☰

Netflix - subtitle downloader

Allows you to download subtitles from Netflix

As of 2021-09-10. See the latest version.

  1. // ==UserScript==
  2. // @name        Netflix - subtitle downloader
  3. // @description Allows you to download subtitles from Netflix
  4. // @license     MIT
  5. // @version     4.0.1
  6. // @namespace   tithen-firion.github.io
  7. // @include     https://www.netflix.com/*
  8. // @grant       unsafeWindow
  9. // @require     https://cdn.jsdelivr.net/gh/Stuk/jszip@579beb1d45c8d586d8be4411d5b2e48dea018c06/dist/jszip.min.js?version=3.1.5
  10. // @require     https://cdn.jsdelivr.net/gh/eligrey/FileSaver.js@283f438c31776b622670be002caf1986c40ce90c/dist/FileSaver.min.js?version=2018-12-29
  11. // ==/UserScript==
  12.  
  13. class ProgressBar {
  14.   constructor(max) {
  15.     this.current = 0;
  16.     this.max = max;
  17.  
  18.     let container = document.querySelector('#userscript_progress_bars');
  19.     if(container === null) {
  20.       container = document.createElement('div');
  21.       container.id = 'userscript_progress_bars'
  22.       document.body.appendChild(container)
  23.       container.style
  24.       container.style.position = 'fixed';
  25.       container.style.top = 0;
  26.       container.style.left = 0;
  27.       container.style.width = '100%';
  28.       container.style.background = 'red';
  29.       container.style.zIndex = '99999999';
  30.     }
  31.  
  32.     this.progressElement = document.createElement('div');
  33.     this.progressElement.innerHTML = 'Click to stop';
  34.     this.progressElement.style.cursor = 'pointer';
  35.     this.progressElement.style.fontSize = '16px';
  36.     this.progressElement.style.textAlign = 'center';
  37.     this.progressElement.style.width = '100%';
  38.     this.progressElement.style.height = '20px';
  39.     this.progressElement.style.background = 'transparent';
  40.     this.stop = new Promise(resolve => {
  41.       this.progressElement.addEventListener('click', () => {resolve(STOP_THE_DOWNLOAD)});
  42.     });
  43.  
  44.     container.appendChild(this.progressElement);
  45.   }
  46.  
  47.   increment() {
  48.     this.current += 1;
  49.     if(this.current <= this.max) {
  50.       let p = this.current / this.max * 100;
  51.       this.progressElement.style.background = `linear-gradient(to right, green ${p}%, transparent ${p}%)`;
  52.     }
  53.   }
  54.  
  55.   destroy() {
  56.     this.progressElement.remove();
  57.   }
  58. }
  59.  
  60. const STOP_THE_DOWNLOAD = 'NETFLIX_SUBTITLE_DOWNLOADER_STOP_THE_DOWNLOAD';
  61.  
  62. const WEBVTT = 'webvtt-lssdh-ios8';
  63. const DFXP = 'dfxp-ls-sdh';
  64. const SIMPLE = 'simplesdh';
  65. const ALL_FORMATS = [WEBVTT, DFXP, SIMPLE];
  66.  
  67. const FORMAT_NAMES = {};
  68. FORMAT_NAMES[WEBVTT] = 'WebVTT';
  69. FORMAT_NAMES[DFXP] = 'DFXP/XML';
  70.  
  71. const EXTENSIONS = {};
  72. EXTENSIONS[WEBVTT] = 'vtt';
  73. EXTENSIONS[DFXP] = 'dfxp';
  74. EXTENSIONS[SIMPLE] = 'xml';
  75.  
  76. const DOWNLOAD_MENU = `<li class="header">Netflix subtitle downloader</li>
  77. <li class="download">Download subs for this episode</li>
  78. <!--<li class="download-all">Download subs from this ep till last available</li>-->
  79. <li class="ep-title-in-filename">Add episode title to filename: <span></span></li>
  80. <li class="force-all-lang">Force Netflix to show all languages: <span></span></li>
  81. <li class="lang-setting">Languages to download: <span></span></li>
  82. <li class="sub-format">Subtitle format: prefer <span></span></li>`;
  83.  
