video rendering, local track creation

lib/src/widget/video_track_renderer.dart

@@ -0,0 +1,49 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_webrtc/flutter_webrtc.dart';
+import '../track/video_track.dart';
+import '../track/local_video_track.dart';
+
+class VideoTrackRenderer extends StatefulWidget {
+  final VideoTrack track;
+  final RTCVideoRenderer renderer;
+
+  VideoTrackRenderer(this.track)
+      : renderer = RTCVideoRenderer(),
+        super(key: ValueKey(track.sid));
+
+  @override
+  State<StatefulWidget> createState() {
+    return _VideoTrackRendererState();
+  }
+}
+
+class _VideoTrackRendererState extends State<VideoTrackRenderer> {
+  final _renderer = RTCVideoRenderer();
+
+  @override
+  void initState() {
+    super.initState();
+    _initRenderer();
+  }
+
+  @override
+  void dispose() {
+    _renderer.dispose();
+    super.dispose();
+  }
+
+  _initRenderer() async {
+    await _renderer.initialize();
+    _renderer.srcObject = widget.track.mediaStream;
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    var isLocal = widget.track is LocalVideoTrack;
+    return RTCVideoView(
+      _renderer,
+      mirror: isLocal,
+      filterQuality: FilterQuality.medium,
+    );
+  }
+}