I want to optimize the delay of 100ms. What should I do?

[344089386]

using LibVLCSharp.Shared;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using Serilog;
using Serilog.Extensions.Logging;
using SIPSorcery.Media;
using SIPSorcery.Net;
using SIPSorcery.Sys;
using SIPSorceryMedia.Abstractions;
using System.Net;
using System.Net.Sockets;
using System.Net.WebSockets;
using System.Timers;
using Websocket.Client;

namespace JanusWebRTCClient
{
    class Program
    {
        private const string JANUS_WEBSOCKET_URL = "ws://192.168.29.198/janus/ws?auth_token=53aab30177eac083a5cf2e73ba0bc4bd3bc7b83639905f8fde06f6b80a109a57";

        static async Task Main(string[] args)
        {
            // 初始化日志
            Log.Logger = new LoggerConfiguration()
                .MinimumLevel.Debug()
                .WriteTo.Console()
                .CreateLogger();
            SIPSorcery.LogFactory.Set(new SerilogLoggerFactory(Log.Logger));

            Console.WriteLine("Starting Janus WebRTC client...");
            LibVLCSharp.Shared.Core.Initialize();
            var libVlc = new LibVLC();
            var mediaPlayer = new MediaPlayer(libVlc);

            var webRTC = new WebRTCVideo();
            webRTC.OnConnected = (sdpPath) =>
            {
                // 关键：使用 demux=h264 来播放原始H.264流
                var options = new[]
                {
                    ":no-audio",
                    ":demux=any",
                    //":rtp-max-dropout=0",
                    //":rtp-max-misorder=0",
                    ":file-caching=0",
                    ":live-caching=0",
                    ":network-caching=0",
                    //":fps=30",
                    //":clock-jitter=0",
                    //":skip-frames",
                    //":drop-late-frames",
                    //":avcodec-threads=0",
                    ":avcodec-hw=any"
                };

                using var media = new Media(libVlc, new Uri(sdpPath), options);
                mediaPlayer.Play(media);
            };

            webRTC.OnDisConnected = () =>
            {
                mediaPlayer.Stop();
            };

            await webRTC.Start(JANUS_WEBSOCKET_URL);
            Console.ReadKey();
        }

        private class WebRTCVideo : IDisposable
        {
            private int _videoPort;
            private string _sdpPath = "";
            private WebsocketClient ws;
            private RTCPeerConnection _peerConnection;
            private RTPSession _rtpSession;
            private System.Timers.Timer timer;
            private static long? _sessionId;
            private static long? _handleId;

            public Action<string> OnConnected { get; set; }
            public Action OnDisConnected { get; set; }

            public async Task Start(string url)
            {
                _sdpPath = Path.GetTempFileName() + ".sdp";
                _videoPort = 5018;
                await ConnectToJanus(url);

                timer = new System.Timers.Timer(15000);
                timer.Elapsed += (s, e) =>
                {
                    var keepaliveReq = new { janus = "keepalive", transaction = Guid.NewGuid().ToString("N").Substring(0, 12) };
                    SendJanusMessage(ws, keepaliveReq);
                };
            }

            private async Task CreateAndSendAnswer(WebsocketClient ws, string sdpOffer)
            {
                RTCConfiguration config = new RTCConfiguration
                {
                    iceServers = new List<RTCIceServer> { new RTCIceServer { urls = "stun:stun.cloudflare.com" } },
                    X_BindAddress = IPAddress.Parse("192.168.28.224")
                };
                _peerConnection = new RTCPeerConnection(config);
                _peerConnection.onicecandidate += (candidate) =>
                {
                    if (candidate != null)
                    {
                        var trickleMsg = new
                        {
                            janus = "trickle",
                            candidate = new
                            {
                                candidate = $"candidate:{candidate.candidate}",
                                sdpMid = candidate.sdpMid,
                                sdpMLineIndex = candidate.sdpMLineIndex
                            },
                            transaction = Guid.NewGuid().ToString("N").Substring(0, 12)
                        };
                        SendJanusMessage(ws, trickleMsg);

                        var trickleCompletedMsg = new
                        {
                            janus = "trickle",
                            candidate = new { completed = true },
                            transaction = Guid.NewGuid().ToString("N").Substring(0, 12)
                        };
                        SendJanusMessage(ws, trickleCompletedMsg);
                    }
                };

                // 监听连接状态
                _peerConnection.onconnectionstatechange += async (state) =>
                {
                    Log.Information($"PeerConnection state: {state}");
                    if (state == RTCPeerConnectionState.connected)
                    {
                        Log.Information("WebRTC connected. Preparing for VLC playback.");

                        _rtpSession = CreateRtpSession(_peerConnection.VideoLocalTrack?.Capabilities);

                        // 请求关键帧
                        var localVideoSsrc = _peerConnection.VideoLocalTrack.Ssrc;
                        var remoteVideoSsrc = _peerConnection.VideoRemoteTrack.Ssrc;
                        var pli = new RTCPFeedback(localVideoSsrc, remoteVideoSsrc, PSFBFeedbackTypesEnum.PLI);
                        _peerConnection.SendRtcpFeedback(SDPMediaTypesEnum.video, pli);

                        _peerConnection.OnRtpPacketReceived += (rep, media, rtpPkt) =>
                        {
                            if (media == SDPMediaTypesEnum.video)
                            {
                                _rtpSession.SendRtpRaw(media, rtpPkt.Payload, rtpPkt.Header.Timestamp, rtpPkt.Header.MarkerBit, rtpPkt.Header.PayloadType);
                            }
                        };

                        _peerConnection.OnRtpClosed += (reason) =>
                        {
                            timer?.Stop();
                            OnDisConnected?.Invoke();
                        };
                        OnConnected?.Invoke(_sdpPath);
                    }
                };

                // 设置并发送Answer
                var sdp = SDP.ParseSDPDescription(sdpOffer);
                foreach (var ann in sdp.Media.Where(m => m.Media == SDPMediaTypesEnum.video))
                {
                    var track = new MediaStreamTrack(ann.Media, false, ann.MediaFormats.Values.ToList(), MediaStreamStatusEnum.RecvOnly);
                    _peerConnection.addTrack(track);
                }

                _peerConnection.setRemoteDescription(new RTCSessionDescriptionInit { type = RTCSdpType.offer, sdp = sdpOffer });
                var answer = _peerConnection.createAnswer(null);
                await _peerConnection.setLocalDescription(answer);

                var answerMessage = new
                {
                    janus = "message",
                    body = new { request = "start" },
                    jsep = new { type = "answer", sdp = answer.sdp },
                    transaction = Guid.NewGuid().ToString("N")
                };
                SendJanusMessage(ws, answerMessage);
            }

            private RTPSession CreateRtpSession(List<SDPAudioVideoMediaFormat> videoFormats)
            {
                var rtpSession = new RTPSession(false, false, false, IPAddress.Parse("192.168.28.224"));
                bool hasVideo = false;

                if (videoFormats != null && videoFormats.Count > 0)
                {
                    MediaStreamTrack videoTrack = new MediaStreamTrack(SDPMediaTypesEnum.video, false, videoFormats, MediaStreamStatusEnum.SendRecv);
                    rtpSession.addTrack(videoTrack);
                    hasVideo = true;
                }

                var sdpOffer = rtpSession.CreateOffer(null);

                if (hasVideo)
                {
                    sdpOffer.Media.Single(x => x.Media == SDPMediaTypesEnum.video).Port = _videoPort;
                }

