[FFmpeg-cvslog] r29978 - trunk/libswscale/swscale.c

[ramiro]

Author: ramiro
Date: Mon Dec  7 04:52:55 2009
New Revision: 29978

Log:
Document the differences between the two asm fragments in initMMX2HScaler().

Modified:
   trunk/libswscale/swscale.c

Modified: trunk/libswscale/swscale.c
==============================================================================
--- trunk/libswscale/swscale.c	Sun Dec  6 23:01:25 2009	(r29977)
+++ trunk/libswscale/swscale.c	Mon Dec  7 04:52:55 2009	(r29978)
@@ -1697,6 +1697,12 @@ static int initMMX2HScaler(int dstW, int
     int xpos, i;
 
     // create an optimized horizontal scaling routine
+    /* This scaler is made of runtime-generated MMX2 code using specially
+     * tuned pshufw instructions. For every four output pixels, if four
+     * input pixels are enough for the fast bilinear scaling, then a chunk
+     * of fragmentB is used. If five input pixels are needed, then a chunk
+     * of fragmentA is used.
+     */
 
     //code fragment