VP9 HDR and AV1 HDR playing at 8 bits instead of 10/12 bits and colors are off

Hi,

I don't want to open a bug report yet as I don't know if this is a known issue or not. I read some of the forums here and I didn't see a mention of my problem.

I have a Beelink SER8 with AMD 8845HS CPU and AMD Radeon 780M GPU, I know overkill but I wanted something that can play everything up to 8K@60 AV1 in software just in case, and everything plays perfectly in SW or HW except VP9 HDR and AV1 HDR videos.

According to my Yamaha AVR, VP9 HDR and AV1 HDR videos plays back at 4:4:4 8 Bits HDR10 mode, so yes my TV switch to HDR and I can see the picture highlights are bright and all but the 8 Bits makes the colors off. I could easily see the colors were off compared to CoreELEC on my AM6B+ for the VP9 HDR files but at first I didn't know why.

HEVC 10 bits HDR movies playback fine at 4:4:4 12 Bits HDR10 according to my AVR and colors are OK.

I tried the stable LibreELEC 12.0.2 and VP9 and AV1 videos always plays back in SW mode even when I say to use VAAPI for VP9 and AV1. The VP9 and AV1 HDR videos plays back at 8 bits HDR with colors being off.

I tried the latest LibreELEC 13 nighlty (april 14th 2025) and VP9 and AV1 videos now plays back in HW mode when I say to use VAAPI for VP9 and AV1. The VP9 and AV1 HDR videos plays back at 8 bits HDR with colors being off both in SW and HW mode.

Anybody else has this behavior and is there a way to fix it. It seems a LibreELEC problem as HEVC plays back fine in HDR. Also, the pixel format is correctly detected in SW mode as yuv420p10le. My test files are 59.94 fps files.

Thanks!

Hi smp,

Yes after testing more it’s not about VP9 or AV1 at all but more about HFR 4k 50/60 HDR not playing at 4:2:2 or 4:2:0 10/12 bits. Apple TV plays at 4:2:2 and am6b+ at 4:2:0.

I was wondering though, can 4:4:4 10 or 12 bits be forced for these 4k 50/60 HDR videos because my Beelink has hdmi 2.1 and will have the bandwidth for that if I am not mistaken?

Maybe an option could be added if it’s not already possible to override that somehow?

Thanks!

Quote from smp

Maybe it has something to do with this.

Damn HDMI Forum! At the end of the article they say to use display port for open source driver.

My Beelink has a display port. Do you support display port in LibreELEC and do you think if I use a dp to hdmi 2.1 adapter it would work and go to 4:4:4 on 4k 50/60?

There seems to ba a way to force 4:2:0 in the amdgpu driver:

Do you think you can implement that in LibreELEC?

The command works and the file is now displayed at 4:2:0 12 bits just like on am6B+ but unfortunately the colors are still "off" compared to all my other players?

I even tried kodi in Windows on the same Beelink mini PC using the same AMD GPU of course and the colors are OK so it's not a limitation of the AMD GPU on the Beelink.

Is it just that LibreELEC badly display HDR with amdgpu driver in general? Or maybe a bug?

No, my Sony TV does not have a PC mode, just a Game mode and it needs to be switched manually by me using the TV remote. I am in Cinema mode on all my players. What I noticed too is that the brightness is way too high on HDR on Beelink in LibreELEC. It is less high and correct on Beelink in Kodi in Windows or on all the other players.

I am on LibreELEC 13 latest nightly, I think it was the same on LibreELEC 12.0.2 official stable but I can try again to see.

I did try using SW or VAAPI HW and both look exactly the same and are wrong.

What is "Mesa" ?

Are you saying if I got an Intel Beelink mini PC all would be ok? I got the AMD so that it would generate less heat and not have that audio passthrough cutting off problem that I read about but I think that audio passthrough bug has been fixed in one of the LibreELEC releases since then.