FFmpeg
af_silenceremove.c
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1 /*
2  * Copyright (c) 2001 Heikki Leinonen
3  * Copyright (c) 2001 Chris Bagwell
4  * Copyright (c) 2003 Donnie Smith
5  * Copyright (c) 2014 Paul B Mahol
6  *
7  * This file is part of FFmpeg.
8  *
9  * FFmpeg is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU Lesser General Public
11  * License as published by the Free Software Foundation; either
12  * version 2.1 of the License, or (at your option) any later version.
13  *
14  * FFmpeg is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17  * Lesser General Public License for more details.
18  *
19  * You should have received a copy of the GNU Lesser General Public
20  * License along with FFmpeg; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22  */
23 
24 #include <float.h> /* DBL_MAX */
25 
26 #include "libavutil/opt.h"
27 #include "libavutil/timestamp.h"
28 #include "audio.h"
29 #include "formats.h"
30 #include "avfilter.h"
31 #include "internal.h"
32 
36 };
37 
41 };
42 
49 };
50 
51 typedef struct SilenceRemoveContext {
52  const AVClass *class;
53 
55 
57  int64_t start_duration;
60  int64_t start_silence;
63 
65  int64_t stop_duration;
68  int64_t stop_silence;
70  int stop_mode;
71 
72  double *start_holdoff;
79 
80  double *stop_holdoff;
87 
88  double window_ratio;
89  double *window;
90  double *window_current;
91  double *window_end;
93  double sum;
94 
95  int restart;
96  int64_t next_pts;
97 
98  int detection;
99  void (*update)(struct SilenceRemoveContext *s, double sample);
100  double(*compute)(struct SilenceRemoveContext *s, double sample);
102 
103 #define OFFSET(x) offsetof(SilenceRemoveContext, x)
104 #define AF AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_AUDIO_PARAM
105 
106 static const AVOption silenceremove_options[] = {
107  { "start_periods", NULL, OFFSET(start_periods), AV_OPT_TYPE_INT, {.i64=0}, 0, 9000, AF },
108  { "start_duration", "set start duration of non-silence part", OFFSET(start_duration_opt), AV_OPT_TYPE_DURATION, {.i64=0}, 0, INT32_MAX, AF },
109  { "start_threshold", "set threshold for start silence detection", OFFSET(start_threshold), AV_OPT_TYPE_DOUBLE, {.dbl=0}, 0, DBL_MAX, AF },
110  { "start_silence", "set start duration of silence part to keep", OFFSET(start_silence_opt), AV_OPT_TYPE_DURATION, {.i64=0}, 0, INT32_MAX, AF },
111  { "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" },
112  { "any", 0, 0, AV_OPT_TYPE_CONST, {.i64=T_ANY}, 0, 0, AF, "mode" },
113  { "all", 0, 0, AV_OPT_TYPE_CONST, {.i64=T_ALL}, 0, 0, AF, "mode" },
114  { "stop_periods", NULL, OFFSET(stop_periods), AV_OPT_TYPE_INT, {.i64=0}, -9000, 9000, AF },
115  { "stop_duration", "set stop duration of non-silence part", OFFSET(stop_duration_opt), AV_OPT_TYPE_DURATION, {.i64=0}, 0, INT32_MAX, AF },
116  { "stop_threshold", "set threshold for stop silence detection", OFFSET(stop_threshold), AV_OPT_TYPE_DOUBLE, {.dbl=0}, 0, DBL_MAX, AF },
117  { "stop_silence", "set stop duration of silence part to keep", OFFSET(stop_silence_opt), AV_OPT_TYPE_DURATION, {.i64=0}, 0, INT32_MAX, AF },
118  { "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" },
119  { "detection", "set how silence is detected", OFFSET(detection), AV_OPT_TYPE_INT, {.i64=D_RMS}, D_PEAK,D_RMS, AF, "detection" },
120  { "peak", "use absolute values of samples", 0, AV_OPT_TYPE_CONST, {.i64=D_PEAK},0, 0, AF, "detection" },
121  { "rms", "use squared values of samples", 0, AV_OPT_TYPE_CONST, {.i64=D_RMS}, 0, 0, AF, "detection" },
