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 "config_components.h"
27
28 #include "libavutil/audio_fifo.h"
29 #include "libavutil/channel_layout.h"
30 #include "libavutil/opt.h"
31 #include "avfilter.h"
32 #include "audio.h"
33 #include "filters.h"
34 #include "formats.h"
35 #include "hermite.h"
36
37 typedef struct AudioGateContext {
38 const AVClass *class;
39
40 double level_in;
41 double level_sc;
42 double attack;
43 double release;
44 double threshold;
45 double ratio;
46 double knee;
47 double makeup;
48 double range;
49 int link;
50 int detection;
51 int mode;
52
53 double thres;
54 double knee_start;
55 double knee_stop;
56 double lin_knee_start;
57 double lin_knee_stop;
58 double lin_slope;
59 double attack_coeff;
60 double release_coeff;
61
62 AVAudioFifo *fifo[2];
63 int64_t pts;
64 } AudioGateContext;
65
66 #define OFFSET(x) offsetof(AudioGateContext, x)
67 #define A AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_RUNTIME_PARAM
68
69 static const AVOption options[] = {
70 { "level_in", "set input level", OFFSET(level_in), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0.015625, 64, A },
71 { "mode", "set mode", OFFSET(mode), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, A, "mode" },
72 { "downward",0, 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, A, "mode" },
73 { "upward", 0, 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, A, "mode" },
74 { "range", "set max gain reduction", OFFSET(range), AV_OPT_TYPE_DOUBLE, {.dbl=0.06125}, 0, 1, A },
75 { "threshold", "set threshold", OFFSET(threshold), AV_OPT_TYPE_DOUBLE, {.dbl=0.125}, 0, 1, A },
76 { "ratio", "set ratio", OFFSET(ratio), AV_OPT_TYPE_DOUBLE, {.dbl=2}, 1, 9000, A },
77 { "attack", "set attack", OFFSET(attack), AV_OPT_TYPE_DOUBLE, {.dbl=20}, 0.01, 9000, A },
78 { "release", "set release", OFFSET(release), AV_OPT_TYPE_DOUBLE, {.dbl=250}, 0.01, 9000, A },
79 { "makeup", "set makeup gain", OFFSET(makeup), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 1, 64, A },
80 { "knee", "set knee", OFFSET(knee), AV_OPT_TYPE_DOUBLE, {.dbl=2.828427125}, 1, 8, A },
81 { "detection", "set detection", OFFSET(detection), AV_OPT_TYPE_INT, {.i64=1}, 0, 1, A, "detection" },
82 { "peak", 0, 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, A, "detection" },
83 { "rms", 0, 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, A, "detection" },
84 { "link", "set link", OFFSET(link), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, A, "link" },
85 { "average", 0, 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, A, "link" },
86 { "maximum", 0, 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, A, "link" },
87 { "level_sc", "set sidechain gain", OFFSET(level_sc), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0.015625, 64, A },
88 { NULL }
89 };
90
91 AVFILTER_DEFINE_CLASS_EXT(agate_sidechaingate, "agate/sidechaingate", options);
92
agate_config_input(AVFilterLink * inlink)93 static int agate_config_input(AVFilterLink *inlink)
94 {
95 AVFilterContext *ctx = inlink->dst;
96 AudioGateContext *s = ctx->priv;
97 double lin_threshold = s->threshold;
98 double lin_knee_sqrt = sqrt(s->knee);
99
100 if (s->detection)
101 lin_threshold *= lin_threshold;
