true, but i take it you get the way CoreAudio is doing it: it means you can drive audio processing from a different interrupt source (e.g. system timer) because you have very accurate idea of the position of the h/w frame pointer. In CoreAudio, the "callback" is decoupled from any PCI, USB or ieee1394 interrupt. Tasty.
.. yes, very tasty. the performance-enhancin "OS-provided" ring-buffer/sample-rate convertor that this allows is also, of course, tasty.
you can, true, though JACK doesn't. JACK uses poll and mmap (the OSS driver uses ioctls and select IIRC); expecting regular audio developers to use poll/mmap on a day to day basis creates very bad reactions :)
it only has to be done right once, though, and from that point on, wrapped in an API and well-promoted as a black-box handling for audio i/o.
-- ; Jay Vaughan
