| /* | |
| * Copyright (c) 2007, 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 javax.imageio.plugins.jpeg; | |
| import java.util.Arrays; | |
| /** | |
| * A class encapsulating a single JPEG Huffman table. | |
| * Fields are provided for the "standard" tables taken | |
| * from Annex K of the JPEG specification. | |
| * These are the tables used as defaults. | |
| * <p> | |
| * For more information about the operation of the standard JPEG plug-in, | |
| * see the <A HREF="../../metadata/doc-files/jpeg_metadata.html">JPEG | |
| * metadata format specification and usage notes</A> | |
| */ | |
| public class JPEGHuffmanTable { | |
| /* The data for the publicly defined tables, as specified in ITU T.81 | |
| * JPEG specification section K3.3 and used in the IJG library. | |
| */ | |
| private static final short[] StdDCLuminanceLengths = { | |
| 0x00, 0x01, 0x05, 0x01, 0x01, 0x01, 0x01, 0x01, | |
| 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, | |
| }; | |
| private static final short[] StdDCLuminanceValues = { | |
| 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, | |
| 0x08, 0x09, 0x0a, 0x0b, | |
| }; | |
| private static final short[] StdDCChrominanceLengths = { | |
| 0x00, 0x03, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, | |
| 0x01, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, | |
| }; | |
| private static final short[] StdDCChrominanceValues = { | |
| 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, | |
| 0x08, 0x09, 0x0a, 0x0b, | |
| }; | |
| private static final short[] StdACLuminanceLengths = { | |
| 0x00, 0x02, 0x01, 0x03, 0x03, 0x02, 0x04, 0x03, | |
| 0x05, 0x05, 0x04, 0x04, 0x00, 0x00, 0x01, 0x7d, | |
| }; | |
| private static final short[] StdACLuminanceValues = { | |
| 0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12, | |
| 0x21, 0x31, 0x41, 0x06, 0x13, 0x51, 0x61, 0x07, | |
| 0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xa1, 0x08, | |
| 0x23, 0x42, 0xb1, 0xc1, 0x15, 0x52, 0xd1, 0xf0, | |
| 0x24, 0x33, 0x62, 0x72, 0x82, 0x09, 0x0a, 0x16, | |
| 0x17, 0x18, 0x19, 0x1a, 0x25, 0x26, 0x27, 0x28, | |
| 0x29, 0x2a, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, | |
| 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, | |
| 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, | |
| 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, | |
| 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, | |
| 0x7a, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, | |
| 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, | |
| 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, | |
| 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, | |
| 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 0xc4, 0xc5, | |
| 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, 0xd3, 0xd4, | |
| 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xe1, 0xe2, | |
| 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, | |
| 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, | |
| 0xf9, 0xfa, | |
| }; | |
| private static final short[] StdACChrominanceLengths = { | |
| 0x00, 0x02, 0x01, 0x02, 0x04, 0x04, 0x03, 0x04, | |
| 0x07, 0x05, 0x04, 0x04, 0x00, 0x01, 0x02, 0x77, | |
| }; | |
| private static final short[] StdACChrominanceValues = { | |
| 0x00, 0x01, 0x02, 0x03, 0x11, 0x04, 0x05, 0x21, | |
| 0x31, 0x06, 0x12, 0x41, 0x51, 0x07, 0x61, 0x71, | |
| 0x13, 0x22, 0x32, 0x81, 0x08, 0x14, 0x42, 0x91, | |
| 0xa1, 0xb1, 0xc1, 0x09, 0x23, 0x33, 0x52, 0xf0, | |
| 0x15, 0x62, 0x72, 0xd1, 0x0a, 0x16, 0x24, 0x34, | |
| 0xe1, 0x25, 0xf1, 0x17, 0x18, 0x19, 0x1a, 0x26, | |
| 0x27, 0x28, 0x29, 0x2a, 0x35, 0x36, 0x37, 0x38, | |
| 0x39, 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, | |
| 0x49, 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, | |
| 0x59, 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, | |
| 0x69, 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, | |
| 0x79, 0x7a, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, | |
| 0x88, 0x89, 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, | |
| 0x97, 0x98, 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, | |
| 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, | |
| 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, | |
| 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, | |
| 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, | |
| 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, | |
| 0xea, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, | |
| 0xf9, 0xfa, | |
| }; | |
| /** | |
| * The standard DC luminance Huffman table. | |
| */ | |
| public static final JPEGHuffmanTable | |
