MULTIMEDIA IN THE INTERNET

INTRODUCTION
We can divide audio and video services into three broad categories: streaming stored
audio/video, streaming live audio/video, and interactive audio/video. Streaming means a user can
listen (or watch) the file after the downloading has started.
In the first category, streaming stored audio/video, the files are compressed and stored on a
server. A client downloads the files through the Internet. This is sometimes referred to as on-demand
audio/video. In the second category, streaming live audio/video refers to the broadcasting of radio
and TV programs through the Internet. In the third category, interactive audio/video refers to the use
of the Internet for interactive audio/video applications. A good example of this application is Internet
telephony and Internet teleconferencing.
2. STREAMING STORED AUDIO/VIDEO
Downloading these types of files from a server can be different from downloading other types of
files.
2.1. First Approach: Using a Web Server
A compressed audio/video file can be downloaded as a text file. The client (browser) can use the
services of HTTP and send a GET message to download the file. The Web server can send the
compressed file to the browser. The browser can then use a help application, normally called a media
player, to play the file. The file needs to download completely before it can be played.
2.2. Second Approach: Using a Web Server with Metafile
In another approach, the media player is directly connected to the Web server for downloading the
audio/video file. The Web server stores two files: the actual audio/video file and a metafile that holds
information about the audio/video file.
1. The HTTP client accesses the Web server using the GET message.
2. The information about the metafile comes in the response.
3. The metafile is passed to the media player.
4. The media player uses the URL in the metafile to access the audio/video file.
5. The Web server responds.