NMT: Rework on FSK process, no more requirement for special sample rates
This commit is contained in:
parent
2d0bc92cde
commit
d447be5e26
|
@ -287,10 +287,13 @@ static void dms_encode_dt(nmt_t *nmt, uint8_t d, uint8_t s, uint8_t n, uint8_t *
|
||||||
#endif
|
#endif
|
||||||
|
|
||||||
/* render wave form */
|
/* render wave form */
|
||||||
fsk_render_frame(nmt, frame, 127, dms->frame_spl);
|
dms->frame_length = fsk_render_frame(nmt, frame, 127, dms->frame_spl);
|
||||||
dms->frame_valid = 1;
|
dms->frame_valid = 1;
|
||||||
dms->frame_pos = 0;
|
dms->frame_pos = 0;
|
||||||
dms->frame_length = nmt->samples_per_bit * 127;
|
if (dms->frame_length > dms->frame_size) {
|
||||||
|
PDEBUG(DDMS, DEBUG_ERROR, "Frame exceeds buffer, please fix!\n");
|
||||||
|
abort();
|
||||||
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
/* encode RR frame and schedule for next transmission */
|
/* encode RR frame and schedule for next transmission */
|
||||||
|
@ -331,10 +334,13 @@ static void dms_encode_rr(nmt_t *nmt, uint8_t d, uint8_t s, uint8_t n)
|
||||||
#endif
|
#endif
|
||||||
|
|
||||||
/* render wave form */
|
/* render wave form */
|
||||||
fsk_render_frame(nmt, frame, 77, dms->frame_spl);
|
dms->frame_length = fsk_render_frame(nmt, frame, 77, dms->frame_spl);
|
||||||
dms->frame_valid = 1;
|
dms->frame_valid = 1;
|
||||||
dms->frame_pos = 0;
|
dms->frame_pos = 0;
|
||||||
dms->frame_length = nmt->samples_per_bit * 77;
|
if (dms->frame_length > dms->frame_size) {
|
||||||
|
PDEBUG(DDMS, DEBUG_ERROR, "Frame exceeds buffer, please fix!\n");
|
||||||
|
abort();
|
||||||
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
/* check if we have to transmit a frame and render it
|
/* check if we have to transmit a frame and render it
|
||||||
|
|
|
@ -26,8 +26,9 @@ typedef struct dms {
|
||||||
/* DMS transmission */
|
/* DMS transmission */
|
||||||
int frame_valid; /* set, if there is a valid frame in sample buffer */
|
int frame_valid; /* set, if there is a valid frame in sample buffer */
|
||||||
int16_t *frame_spl; /* 127 * fsk_bit_length */
|
int16_t *frame_spl; /* 127 * fsk_bit_length */
|
||||||
|
int frame_size; /* total size of buffer */
|
||||||
int frame_pos; /* current sample position in frame_spl */
|
int frame_pos; /* current sample position in frame_spl */
|
||||||
int frame_length; /* number of samples in frame_spl */
|
int frame_length; /* number of samples currently in frame_spl */
|
||||||
uint16_t rx_sync; /* shift register to detect sync */
|
uint16_t rx_sync; /* shift register to detect sync */
|
||||||
double rx_sync_level[256]; /* level infos */
|
double rx_sync_level[256]; /* level infos */
|
||||||
double rx_sync_quality[256]; /* quality infos */
|
double rx_sync_quality[256]; /* quality infos */
|
||||||
|
|
142
src/nmt/dsp.c
142
src/nmt/dsp.c
|
@ -55,7 +55,7 @@
|
||||||
#define MUTE_DURATION 0.280 /* a tiny bit more than two frames */
|
#define MUTE_DURATION 0.280 /* a tiny bit more than two frames */
|
||||||
|
|
||||||
/* two signaling tones */
|
/* two signaling tones */
|
||||||
static double fsk_bits[2] = {
|
static double fsk_freq[2] = {
|
||||||
1800.0,
|
1800.0,
|
||||||
1200.0,
|
1200.0,
|
||||||
};
|
};
|
||||||
|
@ -70,8 +70,9 @@ static double super_freq[5] = {
|
||||||
};
|
};
|
||||||
|
|
||||||
/* table for fast sine generation */
|
/* table for fast sine generation */
|
||||||
