using System;
/*
 * Copyright 2003-2008 by Paulo Soares.
 * 
 * This code was originally released in 2001 by SUN (see class
 * com.sun.media.imageioimpl.plugins.tiff.TIFFFaxDecompressor.java)
 * using the BSD license in a specific wording. In a mail dating from
 * January 23, 2008, Brian Burkhalter (@sun.com) gave us permission
 * to use the code under the following version of the BSD license:
 *
 * Copyright (c) 2005 Sun Microsystems, Inc. All  Rights Reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met: 
 * 
 * - Redistribution of source code must retain the above copyright 
 *   notice, this  list of conditions and the following disclaimer.
 * 
 * - Redistribution in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in 
 *   the documentation and/or other materials provided with the
 *   distribution.
 * 
 * Neither the name of Sun Microsystems, Inc. or the names of 
 * contributors may be used to endorse or promote products derived 
 * from this software without specific prior written permission.
 * 
 * This software is provided "AS IS," without a warranty of any 
 * kind. ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND 
 * WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, 
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY
 * EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL 
 * NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF 
 * USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
 * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR 
 * ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL,
 * CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND
 * REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF OR
 * INABILITY TO USE THIS SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES. 
 * 
 * You acknowledge that this software is not designed or intended for 
 * use in the design, construction, operation or maintenance of any 
 * nuclear facility. 
 */

namespace iTextSharp.text.pdf.codec {
    public class TIFFFaxDecoder {
        
        private int bitPointer, bytePointer;
        private byte[] data;
        private int w, h;
        private int fillOrder;
        
        // Data structures needed to store changing elements for the previous
        // and the current scanline
        private int changingElemSize = 0;
        private int[] prevChangingElems;
        private int[] currChangingElems;
        
        // Element at which to start search in getNextChangingElement
        private int lastChangingElement = 0;
        
        private int compression = 2;
        
        // Variables set by T4Options
        private int uncompressedMode = 0;
        private int fillBits = 0;
        private int oneD;
        
        static int[] table1 = {
            0x00, // 0 bits are left in first byte - SHOULD NOT HAPPEN
            0x01, // 1 bits are left in first byte
            0x03, // 2 bits are left in first byte
            0x07, // 3 bits are left in first byte
            0x0f, // 4 bits are left in first byte
            0x1f, // 5 bits are left in first byte
            0x3f, // 6 bits are left in first byte
            0x7f, // 7 bits are left in first byte
            0xff  // 8 bits are left in first byte
        };
        
        static int[] table2 = {
            0x00, // 0
            0x80, // 1
            0xc0, // 2
            0xe0, // 3
            0xf0, // 4
            0xf8, // 5
            0xfc, // 6
            0xfe, // 7
            0xff  // 8
        };
        
        // Table to be used when fillOrder = 2, for flipping bytes.
        internal static byte[] flipTable = {
            0,  256-128,    64,   256-64,    32,   256-96,    96,   256-32,
            16,  256-112,    80,   256-48,    48,   256-80,   112,   256-16,
            8,  256-120,    72,   256-56,    40,   256-88,   104,   256-24,
            24,  256-104,    88,   256-40,    56,   256-72,   120,    256-8,
            4,  256-124,    68,   256-60,    36,   256-92,   100,   256-28,
            20,  256-108,    84,   256-44,    52,   256-76,   116,   256-12,
            12,  256-116,    76,   256-52,    44,   256-84,   108,   256-20,
            28,  256-100,    92,   256-36,    60,   256-68,   124,    256-4,
            2,  256-126,    66,   256-62,    34,   256-94,    98,   256-30,
            18,  256-110,    82,   256-46,    50,   256-78,   114,   256-14,
            10,  256-118,    74,   256-54,    42,   256-86,   106,   256-22,
            26,  256-102,    90,   256-38,    58,   256-70,   122,    256-6,
            6,  256-122,    70,   256-58,    38,   256-90,   102,   256-26,
            22,  256-106,    86,   256-42,    54,   256-74,   118,   256-10,
            14,  256-114,    78,   256-50,    46,   256-82,   110,   256-18,
            30,   256-98,    94,   256-34,    62,   256-66,   126,    256-2,
            1,  256-127,    65,   256-63,    33,   256-95,    97,   256-31,
            17,  256-111,    81,   256-47,    49,   256-79,   113,   256-15,
            9,  256-119,    73,   256-55,    41,   256-87,   105,   256-23,
            25,  256-103,    89,   256-39,    57,   256-71,   121,    256-7,
            5,  256-123,    69,   256-59,    37,   256-91,   101,   256-27,
            21,  256-107,    85,   256-43,    53,   256-75,   117,   256-11,
            13,  256-115,    77,   256-51,    45,   256-83,   109,   256-19,
            29,   256-99,    93,   256-35,    61,   256-67,   125,    256-3,
            3,  256-125,    67,   256-61,    35,   256-93,    99,   256-29,
            19,  256-109,    83,   256-45,    51,   256-77,   115,   256-13,
            11,  256-117,    75,   256-53,    43,   256-85,   107,   256-21,
            27,  256-101,    91,   256-37,    59,   256-69,   123,    256-5,
            7,  256-121,    71,   256-57,    39,   256-89,   103,   256-25,
            23,  256-105,    87,   256-41,    55,   256-73,   119,    256-9,
            15,  256-113,    79,   256-49,    47,   256-81,   111,   256-17,
            31,   256-97,    95,   256-33,    63,   256-65,   127,    256-1,
        };
        
