fix data channel init error.

Author: cloudwebrtc

lib/src/rtc_peerconnection_impl.dart

@@ -8,16 +8,18 @@ import 'package:dart_webrtc/dart_webrtc.dart';
 import 'package:js/js_util.dart';
 import 'package:platform_detect/platform_detect.dart';
 import 'package:web/web.dart' as web;
-import 'package:webrtc_interface/webrtc_interface.dart';
 
-import 'media_stream_impl.dart';
 import 'media_stream_track_impl.dart';
 import 'rtc_data_channel_impl.dart';
 import 'rtc_dtmf_sender_impl.dart';
 import 'rtc_rtp_receiver_impl.dart';
 import 'rtc_rtp_sender_impl.dart';
 import 'rtc_rtp_transceiver_impl.dart';
 
+extension on web.RTCDataChannelInit {
+  external set binaryType(String value);
+}
+
 /*
  *  PeerConnection
  */
@@ -395,21 +397,29 @@ class RTCPeerConnectionWeb extends RTCPeerConnection {
   @override
   Future<RTCDataChannel> createDataChannel(
       String label, RTCDataChannelInit dataChannelDict) {
-    final map = dataChannelDict.toMap();
+    var dcInit = web.RTCDataChannelInit(
+      id: dataChannelDict.id,
+      ordered: dataChannelDict.ordered,
+      protocol: dataChannelDict.protocol,
+      negotiated: dataChannelDict.negotiated,
+    );
+
     if (dataChannelDict.binaryType == 'binary') {
-      map['binaryType'] = 'arraybuffer'; // Avoid Blob in data channel
+      dcInit.binaryType = 'arraybuffer'; // Avoid Blob in data channel
+    }
+
+    if (dataChannelDict.maxRetransmits > 0) {
+      dcInit.maxRetransmits = dataChannelDict.maxRetransmits;
+    }
+
+    if (dataChannelDict.maxRetransmitTime > 0) {
+      dcInit.maxPacketLifeTime = dataChannelDict.maxRetransmitTime;
     }
 
     final jsDc = _jsPc.createDataChannel(
-        label,
-        web.RTCDataChannelInit(
-          id: map['id'],
-          ordered: map['ordered'],
-          maxPacketLifeTime: map['maxPacketLifeTime'],
-          maxRetransmits: map['maxRetransmits'],
-          protocol: map['protocol'],
-          negotiated: map['negotiated'],
-        ));
+      label,
+      dcInit,
+    );
 
     return Future.value(RTCDataChannelWeb(jsDc));
   }

web/main.dart

@@ -76,15 +76,17 @@ void loopBackTest() async {
         algorithm: Algorithm.kAesGcm,
         keyProvider: keyProvider);
     if (keyProviderOptions.discardFrameWhenCryptorNotReady) {
-      Timer(Duration(seconds: 2), () {
+      Timer(Duration(seconds: 1), () {
         fc.setEnabled(true);
       });
     } else {
       await fc.setEnabled(true);
     }
 
     await fc.setKeyIndex(0);
-    await fc.updateCodec('vp8');
+    if (event.track.kind == 'video') {
+      await fc.updateCodec('vp8');
+    }
     pc2FrameCryptors.add(fc);
   };
   pc2.onConnectionState = (state) {
@@ -138,7 +140,9 @@ void loopBackTest() async {
         keyProvider: keyProvider);
     await fc.setEnabled(true);
     await fc.setKeyIndex(0);
-    await fc.updateCodec('vp8');
+    if (track.kind == 'video') {
+      await fc.updateCodec('vp8');
+    }
     pc1FrameCryptors.add(fc);
   });
 /*
@@ -163,6 +167,8 @@ void loopBackTest() async {
     }
   });
 */
+  var dc = await pc1.createDataChannel(
+      'label', RTCDataChannelInit()..binaryType = 'binary');
   var offer = await pc1.createOffer();
 
   await pc2.addTransceiver(