Non-Rec.709 video has wrong colors/saturation

[sam_nazarko]

Hello,

Can you chuck me:

• cat /sys/class/amhdmitx/amhdmitx0/edid
• cat /sys/class/amhdmitx/amhdmitx0/disp_cap
• cat /sys/class/amhdmitx/amhdmitx0/hdr_cap

So I can see kernel interpretation of your EDID.

@nabsltd

My Rec.709 test files were remuxes of the BluRays of The Bourne Identity and Iron Man. For Rec.2020/HDR, I used remuxes of the UHDs of these discs. Although I used my personal BluRays to make the 1080p remuxes, I downloaded the UHD remuxes because I don’t have a UHD drive in my PC. So, it’s possible there is something wrong with those remuxes, and I’ll check that once I get the UHD drive installed and rip my discs.

So, if I understand correctly:

• BD rips as-is that are non UHD are OK
• BD rips that are expected to be Rec2020 (not yet confirmed) are problematic.

So the issue is with 2020.

@nabsltd

I read some of the other topics about forcing HDR to SDR, and it’s obvious that that conversion is happening even without forcing, as I don’t have the completely washed out colors you normally see with Rec.2020 on a Rec.709 display.

That’s correct. Conversion should take place by default now.
There isn’t an exact science to conversion unfortunately, but there is room for improvement.

@nabsltd

I’d also like to know if the setting changes in /sys/module/am_vecm/parameters need to be done while a video is running, and if they are persistent when stopping/starting videos.

They should be persistent. If you switch mode in a significant way, you could see changes. If you kept playing the same set of demo clips, all encoded as HDR, you should be able to iterate easily enough.

@nabsltd

So, where would be the best place to start?

No fixed approach yet. To be honest – I think experience varies across displays. A set of aggressively tested presets configurable via Kodi will probably be the way to go. I know the SoC vendor (AML) have some improvements in the pipeline; so we’re also looking forward to their improvements

Sam