PFFFT does 1D Fast Fourier Transforms, of single precision real and
complex vectors. It tries do it fast, it tries to be correct, and it
tries to be small. Computations do take advantage of SSE1 instructions
on x86 cpus, Altivec on powerpc cpus, and NEON on ARM cpus.

PFFFT is a fork of Julien Pommier's library on bitbucket with some
changes and additions.

PFFASTCONV does fast convolution (FIR filtering), of single precision
real vectors, utilizing the PFFFT library.

PFDSP contains a few other signal processing functions.