[SCM] libav/experimental: optimization

siretart at users.alioth.debian.org siretart at users.alioth.debian.org
Sun Jun 30 15:41:57 UTC 2013


The following commit has been merged in the experimental branch:
commit f25ba8b39380d3bbe1b58b6422062427d19b787c
Author: Michael Niedermayer <michaelni at gmx.at>
Date:   Wed Oct 20 19:06:29 2004 +0000

    optimization
    
    Originally committed as revision 3616 to svn://svn.ffmpeg.org/ffmpeg/trunk

diff --git a/libavcodec/resample2.c b/libavcodec/resample2.c
index ad303a4..22f787d 100644
--- a/libavcodec/resample2.c
+++ b/libavcodec/resample2.c
@@ -42,7 +42,7 @@
 #define FELEM_MAX INT16_MAX
 #define FELEM_MIN INT16_MIN
 #else
-#define FILTER_SHIFT 24
+#define FILTER_SHIFT 22
 
 #define FELEM int32_t
 #define FELEM2 int64_t
@@ -193,12 +193,12 @@ int av_resample(AVResampleContext *c, short *dst, short *src, int *consumed, int
         }else{
 #ifdef LINEAR
             int64_t v=0;
-            int sub_phase= (frac<<12) / c->src_incr;
+            int sub_phase= (frac<<8) / c->src_incr;
             for(i=0; i<c->filter_length; i++){
-                int64_t coeff= filter[i]*(FELEM2)(4096 - sub_phase) + filter[i + c->filter_length]*(FELEM2)sub_phase;
+                int64_t coeff= filter[i]*(256 - sub_phase) + filter[i + c->filter_length]*sub_phase;
                 v += src[sample_index + i] * coeff;
             }
-            val= v>>12;
+            val= v>>8;
 #else
             for(i=0; i<c->filter_length; i++){
                 val += src[sample_index + i] * (FELEM2)filter[i];

-- 
Libav/FFmpeg packaging



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