ref: 36a83aede9accc17bf02d97d2ac7d1c306e0eff7
dir: /src/vad.c/
/* libSoX effect: Voice Activity Detector (c) 2009 robs@users.sourceforge.net
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or (at
* your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
* General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "sox_i.h"
#include <string.h>
typedef struct {
double * dftBuf, * noiseSpectrum, * spectrum, * measures, meanMeas;
} chan_t;
typedef struct { /* Configuration parameters: */
double bootTime, noiseTcUp, noiseTcDown, noiseReductionAmount;
double measureFreq, measureDuration, measureTc, preTriggerTime;
double hpFilterFreq, lpFilterFreq, hpLifterFreq, lpLifterFreq;
double triggerTc, triggerLevel, searchTime, gapTime;
/* Working variables: */
sox_sample_t * samples;
unsigned dftLen_ws, samplesLen_ns, samplesIndex_ns, flushedLen_ns, gapLen;
unsigned measurePeriod_ns, measuresLen, measuresIndex;
unsigned measureTimer_ns, measureLen_ws, measureLen_ns;
unsigned spectrumStart, spectrumEnd, cepstrumStart, cepstrumEnd; /* bins */
int bootCountMax, bootCount;
double noiseTcUpMult, noiseTcDownMult;
double measureTcMult, triggerMeasTcMult;
double * spectrumWindow, * cepstrumWindow;
chan_t * channels;
} priv_t;
#define GETOPT_FREQ(optstate, c, name, min) \
case c: p->name = lsx_parse_frequency(optstate.arg, &parseIndex); \
if (p->name < min || *parseIndex) return lsx_usage(effp); \
break;
static int create(sox_effect_t * effp, int argc, char * * argv)
{
priv_t * p = (priv_t *)effp->priv;
#define opt_str "+b:N:n:r:f:m:M:h:l:H:L:T:t:s:g:p:"
int c;
lsx_getopt_t optstate;
lsx_getopt_init(argc, argv, opt_str, NULL, lsx_getopt_flag_none, 1, &optstate);
p->bootTime = .35;
p->noiseTcUp = .1;
p->noiseTcDown = .01;
p->noiseReductionAmount = 1.35;
p->measureFreq = 20;
p->measureDuration = 2 / p->measureFreq; /* 50% overlap */
p->measureTc = .4;
p->hpFilterFreq = 50;
p->lpFilterFreq = 6000;
p->hpLifterFreq = 150;
p->lpLifterFreq = 2000;
p->triggerTc = .25;
p->triggerLevel = 7;
p->searchTime = 1;
p->gapTime = .25;
while ((c = lsx_getopt(&optstate)) != -1) switch (c) {
char * parseIndex;
GETOPT_NUMERIC(optstate, 'b', bootTime , .1 , 10)
GETOPT_NUMERIC(optstate, 'N', noiseTcUp , .1 , 10)
GETOPT_NUMERIC(optstate, 'n', noiseTcDown ,.001 , .1)
GETOPT_NUMERIC(optstate, 'r', noiseReductionAmount,0 , 2)
GETOPT_NUMERIC(optstate, 'f', measureFreq , 5 , 50)
GETOPT_NUMERIC(optstate, 'm', measureDuration, .01 , 1)
GETOPT_NUMERIC(optstate, 'M', measureTc , .1 , 1)
GETOPT_FREQ( optstate, 'h', hpFilterFreq , 10)
GETOPT_FREQ( optstate, 'l', lpFilterFreq , 1000)
GETOPT_FREQ( optstate, 'H', hpLifterFreq , 10)
GETOPT_FREQ( optstate, 'L', lpLifterFreq , 1000)
GETOPT_NUMERIC(optstate, 'T', triggerTc , .01 , 1)
GETOPT_NUMERIC(optstate, 't', triggerLevel , 0 , 20)
GETOPT_NUMERIC(optstate, 's', searchTime , .1 , 4)
