Computer Science & Perl Programming

Chapter 51. Managing Streaming Audio

Lincoln D. Stein

Lately I’ve been playing with MPEG level 3(MP3), that wonderful technology that allows me to take a huge CD audio file and reduce its size more than tenfold without perceptible loss of fidelity. The last year has seen an explosion of MP3-related web sites, encoding and playing software, Internet-based CD databases, and even hardware products such as the Diamond Multimedia Rio MP3 player.

One of the neat things that MP3 supports is streaming audio. Instead of downloading the entire MP3 file to disk and then launching a player application to play it, the player retrieves the audio stream directly from the network, playing the music in real time as it downloads. Provided that the available network bandwidth is sufficient, it is much more satisfying to click on a link and instantly hear the music than to wait for a long download to complete.

On the client side, streaming MP3 audio is supported by several of the more popular MP3 players, including WinAmp on Microsoft Windows systems, and the open source Xmms program for Unix machines. On the server side, streaming MP3 audio is supported by the commercial Shoutcast system on Windows platforms, and by the open source Icecast system on Linux and other Unix platforms. In addition to providing streaming MP3 audio to clients, the Shoutcast and Icecast systems implement a form of Internet broadcasting that allows people with the appropriate client software to send an audio stream to an Internet ...