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DMR 12 Rate Updates

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DMR 12 Rate Updates
Other Tweaks to P25 Printing
More experimenting with 34 Rate Trellis Code (busted)
This commit is contained in:
lwvmobile
2022-03-26 00:03:14 -04:00
committed by GitHub
parent 6a649376fc
commit 13ec6855f8
12 changed files with 216 additions and 115 deletions
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218
src/trellis.cpp
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@@ -38,7 +38,10 @@ const unsigned char ENCODE_TABLE[] = {
const unsigned char BIT_MASK_TABLE[] = {0x80U, 0x40U, 0x20U, 0x10U, 0x08U, 0x04U, 0x02U, 0x01U};
#define READ_BIT(p,i) (p[(i)>>3] & BIT_MASK_TABLE[(i)&7])
#define WRITE_BIT(p,i,b) p[(i)>>3] = (b) ? (p[(i)>>3] | BIT_MASK_TABLE[(i)&7]) : (p[(i)>>3] & ~BIT_MASK_TABLE[(i)&7])
//unsigned char state = 0U;
//unsigned int superposition = 0;
//CDMRTrellis::CDMRTrellis()
//{
//}
@@ -49,64 +52,24 @@ const unsigned char BIT_MASK_TABLE[] = {0x80U, 0x40U, 0x20U, 0x10U, 0x08U, 0x04U
//void CDMRTrellis::tribitsToBits(const unsigned char* tribits, unsigned char* payload) const
//void CDMRTrellisTribitsToBits(const unsigned char* tribits, unsigned char* payload) const
void CDMRTrellisTribitsToBits(const unsigned char* tribits, unsigned char* payload)
{
unsigned char bits[144];
// convert tribits to bits
for (int i = 0; i < 48; i++) {
bits[(i * 3) + 0] = (tribits[i] >> 2) & 1;
bits[(i * 3) + 1] = (tribits[i] >> 1) & 1;
bits[(i * 3) + 2] = tribits[i] & 1;
}
// convert bits to bytes
for (int i = 0; i < 144; i++)
payload[i/8] = (payload[i/8] << 1) | bits[i];
}
//unsigned int CDMRTrellis::checkCode(const unsigned char* points, unsigned char* tribits) const
//unsigned int CDMRTrellisCheckCode(const unsigned char* points, unsigned char* tribits) const
unsigned int CDMRTrellisCheckCode(const unsigned char* points, unsigned char* tribits)
{
unsigned char state = 0U;
for (unsigned int i = 0U; i < 49U; i++) {
tribits[i] = 9U;
for (unsigned int j = 0U; j < 8U; j++) {
if (points[i] == ENCODE_TABLE[state * 8U + j]) {
tribits[i] = j;
break;
}
}
if (tribits[i] == 9U) {
return i;
}
state = tribits[i];
}
if (tribits[48U] != 0U)
return 48U;
return 999U;
}
//bool CDMRTrellis::fixCode(unsigned char* points, unsigned int failPos, unsigned char* payload) const
//bool CDMRTrellisFixCode(unsigned char* points, unsigned int failPos, unsigned char* payload) const
bool CDMRTrellisFixCode(unsigned char* points, unsigned int failPos, unsigned char* payload)
{
//unsigned int bestPos = 0U;
//unsigned int bestVal = 0U;
for (unsigned j = 0U; j < 20U; j++) {
unsigned int bestPos = 0U;
unsigned int bestVal = 0U;
fprintf (stderr, " fail%d-", failPos);
for (unsigned int i = 0U; i < 16U; i++) {
points[failPos] = i;
fprintf (stderr, "i%d", i);
unsigned char tribits[49U];
unsigned int pos = CDMRTrellisCheckCode(points, tribits);
if (pos == 999U) {
@@ -126,6 +89,107 @@ bool CDMRTrellisFixCode(unsigned char* points, unsigned int failPos, unsigned ch
return false;
}
void CDMRTrellisTribitsToBits(const unsigned char* tribits, unsigned char* payload)
{
//g4klx version below
/*
for (unsigned int i = 0U; i < 48U; i++) {
unsigned char tribit = tribits[i];
bool b1 = (tribit & 0x04U) == 0x04U;
bool b2 = (tribit & 0x02U) == 0x02U;
bool b3 = (tribit & 0x01U) == 0x01U;
unsigned int n = 143U - i * 3U;
/*
WRITE_BIT(payload, n, b1);
n--;
WRITE_BIT(payload, n, b2);
n--;
WRITE_BIT(payload, n, b3);
}
*/
// boatbod version below...
