Merge pull request #25 from Zombitch/master

Replace updateFirst by update & Wait for full data image in order to display it

example/server-canvas.js

@@ -46,4 +46,4 @@ io.on('connection', function(socket) {
 
 app.get('/', function (req, res) {
 	res.sendFile(__dirname + '/index-canvas.html');
-});
+});

lib/rtsp-ffmpeg.js

@@ -27,6 +27,7 @@ var FFMpeg = function(options) {
 	this.resolution = options.resolution;
 	this.quality = (options.quality === undefined || options.quality === "") ? 3 : options.quality;
 	this.arguments = options.arguments || [];
+	this.imageData = []; // Store the entire data image into this variable. This attribute is replaced each time a full image is received from the stream.
 
 	this.on('newListener', newListener.bind(this));
 	this.on('removeListener', removeListener.bind(this));
@@ -73,7 +74,7 @@ FFMpeg.prototype._args = function() {
 		//, '-vf', 'fps=25'
 		//, '-b:v', '32k'
 		'-f', 'image2'
-		, '-updatefirst', '1'
+		, '-update', '1'
 		, '-'
 	]
 	, this.resolution ? ['-s', this.resolution] : []);
@@ -83,8 +84,25 @@ FFMpeg.prototype._args = function() {
  * Start ffmpeg spawn process
  */
 FFMpeg.prototype.start = function() {
+	var self = this;
 	this.child = spawn(FFMpeg.cmd, this._args());
-	this.child.stdout.on('data', this.emit.bind(this, 'data'));
+	this.child.stdout.on('data', function(data){
+		//The image can be composed of one or multiple chunk when receiving stream data.
+		//Store all bytes into an array until we meet flag "FF D9" that mean it's the end of the image then we can send all data in order to display the full image.
+		for(var idx = 0; idx < data.length-1;idx++){
+			offset = data[idx].toString(16);
+			offset2 = data[idx+1].toString(16);
+
+			if(offset == "ff" && offset2 == "d9"){
+				self.imageData.push(data[idx]);
+				self.imageData.push(data[idx+1]);
+				self.emit('data', Buffer.from(self.imageData));
+				self.imageData = [];
+			}else{
+				self.imageData.push(data[idx]);
+			}
+		}
+	});
 	this.child.stderr.on('data', function(data) {
 		throw new Error(data);
 	});