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	/*
	* Copyright (c) 2001, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package com.sun.imageio.plugins.jpeg;

	import javax.imageio.IIOException;
	import javax.imageio.metadata.IIOInvalidTreeException;
	import javax.imageio.metadata.IIOMetadataNode;
	import javax.imageio.stream.ImageOutputStream;
	import javax.imageio.plugins.jpeg.JPEGQTable;

	import java.io.IOException;
	import java.util.List;
	import java.util.ArrayList;
	import java.util.Iterator;

	import org.w3c.dom.Node;
	import org.w3c.dom.NodeList;
	import org.w3c.dom.NamedNodeMap;

	/**
	* A DQT (Define Quantization Table) marker segment.
	*/
	class DQTMarkerSegment extends MarkerSegment {
	List tables = new ArrayList(); // Could be 1 to 4

	DQTMarkerSegment(float quality, boolean needTwo) {
	super(JPEG.DQT);
	tables.add(new Qtable(true, quality));
	if (needTwo) {
	tables.add(new Qtable(false, quality));
	}
	}

	DQTMarkerSegment(JPEGBuffer buffer) throws IOException {
	super(buffer);
	int count = length;
	while (count > 0) {
	Qtable newGuy = new Qtable(buffer);
	tables.add(newGuy);
	count -= newGuy.data.length+1;
	}
	buffer.bufAvail -= length;
	}

	DQTMarkerSegment(JPEGQTable[] qtables) {
	super(JPEG.DQT);
	for (int i = 0; i < qtables.length; i++) {
	tables.add(new Qtable(qtables[i], i));
	}
	}

	DQTMarkerSegment(Node node) throws IIOInvalidTreeException {
	super(JPEG.DQT);
	NodeList children = node.getChildNodes();
	int size = children.getLength();
	if ((size < 1) \|\| (size > 4)) {
	throw new IIOInvalidTreeException("Invalid DQT node", node);
	}
	for (int i = 0; i < size; i++) {
	tables.add(new Qtable(children.item(i)));
	}
	}

	protected Object clone() {
	DQTMarkerSegment newGuy = (DQTMarkerSegment) super.clone();
	newGuy.tables = new ArrayList(tables.size());
	Iterator iter = tables.iterator();
	while (iter.hasNext()) {
	Qtable table = (Qtable) iter.next();
	newGuy.tables.add(table.clone());
	}
	return newGuy;
	}

	IIOMetadataNode getNativeNode() {
	IIOMetadataNode node = new IIOMetadataNode("dqt");
	for (int i= 0; i<tables.size(); i++) {
	Qtable table = (Qtable) tables.get(i);
	node.appendChild(table.getNativeNode());
	}
	return node;
	}

	/**
	* Writes the data for this segment to the stream in
	* valid JPEG format.
	*/
	void write(ImageOutputStream ios) throws IOException {
	// We don't write DQT segments; the IJG library does.
	}

	void print() {
	printTag("DQT");
	System.out.println("Num tables: "
	+ Integer.toString(tables.size()));
	for (int i= 0; i<tables.size(); i++) {
	Qtable table = (Qtable) tables.get(i);
	table.print();
	}
	System.out.println();
	}

	/**
	* Assuming the given table was generated by scaling the "standard"
	* visually lossless luminance table, extract the scale factor that
	* was used.
	*/
	Qtable getChromaForLuma(Qtable luma) {
	Qtable newGuy = null;
	// Determine if the table is all the same values
	// if so, use the same table
	boolean allSame = true;
	for (int i = 1; i < luma.QTABLE_SIZE; i++) {
	if (luma.data[i] != luma.data[i-1]) {
	allSame = false;
	break;
	}
	}
	if (allSame) {
	newGuy = (Qtable) luma.clone();
	newGuy.tableID = 1;
	} else {
	// Otherwise, find the largest coefficient less than 255. This is
	// the largest value that we know did not clamp on scaling.
	int largestPos = 0;
	for (int i = 1; i < luma.QTABLE_SIZE; i++) {
	if (luma.data[i] > luma.data[largestPos]) {
	largestPos = i;
	}
	}
	// Compute the scale factor by dividing it by the value in the
	// same position from the "standard" table.
	// If the given table was not generated by scaling the standard,
	// the resulting table will still be reasonable, as it will reflect
	// a comparable scaling of chrominance frequency response of the
	// eye.
	float scaleFactor = ((float)(luma.data[largestPos]))
	/ ((float)(JPEGQTable.K1Div2Luminance.getTable()[largestPos]));
	// generate a new table
	JPEGQTable jpegTable =
	JPEGQTable.K2Div2Chrominance.getScaledInstance(scaleFactor,
	true);
	newGuy = new Qtable(jpegTable, 1);
	}
	return newGuy;
	}

