mirror of
https://git.ffmpeg.org/ffmpeg.git
synced 2025-10-30 23:30:55 +00:00
64 lines
2.4 KiB
C
64 lines
2.4 KiB
C
/*
|
|
* copyright (c) 2008 Michael Niedermayer <michaelni@gmx.at>
|
|
*
|
|
* 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 "fft.h"
|
|
#include "synth_filter.h"
|
|
|
|
static void synth_filter_float(FFTContext *imdct,
|
|
float *synth_buf_ptr, int *synth_buf_offset,
|
|
float synth_buf2[32], const float window[512],
|
|
float out[32], const float in[32], float scale)
|
|
{
|
|
float *synth_buf= synth_buf_ptr + *synth_buf_offset;
|
|
int i, j;
|
|
|
|
imdct->imdct_half(imdct, synth_buf, in);
|
|
|
|
for (i = 0; i < 16; i++){
|
|
float a= synth_buf2[i ];
|
|
float b= synth_buf2[i + 16];
|
|
float c= 0;
|
|
float d= 0;
|
|
for (j = 0; j < 512 - *synth_buf_offset; j += 64){
|
|
a += window[i + j ]*(-synth_buf[15 - i + j ]);
|
|
b += window[i + j + 16]*( synth_buf[ i + j ]);
|
|
c += window[i + j + 32]*( synth_buf[16 + i + j ]);
|
|
d += window[i + j + 48]*( synth_buf[31 - i + j ]);
|
|
}
|
|
for ( ; j < 512; j += 64){
|
|
a += window[i + j ]*(-synth_buf[15 - i + j - 512]);
|
|
b += window[i + j + 16]*( synth_buf[ i + j - 512]);
|
|
c += window[i + j + 32]*( synth_buf[16 + i + j - 512]);
|
|
d += window[i + j + 48]*( synth_buf[31 - i + j - 512]);
|
|
}
|
|
out[i ] = a*scale;
|
|
out[i + 16] = b*scale;
|
|
synth_buf2[i ] = c;
|
|
synth_buf2[i + 16] = d;
|
|
}
|
|
*synth_buf_offset= (*synth_buf_offset - 32)&511;
|
|
}
|
|
|
|
av_cold void ff_synth_filter_init(SynthFilterContext *c)
|
|
{
|
|
c->synth_filter_float = synth_filter_float;
|
|
|
|
if (ARCH_ARM) ff_synth_filter_init_arm(c);
|
|
}
|