Fixes for Streamers changing IDs when connecting & Updates to SFU behaviour relating to multi streamer changes.

Frontend/Docs/Settings Panel.md

@@ -19,7 +19,6 @@ This page will be updated with new features and commands as they become availabl
 | **Browser send offer** | The browser will start the WebRTC handshake instead of the Unreal Engine application. This is an advanced setting for users customising the frontend. Primarily for backwards compatibility for 4.x versions of the engine. |
 | **Use microphone** | Will start receiving audio input from your microphone and transmit it to the Unreal Engine. |
 | **Start video muted** | Muted audio when the stream starts. |
-| **Prefer SFU** | Will attempt to use the Selective Forwarding Unit (SFU), if you have one running. |
 | **Is quality controller?** | Makes the encoder of the Pixel Streaming Plugin use the current browser connection to determine the bandwidth available, and therefore the quality of the stream encoding. **See notes below** |
 | **Force mono audio** | Force the browser to request mono audio in the SDP. |
 | **Force TURN** | Will attempt to connect exclusively via the TURN server. Will not work without an active TURN server. |

Frontend/library/src/Config/Config.ts

@@ -23,7 +23,6 @@ export class Flags {
     static FakeMouseWithTouches = 'FakeMouseWithTouches' as const;
     static IsQualityController = 'ControlsQuality' as const;
     static MatchViewportResolution = 'MatchViewportRes' as const;
-    static PreferSFU = 'preferSFU' as const;
     static StartVideoMuted = 'StartVideoMuted' as const;
     static SuppressBrowserKeys = 'SuppressBrowserKeys' as const;
     static UseMic = 'UseMic' as const;
@@ -315,17 +314,6 @@ export class Config {
             )
         );
 
-        this.flags.set(
-            Flags.PreferSFU,
-            new SettingFlag(
-                Flags.PreferSFU,
-                'Prefer SFU',
-                'Try to connect to the SFU instead of P2P.',
-                false,
-                useUrlParams
-            )
-        );
-
         this.flags.set(
             Flags.IsQualityController,
             new SettingFlag(

Frontend/library/src/WebRtcPlayer/WebRtcPlayerController.ts

@@ -1384,12 +1384,6 @@ export class WebRtcPlayerController {
             if (messageStreamerList.ids.length == 1) {
                 // If there's only a single streamer, subscribe to it regardless of what is in the URL
                 autoSelectedStreamerId = messageStreamerList.ids[0];
-            } else if (
-                this.config.isFlagEnabled(Flags.PreferSFU) &&
-                messageStreamerList.ids.includes('SFU')
-            ) {
-                // If the SFU toggle is on and there's an SFU connected, subscribe to it regardless of what is in the URL
-                autoSelectedStreamerId = 'SFU';
             } else if (
                 urlParams.has(OptionParameters.StreamerId) &&
                 messageStreamerList.ids.includes(
@@ -1406,8 +1400,9 @@ export class WebRtcPlayerController {
                 );
             } else {
                 // no auto selected streamer
-                if (this.config.isFlagEnabled(Flags.WaitForStreamer)) {
-                    this.startAutoJoinTimer()
+                if (messageStreamerList.ids.length == 0 && this.config.isFlagEnabled(Flags.WaitForStreamer)) {
+                    this.closeSignalingServer();
+                    this.startAutoJoinTimer();
                 }
             }
             this.pixelStreaming.dispatchEvent(

Frontend/ui-library/src/Config/ConfigUI.ts

@@ -174,10 +174,6 @@ export class ConfigUI {
             psSettingsSection,
             this.flagsUi.get(Flags.StartVideoMuted)
         );
-        this.addSettingFlag(
-            psSettingsSection,
-            this.flagsUi.get(Flags.PreferSFU)
-        );
         this.addSettingFlag(
             psSettingsSection,
             this.flagsUi.get(Flags.IsQualityController)

SFU/config.js

@@ -11,8 +11,18 @@ for(let arg of process.argv){
 }
 
 const config = {
+  // The URL of the signalling server to connect to
   signallingURL: "ws://localhost:8889",
 
