Language code in subtitles problem with Chinese

[mhqschen]

Describe the bug
There are two problems related with the language code for Chinese.

1. The language code in subtitles for Chinese can't be recognized.
   XXX.chi.srt, won't be recognized as "Chinese" but "Chi". While XXX.spa.srt will be successfully phased as "Spanish" and XXX.en.srt will be successfully phased as "English"
   And after tried several common language code for Chinese, I found chi, zh, zho, zh-hk will all be recognized as "Chi"
   On the other hand, ch, chn, chs, cht, cn, zh-cn, zh-cht are not able to be recognized but only shows them as subtitle name.

And this lead to the "Preferred subtitle language" setup not functional.

2. There are 3 option in language choose dropdown for Chinese.
   "Chinese", "Chinese traditional" and "Chinese HongKong"
   When I used the upload subtitle function in browser. No matter what I option choose, the uploaded subtitles will all be renamed to XXX.chi.srt.

System (please complete the following information):

• OS: [e.g. Debian, Windows]
• Virtualization: Docker
• Clients: Browser
• Browser: Microsoft Edge 91 (chromium)
• Jellyfin Version: 10.7.6

Expected behavior
Although Chinese has many branches, the most well known and used ones are "Chinese Simplified" and "Chinese Traditional".
They are used in most mutil-language scenarios and used by Netflix as well.
Better to change from "Chinese", "Chinese traditional" and "Chinese HongKong" to "Chinese Simplified" and "Chinese Traditional".

And hope to have a clear list of language code on wiki page instructing people how to rename their subtitles. And Jellyfin can be able to recognize "Chinese Simplified" and "Chinese Traditional".

If I can expect more, it would be wonderful to be able to fallback to other subtitles with "Chinese" in name when I choose "Preferred subtitle language" to"Chinese Simplified" but there isn't a subtitle in "Chinese Simplified" (same for "Chinese Traditional")

Server Logs
No error

FFmpeg Logs
No error

Browser Console Logs
No error

Screenshots

[webysther]

Same as #9072

[jim608]

I have the same issues
I have responded to this question on discord and when I asked a similar question they said
https://en.wikipedia.org/wiki/IETF_language_tag
the IETF language column in that table is what we use.
its called the "IETF BCP 47" standard or "IETF language codes"
The following is a list of some of the more commonly used primary language subtags. The list represents only a small subset (less than 2 percent) of primary language subtags; the following is a list of some of the more commonly used primary language subtags. The list represents only a small subset (less than 2 percent) of primary language subtags; for full information, the Language Subtag Registry should be consulted directly.
Then I found zh-TW zh-CN on this website https://gist.github.com/traysr/2001377.
Then I found zh-TW zh-CN zh-HK on this website https://www.venea.net/web/culture_code.
The most commonly used Chinese languages are Traditional Chinese, Simplified Chinese and Chinese (Cantonese), others are not commonly used or are basically the same.
Please correct me if I am wrong

[AkiraVoid]

Can confirm this by now

[jellyfin-bot]

This issue has gone 120 days without an update and will be closed within 21 days if there is no new activity. To prevent this issue from being closed, please confirm the issue has not already been fixed by providing updated examples or logs.

If you have any questions you can use one of several ways to contact us.

[felix920506]

still an issue