodeData(netData + 25U, data + 2U + M17_SYNC_LENGTH_BYTES + M17_LICH_FRAGMENT_FEC_LENGTH_BYTES);
+		conv.encodeData(payload, data + 2U + M17_SYNC_LENGTH_BYTES + M17_LICH_FRAGMENT_FEC_LENGTH_BYTES);
 
 		unsigned char temp[M17_FRAME_LENGTH_BYTES];
 		interleaver(data + 2U, temp);
@@ -505,8 +557,12 @@ void CM17Control::writeNetwork()
 
 		writeQueueNet(data);
 
+		m_netLSFn++;
+		if (m_netLSFn >= 6U)
+			m_netLSFn = 0U;
+
 		// EOT handling
-		uint16_t fn = (netData[25U] << 8) + (netData[26U] << 0);
+		uint16_t fn = (netData[28U] << 8) + (netData[29U] << 0);
 		if ((fn & 0x8000U) == 0x8000U) {
 			std::string source = m_netLSF.getSource();
 			std::string dest   = m_netLSF.getDest();
@@ -518,19 +574,19 @@ void CM17Control::writeNetwork()
 
 bool CM17Control::processRFHeader(bool lateEntry)
 {
-	unsigned char packetStream = m_rfLSF.getPacketStream();
+	unsigned char packetStream = m_rfLSF1.getPacketStream();
 	if (packetStream == M17_PACKET_TYPE)
 		return false;
 
-	unsigned char can = m_rfLSF.getCAN();
+	unsigned char can = m_rfLSF1.getCAN();
 	if (can != m_can)
 		return false;
 
-	std::string source = m_rfLSF.getSource();
+	std::string source = m_rfLSF1.getSource();
-	std::string dest   = m_rfLSF.getDest();
+	std::string dest   = m_rfLSF1.getDest();
 
 	if (!m_allowEncryption) {
-		unsigned char type = m_rfLSF.getEncryptionType();
+		unsigned char type = m_rfLSF1.getEncryptionType();
 		if (type != M17_ENCRYPTION_TYPE_NONE) {
 			LogMessage("M17, access attempt with encryption from %s to %s", source.c_str(), dest.c_str());
 			m_rfState = RS_RF_REJECTED;
@@ -547,7 +603,7 @@ bool CM17Control::processRFHeader(bool lateEntry)
 		}
 	}
 
-	unsigned char dataType = m_rfLSF.getDataType();
+	unsigned char dataType = m_rfLSF1.getDataType();
 	switch (dataType) {
 	case M17_DATA_TYPE_DATA:
 		LogMessage("M17, received RF%sdata transmission from %s to %s", lateEntry ? " late entry " : " ", source.c_str(), dest.c_str());
@@ -580,7 +636,7 @@ bool CM17Control::processRFHeader(bool lateEntry)
 		CSync::addM17LinkSetupSync(data + 2U);
 
 		unsigned char setup[M17_LSF_LENGTH_BYTES];
-		m_rfLSF.getLinkSetup(setup);
+		m_rfLSF1.getLinkSetup(setup);
 
 		// Add the convolution FEC
 		CM17Convolution conv;

M17Control.h

@@ -66,9 +66,12 @@ private:
 	unsigned int               m_netFrames;
 	unsigned int               m_rfErrs;
 	unsigned int               m_rfBits;
-	CM17LSF                    m_rfLSF;
+	CM17LSF                    m_rfLSF1;
+	CM17LSF                    m_rfLSF2;
+	CM17LSF                    m_rfLSF3;
 	unsigned int               m_rfLSFn;
 	CM17LSF                    m_netLSF;
+	unsigned int               m_netLSFn;
 	CRSSIInterpolator*         m_rssiMapper;
 	unsigned char              m_rssi;
 	unsigned char              m_maxRSSI;

M17LSF.cpp

@@ -24,6 +24,15 @@
 #include <cassert>
 #include <cstring>
 
+CM17LSF::CM17LSF(const CM17LSF& lsf) :
+m_lsf(NULL),
+m_valid(lsf.m_valid)
+{
+	m_lsf = new unsigned char[M17_LSF_LENGTH_BYTES];
+
+	::memcpy(m_lsf, lsf.m_lsf, M17_LSF_LENGTH_BYTES);
+}
+
 CM17LSF::CM17LSF() :
 m_lsf(NULL),
 m_valid(false)
@@ -197,3 +206,13 @@ void CM17LSF::setFragment(const unsigned char* data, unsigned int n)
 
 	m_valid = CM17CRC::checkCRC16(m_lsf, M17_LSF_LENGTH_BYTES);
 }
+
+CM17LSF& CM17LSF::operator=(const CM17LSF& lsf)
+{
+	if (&lsf != this) {
+		::memcpy(m_lsf, lsf.m_lsf, M17_LSF_LENGTH_BYTES);
+		m_valid = lsf.m_valid;
+	}
+
+	return *this;
+}

M17LSF.h

@@ -23,6 +23,7 @@
 
 class CM17LSF {
 public:
+	CM17LSF(const CM17LSF& lsf);
 	CM17LSF();
 	~CM17LSF();
 
@@ -62,6 +63,8 @@ public:
 	void getFragment(unsigned char* data, unsigned int n) const;
 	void setFragment(const unsigned char* data, unsigned int n);
 