122  { "window", "set duration of window in seconds", OFFSET(window_ratio), AV_OPT_TYPE_DOUBLE, {.dbl=0.02}, 0, 10, AF },
123  { NULL }
124 };
125 
126 AVFILTER_DEFINE_CLASS(silenceremove);
127 
128 static double compute_peak(SilenceRemoveContext *s, double sample)
129 {
130  double new_sum;
131 
132  new_sum = s->sum;
133  new_sum -= *s->window_current;
134  new_sum += fabs(sample);
135 
136  return new_sum / s->window_size;
137 }
138 
140 {
141  s->sum -= *s->window_current;
142  *s->window_current = fabs(sample);
143  s->sum += *s->window_current;
144 
145  s->window_current++;
146  if (s->window_current >= s->window_end)
147  s->window_current = s->window;
148 }
149 
150 static double compute_rms(SilenceRemoveContext *s, double sample)
151 {
152  double new_sum;
153 
154  new_sum = s->sum;
155  new_sum -= *s->window_current;
156  new_sum += sample * sample;
157 
158  return sqrt(new_sum / s->window_size);
159 }
160 
162 {
163  s->sum -= *s->window_current;
164  *s->window_current = sample * sample;
165  s->sum += *s->window_current;
166 
167  s->window_current++;
168  if (s->window_current >= s->window_end)
169  s->window_current = s->window;
170 }
171 
173 {
174  SilenceRemoveContext *s = ctx->priv;
175 
176  if (s->stop_periods < 0) {
177  s->stop_periods = -s->stop_periods;
178  s->restart = 1;
179  }
180 
181  switch (s->detection) {
182  case D_PEAK:
183  s->update = update_peak;
184  s->compute = compute_peak;
185  break;
186  case D_RMS:
187  s->update = update_rms;
188  s->compute = compute_rms;
189  break;
190  }
191 
192  return 0;
193 }
194 
196 {
197  memset(s->window, 0, s->window_size * sizeof(*s->window));
198 
199  s->window_current = s->window;
200  s->window_end = s->window + s->window_size;
201  s->sum = 0;
202 }
203 
205 {
206  AVFilterContext *ctx = inlink->dst;
207  SilenceRemoveContext *s = ctx->priv;
208 
209  s->window_size = FFMAX((inlink->sample_rate * s->window_ratio), 1) * inlink->channels;
210  s->window = av_malloc_array(s->window_size, sizeof(*s->window));
211  if (!s->window)
212  return AVERROR(ENOMEM);
213 
214  clear_window(s);
215 
217  AV_TIME_BASE);
219  AV_TIME_BASE);
221  AV_TIME_BASE);
223  AV_TIME_BASE);
224 
226  sizeof(*s->start_holdoff) *
227  inlink->channels);
228  if (!s->start_holdoff)
229  return AVERROR(ENOMEM);
230 
232  sizeof(*s->start_silence_hold) *
233  inlink->channels);
234  if (!s->start_silence_hold)
235  return AVERROR(ENOMEM);
236 
237  s->start_holdoff_offset = 0;
238  s->start_holdoff_end = 0;
239  s->start_found_periods = 0;
240 
242  sizeof(*s->stop_holdoff) *
243  inlink->channels);
244  if (!s->stop_holdoff)
245  return AVERROR(ENOMEM);
246 
248  sizeof(*s->stop_silence_hold) *
249  inlink->channels);
250  if (!s->stop_silence_hold)
251  return AVERROR(ENOMEM);
252 
253  s->stop_holdoff_offset = 0;
254  s->stop_holdoff_end = 0;
255  s->stop_found_periods = 0;
256 
257  if (s->start_periods)
258  s->mode = SILENCE_TRIM;
259  else
260  s->mode = SILENCE_COPY;
261 
262  return 0;
263 }
264 
266  AVFrame *out, AVFilterLink *outlink,
267  int *nb_samples_written, int *ret, int flush_silence)
268 {
269  AVFrame *silence;
270 
271  if (*nb_samples_written) {
272  out->nb_samples = *nb_samples_written / outlink->channels;
273 
274  out->pts = s->next_pts;
275  s->next_pts += av_rescale_q(out->nb_samples,
276  (AVRational){1, outlink->sample_rate},
277  outlink->time_base);
278 
279  *ret = ff_filter_frame(outlink, out);
