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1/*
2 * Copyright (C) 2001-2010 Krzysztof Foltman, Markus Schmidt, Thor Harald Johansen and others
3 * Copyright (c) 2015 Paul B Mahol
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22/**
23 * @file
24 * Audio (Sidechain) Compressor filter
25 */
26
27#include "libavutil/audio_fifo.h"
28#include "libavutil/avassert.h"
29#include "libavutil/channel_layout.h"
30#include "libavutil/common.h"
31#include "libavutil/opt.h"
32
33#include "audio.h"
34#include "avfilter.h"
35#include "formats.h"
36#include "hermite.h"
37#include "internal.h"
38
39typedef struct SidechainCompressContext {
40 const AVClass *class;
41
42 double level_in;
43 double level_sc;
44 double attack, attack_coeff;
45 double release, release_coeff;
46 double lin_slope;
47 double ratio;
48 double threshold;
49 double makeup;
50 double mix;
51 double thres;
52 double knee;
53 double knee_start;
54 double knee_stop;
55 double lin_knee_start;
56 double adj_knee_start;
57 double compressed_knee_stop;
58 int link;
59 int detection;
60
61 AVAudioFifo *fifo[2];
62 int64_t pts;
63} SidechainCompressContext;
64
65#define OFFSET(x) offsetof(SidechainCompressContext, x)
66#define A AV_OPT_FLAG_AUDIO_PARAM
67#define F AV_OPT_FLAG_FILTERING_PARAM
68
69static const AVOption options[] = {
70 { "level_in", "set input gain", OFFSET(level_in), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0.015625, 64, A|F },
71 { "threshold", "set threshold", OFFSET(threshold), AV_OPT_TYPE_DOUBLE, {.dbl=0.125}, 0.000976563, 1, A|F },
72 { "ratio", "set ratio", OFFSET(ratio), AV_OPT_TYPE_DOUBLE, {.dbl=2}, 1, 20, A|F },
73 { "attack", "set attack", OFFSET(attack), AV_OPT_TYPE_DOUBLE, {.dbl=20}, 0.01, 2000, A|F },
74 { "release", "set release", OFFSET(release), AV_OPT_TYPE_DOUBLE, {.dbl=250}, 0.01, 9000, A|F },
75 { "makeup", "set make up gain", OFFSET(makeup), AV_OPT_TYPE_DOUBLE, {.dbl=2}, 1, 64, A|F },
76 { "knee", "set knee", OFFSET(knee), AV_OPT_TYPE_DOUBLE, {.dbl=2.82843}, 1, 8, A|F },
77 { "link", "set link type", OFFSET(link), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, A|F, "link" },
78 { "average", 0, 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, A|F, "link" },
79 { "maximum", 0, 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, A|F, "link" },
80 { "detection", "set detection", OFFSET(detection), AV_OPT_TYPE_INT, {.i64=1}, 0, 1, A|F, "detection" },
81 { "peak", 0, 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, A|F, "detection" },
82 { "rms", 0, 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, A|F, "detection" },
83 { "level_sc", "set sidechain gain", OFFSET(level_sc), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0.015625, 64, A|F },
84 { "mix", "set mix", OFFSET(mix), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 1, A|F },
85 { NULL }
86};
87
88#define sidechaincompress_options options
89AVFILTER_DEFINE_CLASS(sidechaincompress);
90
91// A fake infinity value (because real infinity may break some hosts)
92#define FAKE_INFINITY (65536.0 * 65536.0)
93
94// Check for infinity (with appropriate-ish tolerance)
95#define IS_FAKE_INFINITY(value) (fabs(value-FAKE_INFINITY) < 1.0)
96
97static double output_gain(double lin_slope, double ratio, double thres,
98 double knee, double knee_start, double knee_stop,
99 double compressed_knee_stop, int detection)
