We’ve previously talked about how to extract audio from an iMovie ’09 project — but how do you add it back into the movie once you’ve done your editing in Soundtrack or a similar application? And, just as important, how do you get it to stay in synch with the movie?
For those who find it too much trouble to click the link above to discover how to extract audio from an iMovie ’09 movie, the gist is that you choose Share -> Export Using QuickTime, and choose the option to export QuickTime to AIFF.
Now that we’re all up to speed, you then proceed thusly. Set about your dirty work in Soundtrack or whatever audio application you care to use and do anything you like except change the duration of the audio file. So, play with the EQ, filter noise, or add an unhealthy amount of reverb, just don’t cut or add anything to the file. (Because if you do, the file won’t be in sync when you add it to your iMovie project.)
When the file is to your liking, save it to the Desktop. Open your iMovie ’09 project and drag the saved audio file from the Desktop to the beginning of the project in the Edit Project pane. That project pane should turn green and the name of your audio should appear in white at the very top of the Edit Project pane. Click the video track, choose Edit -> Mute Track, and play the video. You’ve muted the video’s original audio track and now hear just the enhanced track you added. Everything should be in sync.
You can leave things just as they are or, if you like, you can delete the original audio track. To do so choose Edit -> Detach Audio. The video’s soundtrack will appear as a purple bar beneath the video track. Click on that purple bar and press the Delete key. You’ve now left with just the audio track that you “sweetened” with an audio editor.
New audio track added and original audio detached.