madVR - high quality video renderer (GPU assisted) [Archive] - Page 1267

bob88

15th July 2022, 19:10

What Samsung display do you have, what cable type are you using and which output are you connected to?

This is my projector:
https://www.samsung.com/us/televisions-home-theater/tvs/4k-laser-projectors/120-the-premiere-4k-uhd-hdr-smart-tv-2020-sp-lsp7tfaxza/

This is the cable:
https://www.ebay.com/itm/381457457295?hash=item58d0a2e08f%3Ag%3A16gAAOSwi8pfLSr5&LH_BIN=1

I have it connected to a GeForce RTX 3060Ti

This is the projector info from madVR:
https://imgbb.com/pLmWb49

Its all very expensive equipment and I would like to be able to use it at its full capacity.

As far as I understand even if the projector is HDMI 2.0 it would still allow 12bit at 60Hz...
I would like to resolve this. If it is the cable I could get a refund and replace it...
I just dont know what the issue is.

PS: Just found it in the manual that it should support 60Hz and 10 bit 4:2:2.
Also saw it mention that for best results cable should be less than 3m long. Mine is 3m long... Could that be the issue?

JaylumX

15th July 2022, 21:26

Your PJ device has 3x HDMI 2.0 so if you want 10 bit colour, setting it to 4:2:2 is the only way the achieve that which you did. One of the other guys mentioned this on reading the previous post.

Metaphorically speaking, the hdmi cable you have can allow a "mutant sized watermelon" to passthrough it but unfortunately your PJ device's hole is three times smaller and thus is not large enough for the watermelon to pass. Limitation of hdmi 2.0 unfortunately.

el Filou

15th July 2022, 23:16

Its all very expensive equipment and I would like to be able to use it at its full capacity.You're currently using it at its full capacity.
Unfortunately price is no indication of technical capabilities.PS: Just found it in the manual that it should support 60Hz and 10 bit 4:2:2.Some more information:
- madVR and Windows work with RGB internally, and in most cases it's better to output in RGB.
- RGB uses the same bandwidth as YCbCr 4:4:4, and as your projector supports only 4:2:2 maximum at 10-bit it won't support 10-bit RGB either.
- madVR's dithering is *very* good, so even in 8-bit it's still very good, and as huhn already told you the possibility that you get better picture quality by setting the NVIDIA to YCbCr 4:2:2 10-bit instead of RGB 8-bit is slim to nonexistent.
But you can still try it and check if you can see a difference, it's worth a try.
- If you switch to 24 Hz (not 30!) for movies you could run RGB at 10-bit (or even 12), but there has been stories of NVIDIA cards getting stuck in 8-bit again as soon as you switch back to 60 Hz (which is best to avoid a stuttery UI navigation), so no guarantee (maybe other people can chime in).

bob88

16th July 2022, 00:47

Oh dudes I finally got it. :D
After having it at 60Hz you have to set it to 4:2:2 8bit, click apply and only then do you get the option to make it go to 10 bit. So yeah finally its at 60Hz 10bit 4:2:2 as according to the projector specs. I can actually even make it go up to 12bit.
It seems its only limited to 10bit if it is 4:2:0...
So please excuse my ignorance but to sum it up my best settings would be 60Hz 12bit 4:2:2 right?
However at that setting I only have the option of a limited output dynamic range. Whereas at RGB 8bit it was Full dynamic range.
I guess you will say thats how its supposed to be...
So now in madVR setting "the display expects the following RGB output" should I set it to TV levels? Or is that option irrelevant at this point?
I also have RGB output levels setting in LAV video decoder settings. Should that also be at TV levels? Or "untouched" setting?
Thank you guys for all your help. I dont know what I would do without you. :)

PS:
So this is the info I get in MPC now:
https://i.ibb.co/tXrQ4Vg/Screenshot-2022-07-16-030228.png (https://ibb.co/k1C5xNj)

I notice it says D3D11 8bit... So is it 10bit now? Is it 8, 12?

.m4jX

16th July 2022, 03:25

So please excuse my ignorance but to sum it up my best settings would be 60Hz 12bit 4:2:2 right?

However at that setting I only have the option of a limited output dynamic range.

