Thursday, March 6, 2008
It's okay to use .mp3 files in FCP's timeline in a pinch, (.aiff is preferred) but you'll need to render the audio (usually) first. If you don't render it you'll hear FCP beep repeatedly until you do something about it. A quick way to check to see if you need to render your audio (aside from hearing the beeps) is to look at the two thin render indicator lines at the top of your timeline. If the bottom one is red (hold your mouse over it to get a pop up with info) you need to render your audio.
Why not just render all? Well, if you have effects that are previewed (green bars or even yellow) and just want to check the audio sync or timing you can save rendertime by just rendering your audio. A quick way to do this is to tap Control + Option + R which will just render your audio and leave your video tracks untouched.
Btw, a really fast way to convert .mp3s into .aiff is to open the .mp3 in Quicktime Player, then Export them as .aiff.