Re: [SoX-devel] rate-filters.h coefficients

[Caleb R. <jt...@gm...>]

On Thu, 29 Dec 2011 08:57:33 +0000 (GMT), robs <aq...@ya...> wrote:
> From: Caleb Reach <jt...@gm...>
> >To: sox...@li... 
> >Sent: Thursday, 29 December 2011, 6:09
> >Subject: [SoX-devel] rate-filters.h coefficients
> > 
> >I see a couple of coefficient arrays in rate-filters.h -- how are these
> >generated?
> >
> >They were generated in Matlab using remez (Parks-McClellan algorithm, now known in Matlab as firpm). Originally I had generated all of the filters this way, but then switched to windowed-sinc for most of them to allow the flexibility of response that people seemed to want.
> 
> 
> >
> >  Also, where is the m4 file from which rate-filters.h was generated?
> >
> >Here is the generation part:
> 
> [...]
> FYI, I have a new version of the rate command which is faster in some specific cases (upsample by 4, for example) waiting in the wings (no changes to the filters though); this is currently on trial through its use in the foobar2000 (Windows-only) media player.
> 
> Cheers,
> Rob

Thanks!

You wouldn't happen to still have the Matlab code (or just the
parameters to remez), would you?

Cheers,
Caleb