Autoplay HTML videos on scroll

(function(){ //gett all the video elements on the document var vids = document.getElementsByClassName('_autoplay_vid'); //loop through all the video elements for (var i = vids.length - 1; i >= 0; i--) { //pause all the videos by default vids[i].pause(); } //triger an anonymous function that handles the playy, pause video actions window.onscroll = function(){ for (var i = vids.length - 1; i >= 0; i--) { //get current scrol position var currentYpos = window.pageYOffset || document.documentElement.scrollTop; if ( currentYpos >= vids[i].offsetTop && currentYpos <= vids[i].offsetTop + vids[i].offsetHeight ) { //Play video if the current scroll position //is between the top and bottom of the video element vids[i].play(); }else{ //else pause the video vids[i].pause(); } } }; });