On-demand Youtube embedded player

Hugely improves load speed of pages with lots of embedded Youtube videos by instantly showing clickable and immediately accessible placeholders, then the thumbnails are loaded in background.

Устаревшая версия за 19.12.2015. Перейдите к последней версии.

// ==UserScript==
// @name          On-demand Youtube embedded player
// @description   Hugely improves load speed of pages with lots of embedded Youtube videos by instantly showing clickable and immediately accessible placeholders, then the thumbnails are loaded in background.
// @version       1.3
// @author        wOxxOm
// @namespace     wOxxOm.scripts
// @license       MIT License
// @grant         GM_getValue
// @grant         GM_setValue
// @grant         GM_addStyle
// @grant         GM_xmlhttpRequest
// @run-at        document-start
// @require       https://greatest.deepsurf.us/scripts/12228/code/setMutationHandler.js
// ==/UserScript==

var resizeToFit = GM_getValue('resize', true);
var playHTML5 = GM_getValue('playHTML5', false);
var embedSelector = 'iframe[src*="youtube.com/embed"], embed[src*="youtube.com/v"]';

processNodes(document.querySelectorAll(embedSelector));
document.addEventListener('DOMContentLoaded', function() {
	processNodes(document.querySelectorAll(embedSelector));
	setMutationHandler(document, embedSelector, processNodes);
	GM_addStyle('\
			:root .instant-youtube-container {position:relative; overflow:hidden; cursor:pointer; background-color:black; padding:0; margin:0; font:normal 14px/1.0 sans-serif,Arial,Helvetica,Verdana;}\
			:root .instant-youtube-container .instant-youtube-thumbnail {transition:opacity 0.1s ease-out; opacity:0; padding:0; margin:0}\
			:root .instant-youtube-container .instant-youtube-play-button {position:absolute; left:0; right:0; top:0; bottom:0; margin:auto; width:85px; height:60px}\
			:root .instant-youtube-container .instant-youtube-loading-button {position:absolute; left:0; right:0; top:0; bottom:0; padding:0; margin:auto; display:block; width:20px; height:20px; background: url("data:image/gif;base64,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")}\
			:root .instant-youtube-container:hover .ytp-large-play-button-svg {fill:#CC181E}\
			:root .instant-youtube-container .instant-youtube-link, .instant-youtube-container .instant-youtube-link:link, .instant-youtube-container .instant-youtube-link:visited, .instant-youtube-container .instant-youtube-link:active, .instant-youtube-container .instant-youtube-link:focus {\
				position:absolute; top:50%; left:0; right:0; width:20em; height:1.7em; margin:60px auto; padding:0; border:none; \
				display:block; text-align:center; text-decoration:none; color:white; text-shadow:1px 1px 3px black; font-weight:bold;\
			}\
			:root .instant-youtube-container span.instant-youtube-link {font-weight:normal; font-size:12px}\
			:root .instant-youtube-container .instant-youtube-link:hover {color:white; text-decoration:underline; background:transparent}\
			:root .instant-youtube-container .instant-youtube-embed {position:absolute; left:0; top:0; padding:0; margin:0; height:inherit!important; opacity:0; transition:opacity 2s!important}\
			:root .instant-youtube-container .instant-youtube-link2 {\
				display:none; z-index:9; background-color:rgba(0,0,0,0.5); color: white;\
				width:100%; height: 1.7em; top:0; left:0; right:0; position:absolute; z-index: 9;\
				color:white; text-shadow:1px 1px 2px black; text-align:center; text-decoration:none;\
				margin:0; padding:0.5em 0.5em 0.2em;\
			}\
			:root .instant-youtube-container:hover .instant-youtube-link2 {display:block; margin:0}\
			:root .instant-youtube-container .instant-youtube-link2:hover {text-decoration:underline}\
			:root .instant-youtube-container .instant-youtube-link2 b {color:white}\
			:root .instant-youtube-container .instant-youtube-options {position:absolute; right:0; bottom:0; color:white; text-shadow:1px 1px 2px black; padding:0; margin:0 }\
			:root .instant-youtube-container .instant-youtube-options * {font-size:13px; vertical-align:middle; padding:0; margin:0}\
	');
});