So now in madVR setting "the display expects the following RGB output" should I set it to TV levels? Or is that option irrelevant at this point?

I also have RGB output levels setting in LAV video decoder settings. Should that also be at TV levels? Or "untouched" setting?

I notice it says D3D11 8bit... So is it 10bit now? Is it 8, 12?

If you're sending 4:2:2 your PJ is doing some chroma scaling instead of madVR. There's no "best" with 60Hz, either lose 10bit and gain madVRs 4:4:4 chroma scaling or lose chroma and get 8bit -> 10bit. (or set to 23.976Hz and get both)

It's basically gonna depend on what looks better on your specific PJ.

There is no full range with YCbCr, so you should set TV levels. Though once again, this depends on your PJ. Should be easy to spot if it's wrong though, just watch a dark scene and look at the black levels while switching levels with the keyboard shortcut.

LAV video decoder settings shouldn't matter, just leave it at untouched.

Right now you're not seeing 10bit, did you take the screenshot in fullscreen?

If it's working properly, it should switch from "D3D11 windowed (8 bit)" to "D3D11 fullscreen windowed (10 bit)" once you go fullscreen. (Not really sure about win11 though)

bob88

16th July 2022, 12:11

Well I wouldnt want to go down on the refresh rate because I use this for windows also...
Im not sure why you say the projector will be doing scaling at 4:2:2 when that is supported by the projector. Although all the movies I have are 4:2:0 so not sure if it would matter that its 4:2:2 12bit... Maybe I should just switch to 4:2:0 10bit so it matches the source...?
D3D11 fullscreen windowed still says 8 bit... :(
I tried using Ctrl+Shift+Alt+Y to switch PC and TV levels. I am seeing a difference. PC levels gives darker black. But strangely even after clicking F2 to save the changes it does not change the setting in madVR->projector->properties->output levels. So not sure what Im changing with this if not that... Simultaneously changing output levels in the madVR window causes no difference.

clsid

16th July 2022, 13:00

You obviously don't have any clue how any of this works. So I am just telling you what is best to do so you can stop wasting your own and everyones time.

Output in RGB 4:4:4 60Hz 8-bit full range.

MadVR can automatically switch refreshrate. So you could also use 24Hz 10-bit.

bob88

16th July 2022, 13:27

You are right I dont understand. I am not a video expert. Im just a cancer kid who by some miracle got some money and bought a projector. I just wanted to make it look good. I thought it should be 10bit since everything else is 10bit. Sorry for wasting your time. I wont bother you anymore. Thank you.

huhn

16th July 2022, 16:24

this is a thread about madVR not to setup devices.
just make your own thread and there is a good chance you will get the help you need.

don't change settings you don't understand.

bob88

16th July 2022, 16:52

Currently the only issue that I have is this. If it is not a madVR issue I will happily go ask somewhere else. But I just dont know....

https://i.ibb.co/WxHrJkW/Screenshot-2022-07-16-184926.png (https://ibb.co/bW649sg)

clsid

16th July 2022, 17:22

Outputting 4:2:0 (reduced chroma) is stupid because MadVR always outputs RGB (4:4:4 full chroma). So you are just adding another conversion step. Also you are using the most performance expensive algorithm in MadVR (NGU very high) to upscale the chroma, just to downscale it again later.

NGU very high is pointless to begin with. No visual difference with just "high".

huhn

16th July 2022, 17:27

you have far bigger problems now but it's been talk about before and you don't seem to care about other user answer/advices.

it will not work on windows 11 out of the box. so are madVR level output (luckily for you because setting it to limited is nearly always wrong with ycbcr it is always wrong). yes it is so broken i can't help you.

the difference between 8 and 10 bit is dither noise that's it pretty much it but with 420 compare to 444 you are literally throwing halve the image away.

el Filou tried it in detail already i don't see a reason to repeat this post.

is not recommended to use OS HDR at all.
it's not even recommended to send HDR to PJ in the first place.

but i guess you will just ignore this again...
like with the scaling you now apply. as you said you don't understand this but you do it anyway for some reasons.

