☰

Netflix - subtitle downloader

Allows you to download subtitles from Netflix

  1. // ==UserScript==
  2. // @name        Netflix - subtitle downloader
  3. // @description Allows you to download subtitles from Netflix
  4. // @license     MIT
  5. // @version     4.2.8
  6. // @namespace   tithen-firion.github.io
  7. // @include     https://www.netflix.com/*
  8. // @grant       unsafeWindow
  9. // @require     https://cdn.jsdelivr.net/npm/jszip@3.7.1/dist/jszip.min.js
  10. // @require     https://cdn.jsdelivr.net/npm/file-saver-es@2.0.5/dist/FileSaver.min.js
  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 IMSC1_1 = 'imsc1.1';
  66. const ALL_FORMATS = [IMSC1_1, DFXP, WEBVTT, SIMPLE];
  67. const ALL_FORMATS_prefer_vtt = [WEBVTT, IMSC1_1, DFXP, SIMPLE];
  68.  
  69. const FORMAT_NAMES = {};
  70. FORMAT_NAMES[WEBVTT] = 'WebVTT';
  71. FORMAT_NAMES[DFXP] = 'IMSC1.1/DFXP/XML';
  72.  
  73. const EXTENSIONS = {};
  74. EXTENSIONS[WEBVTT] = 'vtt';
  75. EXTENSIONS[DFXP] = 'dfxp';
  76. EXTENSIONS[SIMPLE] = 'xml';
  77. EXTENSIONS[IMSC1_1] = 'xml';
  78.  
  79. const DOWNLOAD_MENU = `
  80. <ol>
  81. <li class="header">Netflix subtitle downloader</li>
  82. <li class="download">Download subs for this <span class="series">episode</span><span class="not-series">movie</span></li>
  83. <li class="download-to-end series">Download subs from this ep till last available</li>
  84. <li class="download-season series">Download subs for this season</li>
  85. <li class="download-all series">Download subs for all seasons</li>
  86. <li class="ep-title-in-filename">Add episode title to filename: <span></span></li>
  87. <li class="force-all-lang">Force Netflix to show all languages: <span></span></li>
  88. <li class="pref-locale">Preferred locale: <span></span></li>
  89. <li class="lang-setting">Languages to download: <span></span></li>
  90. <li class="sub-format">Subtitle format: prefer <span></span></li>
  91. <li class="batch-delay">Batch delay: <span></span></li>
  92. </ol>
  93. `;
  94.  
  95. const SCRIPT_CSS = `
  96. #subtitle-downloader-menu {
  97.   position: absolute;
  98.   display: none;
  99.   width: 300px;
  100.   top: 0;
  101.   left: calc( 50% - 150px );
  102. }
  103. #subtitle-downloader-menu ol {
  104.   list-style: none;
  105.   position: relative;
  106.   width: 300px;
  107.   background: #333;
  108.   color: #fff;
  109.   padding: 0;
  110.   margin: auto;
  111.   font-size: 12px;
  112.   z-index: 99999998;
  113. }
  114. body:hover #subtitle-downloader-menu { display: block; }
  115. #subtitle-downloader-menu li { padding: 10px; }
  116. #subtitle-downloader-menu li.header { font-weight: bold; }
  117. #subtitle-downloader-menu li:not(.header):hover { background: #666; }
  118. #subtitle-downloader-menu li:not(.header) {
  119.   display: none;
  120.   cursor: pointer;
  121. }
  122. #subtitle-downloader-menu:hover li { display: block; }
  123.  
  124. #subtitle-downloader-menu:not(.series) .series{ display: none; }
  125. #subtitle-downloader-menu.series .not-series{ display: none; }
  126. `;
  127.  
  128. const SUB_TYPES = {
  129.   'subtitles': '',
  130.   'closedcaptions': '[cc]'
  131. };
  132.  
  133. let idOverrides = {};
  134. let subCache = {};
  135. let titleCache = {};
  136.  
  137. let batch = null;
  138. try {
  139.   batch = JSON.parse(sessionStorage.getItem('NSD_batch'));
  140. }
  141. catch(ignore) {}
  142.  