                Console.WriteLine(sdpOffer);

                using (StreamWriter sw = new StreamWriter(_sdpPath))
                {
                    sw.Write(sdpOffer);
                }

                rtpSession.Start();
                rtpSession.SetDestination(SDPMediaTypesEnum.video, new IPEndPoint(IPAddress.Parse("192.168.28.224"), _videoPort), new IPEndPoint(IPAddress.Parse("192.168.28.224"), _videoPort + 1));

                return rtpSession;
            }

            #region WebSocket相关 (保持不变)
            private async Task ConnectToJanus(string url)
            {
                var factory = new Func<ClientWebSocket>(() =>
                {
                    var clientWebSocket = new ClientWebSocket();
                    clientWebSocket.Options.KeepAliveInterval = TimeSpan.FromSeconds(10);
                    clientWebSocket.Options.AddSubProtocol("janus-protocol");
                    return clientWebSocket;
                });
                ws = new WebsocketClient(new Uri(url), factory);
                ws.IsReconnectionEnabled = false;
                ws.DisconnectionHappened.Subscribe(info =>
                {
                    Log.Information("WebRTC WebSocket disconnect");
                    timer?.Stop();
                    OnDisConnected?.Invoke();
                });
                ws.ReconnectionHappened.Subscribe(info =>
                {
                    Log.Information("WebRTC WebSocket connect success");
                    var createSessionReq = new { janus = "create", transaction = Guid.NewGuid().ToString("N").Substring(0, 12) };
                    SendJanusMessage(ws, createSessionReq);
                });
                ws.MessageReceived.Subscribe(async msg => await HandleJanusMessage(ws, msg.Text));
                await ws.Start();
            }

            private async Task HandleJanusMessage(WebsocketClient ws, string msg)
            {
                if (string.IsNullOrEmpty(msg)) return;
                Log.Debug($"Received from Janus: {msg}");

                var response = JObject.Parse(msg);
                var janusType = response["janus"]?.Value<string>();

                switch (janusType)
                {
                    case "success" when response.ContainsKey("data") && !response.ContainsKey("session_id"):
                        _sessionId = response["data"]?["id"]?.Value<long>();
                        Log.Information($"Session created with ID: {_sessionId}");
                        var attachReq = new
                        {
                            janus = "attach",
                            plugin = "janus.plugin.ustreamer",
                            opaque_id = "oid-" + Guid.NewGuid().ToString("N").Substring(0, 12),
                            transaction = Guid.NewGuid().ToString("N").Substring(0, 12)
                        };
                        SendJanusMessage(ws, attachReq);
                        break;

                    case "success" when response.ContainsKey("session_id") && !response.ContainsKey("plugindata"):
                        _handleId = response["data"]?["id"]?.Value<long>();
                        Log.Information($"Attached to streaming plugin with handle ID: {_handleId}");
                        var watchReq = new
                        {
                            janus = "message",
                            body = new { request = "watch" },
                            transaction = Guid.NewGuid().ToString("N").Substring(0, 12)
                        };
                        SendJanusMessage(ws, watchReq);
                        break;

                    case "event" when response.ContainsKey("jsep"):
                        var jsep = response["jsep"];
                        var sdpOffer = jsep["sdp"]?.Value<string>();
                        var sdpType = jsep["type"]?.Value<string>();
                        if (sdpType == "offer" && !string.IsNullOrEmpty(sdpOffer))
                        {
                            Log.Information("Received SDP offer from Janus. Creating answer...");
                            await CreateAndSendAnswer(ws, sdpOffer);
                        }
                        break;

                    case "webrtcup":
                        timer.Start();
                        break;
                }
            }

            private void SendJanusMessage(WebsocketClient ws, object messageObj)
            {
                var message = JObject.FromObject(messageObj);
                if (_sessionId != null) message["session_id"] = _sessionId;
                if (_handleId != null) message["handle_id"] = _handleId;
                var json = JsonConvert.SerializeObject(message);
                Log.Debug($"Sending to Janus: {json}");
                ws.Send(json);
            }
            #endregion

            public void Dispose()
            {
                try
                {
                    _sessionId = null;
                    _handleId = null;
                    ws?.Dispose();
                    //_udpSender?.Close();
                    //_udpSender?.Dispose();
                    _peerConnection?.close();
                    _peerConnection?.Dispose();
                    if (!string.IsNullOrEmpty(_sdpPath) && File.Exists(_sdpPath))
                    {
                        File.Delete(_sdpPath);
                    }
                }
                catch { }
            }
        }
    }
}

log:

Starting Janus WebRTC client...
[10:32:46 INF] WebRTC WebSocket connect success
[10:32:46 DBG] Sending to Janus: {"janus":"create","transaction":"21d6791b69d9"}
[10:32:47 DBG] Received from Janus: {
   "janus": "success",
   "transaction": "21d6791b69d9",
   "data": {
      "id": 158384276970872
   }
}
[10:32:47 INF] Session created with ID: 158384276970872
[10:32:47 DBG] Sending to Janus: {"janus":"attach","plugin":"janus.plugin.ustreamer","opaque_id":"oid-03acc408af63","transaction":"2dde35387fd5","session_id":158384276970872}
[10:32:47 DBG] Received from Janus: {
   "janus": "success",
   "session_id": 158384276970872,
   "transaction": "2dde35387fd5",
   "data": {
      "id": 2699408990676378
   }
}
[10:32:47 INF] Attached to streaming plugin with handle ID: 2699408990676378
[10:32:47 DBG] Sending to Janus: {"janus":"message","body":{"request":"watch"},"transaction":"63179ea4c0e6","session_id":158384276970872,"handle_id":2699408990676378}
[10:32:47 DBG] Received from Janus: {
   "janus": "event",
   "session_id": 158384276970872,
   "sender": 2699408990676378,
   "plugindata": {
      "plugin": "janus.plugin.ustreamer",
      "data": {
         "ustreamer": "event",
         "result": {
            "status": "started"
         }
      }
   },
   "jsep": {
      "type": "offer",
      "sdp": "v=0\r\no=- 1797027044865807995 1 IN IP4 113.89.35.155\r\ns=PiKVM uStreamer\r\nt=0 0\r\na=group:BUNDLE v\r\na=extmap-allow-mixed\r\na=msid-semantic: WMS janus\r\nm=video 9 UDP/TLS/RTP/SAVPF 96 97\r\nc=IN IP4 113.89.35.155\r\na=sendonly\r\na=mid:v\r\na=rtcp-mux\r\na=ice-ufrag:2MIY\r\na=ice-pwd:X4OrwSMpZst5NJrccEeyIB\r\na=ice-options:trickle\r\na=fingerprint:sha-256 CE:A9:32:FF:A6:6C:2F:DE:33:87:91:7F:C7:CD:CB:08:89:2F:0F:5F:4F:BB:8B:E3:65:C8:E8:A3:6D:DF:C4:60\r\na=setup:actpass\r\na=rtpmap:96 H264/90000\r\na=fmtp:96 profile-level-id=42E01F\r\na=fmtp:96 packetization-mode=1\r\na=rtcp-fb:96 nack\r\na=rtcp-fb:96 nack pli\r\na=rtcp-fb:96 goog-remb\r\na=extmap:1 http://www.webrtc.org/experiments/rtp-hdrext/playout-delay\r\na=extmap:2 urn:3gpp:video-orientation\r\na=rtpmap:97 rtx/90000\r\na=fmtp:97 apt=96\r\na=ssrc-group:FID 2876871073 1033412930\r\na=msid:janus janusv0\r\na=ssrc:2876871073 cname:janus\r\na=ssrc:2876871073 msid:janus janusv0\r\na=ssrc:2876871073 mslabel:janus\r\na=ssrc:2876871073 label:janusv0\r\na=ssrc:1033412930 cname:janus\r\na=ssrc:1033412930 msid:janus janusv0\r\na=ssrc:1033412930 mslabel:janus\r\na=ssrc:1033412930 label:janusv0\r\na=candidate:1 1 udp 2013266431 192.168.29.198 33288 typ host\r\na=candidate:2 1 udp 2013266430 fe80::fba6:419f:7d8a:525e 30337 typ host\r\na=candidate:3 1 udp 1677722111 113.89.35.155 33288 typ srflx raddr 192.168.29.198 rport 33288\r\na=end-of-candidates\r\n"
   }
}
[10:32:47 INF] Received SDP offer from Janus. Creating answer...
[10:32:47 DBG] No DTLS certificate is provided in the configuration
[10:32:48 DBG] CreateRtpSocket attempting to create and bind RTP socket(s) on 192.168.28.224:0.
[10:32:48 DBG] CreateBoundSocket attempting to create and bind socket(s) on 192.168.28.224:0 using protocol Udp.
[10:32:48 DBG] CreateBoundSocket successfully bound on 192.168.28.224:51974.
[10:32:48 DBG] Successfully bound RTP socket 192.168.28.224:51974.
[10:32:48 DBG] IceServerResolver starting DNS lookup for ICE server stun:stun.cloudflare.com
[10:32:48 DBG] RTPChannel for 192.168.28.224:51974 started.
[10:32:48 DBG] IceServerResolver resolved stun:stun.cloudflare.com -> 162.159.207.0:3478
[10:32:48 DBG] SCTP windows size for data receiver set at 218.
[10:32:48 DBG] SCTP creating DTLS based association, is DTLS client False, ID 5000:5000:51974.
[10:32:48 DBG] Sending to Janus: {"janus":"trickle","candidate":{"candidate":"candidate:518684609 1 udp 2113937663 192.168.28.224 51974 typ host generation 0","sdpMid":null,"sdpMLineIndex":0},"transaction":"3b043fce8650","session_id":158384276970872,"handle_id":2699408990676378}
[10:32:48 DBG] Sending to Janus: {"janus":"trickle","candidate":{"completed":true},"transaction":"ffee6150ce27","session_id":158384276970872,"handle_id":2699408990676378}
[10:32:48 DBG] RTP ICE Channel discovered 1 local candidates.
[10:32:48 DBG] Sending STUN binding request to ICE server stun:stun.cloudflare.com with address 162.159.207.0:3478.
[10:32:48 DBG] [setRemoteDescription] - Extension:[2 - urn:3gpp:video-orientation]
[10:32:48 DBG] Sending STUN binding request to ICE server stun:stun.cloudflare.com with address 162.159.207.0:3478.
[10:32:48 DBG] Setting remote video track with sdp destination null and control destination null.
[10:32:48 DBG] Sending STUN binding request to ICE server stun:stun.cloudflare.com with address 162.159.207.0:3478.
[10:32:48 DBG] RTP ICE Channel remote credentials set.
[10:32:48 DBG] RTP ICE Channel received remote candidate: 1 1 udp 2013266431 192.168.29.198 33288 typ host generation 0
[10:32:48 DBG] RTP ICE Channel received remote candidate: 2 1 udp 2013266430 fe80::fba6:419f:7d8a:525e 30337 typ host generation 0
[10:32:48 DBG] RTP ICE Channel received remote candidate: 3 1 udp 1677722111 113.89.35.155 33288 typ srflx raddr 192.168.29.198 rport 33288 generation 0
[10:32:48 DBG] LogRemoteSDPSsrcAttributes: Audio:[ ]
 Video: [  [2876871073 - 1033412930 - ] ]
 Text: [  ]
[10:32:48 DBG] Sending STUN binding request to ICE server stun:stun.cloudflare.com with address 162.159.207.0:3478.
[10:32:48 DBG] Adding new candidate pair to checklist for: udp:192.168.28.224:51974 (host)->udp:192.168.29.198:33288 (host)
[10:32:48 DBG] Adding new candidate pair to checklist for: udp:192.168.28.224:51974 (host)->udp:113.89.35.155:33288 (srflx)
[10:32:48 DBG] ICE RTP channel sending connectivity check for udp:192.168.28.224:51974 (host)->udp:192.168.29.198:33288(host) from 192.168.28.224:51974 to 192.168.29.198:33288 (use candidate False).
[10:32:48 DBG] Sending STUN binding request to ICE server stun:stun.cloudflare.com with address 162.159.207.0:3478.
[10:32:48 DBG] STUN binding success response received for ICE server check to stun:stun.cloudflare.com.
[10:32:49 DBG] Adding server reflex ICE candidate for ICE server stun:stun.cloudflare.com and 113.89.35.155:51974.
[10:32:49 DBG] ICE RTP channel sending connectivity check for udp:192.168.28.224:51974 (host)->udp:113.89.35.155:33288 (srflx) from 192.168.28.224:51974 to 113.89.35.155:33288 (use candidate False).
[10:32:49 DBG] Sending to Janus: {"janus":"trickle","candidate":{"candidate":"candidate:187536785 1 udp 1677730047 113.89.35.155 51974 typ srflx raddr 0.0.0.0 rport 0 generation 0","sdpMid":"0","sdpMLineIndex":0},"transaction":"b4cb4c4e1c33","session_id":158384276970872,"handle_id":2699408990676378}
[10:32:49 DBG] Sending to Janus: {"janus":"message","body":{"request":"start"},"jsep":{"type":"answer","sdp":"v=0\r\no=- 55620 0 IN IP4 127.0.0.1\r\ns=sipsorcery\r\nt=0 0\r\na=group:BUNDLE v\r\nm=video 9 UDP/TLS/RTP/SAVP 96 97\r\nc=IN IP4 0.0.0.0\r\na=ice-ufrag:KYSU\r\na=ice-pwd:UXVQUZSLUKWLOSUZZAWCLZMI\r\na=fingerprint:sha-256 24:2A:3F:49:95:B1:80:58:C0:19:06:85:53:7A:27:4F:02:70:81:D1:C9:7E:CC:56:0C:15:BA:70:33:FB:41:2E\r\na=setup:active\r\na=candidate:518684609 1 udp 2113937663 192.168.28.224 51974 typ host generation 0\r\na=ice-options:ice2,trickle\r\na=mid:v\r\na=rtpmap:96 H264/90000\r\na=rtcp-fb:96 transport-cc\r\na=fmtp:96 packetization-mode=1\r\na=rtpmap:97 rtx/90000\r\na=rtcp-fb:97 transport-cc\r\na=fmtp:97 apt=96\r\na=rtcp-mux\r\na=rtcp:9 IN IP4 0.0.0.0\r\na=recvonly\r\na=ssrc:1487256276 cname:31750716-caeb-4964-bb9b-6f19afd1d91e\r\n"},"transaction":"f29acb601c0c4a0780206e01aff0a1ae","session_id":158384276970872,"handle_id":2699408990676378}
[10:32:49 DBG] Sending to Janus: {"janus":"trickle","candidate":{"completed":true},"transaction":"3eac30b9418b","session_id":158384276970872,"handle_id":2699408990676378}
[10:32:49 DBG] Received from Janus: {
   "janus": "success",
   "session_id": 158384276970872,
   "transaction": "63179ea4c0e6",
   "sender": 2699408990676378,
   "plugindata": {
      "plugin": "janus.plugin.ustreamer",
      "data": {
         "ok": true
      }
   }
}
[10:32:49 WRN] The active ICE server reached an unexpected state stun:stun.cloudflare.com.
[10:32:49 DBG] Received from Janus: {
   "janus": "ack",
   "session_id": 158384276970872,
   "transaction": "3b043fce8650"
}
[10:32:49 DBG] Received from Janus: {
   "janus": "ack",
   "session_id": 158384276970872,
   "transaction": "ffee6150ce27"
}
[10:32:49 DBG] Received from Janus: {
   "janus": "ack",
   "session_id": 158384276970872,
   "transaction": "b4cb4c4e1c33"
}
[10:32:49 DBG] Received from Janus: {
   "janus": "event",
   "session_id": 158384276970872,
   "sender": 2699408990676378,
   "plugindata": {
      "plugin": "janus.plugin.ustreamer",
      "data": {
         "ustreamer": "event",
         "result": {
            "status": "started"
         }
      }
   }
}
[10:32:49 DBG] ICE RTP channel remote peer nominated entry from binding request: udp:192.168.29.198:33288 (host).
[10:32:49 DBG] ICE RTP channel stopping ICE server checks in gathering state complete and connection state checking.
[10:32:49 DBG] Received from Janus: {
   "janus": "success",
   "session_id": 158384276970872,
   "transaction": "f29acb601c0c4a0780206e01aff0a1ae",
   "sender": 2699408990676378,
   "plugindata": {
      "plugin": "janus.plugin.ustreamer",
      "data": {
         "ok": true
      }
   }
}
[10:32:49 DBG] ICE RTP channel connected after 393ms udp:192.168.28.224:51974 (host)->udp:192.168.29.198:33288 (host).
[10:32:49 DBG] Received from Janus: {
   "janus": "ack",
   "session_id": 158384276970872,
   "transaction": "3eac30b9418b"
}
[10:32:49 INF] PeerConnection state: connecting
[10:32:49 DBG] ICE connected to remote end point 192.168.29.198:33288.
[10:32:49 DBG] Starting DLS handshake with role active.
[10:32:49 DBG] RTCPeerConnection DoDtlsHandshake started.
[10:32:49 DBG] DTLS commencing handshake as client.
[10:32:49 WRN] ICE RTP channel received an unexpected STUN message 17 from 192.168.29.198:33288.
Json: SIPSorcery.Net.STUNMessage
[10:32:49 DBG] Received from Janus: {
   "janus": "webrtcup",
   "session_id": 158384276970872,
   "sender": 2699408990676378
}
[10:32:49 WRN] RTP or RTCP packet received before secure context ready.
[10:32:49 WRN] RTP or RTCP packet received before secure context ready.
[10:32:49 DBG] RTCPeerConnection DTLS handshake result True, is handshake complete True.
[10:32:49 DBG] RTCPeerConnection remote certificate fingerprint matched expected value of CE:A9:32:FF:A6:6C:2F:DE:33:87:91:7F:C7:CD:CB:08:89:2F:0F:5F:4F:BB:8B:E3:65:C8:E8:A3:6D:DF:C4:60 for sha-256.
[10:32:49 INF] PeerConnection state: connected
[10:32:49 INF] WebRTC connected. Preparing for VLC playback.
[10:32:49 DBG] CreateRtpSocket attempting to create and bind RTP socket(s) on 192.168.28.224:0.
[10:32:49 DBG] Set remote track (video - index=0) SSRC to 2876871073 remote RTP endpoint 192.168.29.198:33288.
[10:32:49 DBG] CreateBoundSocket attempting to create and bind socket(s) on 192.168.28.224:0 using protocol Udp.
[10:32:49 DBG] CreateBoundSocket even port required, closing socket on 192.168.28.224:51975 and retrying on 51976.
[10:32:49 DBG] CreateBoundSocket attempting to create and bind socket(s) on 192.168.28.224:51977 using protocol Udp.
[10:32:49 DBG] CreateBoundSocket successfully bound on 192.168.28.224:51977.
[10:32:49 DBG] Successfully bound RTP socket 192.168.28.224:51976 and control socket 192.168.28.224:51977.
[10:32:49 DBG] RTPChannel for 192.168.28.224:51976 started.
v=0
o=- 1156375561 0 IN IP4 127.0.0.1
s=sipsorcery
c=IN IP4 192.168.28.224
t=0 0
m=video 5018 RTP/AVP 96 97
a=mid:0
a=rtpmap:96 H264/90000
a=rtcp-fb:96 transport-cc
a=fmtp:96 packetization-mode=1
a=rtpmap:97 rtx/90000
a=rtcp-fb:97 transport-cc
a=fmtp:97 apt=96
a=sendrecv
a=ssrc:1405650085 cname:a359c241-fdc2-4943-952f-466b69647110

