libavcodec/vc1dec.c:1577: error: Uninitialized Value
  The value read from oppfield_predA[_] was never initialized.

libavcodec/vc1dec.c:1577:9: 
1575.         samefield_pred[1] = samefield_predA[1];
1576.         oppfield_pred[0] = oppfield_predA[0];
1577.         oppfield_pred[1] = oppfield_predA[1];
              ^
1578.     } else if (c_valid) {
1579.         samefield_pred[0] = samefield_predC[0];
