How to inform the Jellyfin server that a client doesn't support a certain codec?

[hheimbuerger]

I have Jellyfin 10.10.1 set up, things work fine, as far as I can tell it can hardware transcode (QSV) etc.

I've started using the Android (tablet) client. It doesn't come with a media player, from what I understand. My main media player is MX Player, and I'd like to use that for Jellyfin as well.
Currently, I'm playing a file that has an AC3 audio stream, and when I open it via Jellyfin in MX Player, I do get the video stream, but no audio, and a toast stating that AC3 isn't supported by MX Player.
My understanding is that Jellyfin thinks that AC3 is fine to just pass through, because it doesn't know about the capabilities of my video player.

If it would just pass through the video and transcode the audio, I believe it should work.

How do I teach the Jellyfin server (ideally for that specific client/hardware, but if it has to be a user setting, that would be fine too, I guess) that AC3 isn't natively supported by the player and needs transcoding?

PS: For context, the video plays fine on my Nvidia Shield TV via Jellyfin. I think that's because the Android TV client of Jellyfin includes a media player (or maybe Android TV just comes with a media player used by the Jellyfin app) and that media player supports AC3.

[TheDreadPirate]

We have an Android client. And there is also the 3rd party Findroid client.

What kind of tablet is it?

For the record, the Jellyfin clients automatically tell the server a video isn't compatible. MX Player cannot do that.

[hheimbuerger]

Sorry if I didn't make that clear: I am using the official Jellyfin Android app.

You're right, there's an integrated ExoPlayer, but what if I wanted to not use that, and instead use the Jellyfin Settings > Client Settings > Video player type: External option?

MX Player doesn't (necessarily) use the system codecs, I believe it has its own mpv or ffmpeg or so compiled in. And as you've said: an external player cannot report its codec support to the Jellyfin server.

So is there no way for me to manually inform the Jellyfin server about my player-of-choice's codec support list?

[TheDreadPirate]

Ah. Ok. In that case, using an external player AND transcoding is not an option. When using an external player, it will only direct play. Not even with HLS. The server will literally send the unmodified file and hope that your player works.