Message-ID: <37D5164E.1F416250@pentek.com>
Date: Tue, 07 Sep 1999 09:42:38 -0400
From: "Charles Krug Jr." <charles AT pentek DOT com>
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Subject: Re: FFT / spectrum analysis?
References: <37edcd34 DOT 32637391 AT news DOT demon DOT co DOT uk>
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sam AT greenaumARSE!ARSE!ARSE!.demon.co.uk wrote:
> 
> Is there an example anywhere of something that takes sound through the
> sound card, and just displays a simple graphic equaliser sort of
> thing?
> 
> I can find code for taking samples, and code and theory for how to do
> an FFT (and I think I've finally gripped it), but I can't be arsed
> trying it out and debugging it, it's to "slot into" another program
> and I'd rather just adapt something ready-made.
> 

Get yourself a copy of Numerical Recipies in C.  The  functions are
chosen for clarity, rather than speed, but once you grok the source and
profile it, it's not too difficult to tweak it for your application.

Somewhere, I've heard of an MMX version of the fft, but I haven't seen
asm source anywhere.  Perhaps Intel's website has something.

You might even find that the Numerical Recipies version is plenty fast
enough for your desired end result.


Charles