        // The main 10 bit white runs lookup table
        static short[] white = {
            // 0 - 7
            6430,   6400,   6400,   6400,   3225,   3225,   3225,   3225,
            // 8 - 15
            944,    944,    944,    944,    976,    976,    976,    976,
            // 16 - 23
            1456,   1456,   1456,   1456,   1488,   1488,   1488,   1488,
            // 24 - 31
            718,    718,    718,    718,    718,    718,    718,    718,
            // 32 - 39
            750,    750,    750,    750,    750,    750,    750,    750,
            // 40 - 47
            1520,   1520,   1520,   1520,   1552,   1552,   1552,   1552,
            // 48 - 55
            428,    428,    428,    428,    428,    428,    428,    428,
            // 56 - 63
            428,    428,    428,    428,    428,    428,    428,    428,
            // 64 - 71
            654,    654,    654,    654,    654,    654,    654,    654,
            // 72 - 79
            1072,   1072,   1072,   1072,   1104,   1104,   1104,   1104,
            // 80 - 87
            1136,   1136,   1136,   1136,   1168,   1168,   1168,   1168,
            // 88 - 95
            1200,   1200,   1200,   1200,   1232,   1232,   1232,   1232,
            // 96 - 103
            622,    622,    622,    622,    622,    622,    622,    622,
            // 104 - 111
            1008,   1008,   1008,   1008,   1040,   1040,   1040,   1040,
            // 112 - 119
            44,     44,     44,     44,     44,     44,     44,     44,
            // 120 - 127
            44,     44,     44,     44,     44,     44,     44,     44,
            // 128 - 135
            396,    396,    396,    396,    396,    396,    396,    396,
            // 136 - 143
            396,    396,    396,    396,    396,    396,    396,    396,
            // 144 - 151
            1712,   1712,   1712,   1712,   1744,   1744,   1744,   1744,
            // 152 - 159
            846,    846,    846,    846,    846,    846,    846,    846,
            // 160 - 167
            1264,   1264,   1264,   1264,   1296,   1296,   1296,   1296,
            // 168 - 175
            1328,   1328,   1328,   1328,   1360,   1360,   1360,   1360,
            // 176 - 183
            1392,   1392,   1392,   1392,   1424,   1424,   1424,   1424,
            // 184 - 191
            686,    686,    686,    686,    686,    686,    686,    686,
            // 192 - 199
            910,    910,    910,    910,    910,    910,    910,    910,
            // 200 - 207
            1968,   1968,   1968,   1968,   2000,   2000,   2000,   2000,
            // 208 - 215
            2032,   2032,   2032,   2032,     16,     16,     16,     16,
            // 216 - 223
            10257,  10257,  10257,  10257,  12305,  12305,  12305,  12305,
            // 224 - 231
            330,    330,    330,    330,    330,    330,    330,    330,
            // 232 - 239
            330,    330,    330,    330,    330,    330,    330,    330,
            // 240 - 247
            330,    330,    330,    330,    330,    330,    330,    330,
            // 248 - 255
            330,    330,    330,    330,    330,    330,    330,    330,
            // 256 - 263
            362,    362,    362,    362,    362,    362,    362,    362,
            // 264 - 271
            362,    362,    362,    362,    362,    362,    362,    362,
            // 272 - 279
            362,    362,    362,    362,    362,    362,    362,    362,
            // 280 - 287
            362,    362,    362,    362,    362,    362,    362,    362,
            // 288 - 295
            878,    878,    878,    878,    878,    878,    878,    878,
            // 296 - 303
            1904,   1904,   1904,   1904,   1936,   1936,   1936,   1936,
            // 304 - 311
            -18413, -18413, -16365, -16365, -14317, -14317, -10221, -10221,
            // 312 - 319
            590,    590,    590,    590,    590,    590,    590,    590,
            // 320 - 327
            782,    782,    782,    782,    782,    782,    782,    782,
            // 328 - 335
            1584,   1584,   1584,   1584,   1616,   1616,   1616,   1616,
            // 336 - 343
            1648,   1648,   1648,   1648,   1680,   1680,   1680,   1680,
            // 344 - 351
            814,    814,    814,    814,    814,    814,    814,    814,
            // 352 - 359
            1776,   1776,   1776,   1776,   1808,   1808,   1808,   1808,
            // 360 - 367
            1840,   1840,   1840,   1840,   1872,   1872,   1872,   1872,
            // 368 - 375
            6157,   6157,   6157,   6157,   6157,   6157,   6157,   6157,
            // 376 - 383
            6157,   6157,   6157,   6157,   6157,   6157,   6157,   6157,
            // 384 - 391
            -12275, -12275, -12275, -12275, -12275, -12275, -12275, -12275,
            // 392 - 399
            -12275, -12275, -12275, -12275, -12275, -12275, -12275, -12275,
            // 400 - 407
            14353,  14353,  14353,  14353,  16401,  16401,  16401,  16401,
            // 408 - 415
            22547,  22547,  24595,  24595,  20497,  20497,  20497,  20497,
            // 416 - 423
            18449,  18449,  18449,  18449,  26643,  26643,  28691,  28691,
            // 424 - 431
            30739,  30739, -32749, -32749, -30701, -30701, -28653, -28653,
            // 432 - 439
            -26605, -26605, -24557, -24557, -22509, -22509, -20461, -20461,
            // 440 - 447
            8207,   8207,   8207,   8207,   8207,   8207,   8207,   8207,
            // 448 - 455
            72,     72,     72,     72,     72,     72,     72,     72,
            // 456 - 463
            72,     72,     72,     72,     72,     72,     72,     72,
            // 464 - 471
            72,     72,     72,     72,     72,     72,     72,     72,
            // 472 - 479
            72,     72,     72,     72,     72,     72,     72,     72,
            // 480 - 487
            72,     72,     72,     72,     72,     72,     72,     72,
            // 488 - 495
            72,     72,     72,     72,     72,     72,     72,     72,
            // 496 - 503
            72,     72,     72,     72,     72,     72,     72,     72,
            // 504 - 511
            72,     72,     72,     72,     72,     72,     72,     72,
