Specifications

16
A Digital Video Primer
Configuring your system
Whether you’re a professional or a hobbyist, choosing the right combination of soware and
hardware can be a tricky guessing game about future technology developments. You need to
purchase enough power, storage, and exibility to meet your current needs, while being mindful
that technology is inexorably advancing, so you had better conserve enough capital to keep your
systems current, as well as to fund anticipated growth. Not long ago, the more money you paid,
the more capability you bought. But the dierences between results are ultimately becoming
more a matter of the artist’s vision than the cost of the system being used. Today, you can put
together a powerful, desktop-based video production setup for under U.S. $5,000. Here are a few
more questions to consider:
What kind of video will you be putting into the computer? Will you only be working with DV
footage? Do you need to edit footage captured in component or composite video? For example,
many industrial and broadcast users need to capture and record video in the component format
for use with Beta-SP decks, in addition to DV. It would make little sense for such a user to have a
DV-only system.
How time-critical will your productions be? When you add eects like transitions and titles to
video, they usually have to be rendered by the computer into their nal form. e rendering
time can vary from minutes to hours depending on the complexity of your productions. If you
are producing home videos, the time lag isn’t much of a problem. But, if you have clients looking
over your shoulder asking for changes, you might want to purchase a system that can produce
these eects instantly—in real time.
How much video will you be working with? Remember that one hour of standard DV video takes
about 13GB of disk storage. If you are producing a one-hour documentary, you’ll want at least
enough storage for several hours of raw footage. You will oen nd yourself working with four or
ve times as much raw footage as you will eventually use. If you are doing professional editing,
you could be working with 20 or even 50 times the amount of nal footage! Of course, you don’t
need to have all of it available at all times, but you will need to think about the amount of footage
you’ll need to access when conguring your storage.
How will you distribute your finished video? Do you intend to distribute on lm, in SD or HD, on
VHS tape, DVD, or the web?
The CPU
It’s important that you choose a computer with a CPU (central processing unit) that’s powerful
enough to meet the demands your creative process will place on it. Post-production is all about
processing and moving huge amounts of data, while maintaining a steady data rate. Render-
ing complex edits, transitions, lters, composites, and eects places enormous demands on the
system. Although the video captured by your system is compressed, it must be decompressed to
be processed, and then, once rendered, it must be recompressed to be saved and stored.
For example, just for standard NTSC, each frame of uncompressed video consists of 720 x 486
pixels (NTSC). at’s 349,920 pixels per frame. ere are 29.97 frames in every second of video,
so that’s approximately 10,500,000 pixels per second. Each pixel is made up of 3 bytes of color
(RGB), meaning that nearly 31,500,000 bytes (31.5MB) of information must be processed
for every second of video that’s altered in any way. Even for something as seemingly simple as
adjusting brightness or contrast, millions of calculations must be made to get the job done. e
speed at which the task can be completed is dependent upon the power and speed of the proces-
sor. Moreover, your creative process, owing from task to task, can only proceed as rapidly as
each operation is executed, so that it, too, is ultimately dependent on the processor.
When all is said and done, output is CPU-dependent, as well. If you’re planning to export your com-
pleted production in a compressed format, such as one of the MPEG variations or a web-streaming
format, then the power of the CPU will determine the speed of the nal le-creation process.