MadVR in use with LG OLED Thread

[SamuriHL]

I've dialed DTN to 85 for my particular setup. It seems to have a good balance for me. Quite impressive really.

[chros]

Are you sure that DTN works? ADPL value does not change (it's 800 all the time in brackers) if curves are disabled.

[SamuriHL]

I don't know if it "works" but it certainly has an impact on brightness.

[quietvoid]

Originally Posted by chros

Are you sure that DTN works? ADPL value does not change (it's 800 all the time in brackers) if curves are disabled.

It definitely works on my machine.

Without curves: https://slow.pics/c/RCrIeQ2A
With curves: https://slow.pics/c/9C0PpnI2

[chros]

You also only got 870 for ADPL. Dunno about with curves, but without curves it should change (increase).

[quietvoid]

What even is ADPL? The value in the brackets is increasing with DTN enabled..
You can click to change image.

[chros]

Oh, I missed that, sorry. It works here as well, thanks, I should have checked with SM straight away.

So, what does tge new clipping at mastering peak means to us (that is enabled by default) ?
There are lot of contents which have master 1000 nits but maxCLL is above 2000 nits.
Does it mean that madvr now clips at 1000? If so then there's no need for any algo for these contents for sure,

[quietvoid]

You can always compare by reencoding with different metadata.
I assume it's to respect the grading intent.

[SamuriHL]

If only there was a way to override the metadata LOL In my new setup I don't have the Integral 2 connected right now. I don't have a good way to connect it permanently to the system but that is a very good device to have for this kind of stuff.

[chros]

Nah, too much hassle, I'll ask him about this instead.

Back to your settings/curves, couple of observations (@ 870 DPL, I used this to have the same setup, although the diff should not be huge at such high DPLs):
- out of these samples only The Meg (03*tm.mkv) increased the DTN during normal playback
- take a look at the 10*pr.mkv @00:00:22 sec (keyframe):
-- your settings (I think) unnecessarily dims the image, reducing highlights
-- metadata: MDL 4000, maxCLL/FALL 2465/823
-- frame stats: peak 1710, Fall 32.840 (with your setting 19.401) resulting ADPL 870

So, as far as I understand how this works (please correct me if I'm wrong):
- DTN with curves only selects (interpolates between) the right curve(s):
-- based on frame peak (what about the new mastering peak clipping feature?) and resulting FALL
-- if DTN is disabled with curves, only the x1 curves are used
- with 800/870 DPL, only the x1/x2 curves will be used with 2230 (neither the 4x/8x/16x ones), because x2 means 1740 ADPL with 2230 which is really high already
- the frame above uses 2 curves: 509x1 and 2230x1 (but closer to 2230x1)
- the only diff with 2230x1 between your curve vs default is the custom knee: 0.50 vs 256! (that makes the curve less steep, reducing brightness)

Why do we need so small knee with our high DPL? Neo used the 0.50 knee with 100 DPL
So I revert back the 2230x1 curve to default and maybe the 2230x2 as well (although I haven't thought about it yet).

[quietvoid]

I wouldn't say that frame at 22s is unnecessarily dimmer, some of these lights are noticeably closer to being blown out with the default curves.
You can just make it brighter with dynamic clipping at 50 (for this specific scene), without affecting the detail.

This is also so close that I'm not sure you'd appreciate the difference in HDR playback.

I don't believe (anymore) that curves should be used to increase brightness, because you're definitely going to lose detail that way.

[SamuriHL]

I tend to agree. Use the curve to retain as much detail as possible. Brightness vs detail is the compromise, as madshi has said numerous times. You give up one to have the other as they are on opposite sides of the spectrum. TV algorithms it's pretty clear to see the choice they make, unfortunately.

[chros]

Originally Posted by quietvoid

You can just make it brighter with dynamic clipping at 50 (for this specific scene), without affecting the detail.

This was a really good idea, thanks, I updated the post over avsforum:
"dynamic clipping has still an effect on the resulting curves/image (tested with MDL 1000, frame peak before dc 1621 and after dc 1186, so it's above MDL), so it clearly doesn't clip at MDL."

Originally Posted by quietvoid

I wouldn't say that frame at 22s is unnecessarily dimmer, some of these lights are noticeably closer to being blown out with the default curves.

"Closer" means they are still not, so why degrade the image?

Originally Posted by quietvoid

This is also so close that I'm not sure you'd appreciate the difference in HDR playback.

That's true but this can be said about all the other options as well, even with sources that we know, let alone those that we watch for the first time

Originally Posted by quietvoid

I don't believe (anymore) that curves should be used to increase brightness, because you're definitely going to lose detail that way.

At some point, yes, as we can see with the meg and SM, but the question remains: which is that point?

Originally Posted by quietvoid

The curves are not meant to fix the "issues" in MMFR, that's a saturation problem.

Err, I think these curves are supposed to fix the saturation issues at the first place, although MMFR is an extreme example.

[SamuriHL]

No, madshi said saturation will be revisited after the curves are selected. There are people who are choosing to have desaturation options still enabled for some content so the curves are not going to fully fix saturation. They will have an impact, certainly.

