feat: Add support for getCapabilities/setCodecPreferences.

Author: cloudwebrtc

lib/src/factory_impl.dart

@@ -1,12 +1,26 @@
 import 'dart:async';
 import 'dart:convert';
 import 'dart:html' as html;
+import 'package:js/js.dart';
 import 'package:webrtc_interface/webrtc_interface.dart';
 
 import 'media_recorder_impl.dart';
 import 'media_stream_impl.dart';
 import 'navigator_impl.dart';
 import 'rtc_peerconnection_impl.dart';
+import 'rtc_rtp_capailities_imp.dart';
+
+@JS('RTCRtpSender')
+@anonymous
+class RTCRtpSenderJs {
+  external static Object getCapabilities(String kind);
+}
+
+@JS('RTCRtpReceiver')
+@anonymous
+class RTCRtpReceiverJs {
+  external static Object getCapabilities(String kind);
+}
 
 class RTCFactoryWeb extends RTCFactory {
   RTCFactoryWeb._internal();
@@ -47,6 +61,18 @@ class RTCFactoryWeb extends RTCFactory {
 
   @override
   Navigator get navigator => NavigatorWeb();
+
+  @override
+  Future<RTCRtpCapabilities> getRtpReceiverCapabilities(String kind) async {
+    var caps = RTCRtpReceiverJs.getCapabilities(kind);
+    return RTCRtpCapabilitiesWeb.fromJsObject(caps);
+  }
+
+  @override
+  Future<RTCRtpCapabilities> getRtpSenderCapabilities(String kind) async {
+    var caps = RTCRtpSenderJs.getCapabilities(kind);
+    return RTCRtpCapabilitiesWeb.fromJsObject(caps);
+  }
 }
 
 Future<RTCPeerConnection> createPeerConnection(
@@ -60,6 +86,14 @@ Future<MediaStream> createLocalMediaStream(String label) {
   return RTCFactoryWeb.instance.createLocalMediaStream(label);
 }
 
+Future<RTCRtpCapabilities> getRtpReceiverCapabilities(String kind) async {
+  return RTCFactoryWeb.instance.getRtpReceiverCapabilities(kind);
+}
+
+Future<RTCRtpCapabilities> getRtpSenderCapabilities(String kind) async {
+  return RTCFactoryWeb.instance.getRtpSenderCapabilities(kind);
+}
+
 MediaRecorder mediaRecorder() {
   return RTCFactoryWeb.instance.mediaRecorder();
 }

lib/src/rtc_rtp_capailities_imp.dart

@@ -0,0 +1,14 @@
+import 'dart:js_util' as jsutil;
+import 'package:webrtc_interface/webrtc_interface.dart';
+
+class RTCRtpCapabilitiesWeb {
+  static RTCRtpCapabilities fromJsObject(Object object) {
+    return RTCRtpCapabilities.fromMap({
+      'codecs': jsutil.dartify(jsutil.getProperty(object, 'codecs')),
+      'headerExtensions':
+          jsutil.dartify(jsutil.getProperty(object, 'headerExtensions')),
+      'fecMechanisms':
+          jsutil.dartify(jsutil.getProperty(object, 'fecMechanisms')) ?? []
+    });
+  }
+}

lib/src/rtc_rtp_transceiver_impl.dart

@@ -1,6 +1,7 @@
 import 'dart:async';
 import 'dart:js_util' as jsutil;
 
+import 'package:webrtc_interface/src/rtc_rtp_capabilities.dart';
 import 'package:webrtc_interface/webrtc_interface.dart';
 
 import 'media_stream_impl.dart';
@@ -53,6 +54,8 @@ extension RTCRtpTransceiverInitWebExt on RTCRtpTransceiverInit {
       });
 }
 
+
+
 class RTCRtpTransceiverWeb extends RTCRtpTransceiver {
   RTCRtpTransceiverWeb(this._jsTransceiver, _peerConnectionId);
 
@@ -109,4 +112,14 @@ class RTCRtpTransceiverWeb extends RTCRtpTransceiver {
       throw 'Unable to RTCRtpTransceiver::stop: ${e..toString()}';
     }
   }
+
+  @override
+  Future<void> setCodecPreferences(List<RTCRtpCodecCapability> codecs) async {
+    try {
+      jsutil.callMethod(_jsTransceiver, 'setCodecPreferences',
+          [jsutil.jsify(codecs.map((e) => e.toMap()).toList())]);
+    } on Exception catch (e) {
+      throw 'Unable to RTCRtpTransceiver::setCodecPreferences: ${e..toString()}';
+    }
+  }
 }

pubspec.yaml

@@ -7,8 +7,10 @@ environment:
   sdk: '>=2.13.0 <3.0.0'
 
 dependencies:
+  js: ^0.6.4  
   platform_detect: ^2.0.7
-  webrtc_interface: ^1.0.10
+  webrtc_interface: ^1.0.11
+  
 
 dev_dependencies:
   build_runner: ^1.10.0

web/main.dart

@@ -29,8 +29,20 @@ void loopBackTest() async {
   var remotelVideo = RTCVideoElement();
   remote!.append(remotelVideo.htmlElement);
 
+  var acaps = await getRtpSenderCapabilities('audio');
+  print('sender audio capabilities: ${acaps.toMap()}');
+
+  var vcaps = await getRtpSenderCapabilities('video');
+  print('sender video capabilities: ${vcaps.toMap()}');
+  /*
+  capabilities = await getRtpReceiverCapabilities('audio');
+  print('receiver audio capabilities: ${capabilities.toMap()}');
+
+  capabilities = await getRtpReceiverCapabilities('video');
+  print('receiver video capabilities: ${capabilities.toMap()}');
+  */
   var pc2 = await createPeerConnection({});
-  pc2.onTrack = (event) {
+  pc2.onTrack = (event) async {
     if (event.track.kind == 'video') {
       remotelVideo.srcObject = event.streams[0];
     }
@@ -81,6 +93,27 @@ void loopBackTest() async {
     await pc1.addTrack(track, stream);
   });
 
+  var transceivers = await pc1.getTransceivers();
+  transceivers.forEach((transceiver) {
+    print('transceiver: ${transceiver.sender.track!.kind!}');
+    if (transceiver.sender.track!.kind! == 'video') {
+      transceiver.setCodecPreferences([
+        RTCRtpCodecCapability(
+          mimeType: 'video/AV1',
+          clockRate: 90000,
+        )
+      ]);
+    } else if (transceiver.sender.track!.kind! == 'audio') {
+      transceiver.setCodecPreferences([
+        RTCRtpCodecCapability(
+          mimeType: 'audio/PCMA',
+          clockRate: 8000,
+          channels: 1,
+        )
+      ]);
+    }
+  });
+
   var offer = await pc1.createOffer();
 
   await pc2.addTransceiver(