Multiple stream using android libjingle (WebRTC) - webrtc

Question

When I develop WebRTC Android app using libjingle, I'd like to make multiple stream (ex. one is HD another is VGA) via one camera.
However, I can't find any right solution.
When I tried to make VideoSource as followings, I got RuntimeException.
RuntimeException.
videoSource = factory.createVideoSource(videoCapturer, videoConstraints);
06-14 22:55:48.465 13986-15059/com.lgit.webrtc E/AndroidRuntime: FATAL EXCEPTION: EventThread
Process: com.lgit.webrtc, PID: 13986
java.lang.RuntimeException: Capturer can only be taken once!
at org.webrtc.VideoCapturer.takeNativeVideoCapturer(VideoCapturer.java:52)
at org.webrtc.PeerConnectionFactory.createVideoSource(PeerConnectionFactory.java:111)
at com.lgit.webrtcclient.WebRtcClient.setTrack(WebRtcClient.java:452)
at com.lgit.webrtcclient.WebRtcClient.access$1600(WebRtcClient.java:30)
at com.lgit.webrtcclient.WebRtcClient$Peer.<init>(WebRtcClient.java:261)
at com.lgit.webrtcclient.WebRtcClient.addPeer(WebRtcClient.java:270)
at com.lgit.webrtcclient.WebRtcClient.access$900(WebRtcClient.java:30)
at com.lgit.webrtcclient.WebRtcClient$MessageHandler$1.call(WebRtcClient.java:157)
at io.socket.emitter.Emitter.emit(Emitter.java:117)
at io.socket.client.Socket.onevent(Socket.java:340)
at io.socket.client.Socket.onpacket(Socket.java:293)
at io.socket.client.Socket.access$100(Socket.java:19)
at io.socket.client.Socket$2$2.call(Socket.java:111)
at io.socket.emitter.Emitter.emit(Emitter.java:117)
at io.socket.client.Manager.ondecoded(Manager.java:407)
at io.socket.client.Manager.access$1600(Manager.java:20)
at io.socket.client.Manager$7.call(Manager.java:383)
at io.socket.emitter.Emitter.emit(Emitter.java:117)
at io.socket.parser.Parser$Decoder.add(Parser.java:157)
at io.socket.client.Manager.ondata(Manager.java:399)
at io.socket.client.Manager.access$1000(Manager.java:20)
at io.socket.client.Manager$2.call(Manager.java:350)
at io.socket.emitter.Emitter.emit(Emitter.java:117)
at io.socket.engineio.client.Socket.onPacket(Socket.java:497)
at io.socket.engineio.client.Socket.access$900(Socket.java:30)
at io.socket.engineio.client.Socket$5.call(Socket.java:299)
at io.socket.emitter.Emitter.emit(Emitter.java:117)
at io.socket.engineio.client.Transport.onPacket(Transport.java:127)
at io.socket.engineio.client.Transport.onData(Transport.java:119)
at io.socket.engineio.client.transports.WebSocket.access$300(WebSocket.java:32)
at io.socket.engineio.client.transports.WebSocket$1$3.run(WebSocket.java:111)
at io.socket.thread.EventThread$2.run(EventThread.java:75)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:818)