REAL TIME: why?
For low latency
- write data as close as possible to when it will be audible
- read data as soon as the audio interface makes it available
- tricks with mmap + non-audio-clock source: non-portable,
but occasionally useful.
How come so many apps don't do this?
- don't have low latency requirements
- buffer significant amounts of data
- lack real-time parameter control during playback
- even in media players like XMMS, users notice
"lag" between modifying the gain/EQ controls and hearing result.
- low latency/real time programming is always a tradeoff:
- applications become more sensitive to OS problems
- applications become more responsive to user control