Filter afftfilt
  Apply arbitrary expressions to samples in frequency domain.
    Inputs:
       #0: default (audio)
    Outputs:
       #0: default (audio)
afftfilt AVOptions:
  real              <string>     ..F.A.... set channels real expressions (default "re")
  imag              <string>     ..F.A.... set channels imaginary expressions (default "im")
  win_size          <int>        ..F.A.... set window size (from 16 to 131072) (default 4096)
  win_func          <int>        ..F.A.... set window function (from 0 to 19) (default hann)
     rect                         ..F.A.... Rectangular
     bartlett                     ..F.A.... Bartlett
     hann                         ..F.A.... Hann
     hanning                      ..F.A.... Hanning
     hamming                      ..F.A.... Hamming
     blackman                     ..F.A.... Blackman
     welch                        ..F.A.... Welch
     flattop                      ..F.A.... Flat-top
     bharris                      ..F.A.... Blackman-Harris
     bnuttall                     ..F.A.... Blackman-Nuttall
     bhann                        ..F.A.... Bartlett-Hann
     sine                         ..F.A.... Sine
     nuttall                      ..F.A.... Nuttall
     lanczos                      ..F.A.... Lanczos
     gauss                        ..F.A.... Gauss
     tukey                        ..F.A.... Tukey
     dolph                        ..F.A.... Dolph-Chebyshev
     cauchy                       ..F.A.... Cauchy
     parzen                       ..F.A.... Parzen
     poisson                      ..F.A.... Poisson
     bohman                       ..F.A.... Bohman
  overlap           <float>      ..F.A.... set window overlap (from 0 to 1) (default 0.75)


