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5th August 2018, 14:17 | #51961 | Link | |
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Just now madshi is interested in improving HDR->SDR mapping, which development go on at another forum.
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6th August 2018, 01:32 | #51963 | Link |
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Is HDR content (i.e., 4k UHD 10-bit Blu-ray) supposed to look much darker than SDR on an 8-bit monitor, or are my madVR settings causing this problem? As a demonstration:
This is not just one movie, though. Every 4K UHD Blu-ray movie that I've compared with its ordinary 1080p Blu-ray version has had this darkness problem. I have an 8-bit monitor with 300 max cd/m^2 ("nits"). I use madVR with mpc-hc and my madVR's HDR settings can be seen here. My OSD information is here. Any advice would be greatly appreciated Thanks! |
6th August 2018, 08:36 | #51965 | Link | |
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Overall, HDR to SDR will always look a bit darker though. Last edited by AngelGraves13; 6th August 2018 at 08:38. |
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6th August 2018, 08:52 | #51966 | Link | |
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6th August 2018, 13:58 | #51968 | Link |
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HI, got a quick question, since the last few Nvidia drivers , I've lost the bit setting option in the Nvidia panel (8 / 12 bits)
Currently using : GeForce Game Ready Driver 398.82 WHQL Is this correct ? having not bit choice anymore ? Thanks for any reply ;-) |
6th August 2018, 14:22 | #51969 | Link | |
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There are different approaches to tone mapping. BT.2390 happens to be on the harsh side and compresses most of the content range to a lower nits. In the future, more dynamic tone mapping may be available or different tone mapping curves. This should make the image a little brighter. Personally, I've adapted to the darker image and find that the HDR version can have detail that isn't possible in SDR because the brightest information is clipped. Try using a lower target nits and/or brightening your display when watching HDR content. Changing the gamma curve in calibration can also help sometimes. The target nits value is the PQ container and not the brightness of your SDR display. The conversion from PQ to gamma does not translate directly and will vary by display depending on its brightness and gamma curve. Two displays with the same relative brightness can require different target nits.
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HOW TO - Set up madVR for Kodi DSPlayer & External Media Players Last edited by Warner306; 6th August 2018 at 15:57. |
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6th August 2018, 14:27 | #51970 | Link |
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You are probably using the default color settings. Switch to "Use Nvidia color settings." If it is still not there, try a reboot. If still not there, you need to clean and reinstall your drivers.
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HOW TO - Set up madVR for Kodi DSPlayer & External Media Players |
6th August 2018, 14:31 | #51971 | Link | |
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Maybe I overlooked another option (switching to Nvidia colors) I tried DDU a few times , but when logging into Safe Boot (option 4) I get a Stack Buffer Overflow and can't log in to Win ;-( I'm on the Win Insiders program , Skip-ahead ring Many thanks for your suggestion will try it when I get home , if not I'll do a fresh install when the Win Insider ROM's are available again (Redstone 5) |
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6th August 2018, 15:13 | #51972 | Link |
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@ Warner360,
Not sure if it has been covered before, but is there a calculation for target nits? My Samsung KS8000 has a claimed nits of 1,000 in HDR mode, but using the new HDR to SDR algo, anything over a target nits of 125 makes the image too dark.
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6th August 2018, 15:19 | #51973 | Link | |
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There is no current way to calculate this. It may help to label this setting "target HDR nits" or "target PQ nits" because it is unrelated to the brightness of your display. It is a measure of how much compression is applied to the original curve in absolute nits, not relative nits. I have two displays that are around 150 nits. One uses a setting of 350-400 nits, the other 450-500 nits with the same 2.40 gamma curve to achieve similar relative brightness. Your result is nonsense. If you have an HDR display that bright, you wouldn't benefit much from HDR -> SDR, anyways. Passthrough would be the way to go.