            // 512 - 519
            104,    104,    104,    104,    104,    104,    104,    104,
            // 520 - 527
            104,    104,    104,    104,    104,    104,    104,    104,
            // 528 - 535
            104,    104,    104,    104,    104,    104,    104,    104,
            // 536 - 543
            104,    104,    104,    104,    104,    104,    104,    104,
            // 544 - 551
            104,    104,    104,    104,    104,    104,    104,    104,
            // 552 - 559
            104,    104,    104,    104,    104,    104,    104,    104,
            // 560 - 567
            104,    104,    104,    104,    104,    104,    104,    104,
            // 568 - 575
            104,    104,    104,    104,    104,    104,    104,    104,
            // 576 - 583
            4107,   4107,   4107,   4107,   4107,   4107,   4107,   4107,
            // 584 - 591
            4107,   4107,   4107,   4107,   4107,   4107,   4107,   4107,
            // 592 - 599
            4107,   4107,   4107,   4107,   4107,   4107,   4107,   4107,
            // 600 - 607
            4107,   4107,   4107,   4107,   4107,   4107,   4107,   4107,
            // 608 - 615
            266,    266,    266,    266,    266,    266,    266,    266,
            // 616 - 623
            266,    266,    266,    266,    266,    266,    266,    266,
            // 624 - 631
            266,    266,    266,    266,    266,    266,    266,    266,
            // 632 - 639
            266,    266,    266,    266,    266,    266,    266,    266,
            // 640 - 647
            298,    298,    298,    298,    298,    298,    298,    298,
            // 648 - 655
            298,    298,    298,    298,    298,    298,    298,    298,
            // 656 - 663
            298,    298,    298,    298,    298,    298,    298,    298,
            // 664 - 671
            298,    298,    298,    298,    298,    298,    298,    298,
            // 672 - 679
            524,    524,    524,    524,    524,    524,    524,    524,
            // 680 - 687
            524,    524,    524,    524,    524,    524,    524,    524,
            // 688 - 695
            556,    556,    556,    556,    556,    556,    556,    556,
            // 696 - 703
            556,    556,    556,    556,    556,    556,    556,    556,
            // 704 - 711
            136,    136,    136,    136,    136,    136,    136,    136,
            // 712 - 719
            136,    136,    136,    136,    136,    136,    136,    136,
            // 720 - 727
            136,    136,    136,    136,    136,    136,    136,    136,
            // 728 - 735
            136,    136,    136,    136,    136,    136,    136,    136,
            // 736 - 743
            136,    136,    136,    136,    136,    136,    136,    136,
            // 744 - 751
            136,    136,    136,    136,    136,    136,    136,    136,
            // 752 - 759
            136,    136,    136,    136,    136,    136,    136,    136,
            // 760 - 767
            136,    136,    136,    136,    136,    136,    136,    136,
            // 768 - 775
            168,    168,    168,    168,    168,    168,    168,    168,
            // 776 - 783
            168,    168,    168,    168,    168,    168,    168,    168,
            // 784 - 791
            168,    168,    168,    168,    168,    168,    168,    168,
            // 792 - 799
            168,    168,    168,    168,    168,    168,    168,    168,
            // 800 - 807
            168,    168,    168,    168,    168,    168,    168,    168,
            // 808 - 815
            168,    168,    168,    168,    168,    168,    168,    168,
            // 816 - 823
            168,    168,    168,    168,    168,    168,    168,    168,
            // 824 - 831
            168,    168,    168,    168,    168,    168,    168,    168,
            // 832 - 839
            460,    460,    460,    460,    460,    460,    460,    460,
            // 840 - 847
            460,    460,    460,    460,    460,    460,    460,    460,
            // 848 - 855
            492,    492,    492,    492,    492,    492,    492,    492,
            // 856 - 863
            492,    492,    492,    492,    492,    492,    492,    492,
            // 864 - 871
            2059,   2059,   2059,   2059,   2059,   2059,   2059,   2059,
            // 872 - 879
            2059,   2059,   2059,   2059,   2059,   2059,   2059,   2059,
            // 880 - 887
            2059,   2059,   2059,   2059,   2059,   2059,   2059,   2059,
            // 888 - 895
            2059,   2059,   2059,   2059,   2059,   2059,   2059,   2059,
            // 896 - 903
            200,    200,    200,    200,    200,    200,    200,    200,
            // 904 - 911
            200,    200,    200,    200,    200,    200,    200,    200,
            // 912 - 919
            200,    200,    200,    200,    200,    200,    200,    200,
            // 920 - 927
            200,    200,    200,    200,    200,    200,    200,    200,
            // 928 - 935
            200,    200,    200,    200,    200,    200,    200,    200,
            // 936 - 943
            200,    200,    200,    200,    200,    200,    200,    200,
            // 944 - 951
            200,    200,    200,    200,    200,    200,    200,    200,
            // 952 - 959
            200,    200,    200,    200,    200,    200,    200,    200,
            // 960 - 967
            232,    232,    232,    232,    232,    232,    232,    232,
            // 968 - 975
            232,    232,    232,    232,    232,    232,    232,    232,
            // 976 - 983
            232,    232,    232,    232,    232,    232,    232,    232,
            // 984 - 991
            232,    232,    232,    232,    232,    232,    232,    232,
            // 992 - 999
            232,    232,    232,    232,    232,    232,    232,    232,
            // 1000 - 1007
            232,    232,    232,    232,    232,    232,    232,    232,
            // 1008 - 1015
            232,    232,    232,    232,    232,    232,    232,    232,
            // 1016 - 1023
            232,    232,    232,    232,    232,    232,    232,    232,
        };
        
