MadVR in use with LG OLED Thread

[SamuriHL]

Hey the curve work is important! :P LOL Yes, ALL of these topics are relevant to our OLEDs when using madvr. I calibrated my SDR dark mode for rec709 2.4 gamma 100 nits. So my gamma setting stays at 2.2 on the C8 but the LUT is calibrated for 2.4. That gets a little confusing for people. Trying to calibrate my bright mode for DCI P3 2.2 and having some issues but it looks like I screwed up the calibration process by missing a step. Once that's done I'll set up profiles in madvr to be able to switch between my dark mode 2.4 rec709 and bright mode 2.2 dci p3. No need to limit one's self to only one setting. :D

[Asmodian]

If that's the case then why are both offered as Gamma options? There must be some difference. I read a long time ago that BT.1886 was better but that was when I first got my C7.

Swap between the two when viewing different scenes. Do you notice a difference?

On my C7, C9, and CX I did/do not.

Anyway, BT.1886 is at least very close to a gamma of 2.4, so 2.4 is a the correct setting in madVR.

[quietvoid]

Hmm, I just noticed Dolby Vision was locked into Wide Color Gamut.

[chros]

Yes, but I think it is not the regular wide mode, just as brightness/contrast are not the same in DV mode.

[quietvoid]

Looked at HDR10 again and I still want to believe. Wide looks closer to what I'd expect than Auto, with madVR set to DCI-P3.
But apparently it's still wrong.

Eh, switching from Dolby Vision to Auto looks about the same saturation levels, except madVR is even more saturated.
And madVR still has issues with darker shadows it seems, maybe because of the DTN.

[SamuriHL]

Very possibly. I had to factory reset the C8 for some stupid things it was doing with my LUTS. Now after the reset, for HDR it has some weird slider thing for color temp. Um, WHAT? WTF is that? I need to get it back to my D65 measured color temp.

[VBB]

LOL I just read your chat with Leon. Hope you get it all sorted out!

[SamuriHL]

Yea, stupid C8 wasn't resetting that LUT no matter what I did until I factory kicked it in the ass. As I said, cannon to kill a fly but it worked. I now have a dark mode rec709 2.4 LUT and a bright mode DCI P3 2.2 LUT. It's looking quite good. madvr will be happy about the DCI P3 LUT.

[quietvoid]

Was playing around with low DTN and it certainly looks closer to the Dolby Vision image, although less contrasty looking.

Now I don't know which I like better :(
Low DTN definitely seems to have the correct shadows, but everything is bright and specular highlights blend in with the surroundings.

At least now that the curves are better, the possibility is there.

[SamuriHL]

DTN is tunable which is great. The curves are looking REALLY good at this point. Now we have options.

[Cinemancave]

I've been using MadVR DTM with my projector for a long time, but want to try this out on my OLED now. I just want to know what settings you guys are using on the TV side of things and what format you are outputting this in?

I am having a hard time grasping this concept for the TVs when compared to the tonemapping for projectors: Converting HDR to a fixed SDR gamma curve seems somewhat "stable", but on an OLED we want to force it into HDR mode right? Which leads to MadVR DTM followed by the TV's own tonemapping on top of this? Or can you disable the TVs own tonemapping somehow - maybe putting it in HDR Game Mode and putting it into HGIG? If we are dealing with the TVs own DTM on top of MadVRs then isn't this impossible to figure out since we don't know what the TV is doing?

What would be some basic settings I should use to try this out?

[SamuriHL]

Look back to quietvoids latest post that contains a link to his settings and his signature has a link to his curve.

As for how this works a lot of testing went into figuring out what the TV does at various nit levels. At 1000 nits it more or less tracks eotf. That is what we want. So what we're doing is determining the real display nit for the oled and telling madvr to tonemap to that. This forces the TV to use an internal tonemapping curve that is less aggressive than the higher nit curves. You're still getting the TV tonemapping on top of what madvr is doing but because you're forcing it to use a curve that tracks eotf it's the least manipulation we can get. On later models of LG oled you can even calibrate your curve to match exactly up to your measured max nit level which is ideal.

Sent from my SM-G998U1 using Tapatalk

[Cinemancave]

Great thanks!

