Filter histeq
  Apply global color histogram equalization.
    Inputs:
       #0: default (video)
    Outputs:
       #0: default (video)
histeq AVOptions:
  strength          <float>      ..FV..... set the strength (from 0 to 1) (default 0.2)
  intensity         <float>      ..FV..... set the intensity (from 0 to 1) (default 0.21)
  antibanding       <int>        ..FV..... set the antibanding level (from 0 to 2) (default none)
     none            0            ..FV..... apply no antibanding
     weak            1            ..FV..... apply weak antibanding
     strong          2            ..FV..... apply strong antibanding

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

