Jellyfin not extracting lossy 5.1 DTS Audio core from 7.1 DTS-HD Master Audio track, resulting in no sound and no transcoding attempt

[marbat88]

Versions

• Jellyfin Server Version: 10.9.9
• Roku Client Version: 2.1.4
• Roku Software Version: 13.1.4
• Roku Build: 1510-30
• TV Model: TCL 65R617
• TV Roku Hardware: 7121X
• Receiver Model: Denon X1500H
• Receiver Firmware: 3700-9121-8042-4030
• Receiver DTS Version: 3.90.50.00

Describe the bug

TCL Roku TV is running the Jellyfin client, audio goes from TV to receiver via ARC (not eARC). Receiver is set up for 5.1 (no speakers connected for 7.1, and the amp for the absent speakers is assigned to ZONE2).

There appears to be a bug with extracting a lossy 5.1 DTS Audio core from 7.1 DTS-HD Master Audio tracks. This isn't happening, and is resulting in no sound. I swear this previously worked, but I am not sure when it stopped working.

If I force a video transcode via max resolution settings, the audio is also transcoded and works, but this nukes both video and audio quality.

How To Reproduce

When playing any video with 7.1 DTS-HD Master Audio, there is no sound, and no attempt at transcoding. The receiver does not detect any audio being passed to it. There is nothing of use in the Jellyfin logs, because Jellyfin thinks it is direct playing.

Expected behavior

I would expect the behavior to be the same as for 5.1 DTS-HD Master Audio tracks, which are working correctly and passing the lossy core to the receiver. Since the TV/receiver are using ARC (not eARC), the Jellyfin client should be passing the lossy 5.1 DTS Audio core from the 7.1 DTS-HD Master Audio track to the receiver directly, without transcoding.

Additionally, when forcing a video transcode, it is not clear why audio is also transcoded when it should direct play, as above. In this situation, ironically, my ghetto fix shouldn't be addressing the problem of no sound.

I appreciate the help! Love Jellyfin and the community.