Notes

LOCAL YOUTUBE DOWNLOADER
KANALIN KRALI YOUTUBE ZİYARET EDİN

// ==UserScript==
// @name Local YouTube Downloader
// @name:zh-TW 本地 YouTube 下載器
// @name:zh-CN 本地 YouTube 下载器
// @namespace https://blog.maple3142.net/
// @version 0.6.11
// @description Get youtube raw link without external service.
// @description:zh-TW 不需要透過第三方的服務就能下載 YouTube 影片。
// @description:zh-CN 不需要透过第三方的服务就能下载 YouTube 影片。
// @author maple3142
// @match https://*.youtube.com/*
// @require https://cdnjs.cloudflare.com/ajax/libs/hyperapp/1.2.6/hyperapp.js
// @require https://unpkg.com/[email protected]/xfetch.min.js
// @compatible firefox >=52
// @compatible chrome >=55
// @license MIT
// ==/UserScript==

;(function() {
'use strict'
const DEBUG = false
const create$p = console =>
Object.keys(console)
.map(k => [k, (...args) => (DEBUG ? console[k]('YTDL: ' + args[0], ...args.slice(1)) : void 0)])
.reduce((acc, [k, fn]) => ((acc[k] = fn), acc), {})
const $p = create$p(console)

const LANG_FALLBACK = 'en'
const LOCALE = {
en: {
togglelinks: 'Show/Hide Links',
stream: 'Stream',
adaptive: 'Adaptive',
videoid: 'Video Id: {{id}}',
thumbnail: 'Thumbnail',
inbrowser_adaptive_merger: 'In browser adaptive video & audio merger'
},
'zh-tw': {
togglelinks: '顯示 / 隱藏連結',
stream: '串流 Stream',
adaptive: '自適應 Adaptive',
videoid: '影片 Id: {{id}}',
thumbnail: '影片縮圖',
inbrowser_adaptive_merger: '瀏覽器版自適應影片及聲音合成器'
},
zh: {
togglelinks: '显示 / 隐藏 下载链接',
stream: '串流 Stream',
adaptive: '自适应 Adaptive',
videoid: '视频 ID: {{id}}',
thumbnail: '封面图',
inbrowser_adaptive_merger: '浏览器版自适应视频及声音合成器'
}
}
const YT_THUMB_RES_ORDER = ['maxresdefault', 'hqdefault', 'mqdefault', 'sddefault', 'default']
const checkImgExists = url =>
new Promise(res => {
const img = new Image()
img.onload = () => res(true)
img.onerror = () => res(false)
img.src = url
})
const findLang = l => {
// language resolution logic: zh-tw --(if not exists)--> zh --(if not exists)--> LANG_FALLBACK(en)
l = l.toLowerCase()
if (l in LOCALE) return l
else if (l.length > 2) return findLang(l.split('-')[0])
else return LANG_FALLBACK
}

