Horizontal Lines During Video

Question

Horizontal Lines During Video

I'm hearing lots of problems with horizontal lines and all on the 20" iMac. I'm having a similar problem, but different circumstances.

See, whenever I play video, including DVDs, files in Quicktime, and even footage in the Viewer in Final Cut Pro, there are strange horizontal lines that show whenever there's significant motion onscreen.

For example:
http://files.upl.silentwhisper.net/upload0/Picture_1-rxc.png (from a DVD)
http://files.upl.silentwhisper.net/upload0/Picture_3.png (DV video in Final Cut Pro)
(2 .png files there)

I've updated to 10.4.7, but the problem persists. Even my girlfriend is having the problem, and she bought a stock 20" from the Apple Store, whereas mine was ordered online.

One last thing - when I made a movie on her iMac recently, the lines even showed up on the DVD copy, when played on a DVD player. What's the deal? Anyone know?

Thanks in advance for any assistance.

~ Joseph

P.S. I posted this over in the iMac Display forum as well, but no one has replied to it - I brought it over here in the hopes that someone could answer my question.

20" iMac Intel Core Duo, Mac OS X (10.4.6)

Posted on Jul 17, 2006 3:30 AM

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Answer 1

Jul 17, 2006 4:31 AM in response to Community User

I've seen lines like that on PC's as well. Sometimes DVDs played on ordinary domestic DVD players do it too. I think it's something to do with the video interlacing of the movie file. Often when people create video material they have some settings wrong or up too high for other peoples computers/DVD players to be able to play properly.

It is funny how it is doing this for every video format played on your iMac though, including commercially produced DVDs.

I'm not sure what to suggest really. Hopefully someone with a bit more knowledge might help out.

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Answer 2

Jul 17, 2006 7:25 PM in response to Community User

Ugh. I just exported a Quicktime video from Final Cut Pro, and the lines are even MORE prominent. Any solutions from anyone?

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Answer 3

Jul 18, 2006 6:48 AM in response to Community User

Have your tried viewing it on other hardware, say another iMac or even gasp an IBM/PC compatible, or writing it to DVD to view on a consumer DVD player? Try this out to see if the horizontal lines appear on these as well.

I know it won't solve any problems, but at least you'll find out whether it's a problem with the iMac playing he video or a problem with the video files you are creating.

Actually, I think I'm going to try and dig out some of my old video stuff to see how that plays on my iMac. I'll report back if I expereince anything like you are.

Best of luck!

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Answer 4

Jul 18, 2006 8:25 AM in response to Community User

The video files you are watching are interlaced. Nothing wrong with your iMac.

When you watch DVDs using Apple DVD Player you do not notice this because it deinterlaces the movie by default. Go to DVD Player/Video and uncheck Deinterlace and you will see the same lines on all DVDs.

QT does not have a setting to deinterlace so if you want to watch an interlaced video on your computer use VLC.

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Answer 5

Jul 19, 2006 2:18 AM in response to Rafael Marino

Like I said earlier, I actually made a DVD copy of one of my movies and played it on a commercial DVD player, and the lines were still there - even when not playing on any computer.

Also, I tried viewing it in DVD Player with Deinterlace checked and it made the lines even worse than it was with it unchecked.

I don't know what the problem is - this is happening for all videos from outside sources (DVDs and DV camera-imported) for some reason - meaning that when I play things like anime, the lines don't show up.

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Answer 6

Jul 25, 2006 2:27 PM in response to Community User

Trying again - anyone happen to know what's causing this?

20" iMac Intel Core Duo Mac OS X (10.4.7)

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