madVR - General discussion thread

[alps006]

Thanks, huhn. That makes sense. I have great results enabling that option. Good natural colors without oversaturation.

Originally Posted by huhn

the option under "tone map using pixel shaders" is most likely a renamed from send HDR meta data to this because it make more sense.

the difference is that madVR will alter the image before sending it to the display but with that option it is still "HDR" type not SDR like with passthrough.

[mclingo]

off topic WINDOWS 1809 issue - you cant make the task bar black that I can find, you can get it very dark grey but not black, this unfortunately means that even if you hide the task bar to stop burn in on OLEDS there is still a line of grey pixels along the bottom of the screen which are there all the time, this is bad for OLEDS.

The only fix i've found so far is to install CLASSIC SHELL where you can set the task bar as fully black, not ideal.

[Warner306]

Originally Posted by mclingo

This is why I think its a MADVR bug but MADSHI does not so it will probably never get fixed unless more people report the same issue, that doesnt look like its going to happen, either it is my system or there just arent that many people with similar enough setups.

The over saturation can be quite subtle in some movies though, could be some people just arent noticing it.

I could very happily live with the workaround permanently though, it has no other negative impact luckily.

Did you ever determine if your display is calibrated for BT.709 in its color settings? If you select BT.2020, madVR would send BT.2020 to the display. You can confirm this in the OSD. The video driver would have to be lucky to accidentally convert BT.2020 to BT.709 and send it to the display without corrupting the image.

[Warner306]

Originally Posted by SamuriHL

I'll probably be this weekend before I can get to that. Yes, I knew they use 1000 nits for the OLED setting. No, I'm not messing with the other sliders. However, the presets for HDR on the panasonic definitely change the picture.

That situation is what led me to the conclusion that the TV's tone mapping is not disabled. If I go down to 100 nits it's the same brightness as 1000. Maybe my conclusion is wrong and that the pixel shading isn't working when HDR mode is enabled. No matter what I change in madvr with pixel shader enabled in HDR mode, the picture does not seem to change so your assertion could be more correct than mine.

It is more than a problem of the display disabling its tone mapping if 100 nits from madVR is the same brightness as 10,000 nits. When you select 100 nits, the entire range is supposed to be compressed to 100 nits. This would make the image very dark. The display can't reverse engineer these altered RGB values to restore the original source brightness.

[mclingo]

Originally Posted by Warner306

Did you ever determine if your display is calibrated for BT.709 in its color settings? If you select BT.2020, madVR would send BT.2020 to the display. You can confirm this in the OSD. The video driver would have to be lucky to accidentally convert BT.2020 to BT.709 and send it to the display without corrupting the image.

Hi, unfortunately my TV doesnt have any such settings, it set as stock with minor changes to low IRE colour settings only, I used to have a Sony LCD which did so I know what you mean.

However, this also happens with my Samsung TV so i've pretty much ruled Mt TV and AVR out of the equation.

I'm probs going to have to re-image my HTPC but I'm really reluctant to do that as its a 3 day build at least as its also a server with 12 disks in it - but also, if I dont know what is causing it, if it comes back I'll be back to square one and 3 days down.

I was hoping MADSHI had an AMD contact but because there are only a couple of people with this problem, and thats its defeatable, he's not really got time to look at it, which is fair enough.

I was just hoping that with the way it manifested itself it would be obvious to someone what was going on.

Thanks for your interest though

[SamuriHL]

Originally Posted by Warner306

It is more than a problem of the display disabling its tone mapping if 100 nits from madVR is the same brightness as 10,000 nits. When you select 100 nits, the entire range is supposed to be compressed to 100 nits. This would make the image very dark. The display can't reverse engineer these altered RGB values to restore the original source brightness.

That's quite true, but, the result I'm getting is exactly what I described. So something is very wrong and possibly with my setup. I'll see if I can look at it and figure out what's going on. Cause I agree with you, 100 nits should NOT be displaying the same brightness.

EDIT: Yea something's very wrong here. I went back to madvr 0.9.17 and I'm seeing the same problem so it's not the latest test builds. I'm getting the exact same output from the tone mapping option as I do with passthrough. Doesn't matter what I change on the tonemapping option.

