JMFImageToken.java example

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ptii-master
/* A token that contains a javax.media.Buffer.

 Copyright (c) 2002-2006 The Regents of the University of California.
 All rights reserved.
 Permission is hereby granted, without written agreement and without
 license or royalty fees, to use, copy, modify, and distribute this
 software and its documentation for any purpose, provided that the above
 copyright notice and the following two paragraphs appear in all copies
 of this software.

 IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY
 FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
 ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
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 INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
 PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
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 PT_COPYRIGHT_VERSION_2
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 */
package ptolemy.actor.lib.jmf;

import java.awt.Image;

import javax.media.Buffer;
import javax.media.format.VideoFormat;
import javax.media.util.BufferToImage;

import ptolemy.data.ImageToken;
import ptolemy.data.type.BaseType;
import ptolemy.data.type.Type;

//////////////////////////////////////////////////////////////////////////
//// JMFImageToken

/**
 A token that contains a javax.media.Buffer.  This token is used when
 dealing with images in the Java Media Framework (JMF) library.  Because
 it extends ImageToken, it can be used with the standard image processing
 tools by simply casting it, and calling asAWTImage().

 @author James Yeh
 @version $Id$
 @since Ptolemy II 3.0
 @Pt.ProposedRating Red (cxh)
 @Pt.AcceptedRating Red (cxh)
 */
public class JMFImageToken extends ImageToken {
    /** Construct a token with a specified Buffer.
     *  @param value The buffer.
     */
    public JMFImageToken(Buffer value) {
        _value = value;
    }

    ///////////////////////////////////////////////////////////////////
    ////                         public methods                    ////

    /** Convert a javax.media.Buffer to a java.awt.Image and return it.
     *  A new javax.media.util.BufferToImage is created when the
     *  video format of the Buffer changes.
     */
    public Image asAWTImage() {
        if ((_bufferToImage == null) || (_videoFormat != _value.getFormat())) {
            _videoFormat = (VideoFormat) _value.getFormat();
            _bufferToImage = new BufferToImage(_videoFormat);
        }

        _awtImage = _bufferToImage.createImage(_value);
        return _awtImage;
    }

    /** Return the type of this token.
     *  @return BaseType.OBJECT
     */
    public Type getType() {
        return BaseType.OBJECT;
    }

    /** Return the value of this token.
     *  @return The value of this token.
     */
    public Buffer getValue() {
        return _value;
    }

    /** Return a description of the token.
     *  If possible, derived classes should override this method and
     *  return the value of this token as a string that can be parsed
     *  by the expression language to recover a token with the same value.
     *  Unfortunately, in this base class, we can only return the
     *  a partial description of the token.
     *  @return A string representation of a record that partially
     *  describes the token.
     */
    public String toString() {
        // FIXME: return a value that can be parsed by the expression language.
        Image image = asAWTImage();
        return "{type=\"" + getClass() + "\" width=\"" + image.getWidth(null)
                + "\" height=\"" + image.getHeight(null) + "\" format=\""
                + _videoFormat + "\"}";
    }

    ///////////////////////////////////////////////////////////////////
    ////                         private variables                 ////
    private Buffer _value;

    private static BufferToImage _bufferToImage;

    private VideoFormat _videoFormat;

    private Image _awtImage;
}