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EDACS and Analog Monitoring - Apply Filtering Stack (DE,DC,PE, CL); Misc;

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lwvmobile
2024-02-12 13:18:56 -05:00
parent 374999df1f
commit de5b99dbb9
3 changed files with 86 additions and 23 deletions
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6
include/dsd.h
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@@ -1250,6 +1250,12 @@ void edacs(dsd_opts * opts, dsd_state * state);
unsigned long long int edacs_bch (unsigned long long int message);
void eot_cc(dsd_opts * opts, dsd_state * state); //end of TX return to CC
//misc generic audio filtering for analog at 48k/1
void analog_deemph_filter(short * input, int len);
void analog_preemph_filter(short * input, int len);
void analog_dc_block_filter(short * input, int len);
void analog_clipping_filter(short * input, int len);
//csv imports
int csvGroupImport(dsd_opts * opts, dsd_state * state);
int csvLCNImport(dsd_opts * opts, dsd_state * state);

31
src/dsd_symbol.c
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@@ -288,12 +288,21 @@ getSymbol (dsd_opts * opts, dsd_state * state, int have_sync)
if (opts->audio_in_type != 3 && opts->monitor_input_audio == 1)
opts->rtl_rms = raw_rms(state->analog_out, 960, 1);
//debug
// opts->rtl_rms = 101;
//raw wav file saving -- only write when not NXDN, dPMR, or M17 due to noise that can cause tons of false positives when no sync
if (opts->wav_out_raw != NULL && opts->frame_nxdn48 == 0 && opts->frame_nxdn96 == 0 && opts->frame_dpmr == 0 && opts->frame_m17 == 0)
{
sf_write_short(opts->wav_out_raw, state->analog_out, 960);
sf_write_sync (opts->wav_out_raw);
}
//make it a little quieter
// for (int x = 0; x < 960; x++)
// state->analog_out[x] /= 4;
//test running analog audio through a de-emphasis filter
analog_deemph_filter(state->analog_out, 960);
//and dc_block filter analog_dc_block_filter
analog_dc_block_filter(state->analog_out, 960);
//test running analog audio through a pre-emphasis filter
analog_preemph_filter(state->analog_out, 960);
//test running analog short sample clipping filter
analog_clipping_filter(state->analog_out, 960);
//seems to be working now, but RMS values are lower on actual analog signal than on no signal but noise
if ( (opts->rtl_rms > opts->rtl_squelch_level) && opts->monitor_input_audio == 1 && state->carrier == 0 ) //added carrier check here in lieu of disabling it above
@@ -323,12 +332,12 @@ getSymbol (dsd_opts * opts, dsd_state * state, int have_sync)
state->last_vc_sync_time = time(NULL);
}
//raw wav file saving -- only write when not NXDN, dPMR, or M17 due to noise that can cause tons of false positives when no sync
if (opts->wav_out_raw != NULL && opts->frame_nxdn48 == 0 && opts->frame_nxdn96 == 0 && opts->frame_dpmr == 0 && opts->frame_m17 == 0)
{
sf_write_short(opts->wav_out_raw, state->analog_out, 960);
sf_write_sync (opts->wav_out_raw);
}
//raw wav file saving -- save the WAV file samples before we apply filtering to them
// if (opts->wav_out_raw != NULL && opts->frame_nxdn48 == 0 && opts->frame_nxdn96 == 0 && opts->frame_dpmr == 0 && opts->frame_m17 == 0)
// {
// sf_write_short(opts->wav_out_raw, state->analog_out, 960);
// sf_write_sync (opts->wav_out_raw);
// }
memset (state->analog_out, 0, sizeof(state->analog_out));
state->analog_sample_counter = 0;

