QuickTime flickering during Video Tutorials?

Problem introduced by 10.5.3 on my MacBook Pro (Summer 2007)! I never had any serious graphics issues before the update.

I'm still getting graphics glitches on my 4,1 macbook pro under 10.5.3. They just took a day to return.

Glitches are described here: http://apcmag.com/appleslatest_notebooks_plagued_with_graphicsglitches.htm

I have a hard time believing that this issue is not actually resolved after a .3 download. Apple is clearly aware of this problem. In the past, Apple has actually deleted entire threads on this forum when they weren't able to fix a problem, but were aware of its existence.

This time, they have kept the thread up, which is implicit acknowledgement that they have a viable solution.

If they were truly stumped, they'd try to sweep it under the rug (by censoring discussion of it).

In other words, they are proud of this update, knowing that it works.

My best guess is that there are at least two kinds of graphics problems, only one of which was solved by the update. One clue is the fact that posters to this thread are talking about BOTH MacBooks and MacBook Pros, each of which has a very different kind of graphics card.

I can confirm that 10.5.3 fixed the problem on my MacBook and that the problem has not returned since. I know other people who had the same problem on the same kind of computer and it's fixed for all of them as well. So, if MacBook Pro owners are still seeing an issue then it's almost certainly a different one. But unfortunately this thread is posted in the "QuickTime" forum and not the "MacBook" or "MacBook Pro" forum, and most people don't fully understand the differences between the two lines of notebooks, so we're likely to continue seeing people shouting back and forth about their "identical" problems not being solved.

I wish it did. I just spent a lot of money on a new computer, and reformatting it to install an older version of the operating system so I can scroll through mail, xcode, and web pages without everything getting smeared across the screen seems a bit extreme.

I like OSX and I own an 8-core Mac Pro and a Dual G5, along with this MacBook Pro, I really wish apple would listen to it's users and fix this. I was so happy when it seemed like the issue had gone away on 10.5.3, but after a day it's come back, I'm now considering selling this Laptop to buy parts for my porsche, because there is no point in having it anymore if I can't scroll web pages without graphics corruption.

Except 10.5.3 doesn't fix it on my laptop either.

Then the problem maybe hardware? take it in to the apple store or call it in for support my macbook has been corrected and so have many others.

With my MacBook Air, I have experienced the flickering in QT movies.

E.g. the movies found on this page flicker:

http://www.apple.com/iphone/

But those found here, don't:

http://www.apple.com/iphone/ads/ad19/

This indicates to me that this isn't primarily a hardware problem, but instead something to do with the encoding of the movies presented. For me on my Air, the "old" iPhone ads work flawlessly, but the new ones flicker.

Maybe a combination of hardware and software ... but then again, why would "old" QuickTime movies work, and "new" ones wouldn't?

/M

MacBook 2.4GHz...AND...Mac Pro 2.66GHz....same thing here. Although the flickering on the first set isn't like the flickering prior to installing 10.5.3 on my MacBook. It's more of a hard quick bands of white flashes, not the fading flickering as before.

But yes, I can confirm, I get flickering on the first set here:
http://www.apple.com/iphone/

But not any flickering here:
http://www.apple.com/iphone/ads/ad19/

-Kevin

The flickering is still easily demonstrable under 10.5.3 on this page:

http://www.abc.net.au/tv/newtv/

See the main animation on the page that moves the promotion every few seconds.

And to add to that.. I can also see that the flickering is demonstrably worse when the MacBook Pro is on battery power. The flickering gets about 80% better on power.

I went to that website (http://www.abc.net.au/tv/newtv/)and animation was flawless on battery power and I had a really bad flickering issue before 10.5.3 on my MacBook.

That is really interesting! Right now for me it is still flickering. The amazing thing is I can actually screen capture the flicker using ScreenFlow, which suggests it's very much a software problem than a hardware one (e.g. if software is able to capture the flicker, then clearly the display problem is occurring in software too.)

http://danwarne.com/flicker-example.m4v

That's interesting that you can capture it, I think there's more than one problem here.

I'm convinced that some of the flickering problems are due to the way the graphics card and drivers deal with dithering.

This is what I have gathered from reading nvidia's forums and references and a bunch of other stuff. Correct any of this if I'm wrong.

Basically, all laptop screens are '6 bit' - they have faster response times, are much less expensive, and are often lower power. Each channel (Red / green / blue) has 6 bits of information, for 64 levels. That's about 262144 colours. To reproduce the '8 bit' per channel or 24 bit per pixel image, the '6 bit' colours are cycled very quickly, which to the eye looks like '8 bit'. For example, to reproduce the '8 bit' level 65 (out of 256 levels) on a 6 bit display, the display could cycle levels 16 16 16 17 ( out of 64 levels), the average of which is the same value. As the response times are fast enough to do this, we normally don't notice it. Also the brightness change is slightly damped, which smooths it out a little bit more. On moving images it would be very hard to notice at all as the level are constantly changing anyway.

This is called 'dithering', and must be performed inside the graphics hardware, before the image gets converted from 8 to 6 bit. The logical place to do so is the graphics card.

However, If the dithering algorithm uses a regular pattern to produce the dither, there will always be a set of patterns that produce interference with the graphics card pattern. For example, in the idiotic case, the card cycles all the lowest values at the same time. This would produce the effect of the whole screen slightly flashing and would be quite noticeable. Other patterns might do a cross-hatched, moving stripes, or other patterns that balance the overall brightness. These moving patterns are often noticeable when you move your eyes at certain speeds, as the pattern moves with your eyes. However, any regular dither pattern will always have some patterns that interfere with it in some way, in particular patterns that are nearly the same as the cross hatched pattern. This is because they cancel out with the cycled dither pattern and the net result is the same flashing as with the 'idiot case' pattern.

The only real solution to dithering is a semi-randomised pattern. No other pattern could possible interfere with this. However it might give a very slight 'noisy' effect.

I believe that the 10.5.3 update fixed people's flickers in some cases by changing the modes of graphics cards to more complex dither patterns.

What I don't get is how my 6 year old Powerbook 800 DVI has never exhibited any noticeable dither patterns, yet my spanking new MBP has problems.

Also, the problem can recur with the 10.5.3 update. I suspect it may be related to using multiple monitors. Rebooting fixes it again. This suggests to me that the configuration of the graphics card is changed when adjusting for the second display and the dithering fix is lost, even going back to the single display.

Embarrassingly, I must recant on my previous post which praised apple up and down for "solving" the quicktime flickering problem.

Yes, X.5.3 does eliminate flickering in the mpeg's I've played back. HOWEVER, there are still strange artifacts in full screen mode. When the controller is visible, all is well. When the controller disappears, however, a set of "border" lines top and bottom and on the sides, appears.

I have to agree with an article I recently read: 10.5 has been rushed to market. It's a fun OS and relatively speedy, but it's on the verge of becoming Microsoft Office style "bloatware," with too many features which quite frankly, do not really add any new functionality, but simply duplicates functions (a la stacks). Not only is Leopard edging closer and closer to "bloatware" territory, it's buggy bloatware to boot (no pun intended).

Please, please, please, Apple, take care of your 10.5 customers FIRST. DO NOT RUSH OUT 10.6. Are you listening, Stevie Boy?!?


PS: Is there a way to add attachments so I can post a picture of the borderline artifact problem?

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