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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 | ||
33 | enum SilenceMode { | |
34 | SILENCE_TRIM, | |
35 | SILENCE_TRIM_FLUSH, | |
36 | SILENCE_COPY, | |
37 | SILENCE_COPY_FLUSH, | |
38 | SILENCE_STOP | |
39 | }; | |
40 | ||
41 | typedef struct SilenceRemoveContext { | |
42 | const AVClass *class; | |
43 | ||
44 | enum SilenceMode mode; | |
45 | ||
46 | int start_periods; | |
47 | int64_t start_duration; | |
48 | double start_threshold; | |
49 | ||
50 | int stop_periods; | |
51 | int64_t stop_duration; | |
52 | double stop_threshold; | |
53 | ||
54 | double *start_holdoff; | |
55 | size_t start_holdoff_offset; | |
56 | size_t start_holdoff_end; | |
57 | int start_found_periods; | |
58 | ||
59 | double *stop_holdoff; | |
60 | size_t stop_holdoff_offset; | |
61 | size_t stop_holdoff_end; | |
62 | int stop_found_periods; | |
63 | ||
64 | double *window; | |
65 | double *window_current; | |
66 | double *window_end; | |
67 | int window_size; | |
68 | double rms_sum; | |
69 | ||
70 | int leave_silence; | |
71 | int restart; | |
72 | int64_t next_pts; | |
73 | } SilenceRemoveContext; | |
74 | ||
75 | #define OFFSET(x) offsetof(SilenceRemoveContext, x) | |
76 | #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_AUDIO_PARAM | |
77 | static const AVOption silenceremove_options[] = { | |
78 | { "start_periods", NULL, OFFSET(start_periods), AV_OPT_TYPE_INT, {.i64=0}, 0, 9000, FLAGS }, | |
79 | { "start_duration", NULL, OFFSET(start_duration), AV_OPT_TYPE_DURATION, {.i64=0}, 0, 9000, FLAGS }, | |
80 | { "start_threshold", NULL, OFFSET(start_threshold), AV_OPT_TYPE_DOUBLE, {.dbl=0}, 0, DBL_MAX, FLAGS }, | |
81 | { "stop_periods", NULL, OFFSET(stop_periods), AV_OPT_TYPE_INT, {.i64=0}, -9000, 9000, FLAGS }, | |
82 | { "stop_duration", NULL, OFFSET(stop_duration), AV_OPT_TYPE_DURATION, {.i64=0}, 0, 9000, FLAGS }, | |
83 | { "stop_threshold", NULL, OFFSET(stop_threshold), AV_OPT_TYPE_DOUBLE, {.dbl=0}, 0, DBL_MAX, FLAGS }, | |
84 | { "leave_silence", NULL, OFFSET(leave_silence), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS }, | |
85 | { NULL } | |
86 | }; | |
87 | ||
88 | AVFILTER_DEFINE_CLASS(silenceremove); | |
89 | ||
90 | static av_cold int init(AVFilterContext *ctx) | |
91 | { | |
92 | SilenceRemoveContext *s = ctx->priv; | |
93 | ||
94 | if (s->stop_periods < 0) { | |
95 | s->stop_periods = -s->stop_periods; | |
96 | s->restart = 1; | |
97 | } | |
98 | ||
99 | return 0; | |
100 | } | |
101 | ||
102 | static void clear_rms(SilenceRemoveContext *s) | |
103 | { | |
104 | memset(s->window, 0, s->window_size * sizeof(*s->window)); | |
105 | ||
106 | s->window_current = s->window; | |
107 | s->window_end = s->window + s->window_size; | |
108 | s->rms_sum = 0; | |
109 | } | |
110 | ||
111 | static int config_input(AVFilterLink *inlink) | |
112 | { | |
113 | AVFilterContext *ctx = inlink->dst; | |
114 | SilenceRemoveContext *s = ctx->priv; | |
115 | ||
116 | s->window_size = (inlink->sample_rate / 50) * inlink->channels; | |
117 | s->window = av_malloc_array(s->window_size, sizeof(*s->window)); | |
118 | if (!s->window) | |
119 | return AVERROR(ENOMEM); | |
120 | ||
121 | clear_rms(s); | |
122 | ||
123 | s->start_duration = av_rescale(s->start_duration, inlink->sample_rate, | |
124 | AV_TIME_BASE); | |
125 | s->stop_duration = av_rescale(s->stop_duration, inlink->sample_rate, | |
126 | AV_TIME_BASE); | |
127 | ||
128 | s->start_holdoff = av_malloc_array(FFMAX(s->start_duration, 1), | |
129 | sizeof(*s->start_holdoff) * | |
130 | inlink->channels); | |
131 | if (!s->start_holdoff) | |
132 | return AVERROR(ENOMEM); | |
