Apple Final Cut Pro 5 - Manual (Page 295)

294 Part IV Logging, Capturing, and Importing
Capturing Audio From an Audio Deck Using Device Control
Final Cut Pro allows you to capture audio from a device-controllable audio deck such as
a professional DAT (digital audio tape) decks or a digital multitrack recorder. This is
mainly useful when capturing audio that was acquired via dual system recording, in
which video and audio were recorded simultaneously to different devices.
As with capturing video, your audio tapes must have timecode recorded on them or
you cannot set In and Out points for capture. Audio decks may be controllable if they
use one of the standard device control protocols (typically, RS-422) supported by
Final Cut Pro.
If you’re planning to capture dual system audio using device control, make sure that your
audio deck is genlocked with the audio or video interface you are using for capture. For
more information on connecting a device-controllable audio deck to your computer, see
“
Connecting Audio Devices ” on page 204. For more information on capturing
synchronized audio, see Volume IV, Chapter 24, “Capture Settings and Presets.”
About Audio Peaks
When you capture audio, clipping occurs if any part of the audio signal goes over
0 dBFS. Because 0 dBFS is the maximum digital level possible, all levels that would
have been above 0 dBFS are set to the maximum audio level, causing clipping. Due to
the nature of digital audio recording, such clipped audio typically results in a crackly,
brittle-sounding clip that is unsuitable for use. All occurrences of clipped audio
appear as 0 dBFS peaks. Excessive peaks indicate that your audio was recorded at
unsuitable levels.
Final Cut Pro alerts you when an audio channel is peaking by lighting up its peak
indicator in the Clip Settings tab of the Log and Capture window. If the peak indicator
is lit, you should reduce the gain for that channel on your audio interface.
If you have already captured a clip and it has peaks in the audio, you can either
recapture the audio at a better level or edit the audio appropriately to avoid the
peaks. You can use the Mark Audio Peaks command to identify audio peaks in clips or
sequences. It’s then up to you to decide whether to avoid using those sections of
audio or rerecord them. For detailed information about the Mark Audio Peaks
command, see Volume IV, Chapter 9, “Diagnostic Tools for Clips.”