[aron7awol]

Originally Posted by chros

So, as far as I understand how this works (please correct me if I'm wrong):
- DTN with curves only selects (interpolates between) the right curve(s):

Agreed, and I guess I'd say this is sort of all DTN ever did, was set the BT.2390 curve used based on peak and the resulting compression of target/DPL.

Originally Posted by chros

-- if DTN is disabled with curves, only the x1 curves are used

Agreed, as without DTN there is no compression.

Originally Posted by chros

- with 800/870 DPL, only the x1/x2 curves will be used with 2230 (neither the 4x/8x/16x ones), because x2 means 1740 ADPL with 2230 which is really high already

Well, a frame with peak and target >1740 would result in compression >2x so it should interpolate using the 2230x4 curve as well in those scenarios. And then even as we go further to frames and targets >3480 it would use that 2230x4 to interpolate along with 2230x8 (and 10000x4 and 10000x8), and even more extreme cases with frames > 6,960 we would interpolate between 2230x8, 2230x16, 10000x8, 10000x16. So really, almost all curves can be used with almost all DPLs in the right scenarios.

Originally Posted by chros

- the frame above uses 2 curves: 509x1 and 2230x1 (but closer to 2230x1)

Agreed, since DTN doesn't kick in, there is no compression and so it only needs to interpolate between 2 curves. As soon as DTN kicks in (and thus results in compression) we interpolate between 4 curves, except in the coincidental cases where peak and/or compression happen to land exactly on one of the options.

[chros]

Originally Posted by aron7awol

Well, a frame with peak and target >1740 would result in compression >2x so it should interpolate using the 2230x4 curve as well in those scenarios. And then even as we go further to frames and targets >3480 it would use that 2230x4 to interpolate along with 2230x8 (and 10000x4 and 10000x8), and even more extreme cases with frames > 6,960 we would interpolate between 2230x8, 2230x16, 10000x8, 10000x16. So really, almost all curves can be used with almost all DPLs in the right scenarios.

Yes, you are right, sorry, I meant titles under that 2230 curve.

Originally Posted by aron7awol

Agreed, since DTN doesn't kick in, there is no compression and so it only needs to interpolate between 2 curves. As soon as DTN kicks in (and thus results in compression) we interpolate between 4 curves, except in the coincidental cases where peak and/or compression happen to land exactly on one of the options.

About this: I wanted to test elevated black with Mehanik's black clipping pattern (01. Black level\01. black-level-v1.mp4), but the image doesn't change at all when I modify the 110x1 curve!!!
Can you guys reproduce it? (either in SDR or HDR ouptut)
Video stat: frame peak 11 nits, FALL 0.051.
Curve 110x1 mod: I moved up the first 11 (!) points to around 10 nits!
There's no change in the image at all when you switch off/on the curves.
What's happening here?

Edit: it doesn't change either if you set all the points to the max (e.g. by clicking the "create bt.2390 curve now" with its default settings).

Lastly, as he stated, madvr now should clip at MDL straight away (although it doesn't seem to work now).
But if that will be the default behavior then there won't be need for DTN at all for MDL 1000 titles!!! (which I guess the 70% percent of all the content today, at least)

[quietvoid]

Originally Posted by chros

Lastly, as he stated, madvr now should clip at MDL straight away (although it doesn't seem to work now).

I had posted an example where the MDL clipping worked: https://www.avsforum.com/threads/imp...#post-60401221

[quietvoid]

Anyways I ended up making a minimum steepness + half max knee file, seems to be better than what I had done for Neo-XP's adapted one.
It's in my signature.

Alternatively, here's Neo-XP's 1.2 curves adjusted for 870 DPL: https://gist.github.com/quietvoid/d7...2d21aa56b77beb
It's a bit more contrasty/darker, see https://www.avsforum.com/threads/imp...#post-60518938

Since it lowers brightness a bit more, I lowered DTN and increased the FALL detail to gain back some brightness. But again that's totally subjective.
Settings: https://postimg.cc/n9Fr9s7r

Now I need to start actually watching stuff.

[chros]

Originally Posted by quietvoid

I had posted an example where the MDL clipping worked: https://www.avsforum.com/threads/imp...#post-60401221

Omg, that was a month ago and I almost forgot about it Thanks
Yes, that option works in b123 but not with b124/125.

Anyway, can you guys experiment with that option at the MDL value if you will have time whether it's needed or not? I'll do the same.
Because if he fixes it there won't be turning back ...

Originally Posted by quietvoid

Anyways I ended up making a minimum steepness file, seems to be better than what I had done for Neo-XP's adapted one.
It's in my signature.

Cheers, I'll take a look some other day.

Originally Posted by quietvoid

Now I need to start actually watching stuff.

Sure

PS: I gathered up the madvr beta changlog into 1 file from b100 (I haven't gone back more, yet?), I'll plan to update it in the future (I've also put the link in the post of the link in my signature).

[jigar24]

My 1080p bluray player (couple years old) has options for 4:2:2 ycbcr, 4:4:4 ycbcr, or RGB. With the UHD players I believe they offer those choices too, along with up to 12bit output. By default on 'auto' pretty sure they all output ycbcr at either 4:2:2 or 4:4:4