/*
 * $RCSfile: StdEntropyDecoder.java,v $
 * $Revision: 1.1 $
 * $Date: 2005/02/11 05:02:07 $
 * $State: Exp $
 *
 * Class:                   StdEntropyDecoder
 *
 * Description:             Entropy decoding engine of stripes in code-blocks
 *
 *
 *
 * COPYRIGHT:
 *
 * This software module was originally developed by Raphaël Grosbois and
 * Diego Santa Cruz (Swiss Federal Institute of Technology-EPFL); Joel
 * Askelöf (Ericsson Radio Systems AB); and Bertrand Berthelot, David
 * Bouchard, Félix Henry, Gerard Mozelle and Patrice Onno (Canon Research
 * Centre France S.A) in the course of development of the JPEG2000
 * standard as specified by ISO/IEC 15444 (JPEG 2000 Standard). This
 * software module is an implementation of a part of the JPEG 2000
 * Standard. Swiss Federal Institute of Technology-EPFL, Ericsson Radio
 * Systems AB and Canon Research Centre France S.A (collectively JJ2000
 * Partners) agree not to assert against ISO/IEC and users of the JPEG
 * 2000 Standard (Users) any of their rights under the copyright, not
 * including other intellectual property rights, for this software module
 * with respect to the usage by ISO/IEC and Users of this software module
 * or modifications thereof for use in hardware or software products
 * claiming conformance to the JPEG 2000 Standard. Those intending to use
 * this software module in hardware or software products are advised that
 * their use may infringe existing patents. The original developers of
 * this software module, JJ2000 Partners and ISO/IEC assume no liability
 * for use of this software module or modifications thereof. No license
 * or right to this software module is granted for non JPEG 2000 Standard
 * conforming products. JJ2000 Partners have full right to use this
 * software module for his/her own purpose, assign or donate this
 * software module to any third party and to inhibit third parties from
 * using this software module for non JPEG 2000 Standard conforming
 * products. This copyright notice must be included in all copies or
 * derivative works of this software module.
 *
 * Copyright (c) 1999/2000 JJ2000 Partners.
 * */
package jj2000.j2k.entropy.decoder;
import java.awt.Point;

import jj2000.j2k.wavelet.synthesis.*;
import jj2000.j2k.wavelet.*;
import jj2000.j2k.entropy.*;
import jj2000.j2k.decoder.*;
import jj2000.j2k.image.*;
import jj2000.j2k.util.*;
import jj2000.j2k.io.*;
import jj2000.j2k.*;

/**
 * This class implements the JPEG 2000 entropy decoder, which codes stripes in
 * code-blocks. This entropy decoding engine decodes one code-block at a time.
 *
 * The code-block are rectangular, with dimensions which must be powers of
 * 2. Each dimension has to be no smaller than 4 and no larger than 256. The
 * product of the two dimensions (i.e. area of the code-block) may not exceed
 * 4096.
 *
 * Context 0 of the MQ-coder is used as the uniform one (uniform, non-adaptive
 * probability distribution). Context 1 is used for RLC coding. Contexts 2-10
 * are used for zero-coding (ZC), contexts 11-15 are used for sign-coding (SC)
 * and contexts 16-18 are used for magnitude-refinement (MR).
 *
 * <P>This implementation also provides some timing features. They can be
 * enabled by setting the 'DO_TIMING' constant of this class to true and
 * recompiling. The timing uses the 'System.currentTimeMillis()' Java API
 * call, which returns wall clock time, not the actual CPU time used. The
 * timing results will be printed on the message output. Since the times
 * reported are wall clock times and not CPU usage times they can not be added
 * to find the total used time (i.e. some time might be counted in several
 * places). When timing is disabled ('DO_TIMING' is false) there is no penalty
 * if the compiler performs some basic optimizations. Even if not the penalty
 * should be negligeable.
 * */
public class StdEntropyDecoder extends EntropyDecoder
    implements StdEntropyCoderOptions {

    /** Whether to collect timing information or not: false. Used as a compile
     * time directive. */
    private final static boolean DO_TIMING = false;

    /** The cumulative wall time for the entropy coding engine, for each
     * component. */
    private long time[];

    /** The bit based input for arithmetic coding bypass (i.e. raw) coding */
    private ByteToBitInput bin;

    /** The MQ decoder to use. It has in as the underlying source of coded
     * data. */
    private MQDecoder mq;

    /** The decoder spec */
    private DecoderSpecs decSpec;

    /** The options that are turned on, as flag bits. The options are
     * 'OPT_TERM_PASS', 'OPT_RESET_MQ', 'OPT_VERT_STR_CAUSAL', 'OPT_BYPASS' and
     * 'OPT_SEG_SYMBOLS' as defined in the StdEntropyCoderOptions interface
     *
     * @see StdEntropyCoderOptions
     **/
    private int options;

    /** Flag to indicate if we should try to detect errors or just ignore any
     * error resilient information */
    private final boolean doer;

    /** Flag to indicate if we should be verbose about bit stream errors
        detected with the error resilience options */
    private final boolean verber;

    /** Number of bits used for the Zero Coding lookup table */
    private static final int ZC_LUT_BITS = 8;

    /** Zero Coding context lookup tables for the LH global orientation */
    private static final int ZC_LUT_LH[] = new int[1<<ZC_LUT_BITS];

    /** Zero Coding context lookup tables for the HL global orientation */
    private static final int ZC_LUT_HL[] = new int[1<<ZC_LUT_BITS];

    /** Zero Coding context lookup tables for the HH global orientation */
    private static final int ZC_LUT_HH[] = new int[1<<ZC_LUT_BITS];

    /** Number of bits used for the Sign Coding lookup table */
    private static final int SC_LUT_BITS = 9;

    /** Sign Coding context lookup table. The index into the table is a 9 bit
     * index, which correspond the the value in the 'state' array shifted by
     * 'SC_SHIFT'. Bits 8-5 are the signs of the horizontal-left,
     * horizontal-right, vertical-up and vertical-down neighbors,
     * respectively. Bit 4 is not used (0 or 1 makes no difference). Bits 3-0
     * are the significance of the horizontal-left, horizontal-right,
     * vertical-up and vertical-down neighbors, respectively. The least 4 bits
     * of the value in the lookup table define the context number and the sign
     * bit defines the "sign predictor". */
    private static final int SC_LUT[] = new int[1<<SC_LUT_BITS];

    /** The mask to obtain the context index from the 'SC_LUT' */
    private static final int SC_LUT_MASK = (1<<4)-1;

    /** The shift to obtain the sign predictor from the 'SC_LUT'. It must be
     * an unsigned shift. */
    private static final int SC_SPRED_SHIFT = 31;

    /** The sign bit for int data */
    private static final int INT_SIGN_BIT = 1<<31;

    /** The number of bits used for the Magnitude Refinement lookup table */
    private static final int MR_LUT_BITS = 9;

    /** Magnitude Refinement context lookup table */
    private static final int MR_LUT[] = new int[1<<MR_LUT_BITS];

    /** The number of contexts used */
    private static final int NUM_CTXTS = 19;

    /** The RLC context */
    private static final int RLC_CTXT = 1;

    /** The UNIFORM context (with a uniform probability distribution which
     * does not adapt) */
    private static final int UNIF_CTXT = 0;

    /** The initial states for the MQ coder */
    private static final int MQ_INIT[] = {46, 3, 4, 0, 0, 0, 0, 0, 0, 0, 0,
                                          0, 0, 0, 0, 0, 0, 0, 0};

    /** The 4 symbol segmentation marker (decimal 10, which is binary sequence
        1010) */
    private static final int SEG_SYMBOL = 10;

