Filter edgedetect
  Detect and draw edge.
    Inputs:
       #0: default (video)
    Outputs:
       #0: default (video)
edgedetect AVOptions:
  high              <double>     ..FV...... set high threshold (from 0 to 1) (default 0.196078)
  low               <double>     ..FV...... set low threshold (from 0 to 1) (default 0.0784314)
  mode              <int>        ..FV...... set mode (from 0 to 2) (default wires)
     wires           0            ..FV...... white/gray wires on black
     colormix        1            ..FV...... mix colors
     canny           2            ..FV...... detect edges on planes
  planes            <flags>      ..FV...... set planes to filter (default y+u+v+r+g+b)
     y                            ..FV...... filter luma plane
     u                            ..FV...... filter u plane
     v                            ..FV...... filter v plane
     r                            ..FV...... filter red plane
     g                            ..FV...... filter green plane
     b                            ..FV...... filter blue plane

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

