ffmpeg/libavfilter/af_silenceremove.c

947 lines
33 KiB
C

/*
* Copyright (c) 2001 Heikki Leinonen
* Copyright (c) 2001 Chris Bagwell
* Copyright (c) 2003 Donnie Smith
* Copyright (c) 2014 Paul B Mahol
*
* This file is part of FFmpeg.
*
* FFmpeg 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.
*
* FFmpeg 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 FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <float.h> /* DBL_MAX */
#include "libavutil/opt.h"
#include "libavutil/timestamp.h"
#include "audio.h"
#include "formats.h"
#include "avfilter.h"
#include "internal.h"
enum SilenceDetect {
D_PEAK,
D_RMS,
};
enum ThresholdMode {
T_ANY,
T_ALL,
};
enum SilenceMode {
SILENCE_TRIM,
SILENCE_TRIM_FLUSH,
SILENCE_COPY,
SILENCE_COPY_FLUSH,
SILENCE_STOP
};
typedef struct SilenceRemoveContext {
const AVClass *class;
enum SilenceMode mode;
int start_periods;
int64_t start_duration;
int64_t start_duration_opt;
double start_threshold;
int64_t start_silence;
int64_t start_silence_opt;
int start_mode;
int stop_periods;
int64_t stop_duration;
int64_t stop_duration_opt;
double stop_threshold;
int64_t stop_silence;
int64_t stop_silence_opt;
int stop_mode;
AVFrame *start_holdoff;
AVFrame *start_silence_hold;
size_t start_holdoff_offset;
size_t start_holdoff_end;
size_t start_silence_offset;
size_t start_silence_end;
int start_found_periods;
AVFrame *stop_holdoff;
AVFrame *stop_silence_hold;
size_t stop_holdoff_offset;
size_t stop_holdoff_end;
size_t stop_silence_offset;
size_t stop_silence_end;
int stop_found_periods;
double window_ratio;
AVFrame *window;
int window_offset;
int window_size;
double sum;
int restart;
int64_t next_pts;
int detection;
void (*update)(struct SilenceRemoveContext *s, AVFrame *frame, int ch, int offset);
double (*compute)(struct SilenceRemoveContext *s, AVFrame *frame, int ch, int offset);
void (*copy)(struct SilenceRemoveContext *s, AVFrame *out, AVFrame *in,
int ch, int out_offset, int in_offset);
} SilenceRemoveContext;
#define OFFSET(x) offsetof(SilenceRemoveContext, x)
#define AF AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_AUDIO_PARAM
static const AVOption silenceremove_options[] = {
{ "start_periods", NULL, OFFSET(start_periods), AV_OPT_TYPE_INT, {.i64=0}, 0, 9000, AF },
{ "start_duration", "set start duration of non-silence part", OFFSET(start_duration_opt), AV_OPT_TYPE_DURATION, {.i64=0}, 0, INT32_MAX, AF },
{ "start_threshold", "set threshold for start silence detection", OFFSET(start_threshold), AV_OPT_TYPE_DOUBLE, {.dbl=0}, 0, DBL_MAX, AF },
{ "start_silence", "set start duration of silence part to keep", OFFSET(start_silence_opt), AV_OPT_TYPE_DURATION, {.i64=0}, 0, INT32_MAX, AF },
{ "start_mode", "set which channel will trigger trimming from start", OFFSET(start_mode), AV_OPT_TYPE_INT, {.i64=T_ANY}, T_ANY, T_ALL, AF, "mode" },
{ "any", 0, 0, AV_OPT_TYPE_CONST, {.i64=T_ANY}, 0, 0, AF, "mode" },
{ "all", 0, 0, AV_OPT_TYPE_CONST, {.i64=T_ALL}, 0, 0, AF, "mode" },
{ "stop_periods", NULL, OFFSET(stop_periods), AV_OPT_TYPE_INT, {.i64=0}, -9000, 9000, AF },
{ "stop_duration", "set stop duration of non-silence part", OFFSET(stop_duration_opt), AV_OPT_TYPE_DURATION, {.i64=0}, 0, INT32_MAX, AF },
{ "stop_threshold", "set threshold for stop silence detection", OFFSET(stop_threshold), AV_OPT_TYPE_DOUBLE, {.dbl=0}, 0, DBL_MAX, AF },
{ "stop_silence", "set stop duration of silence part to keep", OFFSET(stop_silence_opt), AV_OPT_TYPE_DURATION, {.i64=0}, 0, INT32_MAX, AF },
{ "stop_mode", "set which channel will trigger trimming from end", OFFSET(stop_mode), AV_OPT_TYPE_INT, {.i64=T_ANY}, T_ANY, T_ALL, AF, "mode" },
