rewrite h261 loop filter

no malloc(64) memcpy free stuff
no filter1 A->B then filter2 A->B (yes not B->A)
no incorrect rouding after the 1d filter

Originally committed as revision 3177 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 22 insertions, 26 deletions

diff --git a/libavcodec/dsputil.c b/libavcodec/dsputil.c
index 63fb32e426..3e3e550b11 100644
--- a/libavcodec/dsputil.c
+++ b/libavcodec/dsputil.c
@@ -2360,32 +2360,29 @@ static void h263_h_loop_filter_c(uint8_t *src, int stride, int qscale){
     }
 }
 
-static void h261_v_loop_filter_c(uint8_t *dest,uint8_t *src, int stride){
-    int i,j,xy,yz;
-    int res;
-    for(i=0; i<8; i++){
-        for(j=1; j<7; j++){
-            xy = j * stride + i;
-            yz = j * 8 + i;
-            res = (int)src[yz-1*8] + ((int)(src[yz+0*8]) * 2) + (int)src[yz+1*8];
-            res +=2;
-            res >>=2;
-            dest[xy] = (uint8_t)res;
+static void h261_loop_filter_c(uint8_t *src, int stride){
+    int x,y,xy,yz;
+    int temp[64];
+
+    for(x=0; x<8; x++){
+        temp[x      ] = 4*src[x           ];
+        temp[x + 7*8] = 4*src[x + 7*stride];
+    }
+    for(y=1; y<7; y++){
+        for(x=0; x<8; x++){
+            xy = y * stride + x;
+            yz = y * 8 + x;
+            temp[yz] = src[xy - stride] + 2*src[xy] + src[xy + stride];
         }
     }
-}
-
-static void h261_h_loop_filter_c(uint8_t *dest,uint8_t *src, int stride){
-    int i,j,xy,yz;
-    int res;    
-    for(i=1; i<7; i++){
-        for(j=0; j<8; j++){
-            xy = j * stride + i;
-            yz = j * 8 + i;
-            res = (int)src[yz-1] + ((int)(src[yz]) *2) + (int)src[yz+1];
-            res+=2;
-            res>>=2;
-            dest[xy] = (uint8_t)res;
+        
+    for(y=0; y<8; y++){
+        src[  y*stride] = (temp[  y*8] + 2)>>2;
+        src[7+y*stride] = (temp[7+y*8] + 2)>>2;
+        for(x=1; x<7; x++){
+            xy = y * stride + x;
+            yz = y * 8 + x;
+            src[xy] = (temp[yz-1] + 2*temp[yz] + temp[yz+1] + 8)>>4;
         }
     }
 }
@@ -3325,8 +3322,7 @@ void dsputil_init(DSPContext* c, AVCodecContext *avctx)
     c->h263_h_loop_filter= h263_h_loop_filter_c;
     c->h263_v_loop_filter= h263_v_loop_filter_c;
     
-    c->h261_h_loop_filter= h261_h_loop_filter_c;
-    c->h261_v_loop_filter= h261_v_loop_filter_c;
+    c->h261_loop_filter= h261_loop_filter_c;
     
     c->try_8x8basis= try_8x8basis_c;
     c->add_8x8basis= add_8x8basis_c;