  143. let batchAll = null;
  144. let batchSeason = null;
  145. let batchToEnd = null;
  146.  
  147. let epTitleInFilename = localStorage.getItem('NSD_ep-title-in-filename') === 'true';
  148. let forceSubs = localStorage.getItem('NSD_force-all-lang') !== 'false';
  149. let prefLocale = localStorage.getItem('NSD_pref-locale') || '';
  150. let langs = localStorage.getItem('NSD_lang-setting') || '';
  151. let subFormat = localStorage.getItem('NSD_sub-format') || WEBVTT;
  152. let batchDelay = parseFloat(localStorage.getItem('NSD_batch-delay') || '0');
  153.  
  154. const setEpTitleInFilename = () => {
  155.   document.querySelector('#subtitle-downloader-menu .ep-title-in-filename > span').innerHTML = (epTitleInFilename ? 'on' : 'off');
  156. };
  157. const setForceText = () => {
  158.   document.querySelector('#subtitle-downloader-menu .force-all-lang > span').innerHTML = (forceSubs ? 'on' : 'off');
  159. };
  160. const setLocaleText = () => {
  161.   document.querySelector('#subtitle-downloader-menu .pref-locale > span').innerHTML = (prefLocale === '' ? 'disabled' : prefLocale);
  162. };
  163. const setLangsText = () => {
  164.   document.querySelector('#subtitle-downloader-menu .lang-setting > span').innerHTML = (langs === '' ? 'all' : langs);
  165. };
  166. const setFormatText = () => {
  167.   document.querySelector('#subtitle-downloader-menu .sub-format > span').innerHTML = FORMAT_NAMES[subFormat];
  168. };
  169. const setBatchDelayText = () => {
  170.   document.querySelector('#subtitle-downloader-menu .batch-delay > span').innerHTML = batchDelay;
  171. };
  172.  
  173. const setBatch = b => {
  174.   if(b === null)
  175.     sessionStorage.removeItem('NSD_batch');
  176.   else
  177.     sessionStorage.setItem('NSD_batch', JSON.stringify(b));
  178. };
  179.  
  180. const toggleEpTitleInFilename = () => {
  181.   epTitleInFilename = !epTitleInFilename;
  182.   if(epTitleInFilename)
  183.     localStorage.setItem('NSD_ep-title-in-filename', epTitleInFilename);
  184.   else
  185.     localStorage.removeItem('NSD_ep-title-in-filename');
  186.   setEpTitleInFilename();
  187. };
  188. const toggleForceLang = () => {
  189.   forceSubs = !forceSubs;
  190.   if(forceSubs)
  191.     localStorage.removeItem('NSD_force-all-lang');
  192.   else
  193.     localStorage.setItem('NSD_force-all-lang', forceSubs);
  194.   document.location.reload();
  195. };
  196. const setPreferredLocale = () => {
  197.   const result = prompt('Netflix limited "force all subtitles" usage. Now you have to set a preferred locale to show subtitles for that language.\nPossible values (you can enter only one at a time!):\nar, cs, da, de, el, en, es, es-ES, fi, fr, he, hi, hr, hu, id, it, ja, ko, ms, nb, nl, pl, pt, pt-BR, ro, ru, sv, ta, te, th, tr, uk, vi, zh', prefLocale);
  198.   if(result !== null) {
  199.     prefLocale = result;
  200.     if(prefLocale === '')
  201.       localStorage.removeItem('NSD_pref-locale');
  202.     else
  203.       localStorage.setItem('NSD_pref-locale', prefLocale);
  204.     document.location.reload();
  205.   }
  206. };
  207. const setLangToDownload = () => {
  208.   const result = prompt('Languages to download, comma separated. Leave empty to download all subtitles.\nExample: en,de,fr', langs);
  209.   if(result !== null) {
  210.     langs = result;
  211.     if(langs === '')
  212.       localStorage.removeItem('NSD_lang-setting');
  213.     else
  214.       localStorage.setItem('NSD_lang-setting', langs);
  215.     setLangsText();
  216.   }
  217. };
  218. const setSubFormat = () => {
  219.   if(subFormat === WEBVTT) {
  220.     localStorage.setItem('NSD_sub-format', DFXP);
  221.     subFormat = DFXP;
  222.   }
  223.   else {
  224.     localStorage.removeItem('NSD_sub-format');
  225.     subFormat = WEBVTT;
  226.   }
  227.   setFormatText();
  228. };
  229. const setBatchDelay = () => {
  230.   let result = prompt('Delay (in seconds) between switching pages when downloading subs in batch:', batchDelay);
  231.   if(result !== null) {
  232.     result = parseFloat(result.replace(',', '.'));
  233.     if(result < 0 || !Number.isFinite(result))
  234.       result = 0;
  235.     batchDelay = result;
  236.     if(batchDelay == 0)
  237.       localStorage.removeItem('NSD_batch-delay');
  238.     else
  239.       localStorage.setItem('NSD_batch-delay', batchDelay);
  240.     setBatchDelayText();
  241.   }
  242. };
  243.  
