api/language-codes: remove region part of the language code

and convert language codes if they're not 3 characters long

api/src/misc/language-codes.js

@@ -49,5 +49,6 @@ const maps = {
 }
 
 export const convertLanguageCode = (code) => {
+    code = code.split("-")[0].split("_")[0];
     return maps[code.length]?.[code.toLowerCase()] || null;
 }

api/src/processing/match-action.js

@@ -263,8 +263,9 @@ export default function({
 
     // extractors usually return ISO 639-1 language codes,
     // but video players expect ISO 639-2, so we convert them here
-    if (defaultParams.fileMetadata?.sublanguage?.length === 2) {
-        const code = convertLanguageCode(defaultParams.fileMetadata.sublanguage);
+    const sublanguage = defaultParams.fileMetadata?.sublanguage;
+    if (sublanguage && sublanguage.length !== 3) {
+        const code = convertLanguageCode(sublanguage);
         if (code) {
             defaultParams.fileMetadata.sublanguage = code;
         } else {