Filter mergeplanes
  Merge planes.
    Inputs:
        dynamic (depending on the options)
    Outputs:
       #0: default (video)
mergeplanes AVOptions:
  mapping           <int>        ..FV..... set input to output plane mapping (from 0 to 8.58993e+008) (default 0)
  format            <pix_fmt>    ..FV..... set output pixel format (default yuva444p)


