Single peer connection support (#1682)

Co-authored-by: boks1971 <raja.gobi@tutanota.com>

Author: lukasIO

.changeset/yellow-birds-tickle.md

@@ -0,0 +1,5 @@
+---
+"livekit-client": patch
+---
+
+Single peer connection support

examples/demo/demo.ts

@@ -131,6 +131,7 @@ const appActions = {
       encryption: e2eeEnabled
         ? { keyProvider: state.e2eeKeyProvider, worker: new E2EEWorker() }
         : undefined,
+      singlePeerConnection: true,
     };
     if (
       roomOpts.publishDefaults?.videoCodec === 'av1' ||
@@ -826,16 +827,16 @@ function renderParticipant(participant: Participant, remove: boolean = false) {
     };
   }
   const videoElm = <HTMLVideoElement>container.querySelector(`#video-${identity}`);
-  const audioELm = <HTMLAudioElement>container.querySelector(`#audio-${identity}`);
+  const audioElm = <HTMLAudioElement>container.querySelector(`#audio-${identity}`);
   if (remove) {
     div?.remove();
     if (videoElm) {
       videoElm.srcObject = null;
       videoElm.src = '';
     }
-    if (audioELm) {
-      audioELm.srcObject = null;
-      audioELm.src = '';
+    if (audioElm) {
+      audioElm.srcObject = null;
+      audioElm.src = '';
     }
     return;
   }
@@ -899,13 +900,13 @@ function renderParticipant(participant: Participant, remove: boolean = false) {
   if (micEnabled) {
     if (!isLocalParticipant(participant)) {
       // don't attach local audio
-      audioELm.onloadeddata = () => {
+      audioElm.onloadeddata = () => {
         if (participant.joinedAt && participant.joinedAt.getTime() < startTime) {
           const fromJoin = Date.now() - startTime;
           appendLog(`RemoteAudioTrack ${micPub?.trackSid} played ${fromJoin}ms from start`);
         }
       };
-      micPub?.audioTrack?.attach(audioELm);
+      micPub?.audioTrack?.attach(audioElm);
     }
     micElm.className = 'mic-on';
     micElm.innerHTML = '<i class="fas fa-microphone"></i>';

package.json

@@ -108,5 +108,5 @@
     "vite": "7.1.8",
     "vitest": "^3.0.0"
   },
-  "packageManager": "pnpm@10.14.0"
+  "packageManager": "pnpm@10.15.0"
 }

pnpm-lock.yaml

@@ -4,10 +4,13 @@ import {
   AudioTrackFeature,
   ClientInfo,
   ConnectionQualityUpdate,
+  ConnectionSettings,
   DisconnectReason,
+  JoinRequest,
   JoinResponse,
   LeaveRequest,
   LeaveRequest_Action,
+  MediaSectionsRequirement,
   MuteTrackRequest,
   ParticipantInfo,
   Ping,
@@ -38,6 +41,7 @@ import {
   UpdateTrackSettings,
   UpdateVideoLayers,
   VideoLayer,
+  WrappedJoinRequest,
   protoInt64,
 } from '@livekit/protocol';
 import log, { LoggerNames, getLogger } from '../logger';
@@ -66,6 +70,7 @@ export interface SignalOptions {
   maxRetries: number;
   e2eeEnabled: boolean;
   websocketTimeout: number;
+  singlePeerConnection: boolean;
 }
 
 type SignalMessage = SignalRequest['message'];
@@ -155,6 +160,8 @@ export class SignalClient {
 
   onRoomMoved?: (res: RoomMovedResponse) => void;
 
+  onMediaSectionsRequirement?: (requirement: MediaSectionsRequirement) => void;
+
   connectOptions?: ConnectOpts;
 
   ws?: WebSocketStream;
@@ -271,7 +278,9 @@ export class SignalClient {
 
     this.connectOptions = opts;
     const clientInfo = getClientInfo();
-    const params = createConnectionParams(token, clientInfo, opts);
+    const params = opts.singlePeerConnection
+      ? createJoinRequestConnectionParams(token, clientInfo, opts)
+      : createConnectionParams(token, clientInfo, opts);
     const rtcUrl = createRtcUrl(url, params);
     const validateUrl = createValidateUrl(rtcUrl);
 