  84. const SCRIPT_CSS = `
  85. .subtitle-downloader-menu {
  86.   list-style: none;
  87.   position: relative;
  88.   display: none;
  89.   width: 300px;
  90.   background: #333;
  91.   color: #fff;
  92.   padding: 0;
  93.   margin: auto;
  94.   font-size: 12px;
  95. }
  96. body:hover .subtitle-downloader-menu { display: block; }
  97. .subtitle-downloader-menu li { padding: 10px; }
  98. .subtitle-downloader-menu li.header { font-weight: bold; }
  99. .subtitle-downloader-menu li:not(.header):hover { background: #666; }
  100. .subtitle-downloader-menu li:not(.header) {
  101.   display: none;
  102.   cursor: pointer;
  103. }
  104. .subtitle-downloader-menu:hover li { display: block; }
  105. `;
  106.  
  107. const SUB_TYPES = {
  108.   'subtitles': '',
  109.   'closedcaptions': '[cc]'
  110. };
  111.  
  112. let idOverrides = {};
  113. let zip;
  114. let subCache = {};
  115. let titleCache = {};
  116. let batch = false;
  117.  
  118. let epTitleInFilename = localStorage.getItem('NSD_ep-title-in-filename') === 'true';
  119. let forceSubs = localStorage.getItem('NSD_force-all-lang') !== 'false';
  120. let langs = localStorage.getItem('NSD_lang-setting') || '';
  121. let subFormat = localStorage.getItem('NSD_sub-format') || WEBVTT;
  122.  
  123. const setEpTitleInFilename = () => {
  124.   document.querySelector('.subtitle-downloader-menu > .ep-title-in-filename > span').innerHTML = (epTitleInFilename ? 'on' : 'off');
  125. };
  126. const setForceText = () => {
  127.   document.querySelector('.subtitle-downloader-menu > .force-all-lang > span').innerHTML = (forceSubs ? 'on' : 'off');
  128. };
  129. const setLangsText = () => {
  130.   document.querySelector('.subtitle-downloader-menu > .lang-setting > span').innerHTML = (langs === '' ? 'all' : langs);
  131. };
  132. const setFormatText = () => {
  133.   document.querySelector('.subtitle-downloader-menu > .sub-format > span').innerHTML = FORMAT_NAMES[subFormat];
  134. };
  135.  
  136. const toggleEpTitleInFilename = () => {
  137.   epTitleInFilename = !epTitleInFilename;
  138.   if(epTitleInFilename)
  139.     localStorage.setItem('NSD_ep-title-in-filename', epTitleInFilename);
  140.   else
  141.     localStorage.removeItem('NSD_ep-title-in-filename');
  142.   setEpTitleInFilename();
  143. };
  144. const toggleForceLang = () => {
  145.   forceSubs = !forceSubs;
  146.   if(forceSubs)
  147.     localStorage.removeItem('NSD_force-all-lang');
  148.   else
  149.     localStorage.setItem('NSD_force-all-lang', forceSubs);
  150.   document.location.reload();
  151. };
  152. const setLangToDownload = () => {
  153.   const result = prompt('Languages to download, comma separated. Leave empty to download all subtitles.\nExample: en,de,fr', langs);
  154.   if(result !== null) {
  155.     langs = result;
  156.     if(langs === '')
  157.       localStorage.removeItem('NSD_lang-setting');
  158.     else
  159.       localStorage.setItem('NSD_lang-setting', langs);
  160.     setLangsText();
  161.   }
  162. };
  163. const setSubFormat = () => {
  164.   if(subFormat === WEBVTT) {
  165.     localStorage.setItem('NSD_sub-format', DFXP);
  166.     subFormat = DFXP;
  167.   }
  168.   else {
  169.     localStorage.removeItem('NSD_sub-format');
  170.     subFormat = WEBVTT;
  171.   }
  172.   setFormatText();
  173. };
  174.  
  175. const asyncSleep = (seconds, value) => new Promise(resolve => {
  176.   window.setTimeout(resolve, seconds * 1000, value);
  177. });
  178.  
  179. const popRandomElement = arr => {
  180.   return arr.splice(arr.length * Math.random() << 0, 1)[0];
  181. };
  182.  