int dsp_sine_super[256];
|
uint16_t dsp_tone_bit[2][2][256]; /* polarity, bit, phase */
|
||||||
int dsp_sine_dialtone[256];
|
uint16_t dsp_sine_super[256];
|
||||||
|
uint16_t dsp_sine_dialtone[256];
|
||||||
|
|
||||||
/* global init for FSK */
|
/* global init for FSK */
|
||||||
void dsp_init(void)
|
void dsp_init(void)
|
||||||
|
@ -82,8 +83,17 @@ void dsp_init(void)
|
||||||
PDEBUG(DDSP, DEBUG_DEBUG, "Generating sine table for supervisory signal.\n");
|
PDEBUG(DDSP, DEBUG_DEBUG, "Generating sine table for supervisory signal.\n");
|
||||||
for (i = 0; i < 256; i++) {
|
for (i = 0; i < 256; i++) {
|
||||||
s = sin((double)i / 256.0 * 2.0 * PI);
|
s = sin((double)i / 256.0 * 2.0 * PI);
|
||||||
|
/* supervisor sine */
|
||||||
dsp_sine_super[i] = (int)(s * TX_PEAK_SUPER);
|
dsp_sine_super[i] = (int)(s * TX_PEAK_SUPER);
|
||||||
|
/* dialtone sine */
|
||||||
dsp_sine_dialtone[i] = (int)(s * TX_PEAK_DIALTONE);
|
dsp_sine_dialtone[i] = (int)(s * TX_PEAK_DIALTONE);
|
||||||
|
/* bit(1) 1 cycle */
|
||||||
|
dsp_tone_bit[0][1][i] = (int)(s * TX_PEAK_FSK);
|
||||||
|
dsp_tone_bit[1][1][i] = (int)(-s * TX_PEAK_FSK);
|
||||||
|
/* bit(0) 1.5 cycles */
|
||||||
|
s = sin((double)i / 256.0 * 3.0 * PI);
|
||||||
|
dsp_tone_bit[0][0][i] = (int)(s * TX_PEAK_FSK);
|
||||||
|
dsp_tone_bit[1][0][i] = (int)(-s * TX_PEAK_FSK);
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
|
@ -97,46 +107,24 @@ int dsp_init_sender(nmt_t *nmt)
|
||||||
/* attack (3ms) and recovery time (13.5ms) according to NMT specs */
|
/* attack (3ms) and recovery time (13.5ms) according to NMT specs */
|
||||||
init_compandor(&nmt->cstate, 8000, 3.0, 13.5, COMPANDOR_0DB);
|
init_compandor(&nmt->cstate, 8000, 3.0, 13.5, COMPANDOR_0DB);
|
||||||
|
|
||||||
if ((nmt->sender.samplerate % (BIT_RATE * STEPS_PER_BIT))) {
|
|
||||||
PDEBUG(DDSP, DEBUG_ERROR, "Sample rate must be a multiple of %d bits per second.\n", BIT_RATE * STEPS_PER_BIT);
|
|
||||||
return -EINVAL;
|
|
||||||
}
|
|
||||||
|
|
||||||
/* this should not happen. it is implied by previous check */
|
/* this should not happen. it is implied by previous check */
|
||||||
if (nmt->supervisory && nmt->sender.samplerate < 12000) {
|
if (nmt->supervisory && nmt->sender.samplerate < 12000) {
|
||||||
PDEBUG(DDSP, DEBUG_ERROR, "Sample rate must be at least 12000 Hz to process supervisory signal.\n");
|
PDEBUG(DDSP, DEBUG_ERROR, "Sample rate must be at least 12000 Hz to process FSK+supervisory signal.\n");
|
||||||
return -EINVAL;
|
return -EINVAL;
|
||||||
}
|
}
|
||||||
|
|
||||||
PDEBUG_CHAN(DDSP, DEBUG_DEBUG, "Init DSP for Transceiver.\n");
|
PDEBUG_CHAN(DDSP, DEBUG_DEBUG, "Init DSP for Transceiver.\n");
|
||||||
|
|
||||||
/* allocate sample for 2 bits with 2 polarities */
|
|
||||||
nmt->samples_per_bit = nmt->sender.samplerate / BIT_RATE;
|
|
||||||
PDEBUG(DDSP, DEBUG_DEBUG, "Using %d samples per bit duration.\n", nmt->samples_per_bit);
|
|
||||||
nmt->fsk_filter_step = nmt->samples_per_bit / STEPS_PER_BIT;
|
|
||||||
PDEBUG(DDSP, DEBUG_DEBUG, "Using %d samples per filter step.\n", nmt->fsk_filter_step);
|
|
||||||
nmt->fsk_sine[0][0] = calloc(4, nmt->samples_per_bit * sizeof(int16_t));
|
|
||||||
nmt->fsk_sine[0][1] = nmt->fsk_sine[0][0] + nmt->samples_per_bit;
|
|
||||||
nmt->fsk_sine[1][0] = nmt->fsk_sine[0][1] + nmt->samples_per_bit;
|
|
||||||
nmt->fsk_sine[1][1] = nmt->fsk_sine[1][0] + nmt->samples_per_bit;
