monitorstream.java

Myjxta的源代码 基于JXTA的P2P即时通信系统

/*
 * Copyright (c) 1996-2001 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Sun grants you ("Licensee") a non-exclusive, royalty free, license to use,
 * modify and redistribute this software in source and binary code form,
 * provided that i) this copyright notice and license appear on all copies of
 * the software; and ii) Licensee does not utilize the software in a manner
 * which is disparaging to Sun.
 *
 * This software is provided "AS IS," without a warranty of any kind. ALL
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 * IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
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 * This software is not designed or intended for use in on-line control of
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 * the design, construction, operation or maintenance of any nuclear
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package net.jxta.myjxta.plugins.vijxta;

import javax.media.Buffer;
import javax.media.control.MonitorControl;
import javax.media.format.VideoFormat;
import javax.media.protocol.BufferTransferHandler;
import javax.media.protocol.ContentDescriptor;
import javax.media.protocol.PushBufferStream;
import javax.media.util.BufferToImage;
import javax.swing.*;
import java.awt.*;
import java.io.IOException;


/**
 *   This push buffer stream mimics a monitor control by intercepting the video 
 *   buffer, turning it into an Image then passes the stream onto the DS's
 *   endpoint.   This class is taken from the jmf solutions page at SUN and 
 *   adapted for this myJxta video module.
 *      http://java.sun.com/products/java-media/jmf/2.1.1/solutions/JVidCap.html
 *   Without this example source it would have taken another week to figure out
 *   how JMF data source's interact.
 *@author  unknown@sun
 *@modified 2005-04-06 jamoore moded to fit viJxta
 *@modified 2005-04-06 jamoore added imageCapture listener and image dispatch
 */
public final class MonitorStream
        implements PushBufferStream, MonitorControl, BufferTransferHandler {
    
    PushBufferStream actual = null;
    boolean dataAvailable = false;
    final boolean terminate = false;
    boolean enabled = false;
    final Object bufferLock = new Object ();
    final Buffer cbuffer = new Buffer ();
    BufferTransferHandler transferHandler = null;
    MonitorComponent component = null;
    final MonitorCDS cds;
    BufferToImage bti = null;
    ImageCaptureListener imageCaptureListener = null;
    
    MonitorStream (PushBufferStream actual, MonitorCDS cds) {
        this.actual = actual;
        actual.setTransferHandler (this);
        this.cds = cds;
    }
    
    public void addImageCaptureListener (ImageCaptureListener imageCaptureListener) {
        
        this.imageCaptureListener = imageCaptureListener;
    }
    
    public javax.media.Format getFormat () {
        return actual.getFormat ();
    }
    
    public void read (Buffer buffer) throws IOException {
        // Wait for data to be available
        // Doesn't get used much because the transferData
        // call is made when data IS available. And most
        // Processors/Players read the data in the same
        // thread that called transferData, although that's
        // not a safe assumption to make
        if (!dataAvailable) {
            synchronized (bufferLock) {
                while (!dataAvailable && !terminate) {
                    try {
                        bufferLock.wait (1000);
                    } catch (InterruptedException ie) {
                    }
                }
            }
        }
        
        if (dataAvailable) {
            synchronized (bufferLock) {
                // Copy the buffer attributes, but swap the data
                // attributes so that no extra copy is made.
                buffer.copy (cbuffer, true);
                dataAvailable = false;
            }
        }
        return;
    }
    
    public void transferData (PushBufferStream pbs) {
        // Get the data from the original source stream
        synchronized (bufferLock) {
            try {
                pbs.read (cbuffer);
            } catch (IOException ioe) {
                return;
            }
            dataAvailable = true;
            bufferLock.notifyAll ();
        }
        
        // Display data if monitor is active
        if (isEnabled ()) {
            if (bti == null) {
                VideoFormat vf = (VideoFormat) cbuffer.getFormat ();
                bti = new BufferToImage (vf);
            }
            if (bti != null && component != null) {
                Image im = bti.createImage (cbuffer);
                //Graphics g = component.getGraphics ();
                component.drawImage(im);
                //Dimension size = component.getSize ();
                //if (g != null) {
                //    g.drawImage (im, 0, 0, component);
                    
                //}
                
                if(imageCaptureListener != null) {

                    imageCaptureListener.imageCaptured (im);
                }
            }
        }
        
        // Maybe synchronize this with setTransferHandler() ?
        if (transferHandler != null && cds.delStarted)
            transferHandler.transferData (this);
    }
    
    public void setTransferHandler (BufferTransferHandler transferHandler) {
        this.transferHandler = transferHandler;
    }
    
    public boolean setEnabled (boolean value) {
        enabled = value;
        if (value == false) {
            if (!cds.delStarted) {
                try {
                    cds.stopDelegate ();
                } catch (IOException ioe) {
                    ioe.printStackTrace ();
                }
            }
        } else {
            // Start the capture datasource if the monitor is enabled
            try {
                cds.startDelegate ();
            } catch (IOException ioe) {
                ioe.printStackTrace ();
            }
        }
        return enabled;
    }
    
    public boolean isEnabled () {
        return enabled;
    }
    
    public Component getControlComponent () {
        if (component == null) {
            Dimension size = ((VideoFormat)getFormat ()).getSize ();
            component = new MonitorComponent (size);
            component.setSize (size);
        }
        return component;
    }
    
    public float setPreviewFrameRate (float rate) {
        System.err.println ("TODO");
        return rate;
    }
    
    public ContentDescriptor getContentDescriptor () {
        return actual.getContentDescriptor ();
    }
    
    public long getContentLength () {
        return actual.getContentLength ();
    }
    
    public boolean endOfStream () {
        return actual.endOfStream ();
    }
    
    public Object [] getControls () {
        return new Object[0];
    }
    
    public Object getControl (String str) {
        return null;
    }
    
    final class MonitorComponent extends JComponent { // Canvas {
        private final Dimension size;
        private Image image = null;
        
        public MonitorComponent (Dimension size) {
            super ();
            this.size = size;
        }
        
        public void paintComponent(Graphics g) {
            
            Graphics2D g2 = (Graphics2D) g;
            
            g2.drawImage (image,0,0,null);
            
            g2.dispose ();
        }
        
        public void drawImage(Image image) {
            
            this.image = image;
            
            repaint();
        }
        
        public Dimension getPreferredSize () {
            return size;
        }
    }
}