Welcome to Doom9's Forum, THE in-place to be for everyone interested in DVD conversion.

Before you start posting please read the forum rules. By posting to this forum you agree to abide by the rules.

 

Go Back   Doom9's Forum > Hardware & Software > Software players

Reply
 
Thread Tools Search this Thread Display Modes
Old 4th February 2019, 20:42   #54581  |  Link
tp4tissue
Registered User
 
tp4tissue's Avatar
 
Join Date: May 2013
Posts: 654
Quote:
Originally Posted by Warner306 View Post
I wouldn't be against raising the value of reference white slightly for PQ HDR content. The problem is all existing HDR displays are tuned to tone map for a reference white of 100 nits, so I don't know how you would get around that without breaking support for all legacy HDR displays. I don't think HDR is too dark when viewed without ambient light in the room.

I noticed that calibrating to 2.2/2.4 (relative) gamma on LCD is much more similar in appearance to 2.2/2.4 (absolute) gamma (1886) on CRT/Plasma/OLED, vs using absolute gamma (1886) on LCD which makes everything greyish.

So, the near crush dark tones when using relative gamma on LCD is probably Correct. It's just more crush like in home environments where the room light is on.

The moral of the story is, it's suppose to look like that, just turn the lights off.
__________________
Ghetto | 2500k 5Ghz

Last edited by tp4tissue; 4th February 2019 at 20:46.
tp4tissue is offline   Reply With Quote
Old 4th February 2019, 22:00   #54582  |  Link
SamuriHL
Registered User
 
SamuriHL's Avatar
 
Join Date: May 2004
Posts: 5,019
Shockingly 418.82 didn't break HDR switching. LOL
__________________
HTPC: Windows 10, I9 9900k, RTX 2070 Founder's Edition, Pioneer Elite VSX-LX303, LG C8 65" OLED
SamuriHL is offline   Reply With Quote
Old 4th February 2019, 23:14   #54583  |  Link
tp4tissue
Registered User
 
tp4tissue's Avatar
 
Join Date: May 2013
Posts: 654
Weird Gamut behavior.

So on my ATI card, my spare bedroom tv reports a slightly wider Gamut +10% vs my Nvidia Card.

Is it because the Nvidia card is using the alpha channels differently ?

Does madvr use alpha channels in output or only 24bit.
__________________
Ghetto | 2500k 5Ghz
tp4tissue is offline   Reply With Quote
Old 4th February 2019, 23:16   #54584  |  Link
nevcairiel
Registered Developer
 
Join Date: Mar 2010
Location: Hamburg/Germany
Posts: 10,098
There is no alpha channel on the output. Different results might be up to dithering.
__________________
LAV Filters - open source ffmpeg based media splitter and decoders
nevcairiel is offline   Reply With Quote
Old 4th February 2019, 23:33   #54585  |  Link
tp4tissue
Registered User
 
tp4tissue's Avatar
 
Join Date: May 2013
Posts: 654
Quote:
Originally Posted by nevcairiel View Post
There is no alpha channel on the output. Different results might be up to dithering.
Hrrrm..

I guess that must be the tv's gamut clamping software intervening with the nvidia output.

Is there a fundamental output difference between ATI and Nvidia, some sort of flags ??

Because both these cards are setup for 8bit rgb, yet the ATI results in the +10% , quite large a swing.
__________________
Ghetto | 2500k 5Ghz
tp4tissue is offline   Reply With Quote
Old 4th February 2019, 23:46   #54586  |  Link
huhn
Registered User
 
Join Date: Oct 2012
Posts: 7,017
nvidia has full support for the HDMI content type so try that. afaik AMD doesn't have an option for that maybe in registry like so many more options.
huhn is offline   Reply With Quote
Old 4th February 2019, 23:49   #54587  |  Link
tp4tissue
Registered User
 
tp4tissue's Avatar
 
Join Date: May 2013
Posts: 654
Quote:
Originally Posted by huhn View Post
nvidia has full support for the HDMI content type so try that. afaik AMD doesn't have an option for that maybe in registry like so many more options.
What do you mean by hdmi content type.

