Use h264_chroma funcs in B-frames MC too

Originally committed as revision 6235 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/vc1.c

@@ -2075,8 +2075,10 @@ static void vc1_interp_mc(VC1Context *v)
     if(s->flags & CODEC_FLAG_GRAY) return;
     /* Chroma MC always uses qpel blilinear */
     uvdxy = ((uvmy & 3) << 2) | (uvmx & 3);
-    dsp->avg_qpel_pixels_tab[1][uvdxy](s->dest[1], srcU, s->uvlinesize);
-    dsp->avg_qpel_pixels_tab[1][uvdxy](s->dest[2], srcV, s->uvlinesize);
+    uvmx = (uvmx&3)<<1;
+    uvmy = (uvmy&3)<<1;
+    dsp->avg_h264_chroma_pixels_tab[0](s->dest[1], srcU, s->uvlinesize, 8, uvmx, uvmy);
+    dsp->avg_h264_chroma_pixels_tab[0](s->dest[2], srcV, s->uvlinesize, 8, uvmx, uvmy);
 }
 
 static always_inline int scale_mv(int value, int bfrac, int inv, int qs)