So in "Edit custom TM curves" I paste all curves from his signature, or do I choose one?

I have a CX and calibration equipment, has anyone written a how-to on matching up the curves?

[quietvoid]

You have to import the curves with the button at the bottom of the curve editor.
Not sure what you mean about matching the curves.

[SamuriHL]

It's not about "matching up the curves". I think my explanation confused you as I'm talking about 2 very different things. Let me try again.

Topic 1: madvr

This is using quietvoid's settings, and importing his custom curve into madvr while setting your real display nits to whatever you measure with your calibration equipment.

Topic 2: TV

This is where you can, if you have the right equipment and software, calibrate your TV's HDR mode to follow a curve to your display's real display nits.

https://www.youtube.com/watch?v=AJ_CYgfwo7o

Watch that video from Vincent for a better explanation.

[SamuriHL]

You have to import the curves with the button at the bottom of the curve editor.
Not sure what you mean about matching the curves.

I think I confused it by talking about matching the TV's tonemapping to follow EOTF using a custom curve. Which is true but it already does that up to 700 nits, as we know. On the C9 and newer OLEDs they can change that curve to follow EOTF up to the measured max luminance of the display so that it rolls off or clips at a higher point than the built in 700 nits tone mapping. In theory, this should allow them to mostly bypass internal tone mapping altogether if they're using madvr because the content will already fit within the TV's custom curve. Since I don't have a C9 or higher, I've no idea if that is true or not. Theoretically it should be, but, in practice with these panels? Who knows....

[Cinemancave]

Interesting how this all lines up: I did som googling and found the template for Device Control which allows the user to control the luminance point and tonemapping settings like Vincent showed in the video you just linked to. So I am going to use it and see how this all looks with 100% roll-off, basically clipping everything above my panel's peak brightness and then letting MadVR do its' thing :)

Thank you for your quick replies. I will report back.

[VBB]

Since we're always wondering if Sony OLEDs behave differently: I just found out that the OP, Sunset1982 (a fellow German), actually owns an A9F. He is also planning to buy the new A90J. Last time I spoke with him over at AVS, he wasn't even aware he had created this thread. I'll try to get him to post his impressions here.

[chros]

That would be really nice, thanks, especially in graphic/game modes to get chroma 444 :)

[Sunset1982]

Hey guys, VBB told me I could help here out with my sony tv. I don't have a htpc atm, but maybe I can help you guys. I laso have my old LG C8 in my living room. I am very busy at work these days, but I will do what I can to read the last few pages of this thread. Any questions I can answer in the meanwhile or something to test for the weekend?

[chros]

Cheers, but if you don't have a PC with it ... :) I think we would be mostly interested in how it performs with chroma 444 (graphic/game modes) at 23p with SDR/HDR10.

[Sunset1982]

I still have a pc at home, but it is in another room. I could take it and test some things, but before that I have to know what exactly I should test and how (what patterns)

[SamuriHL]

They're really interested to see if 444 mode introduces artifacts in the video. Banding is one of the biggest issues. Near black level issues are another. I'm sure they'll dig up the patterns again for you to try. It would be useful indeed. Especially given that these consumer OLED panels are all made by LG with different electronics based on the MFG of the TV itself. Has Sony solved these issues? Or are they still prevalent.....that's what they wanna know.

[chros]

Yes. But first of all can you tell us for sure whether it has the new Evo panel? :) (It's still an impressive set even if it doesn't.)

[SamuriHL]

Leon is the best. So my C8 I had a mode calibrated for rec.709 2.4 dark and another DCI-P3 2.2 for bright. But I learned today from Leon that these LG OLEDs have 2 different LUT slots on each picture mode....one for SDR rec.2020 and another for SDR rec.709. And with the latest device control and LG templates for ColourSpace, you can load them both at the same time. :D So for the moment I just did my bright mode to have DCI-P3 for the SDR rec.2020 LUT and rec.709 for the rec.709 LUT. To get the LG to switch between them you simply need to force the bt.2020 flag. My TiVo already does this when outputting 4k. And the SHIELD can do that if you tell it to always output bt.2020. And as we know, madvr can be told to send the bt.2020 flag on nVidia cards. It works beautifully!

