[PD] bug in freeverb???

Julius Smith jos at ccrma.stanford.edu
Wed Jul 1 21:22:45 CEST 2009

Hmmm, this sounds like underflow traps ("denormals").  You should 
also be able to add a small constant to the input signal.

I notice gcc has the option


which may make the problem disappear if my theory is correct.  (I 
hope the FPU simply sets underflows quietly to zero when no trap can 
be generated.)
There is also


which is more aggressive.

- jos

At 11:30 AM 7/1/2009, Matt Barber wrote:
>We have also had this problem, and have found that normally one can
>avoid it by salting the [freeverb~] object with a minuscule amount of
>noise at all times.
> > Message: 5
> > Date: Wed, 1 Jul 2009 09:57:43 -0700 (PDT)
> > From: Andres Ferrari <anfex at yahoo.com>
> > Subject: [PD] bug in freeverb???
> > To: pd-list at iem.at
> > Message-ID: <166347.29167.qm at web111408.mail.gq1.yahoo.com>
> > Content-Type: text/plain; charset=iso-8859-1
> >
> >
> > when is connected into freeverb any signal multiplied by zero
> > the CPU usage begin to up and up to the limit, and if the patch 
> is heavy by far exceeds the 100%....sound and everything becomes a mess.
> >
> > This happens to me only in leopard.
> >
> > In osx 10.4 (ppc) and windows I've never had that problem.
> > Andr?s Ferrari G.
> >
> > http://www.myspace.com/anfex
> >
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Julius O. Smith III <jos at ccrma.stanford.edu>
Prof. of Music and Assoc. Prof. (by courtesy) of Electrical Engineering
CCRMA, Stanford University

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