Table of Contents
Advertisement
151
The Wide World of Multimedia
Playing Back Sound, Video and Animation Files
Digital Audio Wave Files
Digital audio uses computer-based technology to record, handle
and recreate sound. Digital audio systems sample the waveform at
fixed time intervals, for example, at 30 times per second, and
reduce the sound to a sequence of numbers.
When you play back a digital waveform or wave file, the software
transforms the numeric data back into its original acoustic wave-
form.
If you use the microphone to record sounds, the computer stores
them as wave files.
Wave files have the extension .WAV.
MIDI Files
Musical Instrument Digital Interface (MIDI) is a standard lan-
guage used by composers to create music to be played by a syn-
thesizer. MIDI songs consist of commands, not actual digital
sounds. For this reason, the size of a MIDI file is much smaller
than a .WAV file.
You can connect an external MIDI device, such as a keyboard with
a built-in synthesizer, or you can play MIDI files using the com-
puter's internal synthesizer.
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 by 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 the
- Quick Links:
- The System
Hide quick links:
Advertisement
Table of Contents