[10:32:49 DBG] Video depacketisation codec set to H264 for SSRC 2876871073.
[10:32:49 DBG] Starting RTCP session for a359c241-fdc2-4943-952f-466b69647110.
[10:32:49 DBG] Starting RTCP session for 31750716-caeb-4964-bb9b-6f19afd1d91e.
[0000021d94af6660] main decoder error: buffer deadlock prevented
MultiFramedRTPSource::doGetNextFrame1(): The total received frame size exceeds the client's buffer size (250000).  66670 bytes of trailing data will be dropped!
[0000021d94896b40] main input error: ES_OUT_SET_(GROUP_)PCR  is called too late (pts_delay increased to 0 ms)
[0000021d94af6660] main decoder error: buffer deadlock prevented
[0000021d94896b40] main input error: ES_OUT_SET_(GROUP_)PCR  is called too late (pts_delay increased to 98 ms)
[0000021d94af6660] avcodec decoder: Using D3D11VA (AMD Radeon(TM) Graphics, vendor 1002(ATI), device 1636, revision d1)for hardware decoding
[0000021d94af6660] main decoder error: buffer deadlock prevented
[0000021d94896b40] main input error: ES_OUT_SET_(GROUP_)PCR  is called too late (pts_delay increased to 112 ms)
[0000021d94af6660] main decoder error: buffer deadlock prevented
[10:32:53 DBG] Sending key video RTCP packet size 76 to 192.168.28.224:5019.
[0000021d94bd8c60] direct3d11 vout display error: Could not create the depth stencil texture. (hr=0x80070057)