GETOPT_NUMERIC(optstate, 'g', gapTime , .1 , 1)
GETOPT_NUMERIC(optstate, 'p', preTriggerTime, 0 , 4)
default: lsx_fail("invalid option `-%c'", optstate.opt); return lsx_usage(effp);
}
return optstate.ind !=argc? lsx_usage(effp) : SOX_SUCCESS;
}
static int start(sox_effect_t * effp)
{
priv_t * p = (priv_t *)effp->priv;
unsigned i, fixedPreTriggerLen_ns, searchPreTriggerLen_ns;
fixedPreTriggerLen_ns = p->preTriggerTime * effp->in_signal.rate + .5;
fixedPreTriggerLen_ns *= effp->in_signal.channels;
p->measureLen_ws = effp->in_signal.rate * p->measureDuration + .5;
p->measureLen_ns = p->measureLen_ws * effp->in_signal.channels;
for (p->dftLen_ws = 16; p->dftLen_ws < p->measureLen_ws; p->dftLen_ws <<= 1);
lsx_debug("dftLen_ws=%u measureLen_ws=%u", p->dftLen_ws, p->measureLen_ws);
p->measurePeriod_ns = effp->in_signal.rate / p->measureFreq + .5;
p->measurePeriod_ns *= effp->in_signal.channels;
p->measuresLen = ceil(p->searchTime * p->measureFreq);
searchPreTriggerLen_ns = p->measuresLen * p->measurePeriod_ns;
p->gapLen = p->gapTime * p->measureFreq + .5;
p->samplesLen_ns =
fixedPreTriggerLen_ns + searchPreTriggerLen_ns + p->measureLen_ns;
lsx_Calloc(p->samples, p->samplesLen_ns);
lsx_Calloc(p->channels, effp->in_signal.channels);
for (i = 0; i < effp->in_signal.channels; ++i) {
chan_t * c = &p->channels[i];
lsx_Calloc(c->dftBuf, p->dftLen_ws);
lsx_Calloc(c->spectrum, p->dftLen_ws);
lsx_Calloc(c->noiseSpectrum, p->dftLen_ws);
lsx_Calloc(c->measures, p->measuresLen);
}
lsx_Calloc(p->spectrumWindow, p->measureLen_ws);
for (i = 0; i < p->measureLen_ws; ++i)
p->spectrumWindow[i] = -2./ SOX_SAMPLE_MIN / sqrt((double)p->measureLen_ws);
lsx_apply_hann(p->spectrumWindow, (int)p->measureLen_ws);
p->spectrumStart = p->hpFilterFreq / effp->in_signal.rate * p->dftLen_ws + .5;
p->spectrumStart = max(p->spectrumStart, 1);
p->spectrumEnd = p->lpFilterFreq / effp->in_signal.rate * p->dftLen_ws + .5;
p->spectrumEnd = min(p->spectrumEnd, p->dftLen_ws / 2);
lsx_Calloc(p->cepstrumWindow, p->spectrumEnd - p->spectrumStart);
for (i = 0; i < p->spectrumEnd - p->spectrumStart; ++i)
p->cepstrumWindow[i] = 2 / sqrt((double)p->spectrumEnd - p->spectrumStart);
lsx_apply_hann(p->cepstrumWindow,(int)(p->spectrumEnd - p->spectrumStart));
p->cepstrumStart = ceil(effp->in_signal.rate * .5 / p->lpLifterFreq);
p->cepstrumEnd = floor(effp->in_signal.rate * .5 / p->hpLifterFreq);
p->cepstrumEnd = min(p->cepstrumEnd, p->dftLen_ws / 4);
if (p->cepstrumEnd <= p->cepstrumStart)
return SOX_EOF;
p->noiseTcUpMult = exp(-1 / (p->noiseTcUp * p->measureFreq));
p->noiseTcDownMult = exp(-1 / (p->noiseTcDown * p->measureFreq));
p->measureTcMult = exp(-1 / (p->measureTc * p->measureFreq));
p->triggerMeasTcMult = exp(-1 / (p->triggerTc * p->measureFreq));
p->bootCountMax = p->bootTime * p->measureFreq - .5;
