[SCM] libav/experimental: Simplify code to set cbp_* this seems 1 cpu cycle slower even though we practically just remove code. Speed loss seems caused by the merge of if(left_type), iam commiting this anyway as i cant imagine this to be anything but compiler messup.

siretart at users.alioth.debian.org siretart at users.alioth.debian.org
Sun Jun 30 17:01:54 UTC 2013


The following commit has been merged in the experimental branch:
commit 59b5370f0258243048708991c579570b322e3e02
Author: Michael Niedermayer <michaelni at gmx.at>
Date:   Fri Feb 26 09:13:40 2010 +0000

    Simplify code to set cbp_*
    this seems 1 cpu cycle slower even though we practically just remove code.
    Speed loss seems caused by the merge of if(left_type), iam commiting this
    anyway as i cant imagine this to be anything but compiler messup.
    
    Originally committed as revision 22073 to svn://svn.ffmpeg.org/ffmpeg/trunk

diff --git a/libavcodec/h264.h b/libavcodec/h264.h
index 2e77184..5d615cf 100644
--- a/libavcodec/h264.h
+++ b/libavcodec/h264.h
@@ -947,24 +947,16 @@ static void fill_decode_caches(H264Context *h, int mb_type){
         // top_cbp
         if(top_type) {
             h->top_cbp = h->cbp_table[top_xy];
-        } else if(IS_INTRA(mb_type)) {
-            h->top_cbp = 0x1CF;
         } else {
-            h->top_cbp = 0x00F;
+            h->top_cbp = IS_INTRA(mb_type) ? 0x1CF : 0x00F;
         }
         // left_cbp
         if (left_type[0]) {
             h->left_cbp = h->cbp_table[left_xy[0]] & 0x1f0;
-        } else if(IS_INTRA(mb_type)) {
-            h->left_cbp = 0x1CF;
-        } else {
-            h->left_cbp = 0x00F;
-        }
-        if (left_type[0]) {
             h->left_cbp |= ((h->cbp_table[left_xy[0]]>>((left_block[0]&(~1))+1))&0x1) << 1;
-        }
-        if (left_type[1]) {
             h->left_cbp |= ((h->cbp_table[left_xy[1]]>>((left_block[2]&(~1))+1))&0x1) << 3;
+        } else {
+            h->left_cbp = IS_INTRA(mb_type) ? 0x1CF : 0x00F;
         }
     }
     }

-- 
Libav/FFmpeg packaging



More information about the pkg-multimedia-commits mailing list