Filter zoompan
  Apply Zoom & Pan effect.
    Inputs:
       #0: default (video)
    Outputs:
       #0: default (video)
zoompan AVOptions:
  zoom              <string>     ..FV.... set the zoom expression (default "1")
  z                 <string>     ..FV.... set the zoom expression (default "1")
  x                 <string>     ..FV.... set the x expression (default "0")
  y                 <string>     ..FV.... set the y expression (default "0")
  d                 <string>     ..FV.... set the duration expression (default "90")
  s                 <image_size> ..FV.... set the output image size (default "hd720")
  fps               <video_rate> ..FV.... set the output framerate (default "25")

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