{ "detection", "set how silence is detected", OFFSET(detection), AV_OPT_TYPE_INT, {.i64=D_RMS}, D_PEAK,D_RMS, AF, "detection" },
{ "peak", "use absolute values of samples", 0, AV_OPT_TYPE_CONST, {.i64=D_PEAK},0, 0, AF, "detection" },
{ "rms", "use squared values of samples", 0, AV_OPT_TYPE_CONST, {.i64=D_RMS}, 0, 0, AF, "detection" },
{ "window", "set duration of window in seconds", OFFSET(window_ratio), AV_OPT_TYPE_DOUBLE, {.dbl=0.02}, 0, 10, AF },
{ NULL }
};
AVFILTER_DEFINE_CLASS(silenceremove);
static void copy_double(SilenceRemoveContext *s, AVFrame *out, AVFrame *in,
int ch, int out_offset, int in_offset)
{
const double *srcp = (const double *)in->data[0];
const double src = srcp[in->channels * in_offset + ch];
double *dstp = (double *)out->data[0];
dstp[out->channels * out_offset + ch] = src;
}
static void copy_doublep(SilenceRemoveContext *s, AVFrame *out, AVFrame *in,
int ch, int out_offset, int in_offset)
{
const double *srcp = (const double *)in->extended_data[ch];
const double src = srcp[in_offset];
double *dstp = (double *)out->extended_data[ch];
dstp[out_offset] = src;
}
static void copy_float(SilenceRemoveContext *s, AVFrame *out, AVFrame *in,
int ch, int out_offset, int in_offset)
{
const float *srcp = (const float *)in->data[0];
const float src = srcp[in->channels * in_offset + ch];
float *dstp = (float *)out->data[0];
dstp[out->channels * out_offset + ch] = src;
}
static void copy_floatp(SilenceRemoveContext *s, AVFrame *out, AVFrame *in,
int ch, int out_offset, int in_offset)
{
const float *srcp = (const float *)in->extended_data[ch];
const float src = srcp[in_offset];
float *dstp = (float *)out->extended_data[ch];
dstp[out_offset] = src;
}
static double compute_peak_double(SilenceRemoveContext *s, AVFrame *frame, int ch, int offset)
{
const double *samples = (const double *)frame->data[0];
const double *wsamples = (const double *)s->window->data[0];
double sample = samples[frame->channels * offset + ch];
double wsample = wsamples[frame->channels * s->window_offset + ch];
double new_sum;
new_sum = s->sum;
new_sum -= wsample;
new_sum += fabs(sample);
return new_sum / s->window_size;
}
static void update_peak_double(SilenceRemoveContext *s, AVFrame *frame, int ch, int offset)
{
const double *samples = (const double *)frame->data[0];
double *wsamples = (double *)s->window->data[0];
double sample = samples[frame->channels * offset + ch];
double *wsample = &wsamples[frame->channels * s->window_offset + ch];
s->sum -= *wsample;
*wsample = fabs(sample);
s->sum += *wsample;
}
static double compute_peak_float(SilenceRemoveContext *s, AVFrame *frame, int ch, int offset)
{
const float *samples = (const float *)frame->data[0];
const float *wsamples = (const float *)s->window->data[0];
float sample = samples[frame->channels * offset + ch];
float wsample = wsamples[frame->channels * s->window_offset + ch];
float new_sum;
new_sum = s->sum;
new_sum -= wsample;
new_sum += fabsf(sample);
return new_sum / s->window_size;
}
static void update_peak_float(SilenceRemoveContext *s, AVFrame *frame, int ch, int offset)
{
const float *samples = (const float *)frame->data[0];
float *wsamples = (float *)s->window->data[0];
float sample = samples[frame->channels * offset + ch];
float *wsample = &wsamples[frame->channels * s->window_offset + ch];
s->sum -= *wsample;
*wsample = fabsf(sample);
s->sum += *wsample;
}
static double compute_rms_double(SilenceRemoveContext *s, AVFrame *frame, int ch, int offset)
{
