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Disable the LICH CRC and clean up the payload checksum handling.

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This commit is contained in:
Jonathan Naylor
2021-03-27 14:51:53 +00:00
parent 8efd77132f
commit 4422444179
2 changed files with 21 additions and 36 deletions
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43
M17Control.cpp
View File

@@ -217,8 +217,8 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
unsigned char lich[M17_LICH_FRAGMENT_LENGTH_BYTES]; unsigned char lich[M17_LICH_FRAGMENT_LENGTH_BYTES];
CM17Utils::combineFragmentLICH(lich1, lich2, lich3, lich4, lich); CM17Utils::combineFragmentLICH(lich1, lich2, lich3, lich4, lich);
if (!CM17CRC::checkCRC4(lich, M17_LICH_FRAGMENT_LENGTH_BYTES)) // if (!CM17CRC::checkCRC4(lich, M17_LICH_FRAGMENT_LENGTH_BYTES))
return false; // return false;
m_rfLSFn = (lich4 >> 5) & 0x07U; m_rfLSFn = (lich4 >> 5) & 0x07U;
m_rfLSF.setFragment(lich, m_rfLSFn); m_rfLSF.setFragment(lich, m_rfLSFn);
@@ -249,7 +249,7 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
} }
} }
if ((m_rfState == RS_RF_AUDIO || m_rfState == RS_RF_DATA) && data[0U] == TAG_DATA) { if (m_rfState == RS_RF_AUDIO && data[0U] == TAG_DATA) {
#if defined(DUMP_M17) #if defined(DUMP_M17)
writeFile(data + 2U); writeFile(data + 2U);
#endif #endif
@@ -261,28 +261,13 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
if (valid) { if (valid) {
m_rfFN = (frame[0U] << 8) + (frame[1U] << 0); m_rfFN = (frame[0U] << 8) + (frame[1U] << 0);
} else { } else {
// Create a silence frame
m_rfFN++; m_rfFN++;
// The new FN // The new FN
frame[0U] = m_rfFN >> 8; frame[0U] = m_rfFN >> 8;
frame[1U] = m_rfFN >> 0; frame[1U] = m_rfFN >> 0;
// Add silent audio // Recalculate the CRC
unsigned char dataType = m_rfLSF.getDataType();
switch (dataType) {
case M17_DATA_TYPE_VOICE:
::memcpy(frame + M17_FN_LENGTH_BYTES + 0U, M17_3200_SILENCE, 8U);
::memcpy(frame + M17_FN_LENGTH_BYTES + 8U, M17_3200_SILENCE, 8U);
break;
case M17_DATA_TYPE_VOICE_DATA:
::memcpy(frame + M17_FN_LENGTH_BYTES + 0U, M17_1600_SILENCE, 8U);
break;
default:
break;
}
// Add the CRC
CM17CRC::encodeCRC16(frame, M17_FN_LENGTH_BYTES + M17_PAYLOAD_LENGTH_BYTES + M17_CRC_LENGTH_BYTES); CM17CRC::encodeCRC16(frame, M17_FN_LENGTH_BYTES + M17_PAYLOAD_LENGTH_BYTES + M17_CRC_LENGTH_BYTES);
} }
@@ -301,7 +286,7 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
lich[5U] = (m_rfLSFn & 0x07U) << 5; lich[5U] = (m_rfLSFn & 0x07U) << 5;
// Add the CRC // Add the CRC
CM17CRC::encodeCRC4(lich, M17_LICH_FRAGMENT_LENGTH_BYTES); // CM17CRC::encodeCRC4(lich, M17_LICH_FRAGMENT_LENGTH_BYTES);
unsigned int frag1, frag2, frag3, frag4; unsigned int frag1, frag2, frag3, frag4;
CM17Utils::splitFragmentLICH(lich, frag1, frag2, frag3, frag4); CM17Utils::splitFragmentLICH(lich, frag1, frag2, frag3, frag4);
@@ -318,19 +303,19 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
conv.encodeData(frame, rfData + 2U + M17_SYNC_LENGTH_BYTES + M17_LICH_FRAGMENT_FEC_LENGTH_BYTES); conv.encodeData(frame, rfData + 2U + M17_SYNC_LENGTH_BYTES + M17_LICH_FRAGMENT_FEC_LENGTH_BYTES);
// Calculate the BER // Calculate the BER
if (valid) {
unsigned int errors = 0U; unsigned int errors = 0U;
for (unsigned int i = 2U; i < (M17_FRAME_LENGTH_BYTES + 2U); i++) for (unsigned int i = 0U; i < (M17_FN_LENGTH_BYTES + M17_PAYLOAD_LENGTH_BYTES); i++) {
errors += countBits(rfData[i] ^ data[i]); unsigned int offset = i + 2U + M17_SYNC_LENGTH_BYTES + M17_LICH_FRAGMENT_FEC_LENGTH_BYTES;
errors += countBits(rfData[offset] ^ data[offset]);
}
LogDebug("M17, FN: %u, errs: %u/384 (%.1f%%)", m_rfFN & 0x7FU, errors, float(errors) / 3.84F); LogDebug("M17, FN: %u, errs: %u/144 (%.1f%%)", m_rfFN & 0x7FU, errors, float(errors) / 1.44F);
m_rfBits += M17_FRAME_LENGTH_BITS; m_rfBits += M17_FN_LENGTH_BITS + M17_PAYLOAD_LENGTH_BITS;
m_rfErrs += errors; m_rfErrs += errors;
float ber = float(m_rfErrs) / float(m_rfBits); float ber = float(m_rfErrs) / float(m_rfBits);
m_display->writeM17BER(ber); m_display->writeM17BER(ber);
}
unsigned char temp[M17_FRAME_LENGTH_BYTES]; unsigned char temp[M17_FRAME_LENGTH_BYTES];
interleaver(rfData + 2U, temp); interleaver(rfData + 2U, temp);
@@ -358,8 +343,8 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
if (m_rfLSFn >= 6U) if (m_rfLSFn >= 6U)
m_rfLSFn = 0U; m_rfLSFn = 0U;
// EOT? // Only check for the EOT marker if the frame has a valid CRC
if ((m_rfFN & 0x8000U) == 0x8000U) { if (valid && (m_rfFN & 0x8000U) == 0x8000U) {
std::string source = m_rfLSF.getSource(); std::string source = m_rfLSF.getSource();
std::string dest = m_rfLSF.getDest(); std::string dest = m_rfLSF.getDest();
@@ -523,7 +508,7 @@ void CM17Control::writeNetwork()
lich[5U] = (m_netLSFn & 0x07U) << 5; lich[5U] = (m_netLSFn & 0x07U) << 5;
// Add the CRC // Add the CRC
CM17CRC::encodeCRC4(lich, M17_LICH_FRAGMENT_LENGTH_BYTES); // CM17CRC::encodeCRC4(lich, M17_LICH_FRAGMENT_LENGTH_BYTES);
unsigned int frag1, frag2, frag3, frag4; unsigned int frag1, frag2, frag3, frag4;
CM17Utils::splitFragmentLICH(lich, frag1, frag2, frag3, frag4); CM17Utils::splitFragmentLICH(lich, frag1, frag2, frag3, frag4);

2
Version.h
View File

@@ -19,6 +19,6 @@
#if !defined(VERSION_H) #if !defined(VERSION_H)
#define VERSION_H #define VERSION_H
const char* VERSION = "20210326"; const char* VERSION = "20210327";
#endif #endif