[PD] Building a compressor in PD?

[Roman Haefeli]

hm.. don't quite know, how to answer this, i'd say yes and no. basically
'waveshaping' means adding non-linear distortions to a signal, a
process, which enriches the frequency spectrum of the signal (->
spectrum is altered). the goal of all dynamic processing fx as gates,
compressors, limters, expanders is to only affect the dynamics of the
signal, but not the spectrum. but yeah, they are somehow related: if you
use very insane settings for a compressor, let's say 0ms for attack and
decay, then you have actually a waveshaper. let's say you use very small
values but not 0, then it is actually not exactly a waveshaper anymore,
althouth the spectrum might still be altered. a waveshaper uses table
look-up, so each input value has its corresponding output value, but a
compressor with very short attack and decay is more kind of an 'adaptive
waveshaper' (i am not that much an expert, so this term might not make
any sense). however, what happens is more complex, because the current
output value is not only dependent on the actual input value, but also
on previous input values (and also if we are actually in 'attack' state
or 'release' state).

roman



On Tue, 2007-11-27 at 18:50 -0600, Kyle Klipowicz wrote:
> I may be wrong, but might some of the waveshaping tutorials help with
> this? Is compressions essentially a form of waveshaping with an attack
> and decay envelope?
> 
> ~Kyle
> 
> On Nov 27, 2007 6:24 PM, Roman Haefeli <reduzierer at yahoo.de> wrote:
> > i once made a compressor with (almost) plain pd (i think, it uses a few
> > objectclasses from zexy). it is part of dynlib for netpd and is called
> > [rcomp~].
> >
> > http://www.netpd.org/dynlib
> >
> > roman
> >
> >
> >
> >
> > On Tue, 2007-11-27 at 16:08 -0800, Vreahli the Audio Bandit wrote:
> > > Heya - I'm just curious - is it even possible to build a compressor in
> > > PD without coding it in C? The only way I can think of getting the
> > > overall loudness of a signal is by checking audio rate stuff - which
> > > won't work with control rate values. Just a curiosity. :)
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> 


		
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