Resampling libs

On Aug 16, 10:58&#4294967295;am, "Ronaldo Souza" <nos...@nospam.org> wrote:
> Can anyone recommend a good resampling lib? I need to handle rather
> small buffers (100s of Ks of signed 16 bits) but also really long
> streams, often covering 24+ hours @250sps, so speed is important.
>
> BTW, tipically I'll be downsampling from 250sps to 200sps, but there
> will be other scenarios within the range 100sps <= In/Out sampling freq
> <= 5000sps.

You can take this very short simple Tiny Basic code for
windowed-Sinc resampling, and optimize as needed.
 http://www.nicholson.com/rhn/dsp.html#3
Common optimizations include using a cache, or table lookup,
or table interpolation for the windowed-Sinc function instead
of (slowly) recalculating it for every tap for every point.


YMMV.
--
rhn A.T nicholson d.0.t C-o-M

> Tim Wescott wrote:
> 
> Applying a library like Secret Rabbit Code blindly may work, and it
> may not.  If it does work, you're lucky.  If it doesn't work, and it
> breaks in the lab, you're a lot more lucky than if it breaks all over
> a customer.
> So try it, test the heck out of it, and keep your fingers crossed.

I'm painfully aware of this and believe me, my fingers are crossed so
tightly that I might get gangrene or something.




> There's quite a few regulars in this group that consult; if it breaks
> in a way that convinces the powers that be that it needs a fix in a
> hurry you've got some experts available to trade money for fixes.  Or
> you can ask all the background questions, and we'll help you get
> through it slowly.


IMHO, consulting with somemone like Vladimir would be not only the
correct choice, but also the best bang for the buck, but I'm "just" a
tech guy and "have no understanding of our financial problems..." so,
I'll give it a try and if (when?) it all tumbles down, I'll have to
frame the problem from a $ POV, so they'll understand.


 
> Get Rick Lyons's book ("Understanding Digital Signal Processing").
> If you can get through it fast enough then maybe by the time the
> algorithm breaks you'll know why and can fix it.


Thanks. <browsing Amazon...>


Best regards,
Ronaldo

> Ron N. wrote:
> You can take this very short simple Tiny Basic code for
> windowed-Sinc resampling, and optimize as needed.
>  http://www.nicholson.com/rhn/dsp.html#3
> Common optimizations include using a cache, or table lookup,
> or table interpolation for the windowed-Sinc function instead
> of (slowly) recalculating it for every tap for every point.


Thanks a bunch, Ron. 

Best Regards,
Ronaldo