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C-Netz: Remove global variables, because they don't speed up anything

This commit is contained in:
Andreas Eversberg 2016-10-07 09:14:22 +02:00
parent 27938d111e
commit 33e0bc5f4e
1 changed files with 61 additions and 107 deletions
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168
src/cnetz/fsk_fm_demod.c
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@ -115,23 +115,10 @@
//#define DEBUG_DECODER if (fsk->cnetz->dsp_mode == DSP_MODE_SPK_V) //#define DEBUG_DECODER if (fsk->cnetz->dsp_mode == DSP_MODE_SPK_V)
//#define DEBUG_DECODER if (fsk->cnetz->dsp_mode == DSP_MODE_SPK_V && sync) //#define DEBUG_DECODER if (fsk->cnetz->dsp_mode == DSP_MODE_SPK_V && sync)
static int len, half;
static int16_t *spl;
static int pos;
static double bits_per_sample, next_bit;
static int level_threshold;
static double bit_time, bit_time_uncorrected;
static enum fsk_sync sync;
static int last_change_positive;
static double sync_level;
static double sync_time;
static double sync_jitter;
static int bit_count;
static int16_t *speech_buffer;
static int speech_size, speech_count;
int fsk_fm_init(fsk_fm_demod_t *fsk, cnetz_t *cnetz, int samplerate, double bitrate) int fsk_fm_init(fsk_fm_demod_t *fsk, cnetz_t *cnetz, int samplerate, double bitrate)
{ {
int len, half;
memset(fsk, 0, sizeof(*fsk)); memset(fsk, 0, sizeof(*fsk));
if (samplerate < 48000) { if (samplerate < 48000) {
PDEBUG(DDSP, DEBUG_ERROR, "Sample rate must be at least 48000 Hz!\n"); PDEBUG(DDSP, DEBUG_ERROR, "Sample rate must be at least 48000 Hz!\n");
@ -177,7 +164,7 @@ static inline void get_levels(fsk_fm_demod_t *fsk, int *_min, int *_max, int *_a
bit_offset = i + ((i + 2) >> 2) * 62; bit_offset = i + ((i + 2) >> 2) * 62;
else else
bit_offset = i; bit_offset = i;
t = fmod(fsk->change_when[(fsk->change_pos - 1 - i) & 0xff] - bit_time + (double)bit_offset + BITS_PER_SUPERFRAME, BITS_PER_SUPERFRAME); t = fmod(fsk->change_when[(fsk->change_pos - 1 - i) & 0xff] - fsk->bit_time + (double)bit_offset + BITS_PER_SUPERFRAME, BITS_PER_SUPERFRAME);
if (t > BITS_PER_SUPERFRAME / 2) if (t > BITS_PER_SUPERFRAME / 2)
t -= BITS_PER_SUPERFRAME; t -= BITS_PER_SUPERFRAME;
//if (fsk->cnetz->dsp_mode == DSP_MODE_SPK_V) //if (fsk->cnetz->dsp_mode == DSP_MODE_SPK_V)
@ -203,7 +190,7 @@ static inline void get_levels(fsk_fm_demod_t *fsk, int *_min, int *_max, int *_a
* sync_time is the absolute time within the super frame. * sync_time is the absolute time within the super frame.
*/ */
sync_average = time / (double)count; sync_average = time / (double)count;
sync_time = fmod(sync_average + bit_time + BITS_PER_SUPERFRAME, BITS_PER_SUPERFRAME); sync_time = fmod(sync_average + fsk->bit_time + BITS_PER_SUPERFRAME, BITS_PER_SUPERFRAME);
*_probes = count; *_probes = count;
*_min = min; *_min = min;
@ -219,7 +206,7 @@ static inline void get_levels(fsk_fm_demod_t *fsk, int *_min, int *_max, int *_a
* for the time to sample the bit. * for the time to sample the bit.