72
src/edacs-fme.c
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@@ -91,20 +91,57 @@ long int gen_rms(short *samples, int len, int step)
return rms;
}
//super generic pre-emphasis filter with alpha value of 1 for short sample input / output
static short pstate = 1;
void analog_preemph_filter(short * input, int len)
{
int i;
for (i = 0; i < len; i++)
{
//debug
// fprintf (stderr, " I:%d;", input[i]);
input[i] = input[i] - 1 * pstate;
pstate = input[i];
//debug
// fprintf (stderr, " O:%d;;", input[i]);
//increase gain value slightly
input[i] *= 1.5;
//debug
// fprintf (stderr, " O2:%d;;;", input[i]);
}
}
//super generic short sample clipping filter, prevent short values from exceeding tolerable clip value
void analog_clipping_filter(short * input, int len)
{
int i;
for (i = 0; i < len; i++)
{
if (input[i] > 32760)
input[i] = 32760;
else if (input[i] < -32760)
input[i] = -32760;
}
}
//modified from version found in rtl_fm
static short avg = 0;
void analog_deemph_filter(short * input, int len)
{
// static short avg; // cheating...
int i, d;
// static short avg; // cheating...
int i, d;
// int a = (int)round(1.0/((1.0-exp(-1.0/(96000 * 75e-6))))); //48000 is rate out, but doubling it sounds 'beefier'
int a = 8; //result of calc above is 8, so save a cycle on the low end CPUs
// de-emph IIR
// avg = avg * (1 - alpha) + sample * alpha;
// de-emph IIR
// avg = avg * (1 - alpha) + sample * alpha;
for (i = 0; i < len; i++)
for (i = 0; i < len; i++)
{
d = input[i] - avg;
if (d > 0)
@@ -113,7 +150,7 @@ void analog_deemph_filter(short * input, int len)
avg += (d - a/2) / a;
input[i] = (short)avg;
}
}
}
//modified from version found in rtl_fm
@@ -136,6 +173,10 @@ void analog_dc_block_filter(short * input, int len)
//listening to and playing back analog audio
void edacs_analog(dsd_opts * opts, dsd_state * state, int afs, unsigned char lcn)
{
//reset static states for new channel
pstate = 1;
avg = 0;
dc_avg = 0;
int i, result;
int count = 5; //RMS has a 5 count (5 * 180ms) now before cutting off;
@@ -270,7 +311,7 @@ void edacs_analog(dsd_opts * opts, dsd_state * state, int afs, unsigned char lcn
sr += digitize (opts, state, (int)analog1[i]);
}
//test running analog audio through a deemphasis filter
//test running analog audio through a de-emphasis filter
analog_deemph_filter(analog1, 960);
analog_deemph_filter(analog2, 960);
analog_deemph_filter(analog3, 960);
@@ -278,7 +319,14 @@ void edacs_analog(dsd_opts * opts, dsd_state * state, int afs, unsigned char lcn
analog_dc_block_filter(analog1, 960);
analog_dc_block_filter(analog2, 960);
analog_dc_block_filter(analog3, 960);
//test running analog audio through a pre-emphasis filter
analog_preemph_filter(analog1, 960);
analog_preemph_filter(analog2, 960);
analog_preemph_filter(analog3, 960);
//test running analog short sample clipping filter
analog_clipping_filter(analog1, 960);
analog_clipping_filter(analog2, 960);
analog_clipping_filter(analog3, 960);
//reconfigured to use seperate audio out stream that is always 48k short
if (opts->audio_out_type == 0 && opts->slot1_on == 1)
@@ -769,11 +817,11 @@ void edacs(dsd_opts * opts, dsd_state * state)
if (opts->use_rigctl == 1)
{
//only set bandwidth IF we have an original one to fall back to (experimental, but requires user to set the -B 12000 value manually)
// if (opts->setmod_bw != 0 && command == 0xEE) SetModulation(opts->rigctl_sockfd, 7000); //narrower bandwidth, but has issues with dotting sequence
// else if (opts->setmod_bw != 0) SetModulation(opts->rigctl_sockfd, opts->setmod_bw);
//only set bandwidth IF we have an original one to fall back to (experimental, but requires user to set the -B 12000 or -B 24000 value manually)
if (opts->setmod_bw != 0 && command == 0xEE) SetModulation(opts->rigctl_sockfd, 7000); //narrower bandwidth, but has issues with dotting sequence
else if (opts->setmod_bw != 0) SetModulation(opts->rigctl_sockfd, opts->setmod_bw);
if (opts->setmod_bw != 0) SetModulation(opts->rigctl_sockfd, opts->setmod_bw);
// if (opts->setmod_bw != 0) SetModulation(opts->rigctl_sockfd, opts->setmod_bw);
SetFreq(opts->rigctl_sockfd, state->trunk_lcn_freq[lcn-1]); //minus one because our index starts at zero
state->edacs_tuned_lcn = lcn;