Could someone with dithering problems who is using a Mac do these steps for me? Go to Terminal/iTerm, run kextstat and save the output to a file? Also please list what model of Mac you have, OS X version, and what GPU and if it has switchable graphics. This is useful: http://www.everymac.com/mac-identification/how-to-find-apple-model-family-numbers-for-mac-identification.html An example (in my case): 2015 15" Macbook Pro, Switchable Intel Iris Pro and AMD R9 370X graphics. You can use code tags to paste it without it obscuring the rest of the post ``` like this ``` like this if(window.hljsLoader && !document.currentScript.parentNode.hasAttribute('data-s9e-livepreview-onupdate')) { window.hljsLoader.highlightBlocks(document.currentScript.parentNode); } Or if it's too big email me, jtl at teamclassified dot ca I tested this morning and might have a way to modify the code of the kexts, which might allow to me to disable the dithering. Let's face it. Amulet Hotkey and the others are useless. Seems like I'm the best shot for the time being. Thanks

JTL Oops. And I accidently caused my laptop to stop booting because I accidently corrupted one of the .kexts while editing it. Goes to show you should always make backups.

Note: Modifying the existing kexts and just injecting code to turn off dithering would be safer and survive OS upgrades. Being able to edit the kext code is a good first step though. The only information about Amulet Hotkey's kext is this screenshot https://2.bp.blogspot.com/-gf7GValbbu4/UIqMb-KqKKI/AAAAAAAAAas/3e5uUtw3ItU/s1600/photo%2B%252810%2529.JPG Notice after ahkinject the <4 3> . That corresponds with the other "required" kexts I think, kext number 3 is IOKit which is a method for drivers to interface with haradware. Don't know much about it.

I'd love it if you got somewhere with this. I'll pull a couple different Macbooks' data for you later today.

Gurm Thanks. The hard part after this is figuring out what functions actually control the dithering. Like I mentioned above I accidently NOP'd (no operation) the wrong function causing my laptop to stop booting. I just copied the kext back into place and it was fixed though. Still annoying.

Very excited by this prospect JTL - it could make a big difference to a lot of people's lives if you could work it out. I no longer use Macbooks I'm afraid, had to chop them out my life!

si_edgey Unfortunate. Not making any promises but now that my vision is stabilizing and I have more time, why not do it?

I think the best goal would be for me to develop a new NVinject of sorts that does IORegistry injection, but works with newer OS X versions and 64-bit, etc. If you disable SIP it let's the kext be fully used without signing (which costs $100 a year) so this is good for testing. If we have a full version that works and we know it I can just pony up the $100 to make an easy-to-use signed version. Also I was looking through the AMD kexts and saw something interesting. jtl-macbookpro:Apple kexts jtl$ strings AMDSupport |grep AAPL AAPL,slot-name AAPL%02X, AAPL,gray-value AAPL00,T1 AAPL00,T2 AAPL00,T3 AAPL00,T4 AAPL00,T5 AAPL00,T6 AAPL00,T7 AAPL00,LinkFormat AAPL00,PixelFormat AAPL00,Dither [sic] if(window.hljsLoader && !document.currentScript.parentNode.hasAttribute('data-s9e-livepreview-onupdate')) { window.hljsLoader.highlightBlocks(document.currentScript.parentNode); } Now if we check the NVinject's Info.plist <key>entriesToAdd</key> <dict> <key>AAPL01,Dither</key> <data> AAAAAQ== </data> </dict> if(window.hljsLoader && !document.currentScript.parentNode.hasAttribute('data-s9e-livepreview-onupdate')) { window.hljsLoader.highlightBlocks(document.currentScript.parentNode); } So there is a difference.

@vinkenvvt I remember you did something with Clover EFI and it didn't work, which one was that?