133 | ||
134 | s->start_holdoff_offset = 0; | |
135 | s->start_holdoff_end = 0; | |
136 | s->start_found_periods = 0; | |
137 | ||
138 | s->stop_holdoff = av_malloc_array(FFMAX(s->stop_duration, 1), | |
139 | sizeof(*s->stop_holdoff) * | |
140 | inlink->channels); | |
141 | if (!s->stop_holdoff) | |
142 | return AVERROR(ENOMEM); | |
143 | ||
144 | s->stop_holdoff_offset = 0; | |
145 | s->stop_holdoff_end = 0; | |
146 | s->stop_found_periods = 0; | |
147 | ||
148 | if (s->start_periods) | |
149 | s->mode = SILENCE_TRIM; | |
150 | else | |
151 | s->mode = SILENCE_COPY; | |
152 | ||
153 | return 0; | |
154 | } | |
155 | ||
156 | static int config_output(AVFilterLink *outlink) | |
157 | { | |
158 | outlink->flags |= FF_LINK_FLAG_REQUEST_LOOP; | |
159 | ||
160 | return 0; | |
161 | } | |
162 | ||
163 | static double compute_rms(SilenceRemoveContext *s, double sample) | |
164 | { | |
165 | double new_sum; | |
166 | ||
167 | new_sum = s->rms_sum; | |
168 | new_sum -= *s->window_current; | |
169 | new_sum += sample * sample; | |
170 | ||
171 | return sqrt(new_sum / s->window_size); | |
172 | } | |
173 | ||
174 | static void update_rms(SilenceRemoveContext *s, double sample) | |
175 | { | |
176 | s->rms_sum -= *s->window_current; | |
177 | *s->window_current = sample * sample; | |
178 | s->rms_sum += *s->window_current; | |
179 | ||
180 | s->window_current++; | |
181 | if (s->window_current >= s->window_end) | |
182 | s->window_current = s->window; | |
183 | } | |
184 | ||
185 | static void flush(AVFrame *out, AVFilterLink *outlink, | |
186 | int *nb_samples_written, int *ret) | |
187 | { | |
188 | if (*nb_samples_written) { | |
189 | out->nb_samples = *nb_samples_written / outlink->channels; | |
190 | *ret = ff_filter_frame(outlink, out); | |
191 | *nb_samples_written = 0; | |
192 | } else { | |
193 | av_frame_free(&out); | |
194 | } | |
195 | } | |
196 | ||
197 | static int filter_frame(AVFilterLink *inlink, AVFrame *in) | |
198 | { | |
199 | AVFilterContext *ctx = inlink->dst; | |
200 | AVFilterLink *outlink = ctx->outputs[0]; | |
201 | SilenceRemoveContext *s = ctx->priv; | |
202 | int i, j, threshold, ret = 0; | |
203 | int nbs, nb_samples_read, nb_samples_written; | |
204 | double *obuf, *ibuf = (double *)in->data[0]; | |
205 | AVFrame *out; | |
206 | ||
207 | nb_samples_read = nb_samples_written = 0; | |
208 | ||
209 | switch (s->mode) { | |
210 | case SILENCE_TRIM: | |
211 | silence_trim: | |
212 | nbs = in->nb_samples - nb_samples_read / inlink->channels; | |
213 | if (!nbs) | |
214 | break; | |
215 | ||
216 | for (i = 0; i < nbs; i++) { | |
217 | threshold = 0; | |
218 | for (j = 0; j < inlink->channels; j++) { | |
219 | threshold |= compute_rms(s, ibuf[j]) > s->start_threshold; | |
220 | } | |
221 | ||
222 | if (threshold) { | |
223 | for (j = 0; j < inlink->channels; j++) { | |
224 | update_rms(s, *ibuf); | |
225 | s->start_holdoff[s->start_holdoff_end++] = *ibuf++; | |
226 | nb_samples_read++; | |
227 | } | |
228 | ||
229 | if (s->start_holdoff_end >= s->start_duration * inlink->channels) { | |
230 | if (++s->start_found_periods >= s->start_periods) { | |
231 | s->mode = SILENCE_TRIM_FLUSH; | |
232 | goto silence_trim_flush; | |
233 | } | |
234 | ||
235 | s->start_holdoff_offset = 0; | |
236 | s->start_holdoff_end = 0; | |
237 | } | |
238 | } else { | |
239 | s->start_holdoff_end = 0; | |
240 | ||
241 | for (j = 0; j < inlink->channels; j++) | |
242 | update_rms(s, ibuf[j]); | |
243 | ||
244 | ibuf += inlink->channels; | |
245 | nb_samples_read += inlink->channels; | |
246 | } | |
247 | } | |
248 | break; | |
249 | ||
250 | case SILENCE_TRIM_FLUSH: | |