[344089386]

One more question, please.
Using port 5018 will be fine.
Using random ports is prone to causing errors: live555 demux error: no data received in 10s, aborting
Tell me what's going on.

[sipsorcery]

Which delay are you referring to?

You can use this property to set the RTP port. You can use the bindPort ctor parameter to control the RTP port for WebRTC connections.

[344089386]

What I'm referring to is the delay in real-time rendering of the image.
My display is dynamic, and the content shown will be 0.2 seconds slower than the actual time.

[sipsorcery]

What I'm referring to is the delay in real-time rendering of the image. My display is dynamic, and the content shown will be 0.2 seconds slower than the actual time.

If this includes the network transit time that's actually not too bad depending on the path.

Other than the network the main issue is that this library uses a combination of native & managed code in the video pipeline. Other libraries like Pion keep the video pipeline completely in native code for speed. In theory the native/managed boundary impact can be significantly reduced but no effort has been undertaken on this to date. It all boils down to finding the most efficient way to get the video frames out of the RTP packets (managed), decoded by FFmpeg (native) and displayed on the screen.

[344089386]

using LibVLCSharp.Shared;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using Serilog;
using Serilog.Extensions.Logging;
using SIPSorcery.Media;
using SIPSorcery.Net;
using SIPSorcery.Sys;
using SIPSorceryMedia.Abstractions;
using System.Net;
using System.Net.Sockets;
using System.Net.WebSockets;
using System.Timers;
using Websocket.Client;

namespace JanusWebRTCClient
{
    class Program
    {
        private const string JANUS_WEBSOCKET_URL = "ws://192.168.29.198/janus/ws?auth_token=4f0e2fa0cb1ddd0cbc54bcb83398b5c4d470cf9baebefe85c7aa187f9411c492";

        static async Task Main(string[] args)
        {
            // 初始化日志
            Log.Logger = new LoggerConfiguration()
                .MinimumLevel.Debug()
                .WriteTo.Console()
                .CreateLogger();
            SIPSorcery.LogFactory.Set(new SerilogLoggerFactory(Log.Logger));

            Console.WriteLine("Starting Janus WebRTC client...111");
            LibVLCSharp.Shared.Core.Initialize();
            var libVlc = new LibVLC();
            var mediaPlayer = new MediaPlayer(libVlc);

            var webRTC = new WebRTCVideo();
            webRTC.OnConnected = (sdpPath, videoPort) =>
            {
                // 关键：使用 demux=h264 来播放原始H.264流
                var options = new[]
                {
                    ":no-audio",
                    ":demux=any",
                    //":rtp-max-dropout=0",
                    //":rtp-max-misorder=0",
                    ":file-caching=0",
                    ":live-caching=0",
                    ":network-caching=0",
                    //":fps=30",
                    //":clock-jitter=0",
                    //":skip-frames",
                    //":drop-late-frames",
                    //":avcodec-threads=0",
                    ":avcodec-hw=any"
                };

                using var media = new Media(libVlc, new Uri(sdpPath), options);
                mediaPlayer.Play(media);
            };

            webRTC.OnDisConnected = () =>
            {
                mediaPlayer.Stop();
            };

            await webRTC.Start(JANUS_WEBSOCKET_URL);
            Console.ReadKey();
        }

        private class WebRTCVideo : IDisposable
        {
            private int _videoPort = 5018;
            private string _sdpPath = "";
            private WebsocketClient ws;
            private RTCPeerConnection _peerConnection;
            private RTPSession _rtpSession;
            private System.Timers.Timer timer;
            private static long? _sessionId;
            private static long? _handleId;

            public Action<string, int> OnConnected { get; set; }
            public Action OnDisConnected { get; set; }

            public async Task Start(string url)
            {
                _sdpPath = Path.GetTempFileName() + ".sdp";
                //_videoPort = UdpPortHelper.GetRandomAvailableUdpPort(20000, 40000);
                _videoPort = 40000;
                await ConnectToJanus(url);

                timer = new System.Timers.Timer(25000);
                timer.Elapsed += (s, e) =>
                {
                    var keepaliveReq = new { janus = "keepalive", transaction = Guid.NewGuid().ToString("N").Substring(0, 12) };
                    SendJanusMessage(ws, keepaliveReq);
                };
            }

            private async Task CreateAndSendAnswer(WebsocketClient ws, string sdpOffer)
            {
                RTCConfiguration config = new RTCConfiguration
                {
                    //iceServers = new List<RTCIceServer> { new RTCIceServer { urls = "stun:stun.cloudflare.com" } },
                    X_BindAddress = IPAddress.Parse("192.168.20.96"),
                };
                _peerConnection = new RTCPeerConnection(config, _videoPort);
                _peerConnection.onicecandidate += (candidate) =>
                {
                    if (candidate != null)
                    {
                        var trickleMsg = new
                        {
                            janus = "trickle",
                            candidate = new
                            {
                                candidate = $"candidate:{candidate.candidate}",
                                sdpMid = candidate.sdpMid,
                                sdpMLineIndex = candidate.sdpMLineIndex
                            },
                            transaction = Guid.NewGuid().ToString("N").Substring(0, 12)
                        };
                        SendJanusMessage(ws, trickleMsg);
                    }
                };

                // 监听连接状态
                _peerConnection.onconnectionstatechange += async (state) =>
                {
                    Log.Information($"PeerConnection state: {state}");
                    if (state == RTCPeerConnectionState.connected)
                    {
                        Log.Information("WebRTC connected. Preparing for VLC playback.");

                        _rtpSession = CreateRtpSession(_peerConnection.VideoLocalTrack?.Capabilities);

                        // 请求关键帧
                        var localVideoSsrc = _peerConnection.VideoLocalTrack.Ssrc;
                        var remoteVideoSsrc = _peerConnection.VideoRemoteTrack.Ssrc;
                        var pli = new RTCPFeedback(localVideoSsrc, remoteVideoSsrc, PSFBFeedbackTypesEnum.PLI);
                        _peerConnection.SendRtcpFeedback(SDPMediaTypesEnum.video, pli);

