New WIN app - peak brightness of the display setting doesn't do anything

[Mahinepua 81]

Again having another go with the latest WIN app to see if its improved and the 'peak brightness of the display' setting has no effect on tone mapping. I can enter any number and the picture doesn't change. 

It used to work on early versions, is it currently functional? and which content does it apply to? HDR & DV only?

Assume the MPV setting is target-peak its trying to replicate?

Does the setting also affect SDR content or only when tone mapping, when it works of course. 

[Luke 42077]

Hi there, can you please show a screenshot example? Thanks.

[Mahinepua 81]

Hi Luke, not easily.

All I'm doing is changing peak values from 50 to 1000 and within that range while playing various HDR and DV samples that are being tone mapped.

HDR passthrough is turned off, I've tried leaving tone mapping on auto and also manually selecting different options. 

The setting stopped working quite a few versions back and not long after I reverted to 3.020.

Is it working for you?

 

[Guest]

--target-peak in mpv is global, it effects everything unless you create profiles. That option was created long before passthrough was possible. So we would apply it to tonemapping, as that was its original intent. Now we have passthrough and inverse tone-mapping. If i remember correctly, softworkz is only applying target-peak to passthrough. We needed to change the default because it would effect SDR content. So I think softworkz limited its function to only when Windows HDR was enabled and HDR media was being played, so it would  also not be applied to tone-mapping. 

Edited May 17, 2025 by generiq

[Mahinepua 81]

sounds like a bit of a mess.

'So we would apply it to tonemapping, as that was its original intent' - this I how I assumed it should work.

thanks again for the profiles you did for me.

Edited May 17, 2025 by Mahinepua

[Guest]

25 minutes ago, Mahinepua said:

So we would apply it to tonemapping, as that was its original intent' - this I how I assumed it should work.

Yes and no. Puritanically, target-peak is for the screen, but mpv's base operation is software. When we were testing hassn's tone-mapping updates years ago (long before libplacebo), he explained that he never wanted the display to have any part in the tone-mapping process. He called it garbage, and the software was written to fully assume the responsibility of the reshaping and mapping. Again, this is before passthrough was even considered. So, target-peak was very much a part of the equation, and has never been changed. It is still intended to be part of the tonemapping process. But some consider this to be wrong. Personally, hassn has my full support on this. What he has achieved, i believe to be superior. Even though my display is fully calibrated by ASUS, I still want mpv to do the work, and not my display. Ive been around hassn's work long enough that he has my trust. Ask yourself, how can every display be equal? They can't. A $10,000 professionally calibrated display is not going to have the same result as a $500 display from Walmart. Every display will have its own peak value,  and most of the time the average person won't know what it is. So mpv levels the field, and target-peak is intended to be part of that. This is why I still use mpv directly. You'll read that tone-mapping output should be as close to the SDR version as possible. So say the puritans...even hassn says that. And yet we are provided with many options, to satisfy personal choice. This is how it should always be. Otherwise, we wouldn't have multiple versions of the same video. SDR, HLG, HDR10, HDR10+, DV 5, DV 8.1 ...and on we go. They cant all be 'correct'. Human perception is the largest part of the equation.

52 minutes ago, Mahinepua said:

sounds like a bit of a mess.

It can seem that way, but once you understand why it works this way, it begins to make sense. Much has changed since then and kasper has added functionality to try and compensate for present day demands. It isnt perfect but its one of the best out there. 

58 minutes ago, Mahinepua said:

thanks again for the profiles you did for me.

You're welcome. 

[Guest]

Just take a look at this massive thread.

https://github.com/mpv-player/mpv/issues/6405

hassn has rewritten the algorithms again, since then. He did that when he finally implemented libplacebo/gpu-next 

[Guest]

Very interesting what haasn says here

https://github.com/mpv-player/mpv/issues/6405#issuecomment-449980177

[Guest]

--traget-peak is finally being updated. It will no longer be a global function. Other changes are also coming.

[Mahinepua 81]

Assume color space specific settings will be included in Theatre beta at some point? Even simply having different SDR & HDR/DV settings would be fine.

What are the other changes?