251 | silence_trim_flush: | |
252 | nbs = s->start_holdoff_end - s->start_holdoff_offset; | |
253 | nbs -= nbs % inlink->channels; | |
254 | if (!nbs) | |
255 | break; | |
256 | ||
257 | out = ff_get_audio_buffer(inlink, nbs / inlink->channels); | |
258 | if (!out) { | |
259 | av_frame_free(&in); | |
260 | return AVERROR(ENOMEM); | |
261 | } | |
262 | ||
263 | memcpy(out->data[0], &s->start_holdoff[s->start_holdoff_offset], | |
264 | nbs * sizeof(double)); | |
265 | s->start_holdoff_offset += nbs; | |
266 | ||
267 | ret = ff_filter_frame(outlink, out); | |
268 | ||
269 | if (s->start_holdoff_offset == s->start_holdoff_end) { | |
270 | s->start_holdoff_offset = 0; | |
271 | s->start_holdoff_end = 0; | |
272 | s->mode = SILENCE_COPY; | |
273 | goto silence_copy; | |
274 | } | |
275 | break; | |
276 | ||
277 | case SILENCE_COPY: | |
278 | silence_copy: | |
279 | nbs = in->nb_samples - nb_samples_read / inlink->channels; | |
280 | if (!nbs) | |
281 | break; | |
282 | ||
283 | out = ff_get_audio_buffer(inlink, nbs); | |
284 | if (!out) { | |
285 | av_frame_free(&in); | |
286 | return AVERROR(ENOMEM); | |
287 | } | |
288 | obuf = (double *)out->data[0]; | |
289 | ||
290 | if (s->stop_periods) { | |
291 | for (i = 0; i < nbs; i++) { | |
292 | threshold = 1; | |
293 | for (j = 0; j < inlink->channels; j++) | |
294 | threshold &= compute_rms(s, ibuf[j]) > s->stop_threshold; | |
295 | ||
296 | if (threshold && s->stop_holdoff_end && !s->leave_silence) { | |
297 | s->mode = SILENCE_COPY_FLUSH; | |
298 | flush(out, outlink, &nb_samples_written, &ret); | |
299 | goto silence_copy_flush; | |
300 | } else if (threshold) { | |
301 | for (j = 0; j < inlink->channels; j++) { | |
302 | update_rms(s, *ibuf); | |
303 | *obuf++ = *ibuf++; | |
304 | nb_samples_read++; | |
305 | nb_samples_written++; | |
306 | } | |
307 | } else if (!threshold) { | |
308 | for (j = 0; j < inlink->channels; j++) { | |
309 | update_rms(s, *ibuf); | |
310 | if (s->leave_silence) { | |
311 | *obuf++ = *ibuf; | |
312 | nb_samples_written++; | |
313 | } | |
314 | ||
315 | s->stop_holdoff[s->stop_holdoff_end++] = *ibuf++; | |
316 | nb_samples_read++; | |
317 | } | |
318 | ||
319 | if (s->stop_holdoff_end >= s->stop_duration * inlink->channels) { | |
320 | if (++s->stop_found_periods >= s->stop_periods) { | |
321 | s->stop_holdoff_offset = 0; | |
322 | s->stop_holdoff_end = 0; | |
323 | ||
324 | if (!s->restart) { | |
325 | s->mode = SILENCE_STOP; | |
326 | flush(out, outlink, &nb_samples_written, &ret); | |
327 | goto silence_stop; | |
328 | } else { | |
329 | s->stop_found_periods = 0; | |
330 | s->start_found_periods = 0; | |
331 | s->start_holdoff_offset = 0; | |
332 | s->start_holdoff_end = 0; | |
333 | clear_rms(s); | |
334 | s->mode = SILENCE_TRIM; | |
335 | flush(out, outlink, &nb_samples_written, &ret); | |
336 | goto silence_trim; | |
337 | } | |
338 | } | |
339 | s->mode = SILENCE_COPY_FLUSH; | |
340 | flush(out, outlink, &nb_samples_written, &ret); | |
341 | goto silence_copy_flush; | |
342 | } | |
343 | } | |
344 | } | |
345 | flush(out, outlink, &nb_samples_written, &ret); | |
346 | } else { | |
347 | memcpy(obuf, ibuf, sizeof(double) * nbs * inlink->channels); | |
348 | ret = ff_filter_frame(outlink, out); | |
349 | } | |
350 | break; | |
351 | ||
352 | case SILENCE_COPY_FLUSH: | |
353 | silence_copy_flush: | |
354 | nbs = s->stop_holdoff_end - s->stop_holdoff_offset; | |
355 | nbs -= nbs % inlink->channels; | |
356 | if (!nbs) | |
357 | break; | |
358 | ||
359 | out = ff_get_audio_buffer(inlink, nbs / inlink->channels); | |
360 | if (!out) { | |
361 | av_frame_free(&in); | |
