Considerations When Exporting Audio

Depending on your project’s needs, you may be able to use the edited audio from Final Cut Pro directly in the film’s release print. More often you will want to finish the edited audio using a specialized application or a facility specializing in audio finishing. This is typically where sound effects, music, and any dialogue are added or enhanced.

There are a couple of items to consider when exporting audio:

If you decide to recapture and reedit the audio at an audio post-production facility, see Exporting an Audio EDL for details.

OMF Files

An OMF file contains not only the audio, but also a description of the audio edits. Digital Audio Workstations (DAWs) that can import OMF files can take advantage of having the edit In and Out points along with other information, such as cross fades, enabling them to make small changes. OMF files typically contain all of the audio tracks used in the program (other export formats have limits).

Another advantage of OMF files is that they can contain the audio and edit information from non-timecode-based sources, such as audio CDs. (Audio EDLs describe only edits using timecode-based sources and do not include any references to sources such as audio CDs.)

See the Final Cut Pro documentation for information about exporting OMF files.

AIFF Files

An AIFF file contains only the audio and cannot be easily changed. You must export a separate file for each audio track. As with OMF files, AIFF files can contain the audio from non-timecode-based sources, such as audio CDs. (Audio EDLs describe only edits using timecode-based sources.)

See the Final Cut Pro documentation for information about exporting multiple tracks as AIFF files.

Audio Speed

Often the playback speed of the edited audio is slightly different from what it was when it was originally recorded (its natural speed). This compensates for film speed changes made during the telecine transfer. Anytime you are editing at 29.97 fps or 23.98 fps, the audio is running 0.1 percent slower than its natural speed. If you are editing at 25 fps and the telecine transfer film rate was 25 fps, the audio is 4 percent faster.

This speed difference is maintained when you export an AIFF or OMF file. Make sure to find out the requirements of your audio post-production facility with regard to audio speed issues before you export the files.