Bin used for establishing ICE connection, sending and receiving messages.

architecture-and-pad-semantic

Architecture and pad semantic

Both input and output pads are dynamic ones. One instance of Libnice Bin is responsible for handling only one ICE stream which can have multiple components. Each pad is responsible for carrying data from/to one component.

linking-using-output-pad

Linking using output pad

To receive messages after establishing ICE connection you have to link Libnice Bin to your element via Pad.ref(:output, component_id). component_id is an id of component from which your element will receive messages. E.g. if you passed as n_components 2 it means that there will be two components and you can link Libnice Bin to your element via Pad.ref(:output, 1) and Pad.ref(:output, 2).

Important: you can link to Libnice Bin using its output pad in any moment you want but if you don't want to miss any messages do it before playing your pipeline.

Important: you can't link multiple elements using the same component_id. Messages from one component can be conveyed only to one element.

linking-using-input-pad

Linking using input pad

To send messages after establishing ICE connection you have to link to Libnice Bin via Pad.ref(:input, component_id). component_id is an id of component which will be used to send messages via net. To send data from multiple elements via the same component_id you have to use membrane_funnel_plugin.

messages-api

Messages API

You can send following messages to Libnice Bin:

• :gather_candidates

• {:set_remote_credentials, credentials} - credentials are string in form of "ufrag passwd"

• {:set_remote_candidate, candidate, component_id} - candidate is a string in form of SDP attribute i.e. it has prefix "a=" e.g. "a=candidate 1 "

• {:parse_remote_sdp, sdp}

• :peer_candidate_gathering_done

notifications-api

Notifications API

• {:new_candidate_full, candidate} Triggered by: :gather_candidates

• :candidate_gathering_done Triggered by: :gather_candidates

• {:new_remote_candidate_full, candidate} Triggered by: {:set_remote_candidate, candidate, component_id} or {:parse_remote_sdp, sdp}

sending-and-receiving-messages

Sending and receiving messages

To send or receive messages just link to Libnice Bin using relevant pads. As soon as connection is established your element will receive demands from Libnice Sink or messages from Libnice Source.

bin-options

Bin options

Passed via struct Membrane.Libnice.Bin.t/0

• n_components

  integer()

  Default value: 1
  Number of components that will be created in the stream

• stream_name

  String.t()

  Default value: ""
  Name of the stream

• stun_servers

  [ExLibnice.stun_server()]

  Default value: []
  List of stun servers

• turn_servers

  [ExLibnice.relay_info()]

  Default value: []
  List of turn servers

• controlling_mode

  boolean()

  Default value: false
  Refer to RFC 8445 section 4 - Controlling and Controlled Agent

• port_range

  Range.t()

  Default value: 0..0
  The port range to use

• handshake_module

  module()

  Default value: Handshake.Default
  Module implementing Handshake behaviour

• handshake_opts

  keyword()

  Default value: []
  Options for handshake module. They will be passed to init function of hsk_module

pads

Pads

input

:input

output

:output