function processNodes(nodes) {
	for (var i=0, nl=nodes.length, n; i<nl && (n=nodes[i]); i++) {
		if (!n.parentNode || n.className.indexOf('instant-youtube-') >= 0 || n.src.indexOf('autoplay=1') > 0)
			continue;

		var id = n.src.match(/(?:embed\/|v[=\/])([^\s,.()\[\]?]+?)(?:[&?\/].*|$)/);
		if (!id)
			continue;
		id = id[1];

		for (var np=n.parentNode, npw; np && !(npw=np.clientWidth); np=np.parentNode) {}
		var containerWidth = resizeToFit ? npw : n.clientWidth;
		var containerHeight = resizeToFit ? npw / 16 * 9 : n.clientHeight;

		var div = document.createElement('div');
		div.className = 'instant-youtube-container';
		div.srcEmbed = n.src;
		div.style.maxWidth = containerWidth + 'px';
		div.style.height = containerHeight + 'px';
		div.originalWidth = n.width;
		div.originalHeight = n.height;

		var img = div.appendChild(document.createElement('img'));
		img.className = 'instant-youtube-thumbnail';
		img.src = 'https://i.ytimg.com/vi' + (window.chrome?'_webp':'') + '/' + id + '/maxresdefault.' + (window.chrome?'webp':'jpg');
		if (n.clientHeight) {
			img.style.maxWidth = 'auto';
			img.style.width = (containerHeight / 9 * 16) + 'px';
			img.style.marginLeft = Math.round((containerWidth - containerHeight / 9 * 16) / 2) + 'px';
		}
		img.title = 'Shift-click to play directly as HTML5 video';
		img.onload = function(e) {
			var img = e.target;
			if (img.naturalWidth <= 120)
				img.onerror(e);
			else {
				img.style.marginTop = ((img.parentNode.clientHeight - img.clientHeight) / 2).toFixed(1) + 'px';
				img.style.setProperty('opacity', '1');
			}
		}
		img.onerror = function(e) {
			var img = e.target;
			if (img.src.indexOf('maxresdefault') > 0)
				img.src = img.src.replace('maxresdefault','hqdefault');
			else if (img.src.indexOf('hqdefault.webp') > 0)
				img.src = img.src.replace('_webp','').replace('.webp','.jpg');
		};