  244. const asyncSleep = (seconds, value) => new Promise(resolve => {
  245.   window.setTimeout(resolve, seconds * 1000, value);
  246. });
  247.  
  248. const popRandomElement = arr => {
  249.   return arr.splice(arr.length * Math.random() << 0, 1)[0];
  250. };
  251.  
  252. const processSubInfo = async result => {
  253.   const tracks = result.timedtexttracks;
  254.   const subs = {};
  255.   let reportError = true;
  256.   for(const track of tracks) {
  257.     if(track.isNoneTrack)
  258.       continue;
  259.  
  260.     let type = SUB_TYPES[track.rawTrackType];
  261.     if(typeof type === 'undefined')
  262.       type = `[${track.rawTrackType}]`;
  263.     const variant = (typeof track.trackVariant === 'undefined' ? '' : `-${track.trackVariant}`);
  264.     const lang = track.language + type + variant + (track.isForcedNarrative ? '-forced' : '');
  265.  
  266.     const formats = {};
  267.     for(let format of ALL_FORMATS) {
  268.       const downloadables = track.ttDownloadables[format];
  269.       if(typeof downloadables !== 'undefined') {
  270.         let urls;
  271.         if(typeof downloadables.downloadUrls !== 'undefined')
  272.           urls = Object.values(downloadables.downloadUrls);
  273.         else if(typeof downloadables.urls !== 'undefined')
  274.           urls = downloadables.urls.map(({url}) => url);
  275.         else {
  276.           console.log('processSubInfo:', lang, Object.keys(downloadables));
  277.           if(reportError) {
  278.             reportError = false;
  279.             alert("Can't find subtitle URL, check the console for more information!");
  280.           }
  281.           continue;
  282.         }
  283.         formats[format] = [urls, EXTENSIONS[format]];
  284.       }
  285.     }
  286.  
  287.     if(Object.keys(formats).length > 0) {
  288.       for(let i = 0; ; ++i) {
  289.         const langKey = lang + (i == 0 ? "" : `-${i}`);
  290.         if(typeof subs[langKey] === "undefined") {
  291.           subs[langKey] = formats;
  292.           break;
  293.         }
  294.       }
  295.     }
  296.   }
  297.   subCache[result.movieId] = subs;
  298. };
  299.  
  300. const checkSubsCache = async menu => {
  301.   while(getSubsFromCache(true) === null) {
  302.     await asyncSleep(0.1);
  303.   }
  304.  
  305.   // show menu if on watch page
  306.   menu.style.display = (document.location.pathname.split('/')[1] === 'watch' ? '' : 'none');
  307.  
  308.   if(batch !== null && batch.length > 0) {
  309.     downloadBatch(true);
  310.   }
  311. };
  312.  