const format = s => d => s.replace(/{{(w+?)}}/g, (m, g1) => d[g1])
const $ = (s, x = document) => x.querySelector(s)
const $el = (tag, opts) => {
const el = document.createElement(tag)
Object.assign(el, opts)
return el
}
const xhrget = url =>
// not sure why `fetch` doesn't work here
new Promise((res, rej) => {
const xhr = new XMLHttpRequest()
xhr.open('GET', url)
xhr.onreadystatechange = () => {
if (xhr.readyState === xhr.DONE) {
res(xhr.responseText)
}
}
xhr.onerror = rej
xhr.send()
})
const getytplayer = async () => {
if (typeof ytplayer !== 'undefined' && ytplayer.config) return ytplayer
$p.log('No ytplayer is founded')
const html = await xf.get(location.href).text()
const d = /<script >(var ytplayer[sS]*?)ytplayer.load/.exec(html)
let config = eval(d[1])
unsafeWindow.ytplayer = {
config
}
$p.log('ytplayer fetched: %o', unsafeWindow.ytplayer)
return ytplayer
}
const parsedecsig = data => {
try {
if (data.startsWith('var script')) {
// they inject the script via script tag
const obj = {}
const document = { createElement: () => obj, head: { appendChild: () => {} } }
eval(data)
data = obj.innerHTML
}
const fnnameresult = /yt.akamaized.net.*encodeURIComponent((w+)/.exec(data)
const fnname = fnnameresult[1]
const _argnamefnbodyresult = new RegExp(fnname + '=function\((.+?)\){(.+?)}').exec(data)
const [_, argname, fnbody] = _argnamefnbodyresult
const helpernameresult = /;(.+?)..+?(/.exec(fnbody)
const helpername = helpernameresult[1]
const helperresult = new RegExp('var ' + helpername + '={[\s\S]+?};').exec(data)
const helper = helperresult[0]
$p.log(`parsedecsig result: ${argname} => { ${helper}n${fnbody}}`)
return new Function([argname], helper + 'n' + fnbody)
} catch (e) {
$p.error('parsedecsig error: %o', e)
$p.info('script content: %s', data)
$p.info(
'If you encounter this error, please copy the full "script content" to https://pastebin.com/ for me.'
)
}
}
const getdecsig = path => xhrget('https://www.youtube.com' + path).then(parsedecsig)
const parseQuery = s => [...new URLSearchParams(s).entries()].reduce((acc, [k, v]) => ((acc[k] = v), acc), {})
const getVideo = async (id, decsig) => {
return xf
.get(`https://www.youtube.com/get_video_info?video_id=${id}&el=detailpage`)
.text()
.then(async data => {
const obj = parseQuery(data)
$p.log(`video ${id} data: %o`, obj)
if (obj.status === 'fail') {
throw obj
}
let stream = []
if (obj.url_encoded_fmt_stream_map) {
stream = obj.url_encoded_fmt_stream_map.split(',').map(parseQuery)
if (stream[0].sp && stream[0].sp.includes('signature')) {
stream = stream
.map(x => ({ ...x, s: decsig(x.s) }))
.map(x => ({ ...x, url: x.url + `&signature=${x.s}` }))
}
}

let adaptive = []
if (obj.adaptive_fmts) {
adaptive = obj.adaptive_fmts.split(',').map(parseQuery)
if (adaptive[0].sp && adaptive[0].sp.includes('signature')) {
adaptive = adaptive
.map(x => ({ ...x, s: decsig(x.s) }))
.map(x => ({ ...x, url: x.url + `&signature=${x.s}` }))
}
}
$p.log(`video ${id} result: %o`, { stream, adaptive })
return { stream, adaptive, meta: obj }
})
}
const workerMessageHandler = async e => {
const decsig = await getdecsig(e.data.path)
const result = await getVideo(e.data.id, decsig)
self.postMessage(result)
}
const ytdlWorkerCode = `
importScripts('https://unpkg.com/[email protected]/xfetch.min.js')
const DEBUG=${DEBUG}
const $p=(${create$p.toString()})(console)
const parseQuery=${parseQuery.toString()}
const xhrget=${xhrget.toString()}
const parsedecsig=${parsedecsig.toString()}
const getdecsig=${getdecsig.toString()}
const getVideo=${getVideo.toString()}
self.onmessage=${workerMessageHandler.toString()}`
const ytdlWorker = new Worker(URL.createObjectURL(new Blob([ytdlWorkerCode])))
const workerGetVideo = (id, path) => {
$p.log(`workerGetVideo start: ${id} ${path}`)
return new Promise((res, rej) => {
const callback = e => {
ytdlWorker.removeEventListener('message', callback)
$p.log('workerGetVideo end: %o', e.data)
res(e.data)
}
ytdlWorker.addEventListener('message', callback)
ytdlWorker.postMessage({ id, path })
})
}

