libavcodec/h264_direct.c:299: error: Uninitialized Value
  The value read from mv[_] was never initialized.

libavcodec/h264_direct.c:299:25: 
297.                         a= mv[0];
298.                     if(ref[1] > 0)
299.                         b= mv[1];
                             ^
300.                     n++;
301.                 }else{
