Netflix - subtitle downloader

Allows you to download subtitles from Netflix

Versión del día 22/02/2020. Echa un vistazo a la versión más reciente.

Tendrás que instalar una extensión para tu navegador como Tampermonkey, Greasemonkey o Violentmonkey si quieres utilizar este script.

Necesitarás instalar una extensión como Tampermonkey o Violentmonkey para instalar este script.

Necesitarás instalar una extensión como Tampermonkey o Violentmonkey para instalar este script.

Necesitarás instalar una extensión como Tampermonkey o Userscripts para instalar este script.

Necesitará instalar una extensión como Tampermonkey para instalar este script.

Necesitarás instalar una extensión para administrar scripts de usuario si quieres instalar este script.

(Ya tengo un administrador de scripts de usuario, déjame instalarlo)

Necesitará instalar una extensión como Stylus para instalar este estilo.

Necesitará instalar una extensión como Stylus para instalar este estilo.

Necesitará instalar una extensión como Stylus para instalar este estilo.

Necesitará instalar una extensión del gestor de estilos de usuario para instalar este estilo.

Necesitará instalar una extensión del gestor de estilos de usuario para instalar este estilo.

Necesitará instalar una extensión del gestor de estilos de usuario para instalar este estilo.

(Ya tengo un administrador de estilos de usuario, déjame instalarlo)

// ==UserScript==
// @name        Netflix - subtitle downloader
// @description Allows you to download subtitles from Netflix
// @license     MIT
// @version     3.2.1
// @namespace   tithen-firion.github.io
// @include     https://www.netflix.com/*
// @grant       unsafeWindow
// @require     https://cdn.jsdelivr.net/gh/Stuk/jszip@579beb1d45c8d586d8be4411d5b2e48dea018c06/dist/jszip.min.js?version=3.1.5
// @require     https://cdn.jsdelivr.net/gh/eligrey/FileSaver.js@283f438c31776b622670be002caf1986c40ce90c/dist/FileSaver.min.js?version=2018-12-29
// ==/UserScript==

class ProgressBar { 
  constructor(max) {
    this.current = 0;
    this.max = max;

    let container = document.querySelector('#userscript_progress_bars');
    if(container === null) {
      container = document.createElement('div');
      container.id = 'userscript_progress_bars'
      document.body.appendChild(container)
      container.style
      container.style.position = 'fixed';
      container.style.top = 0;
      container.style.left = 0;
      container.style.width = '100%';
      container.style.background = 'red';
      container.style.zIndex = '99999999';
    }

    this.progressElement = document.createElement('div');
    this.progressElement.style.width = 0;
    this.progressElement.style.height = '10px';
    this.progressElement.style.background = 'green';

    container.appendChild(this.progressElement);
  }
  
  increment() {
    this.current += 1;
    if(this.current <= this.max)
      this.progressElement.style.width = this.current / this.max * 100 + '%';
  }

  destroy() {
    this.progressElement.remove();
  }
}

const MAIN_TITLE = '.player-status-main-title, .ellipsize-text>h4, .video-title>h4';
const TRACK_MENU = '#player-menu-track-settings, .audio-subtitle-controller';
const NEXT_EPISODE = '.player-next-episode:not(.player-hidden), .button-nfplayerNextEpisode';

const WEBVTT = 'webvtt-lssdh-ios8';

const DOWNLOAD_MENU = `<lh class="list-header">Netflix subtitle downloader</lh>
<li class="list-header">Netflix subtitle downloader</li>
<li class="track download">Download subs for this episode</li>
<li class="track download-all">Download subs from this ep till last available</li>
<li class="track force-all-lang">Force Netflix to show all languages: <span></span></li>
<li class="track lang-setting">Languages to download: <span></span></li>`;

const SCRIPT_CSS = `.player-timed-text-tracks, .track-list-subtitles{ border-right:1px solid #000 }
.player-timed-text-tracks+.player-timed-text-tracks, .track-list-subtitles+.track-list-subtitles{ border-right:0 }
.subtitle-downloader-menu { list-style:none }
#player-menu-track-settings .subtitle-downloader-menu li.list-header,
.audio-subtitle-controller .subtitle-downloader-menu lh.list-header{ display:none }`;

