dsd-fme_18_05_2023/src/dsd_symbol.c

326 lines
10 KiB
C

/*
* Copyright (C) 2010 DSD Author
* GPG Key ID: 0x3F1D7FD0 (74EF 430D F7F2 0A48 FCE6 F630 FAA2 635D 3F1D 7FD0)
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
* OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*/
#include "dsd.h"
int
getSymbol (dsd_opts * opts, dsd_state * state, int have_sync)
{
short sample, sample2;
int i, sum, symbol, count;
ssize_t result;
sum = 0;
count = 0;
for (i = 0; i < state->samplesPerSymbol; i++) //right HERE, this is how many samples it will grab, depending on samplesPerSymbol and also rf_mod messing with it too
{
// timing control
if ((i == 0) && (have_sync == 0))
{
if (state->samplesPerSymbol == 20)
{
if ((state->jitter >= 7) && (state->jitter <= 10))
{
i--;
}
else if ((state->jitter >= 11) && (state->jitter <= 14))
{
i++;
}
}
else if (state->rf_mod == 1)
{
if ((state->jitter >= 0) && (state->jitter < state->symbolCenter))
{
i++; // fall back
}
else if ((state->jitter > state->symbolCenter) && (state->jitter < 10))
{
i--; // catch up
}
}
else if (state->rf_mod == 2)
{
if ((state->jitter >= state->symbolCenter - 1) && (state->jitter <= state->symbolCenter))
{
i--;
}
else if ((state->jitter >= state->symbolCenter + 1) && (state->jitter <= state->symbolCenter + 2))
{
i++;
}
}
else if (state->rf_mod == 0)
{
if ((state->jitter > 0) && (state->jitter <= state->symbolCenter))
{
i--; // catch up
}
else if ((state->jitter > state->symbolCenter) && (state->jitter < state->samplesPerSymbol))
{
i++; // fall back
}
}
state->jitter = -1;
}
// Read the new sample from the input
if(opts->audio_in_type == 0)
{
pa_simple_read(opts->pulse_digi_dev_in, &sample, 2, NULL );
state->pulse_raw_out_buffer = sample; //steal raw out buffer sample here?
}
else if (opts->audio_in_type == 1) {
result = sf_read_short(opts->audio_in_file, &sample, 1);
if(result == 0) {
cleanupAndExit (opts, state);
}
}
else if (opts->audio_in_type == 2)
{
#ifdef USE_PORTAUDIO
PaError err = Pa_ReadStream( opts->audio_in_pa_stream, &sample, 1 );
if( err != paNoError )
{
fprintf( stderr, "An error occured while using the portaudio input stream\n" );
fprintf( stderr, "Error number: %d\n", err );
fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) );
}
#endif
}
else if (opts->audio_in_type == 3)
{
#ifdef USE_RTLSDR
// TODO: need to read demodulated stream here
get_rtlsdr_sample(&sample);
#endif
}
#ifdef TRACE_DSD
state->debug_sample_index++;
#endif
// printf ("res: %zd\n, offset: %lld", result, sf_seek(opts->audio_in_file, 0, SEEK_CUR));
if (opts->use_cosine_filter)
{
if (state->lastsynctype >= 10 && state->lastsynctype <= 13)
sample = dmr_filter(sample);
else if (state->lastsynctype == 8 || state->lastsynctype == 9 ||
state->lastsynctype == 16 || state->lastsynctype == 17)
{
if(state->samplesPerSymbol == 20)
{
sample = nxdn_filter(sample);
}
else // the 12.5KHz NXDN filter is the same as the DMR filter
{
sample = dmr_filter(sample);
}
}
}
if ((sample > state->max) && (have_sync == 1) && (state->rf_mod == 0))
{
sample = state->max;
}
else if ((sample < state->min) && (have_sync == 1) && (state->rf_mod == 0))
{
sample = state->min;
}
if (sample > state->center)
{
if (state->lastsample < state->center)
{
state->numflips += 1;
}
if (sample > (state->maxref * 1.25))
{
if (state->lastsample < (state->maxref * 1.25))
{
state->numflips += 1;
}
if ((state->jitter < 0) && (state->rf_mod == 1))
{ // first spike out of place
state->jitter = i;
}
