libavcodec/h264_direct.c:297: error: Uninitialized Value
  The value read from mv[_] was never initialized.

libavcodec/h264_direct.c:297:25: 
295.                     a=b=0;
296.                     if(ref[0] > 0)
297.                         a= mv[0];
                             ^
298.                     if(ref[1] > 0)
299.                         b= mv[1];