[chros]

Yes, indeed, that's how hdr10 works with the bt2020 slot, and that's why DoVi uses the bt790 slot (so it doesn't trigger LG's sh!tty gamut mapping)! :)
The problem with this is the aformentioned low APL issues (e.g. cyan/magenta) where LG's gamut mapping failes miserably.
Why don't you upload the dcip3 into the bt709 slot? (I haven't tried it personally.)
And you can do the same with the python tool.

[SamuriHL]

I did that and rec.709 content becomes oversaturated. By having a rec.709 LUT in the rec.709 slot and a DCI-P3 LUT in the bt.2020 slot, when the bt.2020 flag is enabled it uses the DCI-P3 LUT and when the bt.2020 flag is not enabled, it uses the rec.709 LUT. With this setup, all content looks damn near flawless. The nice part about ColourSpace is that I was able to generate everything from one calibration session's data just by generating the LUT that I wanted. And indeed, I looked at some upscaled 1080p->4k videos using DCI-P3 with the bt.2020 flag enabled in madvr and man it's REALLY nice. I'm quite impressed with this setup.

[quietvoid]

Every time I read about calibration on these TVs I get overwhelmed with info and no idea where to even begin, as there doesn't seem to be a concise guide on manual calibration.
It's even worse for HDR :)

[Asmodian]

What do you mean by manual calibration?

[SamuriHL]

Don't even waste your time trying HDR and DV calibration on these panels. They aren't stable enough. Calibrate the white point balance in the service menu and call it a day for those. For SDR calibration, I use colourspace to create a 3D lut and upload it to one of the picture modes (bright mode, dark mode, whatever). I got a LOT of help from Leon and Ted when I first started out with ColourSpace but it's become much easier to use with each new beta. The quality I get from SDR on the C8 after calibration is nothing short of amazing.

But for HDR, don't bother. Lots of people do, of course, and they're welcome to. But it's not worth the effort.

[quietvoid]

What do you mean by manual calibration?

I think it would be everything other than AutoCal, but that might still be possible for SDR.
I think the issue with HDR is that more expensive equipment or manual intervention is necessary for the 2018 models, while newer have an internal pattern generator?
Though I've noticed most people do HDR calibration with other software than Calman too.

Don't even waste your time trying HDR and DV calibration on these panels. They aren't stable enough. Calibrate the white point balance in the service menu and call it a day for those. For SDR calibration, I use colourspace to create a 3D lut and upload it to one of the picture modes (bright mode, dark mode, whatever). I got a LOT of help from Leon and Ted when I first started out with ColourSpace but it's become much easier to use with each new beta. The quality I get from SDR on the C8 after calibration is nothing short of amazing.

But for HDR, don't bother. Lots of people do, of course, and they're welcome to. But it's not worth the effort.

To be honest I just notice issues in HDR, I have a hard time with natural skin tones in HDR10 only, not even DV.

Maybe there could be improvements in SDR but so far it's been good enough.

I guess I could be looking at this: https://www.lightillusion.com/manual_calibration_guide.html
But even then Calman seems to be cheaper..

[SamuriHL]

I really don't want to get into a comparison between calman and other software and why I dropped calman like a bad habit. Cheaper, however, is a point of view. If you like yearly license fees, then sure calman with Autocal is cheaper... for a couple years anyway.

As for hdr calibration on these panels, it's not about the pattern generator. Pgenerator is an excellent bit accurate external pattern generator and with an hdfury you can do hdr with it. You can also use madtpg if you take the time to set things up properly.

The problem is these panels aren't stable enough to calibrate with hdr. And you can't generate a full 3D lut for hdr. You get a matrix lut which I think is doing primary colors for the most part. The one thing I've seen make a real difference is calibrating the white balance in the service menu. You take one of the temperature settings and calibrate that for d65. Then you set your picture mode to use the color temp that you calibrated. That has a real impact and is about the best you can realistically do for these panels.

I stopped chasing the hdr dv calibration dream a year ago for these panels. I've not looked back.

Sent from my SM-G998U1 using Tapatalk

[quietvoid]

Oh well. Not sure I'm willing to spend 300 USD just to calibrate white point :D
Thanks for the info.