const double *samples = (const double *)frame->data[0];
const double *wsamples = (const double *)s->window->data[0];
double sample = samples[frame->channels * offset + ch];
double wsample = wsamples[frame->channels * s->window_offset + ch];
double new_sum;
new_sum = s->sum;
new_sum -= wsample;
new_sum += sample * sample;
return sqrt(new_sum / s->window_size);
}
static void update_rms_double(SilenceRemoveContext *s, AVFrame *frame, int ch, int offset)
{
const double *samples = (const double *)frame->data[0];
double *wsamples = (double *)s->window->data[0];
double sample = samples[frame->channels * offset + ch];
double *wsample = &wsamples[frame->channels * s->window_offset + ch];
s->sum -= *wsample;
*wsample = sample * sample;
s->sum += *wsample;
}
static double compute_rms_float(SilenceRemoveContext *s, AVFrame *frame, int ch, int offset)
{
const float *samples = (const float *)frame->data[0];
const float *wsamples = (const float *)s->window->data[0];
float sample = samples[frame->channels * offset + ch];
float wsample = wsamples[frame->channels * s->window_offset + ch];
float new_sum;
new_sum = s->sum;
new_sum -= wsample;
new_sum += sample * sample;
return sqrtf(new_sum / s->window_size);
}
static void update_rms_float(SilenceRemoveContext *s, AVFrame *frame, int ch, int offset)
{
const float *samples = (const float *)frame->data[0];
float sample = samples[frame->channels * offset + ch];
float *wsamples = (float *)s->window->data[0];
float *wsample = &wsamples[frame->channels * s->window_offset + ch];
s->sum -= *wsample;
*wsample = sample * sample;
s->sum += *wsample;
}
static double compute_peak_doublep(SilenceRemoveContext *s, AVFrame *frame, int ch, int offset)
{
const double *samples = (const double *)frame->extended_data[ch];
const double *wsamples = (const double *)s->window->extended_data[ch];
double sample = samples[offset];
double wsample = wsamples[s->window_offset];
double new_sum;
new_sum = s->sum;
new_sum -= wsample;
new_sum += fabs(sample);
return new_sum / s->window_size;
}
static void update_peak_doublep(SilenceRemoveContext *s, AVFrame *frame, int ch, int offset)
{
const double *samples = (const double *)frame->extended_data[ch];
double *wsamples = (double *)s->window->extended_data[ch];
double sample = samples[offset];
double *wsample = &wsamples[s->window_offset];
s->sum -= *wsample;
*wsample = fabs(sample);
s->sum += *wsample;
}
static double compute_peak_floatp(SilenceRemoveContext *s, AVFrame *frame, int ch, int offset)
{
const float *samples = (const float *)frame->extended_data[ch];
const float *wsamples = (const float *)s->window->extended_data[ch];
float sample = samples[offset];
float wsample = wsamples[s->window_offset];
float new_sum;
new_sum = s->sum;
new_sum -= wsample;
new_sum += fabsf(sample);
return new_sum / s->window_size;
}
static void update_peak_floatp(SilenceRemoveContext *s, AVFrame *frame, int ch, int offset)
{
const float *samples = (const float *)frame->extended_data[ch];
float *wsamples = (float *)s->window->extended_data[ch];
float sample = samples[offset];
float *wsample = &wsamples[s->window_offset];
s->sum -= *wsample;
*wsample = fabsf(sample);
s->sum += *wsample;
}
static double compute_rms_doublep(SilenceRemoveContext *s, AVFrame *frame, int ch, int offset)
{
const double *samples = (const double *)frame->extended_data[ch];
const double *wsamples = (const double *)s->window->extended_data[ch];
double sample = samples[offset];
double wsample = wsamples[s->window_offset];
double new_sum;
new_sum = s->sum;
new_sum -= wsample;
new_sum += sample * sample;