280  if (*ret < 0)
281  return;
282  *nb_samples_written = 0;
283  } else {
284  av_frame_free(&out);
285  }
286 
287  if (s->stop_silence_end <= 0 || !flush_silence)
288  return;
289 
290  silence = ff_get_audio_buffer(outlink, s->stop_silence_end / outlink->channels);
291  if (!silence) {
292  *ret = AVERROR(ENOMEM);
293  return;
294  }
295 
297  memcpy(silence->data[0],
299  (s->stop_silence_end - s->stop_silence_offset) * sizeof(double));
300  }
301 
302  if (s->stop_silence_offset > 0) {
303  memcpy(silence->data[0] + (s->stop_silence_end - s->stop_silence_offset) * sizeof(double),
304  &s->stop_silence_hold[0],
305  s->stop_silence_offset * sizeof(double));
306  }
307 
308  s->stop_silence_offset = 0;
309  s->stop_silence_end = 0;
310 
311  silence->pts = s->next_pts;
312  s->next_pts += av_rescale_q(silence->nb_samples,
313  (AVRational){1, outlink->sample_rate},
314  outlink->time_base);
315 
316  *ret = ff_filter_frame(outlink, silence);
317 }
318 
320 {
321  AVFilterContext *ctx = inlink->dst;
322  AVFilterLink *outlink = ctx->outputs[0];
323  SilenceRemoveContext *s = ctx->priv;
324  int i, j, threshold, ret = 0;
325  int nbs, nb_samples_read, nb_samples_written;
326  double *obuf, *ibuf = (double *)in->data[0];
327  AVFrame *out;
328 
329  nb_samples_read = nb_samples_written = 0;
330 
331  switch (s->mode) {
332  case SILENCE_TRIM:
333 silence_trim:
334  nbs = in->nb_samples - nb_samples_read / outlink->channels;
335  if (!nbs)
336  break;
337 
338  for (i = 0; i < nbs; i++) {
339  if (s->start_mode == T_ANY) {
340  threshold = 0;
341  for (j = 0; j < outlink->channels; j++) {
342  threshold |= s->compute(s, ibuf[j]) > s->start_threshold;
343  }
344  } else {
345  threshold = 1;
346  for (j = 0; j < outlink->channels; j++) {
347  threshold &= s->compute(s, ibuf[j]) > s->start_threshold;
348  }
349  }
350 
351  if (threshold) {
352  for (j = 0; j < outlink->channels; j++) {
353  s->update(s, *ibuf);
354  s->start_holdoff[s->start_holdoff_end++] = *ibuf++;
355  }
356  nb_samples_read += outlink->channels;
357 
358  if (s->start_holdoff_end >= s->start_duration * outlink->channels) {
359  if (++s->start_found_periods >= s->start_periods) {
361  goto silence_trim_flush;
362  }
363 
364  s->start_holdoff_offset = 0;
365  s->start_holdoff_end = 0;
366  s->start_silence_offset = 0;
367  s->start_silence_end = 0;
368  }
369  } else {
370  s->start_holdoff_end = 0;
371 
372  for (j = 0; j < outlink->channels; j++) {
373  s->update(s, ibuf[j]);
374  if (s->start_silence) {
375  s->start_silence_hold[s->start_silence_offset++] = ibuf[j];
376  s->start_silence_end = FFMIN(s->start_silence_end + 1, outlink->channels * s->start_silence);
377  if (s->start_silence_offset >= outlink->channels * s->start_silence) {
378  s->start_silence_offset = 0;
379  }
380  }
381  }
382 
383  ibuf += outlink->channels;
384  nb_samples_read += outlink->channels;
385  }
386  }
387  break;
388 
389  case SILENCE_TRIM_FLUSH:
390 silence_trim_flush:
392  nbs -= nbs % outlink->channels;
393  if (!nbs)
394  break;
395 
396  out = ff_get_audio_buffer(outlink, nbs / outlink->channels + s->start_silence_end / outlink->channels);
397  if (!out) {
398  av_frame_free(&in);
399  return AVERROR(ENOMEM);
400  }
401 
402  if (s->start_silence_end > 0) {
404  memcpy(out->data[0],
406  (s->start_silence_end - s->start_silence_offset) * sizeof(double));
407  }
408 
409  if (s->start_silence_offset > 0) {
410  memcpy(out->data[0] + (s->start_silence_end - s->start_silence_offset) * sizeof(double),