* if sync is earlier, bit_time is already too late, so * if sync is earlier, bit_time is already too late, so
* we must wait less than 1.5 bits */ * we must wait less than 1.5 bits */
next_bit = 1.5 + sync_average; fsk->next_bit = 1.5 + sync_average;
*_time = sync_time; *_time = sync_time;
} }
if (_jitter) { if (_jitter) {
@ -250,19 +237,19 @@ static inline void got_bit(fsk_fm_demod_t *fsk, int bit, int change_level)
/* count bits, but do not exceed 4 bits per SPK block */ /* count bits, but do not exceed 4 bits per SPK block */
if (fsk->cnetz->dsp_mode == DSP_MODE_SPK_V) { if (fsk->cnetz->dsp_mode == DSP_MODE_SPK_V) {
/* for first bit, we have only half of the modulation deviation, so we multiply level by two */ /* for first bit, we have only half of the modulation deviation, so we multiply level by two */
if (bit_count == 0) if (fsk->bit_count == 0)
change_level *= 2; change_level *= 2;
if (bit_count == 4) if (fsk->bit_count == 4)
return; return;
} }
bit_count++; fsk->bit_count++;
//printf("bit %d\n", bit); //printf("bit %d\n", bit);
fsk->change_levels[fsk->change_pos] = change_level; fsk->change_levels[fsk->change_pos] = change_level;
fsk->change_when[fsk->change_pos++] = bit_time; fsk->change_when[fsk->change_pos++] = fsk->bit_time;
switch (sync) { switch (fsk->sync) {
case FSK_SYNC_NONE: case FSK_SYNC_NONE:
fsk->rx_sync = (fsk->rx_sync << 1) | bit; fsk->rx_sync = (fsk->rx_sync << 1) | bit;
/* use half level of last change for threshold change detection. /* use half level of last change for threshold change detection.
@ -274,26 +261,26 @@ static inline void got_bit(fsk_fm_demod_t *fsk, int bit, int change_level)
* after sync, the theshold is set to half of the average of * after sync, the theshold is set to half of the average of
* all changes in the sync sequence */ * all changes in the sync sequence */
if (change_level) { if (change_level) {
level_threshold = (double)change_level / 2.0; fsk->level_threshold = (double)change_level / 2.0;
} else if ((fsk->rx_sync & 0x1f) == 0x00 || (fsk->rx_sync & 0x1f) == 0x1f) { } else if ((fsk->rx_sync & 0x1f) == 0x00 || (fsk->rx_sync & 0x1f) == 0x1f) {
if (fsk->cnetz->dsp_mode != DSP_MODE_SPK_V) if (fsk->cnetz->dsp_mode != DSP_MODE_SPK_V)
level_threshold = 655; fsk->level_threshold = 655;
} }
if (detect_sync(fsk->rx_sync)) { if (detect_sync(fsk->rx_sync)) {
sync = FSK_SYNC_POSITIVE; fsk->sync = FSK_SYNC_POSITIVE;
got_sync: got_sync:
get_levels(fsk, &min, &max, &avg, &probes, 30, &sync_time, &sync_jitter); get_levels(fsk, &min, &max, &avg, &probes, 30, &fsk->sync_time, &fsk->sync_jitter);
sync_level = (double)avg / 65535.0; fsk->sync_level = (double)avg / 65535.0;
if (sync == FSK_SYNC_NEGATIVE) if (fsk->sync == FSK_SYNC_NEGATIVE)
sync_level = -sync_level; fsk->sync_level = -fsk->sync_level;
// printf("sync (change min=%d%% max=%d%% avg=%d%% sync_time=%.2f jitter=%.2f probes=%d)\n", min * 100 / 65535, max * 100 / 65535, avg * 100 / 65535, sync_time, sync_jitter, probes); // printf("sync (change min=%d%% max=%d%% avg=%d%% sync_time=%.2f jitter=%.2f probes=%d)\n", min * 100 / 65535, max * 100 / 65535, avg * 100 / 65535, fsk->sync_time, fsk->sync_jitter, probes);