    /**
     * The state array for entropy coding. Each element of the state array
     * stores the state of two coefficients. The lower 16 bits store the state
     * of a coefficient in row 'i' and column 'j', while the upper 16 bits
     * store the state of a coefficient in row 'i+1' and column 'j'. The 'i'
     * row is either the first or the third row of a stripe. This packing of
     * the states into 32 bit words allows a faster scan of all coefficients
     * on each coding pass and diminished the amount of data transferred. The
     * size of the state array is increased by 1 on each side (top, bottom,
     * left, right) to handle boundary conditions without any special logic.
     *
     * <P>The state of a coefficient is stored in the following way in the
     * lower 16 bits, where bit 0 is the least significant bit. Bit 15 is the
     * significance of a coefficient (0 if non-significant, 1 otherwise). Bit
     * 14 is the visited state (i.e. if a coefficient has been coded in the
     * significance propagation pass of the current bit-plane). Bit 13 is the
     * "non zero-context" state (i.e. if one of the eight immediate neighbors
     * is significant it is 1, otherwise is 0). Bits 12 to 9 store the sign of
     * the already significant left, right, up and down neighbors (1 for
     * negative, 0 for positive or not yet significant). Bit 8 indicates if
     * the magnitude refinement has already been applied to the
     * coefficient. Bits 7 to 4 store the significance of the left, right, up
     * and down neighbors (1 for significant, 0 for non significant). Bits 3
     * to 0 store the significance of the diagonal coefficients (up-left,
     * up-right, down-left and down-right; 1 for significant, 0 for non
     * significant).
     *
     * <P>The upper 16 bits the state is stored as in the lower 16 bits,
     * but with the bits shifted up by 16.
     *
     * <P>The lower 16 bits are referred to as "row 1" ("R1") while the upper
     * 16 bits are referred to as "row 2" ("R2").
     * */
    private final int state[];

    /** The separation between the upper and lower bits in the state array: 16
     * */
    private static final int STATE_SEP = 16;

    /** The flag bit for the significance in the state array, for row 1. */
    private static final int STATE_SIG_R1 = 1<<15;

    /** The flag bit for the "visited" bit in the state array, for row 1. */
    private static final int STATE_VISITED_R1 = 1<<14;

    /** The flag bit for the "not zero context" bit in the state array, for
     * row 1. This bit is always the OR of bits STATE_H_L_R1, STATE_H_R_R1,
     * STATE_V_U_R1, STATE_V_D_R1, STATE_D_UL_R1, STATE_D_UR_R1, STATE_D_DL_R1
     * and STATE_D_DR_R1. */
    private static final int STATE_NZ_CTXT_R1 = 1<<13;

    /** The flag bit for the horizontal-left sign in the state array, for row
     * 1. This bit can only be set if the STATE_H_L_R1 is also set. */
    private static final int STATE_H_L_SIGN_R1 = 1<<12;

    /** The flag bit for the horizontal-right sign in the state array, for
     * row 1. This bit can only be set if the STATE_H_R_R1 is also set. */
    private static final int STATE_H_R_SIGN_R1 = 1<<11;

    /** The flag bit for the vertical-up sign in the state array, for row
     * 1. This bit can only be set if the STATE_V_U_R1 is also set. */
    private static final int STATE_V_U_SIGN_R1 = 1<<10;

    /** The flag bit for the vertical-down sign in the state array, for row
     * 1. This bit can only be set if the STATE_V_D_R1 is also set. */
    private static final int STATE_V_D_SIGN_R1 = 1<<9;

    /** The flag bit for the previous MR primitive applied in the state array,
        for row 1. */
    private static final int STATE_PREV_MR_R1 = 1<<8;

    /** The flag bit for the horizontal-left significance in the state array,
        for row 1. */
    private static final int STATE_H_L_R1 = 1<<7;

    /** The flag bit for the horizontal-right significance in the state array,
        for row 1. */
    private static final int STATE_H_R_R1 = 1<<6;

    /** The flag bit for the vertical-up significance in the state array, for
     row 1.  */
    private static final int STATE_V_U_R1 = 1<<5;

    /** The flag bit for the vertical-down significance in the state array,
     for row 1.  */
    private static final int STATE_V_D_R1 = 1<<4;

    /** The flag bit for the diagonal up-left significance in the state array,
        for row 1. */
    private static final int STATE_D_UL_R1 = 1<<3;

    /** The flag bit for the diagonal up-right significance in the state
        array, for row 1.*/
    private static final int STATE_D_UR_R1 = 1<<2;

    /** The flag bit for the diagonal down-left significance in the state
        array, for row 1. */
    private static final int STATE_D_DL_R1 = 1<<1;

    /** The flag bit for the diagonal down-right significance in the state
        array , for row 1.*/
    private static final int STATE_D_DR_R1 = 1;

    /** The flag bit for the significance in the state array, for row 2. */
    private static final int STATE_SIG_R2 = STATE_SIG_R1<<STATE_SEP;

    /** The flag bit for the "visited" bit in the state array, for row 2. */
    private static final int STATE_VISITED_R2 = STATE_VISITED_R1<<STATE_SEP;

    /** The flag bit for the "not zero context" bit in the state array, for
     * row 2. This bit is always the OR of bits STATE_H_L_R2, STATE_H_R_R2,
     * STATE_V_U_R2, STATE_V_D_R2, STATE_D_UL_R2, STATE_D_UR_R2, STATE_D_DL_R2
     * and STATE_D_DR_R2. */
    private static final int STATE_NZ_CTXT_R2 = STATE_NZ_CTXT_R1<<STATE_SEP;

   /** The flag bit for the horizontal-left sign in the state array, for row
     * 2. This bit can only be set if the STATE_H_L_R2 is also set. */
    private static final int STATE_H_L_SIGN_R2 = STATE_H_L_SIGN_R1<<STATE_SEP;

    /** The flag bit for the horizontal-right sign in the state array, for
     * row 2. This bit can only be set if the STATE_H_R_R2 is also set. */
    private static final int STATE_H_R_SIGN_R2 = STATE_H_R_SIGN_R1<<STATE_SEP;

    /** The flag bit for the vertical-up sign in the state array, for row
     * 2. This bit can only be set if the STATE_V_U_R2 is also set. */
    private static final int STATE_V_U_SIGN_R2 = STATE_V_U_SIGN_R1<<STATE_SEP;

    /** The flag bit for the vertical-down sign in the state array, for row
     * 2. This bit can only be set if the STATE_V_D_R2 is also set. */
    private static final int STATE_V_D_SIGN_R2 = STATE_V_D_SIGN_R1<<STATE_SEP;

    /** The flag bit for the previous MR primitive applied in the state array,
        for row 2. */
    private static final int STATE_PREV_MR_R2 = STATE_PREV_MR_R1<<STATE_SEP;

    /** The flag bit for the horizontal-left significance in the state array,
        for row 2. */
    private static final int STATE_H_L_R2 = STATE_H_L_R1<<STATE_SEP;

    /** The flag bit for the horizontal-right significance in the state array,
        for row 2. */
    private static final int STATE_H_R_R2 = STATE_H_R_R1<<STATE_SEP;

    /** The flag bit for the vertical-up significance in the state array, for
     row 2.  */
    private static final int STATE_V_U_R2 = STATE_V_U_R1<<STATE_SEP;

    /** The flag bit for the vertical-down significance in the state array,
     for row 2.  */
    private static final int STATE_V_D_R2 = STATE_V_D_R1<<STATE_SEP;

    /** The flag bit for the diagonal up-left significance in the state array,
        for row 2. */
    private static final int STATE_D_UL_R2 = STATE_D_UL_R1<<STATE_SEP;

    /** The flag bit for the diagonal up-right significance in the state
        array, for row 2.*/
    private static final int STATE_D_UR_R2 = STATE_D_UR_R1<<STATE_SEP;

    /** The flag bit for the diagonal down-left significance in the state
        array, for row 2. */
    private static final int STATE_D_DL_R2 = STATE_D_DL_R1<<STATE_SEP;

