A few cr3dlut + MadVR questions

[Blue_MiSfit]

Hey all,

So - I'm trying to figure out what advantages I can percieve from MadVR.

In order to do so, I want to ensure everything is set up correctly so I can do an honest test of MadVR's capabilities!

First of all, I see that MadVR uses cr3dlut to build the LUTs for YV12 -> RGB32 conversion.

As I understand it, there are different LUTs for "SD" and "HD".

In practical terms, 99% of my media is either 16-235 Rec. 601 480p, or 16-235 Bt. 709 1080p / 720p.

Apparently this LUT creations happens the first time you play a video that doesn't have a matching LUT. In other words, I don't have to worry about building LUTs ahead of time, right? I also don't have to worry about MadVR using the correct LUT - it should handle this all automagically. Right? :confused:

Now, I also noticed in the MadVR thread that the shipping version of cr3dlut is outdated, and yesgrey3 suggested using the latest version. How do I update this inside MadVR? I can easily build the necessary LUTs with cr3dlut, but where do I put the LUT files??

I know its a few basic things, but I'm rather confused, and not sure I really need MadVR over EVR-CP or Haali's Renderer. I'm not terribly sensitive to tearing / judder, and my monitor can only do 59.94hz or 60hz at its native 1920x1200, so no "fancy-pants even multiple of 23.976" like I used to be able to pull off with my CRT (Oh how I wish giant CRTs were available, affordable, and practical - or at least 2 out of those 3).

Thanks so much for your input in advance!!

~MiSfit

[yesgrey3]

Apparently this LUT creations happens the first time you play a video that doesn't have a matching LUT. In other words, I don't have to worry about building LUTs ahead of time, right?
Yes, but that way you will use the 3D LUTs only for YV12->RGB32 conversion. If you don't want to use any of the other extra features of the 3D LUTs, you probably will be better served by disabling the 3D LUTs.

I also don't have to worry about MadVR using the correct LUT - it should handle this all automagically. Right? :confused:
Yes. It will select the 3D LUT for SD and HD accordingly with the resolution of the file you are playing. The criteria is explained in madVR thread, I don't remember it exactly... I believe that HD is used when height > 576 or width > 1024

How do I update this inside MadVR? I can easily build the necessary LUTs with cr3dlut, but where do I put the LUT files??
You can update cr3dlut simply by replacing the cr3dlut.exe file contained in madVR's cr3dlut directory.
If you want to replace the files yourself, you have to overwrite the files that are in madVR's directory. If you look carefully, you'll find 4 files:
- "hd - pc.3dlut"
- "hd - video.3dlut"
- "sd - pc.3dlut"
- "sd - video.3dlut"
The files with "pc" in the name are with PC levels (16-235->0-255).
The files with "video" in the name are with Video levels (16-235->16-235)
You just need to create the files, naming them accordingly, and just copy them to madVR's directory.
If you prefer that madVR creates the files for you, just delete them.

PS: If you want fast answers, questions about cr3dlut should be post in the madVR thread or the Gammut conversion thread, because I only monitorize a few threads. Today I decided to take a general look in the forum and found this thread...;)

[Mark_A_W]

Yesgrey, if you notice this...
Could you please explain what you and Madshi are planning to implement using the 3D LUT?

What will using the 3D LUT do that we can't do now? What are the extra features ;)


I'm hoping to get closed loop colour correction (Gamut correction, ruler flat greyscale and gamma correction)?

And of course, no banding!


But I'm a bit lost as to what actually will happen. The main madVR thread is confusing.

[yesgrey3]

Mark_A_W,
I will not disclosure all that I'm planning, because I'm not sure if all my ideas are feasible. I prefer to surprise people instead of deceiving them, so, I prefer a more cautious aproach. madshi feels and think the same way, so you all need to be a little more patient...;)
But I can tell what I already have working, and should release it soon...
I already added the custom gamma curves to cr3dlut. We should be capable to specify the exact gamma curves of our displays and let cr3dlut create a 3D LUT that will compensate for it accuratelly. The results with my projector are very good, I only have to find the reason for a slight problem I am watching, and to add a simpler and faster algorythm for the curve fitting, because the current one (very accurate) is very slow, and only for testing we need a faster algorythm, and keep the more accurate only for the final 3D LUT file.

Stay tunned...

[Mark_A_W]

One more question...

How do you specify the custom gamma curve?

From a measurement? (I have HCFR for instance).

Or manually generated? (There is an application called VideoEqualizer which allows you to drag curves around, and there is PCGG, which I never got my head around..)

http://www.avsforum.com/avs-vb/showthread.php?t=1042160&highlight=videoequalizer

http://www.avsforum.com/avs-vb/showthread.php?t=1097653&highlight=pcgg


I'll stay tuned alright :)