level_threshold = (double)avg / 2.0; fsk->level_threshold = (double)avg / 2.0;
fsk->rx_sync = 0; fsk->rx_sync = 0;
fsk->rx_buffer_count = 0; fsk->rx_buffer_count = 0;
break; break;
} }
if (detect_sync(fsk->rx_sync ^ 0xfffffffff)) { if (detect_sync(fsk->rx_sync ^ 0xfffffffff)) {
sync = FSK_SYNC_NEGATIVE; fsk->sync = FSK_SYNC_NEGATIVE;
goto got_sync; goto got_sync;
} }
break; break;
@ -303,15 +290,15 @@ got_sync:
case FSK_SYNC_POSITIVE: case FSK_SYNC_POSITIVE:
fsk->rx_buffer[fsk->rx_buffer_count] = bit + '0'; fsk->rx_buffer[fsk->rx_buffer_count] = bit + '0';
if (++fsk->rx_buffer_count == 150) { if (++fsk->rx_buffer_count == 150) {
sync = FSK_SYNC_NONE; fsk->sync = FSK_SYNC_NONE;
if (fsk->cnetz->dsp_mode != DSP_MODE_SPK_V) { if (fsk->cnetz->dsp_mode != DSP_MODE_SPK_V) {
/* received 40 bits after start of block */ /* received 40 bits after start of block */
sync_time = fmod(sync_time - (7+33) + BITS_PER_SUPERFRAME, BITS_PER_SUPERFRAME); fsk->sync_time = fmod(fsk->sync_time - (7+33) + BITS_PER_SUPERFRAME, BITS_PER_SUPERFRAME);
} else { } else {
/* received 662 bits after start of block (10 SPK blocks + 1 bit (== 2 level changes)) */ /* received 662 bits after start of block (10 SPK blocks + 1 bit (== 2 level changes)) */
sync_time = fmod(sync_time - (66*10+2) + BITS_PER_SUPERFRAME, BITS_PER_SUPERFRAME); fsk->sync_time = fmod(fsk->sync_time - (66*10+2) + BITS_PER_SUPERFRAME, BITS_PER_SUPERFRAME);
} }
cnetz_decode_telegramm(fsk->cnetz, fsk->rx_buffer, sync_level, sync_time, sync_jitter); cnetz_decode_telegramm(fsk->cnetz, fsk->rx_buffer, fsk->sync_level, fsk->sync_time, fsk->sync_jitter);
} }
break; break;
} }
@ -333,11 +320,11 @@ static inline void find_change(fsk_fm_demod_t *fsk)
change_at = -1; change_at = -1;
change_positive = -1; change_positive = -1;
for (i = 0; i < len; i++) { for (i = 0; i < fsk->bit_buffer_len; i++) {
last_s = s; last_s = s;
s = spl[pos++]; s = fsk->bit_buffer_spl[fsk->bit_buffer_pos++];
if (pos == len) if (fsk->bit_buffer_pos == fsk->bit_buffer_len)
pos = 0; fsk->bit_buffer_pos = 0;
if (i > 0) { if (i > 0) {
if (s - last_s > change_max) { if (s - last_s > change_max) {
change_max = s - last_s; change_max = s - last_s;
@ -355,10 +342,10 @@ static inline void find_change(fsk_fm_demod_t *fsk)
level_min = s; level_min = s;
} }
/* for first bit, we have only half of the modulation deviation, so we divide the threshold by two */ /* for first bit, we have only half of the modulation deviation, so we divide the threshold by two */
if (fsk->cnetz->dsp_mode == DSP_MODE_SPK_V && bit_count == 0) if (fsk->cnetz->dsp_mode == DSP_MODE_SPK_V && fsk->bit_count == 0)
threshold = level_threshold / 2; threshold = fsk->level_threshold / 2;
else else
threshold = level_threshold; threshold = fsk->level_threshold;
/* if we are not in sync, for every detected change we set /* if we are not in sync, for every detected change we set
* next_bit to 1.5, so we wait 1.5 bits for next change * next_bit to 1.5, so we wait 1.5 bits for next change
* if it is not received within this time, there is no change, * if it is not received within this time, there is no change,
