View Full Version : iMac with OS 10.4.11 reading video incorrectly

06-17-2008, 07:10 PM
This condition just popped up a couple of days ago. The iMac is a g5 w 2g ram. I have a 260g HD that is 180g full of mostly video. I just downloaded the most recent version of Quicktime, but I do not know the version. The projects are mostly finished pieces, and I have shared them to tape or dvd or looked at them full screen on the computer. They always looked fine until this glitch popped up on Sunday.

When I boot an iMovie (6.0.3) project, or a Quicktime movie, the video plays back jerky. Audio is okay.

I exported the project in iMovie that I was working on, to video tape. The video track is black but the audio track is okay.

I opened a sampling of completed projects, they all looked the same; audio okay video jerky. It is not a matter of setting the display quality. I opened an external hard drive that is full of completed video. Those files do the same thing.

I tried to import material into a new project. It was the same. I do not think it is iMovie, I think it is in the video board or the operating system. But I have no expertise to support my guess. IMovie is crashing alot and that is new.

I live about one thousand miles from real help. I have a technician in a city about 100 miles away, but I want to try to narrow down the problem before I pack up Big Mac and sent it over there. No one in this city does Mac tech.

I ran Disk Warrior (4) to clean up the hard drive and files. Nothing showed up noticeably wrong, but it made no difference in the video jerkiness.

I think it happened when I was dropping one second cross dissolves into a series of fifty still pictures, but I am not sure. I was just finishing up a one hour video piece when it happened. I tried to load it out to tape, but the result was black video with perfect audio.

Any ideas?


06-17-2008, 08:34 PM
You might try copying the data off to an external Firewire drive and playing it from there, see if that clears up the issue. This is testing if the drive is slow because it is getting fullish or getting fragmented.

If you don't have a Firewire drive then I would kindly suggest you need a spanking. You need one to maintain a backup of your data. Without a backup you are risking everything.

You'll figure it out. It is some little something that is causing this. My expertise is storage, so I naturally look that direction first.


06-17-2008, 10:30 PM
If not that, what about downgrading Quicktime? You mentioned that you recently upgraded.....could that be the culprit?

06-18-2008, 07:49 AM
MacFixIt has 4 posts now on QuickTime 7.5 issues. #4 tells where to download version 7.4 and how to install it. #2 post seems to cover your issue. There are links to the other posts in #4 but you may need to become a member to view them. Membership can be free. k

06-18-2008, 04:43 PM
I've got lots of external drives and lots of stuff backed all the way up the dark side. This project is saved in a former verision, but I hate to lose several hours of work if I do not have to.

When I plug in the other drives and open any projects from them, they act the same way. Audio is clear and smooth, video is jerky and appears out of sync whether it is an iMovie project or a QT project.

I have not tried to open a FCExpress project to see what it does. That might be another test.

I think the troubleshooting key is in the fact that when I export the project to video tape, the picture is black black, but the audio is just fine.

When I talked to my local (Two Hours away) techer I did not think to tell him about the black video and okay audio. He suggested that if I leave the computer on for a couple of weeks, it might fix itself. He also suggested changing the user name in preferences. I did not try that, but I really cannot wait a couple of weeks on the chance that the computer knows best.

I just want to be able to offer him some place to start to figure out my problem, when he gets Big Mac in the mail, again. It only costs $25 so that doesn't kill me, but it takes a day to get there, and a week or two to fix if he needs to order parts and another day back, plus the exposure of the trip.

I considered whether the QT upgrade could be a culprit, but I did that the day before this thing happened. I edited for a couple of hours after I downloaded QT and I had been editing for a few hours the next day before the problem showed up.

I think the jerky video started after I dropped crossdissolves between about 50 stills that were part of a slide show in this longer movie. The whole piece is about an hour. I was in a hurry, and I just kept dragging the effect to the next still frame as fast as the program would let me do it. I actually got ahead of the machines ability to accept the effect, but ultimately it did seem to accept the dissolves, and came up appearing ready to go again. Soon after that, I noticed that the video seemed jerky, even though the audio was fine. That is when I decided to export to video tape in case I could escape disaster by that means. Too bad, no luck!

