Filter gradfun
  Debands video quickly using gradients.
    Inputs:
       #0: default (video)
    Outputs:
       #0: default (video)
gradfun AVOptions:
  strength          <float>      ..FV..... The maximum amount by which the filter will change any one pixel. (from 0.51 to 64) (default 1.2)
  radius            <int>        ..FV..... The neighborhood to fit the gradient to. (from 4 to 32) (default 16)

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

