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