Blackmagic Forum

Hello,

With the release of OBS 28, they have implemented new 10-bit Color Formats:
- P010 (10-bit, 4:2:0, 2 planes)
- I010 (10-bit, 4:2:0, 3 planes)

And two Rec.2100 Color Spaces (HLG and PQ). I wanted to take full advantage of these new recording methods for color grading gameplay cinematics, but I'm having trouble figuring out the proper Color Space Transform method to bring these clips from their HDR formats into a Rec.709 space accurately. I've gotten close, but the parameters end up with either a gamma shift or color shift that doesn't make it accurate. If there are any solutions for this, that would be amazing. Thank you!

-Tim

If you have Color Managed turned on AND have OBS output mov or mp4, the files are recognized as 10 bit Rec 2100. Minor difference between HLG and PQ (as expected: https://www.veneratech.com/hdr-transfer ... ns-hlg-pq/)
If you output in mkv? Then you need to set the input color space manually.

Sample files: https://drive.google.com/file/d/1maT4lD ... sp=sharing

CameraTim wrote:but the parameters end up with either a gamma shift or color shift that doesn't make it accurate.

Doesn't make it accurate compared to what? A CST uses DaVinciDRT as tonemapper by default. This is not the same image you'll see when viewing your HDR recording in something like VLC Player on an SDR display or as you perceive it in the game itself in HDR. As long as you match the gamma properly according to the one used on encoding you're good to go. You may need to grade it to match whatever you want to match it with but if your plan is to grade it in the first place I assume you want something different anyway.

shebbe wrote:Doesn't make it accurate compared to what?

A straight Rec.709 encode from OBS that I compared them to.

Essentially I want to at least get the colors in the right place so it somewhat stays “true to the game”, then any clip when necessary can be manipulated much easier without being destroyed by banding as quickly. I’ve found that using a Forward OOTF is necessary and the colors look very close, but gamma is off. If gamma is all that’s off though, that shouldn’t be hard to correct manually.

Mads Johansen wrote:If you have Color Managed turned on AND have OBS output mov or mp4, the files are recognized as 10 bit Rec 2100. Minor difference between HLG and PQ
If you output in mkv? Then you need to set the input color space manually.

I do encode with mkv, and then remux to mov using FFmpeg. I’ll take a look at those links in the morning.