MMDVM/MMDVMHost
1
0
Fork 0
mirror of https://github.com/g4klx/MMDVMHost synced 2025-12-21 23:45:49 +08:00
Code Issues Packages Projects Releases Wiki Activity

Update M17 to the latest secification, removal of the CRC from the

Browse Source 
stream data.
This commit is contained in:
Jonathan Naylor
2021-04-11 17:31:05 +01:00
parent e6d5ef9055
commit 3a73a25c1e
4 changed files with 9 additions and 28 deletions
Download Patch File Download Diff File Expand all files Collapse all files

27
M17Control.cpp
View File

@@ -75,7 +75,6 @@ m_networkWatchdog(1000U, 0U, 1500U),
m_elapsed(),
m_rfFrames(0U),
m_netFrames(0U),
m_rfFN(0U),
m_rfErrs(0U),
m_rfBits(1U),
m_rfLSF(),
@@ -194,7 +193,6 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
m_aveRSSI = m_rssi;
m_rssiCount = 1U;
m_rfLSFn = 0U;
m_rfFN = 0U;
#if defined(DUMP_M17)
openFile();
@@ -258,22 +256,10 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
writeFile(data + 2U);
#endif
CM17Convolution conv;
unsigned char frame[M17_FN_LENGTH_BYTES + M17_PAYLOAD_LENGTH_BYTES + M17_CRC_LENGTH_BYTES];
unsigned char frame[M17_FN_LENGTH_BYTES + M17_PAYLOAD_LENGTH_BYTES];
conv.decodeData(data + 2U + M17_SYNC_LENGTH_BYTES + M17_LICH_FRAGMENT_FEC_LENGTH_BYTES, frame);
bool valid = CM17CRC::checkCRC16(frame, M17_FN_LENGTH_BYTES + M17_PAYLOAD_LENGTH_BYTES + M17_CRC_LENGTH_BYTES);
if (valid) {
m_rfFN = (frame[0U] << 8) + (frame[1U] << 0);
} else {
m_rfFN++;
// The new FN
frame[0U] = m_rfFN >> 8;
frame[1U] = m_rfFN >> 0;
// Recalculate the CRC
CM17CRC::encodeCRC16(frame, M17_FN_LENGTH_BYTES + M17_PAYLOAD_LENGTH_BYTES + M17_CRC_LENGTH_BYTES);
}
unsigned int fn = ((frame[0U] << 8) + (frame[1U] << 0)) & 0x7FU;
unsigned char rfData[2U + M17_FRAME_LENGTH_BYTES];
@@ -310,7 +296,7 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
errors += CUtils::countBits(rfData[offset] ^ data[offset]);
}
LogDebug("M17, FN: %u, errs: %u/144 (%.1f%%)", m_rfFN & 0x7FU, errors, float(errors) / 1.44F);
LogDebug("M17, FN: %u, errs: %u/144 (%.1f%%)", fn & 0x7FU, errors, float(errors) / 1.44F);
m_rfBits += M17_FN_LENGTH_BITS + M17_PAYLOAD_LENGTH_BITS;
m_rfErrs += errors;
@@ -345,7 +331,7 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
m_rfLSFn = 0U;
// Only check for the EOT marker if the frame has a valid CRC
if (valid && (m_rfFN & 0x8000U) == 0x8000U) {
if ((fn & 0x8000U) == 0x8000U) {
std::string source = m_rfLSF.getSource();
std::string dest = m_rfLSF.getDest();
@@ -520,12 +506,9 @@ 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 + M17_CRC_LENGTH_BYTES];
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 CRC
CM17CRC::encodeCRC16(payload, M17_FN_LENGTH_BYTES + M17_PAYLOAD_LENGTH_BYTES + M17_CRC_LENGTH_BYTES);
// Add the Convolution FEC
CM17Convolution conv;
conv.encodeData(payload, data + 2U + M17_SYNC_LENGTH_BYTES + M17_LICH_FRAGMENT_FEC_LENGTH_BYTES);