Option to control DTX (#25)

* protocol 4

* default to v4

* mediaStreamTrack.enabled

* track start

* private constructor

* remote audio/video tracks

* log sdp

* organize imports

* dtx option (default true)

example/lib/pages/connect.dart

@@ -79,7 +79,7 @@ class _ConnectPageState extends State<ConnectPage> {
         _uriCtrl.text,
         _tokenCtrl.text,
         options: ConnectOptions(
-          defaultPublishOptions: TrackPublishOptions(
+          defaultVideoPublishOptions: VideoPublishOptions(
             simulcast: _simulcast,
           ),
         ),

lib/src/options.dart

@@ -6,23 +6,27 @@ class ConnectOptions {
   /// Auto-subscribe to room tracks upon connect, defaults to true.
   final bool autoSubscribe;
 
-  /// Default options used when publishing a track
-  final TrackPublishOptions defaultPublishOptions;
+  /// Default options used when publishing a video track
+  final VideoPublishOptions defaultVideoPublishOptions;
+
+  /// Default options used when publishing a audio track
+  final AudioPublishOptions defaultAudioPublishOptions;
 
   const ConnectOptions({
     this.autoSubscribe = true,
-    this.defaultPublishOptions = const TrackPublishOptions(),
+    this.defaultVideoPublishOptions = const VideoPublishOptions(),
+    this.defaultAudioPublishOptions = const AudioPublishOptions(),
   });
 }
 
-class TrackPublishOptions {
+class VideoPublishOptions {
   ///
   final VideoEncoding? videoEncoding;
 
   ///
   final bool simulcast;
 
-  const TrackPublishOptions({
+  const VideoPublishOptions({
     this.videoEncoding,
     this.simulcast = false,
   });
@@ -31,3 +35,17 @@ class TrackPublishOptions {
   String toString() =>
       '${runtimeType}(videoEncoding: ${videoEncoding}, simulcast: ${simulcast})';
 }
+
+class AudioPublishOptions {
+  /// DTX (Discontinuous Transmission)
+  /// https://en.wikipedia.org/wiki/Discontinuous_transmission
+  /// defaults to true
+  final bool dtx;
+
+  const AudioPublishOptions({
+    this.dtx = true,
+  });
+
+  @override
+  String toString() => '${runtimeType}(dtx: ${dtx})';
+}

lib/src/participant/local_participant.dart

@@ -23,12 +23,15 @@ class LocalParticipant extends Participant {
   @internal
   final RTCEngine engine;
   @internal
-  final TrackPublishOptions? defaultPublishOptions;
+  final VideoPublishOptions? defaultVideoPublishOptions;
+  @internal
+  final AudioPublishOptions? defaultAudioPublishOptions;
 
   LocalParticipant({
     required this.engine,
     required lk_models.ParticipantInfo info,
-    this.defaultPublishOptions,
+    this.defaultVideoPublishOptions,
+    this.defaultAudioPublishOptions,
     required EventsEmitter<RoomEvent> roomEvents,
   }) : super(
           info.sid,
@@ -39,16 +42,23 @@ class LocalParticipant extends Participant {
   }
 
   /// publish an audio track to the room
-  Future<TrackPublication> publishAudioTrack(LocalAudioTrack track) async {
+  Future<TrackPublication> publishAudioTrack(
+    LocalAudioTrack track, {
+    AudioPublishOptions? options,
+  }) async {
     if (audioTracks.any(
         (e) => e.track?.mediaStreamTrack.id == track.mediaStreamTrack.id)) {
       throw TrackPublishException('track already exists');
     }
 
+    // Use defaultPublishOptions if options is null
+    options = options ?? defaultAudioPublishOptions;
+
     final trackInfo = await engine.addTrack(
       cid: track.getCid(),
       name: track.name,
       kind: track.kind,
+      dtx: options?.dtx,
     );
 
     await track.start();
@@ -73,15 +83,15 @@ class LocalParticipant extends Participant {
   /// Publish a video track to the room
   Future<TrackPublication> publishVideoTrack(
     LocalVideoTrack track, {
-    TrackPublishOptions? options,
+    VideoPublishOptions? options,
   }) async {
     if (videoTracks.any(
         (e) => e.track?.mediaStreamTrack.id == track.mediaStreamTrack.id)) {
       throw TrackPublishException('track already exists');
     }
 
-    // Use default options from `ConnectOptions` if options is null
-    options = options ?? defaultPublishOptions;
+    // Use defaultPublishOptions if options is null
+    options = options ?? defaultVideoPublishOptions;
 
     final trackInfo = await engine.addTrack(
       cid: track.getCid(),

lib/src/room.dart

@@ -75,7 +75,8 @@ class Room extends DisposableChangeNotifier with EventsEmittable<RoomEvent> {
     localParticipant = LocalParticipant(
       engine: engine,
       info: joinResponse.participant,
-      defaultPublishOptions: connectOptions?.defaultPublishOptions,
+      defaultVideoPublishOptions: connectOptions?.defaultVideoPublishOptions,
+      defaultAudioPublishOptions: connectOptions?.defaultAudioPublishOptions,
       roomEvents: events,
     );
 

lib/src/rtc_engine.dart

@@ -136,12 +136,18 @@ class RTCEngine extends Disposable with EventsEmittable<EngineEvent> {
     required String name,
     required lk_models.TrackType kind,
     TrackDimension? dimension,
+    bool? dtx,
   }) async {
     // TODO: Check if cid already published
 
     // send request to add track
     signalClient.sendAddTrack(
-        cid: cid, name: name, type: kind, dimension: dimension);
+      cid: cid,
+      name: name,
+      type: kind,
+      dimension: dimension,
+      dtx: dtx,
+    );
 
     // wait for response, or timeout
     final event = await _signalListener.waitFor<SignalLocalTrackPublishedEvent>(

lib/src/signal_client.dart

@@ -155,16 +155,25 @@ class SignalClient extends Disposable with EventsEmittable<SignalEvent> {
     required String name,
     required lk_models.TrackType type,
     TrackDimension? dimension,
+    bool? dtx,
   }) {
     final req = lk_rtc.AddTrackRequest(
       cid: cid,
       name: name,
       type: type,
     );
-    if (dimension != null) {
+
+    if (type == lk_models.TrackType.VIDEO && dimension != null) {
+      // video specific
       req.width = dimension.width;
       req.height = dimension.height;
     }
+
+    if (type == lk_models.TrackType.AUDIO && dtx != null) {
+      // audio specific
+      req.disableDtx = !dtx;
+    }
+
     _sendRequest(lk_rtc.SignalRequest(
       addTrack: req,
     ));

lib/src/utils.dart

@@ -83,9 +83,9 @@ class Utils {
   static List<rtc.RTCRtpEncoding>? computeVideoEncodings({
     int? width,
     int? height,
-    TrackPublishOptions? options,
+    VideoPublishOptions? options,
   }) {
-    options ??= const TrackPublishOptions();
+    options ??= const VideoPublishOptions();
 
     VideoEncoding? videoEncoding = options.videoEncoding;