return sqrt(new_sum / s->window_size);
}
static void update_rms_doublep(SilenceRemoveContext *s, AVFrame *frame, int ch, int offset)
{
const double *samples = (const double *)frame->extended_data[ch];
double *wsamples = (double *)s->window->extended_data[ch];
double sample = samples[offset];
double *wsample = &wsamples[s->window_offset];
s->sum -= *wsample;
*wsample = sample * sample;
s->sum += *wsample;
}
static double compute_rms_floatp(SilenceRemoveContext *s, AVFrame *frame, int ch, int offset)
{
const float *samples = (const float *)frame->extended_data[ch];
const float *wsamples = (const float *)s->window->extended_data[ch];
float sample = samples[offset];
float wsample = wsamples[s->window_offset];
float new_sum;
new_sum = s->sum;
new_sum -= wsample;
new_sum += sample * sample;
return sqrtf(new_sum / s->window_size);
}
static void update_rms_floatp(SilenceRemoveContext *s, AVFrame *frame, int ch, int offset)
{
const float *samples = (const float *)frame->extended_data[ch];
float *wsamples = (float *)s->window->extended_data[ch];
float sample = samples[offset];
float *wsample = &wsamples[s->window_offset];
s->sum -= *wsample;
*wsample = sample * sample;
s->sum += *wsample;
}
static av_cold int init(AVFilterContext *ctx)
{
SilenceRemoveContext *s = ctx->priv;
if (s->stop_periods < 0) {
s->stop_periods = -s->stop_periods;
s->restart = 1;
}
return 0;
}
static void clear_window(SilenceRemoveContext *s)
{
av_samples_set_silence(s->window->extended_data, 0, s->window_size,
s->window->channels, s->window->format);
s->window_offset = 0;
s->sum = 0;
}
static int config_input(AVFilterLink *inlink)
{
AVFilterContext *ctx = inlink->dst;
SilenceRemoveContext *s = ctx->priv;
s->next_pts = AV_NOPTS_VALUE;
s->window_size = FFMAX((inlink->sample_rate * s->window_ratio), 1);
s->window = ff_get_audio_buffer(ctx->outputs[0], s->window_size);
if (!s->window)
return AVERROR(ENOMEM);
clear_window(s);
s->start_duration = av_rescale(s->start_duration_opt, inlink->sample_rate,
AV_TIME_BASE);
s->start_silence = av_rescale(s->start_silence_opt, inlink->sample_rate,
AV_TIME_BASE);
s->stop_duration = av_rescale(s->stop_duration_opt, inlink->sample_rate,
AV_TIME_BASE);
s->stop_silence = av_rescale(s->stop_silence_opt, inlink->sample_rate,
AV_TIME_BASE);
s->start_holdoff = ff_get_audio_buffer(ctx->outputs[0],
FFMAX(s->start_duration, 1));
if (!s->start_holdoff)
return AVERROR(ENOMEM);
s->start_silence_hold = ff_get_audio_buffer(ctx->outputs[0],
FFMAX(s->start_silence, 1));
if (!s->start_silence_hold)
return AVERROR(ENOMEM);
s->start_holdoff_offset = 0;
s->start_holdoff_end = 0;
s->start_found_periods = 0;
s->stop_holdoff = ff_get_audio_buffer(ctx->outputs[0],
FFMAX(s->stop_duration, 1));
if (!s->stop_holdoff)
return AVERROR(ENOMEM);
s->stop_silence_hold = ff_get_audio_buffer(ctx->outputs[0],
FFMAX(s->stop_silence, 1));
if (!s->stop_silence_hold)
return AVERROR(ENOMEM);
s->stop_holdoff_offset = 0;
s->stop_holdoff_end = 0;
s->stop_found_periods = 0;
if (s->start_periods)
s->mode = SILENCE_TRIM;
else
s->mode = SILENCE_COPY;
switch (inlink->format) {
case AV_SAMPLE_FMT_DBL:
s->copy = copy_double;
switch (s->detection) {
case D_PEAK:
s->update = update_peak_double;
s->compute = compute_peak_double;
break;
case D_RMS:
s->update = update_rms_double;
s->compute = compute_rms_double;
break;
}
break;
case AV_SAMPLE_FMT_FLT:
s->copy = copy_float;
switch (s->detection) {
case D_PEAK:
s->update = update_peak_float;
s->compute = compute_peak_float;
break;
case D_RMS:
s->update = update_rms_float;
s->compute = compute_rms_float;
