Commit 303bd95c authored by Michael Niedermayer's avatar Michael Niedermayer
Browse files

optimize linear filter coeff interpolation code, this also makes the code less prone to overflows

Originally committed as revision 8480 to svn://svn.ffmpeg.org/ffmpeg/trunk
parent d971a5fa
...@@ -268,13 +268,12 @@ int av_resample(AVResampleContext *c, short *dst, short *src, int *consumed, int ...@@ -268,13 +268,12 @@ int av_resample(AVResampleContext *c, short *dst, short *src, int *consumed, int
}else if(sample_index + c->filter_length > src_size){ }else if(sample_index + c->filter_length > src_size){
break; break;
}else if(c->linear){ }else if(c->linear){
int64_t v=0; FELEM2 v2=0;
int sub_phase= (frac<<8) / c->src_incr;
for(i=0; i<c->filter_length; i++){ for(i=0; i<c->filter_length; i++){
FELEML coeff= filter[i]*(256 - sub_phase) + filter[i + c->filter_length]*sub_phase; val += src[sample_index + i] * (FELEM2)filter[i];
v += src[sample_index + i] * coeff; v2 += src[sample_index + i] * (FELEM2)filter[i + c->filter_length];
} }
val= v>>8; val+=(v2-val)*(FELEML)frac / c->src_incr;
}else{ }else{
for(i=0; i<c->filter_length; i++){ for(i=0; i<c->filter_length; i++){
val += src[sample_index + i] * (FELEM2)filter[i]; val += src[sample_index + i] * (FELEM2)filter[i];
......
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