1 /*
2 * Copyright (C) 2001-2010 Krzysztof Foltman, Markus Schmidt, Thor Harald Johansen, Damien Zammit
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21 /**
22 * @file
23 * Audio (Sidechain) Gate filter
24 */
25
26 #include "libavutil/audio_fifo.h"
27 #include "libavutil/avassert.h"
28 #include "libavutil/channel_layout.h"
29 #include "libavutil/opt.h"
30 #include "avfilter.h"
31 #include "audio.h"
32 #include "filters.h"
33 #include "formats.h"
34 #include "hermite.h"
35
36 typedef struct AudioGateContext {
37 const AVClass *class;
38
39 double level_in;
40 double level_sc;
41 double attack;
42 double release;
43 double threshold;
44 double ratio;
45 double knee;
46 double makeup;
47 double range;
48 int link;
49 int detection;
50 int mode;
51
52 double thres;
53 double knee_start;
54 double knee_stop;
55 double lin_knee_start;
56 double lin_knee_stop;
57 double lin_slope;
58 double attack_coeff;
59 double release_coeff;
60
61 AVAudioFifo *fifo[2];
62 int64_t pts;
63 } AudioGateContext;
64
65 #define OFFSET(x) offsetof(AudioGateContext, x)
66 #define A AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_RUNTIME_PARAM
67
68 static const AVOption options[] = {
69 { "level_in", "set input level", OFFSET(level_in), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0.015625, 64, A },
70 { "mode", "set mode", OFFSET(mode), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, A, "mode" },
71 { "downward",0, 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, A, "mode" },
72 { "upward", 0, 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, A, "mode" },
73 { "range", "set max gain reduction", OFFSET(range), AV_OPT_TYPE_DOUBLE, {.dbl=0.06125}, 0, 1, A },
74 { "threshold", "set threshold", OFFSET(threshold), AV_OPT_TYPE_DOUBLE, {.dbl=0.125}, 0, 1, A },
75 { "ratio", "set ratio", OFFSET(ratio), AV_OPT_TYPE_DOUBLE, {.dbl=2}, 1, 9000, A },
76 { "attack", "set attack", OFFSET(attack), AV_OPT_TYPE_DOUBLE, {.dbl=20}, 0.01, 9000, A },
77 { "release", "set release", OFFSET(release), AV_OPT_TYPE_DOUBLE, {.dbl=250}, 0.01, 9000, A },
78 { "makeup", "set makeup gain", OFFSET(makeup), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 1, 64, A },
79 { "knee", "set knee", OFFSET(knee), AV_OPT_TYPE_DOUBLE, {.dbl=2.828427125}, 1, 8, A },
80 { "detection", "set detection", OFFSET(detection), AV_OPT_TYPE_INT, {.i64=1}, 0, 1, A, "detection" },
81 { "peak", 0, 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, A, "detection" },
82 { "rms", 0, 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, A, "detection" },
83 { "link", "set link", OFFSET(link), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, A, "link" },
84 { "average", 0, 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, A, "link" },
85 { "maximum", 0, 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, A, "link" },
86 { "level_sc", "set sidechain gain", OFFSET(level_sc), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0.015625, 64, A },
87 { NULL }
88 };
89
agate_config_input(AVFilterLink * inlink)90 static int agate_config_input(AVFilterLink *inlink)
91 {
92 AVFilterContext *ctx = inlink->dst;
93 AudioGateContext *s = ctx->priv;
94 double lin_threshold = s->threshold;
95 double lin_knee_sqrt = sqrt(s->knee);
96
97 if (s->detection)
98 lin_threshold *= lin_threshold;
99
100 s->attack_coeff = FFMIN(1., 1. / (s->attack * inlink->sample_rate / 4000.));
101 s->release_coeff = FFMIN(1., 1. / (s->release * inlink->sample_rate / 4000.));
102 s->lin_knee_stop = lin_threshold * lin_knee_sqrt;
103 s->lin_knee_start = lin_threshold / lin_knee_sqrt;
104 s->thres = log(lin_threshold);