                        _peerConnection.OnRtpPacketReceived += (rep, media, rtpPkt) =>
                        {
                            if (media == SDPMediaTypesEnum.video)
                            {
                                _rtpSession.SendRtpRaw(media, rtpPkt.Payload, rtpPkt.Header.Timestamp, rtpPkt.Header.MarkerBit, rtpPkt.Header.PayloadType);
                            }
                        };

                        OnConnected?.Invoke(_sdpPath, _videoPort);
                    }
                };

                _peerConnection.OnRtpClosed += (reason) =>
                {
                    timer?.Stop();
                    OnDisConnected?.Invoke();
                };

                // 设置并发送Answer
                var sdp = SDP.ParseSDPDescription(sdpOffer);
                foreach (var ann in sdp.Media.Where(m => m.Media == SDPMediaTypesEnum.video))
                {
                    var track = new MediaStreamTrack(ann.Media, false, ann.MediaFormats.Values.ToList(), MediaStreamStatusEnum.RecvOnly);
                    _peerConnection.addTrack(track);
                }

                _peerConnection.setRemoteDescription(new RTCSessionDescriptionInit { type = RTCSdpType.offer, sdp = sdpOffer });
                var answer = _peerConnection.createAnswer(null);
                await _peerConnection.setLocalDescription(answer);

                var answerMessage = new
                {
                    janus = "message",
                    body = new { request = "start" },
                    jsep = new { type = "answer", sdp = answer.sdp },
                    transaction = Guid.NewGuid().ToString("N")
                };
                SendJanusMessage(ws, answerMessage);
            }

            private RTPSession CreateRtpSession(List<SDPAudioVideoMediaFormat> videoFormats)
            {
                var rtpSession = new RTPSession(false, false, false, IPAddress.Loopback);
                bool hasVideo = false;

                if (videoFormats != null && videoFormats.Count > 0)
                {
                    MediaStreamTrack videoTrack = new MediaStreamTrack(SDPMediaTypesEnum.video, false, videoFormats, MediaStreamStatusEnum.SendRecv);
                    rtpSession.addTrack(videoTrack);
                    hasVideo = true;
                }

                var sdpOffer = rtpSession.CreateOffer(null);

                if (hasVideo)
                {
                    sdpOffer.Media.Single(x => x.Media == SDPMediaTypesEnum.video).Port = _videoPort;
                }

                Log.Debug(sdpOffer.ToString());

                using (StreamWriter sw = new StreamWriter(_sdpPath))
                {
                    sw.Write(sdpOffer);
                }

                rtpSession.Start();
                rtpSession.SetDestination(SDPMediaTypesEnum.video, new IPEndPoint(IPAddress.Loopback, _videoPort), new IPEndPoint(IPAddress.Loopback, _videoPort + 1));

                return rtpSession;
            }

            #region WebSocket相关
            private async Task ConnectToJanus(string url)
            {
                var factory = new Func<ClientWebSocket>(() =>
                {
                    var clientWebSocket = new ClientWebSocket();
                    clientWebSocket.Options.KeepAliveInterval = TimeSpan.FromSeconds(60);
                    clientWebSocket.Options.AddSubProtocol("janus-protocol");
                    return clientWebSocket;
                });
                ws = new WebsocketClient(new Uri(url), factory);
                ws.IsReconnectionEnabled = false;
                ws.DisconnectionHappened.Subscribe(info =>
                {
                    Log.Information("WebRTC WebSocket disconnect");
                    timer?.Stop();
                    OnDisConnected?.Invoke();
                });
                ws.ReconnectionHappened.Subscribe(info =>
                {
                    Log.Information("WebRTC WebSocket connect success");
                    var createSessionReq = new { janus = "create", transaction = Guid.NewGuid().ToString("N").Substring(0, 12) };
                    SendJanusMessage(ws, createSessionReq);
                });
                ws.MessageReceived.Subscribe(async msg => await HandleJanusMessage(ws, msg.Text));
                await ws.Start();
            }

            private async Task HandleJanusMessage(WebsocketClient ws, string msg)
            {
                if (string.IsNullOrEmpty(msg)) return;
                Log.Debug($"Received from Janus: {msg}");

                var response = JObject.Parse(msg);
                var janusType = response["janus"]?.Value<string>();

                switch (janusType)
                {
                    case "success" when response.ContainsKey("data") && !response.ContainsKey("session_id"):
                        _sessionId = response["data"]?["id"]?.Value<long>();
                        Log.Information($"Session created with ID: {_sessionId}");
                        var attachReq = new
                        {
                            janus = "attach",
                            plugin = "janus.plugin.ustreamer",
                            opaque_id = "oid-" + Guid.NewGuid().ToString("N").Substring(0, 12),
                            transaction = Guid.NewGuid().ToString("N").Substring(0, 12)
                        };
                        SendJanusMessage(ws, attachReq);
                        break;

                    case "success" when response.ContainsKey("session_id") && !response.ContainsKey("plugindata"):
                        _handleId = response["data"]?["id"]?.Value<long>();
                        Log.Information($"Attached to streaming plugin with handle ID: {_handleId}");
                        var watchReq = new
                        {
                            janus = "message",
                            body = new { request = "watch" },
                            transaction = Guid.NewGuid().ToString("N").Substring(0, 12)
                        };
                        SendJanusMessage(ws, watchReq);
                        break;

                    case "event" when response.ContainsKey("jsep"):
                        var jsep = response["jsep"];
                        var sdpOffer = jsep["sdp"]?.Value<string>();
                        var sdpType = jsep["type"]?.Value<string>();
                        if (sdpType == "offer" && !string.IsNullOrEmpty(sdpOffer))
                        {
                            Log.Information("Received SDP offer from Janus. Creating answer...");
                            await CreateAndSendAnswer(ws, sdpOffer);
                        }
                        break;

                    case "webrtcup":
                        timer.Start();
                        break;
                }
            }

            private void SendJanusMessage(WebsocketClient ws, object messageObj)
            {
                var message = JObject.FromObject(messageObj);
                if (_sessionId != null) message["session_id"] = _sessionId;
                if (_handleId != null) message["handle_id"] = _handleId;
                var json = JsonConvert.SerializeObject(message);
                Log.Debug($"Sending to Janus: {json}");
                ws.Send(json);
            }
            #endregion

            public void Dispose()
            {
                try
                {
                    _sessionId = null;
                    _handleId = null;
                    ws?.Dispose();
                    _rtpSession?.Close("");
                    _rtpSession?.Dispose();
                    _peerConnection?.close();
                    _peerConnection?.Dispose();
                    if (!string.IsNullOrEmpty(_sdpPath) && File.Exists(_sdpPath))
                    {
                        File.Delete(_sdpPath);
                    }
                }
                catch { }
            }
        }
    }
}

