libavcodec/vc1dec.c:1085: error: Uninitialized Value
  The value read from uvmx_field[_] was never initialized.

libavcodec/vc1dec.c:1085:9: 
1083.     for (i = 0; i < 4; i++) {
1084.         off = (i & 1) * 4 + ((i & 2) ? v_dist * s->uvlinesize : 0);
1085.         uvsrc_x = s->mb_x * 8 +  (i & 1) * 4           + (uvmx_field[i] >> 2);
              ^
1086.         uvsrc_y = s->mb_y * 8 + ((i & 2) ? v_dist : 0) + (uvmy_field[i] >> 2);
1087.         // FIXME: implement proper pull-back (see vc1cropmv.c, vc1CROPMV_ChromaPullBack())
