DataChannel Support Implementation

[mekya]

• Publisher create data channel
• Publisher can send data
• Player listens created data channel
• Players can send data

Provide simple methods and configurations to send and receive message(callback in webrtc_adaptor.js) for ease of use of lovely developers :)

Supported Options - Configurations in AppSettings

• Enable/disable DataChannel
• Player's data can be delivered to whole players and publisher (+Cluster Support)
• Data can be sent only to publisher (+Cluster Support)
• Player can only receive incoming messages (+Cluster Support)
• Video Conference Support

JavaScript Implementation 3
Single Node Implementation 6
Cluster Support 6

[mekya]

In Publishing

DataChannel should be created on client side by in initPeerConnectionmethod.
after following line thiz.remotePeerConnection[streamId].ontrack = function(event) { thiz.onTrack(event, closedStreamId); }

			const dataChannelOptions = {
				ordered: true, // do not guarantee order
			  };
			dataChannel = thiz.remotePeerConnection[streamId].createDataChannel("use_stream_id", dataChannelOptions);
			
			dataChannel.onerror = (error) => {
				console.log("Data Channel Error:", error);
			  };
			  
			  dataChannel.onmessage = (event) => {
				console.log("Got Data Channel Message:", event.data);
			  };
			  
			  dataChannel.onopen = () => {
				dataChannel.send("Hello World!");
			  };
			  
			  dataChannel.onclose = () => {
				console.log("The Data Channel is Closed");
			  };

On Server side, there is ready onDataChannel callback method in WebRTCEncoderAdaptor. Just add observer in that method

@Override
	public void onDataChannel(DataChannel dataChannel) {
		logger.info("onDataChannel for stream Id {}", streamId);
		
		dataChannel.registerObserver(new DataChannel.Observer() {
			
			@Override
			public void onStateChange() {
			}
			
			@Override
			public void onMessage(org.webrtc.DataChannel.Buffer buffer) {
			}
			
			@Override
			public void onBufferedAmountChange(long previousAmount) {
			}
		});
	}

After that you can use send method to send message and receive the message onMessage method.

In Playing

Server side creates the data channel startInternal in WebRTCClient

DataChannel dataChannel = peerConnection.createDataChannel(streamId, new DataChannel.Init());
			
			dataChannel.registerObserver(new DataChannel.Observer() {
				
				@Override
				public void onStateChange() {
					System.out.println("WebRTCClient.startInternal().new Observer() {...}.onStateChange()");
				}
				
				@Override
				public void onMessage(Buffer buffer) {
					System.out.println("WebRTCClient.startInternal().new Observer() {...}.onMessage()");
					
				}
				
				@Override
				public void onBufferedAmountChange(long previousAmount) {
					System.out.println("WebRTCClient.startInternal().new Observer() {...}.onBufferedAmountChange()");
					
				}
			});

Client side, received the callback ondatachannel method as follows.

thiz.remotePeerConnection[streamId].ondatachannel = function(ev) {
				ev.channel.onopen = function() {
					console.log('Data channel is open and ready to be used.');
				};

				ev.channel.onmessage = function(event) {
					console.log('Data Channel OnMessage ');
				}
				ev.channel.onclose = () => {
					console.log("The Data Channel is Closed");
				};

				ev.channel.onerror = (error) => {
					console.log("Data Channel Error:", error);
				};
			}