Greasy Fork

// ==UserScript==
// @name 油管直接翻译 ACT.YouTube.DM.Auto-translate
// @name:zh-CN ACT.YouTube.DM.自动翻译
// @description Automatically translate any non-specified language Subtitles/CC.
// @description:zh-CN 自动翻译任何非指定语言字幕。
// @author ACTCD
// @version 20220327.3
// @license GPL-3.0-or-later
// @namespace ACTCD/Userscripts
// @supportURL https://github.com/ACTCD/Userscripts#contact
// @homepageURL https://github.com/ACTCD/Userscripts
// @updateURL https://raw.githubusercontent.com/ACTCD/Userscripts/main/userjs/ACT.YouTube.DM.Auto-translate.user.js
// @downloadURL https://raw.githubusercontent.com/ACTCD/Userscripts/main/userjs/ACT.YouTube.DM.Auto-translate.user.js
// @match *://*.youtube.com/*
// @match *://www.youtube-nocookie.com/embed/*
// @grant none
// @run-at document-start
// ==/UserScript==

(function () {
'use strict';

const inline_script = () => {
const tlang = navigator.language || 'zh-CN'; // Specified language // 指定语言
const cache = { req_url: null, obj_url: null };
const XMLHttpRequest_open = XMLHttpRequest.prototype.open;
XMLHttpRequest.prototype.open = function () {
const url = new URL(arguments[1], location.href);
if (url.pathname == '/api/timedtext') {
const lang = url.searchParams.get('lang');
if (lang && lang != tlang) {
const req_url = url.href;
if (req_url == cache.req_url) {
arguments[1] = cache.obj_url;
} else {
URL.revokeObjectURL(cache.obj_url);
this.addEventListener('load', event => {
cache.req_url = req_url;
cache.obj_url = URL.createObjectURL(new Blob([this.responseText], { type: 'application/json' }));
});
url.searchParams.set('tlang', tlang);
arguments[1] = url.href;
}
}
}
XMLHttpRequest_open.apply(this, arguments);
};
}

const script = document.createElement("script");
script.textContent = '(' + inline_script + ')();';

if (document.head) {
document.head.appendChild(script);
} else {
new MutationObserver((mutationList, observer) => {
document.head && (observer.disconnect() || document.head.append(script));
}).observe(document, { subtree: true, childList: true });
}

})();