diff options
Diffstat (limited to 'src/anetz/dsp.c')
| -rw-r--r-- | src/anetz/dsp.c | 38 |
1 files changed, 17 insertions, 21 deletions
diff --git a/src/anetz/dsp.c b/src/anetz/dsp.c index e47f7f2..ee5bdd7 100644 --- a/src/anetz/dsp.c +++ b/src/anetz/dsp.c @@ -37,8 +37,6 @@ /* signaling */ #define BANDWIDTH 15000.0 /* maximum bandwidth */ #define TX_PEAK_TONE 8192.0 /* peak amplitude for all tones */ -#warning FIXME: only with emphasis, use seperate option for volume, override by sdr -#define TX_PEAK_PAGE 32766.0 /* peak amplitude paging tone */ #define CHUNK_DURATION 0.010 /* 10 ms */ // FIXME: how long until we detect a tone? @@ -56,7 +54,6 @@ static double fsk_tones[2] = { /* table for fast sine generation */ int dsp_sine_tone[256]; -int dsp_sine_page[256]; /* global init for audio processing */ void dsp_init(void) @@ -68,22 +65,16 @@ void dsp_init(void) for (i = 0; i < 256; i++) { s = sin((double)i / 256.0 * 2.0 * PI); dsp_sine_tone[i] = (int)(s * TX_PEAK_TONE); - s = cos((double)i / 256.0 * 2.0 * PI); - dsp_sine_page[i] = (int)(s * TX_PEAK_PAGE); } if (TX_PEAK_TONE > 32767.0) { fprintf(stderr, "TX_PEAK_TONE definition too high, please fix!\n"); abort(); } - if (TX_PEAK_PAGE > 32767.0) { - fprintf(stderr, "TX_PEAK_PAGE definition too high, please fix!\n"); - abort(); - } } /* Init transceiver instance. */ -int dsp_init_sender(anetz_t *anetz, int page_sequence) +int dsp_init_sender(anetz_t *anetz, double page_gain, int page_sequence) { int16_t *spl; double coeff; @@ -96,6 +87,11 @@ int dsp_init_sender(anetz_t *anetz, int page_sequence) anetz->sender.bandwidth = BANDWIDTH; anetz->sender.sample_deviation = 11000.0 / (double)TX_PEAK_TONE; + anetz->page_gain = page_gain; + if (page_gain * TX_PEAK_TONE > 32767.0) { + page_gain = 32767.0 / TX_PEAK_TONE; + PDEBUG_CHAN(DDSP, DEBUG_NOTICE, "Highest possible gain of paging tones is %.1f dB.\n", log10(page_gain) * 20); + } anetz->page_sequence = page_sequence; audio_init_loss(&anetz->sender.loss, LOSS_INTERVAL, anetz->sender.loss_volume, LOSS_TIME); @@ -245,12 +241,12 @@ void dsp_set_paging(anetz_t *anetz, double *freq) } /* Generate audio stream of 4 simultanious paging tones. Keep phase for next call of function. - * Use TX_PEAK_PAGE for all tones, which gives peak of (TX_PEAK_PAGE / 4) for each individual tone. */ + * Use TX_PEAK_TONE*page_gain for all tones, which gives peak of 1/4th for each individual tone. */ static void fsk_paging_tone(anetz_t *anetz, int16_t *samples, int length) { double phaseshift[4], phase[4]; int i; - int32_t sample; + double sample; for (i = 0; i < 4; i++) { phaseshift[i] = anetz->paging_phaseshift256[i]; @@ -258,11 +254,11 @@ static void fsk_paging_tone(anetz_t *anetz, int16_t *samples, int length) } for (i = 0; i < length; i++) { - sample = (int32_t)dsp_sine_page[((uint8_t)phase[0]) & 0xff] - + (int32_t)dsp_sine_page[((uint8_t)phase[1]) & 0xff] - + (int32_t)dsp_sine_page[((uint8_t)phase[2]) & 0xff] - + (int32_t)dsp_sine_page[((uint8_t)phase[3]) & 0xff]; - *samples++ = sample >> 2; + sample = (int32_t)dsp_sine_tone[((uint8_t)phase[0]) & 0xff] + + (int32_t)dsp_sine_tone[((uint8_t)phase[1]) & 0xff] + + (int32_t)dsp_sine_tone[((uint8_t)phase[2]) & 0xff] + + (int32_t)dsp_sine_tone[((uint8_t)phase[3]) & 0xff]; + *samples++ = sample / 4.0 * anetz->page_gain; phase[0] += phaseshift[0]; phase[1] += phaseshift[1]; phase[2] += phaseshift[2]; @@ -281,7 +277,7 @@ static void fsk_paging_tone(anetz_t *anetz, int16_t *samples, int length) /* Generate audio stream of 4 sequenced paging tones. Keep phase for next call * of function. * - * Use TX_PEAK_PAGE / 2 for each tone, that is twice as much peak per tone. + * Use TX_PEAK_PAGE for each tone, that is four times higher per tone. * * Click removal when changing tones that have individual phase: * When tone changes to next tone, a transition of 2ms is performed. The last @@ -304,12 +300,12 @@ static void fsk_paging_tone_sequence(anetz_t *anetz, int16_t *samples, int lengt while (length) { /* use tone, but during transition of tones, keep phase 0 degrees (high level) until next tone reaches 0 degrees (high level) */ if (!transition) - *samples++ = dsp_sine_page[((uint8_t)phase[tone]) & 0xff] >> 1; + *samples++ = dsp_sine_tone[((uint8_t)phase[tone]) & 0xff] * anetz->page_gain; else { /* fade between old an new tone */ *samples++ - = (double)dsp_sine_page[((uint8_t)phase[(tone - 1) & 3]) & 0xff] * (double)(transition - count) / (double)transition / 2.0 - + (double)dsp_sine_page[((uint8_t)phase[tone]) & 0xff] * (double)count / (double)transition / 2.0; + = (double)dsp_sine_tone[((uint8_t)phase[(tone - 1) & 3]) & 0xff] * (double)(transition - count) / (double)transition / 2.0 * anetz->page_gain + + (double)dsp_sine_tone[((uint8_t)phase[tone]) & 0xff] * (double)count / (double)transition / 2.0 * anetz->page_gain; } phase[0] += phaseshift[0]; phase[1] += phaseshift[1]; |