bob88

16th July 2022, 20:35

I do not want to ignore your advice. I just cant understand how setting it to 8bit is better than having 10bit... But OK I will just set it to RGB and have it 8bit. By the way it does not say anywhere that its 444 but hopefully it is. I will believe in you and that you say its better this way.
I will keep NGU very high because one of the main reasons I bought a powerful GPU is to get the most out of post-processing. It does not load it up to 100% so its not a problem.
As for OS HDR I just did some tests and determined that there is visually no difference between having it off or on. However I did notice that when I made the screenshot of it being off and on there is a significant difference in the screenshot:
https://i.ibb.co/2h3xSY2/off.png (https://ibb.co/NC25rnh)
https://i.ibb.co/SvtfpSS/on.jpg (https://ibb.co/mz9N7pp)
What I see in actuality in both cases is like the dark image when its off. But while I was doing the switch and testing it I did notice the image very briefly go as bright as you can see in the "on" screenshot. So Im beginning to think that its never been actually on and I have not seen HDR yet. (PS: I copied the file to a flash drive and played it through the projector and it gives the same image as the darker screenshot so perhaps HDR is working fine and the brighter screenshot is just some overexposed defect...)
As for your suggestion not to send HDR to the projector at all - I dont understand. What should I set in madVR HDR settings? I would like to have OS HDR on so I can have HDR in youtube and in games and stuff... But if it is a problem I will turn it off.
As for your complaints about Win 11 - Im on your side. Its crap as always. Do you think it would be working better with Win 10? I am potentially willing to reinstall... but hope its not really necessary...

PS:
Here is a bunch of screenshots of settings if you think there is anything else I should change. I promise I wont argue with you and just do as I am told. :)

https://i.ibb.co/RvdsDHn/Screenshot-2022-07-16-225113.png (https://ibb.co/kHvwScn)
https://i.ibb.co/5jWqz7Q/Screenshot-2022-07-16-225132.png (https://ibb.co/vdx2rtN)
https://i.ibb.co/R4p70rN/Screenshot-2022-07-16-225216.png (https://ibb.co/prvnzVQ)
https://i.ibb.co/bLcWnQh/Screenshot-2022-07-16-225240.png (https://ibb.co/S0Fsp5T)
https://i.ibb.co/r6CnfjX/Screenshot-2022-07-16-225253.png (https://ibb.co/KqMCzP8)
https://i.ibb.co/YLk2RYC/Screenshot-2022-07-16-225308.png (https://ibb.co/1mqZvhg)
https://i.ibb.co/93KB5Yj/Screenshot-2022-07-16-225320.png (https://ibb.co/BKWvMsR)
https://i.ibb.co/7YhMwZd/Screenshot-2022-07-16-225331.png (https://ibb.co/r798CzR)
https://i.ibb.co/CWj1sW5/Screenshot-2022-07-16-225346.png (https://ibb.co/7b3YNbJ)
https://i.ibb.co/jgSZqgp/Screenshot-2022-07-16-225436.png (https://ibb.co/NZMnfZ4)
https://i.ibb.co/7jrVqNG/Screenshot-2022-07-16-225447.png (https://ibb.co/HBGYjpr)
https://i.ibb.co/NFfyZVh/Screenshot-2022-07-16-225515.png (https://ibb.co/9pBrs8X)
https://i.ibb.co/XJWfcHH/Screenshot-2022-07-16-225529.png (https://ibb.co/zfmWqdd)

PPS:
OK I thought about it a lot. I think I understand why its better to have RGB 444 rather than 10bit. I also fixed my obviously wrong settings for the dithering by disabling the 2 additional options which I had on.
I set madVR HDR to let madVR decide (so if its wrong it wont be my fault). haha!
Please forgive me but Im gonna keep the OS HDR since it causes no visible difference and enhances other stuff.
I am really sorry for being so annoying. I am working hard on being a better person. I guess I have a log way to go. Thank you very much for your help. God bless you. :)

SirMaster

18th July 2022, 16:40

MadVR can automatically switch refreshrate. So you could also use 24Hz 10-bit.

While you can easily auto-switch refresh rates, I didn't think switching bit-depths automatically worked.

Obviously switching from 24Hz 10-bit to 60hz 8-bit will work as the 60Hz will be forced to 8-bit. But switching back to 24Hz then keeps 8-bit in my experience.

