libavfilter/af_sidechaincompress.c - third_party/ffmpeg - Git at Google

 /*
  * Copyright (C) 2001-2010 Krzysztof Foltman, Markus Schmidt, Thor Harald Johansen and others
  * Copyright (c) 2015 Paul B Mahol
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */

 /**
  * @file
  * Sidechain compressor filter
  */

 #include "libavutil/avassert.h"
 #include "libavutil/channel_layout.h"
 #include "libavutil/common.h"
 #include "libavutil/opt.h"

 #include "audio.h"
 #include "avfilter.h"
 #include "formats.h"
 #include "internal.h"

 typedef struct SidechainCompressContext {
     const AVClass *class;

     double attack, attack_coeff;
     double release, release_coeff;
     double lin_slope;
     double ratio;
     double threshold;
     double makeup;
     double thres;
     double knee;
     double knee_start;
     double knee_stop;
     double lin_knee_start;
     double compressed_knee_stop;
     int link;
     int detection;

     AVFrame *input_frame[2];
 } SidechainCompressContext;

 #define OFFSET(x) offsetof(SidechainCompressContext, x)
 #define A AV_OPT_FLAG_AUDIO_PARAM
 #define F AV_OPT_FLAG_FILTERING_PARAM

 static const AVOption sidechaincompress_options[] = {
     { "threshold", "set threshold",    OFFSET(threshold), AV_OPT_TYPE_DOUBLE, {.dbl=0.125}, 0.000976563,    1, A|F },
     { "ratio",     "set ratio",        OFFSET(ratio),     AV_OPT_TYPE_DOUBLE, {.dbl=2},               1,   20, A|F },
     { "attack",    "set attack",       OFFSET(attack),    AV_OPT_TYPE_DOUBLE, {.dbl=20},           0.01, 2000, A|F },
     { "release",   "set release",      OFFSET(release),   AV_OPT_TYPE_DOUBLE, {.dbl=250},          0.01, 9000, A|F },
     { "makeup",    "set make up gain", OFFSET(makeup),    AV_OPT_TYPE_DOUBLE, {.dbl=2},               1,   64, A|F },
     { "knee",      "set knee",         OFFSET(knee),      AV_OPT_TYPE_DOUBLE, {.dbl=2.82843},         1,    8, A|F },
     { "link",      "set link type",    OFFSET(link),      AV_OPT_TYPE_INT,    {.i64=0},               0,    1, A|F, "link" },
     {   "average", 0,                  0,                 AV_OPT_TYPE_CONST,  {.i64=0},               0,    0, A|F, "link" },
     {   "maximum", 0,                  0,                 AV_OPT_TYPE_CONST,  {.i64=1},               0,    0, A|F, "link" },
     { "detection", "set detection",    OFFSET(detection), AV_OPT_TYPE_INT,    {.i64=1},               0,    1, A|F, "detection" },
     {   "peak",    0,                  0,                 AV_OPT_TYPE_CONST,  {.i64=0},               0,    0, A|F, "detection" },
     {   "rms",     0,                  0,                 AV_OPT_TYPE_CONST,  {.i64=1},               0,    0, A|F, "detection" },
     { NULL }
 };

 AVFILTER_DEFINE_CLASS(sidechaincompress);

 static av_cold int init(AVFilterContext *ctx)
 {
     SidechainCompressContext *s = ctx->priv;

     s->thres = log(s->threshold);
     s->lin_knee_start = s->threshold / sqrt(s->knee);
     s->knee_start = log(s->lin_knee_start);
     s->knee_stop = log(s->threshold * sqrt(s->knee));
     s->compressed_knee_stop = (s->knee_stop - s->thres) / s->ratio + s->thres;

     return 0;
 }

 static inline float hermite_interpolation(float x, float x0, float x1,
                                           float p0, float p1,
                                           float m0, float m1)
 {
     float width = x1 - x0;
     float t = (x - x0) / width;
     float t2, t3;
     float ct0, ct1, ct2, ct3;

     m0 *= width;
     m1 *= width;

     t2 = t*t;
     t3 = t2*t;
     ct0 = p0;
     ct1 = m0;

     ct2 = -3 * p0 - 2 * m0 + 3 * p1 - m1;
     ct3 = 2 * p0 + m0  - 2 * p1 + m1;

     return ct3 * t3 + ct2 * t2 + ct1 * t + ct0;
 }

 // A fake infinity value (because real infinity may break some hosts)
 #define FAKE_INFINITY (65536.0 * 65536.0)

