Filter fftfilt
  Apply arbitrary expressions to pixels in frequency domain.
    Inputs:
       #0: default (video)
    Outputs:
       #0: default (video)
fftfilt AVOptions:
  dc_Y              <int>        ..FV..... adjust gain in Y plane (from 0 to 1000) (default 0)
  dc_U              <int>        ..FV..... adjust gain in U plane (from 0 to 1000) (default 0)
  dc_V              <int>        ..FV..... adjust gain in V plane (from 0 to 1000) (default 0)
  weight_Y          <string>     ..FV..... set luminance expression in Y plane (default "1")
  weight_U          <string>     ..FV..... set chrominance expression in U plane
  weight_V          <string>     ..FV..... set chrominance expression in V plane
  eval              <int>        ..FV..... specify when to evaluate expressions (from 0 to 1) (default init)
     init            0            ..FV..... eval expressions once during initialization
     frame           1            ..FV..... eval expressions per-frame

This filter has support for timeline through the 'enable' option.

