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 order for a Liquidsoap script to run without an active source at startup, it is necessary to include settings.init.force_start := true at the start of the script.

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 := true
settings.server.telnet := 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.