Lousy iMovie HD 6.0.2 playback -- stuttering video and audio

The Media folder familiar to iMovie 4 (and earlier) users is still there, inside what is now the project PACKAGE. The iMovie 5/6 project is a special kind of file, called a package, that can contain other files and folders. (Actually, a package is a special kind of folder that looks and acts like a file.)

Control-click on the project icon and choose "Show Package Contents". You'll see the Media folder.

The QuickTime movie is inside the (new) Cache folder. It's now called "Timeline Movie.mov".

I presume this is to keep meddling fingers from mucking up the
contents of the media folder.

Yup. But we won't let THAT stop us. 🙂

Karl

No problem to make a copy that way (your internal HD is too smal for working with iMovie. Leave the original to be on the safe side on the int.HD.

Frank...

I have had similar problems with my latest iMovie project. Most of my projects are fairly simple (5-10 minutes, a few imported video clips, some transitions, a title or two), and I usually export them for viewing on my .Mac site. This last project, though, was for my son's school project. It was about 18 minutes, and involved about 25 imported mp3 sound effect clips (battle sounds I downloaded from somewhere), a couple of mp3 songs (I'm not sure where my son got those, I probably don't want to know) and 2 or 3 voice-overs (recorded right into iMovie using that little record button thingy).

I'm not sure where the "tipping point" was for our stuttering and jerking problem. My son was doing the editing (after I gave him a basic run down of how iMovie worked) and after a while, came to me complaining that the computer was "lagging" (a common phenomenon when his Xbox overheats). What I did observe was that the stuttering got progressively worse the more he (A) added mp3 sound effect clips, (B) adjusted the volume settings on those imported clips, and (C) adjusted the volumes on the video clips (we didn't extract any audio).

I'm not brave (nor competent) enough to try all the things you're trying, so I'll just hang out here on this thread and see what else you come up with. Thanks for your efforts.

...Ron

Oh, and I thought I'd add this:

Even though my project was stuttering so bad at the end that I couldn't even view it any more, I could export it as a full quality .dv (found that solution for Terri on the iDVD discussions board) and that file was perfect, including all the sound effects and songs. The export took over 2 hours, but it did work and I was able to use that .dv file in iDVD to finish off my son's project.

I don't know exactly how iMovie works, but I suspect
it's basically an edit decision list (a relatively
simple file listing the start and end times of each
clip, and where transitions, titles etc. come in),
plus a QuickTime version of the movie for easy
viewing in iMovie.

That's correct. The list of clips stored in the project file shows the name of the Media file for each clip, plus the frame number of where the clip starts in the Media file and the length of the clip. With some historical data too for Undo-ing.

The QuickTime movie inside the project has a very different data structure, but a similar function. It's a reference movie with no video or audio data of its own, just pointers to the Media files. It knows which frames to play from each Media file, and when.

But when the final movie is
commited for recording to another media (tape, DVD
disk) the source material is taken from the original
clips according to the 'rules' of the edit decision
list. Am I correct? __ ...even close?! ___ Just
guessing.

True.

(doesn't QT work with lesser resolution and
fewer frames/sec? __)

Not quite true. iMovie uses QuickTime for everything it does (except control the iMovie user interface, of course.) All the Media files for video clips are DV Streams, a type of QuickTime movie. There's no separating iMovie video/audio from QuickTime. iMovie is just a front end for invoking QuickTime commands.

(I'm using the word QuickTime here to refer to the underlying system commands and functions that the Mac uses to play and edit video and audio. I'm not referring to QuickTime Player, which, like iMovie, relies on the underlying QuickTime software to do its thing.)

You can, of course, export an iMovie project to any kind of QuickTime movie you want — there are thousands of possibilities. If you want, the exported movie can show a smaller frame size and contain fewer frames per second. (There is no such thing as "resolution" in QuickTime, just frame size, in pixels.)

Which brings me back to the stuttering problem. If
the culprit lies in the handling of audio, then I
wonder if a solution can be far off. Since the
problem didn't exist in earlier versions, shouldn't
it be fairly easy to resolve the problem now? ____
Another wild guess!

It shouldn't be terribly hard to fix, but the problem that's been with us for some time and it's not been fixed. Since not everyone has the problem, the exact cause may be difficult to nail down.

The most anyone has been able to do is say "My guess is it's an audio problem of some kind." which this thread is helping to prove.

Your efforts to hang in there are very helpful. It's providing the most detailed information I've seen. When your work is done, I hope you send feedback to Apple with these details. If someone has their lights on at Apple, they should send you a hard disk and ask for a copy of the original project so they can analyze it properly.

Go here to send your feedback:
http://www.apple.com/feedback/imovie.html

Karl

Hi Frank,
As I mentioned before(yesterday) I have the same problem and therefore I've been reading these posts with much interrest.
I've trashed the biggest of the two projects(the combination of two smaller projects).Didn't help.
After that I did the same as you and deleted the extracted audio.This didn't help a bit.
So I emptied the iMovie trash,did no good either,so for me that doesn't work.
My projects ran without any problems,both about 1 hour each.
But after joining them,it went sour.
Jacqo

Hi all. This is my first post (though I have had Macs since the classic). Apologies if I am telling you something you already know!
I had the same issue (now fixed). - here's the back ground:

Did a 25 minute movie which had many clips/transitions. The file is 16 Gig! It worked fine until I noticed many of the (old) clips had sound from one speaker only. So I extracted the audio, exported it, resaved it in quicktime as mono and dragged it back. There were dozens of them!
Here's where the problems began! the more I re imported the audio, the worse the performance.
I persisted untill all were re imported but the movie sound is intelligible and the video jerky.

The way around it is long but simple - open a new Garage Band file, drag your (closed) imovie to the media pane then drag it from there to the main part of the window.
OR with the imovie open, share it with Garage Band. The conversion takes ages!
Once in GB, don't do anything, just share from within GB with iDVD. Note that sharing the movie with iDVD first produced all sorts of wierd sync issues.

This works fine for me. The only issue is if I need to change anything in the iMovie file if I don't like something, I can't hear/see it properly in iMovie! Fortunately I have the original working one speaker version to reference changes.

Thanks for a great forum!

Greg

Glams
How do you share it with Garage Band through iMovie HD (5.0.2) ??
Under the file menu, then under "share"... there is no choice to share with GB?
Maybe I'm missing something?
Thanks!
TEXASFLOOD

G4 Mirrored super drive Mac OS X (10.4.6)

I actually only started using iMovie when it allowed more than one file to be opened - that in iLife 6. I don't know about 5 but don't think you can share with GB??? I await to be corrected! ( i hope)

My understanding of GB and iMovie is this. My problems occur when iDVD renders my iMovie ie. when iMovie shares to iDVD.
But if I get the iMovie into GB then GB shares to iDVD, I can get iDVD to render a GB file; not an iMovie file! Wow, did that make sense?

Idvd seems to screw up the sound from iMovie if it is too complex, but is fine with the sound from GB.