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#52721 | Link | |
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Join Date: Oct 2012
Posts: 6,882
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stay at the native resolution of your screen and try to frame rate match or use smoothmotion. if madVR can do a 4:2:0 -> RGB conversation has nothing to do with the output resolution or framerate. |
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#52722 | Link | |
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Join Date: Apr 2011
Posts: 121
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Actually i worry that in 3840*2160 30hz mode the output bandwith is insufficient.it may lead to the 4:2:0 conversion to 4:4:4 failure. In my memory 3840*2160 30hz is only suitable for HDMI 1.4 output port. HDMI 1.4 output port only transports 4K video with 4:2:0,not 4k video with 4:4:4 Last edited by suanm; 25th September 2018 at 16:25. |
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#52723 | Link | |
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Join Date: Dec 2014
Posts: 1,127
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I don't totally understand why someone with a display as bright as an OLED would want to use an SDR gamma curve to display HDR content. Projector owners champion this configuration, but it works much better when the display has limited brightness. A PQ curve will do a superior job of separating the various image elements with different amounts of brightness, like it was meant to be presented. A bright sun, for example, will stand out more when presented in PQ than SDR. SDR gamma tends to make large portions of the image brighter or darker. It is also possible to invite banding when the SDR curve is stretched too far, and you will reduce its accuracy without a proper calibration. An HLG curve is a better example of a curve designed for HDR. It uses an SDR gamma curve for the SDR range and a much steeper logarithmic curve for HDR highlights. This will produce a better HDR effect than an SDR gamma curve alone and reduce the chances of banding.
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HOW TO - Set up madVR for Kodi DSPlayer & External Media Players Last edited by Warner306; 25th September 2018 at 16:26. |
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#52724 | Link |
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Join Date: Jun 2017
Posts: 148
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I don't think what you're saying is true at all when using madVR's HDR to SDR. Average brightness totally depends on what you set the target peak nits to. So it could also be darker than HDR passthrough, which is what I'm after, darker overall picture but increased dynamic range compared to LG's tonemapping. Also I've never seen madVR produce any banding when it wasn't a source problem, quite the opposite I think 8-bit with dithering gives smoother gradients than whatever the LG produces when feeding it with 10-bit.
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#52725 | Link | |
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Join Date: May 2004
Posts: 4,883
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Yes, the HDR->SDR is definitely too dark for us LG OLED users. 120 NIT target isn't going to fly. If I were to make any actual recommendations to other people it would be to leave the service menu alone and use HDR passthrough. Hopefully madshi can fix the current issues with the HDR using pixel math option. In any case, I just wanted to clarify that my statement was my own personal opinion for myself and not a general recommendation that people go messing around with very expensive equipment.
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HTPC: Windows 10, I9 9900k, RTX 2070 Founder's Edition, Pioneer Elite VSX-LX303, LG C8 65" OLED |
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#52726 | Link | |
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Join Date: Oct 2012
Posts: 6,882
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and no HDMI 1.4 can do RGB UHD at UHD. why do you even care you are clearly using hdmi 2.0. @Warner306 a 1000 nit HDR image on a 1000 nit display will have the same image between a HDR signal with 1000 nits and an SDR image properly converted from the HDR image. gamma, PQ and HLG are just different ways to store the data. the banding part is a myths a proper dithered image will not show banding. banding is usually produce by the flawed image processing of TVs or other panel related things. when switching between modes on a TV the transistor to power the pixel will not magical be able to produce PQ from gamma or closer to gamma response. |
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#52727 | Link | |
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Join Date: May 2004
Posts: 4,883
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HTPC: Windows 10, I9 9900k, RTX 2070 Founder's Edition, Pioneer Elite VSX-LX303, LG C8 65" OLED |
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#52728 | Link |
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Join Date: Dec 2014
Posts: 1,127
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Just look at the PQ curve. It is very flat at the bottom (almost SDR gamma 2.40) and then rises rapidly when the brightness increases. The SDR gamma curve can't replicate this brightness response. That is why the HLG curve was invented. SDR gamma was also replaced with PQ and HLG because tests found it leads to banding when the brightness range is stretched too far.
If you want to test if your display is handling color correctly, download the Life Untouched 4K HDR Demo. Find this scene and observe the color of the flower petals: Flowers Correct Hue Flowers Incorrect Hue If they are blue, there is a fair to good chance your display is handling color correctly. If they are purple, your display is probably shifting some hues.
