nprofile1qy2hwumn8ghj7un9d3shjtnyd968gmewwp6kyqpq0cq07ulfyc7y2l8rczk9s36g8j65tq3m6xk9us8hr3ua4ktfmaqq05h6ty (nprofile…h6ty) nprofile1qy2hwumn8ghj7un9d3shjtnyd968gmewwp6kyqpqsld6cd53kj8pkz9svnnt54um57nvwrlx9sgya7xhvhl5a5a4f3sqdxhcxx (nprofile…hcxx) Yes ffmpeg uses its own (and AFAIK doesn't use FFTW at all) and yes FFTW kernels are, IME, usually not the fastest.
It's sort of the equivalent to ATLAS in dense LA, if someone still remembers that. Another big "throw a code generator at figuring it out" thing that produces big libs with tons of code with good-but-not-great perf. :)