102
103 s->attack_coeff = FFMIN(1., 1. / (s->attack * inlink->sample_rate / 4000.));
104 s->release_coeff = FFMIN(1., 1. / (s->release * inlink->sample_rate / 4000.));
105 s->lin_knee_stop = lin_threshold * lin_knee_sqrt;
106 s->lin_knee_start = lin_threshold / lin_knee_sqrt;
107 s->thres = log(lin_threshold);
108 s->knee_start = log(s->lin_knee_start);
109 s->knee_stop = log(s->lin_knee_stop);
110
111 return 0;
112 }
113
114 // A fake infinity value (because real infinity may break some hosts)
115 #define FAKE_INFINITY (65536.0 * 65536.0)
116
117 // Check for infinity (with appropriate-ish tolerance)
118 #define IS_FAKE_INFINITY(value) (fabs(value-FAKE_INFINITY) < 1.0)
119
output_gain(double lin_slope,double ratio,double thres,double knee,double knee_start,double knee_stop,double range,int mode)120 static double output_gain(double lin_slope, double ratio, double thres,
121 double knee, double knee_start, double knee_stop,
122 double range, int mode)
123 {
124 double slope = log(lin_slope);
125 double tratio = ratio;
126 double gain = 0.;
127 double delta = 0.;
128
129 if (IS_FAKE_INFINITY(ratio))
130 tratio = 1000.;
131 gain = (slope - thres) * tratio + thres;
132 delta = tratio;
133
134 if (mode) {
135 if (knee > 1. && slope < knee_stop)
136 gain = hermite_interpolation(slope, knee_stop, knee_start, ((knee_stop - thres) * tratio + thres), knee_start, delta, 1.);
137 } else {
138 if (knee > 1. && slope > knee_start)
139 gain = hermite_interpolation(slope, knee_start, knee_stop, ((knee_start - thres) * tratio + thres), knee_stop, delta, 1.);
140 }
141 return FFMAX(range, exp(gain - slope));
142 }
143
gate(AudioGateContext * s,const double * src,double * dst,const double * scsrc,int nb_samples,double level_in,double level_sc,AVFilterLink * inlink,AVFilterLink * sclink)144 static void gate(AudioGateContext *s,
145 const double *src, double *dst, const double *scsrc,
146 int nb_samples, double level_in, double level_sc,
147 AVFilterLink *inlink, AVFilterLink *sclink)
148 {
149 AVFilterContext *ctx = inlink->dst;
150 const double makeup = s->makeup;
151 const double attack_coeff = s->attack_coeff;
152 const double release_coeff = s->release_coeff;
153 int n, c;
154
155 for (n = 0; n < nb_samples; n++, src += inlink->ch_layout.nb_channels, dst += inlink->ch_layout.nb_channels, scsrc += sclink->ch_layout.nb_channels) {
156 double abs_sample = fabs(scsrc[0] * level_sc), gain = 1.0;
157 double factor;
158 int detected;
159
160 if (s->link == 1) {
161 for (c = 1; c < sclink->ch_layout.nb_channels; c++)
162 abs_sample = FFMAX(fabs(scsrc[c] * level_sc), abs_sample);
163 } else {
164 for (c = 1; c < sclink->ch_layout.nb_channels; c++)
165 abs_sample += fabs(scsrc[c] * level_sc);
166
167 abs_sample /= sclink->ch_layout.nb_channels;
168 }
169
170 if (s->detection)
171 abs_sample *= abs_sample;
172
173 s->lin_slope += (abs_sample - s->lin_slope) * (abs_sample > s->lin_slope ? attack_coeff : release_coeff);
174
175 if (s->mode)
176 detected = s->lin_slope > s->lin_knee_start;
177 else
178 detected = s->lin_slope < s->lin_knee_stop;
179
180 if (s->lin_slope > 0.0 && detected)
181 gain = output_gain(s->lin_slope, s->ratio, s->thres,
182 s->knee, s->knee_start, s->knee_stop,
