[PD] rjdj, was : Re: [equalizer] / [lowshelf] / [highshelf] in purepd!

[volker böhm]

On 29 Mar 2009, at 12:53, Frank Barknecht wrote:
> Hallo,
> cyrille henry hat gesagt: // cyrille henry wrote:
>>> I think, currently it's probably a bit slower because of the sin 
>>> (), but maybe
>>> that could be put into a tabread~.
>> i think the sin object is doing a linear interpolation in a 512  
>> point table.
>> (don't know how it is done in expr~, but expr~ is not used for  
>> rjlib because of it's licence, right?)
>
> Attached is an expr-less version of saw~ which from a quick glance at
> the scope looks and sounds the same. It is vanilla in that it uses
> [abs~] and [>~] which are part of 0.42 (and thus RjDj). On older Pd
> versions you can use for example the purepd abstractions for both from
> the SVN in abstractions/purepd

thanks for posting this.
for certain freqs i hear a noticeable periodic "zipping" in the sound  
(try 230 hz e.g.).
since the algorithm is based on the sinc function (sin(x)/x), i  
wonder how pd handles divide by zero in the signal domain. wouldn't  
you have to check for that in the code/patch?
volker.