@ -367,30 +354,30 @@ static inline void find_change(fsk_fm_demod_t *fsk)
* bits after sync average, we measure the first bit * bits after sync average, we measure the first bit
* and then all subsequent bits after 1.0 bits */ * and then all subsequent bits after 1.0 bits */
//DEBUG_DECODER printf("next_bit=%.4f\n", next_bit); //DEBUG_DECODER printf("next_bit=%.4f\n", next_bit);
if (level_max - level_min > threshold && change_at == half) { if (level_max - level_min > threshold && change_at == fsk->bit_buffer_half) {
#ifdef DEBUG_DECODER #ifdef DEBUG_DECODER
DEBUG_DECODER DEBUG_DECODER
printf("receive bit change to %d (level=%d, threshold=%d)\n", change_positive, level_max - level_min, threshold); printf("receive bit change to %d (level=%d, threshold=%d)\n", change_positive, level_max - level_min, threshold);
#endif #endif
last_change_positive = change_positive; fsk->last_change_positive = change_positive;
if (!sync) { if (!fsk->sync) {
next_bit = 1.5; fsk->next_bit = 1.5;
got_bit(fsk, change_positive, level_max - level_min); got_bit(fsk, change_positive, level_max - level_min);
} }
} }
if (next_bit <= 0.0) { if (fsk->next_bit <= 0.0) {
#ifdef DEBUG_DECODER #ifdef DEBUG_DECODER
DEBUG_DECODER { DEBUG_DECODER {
if (sync) if (fsk->sync)
printf("sampling here bit %d\n", last_change_positive); printf("sampling here bit %d\n", fsk->last_change_positive);
else else
printf("no bit change\n"); printf("no bit change\n");
} }
#endif #endif
next_bit += 1.0; fsk->next_bit += 1.0;
got_bit(fsk, last_change_positive, 0); got_bit(fsk, fsk->last_change_positive, 0);
} }
next_bit -= bits_per_sample; fsk->next_bit -= fsk->bits_per_sample;
} }
/* receive FM signal from receiver */ /* receive FM signal from receiver */
@ -399,30 +386,11 @@ void fsk_fm_demod(fsk_fm_demod_t *fsk, int16_t *samples, int length)
int i; int i;
double t; double t;
len = fsk->bit_buffer_len;
half = fsk->bit_buffer_half;
spl = fsk->bit_buffer_spl;
speech_buffer = fsk->speech_buffer;
speech_size = fsk->speech_size;
speech_count = fsk->speech_count;
bits_per_sample = fsk->bits_per_sample;
level_threshold = fsk->level_threshold;
pos = fsk->bit_buffer_pos;
next_bit = fsk->next_bit;
sync = fsk->sync;
last_change_positive = fsk->last_change_positive;
sync_level = fsk->sync_level;
sync_time = fsk->sync_time;
sync_jitter = fsk->sync_jitter;
bit_time = fsk->bit_time;
bit_time_uncorrected = fsk->bit_time_uncorrected;
bit_count = fsk->bit_count;
/* process signaling block, sample by sample */ /* process signaling block, sample by sample */
for (i = 0; i < length; i++) { for (i = 0; i < length; i++) {
spl[pos++] = samples[i]; fsk->bit_buffer_spl[fsk->bit_buffer_pos++] = samples[i];
if (pos == len) if (fsk->bit_buffer_pos == fsk->bit_buffer_len)
pos = 0; fsk->bit_buffer_pos = 0;
/* for each sample process buffer */ /* for each sample process buffer */
if (fsk->cnetz->dsp_mode != DSP_MODE_SPK_V) { if (fsk->cnetz->dsp_mode != DSP_MODE_SPK_V) {
#ifdef DEBUG_DECODER #ifdef DEBUG_DECODER
@ -437,16 +405,16 @@ void fsk_fm_demod(fsk_fm_demod_t *fsk, int16_t *samples, int length)
/* note that we start from 0.5, because we detect change 0.5 bits later, /* note that we start from 0.5, because we detect change 0.5 bits later,