100{
101 double slope = log(lin_slope);
102 double gain = 0.0;
103 double delta = 0.0;
104
105 if (detection)
106 slope *= 0.5;
107
108 if (IS_FAKE_INFINITY(ratio)) {
109 gain = thres;
110 delta = 0.0;
111 } else {
112 gain = (slope - thres) / ratio + thres;
113 delta = 1.0 / ratio;
114 }
115
116 if (knee > 1.0 && slope < knee_stop)
117 gain = hermite_interpolation(slope, knee_start, knee_stop,
118 knee_start, compressed_knee_stop,
119 1.0, delta);
120
121 return exp(gain - slope);
122}
123
124static int compressor_config_output(AVFilterLink *outlink)
125{
126 AVFilterContext *ctx = outlink->src;
127 SidechainCompressContext *s = ctx->priv;
128
129 s->thres = log(s->threshold);
130 s->lin_knee_start = s->threshold / sqrt(s->knee);
131 s->adj_knee_start = s->lin_knee_start * s->lin_knee_start;
132 s->knee_start = log(s->lin_knee_start);
133 s->knee_stop = log(s->threshold * sqrt(s->knee));
134 s->compressed_knee_stop = (s->knee_stop - s->thres) / s->ratio + s->thres;
135
136 s->attack_coeff = FFMIN(1., 1. / (s->attack * outlink->sample_rate / 4000.));
137 s->release_coeff = FFMIN(1., 1. / (s->release * outlink->sample_rate / 4000.));
138
139 return 0;
140}
141
142static void compressor(SidechainCompressContext *s,
143 const double *src, double *dst, const double *scsrc, int nb_samples,
144 double level_in, double level_sc,
145 AVFilterLink *inlink, AVFilterLink *sclink)
146{
147 const double makeup = s->makeup;
148 const double mix = s->mix;
149 int i, c;
150
151 for (i = 0; i < nb_samples; i++) {
152 double abs_sample, gain = 1.0;
153
154 abs_sample = fabs(scsrc[0] * level_sc);
155
156 if (s->link == 1) {
157 for (c = 1; c < sclink->channels; c++)
158 abs_sample = FFMAX(fabs(scsrc[c] * level_sc), abs_sample);
159 } else {
160 for (c = 1; c < sclink->channels; c++)
161 abs_sample += fabs(scsrc[c] * level_sc);
162
163 abs_sample /= sclink->channels;
164 }
165
166 if (s->detection)
167 abs_sample *= abs_sample;
168
169 s->lin_slope += (abs_sample - s->lin_slope) * (abs_sample > s->lin_slope ? s->attack_coeff : s->release_coeff);
170
171 if (s->lin_slope > 0.0 && s->lin_slope > (s->detection ? s->adj_knee_start : s->lin_knee_start))
172 gain = output_gain(s->lin_slope, s->ratio, s->thres, s->knee,
173 s->knee_start, s->knee_stop,
174 s->compressed_knee_stop, s->detection);
175
176 for (c = 0; c < inlink->channels; c++)
177 dst[c] = src[c] * level_in * (gain * makeup * mix + (1. - mix));
178
179 src += inlink->channels;
180 dst += inlink->channels;
181 scsrc += sclink->channels;
182 }
183}
184
185#if CONFIG_SIDECHAINCOMPRESS_FILTER
186static int filter_frame(AVFilterLink *link, AVFrame *frame)
187{
188 AVFilterContext *ctx = link->dst;
189 SidechainCompressContext *s = ctx->priv;
190 AVFilterLink *outlink = ctx->outputs[0];
191 AVFrame *out = NULL, *in[2] = { NULL };
192 double *dst;
193 int nb_samples;
194 int i;
195
196 for (i = 0; i < 2; i++)
197 if (link == ctx->inputs[i])
198 break;
199 av_assert0(i < 2);
200 av_audio_fifo_write(s->fifo[i], (void **)frame->extended_data,
201 frame->nb_samples);
202 av_frame_free(&frame);
203
204 nb_samples = FFMIN(av_audio_fifo_size(s->fifo[0]), av_audio_fifo_size(s->fifo[1]));
205 if (!nb_samples)
206 return 0;
207
208 out = ff_get_audio_buffer(outlink, nb_samples);
209 if (!out)
210 return AVERROR(ENOMEM);
211 for (i = 0; i < 2; i++) {
