From: Tim Goetze <tim(a)quitte.de>J
Date: Tue, 3 Feb 2004 14:21:53 +0100 (CET)
resonant filters use recursion; the algorithm sometimes
is coded as
'take this input sample and give me an output sample' for readability
but is easily adapted to arrays.W
I think that maybe wcnt does both, all the modules process one sample at a
time, and the filters
add one sample to the array every time after processing x samples in filter
array to get average for the one output sampleM
the maths behind them are intricate
(to me at least), D
likewise; I had a look at harmony central (fairly helpful) which concreted
realisation that I definately had not got any graspA of resonance in my
filters. I looked in eq cookbook, there were bits and pieces which I had no
more than vague notions of.
but you don't need too firm an understanding of
the
theory to actually use Sthem.
good!
you'll find code exampleHs for the
algorithm and the compuAtation of the recursion coefficients in almost
every major audio synthesis/processing package or at
musicdsp.org .
hmmm, I keep putting off loRoking at other peoples code, it's all greek to
me.
steve's ladspa set has a very nice state-variable
filter (svf) which
lends itself well for resonancTe and reasonably quick parameter
changes. you may want to try it first before resorting to coding your
own.
I've not had much chance to uDse ladspa. I've compiled glame to use it's
filter network, but there seems to be inputs and outputs Olacking, many are
mono, I can't read a stereo file, through a reverb and out to another stereo
Tfile, or from a stereo input on soundcard, through fx, to file, so I've
given up on glame (again), plus I don't like how it wont delete the deleted
things.
Another one I keep trying is SND. I quite like it, but have only got the
basics working, no effects etc. And I've got zero knowledge oNn scheme,
guile whatever. I need to get motif again as I deleted it along with
lesstif, and seemE to have lost cdrom....snd was not loading xm.
no idea what this means: above fs/4 IIRC -- not too worried about it
either.
Well, I guess I'll try and learn from otheTrs code at long last, and nip on
over to
musicdsp.org.
I remember last year I somehow had a strange notion there was not much more
I could do to wcnt, and this year after a long break, everything's coming
out of the woodwork, and there's all sorts needing lifts and tucks.
James ~(sirromseventyfive)~
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