This is interesting https://developer.apple.com/library/content/documentation/DeviceDrivers/Conceptual/AccessingHardware/AH_Finding_Devices/AH_Finding_Devices.html I made a simple kext that logs to the console app. It works. 151 0 0xffffff7f83e63000 0x2000 0x2000 ca.teamclassified.testkext (1) 194C7603-9A67-39C4-A95B-C1D7780658B8 <4> 2017-09-13 17:23:36.000 kernel[0]: TestKext has loaded

Good work JTL, sounds like progress of some kind. Any joy with the AAPL00 / AAPL01 thing?

OSX dithering - Help wanted

devilgrove

NewDwarf the logs were actually in normal mode!

https://imgur.com/a/9FSlUI0

NewDwarf

devilgrove Hmm. Interesting…

Could you share the output of below command, please?

nvram -p | grep dither

devilgrove

NewDwarf it outputted boot-args dither=0

NewDwarf

devilgrove One more advice. Wait when the command

log show --predicate "processID == 0" | grep Dither

is finished. More likely, you see the old logs. The last string have to report you about disabled dithering.

devilgrove

NewDwarf Wow, you're right! It does say disabled at the end. I didn't even realize that I was looking at log history, I thought the command was constantly checking for some reason. Thank you!

Looks like OSX dithering has finally been solved 🙂

NewDwarf

devilgrove Happy to hear that.

ryans

devilgrove Looks like OSX dithering has finally been solved

Wow, this is a dream. Nice job! Very nice solution, setting the NVRAM param 🙂. Have folks tried it and saw eye strain improvement!

Would be interesting to see if a similar solution exists for Apple silicon.

devilgrove

NewDwarf honestly I wouldn't have been able to find that solution without you assuring that there was a simple solution like that, so thank you. You're also clearly much more knowledgable than I am about OSX disassembly, so I appreciate the troubleshooting as well!

insta42014

NewDwarf Doesn't work on my MacBook Pro 13 2018 (Intel Iris Plus Graphics 655), banding stays the same before and after the command line, and banding is worse on safe mode

When entering the command log show --predicate "processID == 0" | grep Dither, it shows :

0 kernel: (AppleIntelCFLGraphicsFramebuffer) [IGFB][LOG ][DISPLAY ] [Modeset] Dither is disabled with bpc 1

CRoebuck

ryans

I've gained access to an M1 Air later this evening and have a 2020 Intel i5 MBP arriving Monday. Both were unusable previously so will be interesting to try this out.

Will report back

NewDwarf

insta42014 Could you please give more details about banding. I afraid I have no idea what you are talking about.

Using this command, eye strain completely gone for me.

devilgrove

insta42014 The banding might be the same, but is the eyestrain the same?

I mentioned this in another thread, but switching from Safe Mode to normal mode didn't change the banding for me, and the same goes for disabling dithering vs leaving it enabled. The only difference was the eyestrain.

insta42014

NewDwarf

Here's an example of banding/no banding :
https://imgur.com/IDgqF5m

If you look closely on the 3 screenshots below you'll see that banding is the same before (1) and after the command line (2), and that banding is worse on safe mode (3). If temporal dithering was disabled by the command line banding should be the same in (2) as it is in (3)

NewDwarf

insta42014 What is the technical background of that banding? How is it related to the temporal dithering?

Technically, temporal dithering doesn't increase the number of sampling bits. So, dithering is just an illusion in your brain

I would even say, that disabling of the temporal dithering will NOT remove visible gradients (banding in your term) as the display continues to produce 8-bit colours (regardless of the dithering). Moreover, by disabling the temporal dithering, we get rid of two virtual bits.

Anyway, it is interesting to know who is the author of the banding theory and how he/she came to this conclusion…

insta42014

NewDwarf I think that we see the true capabilities of the screen when the system is in safe mode and the intel driver is not enabled. When this is the case the banding is horrible, due to the fact that dithering is disabled. In normal mode, without activated dithering algorithm, we should find the same horrible banding as in safe mode, but your solution does not worsen the banding which remains the same as before on normal mode (the gradients are blurry compared to those in safe mode).

