MP4box has a great local web tool to test the mime type including the codecs parameter:
https://gpac.github.io/mp4box.js/test/filereader.html
Jake Archibald wrote a good article about this topic: https://jakearchibald.com/2022/html-codecs-parameter-for-av1/
I would go with Jellyfin as a server and Mopidy client as outputs. Like an rpi with an audio hat or class d amp hat. Planning to add Snapcast to the mix for multiroom audio but didn’t find the time yet.