[JAVA] visualizzare stream webcamera

[topix93]

Ho una telecamera a cui posso accedere allo streaming video attraverso l'indirizzo http://<camera ip>/video/mjpg.cgi... vorrei inculdere quello stream in una mia finestra.
come posso riuscire a fare ciò?? conoscete qualche libreria che può essermi d'aiuto??

[topix93]

Ho trovato questo esempio, ma non riesco a farlo funzionare in quanto mi restituisce un errore nel metodo 'public void readJPG()'... ecco l'errore che mi restituisce:
com.sun.image.codec.jpeg.ImageFormatException: Not a JPEG file: starts with 0x78 0x2d
at sun.awt.image.codec.JPEGImageDecoderImpl.readJPEGStream(Native Method)
at sun.awt.image.codec.JPEGImageDecoderImpl.decodeAsBufferedImage(Unknown Source)
at AxisCamera.readJPG(AxisCamera.java:102)
at AxisCamera.readMJPGStream(AxisCamera.java:95)
at AxisCamera.initDisplay(AxisCamera.java:51)
at AxisCamera.connect(AxisCamera.java:40)
at AxisCamera.run(AxisCamera.java:127)
at java.lang.Thread.run(Unknown Source)

come posso risolvere?

import java.net.*;
import com.sun.image.codec.jpeg.*;
import java.io.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import javax.swing.*;
/**
 *
 * @author David E. Mireles, Ph.D.
 */
public class AxisCamera extends JPanel implements Runnable {
	public boolean useMJPGStream = true;
	public String jpgURL="http://your-ip-here/axis-cgi/jpg/image.cgi?resolution=352x240";
	public String mjpgURL="http://192.168.1.20/video/mjpg.cgi";
	DataInputStream dis;
	private Image image=null;
	public Dimension imageSize = null;
	public boolean connected = false;
	private boolean initCompleted = false;
	HttpURLConnection huc=null;
	Component parent;
	
	/** Creates a new instance of AxisCamera */
	public AxisCamera (Component parent_) {
		parent = parent_;
	}
	
	public void connect(){
		try{
			MyAuthenticator auth = new MyAuthenticator("admin", "");
			Authenticator.setDefault(auth);
			URL u = new URL(useMJPGStream?mjpgURL:jpgURL);
			huc = (HttpURLConnection) u.openConnection();
			//System.out.println(huc.getContentType());
			InputStream is = huc.getInputStream();
			connected = true;
			BufferedInputStream bis = new BufferedInputStream(is);
			dis= new DataInputStream(bis);
			if (!initCompleted) initDisplay();
		}catch(IOException e){ //incase no connection exists wait and try again, instead of printing the error
			try{
				huc.disconnect();
				Thread.sleep(60);
			}catch(InterruptedException ie){huc.disconnect();connect();}
			connect();
		}catch(Exception e){;}
	}
	
	public void initDisplay(){ //setup the display
		if (useMJPGStream)readMJPGStream();
		else {readJPG();disconnect();}
		imageSize = new Dimension(image.getWidth(this), image.getHeight(this));
		setPreferredSize(imageSize);
		parent.setSize(imageSize);
		parent.validate();
		initCompleted = true;
	}
	
	public void disconnect(){
		try{
			if(connected){
				dis.close();
				connected = false;
			}
		}catch(Exception e){;}
	}
	
	public void paint(Graphics g) { //used to set the image on the panel
		if (image != null)
			g.drawImage(image, 0, 0, this);
	}
	
	public void readStream(){ //the basic method to continuously read the stream
		try{
			if (useMJPGStream){
				while(true){
					readMJPGStream();
					parent.repaint();
				}
			}
			else{
				while(true){
					connect();
					readJPG();
					parent.repaint();
					disconnect();
				}
			}
		}catch(Exception e){;} 
	}
	
	public void readMJPGStream(){ //preprocess the mjpg stream to remove the mjpg encapsulation
		readLine(4,dis); 
		readJPG();
		readLine(1,dis); 
	}
	
	public void readJPG(){ //read the embedded jpeg image
		try{
			JPEGImageDecoder decoder = JPEGCodec.createJPEGDecoder(dis);
			image = decoder.decodeAsBufferedImage();
		}catch(Exception e){e.printStackTrace();disconnect();}
	}
	
	public void readLine(int n, DataInputStream dis){ //used to strip out the header lines
		for (int i=0; i<n;i++){
			readLine(dis);
		}
	}
	
	public void readLine(DataInputStream dis){
		try{
			boolean end = false;
			String lineEnd = "\n"; //assumes that the end of the line is marked with this
			byte[] lineEndBytes = lineEnd.getBytes();
			byte[] byteBuf = new byte[lineEndBytes.length];
			while(!end){
				dis.read(byteBuf,0,lineEndBytes.length);
				String t = new String(byteBuf);
				//System.out.print(t); //uncomment if you want to see what the lines actually look like
				if(t.equals(lineEnd)) end=true;
			}
		}catch(Exception e){e.printStackTrace();}
	}
	public void run() {
		connect();
		readStream();
	}

	public static void main(String[] args) {
		JFrame jframe = new JFrame();
		jframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		AxisCamera axPanel = new AxisCamera(jframe);
		new Thread(axPanel).start();
		jframe.getContentPane().add(axPanel);
		jframe.pack();
		jframe.show();
	}
}