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From: paulr@syma.sussex.ac.uk (Paul Russell)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Questions about sounds and Macrecorder
Message-ID: <5302@syma.sussex.ac.uk>
Date: 7 Jun 91 14:02:09 GMT
References: <1991May31.151435.10888@ux1.cso.uiuc.edu>
Organization: University of Sussex
Lines: 31

From article <1991May31.151435.10888@ux1.cso.uiuc.edu>, by rlsg7229@uxa.cso.uiuc.edu (Robert Lewis Spence):
> I am currently working on an application that will take audio information
> directly into the computer and process it in real time. What this means is
> that instead of running a program that records a length of sound and stores
> it in memory, I need to pull in a single value and do something with it,
> then get the next value, etc. I'm therefore trying to use the Macrecorder
> as a simple A/D converter a sample at a time.

Not wanting to dampen your fireworks, but you won't be able to do much
processing on your samples. At 22 kHz you get around 45 microseconds
maximum per sample to do any real-time processing. Even hand-coded
assembler isn't going to get very much done. You could probably
do a few very simple calculations (eg: simple filtering) and
stuff the data into a buffer, but there just isn't enough time
to do anything more complex.

In order to do serious real-time processing of sound you might
want to consider using a DSP coprocessor (eg: the Motorola 56001,
as used on DigiDesign's AudioMedia board).

Of course, if you're only interested in doing something very
simple with the sound then please feel free to ignore any or
all of the above. :-)

//Paul

-- 
           Paul Russell, Department of Experimental Psychology
         University of Sussex, Falmer, Brighton BN1 9QG, England
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