libavcodec/motion_est_template.c:760: error: Uninitialized Value
  The value read from ymax was never initialized.

libavcodec/motion_est_template.c:760:11: 
758. 
759.     if(   best[0] < xmax && best[0] > xmin
760.        && best[1] < ymax && best[1] > ymin){
               ^
761.         int d;
762.         // ensure that the reference samples for hpel refinement are in the map
