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Note: Removable media drives such as Jaz, Zip, and CD-RW drives are not suitable for
video capture and playback because of their low data transfer rates.
Determining How Much Space You Need
The amount of disk space you need depends on the specifications of the video format
you are using for editing. In some cases, you can capture video at a lower quality (which
saves disk space) for rough editing and then recapture only what you need at higher
quality to create the finished movie. This process is known as offline/online editing. For
more information, see “Offline and Online Editing.”
Know Your Shooting Ratio
Remember that when you start editing a movie, you need to capture much more media
than you will use in the final movie. The ratio between the amount of footage you begin
with and the final duration of the movie is called the shooting ratio. When you are
estimating how much disk space you need for a project, calculate it based on the total
amount of media you plan to capture and use during editing, not the intended duration
of the final movie.
Planning for Additional Media Files
In addition to space for captured files and project files, you need extra space for render
files, graphics, movie files created in other applications (such as animations), additional
audio files, and so on. A loose rule of thumb to determine how much space you need is
to multiply the amount of space needed for your finished program by five.
Ultimately, the amount of extra space you reserve depends on how much additional
media you create during editing. For example, if you use hardly any effects, additional
render files may not be a factor. If you are using only a few graphics files and little
additional audio, these may not be a concern, either.
Keep in mind that although real-time effects don’t require additional drive space for
rendering, you still need to render the effects at high quality for final output, so at that
point you need enough disk space for render files.
Calculating Hard Disk Space Requirements
You can use the table below to estimate how much disk space you need for your project.
60 min.30 min.10 min.5 min.1 min.30 sec.Video data transfer rates
1.8 GB900 MB300 MB150 MB30 MB15 MB500 KB/sec.
OfflineRT (using Photo JPEG)
3.6 GB1.8 GB600 MB300 MB60 MB30 MB1 MB/sec.
Offline-quality M-JPEG
221Chapter 13 Determining Your Hard Disk Storage Options