Surround (AC-3 5.1) not working in tvOS 14

[Tim Tschirner]

I noticed that all my Subler-encoded media files that have AC-3 5.1 audio tracks no longer play back as Surround on tvOS 14 on my Apple TV 4K. Judging by what my receiver sees they seem to be downsampled to simple Stereo - this happens even with files that only have an AC-3 5.1 audio track.

I made sure that both Stereo and 5.1 tracks are present, named properly (“Stereo” and “Surround” respectively) and that audio fallback is set properly.

Still no dice… likely a tvOS issue but wanted to raise this here as well to see if anyone else is observing this as well or if I’m doing something wrong with my encoding.

[JP]

I’m seeing this as well since tvOS 14, but only if “Change Format” is enabled in the Settings tvOS app (Video and Audio/Audio Format).

I suspect this is a tvOS 14 bug, however… Netflix and Disney+ 5.1 surround sound works fine with “Change Format” enabled. I’m stumped…

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[Tim Tschirner]

I’m seeing this with and without “Change Format” enabled - but strangely not on all my systems. I have 4 Apple TV 4K’s - 3 of them are hooked up directly to TVs, 1 to an AV Receiver. The one that is hooked up to the receiver is playing 5.1 audio fine with Home Sharing but the 3 that are hooked up to the TVs do not. The TVs themselves are outputting the audio to soundbars - 2 of them via optical cable, 1 of them via HDMI ARC. All of them play 5.1 Home Sharing files only as Stereo - regardless of settings on the Apple TV - and also regardless if the sound bars are connected or not (verified by looking at the info of the audio stream on the TV).

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To make this even more mysterious, Netflix, Disney+, Prime all play 5.1 surround sound fine on all Apple TV’s….

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This definitely looks like a pretty bad tvOS 14 bug.

[JP]

Yep - be sure to file a report with Apple so we can get back to business!

https://www.apple.com/feedback/appletv.html (Use Feedback Assistant portal if you’re in the tvOS beta program)