@@ -459,6 +468,7 @@ export class SignalClient {
     this.onTokenRefresh = undefined;
     this.onTrickle = undefined;
     this.onClose = undefined;
+    this.onMediaSectionsRequirement = undefined;
   };
 
   async close(updateState: boolean = true) {
@@ -772,6 +782,10 @@ export class SignalClient {
       if (this.onRoomMoved) {
         this.onRoomMoved(msg.value);
       }
+    } else if (msg.case === 'mediaSectionsRequirement') {
+      if (this.onMediaSectionsRequirement) {
+        this.onMediaSectionsRequirement(msg.value);
+      }
     } else {
       this.log.debug('unsupported message', { ...this.logContext, msgCase: msg.case });
     }
@@ -1063,3 +1077,31 @@ function createConnectionParams(
 
   return params;
 }
+
+function createJoinRequestConnectionParams(
+  token: string,
+  info: ClientInfo,
+  opts: ConnectOpts,
+): URLSearchParams {
+  const params = new URLSearchParams();
+  params.set('access_token', token);
+
+  const joinRequest = new JoinRequest({
+    clientInfo: info,
+    connectionSettings: new ConnectionSettings({
+      autoSubscribe: !!opts.autoSubscribe,
+      adaptiveStream: !!opts.adaptiveStream,
+    }),
+    reconnect: !!opts.reconnect,
+    participantSid: opts.sid ? opts.sid : undefined,
+  });
+  if (opts.reconnectReason) {
+    joinRequest.reconnectReason = opts.reconnectReason;
+  }
+  const wrappedJoinRequest = new WrappedJoinRequest({
+    joinRequest: joinRequest.toBinary(),
+  });
+  params.set('join_request', btoa(new TextDecoder('utf-8').decode(wrappedJoinRequest.toBinary())));
+
+  return params;
+}

src/api/SignalClient.ts

@@ -13,6 +13,7 @@ export class TURNCheck extends Checker {
       maxRetries: 0,
       e2eeEnabled: false,
       websocketTimeout: 15_000,
+      singlePeerConnection: false,
     });
 
     let hasTLS = false;

src/connectionHelper/checks/turn.ts

@@ -38,7 +38,7 @@ export class WebRTCCheck extends Checker {
         }
       };
 
-      if (this.room.engine.pcManager) {
+      if (this.room.engine.pcManager?.subscriber) {
         this.room.engine.pcManager.subscriber.onIceCandidateError = (ev) => {
           if (ev instanceof RTCPeerConnectionIceErrorEvent) {
             this.appendWarning(

src/connectionHelper/checks/webrtc.ts

@@ -18,6 +18,7 @@ export class WebSocketCheck extends Checker {
       maxRetries: 0,
       e2eeEnabled: false,
       websocketTimeout: 15_000,
+      singlePeerConnection: false,
     });
     this.appendMessage(`Connected to server, version ${joinRes.serverVersion}.`);
     if (joinRes.serverInfo?.edition === ServerInfo_Edition.Cloud && joinRes.serverInfo?.region) {

src/connectionHelper/checks/websocket.ts

@@ -99,6 +99,13 @@ export interface InternalRoomOptions {
   encryption?: E2EEOptions;
 
   loggerName?: string;
+
+  /**
+   * @experimental
+   * only supported on LiveKit Cloud
+   * and LiveKit OSS >= 1.9.2
+   */
+  singlePeerConnection: boolean;
 }
 
 /**

src/options.ts

@@ -167,7 +167,7 @@ export default class PCTransport extends EventEmitter {
       sdpParsed.media.forEach((media) => {
         const mid = getMidString(media.mid!);
         if (media.type === 'audio') {
-          // mung sdp for opus bitrate settings
+          // munge sdp for opus bitrate settings
           this.trackBitrates.some((trackbr): boolean => {
             if (!trackbr.transceiver || mid != trackbr.transceiver.mid) {
               return false;
@@ -297,7 +297,7 @@ export default class PCTransport extends EventEmitter {
       sdpParsed.media.forEach((media) => {
         ensureIPAddrMatchVersion(media);
         if (media.type === 'audio') {
-          ensureAudioNackAndStereo(media, [], []);
+          ensureAudioNackAndStereo(media, ['all'], []);
         } else if (media.type === 'video') {
           this.trackBitrates.some((trackbr): boolean => {
             if (!media.msid || !trackbr.cid || !media.msid.includes(trackbr.cid)) {
@@ -380,6 +380,10 @@ export default class PCTransport extends EventEmitter {
     return this.pc.addTransceiver(mediaStreamTrack, transceiverInit);
   }
 
+  addTransceiverOfKind(kind: 'audio' | 'video', transceiverInit: RTCRtpTransceiverInit) {
+    return this.pc.addTransceiver(kind, transceiverInit);
+  }
+
   addTrack(track: MediaStreamTrack) {
     if (!this._pc) {
       throw new UnexpectedConnectionState('PC closed, cannot add track');
@@ -623,7 +627,7 @@ function ensureAudioNackAndStereo(
       });
     }
 
-    if (stereoMids.includes(mid)) {
+    if (stereoMids.includes(mid) || (stereoMids.length === 1 && stereoMids[0] === 'all')) {
       media.fmtp.some((fmtp): boolean => {
         if (fmtp.payload === opusPayload) {
           if (!fmtp.config.includes('stereo=1')) {