void GetOrCreateTransceiver(out RtpTransceiver transceiver, out bool isReusingTransceivers)
{
var mediaKind = _track.Kind;
var transceivers = TargetPeerConnection.Native.GetTransceivers();
transceiver = null;
isReusingTransceivers = true;
for (var i = 0; i < transceivers.Count; i++)
{
if (transceivers[i].ReusabilityState == TransceiverReusabilityState.Available &&
false == string.IsNullOrWhiteSpace(transceivers[i].Mid) &&
transceivers[i].MediaKind == mediaKind &&
transceivers[i].Direction != RtpTransceiverDirection.RecvOnly)
{
transceiver = transceivers[i];
break;
}
}
// If no available transceiver, create a new one
if (transceiver is null || true)
{
transceiver = TargetPeerConnection.Native.AddTransceiver(mediaKind, RtpTransceiverDirection.SendOnly);
isReusingTransceivers = false;
}
transceiver.CustomData = this;
}
internal void OnRemoteTrackRemoved(RtpTransceiver transceiver)
{
_signallingThread.EnsureCurrentThread();
VideoRouterThrowHelper.WhenInvalidReceiver(transceiver);
_remoteVideoLinks.RemoveByRemoteTrack(transceiver.Receiver);
_logger.Info($"Removed {transceiver.Receiver} from {_remoteVideoLinks}");
}
public LocalVideoLink(VideoRouter parent, VideoSource source, IPeerConnection target)
{
if (source is null)
{
throw new ArgumentNullException(nameof(source));
}
if (target is null)
{
throw new ArgumentNullException(nameof(target));
}
if (null == source.VideoTrackSource)
{
throw new InvalidProgramException("VideoTrackSource is NULL");
}
TargetPeerConnection = target;
VideoSource = source;
_parent = parent
?? throw new ArgumentNullException(nameof(parent));
// Create track
var trackId = Guid.NewGuid();
_track = parent.PeerConnectionFactory.CreateVideoTrack(trackId.ToString(), source.VideoTrackSource);
// Find the first available transceiver (or create it)
GetOrCreateTransceiver(out var transceiver, out var isReusingTransceiver);
Transceiver = transceiver;
// Next, set/replace the track:
Transceiver.ToBusyState(_track);
// If we're re-using an existing transceivers.
// Transceiver metadata will need to be sent for clients to update their UIs.
// If we are creating new transceivers, no need to do this,
// since PeerConnection will re-negotiate automatically
if (isReusingTransceiver)
{
RaiseTransceiverMetadataUdatedEvent();
}
// If stream id has not been set, set it.
// WebRTC does not allow us to change the stream id, but we don't care either,
// we just want it to be unique.
if (string.IsNullOrWhiteSpace(Transceiver.Sender.StreamId))
{
Transceiver.Sender.StreamId = Guid.NewGuid().ToString();
}
// Add track to peer
_logger.Debug($"Local track created {_track}");
}
public static void WhenInvalidReceiver(RtpTransceiver transceiver)
{
var track = transceiver.Receiver.Track;
if (track == null)
{
throw new InvalidProgramException("Track is NULL");
}
if (string.IsNullOrWhiteSpace(track.Id))
{
throw new ArgumentNullException($"Track id is null for {transceiver}, Track {transceiver.Receiver.Track}");
}
}
internal void OnRemoteTrackAdded(Client client, IPeerConnection peerConnection, RtpTransceiver transceiver)
{
_signallingThread.EnsureCurrentThread();
Require.NotNull(peerConnection);
VideoRouterThrowHelper.WhenInvalidReceiver(transceiver);
// Ignore audio tracks for now
if (transceiver.Receiver.Track.Kind != MediaKind.Video)
{
return;
}
// What's the video source that this track should be connected to?
var transceiverMid = transceiver.Mid;
var videoSource = client.VideoSources
.FirstOrDefault(kv => string.Equals(kv.Value.ExpectedTransceiverMid, transceiverMid, StringComparison.InvariantCultureIgnoreCase))
.Value;
// videoSource could be null when the client doesn't have any input devices,
// therefore it never calls SetRemoteTransceiverMetadata()
if (videoSource != null)
{
VideoRouterThrowHelper.WhenSourceIsEmpty(videoSource, transceiver.Receiver);
var remoteVideoLink = new RemoteVideoLink(peerConnection, videoSource, transceiver.Receiver);
_remoteVideoLinks.AddOrUpdate(remoteVideoLink);
_logger.Info($"Added {remoteVideoLink} into {_remoteVideoLinks}");
}
}
public RtpTransceiverNative(RtpTransceiver rtpTransceiverNative) : base(rtpTransceiverNative)
{
_rtpTransceiver = rtpTransceiverNative;
}
public PlatformRtpTransceiver(RtpTransceiver transceiver) : base(transceiver) => _transceiver = transceiver;
private RTCRtpTransceiver(RtpTransceiver nativeTransceiver) : base(nativeTransceiver)
{
}
