Solve my corrupted audio problem for $$ and eternal gratitude

Question

My video project has corrupted audio suddenly. I've read about other audio problems when exporting, but all I did was save the project while editing, no export. I have the prefs set to extract audio at pasteover, which I've done a lot of for this 2-camera wedding shoot. I also have the second audio track occasionally used for background music. All three tracks (video, audio 1, audio 2) on the timeline have corrupted audio for the entire length of the project. It sounds like a helicopter whirr was added, it's very choppy. Also, both cpus are maxxed out and the process monitor shows iMovie utilizing 180%+ consistently. When iMovie isn't running, it's in the single digits. As soon as I load iMovie the cpus max out. This hasn't happened the whole project, just recently. So what changed? I don't know. I've been doing the same thing the whole time, the pasteovers, the add titles, the add background track, saving the project every couple of minutes. Each time I've saved, it looks like it's listing off different files or clips, not just the changed clips. I've tried deleting the QT movie it created in the cache and let it recreate to see if that would help, but it didn't. Would deleting the files in the waveform cache help? I've got about 30 hours into this project already and would love to resurrect this audio if possible. Either that or it's Jim Beam and call it a day. I thought this was non-destructive editing, but apparently that's just the originals? That doesn't help much when the whole project audio goes in the toilet and I'm looking at redoing this whole project. Anyone who can fix this is getting a big ol' sloppy kiss on the mouth and an iTunes gift certificate.

Answer 1

I've never personally seen the audio problems you describe, but there's some things I'd try before giving up. As you've probably read, it's not unusual to have playback problems in projects containing complex audio. The odds for it seem to increased in QuickTime 7.
1. Try opening the "TimeLine Movie.mov" that's inside the Cache folder of the project in QuickTime Player. If the audio plays okay there, the audio data is intact and you're seeing a playback anomaly in iMovie. (QuickTime Player may choke too, but don't conclude anything from that.)
To access the movie, Control-click on the project icon and choose "Show Package Contents".
2. Try exporting ONLY the project audio to an AIFF file, then import THAT back into the project and replace the audio you have. That will "flatten" the audio and make it much easier to play. (To be safe, on a copy of the project.)
Or if you have QuickTime Pro, you might try extracting all the audio from the Timeline movie.
To export to an AIFF file, choose File > Export, click on QuickTime, set the popUp menu to "Expert Settings", press Share, then from the top popUp menu, choose "Sound to AIFF". Choose the level of quality you want from the bottom popUp menu, then Save.
What may be going on here is that extracting audio has created MANY audio files in the project, some possibly very large. (Each time we extract audio from a clip that is part of a Media file shared with other clips, iMovie extracts ALL the audio from that Media file, not just the audio of the selected clip.) To see what audio files the project contains, look in the Media folder of the project.
If you get this solved, please say how.
Oh, and if you haven't updated to iMovie 7.1, you might try that. There were improvements in handling multiple audio tracks, I read somewhere.
BTW, it's usually not a good idea to change things inside the project package. iMovie can get pretty confused. The Timeline movie is replaced each time we save, so that's not a big deal.
Karl