RTCSessionDescription.constructor

The RTCSessionDescription() constructor creates a new RTCSessionDescription with its properties initialized as described in the specified object.

Syntax

 sessionDescription = new RTCSessionDescription(rtcSessionDescriptionInit);

Values

rtcSessionDescriptionInitOptional

An object providing the default values for the session description; the object conforms to the RTCSessionDescriptionInit dictionary. That dictionary has the following properties:

type

Required. A string which is a member of the RTCSdpType enum; it must have one of the following values:

This enum defines strings that describe the current state of the session description, as used in the type property. The session description's type will be specified using one of these values.

Value	Description
answer	The SDP contained in the sdp property is the definitive choice in the exchange. In other words, this session description describes the agreed-upon configuration, and is being sent to finalize negotiation.
offer	The session description object describes the initial proposal in an offer/answer exchange. The session negotiation process begins with an offer being sent from the caller to the callee.
pranswer	The session description object describes a provisional answer; that is, it's a response to a previous offer or provisional answer.
rollback	This special type with an empty session description is used to roll back to the previous stable state.

sdp

A string containing a SDP message describing the session. This value is an empty string ("") by default and may not be null.

Example

This example uses the constructor to convert an SDP offer into an RTCSessionDescription object.

navigator.getUserMedia({video: true}, function(stream) {
  pc.onaddstream({stream: stream});
  // Adding a local stream won't trigger the onaddstream callback
  pc.addStream(stream);

  pc.createOffer(function(offer) {
    pc.setLocalDescription(new RTCSessionDescription(offer), function() {
      // send the offer to a server to be forwarded to the friend you're calling.
    }, error);
  }, error);
}

Specifications

Browser compatibilityUpdate compatibility data on GitHub

See also

• WebRTC API
• RTCSessionDescription