Multimedia.
A multimedia system.
Multimedia refers to the technologist and applications that integrate different media: text, graphics, sound, video and animation.
Its power resides in interactivity, hypertext and hypermedia. Multimedia software is usually interactive, so you can choose what you want to watch, listen to or write. Hypertext means that you can click on a word and jump to another screen with more information; hypermedia is similar, but works with sounds and images (e.g. the Web).

An IT student says:
‘I use multimedia for my extracurricular activities. I download music from the Net and burn music onto CDs – I copy songs onto CDs. I talk with my friends on the Messenger. I also retouch digital pictures and edit video clips. To run multimedia software you need a fast CPU, expandable RAM and a large hard disk. But what marks a computer out as a multimedia PC is its audio and video capabilities: a sound card, a microphone, a decent pair of speakers, a high-quality monitor and a DVD writer, and its performance depends on all these components working in harmony’


Recognizing file formats.
To identify the type of file, an extension is added to the filename when it is saved on disk.

Common text extensions:

.pdf (portable document format)
.doc (MS Word document)
.rtf (rich text format)
.htm or .html (hypertext markup language for Web files)

Graphics include charts, photos, drawings, buttons, etc.

.gif (graphics interchange format)
.jpg (jpeg – joint photographic experts group)
.tiff (tagged image file)

You can hear sound such as songs, movie soundtracks and speeches.

Common:
audio formats:
.wav (Windows wave audio format)
.ra (RealAudio file)
.mp3 (compressed music files)

Video refers to recording, editing and displaying moving images.

Common formats:
.avi (audio video interleave)
.mov (QuickTime movie)
.mpg (mpeg – moving picture experts group)

Animations are made up of a series of independent pictures put together in sequence to look like moving pictures.

Common formats:
.gif for animated gifs
.swf for Flash files

Files compressed with WinZip have a .zip extension.

A popular format used to compress and distribute movies on DVDs or over the Net is DivX, a digital video codec (Compress, DECompress).

Applications.

• In public places (e.g. museums and stations), there are information kiosks that use multimedia.
• In education, it is used in presentations and computer-based training courses.
• On the Web, audio and video are integrated into web pages. For example, RealPlayer supports streaming, which lets you play sound (e.g. from radio stations) and video files as a continuous stream while they are downloading.
• In virtual reality, users interact with a simulated world: doctors train using virtual surgery; pilots use flight simulators to do their training; people visit virtual exhibitions, etc.
• You can play games om a computer or video games on a dedicated machine, called a video console, which you connect to a TV set. You can also play games on the Net; some websites have a multiplayer facility that enables lots of people to play the same game at the same time.