[Guest]

23 minutes ago, Mahinepua said:

Assume color space specific settings will be included in Theatre beta at some point? Even simply having different SDR & HDR/DV settings would be fine.

What are the other changes?

That is all being rewritten by the mpv guys right now. Once its merged and I get my hands on it, I'll see whats what. But this should make a big difference. 

I've posted the links here

 

Edited July 9, 2025 by generiq

[Guest]

@Mahinepua what exactly are you trying to accomplish? Is it just the luminance for your projector? Ordinarily you would lower the target-peak to achieve a brighter picture. Is this what you're looking for? The majority of the changes that have been made in mpv are only in effect when Windows HDR is enabled. So that doesn't effect your use case. I'll have to experiment and see what options there are for you. In libplacebo, the peak for SDR is set at 203. Your projector is what, around 150 nits?

[Mahinepua 81]

3 hours ago, generiq said:

Is it just the luminance for your projector? Ordinarily you would lower the target-peak to achieve a brighter picture. Is this what you're looking for? 

Yes and for each color profile. Not just for a projector but for TV`s also. All content is being tone mapped.

I already have the ability to do this by sticking with the electron version, there is no advantage using the new app.

[Guest]

56 minutes ago, Mahinepua said:

Yes and for each color profile. Not just for a projector but for TV`s also. All content is being tone mapped.

I already have the ability to do this by sticking with the electron version, there is no advantage using the new app.

Color profile?

SDR stuff can't be being tone-mapped. That would be inverse tonemapping and you have HDR disabled. So we're talking about HDR stuff only? Or do you want to control the luminance of everything?

Edited July 14, 2025 by generiq

[Guest]

Ok, so i was just testing the effects of target-peak with HDR disabled and no peak set (defaults to 203), and played an SDR video. Then tested the same video and set target-peak=15. As expected, the image was brighter at 15. This is what you want, yes?

So what could be done is when HDR is enabled, allow target-peak only for HDR media (this might change based on the new updates. Still checking that). But when HDR is disabled, allow it to operate universally. Then the brightness of tone-mapped HDR media and SDR media should closely match. 

Having one setting for HDR and another for SDR doesn't make sense. You understand that target-peak is for display luminance and not color. 

I think this would be reasonable and fairly easy to implement. It doesn't effect HDR playback.

[Guest]

Okey dokey. So, color management is what this is all primarily about when HDR is enabled. What was happening previously is that the compositor was making most of the decisions, and was generally making a mess. SDR when in SDR is pretty straightforward, so the issue was/is with the Windows HDR compositor. mpv is now taking control of what happens. 

target-peak when set higher than 203 now only effects luma. Prior to this, the primaries would also be set. This invariably lead to gamut expansion. Now, that expansion only happens if you enable inverse-tone-mapping. In my case, target-peak=auto results in 371. So I get a nice boost in contrast with no change to the colors. On other systems it will vary depending on the probing of your system and if a number can be found. In which case I think it defaults 1000, but I'm not certain of that.

This actually might be a good reason to have an SDR target-peak and an HDR target-peak provided. Currently softworkz is disallowing any taget peak to set for SDR, but now target-peak is set to auto by default. So if it is to remain the same, a value of 203 would need to be forced. I think it better to have an option in the settings and just default it to 203. That way if anyone wants a little more contrast in SDR media when Windows HDR is enabled, they can raise the peak to their liking. This is what I do and will continue to do. Because the picture is amazballs!

I would also advocate for adding the inverse-tone-mapping option. Also, hdr-compute-peak is now a good option to use.

If this is as clear as mud, ask questions 

Edited July 14, 2025 by generiq

[Mahinepua 81]

I leave at the default for SDR but for HDR or DV tonemapping the peak brightness setting in the new app has no effect.

It did in the early release versions.

My displays are calibrated for SDR.

Having retried the latest new app the peak brightness when tonemapping seems to be spot on but its stil nice to have the ability to tweak settings for a bit of extra pop.

 

[Guest]

46 minutes ago, Mahinepua said:

Having retried the latest new app the peak brightness when tonemapping seems to be spot on

So you've got what you need?