I now see the necessity of an intermediate buffer and a -B option, so I
agree with you that the PortAudio library ought to determine the buffer
size and we should adapt to varying sizes during performance.

Original Message:
-----------------
From: Victor Lazzarini Victor.Lazzarini@nuim.ie
Date: Mon, 10 Jan 2005 09:48:32 +0000
To: csound-dev@eartha.mills.edu
Subject: [CSOUND-DEV:5660] Re: PortAudio


In addition to the problems on OS X, as I said last week,
portaudio ASIO is also dependent on the driver implementation;
in certain cases, the buffer sizes are only of certain allowed
values (a certain 'granularity') and have a minimum value.
This seems to cause trouble for audio input, but not for
output.

I think we could re-instate one 'hardware' buffer (-B option);
we could follow portaudio's advice in letting the portaudio buffer
be variable as so to be able use the minimum latency possible,
with the user having control of csound hardware buffer.

Victor

At 07:04 10/01/2005, you wrote:
>One problem is that the ksmps size is based on synthesis needs the
>buffer size for rtaudio is based on hardware speeds.  If I remember
>correctly, on OSX that just fails.  If -b is set to a sensible ksmps
>size then the stuttering is way below feasible.  I think that there
>is a need for extra buffering.
>   The code I have on the Mac collects data until there is enough for
>the buffer.  I got distracted by external deadlines so have not
>finished the code.
>==John ffitch

Victor Lazzarini
Music Technology Laboratory
Music Department
National University of Ireland, Maynooth 


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