|
|
||||||
if (!nmt->fsk_sine[0][0]) {
|
|
||||||
PDEBUG(DDSP, DEBUG_ERROR, "No memory!\n");
|
|
||||||
return -ENOMEM;
|
|
||||||
}
|
|
||||||
|
|
||||||
PDEBUG(DDSP, DEBUG_DEBUG, "Using FSK level of %.0f (3.5 KHz deviation @ 1500 Hz)\n", TX_PEAK_FSK);
|
PDEBUG(DDSP, DEBUG_DEBUG, "Using FSK level of %.0f (3.5 KHz deviation @ 1500 Hz)\n", TX_PEAK_FSK);
|
||||||
PDEBUG(DDSP, DEBUG_DEBUG, "Using Supervisory level of %.0f (0.3 KHz deviation @ 4015 Hz)\n", TX_PEAK_SUPER);
|
PDEBUG(DDSP, DEBUG_DEBUG, "Using Supervisory level of %.0f (0.3 KHz deviation @ 4015 Hz)\n", TX_PEAK_SUPER);
|
||||||
|
|
||||||
/* generate sines */
|
nmt->fsk_samples_per_bit = (double)nmt->sender.samplerate / (double)BIT_RATE;
|
||||||
for (i = 0; i < nmt->samples_per_bit; i++) {
|
nmt->fsk_bits_per_sample = 1.0 / nmt->fsk_samples_per_bit;
|
||||||
nmt->fsk_sine[0][0][i] = TX_PEAK_FSK * sin(3.0 * PI * (double)i / (double)nmt->samples_per_bit); /* 1.5 waves */
|
PDEBUG(DDSP, DEBUG_DEBUG, "Use %.4f samples for full bit duration @ %d.\n", nmt->fsk_samples_per_bit, nmt->sender.samplerate);
|
||||||
nmt->fsk_sine[0][1][i] = TX_PEAK_FSK * sin(2.0 * PI * (double)i / (double)nmt->samples_per_bit); /* 1 wave */
|
|
||||||
nmt->fsk_sine[1][0][i] = -nmt->fsk_sine[0][0][i];
|
|
||||||
nmt->fsk_sine[1][1][i] = -nmt->fsk_sine[0][1][i];
|
|
||||||
}
|
|
||||||
|
|
||||||
/* allocate ring buffers, one bit duration */
|
/* allocate ring buffers, one bit duration */
|
||||||
spl = calloc(1, nmt->samples_per_bit * sizeof(*spl));
|
nmt->fsk_filter_size = floor(nmt->fsk_samples_per_bit); /* buffer holds one bit (rounded down) */
|
||||||
|
spl = calloc(1, nmt->fsk_filter_size * sizeof(*spl));
|
||||||
if (!spl) {
|
if (!spl) {
|
||||||
PDEBUG(DDSP, DEBUG_ERROR, "No memory!\n");
|
PDEBUG(DDSP, DEBUG_ERROR, "No memory!\n");
|
||||||
return -ENOMEM;
|
return -ENOMEM;
|
||||||
|
@ -144,16 +132,18 @@ int dsp_init_sender(nmt_t *nmt)
|
||||||
nmt->fsk_filter_spl = spl;
|
nmt->fsk_filter_spl = spl;
|
||||||
nmt->fsk_filter_bit = -1;
|
nmt->fsk_filter_bit = -1;
|
||||||
|
|
||||||
/* allocate transmit buffer for a complete frame */
|
/* allocate transmit buffer for a complete frame, add 10 to be safe */
|
||||||
spl = calloc(166, nmt->samples_per_bit * sizeof(*spl));
|
nmt->frame_size = 166.0 * (double)nmt->fsk_samples_per_bit + 10;
|
||||||
|
spl = calloc(nmt->frame_size, sizeof(*spl));
|
||||||
if (!spl) {
|
if (!spl) {
|
||||||
PDEBUG(DDSP, DEBUG_ERROR, "No memory!\n");
|
PDEBUG(DDSP, DEBUG_ERROR, "No memory!\n");
|
||||||
return -ENOMEM;
|
return -ENOMEM;
|
||||||
}
|
}
|
||||||
nmt->frame_spl = spl;
|
nmt->frame_spl = spl;
|
||||||
|
|
||||||
/* allocate DMS transmit buffer for a complete frame */
|
/* allocate DMS transmit buffer for a complete frame, add 10 to be safe */
|
||||||
spl = calloc(127, nmt->samples_per_bit * sizeof(*spl));
|
nmt->dms.frame_size = 127.0 * (double)nmt->fsk_samples_per_bit + 10;
|
||||||
|
spl = calloc(nmt->dms.frame_size, sizeof(*spl));
|
||||||
if (!spl) {
|
if (!spl) {
|
||||||
PDEBUG(DDSP, DEBUG_ERROR, "No memory!\n");
|
PDEBUG(DDSP, DEBUG_ERROR, "No memory!\n");
|
||||||
return -ENOMEM;
|
return -ENOMEM;
|
||||||
|
@ -171,10 +161,12 @@ int dsp_init_sender(nmt_t *nmt)
|
||||||
|
|
||||||
/* count symbols */
|
/* count symbols */
|
||||||
for (i = 0; i < 2; i++) {
|
for (i = 0; i < 2; i++) {
|
||||||
coeff = 2.0 * cos(2.0 * PI * fsk_bits[i] / (double)nmt->sender.samplerate);
