diff --git a/devices/nos/modules/subtitles/syncing/node-syncsub/.eslintrc.json b/devices/nos/modules/subtitles/syncing/node-syncsub/.eslintrc.json
index f3b55fe..0bdffac 100644
--- a/devices/nos/modules/subtitles/syncing/node-syncsub/.eslintrc.json
+++ b/devices/nos/modules/subtitles/syncing/node-syncsub/.eslintrc.json
@@ -28,7 +28,6 @@
     "default-param-last": ["error"],
     "eqeqeq": ["error", "smart"],
     "func-names": ["warn", "never"],
-    "func-style": ["warn", "expression"],
     "logical-assignment-operators": ["warn", "always"],
     "no-array-constructor": ["error"],
     "no-empty-function": ["warn"],
diff --git a/devices/nos/modules/subtitles/syncing/node-syncsub/lang-codes.ts b/devices/nos/modules/subtitles/syncing/node-syncsub/lang-codes.ts
index ace9612..447efbc 100644
--- a/devices/nos/modules/subtitles/syncing/node-syncsub/lang-codes.ts
+++ b/devices/nos/modules/subtitles/syncing/node-syncsub/lang-codes.ts
@@ -1,4 +1,4 @@
-export const iso6391To3 = new Map([
+export const ISO6391To3 = new Map([
     ['aa', 'aar'],
     ['ab', 'abk'],
     ['af', 'afr'],
@@ -184,3 +184,190 @@ export const iso6391To3 = new Map([
     ['zh', 'zho'],
     ['zu', 'zul'],
 ]);
+
+export const ISO6393To1 = new Map([
+    ['aar', 'aa'],
+    ['abk', 'ab'],
+    ['afr', 'af'],
+    ['aka', 'ak'],
+    ['amh', 'am'],
+    ['ara', 'ar'],
+    ['arg', 'an'],
+    ['asm', 'as'],
+    ['ava', 'av'],
+    ['ave', 'ae'],
+    ['aym', 'ay'],
+    ['aze', 'az'],
+    ['bak', 'ba'],
+    ['bam', 'bm'],
+    ['bel', 'be'],
+    ['ben', 'bn'],
+    ['bis', 'bi'],
+    ['bod', 'bo'],
+    ['bos', 'bs'],
+    ['bre', 'br'],
+    ['bul', 'bg'],
+    ['cat', 'ca'],
+    ['ces', 'cs'],
+    ['cha', 'ch'],
+    ['che', 'ce'],
+    ['chu', 'cu'],
+    ['chv', 'cv'],
+    ['cor', 'kw'],
+    ['cos', 'co'],
+    ['cre', 'cr'],
+    ['cym', 'cy'],
+    ['dan', 'da'],
+    ['deu', 'de'],
+    ['div', 'dv'],
+    ['dzo', 'dz'],
+    ['ell', 'el'],
+    ['eng', 'en'],
+    ['epo', 'eo'],
+    ['est', 'et'],
+    ['eus', 'eu'],
+    ['ewe', 'ee'],
+    ['fao', 'fo'],
+    ['fas', 'fa'],
+    ['fij', 'fj'],
+    ['fin', 'fi'],
+    ['fra', 'fr'],
+    ['fry', 'fy'],
+    ['ful', 'ff'],
+    ['gla', 'gd'],
+    ['gle', 'ga'],
+    ['glg', 'gl'],
+    ['glv', 'gv'],
+    ['grn', 'gn'],
+    ['guj', 'gu'],
+    ['hat', 'ht'],
+    ['hau', 'ha'],
+    ['hbs', 'sh'],
+    ['heb', 'he'],
+    ['her', 'hz'],
+    ['hin', 'hi'],
+    ['hmo', 'ho'],
+    ['hrv', 'hr'],
+    ['hun', 'hu'],
+    ['hye', 'hy'],
+    ['ibo', 'ig'],
+    ['ido', 'io'],
+    ['iii', 'ii'],
+    ['iku', 'iu'],
+    ['ile', 'ie'],
+    ['ina', 'ia'],
+    ['ind', 'id'],
+    ['ipk', 'ik'],
+    ['isl', 'is'],
+    ['ita', 'it'],
+    ['jav', 'jv'],
+    ['jpn', 'ja'],
+    ['kal', 'kl'],