Sorry to bother you guys with my goofy problem! But you have been helpful in the past so here I am again at your door step.


06-19-2008, 09:01 AM
Putting many disolves over a long video project can make the video jerky when played back, but only for that one project. The long video file is on the drive, then each of those rendered disolves are written in the next available free space on the drive, which is usually after the video file. So the beginning of the file is played, then the drive heads have to run to the first disolve, then back to the file, then far away again for the next disolve and so on. Seek times on hard drives are what govern the severety of the jerkiness. I use two striped arrays (4 HDs) to eliminate this, one for video storage and the other for renders. A way to get around this without buying anything new though, would be to export the project to a completed video file. That way all of the disolves or anything else are written into the completed file as one chunk that can easily be printed to tape.

As for the playback probs of the other known good files, I would guess that almost certainly has to be the upgrade of QuickTime. Each version of QT comes with all kinds of codecs needed to playback each type of file. The versions of these codecs change and sometimes are even totally left out of newer versions. I could rant all day about having to install older versions of QT on a dummy system just to get a different version codec to fix something. I should add that QT is an essential part of Final Cut Pro and iMovie, and that it's upgrade affects them as well. Anyway, there are two rules that must always be followed in video work, never upgrade anything (harware or software) until all projects are done, and if it's not broken don't fix it. :) I've had my ass handed to me a couple times over those things, and it all goes hand in hand with regular backups. I used to backup to tape drives and that was slow and a pain, but HDs have been so cheap and fast that it's really easy to backup huge amounts of work. If all else fails, you might have to backup your project and source files and do a fresh reinstall of everything.

oh Martin, how's the film stuff going? I got a new 3CCD camera and it's made my life hell. sigh

06-21-2008, 09:54 PM

Your comments are helpful in trouble shooting the situation I am in. Someone suggested tech tools utility. Any ideas about what that could do that Disk Warrior does not do? I wish I had more interest in the technical stuff, especially being so far out in the boondocks, but I am just not wired up that way.

I am going to look at the Macfixit posts to see if it helps. Thanks you guys and gals! mx


I am still looking for the 2 or 3 min of stuff from a HS class reunion in 1979 that I thought would make a good trial reel, and would be fun to incorporate with some photos from High School, 1954-58. I even have some 8mm movies of some of those times too, which I sure could drag out and cut onto a reel to convert to dv. If I get motivated I might do that, but I am preoccupied with this current glitch.

No matter what, I will send you "Take your own and only one" for conversion. It was probably my second true movie, done in 1966 or 67. I will run it through the projector first, but I bet it is okay.

What is your new camera? I almost got my self one a few months ago, but mine is still doing okay, so I will hang with it until I have to replace it. Did you check out montanaartworks.biz?

Thanks for remembering me.


06-24-2008, 10:17 PM
Kay and others

I did the download and reinstall. It was a partial fix. Video is smoother but still not synced with audio. I did not have time to try any other stuff like print to tape or extract audio and re sync etc. I am in the field on a project again so this post is from a hotel in Missoula. I should have hauled Big Mac along and took it to a local macWizard. But I did not. I will work on it again when I get home.

Apple forum QuickTime denies any culpability. QT aint the problem they say. It is dumb users like me who dont do the voodoo dance sixteen times for every process step. I'd rather pay a techie. Only one problem with that mind set is that there aint no techies in my town. Phooey. Well, I have to bite that bullet for the sake of non linear video editing. No matter what else, it beats working with film! So eat schitt and like it MRmx. Ummmmm! Yummy.

I will let you know when I get it figured out.

Jeff, its in the mail with my latest for profit.


06-24-2008, 11:20 PM
Thanks for the update for those of us following along at home. :)

Nothing against TT, but I seriously doubt it would do a thing for this issue. Folks tend to find a tool or three they like and apply them to every situation, so if someone recommended it.......it is good at what it does, but this ain't it.

To the man who's only tool is a hammer, ever problem looks like a nail.

Or sumpin' like that.

06-25-2008, 07:24 PM
I am in the field on a project again so this post is from a hotel in Missoula.I live an hour North of Missoula. Worst place ever to find Mac products or technical assistance. :D It stinks. :rolleyes: