Filter colorlevels
  Adjust the color levels.
    Inputs:
       #0: default (video)
    Outputs:
       #0: default (video)
colorlevels AVOptions:
  rimin             <double>     ..FV.... set input red black point (from -1 to 1) (default 0)
  gimin             <double>     ..FV.... set input green black point (from -1 to 1) (default 0)
  bimin             <double>     ..FV.... set input blue black point (from -1 to 1) (default 0)
  aimin             <double>     ..FV.... set input alpha black point (from -1 to 1) (default 0)
  rimax             <double>     ..FV.... set input red white point (from -1 to 1) (default 1)
  gimax             <double>     ..FV.... set input green white point (from -1 to 1) (default 1)
  bimax             <double>     ..FV.... set input blue white point (from -1 to 1) (default 1)
  aimax             <double>     ..FV.... set input alpha white point (from -1 to 1) (default 1)
  romin             <double>     ..FV.... set output red black point (from 0 to 1) (default 0)
  gomin             <double>     ..FV.... set output green black point (from 0 to 1) (default 0)
  bomin             <double>     ..FV.... set output blue black point (from 0 to 1) (default 0)
  aomin             <double>     ..FV.... set output alpha black point (from 0 to 1) (default 0)
  romax             <double>     ..FV.... set output red white point (from 0 to 1) (default 1)
  gomax             <double>     ..FV.... set output green white point (from 0 to 1) (default 1)
  bomax             <double>     ..FV.... set output blue white point (from 0 to 1) (default 1)
  aomax             <double>     ..FV.... set output alpha white point (from 0 to 1) (default 1)

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