  313. const processMetadata = data => {
  314.   // add menu when it's not there
  315.   let menu = document.querySelector('#subtitle-downloader-menu');
  316.   if(menu === null) {
  317.     menu = document.createElement('div');
  318.     menu.id = 'subtitle-downloader-menu';
  319.     menu.innerHTML = DOWNLOAD_MENU;
  320.     document.body.appendChild(menu);
  321.     menu.querySelector('.download').addEventListener('click', downloadThis);
  322.     menu.querySelector('.download-to-end').addEventListener('click', downloadToEnd);
  323.     menu.querySelector('.download-season').addEventListener('click', downloadSeason);
  324.     menu.querySelector('.download-all').addEventListener('click', downloadAll);
  325.     menu.querySelector('.ep-title-in-filename').addEventListener('click', toggleEpTitleInFilename);
  326.     menu.querySelector('.force-all-lang').addEventListener('click', toggleForceLang);
  327.     menu.querySelector('.pref-locale').addEventListener('click', setPreferredLocale);
  328.     menu.querySelector('.lang-setting').addEventListener('click', setLangToDownload);
  329.     menu.querySelector('.sub-format').addEventListener('click', setSubFormat);
  330.     menu.querySelector('.batch-delay').addEventListener('click', setBatchDelay);
  331.     setEpTitleInFilename();
  332.     setForceText();
  333.     setLocaleText();
  334.     setLangsText();
  335.     setFormatText();
  336.   }
  337.   // hide menu, at this point sub info is still missing
  338.   menu.style.display = 'none';
  339.   menu.classList.remove('series');
  340.  
  341.   const result = data.video;
  342.   const {type, title} = result;
  343.   if(type === 'show') {
  344.     batchAll = [];
  345.     batchSeason = [];
  346.     batchToEnd = [];
  347.     const allEpisodes = [];
  348.     let currentSeason = 0;
  349.     menu.classList.add('series');
  350.     for(const season of result.seasons) {
  351.       for(const episode of season.episodes) {
  352.         if(episode.id === result.currentEpisode)
  353.           currentSeason = season.seq;
  354.         allEpisodes.push([season.seq, episode.seq, episode.id]);
  355.         titleCache[episode.id] = {
  356.           type, title,
  357.           season: season.seq,
  358.           episode: episode.seq,
  359.           subtitle: episode.title,
  360.           hiddenNumber: episode.hiddenEpisodeNumbers
  361.         };
  362.       }
  363.     }
  364.  
  365.     allEpisodes.sort((a, b) => a[0] - b[0] || a[1] - b[1]);
  366.     let toEnd = false;
  367.     for(const [season, episode, id] of allEpisodes) {
  368.       batchAll.push(id);
  369.       if(season === currentSeason)
  370.         batchSeason.push(id);
  371.       if(id === result.currentEpisode)
  372.         toEnd = true;
  373.       if(toEnd)
  374.         batchToEnd.push(id);
  375.     }
  376.   }
  377.   else if(type === 'movie' || type === 'supplemental') {
  378.     titleCache[result.id] = {type, title};
  379.   }
  380.   else {
  381.   	console.debug('[Netflix Subtitle Downloader] unknown video type:', type, result)
  382.     return;
  383.   }
  384.   checkSubsCache(menu);
  385. };
  386.  
  387. const getVideoId = () => window.location.pathname.split('/').pop();
  388.  
  389. const getXFromCache = (cache, name, silent) => {
  390.   const id = getVideoId();
  391.   if(cache.hasOwnProperty(id))
  392.     return cache[id];
  393.  
  394.   let newID = undefined;
  395.   try {
  396.     newID = unsafeWindow.netflix.falcorCache.videos[id].current.value[1];
  397.   }
  398.   catch(ignore) {}
  399.   if(typeof newID !== 'undefined' && cache.hasOwnProperty(newID))
  400.     return cache[newID];
  401.  
  402.   newID = idOverrides[id];
  403.   if(typeof newID !== 'undefined' && cache.hasOwnProperty(newID))
  404.     return cache[newID];
  405.  
  406.   if(silent === true)
  407.     return null;
  408.  
  409.   alert("Couldn't find the " + name + ". Wait until the player is loaded. If that doesn't help refresh the page.");
  410.   throw '';
  411. };
  412.  
