Originally Posted by damelon
So to add to more of my work on the HTPC front. My issue really isn't anything 4K or HDR related at all. That part works great. Though Madshi is currently working like crazy on MadVR beta testing in regards to real-time tone mapping. There are new beta builds daily. I can't keep up. I am not touching it for now as it is decent enough, but I will check in every few days on this thread to see if the dust starts to settle as far as some standard settings that makes people happy in general.
When I moved to 4K I did a re-build of my HTPC using Windows 10 and a RTX2060 video card which would be capable of doing HDR Tone Mapping. I assumed since I had done this HTPC dance so many times without problems that my issues had to do with 4K HDR only. (Since that was the only thing I was playing too) But yesterday we watched a normal up-scaled 1080p movie and I saw the same clock jittering now and then which basically results in some repeated or dropped frames. I may have been the only one that noticed but I am a picky viewer. Anyway, I had identified the problem this past week and was trying to solve it using MadVR's "Custom Modes". In the past, you would just use reclock and not worry about it. It seems that NVIDIA cards have issues with clock deviation, and of course, RTX cards have very few drivers they can choose from being new video cards. In any case, I was having a lot of problems getting any 3840 x 2160p 23hz optimized modes from MadVR to be accepted my by GPU.
I first upgraded to the latest NVIDIA Drivers, which as of today was 419.17 WHQL. ( I never install Geforce Experience on a HTPC)
Basically, a custom mode takes several clock timings and manually sets them to come up with the refresh frequency. With a bit of tinkering, you can come up with a custom resolution refresh rate and MadVR can toggle it for you at will.
So I think I finally found one that will stick.
In MadVR, I went under Devices -> (My Device) -> display modes -> (Custom Modes Tab)
Then I had to uncheck the tab that said "show native res modes only" Because although the JVC RS540 E-Shifts to 4K, it is natively a 1080p projector. This now displays the 4K Resolutions.
Then I selected the 3840x2160p23 resolution and clicked the "Edit" button.
I selected "Current Timings" and modified the settings that already existed in the boxes using these settings:
Front Porch : 1276
Sync Width : 88
Back Porch : 308
(Total = 5512 Pixels) + Polarity
Front Porch : 8
Sync Width : 10
Back Porch : 76
(Total = 2254 Pixels) + Polarity
Pixel Clock : 297.88 mhz
Resulting in 23.9760825135254 hz refresh rate
My screen did not go black, so my GPU was happy and I told it to create a custom resolution for me, which now shows up in my NVIDIA control panel. Now, NVIDIA shows this as 24Hz, even though I created this as a 23Hz resolution in MadVR. Don't worry, they sync up just fine.
It is the best I have been able to do so far... it isn't perfect yet. This has been much easier in the past when you could just use the Intel CPU to playback the video. HDR has made things more difficult.
So I'm going to have to eat a little crow here... I was wrong. I was wrong that my issue was not HDR related. I was having a judder issue with my RTX2060, and the timings I was using improved it as far as matching the clock rate to the frame rate of the original product. What was really happening was a problem with the 400 series of the NVIDIA drivers (which are required for the RTX series of NVIDIA cards) and HDR rendering in MadVR. I have been spending a lot of time discussing this issue with several people in the HTPC forum here, and no settings I changed could resolve the issue I had. Now, let me be clear. If I played 4K SDR or Upscaled 1080P media, it played flawlessly. When HDR source material would play, it would have constant judder and "hiccup" issues during playback. It was watchable, but it was extremely annoying. May people in the HTPC forum here with RTX cards are having similar problems. I'd suggest if you are buying a GPU to get a used GTX1070ti instead.
At first, we thought that maybe it was the fact that it was the low end of the RTX line. We thought that maybe the RTX2060 couldn't handle the HDR content, so we were lowering all of the settings like Chroma upscaling. We made changes like enabling Vsync in the NVIDIA control panel, enabling/disabling exclusive mode, etc. None of those changes made any difference. Fortunately for me, I had a GTX1080 in my primary computer. So I swapped video cards. Other than test out an occasional build of Star Citizen from time to time I don't really do any gaming anymore, so this wasn't a problem for me. I tried out the GTX1080 with the 398.11 Drivers and the issue went away completely. Now, the timing issues I am quoting above have to be tweaked, but they are pretty much invisible to the naked eye. Last night I watched Aquaman in HDR and it looked incredible.
So now I want to tie in all of this nonsense into a complete review. I was able to watch Aquaman in HDR, I also watched Mortal Engines in 4K SDR, which I re-watched parts of in 4K HDR to test last night as well. I honestly don't know of any reason why I would buy a true 4K projector. The image this projector puts out is perfect as far as I am concerned. I am not doing calculated measurements. I am just sitting in a chair watching a movie. The picture looks like glass. The image is clear and bright and the motion is smooth. Details are great, even in dark scenes. While you can stream 4K content, there are always artifacts from compression that don't exist when using local material. While Mortal Engines wasn't a great movie by any means, it had some beautiful scenes that really took advantage of 4K. As for Aquaman, parts of it could have been Avatar 2 and it would have fooled me. If you are wanting to get the "latest and greatest" 4K projector, do yourself a favor and instead look to get a used JVC RS540 if you can find one.... at least if you have the ability to do the tone mapping externally. (Either through a HTPC or a Panny player) I'm amazed at how great this looks! I'm so happy with this upgrade!