One of the most important aspects of the BeOS is the ability to play,
manipulate and record audio. The BeOS Audio Server is the foundation of all
things audio in the Media OS.
The best way to visualize how audio is handled in the BeOS is as a
stream of data; sound comes in through the microphone jack of the soundcard
(or off of the hard drive), and is played through the operating system
until it heads out the speaker jack of the audio card, which is then passed
through a pair of speakers or headphones.
Software developers who are writing an application that handles audio,
from playing a sound when new email arrives to applying sound effects to
your favorite song, communicate with the Audio Server to get that aspect of
their job done. They simply write commands to the Audio Server, which then
communicates them to the hardware sound card.
For example, let's say that you have a song onto which you want to apply
some sound effects, using a sound program in the BeOS. Using your favorite
BeOS sound program, you tell the CD player to play the appropriate song,
which then reads the audio data of the song from the CD, passing it through
the sound card and then into the BeOS Audio Server.
The audio program you are using to apply sound effects then subscribes
to the audio stream via the Audio Server, applies your effects to the audio
data, and then puts it back into the audio stream, which heads back through
the Audio Server, out to the audio card and on to your speakers or
Note that while the BeOS Audio Server does its job well, it will be
replaced by the even-better Media Server in BeOS Release 4. The Media
Server will do much of the same thing with audio, but will add similar
functionality for video.