Hi Chris,
I curious if you evaluated the (very free) DJBFFT library and if so, if you found it insufficient. I know someone else who is evaluating FFT libraries and just wanted your input if you had already tried it out and found it lacking.
Well, Kim had initially implemented osgOcean using FFTW, and searching for an easy replacement that would remove the GPL limitation, I found FFTSS which has an identical API, so the change was pretty painless (most of the work went into supporting compile-time choice between the two, not in actually supporting FFTSS).
I know Kim looked at a few others and had problems with badly documented API with KissFFT notably, but I don't know which others (if any) he checked out.
I read the articles on FFT benchmarking on DJBFFT's site, and especially noted that they were quite old. They say version 0.75 was released in 1999, and the current version is 0.76. And also, their install docs state "The djbfft installation procedure assumes that you have a UNIX system with gcc." So that kind of put me off, personally, as I don't know if a library dating from 1999 and specifically made for gcc will support newer compilers and Windows... And if it really can be that optimized versus a current library that probably has special optimizations for newer chipsets/SSEx/...
It would be worth a try if we really wanted to compare speed and wanted another alternative. It should be easy to implement another option for choosing DJBFFT in addition to the 3 choices right now (FFTW single-precision, FFTW double-precision, FFTSS). But for now FFTW and FFTSS kind of fill the needs we have (one really fast, the other more flexible licensing-wise).
Hope that clears things up, J-S -- ______________________________________________________ Jean-Sebastien Guay [email protected] http://www.cm-labs.com/ http://whitestar02.webhop.org/ _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
