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+08) (default 0)
  format            <pix_fmt>    ..FV...... set output pixel format (default yuva444p)