+    ['kan', 'kn'],
+    ['kas', 'ks'],
+    ['kat', 'ka'],
+    ['kau', 'kr'],
+    ['kaz', 'kk'],
+    ['khm', 'km'],
+    ['kik', 'ki'],
+    ['kin', 'rw'],
+    ['kir', 'ky'],
+    ['kom', 'kv'],
+    ['kon', 'kg'],
+    ['kor', 'ko'],
+    ['kua', 'kj'],
+    ['kur', 'ku'],
+    ['lao', 'lo'],
+    ['lat', 'la'],
+    ['lav', 'lv'],
+    ['lim', 'li'],
+    ['lin', 'ln'],
+    ['lit', 'lt'],
+    ['ltz', 'lb'],
+    ['lub', 'lu'],
+    ['lug', 'lg'],
+    ['mah', 'mh'],
+    ['mal', 'ml'],
+    ['mar', 'mr'],
+    ['mkd', 'mk'],
+    ['mlg', 'mg'],
+    ['mlt', 'mt'],
+    ['mon', 'mn'],
+    ['mri', 'mi'],
+    ['msa', 'ms'],
+    ['mya', 'my'],
+    ['nau', 'na'],
+    ['nav', 'nv'],
+    ['nbl', 'nr'],
+    ['nde', 'nd'],
+    ['ndo', 'ng'],
+    ['nep', 'ne'],
+    ['nld', 'nl'],
+    ['nno', 'nn'],
+    ['nob', 'nb'],
+    ['nor', 'no'],
+    ['nya', 'ny'],
+    ['oci', 'oc'],
+    ['oji', 'oj'],
+    ['ori', 'or'],
+    ['orm', 'om'],
+    ['oss', 'os'],
+    ['pan', 'pa'],
+    ['pli', 'pi'],
+    ['pol', 'pl'],
+    ['por', 'pt'],
+    ['pus', 'ps'],
+    ['que', 'qu'],
+    ['roh', 'rm'],
+    ['ron', 'ro'],
+    ['run', 'rn'],
+    ['rus', 'ru'],
+    ['sag', 'sg'],
+    ['san', 'sa'],
+    ['sin', 'si'],
+    ['slk', 'sk'],
+    ['slv', 'sl'],
+    ['sme', 'se'],
+    ['smo', 'sm'],
+    ['sna', 'sn'],
+    ['snd', 'sd'],
+    ['som', 'so'],
+    ['sot', 'st'],
+    ['spa', 'es'],
+    ['sqi', 'sq'],
+    ['srd', 'sc'],
+    ['srp', 'sr'],
+    ['ssw', 'ss'],
+    ['sun', 'su'],
+    ['swa', 'sw'],
+    ['swe', 'sv'],
+    ['tah', 'ty'],
+    ['tam', 'ta'],
+    ['tat', 'tt'],
+    ['tel', 'te'],
+    ['tgk', 'tg'],
+    ['tgl', 'tl'],
+    ['tha', 'th'],
+    ['tir', 'ti'],
+    ['ton', 'to'],
+    ['tsn', 'tn'],
+    ['tso', 'ts'],
+    ['tuk', 'tk'],
+    ['tur', 'tr'],
+    ['twi', 'tw'],
+    ['uig', 'ug'],
+    ['ukr', 'uk'],
+    ['urd', 'ur'],
+    ['uzb', 'uz'],
+    ['ven', 've'],
+    ['vie', 'vi'],
+    ['vol', 'vo'],
+    ['wln', 'wa'],
+    ['wol', 'wo'],
+    ['xho', 'xh'],
+    ['yid', 'yi'],
+    ['yor', 'yo'],
+    ['zha', 'za'],
+    ['zho', 'zh'],
+    ['zul', 'zu'],
+]);
diff --git a/devices/nos/modules/subtitles/syncing/node-syncsub/main.ts b/devices/nos/modules/subtitles/syncing/node-syncsub/main.ts
index e1c295f..578bfc3 100755
--- a/devices/nos/modules/subtitles/syncing/node-syncsub/main.ts
+++ b/devices/nos/modules/subtitles/syncing/node-syncsub/main.ts
@@ -1,55 +1,98 @@
-import { readdir } from 'fs';
-import { ffprobe } from 'fluent-ffmpeg';
+import {
+    mkdir,
+    readdir as readDir,
+    rename as mv,
+} from 'fs/promises';
+
+import { ffprobe as ffProbe } from 'fluent-ffmpeg';
 import { spawn } from 'child_process';
-import { iso6391To3 } from './lang-codes';
 
