Liquidsoap supports dynamic creation and destruction of sources during the execution of a script. The following gives an example of this.

First some outlines:

  • This example is meant to create a new source and outputs. It is not easy currently to change a source being streamed
  • The idea is to create a new output using a telnet/server command.

In this example, we will register a command that dynamically create a new output based on an encoded stream and output it to an arbitrary url, as supported by the ffmpeg copy encoder. This script can be used to create a dynamic restreaming platform.

Here’s the code:

settings.init.force_start.set(true)
  settings.server.telnet.set(true)
  
  # Replace the path here with a path to some video files:
  s = playlist("/path/to/files")
  
  streams = ref([])
  count = ref(0)
  
  enc = %ffmpeg(
    format="flv",
    %audio.copy,
    %video.copy
  )
  
  def create_stream(url) =
    if list.assoc.mem(url, !streams) then
      "Stream for url #{url} already exists!"
    else
      out = output.url(id="restream-#{!count}", fallible=true, url=url, enc, s)
      count := !count + 1
      streams := [...!streams, (url, out.shutdown)]
      "OK!"
    end
  end
  
  def delete_stream(url) =
    if not list.assoc.mem(url, !streams) then
      "Stream for url #{url} does not exists!"
    else
      shutdown = list.assoc(url, !streams)
      shutdown()
      streams := list.filter((fun (el) -> fst(el) != url), !streams)
      "OK!"
    end
  end
  
  server.register(namespace="restream",
                  description="Redirect a stream.",
                  usage="start <url>",
                  "start",
                  create_stream)
  server.register(namespace="restream",
                  description="Stop a dynamic playlist.",
                  usage="stop <url>",
                  "stop",
                  delete_stream)

After executing this script, you should see two telnet commands:

  • restream.start <uri>
  • restream.stop <uri>

which you can use to create/destroy dynamically your sources.