Apple VT Hardware Encoder crashes when attempting 8K recordings

[rorygallagher2010]

Hi,
I know this is a bit brave but I was interested in making 8K recordings via OBS on my Mac Studio (The M1 Max base model).

I am using the Apple VT Hardware Encoder to take advantage of the GPU.

I can record up to 4K60 just fine. However if I set the resolution to 8K and attempt to record, I receive an encoding error message.

Does anyone know if this is just a bug, or would this be a fundamental limitation of the Apple encoder? Will it ever be able to support 8K?

Thanks and much respect for the OBS Dev community!

I'm using OBS 27.2.2 on MacOS Monterey

 

[rorygallagher2010]

I keep seeing references online to Apple's VideoToolbox which I'm guessing is what OBS is using under the hood to utilise the Mac hardware encoding capabilities.
(Update: found the source code https://github.com/obsproject/obs-studio/blob/master/plugins/mac-vth264/encoder.c)

Videotoolbox doesn't appear to be well documented API as I found this snippet in reference to it:
"without actual testing, there is no way of knowing the supported codec, codec profile, or encoding bitrate set available on any given device."

So probably the encoder itself simply doesn't support 8k rather than an OBS issue.

Perhaps a developer that knows, might be able to clarify as I'm making total guesses :)

 

[rorygallagher2010]

I found another report of errors occurring at resolutions above 4K with VideoToolbox. This was using Handbrake with the H.265 encoder.

"Perhaps unsurprisingly, when using the H.265 (VideoToolbox) encoder in Handbrake, the encode also fails to execute with any resolution above 4K."

AFAIK, OBS is using the H.264 encoder though

 

[AJ CoRe TV]

I cant get 4k/60 it crashes "overloading" with HECV or H264 Hardware encoders on both M1PRO and M4PRO.... i can only "record" using Apple ProRes hardware encoder Ive googled until the end of the universe and got nothing. I thought upgrading to M4 would help... it did not. I have to turn my ouput setting under 4k/60 to use those hardware encorders.... any help would be appreciated.