Another microopt, 4 cpu cycles for avoidance of FFABS().

Originally committed as revision 21248 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/h264_loopfilter.c

@@ -555,7 +555,7 @@ static av_always_inline void filter_mb_dir(H264Context *h, int mb_x, int mb_y, u
 
                 for( l = 0; !v && l < 1 + (h->slice_type_nos == FF_B_TYPE); l++ ) {
                     v |= ref2frm[l][h->ref_cache[l][b_idx]] != ref2frmn[l][h->ref_cache[l][bn_idx]] |
-                         FFABS( h->mv_cache[l][b_idx][0] - h->mv_cache[l][bn_idx][0] ) >= 4 |
+                         h->mv_cache[l][b_idx][0] - h->mv_cache[l][bn_idx][0] + 3 >= 7U |
                          FFABS( h->mv_cache[l][b_idx][1] - h->mv_cache[l][bn_idx][1] ) >= mvy_limit;
                 }
 
@@ -564,7 +564,7 @@ static av_always_inline void filter_mb_dir(H264Context *h, int mb_x, int mb_y, u
                     for( l = 0; !v && l < 2; l++ ) {
                         int ln= 1-l;
                         v |= ref2frm[l][h->ref_cache[l][b_idx]] != ref2frmn[ln][h->ref_cache[ln][bn_idx]] |
-                            FFABS( h->mv_cache[l][b_idx][0] - h->mv_cache[ln][bn_idx][0] ) >= 4 |
+                            h->mv_cache[l][b_idx][0] - h->mv_cache[ln][bn_idx][0] + 3 >= 7U |
                             FFABS( h->mv_cache[l][b_idx][1] - h->mv_cache[ln][bn_idx][1] ) >= mvy_limit;
                     }
                 }