The RTCRtpTransceiver
property direction
is a string which indicates the transceiver's preferred directionality.
Its value must be one of the strings defined in the table below.
The transceiver's current direction is indicated by the currentDirection
property.
A DOMString
whose value is one of the strings which are a member of the following values, indicating the transceiver's preferred direction.
When setting the value of direction
, the following exception can occur:
-
InvalidStateError
DOMException
-
Thrown if either the receiver's RTCPeerConnection
is closed or the RTCRtpReceiver
is stopped.
When you change the value of direction
, an InvalidStateError
exception will occur if the connection is closed or the receiver is stopped.
If the new value of direction
is in fact different from the existing value, renegotiation of the connection is required, so a negotiationneeded
event is sent to the RTCPeerConnection
.
The value of direction
is used by RTCPeerConnection.createOffer()
or RTCPeerConnection.createAnswer()
in order to generate the SDP generated by each of those methods. The SDP contains an a-line which specifies the directionality. For example, if the direction
is specified as "sendrecv"
, the corresponding SDP a-line is:
a=sendrecv