The Wide World of Multimedia
Playing Back Sound, Video and Animation Files
Part I: Getting To Know Your Computer
146
To learn more about the system’s MIDI capabilities, look up
MIDI in the Windows 95 help index.
MIDI files have the extension .MID.
Video and Animation Files
Full-motion video includes both traditional film and animation. A
video plays back on your VCR at 30 frames per second. To play
back the same video on your computer would require 9 megabytes
of data per second at 640 x 480 resolution.
Since playing back video requires so much data, multimedia appli-
cations that use film or animation normally play back at 15 frames
per second with a resolution of 320 by 200 pixels. This is why
video images are less smooth on a computer than on television.
To reduce the storage required, all video files must be compressed
before they can be distributed and decompressed when you view
them. Two compression and decompression techniques are in
general use.
AVI Files
The most common technique for storing and playing back video
on personal computers is Microsoft’s Audio Video Interleaved
(AVI) format. This software technique displays video using up to
15 frames per second in a small window.
AVI files have the extension .AVI.