 // Check for infinity (with appropriate-ish tolerance)
 #define IS_FAKE_INFINITY(value) (fabs(value-FAKE_INFINITY) < 1.0)

 static double output_gain(double lin_slope, double ratio, double thres,
                           double knee, double knee_start, double knee_stop,
                           double compressed_knee_stop, int detection)
 {
     double slope = log(lin_slope);
     double gain = 0.0;
     double delta = 0.0;

     if (detection)
         slope *= 0.5;

     if (IS_FAKE_INFINITY(ratio)) {
         gain = thres;
         delta = 0.0;
     } else {
         gain = (slope - thres) / ratio + thres;
         delta = 1.0 / ratio;
     }

     if (knee > 1.0 && slope < knee_stop)
         gain = hermite_interpolation(slope, knee_start, knee_stop,
                                      knee_start, compressed_knee_stop,
                                      1.0, delta);

     return exp(gain - slope);
 }

 static int filter_frame(AVFilterLink *link, AVFrame *frame)
 {
     AVFilterContext *ctx = link->dst;
     SidechainCompressContext *s = ctx->priv;
     AVFilterLink *sclink = ctx->inputs[1];
     AVFilterLink *outlink = ctx->outputs[0];
     const double makeup = s->makeup;
     const double *scsrc;
     double *sample;
     int nb_samples;
     int ret, i, c;

     for (i = 0; i < 2; i++)
         if (link == ctx->inputs[i])
             break;
     av_assert0(i < 2 && !s->input_frame[i]);
     s->input_frame[i] = frame;

     if (!s->input_frame[0] || !s->input_frame[1])
         return 0;

     nb_samples = FFMIN(s->input_frame[0]->nb_samples,
                        s->input_frame[1]->nb_samples);

     sample = (double *)s->input_frame[0]->data[0];
     scsrc = (const double *)s->input_frame[1]->data[0];

     for (i = 0; i < nb_samples; i++) {
         double abs_sample, gain = 1.0;

         abs_sample = FFABS(scsrc[0]);

         if (s->link == 1) {
             for (c = 1; c < sclink->channels; c++)
                 abs_sample = FFMAX(FFABS(scsrc[c]), abs_sample);
         } else {
             for (c = 1; c < sclink->channels; c++)
                 abs_sample += FFABS(scsrc[c]);

             abs_sample /= sclink->channels;
         }

         if (s->detection)
             abs_sample *= abs_sample;

         s->lin_slope += (abs_sample - s->lin_slope) * (abs_sample > s->lin_slope ? s->attack_coeff : s->release_coeff);

         if (s->lin_slope > 0.0 && s->lin_slope > s->lin_knee_start)
             gain = output_gain(s->lin_slope, s->ratio, s->thres, s->knee,
                                s->knee_start, s->knee_stop,
                                s->compressed_knee_stop, s->detection);

         for (c = 0; c < outlink->channels; c++)
             sample[c] *= gain * makeup;

         sample += outlink->channels;
         scsrc += sclink->channels;
     }

     ret = ff_filter_frame(outlink, s->input_frame[0]);

     s->input_frame[0] = NULL;
     av_frame_free(&s->input_frame[1]);

     return ret;
 }

 static int request_frame(AVFilterLink *outlink)
 {
     AVFilterContext *ctx = outlink->src;
     SidechainCompressContext *s = ctx->priv;
     int i, ret;

     /* get a frame on each input */
     for (i = 0; i < 2; i++) {
         AVFilterLink *inlink = ctx->inputs[i];
         if (!s->input_frame[i] &&
             (ret = ff_request_frame(inlink)) < 0)
             return ret;

