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A-Netz: Keep phase for each paging tone when played in sequence

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If paging tones are played in sequence, only one tone out of four tones
is played at once. The phase of all tones are calculated as if each tone
would have been sent permanently.
This commit is contained in:
Andreas Eversberg
2016-11-13 05:51:09 +01:00
parent 3cd102c638
commit 52b1ac65f4
5 changed files with 32 additions and 22 deletions
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41
src/anetz/dsp.c
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@@ -48,8 +48,6 @@
#define LOSS_INTERVAL 100 /* filter steps (chunk durations) for one second interval */
#define LOSS_TIME 12 /* duration of signal loss before release */
extern int page_sequence;
/* two signaling tones */
static double fsk_tones[2] = {
2280.0,
@@ -84,7 +82,7 @@ void dsp_init(void)
}
/* Init transceiver instance. */
int dsp_init_sender(anetz_t *anetz)
int dsp_init_sender(anetz_t *anetz, int page_sequence)
{
int16_t *spl;
double coeff;
@@ -93,6 +91,8 @@ int dsp_init_sender(anetz_t *anetz)
PDEBUG(DDSP, DEBUG_DEBUG, "Init DSP for 'Sender'.\n");
anetz->page_sequence = page_sequence;
audio_init_loss(&anetz->sender.loss, LOSS_INTERVAL, anetz->sender.loss_volume, LOSS_TIME);
anetz->samples_per_chunk = anetz->sender.samplerate * CHUNK_DURATION;
@@ -243,7 +243,7 @@ void dsp_set_paging(anetz_t *anetz, double *freq)
* Use TX_PEAK_PAGE for all tones, which gives peak of (TX_PEAK_PAGE / 4) for each individual tone. */
static void fsk_paging_tone(anetz_t *anetz, int16_t *samples, int length)
{
double phaseshift[5], phase[5];
double phaseshift[4], phase[4];
int i;
int32_t sample;
@@ -277,31 +277,38 @@ static void fsk_paging_tone(anetz_t *anetz, int16_t *samples, int length)
* Use TX_PEAK_PAGE / 2 for each tone, that is twice as much peak per tone. */
static void fsk_paging_tone_sequence(anetz_t *anetz, int16_t *samples, int length, int numspl)
{
double phaseshift, phase;
double phaseshift[4], phase[4];
int i;
int tone, count;
phase = anetz->tone_phase256;
for (i = 0; i < 4; i++) {
phaseshift[i] = anetz->paging_phaseshift256[i];
phase[i] = anetz->paging_phase256[i];
}
tone = anetz->paging_tone;
count = anetz->paging_count;
next_tone:
phaseshift = anetz->paging_phaseshift256[tone];
while (length) {
*samples++ = dsp_sine_page[((uint8_t)phase) & 0xff] >> 1;
phase += phaseshift;
if (phase >= 256)
phase -= 256;
*samples++ = dsp_sine_page[((uint8_t)phase[tone]) & 0xff] >> 1;
phase[0] += phaseshift[0];
phase[1] += phaseshift[1];
phase[2] += phaseshift[2];
phase[3] += phaseshift[3];
if (phase[0] >= 256) phase[0] -= 256;
if (phase[1] >= 256) phase[1] -= 256;
if (phase[2] >= 256) phase[2] -= 256;
if (phase[3] >= 256) phase[3] -= 256;
if (++count == numspl) {
count = 0;
if (++tone == 4)
tone = 0;
goto next_tone;
}
length--;
}
anetz->tone_phase256 = phase;
for (i = 0; i < 4; i++) {
anetz->paging_phase256[i] = phase[i];
}
anetz->paging_tone = tone;
anetz->paging_count = count;
}
@@ -341,8 +348,8 @@ void sender_send(sender_t *sender, int16_t *samples, int length)
fsk_tone(anetz, samples, length);
break;
case DSP_MODE_PAGING:
if (page_sequence)
fsk_paging_tone_sequence(anetz, samples, length, page_sequence * anetz->sender.samplerate / 1000);
if (anetz->page_sequence)
fsk_paging_tone_sequence(anetz, samples, length, anetz->page_sequence * anetz->sender.samplerate / 1000);
else
fsk_paging_tone(anetz, samples, length);
break;