411  &s->start_silence_hold[0],
412  s->start_silence_offset * sizeof(double));
413  }
414  }
415 
416  memcpy(out->data[0] + s->start_silence_end * sizeof(double),
418  nbs * sizeof(double));
419 
420  out->pts = s->next_pts;
421  s->next_pts += av_rescale_q(out->nb_samples,
422  (AVRational){1, outlink->sample_rate},
423  outlink->time_base);
424 
425  s->start_holdoff_offset += nbs;
426 
427  ret = ff_filter_frame(outlink, out);
428 
430  s->start_holdoff_offset = 0;
431  s->start_holdoff_end = 0;
432  s->start_silence_offset = 0;
433  s->start_silence_end = 0;
434  s->mode = SILENCE_COPY;
435  goto silence_copy;
436  }
437  break;
438 
439  case SILENCE_COPY:
440 silence_copy:
441  nbs = in->nb_samples - nb_samples_read / outlink->channels;
442  if (!nbs)
443  break;
444 
445  out = ff_get_audio_buffer(outlink, nbs);
446  if (!out) {
447  av_frame_free(&in);
448  return AVERROR(ENOMEM);
449  }
450  obuf = (double *)out->data[0];
451 
452  if (s->stop_periods) {
453  for (i = 0; i < nbs; i++) {
454  if (s->stop_mode == T_ANY) {
455  threshold = 0;
456  for (j = 0; j < outlink->channels; j++) {
457  threshold |= s->compute(s, ibuf[j]) > s->stop_threshold;
458  }
459  } else {
460  threshold = 1;
461  for (j = 0; j < outlink->channels; j++) {
462  threshold &= s->compute(s, ibuf[j]) > s->stop_threshold;
463  }
464  }
465 
466  if (threshold && s->stop_holdoff_end && !s->stop_silence) {
468  flush(s, out, outlink, &nb_samples_written, &ret, 0);
469  goto silence_copy_flush;
470  } else if (threshold) {
471  for (j = 0; j < outlink->channels; j++) {
472  s->update(s, *ibuf);
473  *obuf++ = *ibuf++;
474  }
475  nb_samples_read += outlink->channels;
476  nb_samples_written += outlink->channels;
477  } else if (!threshold) {
478  for (j = 0; j < outlink->channels; j++) {
479  s->update(s, *ibuf);
480  if (s->stop_silence) {
481  s->stop_silence_hold[s->stop_silence_offset++] = *ibuf;
482  s->stop_silence_end = FFMIN(s->stop_silence_end + 1, outlink->channels * s->stop_silence);
483  if (s->stop_silence_offset >= outlink->channels * s->stop_silence) {
484  s->stop_silence_offset = 0;
485  }
486  }
487 
488  s->stop_holdoff[s->stop_holdoff_end++] = *ibuf++;
489  }
490  nb_samples_read += outlink->channels;
491 
492  if (s->stop_holdoff_end >= s->stop_duration * outlink->channels) {
493  if (++s->stop_found_periods >= s->stop_periods) {
494  s->stop_holdoff_offset = 0;
495  s->stop_holdoff_end = 0;
496 
497  if (!s->restart) {
498  s->mode = SILENCE_STOP;
499  flush(s, out, outlink, &nb_samples_written, &ret, 1);
500  goto silence_stop;
501  } else {
502  s->stop_found_periods = 0;
503  s->start_found_periods = 0;
504  s->start_holdoff_offset = 0;
505  s->start_holdoff_end = 0;
506  s->start_silence_offset = 0;
507  s->start_silence_end = 0;
508  clear_window(s);
509  s->mode = SILENCE_TRIM;
510  flush(s, out, outlink, &nb_samples_written, &ret, 1);
511  goto silence_trim;
512  }
513  }
515  flush(s, out, outlink, &nb_samples_written, &ret, 0);
516  goto silence_copy_flush;
517  }
518  }
519  }
520  flush(s, out, outlink, &nb_samples_written, &ret, 0);
521  } else {
522  memcpy(obuf, ibuf, sizeof(double) * nbs * outlink->channels);
523 
524  out->pts = s->next_pts;
525  s->next_pts += av_rescale_q(out->nb_samples,
526  (AVRational){1, outlink->sample_rate},
527  outlink->time_base);
528 
529  ret = ff_filter_frame(outlink, out);
530  }
531  break;
532 
533  case SILENCE_COPY_FLUSH:
534 silence_copy_flush:
536  nbs -= nbs % outlink->channels;
537  if (!nbs)
538  break;
539 
540  out = ff_get_audio_buffer(outlink, nbs / outlink->channels);
541  if (!out) {
542  av_frame_free(&in);
543  return AVERROR(ENOMEM);
544  }
545 
546  memcpy(out->data[0], &s->stop_holdoff[s->stop_holdoff_offset],
547  nbs * sizeof(double));
548  s->stop_holdoff_offset += nbs;
549 
550  out->pts = s->next_pts;
551  s->next_pts += av_rescale_q(out->nb_samples,
552  (AVRational){1, outlink->sample_rate},
553  outlink->time_base);
554 
555  ret = ff_filter_frame(outlink, out);
556 
557  if (s->stop_holdoff_offset == s->stop_holdoff_end) {
558  s->stop_holdoff_offset = 0;
559  s->stop_holdoff_end = 0;
560  s->stop_silence_offset = 0;
561  s->stop_silence_end = 0;
562  s->mode = SILENCE_COPY;
563  goto silence_copy;
564  }
565  break;
566  case SILENCE_STOP:
567 silence_stop:
568  break;
569  }
570 
571  av_frame_free(&in);
572 
573  return ret;
574 }
575 
576 static int request_frame(AVFilterLink *outlink)
577 {
578  AVFilterContext *ctx = outlink->src;
579  SilenceRemoveContext *s = ctx->priv;
580  int ret;
581 
582  ret = ff_request_frame(ctx->inputs[0]);
583  if (ret == AVERROR_EOF && (s->mode == SILENCE_COPY_FLUSH ||
584  s->mode == SILENCE_COPY)) {
585  int nbs = s->stop_holdoff_end - s->stop_holdoff_offset;
586  if (nbs) {
587  AVFrame *frame;
588 
589  frame = ff_get_audio_buffer(outlink, nbs / outlink->channels);
590  if (!frame)
591  return AVERROR(ENOMEM);
592 
593  memcpy(frame->data[0], &s->stop_holdoff[s->stop_holdoff_offset],
594  nbs * sizeof(double));
595 
596  frame->pts = s->next_pts;
597  s->next_pts += av_rescale_q(frame->nb_samples,
598  (AVRational){1, outlink->sample_rate},
599  outlink->time_base);
600 
601  ret = ff_filter_frame(outlink, frame);
602  }
603  s->mode = SILENCE_STOP;
604  }
605  return ret;
606 }
607 
609 {
612  static const enum AVSampleFormat sample_fmts[] = {
614  };
615  int ret;
616 
617  layouts = ff_all_channel_counts();
618  if (!layouts)
619  return AVERROR(ENOMEM);
620  ret = ff_set_common_channel_layouts(ctx, layouts);
621  if (ret < 0)
622  return ret;
623 
624  formats = ff_make_format_list(sample_fmts);
625  if (!formats)
626  return AVERROR(ENOMEM);
627  ret = ff_set_common_formats(ctx, formats);
628  if (ret < 0)
629  return ret;
630 
631  formats = ff_all_samplerates();
632  if (!formats)
633  return AVERROR(ENOMEM);
634  return ff_set_common_samplerates(ctx, formats);
635 }
636 
638 {
639  SilenceRemoveContext *s = ctx->priv;
640 
641  av_freep(&s->start_holdoff);
643  av_freep(&s->stop_holdoff);
645  av_freep(&s->window);
646 }
647 
649  {
650  .name = "default",
651  .type = AVMEDIA_TYPE_AUDIO,
652  .config_props = config_input,
653  .filter_frame = filter_frame,
654  },
655  { NULL }
656 };
657 
659  {
660  .name = "default",
661  .type = AVMEDIA_TYPE_AUDIO,
662  .request_frame = request_frame,
663  },
664  { NULL }
665 };
666 
668  .name = "silenceremove",
669  .description = NULL_IF_CONFIG_SMALL("Remove silence."),
670  .priv_size = sizeof(SilenceRemoveContext),
671  .priv_class = &silenceremove_class,
672  .init = init,
673  .uninit = uninit,
675  .inputs = silenceremove_inputs,
676  .outputs = silenceremove_outputs,
677 };
static int filter_frame(AVFilterLink *inlink, AVFrame *in)
#define NULL
Definition: coverity.c:32
int ff_set_common_channel_layouts(AVFilterContext *ctx, AVFilterChannelLayouts *layouts)
A helper for query_formats() which sets all links to the same list of channel layouts/sample rates...