p->measureTimer_ns = p->measureLen_ns;
p->bootCount = p->measuresIndex = p->flushedLen_ns = p->samplesIndex_ns = 0;
return SOX_SUCCESS;
}
static int flowFlush(sox_effect_t * effp, sox_sample_t const * ibuf,
sox_sample_t * obuf, size_t * ilen, size_t * olen)
{
priv_t * p = (priv_t *)effp->priv;
size_t odone = min(p->samplesLen_ns - p->flushedLen_ns, *olen);
size_t odone1 = min(odone, p->samplesLen_ns - p->samplesIndex_ns);
memcpy(obuf, p->samples + p->samplesIndex_ns, odone1 * sizeof(*obuf));
if ((p->samplesIndex_ns += odone1) == p->samplesLen_ns) {
memcpy(obuf + odone1, p->samples, (odone - odone1) * sizeof(*obuf));
p->samplesIndex_ns = odone - odone1;
}
if ((p->flushedLen_ns += odone) == p->samplesLen_ns) {
size_t olen1 = *olen - odone;
(effp->handler.flow = lsx_flow_copy)(effp, ibuf, obuf +odone, ilen, &olen1);
odone += olen1;
}
else *ilen = 0;
*olen = odone;
return SOX_SUCCESS;
}
static double measure(
priv_t * p, chan_t * c, size_t index_ns, unsigned step_ns, int bootCount)
{
double mult, result = 0;
size_t i;
for (i = 0; i < p->measureLen_ws; ++i, index_ns = (index_ns + step_ns) % p->samplesLen_ns)
c->dftBuf[i] = p->samples[index_ns] * p->spectrumWindow[i];
memset(c->dftBuf + i, 0, (p->dftLen_ws - i) * sizeof(*c->dftBuf));
lsx_safe_rdft((int)p->dftLen_ws, 1, c->dftBuf);
memset(c->dftBuf, 0, p->spectrumStart * sizeof(*c->dftBuf));
for (i = p->spectrumStart; i < p->spectrumEnd; ++i) {
double d = sqrt(sqr(c->dftBuf[2 * i]) + sqr(c->dftBuf[2 * i + 1]));
mult = bootCount >= 0? bootCount / (1. + bootCount) : p->measureTcMult;
c->spectrum[i] = c->spectrum[i] * mult + d * (1 - mult);
d = sqr(c->spectrum[i]);
mult = bootCount >= 0? 0 :
d > c->noiseSpectrum[i]? p->noiseTcUpMult : p->noiseTcDownMult;
c->noiseSpectrum[i] = c->noiseSpectrum[i] * mult + d * (1 - mult);
d = sqrt(max(0, d - p->noiseReductionAmount * c->noiseSpectrum[i]));
c->dftBuf[i] = d * p->cepstrumWindow[i - p->spectrumStart];
}
memset(c->dftBuf + i, 0, ((p->dftLen_ws >> 1) - i) * sizeof(*c->dftBuf));
lsx_safe_rdft((int)p->dftLen_ws >> 1, 1, c->dftBuf);
for (i = p->cepstrumStart; i < p->cepstrumEnd; ++i)
result += sqr(c->dftBuf[2 * i]) + sqr(c->dftBuf[2 * i + 1]);
result = log(result / (p->cepstrumEnd - p->cepstrumStart));
return max(0, 21 + result);
}
static int flowTrigger(sox_effect_t * effp, sox_sample_t const * ibuf,
sox_sample_t * obuf, size_t * ilen, size_t * olen)
{
priv_t * p = (priv_t *)effp->priv;
sox_bool hasTriggered = sox_false;
size_t i, idone = 0, numMeasuresToFlush = 0;
while (idone < *ilen && !hasTriggered) {
p->measureTimer_ns -= effp->in_signal.channels;
for (i = 0; i < effp->in_signal.channels; ++i, ++idone) {
chan_t * c = &p->channels[i];
p->samples[p->samplesIndex_ns++] = *ibuf++;
if (!p->measureTimer_ns) {
size_t x = (p->samplesIndex_ns + p->samplesLen_ns - p->measureLen_ns) % p->samplesLen_ns;
