diff -r 490d5cc509ed -r cf61fcea0001 wp/wp-includes/js/mediaelement/wp-mediaelement.js
--- a/wp/wp-includes/js/mediaelement/wp-mediaelement.js	Tue Jun 09 11:14:17 2015 +0000
+++ b/wp/wp-includes/js/mediaelement/wp-mediaelement.js	Mon Oct 14 17:39:30 2019 +0200
@@ -1,34 +1,82 @@
-/* global mejs, _wpmejsSettings */
-(function ($) {
-	// add mime-type aliases to MediaElement plugin support
-	mejs.plugins.silverlight[0].types.push('video/x-ms-wmv');
-	mejs.plugins.silverlight[0].types.push('audio/x-ms-wma');
+/* global _wpmejsSettings, mejsL10n */
+(function( window, $ ) {
 
-	$(function () {
+	window.wp = window.wp || {};
+
+	function wpMediaElement() {
 		var settings = {};
 
-		if ( typeof _wpmejsSettings !== 'undefined' ) {
-			settings = _wpmejsSettings;
+		/**
+		 * Initialize media elements.
+		 *
+		 * Ensures media elements that have already been initialized won't be
+		 * processed again.
+		 *
+		 * @since 4.4.0
+		 *
+		 * @returns {void}
+		 */
+		function initialize() {
+			if ( typeof _wpmejsSettings !== 'undefined' ) {
+				settings = $.extend( true, {}, _wpmejsSettings );
+			}
+			settings.classPrefix = 'mejs-';
+			settings.success = settings.success || function ( mejs ) {
+				var autoplay, loop;
+
+				if ( mejs.rendererName && -1 !== mejs.rendererName.indexOf( 'flash' ) ) {
+					autoplay = mejs.attributes.autoplay && 'false' !== mejs.attributes.autoplay;
+					loop = mejs.attributes.loop && 'false' !== mejs.attributes.loop;
+
+					if ( autoplay ) {
+						mejs.addEventListener( 'canplay', function() {
+							mejs.play();
+						}, false );
+					}
+
+					if ( loop ) {
+						mejs.addEventListener( 'ended', function() {
+							mejs.play();
+						}, false );
+					}
+				}
+			};
+
+			/**
+			 * Custom error handler.
+			 *
+			 * Sets up a custom error handler in case a video render fails, and provides a download
+			 * link as the fallback.
+			 *
+			 * @since 4.9.3
+			 *
+			 * @param {object} media The wrapper that mimics all the native events/properties/methods for all renderers.
+			 * @param {object} node  The original HTML video, audio, or iframe tag where the media was loaded.
+			 * @returns {string}
+			 */
+			settings.customError = function ( media, node ) {
+				// Make sure we only fall back to a download link for flash files.
+				if ( -1 !== media.rendererName.indexOf( 'flash' ) || -1 !== media.rendererName.indexOf( 'flv' ) ) {
+					return '<a href="' + node.src + '">' + mejsL10n.strings['mejs.download-video'] + '</a>';
+				}
+			};
+
+			// Only initialize new media elements.
+			$( '.wp-audio-shortcode, .wp-video-shortcode' )
+				.not( '.mejs-container' )
+				.filter(function () {
+					return ! $( this ).parent().hasClass( 'mejs-mediaelement' );
+				})
+				.mediaelementplayer( settings );
 		}
 
-		settings.success = settings.success || function (mejs) {
-			var autoplay, loop;
-
-			if ( 'flash' === mejs.pluginType ) {
-				autoplay = mejs.attributes.autoplay && 'false' !== mejs.attributes.autoplay;
-				loop = mejs.attributes.loop && 'false' !== mejs.attributes.loop;
-
-				autoplay && mejs.addEventListener( 'canplay', function () {
-					mejs.play();
-				}, false );
+		return {
+			initialize: initialize
+		};
+	}
 
-				loop && mejs.addEventListener( 'ended', function () {
-					mejs.play();
-				}, false );
-			}
-		};
+	window.wp.mediaelement = new wpMediaElement();
 
-		$('.wp-audio-shortcode, .wp-video-shortcode').mediaelementplayer( settings );
-	});
+	$( window.wp.mediaelement.initialize );
 
-}(jQuery));
+})( window, jQuery );