I've set both outputs to RGB 32bit 8 bit full based on your previous recommendation ?
__________________
Ghetto | 2500k 5Ghz
tp4tissue is offline   Reply With Quote
Old 4th February 2019, 23:49   #54588  |  Link
Warner306
Registered User
 
Join Date: Dec 2014
Posts: 1,127
Quote:
Originally Posted by tp4tissue View Post
Yea, that's what I meant, create an HDR 3Dlut, but ONTOP of Dynamic Tonemapping, output HDR.

Do you know if this feature will be added in the future ?

Seems to be straightforward, is there a specific hitch that it's not already possible ?
I was going to answer your question earlier but missed it.

It is hard to use a 3D LUT this way because DisplayCAL enforces its own roll-off. I don't know how you would do it without excessive doubling processing. The 3D LUT could maybe correct the white balance and white point, but not alter the transfer function with its own roll-off.
Warner306 is offline   Reply With Quote
Old 5th February 2019, 00:00   #54589  |  Link
tp4tissue
Registered User
 
tp4tissue's Avatar
 
Join Date: May 2013
Posts: 654
Quote:
Originally Posted by Warner306 View Post
I was going to answer your question earlier but missed it.

It is hard to use a 3D LUT this way because DisplayCAL enforces its own roll-off. I don't know how you would do it without excessive doubling processing. The 3D LUT could maybe correct the white balance and white point, but not alter the transfer function with its own roll-off.
Why does the tone map function only work with an SDR lut ?

For example, on many tvs, in HDR input mode, the Gamut is larger than its SDR mode.

So, after madvr does the tone map, instead of going to an sdr calibrated table before output, it will go to a wider hdr calibrated table.
__________________
Ghetto | 2500k 5Ghz
tp4tissue is offline   Reply With Quote
Old 5th February 2019, 00:07   #54590  |  Link
el Filou
Registered User
 
el Filou's Avatar
 
Join Date: Oct 2016
Posts: 804
Quote:
Originally Posted by tp4tissue View Post
What do you mean by hdmi content type.
It's an option in HDMI where the source can specify what type of content is sent, e.g. computer graphics/movie/photos/auto.
With NVIDIA you can change that setting in the control panel. Most TVs use a different kind if picture processing depending when that setting is on something other than auto.
__________________
HTPC: Windows 10 20H2, MediaPortal 1, LAV Filters/ReClock/madVR. DVB-C TV, Panasonic GT60, Denon 2310, Core 2 Duo E7400 oc'd, GeForce 1050 Ti 466.27
el Filou is offline   Reply With Quote
Old 5th February 2019, 00:15   #54591  |  Link
huhn
Registered User
 
Join Date: Oct 2012
Posts: 7,017
how do you stop a TV from dynamic tone mapping in HDR mode.

if you do dynamic tone mapping and send this technically wrong image to the TV the TV will do again dynamic tone mapping making it even more wrong so waht'S the point of an 3D LUT here.

just set your Tv up for native gamut or send bt 2020 so it will use the full gamut.

who even told you there is an wider "calibration table" for HDR?

Quote:
What do you mean by hdmi content type.
http://abload.de/img/hdmi-content-typebtumj.png

first result in an search engine
huhn is offline   Reply With Quote
Old 5th February 2019, 00:17   #54592  |  Link
huhn
Registered User
 
Join Date: Oct 2012
Posts: 7,017
Quote:
Originally Posted by el Filou View Post
It's an option in HDMI where the source can specify what type of content is sent, e.g. computer graphics/movie/photos/auto.
With NVIDIA you can change that setting in the control panel. Most TVs use a different kind if picture processing depending when that setting is on something other than auto.
just so you know i have a PC monitor that is resyncing when it is on auto everytime a video is played and stopped.

so auto means nvidia or other software is able to actively change that.
huhn is offline   Reply With Quote
Old 5th February 2019, 02:31   #54593  |  Link
tp4tissue
Registered User
 
tp4tissue's Avatar
 
Join Date: May 2013
Posts: 654
Quote:
Originally Posted by huhn View Post
who even told you there is an wider "calibration table" for HDR?


http://abload.de/img/hdmi-content-typebtumj.png

first result in an search engine

It's not a wider table, but the gamut is wider and different between SDR and HDR modes.

Even in the various different sdr modes, tvs can have different gamuts.



