I realize this is a bit of a longshot as it’s somewhat complex.
Using Google Cast on any app from an Android device to multiple Cast devices (i.e. a group) especially with high bitrate content is very unreliable and frequently cuts out. This is especially the case with Symfonium as it uses the device as a proxy.
Instead, at least for streaming non-cached Jellyfin content, it would be supremely helpful to be able to initiate cast sessions and send queues between the Google Cast device/group and the server but from the app. Plexamp achieves this though admittedly it’s one app for one streaming service, as an example.
The official Jellyfin app and Jellyfin-web UI don’t even have working cast apps so if you were to implement it with your existing Cast receiver, it’d be a first for the Jellyfin ecosystem, as well as make it far more feasible to cast to more than one device at a time.
You got it wrong Symfonium does not proxy the content when casting and server is online.
Your issue is probably Jellyfin in this case. Provide logs to see your issues
Upon closer look, I see that you’re right. I’m not experiencing things cutting out and perhaps at the time I was casting offline content.
What ultimately led me to write this, I guess, is poor (read: not implemented) reporting back to Jellyfin. Currently while casting, Jellyfin is only reading (most of the time) that a song has finished playback. More significant is that Jellyfin believes that it’s the phone streaming the audio rather than the Cast receiver.
Functionally there is no issue. Cosmetically I’d expect the Jellyfin admin console to report that it’s a Cast device streaming the audio and not the Android device, plus the current track position and proper start/end reporting.
And as long as it is streaming from the server and not being proxied by Symfonium, might the queues be shared with the cast receiver? That way my Android TV or smart display (or voice) could be used to skip songs/potentially view the queue.
The start / stop and position are properly updated on Jellyfin during cast, open issue with logs if not for your.
And no the queue can not be shared either sorry.