iMovie: Use 16-bit audio for best results

For best results when creating long movies (over 20 minutes), record footage using 16-bit audio. Recording with 12-bit audio may result in a gradual loss of audio-video synchronization. Check the manual that came with your DV camcorder to find out how to set the audio format.

If you have already created a project with 12-bit audio, you may be able to export the project to QuickTime as follows:

1. Import your 12-bit video footage into a new iMovie project.
   
2. Insert a fresh tape into your camera, and set the camera to 16-bit audio.
   
3. Export the iMovie project that contains the 12-bit audio footage to your DV camcorder set to 16-bit audio.
   
4. Create another new iMovie project.
5. Import the fresh footage from your new tape into this new iMovie Project.
6. Export this project to QuickTime if needed or simply edit the project.
   

This includes versions of iMovie for Mac OS X and Mac OS 9.

Related document

42974: "iMovie: Improving audio and video synchronization"