         /* request the same number of samples on all inputs */
         if (i == 0)
             ctx->inputs[1]->request_samples = s->input_frame[0]->nb_samples;
     }

     return 0;
 }

 static int query_formats(AVFilterContext *ctx)
 {
     AVFilterFormats *formats;
     AVFilterChannelLayouts *layouts = NULL;
     static const enum AVSampleFormat sample_fmts[] = {
         AV_SAMPLE_FMT_DBL,
         AV_SAMPLE_FMT_NONE
     };
     int ret, i;

     if (!ctx->inputs[0]->in_channel_layouts ||
         !ctx->inputs[0]->in_channel_layouts->nb_channel_layouts) {
         av_log(ctx, AV_LOG_WARNING,
                "No channel layout for input 1\n");
             return AVERROR(EAGAIN);
     }

     ff_add_channel_layout(&layouts, ctx->inputs[0]->in_channel_layouts->channel_layouts[0]);
     if (!layouts)
         return AVERROR(ENOMEM);
     ff_channel_layouts_ref(layouts, &ctx->outputs[0]->in_channel_layouts);

     for (i = 0; i < 2; i++) {
         layouts = ff_all_channel_layouts();
         if (!layouts)
             return AVERROR(ENOMEM);
         ff_channel_layouts_ref(layouts, &ctx->inputs[i]->out_channel_layouts);
     }

     formats = ff_make_format_list(sample_fmts);
     if (!formats)
         return AVERROR(ENOMEM);
     ret = ff_set_common_formats(ctx, formats);
     if (ret < 0)
         return ret;

     formats = ff_all_samplerates();
     if (!formats)
         return AVERROR(ENOMEM);
     return ff_set_common_samplerates(ctx, formats);
 }

 static int config_output(AVFilterLink *outlink)
 {
     AVFilterContext *ctx = outlink->src;
     SidechainCompressContext *s = ctx->priv;

     if (ctx->inputs[0]->sample_rate != ctx->inputs[1]->sample_rate) {
         av_log(ctx, AV_LOG_ERROR,
                "Inputs must have the same sample rate "
                "%d for in0 vs %d for in1\n",
                ctx->inputs[0]->sample_rate, ctx->inputs[1]->sample_rate);
         return AVERROR(EINVAL);
     }

     outlink->sample_rate = ctx->inputs[0]->sample_rate;
     outlink->time_base   = ctx->inputs[0]->time_base;
     outlink->channel_layout = ctx->inputs[0]->channel_layout;
     outlink->channels = ctx->inputs[0]->channels;

     s->attack_coeff = FFMIN(1.f, 1.f / (s->attack * outlink->sample_rate / 4000.f));
     s->release_coeff = FFMIN(1.f, 1.f / (s->release * outlink->sample_rate / 4000.f));

     return 0;
 }

 static const AVFilterPad sidechaincompress_inputs[] = {
     {
         .name           = "main",
         .type           = AVMEDIA_TYPE_AUDIO,
         .filter_frame   = filter_frame,
         .needs_writable = 1,
         .needs_fifo     = 1,
     },{
         .name           = "sidechain",
         .type           = AVMEDIA_TYPE_AUDIO,
         .filter_frame   = filter_frame,
         .needs_fifo     = 1,
     },
     { NULL }
 };

 static const AVFilterPad sidechaincompress_outputs[] = {
     {
         .name          = "default",
         .type          = AVMEDIA_TYPE_AUDIO,
         .config_props  = config_output,
         .request_frame = request_frame,
     },
     { NULL }
 };