* because the detector of the change is in the middle of the 1 bit * because the detector of the change is in the middle of the 1 bit
* search window */ * search window */
t = fmod(bit_time, BITS_PER_SPK_BLOCK); t = fmod(fsk->bit_time, BITS_PER_SPK_BLOCK);
if (t < 0.5) { if (t < 0.5) {
next_bit = 1.0 - bits_per_sample; fsk->next_bit = 1.0 - fsk->bits_per_sample;
#ifdef DEBUG_DECODER #ifdef DEBUG_DECODER
if (bit_count) { if (fsk->bit_count) {
DEBUG_DECODER DEBUG_DECODER
printf("start spk_block bit count=%d\n", bit_count); printf("start spk_block bit count=%d\n", fsk->bit_count);
} }
#endif #endif
bit_count = 0; fsk->bit_count = 0;
} else } else
if (t >= 0.5 && t < 5.5) { if (t >= 0.5 && t < 5.5) {
#ifdef DEBUG_DECODER #ifdef DEBUG_DECODER
@ -459,47 +427,33 @@ void fsk_fm_demod(fsk_fm_demod_t *fsk, int16_t *samples, int length)
/* get audio for the duration of 60 bits */ /* get audio for the duration of 60 bits */
/* prevent overflow, if speech_size != 0 and SPK_V /* prevent overflow, if speech_size != 0 and SPK_V
* has been restarted. */ * has been restarted. */
if (speech_count <= speech_size) if (fsk->speech_count <= fsk->speech_size)
speech_buffer[speech_count++] = samples[i]; fsk->speech_buffer[fsk->speech_count++] = samples[i];
} else } else
if (t >= 65.5) { if (t >= 65.5) {
if (speech_count) { if (fsk->speech_count) {
unshrink_speech(fsk->cnetz, speech_buffer, speech_count); unshrink_speech(fsk->cnetz, fsk->speech_buffer, fsk->speech_count);
speech_count = 0; fsk->speech_count = 0;
} }
} }
} }
bit_time += bits_per_sample; fsk->bit_time += fsk->bits_per_sample;
if (bit_time >= BITS_PER_SUPERFRAME) { if (fsk->bit_time >= BITS_PER_SUPERFRAME) {
bit_time -= BITS_PER_SUPERFRAME; fsk->bit_time -= BITS_PER_SUPERFRAME;
} }
/* another clock is used to measure actual super frame time */ /* another clock is used to measure actual super frame time */
bit_time_uncorrected += bits_per_sample; fsk->bit_time_uncorrected += fsk->bits_per_sample;
if (bit_time_uncorrected >= BITS_PER_SUPERFRAME) { if (fsk->bit_time_uncorrected >= BITS_PER_SUPERFRAME) {
bit_time_uncorrected -= BITS_PER_SUPERFRAME; fsk->bit_time_uncorrected -= BITS_PER_SUPERFRAME;
calc_clock_speed(fsk->cnetz, fsk->cnetz->sender.samplerate * 24 / 10, 0, 1); calc_clock_speed(fsk->cnetz, fsk->cnetz->sender.samplerate * 24 / 10, 0, 1);
} }
} }
fsk->level_threshold = level_threshold;
fsk->bit_buffer_pos = pos;
fsk->speech_count = speech_count;
fsk->next_bit = next_bit;
fsk->sync = sync;
fsk->last_change_positive = last_change_positive;
fsk->sync_level = sync_level;
fsk->sync_time = sync_time;
fsk->sync_jitter = sync_jitter;
fsk->bit_time = bit_time;
fsk->bit_time_uncorrected = bit_time_uncorrected;
fsk->bit_count = bit_count;
} }
void fsk_correct_sync(fsk_fm_demod_t *fsk, double offset) void fsk_correct_sync(fsk_fm_demod_t *fsk, double offset)
{ {
bit_time = fmod(bit_time - offset + BITS_PER_SUPERFRAME, BITS_PER_SUPERFRAME); fsk->bit_time = fmod(fsk->bit_time - offset + BITS_PER_SUPERFRAME, BITS_PER_SUPERFRAME);
fsk->bit_time = bit_time;
} }
void fsk_demod_reset(fsk_fm_demod_t *fsk) void fsk_demod_reset(fsk_fm_demod_t *fsk)