  183. const processSubInfo = async result => {
  184.   const tracks = result.timedtexttracks;
  185.   const subs = {};
  186.   for(const track of tracks) {
  187.     if(track.isNoneTrack)
  188.       continue;
  189.  
  190.     let type = SUB_TYPES[track.rawTrackType];
  191.     if(typeof type === 'undefined')
  192.       type = `[${track.rawTrackType}]`;
  193.     const lang = track.language + type + (track.isForcedNarrative ? '-forced' : '');
  194.  
  195.     const formats = {};
  196.     for(let format of ALL_FORMATS) {
  197.       if(typeof track.ttDownloadables[format] !== 'undefined')
  198.         formats[format] = [Object.values(track.ttDownloadables[format].downloadUrls), EXTENSIONS[format]];
  199.     }
  200.  
  201.     if(Object.keys(formats).length > 0)
  202.       subs[lang] = formats;
  203.   }
  204.   subCache[result.movieId] = subs;
  205.  
  206.   // add menu when it's not there
  207.   if(document.querySelector('.subtitle-downloader-menu') === null) {
  208.     let ol = document.createElement('ol');
  209.     ol.setAttribute('class', 'subtitle-downloader-menu player-timed-text-tracks track-list track-list-subtitles');
  210.     ol.innerHTML = DOWNLOAD_MENU;
  211.     document.body.appendChild(ol);
  212.     ol.querySelector('.download').addEventListener('click', downloadThis);
  213.     //ol.querySelector('.download-all').addEventListener('click', downloadAll);
  214.     ol.querySelector('.ep-title-in-filename').addEventListener('click', toggleEpTitleInFilename);
  215.     ol.querySelector('.force-all-lang').addEventListener('click', toggleForceLang);
  216.     ol.querySelector('.lang-setting').addEventListener('click', setLangToDownload);
  217.     ol.querySelector('.sub-format').addEventListener('click', setSubFormat);
  218.     setEpTitleInFilename();
  219.     setForceText();
  220.     setLangsText();
  221.     setFormatText();
  222.   }
  223.  
  224.   if(batch) {
  225.     downloadAll();
  226.   }
  227. };
  228.  
  229. const processMetadata = data => {
  230.   const result = data.video;
  231.   const {type, title} = result;
  232.   if(type === 'show') {
  233.     for(const season of result.seasons) {
  234.       for(const episode of season.episodes) {
  235.         titleCache[episode.id] = {
  236.           type, title,
  237.           season: season.seq,
  238.           episode: episode.seq,
  239.           subtitle: episode.title,
  240.           hiddenNumber: episode.hiddenEpisodeNumbers
  241.         };
  242.       }
  243.     }
  244.   }
  245.   else if(type === 'movie' || type === 'supplemental') {
  246.     titleCache[result.id] = {type, title};
  247.   }
  248.   else {
  249.   	console.debug('[Netflix Subtitle Downloader] unknown video type:', type, result)
  250.   }
  251. };
  252.  
  253. const getXFromCache = (cache, name) => {
  254.   const id = window.location.pathname.split('/').pop();
  255.   if(cache.hasOwnProperty(id))
  256.     return cache[id];
  257.  
  258.   let newID = undefined;
  259.   try {
  260.     newID = unsafeWindow.netflix.falcorCache.videos[id].current.value[1];
  261.   }
  262.   catch(ignore) {}
  263.   if(typeof newID !== 'undefined' && cache.hasOwnProperty(newID))
  264.     return cache[newID];
  265.  
  266.   newID = idOverrides[id];
  267.   if(typeof newID !== 'undefined' && cache.hasOwnProperty(newID))
  268.     return cache[newID];
  269.  
  270.   alert("Couldn't find the " + name + ". Wait until the player is loaded. If that doesn't help refresh the page.");
  271.   throw '';
  272. };
  273.  
  274. const getSubsFromCache = () => getXFromCache(subCache, 'subs');
  275.  
  276. const pad = (number, letter) => `${letter}${number.toString().padStart(2, '0')}`;
  277.  
