Apple Final Cut Express 4 - Manual (Page 891)

Chapter 56 Using RT Extreme 891
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Beep When Playing Unrendered Audio
This option is available only in the Playback Control tab of the System Settings window.
When this option is selected, audio clip items that require rendering are played back as
audible beeps. This is the audio equivalent of the “Unrendered” screen you see when
your video requires rendering. If the Play Base Layer Only option is not selected, the
beeps are not heard. For more information, see “
Play Base Layer Only ” on page 890.
Playback Video Quality
Most codecs support more than one level of playback quality to improve real-time
performance. Some codecs support three playback quality levels—high, medium, and
low—while others support only high and low quality. Selecting a lower playback
quality can increase the number of simultaneous real-time effects you can play.
 Dynamic: This option allows Final Cut Express to automatically change between
high, medium, and low quality as necessary to maintain real-time playback. In this
case, the quality of the video resolution can change frame by frame.
 High: Guarantees full-frame, full-resolution video playback. Video interlacing
is preserved.
 Medium: Displays every other pixel and every other line (this is known as quarter frame
resolution). Because only half the lines are shown, the video is displayed without
interlacing. Media is decompressed using a full-quality decompression algorithm.
 Low: Like the Medium quality option, displays video at quarter frame resolution.
However, your media is decompressed and displayed with a low-quality
decompression algorithm, which requires significantly less processing power.
Playback Frame Rate
The more you reduce the number of frames Final Cut Express calculates each second,
the more effects can be calculated in real time.
 Dynamic: This option varies the displayed frame rate as necessary to achieve the
highest-quality playback with the most effects. When more processing power is
required, Final Cut Express can reduce the frame rate to spend more time calculating
fewer frames. When few or no effects are applied, Final Cut Express can return to
playback at the full frame rate.
 Full: Your sequence plays back at the frame rate (editing timebase) assigned in the
Sequence Settings window.
 Half: Your sequence plays back at half its assigned frame rate. For example, if the
frame rate of your sequence is 24 fps, the playback frame rate is 12 fps.
 Quarter: Your sequence plays back at a quarter of its assigned frame rate. If the frame
rate of your sequence is 24 fps, the playback frame rate is 6 fps.