8 Apr
2005
8 Apr
'05
5:16 a.m.
On Wed, Apr 06, 2005 at 06:34:28PM +0200, Sune Mai wrote:
Convolution is really nice - I use it all the time to
get perfect reverb,
nice guitar amp-sound etc. The only serious drawback is the high
input-output latency of simple FFT based algorithms. [...]
2: Another approach is to split the FIR in blocks of
different sizes, as
can be seen in the bottom figure of this page:
http://www.music.miami.edu/programs/mue/Research/jvandekieft/jvchapter2.htm
This approach has an obvious advantage in that it allows "zero" latency,
while still retaining some of the computational efficiency of the
high-latency FFT based method. [...]
I have not looked into the details of either, but I suspect that this
method is equal to one patented by Lake, and used in their Lake Huron
audio processor.
Such a method is also described in a paper by Bill Gardner in the
Journal of the Audio Engineering Society. (The title is something along
the lines of "Efficient convolution without input-output delay".) I
have heard that Gardner was subsequently informed by Lake that they
already had a patent on this method.
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