    /** The flag bit for the diagonal down-right significance in the state
        array , for row 2.*/
    private static final int STATE_D_DR_R2 = STATE_D_DR_R1<<STATE_SEP;

    /** The mask to isolate the significance bits for row 1 and 2 of the state
     * array. */
    private static final int SIG_MASK_R1R2 = STATE_SIG_R1|STATE_SIG_R2;

    /** The mask to isolate the visited bits for row 1 and 2 of the state
     * array. */
    private static final int VSTD_MASK_R1R2 = STATE_VISITED_R1|STATE_VISITED_R2;

    /** The mask to isolate the bits necessary to identify RLC coding state
     * (significant, visited and non-zero context, for row 1 and 2). */
    private static final int RLC_MASK_R1R2 =
        STATE_SIG_R1|STATE_SIG_R2|
        STATE_VISITED_R1|STATE_VISITED_R2|
        STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2;

    /** The mask to obtain the ZC_LUT index from the 'state' information */
    // This is needed because of the STATE_V_D_SIGN, STATE_V_U_SIGN,
    // STATE_H_R_SIGN, and STATE_H_L_SIGN bits.
    private static final int ZC_MASK = (1<<8)-1;

    /** The shift to obtain the SC index to 'SC_LUT' from the 'state'
     * information, for row 1. */
    private static final int SC_SHIFT_R1 = 4;

    /** The shift to obtain the SC index to 'SC_LUT' from the state
     * information, for row 2. */
    private static final int SC_SHIFT_R2 = SC_SHIFT_R1+STATE_SEP;

    /** The bit mask to isolate the state bits relative to the sign coding
     * lookup table ('SC_LUT'). */
    private static final int SC_MASK = (1<<SC_LUT_BITS)-1;

    /** The mask to obtain the MR index to 'MR_LUT' from the 'state'
     * information. It is to be applied after the 'MR_SHIFT' */
    private static final int MR_MASK = (1<<9)-1;

    /** The source code-block to entropy code (avoids reallocation for each
        code-block). */
    private DecLyrdCBlk srcblk;

    /** The maximum number of bit planes to decode for any code-block */
    private int mQuit;

    /** Static initializer: initializes all the lookup tables. */
    static {
        int i,j;
        double val, deltaMSE;
        int inter_sc_lut[];
        int ds,us,rs,ls;
        int dsgn,usgn,rsgn,lsgn;
        int h,v;

        // Initialize the zero coding lookup tables

        // LH

        // - No neighbors significant
        ZC_LUT_LH[0] = 2;
        // - No horizontal or vertical neighbors significant
        for (i=1; i<16; i++) { // Two or more diagonal coeffs significant
            ZC_LUT_LH[i] = 4;
        }
        for (i=0; i<4; i++) { // Only one diagonal coeff significant
            ZC_LUT_LH[1<<i] = 3;
        }
        // - No horizontal neighbors significant, diagonal irrelevant
        for (i=0; i<16; i++) {
            // Only one vertical coeff significant
            ZC_LUT_LH[STATE_V_U_R1 | i] = 5;
            ZC_LUT_LH[STATE_V_D_R1 | i] = 5;
            // The two vertical coeffs significant
            ZC_LUT_LH[STATE_V_U_R1 | STATE_V_D_R1 | i] = 6;
        }
        // - One horiz. neighbor significant, diagonal/vertical non-significant
        ZC_LUT_LH[STATE_H_L_R1] = 7;
        ZC_LUT_LH[STATE_H_R_R1] = 7;
        // - One horiz. significant, no vertical significant, one or more
        // diagonal significant
        for (i=1; i<16; i++) {
            ZC_LUT_LH[STATE_H_L_R1 | i] = 8;
            ZC_LUT_LH[STATE_H_R_R1 | i] = 8;
        }
        // - One horiz. significant, one or more vertical significant,
        // diagonal irrelevant
        for (i=1; i<4; i++) {
            for (j=0; j<16; j++) {
                ZC_LUT_LH[STATE_H_L_R1 | (i<<4) | j] = 9;
                ZC_LUT_LH[STATE_H_R_R1 | (i<<4) | j] = 9;
            }
        }
        // - Two horiz. significant, others irrelevant
        for (i=0; i<64; i++) {
            ZC_LUT_LH[STATE_H_L_R1 | STATE_H_R_R1 | i] = 10;
        }

        // HL

        // - No neighbors significant
        ZC_LUT_HL[0] = 2;
        // - No horizontal or vertical neighbors significant
        for (i=1; i<16; i++) { // Two or more diagonal coeffs significant
            ZC_LUT_HL[i] = 4;
        }
        for (i=0; i<4; i++) { // Only one diagonal coeff significant
            ZC_LUT_HL[1<<i] = 3;
        }
        // - No vertical significant, diagonal irrelevant
        for (i=0; i<16; i++) {
            // One horiz. significant
            ZC_LUT_HL[STATE_H_L_R1 | i] = 5;
            ZC_LUT_HL[STATE_H_R_R1 | i] = 5;
            // Two horiz. significant
            ZC_LUT_HL[STATE_H_L_R1 | STATE_H_R_R1 | i] = 6;
        }
        // - One vert. significant, diagonal/horizontal non-significant
        ZC_LUT_HL[STATE_V_U_R1] = 7;
        ZC_LUT_HL[STATE_V_D_R1] = 7;
        // - One vert. significant, horizontal non-significant, one or more
        // diag. significant
        for (i=1; i<16; i++) {
            ZC_LUT_HL[STATE_V_U_R1 | i] = 8;
            ZC_LUT_HL[STATE_V_D_R1 | i] = 8;
        }
        // - One vertical significant, one or more horizontal significant,
        // diagonal irrelevant
        for (i=1; i<4; i++) {
            for (j=0; j<16; j++) {
                ZC_LUT_HL[(i<<6) | STATE_V_U_R1 | j] = 9;
                ZC_LUT_HL[(i<<6) | STATE_V_D_R1 | j] = 9;
            }
        }
        // - Two vertical significant, others irrelevant
        for (i=0; i<4; i++) {
            for (j=0; j<16; j++) {
                ZC_LUT_HL[(i<<6) | STATE_V_U_R1 | STATE_V_D_R1 | j] = 10;
            }
        }

        // HH
        int[] twoBits = {3,5,6,9,10,12}; // Figures (between 0 and 15)
        // countaning 2 and only 2 bits on in its binary representation.

        int[] oneBit  = {1,2,4,8}; // Figures (between 0 and 15)
        // countaning 1 and only 1 bit on in its binary representation.

        int[] twoLeast = {3,5,6,7,9,10,11,12,13,14,15}; // Figures
        // (between 0 and 15) countaining, at least, 2 bits on in its
        // binary representation.

        int[] threeLeast = {7,11,13,14,15}; // Figures
        // (between 0 and 15) countaining, at least, 3 bits on in its
        // binary representation.