  413. const getSubsFromCache = silent => getXFromCache(subCache, 'subs', silent);
  414.  
  415. const pad = (number, letter) => `${letter}${number.toString().padStart(2, '0')}`;
  416.  
  417. const safeTitle = title => title.trim().replace(/[:*?"<>|\\\/]+/g, '_').replace(/ /g, '.');
  418.  
  419. const getTitleFromCache = () => {
  420.   const title = getXFromCache(titleCache, 'title');
  421.   const titleParts = [title.title];
  422.   if(title.type === 'show') {
  423.     const season = pad(title.season, 'S');
  424.     if(title.hiddenNumber) {
  425.       titleParts.push(season);
  426.       titleParts.push(title.subtitle);
  427.     }
  428.     else {
  429.       titleParts.push(season + pad(title.episode, 'E'));
  430.       if(epTitleInFilename)
  431.         titleParts.push(title.subtitle);
  432.     }
  433.   }
  434.   return [safeTitle(titleParts.join('.')), safeTitle(title.title)];
  435. };
  436.  
  437. const pickFormat = formats => {
  438.   const preferred = (subFormat === DFXP ? ALL_FORMATS : ALL_FORMATS_prefer_vtt);
  439.  
  440.   for(let format of preferred) {
  441.     if(typeof formats[format] !== 'undefined')
  442.       return formats[format];
  443.   }
  444. };
  445.  
  446.  
  447. const _save = async (_zip, title) => {
  448.   const content = await _zip.generateAsync({type:'blob'});
  449.   saveAs(content, title + '.zip');
  450. };
  451.  
  452. const _download = async _zip => {
  453.   const subs = getSubsFromCache();
  454.   const [title, seriesTitle] = getTitleFromCache();
  455.   const downloaded = [];
  456.  
  457.   let filteredLangs;
  458.   if(langs === '')
  459.     filteredLangs = Object.keys(subs);
  460.   else {
  461.     const regularExpression = new RegExp(
  462.       '^(' + langs
  463.         .replace(/\[/g, '\\[')
  464.         .replace(/\]/g, '\\]')
  465.         .replace(/\-/g, '\\-')
  466.         .replace(/\s/g, '')
  467.         .replace(/,/g, '|')
  468.       + ')'
  469.     );
  470.     filteredLangs = [];
  471.     for(const lang of Object.keys(subs)) {
  472.       if(lang.match(regularExpression))
  473.         filteredLangs.push(lang);
  474.     }
  475.   }
  476.  
  477.   const progress = new ProgressBar(filteredLangs.length);
  478.   let stop = false;
  479.   for(const lang of filteredLangs) {
  480.     const [urls, extension] = pickFormat(subs[lang]);
  481.     while(urls.length > 0) {
  482.       let url = popRandomElement(urls);
  483.       const resultPromise = fetch(url, {mode: "cors"});
  484.       let result;
  485.       try {
  486.         // Promise.any isn't supported in all browsers, use Promise.race instead
  487.         result = await Promise.race([resultPromise, progress.stop, asyncSleep(30, STOP_THE_DOWNLOAD)]);
  488.       }
  489.       catch(e) {
  490.         // the only promise that can be rejected is the one from fetch
  491.         // if that happens we want to stop the download anyway
  492.         result = STOP_THE_DOWNLOAD;
  493.       }
  494.       if(result === STOP_THE_DOWNLOAD) {
  495.         stop = true;
  496.         break;
  497.       }
  498.       progress.increment();
  499.       const data = await result.text();
  500.       if(data.length > 0) {
  501.         downloaded.push({lang, data, extension});
  502.         break;
  503.       }
  504.     }
  505.     if(stop)
  506.       break;
  507.   }
  508.  
  509.   downloaded.forEach(x => {
  510.     const {lang, data, extension} = x;
  511.     _zip.file(`${title}.WEBRip.Netflix.${lang}.${extension}`, data);
  512.   });
  513.  