|
coeff = 2.0 * cos(2.0 * PI * fsk_freq[i] / (double)nmt->sender.samplerate);
|
||||||
nmt->fsk_coeff[i] = coeff * 32768.0;
|
nmt->fsk_coeff[i] = coeff * 32768.0;
|
||||||
PDEBUG(DDSP, DEBUG_DEBUG, "coeff[%d] = %d\n", i, (int)nmt->fsk_coeff[i]);
|
PDEBUG(DDSP, DEBUG_DEBUG, "fsk_coeff[%d] = %d\n", i, (int)nmt->fsk_coeff[i]);
|
||||||
}
|
}
|
||||||
|
nmt->fsk_phaseshift256 = 256.0 / nmt->fsk_samples_per_bit;
|
||||||
|
PDEBUG(DDSP, DEBUG_DEBUG, "fsk_phaseshift = %.4f\n", nmt->fsk_phaseshift256);
|
||||||
|
|
||||||
/* count supervidory tones */
|
/* count supervidory tones */
|
||||||
for (i = 0; i < 5; i++) {
|
for (i = 0; i < 5; i++) {
|
||||||
|
@ -184,13 +176,14 @@ int dsp_init_sender(nmt_t *nmt)
|
||||||
|
|
||||||
if (i < 4) {
|
if (i < 4) {
|
||||||
nmt->super_phaseshift256[i] = 256.0 / ((double)nmt->sender.samplerate / super_freq[i]);
|
nmt->super_phaseshift256[i] = 256.0 / ((double)nmt->sender.samplerate / super_freq[i]);
|
||||||
PDEBUG(DDSP, DEBUG_DEBUG, "phaseshift_super[%d] = %.4f\n", i, nmt->super_phaseshift256[i]);
|
PDEBUG(DDSP, DEBUG_DEBUG, "super_phaseshift[%d] = %.4f\n", i, nmt->super_phaseshift256[i]);
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
super_reset(nmt);
|
super_reset(nmt);
|
||||||
|
|
||||||
/* dial tone */
|
/* dial tone */
|
||||||
nmt->dial_phaseshift256 = 256.0 / ((double)nmt->sender.samplerate / DIALTONE_HZ);
|
nmt->dial_phaseshift256 = 256.0 / ((double)nmt->sender.samplerate / DIALTONE_HZ);
|
||||||
|
PDEBUG(DDSP, DEBUG_DEBUG, "dial_phaseshift = %.4f\n", nmt->dial_phaseshift256);
|
||||||
|
|
||||||
/* dtmf */
|
/* dtmf */
|
||||||
dtmf_init(&nmt->dtmf, 8000);
|
dtmf_init(&nmt->dtmf, 8000);
|
||||||
|
@ -254,8 +247,8 @@ static void fsk_receive_bit(nmt_t *nmt, int bit, double quality, double level)
|
||||||
return;
|
return;
|
||||||
|
|
||||||
/* sync time */
|
/* sync time */
|
||||||
nmt->rx_sample_count_last = nmt->rx_sample_count_current;
|
nmt->rx_bits_count_last = nmt->rx_bits_count_current;
|
||||||
nmt->rx_sample_count_current = nmt->rx_sample_count - nmt->samples_per_bit * 26;
|
nmt->rx_bits_count_current = nmt->rx_bits_count - 26.0;
|
||||||
|
|
||||||
/* rest sync register */
|
/* rest sync register */
|
||||||
nmt->fsk_filter_sync = 0;
|
nmt->fsk_filter_sync = 0;
|
||||||
|
@ -287,7 +280,7 @@ static void fsk_receive_bit(nmt_t *nmt, int bit, double quality, double level)
|
||||||
level /= 140.0; quality /= 140.0;
|
level /= 140.0; quality /= 140.0;
|
||||||
|
|
||||||
/* send telegramm */
|
/* send telegramm */
|
||||||
frames_elapsed = (double)(nmt->rx_sample_count_current - nmt->rx_sample_count_last) / (double)(nmt->samples_per_bit * 166);
|
frames_elapsed = (nmt->rx_bits_count_current - nmt->rx_bits_count_last) / 166.0;
|
||||||
/* convert level so that received level at TX_PEAK_FSK results in 1.0 (100%) */
|
/* convert level so that received level at TX_PEAK_FSK results in 1.0 (100%) */
|
||||||
nmt_receive_frame(nmt, nmt->fsk_filter_frame, quality, level, frames_elapsed);
|
nmt_receive_frame(nmt, nmt->fsk_filter_frame, quality, level, frames_elapsed);
|
||||||
}
|
}
|
||||||
|
@ -297,8 +290,8 @@ static void fsk_receive_bit(nmt_t *nmt, int bit, double quality, double level)
|
||||||
//#define DEBUG_QUALITY
|
//#define DEBUG_QUALITY
|
||||||
|
|
||||||
/* Filter one chunk of audio an detect tone, quality and loss of signal.
