JMF - getting a webcam to take a picture!

Question

Hi everyone,
I am looking for help with JMF please! I am having a lot of trouble with JMF trying to get a webcam to take a picture so that i can then use it fro comparision reasons.....
Hope somebody will be able to give me a push in the right direction, i would really appreciate it!!!
Thanks,
Pam
x

Answer 1

I found out that the exception occured because currentFormat was null.. I added a few more lines to the code which now works without any errors.
However i have a little problem. The picture taken is just black... I don't know why this is happening.
Here is the source.
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.*;
import javax.media.*;
import javax.media.CaptureDeviceInfo;
import javax.media.CaptureDeviceManager;
import javax.media.control.FrameGrabbingControl;
import javax.media.format.VideoFormat;
import javax.media.util.BufferToImage;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGEncodeParam;
import com.sun.image.codec.jpeg.JPEGImageEncoder;
import javax.media.control.FormatControl;
public class FrameCapture {
    static MediaLocator ml;
    static Player player;
    static Component videoScreen;
    static Buffer buf = null;
    static String str = null;
    static BufferToImage btoi = null;
    static BufferedImage bi = null;
    static Image frameImage = null;
    static String filename = null;
    static FormatControl formatControl = null;
    static Format currFormat = null;
    static VideoFormat currentFormat = null;
    public static void main(String[] args) {
        try {
            ml = new MediaLocator("vfw://0");
            player = Manager.createRealizedPlayer(ml);
            player.start();
            videoScreen = player.getVisualComponent();
            Frame frame = new Frame();
            frame.setBounds(10, 10, 300, 300);
            frame.add(videoScreen);
            frame.setVisible(true);
            FrameGrabbingControl fgc = (FrameGrabbingControl)player.getControl("javax.media.control.FrameGrabbingControl");
            if (fgc == null) {
                System.out.println("fgc == null");
            buf = fgc.grabFrame();
            if (buf == null) {
                System.out.println("buf == null");
            btoi = new BufferToImage((VideoFormat) buf.getFormat());
            if (btoi == null) {
                System.out.println("btoi == null");
            formatControl = (FormatControl)player.getControl ( "javax.media.control.FormatControl" );
            if (formatControl == null) {
                System.out.println("formatControl == null");
            currFormat = formatControl.getFormat();
            if (currFormat == null) {
                System.out.println("currFormat == null");
            currentFormat = (VideoFormat)currFormat;
            //VideoFormat currentFormat = (VideoFormat)buf.getFormat();
            if (currentFormat == null) {
                System.out.println("currentFormat == null");
            BufferedImage bi = new BufferedImage ( currentFormat.getSize().width,
                                                   currentFormat.getSize().height,
                                                   BufferedImage.TYPE_INT_RGB );
            Image image = btoi.createImage ( buf );
            Graphics2D g2 = bi.createGraphics();
            g2.drawImage ( image, null, null );
            FileOutputStream out = null;
            try
                filename = "myImage.jpeg";
                out = new FileOutputStream ( filename );
                JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder ( out );
                JPEGEncodeParam param = encoder.getDefaultJPEGEncodeParam ( bi );
                param.setQuality ( 1.0f, false );   // 100% high quality setting, no compression
                encoder.setJPEGEncodeParam ( param );
                encoder.encode ( bi );
                out.close();
            catch ( Exception e )
                System.out.println ("Error saving JPEG : " + e.getMessage());
                e.printStackTrace();
            player.close();
            player.deallocate();
        }catch(Exception e) {
            System.err.println("U r Stupid..: " + e.getMessage());
            e.printStackTrace();
}