Symptom #1: Audio Files Drop Frames and Go Offline After Relaunching FCP
"I import tracks from my audio CD into FCP, but they go offline the next time I restart my project."
"I imported tracks from an audio CD into FCP, but I get dropped-frames warnings every time I play the clip."
"I hear crackling and popping from my imported audio CD tracks."
FCP can easily use audio tracks taken from audio CDs, but if you don't perform the import correctly, you may end up with offline clips or dropped-frames warnings each time you try to access the clips. This occurs because FCP, unlike other nonlinear editors, does not duplicate media when it imports a file.
When you import a file into an FCP project, it creates a clip linked to the media file you imported, rather than generating yet another media file in your scratch disk. This is a very good idea, particularly for importing elements like graphics files and video files rendered out of other applications, such as Apple Motion or Adobe After Effects. It's digital, and it's already on your disk; why duplicate it?
The problem is that some users forget this when importing audio CD tracks. If you insert an audio CD and then choose File > Import > File and select a track from the CD, you are linking the imported clip directly to the CD itself. This creates three separate and distinct problems.
First, the clip in your project will be online only as long as that audio CD is still in the CD tray. If you shut your project down, remove the CD from your Mac, and restart the project, the CD the clip was linked to will have disappeared, forcing the clip offline. FCP will not tell you why the clip is offline, because as far as FCP is concerned, the CD was a legitimate source location. Only you know that it was not a permanent drive.
Second, each time you attempt to play the clip linked to the CD (assuming that the CD is still in the tray and the clip is not offline!), your Mac will have to play the actual CD itself to retrieve the data the clip is linked to. Anyone who has booted a Mac up from an installer CD will tell you that optical disks, like CDs and DVDs, are very slow. FCP will not be able to keep up with the frame rate while trying to read the optical disk and will generate dropped frames alerts.
Finally, if you get this far, you are very likely to end up with crackling or out-of-sync audio. As discussed in the previous lesson on FCP performance troubleshooting, mixing sample rates in an FCP sequence is a pretty bad idea. Audio CD tracks carry a uniform sample rate of 44.1 kHz, which is nonstandard and not acceptable for use with video. Although FCP has the means to resample nonstandard audio on the fly, the results are usually less than acceptable. Resampling at Low Quality in the Audio Playback Quality pop-up menu of the User Preferences dialog can yield crackling or popping artifacting unless you render the material out in an audio mixdown.
There is no reason to end up in this situation. When you want to import an audio CD track, use the Export Queue window included in FCP:
The bonus is that you can import and connect the entire contents of the CD in one conversion step by dragging the entire disk into the Export Queue window.