RTCRtpTransceiver: direction property
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.
Value
A string whose value is one of the strings which are a member of the following values, indicating the transceiver's preferred direction.
Value | RTCRtpSender behavior |
RTCRtpReceiver behavior |
---|---|---|
"sendrecv" |
Offers to send RTP data, and will do so if the other peer accepts the connection and at least one of the sender's encodings is active. | Offers to receive RTP data, and does so if the other peer accepts. |
"sendonly" |
Offers to send RTP data, and will do so if the other peer accepts the connection and at least one of the sender's encodings is active. | Does not offer to receive RTP data and will not do so. |
"recvonly" |
Does not offer to send RTP data, and will not do so. | Offers to receive RTP data, and will do so if the other peer offers. |
"inactive" |
Does not offer to send RTP data, and will not do so. | Does not offer to receive RTP data and will not do so. |
Exceptions
When setting the value of direction
, the following exception can occur:
InvalidStateError
DOMException
-
Thrown if either the receiver's
RTCPeerConnection
is closed or theRTCRtpReceiver
is stopped.
Usage notes
Setting the direction
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
.
Effect on offers and answers
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
Specifications
Specification |
---|
WebRTC: Real-Time Communication in Browsers # dom-rtcrtptransceiver-direction |
Browser compatibility
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