Harbor input
Liquidsoap is also able to receive a source using icecast or shoutcast source protocol with
the input.harbor operator. Using this operator, the running liquidsoap will open
a network socket and wait for an incoming connection.
This operator is very useful to seamlessly add live streams into your final streams: you configure the live source client to connect directly to liquidsoap, and manage the switch to and from the live inside your script.
Additionally, liquidsoap can handle many simulataneous harbor sources on different ports, with finer-grained authentication schemes that can be particularly useful when used with source clients designed for the shoutcast servers.
Parameters
The global parameters for harbor can be retreived using
liquidsoap --conf-descr-key harbor. They are:
-
harbor.bind_addr: IP address on which the HTTP stream receiver should listen. The default is"0.0.0.0". You can use this parameter to restrict connections only to your LAN. -
harbor.timeout: Timeout for source connection, in seconds. Defaults to30.. -
harbor.verbose: Print password used by source clients in logs, for debugging purposes. Defaults to:false -
harbor.reverse_dns: Perform reverse DNS lookup to get the client's hostname from its IP. Defaults to:true -
harbor.icy_formats: Content-type (mime) of formats which allow shout (ICY) metadata update. Defaults to:["audio/mpeg"; "audio/aacp"; "audio/aac"; "audio/x-aac"; "audio/wav"; "audio/wave"]
You also have per-source parameters. You can retreive them using the command
liquidsoap -h input.harbor. The most important one are:
-
user,password: set a permanent login and password for this harbor source. -
auth: Authenticate the user according to a specific function. -
port: Use a custom port for this input. -
icy: Enable ICY (shoutcast) source connections. -
id: The mountpoint registered for the source is also the id of the source.
When using different ports with different harbor inputs, mountpoints are attributed
per-port. Hence, there can be a harbor input with mountpoint "foo" on port 1356
and a harbor input with mountpoint "foo" on port 3567. Additionaly, if an harbor
source uses custom port n with shoutcast (ICY) source protocol enabled, shoutcast
source clients should set their connection port to n+1.
The auth function is a function, that takes a pair (user,password) and returns a boolean representing whether the user
should be granted access or not. Typical example can be:
def auth(user,password) =
# Call an external process to check
# the credentials:
# The script will return the string
# "true" of "false"
#
# First call the script
ret = get_process_lines("/path/to/script \
--user=#{user} --password=#{password}")
# Then get the first line of its output
ret = list.hd(ret)
# Finally returns the boolean represented
# by the output (bool_of_string can also
# be used)
if ret == "true" then
true
else
false
end
end
In the case of the ICY (shoutcast) source protocol, there is no user parameter
for the source connection. Thus, the user used will be the user parameter passed
to the input.harbor source.
When using a custom authentication function, in case of a ICY (shoutcast) connection,
the function will receive this value for the username.
Usage
When using harbor inputs, you first set the required settings, as described above. Then, you define each source using input.harbor("mountpoint"). This source is faillible and will become available when a source client is connected.
The unlabeled parameter is the mount point that the source client may connect
to. It should be "/" for shoutcast source clients.
The source client may use any of the recognized audio input codec. Hence, when using shoucast source clients, you need to have compiled liquidsoap with mp3 decoding support (ocaml-mad)
A sample code can be:
set("harbor.bind_addr","0.0.0.0")
# Some code...
# This defines a source waiting on mount point
# /test-harbor
live = input.harbor("test-harbor",port=8080,password="xxx")
# This is the final stream.
# Uses the live source as soon as available,
# and don't wait for an end of track, since
# we don't want to cut the beginning of the live
# stream.
#
# You may insert a jingle transition here...
radio = fallback(track_sensitive=false,
[live,files])