From 53f0090dcc779da3537736d7e0bab26a1ea2120a Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Fri, 31 Dec 2004 17:37:23 +0000 Subject: [PATCH] faster and slightly less accurate nearest neighbor resampler Originally committed as revision 3789 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/resample2.c | 26 ++++++++++++-------------- 1 file changed, 12 insertions(+), 14 deletions(-) diff --git a/libavcodec/resample2.c b/libavcodec/resample2.c index c713030c8a..0a9e44ef02 100644 --- a/libavcodec/resample2.c +++ b/libavcodec/resample2.c @@ -193,22 +193,20 @@ int av_resample(AVResampleContext *c, short *dst, short *src, int *consumed, int 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; - - if(compensation_distance == 0 && c->filter_length == 1 && c->phase_shift==0){ - assert(index >= 0); - for(dst_index=0; dst_index < dst_size; dst_index++){ - if(index < src_size) - dst[dst_index] = src[index]; - else - break; - frac += dst_incr_frac; - index += dst_incr; - if(frac >= c->src_incr){ - frac -= c->src_incr; - index++; - } + 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; } + frac += dst_index * dst_incr_frac; + index += dst_index * dst_incr; + index += frac / c->src_incr; + frac %= c->src_incr; }else{ for(dst_index=0; dst_index < dst_size; dst_index++){ FELEM *filter= c->filter_bank + c->filter_length*(index & c->phase_mask);