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FFmpeg/libavfilter/asrc_sine.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

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/*
* Copyright (c) 2013 Nicolas George
*
* 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 <float.h>
#include "libavutil/avassert.h"
#include "libavutil/channel_layout.h"
#include "libavutil/eval.h"
#include "libavutil/mem.h"
#include "libavutil/opt.h"
#include "audio.h"
#include "avfilter.h"
#include "filters.h"
#include "formats.h"
#include "internal.h"
typedef struct SineContext {
const AVClass *class;
double frequency;
double beep_factor;
char *samples_per_frame;
AVExpr *samples_per_frame_expr;
int sample_rate;
int64_t duration;
int16_t *sin;
int64_t pts;
uint32_t phi; ///< current phase of the sine (2pi = 1<<32)
uint32_t dphi; ///< phase increment between two samples
unsigned beep_period;
unsigned beep_index;
unsigned beep_length;
uint32_t phi_beep; ///< current phase of the beep
uint32_t dphi_beep; ///< phase increment of the beep
} SineContext;
#define CONTEXT SineContext
#define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
#define OPT_GENERIC(name, field, def, min, max, descr, type, deffield, ...) \
{ name, descr, offsetof(CONTEXT, field), AV_OPT_TYPE_ ## type, \
{ .deffield = def }, min, max, FLAGS, __VA_ARGS__ }
#define OPT_INT(name, field, def, min, max, descr, ...) \
OPT_GENERIC(name, field, def, min, max, descr, INT, i64, __VA_ARGS__)
#define OPT_DBL(name, field, def, min, max, descr, ...) \
OPT_GENERIC(name, field, def, min, max, descr, DOUBLE, dbl, __VA_ARGS__)
#define OPT_DUR(name, field, def, min, max, descr, ...) \
OPT_GENERIC(name, field, def, min, max, descr, DURATION, str, __VA_ARGS__)
#define OPT_STR(name, field, def, min, max, descr, ...) \
OPT_GENERIC(name, field, def, min, max, descr, STRING, str, __VA_ARGS__)
static const AVOption sine_options[] = {
OPT_DBL("frequency", frequency, 440, 0, DBL_MAX, "set the sine frequency",),
OPT_DBL("f", frequency, 440, 0, DBL_MAX, "set the sine frequency",),
OPT_DBL("beep_factor", beep_factor, 0, 0, DBL_MAX, "set the beep frequency factor",),
OPT_DBL("b", beep_factor, 0, 0, DBL_MAX, "set the beep frequency factor",),
OPT_INT("sample_rate", sample_rate, 44100, 1, INT_MAX, "set the sample rate",),
OPT_INT("r", sample_rate, 44100, 1, INT_MAX, "set the sample rate",),
OPT_DUR("duration", duration, 0, 0, INT64_MAX, "set the audio duration",),
OPT_DUR("d", duration, 0, 0, INT64_MAX, "set the audio duration",),
OPT_STR("samples_per_frame", samples_per_frame, "1024", 0, 0, "set the number of samples per frame",),
{NULL}
};
AVFILTER_DEFINE_CLASS(sine);
#define LOG_PERIOD 15
#define AMPLITUDE 4095
#define AMPLITUDE_SHIFT 3
static void make_sin_table(int16_t *sin)
{
unsigned half_pi = 1 << (LOG_PERIOD - 2);
unsigned ampls = AMPLITUDE << AMPLITUDE_SHIFT;
uint64_t unit2 = (uint64_t)(ampls * ampls) << 32;
unsigned step, i, c, s, k, new_k, n2;
/* Principle: if u = exp(i*a1) and v = exp(i*a2), then
exp(i*(a1+a2)/2) = (u+v) / length(u+v) */
sin[0] = 0;
sin[half_pi] = ampls;
for (step = half_pi; step > 1; step /= 2) {
/* k = (1 << 16) * amplitude / length(u+v)
In exact values, k is constant at a given step */
k = 0x10000;
for (i = 0; i < half_pi / 2; i += step) {
s = sin[i] + sin[i + step];
c = sin[half_pi - i] + sin[half_pi - i - step];
n2 = s * s + c * c;
/* Newton's method to solve n² * k² = unit² */
while (1) {
new_k = (k + unit2 / ((uint64_t)k * n2) + 1) >> 1;
if (k == new_k)
break;
k = new_k;
}
sin[i + step / 2] = (k * s + 0x7FFF) >> 16;
sin[half_pi - i - step / 2] = (k * c + 0x8000) >> 16;
}
}
/* Unshift amplitude */
for (i = 0; i <= half_pi; i++)
sin[i] = (sin[i] + (1 << (AMPLITUDE_SHIFT - 1))) >> AMPLITUDE_SHIFT;
