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-rw-r--r--main/dsp.c148
1 files changed, 0 insertions, 148 deletions
diff --git a/main/dsp.c b/main/dsp.c
index 91eea6c9d..0f8955314 100644
--- a/main/dsp.c
+++ b/main/dsp.c
@@ -246,20 +246,6 @@ typedef struct
typedef struct
{
- int block_size;
- goertzel_state_t tone;
- float energy; /* Accumulated energy of the current block */
- int samples_pending; /* Samples remain to complete the current block */
-
- float threshold; /* Energy of the tone relative to energy from all other signals to consider a hit */
-
- int hit_count;
- int miss_count;
-
-} v21_detect_state_t;
-
-typedef struct
-{
goertzel_state_t row_out[4];
goertzel_state_t col_out[4];
int hits_to_begin; /* How many successive hits needed to consider begin of a digit */
@@ -405,7 +391,6 @@ struct ast_dsp {
digit_detect_state_t digit_state;
tone_detect_state_t cng_tone_state;
tone_detect_state_t ced_tone_state;
- v21_detect_state_t v21_state;
};
static void mute_fragment(struct ast_dsp *dsp, fragment_t *fragment)
@@ -479,56 +464,10 @@ static void ast_tone_detect_init(tone_detect_state_t *s, int freq, int duration,
ast_debug(1, "Setup tone %d Hz, %d ms, block_size=%d, hits_required=%d\n", freq, duration, s->block_size, s->hits_required);
}
-static void ast_v21_detect_init(v21_detect_state_t *s, unsigned int sample_rate)
-{
- float x;
- int periods_in_block;
-
- /* If we want to remove tone, it is important to have block size not
- to exceed frame size. Otherwise by the moment tone is detected it is too late
- to squelch it from previous frames. Block size is 20ms at the given sample rate.*/
- s->block_size = (20 * sample_rate) / 1000;
-
- periods_in_block = s->block_size * 1850 / sample_rate;
-
- /* Make sure we will have at least 5 periods at target frequency for analisys.
- This may make block larger than expected packet and will make squelching impossible
- but at least we will be detecting the tone */
- if (periods_in_block < 5) {
- periods_in_block = 5;
- }
-
- /* Now calculate final block size. It will contain integer number of periods */
- s->block_size = periods_in_block * sample_rate / 1850;
-
- goertzel_init(&s->tone, 1850.0, s->block_size, sample_rate);
-
- s->samples_pending = s->block_size;
- s->hit_count = 0;
- s->miss_count = 0;
- s->energy = 0.0;
-
- /* We want tone energy to be amp decibels above the rest of the signal (the noise).
- According to Parseval's theorem the energy computed in time domain equals to energy
- computed in frequency domain. So subtracting energy in the frequency domain (Goertzel result)
- from the energy in the time domain we will get energy of the remaining signal (without the tone
- we are detecting). We will be checking that
- 10*log(Ew / (Et - Ew)) > amp
- Calculate threshold so that we will be actually checking
- Ew > Et * threshold
- */
-
- x = pow(10.0, 16 / 10.0);
- s->threshold = x / (x + 1);
-
- ast_debug(1, "Setup v21 detector, block_size=%d\n", s->block_size);
-}
-
static void ast_fax_detect_init(struct ast_dsp *s)
{
ast_tone_detect_init(&s->cng_tone_state, FAX_TONE_CNG_FREQ, FAX_TONE_CNG_DURATION, FAX_TONE_CNG_DB, s->sample_rate);
ast_tone_detect_init(&s->ced_tone_state, FAX_TONE_CED_FREQ, FAX_TONE_CED_DURATION, FAX_TONE_CED_DB, s->sample_rate);
- ast_v21_detect_init(&s->v21_state, s->sample_rate);
if (s->faxmode & DSP_FAXMODE_DETECT_SQUELCH) {
s->cng_tone_state.squelch = 1;
s->ced_tone_state.squelch = 1;
@@ -580,89 +519,6 @@ static void ast_digit_detect_init(digit_detect_state_t *s, int mf, unsigned int
}
}
-/*! \brief Detect a v21 preamble.
- * This code is derived from the tone_detect code and detects a pattern of 1850
- * Hz tone found in a v21 preamble.
- */
-static int v21_detect(struct ast_dsp *dsp, v21_detect_state_t *s, int16_t *amp, int samples)
-{
- float tone_energy;
- int i;
- int hit = 0;
- int limit;
- int res = 0;
- int16_t *ptr;
- int start, end;
-
- for (start = 0; start < samples; start = end) {
- /* Process in blocks. */
- limit = samples - start;
- if (limit > s->samples_pending) {
- limit = s->samples_pending;
- }
- end = start + limit;
-
- for (i = limit, ptr = amp ; i > 0; i--, ptr++) {
- /* signed 32 bit int should be enough to suqare any possible signed 16 bit value */
- s->energy += (int32_t) *ptr * (int32_t) *ptr;
-
- goertzel_sample(&s->tone, *ptr);
- }
-
- s->samples_pending -= limit;
-
- if (s->samples_pending) {
- /* Finished incomplete (last) block */
- break;
- }
-
- tone_energy = goertzel_result(&s->tone);
-
- /* Scale to make comparable */
- tone_energy *= 2.0;
- s->energy *= s->block_size;
-
- ast_debug(10, "v21 1850 Ew=%.2E, Et=%.2E, s/n=%10.2f\n", tone_energy, s->energy, tone_energy / (s->energy - tone_energy));
-
- hit = 0;
- if (tone_energy > s->energy * s->threshold) {
- ast_debug(10, "Hit! count=%d; miss_count=%d\n", s->hit_count, s->miss_count);
- hit = 1;
- }
-
- if (hit) {
- if (s->miss_count == 3 || (s->hit_count == 1 && s->miss_count == 2)) {
- s->hit_count++;
- } else {
- s->hit_count = 1;
- }
-
- s->miss_count = 0;
- } else {
- s->miss_count++;
- if (s->miss_count > 3) {
- s->hit_count = 0;
- }
- }
-
- if (s->hit_count == 4) {
- ast_debug(1, "v21 preamble detected\n");
- res = 1;
- }
-
- /* Reinitialise the detector for the next block */
- goertzel_reset(&s->tone);
-
- /* Advance to the next block */
- s->energy = 0.0;
- s->samples_pending = s->block_size;
-
- amp += limit;
- }
-
- return res;
-}
-
static int tone_detect(struct ast_dsp *dsp, tone_detect_state_t *s, int16_t *amp, int samples)
{
float tone_energy;
@@ -1599,10 +1455,6 @@ struct ast_frame *ast_dsp_process(struct ast_channel *chan, struct ast_dsp *dsp,
if ((dsp->faxmode & DSP_FAXMODE_DETECT_CED) && tone_detect(dsp, &dsp->ced_tone_state, shortdata, len)) {
fax_digit = 'e';
}
-
- if ((dsp->faxmode & DSP_FAXMODE_DETECT_V21) && v21_detect(dsp, &dsp->v21_state, shortdata, len)) {
- fax_digit = 'g';
- }
}
if (dsp->features & (DSP_FEATURE_DIGIT_DETECT | DSP_FEATURE_BUSY_DETECT)) {
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-27 14:50:23 +0000