Filter convolve
  Convolve first video stream with second video stream.
    slice threading supported
    Inputs:
       #0: main (video)
       #1: impulse (video)
    Outputs:
       #0: default (video)
convolve AVOptions:
  planes            <int>        ..FV..... set planes to convolve (from 0 to 15) (default 7)
  impulse           <int>        ..FV..... when to process impulses (from 0 to 1) (default all)
     first           0            ..FV..... process only first impulse, ignore rest
     all             1            ..FV..... process all impulses
  noise             <float>      ..FV..... set noise (from 0 to 1) (default 1e-007)

framesync AVOptions:
  eof_action        <int>        ..FV..... Action to take when encountering EOF from secondary input  (from 0 to 2) (default repeat)
     repeat          0            ..FV..... Repeat the previous frame.
     endall          1            ..FV..... End both streams.
     pass            2            ..FV..... Pass through the main input.
  shortest          <boolean>    ..FV..... force termination when the shortest input terminates (default false)
  repeatlast        <boolean>    ..FV..... extend last frame of secondary streams beyond EOF (default true)

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