I'm totally OK using 8-bit, but just observing how it's always seemed to operate for me.

chros

18th July 2022, 18:03

It works this way with the ancient nvidia driver I use.

huhn

18th July 2022, 18:19

older driver never cared about the option in the first place.
if you where throwing 10 bit at the driver and it was possible to send 10 bit it will do it.

clsid

18th July 2022, 20:48

I see lots of issues in those settings. Mistakes that many novices make.

Disabling everything on the "trade quality for performance" tab can give major performance issues. With "scale chroma separately" as most common cause.

A high number of frames rendered in advance can give stuttering with NVIDIA GPUs. Recommended value is 1.

Don't enable AYUV in LAV Video. It is disabled by default for good reason. Also do not change the RGB output setting. Don't disable deinterlacing mode.

igvk

19th July 2022, 20:26

How to troubleshoot when madVR fails to automatically set display video mode to one of the modes from the list (differing only in refresh rate)?
It worked for old display, but fails to do so when I changed video card.

The modes can be changed manually to the required refresh rate, but not by madVR.
I tried both latest stable and beta versions.

List of modes is like this:
2560x1600p23, 2560x1600p24, 2560x1600p25, 2560x1600p29, 2560x1600p30, 2560x1600p50, 2560x1600p60

Here is log file from beta 159:
18156

Klaus1189

19th July 2022, 20:32

As already posted many times before, but this thread is ridiculous long, only use 23, 24, 50, 59 and 60, do not use 29 and 30

huhn

19th July 2022, 20:32

windows 11 ?

igvk

19th July 2022, 20:48

Yes, Windows 11.
It worked previously with the same list of modes.

Now I tried to leave only one mode in the list: 2560x1600p50.
It doesn't switch to it.

huhn

19th July 2022, 20:52

on newer window 11 version the device tab will not work properly.
they are mapped to wrong displays.

on my win 11 system i have to use the device setting of a TV that is not connected to control both my displays.
the device settings of both my displays are utterly ignored.

igvk

19th July 2022, 21:04

The device tab looks correct at first glance, though somehow identification items get duplicated multiple times.
So, it's a bug in madVR?

huhn

19th July 2022, 21:08

don't know should be madVR could be windows.
i'm not aware of a different software doing things like this to verify.

igvk

19th July 2022, 21:23

I tried setting the same list of modes to the first (inactive) device in the devices tab.

And it finally worked for the main display.

Looks like a bug.

igvk

19th July 2022, 21:29

And there is another bug:

If I change this list to 1080p50, 1080p60, 2560x1600p50, 2560x1600p60 - it stops working.

Not good.

fotb

21st July 2022, 18:26

Hello all,

Is the HDR to SDR conversion setting only available on version 0.92.11? I am currently using test build 132 and I dont see that option.

Can HDR to SDR conversion be done with a string of rules? If so, can someone provide me with one?

Thanks in advance!

el Filou

21st July 2022, 21:05

Go to "trade quality for performance" settings page and uncheck "don't measure HDR frame peak luminance"

bob88

27th July 2022, 19:37

Hello, :)
Quick question. I think the highlights on my projector are washed out. Thought the problem could be perhaps the fact that windows reports my projector as 1499 nits. So considering I have windows HDR off is madVR affected by windows' peak luminescence settings or is it independent?
10x! :)

el Filou

27th July 2022, 20:40

tony359

27th July 2022, 22:32

A little help on an HDR newbie please!

I have got a old LG C7 OLED and I am learning about HDR calibration and everything.

I am trying to get my HTPC up to speed to be able to play HDR from it. As I only have a 1050ti, I got a DisplayPort -> HDMI 2.1 adaptor which seems to work well(ish) as I am now 4K HDR 4:4:4.

I see that Windows 10 is implementing HDR not the best way. Anyways, I've managed to get HDR when playing MPC-HC with MadVR.

The issue is that the colour gamut is smaller than rec709 and I do not understand why. I have disabled calibration in MadVR, the TV shares the same profile between the PC and the internal Player.

However, the internal player does P3 as expected (green is a bit short of that but it's a 2017 OLED!) while the PC is barely reaching REC709.

See pictures attached.

