[PD] Re: [PD-announce] pd 0.37 test 10 released

Miller Puckette mpuckett at man104-1.ucsd.edu
Sun Aug 31 20:37:11 CEST 2003


...
> 
> I'm glad to hear that some of my suggestions have been incorporated.
> I designed the said array update sensing this way because the same method is
> used in Max/MSP.
> 

I'm worried that, if an array gets updated multiple times at the same logical
time, there won't be any way to see the difference.  Pd has a different way
of dealing with "change detection" in glists (the gl_valid field which is
a counter incremented everytime the thing changes in a specific way).  
Parhaps it's wise to try to make a unified approach...

> > finally, audio latency from portaudio should be 5 msec or so better.
> > I believe I'm getting about 20 msec through-delay on a MSWindoes
> > machine using ASIO now.  I haven't tested this in Mac yet.  (of course,
> > linux is still by far the best in this respect.)
> 
> 20 msec is still not acceptable for use in live electronics.
> Do you think that <= 10 ms can be reached with the current architecture?
> 
I _think_ there's nothing in either portaudio or ASIO that would prevent
Pd from getting down to 5 msec latency or so (as people have managed on
linux).  There may be limitations somewhere else that I don't know about.
There might also be something loose in the code somewhere.  And it might
be that, on Windows or some other OS, callback-based audio is inherently
lower-latency than the poll-and-sleep loop Pd uses.  (I thought for a while
this was true on OSX but now I'm getting confusing results from it.)

I think this is where the remaining tested is needed in preparation for
sewing up version 0.37.

cheers
Miller

> 
> greetings,
> Thomas
> 
> 
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