Filter asoftclip
  Audio Soft Clipper.
    slice threading supported
    Inputs:
       #0: default (audio)
    Outputs:
       #0: default (audio)
asoftclip AVOptions:
  type              <int>        ..F.A....T set softclip type (from -1 to 7) (default tanh)
     hard            -1           ..F.A....T
     tanh            0            ..F.A....T
     atan            1            ..F.A....T
     cubic           2            ..F.A....T
     exp             3            ..F.A....T
     alg             4            ..F.A....T
     quintic         5            ..F.A....T
     sin             6            ..F.A....T
     erf             7            ..F.A....T
  param             <double>     ..F.A....T set softclip parameter (from 0.01 to 3) (default 1)
  oversample        <int>        ..F.A..... set oversample factor (from 1 to 32) (default 1)

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

