Replace an existing ES with another ES in the same track. It
can be used in combination with VLM. Here is an example vlm command file:

  # VLC media player VLM command batch
  # http://www.videolan.org/vlc/

  # MPEG-TS stream
  new ts broadcast enabled
  setup ts input "file:///<path_to_some_file_to_play>"
  setup ts output #duplicate{dst=bridge-out{id=1},select=video,dst=bridge-out{id=0xa3},select=audio}
  setup ts loop

  # Mic input
  new mic broadcast enabled
  setup mic input "alsa://"
  setup mic output #transcode{acodec=mpga,ab=192,channels=2}:bridge-in{id-offset=0}:select{disable=0}:setid{id=0,newid=0xa3}:autodel:std{access=udp,mux=ts,dst=127.0.0.1:1234}

  # Fire it up
  control ts play
  control mic play