Apple Final Cut Pro 5 - Manual (Page 1301)

514 Part III Output
Playing Only the Base Layer of a Sequence
You can improve real-time performance by using the Play Base Layer Only feature.
When this option is selected, Final Cut Pro ignores effects processing altogether in
areas of your sequence where the applied video effects require rendering for real-time
playback (indicated by a red render bar). Motion effects or video filters are ignored and
the clip’s original media is played.
If you have multiple tracks of video, the video clip item on the lowest-numbered visible
video track plays back—all other layered video items are ignored.
For more information on the Real-Time Effects (RT) pop-up menu, see “ Settings and
Options in the RT Pop-Up Menu and Playback Control Tab ” on page 523.
This video transition is not
shown in the Canvas.
Unrendered audio plays
back with audible beeps.
The clip on track V1 is
shown in the Canvas
without effects.
The clip on V2 is shown in
the Canvas without effects.