libavcodec/motion_est_template.c:727: error: Uninitialized Value
  The value read from ymax was never initialized.

libavcodec/motion_est_template.c:727:5: 
725.     CHECK_CLIPPED_MV(x, y+1);
726.     CHECK_CLIPPED_MV(x-1, y);
727.     CHECK_CLIPPED_MV(x, y-1);
         ^
728. 
729.     return dmin;
