[Portaudio] Clueless about the ASIO build

[Phil Burk]

> For about the last three months I've been using the WinMME
> port for real-time performance on my WindowsXP laptop.  The
> latency has been attrocious (on the order of 300-500ms),
> even with very short callback buffers.  After a few trial
> tests, Windows98 seems just as bad.

The default build is configured for worst case latency, which can be pretty
bad.
You can reduce the latency that PortAudio will use by setting the
PA_MIN_LATENCY_MSEC environment variable. For Win98, try:

set PA_MIN_LATENCY_MSEC=50

By tuning XP to favor background tasks, I was able to get below 10 msec
latency.

I will add a page to the web site that describes the various latency issues
for various platforms.

> I've heard some very positive things about the ASIO port,
> and just tried building with it for the first time tonight.
>  Unfortunately, I can't make heads nor tails of it without
> explicit build instructions.

I use Visual C++ 6.0. I checked my setting and I am pretty much just using
what the docs say at:

   http://www.portaudio.com/docs/pa_tut_asio.html

I don't know where the odd C Template stuff is coming from.

Phil Burk