        // - None significant
        ZC_LUT_HH[0] = 2;

        // - One horizontal+vertical significant, none diagonal
        for(i=0; i<oneBit.length; i++)
            ZC_LUT_HH[ oneBit[i]<<4 ] = 3;

        // - Two or more horizontal+vertical significant, diagonal non-signif
        for(i=0; i<twoLeast.length; i++)
            ZC_LUT_HH[ twoLeast[i]<<4 ] = 4;

        // - One diagonal significant, horiz./vert. non-significant
        for(i=0; i<oneBit.length; i++)
            ZC_LUT_HH[ oneBit[i] ] = 5;

        // - One diagonal significant, one horiz.+vert. significant
        for(i=0; i<oneBit.length; i++)
            for(j=0; j<oneBit.length; j++)
                ZC_LUT_HH[ (oneBit[i]<<4) | oneBit[j] ] = 6;

        // - One diag signif, two or more horiz+vert signif
        for(i=0; i<twoLeast.length; i++)
            for(j=0; j<oneBit.length; j++)
                ZC_LUT_HH[ (twoLeast[i]<<4) | oneBit[j] ] = 7;

        // - Two diagonal significant, none horiz+vert significant
        for(i=0; i<twoBits.length; i++)
            ZC_LUT_HH[ twoBits[i] ] = 8;

        // - Two diagonal significant, one or more horiz+vert significant
        for(j=0; j<twoBits.length; j++)
            for(i=1; i<16; i++)
                ZC_LUT_HH[ (i<<4) | twoBits[j] ] = 9;

        // - Three or more diagonal significant, horiz+vert irrelevant
        for(i=0; i<16; i++)
            for(j=0; j<threeLeast.length; j++)
                ZC_LUT_HH[ (i<<4) | threeLeast[j] ] = 10;


        // Initialize the SC lookup tables

        // Use an intermediate sign code lookup table that is similar to the
        // one in the VM text, in that it depends on the 'h' and 'v'
        // quantities. The index into this table is a 6 bit index, the top 3
        // bits are (h+1) and the low 3 bits (v+1).
        inter_sc_lut = new int[36];
        inter_sc_lut[(2<<3)|2] = 15;
        inter_sc_lut[(2<<3)|1] = 14;
        inter_sc_lut[(2<<3)|0] = 13;
        inter_sc_lut[(1<<3)|2] = 12;
        inter_sc_lut[(1<<3)|1] = 11;
        inter_sc_lut[(1<<3)|0] = 12 | INT_SIGN_BIT;
        inter_sc_lut[(0<<3)|2] = 13 | INT_SIGN_BIT;
        inter_sc_lut[(0<<3)|1] = 14 | INT_SIGN_BIT;
        inter_sc_lut[(0<<3)|0] = 15 | INT_SIGN_BIT;

        // Using the intermediate sign code lookup table create the final
        // one. The index into this table is a 9 bit index, the low 4 bits are
        // the significance of the 4 horizontal/vertical neighbors, while the
        // top 4 bits are the signs of those neighbors. The bit in the middle
        // is ignored. This index arrangement matches the state bits in the
        // 'state' array, thus direct addressing of the table can be done from
        // the sate information.
        for (i=0; i<(1<<SC_LUT_BITS)-1; i++) {
            ds = i & 0x01;        // significance of down neighbor
            us = (i >> 1) & 0x01; // significance of up neighbor
            rs = (i >> 2) & 0x01; // significance of right neighbor
            ls = (i >> 3) & 0x01; // significance of left neighbor
            dsgn = (i >> 5) & 0x01; // sign of down neighbor
            usgn = (i >> 6) & 0x01; // sign of up neighbor
            rsgn = (i >> 7) & 0x01; // sign of right neighbor
            lsgn = (i >> 8) & 0x01; // sign of left neighbor
            // Calculate 'h' and 'v' as in VM text
            h = ls*(1-2*lsgn)+rs*(1-2*rsgn);
            h = (h >= -1) ? h : -1;
            h = (h <= 1) ? h : 1;
            v = us*(1-2*usgn)+ds*(1-2*dsgn);
            v = (v >= -1) ? v : -1;
            v = (v <= 1) ? v : 1;
            // Get context and sign predictor from 'inter_sc_lut'
            SC_LUT[i] = inter_sc_lut[(h+1)<<3|(v+1)];
        }
        inter_sc_lut = null;

        // Initialize the MR lookup tables

        // None significant, prev MR off
        MR_LUT[0] = 16;
        // One or more significant, prev MR off
        for (i=1; i<(1<<(MR_LUT_BITS-1)); i++) {
            MR_LUT[i] = 17;
        }
        // Previous MR on, significance irrelevant
        for (; i<(1<<MR_LUT_BITS); i++) {
            MR_LUT[i] = 18;
        }
    }

    /**
     * Instantiates a new entropy decoder engine, with the specified source of
     * data, nominal block width and height.
     *
     * @param src The source of data
     *
     * @param opt The options to use for this encoder. It is a mix of the
     * 'OPT_TERM_PASS', 'OPT_RESET_MQ', 'OPT_VERT_STR_CAUSAL', 'OPT_BYPASS' and
     * 'OPT_SEG_SYMBOLS' option flags.
     *
     * @param doer If true error detection will be performed, if any error
     * detection features have been enabled.
     *
     * @param verber This flag indicates if the entropy decoder should be
     * verbose about bit stream errors that are detected and concealed.
     * */
    public StdEntropyDecoder(CodedCBlkDataSrcDec src, DecoderSpecs decSpec,
                             boolean doer, boolean verber, int mQuit) {
        super(src);

        this.decSpec = decSpec;
        this.doer = doer;
        this.verber = verber;
        this.mQuit = mQuit;

        // If we do timing create necessary structures
        if (DO_TIMING) {
            time = new long[src.getNumComps()];
            // If we are timing make sure that 'finalize' gets called.
            System.runFinalizersOnExit(true);
        }

        // Initialize internal variables
        state = new int[(decSpec.cblks.getMaxCBlkWidth()+2) *
                       ((decSpec.cblks.getMaxCBlkHeight()+1)/2+2)];
    }

    /**
     * Prints the timing information, if collected, and calls 'finalize' on
     * the super class.
     * */
    public void finalize() throws Throwable {
        if (DO_TIMING) {
            int c;
            StringBuffer sb;

            sb = new StringBuffer("StdEntropyDecoder decompression wall "+
                                  "clock time:");
            for (c=0; c<time.length; c++) {
                sb.append("\n  component ");
                sb.append(c);
                sb.append(": ");
                sb.append(time[c]);
                sb.append(" ms");
            }
            FacilityManager.getMsgLogger().
                printmsg(MsgLogger.INFO,sb.toString());
        }
        super.finalize();
    }

    /**
     * Returns the specified code-block in the current tile for the specified
     * component, as a copy (see below).
     *
     * <P>The returned code-block may be progressive, which is indicated by
     * the 'progressive' variable of the returned 'DataBlk' object. If a
     * code-block is progressive it means that in a later request to this
     * method for the same code-block it is possible to retrieve data which is
     * a better approximation, since meanwhile more data to decode for the
     * code-block could have been received. If the code-block is not
     * progressive then later calls to this method for the same code-block
     * will return the exact same data values.
     *
     * <P>The data returned by this method is always a copy of the internal
     * data of this object, if any, and it can be modified "in place" without
     * any problems after being returned. The 'offset' of the returned data is
     * 0, and the 'scanw' is the same as the code-block width. See the
     * 'DataBlk' class.
     *
     * <P>The 'ulx' and 'uly' members of the returned 'DataBlk' object
     * contain the coordinates of the top-left corner of the block, with
     * respect to the tile, not the subband.
     *
     * @param c The component for which to return the next code-block.
     *
     * @param m The vertical index of the code-block to return, in the
     * specified subband.
     *
     * @param n The horizontal index of the code-block to return, in the
     * specified subband.
     *
     * @param sb The subband in which the code-block to return is.
     *
     * @param cblk If non-null this object will be used to return the new
     * code-block. If null a new one will be allocated and returned. If the
     * "data" array of the object is non-null it will be reused, if possible,
     * to return the data.
     *
     * @return The next code-block in the current tile for component 'n', or
     * null if all code-blocks for the current tile have been returned.
     *
     * @see DataBlk
     * */
    public DataBlk getCodeBlock(int c, int m, int n, SubbandSyn sb,
                                DataBlk cblk) {
        long stime = 0L;  // Start time for timed sections
        int zc_lut[];     // The ZC lookup table to use
        int out_data[];   // The outupt data buffer
        int npasses;      // The number of coding passes to perform
        int curbp;        // The current magnitude bit-plane (starts at 30)
        boolean error;    // Error indicator
        int tslen;        // Length of first terminated segment
        int tsidx;        // Index of current terminated segment
        ByteInputBuffer in = null;

        boolean isterm;

        // Get the code-block to decode
        srcblk = src.getCodeBlock(c,m,n,sb,1,-1,srcblk);
        if (DO_TIMING) stime = System.currentTimeMillis();

        // Retrieve options from decSpec
        options = ((Integer)decSpec.ecopts.
                   getTileCompVal(tIdx,c)).intValue();

        // Reset state
        ArrayUtil.intArraySet(state,0);

        // Initialize output code-block
        if (cblk==null) {
            cblk = new DataBlkInt();
        }
        cblk.progressive = srcblk.prog;
        cblk.ulx = srcblk.ulx;
        cblk.uly = srcblk.uly;
        cblk.w = srcblk.w;
        cblk.h = srcblk.h;
        cblk.offset = 0;
        cblk.scanw = cblk.w;
        out_data = (int[])cblk.getData();

        if (out_data == null || out_data.length < srcblk.w*srcblk.h) {
            out_data = new int[srcblk.w*srcblk.h];
            cblk.setData(out_data);
        } else {
            // Set data values to 0
            ArrayUtil.intArraySet(out_data,0);
        }

        if (srcblk.nl <= 0 || srcblk.nTrunc <= 0) {
            // 0 layers => no data to decode => return all 0s
            return cblk;
        }

        // Get the length of the first terminated segment
        tslen = (srcblk.tsLengths == null) ? srcblk.dl : srcblk.tsLengths[0];
        tsidx = 0;
        // Initialize for decoding
        npasses = srcblk.nTrunc;
        if (mq == null) {
            in = new ByteInputBuffer(srcblk.data,0,tslen);
            mq = new MQDecoder(in ,NUM_CTXTS,MQ_INIT);
        }
        else {
            // We always start by an MQ segment
            mq.nextSegment(srcblk.data,0,tslen);
            mq.resetCtxts();
        }
        error = false;

        if ((options & OPT_BYPASS) != 0) {
            if(bin==null){
                if (in == null) in = mq.getByteInputBuffer();
                bin = new ByteToBitInput(in);
            }
        }

        // Choose correct ZC lookup table for global orientation
        switch (sb.orientation) {
        case Subband.WT_ORIENT_HL:
            zc_lut = ZC_LUT_HL;
            break;
        case Subband.WT_ORIENT_LH:
        case Subband.WT_ORIENT_LL:
            zc_lut = ZC_LUT_LH;
            break;
        case Subband.WT_ORIENT_HH:
            zc_lut = ZC_LUT_HH;
            break;
        default:
            throw new Error("JJ2000 internal error");
        }

        // NOTE: we don't currently detect which is the last magnitude
        // bit-plane so that 'isterm' is true for the last pass of it. Doing so
        // would aid marginally in error detection with the predictable error
        // resilient MQ termination. However, determining which is the last
        // magnitude bit-plane is quite hard (due to ROI, quantization, etc.)
        // and in any case the predictable error resilient termination used
        // without the arithmetic coding bypass and/or regular termination
        // modes is almost useless.

        // Loop on bit-planes and passes

        curbp = 30-srcblk.skipMSBP;

        // Check for maximum number of bitplanes quit condition
        if(mQuit != -1 && (mQuit*3-2) < npasses){
            npasses = mQuit*3-2;
        }

        // First bit-plane has only the cleanup pass
        if (curbp >= 0 && npasses > 0) {
            isterm = (options & OPT_TERM_PASS) != 0 ||
                ((options & OPT_BYPASS) != 0 &&
                 (31-NUM_NON_BYPASS_MS_BP-srcblk.skipMSBP)>=curbp);
            error = cleanuppass(cblk,mq,curbp,state,zc_lut,isterm);
            npasses--;
            if (!error || !doer) curbp--;
        }

        // Other bit-planes have the three coding passes
        if (!error || !doer) {
            while (curbp >= 0 && npasses > 0) {

                if((options & OPT_BYPASS) != 0 &&
                   (curbp < 31-NUM_NON_BYPASS_MS_BP-srcblk.skipMSBP)){
                    // Use bypass decoding mode (only all bit-planes
                    // after the first 4 bit-planes).

                    // Here starts a new raw segment
                    bin.setByteArray(null,-1,srcblk.tsLengths[++tsidx]);
                    isterm = (options & OPT_TERM_PASS) != 0;
                    error = rawSigProgPass(cblk,bin,curbp,state,isterm);
                    npasses--;
                    if (npasses <= 0 || (error && doer)) break;

                    if ((options & OPT_TERM_PASS) != 0) {
                        // Start a new raw segment
                        bin.setByteArray(null,-1,srcblk.tsLengths[++tsidx]);
                    }
                    isterm = (options & OPT_TERM_PASS) != 0 ||
                        ((options & OPT_BYPASS) != 0 &&
                         (31-NUM_NON_BYPASS_MS_BP-srcblk.skipMSBP>curbp));
                    error = rawMagRefPass(cblk,bin,curbp,state,isterm);
                }
                else {// Do not use bypass decoding mode
                    if ((options & OPT_TERM_PASS) != 0) {
                        // Here starts a new MQ segment
                        mq.nextSegment(null,-1,srcblk.tsLengths[++tsidx]);
                    }
                    isterm = (options & OPT_TERM_PASS) != 0;
                    error = sigProgPass(cblk,mq,curbp,state,zc_lut,isterm);
                    npasses--;
                    if (npasses <= 0 || (error && doer)) break;

                    if ((options & OPT_TERM_PASS) != 0) {
                        // Here starts a new MQ segment
                        mq.nextSegment(null,-1,srcblk.tsLengths[++tsidx]);
                    }
                    isterm = (options & OPT_TERM_PASS) != 0 ||
                        ((options & OPT_BYPASS) != 0 &&
                         (31-NUM_NON_BYPASS_MS_BP-srcblk.skipMSBP>curbp));
                    error = magRefPass(cblk,mq,curbp,state,isterm);
                }

                npasses--;
                if (npasses <= 0 || (error && doer)) break;

                if ((options & OPT_TERM_PASS) != 0 ||
                    ((options & OPT_BYPASS) != 0 &&
                     (curbp < 31-NUM_NON_BYPASS_MS_BP-srcblk.skipMSBP))) {
                    // Here starts a new MQ segment
                    mq.nextSegment(null,-1,srcblk.tsLengths[++tsidx]);
                }
                isterm = (options & OPT_TERM_PASS) != 0 ||
                    ((options & OPT_BYPASS) != 0 &&
                     (31-NUM_NON_BYPASS_MS_BP-srcblk.skipMSBP)>=curbp);
                error = cleanuppass(cblk,mq,curbp,state,zc_lut,isterm);
                npasses--;
                if (error) break;
                // Goto next bit-plane
                curbp--;
            }
        }

        // If an error ocurred conceal it
        if (error && doer) {
            if (verber) {
                FacilityManager.getMsgLogger().
                    printmsg(MsgLogger.WARNING,
                             "Error detected at bit-plane "+curbp+
                             " in code-block ("+m+","+n+"), sb_idx "+
                             sb.sbandIdx+", res. level "+sb.resLvl+
                             ". Concealing...");
            }

            conceal(cblk,curbp);
        }

        if (DO_TIMING) time[c] += System.currentTimeMillis()-stime;