105 s->knee_start = log(s->lin_knee_start);
106 s->knee_stop = log(s->lin_knee_stop);
107
108 return 0;
109 }
110
111 // A fake infinity value (because real infinity may break some hosts)
112 #define FAKE_INFINITY (65536.0 * 65536.0)
113
114 // Check for infinity (with appropriate-ish tolerance)
115 #define IS_FAKE_INFINITY(value) (fabs(value-FAKE_INFINITY) < 1.0)
116
output_gain(double lin_slope,double ratio,double thres,double knee,double knee_start,double knee_stop,double range,int mode)117 static double output_gain(double lin_slope, double ratio, double thres,
118 double knee, double knee_start, double knee_stop,
119 double range, int mode)
120 {
121 double slope = log(lin_slope);
122 double tratio = ratio;
123 double gain = 0.;
124 double delta = 0.;
125
126 if (IS_FAKE_INFINITY(ratio))
127 tratio = 1000.;
128 gain = (slope - thres) * tratio + thres;
129 delta = tratio;
130
131 if (mode) {
132 if (knee > 1. && slope < knee_stop)
133 gain = hermite_interpolation(slope, knee_stop, knee_start, ((knee_stop - thres) * tratio + thres), knee_start, delta, 1.);
134 } else {
135 if (knee > 1. && slope > knee_start)
136 gain = hermite_interpolation(slope, knee_start, knee_stop, ((knee_start - thres) * tratio + thres), knee_stop, delta, 1.);
137 }
138 return FFMAX(range, exp(gain - slope));
139 }
140
gate(AudioGateContext * s,const double * src,double * dst,const double * scsrc,int nb_samples,double level_in,double level_sc,AVFilterLink * inlink,AVFilterLink * sclink)141 static void gate(AudioGateContext *s,
142 const double *src, double *dst, const double *scsrc,
143 int nb_samples, double level_in, double level_sc,
144 AVFilterLink *inlink, AVFilterLink *sclink)
145 {
146 const double makeup = s->makeup;
147 const double attack_coeff = s->attack_coeff;
148 const double release_coeff = s->release_coeff;
149 int n, c;
150
151 for (n = 0; n < nb_samples; n++, src += inlink->channels, dst += inlink->channels, scsrc += sclink->channels) {
152 double abs_sample = fabs(scsrc[0] * level_sc), gain = 1.0;
153 int detected;
154
155 if (s->link == 1) {
156 for (c = 1; c < sclink->channels; c++)
157 abs_sample = FFMAX(fabs(scsrc[c] * level_sc), abs_sample);
158 } else {
159 for (c = 1; c < sclink->channels; c++)
160 abs_sample += fabs(scsrc[c] * level_sc);
161
162 abs_sample /= sclink->channels;
163 }
164
165 if (s->detection)
166 abs_sample *= abs_sample;
167
168 s->lin_slope += (abs_sample - s->lin_slope) * (abs_sample > s->lin_slope ? attack_coeff : release_coeff);
169
170 if (s->mode)
171 detected = s->lin_slope > s->lin_knee_start;
172 else
173 detected = s->lin_slope < s->lin_knee_stop;
174
175 if (s->lin_slope > 0.0 && detected)
176 gain = output_gain(s->lin_slope, s->ratio, s->thres,
177 s->knee, s->knee_start, s->knee_stop,
178 s->range, s->mode);
179
180 for (c = 0; c < inlink->channels; c++)
181 dst[c] = src[c] * level_in * gain * makeup;
182 }
183 }
184
185 #if CONFIG_AGATE_FILTER
186
187 #define agate_options options
188 AVFILTER_DEFINE_CLASS(agate);
189
query_formats(AVFilterContext * ctx)190 static int query_formats(AVFilterContext *ctx)
191 {
192 AVFilterFormats *formats = NULL;
193 AVFilterChannelLayouts *layouts;
194 int ret;
195
196 if ((ret = ff_add_format(&formats, AV_SAMPLE_FMT_DBL)) < 0)
197 return ret;
198 ret = ff_set_common_formats(ctx, formats);
199 if (ret < 0)
200 return ret;
201
202 layouts = ff_all_channel_counts();
203 if (!layouts)
204 return AVERROR(ENOMEM);
205 ret = ff_set_common_channel_layouts(ctx, layouts);
206 if (ret < 0)
207 return ret;
208
209 formats = ff_all_samplerates();
210 if (!formats)