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HOW TO - Set up madVR for Kodi DSPlayer & External Media Players |
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6th August 2018, 15:33 | #51974 | Link | |
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Even though I have a HDR display at 1,000 nits, I am comparing the new HDR to SDR algo tone mapping, VS HDR Pass through. Oddly enough, the SDR peak brightness of the set is: SDR Real Scene Peak Brightness : 489 cd/m2 SDR Peak 2% Window : 1116 cd/m2 SDR Peak 10% Window : 1332 cd/m2 SDR Peak 25% Window : 723 cd/m2 SDR Peak 50% Window : 528 cd/m2 SDR Peak 100% Window : 532 cd/m2 SDR Sustained 2% Window : 296 cd/m2 SDR Sustained 10% Window : 644 cd/m2 SDR Sustained 25% Window : 522 cd/m2 SDR Sustained 50% Window : 538 cd/m2 SDR Sustained 100% Window : 530 cd/m2 But thanks for your response. K
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LG OLED55BX6LB, Zidoo Z1000 Pro, Yamaha RX-A3060, Polk Signature Fronts & Centre, Wharfedale D300 Atmos surrounds, Polk Signature HTS 10 Sub, DSPeaker Antimode 8033 Cinema Last edited by oldpainlesskodi; 6th August 2018 at 15:45. |
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6th August 2018, 16:04 | #51975 | Link |
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If you convert to SDR and then display on a HDR display and want a HDR-like representation, you would have to manually massively increase the brightness, if the display even lets you reach HDR-levels, because HDR peak brightness is not designed for that in many cases. But that would make normal SDR content quite overly bright, so you would have to compensate for that as well.
Basically, if your display is properly calibrated for SDR content, then converting HDR to SDR should probably use a low nit value, because thats what your TV is setup for. You would have to re-calibrate the TV if you want to target a higher peak brightness in SDR mode. And of course remember to use a 3DLUT for example to restore SDR to its normal brightness. Its a bit of an annoying combination to setup, and if your TV can display HDR properly, using pass-through would be better.
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LAV Filters - open source ffmpeg based media splitter and decoders Last edited by nevcairiel; 6th August 2018 at 16:07. |
6th August 2018, 16:20 | #51976 | Link |
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Using that combination with an HDR display is definitely problematic. HDR presentation at SDR brightness is very difficult to calibrate and the gamma curve makes it even more difficult. Using a low peak nits stacks values too close together and leads to a very flat image appearance and a lack of detail, as well as problems with color. Achieving an HDR presentation at SDR brightness means using a slightly higher peak nits and living with a low value for reference white (100 nits). Most of the original contrast will still be there, but the image will be darker. Not all movies are terribly dark and some match the Blu-ray reasonably well and come with more refined detail, even when downscaled. It depends on the metadata.
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HOW TO - Set up madVR for Kodi DSPlayer & External Media Players |
6th August 2018, 16:52 | #51977 | Link |
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@ Nevcairiel.
Yes, all very true, but as you alluded to, it depends on the set and calibration. Besides projector owners, and owners of SDR displays, there are people with HDR displays that will possibly choose the new HDR to SDR algo, because often the TV manufacturers HDR tone mapping algos are extremely poor. At 125 target nits, and I get more (perceived?) contrast, more pleasing (accurate?) tone mapping and detail than straight HDR passthrough. An example of this is the HDR version of Arrival at 18.02. In HDR mode, there is a loss of contrast and detail in the backround of the helicopter cabin on my TV, but not with the HDR to SDR algo set at 125 nits. As always, it's down to the combination in setup and preferences. K
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LG OLED55BX6LB, Zidoo Z1000 Pro, Yamaha RX-A3060, Polk Signature Fronts & Centre, Wharfedale D300 Atmos surrounds, Polk Signature HTS 10 Sub, DSPeaker Antimode 8033 Cinema Last edited by oldpainlesskodi; 6th August 2018 at 17:33. Reason: Typo |
6th August 2018, 17:50 | #51978 | Link | |
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I feel stupid about this, I wasn't connected to my 4K HDR OLED , but to my 1080P monitor (DVI connected) :-( Many, many thanks ! |
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6th August 2018, 19:47 | #51979 | Link | |
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6th August 2018, 21:20 | #51980 | Link |
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@oldpainlesskodi
I have UE equivalent of KS8000, and using latest test builds madVR tonemapping gives me much better results than passtrough. Set the TV in either "Film" or "Game" mode, set the backlight to 20 and smart LED to High, then set peak target nits in madVR to 1000 if you want HDR, or backlight to 4 and target nits to 480 if you want SDR-like image. |
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direct compute, dithering, error diffusion, madvr, ngu, nnedi3, quality, renderer, scaling, uhd upscaling, upsampling |
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