Black levels / contrast change with subtitles

Okay, I'am suffering from this problem for about two or three weeks on my MacBook Air Late 2014 (MD761RU/B). But for me it happens only in Chrome. It does not happen in Firefox, Safari or even other Chromium-based browsers (like Yandex). I even ended up reinstalling macOS but it didn't help.

I could not get consistent brightness changes on Netflix but today I found a video on Amazon Prime Video where I can clearly and often see this flickering that causing me eye-cancer. By evening I nearly memorised these 2 minutes of video by heart.

After reading halo_bone's post I've tried to play with some settings (contrast especially) in System Preferences / Accessibility / Display section.

First of all, increasing contrast here makes these bursts more noticeable and now you can definitely see them (TBH, I initially thought that it was some kind of optical illusion).

Then I enabled inverted colors and now I could clearly see what @halo_bone says: macOS treats screen differently when there is full screen video without subtitles and when there are subtitles. Here is how I could see it. Most movies have wider aspect-ratio than MacBook display so I had black stripes on the top and on the bottom of the screen. The thing is they were black when there is no subtitles (so these parts of screen are not inverted) and white where there are subtitles. Now I can clearly see that it DOES happen in Chrome and DOES NOT happen in Safari or Firefox (they always have white stripes).

The last part is most mysterious. Previous steps helped me to see the problem more clearly but did not fix it. Then I accidentally (or just for fun) increased the cursor size (WHAAAT?) with slider and then turned it back to its normal size. You won't believe it but after that this annoying flickering just disappeared! I can clearly see in inverted colors mode that flickering is no longer happening. After rebooting the computer it starts to happen again, but it works fine after closing and opening the laptop lit. Turns out that changing cursor size somehow disables special treatment for full-screen video (top and bottom stripes becomes always white).

Resurrecting this for 2017, I am having a similar issue only it doesn't involve subtitles.

In iTunes I am watching a film that I was the cinematographer on. While the film plays both shadow levels and highlights are displayed too bright. Information that is supposed to be hidden in shadow is now seen, highlights that are supposed to have detail are blown out and clipped.

HOWEVER, when I move the cursor and the play/pause control panel pops up suddenly the values jump down to where they are supposed to be. This lasts for a few seconds then slowly transitions back to the incorrect levels.

Additionally when I do turn on subtitles the levels seem to stay at the correct level the entire time!

I do wonder if they're ever going to fix this? I'd love to buy movies from the iTunes Store but as long as they're not watchable due to this bug I'll have to resort to other types of media.

As I'm probably not the only one it would make sense for Apple to fix the issue as they'd get more revenue if their product worked as it should..

Had the same problem on OSX Sierra, mac mini, streaming amazon video through Chrome.

Disabling hardware acceleration in Chrome advanced settings and fixed the problem.

Found the solution here:

https://www.reddit.com/r/PleX/comments/4bfiod/subtitles_affect_the_brightness_of _the_whole_image/?st=j1efi6aw&sh=73e7613…

3,5 years later, I have the same problem with HDMI monitor. I didn’t see it earlier on „normal” settings only with the Night Shift mode. Unfortunately now I see small change every-freaking-time subtitles shows and dissapears even with Night Shift off. I don’t want to mess with terminal etc. but I am clueless how to make HDMI monitor, that I only use with my MacBook at home work properly.

I've finally figured it out! The problem is with using the integrated graphics card vs the discrete graphics card. The issue only happens when the integrated graphics card is used, and for whatever reason MacOS switches to using the discrete graphics card when it displays menu overlays or subtitles in full screen....go figure!

To fix this, go to System Preferences > Energy Saver and uncheck the Automatic graphics switching checkbox. This will make your Mac use only the discrete graphics card. Note that if your Mac only has integrated graphic, then there's no real solution to this it seems.

Just for the record: This has been plaguing me for years with my mac mini late 2012 hooked up to a Sony TV via HDMI. This mac does not have a secondary graphics chip, just the integrated graphics. And when I had given up all hope of this ever getting fixed, Apple seem to have done just that. I‘m on High Sierra 10.13.2 and iTunes 12.7.2.58 and the problem is gone. I did not change my setup for years and I did not tinker with color profiles etc.. So it must have been a recent software update. My guess would be iTunes.