 AVFilter ff_af_sidechaincompress = {
     .name           = "sidechaincompress",
     .description    = NULL_IF_CONFIG_SMALL("Sidechain compressor."),
     .priv_size      = sizeof(SidechainCompressContext),
     .priv_class     = &sidechaincompress_class,
     .init           = init,
     .query_formats  = query_formats,
     .inputs         = sidechaincompress_inputs,
     .outputs        = sidechaincompress_outputs,
 };
	/*
	* Copyright (C) 2001-2010 Krzysztof Foltman, Markus Schmidt, Thor Harald Johansen and others
	* Copyright (c) 2015 Paul B Mahol
	*
	* This file is part of FFmpeg.
	*
	* FFmpeg is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Lesser General Public
	* License as published by the Free Software Foundation; either
	* version 2.1 of the License, or (at your option) any later version.
	*
	* FFmpeg is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* Lesser General Public License for more details.
	*
	* You should have received a copy of the GNU Lesser General Public
	* License along with FFmpeg; if not, write to the Free Software
	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	*/

	/**
	* @file
	* Sidechain compressor filter
	*/

	#include "libavutil/avassert.h"
	#include "libavutil/channel_layout.h"
	#include "libavutil/common.h"
	#include "libavutil/opt.h"

	#include "audio.h"
	#include "avfilter.h"
	#include "formats.h"
	#include "internal.h"

	typedef struct SidechainCompressContext {
	const AVClass *class;

	double attack, attack_coeff;
	double release, release_coeff;
	double lin_slope;
	double ratio;
	double threshold;
	double makeup;
	double thres;
	double knee;
	double knee_start;
	double knee_stop;
	double lin_knee_start;
	double compressed_knee_stop;
	int link;
	int detection;

	AVFrame *input_frame[2];
	} SidechainCompressContext;

	#define OFFSET(x) offsetof(SidechainCompressContext, x)
	#define A AV_OPT_FLAG_AUDIO_PARAM
	#define F AV_OPT_FLAG_FILTERING_PARAM

	static const AVOption sidechaincompress_options[] = {
	{ "threshold", "set threshold", OFFSET(threshold), AV_OPT_TYPE_DOUBLE, {.dbl=0.125}, 0.000976563, 1, A\|F },
	{ "ratio", "set ratio", OFFSET(ratio), AV_OPT_TYPE_DOUBLE, {.dbl=2}, 1, 20, A\|F },
	{ "attack", "set attack", OFFSET(attack), AV_OPT_TYPE_DOUBLE, {.dbl=20}, 0.01, 2000, A\|F },
	{ "release", "set release", OFFSET(release), AV_OPT_TYPE_DOUBLE, {.dbl=250}, 0.01, 9000, A\|F },
	{ "makeup", "set make up gain", OFFSET(makeup), AV_OPT_TYPE_DOUBLE, {.dbl=2}, 1, 64, A\|F },
	{ "knee", "set knee", OFFSET(knee), AV_OPT_TYPE_DOUBLE, {.dbl=2.82843}, 1, 8, A\|F },
	{ "link", "set link type", OFFSET(link), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, A\|F, "link" },
	{ "average", 0, 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, A\|F, "link" },
	{ "maximum", 0, 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, A\|F, "link" },
	{ "detection", "set detection", OFFSET(detection), AV_OPT_TYPE_INT, {.i64=1}, 0, 1, A\|F, "detection" },
	{ "peak", 0, 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, A\|F, "detection" },
	{ "rms", 0, 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, A\|F, "detection" },
	{ NULL }
	};

	AVFILTER_DEFINE_CLASS(sidechaincompress);

	static av_cold int init(AVFilterContext *ctx)
	{
	SidechainCompressContext *s = ctx->priv;

	s->thres = log(s->threshold);
	s->lin_knee_start = s->threshold / sqrt(s->knee);
	s->knee_start = log(s->lin_knee_start);
	s->knee_stop = log(s->threshold * sqrt(s->knee));
	s->compressed_knee_stop = (s->knee_stop - s->thres) / s->ratio + s->thres;

	return 0;
	}

	static inline float hermite_interpolation(float x, float x0, float x1,
	float p0, float p1,
	float m0, float m1)
	{
	float width = x1 - x0;
	float t = (x - x0) / width;
	float t2, t3;
	float ct0, ct1, ct2, ct3;

	m0 *= width;
	m1 *= width;

	t2 = t*t;
	t3 = t2*t;
	ct0 = p0;
	ct1 = m0;

	ct2 = -3 * p0 - 2 * m0 + 3 * p1 - m1;
	ct3 = 2 * p0 + m0 - 2 * p1 + m1;

	return ct3 * t3 + ct2 * t2 + ct1 * t + ct0;
	}

	// A fake infinity value (because real infinity may break some hosts)
	#define FAKE_INFINITY (65536.0 * 65536.0)