Using ditherig.exe in Windows to disable temporal dithering on Intel GPU introduce horrible banding (when it works and when the display isn't true 8-bit), showing the true capabilities of the screen.

I also think that the MacBook Pro display is not even capable of displaying true 8-bit and relies on temporal dithering to show 8-bit and 10-bit.

caboy

NewDwarf

I think the question of weather this works or not may come down to the bit depth of the display panel. There is a command to show what vendors display panel is installed. I don't know if the bit depth information might be available also.

Can you run this command and give us the output please?

ioreg -lw0 | grep IODisplayEDID | sed "/[^<]*</s///" | xxd -p -r | strings -6

A prefix of LTH is Samsung, while LP is LG. All the Samsung displays I have seen are 8-bit. With LG, it may be a mix depending on how old the panel is. The older LG are 6-bit. I am not sure of the newer ones. Again, I don't know what other information may be hidden in the output of "ioreg" (such as bit depth).

The above command will not work on M1 macs. It may or may not work on Monterey on Intel.

Lauda89

insta42014 Honestly the dithering.exe on windows produce a lot of banding but i think that nobody was able to turn a bad device in a good one only with that software..

So if this command works also with the M1/M2 SOC i could buy a new MBP and try if it works also for me..

caboy

insta42014

My experience since 2012 was that some macbooks would give me eye strain / pain and others did not. Laptops with display panels made by LG or AUOptronics would give me eye strain / pain. While Samsung did not. I think the Samsung panels were 8 bit while the other brands panels were 6 bit and had temporal dithering enabled.

Apple has removed the command that shows what vendors panel is in a laptop in newer versions of the OS.

I suspect the reason Apple and other vendors refuse to talk about this issue is because in 2008 Apple was sued by some professional photographers because of temporal dithering. It was making it impossible for them to do their jobs.

ryans

Does dither=0 remove spatial dithering or just temporal dithering? ditherig has the option completely remove both ~ which might be the cause (pure speculation) of the terrible banding.

ryans

Has anyone tried using the NVRAM parameter on an external monitor (an existing usable one preferably)?

caboy

Dithering is used to mask / hide the banding. If dithering is disabled on a system with a mismatched bit depth (8-bit gpu vs 6-bit display), we should see the banding. It is because the display is natively missing the colors needed to show a smooth gradient.

NewDwarf

caboy Dithering is used to hide banding in our brains only. Enabled dithering doesn't increase physical bit-ness of the screen/GPU.

The MacBook Pro's have at least 8-bit GPU/displays. It is enough bit-bess don't notice gradients.

My MacBook Pro 2020 has physical 10-bit screen.

devilgrove

NewDwarf same for my MacBook.

In general, newer MacBooks should never display 6-bit, and banding would technically only occur if native 6-bit color was being shown.

insta42014

NewDwarf The MacBook Pro 2020 doesn't have a true 10-bit screen and if it was the case temporal dithering wouldn't be needed so you wouldn't have had eyestrain in the first place. As far as I know the only Apple display capable of true 10-bit is the Pro Display XDR which costs $5000 and Apple advertises it in their Technology Overview pdf: "P3 wide color gamut and true 10-bit color depth provide over a billion colors and incredibly smooth gradients".

caboy

NewDwarf

caboy Dithering is used to hide banding in our brains only. Enabled dithering doesn't increase bit-ness of the screen/GPU.

My understanding is that dithering is used to emulate missing colors when a GPU has more colors than a display panel can support. eg an 8-bit GPU with a 6-bit display panel. A rapid flicker between two colors to get an average of a missing color.

The banding appears on low bit depth displays (6-bit) because they don't have enough colors to show a smooth gradient. Dithering is used to mask / hide the banding.

It seems most vendors have enabled it by default in all devices this year.

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