break;
}
break;
case AV_SAMPLE_FMT_DBLP:
s->copy = copy_doublep;
switch (s->detection) {
case D_PEAK:
s->update = update_peak_doublep;
s->compute = compute_peak_doublep;
break;
case D_RMS:
s->update = update_rms_doublep;
s->compute = compute_rms_doublep;
break;
}
break;
case AV_SAMPLE_FMT_FLTP:
s->copy = copy_floatp;
switch (s->detection) {
case D_PEAK:
s->update = update_peak_floatp;
s->compute = compute_peak_floatp;
break;
case D_RMS:
s->update = update_rms_floatp;
s->compute = compute_rms_floatp;
break;
}
break;
}
return 0;
}
static void flush(SilenceRemoveContext *s,
AVFrame *out, AVFilterLink *outlink,
int *nb_samples_written, int *ret, int flush_silence)
{
AVFrame *silence;
if (*nb_samples_written) {
out->nb_samples = *nb_samples_written;
out->pts = s->next_pts;
s->next_pts += av_rescale_q(out->nb_samples,
(AVRational){1, outlink->sample_rate},
outlink->time_base);
*ret = ff_filter_frame(outlink, out);
if (*ret < 0)
return;
*nb_samples_written = 0;
} else {
av_frame_free(&out);
}
if (s->stop_silence_end <= 0 || !flush_silence)
return;
silence = ff_get_audio_buffer(outlink, s->stop_silence_end);
if (!silence) {
*ret = AVERROR(ENOMEM);
return;
}
if (s->stop_silence_offset < s->stop_silence_end) {
av_samples_copy(silence->extended_data, s->stop_silence_hold->extended_data, 0,
s->stop_silence_offset,
s->stop_silence_end - s->stop_silence_offset,
outlink->channels, outlink->format);
}
if (s->stop_silence_offset > 0) {
av_samples_copy(silence->extended_data, s->stop_silence_hold->extended_data,
s->stop_silence_end - s->stop_silence_offset,
0, s->stop_silence_offset,
outlink->channels, outlink->format);
}
s->stop_silence_offset = 0;
s->stop_silence_end = 0;
silence->pts = s->next_pts;
s->next_pts += av_rescale_q(silence->nb_samples,
(AVRational){1, outlink->sample_rate},
outlink->time_base);
*ret = ff_filter_frame(outlink, silence);
}
static int filter_frame(AVFilterLink *inlink, AVFrame *in)
{
AVFilterContext *ctx = inlink->dst;
AVFilterLink *outlink = ctx->outputs[0];
SilenceRemoveContext *s = ctx->priv;
int i, j, threshold, ret = 0;
int nbs, nb_samples_read, nb_samples_written;
AVFrame *out;
nb_samples_read = nb_samples_written = 0;
if (s->next_pts == AV_NOPTS_VALUE)
s->next_pts = in->pts;
switch (s->mode) {
case SILENCE_TRIM:
silence_trim:
nbs = in->nb_samples - nb_samples_read;
if (!nbs)
break;
for (i = 0; i < nbs; i++) {
if (s->start_mode == T_ANY) {
threshold = 0;
for (j = 0; j < outlink->channels; j++) {
threshold |= s->compute(s, in, j, nb_samples_read) > s->start_threshold;
}
} else {
threshold = 1;
for (j = 0; j < outlink->channels; j++) {
threshold &= s->compute(s, in, j, nb_samples_read) > s->start_threshold;
}
}
if (threshold) {
for (j = 0; j < outlink->channels; j++) {
s->update(s, in, j, nb_samples_read);
s->copy(s, s->start_holdoff, in, j, s->start_holdoff_end, nb_samples_read);
}
s->window_offset++;
if (s->window_offset >= s->window_size)
s->window_offset = 0;
s->start_holdoff_end++;
nb_samples_read++;
if (s->start_holdoff_end >= s->start_duration) {
if (++s->start_found_periods >= s->start_periods) {
s->mode = SILENCE_TRIM_FLUSH;
goto silence_trim_flush;
}
s->start_holdoff_offset = 0;
s->start_holdoff_end = 0;
s->start_silence_offset = 0;
s->start_silence_end = 0;
}
} else {
s->start_holdoff_end = 0;
for (j = 0; j < outlink->channels; j++) {
s->update(s, in, j, nb_samples_read);
if (s->start_silence)
s->copy(s, s->start_silence_hold, in, j, s->start_silence_offset, nb_samples_read);
}
s->window_offset++;
if (s->window_offset >= s->window_size)
