NV HDR reports colour space settings as bt709

[ghost]

When I switch to OS HDR the colour space is reported as bt2020. With apps that auto switch to HDR like Elden Ring and MadVR the colour space is reported as bt709 and the colours are slightly of even thought my display enables and reports HDR (compared to before).

[ledoge]

Can you provide the exact steps you're using to reproduce this issue? I tried:

1. Having the clamp active with novideo_srgb closed, opening a HDR movie in MPC-HC with madVR, then opening novideo_srgb so that it disables the clamp
2. Not having the clamp active, and opening the same movie

Does that match what you're doing? I'm not seeing an obvious difference, though I'd probably have to measure test patterns to be sure there isn't one.

[ghost]

1. Novideo is active with the clamp active, i play video with mpcbe with madvr, i check novideo and it confirms it is disabled for hdr and then i check my qn90b setting under colour space and it reports bt709. The coloursbare also slightly off.
2. No clamp enabled, opening same video, check qn90b colour space settings and reports as bt2020.
3. Clamp enabled with OS hdr on report as bt2020.

[ledoge]

Weird, when I check the HDMI Diagnostics menu on my C1 it says that it's BT2020. Not sure why we're getting different results...

[ghost]

It still reports gamma as 2084 so it is an hdr signal, just with sdr colour space.

[ghost]

Using MPCBE with Madvr, if I open a video in windowed mode (unchecked "launch files in Fullscreen") and then double-clicked to make it Fullscreen, it reports the colour space as bt2020. If I checked the "launch files in Fullscreen", when video plays it reports colour space as bt709.

[ghost]

Having the clamp active with novideo-srgb closed, the colour space does report as bt2020 but the video does not look like it is in HDR. Brightness and colour is muted.

[ghost]

New developments.

I found out that using MPCBE, lavvideo filter to decode video and MadVR, the display reports as bt709. When I use MPCBE, its internal video filter to decode and MadVR, the display reports as bt2020. My conclusion from my test is that lavvideo was the problem, ergo, I will use MPCBE internal filter from now on.

Elden ring on the other hand still reports as bt709 when it switches to HDR mode though, but for the moment I am happy one problem has been solved.

[ledoge]

Can confirm that the issue occurs when I set MPC-HC to open files in fullscreen. Unfortunately, the only thing I could think of to potentially work around that is to add a delay before disabling the clamp, and that did not work.