posted to tech-kern:
* Simultaneous playback and mixing of multiple streams
* Playback streams can be of different encoding, frequency, precision
and number of channels
* Simultaneous recording to different formats
* One audio device per process
* Sysctls to set the common format frequency, precision and channels
* Independent mixer controls for recording/playback per stream
* Utilizes little cpu time for multiple streams / good performance
* Compatible with existing programs that use OSS/NetBSD audio
* Changes to audioctl(1) to allow specifying process id for corresponding
audio device