+	CM17LSF& operator=(const CM17LSF& lsf);
+
 private:
 	unsigned char* m_lsf;
 	bool           m_valid;

M17Network.cpp

@@ -74,19 +74,19 @@ bool CM17Network::open()
 	}
 }
 
-bool CM17Network::writeHeader(const std::string& source, const std::string& dest, const unsigned char* lsf)
+bool CM17Network::write(const unsigned char* data)
 {
 	if (m_addrLen == 0U)
 		return false;
 
-	assert(lsf != NULL);
+	assert(data != NULL);
 
-	unsigned char buffer[60U];
+	unsigned char buffer[100U];
 
 	buffer[0U] = 'M';
 	buffer[1U] = '1';
 	buffer[2U] = '7';
-	buffer[3U] = 'H';
+	buffer[3U] = ' ';
 
 	// Create a random id for this transmission if needed
 	if (m_outId == 0U) {
@@ -97,52 +97,16 @@ bool CM17Network::writeHeader(const std::string& source, const std::string& dest
 	buffer[4U] = m_outId / 256U;	// Unique session id
 	buffer[5U] = m_outId % 256U;
 
-	::memset(buffer + 6U, ' ', 9U);
+	::memcpy(buffer + 6U, data, 46U);
-	::memcpy(buffer + 6U, source.c_str(), source.size());
 
-	::memset(buffer + 15U, ' ', 9U);
+	// Dummy CRC
-	::memcpy(buffer + 15U, dest.c_str(), dest.size());
+	buffer[52U] = 0x00U;
-
+	buffer[53U] = 0x00U;
-	::memcpy(buffer + 24U, lsf, 28U);
 
 	if (m_debug)
-		CUtils::dump(1U, "M17 header transmitted", buffer, 52U);
+		CUtils::dump(1U, "M17 data transmitted", buffer, 54U);
 
-	return m_socket.write(buffer, 52U, m_addr, m_addrLen);
+	return m_socket.write(buffer, 54U, m_addr, m_addrLen);
-}
-
-bool CM17Network::writeData(const std::string& source, const std::string& dest,const unsigned char* lsf, const unsigned char* data)
-{
-	if (m_addrLen == 0U)
-		return false;
-
-	assert(data != NULL);
-	assert(lsf != NULL);
-
-	unsigned char buffer[50U];
-
-	buffer[0U] = 'M';
-	buffer[1U] = '1';
-	buffer[2U] = '7';
-	buffer[3U] = 'D';
-
-	buffer[4U] = m_outId / 256U;	// Unique session id
-	buffer[5U] = m_outId % 256U;
-
-	::memset(buffer + 6U, ' ', 9U);
-	::memcpy(buffer + 6U, source.c_str(), source.size());
-
-	::memset(buffer + 15U, ' ', 9U);
-	::memcpy(buffer + 15U, dest.c_str(), dest.size());
-
-	::memcpy(buffer + 24U, lsf, 6U);
-
-	::memcpy(buffer + 30U, data, 18U);
-
-	if (m_debug)
-		CUtils::dump(1U, "M17 data transmitted", buffer, 48U);
-
-	return m_socket.write(buffer, 48U, m_addr, m_addrLen);
 }
 
 void CM17Network::clock(unsigned int ms)
@@ -175,7 +139,7 @@ void CM17Network::clock(unsigned int ms)
 	if (::memcmp(buffer + 0U, "PING", 4U) == 0)
 		return;
 
-	if (::memcmp(buffer + 0U, "M17H", 4U) != 0 && ::memcmp(buffer + 0U, "M17D", 4U) != 0) {
+	if (::memcmp(buffer + 0U, "M17 ", 4U) != 0) {
 		CUtils::dump(2U, "M17, received unknown packet", buffer, length);
 		return;
 	}
@@ -188,19 +152,10 @@ void CM17Network::clock(unsigned int ms)
 			return;
 	}
 
-	if (::memcmp(buffer + 0U, "M17H", 4U) == 0) {
+	unsigned char c = length - 6U;
-		unsigned char c = length - 5U;
 	m_buffer.addData(&c, 1U);
 
-		m_buffer.addData(&TAG_HEADER, 1U);
 	m_buffer.addData(buffer + 6U, length - 6U);
-	} else {
-		unsigned char c = length - 5U;
-		m_buffer.addData(&c, 1U);
-
-		m_buffer.addData(&TAG_DATA, 1U);
-		m_buffer.addData(buffer + 6U, length - 6U);
-	}
 }
 
 bool CM17Network::read(unsigned char* data)

M17Network.h

@@ -36,9 +36,7 @@ public:
 
 	void enable(bool enabled);
 
-	bool writeHeader(const std::string& source, const std::string& dest, const unsigned char* lsf);
+	bool write(const unsigned char* data);
-
-	bool writeData(const std::string& source, const std::string& dest, const unsigned char* lsf, const unsigned char* data);
 
 	bool read(unsigned char* data);
 

Version.h

@@ -19,6 +19,6 @@
 #if !defined(VERSION_H)
 #define	VERSION_H
 
-const char* VERSION = "20210822";
+const char* VERSION = "20210826";
 
 #endif