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osmo-cc-ss5-endpoint
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Use notch filter to filter 2600 Hz out of ringback/anouncement

This commit is contained in:
Andreas Eversberg 2023-12-09 20:27:07 +01:00
parent 480179541f
commit 72a9a666a2
2 changed files with 11 additions and 4 deletions
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12
src/common/dsp.c
View File

@ -113,7 +113,8 @@ int dsp_init_inst(dsp_t *dsp, void *priv, const char *name, double samplerate, i
/* notch filter */
if (notch) {
dsp->notch = 1;
iir_notch_init(&dsp->notch_filter, notch, (int)dsp->samplerate, 1, 4);
iir_notch_init(&dsp->notch_in_filter, notch, (int)dsp->samplerate, 1, 4.0);
iir_notch_init(&dsp->notch_out_filter, notch, (int)dsp->samplerate, 1, 1.0);
}
return 0;
@ -393,7 +394,7 @@ static void detect_tones(dsp_t *dsp, sample_t *samples, sample_t **levels_square
/* l is the number of samples required to mute for this interval of one milliseconds */
l = (dsp->ms_count < s + 1) ? dsp->ms_count : s + 1;
if (dsp->notch)
iir_process(&dsp->notch_filter, samples + s + 1 - l, l);
iir_process(&dsp->notch_in_filter, samples + s + 1 - l, l);
else
memset(samples + s + 1 - l, 0, l * sizeof(*samples));
}
@ -575,7 +576,7 @@ static void detect_tones(dsp_t *dsp, sample_t *samples, sample_t **levels_square
/* l is the number of samples that are left */
l = (dsp->ms_count < s) ? dsp->ms_count : s;
if (dsp->notch)
iir_process(&dsp->notch_filter, samples + s - l, l);
iir_process(&dsp->notch_in_filter, samples + s - l, l);
else
memset(samples + s - l, 0, l * sizeof(*samples));
}
@ -613,9 +614,14 @@ static void process_audio(dsp_t *dsp_a, dsp_t *dsp_b, int length)
dsp_b->sit_count = sit_play(samples[1], dsp_b->sit_count, length);
/* modulate tone/digit. if no tone has to be played (or it stopped), count is less than length */
/* apply notch filter when tone 'B' (2600 Hz) is on. */
count1 = assemble_tones(dsp_a, mask, length);
if (dsp_a->tone_transparent && dsp_a->tone == 'B' && dsp_a->notch)
iir_process(&dsp_a->notch_out_filter, samples[0], count1);
mf_mod(dsp_a->mf_mod, mask, samples[0], count1, dsp_a->tone_transparent);
count2 = assemble_tones(dsp_b, mask, length);
if (dsp_b->tone_transparent && dsp_b->tone == 'B' && dsp_b->notch)
iir_process(&dsp_b->notch_out_filter, samples[1], count2);
mf_mod(dsp_b->mf_mod, mask, samples[1], count2, dsp_b->tone_transparent);
/* ! here is the bridge from a to b and from b to a ! */

3
src/common/dsp.h
View File

@ -56,7 +56,8 @@ typedef struct dsp {
int crosstalk; /* mix crosstalk from TX to RX */
int comfort_noise; /* add comfort noise before answer and after disconnect */
int notch;
iir_filter_t notch_filter; /* remove 2600 Hz */
iir_filter_t notch_in_filter; /* remove 2600 Hz from trunk */
iir_filter_t notch_out_filter; /* remove 2600 Hz to trunk */
/* osmo-CC */
uint32_t cc_callref; /* ref to CC call */