[PD] latency

Frank Barknecht fbar at footils.org
Sun Nov 16 20:38:40 CET 2003


Hallo,
Olaf Matthes hat gesagt: // Olaf Matthes wrote:

> mattn-l at rogers.com schrieb:
> > > i have too much on my plate right now to rip all the portaudio out of pd and
> > > replace it with straight CoreAudio calls.  but that's what someone needs to do...
> 
> Yes, I think so too. So the question is whether it's worth to use
> portaudio in general or not. Looking at the sources it seems that since
> the introduction of portaudio into Pd we got at least one additional
> audio buffer (and thus additional latency) for each input and output.
> I know that portaudio makes it easier to develop Pd beacuse all (audio)
> hardware specific things are handled within portaudio. On the other hand
> we waste performance and depend on what portaudio does or allows us to
> do.

I'm not sure, but as I see it, Pd does not use Portaudio in callback
mode, but the blocking in/out Pablio backend of PortAudio. IIR Pd
could stay with PortAudio, but could get much lower latencies by
converting the sound system to be callback based. This OTOH might
require large changes to Pd. 

Ripping PA out of Pd is not a good idea IMO. It will lead to the cross
platform mess we had before and that PA is trying to solve.

ciao
-- 
 Frank Barknecht                               _ ______footils.org__




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