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.

Versione datata 12/05/2015. Vedi la nuova versione l'ultima versione.

Dovrai installare un'estensione come Tampermonkey, Greasemonkey o Violentmonkey per installare questo script.

You will need to install an extension such as Tampermonkey to install this script.

Dovrai installare un'estensione come Tampermonkey o Violentmonkey per installare questo script.

Dovrai installare un'estensione come Tampermonkey o Userscripts per installare questo script.

Dovrai installare un'estensione come ad esempio Tampermonkey per installare questo script.

Dovrai installare un gestore di script utente per installare questo script.

(Ho già un gestore di script utente, lasciamelo installare!)

Dovrai installare un'estensione come ad esempio Stylus per installare questo stile.

Dovrai installare un'estensione come ad esempio Stylus per installare questo stile.

Dovrai installare un'estensione come ad esempio Stylus per installare questo stile.

Dovrai installare un'estensione per la gestione degli stili utente per installare questo stile.

Dovrai installare un'estensione per la gestione degli stili utente per installare questo stile.

Dovrai installare un'estensione per la gestione degli stili utente per installare questo stile.

(Ho già un gestore di stile utente, lasciamelo installare!)

// ==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       1.0.8
// @author        wOxxOm
// @namespace     wOxxOm.scripts
// @license       MIT License
// @grant         GM_getValue
// @grant         GM_setValue
// @grant         GM_addStyle
// @grant         GM_xmlhttpRequest
// @run-at        document-start
// ==/UserScript==

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

processNodes(null, document.querySelectorAll(embedSelector));
document.addEventListener('DOMContentLoaded', function() {
  processNodes(null, document.querySelectorAll(embedSelector));
  setMutationHandler(document, embedSelector, processNodes);
  GM_addStyle('\
      .instant-youtube-container:not(small) {position:relative; overflow:hidden; cursor:pointer; background-color:black}\
      .instant-youtube-container:not(small) .instant-youtube-thumbnail {transition:opacity 0.1s ease-out; opacity:0}\
      .instant-youtube-container:not(small) .instant-youtube-play-button {position:absolute; left:0; right:0; top:0; bottom:0; margin:auto; width:85px; height:60px}\
      .instant-youtube-container:not(small) .instant-youtube-loading-button {position:absolute; left:0; right:0; top:0; bottom:0; margin:auto; display:block; width:20px; height:20px; background: url("data:image/gif;base64,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")}\
      .instant-youtube-container:hover:not(small) .ytp-large-play-button-svg {fill:#CC181E}\
      .instant-youtube-container:not(small) .instant-youtube-link {\
        position:absolute; top:50%; left:0; right:0; width:20em; height:1.7em; margin:60px auto;\
        display:block; text-align:center; text-decoration:none; color:white; text-shadow:1px 1px 3px black;\
        font:14px/1.0 bold Arial,Helvetica,Verdana,Sans-serif;\
      }\
      .instant-youtube-container:not(small) .instant-youtube-link:hover { color:white; text-decoration:underline; background:transparent }\
      .instant-youtube-container:not(small) .instant-youtube-embed {position:absolute; left:0; top:0}\
      .instant-youtube-container:not(small) .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; font:14px/1.0 normal Arial,Helvetica,Verdana,Sans-serif;\
      }\
      .instant-youtube-container:not(small):hover .instant-youtube-link2 {display:block}\
      .instant-youtube-container:not(small) .instant-youtube-link2:hover {text-decoration:underline}\
      .instant-youtube-container:not(small) .instant-youtube-options {position:absolute; right:0; bottom:0; color:white; text-shadow:1px 1px 2px black }\
      .instant-youtube-container:not(small) .instant-youtube-options * {font-size:13px; vertical-align:middle}\
  ');
});

function processNodes(observer, 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[=\/])(.+?)(?:[&?\/].*|$)/);
    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 {
        if (img.src.indexOf('maxresdefault') < 0)
          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"><b>Watch on Youtube</b></a>\
        <span class="instant-youtube-link" style="margin-top:6em">Watch as HTML5</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' : '') + '>\
        </div>\
    ');

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

    div.addEventListener('click', 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';
            n.style.height = h + 'px';
            img.style.width = (h / 9 * 16) + 'px';
            img.style.marginLeft = Math.round((w - h / 9 * 16) / 2) + 'px';
            img.style.marginTop = ((h - img.clientHeight) / 2).toFixed(1) + 'px';
            n.querySelector('input').checked = resizeToFit;
            var video = n.querySelector('video');
            if (video) {
              video.width = w;
              video.height = h;
            }
          });
        }
        return;
      }
      for (var div = e.target; !div.srcEmbed; div = div.parentNode) {}
      var iframeHTML = '<iframe class="instant-youtube-embed" 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>';
      div.removeEventListener('click', clickHandler);
      div.querySelector('svg').outerHTML = '<span class="instant-youtube-loading-button"></span>';
      
      if (!e.shiftKey && e.target.className != 'instant-youtube-link')
        div.insertAdjacentHTML('beforeend', iframeHTML);
      else {
        div.querySelector('span.instant-youtube-link').style.display = 'none';
        GM_xmlhttpRequest({
          method: 'GET',
          url: div.srcEmbed.replace(/\/(embed\/|v[=\/])/, '/watch?v='),
          onload: function(response) {
            var video;
            video = div.appendChild(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;
            if (m = response.responseText.match(/ytplayer\.config\s*=\s*(\{.+?\});/)) {
              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.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)) {
                video.appendChild(document.createElement('source')).src = decodeURIComponent(decodeURIComponent(m[1]));
              }
            }
            if (video.children.length) {
              if (window.chrome) {
                video.addEventListener('click', function(e) { if (e.target.paused) {e.target.play()} else {e.target.pause()} });
              }
              video.interval = (function() {
                return setInterval(function() {
                  if (video.paused)
                    clearInterval(video.interval);
                  else
                    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';
              }
              div.querySelector('img').style.display = 'none';
            } else {
              video.remove();
              div.insertAdjacentHTML('beforeend', iframeHTML);
            }
          }
        });
      } 
    });
  }
  
  return true;
}

function setMutationHandler(baseNode, selector, cb) {
  var ob = new MutationObserver(function(mutations){
    for (var i=0, ml=mutations.length, m; (i<ml) && (m=mutations[i]); i++)
      for (var j=0, nodes=m.addedNodes, nl=nodes.length, n; (j<nl) && (n=nodes[j]); j++)
        if (n.nodeType == 1) 
          if ((n = n.matches(selector) ? [n] : n.querySelectorAll(selector)) && n.length)
            if (!cb(ob, n))
              return;
  });
  ob.observe(baseNode, {subtree:true, childList:true}); 
}