mpv/audio/filter/af_sinesuppress.c

118 lines
3.0 KiB
C

/*
* Copyright (C) 2006 Michael Niedermayer
* Copyright (C) 2004 Alex Beregszaszi
* based upon af_extrastereo.c by Pierre Lombard
*
* This file is part of mpv.
*
* mpv is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* mpv 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with mpv. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <inttypes.h>
#include <math.h>
#include <limits.h>
#include "af.h"
// Data for specific instances of this filter
typedef struct af_sinesuppress_s
{
double freq;
double decay;
double real;
double imag;
double ref;
double pos;
}af_sinesuppress_t;
// Initialization and runtime control
static int control(struct af_instance* af, int cmd, void* arg)
{
switch(cmd){
case AF_CONTROL_REINIT:{
// Sanity check
if(!arg) return AF_ERROR;
mp_audio_copy_config(af->data, (struct mp_audio*)arg);
mp_audio_set_num_channels(af->data, 1);
mp_audio_set_format(af->data, AF_FORMAT_S16);
return af_test_output(af,(struct mp_audio*)arg);
}
}
return AF_UNKNOWN;
}
static int play_s16(struct af_instance *af, struct mp_audio *data)
{
if (!data)
return 0;
if (af_make_writeable(af, data) < 0) {
talloc_free(data);
return -1;
}
af_sinesuppress_t *s = af->priv;
register int i = 0;
int16_t *a = (int16_t*)data->planes[0]; // Audio data
int len = data->samples*data->nch; // Number of samples
for (i = 0; i < len; i++)
{
double co= cos(s->pos);
double si= sin(s->pos);
s->real += co * a[i];
s->imag += si * a[i];
s->ref += co * co;
a[i] -= (s->real * co + s->imag * si) / s->ref;
s->real -= s->real * s->decay;
s->imag -= s->imag * s->decay;
s->ref -= s->ref * s->decay;
s->pos += 2 * M_PI * s->freq / data->rate;
}
MP_VERBOSE(af, "f:%8.2f: amp:%8.2f\n", s->freq, sqrt(s->real*s->real + s->imag*s->imag) / s->ref);
af_add_output_frame(af, data);
return 0;
}
// Allocate memory and set function pointers
static int af_open(struct af_instance* af){
af->control=control;
af->filter_frame = play_s16;
return AF_OK;
}
#define OPT_BASE_STRUCT af_sinesuppress_t
const struct af_info af_info_sinesuppress = {
.info = "Sine Suppress",
.name = "sinesuppress",
.open = af_open,
.priv_size = sizeof(af_sinesuppress_t),
.options = (const struct m_option[]) {
OPT_DOUBLE("freq", freq, 0, OPTDEF_DOUBLE(50.0)),
OPT_DOUBLE("decay", decay, 0, OPTDEF_DOUBLE(0.0001)),
{0}
},
};