Page 119 - DCAP303_MULTIMEDIA_SYSTEMS

Unit 6: Hardware

6.5.2 Amplifiers and Speakers notes
Often the speakers used during a project’s development will not be adequate for its presentation.
Speakers with built-in amplifiers or attached to an external amplifier are important when the
project will be presented to a large audience or in a noisy setting.
6.5.3 Monitors
The monitor needed for development of multimedia projects depends on the type of multimedia
application created, as well as what computer is being used. A wide variety of monitors is available
for both Macintoshes and PCs. High-end, large-screen graphics monitors are available for both,
and they are expensive. Serious multimedia developers will often attach more than one monitor
to their computers, using add-on graphic board. This is because many authoring systems allow
working with several open windows at a time, so we can dedicate one monitor to viewing the
work we are creating or designing, and we can perform various editing tasks in windows on other
monitors that do not block the view of your work. Editing windows that overlap a work view when
developing with Macromedia’s authoring environment, director, on one monitor. Developing in
director is best with at least two monitors, one to view the work the other two view the “score”.
A third monitor is often added by director developers to display the “Cast”.
6.5.4 video Device

No other contemporary message medium has the visual impact of video. With a video digitizing
board installed in a computer, we can display a television picture on your monitor. Some boards
include a frame-grabber feature for capturing the image and turning it in to a colour bitmap,
which can be saved as a PICT or TIFF file and then used as part of a graphic or a background in
your project.

Display of video on any computer platform requires manipulation of an enormous amount of
data. When used in conjunction with videodisc players, which give precise control over the
images being viewed, video cards you place an image in to a window on the computer monitor;
a second television screen dedicated to video is not required. And video cards typically come
with excellent special effects software.

There are many video cards available today. Most of these support various video in a window
sizes, identification of source video, setup of play sequences are segments, special effects, frame
grabbing, digital movie making; and some have built-in television tuners so you can watch your
favourite programs in a window while working on other things. In windows, video overlay boards
are controlled through the Media Control Interface. On the Macintosh, they are often controlled
by external commands and functions (XCMDs and XFCNs) linked to your authoring software.
Good video greatly enhances your project whereas poor video will ruin it. Whether you delivered
your video from tape using VISCA controls, from videodisc, or as a QuickTime or AVI movie, it
is important that your source material be of high quality.

6.5.5 projectors
When it is necessary to show a material to more viewers than can huddle around a computer
monitor, it will be necessary to project it on to large screen or even a white painted wall. Cathode-
ray tube (CRT) projectors, liquid crystal display (LCD) panels attached to an overhead projector,
stand-alone LCD projectors, and light-valve projectors are available to splash the work on to
big-screen surfaces.
The CRT projectors have been around for quite a while they are the original “bigscreen” televisions.
They use three separate projection tubes and lenses (red, green and blue), and three colour channels

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