| /* |
| * 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, |
| }; |