If I set the HDMI content type on AUTO, what is it defaulting to when running madvr (Movie ? or Desktop Program)
__________________
Ghetto | 2500k 5Ghz
tp4tissue is offline   Reply With Quote
Old 5th February 2019, 05:11   #54594  |  Link
huhn
Registered User
 
Join Date: Oct 2012
Posts: 7,017
no clue.

edit: madVR FSE is triggering "games" with FSE and i can't find anything with windowed mode.
is so advance that leaving it will disabled gaming mode in my TV even if i manually enabled it before.
setting the output type to movies in the GPU driver switches my TV into cinema preset(d80 whitepoint close panasonic close call...) and my TV even shows an notification. i didn't find a program that does trigger this in the GPU driver.

so madVR may trigger gaming mode in the nvidia driver which makes sense if you think about it.

Last edited by huhn; 5th February 2019 at 08:28.
huhn is offline   Reply With Quote
Old 5th February 2019, 11:46   #54595  |  Link
chros
Registered User
 
chros's Avatar
 
Join Date: Mar 2002
Posts: 2,156
Quote:
Originally Posted by huhn View Post
edit: madVR FSE is triggering "games" with FSE and i can't find anything with windowed mode.
is so advance that leaving it will disabled gaming mode in my TV even if i manually enabled it before.
setting the output type to movies in the GPU driver switches my TV into cinema preset(d80 whitepoint close panasonic close call...) and my TV even shows an notification. i didn't find a program that does trigger this in the GPU driver.

so madVR may trigger gaming mode in the nvidia driver which makes sense if you think about it.
Interesting finding, thanks, I'll try it out tonight with my old LG TV, maybe ...
__________________
Ryzen 5 2600,Asus Prime b450-Plus,16GB,MSI GTX 1060 Gaming X 6GB(v398.18),Win10 LTSC 1809,MPC-BEx64+LAV+MadVR,Yamaha RX-A870,LG OLED65B8(2160p@23/24/25/29/30/50/59/60Hz) | madvr config
chros is offline   Reply With Quote
Old 5th February 2019, 13:01   #54596  |  Link
Alexkral
Registered User
 
Join Date: Oct 2018
Posts: 255
Quote:
Originally Posted by Warner306 View Post
Soulnight's tool increases or decreases the target nits. Increasing the target nits raises the knee point further up the PQ curve to reduce compression, but it also changes the absolute brightness of all values relative to the output display.
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".
Alexkral is offline   Reply With Quote
Old 5th February 2019, 15:23   #54597  |  Link
Warner306
Registered User
 
Join Date: Dec 2014
Posts: 1,127
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/

Last edited by Warner306; 5th February 2019 at 15:30.
Warner306 is offline   Reply With Quote
Old 5th February 2019, 17:13   #54598  |  Link
Alexkral
Registered User
 
Join Date: Oct 2018
Posts: 255
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.
Alexkral is offline   Reply With Quote
Old 5th February 2019, 17:44   #54599  |  Link
Warner306
Registered User
 
Join Date: Dec 2014
Posts: 1,127
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.

Last edited by Warner306; 5th February 2019 at 17:56.
Warner306 is offline   Reply With Quote
Old 5th February 2019, 19:45   #54600  |  Link
tp4tissue
Registered User
 
tp4tissue's Avatar
 
Join Date: May 2013
Posts: 654
Quote:
Originally Posted by huhn View Post
no clue.

edit: madVR FSE is triggering "games" with FSE and i can't find anything with windowed mode.
is so advance that leaving it will disabled gaming mode in my TV even if i manually enabled it before.
setting the output type to movies in the GPU driver switches my TV into cinema preset(d80 whitepoint close panasonic close call...) and my TV even shows an notification. i didn't find a program that does trigger this in the GPU driver.

so madVR may trigger gaming mode in the nvidia driver which makes sense if you think about it.
How do you find which one it triggers.

My setting box doesn't even have all those options,

I only have Movie, and Desktop Program
__________________
Ghetto | 2500k 5Ghz
tp4tissue is offline   Reply With Quote
Reply

Tags
direct compute, dithering, error diffusion, madvr, ngu, nnedi3, quality, renderer, scaling, uhd upscaling, upsampling

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +1. The time now is 12:44.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.