INTERACT FORUM

Devices => Video Cards, Monitors, Televisions, and Projectors => Topic started by: TheShoe on February 05, 2021, 07:43:29 pm

Title: Minor issue with full RGB vs Limited and madVR
Post by: TheShoe on February 05, 2021, 07:43:29 pm
I have two notable instances that I have found so far where having the entire color chain to the display as FULL RGB produces strange artifacts in the black color - essentially a "snow" or "sparkle" effect appears, almost like static noise in the black end of the color spectrum.

If I change madVR to output limited to the display, the effect completely goes away, but of course blacks are not as black as they could be.

Curious if anyone else has seen this.  I also had this issue on my PS4 Pro with a game where the Pro was configured to output full RGB and the video game showed the exact same effect during cut scenes.  When I changed the Pro to LIMITED, the effect went away.

In my two instances in Media Center that I have noticed so far, it is in:

Labyrinth 4K UHD --> noticeable during the opening credits with the CGI owl flying around
Mulan (animated) 4K UHD --> noticeable on the main menu

PS4Pro --> noticeable in the Wolfenstein - The New Order - Video game, during cut scenes.

I'm feeding an LG OLED 4K (2016) set.  Curious how others are setting madVR under the display/properties setting "the display expects the following RGB output levels".

Desktop is set to FULL RGB.

Title: Re: Minor issue with full RGB vs Limited and madVR
Post by: wer on February 05, 2021, 08:40:49 pm
Shoe, exactly what model of LG OLED do you have?  I have one myself, and some of those have to be set very specifically for 4:4:4 color to work.  Are you aware of the trick?
Title: Re: Minor issue with full RGB vs Limited and madVR
Post by: tij on February 05, 2021, 09:36:42 pm
I used to have sparkle ... especially at 12bit RGB 2160p60 where data rate is highest

For me it was inferior HDMI cable. It was advertised as 4K capable, but failed to mention only 4K at 24fps.

Changing to properly certified HDMI cable resolved sparkle for me.
Title: Re: Minor issue with full RGB vs Limited and madVR
Post by: TheShoe on February 05, 2021, 10:38:06 pm
Shoe, exactly what model of LG OLED do you have?  I have one myself, and some of those have to be set very specifically for 4:4:4 color to work.  Are you aware of the trick?

I have an LG C6OLED (2016 model, last year with 3D).  Not aware of any trick.

Interesting other comment from @tij re: HDMI cables.  They are Audioquest Cinnamon 4K8K HDMI cables, between the nVidia 3090 -> Marantz -> LGTV.

in the nvidia control panel, i have it set to RGB/8bpc/Full @ 4K60.  When playback starts, it changes to RGB/12bpc/Full @ 4K24.  madVr is always configured for Full/10bpc (and changes back to RGB/8bpc @ 4K60 when playback stops).

Title: Re: Minor issue with full RGB vs Limited and madVR
Post by: TheShoe on February 05, 2021, 10:56:41 pm
So it's resolved:

Changing the "Input Icon" to "PC" (which is a stupid description for something that clearly does more than change an icon), it put the HDMI input into PC mode.  From there I did some further tweaking (set Picture Mode to ISF Dark Room), and voila!  The "sparkle" effect is gone...

All other settings in the nVidia control panel and madVR remain as I had them previously.

I used to think audio (room) calibration could drive one nuts...  ;)

Thanks for the hint @wer - some google searching based on what you posted lead me to fiddle with the "Input icon" setting.  I note too some additional items in the LG menu that were not there before...

Title: Re: Minor issue with full RGB vs Limited and madVR
Post by: wer on February 05, 2021, 11:21:56 pm
That Audioquest cable is an 18Gbps cable. So it should do 4:4:4 at 2160p/60Hz, barely, but I believe trying to use HDR at that setting would exceed the bandwidth capabilities of the cable. You would have to lower the frame rate to do 10 or 12bpc at that resolution.

I'd suggest you try a different cable. Get a certified one; you don't have to pay a lot for perfect performance. You can get one that works perfectly for $20-40.  But you can get cables that have problems. I once had a set of cables that had all the proper specs, but ARC just didn't work. The manufacturer was puzzled, and replaced the cables, and the replacements worked fine. So food for thought.

The trick on the TV is that not only do you have to have Ultra Deep Color turned on (HDMI1/2) but you also have to have the icon for the interface changed to the PC icon. It is said on some TVs the label of the interface must also be changed to "PC" but this is not true for my set: the icon must be changed, but not the label. So this may be firmware specific.

Test your configuration with a 4:4:4 test pattern.  Just because you don't get an error message doesn't mean it's working the way you want.
Title: Re: Minor issue with full RGB vs Limited and madVR
Post by: wer on February 05, 2021, 11:22:35 pm
Ah, I see you googled about the trick while I was posting.  Good job.

Be aware, you lose some settings/options when operating at 4:4:4.  For example, you cannot enable TruMotion anti-judder controls.
Title: Re: Minor issue with full RGB vs Limited and madVR
Post by: TheShoe on February 05, 2021, 11:47:11 pm
I did notice that TruMotion is disabled, which is fine.  I don't typically use it - too many artifacts across various videos, even when tuned down.  I do like the de-judder, but the artifacts drive me crazy.

Edit: Notice Real Cinema is also disabled.  This I assume would affect 24p content; is there a way to compensate for this in madVR?



Title: Re: Minor issue with full RGB vs Limited and madVR
Post by: rec head on February 20, 2021, 07:23:06 am
So it's resolved:

Changing the "Input Icon" to "PC" (which is a stupid description for something that clearly does more than change an icon), it put the HDMI input into PC mode.  From there I did some further tweaking (set Picture Mode to ISF Dark Room), and voila!  The "sparkle" effect is gone...

All other settings in the nVidia control panel and madVR remain as I had them previously.

I used to think audio (room) calibration could drive one nuts...  ;)

Thanks for the hint @wer - some google searching based on what you posted lead me to fiddle with the "Input icon" setting.  I note too some additional items in the LG menu that were not there before...

Is this an option in the TV?

I have a 2016 LG 65E6P. I have to admit I'm thinking hard about ditching it and 3D for a newer model.
Title: Re: Minor issue with full RGB vs Limited and madVR
Post by: tij on February 20, 2021, 07:34:19 am
Is this an option in the TV?

I have a 2016 LG 65E6P. I have to admit I'm thinking hard about ditching it and 3D for a newer model.

Yes its an option on TV (if i recall correctly ... its in the "input settings") .. its specify type of input on HDMI ... "PC icon" expect input from PC (also good for gaming) and hence expect 0-255 ... also does not apply any special image processing  to reduce lag

I love 3D on LG OLED (always watch 3D version of movie beford watching UHD version)   ... will keep it until it breaks down
Title: Re: Minor issue with full RGB vs Limited and madVR
Post by: rec head on February 21, 2021, 10:07:00 am
It took me forever to figure out how to set the input to PC. For anyone else looking you need to press the Input button on the TV's remote to get to the Input settings to change to PC. It is not in the normal settings. After I did that I made sure my Nvidia settings were RGB, 24hz, 32 bit, Full. Then the TV became completely washed out, I couldn't even see the mouse pointer over the white background. I restarted the PC and all seems to be well... for now.

It is weird that while playing a movie in Theater View I need to "back" out of the movie to get the TV out of HDR mode. If I press Stop it stays in HDR. This is completely backwards from how it used to work.

Thanks for all the help and sorry to the OP if this thread got hijacked.