libavcodec/vp3.c:781: error: Uninitialized Value
  The value read from motion_x[_] was never initialized.

libavcodec/vp3.c:781:25: 
779.                         SET_CHROMA_MV(motion_x[k], motion_y[k]);
780.                     } else {
781.                         SET_CHROMA_MV(motion_x[0], motion_y[0]);
                             ^
782.                     }
783.                 }
