libavcodec/vc1dec.c:1581: error: Uninitialized Value
  The value read from oppfield_predC[_] was never initialized.

libavcodec/vc1dec.c:1581:9: 
1579.         samefield_pred[0] = samefield_predC[0];
1580.         samefield_pred[1] = samefield_predC[1];
1581.         oppfield_pred[0] = oppfield_predC[0];
              ^
1582.         oppfield_pred[1] = oppfield_predC[1];
1583.     } else if (b_valid) {