362 | return AVERROR(ENOMEM); | |
363 | } | |
364 | ||
365 | memcpy(out->data[0], &s->stop_holdoff[s->stop_holdoff_offset], | |
366 | nbs * sizeof(double)); | |
367 | s->stop_holdoff_offset += nbs; | |
368 | ||
369 | ret = ff_filter_frame(outlink, out); | |
370 | ||
371 | if (s->stop_holdoff_offset == s->stop_holdoff_end) { | |
372 | s->stop_holdoff_offset = 0; | |
373 | s->stop_holdoff_end = 0; | |
374 | s->mode = SILENCE_COPY; | |
375 | goto silence_copy; | |
376 | } | |
377 | break; | |
378 | case SILENCE_STOP: | |
379 | silence_stop: | |
380 | break; | |
381 | } | |
382 | ||
383 | av_frame_free(&in); | |
384 | ||
385 | return ret; | |
386 | } | |
387 | ||
388 | static int request_frame(AVFilterLink *outlink) | |
389 | { | |
390 | AVFilterContext *ctx = outlink->src; | |
391 | SilenceRemoveContext *s = ctx->priv; | |
392 | int ret; | |
393 | ||
394 | ret = ff_request_frame(ctx->inputs[0]); | |
395 | if (ret == AVERROR_EOF && (s->mode == SILENCE_COPY_FLUSH || | |
396 | s->mode == SILENCE_COPY)) { | |
397 | int nbs = s->stop_holdoff_end - s->stop_holdoff_offset; | |
398 | if (nbs) { | |
399 | AVFrame *frame; | |
400 | ||
401 | frame = ff_get_audio_buffer(outlink, nbs / outlink->channels); | |
402 | if (!frame) | |
403 | return AVERROR(ENOMEM); | |
404 | ||
405 | memcpy(frame->data[0], &s->stop_holdoff[s->stop_holdoff_offset], | |
406 | nbs * sizeof(double)); | |
407 | ret = ff_filter_frame(ctx->inputs[0], frame); | |
408 | } | |
409 | s->mode = SILENCE_STOP; | |
410 | } | |
411 | return ret; | |
412 | } | |
413 | ||
414 | static int query_formats(AVFilterContext *ctx) | |
415 | { | |
416 | AVFilterFormats *formats = NULL; | |
417 | AVFilterChannelLayouts *layouts = NULL; | |
418 | static const enum AVSampleFormat sample_fmts[] = { | |
419 | AV_SAMPLE_FMT_DBL, AV_SAMPLE_FMT_NONE | |
420 | }; | |
421 | ||
422 | layouts = ff_all_channel_layouts(); | |
423 | if (!layouts) | |
424 | return AVERROR(ENOMEM); | |
425 | ff_set_common_channel_layouts(ctx, layouts); | |
426 | ||
427 | formats = ff_make_format_list(sample_fmts); | |
428 | if (!formats) | |
429 | return AVERROR(ENOMEM); | |
430 | ff_set_common_formats(ctx, formats); | |
431 | ||
432 | formats = ff_all_samplerates(); | |
433 | if (!formats) | |
434 | return AVERROR(ENOMEM); | |
435 | ff_set_common_samplerates(ctx, formats); | |
436 | ||
437 | return 0; | |
438 | } | |
439 | ||
440 | static av_cold void uninit(AVFilterContext *ctx) | |
441 | { | |
442 | SilenceRemoveContext *s = ctx->priv; | |
443 | ||
444 | av_freep(&s->start_holdoff); | |
445 | av_freep(&s->stop_holdoff); | |
446 | av_freep(&s->window); | |
447 | } | |
448 | ||
449 | static const AVFilterPad silenceremove_inputs[] = { | |
450 | { | |
451 | .name = "default", | |
452 | .type = AVMEDIA_TYPE_AUDIO, | |
453 | .config_props = config_input, | |
454 | .filter_frame = filter_frame, | |
455 | }, | |
456 | { NULL } | |
457 | }; | |
458 | ||
459 | static const AVFilterPad silenceremove_outputs[] = { | |
460 | { | |
461 | .name = "default", | |
462 | .type = AVMEDIA_TYPE_AUDIO, | |
463 | .config_props = config_output, | |
464 | .request_frame = request_frame, | |
465 | }, | |
466 | { NULL } | |
467 | }; | |
468 | ||
469 | AVFilter ff_af_silenceremove = { | |
470 | .name = "silenceremove", | |
471 | .description = NULL_IF_CONFIG_SMALL("Remove silence."), | |
472 | .priv_size = sizeof(SilenceRemoveContext), | |
473 | .priv_class = &silenceremove_class, | |
474 | .init = init, | |
475 | .uninit = uninit, | |
476 | .query_formats = query_formats, | |
477 | .inputs = silenceremove_inputs, | |
478 | .outputs = silenceremove_outputs, | |
479 | }; |