Filter stereotools
  Apply various stereo tools.
    Inputs:
       #0: default (audio)
    Outputs:
       #0: default (audio)
stereotools AVOptions:
  level_in          <double>     ..F.A....T. set level in (from 0.015625 to 64) (default 1)
  level_out         <double>     ..F.A....T. set level out (from 0.015625 to 64) (default 1)
  balance_in        <double>     ..F.A....T. set balance in (from -1 to 1) (default 0)
  balance_out       <double>     ..F.A....T. set balance out (from -1 to 1) (default 0)
  softclip          <boolean>    ..F.A....T. enable softclip (default false)
  mutel             <boolean>    ..F.A....T. mute L (default false)
  muter             <boolean>    ..F.A....T. mute R (default false)
  phasel            <boolean>    ..F.A....T. phase L (default false)
  phaser            <boolean>    ..F.A....T. phase R (default false)
  mode              <int>        ..F.A....T. set stereo mode (from 0 to 10) (default lr>lr)
     lr>lr           0            ..F.A....T.
     lr>ms           1            ..F.A....T.
     ms>lr           2            ..F.A....T.
     lr>ll           3            ..F.A....T.
     lr>rr           4            ..F.A....T.
     lr>l+r          5            ..F.A....T.
     lr>rl           6            ..F.A....T.
     ms>ll           7            ..F.A....T.
     ms>rr           8            ..F.A....T.
     ms>rl           9            ..F.A....T.
     lr>l-r          10           ..F.A....T.
  slev              <double>     ..F.A....T. set side level (from 0.015625 to 64) (default 1)
  sbal              <double>     ..F.A....T. set side balance (from -1 to 1) (default 0)
  mlev              <double>     ..F.A....T. set middle level (from 0.015625 to 64) (default 1)
  mpan              <double>     ..F.A....T. set middle pan (from -1 to 1) (default 0)
  base              <double>     ..F.A....T. set stereo base (from -1 to 1) (default 0)
  delay             <double>     ..F.A....T. set delay (from -20 to 20) (default 0)
  sclevel           <double>     ..F.A....T. set S/C level (from 1 to 100) (default 1)
  phase             <double>     ..F.A....T. set stereo phase (from 0 to 360) (default 0)
  bmode_in          <int>        ..F.A....T. set balance in mode (from 0 to 2) (default balance)
     balance         0            ..F.A....T.
     amplitude       1            ..F.A....T.
     power           2            ..F.A....T.
  bmode_out         <int>        ..F.A....T. set balance out mode (from 0 to 2) (default balance)
     balance         0            ..F.A....T.
     amplitude       1            ..F.A....T.
     power           2            ..F.A....T.

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