		div.insertAdjacentHTML('beforeend', '\
				<svg class="instant-youtube-play-button"><path fill-rule="evenodd" clip-rule="evenodd" fill="#1F1F1F" class="ytp-large-play-button-svg" d="M84.15,26.4v6.35c0,2.833-0.15,5.967-0.45,9.4c-0.133,1.7-0.267,3.117-0.4,4.25l-0.15,0.95c-0.167,0.767-0.367,1.517-0.6,2.25c-0.667,2.367-1.533,4.083-2.6,5.15c-1.367,1.4-2.967,2.383-4.8,2.95c-0.633,0.2-1.316,0.333-2.05,0.4c-0.767,0.1-1.3,0.167-1.6,0.2c-4.9,0.367-11.283,0.617-19.15,0.75c-2.434,0.034-4.883,0.067-7.35,0.1h-2.95C38.417,59.117,34.5,59.067,30.3,59c-8.433-0.167-14.05-0.383-16.85-0.65c-0.067-0.033-0.667-0.117-1.8-0.25c-0.9-0.133-1.683-0.283-2.35-0.45c-2.066-0.533-3.783-1.5-5.15-2.9c-1.033-1.067-1.9-2.783-2.6-5.15C1.317,48.867,1.133,48.117,1,47.35L0.8,46.4c-0.133-1.133-0.267-2.55-0.4-4.25C0.133,38.717,0,35.583,0,32.75V26.4c0-2.833,0.133-5.95,0.4-9.35l0.4-4.25c0.167-0.966,0.417-2.05,0.75-3.25c0.7-2.333,1.567-4.033,2.6-5.1c1.367-1.434,2.967-2.434,4.8-3c0.633-0.167,1.333-0.3,2.1-0.4c0.4-0.066,0.917-0.133,1.55-0.2c4.9-0.333,11.283-0.567,19.15-0.7C35.65,0.05,39.083,0,42.05,0L45,0.05c2.467,0,4.933,0.034,7.4,0.1c7.833,0.133,14.2,0.367,19.1,0.7c0.3,0.033,0.833,0.1,1.6,0.2c0.733,0.1,1.417,0.233,2.05,0.4c1.833,0.566,3.434,1.566,4.8,3c1.066,1.066,1.933,2.767,2.6,5.1c0.367,1.2,0.617,2.284,0.75,3.25l0.4,4.25C84,20.45,84.15,23.567,84.15,26.4z M33.3,41.4L56,29.6L33.3,17.75V41.4z"></path><polygon fill-rule="evenodd" clip-rule="evenodd" fill="#FFFFFF" points="33.3,41.4 33.3,17.75 56,29.6"></polygon></svg>\
				<a class="instant-youtube-link" href="https://www.youtube.com/watch?v=' + id + '" target="_blank">Watch on Youtube</a>\
				<span class="instant-youtube-link" style="top:calc(50% + 2em)">' + (playHTML5 ? 'Play with Youtube player' : 'Play directly (up to 720p)') + '</span>\
				<div class="instant-youtube-options">\
					<label for="instant-youtube-options-resize">Resize to fit</label>\
					<input type="checkbox" id="instant-youtube-options-resize"' + (resizeToFit ? ' checked' : '') + '>\
					<label for="instant-youtube-options-html5" title="Shift-click on thumbnail to switch the mode for that video">Play directly</label>\
					<input type="checkbox" id="instant-youtube-options-html5"' + (playHTML5 ? ' checked' : '') + '>\
				</div>\
		');

		n.parentNode.insertBefore(div, n);
		n.remove();

		div.addEventListener('click', clickHandler);
	}

	return true;
}

function clickHandler(e) {
	if (e.target.href)
		return;
	if (e.target.parentNode.className == 'instant-youtube-options') {
		if (e.target.id == 'instant-youtube-options-resize') {
			resizeToFit = e.target.checked;
			GM_setValue('resize', resizeToFit);
			[].forEach.call(document.querySelectorAll('div.instant-youtube-container'), function(n) {
				var w = n.originalWidth, h = n.originalHeight, img = n.querySelector('img');
				if (resizeToFit) {
					for (var np=n.parentNode, npw; np && !(npw=np.clientWidth); np=np.parentNode) {}
					w = npw;
					h = npw / 16 * 9;
				}
				n.style.maxWidth = w + 'px!important';
				n.style.height = h + 'px!important';
				img.style.width = (h / 9 * 16) + 'px!important';
				img.style.marginLeft = Math.round((w - h / 9 * 16) / 2) + 'px!important';
				img.style.marginTop = ((h - img.clientHeight) / 2).toFixed(1) + 'px!important';
				n.querySelector('input').checked = resizeToFit;
				var video = n.querySelector('video');
				if (video) {
					video.width = w;
					video.height = h;
				}
			});
		} else if (e.target.id == 'instant-youtube-options-html5') {
			playHTML5 = e.target.checked;
			GM_setValue('playHTML5', playHTML5);
			[].forEach.call(document.querySelectorAll('div.instant-youtube-container span.instant-youtube-link'), function(n) {
				n.textContent = playHTML5 ? 'Play with Youtube player' : 'Play directly (up to 720p)';
			});
		}
		return;
	}
	for (var div = e.target; !div.srcEmbed; div = div.parentNode) {}
	div.removeEventListener('click', clickHandler);
	div.querySelector('svg').outerHTML = '<span class="instant-youtube-loading-button"></span>';

	var alternateMode = e.target.className == 'instant-youtube-link' || e.shiftKey;
	if (playHTML5 && alternateMode || !playHTML5 && !alternateMode)
		switchToIFrame.call(div);
	else {
		div.querySelector('span.instant-youtube-link').style.display = 'none';
		GM_xmlhttpRequest({
			method: 'GET',
			url: div.srcEmbed.replace(/\/(embed\/|v[=\/])/, '/watch?v='),
			context: div,
			onload: parseWatchPage
		});
	}
}