Besides that, I am getting the full brightness as expected from both the PC and the LG player.

Can someone please help me? I've tinkered with all possible options (particularly in the HDR section of MadVR) I can think of and I am running out of ideas.
One thing I noticed is that MadVR refuses to fo FSE - but I am reading inconsistent opinions on the internet about whether that's a good or a bad thing.
Thank you for your help!

Update: Been tinkering with this for a few days and I have just discovered something. The DP->HDMI adaptor manufacturer sent me a new FW to try to fix Atmos issues. The new FW somehow does something and I cannot enable 12bit colours anymore, 8bit is the max. With 8bit, colours are ok-ish. Still not as saturated as the LG player but very close.

So the question is: is this a software but or is this an issue with the adaptor? I'd like to think that the adaptor won't change my colours...

bob88

28th July 2022, 01:16

madVR doesn't care about that, that's why you have to tell it the actual peak nits in the settings ("display peak luminance").
And it measures each frame to find out the actual luminance of the content.

I cound not find a "display peak luminance" setting in madVR...
where is it supposed to be?
Calibration? - I have it at disable calibration controls for this display.

huhn

28th July 2022, 03:51

I am trying to get my HTPC up to speed to be able to play HDR from it. As I only have a 1050ti, I got a DisplayPort -> HDMI 2.1 adaptor which seems to work well(ish) as I am now 4K HDR 4:4:4.
but the TV is HDMI 2.0
just send UHD 60 444 or risk the RGB.

The issue is that the colour gamut is smaller than rec709 and I do not understand why. I have disabled calibration in MadVR, the TV shares the same profile between the PC and the internal Player.

However, the internal player does P3 as expected (green is a bit short of that but it's a 2017 OLED!) while the PC is barely reaching REC709.

See pictures attached.
upload it somewhere else so we can look at it.

Can someone please help me? I've tinkered with all possible options (particularly in the HDR section of MadVR) I can think of and I am running out of ideas.
One thing I noticed is that MadVR refuses to fo FSE - but I am reading inconsistent opinions on the internet about whether that's a good or a bad thing.
Thank you for your help!
windows HDR is off yes?

Update: Been tinkering with this for a few days and I have just discovered something. The DP->HDMI adaptor manufacturer sent me a new FW to try to fix Atmos issues. The new FW somehow does something and I cannot enable 12bit colours anymore, 8bit is the max. With 8bit, colours are ok-ish. Still not as saturated as the LG player but very close.

So the question is: is this a software but or is this an issue with the adaptor? I'd like to think that the adaptor won't change my colours...

do yourself a favour use HDMI.

tony359

28th July 2022, 08:50

but the TV is HDMI 2.0
just send UHD 60 444 or risk the RGB.

ahhhh... So wait a minute, I could not enable HDR in Windows and I assumed it was because of lack of bandwidth. I was also maxed out at 4:2:0. My video card is HDMI 2.0b as well, so do I need the higher bandwidth?

So I assume that when going 12bit I am somehow going over the max bandwidth allowed by the TV and somehow colours are bit reduced to compromise?

When you say "just send UHD 60 444" do you mean "420"?

upload it somewhere else so we can look at it.

you mean the picture I attached on my previous message?

windows HDR is off yes?

I believe I tried with both ways. Is that preventing FSE from happening?

do yourself a favour use HDMI.

I cannot disagree with you. But I thought that for HDR 4:4:4 I needed that extra bandwidth which my video card doesn't have?

Thank you a lot for your help!!

Sunspark

28th July 2022, 09:13

do yourself a favour use HDMI.

They already are.. a dp-to-hdmi active adapter is the same thing.

On systems with an integrated GPU a single chip handles the output to both the hdmi and dp ports.

huhn

28th July 2022, 09:56

your TV doesn't have the bandwidth
try 8 bit 444 or RGB there are multiply reports of subpar RGB processing on older LG TV.

ignore FSE.

tony359

28th July 2022, 10:36

Let me answer my own questions:

1. I can do 4K 444 8bit HDR with my existing HDMI setup, no need for extra bandwidth. I reckon the cable I used to test before was not good. I've just had a fiber HDMI cable through my door (it's a long one) and I hope that works too. In short: no need for the DP-> HDMI adaptor.