        // Return decoded block
        return cblk;
    }

    /**
     * Returns the specified code-block in the current tile for the specified
     * component (as a reference or copy).
     *
     * <P>The returned code-block may be progressive, which is indicated by
     * the 'progressive' variable of the returned 'DataBlk'
     * object. If a code-block is progressive it means that in a later request
     * to this method for the same code-block it is possible to retrieve data
     * which is a better approximation, since meanwhile more data to decode
     * for the code-block could have been received. If the code-block is not
     * progressive then later calls to this method for the same code-block
     * will return the exact same data values.
     *
     * <P>The data returned by this method can be the data in the internal
     * buffer of this object, if any, and thus can not be modified by the
     * caller. The 'offset' and 'scanw' of the returned data can be
     * arbitrary. See the 'DataBlk' class.
     *
     * <P>The 'ulx' and 'uly' members of the returned 'DataBlk' object
     * contain the coordinates of the top-left corner of the block, with
     * respect to the tile, not the subband.
     *
     * @param c The component for which to return the next code-block.
     *
     * @param m The vertical index of the code-block to return, in the
     * specified subband.
     *
     * @param n The horizontal index of the code-block to return, in the
     * specified subband.
     *
     * @param sb The subband in which the code-block to return is.
     *
     * @param cblk If non-null this object will be used to return the new
     * code-block. If null a new one will be allocated and returned. If the
     * "data" array of the object is non-null it will be reused, if possible,
     * to return the data.
     *
     * @return The next code-block in the current tile for component 'n', or
     * null if all code-blocks for the current tile have been returned.
     *
     * @see DataBlk
     * */
    public DataBlk getInternCodeBlock(int c, int m, int n, SubbandSyn sb,
                                        DataBlk cblk) {
        return getCodeBlock(c,m,n,sb,cblk);
    }

    /**
     * Performs the significance propagation pass on the specified data and
     * bit-plane. It decodes all insignificant samples which have, at least,
     * one of its immediate eight neighbors already significant, using the ZC
     * and SC primitives as needed. It toggles the "visited" state bit to 1
     * for all those samples.
     *
     * <P>This method also checks for segmentation markers if those are
     * present and returns true if an error is detected, or false
     * otherwise. If an error is detected it means that the bit stream contains
     * some erroneous bit that have led to the decoding of incorrect
     * data. This data affects the whole last decoded bit-plane (i.e. 'bp'). If
     * 'true' is returned the 'conceal' method should be called and no more
     * passes should be decoded for this code-block's bit stream.
     *
     * @param cblk The code-block data to decode
     *
     * @param mq The MQ-coder to use
     *
     * @param bp The bit-plane to decode
     *
     * @param state The state information for the code-block
     *
     * @param zc_lut The ZC lookup table to use in ZC.
     *
     * @param isterm If this pass has been terminated. If the pass has been
     * terminated it can be used to check error resilience.
     *
     * @return True if an error was detected in the bit stream, false otherwise.
     * */
    private boolean sigProgPass(DataBlk cblk, MQDecoder mq, int bp,
                                int state[], int zc_lut[], boolean isterm) {
        int j,sj;        // The state index for line and stripe
        int k,sk;        // The data index for line and stripe
        int dscanw;      // The data scan-width
        int sscanw;      // The state scan-width
        int jstep;       // Stripe to stripe step for 'sj'
        int kstep;       // Stripe to stripe step for 'sk'
        int stopsk;      // The loop limit on the variable sk
        int csj;         // Local copy (i.e. cached) of 'state[j]'
        int setmask;     // The mask to set current and lower bit-planes to 1/2
                         // approximation
        int sym;         // The symbol to code
        int ctxt;        // The context to use
        int data[];      // The data buffer
        int s;           // The stripe index
        boolean causal;  // Flag to indicate if stripe-causal context
                         // formation is to be used
        int nstripes;    // The number of stripes in the code-block
        int sheight;     // Height of the current stripe
        int off_ul,off_ur,off_dr,off_dl; // offsets
        boolean error;   // The error condition

        // Initialize local variables
        dscanw = cblk.scanw;
        sscanw = cblk.w+2;
        jstep = sscanw*STRIPE_HEIGHT/2-cblk.w;
        kstep = dscanw*STRIPE_HEIGHT-cblk.w;
        setmask = (3<<bp)>>1;
        data = (int[]) cblk.getData();
        nstripes = (cblk.h+STRIPE_HEIGHT-1)/STRIPE_HEIGHT;
        causal = (options & OPT_VERT_STR_CAUSAL) != 0;

        // Pre-calculate offsets in 'state' for diagonal neighbors
        off_ul = -sscanw-1;  // up-left
        off_ur =  -sscanw+1; // up-right
        off_dr = sscanw+1;   // down-right
        off_dl = sscanw-1;   // down-left