|
/* Filter one chunk of audio an detect tone, quality and loss of signal.
|
||||||
* The chunk is a window of 10ms. This window slides over audio stream
|
* The chunk is a window of 1/1200s. This window slides over audio stream
|
||||||
* and is processed every 1ms. (one step) */
|
* and is processed every 1/12000s. (one step) */
|
||||||
static inline void fsk_decode_step(nmt_t *nmt, int pos)
|
static inline void fsk_decode_step(nmt_t *nmt, int pos)
|
||||||
{
|
{
|
||||||
double level, result[2], softbit, quality;
|
double level, result[2], softbit, quality;
|
||||||
|
@ -306,11 +299,11 @@ static inline void fsk_decode_step(nmt_t *nmt, int pos)
|
||||||
int16_t *spl;
|
int16_t *spl;
|
||||||
int bit;
|
int bit;
|
||||||
|
|
||||||
max = nmt->samples_per_bit;
|
max = nmt->fsk_filter_size;
|
||||||
spl = nmt->fsk_filter_spl;
|
spl = nmt->fsk_filter_spl;
|
||||||
|
|
||||||
/* count time in samples*/
|
/* count time in bits */
|
||||||
nmt->rx_sample_count += nmt->fsk_filter_step;
|
nmt->rx_bits_count += 0.1;
|
||||||
|
|
||||||
level = audio_level(spl, max);
|
level = audio_level(spl, max);
|
||||||
/* limit level to prevent division by zero */
|
/* limit level to prevent division by zero */
|
||||||
|
@ -430,7 +423,8 @@ void sender_receive(sender_t *sender, int16_t *samples, int length)
|
||||||
{
|
{
|
||||||
nmt_t *nmt = (nmt_t *) sender;
|
nmt_t *nmt = (nmt_t *) sender;
|
||||||
int16_t *spl;
|
int16_t *spl;
|
||||||
int max, pos, step;
|
int max, pos;
|
||||||
|
double step, bps;
|
||||||
int i;
|
int i;
|
||||||
|
|
||||||
/* write received samples to decode buffer */
|
/* write received samples to decode buffer */
|
||||||
|
@ -448,26 +442,32 @@ void sender_receive(sender_t *sender, int16_t *samples, int length)
|
||||||
nmt->super_filter_pos = pos;
|
nmt->super_filter_pos = pos;
|
||||||
|
|
||||||
/* write received samples to decode buffer */
|
/* write received samples to decode buffer */
|
||||||
max = nmt->samples_per_bit;
|
max = nmt->fsk_filter_size;
|
||||||
pos = nmt->fsk_filter_pos;
|
pos = nmt->fsk_filter_pos;
|
||||||
step = nmt->fsk_filter_step;
|
step = nmt->fsk_filter_step;
|
||||||
|
bps = nmt->fsk_bits_per_sample;
|
||||||
spl = nmt->fsk_filter_spl;
|
spl = nmt->fsk_filter_spl;
|
||||||
for (i = 0; i < length; i++) {
|
for (i = 0; i < length; i++) {
|
||||||
#ifdef DEBUG_MODULATOR
|
#ifdef DEBUG_MODULATOR
|
||||||
printf("|%s|\n", debug_amplitude((double)samples[i] / TX_PEAK_FSK / 2.0));
|
printf("|%s|\n", debug_amplitude((double)samples[i] / TX_PEAK_FSK / 2.0));
|
||||||
#endif
|
#endif
|
||||||
|
/* write into ring buffer */
|
||||||
spl[pos++] = samples[i];
|
spl[pos++] = samples[i];
|
||||||
if (nmt->fsk_filter_mute) {
|
if (pos == max)
|
||||||
|
pos = 0;
|
||||||
|
/* muting audio while receiving frame */
|
||||||
|
if (nmt->fsk_filter_mute && !nmt->sender.loopback) {
|
||||||
samples[i] = 0;
|
samples[i] = 0;
|
||||||
nmt->fsk_filter_mute--;
|
nmt->fsk_filter_mute--;
|
||||||
}
|
}
|
||||||
if (pos == max)
|
/* if 1/10th of a bit duration is reached, decode buffer */
|
||||||
pos = 0;
|
step += bps;
|
||||||
/* if filter step has been reched */
|
if (step >= 0.1) {
|
||||||
if (!(pos % step)) {
|
step -= 0.1;
|
||||||
fsk_decode_step(nmt, pos);
|
fsk_decode_step(nmt, pos);
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
nmt->fsk_filter_step = step;
|
||||||
nmt->fsk_filter_pos = pos;
|
nmt->fsk_filter_pos = pos;
|
