A simple method to stop YouTube, Vimeo, and HTML5 videos from playing.

stop-video.js

/**
 * Stop an iframe or HTML5 <video> from playing
 * @param  {Element} element The element that contains the video
 */
var stopVideo = function ( element ) {
	var iframe = element.querySelector( 'iframe');
	var video = element.querySelector( 'video' );
	if ( iframe ) {
		var iframeSrc = iframe.src;
		iframe.src = iframeSrc;
	}
	if ( video ) {
		video.pause();
	}
};