Enhances YouTube with dual language subtitles.
// ==UserScript==
// @name YtDLS: YouTube Dual Language Subtitle (Modified)
// @name:zh-CN YtDLS: Youtube 双语字幕（改）
// @name:zh-TW YtDLS: Youtube 雙語字幕（改）
// @version 2.1.4
// @description Enhances YouTube with dual language subtitles.
// @description:zh-CN 为YouTube添加双语字幕增强功能。
// @description:zh-TW 增強YouTube的雙語字幕功能。
// @author CY Fung
// @author Coink Wang
// @match https://www.youtube.com/*
// @match https://m.youtube.com/*
// @exclude /^https?://\S+\.(txt|png|jpg|jpeg|gif|xml|svg|manifest|log|ini|webp|webm)[^\/]*$/
// @exclude /^https?://\S+_live_chat*$/
// @require https://cdn.jsdelivr.net/gh/culefa/xhProxy@eaa2e84b40290fc63af1ca777f3f545008bf79bb/dist/xhProxy.min.js
// @grant none
// @inject-into page
// @allFrames true
// @run-at document-start
// @namespace Y2BDoubleSubs
// @license MIT
// @supportURL https://github.com/cyfung1031/Y2BDoubleSubs/tree/translation-api
// ==/UserScript==
/* global xhProxy */
/*
original script: https://greasyfork.org/scripts/397363
based on v1.8.0 + PR#18 ( https://github.com/CoinkWang/Y2BDoubleSubs/pull/18 ) [v2.0.0]
added m.youtube.com support based on two scripts (https://greasyfork.org/scripts/457476 & https://greasyfork.org/scripts/464879 ) which are fork from v1.8.0
*/
(() => {
let localeLangFn = () => document.documentElement.lang || navigator.language || 'en' // follow the language used in YouTube Page
// localeLangFn = () => 'zh' // uncomment this line to define the language you wish here
function isValidForHook() {
try {
if (location.pathname === '/live_chat' || location.pathname === '/live_chat_replay') return false;
return true;
} catch (e) {
return false;
}
}
if (!isValidForHook()) return;
const Promise = (async () => { })().constructor;
const fetch = window.fetch.bind(window)
let enableFullWidthSpaceSeparation = true
function encodeFullwidthSpace(text) {
if (!enableFullWidthSpaceSeparation) return text
return text.replace(/\n/g, '\n®\n').replace(/\u3000/g, '\n©\n')
}
function decodeFullwidthSpace(text) {
if (!enableFullWidthSpaceSeparation) return text
return text.replace(/\n©\n/g, '\u3000').replace(/\n®\n/g, '\n')
}
let requestDeferred = Promise.resolve();
const inPlaceArrayPush = (() => {
// for details, see userscript-supports/library/misc.js
const LIMIT_N = typeof AbortSignal !== 'undefined' && typeof (AbortSignal||0).timeout === 'function' ? 50000 : 10000;
return function (dest, source) {
let index = 0;
const len = source.length;
while (index < len) {
let chunkSize = len - index; // chunkSize > 0
if (chunkSize > LIMIT_N) {
chunkSize = LIMIT_N;
dest.push(...source.slice(index, index + chunkSize));
} else if (index > 0) { // to the end
dest.push(...source.slice(index));
} else { // normal push.apply
dest.push(...source);
}
index += chunkSize;
}
}
})();
xhProxy.hook({
onConfig(xhr, config) {
const originalReqUrl = config.url;
if (typeof ytcfg !== 'object' || !originalReqUrl.includes('/api/timedtext') || originalReqUrl.includes('&translate_h00ked')){
this.byPassRequest = true;
}
// config.byPassRequest = true;
// console.log(xhr, config)
},
onRequest(xhr, config) {
// console.log(xhr, config)
},
async onResponse(xhr, config) {
const o = {}
try {
const originalReqUrl = config.url;
if (!originalReqUrl.includes('/api/timedtext') || originalReqUrl.includes('&translate_h00ked')) return;
if (typeof ytcfg !== 'object') return; // not a valid youtube page
let defaultJson = null
const jsonResponse = xhr.xhJson;
if (jsonResponse && jsonResponse.events) defaultJson = jsonResponse;
if (defaultJson === null) return;
const localeLang = localeLangFn()
const langIdx = originalReqUrl.indexOf('lang=')
if (langIdx > 5) {
// &key=yt8&lang=en&fmt=json3&xorb=2&xobt=3&xovt=3
// &key=yt8&lang=ja&fmt=json3&xorb=2&xobt=3&xovt=3
// &key=yt8&lang=ja&name=Romaji&fmt=json3&xorb=2&xobt=3
let ulc = originalReqUrl.charAt(langIdx - 1)
if (ulc === '?' || ulc === '&') {
let usp = new URLSearchParams(originalReqUrl.substring(langIdx))
let uspLang = usp.get('lang')
let uspName = usp.get('name')
if (uspName === 'Romaji') return defaultAction()
if (typeof uspLang === 'string' && uspLang.toLocaleLowerCase() === localeLang.toLocaleLowerCase()) return;
}
}
const lines = []
for (const event of defaultJson.events) {
for (const seg of event.segs) {
if (seg && typeof seg.utf8 === 'string') {
inPlaceArrayPush(lines, seg.utf8.split('\n'));
}
}
}
if (lines.length === 0) return defaultAction()
let linesText = lines.join('\n')
linesText = encodeFullwidthSpace(linesText)
const q = encodeURIComponent(linesText)
o.defaultJson = defaultJson
o.lines = lines
o.requestURL = `https://translate.googleapis.com/translate_a/single?client=gtx&sl=auto&tl=${localeLang}&dj=1&dt=t&dt=rm&q=${q}`
} catch (e) {
console.warn(e)
return;
}
return new Promise(xhrResolve => {
function fetchData() {
return new Promise(requestDeferredResolve => {
fetch(o.requestURL, {
method: "GET",
headers: {
"Accept": "application/json",
"Accept-Encoding": "gzip, deflate, br"
},
credentials: "omit",
referrerPolicy: "no-referrer",
redirect: "error",
keepalive: false,
cache: "default"
})
.then(res => {
requestDeferredResolve()
return res.json()
})
.then(result => {
let resultText = result.sentences.map((function (s) {
return "trans" in s ? s.trans : ""
})).join("")
resultText = decodeFullwidthSpace(resultText)
return resultText.split("\n")
})
.then(translatedLines => {
const { lines, defaultJson } = o
o.lines = null
o.defaultJson = null
const addTranslation = (line, idx) => {
if (line !== lines[i + idx]) return line
let translated = translatedLines[i + idx]
if (line === translated) return line
return `${line}\n${translated}`
}
let i = 0
for (const event of defaultJson.events) {
for (const seg of event.segs) {
if (seg && typeof seg.utf8 === 'string') {
let s = seg.utf8.split('\n')
let st = s.map(addTranslation)
seg.utf8 = st.join('\n')
i += s.length
}
}
}
xhr.xhJson = defaultJson;
xhrResolve()
}).catch(e => {
console.warn(e)
xhrResolve()
})
})
}
requestDeferred = requestDeferred.then(fetchData)
})
}
})
})();