How to track the visibility of the player

JS API request

player.api("visibility");

In response the player will send the percentage of visibility.

You can also track to the event visibility

function PlayerjsEvents(x,y,z){
   if(x=="visibility"){
      console.log("Visibility",z);
   }
}

Tracking visibility works even when the player is inside an iframe and is loaded from another domain. This option based on IntersectionObserver, not all browsers support it at the moment.