||||||
|
|
||||||
if ((nmt->dsp_mode == DSP_MODE_AUDIO || nmt->dsp_mode == DSP_MODE_DTMF)
|
if ((nmt->dsp_mode == DSP_MODE_AUDIO || nmt->dsp_mode == DSP_MODE_DTMF)
|
||||||
|
@ -495,21 +495,32 @@ void sender_receive(sender_t *sender, int16_t *samples, int length)
|
||||||
}
|
}
|
||||||
|
|
||||||
/* render frame */
|
/* render frame */
|
||||||
void fsk_render_frame(nmt_t *nmt, const char *frame, int length, int16_t *sample)
|
int fsk_render_frame(nmt_t *nmt, const char *frame, int length, int16_t *sample)
|
||||||
{
|
{
|
||||||
int bit, polarity;
|
int bit, polarity;
|
||||||
int i;
|
double phaseshift, phase;
|
||||||
|
int count = 0, i;
|
||||||
|
|
||||||
polarity = nmt->fsk_polarity;
|
polarity = nmt->fsk_polarity;
|
||||||
|
phaseshift = nmt->fsk_phaseshift256;
|
||||||
|
phase = nmt->fsk_phase256;
|
||||||
for (i = 0; i < length; i++) {
|
for (i = 0; i < length; i++) {
|
||||||
bit = (frame[i] == '1');
|
bit = (frame[i] == '1');
|
||||||
memcpy(sample, nmt->fsk_sine[polarity][bit], nmt->samples_per_bit * sizeof(*sample));
|
do {
|
||||||
sample += nmt->samples_per_bit;
|
*sample++ = dsp_tone_bit[polarity][bit][((uint8_t)phase) & 0xff];
|
||||||
|
count++;
|
||||||
|
phase += phaseshift;
|
||||||
|
} while (phase < 256.0);
|
||||||
|
phase -= 256.0;
|
||||||
/* flip polarity when we have 1.5 sine waves */
|
/* flip polarity when we have 1.5 sine waves */
|
||||||
if (bit == 0)
|
if (bit == 0)
|
||||||
polarity = 1 - polarity;
|
polarity = 1 - polarity;
|
||||||
}
|
}
|
||||||
|
nmt->fsk_phase256 = phase;
|
||||||
nmt->fsk_polarity = polarity;
|
nmt->fsk_polarity = polarity;
|
||||||
|
|
||||||
|
/* return number of samples created for frame */
|
||||||
|
return count;
|
||||||
}
|
}
|
||||||
|
|
||||||
static int fsk_frame(nmt_t *nmt, int16_t *samples, int length)
|
static int fsk_frame(nmt_t *nmt, int16_t *samples, int length)
|
||||||
|
@ -520,21 +531,24 @@ static int fsk_frame(nmt_t *nmt, int16_t *samples, int length)
|
||||||
int count, max;
|
int count, max;
|
||||||
|
|
||||||
next_frame:
|
next_frame:
|
||||||
if (!nmt->frame) {
|
if (!nmt->frame_length) {
|
||||||
/* request frame */
|
/* request frame */
|
||||||
frame = nmt_get_frame(nmt);
|
frame = nmt_get_frame(nmt);
|
||||||
if (!frame) {
|
if (!frame) {
|
||||||
PDEBUG_CHAN(DDSP, DEBUG_DEBUG, "Stop sending frames.\n");
|
PDEBUG_CHAN(DDSP, DEBUG_DEBUG, "Stop sending frames.\n");
|
||||||
return length;
|
return length;
|
||||||
}
|
}
|
||||||
nmt->frame = 1;
|
|
||||||
nmt->frame_pos = 0;
|
|
||||||
/* render frame */
|
/* render frame */
|
||||||
fsk_render_frame(nmt, frame, 166, nmt->frame_spl);
|
nmt->frame_length = fsk_render_frame(nmt, frame, 166, nmt->frame_spl);
|
||||||
|
nmt->frame_pos = 0;
|
||||||
|
if (nmt->frame_length > nmt->frame_size) {
|
||||||
|
PDEBUG_CHAN(DDSP, DEBUG_ERROR, "Frame exceeds buffer, please fix!\n");
|
||||||
|
abort();
|
||||||
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
/* send audio from frame */
|
/* send audio from frame */
|
||||||
max = nmt->samples_per_bit * 166;
|
max = nmt->frame_length;
|
||||||
count = max - nmt->frame_pos;
|
count = max - nmt->frame_pos;
|
||||||
if (count > length)
|
if (count > length)
|
||||||
count = length;
|
count = length;
|
||||||
|
@ -546,7 +560,7 @@ next_frame:
|
||||||
nmt->frame_pos += count;
|
nmt->frame_pos += count;
|
||||||
/* check for end of telegramm */
|
/* check for end of telegramm */
|