[SamuriHL]

There are other tools where you could do that much cheaper.

https://sourceforge.net/projects/hcfr/

[quietvoid]

Yes, but I don't have a colorimeter :)

[SamuriHL]

Well that would certainly hinder any efforts for calibration, yes. :D

[chros]

@SamuriHL, which TPG did you use?

Yes, but I don't have a colorimeter :)
:D Well, you definitely need one for any calibration/profiling software.
You can get even a used id3pro, or just wait for a price cut e.g. on amazon.

Funny you asked this, we just playing around with this in the last 2 weeks :)
Personally I don't care about SDR either, you can create a decent 3dlut with DisplayCal (either for madvr or for the TV, I only use madvr for SDR).

But about the other 2 :), I wanted to see whether:
- in HDR10 the bloody cyan/magenta issue can be dealt with
- in DoVi removing the glowing in near black scenes (the elevated black + black crush can't be fixed with 1dlut/calibration)

You can read about the process from here (https://hub.displaycal.net/forums/reply/29232/), it's essentially 1dlut calibration (and with synthetic 3dlut, if it's needed), you need HCFR and aiopylgtv (https://github.com/bendavid/aiopylgtv) for this.
I used madTPG as TPG, but even setting this up is problematic but only when using HDR10 output!:
- using the old driver (see my signature) that keeps the display in HDR even when app is not fullscreen
- run a calibration pattern video with metadata 1000/400 (maxCLL/maxFALL) and P3 primaries that triggers the display into HDR10 mode and stays in it
- run madTPG for SDR calibration! :)

I tried tons on different combinations, the results are questionable at best :D

1. HDR10 (in calibration mode, aiming gamma 2.2 for 1dlut):
- Calman: I was interested what it does and can it get rid of our issues. In short: it can't, the issue is still there :D
Also, due to the generated 3dlut (if it's used), colors are completely different from the reference cinema preset :D
- manual 20 point grayscale calibration (TV controls + HCFR): the result is way brighter than the reference preset (I guess due to the used factory 3dlut), our issue is still there :)
- manual 1dlut (HCFR + aiopylgtv): with this we have multiple options: with factory 3dlut or synthetic 3dluts:
- - with factory or absolute synthetic 3dluts: the issue is still presnt :)
- - with perceptual / preserve saturation / saturation synthetic 3dluts: the issue is gone!!! But obviously colors will be off, but after actually seeing what Calman does ... :)

So, now I have 1 preset with custom 20 point 1dlut + saturation synthetic 3dlut, the closest we can get to "reference" preset without having the bloody issue!

Interesting thing is that C9 still has this, C10 users couldn't verify this, but Vincent pointed out some color related issues in his newer DV vs HDR10 video, Philips users also complain about something similar, but interestingly for them it happens with different scenes! :) So it seems that it's a problem with the given brand's implementation.
But why DoVi doesn't have this issue, what do they do differently?! Only if we knew ... :)

2. DoVi, it's more problematic, because you would need external devices to trigger it into Relative mode (to measure gamma 2.2) that I don't have:
- it turned out upon experimentation, that Game preset is just a bit brighter than Cinema and it doesn't have the glowing near black! (neither Cinema home, but that is way brighter)
- manual "blindly" adjusted 5-20 point didn't get rid of the glowing
- I uploaded 700 nits 1dlut (+ factory 3dlut) into Game preset that resulted in / compared to:
- - Cinema (dark): brighter image in normal and bright scenes, but same lightness in dark scenes
- - Cinema (home): darker image in dark scenes, around the same lightness in normal and bright scenes
- - both Cinema and Cinema Home have more vivid / lifeful colors, the 1dlut one is a bit duller colorwise

So, in summary, the image is different than the factory presets and not in a good way. Also, it seem DoVi mode uses different gamma / or-something, otherwise the image wouldn't be brighter for the dark preset.
So, back to factory luts, it seems no dice with DovI for us, only LG can fix their sh!t :)

[SamuriHL]

I tried with both pgenerator (rpi) and madtpg. The problem is there is more than one issue. You can't generate a stable 3D lut for HDR or DV as you know. But, worse, is the bug in the LG panels (ALL of them afaik) that if you upload a 1D lut you've essentially f***ed up black levels. So it's kind of a nonstarter. Would be nice to be able to do the 1D lut to correct grey scale but as soon as you do it black levels are borked due to the LG issue. This is why with ColourSpace we avoid the 1D lut like the plague and focus only on 3D lut which for HDR/DV is pointless. So, yea...factory luts indeed.