Starting Janus WebRTC client...111
[16:44:06 INF] WebRTC WebSocket connect success
[16:44:07 DBG] Sending to Janus: {"janus":"create","transaction":"e51cc1b6cf2e"}
[16:44:07 DBG] Received from Janus: {
   "janus": "success",
   "transaction": "e51cc1b6cf2e",
   "data": {
      "id": 5140119184513903
   }
}
[16:44:07 INF] Session created with ID: 5140119184513903
[16:44:07 DBG] Sending to Janus: {"janus":"attach","plugin":"janus.plugin.ustreamer","opaque_id":"oid-7cd615d8e873","transaction":"f78208a2e79c","session_id":5140119184513903}
[16:44:07 DBG] Received from Janus: {
   "janus": "success",
   "session_id": 5140119184513903,
   "transaction": "f78208a2e79c",
   "data": {
      "id": 8728387951769055
   }
}
[16:44:07 INF] Attached to streaming plugin with handle ID: 8728387951769055
[16:44:07 DBG] Sending to Janus: {"janus":"message","body":{"request":"watch"},"transaction":"db81aeb04ea3","session_id":5140119184513903,"handle_id":8728387951769055}
[16:44:07 DBG] Received from Janus: {
   "janus": "event",
   "session_id": 5140119184513903,
   "sender": 8728387951769055,
   "plugindata": {
      "plugin": "janus.plugin.ustreamer",
      "data": {
         "ustreamer": "event",
         "result": {
            "status": "started"
         }
      }
   },
   "jsep": {
      "type": "offer",
      "sdp": "v=0\r\no=- 6516856266050592241 1 IN IP4 113.89.35.155\r\ns=PiKVM uStreamer\r\nt=0 0\r\na=group:BUNDLE v\r\na=extmap-allow-mixed\r\na=msid-semantic: WMS janus\r\nm=video 9 UDP/TLS/RTP/SAVPF 96 97\r\nc=IN IP4 113.89.35.155\r\na=sendonly\r\na=mid:v\r\na=rtcp-mux\r\na=ice-ufrag:unxt\r\na=ice-pwd:HTEb68b5CxykIY5qCVbpWk\r\na=ice-options:trickle\r\na=fingerprint:sha-256 CE:A9:32:FF:A6:6C:2F:DE:33:87:91:7F:C7:CD:CB:08:89:2F:0F:5F:4F:BB:8B:E3:65:C8:E8:A3:6D:DF:C4:60\r\na=setup:actpass\r\na=rtpmap:96 H264/90000\r\na=fmtp:96 profile-level-id=42E01F\r\na=fmtp:96 packetization-mode=1\r\na=rtcp-fb:96 nack\r\na=rtcp-fb:96 nack pli\r\na=rtcp-fb:96 goog-remb\r\na=extmap:1 http://www.webrtc.org/experiments/rtp-hdrext/playout-delay\r\na=extmap:2 urn:3gpp:video-orientation\r\na=rtpmap:97 rtx/90000\r\na=fmtp:97 apt=96\r\na=ssrc-group:FID 3952121733 2037882686\r\na=msid:janus janusv0\r\na=ssrc:3952121733 cname:janus\r\na=ssrc:3952121733 msid:janus janusv0\r\na=ssrc:3952121733 mslabel:janus\r\na=ssrc:3952121733 label:janusv0\r\na=ssrc:2037882686 cname:janus\r\na=ssrc:2037882686 msid:janus janusv0\r\na=ssrc:2037882686 mslabel:janus\r\na=ssrc:2037882686 label:janusv0\r\na=candidate:1 1 udp 2013266431 192.168.29.198 26310 typ host\r\na=candidate:2 1 udp 2013266430 fe80::fba6:419f:7d8a:525e 35727 typ host\r\na=candidate:3 1 udp 1677722111 113.89.35.155 26310 typ srflx raddr 192.168.29.198 rport 26310\r\na=end-of-candidates\r\n"
   }
}
[16:44:07 INF] Received SDP offer from Janus. Creating answer...
[16:44:07 DBG] No DTLS certificate is provided in the configuration
[16:44:08 DBG] CreateRtpSocket attempting to create and bind RTP socket(s) on 192.168.20.96:40000.
[16:44:08 DBG] CreateBoundSocket attempting to create and bind socket(s) on 192.168.20.96:40000 using protocol Udp.
[16:44:08 DBG] CreateBoundSocket successfully bound on 192.168.20.96:40000.
[16:44:08 DBG] Successfully bound RTP socket 192.168.20.96:40000.
[16:44:08 DBG] RTPChannel for 192.168.20.96:40000 started.
[16:44:08 DBG] SCTP windows size for data receiver set at 218.
[16:44:08 DBG] SCTP creating DTLS based association, is DTLS client False, ID 5000:5000:40000.
[16:44:08 DBG] Sending to Janus: {"janus":"trickle","candidate":{"candidate":"candidate:1481130777 1 udp 2113937663 192.168.20.96 40000 typ host generation 0","sdpMid":null,"sdpMLineIndex":0},"transaction":"e7fa2fa7f425","session_id":5140119184513903,"handle_id":8728387951769055}
[16:44:08 DBG] RTP ICE Channel discovered 1 local candidates.
[16:44:08 DBG] [setRemoteDescription] - Extension:[2 - urn:3gpp:video-orientation]
[16:44:08 DBG] Setting remote video track with sdp destination null and control destination null.
[16:44:08 DBG] RTP ICE Channel remote credentials set.
[16:44:08 DBG] RTP ICE Channel received remote candidate: 1 1 udp 2013266431 192.168.29.198 26310 typ host generation 0
[16:44:08 DBG] RTP ICE Channel received remote candidate: 2 1 udp 2013266430 fe80::fba6:419f:7d8a:525e 35727 typ host generation 0
[16:44:08 DBG] RTP ICE Channel received remote candidate: 3 1 udp 1677722111 113.89.35.155 26310 typ srflx raddr 192.168.29.198 rport 26310 generation 0
[16:44:08 DBG] LogRemoteSDPSsrcAttributes: Audio:[ ]
 Video: [  [3952121733 - 2037882686 - ] ]
 Text: [  ]
[16:44:08 DBG] Sending to Janus: {"janus":"message","body":{"request":"start"},"jsep":{"type":"answer","sdp":"v=0\r\no=- 82379 0 IN IP4 127.0.0.1\r\ns=sipsorcery\r\nt=0 0\r\na=group:BUNDLE v\r\nm=video 9 UDP/TLS/RTP/SAVP 96 97\r\nc=IN IP4 0.0.0.0\r\na=ice-ufrag:QXOK\r\na=ice-pwd:YIHLCTKBQPQKRHCOOUHYEJMD\r\na=fingerprint:sha-256 6E:F6:88:DB:12:6C:F3:F0:C0:07:9B:2E:0E:1E:B9:C2:FC:B5:B9:8B:2B:2C:DF:E5:25:90:D3:4D:A3:44:7C:5C\r\na=setup:active\r\na=candidate:1481130777 1 udp 2113937663 192.168.20.96 40000 typ host generation 0\r\na=ice-options:ice2,trickle\r\na=mid:v\r\na=rtpmap:96 H264/90000\r\na=rtcp-fb:96 transport-cc\r\na=fmtp:96 packetization-mode=1\r\na=rtpmap:97 rtx/90000\r\na=rtcp-fb:97 transport-cc\r\na=fmtp:97 apt=96\r\na=rtcp-mux\r\na=rtcp:9 IN IP4 0.0.0.0\r\na=end-of-candidates\r\na=recvonly\r\na=ssrc:640059059 cname:1f34a490-ca58-4fd8-b579-47ec47279673\r\n"},"transaction":"6aa388947369488888aaa7b5562b5b44","session_id":5140119184513903,"handle_id":8728387951769055}
[16:44:08 DBG] Received from Janus: {
   "janus": "success",
   "session_id": 5140119184513903,
   "transaction": "db81aeb04ea3",
   "sender": 8728387951769055,
   "plugindata": {
      "plugin": "janus.plugin.ustreamer",
      "data": {
         "ok": true
      }
   }
}
[16:44:08 DBG] Received from Janus: {
   "janus": "ack",
   "session_id": 5140119184513903,
   "transaction": "e7fa2fa7f425"
}
[16:44:08 DBG] Received from Janus: {
   "janus": "event",
   "session_id": 5140119184513903,
   "sender": 8728387951769055,
   "plugindata": {
      "plugin": "janus.plugin.ustreamer",
      "data": {
         "ustreamer": "event",
         "result": {
            "status": "started"
         }
      }
   }
}
[16:44:08 DBG] Received from Janus: {
   "janus": "success",
   "session_id": 5140119184513903,
   "transaction": "6aa388947369488888aaa7b5562b5b44",
   "sender": 8728387951769055,
   "plugindata": {
      "plugin": "janus.plugin.ustreamer",
      "data": {
         "ok": true
      }
   }
}
[16:44:08 DBG] Adding new candidate pair to checklist for: udp:192.168.20.96:40000 (host)->udp:192.168.29.198:26310 (host)
[16:44:08 DBG] Adding new candidate pair to checklist for: udp:192.168.20.96:40000 (host)->udp:113.89.35.155:26310 (srflx)
[16:44:08 DBG] ICE RTP channel sending connectivity check for udp:192.168.20.96:40000 (host)->udp:192.168.29.198:26310 (host) from 192.168.20.96:40000 to 192.168.29.198:26310 (use candidate False).
[16:44:08 DBG] ICE RTP channel remote peer nominated entry from binding request: udp:192.168.29.198:26310 (host).
[16:44:08 DBG] ICE RTP channel connected after 184ms udp:192.168.20.96:40000 (host)->udp:192.168.29.198:26310 (host).
[16:44:08 INF] PeerConnection state: connecting
[16:44:08 DBG] ICE connected to remote end point 192.168.29.198:26310.
[16:44:08 DBG] Starting DLS handshake with role active.
[16:44:08 DBG] RTCPeerConnection DoDtlsHandshake started.
[16:44:08 DBG] DTLS commencing handshake as client.
[16:44:08 WRN] ICE RTP channel received an unexpected STUN message 17 from 192.168.29.198:26310.
Json: SIPSorcery.Net.STUNMessage
[16:44:09 DBG] Received from Janus: {
   "janus": "webrtcup",
   "session_id": 5140119184513903,
   "sender": 8728387951769055
}
[16:44:09 DBG] RTCPeerConnection DTLS handshake result True, is handshake complete True.
[16:44:09 WRN] RTP or RTCP packet received before secure context ready.
[16:44:09 DBG] RTCPeerConnection remote certificate fingerprint matched expected value of CE:A9:32:FF:A6:6C:2F:DE:33:87:91:7F:C7:CD:CB:08:89:2F:0F:5F:4F:BB:8B:E3:65:C8:E8:A3:6D:DF:C4:60 for sha-256.
[16:44:09 WRN] RTP or RTCP packet received before secure context ready.
[16:44:09 INF] PeerConnection state: connected
[16:44:09 INF] WebRTC connected. Preparing for VLC playback.
[16:44:09 DBG] CreateRtpSocket attempting to create and bind RTP socket(s) on 127.0.0.1:0.
[16:44:09 DBG] CreateBoundSocket attempting to create and bind socket(s) on 127.0.0.1:0 using protocol Udp.
[16:44:09 DBG] CreateBoundSocket successfully bound on 127.0.0.1:61134.
[16:44:09 DBG] CreateBoundSocket attempting to create and bind socket(s) on 127.0.0.1:61135 using protocol Udp.
[16:44:09 DBG] CreateBoundSocket successfully bound on 127.0.0.1:61135.
[16:44:09 DBG] Successfully bound RTP socket 127.0.0.1:61134 and control socket 127.0.0.1:61135.
[16:44:09 DBG] RTPChannel for 127.0.0.1:61134 started.
[16:44:09 DBG] v=0
o=- 1529406194 0 IN IP4 127.0.0.1
s=sipsorcery
c=IN IP4 127.0.0.1
t=0 0
m=video 40000 RTP/AVP 96 97
a=mid:0
a=rtpmap:96 H264/90000
a=rtcp-fb:96 transport-cc
a=fmtp:96 packetization-mode=1
a=rtpmap:97 rtx/90000
a=rtcp-fb:97 transport-cc
a=fmtp:97 apt=96
a=sendrecv
a=ssrc:1131039254 cname:73773e56-55c4-4fff-aaff-43ecbe81d9c1

