Add dual subtitles to YouTube videos
目前为
// ==UserScript==
// @name YouTube Dual Subtitles for French, German, Russian, Ukrainian
// @namespace http://tampermonkey.net/
// @version 2.0
// @license Unlicense
// @description Add dual subtitles to YouTube videos
// @author Jim Chen
// @homepage https://jimchen.me
// @match https://www.youtube.com/*
// @match https://m.youtube.com/*
// @run-at document-idle
// ==/UserScript==
(function () {
"use strict";
let lastUrl = location.href;
let processingSubtitles = false;
const observer = new MutationObserver(() => {
if (location.href !== lastUrl) {
lastUrl = location.href;
handleVideoNavigation();
}
});
observer.observe(document.body, { childList: true, subtree: true });
handleVideoNavigation();
async function handleVideoNavigation() {
removeSubs();
if (processingSubtitles == true) return;
processingSubtitles = true;
let subtitleURL = await extractSubtitleUrl();
processingSubtitles = false;
if (subtitleURL == null) return;
await addOneSubtitle(subtitleURL + "&tlang=en");
await addOneSubtitle(subtitleURL);
}
async function extractSubtitleUrl() {
function extractYouTubeVideoID() {
const url = window.location.href;
const patterns = {
standard: /(?:https?:\/\/)?(?:www\.)?youtube\.com\/watch\?v=([^&]+)/,
embed: /(?:https?:\/\/)?(?:www\.)?youtube\.com\/embed\/([^?]+)/,
mobile: /(?:https?:\/\/)?(?:www\.)?youtu\.be\/([^?]+)/,
};
let videoID = null;
if (patterns.standard.test(url)) {
videoID = url.match(patterns.standard)[1];
} else if (patterns.embed.test(url)) {
videoID = url.match(patterns.embed)[1];
} else if (patterns.mobile.test(url)) {
videoID = url.match(patterns.mobile)[1];
}
return videoID;
}
let videoID = extractYouTubeVideoID();
if (videoID == null) return;
const playerData = await new Promise((resolve) => {
const checkForPlayer = () => {
let ytAppData = document.querySelector("#movie_player");
let captionData = ytAppData?.getPlayerResponse()?.captions?.playerCaptionsTracklistRenderer?.captionTracks;
if (captionData) {
const fetchedBaseUrl = captionData[0].baseUrl;
const fetchedVideoID = fetchedBaseUrl.match(/[?&]v=([^&]+)/)?.[1];
if (fetchedVideoID !== videoID) setTimeout(checkForPlayer, 1000);
else resolve(captionData);
} else setTimeout(checkForPlayer, 1000);
};
checkForPlayer();
});
if (!playerData) return;
const hasForeignTrack = playerData.some(({ vssId }) => /(ru|uk|de|fr)/.test(vssId));
if (hasForeignTrack) {
const autoGeneratedTrack = playerData.find((track) => ["a.ru", "a.uk", "a.de", "a.fr"].includes(track.vssId));
const manualTrack = playerData.find((track) => ["ru", "uk", "de", "fr"].some((code) => track.vssId.includes(code)));
const otherTrack = autoGeneratedTrack || manualTrack;
if (!otherTrack) return;
return `${otherTrack.baseUrl}&fmt=vtt`;
}
}
async function addOneSubtitle(url, maxRetries = 5, delay = 1000) {
const video = document.querySelector("video");
try {
const response = await fetch(url);
const subtitleData = (await response.text()).replaceAll("align:start position:0%", "");
const track = document.createElement("track");
track.src = "data:text/vtt," + encodeURIComponent(subtitleData);
await new Promise((resolve) => setTimeout(resolve, delay));
video.appendChild(track);
track.track.mode = "showing";
} catch (error) {
if (maxRetries > 0) {
await new Promise((resolve) => setTimeout(resolve, delay));
return addOneSubtitle(url, maxRetries - 1, delay);
}
}
}
function removeSubs() {
const video = document.getElementsByTagName("video")[0];
if (!video) return;
const tracks = video.getElementsByTagName("track");
Array.from(tracks).forEach(function (ele) {
ele.track.mode = "hidden";
ele.parentNode.removeChild(ele);
});
}
})();