  514.   if(await Promise.race([progress.stop, {}]) === STOP_THE_DOWNLOAD)
  515.     stop = true;
  516.   progress.destroy();
  517.  
  518.   return [seriesTitle, stop];
  519. };
  520.  
  521. const downloadThis = async () => {
  522.   const _zip = new JSZip();
  523.   const [title, stop] = await _download(_zip);
  524.   _save(_zip, title);
  525. };
  526.  
  527. const cleanBatch = async () => {
  528.   setBatch(null);
  529.   return;
  530.   const cache = await caches.open('NSD');
  531.   cache.delete('/subs.zip');
  532.   await caches.delete('NSD');
  533. }
  534.  
  535. const readAsBinaryString = blob => new Promise(resolve => {
  536.   const reader = new FileReader();
  537.   reader.onload = function(event) {
  538.     resolve(event.target.result);
  539.   };
  540.   reader.readAsBinaryString(blob);
  541. });
  542.  
  543. const downloadBatch = async auto => {
  544.   const cache = await caches.open('NSD');
  545.   let zip, title, stop;
  546.   if(auto === true) {
  547.     try {
  548.       const response = await cache.match('/subs.zip');
  549.       const blob = await response.blob();
  550.       zip = await JSZip.loadAsync(await readAsBinaryString(blob));
  551.     }
  552.     catch(error) {
  553.       console.error(error);
  554.       alert('An error occured when loading the zip file with subs from the cache. More info in the browser console.');
  555.       await cleanBatch();
  556.       return;
  557.     }
  558.   }
  559.   else
  560.     zip = new JSZip();
  561.  
  562.   try {
  563.     [title, stop] = await _download(zip);
  564.   }
  565.   catch(error) {
  566.     title = 'unknown';
  567. 		stop = true;
  568.   }
  569.  
  570.   const id = parseInt(getVideoId());
  571.   batch = batch.filter(x => x !== id);
  572.  
  573.   if(stop || batch.length == 0) {
  574.     await _save(zip, title);
  575.     await cleanBatch();
  576.   }
  577.   else {
  578.     setBatch(batch);
  579.     cache.put('/subs.zip', new Response(await zip.generateAsync({type:'blob'})));
  580.     await asyncSleep(batchDelay);
  581.     window.location = window.location.origin + '/watch/' + batch[0];
  582.   }
  583. };
  584.  
  585. const downloadAll = () => {
  586.   batch = batchAll;
  587.   downloadBatch();
  588. };
  589.  
  590. const downloadSeason = () => {
  591.   batch = batchSeason;
  592.   downloadBatch();
  593. };
  594.  
  595. const downloadToEnd = () => {
  596.   batch = batchToEnd;
  597.   downloadBatch();
  598. };
  599.  
  600. const processMessage = e => {
  601.   const {type, data} = e.detail;
  602.   if(type === 'subs')
  603.     processSubInfo(data);
  604.   else if(type === 'id_override')
  605.     idOverrides[data[0]] = data[1];
  606.   else if(type === 'metadata')
  607.     processMetadata(data);
  608. }
  609.  
  610. const injection = (ALL_FORMATS) => {
  611.   const MANIFEST_PATTERN = new RegExp('manifest|licensedManifest');
  612.   const forceSubs = localStorage.getItem('NSD_force-all-lang') !== 'false';
  613.   const prefLocale = localStorage.getItem('NSD_pref-locale') || '';
  614.  
  615.   // hide the menu when we go back to the browse list
  616.   window.addEventListener('popstate', () => {
  617.     const display = (document.location.pathname.split('/')[1] === 'watch' ? '' : 'none');
  618.     const menu = document.querySelector('#subtitle-downloader-menu');
  619.     menu.style.display = display;
  620.   });
  621.  
  622.   // hijack JSON.parse and JSON.stringify functions
  623.   ((parse, stringify, open, realFetch) => {
  624.     JSON.parse = function (text) {
  625.       const data = parse(text);
  626.  
