mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-11-26 19:01:44 +02:00
114 lines
4.1 KiB
C
114 lines
4.1 KiB
C
/*
|
|
* audio resampling
|
|
* Copyright (c) 2004-2012 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
|
|
*/
|
|
|
|
/**
|
|
* @file
|
|
* audio resampling
|
|
* @author Michael Niedermayer <michaelni@gmx.at>
|
|
*/
|
|
|
|
int RENAME(swri_resample)(ResampleContext *c, DELEM *dst, const DELEM *src, int *consumed, int src_size, int dst_size, int update_ctx){
|
|
int dst_index, i;
|
|
int index= c->index;
|
|
int frac= c->frac;
|
|
int dst_incr_frac= c->dst_incr % c->src_incr;
|
|
int dst_incr= c->dst_incr / c->src_incr;
|
|
int compensation_distance= c->compensation_distance;
|
|
|
|
av_assert1(c->filter_shift == FILTER_SHIFT);
|
|
av_assert1(c->felem_size == sizeof(FELEM));
|
|
|
|
if(compensation_distance == 0 && c->filter_length == 1 && c->phase_shift==0){
|
|
int64_t index2= ((int64_t)index)<<32;
|
|
int64_t incr= (1LL<<32) * c->dst_incr / c->src_incr;
|
|
dst_size= FFMIN(dst_size, (src_size-1-index) * (int64_t)c->src_incr / c->dst_incr);
|
|
|
|
for(dst_index=0; dst_index < dst_size; dst_index++){
|
|
dst[dst_index] = src[index2>>32];
|
|
index2 += incr;
|
|
}
|
|
index += dst_index * dst_incr;
|
|
index += (frac + dst_index * (int64_t)dst_incr_frac) / c->src_incr;
|
|
frac = (frac + dst_index * (int64_t)dst_incr_frac) % c->src_incr;
|
|
}else{
|
|
for(dst_index=0; dst_index < dst_size; dst_index++){
|
|
FELEM *filter= ((FELEM*)c->filter_bank) + c->filter_length*(index & c->phase_mask);
|
|
int sample_index= index >> c->phase_shift;
|
|
FELEM2 val=0;
|
|
|
|
if(sample_index + c->filter_length > src_size || -sample_index >= src_size){
|
|
break;
|
|
}else if(sample_index < 0){
|
|
for(i=0; i<c->filter_length; i++)
|
|
val += src[FFABS(sample_index + i)] * filter[i];
|
|
}else if(c->linear){
|
|
FELEM2 v2=0;
|
|
for(i=0; i<c->filter_length; i++){
|
|
val += src[sample_index + i] * (FELEM2)filter[i];
|
|
v2 += src[sample_index + i] * (FELEM2)filter[i + c->filter_length];
|
|
}
|
|
val+=(v2-val)*(FELEML)frac / c->src_incr;
|
|
}else{
|
|
for(i=0; i<c->filter_length; i++){
|
|
val += src[sample_index + i] * (FELEM2)filter[i];
|
|
}
|
|
}
|
|
|
|
OUT(dst[dst_index], val);
|
|
|
|
frac += dst_incr_frac;
|
|
index += dst_incr;
|
|
if(frac >= c->src_incr){
|
|
frac -= c->src_incr;
|
|
index++;
|
|
}
|
|
|
|
if(dst_index + 1 == compensation_distance){
|
|
compensation_distance= 0;
|
|
dst_incr_frac= c->ideal_dst_incr % c->src_incr;
|
|
dst_incr= c->ideal_dst_incr / c->src_incr;
|
|
}
|
|
}
|
|
}
|
|
*consumed= FFMAX(index, 0) >> c->phase_shift;
|
|
if(index>=0) index &= c->phase_mask;
|
|
|
|
if(compensation_distance){
|
|
compensation_distance -= dst_index;
|
|
av_assert1(compensation_distance > 0);
|
|
}
|
|
if(update_ctx){
|
|
c->frac= frac;
|
|
c->index= index;
|
|
c->dst_incr= dst_incr_frac + c->src_incr*dst_incr;
|
|
c->compensation_distance= compensation_distance;
|
|
}
|
|
#if 0
|
|
if(update_ctx && !c->compensation_distance){
|
|
#undef rand
|
|
av_resample_compensate(c, rand() % (8000*2) - 8000, 8000*2);
|
|
av_log(NULL, AV_LOG_DEBUG, "%d %d %d\n", c->dst_incr, c->ideal_dst_incr, c->compensation_distance);
|
|
}
|
|
#endif
|
|
|
|
return dst_index;
|
|
}
|