  278. const getTitleFromCache = () => {
  279.   const title = getXFromCache(titleCache, 'title');
  280.   const titleParts = [title.title];
  281.   if(title.type === 'show') {
  282.     const season = pad(title.season, 'S');
  283.     if(title.hiddenNumber) {
  284.       titleParts.push(season);
  285.       titleParts.push(title.subtitle);
  286.     }
  287.     else {
  288.       titleParts.push(season + pad(title.episode, 'E'));
  289.       if(epTitleInFilename)
  290.         titleParts.push(title.subtitle);
  291.     }
  292.   }
  293.   return titleParts.join('.').trim().replace(/[:*?"<>|\\\/]+/g, '_').replace(/ /g, '.');
  294. };
  295.  
  296. const pickFormat = formats => {
  297.   const preferred = ALL_FORMATS.slice();
  298.   if(subFormat === DFXP)
  299.     preferred.push(preferred.shift());
  300.  
  301.   for(let format of preferred) {
  302.     if(typeof formats[format] !== 'undefined')
  303.       return formats[format];
  304.   }
  305. };
  306.  
  307.  
  308. const _save = async (_zip, title) => {
  309.   const content = await _zip.generateAsync({type:'blob'});
  310.   saveAs(content, title + '.zip');
  311. };
  312.  
  313. const _download = async _zip => {
  314.   const subs = getSubsFromCache();
  315.   const title = getTitleFromCache();
  316.   const downloaded = [];
  317.  
  318.   let filteredLangs;
  319.   if(langs === '')
  320.     filteredLangs = Object.keys(subs);
  321.   else {
  322.     const regularExpression = new RegExp(
  323.       '^(' + langs
  324.         .replace(/\[/g, '\\[')
  325.         .replace(/\]/g, '\\]')
  326.         .replace(/\-/g, '\\-')
  327.         .replace(/\s/g, '')
  328.         .replace(/,/g, '|')
  329.       + ')'
  330.     );
  331.     filteredLangs = [];
  332.     for(const lang of Object.keys(subs)) {
  333.       if(lang.match(regularExpression))
  334.         filteredLangs.push(lang);
  335.     }
  336.   }
  337.  
  338.   const progress = new ProgressBar(filteredLangs.length);
  339.   let stop = false;
  340.   for(const lang of filteredLangs) {
  341.     const [urls, extension] = pickFormat(subs[lang]);
  342.     while(urls.length > 0) {
  343.       let url = popRandomElement(urls);
  344.       const resultPromise = fetch(url, {mode: "cors"});
  345.       let result;
  346.       try {
  347.         // Promise.any isn't supported in all browsers, use Promise.race instead
  348.         result = await Promise.race([resultPromise, progress.stop, asyncSleep(30, STOP_THE_DOWNLOAD)]);
  349.       }
  350.       catch(e) {
  351.         // the only promise that can be rejected is the one from fetch
  352.         // if that happens we want to stop the download anyway
  353.         result = STOP_THE_DOWNLOAD;
  354.       }
  355.       if(result === STOP_THE_DOWNLOAD) {
  356.         stop = true;
  357.         break;
  358.       }
  359.       progress.increment();
  360.       const data = await result.text();
  361.       if(data.length > 0) {
  362.         downloaded.push({lang, data, extension});
  363.         break;
  364.       }
  365.     }
  366.     if(stop)
  367.       break;
  368.   }
  369.  
  370.   downloaded.forEach(x => {
  371.     const {lang, data, extension} = x;
  372.     _zip.file(`${title}.WEBRip.Netflix.${lang}.${extension}`, data);
  373.   });
  374.  
  375.   if(await Promise.race([progress.stop, {}]) === STOP_THE_DOWNLOAD)
  376.     stop = true;
  377.   progress.destroy();
  378.  
  379.   return [title, stop];
  380. };
  381.  
  382. const downloadThis = async () => {
  383.   const _zip = new JSZip();
  384.   const [title, stop] = await _download(_zip);
  385.   _save(_zip, title);
  386. };
  387.  
  388. /*const downloadAll = async () => {
  389.   zip = zip || new JSZip();
  390.   batch = true;
  391.   const [title, stop] = await _download(zip);
  392.   const nextEp = document.querySelector(NEXT_EPISODE);
  393.   if(!stop && nextEp)
  394.     nextEp.click();
  395.   else {
  396.     await _save(zip, title);
  397.     zip = undefined;
  398.     batch = false;
  399.   }
  400. };*/
  401.  
