Getting problem in accessing web cam.
- by Chetan
Hi...
I have written code in Java to access web cam,and to save image...
I am getting following exceptions :
Exception in thread "main" java.lang.NullPointerException
at SwingCapture.(SwingCapture.java:40)
at SwingCapture.main(SwingCapture.java:66)
how to remove this exceptions.
here is the code:
import javax.swing.*;
import javax.swing.event.;
import java.io.;
import javax.media.;
import javax.media.format.;
import javax.media.util.;
import javax.media.control.;
import javax.media.protocol.;
import java.util.;
import java.awt.;
import java.awt.image.;
import java.awt.event.;
import com.sun.image.codec.jpeg.;
public class SwingCapture extends Panel implements ActionListener
{
public static Player player = null;
public CaptureDeviceInfo di = null;
public MediaLocator ml = null;
public JButton capture = null;
public Buffer buf = null;
public Image img = null;
public VideoFormat vf = null;
public BufferToImage btoi = null;
public ImagePanel imgpanel = null;
public SwingCapture()
{
setLayout(new BorderLayout());
setSize(320,550);
imgpanel = new ImagePanel();
capture = new JButton("Capture");
capture.addActionListener(this);
String str1 = "vfw:iNTEX IT-308 WC:0";
String str2 = "vfw:Microsoft WDM Image Capture (Win32):0";
di = CaptureDeviceManager.getDevice(str2);
ml = di.getLocator();
try
{
player = Manager.createRealizedPlayer(ml);
player.start();
Component comp;
if ((comp = player.getVisualComponent()) != null)
{
add(comp,BorderLayout.NORTH);
}
add(capture,BorderLayout.CENTER);
add(imgpanel,BorderLayout.SOUTH);
}
catch (Exception e)
{
e.printStackTrace();
}
}
public static void main(String[] args)
{
Frame f = new Frame("SwingCapture");
SwingCapture cf = new SwingCapture();
f.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
playerclose();
System.exit(0);}});
f.add("Center",cf);
f.pack();
f.setSize(new Dimension(320,550));
f.setVisible(true);
}
public static void playerclose()
{
player.close();
player.deallocate();
}
public void actionPerformed(ActionEvent e)
{
JComponent c = (JComponent) e.getSource();
if (c == capture)
{
// Grab a frame
FrameGrabbingControl fgc = (FrameGrabbingControl)
player.getControl("javax.media.control.FrameGrabbingControl");
buf = fgc.grabFrame();
// Convert it to an image
btoi = new BufferToImage((VideoFormat)buf.getFormat());
img = btoi.createImage(buf);
// show the image
imgpanel.setImage(img);
// save image
saveJPG(img,"\test.jpg");
}
}
class ImagePanel extends Panel
{
public Image myimg = null;
public ImagePanel()
{
setLayout(null);
setSize(320,240);
}
public void setImage(Image img)
{
this.myimg = img;
repaint();
}
public void paint(Graphics g)
{
if (myimg != null)
{
g.drawImage(myimg, 0, 0, this);
}
}
}
public static void saveJPG(Image img, String s)
{
BufferedImage bi = new BufferedImage(img.getWidth(null), img.getHeight(null), BufferedImage.TYPE_INT_RGB);
Graphics2D g2 = bi.createGraphics();
g2.drawImage(img, null, null);
FileOutputStream out = null;
try
{
out = new FileOutputStream(s);
}
catch (java.io.FileNotFoundException io)
{
System.out.println("File Not Found");
}
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
JPEGEncodeParam param = encoder.getDefaultJPEGEncodeParam(bi);
param.setQuality(0.5f,false);
encoder.setJPEGEncodeParam(param);
try
{
encoder.encode(bi);
out.close();
}
catch (java.io.IOException io)
{
System.out.println("IOException");
}
}
}
