| /******************************************************************************* |
| * Copyright (c) 2000, 2005 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.swt.internal.image; |
| |
| |
| /** |
| * JPEGHuffmanTable class actually represents two types of object: |
| * 1) A DHT (Define Huffman Tables) segment, which may represent |
| * as many as 4 Huffman tables. In this case, the tables are |
| * stored in the allTables array. |
| * 2) A single Huffman table. In this case, the allTables array |
| * will be null. |
| * The 'reference' field is stored in both types of object, but |
| * 'initialize' is only called if the object represents a DHT. |
| */ |
| final class JPEGHuffmanTable extends JPEGVariableSizeSegment { |
| JPEGHuffmanTable[] allTables; |
| int tableClass; |
| int tableIdentifier; |
| int[] dhMaxCodes; |
| int[] dhMinCodes; |
| int[] dhValPtrs; |
| int[] dhValues; |
| int[] ehCodes; |
| byte[] ehCodeLengths; |
| static byte[] DCLuminanceTable = { |
| (byte)255, (byte)196, 0, 31, 0, 0, 1, 5, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, |
| 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 |
| }; |
| static byte[] DCChrominanceTable = { |
| (byte)255, (byte)196, 0, 31, 1, 0, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, |
| 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 |
| }; |
| static byte[] ACLuminanceTable = { |
| (byte)255, (byte)196, 0, (byte)181, 16, 0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, 125, |
| 1, 2, 3, 0, 4, 17, 5, 18, 33, 49, 65, 6, 19, 81, 97, 7, 34, 113, 20, |
| 50, (byte)129, (byte)145, (byte)161, 8, 35, 66, (byte)177, (byte)193, 21, 82, (byte)209, (byte)240, 36, 51, 98, |
| 114, (byte)130, 9, 10, 22, 23, 24, 25, 26, 37, 38, 39, 40, 41, 42, 52, 53, |
| 54, 55, 56, 57, 58, 67, 68, 69, 70, 71, 72, 73, 74, 83, 84, 85, 86, 87, |
| 88, 89, 90, 99, 100, 101, 102, 103, 104, 105, 106, 115, 116, 117, 118, |
| 119, 120, 121, 122, (byte)131, (byte)132, (byte)133, (byte)134, (byte)135, (byte)136, (byte)137, (byte)138, (byte)146, (byte)147, (byte)148, |
| (byte)149, (byte)150, (byte)151, (byte)152, (byte)153, (byte)154, (byte)162, (byte)163, (byte)164, (byte)165, (byte)166, (byte)167, (byte)168, (byte)169, (byte)170, |
| (byte)178, (byte)179, (byte)180, (byte)181, (byte)182, (byte)183, (byte)184, (byte)185, (byte)186, (byte)194, (byte)195, (byte)196, (byte)197, (byte)198, (byte)199, |
| (byte)200, (byte)201, (byte)202, (byte)210, (byte)211, (byte)212, (byte)213, (byte)214, (byte)215, (byte)216, (byte)217, (byte)218, (byte)225, (byte)226, (byte)227, |
| (byte)228, (byte)229, (byte)230, (byte)231, (byte)232, (byte)233, (byte)234, (byte)241, (byte)242, (byte)243, (byte)244, (byte)245, (byte)246, (byte)247, (byte)248, |
| (byte)249, (byte)250 |
| }; |
| static byte[] ACChrominanceTable = { |
| (byte)255, (byte)196, 0, (byte)181, 17, 0, 2, 1, 2, 4, 4, 3, 4, 7, 5, 4, 4, 0, |
| 1, 2, 119, 0, 1, 2, 3, 17, 4, 5, 33, 49, 6, 18, 65, 81, 7, 97, 113, 19, 34, |
| 50, (byte)129, 8, 20, 66, (byte)145, (byte)161, (byte)177, (byte)193, 9, 35, |
| 51, 82, (byte)240, 21, 98, 114, (byte)209, 10, 22, 36, 52, (byte)225, 37, |
| (byte)241, 23, 24, 25, 26, 38, 39, 40, 41, 42, 53, 54, 55, 56, 57, 58, 67, |
| 68, 69, 70, 71, 72, 73, 74, 83, 84, 85, 86, 87, 88, 89, 90, 99, 100, 101, 102, |
| 103, 104, 105, 106, 115, 116, 117, 118, 119, 120, 121, 122, (byte)130, |
| (byte)131, (byte)132, (byte)133, (byte)134, (byte)135, (byte)136, (byte)137, |
| (byte)138, (byte)146, (byte)147, (byte)148, (byte)149, (byte)150, (byte)151, |
| (byte)152, (byte)153, (byte)154, (byte)162, (byte)163, (byte)164, (byte)165, |
| (byte)166, (byte)167, (byte)168, (byte)169, (byte)170, (byte)178, (byte)179, |
| (byte)180, (byte)181, (byte)182, (byte)183, (byte)184, (byte)185, (byte)186, |
| (byte)194, (byte)195, (byte)196, (byte)197, (byte)198, (byte)199, (byte)200, |
| (byte)201, (byte)202, (byte)210, (byte)211, (byte)212, (byte)213, (byte)214, |
| (byte)215, (byte)216, (byte)217, (byte)218, (byte)226, (byte)227, (byte)228, |
| (byte)229, (byte)230, (byte)231, (byte)232, (byte)233, (byte)234, (byte)242, |
| (byte)243, (byte)244, (byte)245, (byte)246, (byte)247, (byte)248, (byte)249, |
| (byte)250 |
| }; |
| |
| public JPEGHuffmanTable(byte[] reference) { |
| super(reference); |
| } |
| |
| public JPEGHuffmanTable(LEDataInputStream byteStream) { |
| super(byteStream); |
| initialize(); |
| } |
| |
| public JPEGHuffmanTable[] getAllTables() { |
| return allTables; |
| } |
| |
| public static JPEGHuffmanTable getDefaultACChrominanceTable() { |
| JPEGHuffmanTable result = new JPEGHuffmanTable(ACChrominanceTable); |
| result.initialize(); |
| return result; |
| } |
| |
| public static JPEGHuffmanTable getDefaultACLuminanceTable() { |
| JPEGHuffmanTable result = new JPEGHuffmanTable(ACLuminanceTable); |
| result.initialize(); |
| return result; |
| } |
| |
| public static JPEGHuffmanTable getDefaultDCChrominanceTable() { |
| JPEGHuffmanTable result = new JPEGHuffmanTable(DCChrominanceTable); |
| result.initialize(); |
| return result; |
| } |
| |
| public static JPEGHuffmanTable getDefaultDCLuminanceTable() { |
| JPEGHuffmanTable result = new JPEGHuffmanTable(DCLuminanceTable); |
| result.initialize(); |
| return result; |
| } |
| |
| public int[] getDhMaxCodes() { |
| return dhMaxCodes; |
| } |
| |
| public int[] getDhMinCodes() { |
| return dhMinCodes; |
| } |
| |
| public int[] getDhValPtrs() { |
| return dhValPtrs; |
| } |
| |
| public int[] getDhValues() { |
| return dhValues; |
| } |
| |
| public int getTableClass() { |
| return tableClass; |
| } |
| |
| public int getTableIdentifier() { |
| return tableIdentifier; |
| } |
| |
| void initialize() { |
| int totalLength = getSegmentLength() - 2; |
| int ofs = 4; |
| int[] bits = new int[16]; |
| JPEGHuffmanTable[] huffTables = new JPEGHuffmanTable[8]; // maximum is 4 AC + 4 DC |
| int huffTableCount = 0; |
| while (totalLength > 0) { |
| int tc = (reference[ofs] & 0xFF) >> 4; // table class: AC (1) or DC (0) |
| int tid = reference[ofs] & 0xF; // table id: 0-1 baseline, 0-3 prog/ext |
| ofs++; |
| |
| /* Read the 16 count bytes and add them together to get the table size. */ |
| int count = 0; |
| for (int i = 0; i < bits.length; i++) { |
| int bCount = reference[ofs + i] & 0xFF; |
| bits[i] = bCount; |
| count += bCount; |
| } |
| ofs += 16; |
| totalLength -= 17; |
| |
| /* Read the table. */ |
| int[] huffVals = new int[count]; |
| for (int i = 0; i < count; i++) { |
| huffVals[i] = reference[ofs + i] & 0xFF; |
| } |
| ofs += count; |
| totalLength -= count; |
| |
| /* Calculate the lengths. */ |
| int[] huffCodeLengths = new int[50]; // start with 50 and increment as needed |
| int huffCodeLengthsIndex = 0; |
| for (int i = 0; i < 16; i++) { |
| for (int j = 0; j < bits[i]; j++) { |
| if (huffCodeLengthsIndex >= huffCodeLengths.length) { |
| int[] newHuffCodeLengths = new int[huffCodeLengths.length + 50]; |
| System.arraycopy(huffCodeLengths, 0, newHuffCodeLengths, 0, huffCodeLengths.length); |
| huffCodeLengths = newHuffCodeLengths; |
| } |
| huffCodeLengths[huffCodeLengthsIndex] = i + 1; |
| huffCodeLengthsIndex++; |
| } |
| } |
| |
| /* Truncate huffCodeLengths to the correct size. */ |
| if (huffCodeLengthsIndex < huffCodeLengths.length) { |
| int[] newHuffCodeLengths = new int[huffCodeLengthsIndex]; |
| System.arraycopy(huffCodeLengths, 0, newHuffCodeLengths, 0, huffCodeLengthsIndex); |
| huffCodeLengths = newHuffCodeLengths; |
| } |
| |
| /* Calculate the Huffman codes. */ |
| int[] huffCodes = new int[50]; // start with 50 and increment as needed |
| int huffCodesIndex = 0; |
| int k = 1; |
| int code = 0; |
| int si = huffCodeLengths[0]; |
| int p = 0; |
| while (p < huffCodeLengthsIndex) { |
| while ((p < huffCodeLengthsIndex) && (huffCodeLengths[p] == si)) { |
| if (huffCodesIndex >= huffCodes.length) { |
| int[] newHuffCodes = new int[huffCodes.length + 50]; |
| System.arraycopy(huffCodes, 0, newHuffCodes, 0, huffCodes.length); |
| huffCodes = newHuffCodes; |
| } |
| huffCodes[huffCodesIndex] = code; |
| huffCodesIndex++; |
| code++; |
| p++; |
| } |
| code *= 2; |
| si++; |
| } |
| |
| /* Truncate huffCodes to the correct size. */ |
| if (huffCodesIndex < huffCodes.length) { |
| int[] newHuffCodes = new int[huffCodesIndex]; |
| System.arraycopy(huffCodes, 0, newHuffCodes, 0, huffCodesIndex); |
| huffCodes = newHuffCodes; |
| } |
| |
| /* Calculate the maximum and minimum codes */ |
| k = 0; |
| int[] maxCodes = new int[16]; |
| int[] minCodes = new int[16]; |
| int[] valPtrs = new int[16]; |
| for (int i = 0; i < 16; i++) { |
| int bSize = bits[i]; |
| if (bSize == 0) { |
| maxCodes[i] = -1; |
| } else { |
| valPtrs[i] = k; |
| minCodes[i] = huffCodes[k]; |
| k += bSize; |
| maxCodes[i] = huffCodes[k - 1]; |
| } |
| } |
| |
| /* Calculate the eHuffman codes and lengths. */ |
| int[] eHuffCodes = new int[256]; |
| byte[] eHuffSize = new byte[256]; |
| for (int i = 0; i < huffCodesIndex; i++) { |
| eHuffCodes[huffVals[i]] = huffCodes[i]; |
| eHuffSize[huffVals[i]] = (byte)huffCodeLengths[i]; |
| } |
| |
| /* Create the new JPEGHuffmanTable and add it to the allTables array. */ |
| JPEGHuffmanTable dhtTable = new JPEGHuffmanTable(reference); |
| dhtTable.tableClass = tc; |
| dhtTable.tableIdentifier = tid; |
| dhtTable.dhValues = huffVals; |
| dhtTable.dhMinCodes = minCodes; |
| dhtTable.dhMaxCodes = maxCodes; |
| dhtTable.dhValPtrs = valPtrs; |
| dhtTable.ehCodes = eHuffCodes; |
| dhtTable.ehCodeLengths = eHuffSize; |
| huffTables[huffTableCount] = dhtTable; |
| huffTableCount++; |
| } |
| allTables = new JPEGHuffmanTable[huffTableCount]; |
| System.arraycopy(huffTables, 0, allTables, 0, huffTableCount); |
| } |
| |
| public int signature() { |
| return JPEGFileFormat.DHT; |
| } |
| } |