[PD] avoiding collapse of freeverb

Mathieu Bouchard matju at artengine.ca
Sun Jan 9 22:30:50 CET 2011

On Sat, 8 Jan 2011, ronni montoya wrote:

> hello, if i send signals with extreme amplitude to freeverb it
> collapses and it stop making any sound, and then it just output the
> word "nah" if i conect the output to a env~.

what [env~] does is mostly just multiply each sample by itself and add 
them together. thus if you get a Not-a-Number (nan) output, it's because 
something put a nan in the signal itself.

nan is the result of float operations in which it doesn't make sense to 
give a finite result (zero, normal or denormal) and it also doesn't make 
sense to give an "infinity". For example 0 divided by 0, or log of -1.

Pd's internals generally avoid outputting nan (and infinities), but many 
externals don't care about that.

> For avoiding this i tried to connect a clip -1 1 object before
> freeverb but it doesnt work  and freeverb still crashing,

Perhaps the problem isn't really with the extreme amplitudes at all.

> any idea how to avoid this crashing

probably by editing freeverb's source code to fix the bug(s) in it (if 
it's a real crash that causes pd to abort).

If it's just a nan problem, maybe you picked a nonsense setting and 
freeverb didn't prevent you from doing so. (?)

| Mathieu Bouchard ---- tél: +1.514.383.3801 ---- Villeray, Montréal, QC

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