  627.       if (data && data.result && data.result.timedtexttracks && data.result.movieId) {
  628.         window.dispatchEvent(new CustomEvent('netflix_sub_downloader_data', {detail: {type: 'subs', data: data.result}}));
  629.       }
  630.       return data;
  631.     };
  632.  
  633.     JSON.stringify = function (data) {
  634.       /*{
  635.         let text = stringify(data);
  636.         if (text.includes('dfxp-ls-sdh'))
  637.           console.log(text, data);
  638.       }*/
  639.  
  640.       if (data && typeof data.url === 'string' && data.url.search(MANIFEST_PATTERN) > -1) {
  641.         for (let v of Object.values(data)) {
  642.           try {
  643.             if (v.profiles) {
  644.               for(const profile_name of ALL_FORMATS) {
  645.                 if(!v.profiles.includes(profile_name)) {
  646.                   v.profiles.unshift(profile_name);
  647.                 }
  648.               }
  649.             }
  650.             if (v.showAllSubDubTracks != null && forceSubs)
  651.               v.showAllSubDubTracks = true;
  652.             if (prefLocale !== '')
  653.               v.preferredTextLocale = prefLocale;
  654.           }
  655.           catch (e) {
  656.             if (e instanceof TypeError)
  657.               continue;
  658.             else
  659.               throw e;
  660.           }
  661.         }
  662.       }
  663.       if(data && typeof data.movieId === 'number') {
  664.         try {
  665.           let videoId = data.params.sessionParams.uiplaycontext.video_id;
  666.           if(typeof videoId === 'number' && videoId !== data.movieId)
  667.             window.dispatchEvent(new CustomEvent('netflix_sub_downloader_data', {detail: {type: 'id_override', data: [videoId, data.movieId]}}));
  668.         }
  669.         catch(ignore) {}
  670.       }
  671.       return stringify(data);
  672.     };
  673.  
  674.     XMLHttpRequest.prototype.open = function() {
  675.       if(arguments[1] && arguments[1].includes('/metadata?'))
  676.         this.addEventListener('load', async () => {
  677.           let data = this.response;
  678.           if(data instanceof Blob)
  679.             data = JSON.parse(await data.text());
  680.           else if(typeof data === "string")
  681.             data = JSON.parse(data);
  682.           window.dispatchEvent(new CustomEvent('netflix_sub_downloader_data', {detail: {type: 'metadata', data: data}}));
  683.         }, false);
  684.       open.apply(this, arguments);
  685.     };
  686.  
  687.     window.fetch = async (...args) => {
  688.       const response = realFetch(...args);
  689.       if(args[0] && args[0].includes('/metadata?')) {
  690.         const copied = (await response).clone();
  691.         const data = await copied.json();
  692.         window.dispatchEvent(new CustomEvent('netflix_sub_downloader_data', {detail: {type: 'metadata', data: data}}));
  693.       }
  694.       return response;
  695.     };
  696.   })(JSON.parse, JSON.stringify, XMLHttpRequest.prototype.open, window.fetch);
  697. }
  698.  
  699. window.addEventListener('netflix_sub_downloader_data', processMessage, false);
  700.  
  701. // inject script
  702. const sc = document.createElement('script');
  703. sc.innerHTML = '(' + injection.toString() + ')(' + JSON.stringify(ALL_FORMATS) + ')';
  704. document.head.appendChild(sc);
  705. document.head.removeChild(sc);
  706.  
  707. // add CSS style
  708. const s = document.createElement('style');
  709. s.innerHTML = SCRIPT_CSS;
  710. document.head.appendChild(s);
  711.  
  712. const observer = new MutationObserver(function(mutations) {
  713.   mutations.forEach(function(mutation) {
  714.     mutation.addedNodes.forEach(function(node) {
  715.       // add scrollbar - Netflix doesn't expect you to have this manu languages to choose from...
  716.       try {
  717.         (node.parentNode || node).querySelector('.watch-video--selector-audio-subtitle').parentNode.style.overflowY = 'scroll';
  718.       }
  719.       catch(ignore) {}
  720.     });
  721.   });
  722. });
  723. observer.observe(document.body, { childList: true, subtree: true });