212 in[i] = ff_get_audio_buffer(ctx->inputs[i], nb_samples);
213 if (!in[i]) {
214 av_frame_free(&in[0]);
215 av_frame_free(&in[1]);
216 av_frame_free(&out);
217 return AVERROR(ENOMEM);
218 }
219 av_audio_fifo_read(s->fifo[i], (void **)in[i]->data, nb_samples);
220 }
221
222 dst = (double *)out->data[0];
223 out->pts = s->pts;
224 s->pts += nb_samples;
225
226 compressor(s, (double *)in[0]->data[0], dst,
227 (double *)in[1]->data[0], nb_samples,
228 s->level_in, s->level_sc,
229 ctx->inputs[0], ctx->inputs[1]);
230
231 av_frame_free(&in[0]);
232 av_frame_free(&in[1]);
233
234 return ff_filter_frame(outlink, out);
235}
236
237static int request_frame(AVFilterLink *outlink)
238{
239 AVFilterContext *ctx = outlink->src;
240 SidechainCompressContext *s = ctx->priv;
241 int i;
242
243 /* get a frame on each input */
244 for (i = 0; i < 2; i++) {
245 AVFilterLink *inlink = ctx->inputs[i];
246 if (!av_audio_fifo_size(s->fifo[i]))
247 return ff_request_frame(inlink);
248 }
249
250 return 0;
251}
252
253static int query_formats(AVFilterContext *ctx)
254{
255 AVFilterFormats *formats;
256 AVFilterChannelLayouts *layouts = NULL;
257 static const enum AVSampleFormat sample_fmts[] = {
258 AV_SAMPLE_FMT_DBL,
259 AV_SAMPLE_FMT_NONE
260 };
261 int ret, i;
262
263 if (!ctx->inputs[0]->in_channel_layouts ||
264 !ctx->inputs[0]->in_channel_layouts->nb_channel_layouts) {
265 av_log(ctx, AV_LOG_WARNING,
266 "No channel layout for input 1\n");
267 return AVERROR(EAGAIN);
268 }
269
270 if ((ret = ff_add_channel_layout(&layouts, ctx->inputs[0]->in_channel_layouts->channel_layouts[0])) < 0 ||
271 (ret = ff_channel_layouts_ref(layouts, &ctx->outputs[0]->in_channel_layouts)) < 0)
272 return ret;
273
274 for (i = 0; i < 2; i++) {
275 layouts = ff_all_channel_counts();
276 if ((ret = ff_channel_layouts_ref(layouts, &ctx->inputs[i]->out_channel_layouts)) < 0)
277 return ret;
278 }
279
280 formats = ff_make_format_list(sample_fmts);
281 if ((ret = ff_set_common_formats(ctx, formats)) < 0)
282 return ret;
283
284 formats = ff_all_samplerates();
285 return ff_set_common_samplerates(ctx, formats);
286}
287
288static int config_output(AVFilterLink *outlink)
289{
290 AVFilterContext *ctx = outlink->src;
291 SidechainCompressContext *s = ctx->priv;
292
293 if (ctx->inputs[0]->sample_rate != ctx->inputs[1]->sample_rate) {
294 av_log(ctx, AV_LOG_ERROR,
295 "Inputs must have the same sample rate "
296 "%d for in0 vs %d for in1\n",
297 ctx->inputs[0]->sample_rate, ctx->inputs[1]->sample_rate);
298 return AVERROR(EINVAL);
299 }
300
301 outlink->sample_rate = ctx->inputs[0]->sample_rate;
302 outlink->time_base = ctx->inputs[0]->time_base;
303 outlink->channel_layout = ctx->inputs[0]->channel_layout;
304 outlink->channels = ctx->inputs[0]->channels;
305
306 s->fifo[0] = av_audio_fifo_alloc(ctx->inputs[0]->format, ctx->inputs[0]->channels, 1024);
307 s->fifo[1] = av_audio_fifo_alloc(ctx->inputs[1]->format, ctx->inputs[1]->channels, 1024);
308 if (!s->fifo[0] || !s->fifo[1])
309 return AVERROR(ENOMEM);
310
311 compressor_config_output(outlink);
312
313 return 0;
314}
315
316static av_cold void uninit(AVFilterContext *ctx)
317{
318 SidechainCompressContext *s = ctx->priv;
319
320 av_audio_fifo_free(s->fifo[0]);
321 av_audio_fifo_free(s->fifo[1]);
322}
323
324static const AVFilterPad sidechaincompress_inputs[] = {