+  // The ID for this SFU to use. This will show up as a streamer ID on the signalling server
+  SFUId: "SFU",
+
+  // The ID of the streamer to subscribe to. If you leave this blank it will subscribe to the first streamer it sees.
+  subscribeStreamerId: "DefaultStreamer",
+
+  // Delay between list requests when looking for a specifc streamer.
+  retrySubscribeDelaySecs: 10,
+
   mediasoup: {
     worker: {
       rtcMinPort: 40000,

SFU/sfu_server.js

@@ -3,6 +3,10 @@ const WebSocket = require('ws');
 const mediasoup = require('mediasoup_prebuilt');
 const mediasoupSdp = require('mediasoup-sdp-bridge');
 
+if (!config.retrySubscribeDelaySecs) {
+  config.retrySubscribeDelaySecs = 10;
+}
+
 let signalServer = null;
 let mediasoupRouter;
 let streamer = null;
@@ -24,6 +28,35 @@ function connectSignalling(server) {
   });
 }
 
+async function onStreamerList(msg) {
+  let success = false;
+
+  // subscribe to either the configured streamer, or if not configured, just grab the first id
+  if (msg.ids.length > 0) {
+    if (!!config.subscribeStreamerId && config.subscribeStreamerId.length != 0) {
+      if (msg.ids.includes(config.subscribeStreamerId)) {
+        signalServer.send(JSON.stringify({type: 'subscribe', streamerId: config.subscribeStreamerId}));
+        success = true;
+      }
+    } else {
+      signalServer.send(JSON.stringify({type: 'subscribe', streamerId: msg.ids[0]}));
+      success = true;
+    }
+  }
+
+  if (!success) {
+    // did not subscribe to anything
+    setTimeout(function() {
+      signalServer.send(JSON.stringify({type: 'listStreamers'}));
+    }, config.retrySubscribeDelaySecs * 1000);
+  }
+}
+
+async function onIdentify(msg) {
+  signalServer.send(JSON.stringify({type: 'endpointId', id: config.SFUId}));
+  signalServer.send(JSON.stringify({type: 'listStreamers'}));
+}
+
 async function onStreamerOffer(sdp) {
   console.log("Got offer from streamer");
 
@@ -57,6 +90,11 @@ function onStreamerDisconnected() {
     }
     streamer.transport.close();
     streamer = null;
+    signalServer.send(JSON.stringify({type: 'stopStreaming'}));
+
+    setTimeout(function() {
+      signalServer.send(JSON.stringify({type: 'listStreamers'}));
+    }, config.retrySubscribeDelaySecs * 1000);
   }
 }
 
@@ -228,7 +266,7 @@ function onLayerPreference(msg) {
 }
 
 async function onSignallingMessage(message) {
-    //console.log(`Got MSG: ${message}`);
+  //console.log(`Got MSG: ${message}`);
   const msg = JSON.parse(message);
 
   if (msg.type == 'offer') {
@@ -255,6 +293,12 @@ async function onSignallingMessage(message) {
   else if (msg.type == 'layerPreference') {
     onLayerPreference(msg);
   }
+  else if (msg.type == 'streamerList') {
+    onStreamerList(msg);
+  }
+  else if (msg.type == 'identify') {
+    onIdentify(msg);
+  }
 }
 
 async function startMediasoup() {
@@ -276,6 +320,14 @@ async function startMediasoup() {
   return mediasoupRouter;
 }
 
+async function onICEStateChange(identifier, iceState) {
+  console.log("%s ICE state changed to %s", identifier, iceState);
+
+  if (identifier == 'Streamer' && iceState == 'completed') {
+    signalServer.send(JSON.stringify({type: 'startStreaming'}));
+  }
+}
+
 async function createWebRtcTransport(identifier) {
   const {
     listenIps,
@@ -291,7 +343,7 @@ async function createWebRtcTransport(identifier) {
     initialAvailableOutgoingBitrate: initialAvailableOutgoingBitrate
   });
 
-  transport.on("icestatechange", (iceState) => { console.log("%s ICE state changed to %s", identifier, iceState); });
+  transport.on("icestatechange", (iceState) => onICEStateChange(identifier, iceState));
   transport.on("iceselectedtuplechange", (iceTuple) => { console.log("%s ICE selected tuple %s", identifier, JSON.stringify(iceTuple)); });
   transport.on("sctpstatechange", (sctpState) => { console.log("%s SCTP state changed to %s", identifier, sctpState); });