iMovie HD 6 and iDVD 6 Troubleshooting

iMovie HD seems to prefer lots of memory and fast processors, but even on powerful Macs you might see sluggish behavior. Try the following suggestions to improve performance.

Change the playback preference

In iMovie's preferences, click the Playback icon and choose a different Quality setting (Figure A.1).

Figure A.1. If iMovie playback is stuttery, try using a different Quality setting.

Make iMovie window smaller

Use the resize handle on the bottom-right corner of the iMovie window to make it as small as it will go.

Quit other running applications

This frees up more memory for iMovie to use. Although Mac OS X manages memory better than Mac OS 9, I've seen iMovie and iDVD gain some pep if they're not competing with other processes.

Remove third-party plug-ins

Try paring down iMovie to its essentials. Remove any third-party plug-ins, such as those from a previous version, from [Home]/Library/iMovie/ (they may also be in a Plug-ins folder in that iMovie folder, too).

Defragment your hard disk

You can run into performance issues if your hard disk space is severely fragmentedthere aren't enough open stretches of disk space available to write entire files, so the files are broken up into pieces to fit the available free locations.

The best way to defragment a disk is to make a complete backup copy of it, erase the drive, and then restore the data.

Trash iMovie or iDVD preferences

If the program's preferences get corrupted, it places a load on the program's operation. iMovie and iDVD re-create the files they need the next time you launch the program.

To trash iMovie or iDVD preferences:

1.	Quit the application. (You may want to quit all running applications, too.)
2.	Go to your preferences folder at [Home]/Library/Preferences/, and delete the following files (you may not have all of the iMovie files): iMovie Preferences com.apple.imovie.plist com.apple.iMovie3.plist (this is used by iMovie 4, too) com.apple.iDVD.plist

Turn off FileVault

FileVault is a technology introduced in Mac OS X 10.3 that creates an encrypted version of your Home directory. However, iDVD and iMovie store their project files in the Home directory, which means that when FileVault is active, the computer is constantly encrypting and decrypting massive quantities of data on the fly. Turn it off in Mac OS X's Security preference pane.

Fixing out of Sync audio/video

If your audio and video are out of sync in a video clip, try extracting the clip's audio track, which locks the audio to the video (see Chapter 10).

Also, make sure your audio was recorded at 16-bit, not 12-bit. See the following article for more information: http://docs.info.apple.com/article.html?artnum=61636.