manually handle audio tracks for web

lib/src/track/_audio_api.dart

@@ -0,0 +1,9 @@
+import 'package:flutter_webrtc/flutter_webrtc.dart';
+
+void startAudio(String id, MediaStreamTrack stream) {
+  // do nothing
+}
+
+void stopAudio(String id) {
+  // do nothing
+}

lib/src/track/_audio_html.dart

@@ -0,0 +1,53 @@
+// ignore: avoid_web_libraries_in_flutter
+import 'dart:html' as html;
+
+import 'package:flutter_webrtc/flutter_webrtc.dart';
+// ignore: implementation_imports
+import 'package:flutter_webrtc/src/web/media_stream_track_impl.dart';
+
+const audioContainerId = 'livekit_audio_container';
+const audioPrefix = 'livekit_audio_';
+
+void startAudio(String id, MediaStreamTrack track) {
+  if (!(track is MediaStreamTrackWeb)) {
+    return;
+  }
+  var elementId = audioPrefix + id;
+  var audioElement = html.document.getElementById(elementId);
+  if (audioElement == null) {
+    audioElement = html.AudioElement()
+      ..id = elementId
+      ..autoplay = true;
+    findOrCreateAudioContainer().append(audioElement);
+  }
+
+  if (!(audioElement is html.AudioElement)) {
+    return;
+  }
+  var audioStream = html.MediaStream();
+  audioStream.addTrack(track.jsTrack);
+  audioElement.srcObject = audioStream;
+}
+
+void stopAudio(String id) {
+  var audioElement = html.document.getElementById(audioPrefix + id);
+  if (audioElement != null) {
+    if (audioElement is html.AudioElement) {
+      audioElement.srcObject = null;
+    }
+    audioElement.remove();
+  }
+}
+
+html.DivElement findOrCreateAudioContainer() {
+  var div = html.document.getElementById(audioContainerId);
+  if (div != null) {
+    return div as html.DivElement;
+  }
+
+  div = html.DivElement();
+  div.id = audioContainerId;
+  div.style.display = 'none';
+  html.document.body?.append(div);
+  return div as html.DivElement;
+}

lib/src/track/audio_track.dart

@@ -0,0 +1,27 @@
+import 'package:flutter_webrtc/flutter_webrtc.dart';
+
+import '../proto/livekit_models.pbenum.dart';
+import 'local_audio_track.dart';
+import 'track.dart';
+import '_audio_api.dart' if (dart.library.html) '_audio_html.dart' as audio;
+
+class AudioTrack extends Track {
+  MediaStream? mediaStream;
+
+  AudioTrack(String name, MediaStreamTrack track, this.mediaStream)
+      : super(TrackType.AUDIO, name, track);
+
+  start() {
+    if (!(this is LocalAudioTrack)) {
+      audio.startAudio(getCid(), mediaTrack);
+    }
+  }
+
+  @override
+  stop() {
+    mediaStream?.dispose();
+    mediaStream = null;
+    audio.stopAudio(getCid());
+    super.stop();
+  }
+}

lib/src/track/local_audio_track.dart

@@ -1,15 +1,12 @@
 import 'package:flutter_webrtc/flutter_webrtc.dart';
+import 'package:livekit_client/src/track/audio_track.dart';
 
 import '../errors.dart';
-import '../proto/livekit_models.pb.dart';
 import 'options.dart';
-import 'track.dart';
 
-class LocalAudioTrack extends Track {
-  MediaStream? mediaStream;
-
-  LocalAudioTrack(String name, MediaStreamTrack track, this.mediaStream)
-      : super(TrackType.AUDIO, name, track);
+class LocalAudioTrack extends AudioTrack {
+  LocalAudioTrack(String name, MediaStreamTrack track, MediaStream stream)
+      : super(name, track, stream);
 
   static Future<LocalAudioTrack> createTrack(
       [LocalAudioTrackOptions? options]) async {
@@ -28,11 +25,4 @@ class LocalAudioTrack extends Track {
       return Future.error(e);
     }
   }
-
-  @override
-  stop() {
-    super.stop();
-    mediaStream?.dispose();
-    mediaStream = null;
-  }
 }