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HOW TO - Set up madVR for Kodi DSPlayer & External Media Players |
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#52729 | Link | |
Registered Developer
Join Date: Mar 2010
Location: Hamburg/Germany
Posts: 10,049
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All these transfer functions exist to move bitdepth around into areas where it matters for the format in question, because bitdepth is ultimately limited. Gamma/SDR transfer functions are designed for a limited range of brightness, ie. the SDR brightness, so it spreads the bits around for that. If you try to push 1000 nits of brightness into a image transfer designed for ~120 nits or so, there will be a downside to that, because its not aware of the increased range of brightness. PQ is designed to keep more bitdepth for the relevant parts (ie. 0-100 or so), and waste less bits on the 900 remaining nits, which are of less importance then the actual image detail. Of course you can mask these differences with dithering, but ultimately a PQ curve is going to give you a better bitdepth distribution for HDR images, which have the majority of image data in a small subsection of the bitdepth range, and only highlights in 90% of the remaining space - as the transfer should reflect that.
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LAV Filters - open source ffmpeg based media splitter and decoders Last edited by nevcairiel; 25th September 2018 at 17:01. |
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#52730 | Link |
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Join Date: Oct 2012
Posts: 6,882
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@nevcairiel
correctly. properly used bit deep will lower the noise floor and depending on the source notable. i will not dare to say PQ is worse than gamma and they help extreme for lossy compression just like bit deep. but in the end the dispaly will convert everything to something close to gamma with the extra use of the backlight. how do you even create a transistor powered pixel response like PQ with a dynamic brightness? and would it even help at all. fun fact gamma was an artifactly by product from CRTs because that'S how they responded which helps quite alot for image compression these days just imaging it would be linear. but it was not created for SDR in mind it's just what we got. @Warner306 colors have little to nothing to do with gamma or PQ. the color differences don't come from banding or bit deep relations. my first guess would be gamut mapping. that'S the problem of these test they don't dither properly if they dod they would "only" talk about noise not banding. |
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#52731 | Link |
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Join Date: Jun 2017
Posts: 148
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The thing with Oleds is, they are terrible at near-blacks. Not only the uniformity but also the near-black gradation so I totally don't mind some dithering noise which hides this ugliness a little bit and also makes the gradation a little smoother. I wish Oleds would just dither the near-blacks by default like plasmas did. This would solve alot of problems and only cause a bit of noise.
edit: madshi should implement some algorithm to madVR for Oled owners that does heavy dithering to near-blacks and less and less on brighter parts of the picture. ![]() Last edited by j82k; 25th September 2018 at 17:52. |
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#52732 | Link | |||||||||||||||||||
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Join Date: Sep 2006
Posts: 9,137
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Personally, I don't think that's the purpose of HDR. So your question is quite valid. FWIW, the new "report BT.2020 to display" option might help a little, *if* your TV somehow reacts to that. But I suppose most TVs won't. With my projector, SDR is relatively bright, and HDR is quite a bit darker. But that's fine for me. Of course I could try to make SDR darker to match HDR, but what's the point of that? Our eyes adjust very quickly to different brightness levels, at least in a bat cave like mine... ![]() Quote:
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The key difference is that sending PQ means your TV will activate its own HDR -> SDR algorithm. While when sending power/BT.709 gamma, the TV will deactivate it's HDR -> SDR algorithm, and madVR can do that processing instead. Quote:
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For encoding/mastering, dithering doesn't work well. The reason for that is that videos are lossily encoded, and lossy encoders have trouble with noise, grain and dithering. You need to use very high encoding bitrates to make sure that noise, grain and dithering doesn't get completely lost. And even with high bitrates, that stuff still gets lost to some extent. Because of that, for encoding/mastering it's important to have high bitdepth, and PQ helps there, too, with it's more intelligent gamma curves. However, during playback/rendering, the whole chain is fully lossless. There's no lossy compression going on anywhere in between madVR and TV. So every dithered bit should reach the display untouched. As a result, bitdepth is much less important, because madVR's dithering is of very high quality. PQ has the benefit (and curse) of defining an exact nits value for each pixel. But there's not a single consumer display (I know of) that can render BT.2020 10,000nits. So every TV out there has to process the PQ data in such a way that it is fairly represented within the technical limitations of the TV. This process of dumbing the PQ/HDR data down to the capabilities of the TV is usually called "tone mapping". You can let your TV do that, or you can let madVR do that. Which would you rather trust to do this processing in highest quality? ![]() There's no HDR magic going on in TVs. Sending HDR content untouched as PQ to the TV from madVR doesn't magically turn your TV into a HDR miracle. Your TV will simply internally convert PQ to whatever internal format the TV works with. If you let madVR send power/BT.709 gamma to your TV, you simply move the tone mapping from your TV to madVR. That's it. The only difference between an HDR and SDR display is that the HDR TV has a firmware which can do tone mapping. (Ok, some TVs might switch to "overdrive" mode when receiving PQ data.) Quote:
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#52733 | Link | |
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Join Date: Aug 2016
Posts: 1,233
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However if you turn it off it will be off for gaming and TV too where you are most likely yo get static images and therefore burn in. ABL is also something you should not turn off but I have, I just couldnt live with it. I dont doing gaming and I use an all back them / audio hide my taskbar etc etc. So far no problems and my OLED will be 3 years old shortly.