When playing a film with subtitles switched on the brightness level is now no longer changing. Instead it is fixed at the level it was at before the fix when subtitles and / or the iTunes controls were showing. Meaning the brighter setting.

I'm on the same OS X and iTunes versions, and the issue occurs on my MacBook Pro. It's got a secondary graphics card though so I don't know if that makes a difference. I just use Chrome for Netflix as the issue occurs only in Safari and iTunes, or I disable automatic graphics switching. Not an ideal solution but workable until Apple fix this.

I have the same problem, MacBook Pro Mid-2014 and with integrated graphic card only. It only happens in fullscreen. As soon as I close fullscreen, I have to contrast change. Still don't have a solution...

So i've just updated to High Sierra 10.13.3 and same thing happend.

Before that, on Sierra everything was working perfectly.

The contrast change occurs on YouTube videos and Netflix only on Safari.

It doesn't appears when using Chrome so there is a workaround but still, I want to use the browser that I choose.

Same issues here, can't believe this post dates back 4 years (and there's similar posts on Apple from earlier years that have been closed out of commenting).

This used to not happen, I purchased a lot of movies and tv shows on iTunes over the past 5-6 years and it used to work fine. I believe is was one of the OS updates that probably broke it. I've fought it on MacBook Pros with dedicated graphics, as well as Airs with integrated cards, so I don't think that's necessarily the problem. And yes, it only happens when the OS manages the video colors -- iTunes, Netflix via Safari. Netflix looks fine on Chrome and other independent browsers.. when subtitles appear or a GUI is up, the picture is the same as it is when it's just the video content on screen. If playing iTunes material or Netflix in Safari, the picture's black levels and contrast bounces back and forth every time a GUI element appears on screen (playback controls, subtitle, etc).

I believe this is similar to the Nvidia controls in Windows where you can set if what levels VIDEO content plays back with. You can specify 0-255 (full) or 16-235 (limited). I think OSX is trying to do the same thing automagically and set "full screen video content" to 16-235, but then any GUI content pops up on screen and kicks the display output to 0-255 while it's up. Back and forth, back and forth.

Really quite an oversight by Apple, can't believe it's not fixed after 4+ years, or that no-one from the companies licensing this content has noticed and demanded it to be fixed. Netflix, for starters, should be all over this.

My current workaround is to leave something on screen. This will force the display to always be in the more "limited" levels range and not pop back and forth. It's obvious the expanded levels are too contrasty and dropping blacks beyond where they should be; shadow details totally disappear into black, for example. So, in Safari I'll just fullscreen the browser (and not Netflix itself) and that leaves a bright title bar up top which *****, but at least the video looks right. iTunes/quicktime is a little better, you can leave your mouse cursor over a playback control button and that'll stay on screen forcing the levels to remain correct/consistent. These controls are still distracting but at least it's mostly a dark gray color.

Of course, the other workaround is purchase from competitors. Don't use Safari, don't use iTunes... sadly, but if they don't fix this, not much choice.

Get on it Apple!

Wow, cursor size change has actually solved this issue for me, thanks!

Having the exact same issue in iTunes only. Not in VLC, Apple DVD Player, QuickTime, or anything else. I have tried everything I can from TV settings to every conceivable iTunes/Mac OS setting, changing HDMI cables and even wiping the drive and reinstalling the OS.

Every time a block of type appears the entire blackpoint or gamma or contrast is drastically shifted. This is now intolerable. The entire image of the video is back and forth, pulsating dark to light with every sentence of dialogue.

I've also noticed it does the same thing when moving the mouse and the controller box (the box with play, ff, rewind, etc) appears too.

Me too.

Via HDMI, the contrast/gamma keeps changing with subtitles.

On a Cinema display this does not happen.

So apparently this only happens for

- HD content

- fullscreen

- HDMI out

- subtitles in use

I'll try to report this to Apple as well.

Your post made me realize something new about it only happening in fullscreen. It also made try yet again to fix it thinking about fullscreen only causing it and I think there may be a solution.

From within iTunes select View > Video Playback > in Seperate Window. It can still be in complete fullscreen and the flashing is gone. In fact it opens videos much faster than the way I've always done it before which was just playing in the Main iTunes window.

Try it out, think it's ok with this option but not 100% sure.