[quietvoid]

I'm curious if this is the same issue as what you refer to as the cyan/magenta issue:

HDR10 / Dolby Vision
https://i.postimg.cc/kBvMHf6G/HDR10.jpg (https://postimg.cc/kBvMHf6G) https://i.postimg.cc/G433nGGQ/DoVi.jpg (https://postimg.cc/G433nGGQ)

Unfortunately if I were to buy a colorimeter, I could only make use of it for the OLED TV, since my current Linux setup has no support for ICC profiles either.
Hard to justify the cost given that I've only got ~670 hours on the TV in the past 2 years.

[SamuriHL]

P.S. I have the equipment to do a DV calibration and have done so before. The results were a mixed bag. Some things did improve. Others, like black levels, were much worse. I came to the conclusion that everyone else that is far better at this than me came to....Don't bother and just do the SM WB correction and leave the factory luts alone. It's annoying cause if LG fixed their s*** as you say, then we could definitely improve things especially with greyscale. But....no.

[QBhd]

.... I've only got ~670 hours on the TV in the past 2 years.

LOL

In less than 2 years (I just checked, it is 2 days short of my 2yr anniversary!!) I have 4,545 hours

QB

[chros]

I'm curious if this is the same issue as what you refer to as the cyan/magenta issue:
I don't think so, the issue affects low APL scenes, if you have netflix DV then you can see it for yourself with this sample (https://forum.doom9.org/showthread.php?p=1925528#post1925528).

About luts, if you want, I can upload 1dlut and 3dlut to try out if you have a spare preset (e.g. technicolor).

I tried with both pgenerator (rpi) and madtpg. The problem is there is more than one issue.
So which one did you use finally? I'm asking because as it turned out ColorSpace has an issue with madvr (former wokrs with full range, latter requires limited).

This is why with ColourSpace we avoid the 1D lut like the plague and focus only on 3D lut which for HDR/DV is pointless. So, yea...factory luts indeed.
This works with SDR, but who cares about it anymore?! :)

But, worse, is the bug in the LG panels (ALL of them afaik) that if you upload a 1D lut you've essentially f***ed up black levels. So it's kind of a nonstarter. Would be nice to be able to do the 1D lut to correct grey scale but as soon as you do it black levels are borked due to the LG issue.
Do they actually know what they talk about? Couple of measurements in calibration mode:
- cinema HDR with factory luts (https://imgbox.com/g/prESCcCuKa)
- cinema HDR with unity luts (https://imgbox.com/feP2kNRj#)
- cinema DoVi with factory luts (https://imgbox.com/M90rDRkN) (Oppo displays HDR10 20 points HCFR grayscale patterns and upconverts them into DoVi)

Now, if you flatten the gamma to power gamma 2.2, then you will get brighter image!
While experimenting with synthetic 3dluts, it's clear that there are bunch of possibilities that will modify the overall gamma no matter what 1dlut is used (so you have to modify the 1dlut while the 3dlut is in place), and we don't have a clue how the factory absolute 3dlut was created, let alone how actually the whole chain is supposed to work (not just in theory).
My best guess now is that the gamma shouldn't be flat 2.2, but the rotated S curve we have seen in those images.

[SamuriHL]

I use pgenerator exclusively now.

I've not tried playing around with synthetic luts. I've seen people post about them but creating them is above my pay grade. I'm by no means any kind of expert in calibration at all. I know the process that was taught to me but deviating from that is beyond my capability.

As for who cares about sdr well I still do as I watch a lot of upscaled content. Having an accurate sdr picture mode is nice. Maybe someday we'll get a TV that allows us to have accurate hdr and dv too.

Sent from my SM-G998U1 using Tapatalk

[quietvoid]

I don't think so, the issue affects low APL scenes, if you have netflix DV then you can see it for yourself with this sample (https://forum.doom9.org/showthread.php?p=1925528#post1925528).

About luts, if you want, I can upload 1dlut and 3dlut to try out if you have a spare preset (e.g. technicolor).

