libavcodec/vp3.c:853: error: Uninitialized Value
  The value read from motion_y[_] was never initialized.

libavcodec/vp3.c:853:29: 
851.                         } else {
852.                             s->motion_val[1][frag][0] = motion_x[0];
853.                             s->motion_val[1][frag][1] = motion_y[0];
                                 ^
854.                         }
855.                     }
