force-youtube-av1.js

// ==UserScript==
// @name                Use YouTube AV1
// @description         Use AV1 for video playback on YouTube
// @name:zh-TW          使用 YouTube AV1
// @description:zh-TW   使用 AV1 進行 YouTube 影片播放
// @name:zh-HK          使用 YouTube AV1
// @description:zh-HK   使用 AV1 進行 YouTube 影片播放
// @name:zh-CN          使用 YouTube AV1
// @description:zh-CN   使用 AV1 进行 YouTube 视频播放
// @name:ja             YouTube AV1 の使用
// @description:ja      YouTube の動画再生に AV1 を使用する
// @name:ko             YouTube AV1 사용
// @description:ko      YouTube의 동영상 재생에 AV1을 사용하기
// @name:vi             Sử dụng YouTube AV1
// @description:vi      Sử dụng AV1 để phát video trên YouTube
// @name:de             YouTube AV1 verwenden
// @description:de      Verwende AV1 für die Videowiedergabe auf YouTube
// @name:fr             Utiliser YouTube AV1
// @description:fr      Utiliser AV1 pour la lecture des vidéos sur YouTube
// @name:it             Usa YouTube AV1
// @description:it      Usa AV1 per la riproduzione dei video su YouTube
// @name:es             Usar AV1 en YouTube
// @description:es      Usar AV1 para la reproducción de videos en YouTube
// @namespace           http://tampermonkey.net/
// @version             2.4.3
// @author              CY Fung
// @match               https://www.youtube.com/*
// @match               https://www.youtube.com/embed/*
// @match               https://www.youtube-nocookie.com/embed/*
// @exclude             https://www.youtube.com/live_chat*
// @exclude             https://www.youtube.com/live_chat_replay*
// @exclude             /^https?://\S+\.(txt|png|jpg|jpeg|gif|xml|svg|manifest|log|ini)[^\/]*$/
// @icon                https://www.google.com/s2/favicons?sz=64&domain=youtube.com
// @grant               none
// @run-at              document-start
// @license             MIT
//
// @compatible          firefox Violentmonkey
// @compatible          firefox Tampermonkey
// @compatible          firefox FireMonkey
// @compatible          chrome Violentmonkey
// @compatible          chrome Tampermonkey
// @compatible          opera Violentmonkey
// @compatible          opera Tampermonkey
// @compatible          safari Stay
// @compatible          edge Violentmonkey
// @compatible          edge Tampermonkey
// @compatible          brave Violentmonkey
// @compatible          brave Tampermonkey
//
// @unwrap
// @allFrames           true
// @inject-into         page
// ==/UserScript==



(function (__Promise__) {
  'use strict';

  /** @type {globalThis.PromiseConstructor} */
  const Promise = (async () => { })().constructor; // YouTube hacks Promise in WaterFox Classic and "Promise.resolve(0)" nevers resolve.

  console.debug("force-youtube-av1", "injected");



  const flagConfig = () => {

    let firstDa = true;
    let cid = 0;
    const { setInterval, clearInterval, setTimeout } = window;
    const tn = () => {

      const da = (window.ytcfg && window.ytcfg.data_) ? window.ytcfg.data_ : null;
      if (!da) return;

      const isFirstDa = firstDa;
      firstDa = false;

      for (const EXPERIMENT_FLAGS of [da.EXPERIMENT_FLAGS, da.EXPERIMENTS_FORCED_FLAGS]) {

        if (EXPERIMENT_FLAGS) {
          // EXPERIMENT_FLAGS.html5_disable_av1_hdr = false;
          // EXPERIMENT_FLAGS.html5_prefer_hbr_vp9_over_av1 = false;
          // EXPERIMENT_FLAGS.html5_account_onesie_format_selection_during_format_filter = false;
        }

      }

      if (isFirstDa) {


        let mo = new MutationObserver(() => {

          mo.disconnect();
          mo.takeRecords();
          mo = null;
          setTimeout(() => {
            cid && clearInterval.call(window, cid);
            cid = 0;
            tn();
          })
        });
        mo.observe(document, { subtree: true, childList: true });


      }


    };
    cid = setInterval.call(window, tn);

  };


  const supportedFormatsConfig = () => {


    function typeTest(type) {

      if (typeof type === 'string' && type.startsWith('video/')) {
        if (type.includes('av01')) {
          if (/codecs[\x20-\x7F]+\bav01\b/.test(type)) return true;
        } else if (type.includes('av1')) {
          if (/codecs[\x20-\x7F]+\bav1\b/.test(type)) return true;
        }
      }

    }

    // return a custom MIME type checker that can defer to the original function
    function makeModifiedTypeChecker(origChecker, dx) {
      // Check if a video type is allowed
      return function (type) {
        let res = undefined;
        if (type === undefined) res = false;
        else res = typeTest(type);
        if (res === undefined) res = origChecker.apply(this, arguments);
        else res = !dx ? res : (res ? "probably" : "");

        // console.debug(20, type, res)

        return res;
      };
    }

    // Override video element canPlayType() function
    const proto = (HTMLVideoElement || 0).prototype;
    if (proto && typeof proto.canPlayType == 'function') {
      proto.canPlayType = makeModifiedTypeChecker(proto.canPlayType, true);
    }

    // Override media source extension isTypeSupported() function
    const mse = window.MediaSource;
    // Check for MSE support before use
    if (mse && typeof mse.isTypeSupported == 'function') {
      mse.isTypeSupported = makeModifiedTypeChecker(mse.isTypeSupported);
    }


  }

  function enableAV1() {


    // This is the setting to force AV1
    // localStorage['yt-player-av1-pref'] = '8192';
    try {
      Object.defineProperty(localStorage.constructor.prototype, 'yt-player-av1-pref', {
        get() {
          if (this === localStorage) return '8192';
          return this.getItem('yt-player-av1-pref');
        },
        set(nv) {
          this.setItem('yt-player-av1-pref', nv);
          return true;
        },
        enumerable: true,
        configurable: true
      });
    } catch (e) {
      // localStorage['yt-player-av1-pref'] = '8192';
    }

    if (localStorage['yt-player-av1-pref'] !== '8192') {

      console.warn('Use YouTube AV1 is not supported in your browser.');
      return;
    }


    console.debug("force-youtube-av1", "AV1 enabled");


    // flagConfig();
    supportedFormatsConfig();



  }




  let promise = null;

  try {
    promise = navigator.mediaCapabilities.decodingInfo({
      type: "file",
      video: {
        contentType: "video/mp4; codecs=av01.0.05M.08.0.110.05.01.06.0",
        height: 1080,
        width: 1920,
        framerate: 30,
        bitrate: 2826848,
      },
      audio: {
        contentType: "audio/webm; codecs=opus",
        channels: "2.1",
        samplerate: 44100,
        bitrate: 255236,
      }
    });
  } catch (e) {
    promise = null;
  }


  const callback = (result) => {

    if (result && result.supported && result.smooth) enableAV1();
    else {
      console.warn("force-youtube-av1", 'Your browser does not support AV1. You might conside to use the latest version of Google Chrome or Mozilla FireFox.');
    }
  };

  (promise || Promise.resolve(0)).catch(callback).then(callback);



})(Promise);