libavcodec/vc1dec.c:3658: error: Uninitialized Value
  The value read from is_intra[_] was never initialized.

libavcodec/vc1dec.c:3658:17: 
3656.                 }
3657.                 if(i == 4) vc1_mc_4mv_chroma(v, 0);
3658.                 v->mb_type[0][s->block_index[i]] = is_intra[i];
                      ^
3659.                 if(!coded_inter) coded_inter = !is_intra[i] & is_coded[i];
3660.             }
