Prepping the Video
To reduce your video clip’s size and bandwidth, you should first remove unwanted data. Because you’ll be writing your own score, you don’t need to keep the original soundtrack (if there is one). Go to the Edit menu and select Delete Tracks; if a Sound Track is present, delete it to create a “silent movie.”
You can also edit out unwanted video, such as leading and trailing footage or glitched frames and scenes. Select a region of the video for editing by positioning the triangles underneath the progress bar in the QuickTime Player window (see Fig. 2). You can also hold the shift key and drag the cursor across the bar itself. The selected area becomes highlighted, so you can cut, copy, or paste the video to suit your needs.
When the clip is down to its bare essentials, select Save As from the File menu. You will be asked whether you want to Save Normally or Make Movie Self-Contained. The first option creates a “pointer” file that contains information about the movie and the edits you made, but lacks the actual video data. This allows for efficient file storage, because you could conceivably have multiple movie versions based on the same video images. For this situation, however, you want to apply the changes you made to the data (cutting out the unused parts), so choose the Self-Contained option. This creates a flat file that includes all the necessary data in one bundle. This format is cross-platform compatible and Windows friendly.
Shrinking the Video
Now that your clip is in its final edited form, use the Export command in the File menu to produce a new low-bandwidth video clip for your sequencer. The Export dialog box provides access to a variety of output parameters that control QuickTime Player’s extensive file conversion and compression features. For example, you can export a QuickTime movie as an AVI file for Windows or as a digital video stream, and you can export the soundtrack as an AIFF or WAV file at various sampling rates and resolutions. For this situation, select Movie to QuickTime Movie, because you want to end up with an MOV file.
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FIG. 4: The Movie Settings dialog box provides access to a number of video and soundtrack parameters. |
You can try the Sorenson Video compression scheme if you prefer; it’s one of the most efficient in terms of file size and online transfer time. But be aware that it requires an enormous amount of computational power. The version that ships with QuickTime Player can take as long as 30 minutes to encode a single minute of 240 5 180, 30 fps video on a reasonably speedy machine. Sorenson sells a Pro version of its encoder, however, that is much faster and provides access to a number of additional processing parameters.
Regardless of which compression scheme you choose, set the Frames Per Second field to the original frame rate. (Refer to the Frame Rate from the Get Info dialog box for this number.) Leave the other parameters at their suggested values. Now go back to the Movie Settings dialog box and click on the Size button in the Video section to open the Export Size Settings panel. Set the frame size to 160 5 120 or 240 5 180, particularly if you intend to work at 30 fps, because this places a minimum burden on most machines. If you have a speedy CPU and a big monitor, you can try using the 320 5 240 resolution for better clarity, but remember that QuickTime will not solely compete for processor time.
In general, the object is to decrease your clip’s bandwidth to a point where the QuickTime, MIDI, and audio drivers run smoothly and synch-ronously. When you’ve squeezed the clip as much as you can, click on Save to apply the changes. The final QuickTime movie should be appreciably smaller than the original, and the required bandwidth should be greatly reduced.
Reprinted with
permission from 
Magazine, January, 2001
© 2001, Intertec Publishing, A Primedia Company All Rights Reserved
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