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author | Paul B Mahol <onemda@gmail.com> | 2015-09-17 09:38:23 +0000 |
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committer | Paul B Mahol <onemda@gmail.com> | 2015-09-22 22:07:36 +0200 |
commit | ed4257de2d74ce5e5ae77ae96d58c58f1bbaeacd (patch) | |
tree | 0f2f957ccf4856bcbc1d1a6c1553f28a6f1dad1f /libavfilter/af_agate.c | |
parent | 31623e9d1ea960035cee59839e016397a559dab3 (diff) | |
download | ffmpeg-ed4257de2d74ce5e5ae77ae96d58c58f1bbaeacd.tar.gz |
avfilter: add agate filter
Signed-off-by: Paul B Mahol <onemda@gmail.com>
Diffstat (limited to 'libavfilter/af_agate.c')
-rw-r--r-- | libavfilter/af_agate.c | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/libavfilter/af_agate.c b/libavfilter/af_agate.c new file mode 100644 index 0000000000..46ee226235 --- /dev/null +++ b/libavfilter/af_agate.c @@ -0,0 +1,237 @@ +/* + * Copyright (C) 2001-2010 Krzysztof Foltman, Markus Schmidt, Thor Harald Johansen, Damien Zammit + * + * 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 + */ + +#include "libavutil/channel_layout.h" +#include "libavutil/opt.h" +#include "avfilter.h" +#include "audio.h" +#include "formats.h" +#include "hermite.h" + +typedef struct AudioGateContext { + const AVClass *class; + + double level_in; + double attack; + double release; + double threshold; + double ratio; + double knee; + double makeup; + double range; + int link; + int detection; + + double thres; + double knee_start; + double lin_knee_stop; + double knee_stop; + double lin_slope; + double attack_coeff; + double release_coeff; +} AudioGateContext; + +#define OFFSET(x) offsetof(AudioGateContext, x) +#define A AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM + +static const AVOption agate_options[] = { + { "level_in", "set input level", OFFSET(level_in), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0.015625, 64, A }, + { "range", "set max gain reduction", OFFSET(range), AV_OPT_TYPE_DOUBLE, {.dbl=0.06125}, 0, 1, A }, + { "threshold", "set threshold", OFFSET(threshold), AV_OPT_TYPE_DOUBLE, {.dbl=0.125}, 0, 1, A }, + { "ratio", "set ratio", OFFSET(ratio), AV_OPT_TYPE_DOUBLE, {.dbl=2}, 1, 9000, A }, + { "attack", "set attack", OFFSET(attack), AV_OPT_TYPE_DOUBLE, {.dbl=20}, 0.01, 9000, A }, + { "release", "set release", OFFSET(release), AV_OPT_TYPE_DOUBLE, {.dbl=250}, 0.01, 9000, A }, + { "makeup", "set makeup gain", OFFSET(makeup), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 1, 64, A }, + { "knee", "set knee", OFFSET(knee), AV_OPT_TYPE_DOUBLE, {.dbl=2.828427125}, 1, 8, A }, + { "detection", "set detection", OFFSET(detection), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, A, "detection" }, + { "peak", 0, 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, A, "detection" }, + { "rms", 0, 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, A, "detection" }, + { "link", "set link", OFFSET(link), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, A, "link" }, + { "average", 0, 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, A, "link" }, + { "maximum", 0, 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, A, "link" }, + { NULL } +}; + +AVFILTER_DEFINE_CLASS(agate); + +static int query_formats(AVFilterContext *ctx) +{ + AVFilterFormats *formats = NULL; + AVFilterChannelLayouts *layouts; + int ret; + + ff_add_format(&formats, AV_SAMPLE_FMT_DBL); + ret = ff_set_common_formats(ctx, formats); + if (ret < 0) + return ret; + + layouts = ff_all_channel_counts(); + if (!layouts) + return AVERROR(ENOMEM); + ret = ff_set_common_channel_layouts(ctx, layouts); + if (ret < 0) + return