211 return AVERROR(ENOMEM);
212
213 return ff_set_common_samplerates(ctx, formats);
214 }
215
filter_frame(AVFilterLink * inlink,AVFrame * in)216 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
217 {
218 const double *src = (const double *)in->data[0];
219 AVFilterContext *ctx = inlink->dst;
220 AVFilterLink *outlink = ctx->outputs[0];
221 AudioGateContext *s = ctx->priv;
222 AVFrame *out;
223 double *dst;
224
225 if (av_frame_is_writable(in)) {
226 out = in;
227 } else {
228 out = ff_get_audio_buffer(outlink, in->nb_samples);
229 if (!out) {
230 av_frame_free(&in);
231 return AVERROR(ENOMEM);
232 }
233 av_frame_copy_props(out, in);
234 }
235 dst = (double *)out->data[0];
236
237 gate(s, src, dst, src, in->nb_samples,
238 s->level_in, s->level_in, inlink, inlink);
239
240 if (out != in)
241 av_frame_free(&in);
242 return ff_filter_frame(outlink, out);
243 }
244
245 static const AVFilterPad inputs[] = {
246 {
247 .name = "default",
248 .type = AVMEDIA_TYPE_AUDIO,
249 .filter_frame = filter_frame,
250 .config_props = agate_config_input,
251 },
252 { NULL }
253 };
254
255 static const AVFilterPad outputs[] = {
256 {
257 .name = "default",
258 .type = AVMEDIA_TYPE_AUDIO,
259 },
260 { NULL }
261 };
262
263 AVFilter ff_af_agate = {
264 .name = "agate",
265 .description = NULL_IF_CONFIG_SMALL("Audio gate."),
266 .query_formats = query_formats,
267 .priv_size = sizeof(AudioGateContext),
268 .priv_class = &agate_class,
269 .inputs = inputs,
270 .outputs = outputs,
271 .process_command = ff_filter_process_command,
272 .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
273 };
274
275 #endif /* CONFIG_AGATE_FILTER */
276
277 #if CONFIG_SIDECHAINGATE_FILTER
278
279 #define sidechaingate_options options
280 AVFILTER_DEFINE_CLASS(sidechaingate);
281
activate(AVFilterContext * ctx)282 static int activate(AVFilterContext *ctx)
283 {
284 AudioGateContext *s = ctx->priv;
285 AVFrame *out = NULL, *in[2] = { NULL };
286 int ret, i, nb_samples;
287 double *dst;
288
289 FF_FILTER_FORWARD_STATUS_BACK_ALL(ctx->outputs[0], ctx);
290 if ((ret = ff_inlink_consume_frame(ctx->inputs[0], &in[0])) > 0) {
291 av_audio_fifo_write(s->fifo[0], (void **)in[0]->extended_data,
292 in[0]->nb_samples);
293 av_frame_free(&in[0]);
294 }
295 if (ret < 0)
296 return ret;
297 if ((ret = ff_inlink_consume_frame(ctx->inputs[1], &in[1])) > 0) {
298 av_audio_fifo_write(s->fifo[1], (void **)in[1]->extended_data,
299 in[1]->nb_samples);
300 av_frame_free(&in[1]);
301 }
302 if (ret < 0)
303 return ret;
304
305 nb_samples = FFMIN(av_audio_fifo_size(s->fifo[0]), av_audio_fifo_size(s->fifo[1]));
306 if (nb_samples) {
307 out = ff_get_audio_buffer(ctx->outputs[0], nb_samples);
308 if (!out)
309 return AVERROR(ENOMEM);
310 for (i = 0; i < 2; i++) {
311 in[i] = ff_get_audio_buffer(ctx->inputs[i], nb_samples);
312 if (!in[i]) {
313 av_frame_free(&in[0]);
314 av_frame_free(&in[1]);
315 av_frame_free(&out);
316 return AVERROR(ENOMEM);
317 }
318 av_audio_fifo_read(s->fifo[i], (void **)in[i]->data, nb_samples);
319 }
320
321 dst = (double *)out->data[0];
322 out->pts = s->pts;
323 s->pts += av_rescale_q(nb_samples, (AVRational){1, ctx->outputs[0]->sample_rate}, ctx->outputs[0]->time_base);
324
325 gate(s, (double *)in[0]->data[0], dst,
326 (double *)in[1]->data[0], nb_samples,
327 s->level_in, s->level_sc,
328 ctx->inputs[0], ctx->inputs[1]);
329
330 av_frame_free(&in[0]);
331 av_frame_free(&in[1]);
332
333 ret = ff_filter_frame(ctx->outputs[0], out);
334 if (ret < 0)
335 return ret;
336 }
337 FF_FILTER_FORWARD_STATUS(ctx->inputs[0], ctx->outputs[0]);
338 FF_FILTER_FORWARD_STATUS(ctx->inputs[1], ctx->outputs[0]);
