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Level 1

19 points

Black levels / contrast change with subtitles

Hello everybody,

since the last updates of iTunes (11.1.5) + OS X (10.9.2), watching a movie with subtitles is no more comfortable. I see that other people on the forum also encountered the problem.

I'll try to be clear and detailed:

Each time a subtitle is displayed, the black level (or the contrast if you prefer) on the full screen slightly becomes brighter. The result is a flashing movie each time someone is speaking (subtitles). This was not present before the very last updates. This is especially very annoying when watching a movie with top/down black bars (cinema 2:1 image ratio), as there is a big area of black pixels. Or watching a story in space (try Gravity...). I would say: it is not watchable...

This happens (in my case) when using full screen mode, HD movie, and HDTV connected via HDMI. Maybe in other situation also, I don't know.

But for instance, wathching the HD version using a window (not clicking on fullscreen double arrow) on the TV, or SD version in full screen on an external monitor (which is not HDCP compatible), or SD version of the movie in full screen to the TV via HDMI, the issue is not visible. In fact the problem is not present in these situations because the contrast levels on the full screen remains brighter always, even when there is no subtitle. So there is no flashing behaviour. But the black is "not black" anymore. It is dark grey.

Do you know whether this is already reported to Apple dev team? Is it a known issue?

Should I report?

Thanks.

Mac mini (Late 2012), OS X Mavericks (10.9.2)

Posted on Mar 24, 2014 2:24 AM

Best reply

gagarski

Level 1

13 points

Posted on Mar 11, 2018 4:33 PM

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).

View in context

55 replies

Apr 30, 2014 12:03 AM in response to Oliver Weinitschke

Testing a bit more:

It seems the image actually gets darker, when there are no overlays in use, like subtitles, or the control bar. When the control bar is visible, this also brightens the image, like subtitles do.

So seems like the "direct" streaming of video content over HDMI, without overlays, does not use the right gamma/brightness/contrast values.

May 10, 2014 4:28 AM in response to Olivier VM

same here: gamma shift only in fullscreen over hdmi - but happens in iTunes with rented or streamed movies and ALSO in Quicktimeplayer X with h264 coded non iTunes Videos.

May 26, 2014 7:54 AM in response to Olivier VM

I have a new mac mini, and i've been searching a soluton to this. Exactly the same problem here. This is ridiculous, i can play the same video with the same setup (TV and HDMI) perfectly in Windows.

Jun 19, 2014 4:58 AM in response to Olivier VM

Hello,

I have the same problem here.... And still looking for a permanent solution....

Hopefully someone from apple will read this post and work on that problem...

Jul 19, 2014 9:34 AM in response to Charles.G

Same here. OS X 10.9.4, iTunes 11.3, and my HD rental of Snowpiercer was unwatchably dark, except when I paused the movie and the controls appeared onscreen. Then the contrast lightened up notably. Same thing happened with another HD movie purchased from iTunes, but doesn't seem to happen with earlier SD downloads. New Mac Mini hooked up to a tv via HDMI.

Aug 11, 2014 2:09 PM in response to Olivier VM

I'm having the exact same problem. I'm on a Mac Mini 2012, hooked via HDMI and contrast/shadows becomes darker each time the iTunes progress OSD disappears. When the OSD is displayed the video looks like it is supposed to, with all the shadows and everything. Apple please fix this!

I've also tried to play around with the "Colour" in the Display settings and no-go, problem still remains.

Aug 28, 2014 11:15 PM in response to Michael Björk

Same issue here with the Mac Mini 2012. It's definitely an iTunes issue (that I didn't see with older versions) as subtitles on Netflix (i.e. Safari) do not cause the annoying changes of the brightness level. I already submitted a bug report to Apple via the feedback site and hope that this problem will be fixed in the next release of iTunes. Movies really become unwatchable if subtitles are switched on. Unfortunately, rented iTunes movies cannot be played with any other player than iTunes, as far as I know.

Osti

Level 1

0 points

Sep 1, 2014 11:17 PM in response to Olivier VM

This is a terribly annoying issue. I have tried just about everything (including U-96's proposed method), but to no avail.

My first way of tackling this was to simply play the film in a window with a black desktop background. Unfortunately, this leaves the menu bar along the top of the screen. Since a couple of OSX-es ago, the menu bar can no longer be hidden (using any technique I know of), so this really reduces the viewing enjoyment.