s->window_offset = 0;
nb_samples_read++;
s->start_silence_offset++;
if (s->start_silence) {
s->start_silence_end = FFMIN(s->start_silence_end + 1, s->start_silence);
if (s->start_silence_offset >= s->start_silence)
s->start_silence_offset = 0;
}
}
}
break;
case SILENCE_TRIM_FLUSH:
silence_trim_flush:
nbs = s->start_holdoff_end - s->start_holdoff_offset;
if (!nbs)
break;
out = ff_get_audio_buffer(outlink, nbs + s->start_silence_end);
if (!out) {
av_frame_free(&in);
return AVERROR(ENOMEM);
}
if (s->start_silence_end > 0) {
if (s->start_silence_offset < s->start_silence_end) {
av_samples_copy(out->extended_data, s->start_silence_hold->extended_data, 0,
s->start_silence_offset,
s->start_silence_end - s->start_silence_offset,
outlink->channels, outlink->format);
}
if (s->start_silence_offset > 0) {
av_samples_copy(out->extended_data, s->start_silence_hold->extended_data,
s->start_silence_end - s->start_silence_offset,
0, s->start_silence_offset,
outlink->channels, outlink->format);
}
}
av_samples_copy(out->extended_data, s->start_holdoff->extended_data,
s->start_silence_end,
s->start_holdoff_offset, nbs,
outlink->channels, outlink->format);
out->pts = s->next_pts;
s->next_pts += av_rescale_q(out->nb_samples,
(AVRational){1, outlink->sample_rate},
outlink->time_base);
s->start_holdoff_offset += nbs;
ret = ff_filter_frame(outlink, out);
if (s->start_holdoff_offset == s->start_holdoff_end) {
s->start_holdoff_offset = 0;
s->start_holdoff_end = 0;
s->start_silence_offset = 0;
s->start_silence_end = 0;
s->mode = SILENCE_COPY;
goto silence_copy;
}
break;
case SILENCE_COPY:
silence_copy:
nbs = in->nb_samples - nb_samples_read;
if (!nbs)
break;
out = ff_get_audio_buffer(outlink, nbs);
if (!out) {
av_frame_free(&in);
return AVERROR(ENOMEM);
}
if (s->stop_periods) {
for (i = 0; i < nbs; i++) {
if (s->stop_mode == T_ANY) {
threshold = 0;
for (j = 0; j < outlink->channels; j++) {
threshold |= s->compute(s, in, j, nb_samples_read) > s->stop_threshold;
}
} else {
threshold = 1;
for (j = 0; j < outlink->channels; j++) {
threshold &= s->compute(s, in, j, nb_samples_read) > s->stop_threshold;
}
}
if (threshold && s->stop_holdoff_end && !s->stop_silence) {
s->mode = SILENCE_COPY_FLUSH;
flush(s, out, outlink, &nb_samples_written, &ret, 0);
goto silence_copy_flush;
} else if (threshold) {
for (j = 0; j < outlink->channels; j++) {
s->update(s, in, j, nb_samples_read);
s->copy(s, out, in, j, nb_samples_written, nb_samples_read);
}
s->window_offset++;
if (s->window_offset >= s->window_size)
s->window_offset = 0;
nb_samples_read++;
nb_samples_written++;
} else if (!threshold) {
for (j = 0; j < outlink->channels; j++) {
s->update(s, in, j, nb_samples_read);
if (s->stop_silence) {
s->copy(s, s->stop_silence_hold, in, j, s->stop_silence_offset, nb_samples_read);
s->stop_silence_end = FFMIN(s->stop_silence_end + 1, s->stop_silence);
if (s->stop_silence_offset >= s->stop_silence) {
s->stop_silence_offset = 0;
}
}
s->copy(s, s->stop_holdoff, in, j, s->stop_holdoff_end, nb_samples_read);
}
s->window_offset++;
if (s->window_offset >= s->window_size)
s->window_offset = 0;
nb_samples_read++;
s->stop_holdoff_end++;
if (s->stop_holdoff_end >= s->stop_duration) {
if (++s->stop_found_periods >= s->stop_periods) {
s->stop_holdoff_offset = 0;
s->stop_holdoff_end = 0;
if (!s->restart) {
s->mode = SILENCE_STOP;
flush(s, out, outlink, &nb_samples_written, &ret, 1);
goto silence_stop;
} else {
s->stop_found_periods = 0;
s->start_found_periods = 0;
s->start_holdoff_offset = 0;
s->start_holdoff_end = 0;
s->start_silence_offset = 0;