339 if (ff_outlink_frame_wanted(ctx->outputs[0])) {
340 if (!av_audio_fifo_size(s->fifo[0]))
341 ff_inlink_request_frame(ctx->inputs[0]);
342 if (!av_audio_fifo_size(s->fifo[1]))
343 ff_inlink_request_frame(ctx->inputs[1]);
344 }
345 return 0;
346 }
347
scquery_formats(AVFilterContext * ctx)348 static int scquery_formats(AVFilterContext *ctx)
349 {
350 AVFilterFormats *formats;
351 AVFilterChannelLayouts *layouts = NULL;
352 static const enum AVSampleFormat sample_fmts[] = {
353 AV_SAMPLE_FMT_DBL,
354 AV_SAMPLE_FMT_NONE
355 };
356 int ret, i;
357
358 if (!ctx->inputs[0]->incfg.channel_layouts ||
359 !ctx->inputs[0]->incfg.channel_layouts->nb_channel_layouts) {
360 av_log(ctx, AV_LOG_WARNING,
361 "No channel layout for input 1\n");
362 return AVERROR(EAGAIN);
363 }
364
365 if ((ret = ff_add_channel_layout(&layouts, ctx->inputs[0]->incfg.channel_layouts->channel_layouts[0])) < 0 ||
366 (ret = ff_channel_layouts_ref(layouts, &ctx->outputs[0]->incfg.channel_layouts)) < 0)
367 return ret;
368
369 for (i = 0; i < 2; i++) {
370 layouts = ff_all_channel_counts();
371 if ((ret = ff_channel_layouts_ref(layouts, &ctx->inputs[i]->outcfg.channel_layouts)) < 0)
372 return ret;
373 }
374
375 formats = ff_make_format_list(sample_fmts);
376 if ((ret = ff_set_common_formats(ctx, formats)) < 0)
377 return ret;
378
379 formats = ff_all_samplerates();
380 return ff_set_common_samplerates(ctx, formats);
381 }
382
scconfig_output(AVFilterLink * outlink)383 static int scconfig_output(AVFilterLink *outlink)
384 {
385 AVFilterContext *ctx = outlink->src;
386 AudioGateContext *s = ctx->priv;
387
388 if (ctx->inputs[0]->sample_rate != ctx->inputs[1]->sample_rate) {
389 av_log(ctx, AV_LOG_ERROR,
390 "Inputs must have the same sample rate "
391 "%d for in0 vs %d for in1\n",
392 ctx->inputs[0]->sample_rate, ctx->inputs[1]->sample_rate);
393 return AVERROR(EINVAL);
394 }
395
396 outlink->sample_rate = ctx->inputs[0]->sample_rate;
397 outlink->time_base = ctx->inputs[0]->time_base;
398 outlink->channel_layout = ctx->inputs[0]->channel_layout;
399 outlink->channels = ctx->inputs[0]->channels;
400
401 s->fifo[0] = av_audio_fifo_alloc(ctx->inputs[0]->format, ctx->inputs[0]->channels, 1024);
402 s->fifo[1] = av_audio_fifo_alloc(ctx->inputs[1]->format, ctx->inputs[1]->channels, 1024);
403 if (!s->fifo[0] || !s->fifo[1])
404 return AVERROR(ENOMEM);
405
406
407 agate_config_input(ctx->inputs[0]);
408
409 return 0;
410 }
411
uninit(AVFilterContext * ctx)412 static av_cold void uninit(AVFilterContext *ctx)
413 {
414 AudioGateContext *s = ctx->priv;
415
416 av_audio_fifo_free(s->fifo[0]);
417 av_audio_fifo_free(s->fifo[1]);
418 }
419
420 static const AVFilterPad sidechaingate_inputs[] = {
421 {
422 .name = "main",
423 .type = AVMEDIA_TYPE_AUDIO,
424 },{
425 .name = "sidechain",
426 .type = AVMEDIA_TYPE_AUDIO,
427 },
428 { NULL }
429 };
430
431 static const AVFilterPad sidechaingate_outputs[] = {
432 {
433 .name = "default",
434 .type = AVMEDIA_TYPE_AUDIO,
435 .config_props = scconfig_output,
436 },
437 { NULL }
438 };
439
440 AVFilter ff_af_sidechaingate = {
441 .name = "sidechaingate",
442 .description = NULL_IF_CONFIG_SMALL("Audio sidechain gate."),
443 .priv_size = sizeof(AudioGateContext),
444 .priv_class = &sidechaingate_class,
445 .query_formats = scquery_formats,
446 .activate = activate,
447 .uninit = uninit,
448 .inputs = sidechaingate_inputs,
449 .outputs = sidechaingate_outputs,
450 .process_command = ff_filter_process_command,
451 .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
452 };
453 #endif /* CONFIG_SIDECHAINGATE_FILTER */
454