/*
* $RCSfile: JPEGTileDecoder.java,v $
*
* Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
*
* Use is subject to license terms.
*
* $Revision: 1.1 $
* $Date: 2005/02/11 04:56:57 $
* $State: Exp $
*/package com.lightcrafts.media.jai.tilecodec;
import java.awt.Point;
import java.awt.RenderingHints;
import java.awt.image.Raster;
import java.awt.image.WritableRaster;
import java.awt.image.SampleModel;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import com.lightcrafts.mediax.jai.ParameterListDescriptor;
import com.lightcrafts.mediax.jai.RasterFactory;
import com.lightcrafts.mediax.jai.tilecodec.TileCodecDescriptor;
import com.lightcrafts.mediax.jai.tilecodec.TileCodecParameterList;
import com.lightcrafts.mediax.jai.tilecodec.TileDecoderImpl;
import com.lightcrafts.mediax.jai.util.ImagingListener;
import com.sun.image.codec.jpeg.JPEGDecodeParam;
import com.sun.image.codec.jpeg.JPEGImageDecoder;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGQTable;
import com.lightcrafts.media.jai.util.ImageUtil;
/**
* A concrete implementation of the <code>TileDecoderImpl</code> class
* for the jpeg tile codec.
*/
public class JPEGTileDecoder extends TileDecoderImpl {
/* The associated TileCodecDescriptor */
private TileCodecDescriptor tcd = null;
/**
* Constructs a <code>JPEGTileDecoder</code>.
* <code>JPEGTileDecoder</code> may throw a
* <code>IllegalArgumentException</code> if <code>param</code>'s
* <code>getParameterListDescriptor()</code> method does not return
* the same descriptor as that from the associated
* <code>TileCodecDescriptor</code>'s
* <code>getParameterListDescriptor</code> method for the "tileDecoder"
* registry mode.
*
* <p> If param is null, then the default parameter list for decoding
* as defined by the associated <code>TileCodecDescriptor</code>'s
* <code>getDefaultParameters()</code> method will be used for decoding.
*
* @param input The <code>InputStream</code> to decode data from.
* @param param The object containing the tile decoding parameters.
* @throws IllegalArgumentException if input is null.
* @throws IllegalArgumentException if param is not appropriate.
*/
public JPEGTileDecoder(InputStream input, TileCodecParameterList param) {
super("jpeg", input, param);
tcd = TileCodecUtils.getTileCodecDescriptor("tileDecoder", "jpeg");
}
/**
* Returns a <code>Raster</code> that contains the decoded contents
* of the <code>InputStream</code> associated with this
* <code>TileDecoder</code>.
*
* <p>This method can perform the decoding correctly only when
* <code>includesLocationInfoInfo()</code> returns true.
*
* @throws IOException if an I/O error occurs while reading from the
* associated InputStream.
* @throws IllegalArgumentException if the associated
* TileCodecDescriptor's includesLocationInfoInfo() returns false.
*/
public Raster decode() throws IOException{
if (!tcd.includesLocationInfo())
throw new IllegalArgumentException(
JaiI18N.getString("JPEGTileDecoder0") );
return decode(null);
}
public Raster decode(Point location) throws IOException{
SampleModel sm = null;
byte[] data = null;
ObjectInputStream ois = new ObjectInputStream(inputStream);
try {
// read the quality and qualitySet from the stream
paramList.setParameter("quality", ois.readFloat());
paramList.setParameter("qualitySet", ois.readBoolean());
sm = TileCodecUtils.deserializeSampleModel(ois.readObject());
location = (Point)ois.readObject();
data = (byte[]) ois.readObject();
}
catch (ClassNotFoundException e) {
ImagingListener listener =
ImageUtil.getImagingListener((RenderingHints)null);
listener.errorOccurred(JaiI18N.getString("ClassNotFound"),
e, this, false);
// e.printStackTrace();
return null;
}
finally {
ois.close();
}
ByteArrayInputStream bais = new ByteArrayInputStream(data);
JPEGImageDecoder decoder = JPEGCodec.createJPEGDecoder(bais);
Raster ras = decoder.decodeAsRaster()
.createTranslatedChild(location.x, location.y);
extractParameters(decoder.getJPEGDecodeParam(),
ras.getSampleModel().getNumBands());
// set the original sample model to the decoded raster
if (sm != null) {
int minX = ras.getMinX();
int minY = ras.getMinY();
int h = ras.getHeight();
int w = ras.getWidth();
double[] buf = ras.getPixels(minX, minY, w, h, (double[])null);
ras = RasterFactory.createWritableRaster(sm,
new Point(minX, minY));
((WritableRaster)ras).setPixels(minX, minY, w, h, buf);
}
return ras;
}
private void extractParameters(JPEGDecodeParam jdp, int bandNum) {
// extract the horizontal subsampling rates
int[] horizontalSubsampling = new int[bandNum];
for (int i = 0; i < bandNum; i++)
horizontalSubsampling[i] = jdp.getHorizontalSubsampling(i);
paramList.setParameter("horizontalSubsampling", horizontalSubsampling);
// extract the vertical subsampling rates
int[] verticalSubsampling = new int[bandNum];
for (int i = 0; i < bandNum; i++)
verticalSubsampling[i] = jdp.getVerticalSubsampling(i);
paramList.setParameter("verticalSubsampling", verticalSubsampling);
// if the quality is not set, extract the quantization tables from
// the stream; otherwise, define them with the default values.
if (!paramList.getBooleanParameter("qualitySet"))
for (int i = 0; i < 4; i++) {
JPEGQTable table = jdp.getQTable(i);
paramList.setParameter("quantizationTable"+i,
(table == null) ? null : table.getTable());
}
else {
ParameterListDescriptor pld
= paramList.getParameterListDescriptor();
for (int i = 0; i < 4; i++) {
paramList.setParameter("quantizationTable"+i,
pld.getParamDefaultValue("quantizationTable"+i));
}
}
// extract the quantizationTableMapping
int[] quanTableMapping = new int[bandNum];
for (int i = 0; i < bandNum; i++)
quanTableMapping[i] = jdp.getQTableComponentMapping(i);
paramList.setParameter("quantizationTableMapping", quanTableMapping);
// extract the writeTableInfo and writeImageInfo
paramList.setParameter("writeTableInfo", jdp.isTableInfoValid());
paramList.setParameter("writeImageInfo", jdp.isImageInfoValid());
// extract the restart interval
paramList.setParameter("restartInterval", jdp.getRestartInterval());
// define writeJFIFHeader by examing the APP0_MARKER is set or not
paramList.setParameter("writeJFIFHeader",
jdp.getMarker(JPEGDecodeParam.APP0_MARKER));
}
}