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6. Click the Audio Mixdown Options button to open a dialog of audio mixdown
options. Click the Help button in the dialog for help choosing options.
7. Click Save to export your video.
Optimizing Video Performance
Here are a few tips to optimize video performance:
• If you intend to do a lot of seeking around or looping and editing while a video
file is loaded, make sure that your video file has sufficient keyframes. Since
each frame has to be computed from the last keyframe encountered, if you
have very few keyframes in the video, performance may be slow. To change the
number of keyframes, you may recompress the file using the File-Export
Video command and specify more frequent keyframes. Choose a suitable
video compressor such as Cinepak and change the KeyFrame Rate parameter
to a number between 1-5. A value of 1 makes every frame a keyframe, and
higher numbers insert a keyframe after that many frames.
• Changing the video properties of an AVI file, such as Trim and Start time, can
make realtime performance slightly slower. You can make these changes
permanent (and thereby reduce the load on your CPU) by using the File-
Export Video command.
• Playing videos at a resolution (video size) of 320x240 is usually a high enough
resolution to monitor the video while you’re composing a soundtrack. You can
still choose to stretch the video to full screen at this resolution. You set the
video size on the Render Quality tab of the Video Properties dialog. Using a
higher resolution can bog down your computer if you’re processing audio
tracks at the same time.
Using the Video Thumbnails Pane
At the top of the Track view in SONAR Producer is the Video Thumbnails pane,
which displays individual frames of your video at certain time intervals of your
project. The time interval between displayed frames is determined by the zoom
level you choose. If you zoom in far enough, you can view each individual frame of
your video.
Note 1: if you’re playing back a highly compressed movie (not many keyframes in
the file), it can take about a minute to redraw video thumbnails when you’re
playing the movie or resizing a window.
Note 2: some Windows Media videos do not report their frame rate to SONAR.
SONAR can play these files, but cannot create thumbnails from them, so no
thumbnails appear in the thumbnail pane.
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