libavcodec/motionpixels.c:270: error: Uninitialized Value
  The value read from p.v was never initialized.

libavcodec/motionpixels.c:270:17: 
268.             p.y += mp_gradient(mp, 0, mp_get_vlc(mp, gb));
269.             if ((y & 3) == 0) {
270.                 p.v += mp_gradient(mp, 1, mp_get_vlc(mp, gb));
                     ^
271.                 p.u += mp_gradient(mp, 2, mp_get_vlc(mp, gb));
272.             }
