libavcodec/mpegvideo_enc.c:2935: error: Uninitialized Value
  The value read from best_s.mv_dir was never initialized.

libavcodec/mpegvideo_enc.c:2935:34: 
2933.                             mx=my=0; //FIXME find the one we actually used
2934.                             ff_mpeg4_set_direct_mv(s, mx, my);
2935.                         }else if(best_s.mv_dir&MV_DIR_BACKWARD){
                                       ^
2936.                             mx= s->mv[1][0][0];
2937.                             my= s->mv[1][0][1];