2. Yes, enabling Windows HDR prevents FSE from working. I disabled it and it works.

3. Currently I am going 4K HDR 444 60Hz. MPCHC will display wrong colours when in windowed mode, but will work properly when in FSE. I checked the colours and they match what the LG can do. Brightness finally seems to be correct (as in: matching what the LG can do without tone mapping)

So far so good, thanks huhn for your help as usual. You also saved me some money on the DP adaptor!

Next step, calibrating this thing, which I am somehow unable to do. DisplayCal forum is a bit quiet these days though...

Thanks again!!!

Missed the "ignore FSE" thing. You say it's not important?

SunSpark
You are correct. Still, I feel that removing an adaptor with its own FW and potential glitches can't be a bad thing. If my TV doesn't have the bandwidth anyways, then it's pointless. Again, I think I was misled by a bad cable as Windows would refuse to engage HDR on my previous tests. With a different cable all seems to be working correctly in UHD 60hz 444.

bob88

28th July 2022, 20:08

Sorry I cound not find a "display peak luminescence" setting in madVR.
The only thing related which I can find is "peak nits" under "tone map HDR using 3DLUT". Is that what I am supposed to be using?
It asks for a 3DLUT file. I have no idea what that is or where to find it. Its not provided at the official website.
Im sorry I dont want to be annoying again. I just have no idea how its supposed to be set.
PS: Sorry I guess I didnt see it. There is also "target peak nits" under "tone map HDR using pixel shaders". However nothing I change there seems to have any effect on the picture... Actually none of the HDR options in madVR seem to have any effect. Its all the same regardless of what I change.

Freekystar

28th July 2022, 20:48

https://user-images.githubusercontent.com/108274310/181617624-adde24d4-0d7d-4ef1-b9f6-bd99df32dcce.png
https://user-images.githubusercontent.com/108274310/181617800-b72891ad-d0b8-40f4-bb8f-cac79429b5cc.png

MPC-HC: 1.9.2.2
CPU: i9-9900k
GPU: 2080TI - Drivers: 516.59
OS: Windows 10
MadVR: Yes, version 0.9.2.17
KB5011831: Not installed or at least not visible in installed updates, probably merged with another update. The most recent Windows Update is from 13-07-2022: **KB5015807**

I have not updated my graphics drivers or anything else related to video- or audio-playback or it's devices.

For some reason I'm getting this error occasionally while going from full-screen to windowed by double-clicking on the screen, I tried different versions of MPC-HC 1.9.21.2 and 1.9.20 but it also seems to happen in those. Strangely enough today is the first time I've noticed this happening as I do this switching quite often.

When I change the Video Renderer to Video Mixing Renderer 9 (renderless) it doesn't seem to happen, but then again there is no specific set amount of clicks I have to do for it to happen in the first place, it can happen after doing it just the one time while I'm watching something but it can also happen after spam clicking for a minute or perhaps a bit longer.

Does anybody else experience this and can you reproduce it as well by going full-screen and spam clicking to pause/unpause with MPC-HC 19.2.2 and MadVR 0.9.2.17?

tony359

28th July 2022, 20:54

bob88

29th July 2022, 12:24

I'm a newbie on HDR but I think so. The setting you're looking for is tone map HDR using pixel shaders.

Basically anything over the max capability of your display will get clipped unless it's tone mapped. When you tone map, you're telling the player what the peak luminance of your display is. At that point the player will change the gamma curve to make sure that clipping does not happen - but not by just lowering the whole picture's brightness.

So yes, that would be the setting. It will only work if you are playing content which is over that peak luminance number, if your peak luminance is 1500nits (the max brightness of your display), madVR won't touch the picture unless there is something in it which goes over 1500 nits.

But if you play some content which does not contain anything above that number, madVR won't touch it.

I hope this makes sense.

It does make sense bro! Thanks!
One question thought. The site of my projector says peak nits is 2200, last spec in the list:
https://www.samsung.com/us/televisions-home-theater/tvs/4k-laser-projectors/120-the-premiere-4k-uhd-hdr-smart-tv-2020-sp-lsp7tfaxza/#specs
But earlier somebody posted something about this value possibly being incorrect. Do you guys think I should set madVR to 2200 nits? Would that be appropriate?
Also tone mapping curve that is available for selection in madVR is BT2390. But my projector supposedly works with BT2020. Its still fine if I use BT2390 right?

