Is this video Proof of Mac dithering?

ryans

Hi,

I came across a Twitch streamer who streams his coding (chau_codes) on Mac. I see this fast flicker that looks like dithering...perhaps it is being slowed down enough to notice?

I can't upload >10MB videos directly to LEDStrain, so here is the video: https://drive.google.com/file/d/1z2qjjSo-l1bbm6avQ7CwTVtj6QY8bNML/view?usp=sharing.

If you focus on the white area, you can see a "flicker" or "shimmer". I am not sure if this is dithering or some artifact of the capture card etc.

Does anyone else notice this flicker in the video? It's most visible for white (or near white) in Safari.

Try watching it a few times in 1080p and see if you can pick up on the flicker!

(I captured the video using the built-in Windows 10 XBox Game Bar, which to my limited knowledge, is a lossless capture; Google Drive probably did some compression on its side).

Edit: The flicker is very noticeable on my BenQ monitor but much harder to see on my Thinkpad laptop. Interesting.

JTL

To answer the question for other curious users, there is pixel changes in that video but since its a compressed screen recording of a Twitch.tv livestream the resulting file is several "generations" away from the unknown capture source, so its potentially ambiguous.

Alyosha2001

Yes, that's definitely flicker. If they were compression artefacts they'd be all over the place

What's more interesting is that only the grey highlighted part of the screen is recorded to flicker

JTL

Alyosha2001 What's more interesting is that only the grey highlighted part of the screen is recorded to flicker

Unless we're thinking about two different sections of the video, that's not quite accurate.

insta42014

One way to detect temporal dithering on MacBook Pro with Intel CPU is to use a screen background of the color “Space Grey Pro" in the settings and compare the banding on the identification window between normal mode and safe mode. The banding should be worse on safe mode when temporal dithering is disabled. This also shows that setting SwitchResX to 8 bits doesn't disable temporal dithering but only reduces it.

ryans

insta42014 Yeah, I recall a post from a user here who made a gradient their desktop background -- and everytime they looked at it, ensured banding was there.

@NewDwarf do you see banding with your solution?

devilgrove

insta42014 Not sure if something is wrong with my computer, but I don't get any banding regardless of what mode I'm in when I use that background. I do notice a difference in strain when I'm in Safe Mode, however.

caboy

I just posted this in another thread. This is a youtube clip of a macbook pro 2021 16". Filmed with an iphone at 240fps, then slowed down. Thinking about it now, it could also be the OLED PWM.

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

insta42014

caboy MacBook Pro 2021 16 uses mini-LED display not OLED, and PWM wouldn't look like this

hayder1983

Perhaps contact the website, they could try to do the same movie in safe mode. Perhaps it doent help anymore?!