/******************************************************************************* * Copyright (c) 2000, 2004 IBM Corporation and others. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Common Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/cpl-v10.html *  * Contributors: *     IBM Corporation - initial API and implementation *******************************************************************************/package org.eclipse.swt.internal.image;import org.eclipse.swt.*;final class JPEGFrameHeader extends JPEGVariableSizeSegment {	int maxVFactor;	int maxHFactor;	public int[] componentIdentifiers;	public int[][] componentParameters;	public JPEGFrameHeader(byte[] reference) {		super(reference);	}		public JPEGFrameHeader(LEDataInputStream byteStream) {		super(byteStream);		initializeComponentParameters();	}		public int getSamplePrecision() {		return reference[4] & 0xFF;	}		public int getNumberOfLines() {		return (reference[5] & 0xFF) << 8 | (reference[6] & 0xFF);	}		public int getSamplesPerLine() {		return (reference[7] & 0xFF) << 8 | (reference[8] & 0xFF);	}		public int getNumberOfImageComponents() {		return reference[9] & 0xFF;	}		public void setSamplePrecision(int precision) {		reference[4] = (byte)(precision & 0xFF);	}		public void setNumberOfLines(int anInteger) {		reference[5] = (byte)((anInteger & 0xFF00) >> 8);		reference[6] = (byte)(anInteger & 0xFF);	}		public void setSamplesPerLine(int samples) {		reference[7] = (byte)((samples & 0xFF00) >> 8);		reference[8] = (byte)(samples & 0xFF);	}		public void setNumberOfImageComponents(int anInteger) {		reference[9] = (byte)(anInteger & 0xFF);	}		public int getMaxHFactor() {		return maxHFactor;	}		public int getMaxVFactor() {		return maxVFactor;	}		public void setMaxHFactor(int anInteger) {		maxHFactor = anInteger;	}		public void setMaxVFactor(int anInteger) {		maxVFactor = anInteger;	}		/* Used when decoding. */	void initializeComponentParameters() {		int nf = getNumberOfImageComponents();		componentIdentifiers = new int[nf];		int[][] compSpecParams = new int[0][];		int hmax = 1;		int vmax = 1;		for (int i = 0; i < nf; i++) {			int ofs = i * 3 + 10;			int ci = reference[ofs] & 0xFF;			componentIdentifiers[i] = ci;			int hi = (reference[ofs + 1] & 0xFF) / 16;			int vi = (reference[ofs + 1] & 0xFF) % 16;			int tqi = reference[ofs + 2] & 0xFF;			if (hi > hmax) {				hmax = hi;			}			if (vi > vmax) {				vmax = vi;			}			int[] compParam = new int[5];			compParam[0] = tqi;			compParam[1] = hi;			compParam[2] = vi;			if (compSpecParams.length <= ci) {				int[][] newParams = new int[ci + 1][];				System.arraycopy(compSpecParams, 0, newParams, 0, compSpecParams.length);				compSpecParams = newParams;			}			compSpecParams[ci] = compParam;		}		int x = getSamplesPerLine();		int y = getNumberOfLines();		int[] multiples = new int[] { 8, 16, 24, 32 };		for (int i = 0; i < nf; i++) {			int[] compParam = compSpecParams[componentIdentifiers[i]];			int hi = compParam[1];			int vi = compParam[2];			int compWidth = (x * hi + hmax - 1) / hmax;			int compHeight = (y * vi + vmax - 1) / vmax;			int dsWidth = roundUpToMultiple(compWidth, multiples[hi - 1]);			int dsHeight = roundUpToMultiple(compHeight, multiples[vi - 1]);			compParam[3] = dsWidth;			compParam[4] = dsHeight;		}		setMaxHFactor(hmax);		setMaxVFactor(vmax);		componentParameters = compSpecParams;	}		/* Used when encoding. */	public void initializeContents() {		int nf = getNumberOfImageComponents();		if (nf == 0 || nf != componentParameters.length) {			SWT.error(SWT.ERROR_INVALID_IMAGE);		}		int hmax = 0;		int vmax = 0;		int[][] compSpecParams = componentParameters;		for (int i = 0; i < nf; i++) {			int ofs = i * 3 + 10;			int[] compParam = compSpecParams[componentIdentifiers[i]];			int hi = compParam[1];			int vi = compParam[2];			if (hi * vi > 4) {				SWT.error(SWT.ERROR_INVALID_IMAGE);			}			reference[ofs] = (byte)(i + 1);			reference[ofs + 1] = (byte)(hi * 16 + vi);			reference[ofs + 2] = (byte)(compParam[0]);			if (hi > hmax) hmax = hi;			if (vi > vmax) vmax = vi;		}		int x = getSamplesPerLine();		int y = getNumberOfLines();		int[] multiples = new int[] {8, 16, 24, 32};		for (int i = 0; i < nf; i++) {			int[] compParam = compSpecParams[componentIdentifiers[i]];			int hi = compParam[1];			int vi = compParam[2];			int compWidth = (x * hi + hmax - 1) / hmax;			int compHeight = (y * vi + vmax - 1) / vmax;			int dsWidth = roundUpToMultiple(compWidth, multiples[hi - 1]);			int dsHeight = roundUpToMultiple(compHeight, multiples[vi - 1]);			compParam[3] = dsWidth;			compParam[4] = dsHeight;		}		setMaxHFactor(hmax);		setMaxVFactor(vmax);	}		int roundUpToMultiple(int anInteger, int mInteger) {		int a = anInteger + mInteger - 1;		return a - (a % mInteger);	}		/*	 * Verify the information contained in the receiver is correct.	 * Answer true if the header contains a valid marker. Otherwise,	 * answer false. Valid Start Of Frame markers are:	 *	SOF_0  - Baseline DCT, Huffman coding	 *	SOF_1  - Extended sequential DCT, Huffman coding	 *	SOF_2  - Progressive DCT, Huffman coding	 *	SOF_3  - Lossless (sequential), Huffman coding	 *	SOF_5  - Differential sequential, Huffman coding	 *	SOF_6  - Differential progressive, Huffman coding	 *	SOF_7  - Differential lossless, Huffman coding	 *	SOF_9  - Extended sequential DCT, arithmetic coding	 *	SOF_10 - Progressive DCT, arithmetic coding	 *	SOF_11 - Lossless (sequential), arithmetic coding	 *	SOF_13 - Differential sequential, arithmetic coding	 *	SOF_14 - Differential progressive, arithmetic coding	 *	SOF_15 - Differential lossless, arithmetic coding	 */	public boolean verify() {		int marker = getSegmentMarker();		return (marker >= JPEGFileFormat.SOF0 && marker <= JPEGFileFormat.SOF3) ||			(marker >= JPEGFileFormat.SOF5 && marker <= JPEGFileFormat.SOF7) ||			(marker >= JPEGFileFormat.SOF9 && marker <= JPEGFileFormat.SOF11) ||			(marker >= JPEGFileFormat.SOF13 && marker <= JPEGFileFormat.SOF15);	}	public boolean isProgressive() {		int marker = getSegmentMarker();		return marker == JPEGFileFormat.SOF2			|| marker == JPEGFileFormat.SOF6			|| marker == JPEGFileFormat.SOF10			|| marker == JPEGFileFormat.SOF14;	}		public boolean isArithmeticCoding() {		return getSegmentMarker() >= JPEGFileFormat.SOF9;	}}