code: def stop_video(self, tick):
          
          if self.cnt_video == self.n_video:
              if tick >= self.end_diff:
                  self.idx_button.setText('Start')
                  self.video.stop()
docs: Stop video if tick is more than the end, only for last file.
  
          Parameters
          ----------
          tick : int
              time in ms from the beginning of the file
  
          useless?