Regression: New Emby for Android app (3.5.16) ignores "Convert to AC3" for AAC 5.1 on TV with ARC systems

[SvenKlomp 0]

Hello,

I am experiencing a regression where the new Emby for Android app fails to transcode AAC 5.1 to AC3, resulting in stereo output, while the older Emby for Android TV app handles this correctly on the exact same hardware.

I am using a TCL QD Mini-LED 65C89K (2025 model) connected via HDMI-ARC to a Denon AVR-X2500H. My TV audio output is set to Passthrough, and I have enabled the option “Convert unsupported surround audio to Dolby Digital (AC3)” in the Emby app.

The issue is that my AVR does not support AAC audio and, because it only has ARC (no eARC), it cannot receive multichannel PCM. This means all multichannel audio must be provided as an AC3 or DTS bitstream for proper 5.1 playback.

The older Emby for Android TV app correctly detects this limitation and transcodes AAC 5.1 to AC3 5.1, allowing my Denon to receive Dolby Digital 5.1. However, the new Emby for Android app (3.5.16) incorrectly chooses to Direct Play the AAC 5.1 track. ExoPlayer decodes the AAC internally and sends it as PCM to the TV, but due to ARC limitations, the TV is forced to downmix this to PCM stereo before it reaches my AVR.

The root cause appears to be that the new app’s capability detection treats AAC 5.1 as “supported” because the TV can decode AAC locally, ignoring the fact that multichannel AAC cannot be forwarded over ARC. As a result, the “Convert to AC3” setting is ignored for AAC 5.1 tracks in this scenario.

My expectation is that the new Android app should mirror the behavior of the old Android TV app: if AAC 5.1 cannot be delivered to the AVR in multichannel form on an ARC system, the app should automatically trigger AC3 transcoding.

I have attached both the Emby for Android app log and the Emby Server log to this post.

Thank you for looking into this!

emby_android_1769260116703.txt embyserver.txt

Edited January 24 by SvenKlomp
Typo and title change

[SvenKlomp 0]

@Luke@ebrAny help you can offer would be greatly appreciated!

[ebr 16169]

On 1/24/2026 at 10:09 AM, SvenKlomp said:

The root cause appears to be that the new app’s capability detection treats AAC 5.1 as “supported” because the TV can decode AAC locally, ignoring the fact that multichannel AAC cannot be forwarded over ARC. As a result, the “Convert to AC3” setting is ignored for AAC 5.1 tracks in this scenario.

This is correct for the standard app at this point.

[SvenKlomp 0]

Thanks for confirming. Is this behavior planned to be changed soon? This is essential for those of us using (non-e)ARC systems.