madVR - General discussion thread

[mclingo]

lovely, i'll have a look then.

[iSeries]

I don't think MadVR is able to prevent the TV from tonemapping - or at least it defintely doesn't in my C7. So if you tonemap with MadVR and output as HDR, the TV is still going to tonemap, which is of course unfortunate.

[mclingo]

ah right, might explain why it doesnt look any different at all to my eyes, I thought someone had said that wasnt true, no point using then I guess, cheers anyway.

[SamuriHL]

Yea I was trying to figure out if my C8 was disabling tone mapping or not if madvr was doing it and it doesn't appear to be the case. The TV is still tone mapping from what I can see. (Murder on the Orient Express was a much better test case for trying to figure that out in my case). What I don't understand is how the dynamic tone mapping on the Panasonic UB820 gets around this issue (if it actually does but in my testing it sure seems to). I tried with the LG's dynamic tone mapping on and off and it didn't seem to make any difference. I would have thought, and madshi agreed with the theory, that turning on dynamic tone mapping in the LG would mostly disable the tone mapping if it is already sent a properly tone mapped image for the max nit level for the display. That didn't appear to be the case, unfortunately.

[mclingo]

oh cool, thanks

[Sunset1982]

Originally Posted by blu3wh0

PC mode will only work right for SDR, it always uses REC 709 for HDR (unless you have the fix in the 2018 models). RGB 4:4:4 is important because that's what madVR and the video process in, anything else will require conversion. HDR mode will require taking this hit, but I let my TV process from 4:4:4 to 4:2:2.

The downside of LG's PC mode is, that it only works in 60hz mode. If you switch to 23/24 Hz the full 4:4:4 support drops... so you can not play movies in 24p with full 4:4:4. You would have to use 60hz mode an maybe smooth motion to get the movie judder free with full 4:4:4 support. Thats the only thing left that is still annoying. Anything else is running good an I am really satisfied with my setup.

My latest and working setup:

Windows 10 1809
Kodi DS Player 17.6
AMD RX480, 8GB with driver 18.9.3
madvr 0.92.17
lav filters 0.72.0-15
xysubfilter 3.1.0.751

LG 65" C8 OLED (Frimware 04.10.05) / Black Level: high
AMD settings: RGB Full, 10 bit
madvr: 0-255

[mclingo]

no issues here in PC mode, switches 23/24 fine, something is wrong there, thats kind of the point of PC mode

[mclingo]

you defo got deep colour enabled on all HDMI port?

[Sunset1982]

it will switch fine, but you wont get the full 4:4:4 support...

[mclingo]

you mean you cant set your PC desktop to 4:4:4 FULL RGB @23hz, are other resolutions greyed out, or does it just do nothing?. Doesnt MADVR output 4:4:4 full RGB 23hz when playing a movie?

i'll have a look at this later when I get home, i'm currently upgrading to 1803, and then to 1809 which i'm sure is going to be a mistake

[blu3wh0]

Originally Posted by Sunset1982

The downside of LG's PC mode is, that it only works in 60hz mode. If you switch to 23/24 Hz the full 4:4:4 support drops... so you can not play movies in 24p with full 4:4:4. You would have to use 60hz mode an maybe smooth motion to get the movie judder free with full 4:4:4 support. Thats the only thing left that is still annoying. Anything else is running good an I am really satisfied with my setup.

My latest and working setup:

Windows 10 1809
Kodi DS Player 17.6
AMD RX480, 8GB with driver 18.9.3
madvr 0.92.17
lav filters 0.72.0-15
xysubfilter 3.1.0.751

LG 65" C8 OLED (Frimware 04.10.05) / Black Level: high
AMD settings: RGB Full, 10 bit
madvr: 0-255

Have you actually tested this? When I tested 4K 4:4:4 PC mode on my TV, it displayed 4:4:4 properly on 23Hz, result was the same as 60Hz. I tested using "the quick brown fox" picture that is usually recommended, but you should be able to use any 4:4:4 test. Also, you know when it's properly active if most of the picture options are disabled, it will switch to a different mode on it's own if it doesn't work. FYI, 1080p 4:4:4 23Hz does not work under these conditions. You can also switch back and forth between any other mode and PC mode to easily tell the difference between these tests under the exact same settings.