  402. const processMessage = e => {
  403.   const {type, data} = e.detail;
  404.   if(type === 'subs')
  405.     processSubInfo(data);
  406.   else if(type === 'id_override')
  407.     idOverrides[data[0]] = data[1];
  408.   else if(type === 'metadata')
  409.     processMetadata(data);
  410. }
  411.  
  412. const injection = () => {
  413.   const WEBVTT = 'webvtt-lssdh-ios8';
  414.   const MANIFEST_PATTERN = new RegExp('manifest|licensedManifest');
  415.   const forceSubs = localStorage.getItem('NSD_force-all-lang') !== 'false';
  416.  
  417.   // hijack JSON.parse and JSON.stringify functions
  418.   ((parse, stringify, open) => {
  419.     JSON.parse = function (text) {
  420.       const data = parse(text);
  421.  
  422.       if (data && data.result && data.result.timedtexttracks && data.result.movieId) {
  423.         window.dispatchEvent(new CustomEvent('netflix_sub_downloader_data', {detail: {type: 'subs', data: data.result}}));
  424.       }
  425.       return data;
  426.     };
  427.  
  428.     JSON.stringify = function (data) {
  429.       /*{
  430.         let text = stringify(data);
  431.         if (text.includes('dfxp-ls-sdh'))
  432.           console.log(text, data);
  433.       }*/
  434.  
  435.       if (data && typeof data.url === 'string' && data.url.search(MANIFEST_PATTERN) > -1) {
  436.         for (let v of Object.values(data)) {
  437.           try {
  438.             if (v.profiles)
  439.               v.profiles.unshift(WEBVTT);
  440.             if (v.showAllSubDubTracks != null && forceSubs)
  441.               v.showAllSubDubTracks = true;
  442.           }
  443.           catch (e) {
  444.             if (e instanceof TypeError)
  445.               continue;
  446.             else
  447.               throw e;
  448.           }
  449.         }
  450.       }
  451.       if(data && typeof data.movieId === 'number') {
  452.         try {
  453.           let videoId = data.params.sessionParams.uiplaycontext.video_id;
  454.           if(typeof videoId === 'number' && videoId !== data.movieId)
  455.             window.dispatchEvent(new CustomEvent('netflix_sub_downloader_data', {detail: {type: 'id_override', data: [videoId, data.movieId]}}));
  456.         }
  457.         catch(ignore) {}
  458.       }
  459.       return stringify(data);
  460.     };
  461.  
  462.     XMLHttpRequest.prototype.open = function() {
  463.       if(arguments[1] && arguments[1].includes('/metadata?'))
  464.         this.addEventListener('load', () => {
  465.           window.dispatchEvent(new CustomEvent('netflix_sub_downloader_data', {detail: {type: 'metadata', data: this.response}}));
  466.         }, false);
  467.       open.apply(this, arguments);
  468.     };
  469.   })(JSON.parse, JSON.stringify, XMLHttpRequest.prototype.open);
  470. }
  471.  
  472. window.addEventListener('netflix_sub_downloader_data', processMessage, false);
  473.  
  474. // inject script
  475. const sc = document.createElement('script');
  476. sc.innerHTML = '(' + injection.toString() + ')()';
  477. document.head.appendChild(sc);
  478. document.head.removeChild(sc);
  479.  
  480. // add CSS style
  481. const s = document.createElement('style');
  482. s.innerHTML = SCRIPT_CSS;
  483. document.head.appendChild(s);
  484.  
  485. const observer = new MutationObserver(function(mutations) {
  486.   mutations.forEach(function(mutation) {
  487.     mutation.addedNodes.forEach(function(node) {
  488.       // add scrollbar - Netflix doesn't expect you to have this manu languages to choose from...
  489.       try {
  490.         (node.parentNode || node).querySelector('.watch-video--selector-audio-subtitle').parentNode.style.overflowY = 'scroll';
  491.       }
  492.       catch(ignore) {}
  493.     });
  494.   });
  495. });
  496. observer.observe(document.body, { childList: true, subtree: true });