-const SUB_EXT_LENGTH = 7;
+import { ISO6391To3, ISO6393To1 } from './lang-codes';
 
 
-const FILE = process.argv[2];
+/**
+ * These are the cli arguments
+ *
+ * @param directory the directory in which we want to sync the subtitles
+ * @param languages a comma-separated list of languages (3 letters) to sync the subtitles
+ */
+const DIR = process.argv[2];
+let langs = process.argv[3].split(',');
 
-const main = () => {
-    const BASE_NAME = FILE.substring(
-        FILE.lastIndexOf('/') + 1,
-        FILE.length - SUB_EXT_LENGTH,
-    );
 
-    const DIR = FILE.substring(0, FILE.lastIndexOf('/'));
+// Check if there are 2 params
+if (DIR && langs) {
+    main();
+}
+else {
+    console.error('Error: no argument passed');
+    process.exit(1);
+}
 
-    readdir(DIR, (_, files) => {
-        const VIDEO = `${DIR}/${files.filter((f) =>
-            f.includes(BASE_NAME) &&
-            !f.endsWith('.nfo') &&
-            !f.endsWith('.srt'))[0]}`;
+function getVideoPath(files: string[]) {
+    const fileName = DIR.split('/').at(-1) ?? '';
 
-        ffprobe(VIDEO, (_e, data) => {
-            const LANG = iso6391To3.get(FILE.split('.').at(-2) ?? 'en') ?? 'eng';
+    return `${DIR}/${files.filter((f) =>
+        f.includes(fileName) &&
+        !f.endsWith('.nfo') &&
+        !f.endsWith('.srt'))[0]}`;
+}
 
-            const OUT_FILE = `${BASE_NAME}.synced.${LANG.substring(0, 2)}.srt`;
-            const OUT_PATH = `${DIR}/${OUT_FILE}`;
+async function main() {
+    const files = await readDir(DIR);
 
-            if (files.includes(OUT_FILE)) {
-                console.warn('Synced subtitles already exist, not doing anything');
-                process.exit(0);
+    const VIDEO = getVideoPath(files);
+    const BASE_NAME = VIDEO.split('/').at(-1)?.replace(/\.[^.]*$/, '');
+
+    // Check if backup folder already exists and create it if not
+    if (!files.some((f) => f.endsWith('.srt.bak'))) {
+        await mkdir(`${DIR}/.srt.bak`);
+    }
+    else {
+        const backups = await readDir(`${DIR}/.srt.bak`);
+
+        // Remove synced subtitles from the list to sync
+        // langs - backups
+        langs = langs.filter((n) => !backups
+            .some((s) => n === ISO6391To3.get(s.split('.').at(-2) ?? '')));
+    }
+
+    if (langs.length === 0) {
+        console.warn('Subtitles have already been synced');
+        process.exit(0);
+    }
+
+    // ffprobe the video file to see available audio tracks
+    ffProbe(VIDEO, (_e, data) => {
+        const AVAIL_LANGS = data.streams
+            .filter((s) => s.codec_type === 'audio')
+            .map((s) => s['tags']['language']);
+
+        // Sync subtitles one by one
+        langs.forEach(async(lang) => {
+            const FILE_NAME = `${BASE_NAME}.${ISO6393To1.get(lang)}.srt`;
+            const IN_FILE = `${DIR}/.srt.bak/${FILE_NAME}`;
+            const OUT_FILE = `${DIR}/${FILE_NAME}`;
+
+            if (files.includes(FILE_NAME)) {
+                await mv(OUT_FILE, IN_FILE);
+            }
+            else {
+                // TODO: check data and extract sub
             }
-
-            const availLangs = data.streams
-                .filter((s) => s.codec_type === 'audio')
-                .map((s) => s['tags']['language']);
 
             const cmd = [
                 '--cli sync',
-                `--sub-lang ${LANG}`,
+                `--sub-lang ${lang}`,
 
-                `--ref-stream-by-lang ${availLangs.includes(LANG) ? LANG : availLangs[0]}`,
+                `--ref-stream-by-lang ${AVAIL_LANGS.includes(lang) ?
+                    lang :
+                    AVAIL_LANGS[0]}`,
                 '--ref-stream-by-type "audio"',
 
-                `--sub '${FILE}'`,
-                `--out '${OUT_PATH}'`,
-                // `--out '${OUT_PATH}'`,
+                `--sub '${IN_FILE}'`,
+                `--out '${OUT_FILE}'`,
                 `--ref '${VIDEO}'`,
-
-                // '--overwrite',
             ];
 
             spawn('subsync', cmd, {
@@ -58,18 +101,4 @@ const main = () => {
             });
         });
     });
-};
-
-if (FILE) {
-    if (FILE.includes('synced.srt')) {
-        console.warn('Won\'t sync already synced subtitles, not doing anything');
-        process.exit(0);
-    }
-    else {
-        main();
-    }
-}
-else {
-    console.error('Error: no argument passed');
-    process.exit(1);
 }