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C-Netz: Send 5280 Hz test tone on idle speech channel

This commit is contained in:
Andreas Eversberg 2016-05-13 08:44:42 +02:00
parent bbab972b51
commit 5a9c9c7401
1 changed files with 34 additions and 1 deletions
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35
src/cnetz/dsp.c
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@ -216,6 +216,39 @@ void calc_clock_speed(cnetz_t *cnetz, uint64_t samples, int tx, int result)
PDEBUG(DDSP, DEBUG_NOTICE, "Clock: RX=%.2f TX=%.2f; Signal: RX=%.2f TX=%.2f ppm\n", speed_ppm_rx[0], speed_ppm_tx[0], speed_ppm_rx[1], speed_ppm_tx[1]);
}
static int fsk_testtone_encode(cnetz_t *cnetz)
{
int16_t *spl;
double phase, bitstep;
int i, count;
spl = cnetz->fsk_tx_buffer;
phase = cnetz->fsk_tx_phase;
bitstep = cnetz->fsk_tx_bitstep * 256.0;
/* add 198 bits of noise */
for (i = 0; i < 99; i++) {
do {
*spl++ = ramp_up[(int)phase];
phase += bitstep;
} while (phase < 256.0);
phase -= 256.0;
do {
*spl++ = ramp_down[(int)phase];
phase += bitstep;
} while (phase < 256.0);
phase -= 256.0;
}
/* depending on the number of samples, return the number */
count = ((uintptr_t)spl - (uintptr_t)cnetz->fsk_tx_buffer) / sizeof(*spl);
cnetz->fsk_tx_phase = phase;
cnetz->fsk_tx_buffer_length = count;
return count;
}
static int fsk_nothing_encode(cnetz_t *cnetz)
{
int16_t *spl;
@ -652,7 +685,7 @@ again:
break;
case DSP_MODE_OFF:
default:
fsk_nothing_encode(cnetz);
fsk_testtone_encode(cnetz);
}
if (cnetz->dsp_mode == DSP_MODE_SPK_V) {