const { app, h } = hyperapp
const state = {
hide: true,
id: '',
stream: [],
adaptive: [],
thumbnail: null,
dark: false,
lang: findLang(navigator.language),
strings: LOCALE[findLang(navigator.language)]
}
$p.log(`default language: ${state.lang}`)
const actions = {
toggleHide: () => state => ({ hide: !state.hide }),
setState: newstate => state => newstate,
setLang: lang => state => {
const target = findLang(lang)
$p.log(`language change to: ${target}`)
return {
lang: target,
strings: LOCALE[target]
}
},
setDark: dark => state => ({ dark }),
getState: () => state => state
}
const view = (state, actions) =>
h('div', { className: 'box' + (state.dark ? ' dark' : '') }, [
h(
'div',
{ onclick: () => actions.toggleHide(), className: 'box-toggle t-center fs-14px' },
state.strings.togglelinks
),
h('div', { className: state.hide ? 'hide' : '' }, [
h('div', { className: 't-center fs-14px' }, format(state.strings.videoid, state)),
h('div', { className: 't-center fs-14px' }, [
h('a', { href: state.thumbnail, target: '_blank' }, state.strings.thumbnail)
]),
h('div', { className: 'd-flex' }, [
h(
'div',
{ className: 'f-1 of-h' },
[h('div', { className: 't-center fs-14px' }, state.strings.stream)].concat(
state.stream.map(x =>
h(
'a',
{
href: x.url + '&title=' + state.meta.title,
title: x.type,
target: '_blank',
className: 'ytdl-link-btn fs-14px'
},
x.quality || x.type
)
)
)
),
h(
'div',
{ className: 'f-1 of-h' },
[h('div', { className: 't-center fs-14px' }, state.strings.adaptive)].concat(
state.adaptive.map(x =>
h(
'a',
{
href: x.url + '&title=' + state.meta.title,
title: x.type,
target: '_blank',
className: 'ytdl-link-btn fs-14px'
},
(x.quality_label ? x.quality_label + ':' : '') + x.type
)
)
)
)
]),
h(
'div',
{ className: 'of-h t-center' },
h(
'a',
{ href: 'https://maple3142.github.io/mergemp4/', target: '_blank' },
state.strings.inbrowser_adaptive_merger
)
)
])
])
const shadowHost = $el('div')
const shadow = shadowHost.attachShadow ? shadowHost.attachShadow({ mode: 'closed' }) : shadowHost // no shadow dom
const container = $el('div')
shadow.appendChild(container)
const $app = app(state, actions, view, container)
if (DEBUG) unsafeWindow.$app = $app
const load = async id => {
const ytplayer = await getytplayer()
return workerGetVideo(id, ytplayer.config.assets.js)
.then(async data => {
$p.log('video loaded: %s', id)
$app.setState({
id,
stream: data.stream,
adaptive: data.adaptive,
meta: data.meta
})
if (ytplayer.config.args.host_language) $app.setLang(ytplayer.config.args.host_language)

// find highest resolution thumbnail
let url = data.meta.thumbnail_url
for (const res of YT_THUMB_RES_ORDER) {
const u = url.replace('default', res)
if (await checkImgExists(u)) {
// if thumbnail exists
url = u
break
}
}
$app.setState({ thumbnail: url })
})
.catch(err => $p.error('load', err))
}
let prevurl = null
setInterval(() => {
const el = $('#info-contents') || $('#watch-header') || $('ytm-item-section-renderer>lazy-list')
if (el && !el.contains(shadowHost)) el.appendChild(shadowHost)
if (location.href !== prevurl && location.pathname === '/watch') {
prevurl = location.href
$app.setState({
hide: true
})
const id = parseQuery(location.search).v
$p.log(`start loading new video: ${id}`)
load(id)
}
}, 1000)
// listen to dark mode toggle
const $html = $('html')
new MutationObserver(() => {
$app.setDark($html.getAttribute('dark') === 'true')
}).observe($html, { attributes: true })
$app.setDark($html.getAttribute('dark') === 'true')
const css = `
.hide{
display: none;
}
.t-center{
text-align: center;
}
.d-flex{
display: flex;
}
.f-1{
flex: 1;
}
.fs-14px{
font-size: 14px;
}
.of-h{
overflow: hidden;
}
.box{
border-bottom: 1px solid var(--yt-border-color);
font-family: Arial;
}
.box-toggle{
margin: 3px;
user-select: none;
-moz-user-select: -moz-none;
}
.box-toggle:hover{
color: blue;
}
.ytdl-link-btn{
display: block;
border: 1px solid !important;
border-radius: 3px;
text-decoration: none !important;
outline: 0;
text-align: center;
padding: 2px;
margin: 5px;
color: black;
}
a.ytdl-link-btn{
text-decoration: none;
}
a.ytdl-link-btn:hover{
color: blue;
}
.box.dark{
color: var(--ytd-video-primary-info-renderer-title-color, var(--yt-primary-text-color));
}
.box.dark .ytdl-link-btn{
color: var(--ytd-video-primary-info-renderer-title-color, var(--yt-primary-text-color));
}
.box.dark .ytdl-link-btn:hover{
color: rgba(200, 200, 255, 0.8);
}
.box.dark .box-toggle:hover{
color: rgba(200, 200, 255, 0.8);
}
`
shadow.appendChild($el('style', { textContent: css }))
})()