247 lines
7.9 KiB
C
247 lines
7.9 KiB
C
/*
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* Copyright (C) 2010 DSD Author
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* GPG Key ID: 0x3F1D7FD0 (74EF 430D F7F2 0A48 FCE6 F630 FAA2 635D 3F1D 7FD0)
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*
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* Permission to use, copy, modify, and/or distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
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* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
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* AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
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* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
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* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
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* OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
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* PERFORMANCE OF THIS SOFTWARE.
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*/
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#include "dsd.h"
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int
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getSymbol (dsd_opts * opts, dsd_state * state, int have_sync)
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{
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short sample;
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int i, sum, symbol, count;
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ssize_t result;
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sum = 0;
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count = 0;
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for (i = 0; i < state->samplesPerSymbol; i++)
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{
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// timing control
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if ((i == 0) && (have_sync == 0))
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{
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if (state->samplesPerSymbol == 20)
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{
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if ((state->jitter >= 7) && (state->jitter <= 10))
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{
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i--;
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}
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else if ((state->jitter >= 11) && (state->jitter <= 14))
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{
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i++;
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}
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}
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else if (state->rf_mod == 1)
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{
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if ((state->jitter >= 0) && (state->jitter < state->symbolCenter))
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{
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i++; // fall back
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}
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else if ((state->jitter > state->symbolCenter) && (state->jitter < 10))
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{
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i--; // catch up
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}
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}
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else if (state->rf_mod == 2)
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{
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if ((state->jitter >= state->symbolCenter - 1) && (state->jitter <= state->symbolCenter))
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{
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i--;
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}
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else if ((state->jitter >= state->symbolCenter + 1) && (state->jitter <= state->symbolCenter + 2))
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{
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i++;
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}
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}
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else if (state->rf_mod == 0)
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{
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if ((state->jitter > 0) && (state->jitter <= state->symbolCenter))
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{
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i--; // catch up
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}
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else if ((state->jitter > state->symbolCenter) && (state->jitter < state->samplesPerSymbol))
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{
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i++; // fall back
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}
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}
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state->jitter = -1;
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}
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if(opts->audio_in_type == 0) {
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result = read (opts->audio_in_fd, &sample, 2);
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}
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else {
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result = sf_read_short(opts->audio_in_file, &sample, 1);
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if(result == 0) {
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cleanupAndExit (opts, state);
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}
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}
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// printf("res: %zd\n, offset: %lld", result, sf_seek(opts->audio_in_file, 0, SEEK_CUR));
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{
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#define NZEROS 60
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#define GAIN 7.423339364e+00
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static float xv[NZEROS+1];
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static float xcoeffs[] =
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{ -0.0083649323, -0.0265444850, -0.0428141462, -0.0537571943,
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-0.0564141052, -0.0489161045, -0.0310068662, -0.0043393881,
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+0.0275375106, +0.0595423283, +0.0857543325, +0.1003565948,
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+0.0986944931, +0.0782804830, +0.0395670487, -0.0136691535,
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-0.0744390415, -0.1331834575, -0.1788967208, -0.2005995448,
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-0.1889627181, -0.1378439993, -0.0454976231, +0.0847488694,
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+0.2444859269, +0.4209222342, +0.5982295474, +0.7593684540,
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+0.8881539892, +0.9712773915, +0.9999999166, +0.9712773915,
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+0.8881539892, +0.7593684540, +0.5982295474, +0.4209222342,
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+0.2444859269, +0.0847488694, -0.0454976231, -0.1378439993,
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-0.1889627181, -0.2005995448, -0.1788967208, -0.1331834575,
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-0.0744390415, -0.0136691535, +0.0395670487, +0.0782804830,
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+0.0986944931, +0.1003565948, +0.0857543325, +0.0595423283,
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+0.0275375106, -0.0043393881, -0.0310068662, -0.0489161045,
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-0.0564141052, -0.0537571943, -0.0428141462, -0.0265444850,
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-0.0083649323,
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};
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float sum; int i;
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for (i = 0; i < NZEROS; i++)
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xv[i] = xv[i+1];
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xv[NZEROS] = sample; // unfiltered sample in
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sum = 0.0;
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for (i = 0; i <= NZEROS; i++)
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sum += (xcoeffs[i] * xv[i]);
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sample = sum / GAIN; // filtered sample out
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}
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if ((sample > state->max) && (have_sync == 1) && (state->rf_mod == 0))
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{
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sample = state->max;
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}
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else if ((sample < state->min) && (have_sync == 1) && (state->rf_mod == 0))
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{
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sample = state->min;
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}
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if (sample > state->center)
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{
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if (state->lastsample < state->center)
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{
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state->numflips += 1;
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}
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if (sample > (state->maxref * 1.25))
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{
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if (state->lastsample < (state->maxref * 1.25))
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{
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state->numflips += 1;
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}
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if ((state->jitter < 0) && (state->rf_mod == 1))
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{ // first spike out of place
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state->jitter = i;
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}
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if ((opts->symboltiming == 1) && (have_sync == 0) && (state->lastsynctype != -1))
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{
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printf ("O");
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}
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}
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else
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{
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if ((opts->symboltiming == 1) && (have_sync == 0) && (state->lastsynctype != -1))
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{
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printf ("+");
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}
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if ((state->jitter < 0) && (state->lastsample < state->center) && (state->rf_mod != 1))
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{ // first transition edge
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state->jitter = i;
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}
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}
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}
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else
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{ // sample < 0
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if (state->lastsample > state->center)
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{
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state->numflips += 1;
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}
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if (sample < (state->minref * 1.25))
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{
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if (state->lastsample > (state->minref * 1.25))
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{
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state->numflips += 1;
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}
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if ((state->jitter < 0) && (state->rf_mod == 1))
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{ // first spike out of place
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state->jitter = i;
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}
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if ((opts->symboltiming == 1) && (have_sync == 0) && (state->lastsynctype != -1))
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{
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printf ("X");
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}
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}
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else
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{
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if ((opts->symboltiming == 1) && (have_sync == 0) && (state->lastsynctype != -1))
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{
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printf ("-");
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}
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if ((state->jitter < 0) && (state->lastsample > state->center) && (state->rf_mod != 1))
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{ // first transition edge
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state->jitter = i;
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}
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}
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}
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if (state->samplesPerSymbol == 20)
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{
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if ((i >= 9) && (i <= 11))
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{
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sum += sample;
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count++;
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}
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}
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if (state->samplesPerSymbol == 5)
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{
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if (i == 2)
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{
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sum += sample;
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count++;
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}
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}
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else
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{
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if (((i >= state->symbolCenter - 1) && (i <= state->symbolCenter + 2) && (state->rf_mod == 0)) || (((i == state->symbolCenter) || (i == state->symbolCenter + 1)) && (state->rf_mod != 0)))
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{
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sum += sample;
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count++;
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}
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}
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state->lastsample = sample;
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}
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symbol = (sum / count);
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if ((opts->symboltiming == 1) && (have_sync == 0) && (state->lastsynctype != -1))
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{
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if (state->jitter >= 0)
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{
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printf (" %i\n", state->jitter);
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}
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else
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{
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printf ("\n");
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}
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}
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state->symbolcnt++;
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return (symbol);
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}
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