Multichannel audio playing stereo

[vertigo346]

Hi everyone, I hope someone can help me troubleshoot this issue, although I've searched this and found other similar problems (e.g. this and this) with no solution.

I recently installed Jellyfin media server (10.10.7) on my Debian media server (Intel N97) and trying to play videos to a Sony A80k on the Android TV 0.18.8 native app. The TV is hooked up to a Yamaha RX-V385 A/V receiver via eARC.

My problem is that several multichannel videos are outputting stereo instead of letting my A/V receiver going the downmixing to its speaker setup (3.0). In other words, I'm losing the center speaker. On Plex, the same videos are using my full range of speakers; only Jellyfin output those multichannel sources as stereo.

The dashboard says the file is direct playing. Also, my A/V receiver shows DD+, which makes me believe the change is being made somewhere by Jellyfin.

I have tested the suggsted fixes mentioned in other threads with similar issues (e.g. refresh rate switching off, using an external player, prefer FFMPEG) to no avail.

During my investigations, I've noticed that the issues seems to happen on the following audio formats:

• AAC
  
• TrueHD
  

Multichannel AC3 audio plays correctly, only AAC downmixes to stereo.

Again, I'm puzzled by the fact that Plex plays those files correctly (therefore I doubt it's a TV, receiver or connection issue), and I'd very much like to find out why this is happening.

Thanks in advance, I hope this can fixed either through troubleshooting or in a future app release