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FFmpeg/libavfilter/af_tremolo.c
Andreas Rheinhardt 790f793844 avutil/common: Don't auto-include mem.h
There are lots of files that don't need it: The number of object
files that actually need it went down from 2011 to 884 here.

Keep it for external users in order to not cause breakages.

Also improve the other headers a bit while just at it.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2024-03-31 00:08:43 +01:00

136 lines
3.9 KiB
C

/*
* Copyright (c) 2015 Kyle Swanson <k@ylo.ph>.
*
* 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/mem.h"
#include "libavutil/opt.h"
#include "avfilter.h"
#include "internal.h"
#include "audio.h"
typedef struct TremoloContext {
const AVClass *class;
double freq;
double depth;
double *table;
int table_size;
int index;
} TremoloContext;
#define OFFSET(x) offsetof(TremoloContext, x)
#define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
static const AVOption tremolo_options[] = {
{ "f", "set frequency in hertz", OFFSET(freq), AV_OPT_TYPE_DOUBLE, {.dbl = 5.0}, 0.1, 20000.0, FLAGS },
{ "d", "set depth as percentage", OFFSET(depth), AV_OPT_TYPE_DOUBLE, {.dbl = 0.5}, 0.0, 1.0, FLAGS },
{ NULL }
};
AVFILTER_DEFINE_CLASS(tremolo);
static int filter_frame(AVFilterLink *inlink, AVFrame *in)
{
AVFilterContext *ctx = inlink->dst;
AVFilterLink *outlink = ctx->outputs[0];
TremoloContext *s = ctx->priv;
const double *src = (const double *)in->data[0];
const int channels = inlink->ch_layout.nb_channels;
const int nb_samples = in->nb_samples;
AVFrame *out;
double *dst;
int n, c;
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);
}
dst = (double *)out->data[0];
for (n = 0; n < nb_samples; n++) {
for (c = 0; c < channels; c++)
dst[c] = src[c] * s->table[s->index];
dst += channels;
src += channels;
s->index++;
if (s->index >= s->table_size)
s->index = 0;
}
if (in != out)
av_frame_free(&in);
return ff_filter_frame(outlink, out);
}
static av_cold void uninit(AVFilterContext *ctx)
{
TremoloContext *s = ctx->priv;
av_freep(&s->table);
}
static int config_input(AVFilterLink *inlink)
{
AVFilterContext *ctx = inlink->dst;
TremoloContext *s = ctx->priv;
const double offset = 1. - s->depth / 2.;
int i;
s->table_size = lrint(inlink->sample_rate / s->freq + 0.5);
s->table = av_malloc_array(s->table_size, sizeof(*s->table));
if (!s->table)
return AVERROR(ENOMEM);
for (i = 0; i < s->table_size; i++) {
double env = s->freq * i / inlink->sample_rate;
env = sin(2 * M_PI * fmod(env + 0.25, 1.0));
s->table[i] = env * (1 - fabs(offset)) + offset;
}
s->index = 0;
return 0;
}
static const AVFilterPad avfilter_af_tremolo_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_AUDIO,
.config_props = config_input,
.filter_frame = filter_frame,
},
};
const AVFilter ff_af_tremolo = {
.name = "tremolo",
.description = NULL_IF_CONFIG_SMALL("Apply tremolo effect."),
.priv_size = sizeof(TremoloContext),
.priv_class = &tremolo_class,
.uninit = uninit,
FILTER_INPUTS(avfilter_af_tremolo_inputs),
FILTER_OUTPUTS(ff_audio_default_filterpad),
FILTER_SINGLE_SAMPLEFMT(AV_SAMPLE_FMT_DBL),
.flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
};