madVR - high quality video renderer (GPU assisted)

[Tobiwan]

I have a question about BT.2020, how did I know that I can use it? Does the monitor need to support BT.2020 or the GPU? Or can everyone use the new BT.2020 and it works?

[tp4tissue]

Consumer bt2020 displays do not exist.

What we have now at the highest are dci-p3 displays. If you make 3dluts, make a p3 lut if the gamut of your device is larger than Rec709 (which is more/less the same as SRGB).

[tp4tissue]

@fourbigkids

Pixel shift is usually able to sharpen edges, but may blur certain types of textures, because the shift is an overlap of half a pixel

You'll have to test it to find out if you like what it does.

If you output 4K to 4K that's one step with chroma upscaling

If you output 4K to 1080p, that adds a downscaling step, which may require you to lower the chroma upscaling setting.

Either one may be sharper depending on content and viewing distance.

Upscaling anything lower than 1080p to 1080p is a non-issue.

[Tobiwan]

So if I understand it right it doesn't give me any benefit to set BT.2020 instead of BT.709 for my monitor? I never use 3DLUT or yCMS to calibrate, I always use "already calibrated" with BT.709, PPC and 2.40 gamma.

[tp4tissue]

Originally Posted by Tobiwan

So if I understand it right it doesn't give me any benefit to set BT.2020 instead of BT.709 for my monitor? I never use 3DLUT or yCMS to calibrate, I always use "already calibrated" with BT.709, PPC and 2.40 gamma.

In order to set bt2020, the monitor has to have a bt2020 mode, and be operating In that mode.

There are no BT2020 consumer monitors, so that is not an option.

If you do not have a calibrated monitor, pick disable calibration

[Tobiwan]

Thanks tp4tissue!

[Manni]

Originally Posted by tp4tissue

In order to set bt2020, the monitor has to have a bt2020 mode, and be operating In that mode.

There are no BT2020 consumer monitors, so that is not an option.

If you do not have a calibrated monitor, pick disable calibration

This isn't correct.

There are no consumer monitor covering 100% of BT2020, but there are many consumer and monitors and projectors offering a BT2020 mode that covers above rec-709, often up to P3 and for some projectors like the RS4500/Z1 beyond P3.

So there is an advantage to selecting a BT2020 mode in the display/projector, even if the projector is unable to cover BT2020 fully. For example, with my rs2000 that covers close to 100% of P3 with its P3 filter, I benefit a lot from selecting the BT2020 calibration (around 100% of P3 with a P3 filter) or the HDR calibration (around 90% of P3 without filter). Both deliver a significantly larger color volume than the rec-709 calibration, for HDR/SDR WCG content of course.

With madVR, especially if you use 3D LUTs, it's usually better to select a DCI-P3 calibration as it tends to be closer to the actual capability of the display and madVR can simply discard the BT2020 container and deliver P3 which is used to grade the majority of current content, even if it's delivered within a BT2020 container. But with a consumer source you don't have the choice, they either output rec-709 or BT2020 so you have to select one or the other if you want to track the correct saturations.

[el Filou]

Originally Posted by tp4tissue

If you output 4K to 1080p, that adds a downscaling step, which may require you to lower the chroma upscaling setting.

Or check "scale chroma separately if it saves performance", which will allow use of better downscaling and/or not compromise on HDR tonemapping quality if you are GPU limited.

[cyberscott]

Originally Posted by RXP

Does anyone know if the LG C6 is fine for 12 bit output or should I just leave it at 8 or 10 bit?

I own a LG C6 and I've noticed no additional banding or issues with 12 bit enabled in the Nvidia control panel with madVR. Of course, all equipment has variations so best thing to do is a "stare and compare" with a paused video or better yet a .pgn screen capture with 12 bit on and off.
Even so, madVR's 8 bit processing is excellent so even with 12 bit not enable, you'd be hard pressed to see a difference, I'd think.

[ryrynz]

Yeah that's usually the case.. The benefits of using 10/12bit are typically small to non apparent.

