FFTReal 2.1 -- The most optimized and versitile SIMD vector or scalar forward/inverse FFT real/complex transform developed by the Russian-American software engineer and the inventor of MacAmp and Winamp

NEW (v1.67): Updated to v2.1 (Fixed NEON compilation issue with Xcode v26.1 (17B54)) for some reason .f[2] and .f[4] suddenly stopped working and had to be replaced with (float*)addr + 2, + 4 throughout entire NEON code. God knows?

How to reach me: Dmitry Boldyrev subband@gmail.com or subband@protonmail.com

This is the best (fastest, most precise and best sounding) real FFT/iFFT transform available in existence! I have gone through at least 10, and kept upgrading until I found this one, so I arranged it into a templated class that suports base types like float and double as well as simd vectors like simd_float8, simd_double4, which can be specified as a template parameter T.

This is what I am using for now in all of my audio projects instead of AVFFT, PFFFT, etc. It is by far the best sounding and precise FFT algorithm I found. Now, go make some awesome audio apps! // compute_fft_size() is an inline const function in your class

  const int fft_size = compute_fft_size(1024); 
  { 
        // Delcare instance of FFTReal
        FFTReal<simd_double2> fft(fft_size);

        fft.real_fft(data_in, data_out);
        
        // ... process data_out here ...
        
        // 3rd parameter optional, true = scale by 1/length, 
        // omitted or false = don't scale
        
        fft.real_ifft(data_out, data_in, true); 
  }

This style of initialization was not possible the way class was setup before (static), which required maximum FFT size initialization. Well, enjoy the world's best FFT class in the world! =)

Dmitry subband@protonmail.com