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/*
* simple voice removal filter
*
* copyright (c) 2006 Reynaldo H. Verdejo Pinochet
* Based on code by Alex Beregszaszi for his 'center' filter.
*
* This file is part of MPlayer.
*
* MPlayer 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.
*
* MPlayer 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 MPlayer; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "af.h"
// Data for specific instances of this filter
// Initialization and runtime control
static int control(struct af_instance* af, int cmd, void* arg)
{
switch(cmd){
case AF_CONTROL_REINIT:
mp_audio_copy_config(af->data, (struct mp_audio*)arg);
mp_audio_set_format(af->data, AF_FORMAT_FLOAT);
return af_test_output(af,(struct mp_audio*)arg);
}
return AF_UNKNOWN;
}
// Filter data through filter
static int play(struct af_instance* af, struct mp_audio* data, int flags)
{
struct mp_audio* c = data; // Current working data
float* a = c->planes[0]; // Audio data
int nch = c->nch; // Number of channels
int len = c->samples*nch; // Number of samples in current audio block
register int i;
/*
FIXME1 add a low band pass filter to avoid suppressing
centered bass/drums
FIXME2 better calculated* attenuation factor
*/
for(i=0;i<len;i+=nch)
{
a[i] = (a[i] - a[i+1]) * 0.7;
a[i+1]=a[i];
}
return 0;
}
// Allocate memory and set function pointers
static int af_open(struct af_instance* af){
af->control = control;
af->filter = play;
return AF_OK;
}
// Description of this filter
struct af_info af_info_karaoke = {
.info = "Simple karaoke/voice-removal audio filter",
.name = "karaoke",
.flags = AF_FLAGS_NOT_REENTRANT,
.open = af_open,
};
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