libavcodec/vc1dec.c:3659: error: Uninitialized Value
  The value read from is_intra[_] was never initialized.

libavcodec/vc1dec.c:3659:49: 
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.             }
3661.             // if there are no coded blocks then don't do anything more
