libavcodec/motion_est_template.c:915: error: Uninitialized Value
  The value read from ymax was never initialized.

libavcodec/motion_est_template.c:915:16: 
913.         const int y= best[1];
914. 
915.         start= FFMAX(0, y + dia_size - ymax);
                    ^
916.         end  = FFMIN(dia_size, xmax - x + 1);
917.         for(dir= start; dir<end; dir++){