        // Decode stripe by stripe
        sk = cblk.offset;
        sj = sscanw+1;
        for (s = nstripes-1; s >= 0; s--, sk+=kstep, sj+=jstep) {
            sheight = (s != 0) ? STRIPE_HEIGHT :
                cblk.h-(nstripes-1)*STRIPE_HEIGHT;
            stopsk = sk+cblk.w;
            // Scan by set of 1 stripe column at a time
            for (; sk < stopsk; sk++, sj++) {
                // Do half top of column
                j = sj;
                csj = state[j];
                // If any of the two samples is not significant and has a
                // non-zero context (i.e. some neighbor is significant) we can
                // not skip them
                if ((((~csj) & (csj<<2)) & SIG_MASK_R1R2) != 0) {
                    k = sk;
                    // Scan first row
                    if ((csj & (STATE_SIG_R1|STATE_NZ_CTXT_R1)) ==
                        STATE_NZ_CTXT_R1) {
                        // Use zero coding
                        if (mq.decodeSymbol(zc_lut[csj&ZC_MASK]) != 0) {
                            // Became significant
                            // Use sign coding
                            ctxt = SC_LUT[(csj>>>SC_SHIFT_R1)&SC_MASK];
                            sym = mq.decodeSymbol(ctxt & SC_LUT_MASK) ^
                                (ctxt>>>SC_SPRED_SHIFT);
                            // Update data
                            data[k] = (sym<<31) | setmask;
                            // Update state information (significant bit,
                            // visited bit, neighbor significant bit of
                            // neighbors, non zero context of neighbors, sign
                            // of neighbors)
                            if (!causal) {
                                // If in causal mode do not change contexts of
                                // previous stripe.
                                state[j+off_ul] |=
                                    STATE_NZ_CTXT_R2|STATE_D_DR_R2;
                                state[j+off_ur] |=
                                    STATE_NZ_CTXT_R2|STATE_D_DL_R2;
                            }
                            // Update sign state information of neighbors
                            if (sym != 0) {
                                csj |= STATE_SIG_R1|STATE_VISITED_R1|
                                    STATE_NZ_CTXT_R2|
                                    STATE_V_U_R2|STATE_V_U_SIGN_R2;
                                if (!causal) {
                                    // If in causal mode do not change
                                    // contexts of previous stripe.
                                    state[j-sscanw] |= STATE_NZ_CTXT_R2|
                                        STATE_V_D_R2|STATE_V_D_SIGN_R2;
                                }
                                state[j+1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_H_L_R1|STATE_H_L_SIGN_R1|
                                    STATE_D_UL_R2;
                                state[j-1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_H_R_R1|STATE_H_R_SIGN_R1|
                                    STATE_D_UR_R2;
                            }
                            else {
                                csj |= STATE_SIG_R1|STATE_VISITED_R1|
                                    STATE_NZ_CTXT_R2|STATE_V_U_R2;
                                if (!causal) {
                                    // If in causal mode do not change
                                    // contexts of previous stripe.
                                    state[j-sscanw] |= STATE_NZ_CTXT_R2|
                                        STATE_V_D_R2;
                                }
                                state[j+1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_H_L_R1|STATE_D_UL_R2;
                                state[j-1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_H_R_R1|STATE_D_UR_R2;
                            }
                        }
                        else {
                            csj |= STATE_VISITED_R1;
                        }
                    }
                    if (sheight < 2) {
                        state[j] = csj;
                        continue;
                    }
                    // Scan second row
                    if ((csj & (STATE_SIG_R2|STATE_NZ_CTXT_R2)) ==
                        STATE_NZ_CTXT_R2) {
                        k += dscanw;
                        // Use zero coding
                        if (mq.decodeSymbol(zc_lut[(csj>>>STATE_SEP)&
                                                  ZC_MASK]) != 0) {
                            // Became significant
                            // Use sign coding
                            ctxt = SC_LUT[(csj>>>SC_SHIFT_R2)&SC_MASK];
                            sym = mq.decodeSymbol(ctxt & SC_LUT_MASK) ^
                                (ctxt>>>SC_SPRED_SHIFT);
                            // Update data
                            data[k] = (sym<<31) | setmask;
                            // Update state information (significant bit,
                            // visited bit, neighbor significant bit of
                            // neighbors, non zero context of neighbors, sign
                            // of neighbors)
                            state[j+off_dl] |= STATE_NZ_CTXT_R1|STATE_D_UR_R1;
                            state[j+off_dr] |= STATE_NZ_CTXT_R1|STATE_D_UL_R1;
                            // Update sign state information of neighbors
                            if (sym != 0) {
                                csj |= STATE_SIG_R2|STATE_VISITED_R2|
                                    STATE_NZ_CTXT_R1|
                                    STATE_V_D_R1|STATE_V_D_SIGN_R1;
                                state[j+sscanw] |= STATE_NZ_CTXT_R1|
                                    STATE_V_U_R1|STATE_V_U_SIGN_R1;
                                state[j+1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_D_DL_R1|
                                    STATE_H_L_R2|STATE_H_L_SIGN_R2;
                                state[j-1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_D_DR_R1|
                                    STATE_H_R_R2|STATE_H_R_SIGN_R2;
                            }
                            else {
                                csj |= STATE_SIG_R2|STATE_VISITED_R2|
                                    STATE_NZ_CTXT_R1|STATE_V_D_R1;
                                state[j+sscanw] |= STATE_NZ_CTXT_R1|
                                    STATE_V_U_R1;
                                state[j+1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_D_DL_R1|STATE_H_L_R2;
                                state[j-1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_D_DR_R1|STATE_H_R_R2;
                            }
                        }
                        else {
                            csj |= STATE_VISITED_R2;
                        }
                    }
                    state[j] = csj;
                }
                // Do half bottom of column
                if (sheight < 3) continue;
                j += sscanw;
                csj = state[j];
                // If any of the two samples is not significant and has a
                // non-zero context (i.e. some neighbor is significant) we can
                // not skip them
                if ((((~csj) & (csj<<2)) & SIG_MASK_R1R2) != 0) {
                    k = sk+(dscanw<<1);
                    // Scan first row
                    if ((csj & (STATE_SIG_R1|STATE_NZ_CTXT_R1)) ==
                        STATE_NZ_CTXT_R1) {
                        // Use zero coding
                        if (mq.decodeSymbol(zc_lut[csj&ZC_MASK]) != 0) {
                            // Became significant
                            // Use sign coding
                            ctxt = SC_LUT[(csj>>>SC_SHIFT_R1)&SC_MASK];
                            sym = mq.decodeSymbol(ctxt & SC_LUT_MASK) ^
                                (ctxt>>>SC_SPRED_SHIFT);
                            // Update data
                            data[k] = (sym<<31) | setmask;
                            // Update state information (significant bit,
                            // visited bit, neighbor significant bit of
                            // neighbors, non zero context of neighbors, sign
                            // of neighbors)
                            state[j+off_ul] |=
                                STATE_NZ_CTXT_R2|STATE_D_DR_R2;
                            state[j+off_ur] |=
                                STATE_NZ_CTXT_R2|STATE_D_DL_R2;
                            // Update sign state information of neighbors
                            if (sym != 0) {
                                csj |= STATE_SIG_R1|STATE_VISITED_R1|
                                    STATE_NZ_CTXT_R2|
                                    STATE_V_U_R2|STATE_V_U_SIGN_R2;
                                state[j-sscanw] |= STATE_NZ_CTXT_R2|
                                    STATE_V_D_R2|STATE_V_D_SIGN_R2;
                                state[j+1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_H_L_R1|STATE_H_L_SIGN_R1|
                                    STATE_D_UL_R2;
                                state[j-1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_H_R_R1|STATE_H_R_SIGN_R1|
                                    STATE_D_UR_R2;
                            }
                            else {
                                csj |= STATE_SIG_R1|STATE_VISITED_R1|
                                    STATE_NZ_CTXT_R2|STATE_V_U_R2;
                                state[j-sscanw] |= STATE_NZ_CTXT_R2|
                                    STATE_V_D_R2;
                                state[j+1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_H_L_R1|STATE_D_UL_R2;
                                state[j-1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_H_R_R1|STATE_D_UR_R2;
                            }
                        }
                        else {
                            csj |= STATE_VISITED_R1;
                        }
                    }
                    if (sheight < 4) {
                        state[j] = csj;
                        continue;
                    }
                    // Scan second row
                    if ((csj & (STATE_SIG_R2|STATE_NZ_CTXT_R2)) ==
                        STATE_NZ_CTXT_R2) {
                        k += dscanw;
                        // Use zero coding
                        if (mq.decodeSymbol(zc_lut[(csj>>>STATE_SEP)&
                                                  ZC_MASK]) != 0) {
                            // Became significant
                            // Use sign coding
                            ctxt = SC_LUT[(csj>>>SC_SHIFT_R2)&SC_MASK];
                            sym = mq.decodeSymbol(ctxt & SC_LUT_MASK) ^
                                (ctxt>>>SC_SPRED_SHIFT);
                            // Update data
                            data[k] = (sym<<31) | setmask;
                            // Update state information (significant bit,
                            // visited bit, neighbor significant bit of
                            // neighbors, non zero context of neighbors, sign
                            // of neighbors)
                            state[j+off_dl] |= STATE_NZ_CTXT_R1|STATE_D_UR_R1;
                            state[j+off_dr] |= STATE_NZ_CTXT_R1|STATE_D_UL_R1;
                            // Update sign state information of neighbors
                            if (sym != 0) {
                                csj |= STATE_SIG_R2|STATE_VISITED_R2|
                                    STATE_NZ_CTXT_R1|
                                    STATE_V_D_R1|STATE_V_D_SIGN_R1;
                                state[j+sscanw] |= STATE_NZ_CTXT_R1|
                                    STATE_V_U_R1|STATE_V_U_SIGN_R1;
                                state[j+1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_D_DL_R1|
                                    STATE_H_L_R2|STATE_H_L_SIGN_R2;
                                state[j-1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_D_DR_R1|
                                    STATE_H_R_R2|STATE_H_R_SIGN_R2;
                            }
                            else {
                                csj |= STATE_SIG_R2|STATE_VISITED_R2|
                                    STATE_NZ_CTXT_R1|STATE_V_D_R1;
                                state[j+sscanw] |= STATE_NZ_CTXT_R1|
                                    STATE_V_U_R1;
                                state[j+1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_D_DL_R1|STATE_H_L_R2;
                                state[j-1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_D_DR_R1|STATE_H_R_R2;
                            }
                        }
                        else {
                            csj |= STATE_VISITED_R2;
                        }
                    }
                    state[j] = csj;
                }
            }
        }

        error = false;

        // Check the error resilient termination
        if (isterm && (options & OPT_PRED_TERM) != 0) {
            error = mq.checkPredTerm();
        }

        // Reset the MQ context states if we need to
        if ((options & OPT_RESET_MQ) != 0) {
            mq.resetCtxts();
        }