double meas = measure(p, c, x, effp->in_signal.channels, p->bootCount);
c->measures[p->measuresIndex] = meas;
c->meanMeas = c->meanMeas * p->triggerMeasTcMult +
meas *(1 - p->triggerMeasTcMult);
if (hasTriggered |= c->meanMeas >= p->triggerLevel) {
unsigned n = p->measuresLen, k = p->measuresIndex;
unsigned j, jTrigger = n, jZero = n;
for (j = 0; j < n; ++j, k = (k + n - 1) % n)
if (c->measures[k] >= p->triggerLevel && j <= jTrigger + p->gapLen)
jZero = jTrigger = j;
else if (!c->measures[k] && jTrigger >= jZero)
jZero = j;
j = min(j, jZero);
numMeasuresToFlush = range_limit(j, numMeasuresToFlush, n);
}
lsx_debug_more("%12g %12g %u",
meas, c->meanMeas, (unsigned)numMeasuresToFlush);
}
}
if (p->samplesIndex_ns == p->samplesLen_ns)
p->samplesIndex_ns = 0;
if (!p->measureTimer_ns) {
p->measureTimer_ns = p->measurePeriod_ns;
++p->measuresIndex;
p->measuresIndex %= p->measuresLen;
if (p->bootCount >= 0)
p->bootCount = p->bootCount == p->bootCountMax? -1 : p->bootCount + 1;
}
}
if (hasTriggered) {
size_t ilen1 = *ilen - idone;
p->flushedLen_ns = (p->measuresLen - numMeasuresToFlush) * p->measurePeriod_ns;
p->samplesIndex_ns = (p->samplesIndex_ns + p->flushedLen_ns) % p->samplesLen_ns;
(effp->handler.flow = flowFlush)(effp, ibuf, obuf, &ilen1, olen);
idone += ilen1;
}
else *olen = 0;
*ilen = idone;
return SOX_SUCCESS;
}
static int drain(sox_effect_t * effp, sox_sample_t * obuf, size_t * olen)
{
size_t ilen = 0;
return effp->handler.flow(effp, NULL, obuf, &ilen, olen);
}
static int stop(sox_effect_t * effp)
{
priv_t * p = (priv_t *)effp->priv;
unsigned i;
for (i = 0; i < effp->in_signal.channels; ++i) {
chan_t * c = &p->channels[i];
free(c->measures);
free(c->noiseSpectrum);
free(c->spectrum);
free(c->dftBuf);
}
free(p->channels);
free(p->cepstrumWindow);
free(p->spectrumWindow);
free(p->samples);
return SOX_SUCCESS;
}
sox_effect_handler_t const * lsx_vad_effect_fn(void)
{
static sox_effect_handler_t handler = {"vad", NULL,
SOX_EFF_MCHAN | SOX_EFF_LENGTH | SOX_EFF_MODIFY,
create, start, flowTrigger, drain, stop, NULL, sizeof(priv_t)
};
static char const * lines[] = {
"[options]",
"\t-t trigger-level (7)",
"\t-T trigger-time-constant (0.25 s)",
"\t-s search-time (1 s)",
"\t-g allowed-gap (0.25 s)",
"\t-p pre-trigger-time (0 s)",
"Advanced options:",
"\t-b noise-est-boot-time (0.35 s)",
"\t-N noise-est-time-constant-up (0.1 s)",
"\t-n noise-est-time-constant-down (0.01 s)",
"\t-r noise-reduction-amount (1.35)",
"\t-f measurement-frequency (20 Hz)",
"\t-m measurement-duration (0.1 s)",
"\t-M measurement-time-constant (0.4 s)",
"\t-h high-pass-filter (50 Hz)",
"\t-l low-pass-filter (6000 Hz)",
"\t-H high-pass-lifter (150 Hz)",
"\t-L low-pass-lifter (2000 Hz)",
};
static char * usage;
handler.usage = lsx_usage_lines(&usage, lines, array_length(lines));
return &handler;
}