Android TV client outputting multi-channel FLAC albums in stereo

[retrofan01]

When I play a multichannel FLAC album on Jellyfin 0.18.8 on my NVIDIA Shield TV Pro through a Denon AVR-X2800H receiver, the input signal on the Denon shows FL and FR (i.e. stereo) as the only active channels. All of my speakers (SW, FL, C, FR, SL, SR) show as active. Movies and TV shows played on the Jellyfin Android TV client do not have this problem and display the correct input signal. Other apps on the Shield (e.g. Netflix, Disney+) also do not have this problem.

In the Jellyfin app settings, Playback -> Audio -> Audio output is set to Direct and Playback -> Advanced playback preferences -> Audio -> Bitstream Dolby Digital audio is enabled. Developer Options -> Prefer FFmpeg for audio playback is disabled. What's preventing Jellyfin from passing through the multichannel FLAC audio correctly and how can this be rectified?

[TheDreadPirate]

I chatted with Android TV app dev and it is possible this is an issue with Android TV not correctly communicating channel support for FLAC.  He is not aware of anything in the playback code that would cause 3+ channel FLAC music to down mix to stereo.

The ATV app is currently undergoing an overhaul and part of that overhaul includes more debugging tools.  Specifically having the ATV client send to the Jellyfin server what the device's OS and firmware reports for codec and channel count compatibility.

No ETA on that, but it will help us debug this and similar issues in the future.

[retrofan01]

Thanks for pointing me on the right track - I went to Android Settings -> Devices Preferences -> Display & Sound -> Advanced sound settings and set 'Dolby audio processing' to disabled. This seems to have solved the issue although I didn't realise the Jellyfin client didn't have gapless playback.

I've switched to Symfonium instead (still using Jellyfin as the backend music server) and gapless playback with 5.1 input signal seems to work correctly.

[TheDreadPirate]

Why would that setting affect how FLAC is processed?

But ok. IMO, you should submit a bug report on the app's github. That definitely should cause FLAC to behave differently.

https://github.com/jellyfin/jellyfin-androidtv/issues