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Disable AV1 for video playback on YouTube
// ==UserScript==
// @name Disable YouTube AV1
// @description Disable AV1 for video playback on YouTube
// @name:zh-TW 停用 YouTube AV1
// @description:zh-TW 停用 YouTube 的 AV1 影片播放
// @name:zh-HK 停用 YouTube AV1
// @description:zh-HK 停用 YouTube 的 AV1 影片播放
// @name:zh-CN 停用 YouTube AV1
// @description:zh-CN 停用 YouTube 的 AV1 视频播放
// @name:ja YouTube AV1 停用
// @description:ja YouTube の動画再生に AV1 を停用する
// @name:ko YouTube AV1 비활성화
// @description:ko YouTube의 동영상 재생에 AV1을 비활성화하기
// @name:vi Vô hiệu hóa YouTube AV1
// @description:vi Vô hiệu hóa AV1 để phát video trên YouTube
// @name:de YouTube AV1 deaktivieren
// @description:de Deaktiviert AV1 für die Videowiedergabe auf YouTube
// @name:fr Désactiver YouTube AV1
// @description:fr Désactivez AV1 pour la lecture des vidéos sur YouTube
// @name:it Disabilita YouTube AV1
// @description:it Disabilita AV1 per la riproduzione dei video su YouTube
// @name:es Desactivar AV1 en YouTube
// @description:es Desactivar AV1 para la reproducción de videos en YouTube
// @namespace http://tampermonkey.net/
// @version 2.4.5
// @author CY Fung
// @match https://www.youtube.com/*
// @match https://www.youtube.com/embed/*
// @match https://www.youtube-nocookie.com/embed/*
// @match https://m.youtube.com/*
// @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 chrome
// @compatible firefox
// @compatible opera
// @compatible edge
// @compatible safari
// @unwrap
// @allFrames true
// @inject-into page
// ==/UserScript==
(function () {
'use strict';
console.debug("disable-youtube-av1", "injected");
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 false;
} else if (type.includes('av1')) {
if (/codecs[\x20-\x7F]+\bav1\b/.test(type)) return false;
}
}
}
// 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 disableAV1() {
// This is the setting to disable AV1 [ 480p (or below) - AV1, above 480p - VP9 ]
// localStorage['yt-player-av1-pref'] = '480';
try {
Object.defineProperty(localStorage.constructor.prototype, 'yt-player-av1-pref', {
get() {
if (this === localStorage) return '480';
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'] = '480';
}
if (localStorage['yt-player-av1-pref'] !== '480') {
console.warn('disable-youtube-av1', '"yt-player-av1-pref = 480" is not supported in your browser.');
return;
}
console.debug("disable-youtube-av1", "AV1 disabled by yt-player-av1-pref = 480");
}
disableAV1();
supportedFormatsConfig();
})();