FFmpeg/libavfilter/af_asubboost.c
Paul B Mahol 94ea760c6f avfilter/af_asubboost: make wet option apply to final output
Also changes some default values for options after this change.
This makes distinction between feedback and wet option.
Before they would produce same output if values were swapped.
2020-11-28 22:07:18 +01:00

260 lines
7.6 KiB
C

/*
* 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/ffmath.h"
#include "libavutil/opt.h"
#include "avfilter.h"
#include "audio.h"
#include "formats.h"
typedef struct ASubBoostContext {
const AVClass *class;
double dry_gain;
double wet_gain;
double feedback;
double decay;
double delay;
double cutoff;
double slope;
double a0, a1, a2;
double b0, b1, b2;
int *write_pos;
int buffer_samples;
AVFrame *w;
AVFrame *buffer;
} ASubBoostContext;
static int query_formats(AVFilterContext *ctx)
{
AVFilterFormats *formats = NULL;
AVFilterChannelLayouts *layouts = NULL;
static const enum AVSampleFormat sample_fmts[] = {
AV_SAMPLE_FMT_DBLP,
AV_SAMPLE_FMT_NONE
};
int ret;
formats = ff_make_format_list(sample_fmts);
if (!formats)
return AVERROR(ENOMEM);
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();
return ff_set_common_samplerates(ctx, formats);
}
static int get_coeffs(AVFilterContext *ctx)
{
ASubBoostContext *s = ctx->priv;
AVFilterLink *inlink = ctx->inputs[0];
double w0 = 2 * M_PI * s->cutoff / inlink->sample_rate;
double alpha = sin(w0) / 2 * sqrt(2. * (1. / s->slope - 1.) + 2.);
s->a0 = 1 + alpha;
s->a1 = -2 * cos(w0);
s->a2 = 1 - alpha;
s->b0 = (1 - cos(w0)) / 2;
s->b1 = 1 - cos(w0);
s->b2 = (1 - cos(w0)) / 2;
s->a1 /= s->a0;
s->a2 /= s->a0;
s->b0 /= s->a0;
s->b1 /= s->a0;
s->b2 /= s->a0;
s->buffer_samples = inlink->sample_rate * s->delay / 1000;
return 0;
}
static int config_input(AVFilterLink *inlink)
{
AVFilterContext *ctx = inlink->dst;
ASubBoostContext *s = ctx->priv;
s->buffer = ff_get_audio_buffer(inlink, inlink->sample_rate / 10);
s->w = ff_get_audio_buffer(inlink, 2);
s->write_pos = av_calloc(inlink->channels, sizeof(*s->write_pos));
if (!s->buffer || !s->w || !s->write_pos)
return AVERROR(ENOMEM);
return get_coeffs(ctx);
}
typedef struct ThreadData {
AVFrame *in, *out;
} ThreadData;
static int filter_channels(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
{
ASubBoostContext *s = ctx->priv;
ThreadData *td = arg;
AVFrame *out = td->out;
AVFrame *in = td->in;
const double mix = ctx->is_disabled ? 0. : 1.;
const double wet = ctx->is_disabled ? 1. : s->wet_gain;
const double dry = ctx->is_disabled ? 1. : s->dry_gain;
const double feedback = s->feedback, decay = s->decay;
const double b0 = s->b0;
const double b1 = s->b1;
const double b2 = s->b2;
const double a1 = -s->a1;
const double a2 = -s->a2;
const int start = (in->channels * jobnr) / nb_jobs;
const int end = (in->channels * (jobnr+1)) / nb_jobs;
const int buffer_samples = s->buffer_samples;
for (int ch = start; ch < end; ch++) {
const double *src = (const double *)in->extended_data[ch];
double *dst = (double *)out->extended_data[ch];
double *buffer = (double *)s->buffer->extended_data[ch];
double *w = (double *)s->w->extended_data[ch];
int write_pos = s->write_pos[ch];
for (int n = 0; n < in->nb_samples; n++) {
double out_sample;
out_sample = src[n] * b0 + w[0];
w[0] = b1 * src[n] + w[1] + a1 * out_sample;
w[1] = b2 * src[n] + a2 * out_sample;
buffer[write_pos] = buffer[write_pos] * decay + out_sample * feedback;
dst[n] = (src[n] * dry + buffer[write_pos] * mix) * wet;
if (++write_pos >= buffer_samples)
write_pos = 0;
}
s->write_pos[ch] = write_pos;
}
return 0;
}
static int filter_frame(AVFilterLink *inlink, AVFrame *in)
{
AVFilterContext *ctx = inlink->dst;
AVFilterLink *outlink = ctx->outputs[0];
ThreadData td;
AVFrame *out;
if (av_frame_is_writable(in)) {
out = in;
} else {
out = ff_get_audio_buffer(outlink, in->nb_samples);
if (!out) {
av_frame_free(&in);
return AVERROR(ENOMEM);
}
av_frame_copy_props(out, in);
}
td.in = in; td.out = out;
ctx->internal->execute(ctx, filter_channels, &td, NULL, FFMIN(inlink->channels,
ff_filter_get_nb_threads(ctx)));
if (out != in)
av_frame_free(&in);
return ff_filter_frame(outlink, out);
}
static av_cold void uninit(AVFilterContext *ctx)
{
ASubBoostContext *s = ctx->priv;
av_frame_free(&s->buffer);
av_frame_free(&s->w);
av_freep(&s->write_pos);
}
static int process_command(AVFilterContext *ctx, const char *cmd, const char *args,
char *res, int res_len, int flags)
{
int ret;
ret = ff_filter_process_command(ctx, cmd, args, res, res_len, flags);
if (ret < 0)
return ret;
return get_coeffs(ctx);
}
#define OFFSET(x) offsetof(ASubBoostContext, x)
#define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_RUNTIME_PARAM
static const AVOption asubboost_options[] = {
{ "dry", "set dry gain", OFFSET(dry_gain), AV_OPT_TYPE_DOUBLE, {.dbl=0.7}, 0, 1, FLAGS },
{ "wet", "set wet gain", OFFSET(wet_gain), AV_OPT_TYPE_DOUBLE, {.dbl=0.7}, 0, 1, FLAGS },
{ "decay", "set decay", OFFSET(decay), AV_OPT_TYPE_DOUBLE, {.dbl=0.7}, 0, 1, FLAGS },
{ "feedback", "set feedback", OFFSET(feedback), AV_OPT_TYPE_DOUBLE, {.dbl=0.9}, 0, 1, FLAGS },
{ "cutoff", "set cutoff", OFFSET(cutoff), AV_OPT_TYPE_DOUBLE, {.dbl=100}, 50, 900, FLAGS },
{ "slope", "set slope", OFFSET(slope), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0.0001, 1, FLAGS },
{ "delay", "set delay", OFFSET(delay), AV_OPT_TYPE_DOUBLE, {.dbl=20}, 1, 100, FLAGS },
{ NULL }
};
AVFILTER_DEFINE_CLASS(asubboost);
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_asubboost = {
.name = "asubboost",
.description = NULL_IF_CONFIG_SMALL("Boost subwoofer frequencies."),
.query_formats = query_formats,
.priv_size = sizeof(ASubBoostContext),
.priv_class = &asubboost_class,
.uninit = uninit,
.inputs = inputs,
.outputs = outputs,
.process_command = process_command,
.flags = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL |
AVFILTER_FLAG_SLICE_THREADS,
};