Edit: I use Nvidia with it's funky 12 bit depth limitation for hdmi, so I have display resolution 4K RGB 4:4:4 12 bits as my setting, not as a TV resolution option that it might be setting for 1080p. I never investigated further since what I needed worked.

[Warner306]

Originally Posted by SamuriHL

Yea I was trying to figure out if my C8 was disabling tone mapping or not if madvr was doing it and it doesn't appear to be the case. The TV is still tone mapping from what I can see. (Murder on the Orient Express was a much better test case for trying to figure that out in my case). What I don't understand is how the dynamic tone mapping on the Panasonic UB820 gets around this issue (if it actually does but in my testing it sure seems to). I tried with the LG's dynamic tone mapping on and off and it didn't seem to make any difference. I would have thought, and madshi agreed with the theory, that turning on dynamic tone mapping in the LG would mostly disable the tone mapping if it is already sent a properly tone mapped image for the max nit level for the display. That didn't appear to be the case, unfortunately.

Can you take some screenshots of the Panasonic Blu-ray player to show what it is and isn't doing vs. madVR. I know the Panasonic preset for an OLED is 1,000 nits. This would mean only titles over 1,000 nits would receive any tone mapping at all. That is about 20% of currently available HDR movies. Are you changing other sliders to alter the 1,000 nits OLED preset?

I question whether the madVR pixel shader is working at all. One person said 100 nits was working fine. In absolute PQ nits, this would make the image almost entirely black. The image should get darker and darker as the target nits is lowered. It isn't possible for the display to make the input brighter because PQ values are absolute in terms of luminance. So 100 nits peak should be shown at 100 nits; 500 nits at 500 nits, etc. Tone mapping might make the image darker (reduce the luminance of some input values to match the brightness capabilities of the display), but the majority of displays will not make the image brighter. I would expect the color would change in some way when you use pixel shader, but changes in brightness should be more apparent with lower target nits. If this isn't happening, I would think pixel shader is not working correctly.

[mclingo]

just installing 1809 now, wish me luck !

.....although as i'm typing this i'm thinking... why are you doing this Mclingo...

[SamuriHL]

Originally Posted by Warner306

Can you take some screenshots of the Panasonic Blu-ray player to show what it is and isn't doing vs. madVR. I know the Panasonic preset for an OLED is 1,000 nits. This would mean only titles over 1,000 nits would receive any tone mapping at all. That is about 20% of currently available HDR movies. Are you changing other sliders to alter the 1,000 nits OLED preset?

I question whether the madVR pixel shader is working at all. One person said 100 nits was working fine. In absolute PQ nits, this would make the image almost entirely black. The image should get darker and darker as the target nits is lowered. It isn't possible for the display to make the input brighter because PQ values are absolute in terms of luminance. So 100 nits peak should be shown at 100 nits; 500 nits at 500 nits, etc. Tone mapping might make the image darker (reduce the luminance of some input values to match the brightness capabilities of the display), but the majority of displays will not make the image brighter. I would expect the color would change in some way when you use pixel shader, but changes in brightness should be more apparent with lower target nits. If this isn't happening, I would think pixel shader is not working correctly.

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.

[SamuriHL]

Originally Posted by mclingo

just installing 1809 now, wish me luck !

.....although as i'm typing this i'm thinking... why are you doing this Mclingo...

I've had it installed for a few days now. It's fine.

[mclingo]

yeah, its went fairly well all things considered, It did cause the colour saturation issue on mine again which I now cant fix, I can only workaround it. Its really really odd that its only MADVR/SDR/23HZ material, everything else is ok. whats equally or even more odd is that when I calibrate in MADVR for BT2020 to fix this, it doesnt have any knock on effect on the other videos which were playing HDR / SDR @60hz, you;d think these would be changed in some way by MADVRs calibration for BT2020. odd.

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.

[alps006]

I asked this same question elsewhere.Is there a difference between "passthrough HDR to dispaly" and "output video in HDR format" options in latest version of madVR? Thanks!

[huhn]

"output video in HDR format" where is this option?

[alps006]

It is under "devices" "hdr". I am using v0.92.17 with a recent test build.

Originally Posted by huhn

"output video in HDR format" where is this option?

[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.