mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-12-02 03:06:28 +02:00
1fb0d4b8a6
Part of the QCELP patch by Kenan Gillet, kenan.gillet gmail com Originally committed as revision 15754 to svn://svn.ffmpeg.org/ffmpeg/trunk
108 lines
2.7 KiB
C
108 lines
2.7 KiB
C
/*
|
|
* various filters for ACELP-based codecs
|
|
*
|
|
* Copyright (c) 2008 Vladimir Voroshilov
|
|
*
|
|
* 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 <inttypes.h>
|
|
|
|
#include "avcodec.h"
|
|
#include "celp_filters.h"
|
|
|
|
void ff_celp_convolve_circ(
|
|
int16_t* fc_out,
|
|
const int16_t* fc_in,
|
|
const int16_t* filter,
|
|
int len)
|
|
{
|
|
int i, k;
|
|
|
|
memset(fc_out, 0, len * sizeof(int16_t));
|
|
|
|
/* Since there are few pulses over an entire subframe (i.e. almost
|
|
all fc_in[i] are zero) it is faster to loop over fc_in first. */
|
|
for(i=0; i<len; i++)
|
|
{
|
|
if(fc_in[i])
|
|
{
|
|
for(k=0; k<i; k++)
|
|
fc_out[k] += (fc_in[i] * filter[len + k - i]) >> 15;
|
|
|
|
for(k=i; k<len; k++)
|
|
fc_out[k] += (fc_in[i] * filter[ k - i]) >> 15;
|
|
}
|
|
}
|
|
}
|
|
|
|
int ff_celp_lp_synthesis_filter(
|
|
int16_t *out,
|
|
const int16_t* filter_coeffs,
|
|
const int16_t* in,
|
|
int buffer_length,
|
|
int filter_length,
|
|
int stop_on_overflow,
|
|
int rounder)
|
|
{
|
|
int i,n;
|
|
|
|
// These two lines are to avoid a -1 subtraction in the main loop
|
|
filter_length++;
|
|
filter_coeffs--;
|
|
|
|
for(n=0; n<buffer_length; n++)
|
|
{
|
|
int sum = rounder;
|
|
for(i=1; i<filter_length; i++)
|
|
sum -= filter_coeffs[i] * out[n-i];
|
|
|
|
sum = (sum >> 12) + in[n];
|
|
|
|
if(sum + 0x8000 > 0xFFFFU)
|
|
{
|
|
if(stop_on_overflow)
|
|
return 1;
|
|
sum = (sum >> 31) ^ 32767;
|
|
}
|
|
out[n] = sum;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
void ff_celp_lp_synthesis_filterf(
|
|
float *out,
|
|
const float* filter_coeffs,
|
|
const float* in,
|
|
int buffer_length,
|
|
int filter_length)
|
|
{
|
|
int i,n;
|
|
|
|
// These two lines are to avoid a -1 subtraction in the main loop
|
|
filter_length++;
|
|
filter_coeffs--;
|
|
|
|
for(n=0; n<buffer_length; n++)
|
|
{
|
|
out[n] = in[n];
|
|
for(i=1; i<filter_length; i++)
|
|
out[n] += filter_coeffs[i] * out[n-i];
|
|
}
|
|
}
|