if ((opts->symboltiming == 1) && (have_sync == 0) && (state->lastsynctype != -1))
{
fprintf (stderr, "O");
}
}
else
{
if ((opts->symboltiming == 1) && (have_sync == 0) && (state->lastsynctype != -1))
{
fprintf (stderr, "+");
}
if ((state->jitter < 0) && (state->lastsample < state->center) && (state->rf_mod != 1))
{ // first transition edge
state->jitter = i;
}
}
}
else
{ // sample < 0
if (state->lastsample > state->center)
{
state->numflips += 1;
}
if (sample < (state->minref * 1.25))
{
if (state->lastsample > (state->minref * 1.25))
{
state->numflips += 1;
}
if ((state->jitter < 0) && (state->rf_mod == 1))
{ // first spike out of place
state->jitter = i;
}
if ((opts->symboltiming == 1) && (have_sync == 0) && (state->lastsynctype != -1))
{
fprintf (stderr, "X");
}
}
else
{
if ((opts->symboltiming == 1) && (have_sync == 0) && (state->lastsynctype != -1))
{
fprintf (stderr, "-");
}
if ((state->jitter < 0) && (state->lastsample > state->center) && (state->rf_mod != 1))
{ // first transition edge
state->jitter = i;
}
}
}
if (state->samplesPerSymbol == 20) //nxdn 4800 baud 2400 symbol rate
{
if ((i >= 9) && (i <= 11))
{
sum += sample;
count++;
}
}
if (state->samplesPerSymbol == 5) //provoice or gfsk
{
if (i == 2)
{
sum += sample;
count++;
}
}
else
{
if (state->rf_mod == 0)
{
// 0: C4FM modulation
if ((i >= state->symbolCenter - 1) && (i <= state->symbolCenter + 2))
{
sum += sample;
count++;
}
#ifdef TRACE_DSD
if (i == state->symbolCenter - 1) {
state->debug_sample_left_edge = state->debug_sample_index - 1;
}
if (i == state->symbolCenter + 2) {
state->debug_sample_right_edge = state->debug_sample_index - 1;
}
#endif
}
else
{
// 1: QPSK modulation
// 2: GFSK modulation
// Note: this has been changed to use an additional symbol to the left
// On the p25_raw_unencrypted.flac it is evident that the timing
// comes one sample too late.
// This change makes a significant improvement in the BER, at least for
// this file.
//if ((i == state->symbolCenter) || (i == state->symbolCenter + 1))
if ((i == state->symbolCenter - 1) || (i == state->symbolCenter + 1))
{
sum += sample;
count++;
}
#ifdef TRACE_DSD
//if (i == state->symbolCenter) {
if (i == state->symbolCenter - 1) {
state->debug_sample_left_edge = state->debug_sample_index - 1;
}
if (i == state->symbolCenter + 1) {
state->debug_sample_right_edge = state->debug_sample_index - 1;
}
#endif
}
}
state->lastsample = sample;
//steal sample here for rtl input or stdin input
state->input_sample_buffer = sample; //sample or sum, honestly this seemt to be best place to grab this sadly, sounds terrible most everywhere else
}
symbol = (sum / count);
if ((opts->symboltiming == 1) && (have_sync == 0) && (state->lastsynctype != -1))
{
if (state->jitter >= 0)
{
fprintf (stderr, " %i\n", state->jitter);
}
else
{
fprintf (stderr, "\n");
}
}
#ifdef TRACE_DSD
if (state->samplesPerSymbol == 10) {
float left, right;
if (state->debug_label_file == NULL) {
state->debug_label_file = fopen ("pp_label.txt", "w");
}
left = state->debug_sample_left_edge / SAMPLE_RATE_IN;
right = state->debug_sample_right_edge / SAMPLE_RATE_IN;
if (state->debug_prefix != '\0') {
if (state->debug_prefix == 'I') {
fprintf(state->debug_label_file, "%f\t%f\t%c%c %i\n", left, right, state->debug_prefix, state->debug_prefix_2, symbol);
} else {
fprintf(state->debug_label_file, "%f\t%f\t%c %i\n", left, right, state->debug_prefix, symbol);
}
} else {
fprintf(state->debug_label_file, "%f\t%f\t%i\n", left, right, symbol);
}
}
#endif
state->symbolcnt++;
return (symbol);
}