	// Check for infinity (with appropriate-ish tolerance)
	#define IS_FAKE_INFINITY(value) (fabs(value-FAKE_INFINITY) < 1.0)

	static double output_gain(double lin_slope, double ratio, double thres,
	double knee, double knee_start, double knee_stop,
	double compressed_knee_stop, int detection)
	{
	double slope = log(lin_slope);
	double gain = 0.0;
	double delta = 0.0;

	if (detection)
	slope *= 0.5;

	if (IS_FAKE_INFINITY(ratio)) {
	gain = thres;
	delta = 0.0;
	} else {
	gain = (slope - thres) / ratio + thres;
	delta = 1.0 / ratio;
	}

	if (knee > 1.0 && slope < knee_stop)
	gain = hermite_interpolation(slope, knee_start, knee_stop,
	knee_start, compressed_knee_stop,
	1.0, delta);

	return exp(gain - slope);
	}

	static int filter_frame(AVFilterLink link, AVFrame frame)
	{
	AVFilterContext *ctx = link->dst;
	SidechainCompressContext *s = ctx->priv;
	AVFilterLink *sclink = ctx->inputs[1];
	AVFilterLink *outlink = ctx->outputs[0];
	const double makeup = s->makeup;
	const double *scsrc;
	double *sample;
	int nb_samples;
	int ret, i, c;

	for (i = 0; i < 2; i++)
	if (link == ctx->inputs[i])
	break;
	av_assert0(i < 2 && !s->input_frame[i]);
	s->input_frame[i] = frame;

	if (!s->input_frame[0] \|\| !s->input_frame[1])
	return 0;

	nb_samples = FFMIN(s->input_frame[0]->nb_samples,
	s->input_frame[1]->nb_samples);

	sample = (double *)s->input_frame[0]->data[0];
	scsrc = (const double *)s->input_frame[1]->data[0];

	for (i = 0; i < nb_samples; i++) {
	double abs_sample, gain = 1.0;

	abs_sample = FFABS(scsrc[0]);

	if (s->link == 1) {
	for (c = 1; c < sclink->channels; c++)
	abs_sample = FFMAX(FFABS(scsrc[c]), abs_sample);
	} else {
	for (c = 1; c < sclink->channels; c++)
	abs_sample += FFABS(scsrc[c]);

	abs_sample /= sclink->channels;
	}

	if (s->detection)
	abs_sample *= abs_sample;

	s->lin_slope += (abs_sample - s->lin_slope) * (abs_sample > s->lin_slope ? s->attack_coeff : s->release_coeff);

	if (s->lin_slope > 0.0 && s->lin_slope > s->lin_knee_start)
	gain = output_gain(s->lin_slope, s->ratio, s->thres, s->knee,
	s->knee_start, s->knee_stop,
	s->compressed_knee_stop, s->detection);

	for (c = 0; c < outlink->channels; c++)
	sample[c] = gain makeup;

	sample += outlink->channels;
	scsrc += sclink->channels;
	}

	ret = ff_filter_frame(outlink, s->input_frame[0]);

	s->input_frame[0] = NULL;
	av_frame_free(&s->input_frame[1]);

	return ret;
	}

	static int request_frame(AVFilterLink *outlink)
	{
	AVFilterContext *ctx = outlink->src;
	SidechainCompressContext *s = ctx->priv;
	int i, ret;

	/* get a frame on each input */
	for (i = 0; i < 2; i++) {
	AVFilterLink *inlink = ctx->inputs[i];
	if (!s->input_frame[i] &&
	(ret = ff_request_frame(inlink)) < 0)
	return ret;