.m4jX

29th July 2022, 13:26

Do you guys think I should set madVR to 2200 nits? Would that be appropriate?

If only.

Couldn't find peak nits for the LSP7T, but the review for the LSP9T on avforums says:
the projector tracks the PQ curve until rolls off at its peak brightness of around 175 nits.

The LSP9T is brighter than the LSP7T, so try something around 100-150 nits.

Check out the madvr mapping for projector thread on avsforum for some examples of setttings for projector users.

tony359

29th July 2022, 15:29

if it's a projector, the peak brightness depends on the size of the screen, no?

2200 is LUMEN. That is what comes out from the lens. Depending on how large is your screen you'll get more or less NITS.

PS: 2200 lumen is probably in Samsung's marketing dept's mind. For an accurate reproduction (i.e. not using the VIVID or DYNAMIC preset) the actual output is likely to be much lower than that.

bob88

29th July 2022, 18:02

Thank you. I guess I will just set it at 150 nits then.
I found this interesting thing:
https://www.avsforum.com/threads/madvr-tool-madmeasurehdr-optimizer-measurements-dynamic-clipping-target-nits.3040072/#post-57368036
Not sure if I should make the effort to try and understand it considering its in German... I guess its not going to give me anything much different than 150...
I could potentially measure the exact size of the screen and divide the 2200 lumens on that. Not sure what the exact equation would have to be though to get it in nits...

el Filou

29th July 2022, 19:31

PS: Sorry I guess I didnt see it. There is also "target peak nits" under "tone map HDR using pixel shaders". However nothing I change there seems to have any effect on the picture... Actually none of the HDR options in madVR seem to have any effect. Its all the same regardless of what I change.Yes that's the one I was talking about, it's named differently because I'm using a later version.
If you'll see changes or not depends on many things, most notably the value entered for peak nits, and also the type of movie.
I think you should still see obvious changes with different peak nits values.I found this interesting thing:
https://www.avsforum.com/threads/madvr-tool-madmeasurehdr-optimizer-measurements-dynamic-clipping-target-nits.3040072/#post-57368036
Not sure if I should make the effort to try and understand it considering its in German... That optimizer tool was for some very specific test versions of madVR where it needed to first analyse a whole movie to produce a measurement file which it would then use to make better tonemapping decisions during playback. That tool could optimise/modify those files. It shouldn't be used anymore.

tony359

31st July 2022, 11:18

bob88

Again, I would not take that "2200" number as accurate. Projector manufacturers are notoriously inaccurate when it comes to declaring output. 2200lumen is likely happening in the brightest and most inaccurate mode you've got! :)
If you send me your screen size and you find online a review that gives you the actual lumen output from your projector in a reasonable preset, I can do the math for you! :)

---

I have a general question on tone mapping.

I think I understand why it happens: it's there to deal with the "short blanket" of some modern TVs. That is, my C7 OLED can do 650 nits and if the movie is graded to reach, say, 1000, tone mapping will change the gamma curve to make sure that values between 650 and 1000 don't get clipped but won't just darken the whole picture. A big needed compromise.

Now, my LG has what they call an "dynamic tone mapping" or something similar which claims to do tone mapping dynamically. You just set "dynamic contrast" to "low" and the TV will take care of that. The picture will "pop" more but I've noticed that even darker scenes - with no bright spots whatsoever - are brighten up. What is the point with that? Maybe LG's implementation gets the maximum Peak Luminance from the media being played - that is, the maximum brightness achieved during the whole movie - and applies a tone mapping to the whole content, and not only to those frames where the peak luminance exceeds the screen capabilities?

Also, I'd imagine that all sort of errors could happen when relying on those algorithms. If content is graded in a 4000 nits container, but only going to a maximum of - say - 600nits, will the TV look at the 4000 number or at the actual peak luminance value?

How does BT2390 works on this regard? I see there is an option to have madVR analyse each frame for peak luminance, what is the behaviour when that option is on or off?

Thanks!