| StdDCLuminance = new JPEGHuffmanTable(StdDCLuminanceLengths, | |
| StdDCLuminanceValues, false); | |
| /** | |
| * The standard DC chrominance Huffman table. | |
| */ | |
| public static final JPEGHuffmanTable | |
| StdDCChrominance = new JPEGHuffmanTable(StdDCChrominanceLengths, | |
| StdDCChrominanceValues, false); | |
| /** | |
| * The standard AC luminance Huffman table. | |
| */ | |
| public static final JPEGHuffmanTable | |
| StdACLuminance = new JPEGHuffmanTable(StdACLuminanceLengths, | |
| StdACLuminanceValues, false); | |
| /** | |
| * The standard AC chrominance Huffman table. | |
| */ | |
| public static final JPEGHuffmanTable | |
| StdACChrominance = new JPEGHuffmanTable(StdACChrominanceLengths, | |
| StdACChrominanceValues, false); | |
| private short[] lengths; | |
| private short[] values; | |
| /** | |
| * Creates a Huffman table and initializes it. The input arrays are copied. | |
| * The arrays must describe a possible Huffman table. | |
| * For example, 3 codes cannot be expressed with a single bit. | |
| * | |
| * @param lengths an array of {@code short}s where {@code lengths[k]} | |
| * is equal to the number of values with corresponding codes of | |
| * length {@code k + 1} bits. | |
| * @param values an array of shorts containing the values in | |
| * order of increasing code length. | |
| * @throws IllegalArgumentException if {@code lengths} or | |
| * {@code values} are null, the length of {@code lengths} is | |
| * greater than 16, the length of {@code values} is greater than 256, | |
| * if any value in {@code lengths} or {@code values} is less | |
| * than zero, or if the arrays do not describe a valid Huffman table. | |
| */ | |
| public JPEGHuffmanTable(short[] lengths, short[] values) { | |
| if (lengths == null || values == null || | |
| lengths.length == 0 || values.length == 0 || | |
| lengths.length > 16 || values.length > 256) { | |
| throw new IllegalArgumentException("Illegal lengths or values"); | |
| } | |
| for (int i = 0; i<lengths.length; i++) { | |
| if (lengths[i] < 0) { | |
| throw new IllegalArgumentException("lengths["+i+"] < 0"); | |
| } | |
| } | |
| for (int i = 0; i<values.length; i++) { | |
| if (values[i] < 0) { | |
| throw new IllegalArgumentException("values["+i+"] < 0"); | |
| } | |
| } | |
| this.lengths = Arrays.copyOf(lengths, lengths.length); | |
| this.values = Arrays.copyOf(values, values.length); | |
| validate(); | |
| } | |
| private void validate() { | |
| int sumOfLengths = 0; | |
| for (int i=0; i<lengths.length; i++) { | |
| sumOfLengths += lengths[i]; | |
| } | |
| if (sumOfLengths != values.length) { | |
| throw new IllegalArgumentException("lengths do not correspond " + | |
| "to length of value table"); | |
| } | |
| } | |
| /* Internal version which avoids the overhead of copying and checking */ | |
| private JPEGHuffmanTable(short[] lengths, short[] values, boolean copy) { | |
| if (copy) { | |
| this.lengths = Arrays.copyOf(lengths, lengths.length); | |
| this.values = Arrays.copyOf(values, values.length); | |
| } else { | |
| this.lengths = lengths; | |
| this.values = values; | |
| } | |
| } | |
| /** | |
| * Returns an array of {@code short}s containing the number of values | |
| * for each length in the Huffman table. The returned array is a copy. | |
| * | |
| * @return a {@code short} array where {@code array[k-1]} | |
| * is equal to the number of values in the table of length {@code k}. | |
| * @see #getValues | |
| */ | |
| public short[] getLengths() { | |
| return Arrays.copyOf(lengths, lengths.length); | |
| } | |
| /** | |
| * Returns an array of {@code short}s containing the values arranged | |
| * by increasing length of their corresponding codes. | |
| * The interpretation of the array is dependent on the values returned | |
| * from {@code getLengths}. The returned array is a copy. | |
| * | |
| * @return a {@code short} array of values. | |
| * @see #getLengths | |
| */ | |
| public short[] getValues() { | |
| return Arrays.copyOf(values, values.length); | |
| } | |
| /** | |
| * Returns a {@code String} representing this Huffman table. | |
| * @return a {@code String} representing this Huffman table. | |
| */ | |
| public String toString() { | |
| String ls = System.getProperty("line.separator", "\n"); | |
| StringBuilder sb = new StringBuilder("JPEGHuffmanTable"); | |
| sb.append(ls).append("lengths:"); | |
| for (int i=0; i<lengths.length; i++) { | |
| sb.append(" ").append(lengths[i]); | |
| } | |
| sb.append(ls).append("values:"); | |
| for (int i=0; i<values.length; i++) { | |
| sb.append(" ").append(values[i]); | |
| } | |
| return sb.toString(); | |
| } | |
| } |