        // Additional make up codes for both White and Black runs
        static short[] additionalMakeup = {
            28679,  28679,  31752,  unchecked((short)32777),
            unchecked((short)33801),  unchecked((short)34825),  unchecked((short)35849),  unchecked((short)36873),
            unchecked((short)29703),  unchecked((short)29703),  unchecked((short)30727),  unchecked((short)30727),
            unchecked((short)37897),  unchecked((short)38921),  unchecked((short)39945),  unchecked((short)40969)
        };
        
        // Initial black run look up table, uses the first 4 bits of a code
        static short[] initBlack = {
            // 0 - 7
            3226,  6412,    200,    168,    38,     38,    134,    134,
            // 8 - 15
            100,    100,    100,    100,    68,     68,     68,     68
        };
        
        //
        static short[] twoBitBlack = {292, 260, 226, 226};   // 0 - 3
        
        // Main black run table, using the last 9 bits of possible 13 bit code
        static short[] black = {
            // 0 - 7
            62,     62,     30,     30,     0,      0,      0,      0,
            // 8 - 15
            0,      0,      0,      0,      0,      0,      0,      0,
            // 16 - 23
            0,      0,      0,      0,      0,      0,      0,      0,
            // 24 - 31
            0,      0,      0,      0,      0,      0,      0,      0,
            // 32 - 39
            3225,   3225,   3225,   3225,   3225,   3225,   3225,   3225,
            // 40 - 47
            3225,   3225,   3225,   3225,   3225,   3225,   3225,   3225,
            // 48 - 55
            3225,   3225,   3225,   3225,   3225,   3225,   3225,   3225,
            // 56 - 63
            3225,   3225,   3225,   3225,   3225,   3225,   3225,   3225,
            // 64 - 71
            588,    588,    588,    588,    588,    588,    588,    588,
            // 72 - 79
            1680,   1680,  20499,  22547,  24595,  26643,   1776,   1776,
            // 80 - 87
            1808,   1808, -24557, -22509, -20461, -18413,   1904,   1904,
            // 88 - 95
            1936,   1936, -16365, -14317,    782,    782,    782,    782,
            // 96 - 103
            814,    814,    814,    814, -12269, -10221,  10257,  10257,
            // 104 - 111
            12305,  12305,  14353,  14353,  16403,  18451,   1712,   1712,
            // 112 - 119
            1744,   1744,  28691,  30739, -32749, -30701, -28653, -26605,
            // 120 - 127
            2061,   2061,   2061,   2061,   2061,   2061,   2061,   2061,
            // 128 - 135
            424,    424,    424,    424,    424,    424,    424,    424,
            // 136 - 143
            424,    424,    424,    424,    424,    424,    424,    424,
            // 144 - 151
            424,    424,    424,    424,    424,    424,    424,    424,
            // 152 - 159
            424,    424,    424,    424,    424,    424,    424,    424,
            // 160 - 167
            750,    750,    750,    750,   1616,   1616,   1648,   1648,
            // 168 - 175
            1424,   1424,   1456,   1456,   1488,   1488,   1520,   1520,
            // 176 - 183
            1840,   1840,   1872,   1872,   1968,   1968,   8209,   8209,
            // 184 - 191
            524,    524,    524,    524,    524,    524,    524,    524,
            // 192 - 199
            556,    556,    556,    556,    556,    556,    556,    556,
            // 200 - 207
            1552,   1552,   1584,   1584,   2000,   2000,   2032,   2032,
            // 208 - 215
            976,    976,   1008,   1008,   1040,   1040,   1072,   1072,
            // 216 - 223
            1296,   1296,   1328,   1328,    718,    718,    718,    718,
            // 224 - 231
            456,    456,    456,    456,    456,    456,    456,    456,
            // 232 - 239
            456,    456,    456,    456,    456,    456,    456,    456,
            // 240 - 247
            456,    456,    456,    456,    456,    456,    456,    456,
            // 248 - 255
            456,    456,    456,    456,    456,    456,    456,    456,
            // 256 - 263
            326,    326,    326,    326,    326,    326,    326,    326,
            // 264 - 271
            326,    326,    326,    326,    326,    326,    326,    326,
            // 272 - 279
            326,    326,    326,    326,    326,    326,    326,    326,
            // 280 - 287
            326,    326,    326,    326,    326,    326,    326,    326,
            // 288 - 295
            326,    326,    326,    326,    326,    326,    326,    326,
            // 296 - 303
            326,    326,    326,    326,    326,    326,    326,    326,
            // 304 - 311
            326,    326,    326,    326,    326,    326,    326,    326,
            // 312 - 319
            326,    326,    326,    326,    326,    326,    326,    326,
            // 320 - 327
            358,    358,    358,    358,    358,    358,    358,    358,
            // 328 - 335
            358,    358,    358,    358,    358,    358,    358,    358,
            // 336 - 343
            358,    358,    358,    358,    358,    358,    358,    358,
            // 344 - 351
            358,    358,    358,    358,    358,    358,    358,    358,
            // 352 - 359
            358,    358,    358,    358,    358,    358,    358,    358,
            // 360 - 367
            358,    358,    358,    358,    358,    358,    358,    358,
            // 368 - 375
            358,    358,    358,    358,    358,    358,    358,    358,
            // 376 - 383
            358,    358,    358,    358,    358,    358,    358,    358,
            // 384 - 391
            490,    490,    490,    490,    490,    490,    490,    490,
            // 392 - 399
            490,    490,    490,    490,    490,    490,    490,    490,
            // 400 - 407
            4113,   4113,   6161,   6161,    848,    848,    880,    880,
            // 408 - 415
            912,    912,    944,    944,    622,    622,    622,    622,
            // 416 - 423
            654,    654,    654,    654,   1104,   1104,   1136,   1136,
            // 424 - 431
            1168,   1168,   1200,   1200,   1232,   1232,   1264,   1264,
            // 432 - 439
            686,    686,    686,    686,   1360,   1360,   1392,   1392,
            // 440 - 447
            12,     12,     12,     12,     12,     12,     12,     12,
            // 448 - 455
            390,    390,    390,    390,    390,    390,    390,    390,
            // 456 - 463
            390,    390,    390,    390,    390,    390,    390,    390,
            // 464 - 471
            390,    390,    390,    390,    390,    390,    390,    390,
            // 472 - 479
            390,    390,    390,    390,    390,    390,    390,    390,
            // 480 - 487
            390,    390,    390,    390,    390,    390,    390,    390,
            // 488 - 495
            390,    390,    390,    390,    390,    390,    390,    390,
            // 496 - 503
            390,    390,    390,    390,    390,    390,    390,    390,
            // 504 - 511
            390,    390,    390,    390,    390,    390,    390,    390,
        };
        
        static byte[] twoDCodes = {
            // 0 - 7
            80,     88,     23,     71,     30,     30,     62,     62,
            // 8 - 15
            4,      4,      4,      4,      4,      4,      4,      4,
            // 16 - 23
            11,     11,     11,     11,     11,     11,     11,     11,
            // 24 - 31
            11,     11,     11,     11,     11,     11,     11,     11,
            // 32 - 39
            35,     35,     35,     35,     35,     35,     35,     35,
            // 40 - 47
            35,     35,     35,     35,     35,     35,     35,     35,
            // 48 - 55
            51,     51,     51,     51,     51,     51,     51,     51,
            // 56 - 63
            51,     51,     51,     51,     51,     51,     51,     51,
            // 64 - 71
            41,     41,     41,     41,     41,     41,     41,     41,
            // 72 - 79
            41,     41,     41,     41,     41,     41,     41,     41,
            // 80 - 87
            41,     41,     41,     41,     41,     41,     41,     41,
            // 88 - 95
            41,     41,     41,     41,     41,     41,     41,     41,
            // 96 - 103
            41,     41,     41,     41,     41,     41,     41,     41,
            // 104 - 111
            41,     41,     41,     41,     41,     41,     41,     41,
            // 112 - 119
            41,     41,     41,     41,     41,     41,     41,     41,
            // 120 - 127
            41,     41,     41,     41,     41,     41,     41,     41,
        };
        
        /**
        * @param fillOrder   The fill order of the compressed data bytes.
        * @param w
        * @param h
        */
        public TIFFFaxDecoder(int fillOrder, int w, int h) {
            this.fillOrder = fillOrder;
            this.w = w;
            this.h = h;
            
            this.bitPointer = 0;
            this.bytePointer = 0;
            this.prevChangingElems = new int[w];
            this.currChangingElems = new int[w];
        }

        public static void ReverseBits(byte[] b) {
            for (int k = 0; k < b.Length; ++k)
                b[k] = flipTable[b[k] & 0xff];
        }

        
        // One-dimensional decoding methods
        
        public void Decode1D(byte[] buffer, byte[] compData,
        int startX, int height) {
            this.data = compData;
            
            int lineOffset = 0;
            int scanlineStride = (w + 7)/8;
            
            bitPointer = 0;
            bytePointer = 0;
            
            for (int i = 0; i < height; i++) {
                DecodeNextScanline(buffer, lineOffset, startX);
                lineOffset += scanlineStride;
            }
        }
        
        public void DecodeNextScanline(byte[] buffer,
        int lineOffset, int bitOffset) {
            int bits = 0, code = 0, isT = 0;
            int current, entry, twoBits;
            bool isWhite = true;
            
            // Initialize starting of the changing elements array
            changingElemSize = 0;
            
            // While scanline not complete
            while (bitOffset < w) {
                while (isWhite) {
                    // White run
                    current = NextNBits(10);
                    entry = white[current];
                    
