What's the equivalent function in KissFFT for fftw_plan_dft_r2c_1d() from FFTW?

Question

I've got a project that uses fftw_plan_dft_r2c_1d and fftw_plan_dft_c2r_1d from FFTW, as well as fftw_execute. What are the equivalent functions in KissFFT?

Answer 1

You need to use the real-optimised functions in kiss_fftr.h (in the tools subdirectory). Use kiss_fftr_alloc instead of setting up FFTW "plans" with fftw_plan_dft_r2c_1d and fftw_plan_dft_c2r_1d. Use kiss_fftr and kiss_fftri to do the forward/inverse transforms instead of calling FFTW's fftw_execute. Don't forget to call kiss_fftr_free when you're done.