||||||
if (nmt->frame_pos == max) {
|
if (nmt->frame_pos == max) {
|
||||||
nmt->frame = 0;
|
nmt->frame_length = 0;
|
||||||
/* we need more ? */
|
/* we need more ? */
|
||||||
if (length)
|
if (length)
|
||||||
goto next_frame;
|
goto next_frame;
|
||||||
|
@ -666,7 +680,7 @@ void nmt_set_dsp_mode(nmt_t *nmt, enum dsp_mode mode)
|
||||||
{
|
{
|
||||||
/* reset telegramm */
|
/* reset telegramm */
|
||||||
if (mode == DSP_MODE_FRAME && nmt->dsp_mode != mode)
|
if (mode == DSP_MODE_FRAME && nmt->dsp_mode != mode)
|
||||||
nmt->frame = 0;
|
nmt->frame_length = 0;
|
||||||
|
|
||||||
PDEBUG_CHAN(DDSP, DEBUG_DEBUG, "DSP mode %s -> %s\n", nmt_dsp_mode_name(nmt->dsp_mode), nmt_dsp_mode_name(mode));
|
PDEBUG_CHAN(DDSP, DEBUG_DEBUG, "DSP mode %s -> %s\n", nmt_dsp_mode_name(nmt->dsp_mode), nmt_dsp_mode_name(mode));
|
||||||
nmt->dsp_mode = mode;
|
nmt->dsp_mode = mode;
|
||||||
|
|
|
@ -2,7 +2,7 @@
|
||||||
void dsp_init(void);
|
void dsp_init(void);
|
||||||
int dsp_init_sender(nmt_t *nmt);
|
int dsp_init_sender(nmt_t *nmt);
|
||||||
void dsp_cleanup_sender(nmt_t *nmt);
|
void dsp_cleanup_sender(nmt_t *nmt);
|
||||||
void fsk_render_frame(nmt_t *nmt, const char *frame, int length, int16_t *sample);
|
int fsk_render_frame(nmt_t *nmt, const char *frame, int length, int16_t *sample);
|
||||||
void nmt_set_dsp_mode(nmt_t *nmt, enum dsp_mode mode);
|
void nmt_set_dsp_mode(nmt_t *nmt, enum dsp_mode mode);
|
||||||
void super_reset(nmt_t *nmt);
|
void super_reset(nmt_t *nmt);
|
||||||
|
|
||||||
|
|
|
@ -91,17 +91,17 @@ typedef struct nmt {
|
||||||
|
|
||||||
/* dsp states */
|
/* dsp states */
|
||||||
enum dsp_mode dsp_mode; /* current mode: audio, durable tone 0 or 1, paging */
|
enum dsp_mode dsp_mode; /* current mode: audio, durable tone 0 or 1, paging */
|
||||||
int samples_per_bit; /* number of samples for one bit (1200 Baud) */
|
double fsk_samples_per_bit; /* number of samples for one bit (1200 Baud) */
|
||||||
|
double fsk_bits_per_sample; /* fraction of a bit per sample */
|
||||||
int super_samples; /* number of samples in buffer for supervisory detection */
|
int super_samples; /* number of samples in buffer for supervisory detection */
|
||||||
int fsk_coeff[2]; /* coefficient k = 2*cos(2*PI*f/samplerate), k << 15 */
|
int fsk_coeff[2]; /* coefficient k = 2*cos(2*PI*f/samplerate), k << 15 */
|
||||||
int super_coeff[5]; /* coefficient for supervisory signal */
|
int super_coeff[5]; /* coefficient for supervisory signal */
|
||||||
int16_t *fsk_sine[2][2]; /* 4 pointers to 4 precalc. sine curves */
|
|
||||||
int fsk_polarity; /* current polarity state of bit */
|
int fsk_polarity; /* current polarity state of bit */
|
||||||
int samples_per_chunk; /* how many samples lasts one chunk */
|
int16_t *fsk_filter_spl; /* array to hold ring buffer for bit decoding */
|
||||||
int16_t *fsk_filter_spl; /* array with samples_per_chunk */
|
int fsk_filter_size; /* size of ring buffer */
|
||||||
int fsk_filter_pos; /* current sample position in filter_spl */
|
int fsk_filter_pos; /* position to write next sample */
|
||||||
int fsk_filter_step; /* number of samples for each analyzation */
|
double fsk_filter_step; /* counts bit duration, to trigger decoding every 10th bit */
|
||||||
int fsk_filter_bit; /* last bit, so we detect a bit change */
|
int fsk_filter_bit; /* last bit state, so we detect a bit change */
|
||||||
int fsk_filter_sample; /* count until it is time to sample bit */
