libavcodec/vp3.c:834: error: Uninitialized Value
  The value read from motion_y[_] was never initialized.

libavcodec/vp3.c:834:25: 
832.                     } else {
833.                         motion_x[1] = motion_x[0];
834.                         motion_y[1] = motion_y[0];
                             ^
835.                     }
836.                     motion_x[0] = (motion_x[0] >> 1) | (motion_x[0] & 1);