	/* request the same number of samples on all inputs */
	if (i == 0)
	ctx->inputs[1]->request_samples = s->input_frame[0]->nb_samples;
	}

	return 0;
	}

	static int query_formats(AVFilterContext *ctx)
	{
	AVFilterFormats *formats;
	AVFilterChannelLayouts *layouts = NULL;
	static const enum AVSampleFormat sample_fmts[] = {
	AV_SAMPLE_FMT_DBL,
	AV_SAMPLE_FMT_NONE
	};
	int ret, i;

	if (!ctx->inputs[0]->in_channel_layouts \|\|
	!ctx->inputs[0]->in_channel_layouts->nb_channel_layouts) {
	av_log(ctx, AV_LOG_WARNING,
	"No channel layout for input 1\n");
	return AVERROR(EAGAIN);
	}

	ff_add_channel_layout(&layouts, ctx->inputs[0]->in_channel_layouts->channel_layouts[0]);
	if (!layouts)
	return AVERROR(ENOMEM);
	ff_channel_layouts_ref(layouts, &ctx->outputs[0]->in_channel_layouts);

	for (i = 0; i < 2; i++) {
	layouts = ff_all_channel_layouts();
	if (!layouts)
	return AVERROR(ENOMEM);
	ff_channel_layouts_ref(layouts, &ctx->inputs[i]->out_channel_layouts);
	}

	formats = ff_make_format_list(sample_fmts);
	if (!formats)
	return AVERROR(ENOMEM);
	ret = ff_set_common_formats(ctx, formats);
	if (ret < 0)
	return ret;

	formats = ff_all_samplerates();
	if (!formats)
	return AVERROR(ENOMEM);
	return ff_set_common_samplerates(ctx, formats);
	}

	static int config_output(AVFilterLink *outlink)
	{
	AVFilterContext *ctx = outlink->src;
	SidechainCompressContext *s = ctx->priv;

	if (ctx->inputs[0]->sample_rate != ctx->inputs[1]->sample_rate) {
	av_log(ctx, AV_LOG_ERROR,
	"Inputs must have the same sample rate "
	"%d for in0 vs %d for in1\n",
	ctx->inputs[0]->sample_rate, ctx->inputs[1]->sample_rate);
	return AVERROR(EINVAL);
	}

	outlink->sample_rate = ctx->inputs[0]->sample_rate;
	outlink->time_base = ctx->inputs[0]->time_base;
	outlink->channel_layout = ctx->inputs[0]->channel_layout;
	outlink->channels = ctx->inputs[0]->channels;

	s->attack_coeff = FFMIN(1.f, 1.f / (s->attack * outlink->sample_rate / 4000.f));
	s->release_coeff = FFMIN(1.f, 1.f / (s->release * outlink->sample_rate / 4000.f));

	return 0;
	}

	static const AVFilterPad sidechaincompress_inputs[] = {
	{
	.name = "main",
	.type = AVMEDIA_TYPE_AUDIO,
	.filter_frame = filter_frame,
	.needs_writable = 1,
	.needs_fifo = 1,
	},{
	.name = "sidechain",
	.type = AVMEDIA_TYPE_AUDIO,
	.filter_frame = filter_frame,
	.needs_fifo = 1,
	},
	{ NULL }
	};

	static const AVFilterPad sidechaincompress_outputs[] = {
	{
	.name = "default",
	.type = AVMEDIA_TYPE_AUDIO,
	.config_props = config_output,
	.request_frame = request_frame,
	},
	{ NULL }
	};

	AVFilter ff_af_sidechaincompress = {
	.name = "sidechaincompress",
	.description = NULL_IF_CONFIG_SMALL("Sidechain compressor."),
	.priv_size = sizeof(SidechainCompressContext),
	.priv_class = &sidechaincompress_class,
	.init = init,
	.query_formats = query_formats,
	.inputs = sidechaincompress_inputs,
	.outputs = sidechaincompress_outputs,
	};