                    // Get the 3 fields from the entry
                    isT = entry & 0x0001;
                    bits = (entry >> 1) & 0x0f;
                    
                    if (bits == 12) {          // Additional Make up code
                        // Get the next 2 bits
                        twoBits = NextLesserThan8Bits(2);
                        // Consolidate the 2 new bits and last 2 bits into 4 bits
                        current = ((current << 2) & 0x000c) | twoBits;
                        entry = additionalMakeup[current];
                        bits = (entry >> 1) & 0x07;     // 3 bits 0000 0111
                        code  = (entry >> 4) & 0x0fff;  // 12 bits
                        bitOffset += code; // Skip white run
                        
                        UpdatePointer(4 - bits);
                    } else if (bits == 0) {     // ERROR
                        throw new Exception("Invalid code encountered.");
                    } else if (bits == 15) {    // EOL
                        throw new Exception("EOL code word encountered in White run.");
                    } else {
                        // 11 bits - 0000 0111 1111 1111 = 0x07ff
                        code = (entry >> 5) & 0x07ff;
                        bitOffset += code;
                        
                        UpdatePointer(10 - bits);
                        if (isT == 0) {
                            isWhite = false;
                            currChangingElems[changingElemSize++] = bitOffset;
                        }
                    }
                }
                
                // Check whether this run completed one width, if so
                // advance to next byte boundary for compression = 2.
                if (bitOffset == w) {
                    if (compression == 2) {
                        AdvancePointer();
                    }
                    break;
                }
                
                while (isWhite == false) {
                    // Black run
                    current = NextLesserThan8Bits(4);
                    entry = initBlack[current];
                    
                    // Get the 3 fields from the entry
                    isT = entry & 0x0001;
                    bits = (entry >> 1) & 0x000f;
                    code = (entry >> 5) & 0x07ff;
                    
                    if (code == 100) {
                        current = NextNBits(9);
                        entry = black[current];
                        
                        // Get the 3 fields from the entry
                        isT = entry & 0x0001;
                        bits = (entry >> 1) & 0x000f;
                        code = (entry >> 5) & 0x07ff;
                        
                        if (bits == 12) {
                            // Additional makeup codes
                            UpdatePointer(5);
                            current = NextLesserThan8Bits(4);
                            entry = additionalMakeup[current];
                            bits = (entry >> 1) & 0x07;     // 3 bits 0000 0111
                            code  = (entry >> 4) & 0x0fff;  // 12 bits
                            
                            SetToBlack(buffer, lineOffset, bitOffset, code);
                            bitOffset += code;
                            
                            UpdatePointer(4 - bits);
                        } else if (bits == 15) {
                            // EOL code
                            throw new Exception("EOL code word encountered in Black run.");
                        } else {
                            SetToBlack(buffer, lineOffset, bitOffset, code);
                            bitOffset += code;
                            
                            UpdatePointer(9 - bits);
                            if (isT == 0) {
                                isWhite = true;
                                currChangingElems[changingElemSize++] = bitOffset;
                            }
                        }
                    } else if (code == 200) {
                        // Is a Terminating code
                        current = NextLesserThan8Bits(2);
                        entry = twoBitBlack[current];
                        code = (entry >> 5) & 0x07ff;
                        bits = (entry >> 1) & 0x0f;
                        
                        SetToBlack(buffer, lineOffset, bitOffset, code);
                        bitOffset += code;
                        
                        UpdatePointer(2 - bits);
                        isWhite = true;
                        currChangingElems[changingElemSize++] = bitOffset;
                    } else {
                        // Is a Terminating code
                        SetToBlack(buffer, lineOffset, bitOffset, code);
                        bitOffset += code;
                        
                        UpdatePointer(4 - bits);
                        isWhite = true;
                        currChangingElems[changingElemSize++] = bitOffset;
                    }
                }
                
                // Check whether this run completed one width
                if (bitOffset == w) {
                    if (compression == 2) {
                        AdvancePointer();
                    }
                    break;
                }
            }
            
            currChangingElems[changingElemSize++] = bitOffset;
        }
        
        // Two-dimensional decoding methods
        
        public void Decode2D(byte[] buffer,
        byte[] compData,
        int startX,
        int height,
        long tiffT4Options) {
            this.data = compData;
            compression = 3;
            
            bitPointer = 0;
            bytePointer = 0;
            
            int scanlineStride = (w + 7)/8;
            
            int a0, a1, b1, b2;
            int[] b = new int[2];
            int entry, code, bits;
            bool isWhite;
            int currIndex = 0;
            int[] temp;
            
            // fillBits - dealt with this in readEOL
            // 1D/2D encoding - dealt with this in readEOL
            
            // uncompressedMode - haven't dealt with this yet.
            
            
            oneD = (int)(tiffT4Options & 0x01);
            uncompressedMode = (int)((tiffT4Options & 0x02) >> 1);
            fillBits = (int)((tiffT4Options & 0x04) >> 2);
            
            // The data must start with an EOL code
            if (ReadEOL(true) != 1) {
                throw new Exception("First scanline must be 1D encoded.");
            }
            
            int lineOffset = 0;
            int bitOffset;
            
            // Then the 1D encoded scanline data will occur, changing elements
            // array gets set.
            DecodeNextScanline(buffer, lineOffset, startX);
            lineOffset += scanlineStride;
            
            for (int lines = 1; lines < height; lines++) {
                
                // Every line must begin with an EOL followed by a bit which
                // indicates whether the following scanline is 1D or 2D encoded.
                if (ReadEOL(false) == 0) {
                    // 2D encoded scanline follows
                    
                    // Initialize previous scanlines changing elements, and
                    // initialize current scanline's changing elements array
                    temp = prevChangingElems;
                    prevChangingElems = currChangingElems;
                    currChangingElems = temp;
                    currIndex = 0;
                    
                    // a0 has to be set just before the start of this scanline.
                    a0 = -1;
                    isWhite = true;
                    bitOffset = startX;
                    
                    lastChangingElement = 0;
                    
                    while (bitOffset < w) {
                        // Get the next changing element
                        GetNextChangingElement(a0, isWhite, b);
                        
                        b1 = b[0];
                        b2 = b[1];
                        
                        // Get the next seven bits
                        entry = NextLesserThan8Bits(7);
                        
                        // Run these through the 2DCodes table
                        entry = (int)(twoDCodes[entry] & 0xff);
                        
                        // Get the code and the number of bits used up
                        code = (entry & 0x78) >> 3;
                        bits = entry & 0x07;
                        
                        if (code == 0) {
                            if (!isWhite) {
                                SetToBlack(buffer, lineOffset, bitOffset,
                                b2 - bitOffset);
                            }
                            bitOffset = a0 = b2;
                            