ret; + + formats = ff_all_samplerates(); + if (!formats) + return AVERROR(ENOMEM); + + return ff_set_common_samplerates(ctx, formats); +} + +static int config_input(AVFilterLink *inlink) +{ + AVFilterContext *ctx = inlink->dst; + AudioGateContext *s = ctx->priv; + double lin_threshold = s->threshold; + double lin_knee_sqrt = sqrt(s->knee); + double lin_knee_start; + + if (s->detection) + lin_threshold *= lin_threshold; + + s->attack_coeff = FFMIN(1., 1. / (s->attack * inlink->sample_rate / 4000.)); + s->release_coeff = FFMIN(1., 1. / (s->release * inlink->sample_rate / 4000.)); + s->lin_knee_stop = lin_threshold * lin_knee_sqrt; + lin_knee_start = lin_threshold / lin_knee_sqrt; + s->thres = log(lin_threshold); + s->knee_start = log(lin_knee_start); + s->knee_stop = log(s->lin_knee_stop); + + return 0; +} + +// 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 lin_knee_stop, double range) +{ + if (lin_slope < lin_knee_stop) { + double slope = log(lin_slope); + double tratio = ratio; + double gain = 0.; + double delta = 0.; + + if (IS_FAKE_INFINITY(ratio)) + tratio = 1000.; + gain = (slope - thres) * tratio + thres; + delta = tratio; + + if (knee > 1. && slope > knee_start) { + gain = hermite_interpolation(slope, knee_start, knee_stop, ((knee_start - thres) * tratio + thres), knee_stop, delta, 1.); + } + return FFMAX(range, exp(gain - slope)); + } + + return 1.; +} + +static int filter_frame(AVFilterLink *inlink, AVFrame *in) +{ + AVFilterContext *ctx = inlink->dst; + AVFilterLink *outlink = ctx->outputs[0]; + AudioGateContext *s = ctx->priv; + const double *src = (const double *)in->data[0]; + const double makeup = s->makeup; + const double attack_coeff = s->attack_coeff; + const double release_coeff = s->release_coeff; + const double level_in = s->level_in; + AVFrame *out = NULL; + double *dst; + int n, c; + + if (av_frame_is_writable(in)) { + out = in; + } else { + AVFrame *out = ff_get_audio_buffer(inlink, in->nb_samples); + if (!out) { + av_frame_free(&in); + return AVERROR(ENOMEM); + } + av_frame_copy_props(out, in); + } + dst = (double *)out->data[0]; + + for (n = 0; n < in->nb_samples; n++, src += inlink->channels, dst += inlink->channels) { + double abs_sample = FFABS(src[0]), gain = 1.0; + + for (c = 0; c < inlink->channels; c++) + dst[c] = src[c] * level_in; + + if (s->link == 1) { + for (c = 1; c < inlink->channels; c++) + abs_sample = FFMAX(FFABS(src[c]), abs_sample); + } else { + for (c = 1; c < inlink->channels; c++) + abs_sample += FFABS(src[c]); + + abs_sample /= inlink->channels; + } + + if (s->detection) + abs_sample *= abs_sample; + + s->lin_slope += (abs_sample - s->lin_slope) * (abs_sample > s->lin_slope ? attack_coeff : release_coeff); + if (s->lin_slope > 0.0) + gain = output_gain(s->lin_slope, s->ratio, s->thres, + s->knee, s->knee_start, s->knee_stop, + s->lin_knee_stop, s->range); + + for (c = 0; c < inlink->channels; c++) + dst[c] *= gain * makeup; + } + + if (out != in) + av_frame_free(&in); + return ff_filter_frame(outlink, out); +} + +static const AVFilterPad inputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_AUDIO, + .filter_frame = filter_frame, + .config_props = config_input, + }, + { NULL } +}; + +static const AVFilterPad outputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_AUDIO, + }, + { NULL } +}; + +AVFilter ff_af_agate = { + .name = "agate", + .description = NULL_IF_CONFIG_SMALL("Audio gate."), + .query_formats = query_formats, + .priv_size = sizeof(AudioGateContext), + .priv_class = &agate_class, + .inputs = inputs, + .outputs = outputs, +}; 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