[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();
}
}