Preview window displays wobbly video

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Level 1

16 points

Preview window displays wobbly video

All of a sudden, when I preview 1080/60i footage from my Samsung SC-HMX20, instead of seeing the interlacing lines, the edges of the video wobble or warble. I say all of a sudden because it wasn't doing this yesterday, and it's happening with video that I shot and imported yesterday, not new stuff. Yesterday when I previewed video, I could see the interlacing lines, but nothing like this. The video looks the same if previewing the project or an event clip. However, It looks fine if you scrub with your mouse on either the project or a clip, but playing is definitely messed up. The raw .mp4 files still play fine in Quicktime (albeit with obvious interlacing lines).

I did install the Safari 4 beta yesterday. I tried removing it and still got the same results. The only thing I've done with the computer is export a project consisting of the same afflicted 1080/60i clips via the Export using Quicktime feature to a 1280x720 file.

Previewing: http://dl.getdropbox.com/u/33921/Picture%201.png

Scrubbing: http://dl.getdropbox.com/u/33921/Picture%202.png

Very strange, anyone have any ideas?

Thanks in advance.

Robo

iMac 24" 2.8GHz (early 2008), Mac OS X (10.5.6)

Posted on Feb 25, 2009 7:31 PM

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Answer 1

Feb 25, 2009 10:03 PM in response to Robotronic

I've seen the same thing. iMovie09 doesn't use single field processing for 60i video by default, and the preview window 'sometimes' tries to display both fields in a shrinked window to produce those wobbles. I suspect if you restart iMovie or your mac you won't see it next time. It's been randomly coming and going in my case, but it doesn't affect the output result.

And don't export to 1280x720. The longest thread on this forum now is about that very issue, and iMovie09 doesn't use single field process for output size larger than 960x540, which makes anything other than full 1920x1080 output useless for 60i video. You'll have to export full 1080i video and deinterlace/resize it to 720p in JES deinterlacer, or just export 960x540 and blow it up to 720p.

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Answer 2

Feb 26, 2009 4:49 AM in response to Robotronic

Are you using the image stabilization on this footage?

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Answer 3

Robotronic Author

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16 points

Feb 26, 2009 5:15 AM in response to Euisung Lee

I have tried restarting iMovie and my Mac, but I get the same result.

I saw the thread about interlacing and briefly skimmed it. I did a test of this camera recording at 1080/60i, 1080/30p and 480/60p, mixed footage from all three settings in an iMovie project, and exported via Quicktime to 1280x720, and I do not see any interlacing artifacts. Doesn't that go against what that other thread is about?

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Answer 4

Robotronic Author

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Feb 26, 2009 5:16 AM in response to AppleMan1958

No, I haven't done any stabilization on this footage, but I have tried it on footage from my Kodak Zi6, and it fails miserably.

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Answer 5

tjworld

Level 1

14 points

Feb 26, 2009 5:28 AM in response to Robotronic

I noticed you mention a Zi6. I just upgraded from iMovie 08 to 09 and am having real problems. Import clips into the event browser ok, clips at Hd 30fps. When I drag them into the project window the clips seem to stutter and stop randomly. Anyone else found this or know what I might be doing wrong? Am a bit new to this, but always found iMovie 08 great and was really excited about 09! there seem to be many strands of problems on this forum.

any ideas anyone?

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Answer 6

Robotronic Author

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16 points

Feb 26, 2009 5:52 AM in response to tjworld

Now that you mention it, I've only done one project with '09 using footage from my Zi6, and it does skip and stutter when previewing the project, especially when transitioning from one clip to the next. You might want to start another thread about that.

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Answer 7

Feb 26, 2009 8:58 AM in response to Robotronic

Robotronic wrote:
I did a test of this camera recording at 1080/60i, 1080/30p and 480/60p, mixed footage from all three settings in an iMovie project, and exported via Quicktime to 1280x720, and I do not see any interlacing artifacts. Doesn't that go against what that other thread is about?

It does indeed, if 1080 60i footage was imported at full size (1920x1080) and not large size (960x540).

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Answer 8

Feb 26, 2009 11:33 AM in response to Robotronic

Robotronic I believe *Euisung Lee* is on to something!

How about importing, editing & exporting in the same dimensions as the video was shot.
This should eliminate the wobbly video because it is not being scaled down -- although your content will still be interlaced.

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Answer 9

Robotronic Author

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16 points

Feb 26, 2009 5:39 PM in response to iphonejunky

iphonejunky wrote:
Robotronic I believe *Euisung Lee* is on to something!

How about importing, editing & exporting in the same dimensions as the video was shot.
This should eliminate the wobbly video because it is not being scaled down -- although your content will still be interlaced.

I think you might be misunderstanding the issue (unless I'm misunderstanding what you're saying). The exported video is not wobbling; the wobbling occurs while working on my project and previewing either a clip from an event, or a clip that's been added to the project. Exported video is just fine.

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Answer 10

Robotronic Author

Level 1

16 points

Feb 26, 2009 7:08 PM in response to Euisung Lee

Euisung Lee wrote:

Robotronic wrote:
I did a test of this camera recording at 1080/60i, 1080/30p and 480/60p, mixed footage from all three settings in an iMovie project, and exported via Quicktime to 1280x720, and I do not see any interlacing artifacts. Doesn't that go against what that other thread is about?

It does indeed, if 1080 60i footage was imported at full size (1920x1080) and not large size (960x540).

Yes, I did import the 1080/60i at full resolution, but via File-> Import -> Movies, not via the standard camera browsing import window, as it doesn't work (see my other thread: http://discussions.apple.com/message.jspa?messageID=9062336). Could that be what's "fixing" the interlacing after export issue?

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Answer 11

Feb 27, 2009 12:13 AM in response to Robotronic

Robotronic wrote:
Yes, I did import the 1080/60i at full resolution, but via File-> Import -> Movies, not via the standard camera browsing import window, as it doesn't work (see my other thread: http://discussions.apple.com/message.jspa?messageID=9062336). Could that be what's "fixing" the interlacing after export issue?

Possibly so, but not sure. Am I right to understand that your cam is not AVCHD one, but it records h264 quicktime movies? If so, iMovie won't attempt to convert movies on import, and the fact that you see wobbly distortion on viewing window indicates that 1080i 60 movie remains as is. I'm curious how it could be exported to 720p without interlace artifact. Perhaps iMovie09 drops lower field on h264 1080i movies the same way it used to in version08, but not for AIC 1080i ones. Quite inconsistent.

Whatever it is, iMovie09 current version shows quite a lot of random behaviors. Perhaps the lack of single field processing for 60i video was not a design but a temporary bug. I guess we'll know more when next update comes out. :-/

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