Disable B-frames decoding until I return and finish their proper decoding.

Originally committed as revision 5980 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/vc1.c

@@ -3278,6 +3278,7 @@ static int vc1_decode_frame(AVCodecContext *avctx,
         return -1;
 
     if(s->pict_type != I_TYPE && !v->res_rtm_flag)return -1;
+    if(s->pict_type == B_TYPE)return -1;
 
     // for hurry_up==5
     s->current_picture.pict_type= s->pict_type;