B. Audio Function Module
At present commonly used drivers under Linux programs to
basically have two kinds: OSS and ALSA. In the design of this
system, the programming interface is OSS (Open Sound
System), it consists of a complete set of kernel driver modules
for the vast majority, which can provide a unified programming
interface card. OSS has become audio programming criterion
of truth in Linux, OSS application can work well on most
sound.
For Linux application programmer, audio programming
interface is actually a set of audio equipment files, through
them it can read data from sound card, or write data to sound
card, and can control the sampling frequency and track number
set, etc. The system of the module of audio is through reading
and writing /dev/dsp device, can achieve sound recording or
broadcast, read, write equivalent of recording equipment is
equivalent to playback.