|
int fsk_filter_sample; /* count until it is time to sample bit */
|
||||||
uint16_t fsk_filter_sync; /* shift register to detect sync */
|
uint16_t fsk_filter_sync; /* shift register to detect sync */
|
||||||
int fsk_filter_in_sync; /* if we are in sync and receive bits */
|
int fsk_filter_in_sync; /* if we are in sync and receive bits */
|
||||||
|
@ -116,12 +116,15 @@ typedef struct nmt {
|
||||||
double super_phase256; /* current phase */
|
double super_phase256; /* current phase */
|
||||||
double dial_phaseshift256; /* how much the phase of sine wave changes per sample */
|
double dial_phaseshift256; /* how much the phase of sine wave changes per sample */
|
||||||
double dial_phase256; /* current phase */
|
double dial_phase256; /* current phase */
|
||||||
int frame; /* set, if there is a valid frame */
|
double fsk_phaseshift256; /* how much the phase of fsk synbol changes per sample */
|
||||||
int16_t *frame_spl; /* 166 * fsk_bit_length */
|
double fsk_phase256; /* current phase */
|
||||||
|
int16_t *frame_spl; /* samples to store a complete rendered frame */
|
||||||
|
int frame_size; /* total size of sample buffer */
|
||||||
|
int frame_length; /* current length of data in sample buffer */
|
||||||
int frame_pos; /* current sample position in frame_spl */
|
int frame_pos; /* current sample position in frame_spl */
|
||||||
uint64_t rx_sample_count; /* sample counter */
|
double rx_bits_count; /* sample counter */
|
||||||
uint64_t rx_sample_count_current;/* sample counter of current frame */
|
double rx_bits_count_current; /* sample counter of current frame */
|
||||||
uint64_t rx_sample_count_last; /* sample counter of last frame */
|
double rx_bits_count_last; /* sample counter of last frame */
|
||||||
int super_detected; /* current detection state flag */
|
int super_detected; /* current detection state flag */
|
||||||
int super_detect_count; /* current number of consecutive detections/losses */
|
int super_detect_count; /* current number of consecutive detections/losses */
|
||||||
|
|
||||||
|
|
|
@ -55,12 +55,14 @@ void dms_all_sent(nmt_t *nmt)
|
||||||
}
|
}
|
||||||
|
|
||||||
/* receive bits from DMS */
|
/* receive bits from DMS */
|
||||||
void fsk_render_frame(nmt_t *nmt, const char *frame, int length, int16_t *sample)
|
int fsk_render_frame(nmt_t *nmt, const char *frame, int length, int16_t *sample)
|
||||||
{
|
{
|
||||||
printf("(getting %d bits from DMS layer)\n", length);
|
printf("(getting %d bits from DMS layer)\n", length);
|
||||||
|
|
||||||
memcpy(current_bits, frame, length);
|
memcpy(current_bits, frame, length);
|
||||||
current_bit_count = length;
|
current_bit_count = length;
|
||||||
|
|
||||||
|
return nmt->fsk_samples_per_bit * length;
|
||||||
}
|
}
|
||||||
|
|
||||||
nmt_t *alloc_nmt(void)
|
nmt_t *alloc_nmt(void)
|
||||||
|
@ -69,8 +71,9 @@ nmt_t *alloc_nmt(void)
|
||||||
|
|
||||||
nmt = calloc(sizeof(*nmt), 1);
|
nmt = calloc(sizeof(*nmt), 1);
|
||||||
dms_init_sender(nmt);
|
dms_init_sender(nmt);
|
||||||
nmt->dms.frame_spl = calloc(1000000, 1);
|
nmt->fsk_samples_per_bit = 40;
|
||||||
nmt->samples_per_bit = 40;
|
nmt->dms.frame_size = nmt->fsk_samples_per_bit * 127 + 10;
|
||||||
|
nmt->dms.frame_spl = calloc(nmt->dms.frame_size, sizeof(nmt->dms.frame_spl[0]));
|
||||||
|
|
||||||
dms_reset(nmt);
|
dms_reset(nmt);
|
||||||
|
|
||||||
|
|
Loading…
Reference in New Issue