334 Chapter 19 – Audio on the WebNonstreaming versus Streaming
Web Design in a Nutshell, eMatter Editionrequire a long time to download, particularly over dial-up modem connections.
For instance, a 1-minute WAVE file of CD-quality audio requires over 10 MB of
disk space! (Of course, this can be reduced by sacrificing sound quality, as
discussed later.)How it worksStatic audio files tend to be in common audio formats, and are transferred via a
simple FTP transaction like any other web file.
When the user’s browser detects the audio file, it will either launch an external
player or use a plug-in to play the audio. Which player it uses depends on the
platform, the browser, its version, and its configuration, therefore the web site
designer cannot directly control which player will be used.
Some common Macintosh external players include SoundMachine and SoundApp.
MediaPlayer is a common player on the Windows operating system. Internet
Explorer versions 3 and higher can play many audio file formats natively. Netscape
Navigator 3.0 and higher uses the LiveAudio plug-in to play most audio files. The
QuickTime player is available for both platforms and as a plug-in to both
browsers.Advantages- It doesn’t require special server software.
- It is simple to create audio files in standard formats.
Disadvantages- Large file sizes can result in unacceptably long waits for the files to download
and begin playing. - Because the audio file is copied to the hard drive, it is more difficult for art-
ists and publishers to limit distribution and protect copyrights.
Streaming Audio
Streaming audio technology was developed to address the problem of unaccept-
able download times. Streaming media (be it audio or video) begins playing
almost immediately after the request is made, and continues playing as the audio
data is being transferred. Some vendors offer live broadcast capabilities.
In some streaming solutions, such as those from RealNetworks and Xing Tech-
nology’s Streamworks, the server holds open a special connection (UDP) through
which it pushes data continuously. In this method, the source audio file itself is
never transferred to the user’s machine. Others, such as QuickTime 3.0 and Shock-
wave, do load files into the user’s cache, but have players that allow playback
after only a fraction of the total data is loaded.