gistfile1.js

/*
 * (C) Copyright 2013 Kurento (http://kurento.org/)
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Lesser General Public License
 * (LGPL) version 2.1 which accompanies this distribution, and is available at
 * http://www.gnu.org/licenses/lgpl-2.1.html
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 */

var kurento = require('kurento-client');
var express = require('express');
var app = express();
var bodyParser = require('body-parser');
app.use(bodyParser.text({type : 'application/sdp'}));
var path = require('path');
app.set('port', process.env.PORT || 8080);

/*
 * Definition of constants
 */


//YOU MUST SET THIS TO THE HOST:PORT WHERE YOUR MEDIA SERVER IS LOCATED
const ws_uri = "ws://localhost:8888/kurento";

/*
 * Definition of global variables.
 */

var pipeline = null;

/*
 * Server startup
 */

var port = app.get('port');
var server = app.listen(port, function() {
	console.log('Express server started ');
	console.log('Connect to http://<host_name>:' + port + '/');
});

/*
 * Definition of functions
 */

function sendError(res, code, error) {
	console.log("Error " + error);
	res.type('text/plain');
	res.status(code);
	res.send(error);
}

/*
 * Code for recovering a media pipeline.
 * */
function getPipeline(callback) {
	if (pipeline !== null) {
		return callback(null, pipeline);
	}

	kurento(ws_uri, function(error, kurentoClient) {
		if (error) {
			return callback(error);
		}

		kurentoClient.create('MediaPipeline', function(error, _pipeline) {
			if (error) {
				return callback(error);
			}

			pipeline = _pipeline;
			return callback(null, pipeline);
		});
	});
}

/*
 * Code for processing REST request from client.
 * */
app.post('/helloworld', function(req, res) {
	var sdpOffer = req.body;

	console.log("Request received from client with sdpOffer = ");
	console.log(sdpOffer);

	console.log("Obtaining MediaPipeline");
	getPipeline(function(error, pipeline) {
		if (error) {
			return sendError(res, 500, error);
		}

		console.log("Creating RecorderEndpoint");
		recordParams = {
			//mediaPipeline: pipeline, //This cannot be specified when using pipeline.create('RecorderEndpoint', ...)
			//stopOnEndOfStream: true, //This is not mandatory and I think you should remove it if you don't know precisely what it's doing
			//uri: ws_uri //This needs to point to a file where you want to record the media
			uri : "file:///tmp/the_file_name_i_want.webm" //The media server user must have wirte permissions for creating this file
		};
		//var recorderEndpoint; //Very bad idea, this generates concurrency problems in your code. You are using below this variable and it may have not been initialized when you do so, because it's initialization happens asynchronously
		pipeline.create("RecorderEndpoint", recordParams, function(error, recorderEndpoint) {
			if (error) {
				console.log("Recorder problem");
				return sendError(res, 500, error);
			}

			//recorderEndpoint = recorder; //just use the variable given from the callback.
			recorderEndpoint.record();
			//}); //You must put all code usirng the recorder endpoint inside the callback. Otherwise you have a race condition.

			console.log("Creating WebRtcEndpoint");
			pipeline.create('WebRtcEndpoint', function(error, webRtcEndpoint) {
				if (error) {
					return sendError(res, 500, error);
				}

				console.log("Processing sdpOffer at server and generating sdpAnswer");
				webRtcEndpoint.processOffer(sdpOffer, function(error, sdpAnswer) {
					if (error) {
						webRtcEndpoint.release();
						return sendError(res, 500, error);
					}

					console.log("Connecting loopback");
					webRtcEndpoint.connect(webRtcEndpoint, function(error) {
						if(error){
							webRtcEndpoint.release();
							return sendError(res, 500, error);
						}
						console.log("Sending sdpAnswer to client");
						console.log(sdpAnswer);

						webRtcEndpoint.connect(recorderEndpoint, function(error) {
							if(error) {
								webRtcEndpoint.release();
								return sendError(res, 500, error);
							}
							//recorderEndpoint.record(); //You are alredy invoking recorderEndpoit.record() above.
						});
						
						res.type('application/sdp');
						res.send(sdpAnswer);
					});		
				});
			});
		});
	});
});

app.use(express.static(path.join(__dirname, 'static')));