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LG OLED EF950-YAM RX-V685-RYZEN 3600 - 16GBRAM - WIN10 RX 5700 |
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#52734 | Link | |
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Join Date: May 2004
Posts: 4,883
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When using the HDR pixel shader math option the image is EXTREMELY dark. This was reported earlier for v0.9.16 I believe.
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HTPC: Windows 10, I9 9900k, RTX 2070 Founder's Edition, Pioneer Elite VSX-LX303, LG C8 65" OLED |
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#52735 | Link | |
Registered Developer
Join Date: Sep 2006
Posts: 9,137
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#52736 | Link | |
Registered User
Join Date: May 2004
Posts: 4,883
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![]() Separate issue....HDR using pixel shader math (meaning sending HDR as you know) is very dark no matter what it's set to. That's recent to v0.9.16. So two completely different things.
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HTPC: Windows 10, I9 9900k, RTX 2070 Founder's Edition, Pioneer Elite VSX-LX303, LG C8 65" OLED |
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#52739 | Link |
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Join Date: Oct 2016
Posts: 733
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On my plasma I'm setting HDR nits to 200 and it's plenty bright.
I use one of the three calibrated profiles (there's Custom, Pro 1, Pro 2) which I've set to maximum brightness, and manualy select it when I play an HDR movie with madVR.
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HTPC: Windows 10 1909, MediaPortal 1, LAV Filters, ReClock, madVR. DVB-C TV, Panasonic GT60, 6.0 speakers Denon 2310, Core 2 Duo E7400, GeForce 1050 Ti |
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#52740 | Link | |
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Join Date: May 2015
Posts: 18
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The only reason it's on PC mode to begin with is because that's how the calibrator set it up, starting playback and MadVR display mode switching turns the TV into Home Theatre mode and onto the calibrated settings Now that I think about it I could just leave it in home theatre mode all the time For reference, the earlier reply to my post in March about colour differences for HDR in PC vs HT is here: https://forum.doom9.org/showthread.p...56#post1837356 "On 2016 LG Oleds (not sure about 2017) HDR is messed up when using PC HDMI input icon. Not sure what the TV is doing with HDR in pc-mode but it looks as if it was using a wrong color gamut or something like that. I haven't watched mad max in HDR yet, so I don't know how colorful it is but other movies will look desaturated and dull when using pc-mode HDR. " "Home Theater seems to have much better coverage on my TV. It is still mostly 4:4:4 but 4:2:2 shows up more than it does when set to PC, so there is extra processing that has some color blending. Good for video but not great for a monitor or precise chroma upscaling." "Make sure you enable Deep Color on that HDMI input, because my E6 does UHD at 23.976 / 24 on the PC label. However, PC label absolutely ruins HDR on the LG E6, locks settings, and makes it look washed out. You also cannot get 4:4:4 without using the "PC" label. So if you are using the display as both a desktop monitor and an HTPC, gotta switch between PC mode and non-PC mode depending on HDR. It sucks, shame on LG for never fixing it. " So I guess you could leave it on Home Theatre if all you do is watch video's, but my PC is not just a HTPC Last edited by famasfilms; 25th September 2018 at 21:17. |
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Tags |
direct compute, dithering, error diffusion, madvr, ngu, nnedi3, quality, renderer, scaling, uhd upscaling, upsampling |
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