1 /*

     2  * Copyright (c) 2005, 2015, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 package com.sun.imageio.plugins.tiff;

    26 

    27 import java.io.IOException;

    28 

    29 public class TIFFPackBitsUtil {

    30 

    31     byte[] dstData = new byte[8192];

    32     int dstIndex = 0;

    33 

    34     public TIFFPackBitsUtil() {

    35     }

    36 

    37     private void ensureCapacity(int bytesToAdd) {

    38         if (dstIndex + bytesToAdd > dstData.length) {

    39             byte[] newDstData = new byte[Math.max((int)(dstData.length*1.2f),

    40                                                   dstIndex + bytesToAdd)];

    41             System.arraycopy(dstData, 0, newDstData, 0, dstData.length);

    42             dstData = newDstData;

    43         }

    44     }

    45 

    46     public byte[] decode(byte[] srcData) throws IOException {

    47         int inIndex = 0;

    48         while (inIndex < srcData.length) {

    49             byte b = srcData[inIndex++];

    50 

    51             if (b >= 0 && b <= 127) {

    52                 // Literal run packet

    53 

    54                 ensureCapacity(b + 1);

    55                 for (int i = 0; i < b + 1; i++) {

    56                     dstData[dstIndex++] = srcData[inIndex++];

    57                 }

    58             } else if (b <= -1 && b >= -127) {

    59                 // 2-byte encoded run packet

    60                 byte repeat = srcData[inIndex++];

    61                 ensureCapacity(-b + 1);

    62                 for (int i = 0; i < (-b + 1); i++) {

    63                     dstData[dstIndex++] = repeat;

    64                 }

    65             } else {

    66                 // No-op packet, do nothing

    67                 ++inIndex;

    68             }

    69         }

    70 

    71         byte[] newDstData = new byte[dstIndex];

    72         System.arraycopy(dstData, 0, newDstData, 0, dstIndex);

    73         return newDstData;

    74     }

    75 }