[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

*To*: f-cpu@seul.org*Subject*: Re: [f-cpu] just for fun (or: maths can be useful)*From*: Yann Guidon <whygee@f-cpu.org>*Date*: Wed, 19 Sep 2001 01:00:02 +0200*Delivered-To*: f-cpu@seul.org*Delivery-Date*: Tue, 18 Sep 2001 19:00:01 -0400*Organization*: http://www.f-cpu.org*References*: <3BA6389B.9E3B4810@f-cpu.org> <20010918212744.0eb4f5ee.philippe.trbich@free.fr>*Reply-To*: f-cpu@seul.org*Sender*: owner-f-cpu@seul.org

hi, philippe.trbich@free.fr wrote: > On Mon, 17 Sep 2001 19:53:31 +0200 > Yann Guidon <whygee@f-cpu.org> wrote: > > if you want to try some speed FFT, try http:/www.fftw.org. i know FFTW for a while but i do not need to analyze megasamples in a row or PVM or codelets... There are many reasons for me to not use it. it's rather a "mathematical tool", i need a small "real case" tool. btw, i found that i need more a DCT than a FFT : this is due to the fact that DCT can catch one lower frequency component, thus reducing the spectrum spread when there is a large difference between sample 0 and sample N-1. This is why the DCT is used in JPEG instead of FFT and i have a rather similar need. And FFT requires windowing, DCT doesn't. I could derive a 8-tap DCT from a 16-tap FFT (winograd if possible) but i don't have any 16-point winograd code :-( and i don't know yet how to derive the DCT from the 8-tap winograd code. The possibilities i know require too much overhead (require much more multiplies than needed). > Cordially. WHYGEE ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ************************************************************* To unsubscribe, send an e-mail to majordomo@seul.org with unsubscribe f-cpu in the body. http://f-cpu.seul.org/

**References**:**[f-cpu] just for fun (or: maths can be useful)***From:*Yann Guidon <whygee@f-cpu.org>

**Re: [f-cpu] just for fun (or: maths can be useful)***From:*philippe.trbich@free.fr

- Prev by Date:
**Re: [f-cpu] License issues GPL/LGPL and Juergen Goeritz' SoC** - Next by Date:
**encore une couche (was: Re: [f-cpu] License issues GPL/LGPL and Juergen Goeritz' SoC)** - Prev by thread:
**Re: [f-cpu] just for fun (or: maths can be useful)** - Next by thread:
**[f-cpu] [Fwd: RE: MAC address]** - Index(es):