libavcodec/h264_direct.c:357: error: Uninitialized Value
  The value read from ref[_] was never initialized.

libavcodec/h264_direct.c:357:21: 
355.                 a =
356.                 b = 0;
357.                 if (ref[0] > 0)
                         ^
358.                     a = mv[0];
359.                 if (ref[1] > 0)