Definition: formats.c:549
void(* update)(struct SilenceRemoveContext *s, double sample)
This structure describes decoded (raw) audio or video data.
Definition: frame.h:268
SilenceDetect
AVOption.
Definition: opt.h:246
static void flush(SilenceRemoveContext *s, AVFrame *out, AVFilterLink *outlink, int *nb_samples_written, int *ret, int flush_silence)
static const AVFilterPad silenceremove_outputs[]
Main libavfilter public API header.
AVFilter ff_af_silenceremove
#define sample
AVFilterFormats * ff_make_format_list(const int *fmts)
Create a list of supported formats.
Definition: formats.c:283
const char * name
Pad name.
Definition: internal.h:60
AVFilterLink ** inputs
array of pointers to input links
Definition: avfilter.h:346
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1080
#define av_cold
Definition: attributes.h:82
AVOptions.
timestamp utils, mostly useful for debugging/logging purposes
SilenceMode
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:361
static av_cold int init(AVFilterContext *ctx)
#define AVERROR_EOF
End of file.
Definition: error.h:55
A filter pad used for either input or output.
Definition: internal.h:54
int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq)
Rescale a 64-bit integer by 2 rational numbers.
Definition: mathematics.c:142
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:260
int ff_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats)
A helper for query_formats() which sets all links to the same list of formats.
Definition: formats.c:568
AVFrame * ff_get_audio_buffer(AVFilterLink *link, int nb_samples)
Request an audio samples buffer with a specific set of permissions.
Definition: audio.c:86
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:202
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
void * priv
private data for use by the filter
Definition: avfilter.h:353
#define FFMAX(a, b)
Definition: common.h:94
ThresholdMode
double(* compute)(struct SilenceRemoveContext *s, double sample)
static int query_formats(AVFilterContext *ctx)
static int config_input(AVFilterLink *inlink)
int64_t av_rescale(int64_t a, int64_t b, int64_t c)
Rescale a 64-bit integer with rounding to nearest.
Definition: mathematics.c:129
#define AV_TIME_BASE
Internal time base represented as integer.
Definition: avutil.h:254
#define FFMIN(a, b)
Definition: common.h:96
static const AVFilterPad silenceremove_inputs[]
typedef void(APIENTRY *FF_PFNGLACTIVETEXTUREPROC)(GLenum texture)
AVFormatContext * ctx
Definition: movenc.c:48
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
#define s(width, name)
Definition: cbs_vp9.c:257
static int request_frame(AVFilterLink *outlink)
AVFILTER_DEFINE_CLASS(silenceremove)
enum SilenceMode mode
static const AVFilterPad outputs[]
Definition: af_acontrast.c:203
A list of supported channel layouts.
