Apple Final Cut Express 4 - Manual (Page 158)

158 Part III Setting Up Your Editing System
Example Calculation for Disk Space Requirements
Suppose you want to create a music video that’s approximately four minutes long
using DV video for capture, editing, and output. Consider a shooting ratio of 15:1,
meaning you shot 15 times more footage than you will use in the final movie.
Total duration of media captured to disk:
 15 x 4 minutes = 60 minutes
Data rate requirements for DV media:
 3.6 MB/sec. video data rate x 60 seconds = 216 MB/min.
Calculated disk space requirements for media:
 60 minutes x 216 MB/min. = 12960 MB
 12,960 MB ÷1024 MB per GB = 12.66 GB
Multiply final movie length by a safety margin of 5 for extra files:
 4 minutes x 216 MB/min. = 864 MB x 5 = 4320 MB
 4320 MB ÷ 1024 MB per GB = 4.22 GB
Total disk space requirements:
 12.66 GB + 4.22 GB = 16.88 GB
Round your calculation up to 17 GB to be safe. This is the amount of disk space you’ll
need for this one project. If you plan to work on multiple projects at the same time,
estimate the amount for each project and add these numbers together.
Note: These calculations are also important when planning how to archive your
projects when they are finished, though many people choose to archive only the
project file and not back up their media files (since the original footage is stored on
tape, you can always recapture the footage if necessary).