	Qtable getQtableFromNode(Node node) throws IIOInvalidTreeException {
	return new Qtable(node);
	}

	/**
	* A quantization table within a DQT marker segment.
	*/
	class Qtable implements Cloneable {
	int elementPrecision;
	int tableID;
	final int QTABLE_SIZE = 64;
	int [] data; // 64 elements, in natural order

	/**
	* The zigzag-order position of the i'th element
	* of a DCT block read in natural order.
	*/
	private final int [] zigzag = {
	0, 1, 5, 6, 14, 15, 27, 28,
	2, 4, 7, 13, 16, 26, 29, 42,
	3, 8, 12, 17, 25, 30, 41, 43,
	9, 11, 18, 24, 31, 40, 44, 53,
	10, 19, 23, 32, 39, 45, 52, 54,
	20, 22, 33, 38, 46, 51, 55, 60,
	21, 34, 37, 47, 50, 56, 59, 61,
	35, 36, 48, 49, 57, 58, 62, 63
	};

	Qtable(boolean wantLuma, float quality) {
	elementPrecision = 0;
	JPEGQTable base = null;
	if (wantLuma) {
	tableID = 0;
	base = JPEGQTable.K1Div2Luminance;
	} else {
	tableID = 1;
	base = JPEGQTable.K2Div2Chrominance;
	}
	if (quality != JPEG.DEFAULT_QUALITY) {
	quality = JPEG.convertToLinearQuality(quality);
	if (wantLuma) {
	base = JPEGQTable.K1Luminance.getScaledInstance
	(quality, true);
	} else {
	base = JPEGQTable.K2Div2Chrominance.getScaledInstance
	(quality, true);
	}
	}
	data = base.getTable();
	}

	Qtable(JPEGBuffer buffer) throws IIOException {
	elementPrecision = buffer.buf[buffer.bufPtr] >>> 4;
	tableID = buffer.buf[buffer.bufPtr++] & 0xf;
	if (elementPrecision != 0) {
	// IJG is compiled for 8-bits, so this shouldn't happen
	throw new IIOException ("Unsupported element precision");
	}
	data = new int [QTABLE_SIZE];
	// Read from zig-zag order to natural order
	for (int i = 0; i < QTABLE_SIZE; i++) {
	data[i] = buffer.buf[buffer.bufPtr+zigzag[i]] & 0xff;
	}
	buffer.bufPtr += QTABLE_SIZE;
	}

	Qtable(JPEGQTable table, int id) {
	elementPrecision = 0;
	tableID = id;
	data = table.getTable();
	}

	Qtable(Node node) throws IIOInvalidTreeException {
	if (node.getNodeName().equals("dqtable")) {
	NamedNodeMap attrs = node.getAttributes();
	int count = attrs.getLength();
	if ((count < 1) \|\| (count > 2)) {
	throw new IIOInvalidTreeException
	("dqtable node must have 1 or 2 attributes", node);
	}
	elementPrecision = 0;
	tableID = getAttributeValue(node, attrs, "qtableId", 0, 3, true);
	if (node instanceof IIOMetadataNode) {
	IIOMetadataNode ourNode = (IIOMetadataNode) node;
	JPEGQTable table = (JPEGQTable) ourNode.getUserObject();
	if (table == null) {
	throw new IIOInvalidTreeException
	("dqtable node must have user object", node);
	}
	data = table.getTable();
	} else {
	throw new IIOInvalidTreeException
	("dqtable node must have user object", node);
	}
	} else {
	throw new IIOInvalidTreeException
	("Invalid node, expected dqtable", node);
	}
	}

	protected Object clone() {
	Qtable newGuy = null;
	try {
	newGuy = (Qtable) super.clone();
	} catch (CloneNotSupportedException e) {} // won't happen
	if (data != null) {
	newGuy.data = (int []) data.clone();
	}
	return newGuy;
	}

	IIOMetadataNode getNativeNode() {
	IIOMetadataNode node = new IIOMetadataNode("dqtable");
	node.setAttribute("elementPrecision",
	Integer.toString(elementPrecision));
	node.setAttribute("qtableId",
	Integer.toString(tableID));
	node.setUserObject(new JPEGQTable(data));
	return node;
	}

	void print() {
	System.out.println("Table id: " + Integer.toString(tableID));
	System.out.println("Element precision: "
	+ Integer.toString(elementPrecision));

	(new JPEGQTable(data)).toString();
	/*
	for (int i = 0; i < 64; i++) {
	if (i % 8 == 0) {
	System.out.println();
	}
	System.out.print(" " + Integer.toString(data[i]));
	}
	System.out.println();
	*/
	}
	}
	}

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