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 ``` 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"#p3010 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 ``. 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"#p3013 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"#p3015 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] ``` Now if we check the NVinject's Info.plist ``` entriesToAdd AAPL01,Dither AAAAAQ== ``` So there is a difference.

@"vinkenvvt"#13 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 ` `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

JTL

Gurm Well. I don't think that's going to be an issue.

Unlike nVidia Optimus the switchable graphics on Macbooks are fundamentally different. According to an Apple display engineer I spoke with a number of years ago the switchable graphics works via a "mux chip" that's hooked up to the display and the output of the nVidia and Intel cards. It has a driver on OS X that "signals it" to switch cards when needed and it completely disconnects the screen from the Intel card and "connects it" to the nVidia card. And before you say "Well the screen doesn't turn off when switching cards". That's probably because it switches so fast it just drops a frame or two. This is 100% confirmed under Linux with raw I/O access.

Gurm

Nice. What I meant was more along the lines of ... there used to be an app that let us tell the machine to ONLY use nVidia, that doesn't work under newer versions of OSX. So we'll have to figure out a way to not have it switch back to Intel.

JTL

Gurm gfxCardStatus Ah. Can't really help you there. I still use El Capitan. Works for me.

https://github.com/steveschow/gfxCardStatus/issues/24

JTL

All I'm willing to say at this time publicly is that some major technical hurdles have been overcome, with regards to the framework needed for injecting the code for disabling the dithering in the AMD/Nvidia kexts under OS X, but it's not done yet.

diop Will Intel be a possibility in the future? Or could the ditherig tool be ported over to OS X?

If someone makes a Linux version of the dithering tool, it might be possible for it to work under OS X. Again, not making any promises here.

diop

Looks like a UK Apple Service Provider either re-sell or are involved with AHK as I discovered this post.

Link: https://www.jigsaw24.com/news/amulet-hotkey-fix-temporal-dithering-for-latest-macos

"If you're using Amulet Hotkey for KVM over IP, be warned that installing the latest version of macOS on your endpoints automatically re-enables temporal dithering.

This vastly increases the amount of information you're forced to handle over IP and, as a result, will have a negative impact on the quality of your image.

Happily, Amulet Hotkey are already aware of the issue, and have released a kernel extension that allows you to disable temporal dithering at the driver level, regardless of which version of macOS you're running. (If you're running an earlier version of macOS or OS X, the fix should already be in place – contact us if you find this isn't the case.)

The usual caveats apply: the fix will only work with Amulet hardware and software, not with that from third parties; the kext itself is not available publicly – in a delightfully cloak-and-dagger scenario, you need to get in touch with our team on the details below, and they'll send you a temporary download link and instructions for how to install it."

ryans

diop "The fix will only work with with Amulet hardware and software" 🙁

JTL

ryans It only works "with Amulet hardware" because there is code to check if the Amulet box is plugged in or not. It was a delibrate design decision to lock out competition.

ryans

JTL True, in Amulet's case, the dithering is a nightmare because static images never exist. I think Apple should allow us to turn off dithering.

Gurm

I'm hoping at some point we can disassemble or hack Amulet's driver. I think it's pretty frustrating that a solution exists but we can't use it!

ryans

Gurm I agree it's frustrating. We should petition Apple to allow us to do this...if we can't get through via support, maybe we can find engineers at Apple on LinkedIn or similar and try to make them aware of this issue. Most people are under the impression that dithering is not perceptible by humans, but as we know, it can still have an adverse affect on us.

I don't use OS X and I don't know much about Kexts, so one possibility could be to use Rent-A-Coder or something like that, and maybe pay someone that has the experience to make one for us (and make sure we get the source code). I'd be happy to chip in for this for our community. As JTL mentioned in another thread, disabling dithering is a competitive advantage for the Amulet folks, unrelated to eye strain.

The fact that it can be done on OS X is very encouraging. I don't know if iOS is known to dither, but it's very locked down, and I strongly suspect it's not possible to disable or alter without jailbreaking.

JTL

ryans I've been working on this for 6 months and have made very good progress. No need for any "Rent-a-Coder" or similar.

Email me and I'll give you a "brain dump" of all my research so far.

ryans

JTL I'd love to release an open source program that disabled dithering on OSX just to spite Amulet Hotkey. They know we are suffering and just don't care.

Seefree

JTL are you implying that you found a way to disable the temporal and spatial dithering in macOS?

What is a good way to test eyestrain caused by macbook dithering ? Is the recovery mode option still viable with he latest macos and intel integrated gpu?

ryans

Came across this, don't know if it'll make an improvement for us:

https://techcrunch.com/2018/03/30/macos-finally-gains-external-gpu-support/

JTL

ryans Doubt it, the issue is the graphics driver, not the actual GPU itself (with exception of possibly GTX 9/10xx)

JTL

ryans 😃

JTL

Seefree are you implying that you found a way to disable the temporal and spatial dithering in macOS?

Getting very close. I found a way to make it worse, now to make it better 🙂

What is a good way to test eyestrain caused by macbook dithering ? Is the recovery mode option still viable with he latest macos and intel integrated gpu?

Unsure

ryans

JTL I came across this: https://communities.intel.com/message/535654#535654

JTL

ryans I saw that, your point?

I have the 2015 15" MBP with dedicated graphics, which running Linux always uses the AMD GPU unless using special EFI hacks.

I haven't tried it with Linux in quite a while but Ubuntu 16.04 (I think that was it) was fine.

ryans

I wonder if a high speed camera (like 1000FPS) that took a video of a laptop or smartphone that caused issues, and we slowed it down, we'd be able to detect dithering or other sources of flicker?

One of the biggest problems we have on here right now is there's no reliable test for anything but PWM (using a smartphone camera, but even that is not 100%)

JTL

ryans With regards to PWM, get a high quality oscilloscope and photodiode. Both can be purchased for <$1000. Have a look at @TechSensitive's posts.

With regards to dithering. I want to try a lossless PCIe capture card to check several display outputs in slow motion. Can be purchased for ~$400 at most on eBay.

There's a company in Vancouver that makes a high speed camera that does up to 21,000 fps. It costs $3000 but I know someone who works there and I might be able to test one at their offices.

http://www.krontech.ca/

caboy

ryans

I found this on youtube. These folks used an iphone and filmed at 240fps then slowed it down. The flicker is visible. This is showing a Macbook Pro 2021.

https://www.youtube.com/shorts/9JCQ_p4olWw

[Edit]

Thinking about it now, this might also be showing the OLED PWM flicker. This is an OLED model.

« Previous Page Next Page »