183 s->range, s->mode);
184
185 factor = ctx->is_disabled ? 1.f : level_in * gain * makeup;
186 for (c = 0; c < inlink->ch_layout.nb_channels; c++)
187 dst[c] = src[c] * factor;
188 }
189 }
190
191 #if CONFIG_AGATE_FILTER
192
filter_frame(AVFilterLink * inlink,AVFrame * in)193 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
194 {
195 const double *src = (const double *)in->data[0];
196 AVFilterContext *ctx = inlink->dst;
197 AVFilterLink *outlink = ctx->outputs[0];
198 AudioGateContext *s = ctx->priv;
199 AVFrame *out;
200 double *dst;
201
202 if (av_frame_is_writable(in)) {
203 out = in;
204 } else {
205 out = ff_get_audio_buffer(outlink, in->nb_samples);
206 if (!out) {
207 av_frame_free(&in);
208 return AVERROR(ENOMEM);
209 }
210 av_frame_copy_props(out, in);
211 }
212 dst = (double *)out->data[0];
213
214 gate(s, src, dst, src, in->nb_samples,
215 s->level_in, s->level_in, inlink, inlink);
216
217 if (out != in)
218 av_frame_free(&in);
219 return ff_filter_frame(outlink, out);
220 }
221
222 static const AVFilterPad inputs[] = {
223 {
224 .name = "default",
225 .type = AVMEDIA_TYPE_AUDIO,
226 .filter_frame = filter_frame,
227 .config_props = agate_config_input,
228 },
229 };
230
231 static const AVFilterPad outputs[] = {
232 {
233 .name = "default",
234 .type = AVMEDIA_TYPE_AUDIO,
235 },
236 };
237
238 const AVFilter ff_af_agate = {
239 .name = "agate",
240 .description = NULL_IF_CONFIG_SMALL("Audio gate."),
241 .priv_class = &agate_sidechaingate_class,
242 .priv_size = sizeof(AudioGateContext),
243 FILTER_INPUTS(inputs),
244 FILTER_OUTPUTS(outputs),
245 FILTER_SINGLE_SAMPLEFMT(AV_SAMPLE_FMT_DBL),
246 .process_command = ff_filter_process_command,
247 .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
248 };
249
250 #endif /* CONFIG_AGATE_FILTER */
251
252 #if CONFIG_SIDECHAINGATE_FILTER
253
activate(AVFilterContext * ctx)254 static int activate(AVFilterContext *ctx)
255 {
256 AudioGateContext *s = ctx->priv;
257 AVFrame *out = NULL, *in[2] = { NULL };
258 int ret, i, nb_samples;
259 double *dst;
260
261 FF_FILTER_FORWARD_STATUS_BACK_ALL(ctx->outputs[0], ctx);
262 if ((ret = ff_inlink_consume_frame(ctx->inputs[0], &in[0])) > 0) {
263 av_audio_fifo_write(s->fifo[0], (void **)in[0]->extended_data,
264 in[0]->nb_samples);
265 av_frame_free(&in[0]);
266 }
267 if (ret < 0)
268 return ret;
269 if ((ret = ff_inlink_consume_frame(ctx->inputs[1], &in[1])) > 0) {
270 av_audio_fifo_write(s->fifo[1], (void **)in[1]->extended_data,
271 in[1]->nb_samples);
272 av_frame_free(&in[1]);
273 }
274 if (ret < 0)
275 return ret;
276
277 nb_samples = FFMIN(av_audio_fifo_size(s->fifo[0]), av_audio_fifo_size(s->fifo[1]));
278 if (nb_samples) {
279 out = ff_get_audio_buffer(ctx->outputs[0], nb_samples);
280 if (!out)
281 return AVERROR(ENOMEM);
282 for (i = 0; i < 2; i++) {
283 in[i] = ff_get_audio_buffer(ctx->inputs[i], nb_samples);
284 if (!in[i]) {
285 av_frame_free(&in[0]);
286 av_frame_free(&in[1]);
287 av_frame_free(&out);
288 return AVERROR(ENOMEM);
289 }
290 av_audio_fifo_read(s->fifo[i], (void **)in[i]->data, nb_samples);
291 }
292
293 dst = (double *)out->data[0];
294 out->pts = s->pts;
295 s->pts += av_rescale_q(nb_samples, (AVRational){1, ctx->outputs[0]->sample_rate}, ctx->outputs[0]->time_base);
