Re: [linux-audio-dev] CSL-0.1.2 Release

[Abramo Bagnara <abramo alsa-project org>]

Paul Davis wrote:
> 
> >No, they don't. They asked to me to make this feasible. The point is the
> >ability to send sample in advance and then retract them if it's needed
> >(by example because another event occurred). This help to reduce
> >latency. Obviously the alternative is to generate audio "just in time"
> >with a tiny chunk size, but this may have a negative impact on
> >performance.
> 
> the semantics of snd_pcm_rewind() can be handled within a callback
> model. the application simply uses its own buffering rather than
> relying on that of the library. the application does whatever it wants
> with the data until a callback delivers it "just in time" to the audio
> h/w.

Of course, but with this model you may arrive too late. The point of
snd_pcm_rewind is the ability to transfer data as near as possible to
hardware layer and then rectract it if this is needed.

No need to say that if we have available_mips=2*needed_mips, a low
latency OS and all other nice stuffs we'd love, this is not needed, but
you known that often this is not a perfect world.

I agree to have inserted snd_pcm_rewind to cope with this damn imperfect
world ;-)

-- 
Abramo Bagnara                       mailto:abramo alsa-project org

Opera Unica                          Phone: +39.546.656023
Via Emilia Interna, 140
48014 Castel Bolognese (RA) - Italy

ALSA project               http://www.alsa-project.org
It sounds good!