[16:44:09 DBG] Starting RTCP session for 73773e56-55c4-4fff-aaff-43ecbe81d9c1.
[16:44:09 DBG] Set remote track (video - index=0) SSRC to 3952121733 remote RTP endpoint 192.168.29.198:26310.
[16:44:09 DBG] Video depacketisation codec set to H264 for SSRC 3952121733.
[16:44:09 DBG] Starting RTCP session for 1f34a490-ca58-4fd8-b579-47ec47279673.
[16:44:14 DBG] Sending key video RTCP packet size 76 to 127.0.0.1:40001.
[16:44:18 DBG] Sending key video RTCP packet size 76 to 127.0.0.1:40001.
[00000244142aa150] live555 demux error: no data received in 10s, aborting
[16:44:23 DBG] Sending key video RTCP packet size 76 to 127.0.0.1:40001.
[16:44:27 DBG] Sending key video RTCP packet size 76 to 127.0.0.1:40001.

I used bindPort, but still got an error: live555 demux error: no data received within 10 seconds, aborting.

[344089386]

What I'm referring to is the delay in real-time rendering of the image. My display is dynamic, and the content shown will be 0.2 seconds slower than the actual time.

If this includes the network transit time that's actually not too bad depending on the path.

Other than the network the main issue is that this library uses a combination of native & managed code in the video pipeline. Other libraries like Pion keep the video pipeline completely in native code for speed. In theory the native/managed boundary impact can be significantly reduced but no effort has been undertaken on this to date. It all boils down to finding the most efficient way to get the video frames out of the RTP packets (managed), decoded by FFmpeg (native) and displayed on the screen.

Does it mean that using the LibVLCSharp library to directly play the sdp file is not the right approach, resulting in delays?