// convert tribits to bits
unsigned char bits[144];
for (int i = 0; i < 48; i++) {
bits[(i * 3) + 0] = (tribits[i] >> 2) & 1;
bits[(i * 3) + 1] = (tribits[i] >> 1) & 1;
bits[(i * 3) + 2] = tribits[i] & 1;
}
// convert bits to bytes
for (int i = 0; i < 144; i++)
payload[i/8] = (payload[i/8] << 1) | bits[i];
}
//unsigned int CDMRTrellis::checkCode(const unsigned char* points, unsigned char* tribits) const
//unsigned int CDMRTrellisCheckCode(const unsigned char* points, unsigned char* tribits) const
/*
unsigned int CDMRTrellisCheckCode(const unsigned char* points, unsigned char* tribits)
{
//replace i with superposition; revert back if totally borked
//unsigned char state = 0U;
//for (unsigned int i = 0U; i < 49U; i++) {
//tribits[i] = 9U;
for (superposition; superposition < 49U; superposition++) {
tribits[superposition] = 9U;
for (unsigned int j = 0U; j < 8U; j++) {
if (points[superposition] == ENCODE_TABLE[state * 8U + j]) {
tribits[superposition] = j;
break;
}
}
if (tribits[superposition] == 9) {
return superposition;
//experiment placing fixcode right in here instead
//or we need to find a way to update state outside of this function
}
state = tribits[superposition];
}
//if (tribits[48U] != 0U)
//return 48U;
return 999U;
}
*/
unsigned int CDMRTrellisCheckCode(const unsigned char* points, unsigned char* tribits)
{
unsigned char state = 0U;
for (unsigned int i = 0U; i < 49U; i++) {
tribits[i] = 9U;
for (unsigned int j = 0U; j < 8U; j++) {
if (points[i] == ENCODE_TABLE[state * 8U + j]) {
tribits[i] = j;
break;
}
}
if (tribits[i] == 9U)
return i;
state = tribits[i];
}
if (tribits[48U] != 0U)
return 48U;
return 999U;
}
//void CDMRTrellis::deinterleave(const unsigned char* data, signed char* dibits) const
//void CDMRTrellisDeinterleave(const unsigned char* data, signed char* dibits) const
void CDMRTrellisDeinterleave(const unsigned char* data, signed char* dibits)
@@ -288,7 +352,7 @@ void CDMRTrellisBitsToTribits(const unsigned char* payload, unsigned char* tribi
tribit |= b2 ? 2U : 0U;
tribit |= b3 ? 1U : 0U;
tribits[i] = tribit;
//tribits[i] = tribit;
}
tribits[48U] = 0U;
@@ -304,7 +368,7 @@ bool CDMRTrellisDecode(const unsigned char* data, unsigned char* payload)
fprintf (stderr, "\n Raw Trellis Dibits inside Decoder\n ");
for (short i = 0; i < 98; i++)
{
fprintf (stderr, "[%X]", data[i]);
fprintf (stderr, "[%0d]", data[i]);
}
}
signed char dibits[98U];
@@ -321,37 +385,69 @@ bool CDMRTrellisDecode(const unsigned char* data, unsigned char* payload)
CDMRTrellisDibitsToPoints(dibits, points);
if (1 == 1)
{
fprintf (stderr, "\n Trellis Points inside Decoder (what the fuck are points?)\n ");
fprintf (stderr, "\n Trellis Points inside Decoder (no higher than 15U?)\n ");
for (short i = 0; i < 49; i++)
{
fprintf (stderr, "[%X]", points[i]);
fprintf (stderr, "[%02u]", points[i]);
}
}
// Check the original code
unsigned char tribits[49U];
unsigned int failPos = CDMRTrellisCheckCode(points, tribits);
if (failPos == 999U) {
CDMRTrellisTribitsToBits(tribits, payload);
if (1 == 1)
{
fprintf (stderr, "\nTrellis Payload Tribits to Bits failPos == 999U\n ");
for (short i = 0; i < 18; i++)
{
fprintf (stderr, "[%02u]", payload[i]);
}
}
return true;
}
if (1 == 1)
{
fprintf (stderr, "\n Trellis Tribits inside Decoder\n ");
for (short i = 0; i < 49; i++)
{
fprintf (stderr, "[%X]", tribits[i]); //shouldn't have any values greater that 0x7?
}
}
unsigned char savePoints[49U];
for (unsigned int i = 0U; i < 49U; i++)
savePoints[i] = points[i];
bool ret = CDMRTrellisFixCode(points, failPos, payload);
if (ret)
return true;
if (ret){
if (1 == 1)
{
fprintf (stderr, "\n Trellis Tribits inside Decoder\n ");
for (short i = 0; i < 49; i++)
{
fprintf (stderr, "[%0u]", tribits[i]); //shouldn't have any values greater that 0x7?
}
}
if (1 == 1)
{
fprintf (stderr, "\nTrellis Payload Tribits to Bits fix return true\n "); //this one seems to be happening
for (short i = 0; i < 18; i++)
{
fprintf (stderr, "[%02X]", payload[i]);
}
}
return true; }
if (failPos == 0U)
return false;
{
if (1 == 1)
{
fprintf (stderr, "\nTrellis Payload Tribits to Bits failPos == 0U\n ");
for (short i = 0; i < 18; i++)
{
fprintf (stderr, "[%02X]", payload[i]);
}
}
return false; }
// Backtrack one place for a last go
return CDMRTrellisFixCode(savePoints, failPos - 1U, payload);