Definition: formats.h:85
if(ret)
static double compute_peak(SilenceRemoveContext *s, double sample)
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:58
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several inputs
uint8_t pi<< 24) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_U8, uint8_t,(*(const uint8_t *) pi-0x80)*(1.0f/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_U8, uint8_t,(*(const uint8_t *) pi-0x80)*(1.0/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S16, int16_t,(*(const int16_t *) pi >> 8)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S16, int16_t,*(const int16_t *) pi *(1.0f/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S16, int16_t,*(const int16_t *) pi *(1.0/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S32, int32_t,(*(const int32_t *) pi >> 24)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S32, int32_t,*(const int32_t *) pi *(1.0f/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S32, int32_t,*(const int32_t *) pi *(1.0/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_FLT, float, av_clip_uint8(lrintf(*(const float *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_FLT, float, av_clip_int16(lrintf(*(const float *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_FLT, float, av_clipl_int32(llrintf(*(const float *) pi *(1U<< 31)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_DBL, double, av_clip_uint8(lrint(*(const double *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_DBL, double, av_clip_int16(lrint(*(const double *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_DBL, double, av_clipl_int32(llrint(*(const double *) pi *(1U<< 31))))#define SET_CONV_FUNC_GROUP(ofmt, ifmt) static void set_generic_function(AudioConvert *ac){}void ff_audio_convert_free(AudioConvert **ac){if(!*ac) return;ff_dither_free(&(*ac) ->dc);av_freep(ac);}AudioConvert *ff_audio_convert_alloc(AVAudioResampleContext *avr, enum AVSampleFormat out_fmt, enum AVSampleFormat in_fmt, int channels, int sample_rate, int apply_map){AudioConvert *ac;int in_planar, out_planar;ac=av_mallocz(sizeof(*ac));if(!ac) return NULL;ac->avr=avr;ac->out_fmt=out_fmt;ac->in_fmt=in_fmt;ac->channels=channels;ac->apply_map=apply_map;if(avr->dither_method!=AV_RESAMPLE_DITHER_NONE &&av_get_packed_sample_fmt(out_fmt)==AV_SAMPLE_FMT_S16 &&av_get_bytes_per_sample(in_fmt) > 2){ac->dc=ff_dither_alloc(avr, out_fmt, in_fmt, channels, sample_rate, apply_map);if(!ac->dc){av_free(ac);return NULL;}return ac;}in_planar=ff_sample_fmt_is_planar(in_fmt, channels);out_planar=ff_sample_fmt_is_planar(out_fmt, channels);if(in_planar==out_planar){ac->func_type=CONV_FUNC_TYPE_FLAT;ac->planes=in_planar?ac->channels:1;}else if(in_planar) ac->func_type=CONV_FUNC_TYPE_INTERLEAVE;else ac->func_type=CONV_FUNC_TYPE_DEINTERLEAVE;set_generic_function(ac);if(ARCH_AARCH64) ff_audio_convert_init_aarch64(ac);if(ARCH_ARM) ff_audio_convert_init_arm(ac);if(ARCH_X86) ff_audio_convert_init_x86(ac);return ac;}int ff_audio_convert(AudioConvert *ac, AudioData *out, AudioData *in){int use_generic=1;int len=in->nb_samples;int p;if(ac->dc){av_log(ac->avr, AV_LOG_TRACE,"%d samples - audio_convert: %s to %s (dithered)\n", len, av_get_sample_fmt_name(ac->in_fmt), av_get_sample_fmt_name(ac->out_fmt));return ff_convert_dither(ac-> in
static av_cold void uninit(AVFilterContext *ctx)
Describe the class of an AVClass context structure.
Definition: log.h:67
Filter definition.
Definition: avfilter.h:144
static void update_rms(SilenceRemoveContext *s, double sample)
Rational number (pair of numerator and denominator).
Definition: rational.h:58
static double compute_rms(SilenceRemoveContext *s, double sample)
static void clear_window(SilenceRemoveContext *s)
#define AF
const char * name
Filter name.
Definition: avfilter.h:148
AVFilterLink ** outputs
array of pointers to output links
Definition: avfilter.h:350
enum MovChannelLayoutTag * layouts
Definition: mov_chan.c:434
AVFilterFormats * ff_all_samplerates(void)
Definition: formats.c:395
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:282
The exact code depends on how similar the blocks are and how related they are to the and needs to apply these operations to the correct inlink or outlink if there are several Macros are available to factor that when no extra processing is inlink
static void update_peak(SilenceRemoveContext *s, double sample)
static const AVOption silenceremove_options[]
A list of supported formats for one end of a filter link.
Definition: formats.h:64
An instance of a filter.
Definition: avfilter.h:338
static enum AVSampleFormat sample_fmts[]
Definition: adpcmenc.c:701
FILE * out
Definition: movenc.c:54
#define av_freep(p)
#define av_malloc_array(a, b)
int ff_request_frame(AVFilterLink *link)
Request an input frame from the filter at the other end of the link.
Definition: avfilter.c:407
formats
Definition: signature.h:48
internal API functions
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later.That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another.Frame references ownership and permissions
AVFilterChannelLayouts * ff_all_channel_counts(void)
Construct an AVFilterChannelLayouts coding for any channel layout, with known or unknown disposition...
Definition: formats.c:410
#define OFFSET(x)
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:334
int ff_set_common_samplerates(AVFilterContext *ctx, AVFilterFormats *samplerates)
Definition: formats.c:556