[SamuriHL]

Ok, got some help from madshi on this. First, the assumption that 100 nits with HDR turned on would automatically be dark was wrong. There is simply no way to know what the TV is going to do. In my LG C8's case, it cranks up the brightness. Second, he gave me some excellent source material to show what's going on with. One is his 10000 nit color test pattern (32 bit players only) and the other is the spear in BvS. HDR tone mapping is *DEFINITELY* active and working. And with those 2 different source materials it's a huge difference. WAY more detail in the spear scene and even his test pattern with tone mapping enabled in madvr. Now I'll have to play some more tomorrow.

[mclingo]

Originally Posted by SamuriHL

Ok, got some help from madshi on this. First, the assumption that 100 nits with HDR turned on would automatically be dark was wrong. There is simply no way to know what the TV is going to do. In my LG C8's case, it cranks up the brightness. Second, he gave me some excellent source material to show what's going on with. One is his 10000 nit color test pattern (32 bit players only) and the other is the spear in BvS. HDR tone mapping is *DEFINITELY* active and working. And with those 2 different source materials it's a huge difference. WAY more detail in the spear scene and even his test pattern with tone mapping enabled in madvr. Now I'll have to play some more tomorrow.

no fair, I cant turn my tone mapping off on my TV

[blu3wh0]

Originally Posted by SamuriHL

Ok, got some help from madshi on this. First, the assumption that 100 nits with HDR turned on would automatically be dark was wrong. There is simply no way to know what the TV is going to do. In my LG C8's case, it cranks up the brightness. Second, he gave me some excellent source material to show what's going on with. One is his 10000 nit color test pattern (32 bit players only) and the other is the spear in BvS. HDR tone mapping is *DEFINITELY* active and working. And with those 2 different source materials it's a huge difference. WAY more detail in the spear scene and even his test pattern with tone mapping enabled in madvr. Now I'll have to play some more tomorrow.

When I initially tested this on a couple of movies, like you, I really couldn't tell the difference between passthrough and madVR tone mapping, no matter what peak brightness I chose. So, it's good to hear that there is actually a more subtle improvement. It sounds like we have no control over the brightness output of our TVs, but color/detail is not touched. In this case, what are the best options for madVR tone mapping with HDR output? What peak brightness should we set if this actually has no impact on our TVs? Or does this have some other subtle impact that we just haven't seen yet? I always have dynamic tone mapping on since it better represents what the brightness should be during the scene. Do these two things, dynamic tone mapping and madVR ton mapping, actually work together properly? I may do some testing this weekend since this sounds more promising now, meaning we could actually see some benefit from the HDR to SDR processing work. I just can't see myself watching HDR movies in SDR on our TVs due to the significantly limited brightness output.

[SamuriHL]

Your questions are very difficult to answer because it depends on a lot of variables. And I'm not entirely sure myself what looks "best" at the moment. Now that I have scenes which definitely show the differences it's a matter of sitting and testing. I'd start by using a target nit close to your TV max. For oled between 700 and 800. Then the restore details you'll have to play with. With hdr on I prefer a higher setting. Also make sure to turn on the color gamit option in the trade performance options. I highly recommend testing it on the BvS spear scene as you will see quite clearly what's happening with the picture with those options.

Sent from my Pixel XL using Tapatalk

[SamuriHL]

Originally Posted by mclingo

no fair, I cant turn my tone mapping off on my TV

That doesn't mean the option is entirely useless. Even if your TV is tone mapping you could benefit. Think about it this way... Your TV tone maps when the movie is above the limits of the TV. In theory, and I stress the theory part of this because as madshi said we don't actually know what the TV does internally, if you make it closer to the TV parameters the internal tone mapping should have less to do. Try what I recommend in my previous post and see what happens. It'll become very clear if there's a benefit or not.

Sent from my Pixel XL using Tapatalk

[mclingo]

i tried it, it seemed to made no difference I could see, should I try a different value than 400 nits, what else can i try / change?

[SamuriHL]

What scene did you try it on? In motion it's hard to see the benefits clearly. Paused in the right scene the impact becomes crystal clear. I typically target about 800 nits.