                            // Set pointer to consume the correct number of bits.
                            UpdatePointer(7 - bits);
                        } else if (code == 1) {
                            // Horizontal
                            UpdatePointer(7 - bits);
                            
                            // identify the next 2 codes.
                            int number;
                            if (isWhite) {
                                number = DecodeWhiteCodeWord();
                                bitOffset += number;
                                currChangingElems[currIndex++] = bitOffset;
                                
                                number = DecodeBlackCodeWord();
                                SetToBlack(buffer, lineOffset, bitOffset, number);
                                bitOffset += number;
                                currChangingElems[currIndex++] = bitOffset;
                            } else {
                                number = DecodeBlackCodeWord();
                                SetToBlack(buffer, lineOffset, bitOffset, number);
                                bitOffset += number;
                                currChangingElems[currIndex++] = bitOffset;
                                
                                number = DecodeWhiteCodeWord();
                                bitOffset += number;
                                currChangingElems[currIndex++] = bitOffset;
                            }
                            
                            a0 = bitOffset;
                        } else if (code <= 8) {
                            // Vertical
                            a1 = b1 + (code - 5);
                            
                            currChangingElems[currIndex++] = a1;
                            
                            // We write the current color till a1 - 1 pos,
                            // since a1 is where the next color starts
                            if (!isWhite) {
                                SetToBlack(buffer, lineOffset, bitOffset,
                                a1 - bitOffset);
                            }
                            bitOffset = a0 = a1;
                            isWhite = !isWhite;
                            
                            UpdatePointer(7 - bits);
                        } else {
                            throw new Exception("Invalid code encountered while decoding 2D group 3 compressed data.");
                        }
                    }
                    
                    // Add the changing element beyond the current scanline for the
                    // other color too
                    currChangingElems[currIndex++] = bitOffset;
                    changingElemSize = currIndex;
                } else {
                    // 1D encoded scanline follows
                    DecodeNextScanline(buffer, lineOffset, startX);
                }
                
                lineOffset += scanlineStride;
            }
        }
        
        public void DecodeT6(byte[] buffer,
        byte[] compData,
        int startX,
        int height,
        long tiffT6Options) {
            this.data = compData;
            compression = 4;
            
            bitPointer = 0;
            bytePointer = 0;
            
            int scanlineStride = (w + 7)/8;
            
            int a0, a1, b1, b2;
            int entry, code, bits;
            bool isWhite;
            int currIndex;
            int[] temp;
            
            // Return values from getNextChangingElement
            int[] b = new int[2];
            
            // uncompressedMode - have written some code for this, but this
            // has not been tested due to lack of test images using this optional
            
            uncompressedMode = (int)((tiffT6Options & 0x02) >> 1);
            
            // Local cached reference
            int[] cce = currChangingElems;
            
            // Assume invisible preceding row of all white pixels and insert
            // both black and white changing elements beyond the end of this
            // imaginary scanline.
            changingElemSize = 0;
            cce[changingElemSize++] = w;
            cce[changingElemSize++] = w;
            
            int lineOffset = 0;
            int bitOffset;
            
            for (int lines = 0; lines < height; lines++) {
                // a0 has to be set just before the start of the scanline.
                a0 = -1;
                isWhite = true;
                
                // Assign the changing elements of the previous scanline to
                // prevChangingElems and start putting this new scanline's
                // changing elements into the currChangingElems.
                temp = prevChangingElems;
                prevChangingElems = currChangingElems;
                cce = currChangingElems = temp;
                currIndex = 0;
                
                // Start decoding the scanline at startX in the raster
                bitOffset = startX;
                
                // Reset search start position for getNextChangingElement
                lastChangingElement = 0;
                
                // Till one whole scanline is decoded
                while (bitOffset < w) {
                    // Get the next changing element
                    GetNextChangingElement(a0, isWhite, b);
                    b1 = b[0];
                    b2 = b[1];
                    
                    // Get the next seven bits
                    entry = NextLesserThan8Bits(7);
                    // Run these through the 2DCodes table
                    entry = (int)(twoDCodes[entry] & 0xff);
                    
                    // Get the code and the number of bits used up
                    code = (entry & 0x78) >> 3;
                    bits = entry & 0x07;
                    
                    if (code == 0) { // Pass
                        // We always assume WhiteIsZero format for fax.
                        if (!isWhite) {
                            SetToBlack(buffer, lineOffset, bitOffset,
                            b2 - bitOffset);
                        }
                        bitOffset = a0 = b2;
                        
                        // Set pointer to only consume the correct number of bits.
                        UpdatePointer(7 - bits);
                    } else if (code == 1) { // Horizontal
                        // Set pointer to only consume the correct number of bits.
                        UpdatePointer(7 - bits);
                        
                        // identify the next 2 alternating color codes.
                        int number;
                        if (isWhite) {
                            // Following are white and black runs
                            number = DecodeWhiteCodeWord();
                            bitOffset += number;
                            cce[currIndex++] = bitOffset;
                            
                            number = DecodeBlackCodeWord();
                            SetToBlack(buffer, lineOffset, bitOffset, number);
                            bitOffset += number;
                            cce[currIndex++] = bitOffset;
                        } else {
                            // First a black run and then a white run follows
                            number = DecodeBlackCodeWord();
                            SetToBlack(buffer, lineOffset, bitOffset, number);
                            bitOffset += number;
                            cce[currIndex++] = bitOffset;
                            
                            number = DecodeWhiteCodeWord();
                            bitOffset += number;
                            cce[currIndex++] = bitOffset;
                        }
                        
                        a0 = bitOffset;
                    } else if (code <= 8) { // Vertical
                        a1 = b1 + (code - 5);
                        cce[currIndex++] = a1;
                        
                        // We write the current color till a1 - 1 pos,
                        // since a1 is where the next color starts
                        if (!isWhite) {
                            SetToBlack(buffer, lineOffset, bitOffset,
                            a1 - bitOffset);
                        }
                        bitOffset = a0 = a1;
                        isWhite = !isWhite;
                        
                        UpdatePointer(7 - bits);
                    } else if (code == 11) {
                        if (NextLesserThan8Bits(3) != 7) {
                            throw new Exception("Invalid code encountered while decoding 2D group 4 compressed data.");
                        }
                        
                        int zeros = 0;
                        bool exit = false;
                        
                        while (!exit) {
                            while (NextLesserThan8Bits(1) != 1) {
                                zeros++;
                            }
                            
                            if (zeros > 5) {
                                // Exit code
                                
                                // Zeros before exit code
                                zeros = zeros - 6;
                                