const SUB_TYPES = {
  'subtitles': '',
  'closedcaptions': '[cc]'
};

let zip;
let subCache = {};
let batch = false;

let forceSubs = localStorage.getItem('NSD_force-all-lang') !== 'false';
let langs = localStorage.getItem('NSD_lang-setting') || '';

const setForceText = () => {
	document.querySelector('.subtitle-downloader-menu > .force-all-lang > span').innerHTML = (forceSubs ? 'on' : 'off');
};
const setLangsText = () => {
	document.querySelector('.subtitle-downloader-menu > .lang-setting > span').innerHTML = (langs === '' ? 'all' : langs);
};

const toggleForceLang = () => {
	forceSubs = !forceSubs;
  if(forceSubs)
    localStorage.removeItem('NSD_force-all-lang');
  else
    localStorage.setItem('NSD_force-all-lang', forceSubs);
  document.location.reload();
};
const setLangToDownload = () => {
  const result = prompt('Languages to download, comma separated. Leave empty to download all subtitles.\nExample: en,de,fr', langs);
  if(result !== null) {
    langs = result;
    if(langs === '')
      localStorage.removeItem('NSD_lang-setting');
    else
      localStorage.setItem('NSD_lang-setting', langs);
    setLangsText();
  }
};

const popRandomElement = arr => {
  return arr.splice(arr.length * Math.random() << 0, 1)[0];
};

// get show name or full name with episode number
const __getTitle = full => {
  if(typeof full === 'undefined')
    full = true;
  const titleElement = document.querySelector(MAIN_TITLE);
  if(titleElement === null)
    return null;
  const title = [titleElement.textContent.replace(/[:*?"<>|\\\/]+/g, '_').replace(/ /g, '.')];
  if(full) {
    const episodeElement = titleElement.nextElementSibling;
    if(episodeElement) {
      const m = episodeElement.textContent.match(/^[^\d]*(\d+)[^\d]+(\d+)[^\d]*$/);
      if(m && m.length == 3) {
        title.push(`S${m[1].padStart(2, '0')}E${m[2].padStart(2, '0')}`);
      }
      else {
        title.push(episodeElement.textContent.trim().replace(/[:*?"<>|\\\/]+/g, '_').replace(/ /g, '.'));
      }
    }
    title.push('WEBRip.Netflix');
  }
  return title.join('.');
};
// helper function, periodically checking for the title and resolving promise if found
const _getTitle = (full, resolve) => {
  const title = __getTitle(full);
  if(title === null)
    window.setTimeout(_getTitle, 200, full, resolve);
  else
    resolve(title);
};
// promise of a title
const getTitle = full => new Promise(resolve => {
  _getTitle(full, resolve);
});

const processSubInfo = async result => {
  const tracks = result.timedtexttracks;
  const titleP = getTitle();
  const subs = {};
  for(const track of tracks) {
    if(track.isNoneTrack)
      continue;
    if(typeof track.ttDownloadables[WEBVTT] === 'undefined')
      continue;

    let type = SUB_TYPES[track.rawTrackType];
    if(typeof type === 'undefined')
      type = `[${track.rawTrackType}]`;
    const lang = track.language + type + (track.isForcedNarrative ? '-forced' : '');
    subs[lang] = Object.values(track.ttDownloadables[WEBVTT].downloadUrls);
  }
  subCache[result.movieId] = {titleP, subs};

  if(batch) {
    downloadAll();
  }
};

const getMovieID = () => window.location.pathname.split('/').pop();


const _save = async (_zip, title) => {
  const content = await _zip.generateAsync({type:'blob'});
  saveAs(content, title + '.zip');
};

const _download = async _zip => {
  const showTitle = getTitle(false);
  const {titleP, subs} = subCache[getMovieID()];
  const downloaded = [];