296
297 gate(s, (double *)in[0]->data[0], dst,
298 (double *)in[1]->data[0], nb_samples,
299 s->level_in, s->level_sc,
300 ctx->inputs[0], ctx->inputs[1]);
301
302 av_frame_free(&in[0]);
303 av_frame_free(&in[1]);
304
305 ret = ff_filter_frame(ctx->outputs[0], out);
306 if (ret < 0)
307 return ret;
308 }
309 FF_FILTER_FORWARD_STATUS(ctx->inputs[0], ctx->outputs[0]);
310 FF_FILTER_FORWARD_STATUS(ctx->inputs[1], ctx->outputs[0]);
311 if (ff_outlink_frame_wanted(ctx->outputs[0])) {
312 if (!av_audio_fifo_size(s->fifo[0]))
313 ff_inlink_request_frame(ctx->inputs[0]);
314 if (!av_audio_fifo_size(s->fifo[1]))
315 ff_inlink_request_frame(ctx->inputs[1]);
316 }
317 return 0;
318 }
319
scquery_formats(AVFilterContext * ctx)320 static int scquery_formats(AVFilterContext *ctx)
321 {
322 static const enum AVSampleFormat sample_fmts[] = {
323 AV_SAMPLE_FMT_DBL,
324 AV_SAMPLE_FMT_NONE
325 };
326 int ret = ff_channel_layouts_ref(ff_all_channel_counts(),
327 &ctx->inputs[1]->outcfg.channel_layouts);
328 if (ret < 0)
329 return ret;
330
331 /* This will link the channel properties of the main input and the output;
332 * it won't touch the second input as its channel_layouts is already set. */
333 if ((ret = ff_set_common_all_channel_counts(ctx)) < 0)
334 return ret;
335
336 if ((ret = ff_set_common_formats_from_list(ctx, sample_fmts)) < 0)
337 return ret;
338
339 return ff_set_common_all_samplerates(ctx);
340 }
341
scconfig_output(AVFilterLink * outlink)342 static int scconfig_output(AVFilterLink *outlink)
343 {
344 AVFilterContext *ctx = outlink->src;
345 AudioGateContext *s = ctx->priv;
346
347 outlink->time_base = ctx->inputs[0]->time_base;
348
349 s->fifo[0] = av_audio_fifo_alloc(ctx->inputs[0]->format, ctx->inputs[0]->ch_layout.nb_channels, 1024);
350 s->fifo[1] = av_audio_fifo_alloc(ctx->inputs[1]->format, ctx->inputs[1]->ch_layout.nb_channels, 1024);
351 if (!s->fifo[0] || !s->fifo[1])
352 return AVERROR(ENOMEM);
353
354
355 agate_config_input(ctx->inputs[0]);
356
357 return 0;
358 }
359
uninit(AVFilterContext * ctx)360 static av_cold void uninit(AVFilterContext *ctx)
361 {
362 AudioGateContext *s = ctx->priv;
363
364 av_audio_fifo_free(s->fifo[0]);
365 av_audio_fifo_free(s->fifo[1]);
366 }
367
368 static const AVFilterPad sidechaingate_inputs[] = {
369 {
370 .name = "main",
371 .type = AVMEDIA_TYPE_AUDIO,
372 },{
373 .name = "sidechain",
374 .type = AVMEDIA_TYPE_AUDIO,
375 },
376 };
377
378 static const AVFilterPad sidechaingate_outputs[] = {
379 {
380 .name = "default",
381 .type = AVMEDIA_TYPE_AUDIO,
382 .config_props = scconfig_output,
383 },
384 };
385
386 const AVFilter ff_af_sidechaingate = {
387 .name = "sidechaingate",
388 .description = NULL_IF_CONFIG_SMALL("Audio sidechain gate."),
389 .priv_class = &agate_sidechaingate_class,
390 .priv_size = sizeof(AudioGateContext),
391 .activate = activate,
392 .uninit = uninit,
393 FILTER_INPUTS(sidechaingate_inputs),
394 FILTER_OUTPUTS(sidechaingate_outputs),
395 FILTER_QUERY_FUNC(scquery_formats),
396 .process_command = ff_filter_process_command,
397 .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL,
398 };
399 #endif /* CONFIG_SIDECHAINGATE_FILTER */
400