                                if (!isWhite && (zeros > 0)) {
                                    cce[currIndex++] = bitOffset;
                                }
                                
                                // Zeros before the exit code
                                bitOffset += zeros;
                                if (zeros > 0) {
                                    // Some zeros have been written
                                    isWhite = true;
                                }
                                
                                // Read in the bit which specifies the color of
                                // the following run
                                if (NextLesserThan8Bits(1) == 0) {
                                    if (!isWhite) {
                                        cce[currIndex++] = bitOffset;
                                    }
                                    isWhite = true;
                                } else {
                                    if (isWhite) {
                                        cce[currIndex++] = bitOffset;
                                    }
                                    isWhite = false;
                                }
                                
                                exit = true;
                            }
                            
                            if (zeros == 5) {
                                if (!isWhite) {
                                    cce[currIndex++] = bitOffset;
                                }
                                bitOffset += zeros;
                                
                                // Last thing written was white
                                isWhite = true;
                            } else {
                                bitOffset += zeros;
                                
                                cce[currIndex++] = bitOffset;
                                SetToBlack(buffer, lineOffset, bitOffset, 1);
                                ++bitOffset;
                                
                                // Last thing written was black
                                isWhite = false;
                            }
                            
                        }
                    } else {
                        //micah_tessler@yahoo.com
                        //Microsoft TIFF renderers seem to treat unknown codes as line-breaks
                        //That is, they give up on the current line and move on to the next one
                        //set bitOffset to w to move on to the next scan line.
                        bitOffset = w;
                        UpdatePointer(7 - bits);
                    }
                }
                
                // Add the changing element beyond the current scanline for the
                // other color too
                //make sure that the index does not exceed the bounds of the array
                if (currIndex < cce.Length) 
                cce[currIndex++] = bitOffset;
                
                // Number of changing elements in this scanline.
                changingElemSize = currIndex;
                
                lineOffset += scanlineStride;
            }
        }
        
        private void SetToBlack(byte[] buffer,
        int lineOffset, int bitOffset,
        int numBits) {
            int bitNum = 8*lineOffset + bitOffset;
            int lastBit = bitNum + numBits;
            
            int byteNum = bitNum >> 3;
            
            // Handle bits in first byte
            int shift = bitNum & 0x7;
            if (shift > 0) {
                int maskVal = 1 << (7 - shift);
                byte val = buffer[byteNum];
                while (maskVal > 0 && bitNum < lastBit) {
                    val |= (byte)maskVal;
                    maskVal >>= 1;
                    ++bitNum;
                }
                buffer[byteNum] = val;
            }
            
            // Fill in 8 bits at a time
            byteNum = bitNum >> 3;
            while (bitNum < lastBit - 7) {
                buffer[byteNum++] = (byte)255;
                bitNum += 8;
            }
            
            // Fill in remaining bits
            while (bitNum < lastBit) {
                byteNum = bitNum >> 3;
                buffer[byteNum] |= (byte)(1 << (7 - (bitNum & 0x7)));
                ++bitNum;
            }
        }
        
        // Returns run length
        private int DecodeWhiteCodeWord() {
            int current, entry, bits, isT, twoBits, code = -1;
            int runLength = 0;
            bool isWhite = true;
            
            while (isWhite) {
                current = NextNBits(10);
                entry = white[current];
                
                // Get the 3 fields from the entry
                isT = entry & 0x0001;
                bits = (entry >> 1) & 0x0f;
                
                if (bits == 12) {           // Additional Make up code
                    // Get the next 2 bits
                    twoBits = NextLesserThan8Bits(2);
                    // Consolidate the 2 new bits and last 2 bits into 4 bits
                    current = ((current << 2) & 0x000c) | twoBits;
                    entry = additionalMakeup[current];
                    bits = (entry >> 1) & 0x07;     // 3 bits 0000 0111
                    code = (entry >> 4) & 0x0fff;   // 12 bits
                    runLength += code;
                    UpdatePointer(4 - bits);
                } else if (bits == 0) {     // ERROR
                    throw new Exception("Invalid code encountered.");
                } else if (bits == 15) {    // EOL
                    throw new Exception("EOL code word encountered in White run.");
                } else {
                    // 11 bits - 0000 0111 1111 1111 = 0x07ff
                    code = (entry >> 5) & 0x07ff;
                    runLength += code;
                    UpdatePointer(10 - bits);
                    if (isT == 0) {
                        isWhite = false;
                    }
                }
            }
            
            return runLength;
        }
        
        // Returns run length
        private int DecodeBlackCodeWord() {
            int current, entry, bits, isT, code = -1;
            int runLength = 0;
            bool isWhite = false;
            
            while (!isWhite) {
                current = NextLesserThan8Bits(4);
                entry = initBlack[current];
                
                // Get the 3 fields from the entry
                isT = entry & 0x0001;
                bits = (entry >> 1) & 0x000f;
                code = (entry >> 5) & 0x07ff;
                
                if (code == 100) {
                    current = NextNBits(9);
                    entry = black[current];
                    
                    // Get the 3 fields from the entry
                    isT = entry & 0x0001;
                    bits = (entry >> 1) & 0x000f;
                    code = (entry >> 5) & 0x07ff;
                    
                    if (bits == 12) {
                        // Additional makeup codes
                        UpdatePointer(5);
                        current = NextLesserThan8Bits(4);
                        entry = additionalMakeup[current];
                        bits = (entry >> 1) & 0x07;     // 3 bits 0000 0111
                        code  = (entry >> 4) & 0x0fff;  // 12 bits
                        runLength += code;
                        
                        UpdatePointer(4 - bits);
                    } else if (bits == 15) {
                        // EOL code
                        throw new Exception("EOL code word encountered in Black run.");
                    } else {
                        runLength += code;
                        UpdatePointer(9 - bits);
                        if (isT == 0) {
                            isWhite = true;
                        }
                    }
                } else if (code == 200) {
                    // Is a Terminating code
                    current = NextLesserThan8Bits(2);
                    entry = twoBitBlack[current];
                    code = (entry >> 5) & 0x07ff;
                    runLength += code;
                    bits = (entry >> 1) & 0x0f;
                    UpdatePointer(2 - bits);
                    isWhite = true;
                } else {
                    // Is a Terminating code
                    runLength += code;
                    UpdatePointer(4 - bits);
                    isWhite = true;
                }
            }
            
            return runLength;
        }
        
        private int ReadEOL(bool isFirstEOL) {
            if (fillBits == 0) {
                int next12Bits = NextNBits(12);
                if (isFirstEOL && next12Bits == 0) {
                    
                    // Might have the case of EOL padding being used even
                    // though it was not flagged in the T4Options field.
                    // This was observed to be the case in TIFFs produced
                    // by a well known vendor who shall remain nameless.
                    
                    if (NextNBits(4) == 1) {
                        
                        // EOL must be padded: reset the fillBits flag.
                        
