[Ffmpeg-cvslog] r8480 - trunk/libavcodec/resample2.c
michael
subversion
Thu Mar 22 12:10:30 CET 2007
Author: michael
Date: Thu Mar 22 12:10:30 2007
New Revision: 8480
Modified:
trunk/libavcodec/resample2.c
Log:
optimize linear filter coeff interpolation code, this also makes the code less prone to overflows
Modified: trunk/libavcodec/resample2.c
==============================================================================
--- trunk/libavcodec/resample2.c (original)
+++ trunk/libavcodec/resample2.c Thu Mar 22 12:10:30 2007
@@ -268,13 +268,12 @@ int av_resample(AVResampleContext *c, sh
}else if(sample_index + c->filter_length > src_size){
break;
}else if(c->linear){
- int64_t v=0;
- int sub_phase= (frac<<8) / c->src_incr;
+ FELEM2 v2=0;
for(i=0; i<c->filter_length; i++){
- FELEML coeff= filter[i]*(256 - sub_phase) + filter[i + c->filter_length]*sub_phase;
- v += src[sample_index + i] * coeff;
+ val += src[sample_index + i] * (FELEM2)filter[i];
+ v2 += src[sample_index + i] * (FELEM2)filter[i + c->filter_length];
}
- val= v>>8;
+ 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];
More information about the ffmpeg-cvslog
mailing list