Oh okay, no idea what's happening with my HDR10 then.
It seems to just have really not smooth shadow to midtone gradients.

Dynamic tonemapping helps brighten things and looks better.
Same for dynamic contrast.

Otherwise I couldn't find other settings that improve anything.

Wonder if I can generate a 3D LUT myself with DisplayCAL without any equipment?
Otherwise it could be useful to try out yours.

Couldn't exactly reproduce the config discussed over at the DisplayCAL forums, and attachments require an account :|
Also seems that I can't create a 3D LUT, button is greyed out. Edit: Okay there's a separate LUT creator.

[SamuriHL]

Generating a LUT without measuring is....um, less than useful. That's because natively every panel is different. When a pixel asks for red (255,0,0) or (235,0,0) your native panel will display what it thinks of as red. But there's going to be a deviation error. Maybe it's small under 5. If so, great. Maybe it's bigger. The way to determine that is to measure it against a calibrated meter. The more accurate the meter, the better, which is why professionals profile the meter. I don't have a way to do that with mine so I just use my meter. Anyway, using all those measurements, the LookUp Table (LUT) is created to correct your native panel's deviations. Maybe red is really (254,1,0) or (234,1,0) or whatever. The LUT tells the panel how to correct it. I get it, this is all basic knowledge and all that. BUT the reason I mention it is because a LUT created for one panel is going to very likely wildly throw off another one and make things worse not better. Creating a "generic LUT" is not really possible. It must be measured to be accurate.

[quietvoid]

I'm aware of all that, I'm just trying to figure out if my panel's default HDR LUT is causing issues.
So far I tried uploading a synthetic LUT but it was really bad (probably my fault).

Then I did a DDC reset and the image is much improved, but my white balance controls are now disabled for some reason and I can't fix it :(
Comparing my now borked technicolorExpert preset to Cinema, shadows seem much more accurate.
Before doing anything, both presets would look the same.

Maybe I'm stuck with having to do a factory reset.
Ah: WARNING: When running the ddc_reset or uploading LUT data on 2018 models the only way to restore the factory LUTs and behaviour for a given input mode is to do a factory reset of the TV.

Now I just don't know how to set Warm2 back.

[quietvoid]

Anyways, factory reset and reuploaded the synthetic 3D LUT and my issue isn't fixed.
I don't know what the 1D LUT is for but it seems to be the culprit.

Edit: Apparently it's for the greyscale in HDR, so maybe I'm actually gonna have to get a colorimeter to correct this..
j82k's 1D LUT is brighter (no idea if correct) and fixes the issue but now I doubt my whitepoint is correct, seems too cool.

[SamuriHL]

I suppose I can take another crack at HDR calibration at some point. I've not done one in ColourSpace as I don't typically touch 1D lut for anything, but, I suppose I can find a mode I'm not using (gaming mode perhaps) and try a calibration and see what happens. Won't be til later this weekend if I do it.

EDIT: Also something to be aware of. Uploading a 1D lut BYPASSES the service menu white point adjustments.

[quietvoid]

Right, I guess the only way to correctly do the greyscale is with a proper (not synthetic) 3D LUT.
Otherwise I have no idea how to adjust whitepoint, maybe with both 1D and 3D LUTs like @chros is doing..

Still a bunch more research to do.

[SamuriHL]

The greyscale is done through the 1D lut. The 3D lut handles the entire colorspace. Think of this as building off of the 1D lut. But LG has stupid bugs with 1D luts that cause all kinds of irritating issues. Supposedly the latest Calman beta "fixes" those issues or works around them or some such. I've no desire to shell out more money to find out. The reason the 1D lut bypasses the service menu white point, though, is that it contains the entire greyscale correction from white (255,255,255) 109% to black (16,16,16) 0% (assuming video levels not full). The idea is that you want to filter through as little processing as possible. I have my doubts about whether we can get a proper HDR calibration but hey I'm game to try. Also, just so you're aware, when doing the LUTs for HDR, you measure at 2.2 gamma and when the LUT is uploaded it's converted to PQ so I'm told. So it's not REALLY a 2.2 gamma for HDR even though the TV uses that to calculate it. I've no idea how that works in reality but that's what calman and colourspace tell us.