libavcodec/vc1dec.c:3758: error: Uninitialized Value
  The value read from is_coded[_] was never initialized.

libavcodec/vc1dec.c:3758:21: 
3756.                         v->c_avail = v->mb_type[0][s->block_index[i] - 1];
3757. 
3758.                     vc1_decode_intra_block(v, s->block[i], i, is_coded[i], mquant,
                          ^
3759.                                            (i & 4) ? v->codingset2 : v->codingset);
3760.                     if ((i>3) && (s->flags & CODEC_FLAG_GRAY))