  let filteredLangs;
  if(langs === '')
    filteredLangs = Object.keys(subs);
  else {
    const regularExpression = new RegExp('^(' + langs.replace(/\-/g, '\\-').replace(/\s/g, '').replace(/,/g, '|') + ')');
    filteredLangs = [];
    for(const lang of Object.keys(subs)) {
    	if(lang.match(regularExpression))
        filteredLangs.push(lang);
    }
  }

  const progress = new ProgressBar(filteredLangs.length);
  for(const lang of filteredLangs) {
    const urls = subs[lang]
    while(urls.length > 0) {
      let url = popRandomElement(urls);
      const result = await fetch(url, {mode: "cors"});
      progress.increment();
      const data = await result.text();
      if(data.length > 0) {
        downloaded.push({lang, data});
        break;
      }
    }
  }
  progress.destroy();
  const title = await titleP;

  downloaded.forEach(x => {
    const {lang, data} = x;
    _zip.file(`${title}.${lang}.vtt`, data);
  });

  return await showTitle;
};

const downloadThis = async () => {
  const _zip = new JSZip();
  const showTitle = await _download(_zip);
  _save(_zip, showTitle);
};

const downloadAll = async () => {
  zip = zip || new JSZip();
  batch = true;
  const showTitle = await _download(zip);
  const nextEp = document.querySelector(NEXT_EPISODE);
  if(nextEp)
    nextEp.click();
  else {
    await _save(zip, showTitle);
    zip = undefined;
    batch = false;
  }
};

const processMessage = e => {
  processSubInfo(e.detail);
}

const injection = () => {
  const WEBVTT = 'webvtt-lssdh-ios8';
  const MANIFEST_URL = "/manifest";
  const forceSubs = localStorage.getItem('NSD_force-all-lang') !== 'false';

  // hijack JSON.parse and JSON.stringify functions
  ((parse, stringify) => {
    JSON.parse = function (text) {
      const data = parse(text);
      if (data && data.result && data.result.timedtexttracks && data.result.movieId) {
        window.dispatchEvent(new CustomEvent('netflix_sub_downloader_data', {detail: data.result}));
      }
      return data;
    };
    JSON.stringify = function (data) {
      if (data && data.url === MANIFEST_URL) {
        for (let v of Object.values(data)) {
        	try {
            if (v.profiles)
              v.profiles.unshift(WEBVTT);
            if (v.showAllSubDubTracks != null && forceSubs)
              v.showAllSubDubTracks = true;
          }
          catch (e) {
            if (e instanceof TypeError)
              continue;
            else
              throw e;
          }
        }
      }
      return stringify(data);
    };
  })(JSON.parse, JSON.stringify);
}

window.addEventListener('netflix_sub_downloader_data', processMessage, false);

// inject script
const sc = document.createElement('script');
sc.innerHTML = '(' + injection.toString() + ')()';
document.head.appendChild(sc);
document.head.removeChild(sc);

// add CSS style
const s = document.createElement('style');
s.innerHTML = SCRIPT_CSS;
document.head.appendChild(s);

// add menu when it's not there
const observer = new MutationObserver(function(mutations) {
  mutations.forEach(function(mutation) {
    mutation.addedNodes.forEach(function(node) {
      if(node.nodeName.toUpperCase() == 'DIV') {
        let trackMenu = (node.parentNode || node).querySelector(TRACK_MENU);
        if(trackMenu !== null && trackMenu.querySelector('.subtitle-downloader-menu') === null) {
          let ol = document.createElement('ol');
          ol.setAttribute('class', 'subtitle-downloader-menu player-timed-text-tracks track-list track-list-subtitles');
          ol.innerHTML = DOWNLOAD_MENU;
          trackMenu.appendChild(ol);
          ol.querySelector('.download').addEventListener('click', downloadThis);
          ol.querySelector('.download-all').addEventListener('click', downloadAll);
          ol.querySelector('.force-all-lang').addEventListener('click', toggleForceLang);
          ol.querySelector('.lang-setting').addEventListener('click', setLangToDownload);
          setForceText();
          setLangsText();
        }
      }
    });
  });
});
observer.observe(document.body, { childList: true, subtree: true });