how to check that the particular cell is visible or not in table view iOS (swift 3.0)? : I have Tableview and some cell in table view, i have to play the video in every cell (single video at a time)

and when i scroll the table view, if current cell is playing and visible than the video should be continue and if cell is not visible(after scrolling) than video should be stop.

 so how can i determine that which cell is visible in table view and which is not?
please help me as soon as possible.  