[tp4tissue]

@cybscott

Does it show banding even at rgb 444, 12bit @ 23/24 hz ?

Sometimes it's the sharpening algorithm which screw up 4:2:2 conversion, leading to (banding), but it's not actually banding, it's just bad sharpening.

[fourbigkids]

Thanks @tp4tissue and @el Filou. Looks like I have some testing to do! :-)

[cyberscott]

Originally Posted by tp4tissue

@cybscott

Does it show banding even at rgb 444, 12bit @ 23/24 hz ?

Sometimes it's the sharpening algorithm which screw up 4:2:2 conversion, leading to (banding), but it's not actually banding, it's just bad sharpening.

For my HTPC set-up, I exclusively use RGB Full, 444 @ 4k. The C6 HDMI input is set to "PC" I have madVR set to use "switch to matching display mode" for 2160p23, 2160p29, 2160p50, and 2160p59. My current video card is a RTX 2080 TI.
Some of the videos I watch have banding already in the source and some with little to no banding in the source. If I look at a scene that has little to no banding, running the Nvidia control panel at 12 bit with the appropriate display mode, it does NOT add any additional banding or video noise that was already part of the source.
I don't typically use any additional sharpening algorithms beyond what is built into NGU-AA, which I use exclusively for my content.

[Alexkral]

Originally Posted by Manni

With madVR, especially if you use 3D LUTs, it's usually better to select a DCI-P3 calibration as it tends to be closer to the actual capability of the display and madVR can simply discard the BT2020 container and deliver P3 which is used to grade the majority of current content, even if it's delivered within a BT2020 container. But with a consumer source you don't have the choice, they either output rec-709 or BT2020 so you have to select one or the other if you want to track the correct saturations.

I guess you mean select a DCI-P3 calibration on the screen if it happens to have one, or create it, because otherwise sending DCI-P3 is wrong.

[Manni]

Originally Posted by Alexkral

I guess you mean select a DCI-P3 calibration on the screen if it happens to have one, or create it, because otherwise sending DCI-P3 is wrong.

Re-read what I wrote, and that is clearly what I said in the context of my post. Remember we were discussing display modes. I also mentioned the BT2020 container, but maybe that's too technical

[j82k]

I suggest everyone running their LG Oleds at 12-bit or in PC-mode to check out Rtings 16-bit gradient test pattern played in madVR.

https://www.rtings.com/images/test-m...ent-16-bit.tif

My LG C8 shows noticeable banding, especially visible in the darker green gradient when using either 12-bit or 8/12-bit PC-mode. In 8-bit, non-pc mode it looks fine.
It was the same on my C6 so I don't really understand if something is wrong with my setup or if other people just don't notice the banding.

By the way PC-mode also forces 3:2 pulldown even when outputting 23.976 Hz.
So you get 4:4:4 chroma and lower input lag but you'll also get color banding and forced 3:2 pulldown.

[SamuriHL]

Yup, that's well known for the C8, unfortunately.

[jmone]

So I spent the afternoon trying to get my JVC x7500 working without dropping/repeating frames and I think I've worked it out. The JVC is very picky about what signal it will accept and all the ones offered by madVR outside the normal ones did not work. So I started with the EDID / CTA profile (but it would have a drop/add about 1 per hour) and tweaked that a bit. While madVR's config GUI says this setting will last 7.79 hours, I can confirm it worked perfectly for just under 2 hours. Interestly, is that madVR kept updating the reported display calculation from 23.9758 @ 1 min, to 23.97608 but the end of the movie as well as the expect drop.repeat frames.

[arcspin]

@jmone
Can you please tell us what you did to tweak your settings.

I'm in a similar situation and would very much appreciate some guidance.
I have read the tutorial found here:
http://madvr.com/crt/CustomResTutorial.html

Is it something similar you did?



Best regards

[jmone]

@arcspin, yes that is the correct tut but I then manually changed the values as per the 1st pic (just type them in then press "test mode" to see if they work for you).