Sent from my Pixel XL using Tapatalk

[mclingo]

just what I had available, interstellar 4K HDR, the bit when they visit the cloud planet, coming down through the clouds, thought that would be good to show any highlights that were brought out.

My TV does 400 nits max at 2%, drops off horribly after that.

[SamuriHL]

Then keep the target nits at 400. As for the scene, it might be a good one to show or it might not. If you look at the AVS thread, there's a post from april that has a few of the test scenes that they're using to evaluate the changes in each test build. One of them is what they call the green spear scene from BvS and that's the one I used to see exactly what kind of differences I get from madvr tone mapping vs pass-through. I would recommend that. Or madshi's 10000 nit color test pattern. For that you'll have to install a 32 bit player if you don't have one, and then install his filter. I will tell you that is an amazing test pattern to see the differences. As soon as I loaded that up my mind was blown.

[mclingo]

my chain is still 32 bit as KODI DS was always more stable in 32 bit, it might be ok now, just havent tried it. I have a look at those test patterns then.

[mclingo]

just had a go at MADSHIs test patters. Ran this installer, nothing seemed to happen, opened one of he files with MPC-HC which has MADVR set as renderer, "failed to render", i'm trying this over an RDP connection from work to home, i'll try it again when i get home later.

[mclingo]

out of interest, why dont NVIDIA provide 23,976 native like AMD, is this hard coded into the architecture or something, seems really odd they've ignored this for so long, it would surely solve lots of CRU and driver issues?

[Warner306]

Originally Posted by SamuriHL

Ok, got some help from madshi on this. First, the assumption that 100 nits with HDR turned on would automatically be dark was wrong. There is simply no way to know what the TV is going to do. In my LG C8's case, it cranks up the brightness. Second, he gave me some excellent source material to show what's going on with. One is his 10000 nit color test pattern (32 bit players only) and the other is the spear in BvS. HDR tone mapping is *DEFINITELY* active and working. And with those 2 different source materials it's a huge difference. WAY more detail in the spear scene and even his test pattern with tone mapping enabled in madvr. Now I'll have to play some more tomorrow.

You should post some screenshots, so others can see what is supposed to be happening. It still sounds wacky when 100 nits and 1,000 nits produces the same brightness. I know the 2018 LG OLEDs have very dynamic tone mapping, but it sounds a little too dynamic. The PQ gamma curve is supposed to be predictable.

For example, you may have an RGB value of R(668) G(668) B(668). This is white to be shown at exactly 400 nits.

madVR might tone map this to R(519) G(519) B(519). This is white to be shown at exactly 100 nits.

Dynamic tone mapping is supposed to show the 400 nits white as close as possible to 400 nits to reduce compression whenever possible based on the brightness of the scene. Increasing the brightness of any value would destroy the intent of the original HDR grade. So the 100 nits white should also be shown at 100 nits. No HDR content would be graded to 100 nits. I don't know how the display would know to make this brighter. The image only gets darker to preserve detail, never brighter, unless the display is butchering the source.

Like I said, some screenshots would be helpful. Many will be confused by your results and probably won't know what to look for.

[Warner306]

Originally Posted by mclingo

Hi, unfortunately my TV doesnt have any such settings, it set as stock with minor changes to low IRE colour settings only, I used to have a Sony LCD which did so I know what you mean.

However, this also happens with my Samsung TV so i've pretty much ruled Mt TV and AVR out of the equation.

I'm probs going to have to re-image my HTPC but I'm really reluctant to do that as its a 3 day build at least as its also a server with 12 disks in it - but also, if I dont know what is causing it, if it comes back I'll be back to square one and 3 days down.

I was hoping MADSHI had an AMD contact but because there are only a couple of people with this problem, and thats its defeatable, he's not really got time to look at it, which is fair enough.

I was just hoping that with the way it manifested itself it would be obvious to someone what was going on.

Thanks for your interest though

I just looked up your display at Rtings.com. The color gamut should be set to "Standard" for BT.709 and "Wide" for BT.2020.

Quote:

"You can get a slightly wider color gamut when 'Color Gamut' is set to wide, but this isn't recommended for normal content because the colors will be over saturated."