Ndtyjky

I’ m currently debugging a webrtc UWP app, and it is fairly working.

But it happens that the remote stream is not displayed on my MediaElement each time. It’s like the video track is not received although I add it ASAP as recommended. I can’t figure out why it is happening ; is it a code or a network problem ? I grab the stream randomly whatever the network, sometimes successfully, other times not (staying with the same confits).

I use the google STUN servers, and the google webrtc « peer connection server » signaling server on a remote windows server, nothing is installed on my LAN (but my UWP program).

I don’t know what to do to figure out the cause ... any help would be appreciated.

private void Signaller_OnMessageFromPeer(int peerId, string message)

{

    Task.Run(async () =>

    {

        // Debug.Assert(_peerId == peerId || _peerId == -1);

        Debug.Assert(message.Length > 0);

        if (_peerId != peerId && _peerId != -1)

        {

            Debug.WriteLine("[Error] Conductor: Received a message from unknown peer while already in a conversation with a different peer.");

            return;

        }



        if (!JsonObject.TryParse(message, out JsonObject jMessage))

        {

            Debug.WriteLine("[Error] Conductor: Received unknown message." + message);

            return;

        }



        string type = jMessage.ContainsKey(kSessionDescriptionTypeName) ? jMessage.GetNamedString(kSessionDescriptionTypeName) : null;



        if (_peerConnection == null)

        {

            if (!String.IsNullOrEmpty(type))

            {

                // Create the peer connection only when call is

                // about to get initiated. Otherwise ignore the

                // messages from peers which could be a result

                // of old (but not yet fully closed) connections.

                if (type == "offer" || type == "answer")

                {

                    Debug.Assert(_peerId == -1);

                    _peerId = peerId;

                    connectToPeerCancelationTokenSource = new CancellationTokenSource();

                    connectToPeerTask                   = CreatePeerConnection(connectToPeerCancelationTokenSource.Token);

                    bool connectResult                  = await connectToPeerTask;

                    connectToPeerTask                   = null;



                    connectToPeerCancelationTokenSource.Dispose();



                    if (!connectResult)

                    {

                        Debug.WriteLine("[Error] Conductor: Failed to initialize our PeerConnection instance");

                        await Signaller.SignOut();

                        return;

                    }

                    else if (_peerId != peerId)

                    {

                        Debug.WriteLine("[Error] Conductor: Received a message from unknown peer while already in a conversation with a different peer.");

                        return;

                    }

                }

            }

            else

            {

                Debug.WriteLine("[Warn] Conductor: Received an untyped message after closing peer connection.");

                return;

            }

        }



        if (!String.IsNullOrEmpty(type))

        {

            if (type == "offer-loopback")

            {

                // Loopback not supported

                Debug.Assert(false);

            }



            string sdp = jMessage.ContainsKey(kSessionDescriptionSdpName) ? jMessage.GetNamedString(kSessionDescriptionSdpName) : null;



            if (String.IsNullOrEmpty(sdp))

            {

                Debug.WriteLine("[Error] Conductor: Can't parse received session description message.");

                return;

            }



            RTCSdpType sdpType = RTCSdpType.Offer;



            switch (type)

            {

                case "offer":

                    sdpType = RTCSdpType.Offer;

                    break;

                case "answer":

                    sdpType = RTCSdpType.Answer;

                    break;

                case "pranswer":

                    sdpType = RTCSdpType.Pranswer;

                    break;

                default:

                    Debug.Assert(false, type);

                    break;

            }



            Debug.WriteLine("Conductor: Received session description: " + message + "rn" + sdp);

            await _peerConnection.SetRemoteDescription(new RTCSessionDescription(sdpType, sdp));



            if (sdpType == RTCSdpType.Offer)

            {

                RTCSessionDescription answer = await _peerConnection.CreateAnswer();

                await _peerConnection.SetLocalDescription(answer);

                // Send answer

                SendSdp(answer);



                Debug.WriteLine(String.Format("Conductor: Session Description to be sent : {0}", answer.Sdp));

            }

        }

        else

        {

            var sdpMid = jMessage.ContainsKey(kCandidateSdpMidName)                 ? jMessage.GetNamedString(kCandidateSdpMidName)         : null;

            var sdpMlineIndex = jMessage.ContainsKey(kCandidateSdpMlineIndexName)   ? jMessage.GetNamedNumber(kCandidateSdpMlineIndexName)  : -1;

            var sdp = jMessage.ContainsKey(kCandidateSdpName)                       ? jMessage.GetNamedString(kCandidateSdpName)            : null;



            if (String.IsNullOrEmpty(sdpMid) || sdpMlineIndex == -1 || String.IsNullOrEmpty(sdp))

            {

                Debug.WriteLine("[Error] Conductor: Can't parse received message.n" + message);

                return;

            }



            var candidate = new RTCIceCandidate(sdp, sdpMid, (ushort)sdpMlineIndex);

            await _peerConnection.AddIceCandidate(candidate);



            Debug.WriteLine("Conductor: Received candidate : " + message);

        }

    }).Wait();

}