[FFmpeg-devel] 4xm idct computation

[yann.lepetitcorps at free.fr]

> > > Perhaps that the y*stride can to be factorised into the
> > ff_snow_pred_block()
> > > func because this was very redundant ?
> > > (the same thing with the y*src_stride into ff_snow_inner_add_yblock() )

With this diff, the factorisation into ff_snow_pred_block() is really more
apparent :)


diff --git a/libavcodec/snow.c b/libavcodec/snow.c
index 0ce9b28..5b256d4 100644
--- a/libavcodec/snow.c
+++ b/libavcodec/snow.c
@@ -288,41 +288,31 @@ static void mc_block(Plane *p, uint8_t *dst, const uint8_t
*src, int stride, int
 }

 void ff_snow_pred_block(SnowContext *s, uint8_t *dst, uint8_t *tmp, int stride,
int sx, int sy, int b_w, int b_h, BlockNode *block, int plane_index, int w, int
h){
+
     if(block->type & BLOCK_INTRA){
         int x, y;
         const unsigned color  = block->color[plane_index];
         const unsigned color4 = color*0x01010101;
         if(b_w==32){
-            for(y=0; y < b_h; y++){
-                *(uint32_t*)&dst[0 + y*stride]= color4;
-                *(uint32_t*)&dst[4 + y*stride]= color4;
-                *(uint32_t*)&dst[8 + y*stride]= color4;
-                *(uint32_t*)&dst[12+ y*stride]= color4;
-                *(uint32_t*)&dst[16+ y*stride]= color4;
-                *(uint32_t*)&dst[20+ y*stride]= color4;
-                *(uint32_t*)&dst[24+ y*stride]= color4;
-                *(uint32_t*)&dst[28+ y*stride]= color4;
+            for(y=0; y < b_h; y++, dst += stride){
+                memset(dst,color4, 32);
             }
         }else if(b_w==16){
-            for(y=0; y < b_h; y++){
-                *(uint32_t*)&dst[0 + y*stride]= color4;
-                *(uint32_t*)&dst[4 + y*stride]= color4;
-                *(uint32_t*)&dst[8 + y*stride]= color4;
-                *(uint32_t*)&dst[12+ y*stride]= color4;
+            for(y=0; y < b_h; y++, dst += stride){
+                memset(dst,color4, 16);
             }
         }else if(b_w==8){
-            for(y=0; y < b_h; y++){
-                *(uint32_t*)&dst[0 + y*stride]= color4;
-                *(uint32_t*)&dst[4 + y*stride]= color4;
+            for(y=0; y < b_h; y++, dst += stride){
+                memset(dst,color4, 8);
             }
         }else if(b_w==4){
-            for(y=0; y < b_h; y++){
-                *(uint32_t*)&dst[0 + y*stride]= color4;
+            for(y=0; y < b_h; y++, dst += stride){
+                *(uint32_t*)dst= color4;
             }
         }else{
-            for(y=0; y < b_h; y++){
+            for(y=0; y < b_h; y++, dst += stride){
                 for(x=0; x < b_w; x++){
-                    dst[x + y*stride]= color;
+                    dst[x]= color;
                 }
             }
         }

@+
Yannoo