/* Use symmetries to fill the other three quarters */
for (i = 0; i < half_pi; i++)
sin[half_pi * 2 - i] = sin[i];
for (i = 0; i < 2 * half_pi; i++)
sin[i + 2 * half_pi] = -sin[i];
}
static const char *const var_names[] = {
"n",
"pts",
"t",
"TB",
NULL
};
enum {
VAR_N,
VAR_PTS,
VAR_T,
VAR_TB,
VAR_VARS_NB
};
static av_cold int init(AVFilterContext *ctx)
{
int ret;
SineContext *sine = ctx->priv;
if (!(sine->sin = av_malloc(sizeof(*sine->sin) << LOG_PERIOD)))
return AVERROR(ENOMEM);
sine->dphi = ldexp(sine->frequency, 32) / sine->sample_rate + 0.5;
make_sin_table(sine->sin);
if (sine->beep_factor) {
sine->beep_period = sine->sample_rate;
sine->beep_length = sine->beep_period / 25;
sine->dphi_beep = ldexp(sine->beep_factor * sine->frequency, 32) /
sine->sample_rate + 0.5;
}
ret = av_expr_parse(&sine->samples_per_frame_expr,
sine->samples_per_frame, var_names,
NULL, NULL, NULL, NULL, 0, sine);
if (ret < 0)
return ret;
return 0;
}
static av_cold void uninit(AVFilterContext *ctx)
{
SineContext *sine = ctx->priv;
av_expr_free(sine->samples_per_frame_expr);
sine->samples_per_frame_expr = NULL;
av_freep(&sine->sin);
}
static av_cold int query_formats(AVFilterContext *ctx)
{
SineContext *sine = ctx->priv;
static const AVChannelLayout chlayouts[] = { AV_CHANNEL_LAYOUT_MONO, { 0 } };
int sample_rates[] = { sine->sample_rate, -1 };
static const enum AVSampleFormat sample_fmts[] = { AV_SAMPLE_FMT_S16,
AV_SAMPLE_FMT_NONE };
int ret = ff_set_common_formats_from_list(ctx, sample_fmts);
if (ret < 0)
return ret;
ret = ff_set_common_channel_layouts_from_list(ctx, chlayouts);
if (ret < 0)
return ret;
return ff_set_common_samplerates_from_list(ctx, sample_rates);
}
static av_cold int config_props(AVFilterLink *outlink)
{
SineContext *sine = outlink->src->priv;
sine->duration = av_rescale(sine->duration, sine->sample_rate, AV_TIME_BASE);
return 0;
}
static int activate(AVFilterContext *ctx)
{
AVFilterLink *outlink = ctx->outputs[0];
SineContext *sine = ctx->priv;
AVFrame *frame;
double values[VAR_VARS_NB] = {
[VAR_N] = outlink->frame_count_in,
[VAR_PTS] = sine->pts,
[VAR_T] = sine->pts * av_q2d(outlink->time_base),
[VAR_TB] = av_q2d(outlink->time_base),
};
int i, nb_samples = lrint(av_expr_eval(sine->samples_per_frame_expr, values, sine));
int16_t *samples;
if (!ff_outlink_frame_wanted(outlink))
return FFERROR_NOT_READY;
if (nb_samples <= 0) {
av_log(sine, AV_LOG_WARNING, "nb samples expression evaluated to %d, "
"defaulting to 1024\n", nb_samples);
nb_samples = 1024;
}
if (sine->duration) {
nb_samples = FFMIN(nb_samples, sine->duration - sine->pts);
av_assert1(nb_samples >= 0);
if (!nb_samples) {
ff_outlink_set_status(outlink, AVERROR_EOF, sine->pts);
return 0;
}
}
if (!(frame = ff_get_audio_buffer(outlink, nb_samples)))
return AVERROR(ENOMEM);
samples = (int16_t *)frame->data[0];
for (i = 0; i < nb_samples; i++) {
samples[i] = sine->sin[sine->phi >> (32 - LOG_PERIOD)];
sine->phi += sine->dphi;
if (sine->beep_index < sine->beep_length) {
samples[i] += sine->sin[sine->phi_beep >> (32 - LOG_PERIOD)] * 2;
sine->phi_beep += sine->dphi_beep;
}
if (++sine->beep_index == sine->beep_period)
sine->beep_index = 0;
}
frame->pts = sine->pts;
sine->pts += nb_samples;
return ff_filter_frame(outlink, frame);
}
static const AVFilterPad sine_outputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_AUDIO,
.config_props = config_props,
},
};
const AVFilter ff_asrc_sine = {
.name = "sine",
.description = NULL_IF_CONFIG_SMALL("Generate sine wave audio signal."),
.init = init,
.uninit = uninit,
.activate = activate,
.priv_size = sizeof(SineContext),
.inputs = NULL,
FILTER_OUTPUTS(sine_outputs),
FILTER_QUERY_FUNC(query_formats),
.priv_class = &sine_class,
};
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