Filter asendcmd
  Send commands to filters.
    Inputs:
       #0: default (audio)
    Outputs:
       #0: default (audio)
asendcmd AVOptions:
  commands          <string>     ..FVA.... set commands
  c                 <string>     ..FVA.... set commands
  filename          <string>     ..FVA.... set commands file
  f                 <string>     ..FVA.... set commands file


