Class MediaLine

Media line abstraction for a peer connection.

This container binds together a source component (MediaTrackSource) and/or a receiver component (MediaReceiver) on one side, with a transceiver on the other side. The media line is a declarative representation of this association, which is then turned into a binding by the implementation during an SDP negotiation. This forms the core of the algorithm allowing automatic transceiver pairing between the two peers based on the declaration of intent of the user.

Assigning Unity components to the Source and Receiver properties serves as an indication of the user intent to send and/or receive media through the transceiver, and is used during the SDP exchange to derive the to negotiate. After the SDP negotiation is completed, the Transceiver property refers to the transceiver associated with this media line, and which the sender and receiver will use.

Users typically interact with this class through the peer connection transceiver collection in the Unity inspector window, though direct manipulation via code is also possible.

Inheritance

Object

MediaLine

Inherited Members

Object.ToString()

Object.Equals(Object)

Object.Equals(Object, Object)

Object.ReferenceEquals(Object, Object)

Object.GetHashCode()

Object.GetType()

Object.MemberwiseClone()

Namespace: Microsoft.MixedReality.WebRTC.Unity

Assembly: cs.temp.dll.dll

Syntax

public class MediaLine

Properties

LocalTrack

Local track created from a local source.

Declaration

public LocalMediaTrack LocalTrack { get; }

Property Value

Type	Description
LocalMediaTrack

Remarks

This is non-null when a live source is attached to the MediaLine, and the owning PeerConnection is connected.

MediaKind

Kind of media of the media line and its attached transceiver.

This is assiged when the media line is created with AddMediaLine(MediaKind) and is immutable for the lifetime of the peer connection.

Declaration

public MediaKind MediaKind { get; }

Property Value

Type	Description
MediaKind

Peer

PeerConnection owning this MediaLine.

Declaration

public PeerConnection Peer { get; }

Property Value

Type	Description
PeerConnection

Receiver

Media receiver consuming the media received through the transceiver attached to this media line.

Declaration

public MediaReceiver Receiver { get; set; }

Property Value

Type	Description
MediaReceiver

Remarks

This must be an instance of a class derived from AudioReceiver or VideoReceiver depending on whether MediaKind is or , respectively.

If this is non-null then the peer connection will negotiate receiving some media, otherwise it will signal the remote peer that it does not wish to receive (send-only or inactive).

If Transceiver is valid, that is a first session negotiation has already been conducted, then changing this value raises a event on the peer connection of Transceiver.

Must be changed on the main Unity app thread.

SenderTrackName

Name of the local media track this component will create when calling . If left empty, the implementation will generate a unique name for the track (generally a GUID).

Declaration

public string SenderTrackName { get; set; }

Property Value

Type	Description
String

Remarks

This value must comply with the 'msid' attribute rules as defined in https://tools.ietf.org/html/draft-ietf-mmusic-msid-05#section-2, which in particular constraints the set of allowed characters to those allowed for a 'token' element as specified in https://tools.ietf.org/html/rfc4566#page-43:

• Symbols [!#$%'*+-.^_`{|}~] and ampersand &
• Alphanumerical characters [A-Za-z0-9]

Users can manually test if a string is a valid SDP token with the utility method Validate(String, Boolean). The property setter will use this and throw an if the token is not a valid SDP token.

The sender track name is taken into account each time the track is created. If this property is assigned after the track was created (already negotiated), the value will be used only for the next negotiation, and the current sender track will keep its current track name (either a previous value or a generated one).

See Also

Validate(String, Boolean)

Source

Media source producing the media to send through the transceiver attached to this media line.

Declaration

public MediaTrackSource Source { get; set; }

Property Value

Type	Description
MediaTrackSource

Remarks

This must be an instance of a class derived from AudioTrackSource or VideoTrackSource depending on whether MediaKind is or , respectively.

Internally the peer connection will automatically create and manage a media track to bridge the media source with the transceiver.

If this is non-null then the peer connection will negotiate sending some media, otherwise it will signal the remote peer that it does not wish to send (receive-only or inactive).

If Transceiver is valid, that is a first session negotiation has already been completed, then changing this value raises a event on the peer connection of Transceiver.

Must be changed on the main Unity app thread.

Transceiver

Transceiver attached with this media line.

On the offering peer this changes during StartConnection(), while this is updated by when receiving an offer on the answering peer.

Because transceivers cannot be destroyed, once this property is assigned a non-null value it keeps that value until the peer connection owning the media line is closed.

Declaration

public Transceiver Transceiver { get; }

Property Value

Type	Description
Transceiver