Set edges based on cbp and mv partitioning, not just skiped MBs.

This is faster for videos that have lots of MBs that fall in this category.

Originally committed as revision 21400 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/h264_loopfilter.c

@@ -425,12 +425,12 @@ static av_always_inline void filter_mb_dir(H264Context *h, int mb_x, int mb_y, u
     const int mbm_xy = dir == 0 ? mb_xy -1 : h->top_mb_xy;
     const int mbm_type = s->current_picture.mb_type[mbm_xy];
 
-    const int edges = (mb_type & (MB_TYPE_16x16|MB_TYPE_SKIP))
-                              == (MB_TYPE_16x16|MB_TYPE_SKIP) ? 1 : 4;
     // how often to recheck mv-based bS when iterating between edges
     static const uint8_t mask_edge_tab[2][8]={{0,3,3,3,1,1,1,1},
                                               {0,3,1,1,3,3,3,3}};
     const int mask_edge = mask_edge_tab[dir][(mb_type>>3)&7];
+    const int edges = mask_edge== 3 && !(h->cbp&15) ? 1 : 4;
+
     // how often to recheck mv-based bS when iterating along each edge
     const int mask_par0 = mb_type & (MB_TYPE_16x16 | (MB_TYPE_8x16 >> dir));
     int start =   h->slice_table[mbm_xy] == 0xFFFF