s->start_silence_end = 0;
clear_window(s);
s->mode = SILENCE_TRIM;
flush(s, out, outlink, &nb_samples_written, &ret, 1);
goto silence_trim;
}
}
s->mode = SILENCE_COPY_FLUSH;
flush(s, out, outlink, &nb_samples_written, &ret, 0);
goto silence_copy_flush;
}
}
}
flush(s, out, outlink, &nb_samples_written, &ret, 0);
} else {
av_samples_copy(out->extended_data, in->extended_data,
nb_samples_written,
nb_samples_read, nbs,
outlink->channels, outlink->format);
out->pts = s->next_pts;
s->next_pts += av_rescale_q(out->nb_samples,
(AVRational){1, outlink->sample_rate},
outlink->time_base);
ret = ff_filter_frame(outlink, out);
}
break;
case SILENCE_COPY_FLUSH:
silence_copy_flush:
nbs = s->stop_holdoff_end - s->stop_holdoff_offset;
if (!nbs)
break;
out = ff_get_audio_buffer(outlink, nbs);
if (!out) {
av_frame_free(&in);
return AVERROR(ENOMEM);
}
av_samples_copy(out->extended_data, s->stop_holdoff->extended_data, 0,
s->stop_holdoff_offset, nbs,
outlink->channels, outlink->format);
s->stop_holdoff_offset += nbs;
out->pts = s->next_pts;
s->next_pts += av_rescale_q(out->nb_samples,
(AVRational){1, outlink->sample_rate},
outlink->time_base);
ret = ff_filter_frame(outlink, out);
if (s->stop_holdoff_offset == s->stop_holdoff_end) {
s->stop_holdoff_offset = 0;
s->stop_holdoff_end = 0;
s->stop_silence_offset = 0;
s->stop_silence_end = 0;
s->mode = SILENCE_COPY;
goto silence_copy;
}
break;
case SILENCE_STOP:
silence_stop:
break;
}
av_frame_free(&in);
return ret;
}
static int request_frame(AVFilterLink *outlink)
{
AVFilterContext *ctx = outlink->src;
SilenceRemoveContext *s = ctx->priv;
int ret;
ret = ff_request_frame(ctx->inputs[0]);
if (ret == AVERROR_EOF && (s->mode == SILENCE_COPY_FLUSH ||
s->mode == SILENCE_COPY)) {
int nbs = s->stop_holdoff_end - s->stop_holdoff_offset;
if (nbs) {
AVFrame *frame;
frame = ff_get_audio_buffer(outlink, nbs);
if (!frame)
return AVERROR(ENOMEM);
av_samples_copy(frame->extended_data, s->stop_holdoff->extended_data, 0,
s->stop_holdoff_offset, nbs,
outlink->channels, outlink->format);
frame->pts = s->next_pts;
s->next_pts += av_rescale_q(frame->nb_samples,
(AVRational){1, outlink->sample_rate},
outlink->time_base);
ret = ff_filter_frame(outlink, frame);
}
s->mode = SILENCE_STOP;
}
return ret;
}
static int query_formats(AVFilterContext *ctx)
{
static const enum AVSampleFormat sample_fmts[] = {
AV_SAMPLE_FMT_FLT, AV_SAMPLE_FMT_FLTP,
AV_SAMPLE_FMT_DBL, AV_SAMPLE_FMT_DBLP,
AV_SAMPLE_FMT_NONE
};
int ret = ff_set_common_all_channel_counts(ctx);
if (ret < 0)
return ret;
ret = ff_set_common_formats_from_list(ctx, sample_fmts);
if (ret < 0)
return ret;
return ff_set_common_all_samplerates(ctx);
}
static av_cold void uninit(AVFilterContext *ctx)
{
SilenceRemoveContext *s = ctx->priv;
av_frame_free(&s->start_holdoff);
av_frame_free(&s->start_silence_hold);
av_frame_free(&s->stop_holdoff);
av_frame_free(&s->stop_silence_hold);
av_frame_free(&s->window);
}
static const AVFilterPad silenceremove_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_AUDIO,
.config_props = config_input,
.filter_frame = filter_frame,
},
};
static const AVFilterPad silenceremove_outputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_AUDIO,
.request_frame = request_frame,
},
};
const AVFilter ff_af_silenceremove = {
.name = "silenceremove",
.description = NULL_IF_CONFIG_SMALL("Remove silence."),
.priv_size = sizeof(SilenceRemoveContext),
.priv_class = &silenceremove_class,
.init = init,
.uninit = uninit,
.query_formats = query_formats,
FILTER_INPUTS(silenceremove_inputs),
FILTER_OUTPUTS(silenceremove_outputs),
};