Choosing Source and Auxiliary Timecode Track Display
QuickTime media files can have several timecode tracks, although they typically start
with one. The timecode track written when you first capture a media file is called the
source timecode track. You can add additional timecode tracks to the media file after
you capture. These are called auxiliary (aux) timecode tracks.
Auxiliary timecode tracks do not refer to the original timecode from your source tape,
since this is the purpose of the source timecode track. Instead, they can refer to
timecode on a different tape, such as an independent audio tape recorded at the same
time as the video. In these dual system productions (in which video and audio were
recorded separately), the timecode on the videotape and the audio tape are often not
the same; yet in post-production, you need to synchronize the video and audio media
files together to edit.
Adding auxiliary timecode tracks to your media files allows you to add matching
timecode to both media files without removing the original source timecode—which is
still important for referring back to your original tapes.
In Final Cut Pro, you can choose which timecode track to display for each clip: source,
Aux 1, or Aux 2. Many clips only have a source timecode track, so in these cases there is
no option to display Aux 1 or Aux 2 timecode.