function parseWatchPage(response) {
	var div = response.context;
	var video = document.createElement('video');
	video.controls = true;
	video.autoplay = true;
	video.width = div.clientWidth;
	video.height = div.clientHeight;
	video.className = 'instant-youtube-embed';
	video.volume = GM_getValue('volume', 0.5);

	var m = response.responseText.match(/ytplayer\.config\s*=\s*(\{.+?\});\s*ytplayer\.load/);
	if (m) {
		var cfg = JSON.parse(m[1]), streams = {};
		cfg.args.url_encoded_fmt_stream_map.split(',').forEach(function(stream) {
			var params = {};
			stream.split('&').forEach(function(kv) { params[kv.split('=')[0]] = decodeURIComponent(kv.split('=')[1]) });
			streams[params.itag] = params;
		});
		cfg.args.fmt_list.split(',').forEach(function(fmt) {
			var itag = fmt.split('/')[0], dimensions = fmt.split('/')[1], stream = streams[itag];
			if (stream) {
				var source = video.appendChild(document.createElement('source'));
				source.onerror = switchToIFrame.bind(div);
				source.src = stream.url;
				source.title = stream.quality + ', ' + dimensions + ', ' + stream.type;
			}
		});
	} else {
		var rx = /url=([^=]+?mime%3Dvideo%252F(?:mp4|webm)[^=]+?)(?:,quality|,itag|.u0026)/g;
		var text = response.responseText.split('url_encoded_fmt_stream_map')[1];
		while (m = rx.exec(text)) {
			var source = document.createElement('source');
			source.onerror = switchToIFrame.bind(div);
			video.appendChild(source).src = decodeURIComponent(decodeURIComponent(m[1]));
		}
	}
	if (video.children.length) {
		if (window.chrome) {
			video.addEventListener('click', function(e) { if (this.paused) {this.play()} else {this.pause()} });
		}
		video.interval = (function() {
			return setInterval(function() {
				if (video.volume != GM_setValue('volume', 0.5))
					GM_setValue('volume', video.volume);
			}, 1000);
		})();
		var title = response.responseText.match(/<title>(.+?)(?:\s*-\s*YouTube)?<\/title>/);
		if (title) {
			var a = div.querySelector('.instant-youtube-link');
			a.innerHTML = '<b>' + title[1] + '</b> - watch on Youtube';
			a.className = 'instant-youtube-link2';
		}
		var img = div.querySelector('img');
		img.style.transition = 'opacity 1s';
		img.style.opacity = 0;
		video.onloadeddata = function(e) {
			div.appendChild(this);
			this.style.opacity = 1;
		};
	} else {
		switchToIFrame.call(div);
	}
	div.querySelector('.instant-youtube-options').style.display = 'none';
}

function switchToIFrame(e) {
	var div = this;
	var iframeHTML = '<iframe class="instant-youtube-embed" allowtransparency="true" src="' + div.srcEmbed + (div.srcEmbed.indexOf('?') > 0 ? '' : '?') +
		'&autoplay=1' +
		'&autohide=2' +
		'&border=0' +
		'&controls=1' +
		'&fs=1' +
		'&showinfo=1' +
		'&ssl=1' +
		'&theme=dark' +
		'" frameborder="0" allowfullscreen="allowfullscreen" width="' + div.clientWidth + '" height="' + div.clientHeight + '"></iframe>';
	console.log('Youtube forbids direct linking on %s, switched to IFRAME player', div.srcEmbed);
	div.insertAdjacentHTML('beforeend', iframeHTML);
	div.lastElementChild.onload = function() {
		this.style.opacity = 1;
		this.ontransitionend = function() {
			this.closest('.instant-youtube-container').querySelector('img').style.display = 'none';
		};
	};
	if (e && e.target) {
		var video = e.target.parentNode;
		while (video.lastElementChild)
			video.lastElementChild.remove();
	}
}