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#54601 | Link |
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Join Date: Oct 2018
Posts: 131
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Actually what you are changing with the target peak nits parameter is the absolute (only relative to the mastering display luminances) value of the knee point, which affects all the values above it. After that, all the image values need to be normalized to the [0, 1] SDR relative range, which raises the global brightness. That's why I thought that the dynamic curves where doing the same, but after reading in more detail the specs this doesn't seem to be the case. For Dolby Vision the target luminances don't change, but for HDR10+ there is indeed a parameter called TargetedSystemDisplayActualPeakLuminance which is a 2D LUT that affects all values, and is intented to take into account the "peak luminance that a display is capable of delivering while rendering the scene", which "depends on the spatial distribution of the luminance levels of the pixels in the scene and the power consumption limits of the display".
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#54602 | Link |
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Join Date: Dec 2014
Posts: 1,126
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I have no idea what that means. But the knee point is just the point on the original PQ curve where the tone mapping curve begins. Values above the knee point are rolled-off or reduced in brightness. The shape of the tone curve determines how much values are rolled-off. It isn't really magic. Each luminance value is lower than the original by an increasing amount up to the display peak.
Dolby Vision would just provide formulas for different displays to reduce the overall dynamic range of the source for each scene based on a content flag indicating the peak brightness of the scene. It probably wouldn't be that different than what madVR is already doing. Tone mapping uses pretty standard formulas. It just needs to know how bright the input is in order to compress it. This is what a 700 nits tone curve might look like: https://i.postimg.cc/4NQWBHtC/PQ-Tone-Mapping-Curve.jpg There is also an article here on tone curves: https://www.insightmedia.info/should...-the-pq-curve/
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HOW TO - Set up madVR for Kodi DSPlayer & External Media Players Last edited by Warner306; 5th February 2019 at 15:30. |
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#54603 | Link |
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Join Date: Oct 2018
Posts: 131
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Ha ha, I read that article yesterday, really.
I don't know what you didn't understand so I can't help, but as you said it isn't really magic. I've written a pixel shader implementing the curve, so I know how it works, and it's not very difficult to at least get an idea of the process by just looking at the maths. https://www.itu.int/dms_pub/itu-r/op...2018-PDF-E.pdf It only doesn't include the last scaling step. Last edited by Alexkral; 6th February 2019 at 06:24. |
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#54604 | Link |
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Join Date: Dec 2014
Posts: 1,126
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I've seen that. Honestly, to a lay person that article is just nonsense. Tone mapping intelligently compresses luminance. It doesn't do much more than that.
madVR is tone mapping in PQ nits as per BT.2390 to a target display brightness. But this has to be converted to an SDR gamma curve. The gamma curve should always provide an optimum result within its actual target brightness, but it is often better to use the relative gamma curve to spread out BT.2390 (go above the display target brightness) to get more contrast. Changing the target nits kind of makes the PQ curve disappear because the mapped values are no longer 1:1 with BT.2390 in terms of absolute luminance, but it works because the gamma curve increases or decreases overall contrast in a uniform manner.
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HOW TO - Set up madVR for Kodi DSPlayer & External Media Players Last edited by Warner306; 5th February 2019 at 17:56. |
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#54605 | Link | |
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Join Date: May 2013
Posts: 408
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Quote:
My setting box doesn't even have all those options, I only have Movie, and Desktop Program ![]()
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#54606 | Link |
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Join Date: Oct 2016
Posts: 546
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I also only have those two. Probably depends on what the display advertises, but my TV settings have the same ones listed here (they can be allowed or denied individually for use with the auto mode): https://www.hdmi.org/manufacturer/hd...tent_type.aspx
As with all 'automagic' features it can be difficult to find out what changes are applied and when.
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HTPC: Windows 10 1809, 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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#54607 | Link |
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Join Date: Mar 2002
Posts: 1,504
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It's the same here with my Tv, and the TV doesn't do anything different when I select any of those
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Ryzen 5 2600,Asus Prime b450-Plus,16GB,MSI GTX 1060 Gaming X 6GB(v385.28),Win10 LTSB 1607,MPC-BEx64+LAV+MadVR,Yamaha RX-A870,LG OLED65B8(2160p@23/24/25/29/30/50/59/60Hz) |
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#54608 | Link | |
Registered User
Join Date: Oct 2012
Posts: 5,964
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Quote:
it only cared about movie and games the rest did do anything at least i couldn't find it. games option activates gaming mode on my screen. and movies option switched my preset to cinema. why photo or graphics doesn't change the preset to the graphic or photos i don't have a clue. if in doubt GPU driver bug. with auto madVR will activated gaming mode in FSE so it has to be gaming. |
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#54610 | Link |
Registered Developer
Join Date: Mar 2010
Location: Hamburg/Germany
Posts: 9,833
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Never turn off any dithering.
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LAV Filters - open source ffmpeg based media splitter and decoders |
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#54611 | Link |
Registered User
Join Date: Dec 2002
Posts: 5,494
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LAV only dithers when it has to convert the output format. If you use madvr and don't deactivate any of the default output formats in LAV Video this basically never happens. Like nevcairiel said: never turn off dithering in madvr. It's necessary as madvr does all kinds of processing (like chroma upscaling) in high bitdepth.
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#54612 | Link |
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Join Date: Apr 2015
Posts: 60
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@Manni
Would you please check if 418.81 passthrough still sends bogus metadata? Edit: You have already answered that in another thread, Thanks!
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ZOTAC MAGNUS EN1060K: Win 10 x64 + Kodi DSPlayer x64 LG OLED65C8 / Denon AVR-X3200W / KEF E305+ONKYO SKH-410 / Synology DS2415+ / Logitech Harmony 950 Last edited by sat4all; 7th February 2019 at 22:50. |
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#54613 | Link | |
X Cinema Projectionist NZ
Join Date: Feb 2006
Location: Auckland NZ
Posts: 280
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Quote:
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#54615 | Link |
Registered Developer
Join Date: Mar 2010
Location: Hamburg/Germany
Posts: 9,833
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Most people should probably never touch any of the dithering settings, and they would get an optimal experience that way even.
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LAV Filters - open source ffmpeg based media splitter and decoders |
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#54616 | Link | |
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Join Date: May 2013
Posts: 408
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Quote:
I've always wondered, because it always looks the same on output, so I just assumed madvr was doing everything ?. ![]()
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#54619 | Link |
X Cinema Projectionist NZ
Join Date: Feb 2006
Location: Auckland NZ
Posts: 280
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I have the new JVC NX9 projector and want to try using the pixel shader tone mapping in madvr rather than the auto tone mapping in my NX9. However since Im new to this and dont understand, what "target peak nits" setting should I use on madvr for my NX9 projector? Thank you in advance...
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#54620 | Link |
Registered User
Join Date: May 2004
Posts: 4,322
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Looks like that projector is somewhere around 185 nits max. I could be off so hopefully someone else chimes in that knows what they're talking about (hint not me! LOL)
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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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Tags |
direct compute, dithering, error diffusion, madvr, ngu, nnedi3, quality, renderer, scaling, uhd upscaling, upsampling |
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