                        fillBits = 1;
                        return 1;
                    }
                }
                if (next12Bits != 1) {
                    throw new Exception("Scanline must begin with EOL code word.");
                }
            } else if (fillBits == 1) {
                
                // First EOL code word xxxx 0000 0000 0001 will occur
                // As many fill bits will be present as required to make
                // the EOL code of 12 bits end on a byte boundary.
                
                int bitsLeft = 8 - bitPointer;
                
                if (NextNBits(bitsLeft) != 0) {
                    throw new Exception("All fill bits preceding EOL code must be 0.");
                }
                
                // If the number of bitsLeft is less than 8, then to have a 12
                // bit EOL sequence, two more bytes are certainly going to be
                // required. The first of them has to be all zeros, so ensure
                // that.
                if (bitsLeft < 4) {
                    if (NextNBits(8) != 0) {
                        throw new Exception("All fill bits preceding EOL code must be 0.");
                    }
                }
                
                // There might be a random number of fill bytes with 0s, so
                // loop till the EOL of 0000 0001 is found, as long as all
                // the bytes preceding it are 0's.
                int n;
                while ((n = NextNBits(8)) != 1) {
                    
                    // If not all zeros
                    if (n != 0) {
                        throw new Exception("All fill bits preceding EOL code must be 0.");
                    }
                }
            }
            
            // If one dimensional encoding mode, then always return 1
            if (oneD == 0) {
                return 1;
            } else {
                // Otherwise for 2D encoding mode,
                // The next one bit signifies 1D/2D encoding of next line.
                return NextLesserThan8Bits(1);
            }
        }
        
        private void GetNextChangingElement(int a0, bool isWhite, int[] ret) {
            // Local copies of instance variables
            int[] pce = this.prevChangingElems;
            int ces = this.changingElemSize;
            
            // If the previous match was at an odd element, we still
            // have to search the preceeding element.
            // int start = lastChangingElement & ~0x1;
            int start = lastChangingElement > 0 ? lastChangingElement - 1 : 0;
            if (isWhite) {
                start &= ~0x1; // Search even numbered elements
            } else {
                start |= 0x1; // Search odd numbered elements
            }
            
            int i = start;
            for (; i < ces; i += 2) {
                int temp = pce[i];
                if (temp > a0) {
                    lastChangingElement = i;
                    ret[0] = temp;
                    break;
                }
            }
            
            if (i + 1 < ces) {
                ret[1] = pce[i + 1];
            }
        }
        
        private int NextNBits(int bitsToGet) {
            byte b, next, next2next;
            int l = data.Length - 1;
            int bp = this.bytePointer;
            
            if (fillOrder == 1) {
                b = data[bp];
                
                if (bp == l) {
                    next = 0x00;
                    next2next = 0x00;
                } else if ((bp + 1) == l) {
                    next = data[bp + 1];
                    next2next = 0x00;
                } else {
                    next = data[bp + 1];
                    next2next = data[bp + 2];
                }
            } else if (fillOrder == 2) {
                b = flipTable[data[bp] & 0xff];
                
                if (bp == l) {
                    next = 0x00;
                    next2next = 0x00;
                } else if ((bp + 1) == l) {
                    next = flipTable[data[bp + 1] & 0xff];
                    next2next = 0x00;
                } else {
                    next = flipTable[data[bp + 1] & 0xff];
                    next2next = flipTable[data[bp + 2] & 0xff];
                }
            } else {
                throw new Exception("TIFF_FILL_ORDER tag must be either 1 or 2.");
            }
            
            int bitsLeft = 8 - bitPointer;
            int bitsFromNextByte = bitsToGet - bitsLeft;
            int bitsFromNext2NextByte = 0;
            if (bitsFromNextByte > 8) {
                bitsFromNext2NextByte = bitsFromNextByte - 8;
                bitsFromNextByte = 8;
            }
            
            bytePointer++;
            
            int i1 = (b & table1[bitsLeft]) << (bitsToGet - bitsLeft);
            int i2 = (next & table2[bitsFromNextByte]) >> (8 - bitsFromNextByte);
            
            int i3 = 0;
            if (bitsFromNext2NextByte != 0) {
                i2 <<= bitsFromNext2NextByte;
                i3 = (next2next & table2[bitsFromNext2NextByte]) >>
                (8 - bitsFromNext2NextByte);
                i2 |= i3;
                bytePointer++;
                bitPointer = bitsFromNext2NextByte;
            } else {
                if (bitsFromNextByte == 8) {
                    bitPointer = 0;
                    bytePointer++;
                } else {
                    bitPointer = bitsFromNextByte;
                }
            }
            
            int i = i1 | i2;
            return i;
        }
        
        private int NextLesserThan8Bits(int bitsToGet) {
            byte b, next;
            int l = data.Length - 1;
            int bp = this.bytePointer;
            
            if (fillOrder == 1) {
                b = data[bp];
                if (bp == l) {
                    next = 0x00;
                } else {
                    next = data[bp + 1];
                }
            } else if (fillOrder == 2) {
                b = flipTable[data[bp] & 0xff];
                if (bp == l) {
                    next = 0x00;
                } else {
                    next = flipTable[data[bp + 1] & 0xff];
                }
            } else {
                throw new Exception("TIFF_FILL_ORDER tag must be either 1 or 2.");
            }
            
            int bitsLeft = 8 - bitPointer;
            int bitsFromNextByte = bitsToGet - bitsLeft;
            
            int shift = bitsLeft - bitsToGet;
            int i1, i2;
            if (shift >= 0) {
                i1 = (b & table1[bitsLeft]) >> shift;
                bitPointer += bitsToGet;
                if (bitPointer == 8) {
                    bitPointer = 0;
                    bytePointer++;
                }
            } else {
                i1 = (b & table1[bitsLeft]) << (-shift);
                i2 = (next & table2[bitsFromNextByte]) >> (8 - bitsFromNextByte);
                
                i1 |= i2;
                bytePointer++;
                bitPointer = bitsFromNextByte;
            }
            
            return i1;
        }
        
        // Move pointer backwards by given amount of bits
        private void UpdatePointer(int bitsToMoveBack) {
            int i = bitPointer - bitsToMoveBack;
            
            if (i < 0) {
                bytePointer--;
                bitPointer = 8 + i;
            } else {
                bitPointer = i;
            }
        }
        
        // Move to the next byte boundary
        private bool AdvancePointer() {
            if (bitPointer != 0) {
                bytePointer++;
                bitPointer = 0;
            }
            
            return true;
        }
    }
}
