MPC-HC + madVR - HDR pass through only works when MPC-HC is windowed.

[mpchelp10]

I am playing a 4k HDR bluray with MPC-HC + madVR on a "fake" HDR screen (8+2 bits). If MPC-HC is windowed, I see the HDR. If I make MPC-HC fullscreen, the colors dull. If MPC-HC is not in focus or I bring up the seekbar, the colors go back to HDR. If MPC-HC is fullscreen and I have Task Manager open and set to Always on Top, the colors are back to HDR. Why is this? I installed MPC-HC/madVR using K-Lite code pack. Everything is default settings.
I am on Windows 10. Full screen is "regular" fullscreen, not full screen exclusive.
iGPU: HD 630
dGPU: NVIDIA 1050 Ti Max Q
both drivers are up to date

[RipThejacker]

yep same deal, happens on both HC and BE

[Aleksoid1978]

Try https://github.com/Aleksoid1978/VideoRenderer/releases

[RipThejacker]

Try https://github.com/Aleksoid1978/VideoRenderer/releases

hey thanks so much, idk even know why its working now, but thank you, though not sure how its working when I set it back to madvr??
not gonna question it haha

[RipThejacker]

hey thanks so much, idk even know why its working now, but thank you, though not sure how its working when I set it back to madvr??
not gonna question it haha

actually i just thought it worked, damnit! square one

[clsid]

Since it is a fake HDR screen, you should disable HDR passthrough.

[VBB]

I think he means "fake" as in not 10-bit, but HDR-capable. And that was the OP, not the poster from yesterday ;)

[Maryoum]

I'm having the same issue. Any fix?

[Klaus1189]

What GPU?
What driver?
MPC-BE fine or the same?

[synth89]

I was having the same issues with HDR windowed vs full screen mode. I came up with a solution for my HDR-capable monitor, haven't tested it on an HDR TV, but principle should work the same.

Software/hardware setup:
MPC-HC (v1.9.18)
madVR (v0.92.17)
Windows 10 (v21H2)
HDR-capable monitor (Dell S2721DGF, HDR400)
AMD Radeon video card with HDR support

Software settings:
MPC-HC->Options->Playback->Output->DirectShow Video->madVR [enabled]
madVR->devices->[HDR device]->properties->the native display bitdepth is: [10 bit (or higher)]
madVR->devices->[HDR device]->hdr->tone map HDR using pixel shaders->target peak nits: [enter your HDR device's peak nits], (NOTE: the peak nits value can be found under '[HDR device]->identification->desired max luminance, can also check reviews like on rtings)
madVR->devices->[HDR device]->hdr->tone map HDR using pixel shaders->tone mapping curve: [BT.2390]
madVR->devices->[HDR device]->hdr->output video in HDR format [enabled]
madVR->rendering->general settings->enable automatic fullscreen exclusive mode [enabled] (NOTE: can also be set to disabled, with same result)

Windows 10 settings:
Settings->System->Display->Use HDR [Set to On]

A few things are going on here to fix the windowed vs full screen mode issue:
- Normally when you toggle to full screen mode, you are seeing an incorrect map of luminance values from your source HDR material (with different peak values between source and destination device), which is manifesting as "washed out" in full screen mode
- In windowed mode, Windows 10 is doing an approximate map of the peak nits values, aligned to your HDR device's peak nit value. However, in the case of an HDR1000 mastered movie (or higher) mapped to an HDR400 monitor, you'll notice the "bright" areas of the video are almost too bright, and it is clipping at the upper end of the luminance range.
- In full screen mode, madVR is passing the HDR info directly to your screen, including the meta data, without tone mapping of the luminance. In this example, HDR1000 content going to a HDR400 monitor, it causes it to look washed out, and not have proper peak luminance values.
- By using "tone map HDR using pixel shaders", you are fixing the issue in windowed and full screen mode by properly mapping the HDR1000 content luminance values to a narrower HDR400 luminance range (but still aligning peak values properly) directly through madVR, before it gets sent to the HDR device. Changing between "windowed full screen" vs "full screen" will now yield the correct result.

The luminance tone mapping to match source content to device capabilities is slowly being improved at the software/hardware level for PCs, so hopefully these sorts of manual adjustments become a thing of the past. Microsoft should add proper software tone mapping at the OS level and it would make things alot easier. (ie. Windows 11?) AMD has a good blog post how they've incorporated this technology as part of their Freesync Premium Pro open source tech stack. https://gpuopen.com/learn/using-amd-freesync-2-hdr-tone-mapping/

[DMU]

In non-full-screen windowed mode, you will never get the correct HDR metadata on the display device.

[nevcairiel]

I would expect a display device to do a reasonable job at tonemapping if its receiving a HDR signal with too high peak luminance. Unfortunately, PC HDR displays in particular (especially those with HDR400, which is barely HDR to begin with), are just pretty cheap HDR implementations and don't put much (or any) effort into the feature, other then having a checkbox on their spec sheet.

Of course you can say Windows or the graphics driver should pick up the slack, but luckily when playing video, the video renderer can also just do it, and likely do a better job.