[sdiy] Re: [Fpga-synth] Hello! and an Idea!

[René Schmitz]

Jeff Farr wrote:

> This is all leading me to another technique.  Start with how it's done
> on a known system and then assess how that system can be implemented
> with the hardware I've got.  At the moment I've only got some info on
> "BruteFIR" which is an open source convolution engine, which I'm not
> sure shares enough in common to be really useful.  Research time.

You have to do an "overlap and add", i.e. you compute a lot more short 
length FFTs, instead of a big one. Martin Czech has mentioned this 
technique, in conjunction with his IR related work.
There was some C-Sourcecode available on his site. (Which appears to 
have vanished off the face of the web....)
An overlap-add has the advantage that you can do much longer 
convolutions (or IRs if you will), and you don't introduce as much delay 
as for a brute force convolution.

> Subthought:  If someone was going to implement this with DSP's would
> they have access to more multipliers or would they use some trickery?

Trickery.

Cheers,
  René

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uzs159 at uni-bonn.de
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