Yesterday, I bumped across another method that reduces the visual interference: in full screen, move the control pane to the lower right corner of the monitor. A tiny portion of it remains visible. Leave the mouse pointer hovering over the pane. It won't go away until you move the mouse pointer outside the box. This leaves you permanently in the lower contrast/higher brightness "subtitles" layer with a bulky "close" box in the top left and a tiny grey square in the bottom right; and no flicker.

It is way less than perfect, and I am sad that this bug hasn't been fixed yet. I guess the majority of Apple's engineers enjoy their films without subtitles!

poitvd

Level 1

0 points

Sep 16, 2014 6:14 AM in response to Olivier VM

hey. yesterday i tested itunes a little. and it seems that if you chose to have english subtitles on the screen does not go in high contrast mode, i have tested with subtitles called english cc. i dont know if every movie has it. but it is a temp solution inntil it gets fixed. and sorry for my bad english. i hope you guys understand=)

U-96

Level 1

51 points

Sep 27, 2014 1:13 PM in response to poitvd

Hey, been months since I looked in on this thread. I had tried absolutely everything possible to fix this and sorry to say it never was resolved until I absolutely had had enough. I wiped the drive clean of that disaster Mavericks and put Mountain Lion back on. I'm sure I don't even have to say this but - the problem is completely gone. With no adjusting of anything in any way, Mountain Lion (even up to the current version 10.8.5) just works.

Mavericks was the last straw for me with it's attitude of "Hey User, you're going to be using this computer the way I want you to."

PS - I know this is the bottom of the barrel option for help but I had to do whatever it took to get around the bright to dark, bright to dark, bright to dark, over and over again.

radio662

Level 1

4 points

Oct 12, 2014 4:05 AM in response to U-96

Same problem her on Maverick. I decided to buy a movie twice and am feeling sorrow now. The brightness blacks keep flashing and my mother who was watching too didn't like the movie at all because it was a dark movie and a lot of the scenes where invisible. No problem with VLC.

On my main projector I am back to Mountain Lion a long time now because even VLC plays better on ML.

hartze11

Level 1

0 points

Oct 12, 2014 4:46 PM in response to Olivier VM

Anyone had any luck with this issue?

I'm watching iTunes from a 2012 Mac Mini (10.9.5), on a Vizio TV (HDMI) and the black levels are really bad on the movies (such as the dark parts of Edge of Tomorrow).

About the only work-around is to leave the mouse cursor hovering over the pause/play/rewind control bar, which for some reason brings the brightness levels up to where is should be... I have not tried other video adapters, e.g. Display Port to DVI, VGA or HDMI. The built-in HDMI port should just work!

I have not confirmed if this is an issue with VLC, etc., but this does remind me of a problem I had in the past with HDMI clipping issues, and was forced to use a third party app ("Gamma Control") to rectify the problem before Apple release a fix in the 10.8.x branch IIRC. See:

http://www.xlr8yourmac.com/feedback/2012MiniHDMIVideoProblems.html

for a description of the clipping problem, but that was a global problem with the video, and I think this one is related to iTunes only (video looks OK on the desktop and other apps).

radio662

Level 1

4 points

Oct 16, 2014 2:51 AM in response to hartze11

I reported this problem to Apple support but it seems they don't get it at all. First they inquire about my mother and than they are going to investigate the movie. LOL.

Oct 16, 2014 5:15 PM in response to Olivier VM

I thought I'd read on some other threat that Yosemite would fix this problem, but nope. HD videos purchased from iTunes are still too dark in fullscreen mode when the playback controls aren't onscreen. Seems to be some issue with how Apple transmits information via HDMI. I'm wondering whether I need to buy a newer, more modern HDMI cable -- mine dates from around 2009, and I occasionally get HDCP errors about how I'm not allowed to play the content I've legally purchased via an HDMI cable on my own dang TV.

radio662

Level 1

4 points

Oct 17, 2014 4:05 AM in response to Nathan Alderman

I don't think it is in the cables because other players work fine besides hdmi is digital so it either works or works not.

How do you report these incidents to Apple? I did it as a report to a movie but I got the money back they did not like my blunt reply and nothing is done. Guess they did not learn from Steve Jobs that the product should be central and not the flattering.

Black levels / contrast change with subtitles