325 {
326 .name = "main",
327 .type = AVMEDIA_TYPE_AUDIO,
328 .filter_frame = filter_frame,
329 },{
330 .name = "sidechain",
331 .type = AVMEDIA_TYPE_AUDIO,
332 .filter_frame = filter_frame,
333 },
334 { NULL }
335};
336
337static const AVFilterPad sidechaincompress_outputs[] = {
338 {
339 .name = "default",
340 .type = AVMEDIA_TYPE_AUDIO,
341 .config_props = config_output,
342 .request_frame = request_frame,
343 },
344 { NULL }
345};
346
347AVFilter ff_af_sidechaincompress = {
348 .name = "sidechaincompress",
349 .description = NULL_IF_CONFIG_SMALL("Sidechain compressor."),
350 .priv_size = sizeof(SidechainCompressContext),
351 .priv_class = &sidechaincompress_class,
352 .query_formats = query_formats,
353 .uninit = uninit,
354 .inputs = sidechaincompress_inputs,
355 .outputs = sidechaincompress_outputs,
356};
357#endif /* CONFIG_SIDECHAINCOMPRESS_FILTER */
358
359#if CONFIG_ACOMPRESSOR_FILTER
360static int acompressor_filter_frame(AVFilterLink *inlink, AVFrame *in)
361{
362 const double *src = (const double *)in->data[0];
363 AVFilterContext *ctx = inlink->dst;
364 SidechainCompressContext *s = ctx->priv;
365 AVFilterLink *outlink = ctx->outputs[0];
366 AVFrame *out;
367 double *dst;
368
369 if (av_frame_is_writable(in)) {
370 out = in;
371 } else {
372 out = ff_get_audio_buffer(inlink, in->nb_samples);
373 if (!out) {
374 av_frame_free(&in);
375 return AVERROR(ENOMEM);
376 }
377 av_frame_copy_props(out, in);
378 }
379 dst = (double *)out->data[0];
380
381 compressor(s, src, dst, src, in->nb_samples,
382 s->level_in, s->level_in,
383 inlink, inlink);
384
385 if (out != in)
386 av_frame_free(&in);
387 return ff_filter_frame(outlink, out);
388}
389
390static int acompressor_query_formats(AVFilterContext *ctx)
391{
392 AVFilterFormats *formats;
393 AVFilterChannelLayouts *layouts;
394 static const enum AVSampleFormat sample_fmts[] = {
395 AV_SAMPLE_FMT_DBL,
396 AV_SAMPLE_FMT_NONE
397 };
398 int ret;
399
400 layouts = ff_all_channel_counts();
401 if (!layouts)
402 return AVERROR(ENOMEM);
403 ret = ff_set_common_channel_layouts(ctx, layouts);
404 if (ret < 0)
405 return ret;
406
407 formats = ff_make_format_list(sample_fmts);
408 if (!formats)
409 return AVERROR(ENOMEM);
410 ret = ff_set_common_formats(ctx, formats);
411 if (ret < 0)
412 return ret;
413
414 formats = ff_all_samplerates();
415 if (!formats)
416 return AVERROR(ENOMEM);
417 return ff_set_common_samplerates(ctx, formats);
418}
419
420#define acompressor_options options
421AVFILTER_DEFINE_CLASS(acompressor);
422
423static const AVFilterPad acompressor_inputs[] = {
424 {
425 .name = "default",
426 .type = AVMEDIA_TYPE_AUDIO,
427 .filter_frame = acompressor_filter_frame,
428 },
429 { NULL }
430};
431
432static const AVFilterPad acompressor_outputs[] = {
433 {
434 .name = "default",
435 .type = AVMEDIA_TYPE_AUDIO,
436 .config_props = compressor_config_output,
437 },
438 { NULL }
439};
440
441AVFilter ff_af_acompressor = {
442 .name = "acompressor",
443 .description = NULL_IF_CONFIG_SMALL("Audio compressor."),
444 .priv_size = sizeof(SidechainCompressContext),
445 .priv_class = &acompressor_class,
446 .query_formats = acompressor_query_formats,
447 .inputs = acompressor_inputs,
448 .outputs = acompressor_outputs,
449};
450#endif /* CONFIG_ACOMPRESSOR_FILTER */
451
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