[Bug]: Apple TV HDR10+ plays as plain HDR10 (Both MKV in Aether and MP4 in AVPlayer)

[DrHurt]

Summary

MKV HDR10+ -> Plozzigen -> TV HDMI shows plain HDR
MP4 HDR10+ -> AVPlayer -> TV HDMI shows plain HDR

Same files, same server, same TV with Moonfin (also AetherEngine) -> TV HDMI shows HDR10+

This makes me think the bug is an app / view configuration issue rather than engine.

While on that, likely not a Plozz bug, but HDR10+ logos on Emby:
Files don't get tagged as HDR10+ on the Plozz details page with Emby, just a generic HDR10 logo. Emby theoretically supports reporting Hdr10Plus via Enum ExtendedVideoTypes but Emby is notoriously bad at reporting formats so it might genuinely be missing server side. Might be worth a quick check on your end to make sure if wired correctly / confirm its a server issue.

Steps to reproduce

Play HDR10+ on Apple TV using Plozz

Expected behavior

TV should shows HDR10+ logo

Actual behavior

TV shows plain HDR

Affected backend(s)

All backends

Plozz version & build

36

tvOS version

27

Apple TV model

4k 2022

Logs / screenshots

No response

[DrHurt]

Build 37 still doesn’t work correctly despite the AetherEngine update.

[brandomoore]

Might be fixed in build 39. I do not have a TV with HDR10+ so this is difficult for me to test. Let me know how it goes whenever it's released please

[DrHurt]

I did more experimenting. Lots of findings.

Used SMB this time to bypass Emby device profiles.
Used Plozz on my iPhone as a control (iPhones have native HDR10+ support)

File: HDR10+ mp4 (specialised metadata test file: brightness flickers via metadata, no flicker if only base layer is played)

Results:

• On iPhone (SMB): Overlay shows HDR10+ and brightness flickers confirming metadata is decoded
• On TV (SMB): Overlay shows HDR10 and brightness doesn't flicker (confirming Plozz is playing the base layer without metadata)
• On iPhone (Emby) -> Overlay says HDR10 without plus BUT brightness flickers confirming metadata is decoded despite label

Thoughts:

• Emby device profile is not the problem as the issue is reproducible via SMB share on TV and NOT reproducible via Emby on iPhone.
• Overlay is unreliable. It doesn't always seem to be reading from engine (across different sources)
• Problem is Plozz on tvOS. iPhone works fine with Emby & SMB.

[DrHurt]

Unfortunately build 39 hasn't fixed the problem.

HDR10+ still plays as HDR10 (mp4, mkv, avplayer, aether)

No HDR10+ logos on Emby, server file probe issue most likely. I've raised a ticket with Emby support and they said they're looking into it.

HDR10+ logos do show with Jellyfin likely because the server is identifying the files correctly during library scan. They play as HDR10 though.

[DrHurt]

I think the problem might be related to Plozz enforcing its own AVDisplayCriteria?
AetherEngine handles this itself and Plozz should yield when using AetherEngine. tvOS is very sensitive to display criteria.

[brandomoore]

Thanks for testing, I'll take a look again today

[brandomoore]

I think the problem might be related to Plozz enforcing its own AVDisplayCriteria? AetherEngine handles this itself and Plozz should yield when using AetherEngine. tvOS is very sensitive to display criteria.

We already delegate display matching to AetherEngine, so I don't think this is it

[DrHurt]

Just saw the last commit and wanted to point out that EDR headroom is no longer reliable at telling current panel mode (dynamic range) on tvOS 27.

Aether now attempts HDR master playlist, and if avplayer rejects it, it’s taken as a verdict that panel is not in HDR mode.

This was implemented last week when I reported it to Vincent (Aether dev)

[DrHurt]

I spoke to Vincent and he has now added a combined HDR10Plus and Atmos probe directly to the engine via a new probe(url:options:detecting:atmosDetection:hdr10PlusDetection:) (engine 7.9.0).

This allows getting both missing formats via a single call / connection useful for Emby and custom sources with no data providers such as SMB or WebDAV (and maybe local files in the future)

[brandomoore]

Hmm well the Plozz probe seems to be working in my testing but AetherEngine is probably a better place for it and I cannot test it myself, so I will likely just delete all that work lol, but I'll check it out and see