        // Return error condition
        return error;
    }

    /**
     * Performs the significance propagation pass on the specified data and
     * bit-plane. It decodes all insignificant samples which have, at least, one
     * of its immediate eight neighbors already significant, using the ZC and
     * SC primitives as needed. It toggles the "visited" state bit to 1 for
     * all those samples.
     *
     * <P>This method bypasses the arithmetic coder and reads "raw" symbols
     * from the bit stream.
     *
     * <P>This method also checks for segmentation markers if those are
     * present and returns true if an error is detected, or false
     * otherwise. If an error is detected it measn that the bit stream contains
     * some erroneous bit that have led to the decoding of incorrect
     * data. This data affects the whole last decoded bit-plane (i.e. 'bp'). If
     * 'true' is returned the 'conceal' method should be called and no more
     * passes should be decoded for this code-block's bit stream.
     *
     * @param cblk The code-block data to decode
     *
     * @param bin The raw bit based input
     *
     * @param bp The bit-plane to decode
     *
     * @param state The state information for the code-block
     *
     * @param isterm If this pass has been terminated. If the pass has been
     * terminated it can be used to check error resilience.
     *
     * @return True if an error was detected in the bit stream, false otherwise.
     * */
    private boolean rawSigProgPass(DataBlk cblk, ByteToBitInput bin, int bp,
                                   int state[], boolean isterm) {
        int j,sj;        // The state index for line and stripe
        int k,sk;        // The data index for line and stripe
        int dscanw;      // The data scan-width
        int sscanw;      // The state scan-width
        int jstep;       // Stripe to stripe step for 'sj'
        int kstep;       // Stripe to stripe step for 'sk'
        int stopsk;      // The loop limit on the variable sk
        int csj;         // Local copy (i.e. cached) of 'state[j]'
        int setmask;     // The mask to set current and lower bit-planes to 1/2
                         // approximation
        int sym;         // The symbol to code
        int data[];      // The data buffer
        int s;           // The stripe index
        boolean causal;  // Flag to indicate if stripe-causal context
                         // formation is to be used
        int nstripes;    // The number of stripes in the code-block
        int sheight;     // Height of the current stripe
        int off_ul,off_ur,off_dr,off_dl; // offsets
        boolean error;   // The error condition

        // Initialize local variables
        dscanw = cblk.scanw;
        sscanw = cblk.w+2;
        jstep = sscanw*STRIPE_HEIGHT/2-cblk.w;
        kstep = dscanw*STRIPE_HEIGHT-cblk.w;
        setmask = (3<<bp)>>1;
        data = (int[]) cblk.getData();
        nstripes = (cblk.h+STRIPE_HEIGHT-1)/STRIPE_HEIGHT;
        causal = (options & OPT_VERT_STR_CAUSAL) != 0;

        // Pre-calculate offsets in 'state' for diagonal neighbors
        off_ul = -sscanw-1;  // up-left
        off_ur =  -sscanw+1; // up-right
        off_dr = sscanw+1;   // down-right
        off_dl = sscanw-1;   // down-left

        // Decode stripe by stripe
        sk = cblk.offset;
        sj = sscanw+1;
        for (s = nstripes-1; s >= 0; s--, sk+=kstep, sj+=jstep) {
            sheight = (s != 0) ? STRIPE_HEIGHT :
                cblk.h-(nstripes-1)*STRIPE_HEIGHT;
            stopsk = sk+cblk.w;
            // Scan by set of 1 stripe column at a time
            for (; sk < stopsk; sk++, sj++) {
                // Do half top of column
                j = sj;
                csj = state[j];
                // If any of the two samples is not significant and has a
                // non-zero context (i.e. some neighbor is significant) we can
                // not skip them
                if ((((~csj) & (csj<<2)) & SIG_MASK_R1R2) != 0) {
                    k = sk;
                    // Scan first row
                    if ((csj & (STATE_SIG_R1|STATE_NZ_CTXT_R1)) ==
                        STATE_NZ_CTXT_R1) {
                        // Use zero coding
                        if (bin.readBit() != 0) {
                            // Became significant
                            // Use sign coding
                            sym = bin.readBit();
                            // Update data
                            data[k] = (sym<<31) | setmask;
                            // Update state information (significant bit,
                            // visited bit, neighbor significant bit of
                            // neighbors, non zero context of neighbors, sign
                            // of neighbors)
                            if (!causal) {
                                // If in causal mode do not change contexts of
                                // previous stripe.
                                state[j+off_ul] |=
                                    STATE_NZ_CTXT_R2|STATE_D_DR_R2;
                                state[j+off_ur] |=
                                    STATE_NZ_CTXT_R2|STATE_D_DL_R2;
                            }
                            // Update sign state information of neighbors
                            if (sym != 0) {
                                csj |= STATE_SIG_R1|STATE_VISITED_R1|
                                    STATE_NZ_CTXT_R2|
                                    STATE_V_U_R2|STATE_V_U_SIGN_R2;
                                if (!causal) {
                                    // If in causal mode do not change
                                    // contexts of previous stripe.
                                    state[j-sscanw] |= STATE_NZ_CTXT_R2|
                                        STATE_V_D_R2|STATE_V_D_SIGN_R2;
                                }
                                state[j+1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_H_L_R1|STATE_H_L_SIGN_R1|
                                    STATE_D_UL_R2;
                                state[j-1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_H_R_R1|STATE_H_R_SIGN_R1|
                                    STATE_D_UR_R2;
                            }
                            else {
                                csj |= STATE_SIG_R1|STATE_VISITED_R1|
                                    STATE_NZ_CTXT_R2|STATE_V_U_R2;
                                if (!causal) {
                                    // If in causal mode do not change
                                    // contexts of previous stripe.
                                    state[j-sscanw] |= STATE_NZ_CTXT_R2|
                                        STATE_V_D_R2;
                                }
                                state[j+1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_H_L_R1|STATE_D_UL_R2;
                                state[j-1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_H_R_R1|STATE_D_UR_R2;
                            }
                        }
                        else {
                            csj |= STATE_VISITED_R1;
                        }
                    }
                    if (sheight < 2) {
                        state[j] = csj;
                        continue;
                    }
                    if ((csj & (STATE_SIG_R2|STATE_NZ_CTXT_R2)) ==
                        STATE_NZ_CTXT_R2) {
                        k += dscanw;
                        // Use zero coding
                        if (bin.readBit() != 0) {
                            // Became significant
                            // Use sign coding
                            sym = bin.readBit();
                            // Update data
                            data[k] = (sym<<31) | setmask;
                            // Update state information (significant bit,
                            // visited bit, neighbor significant bit of
                            // neighbors, non zero context of neighbors, sign
                            // of neighbors)
                            state[j+off_dl] |= STATE_NZ_CTXT_R1|STATE_D_UR_R1;
                            state[j+off_dr] |= STATE_NZ_CTXT_R1|STATE_D_UL_R1;
                            // Update sign state information of neighbors
                            if (sym != 0) {
                                csj |= STATE_SIG_R2|STATE_VISITED_R2|
                                    STATE_NZ_CTXT_R1|
                                    STATE_V_D_R1|STATE_V_D_SIGN_R1;
                                state[j+sscanw] |= STATE_NZ_CTXT_R1|
                                    STATE_V_U_R1|STATE_V_U_SIGN_R1;
                                state[j+1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_D_DL_R1|
                                    STATE_H_L_R2|STATE_H_L_SIGN_R2;
                                state[j-1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_D_DR_R1|
                                    STATE_H_R_R2|STATE_H_R_SIGN_R2;
                            }
                            else {
                                csj |= STATE_SIG_R2|STATE_VISITED_R2|
                                    STATE_NZ_CTXT_R1|STATE_V_D_R1;
                                state[j+sscanw] |= STATE_NZ_CTXT_R1|
                                    STATE_V_U_R1;
                                state[j+1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_D_DL_R1|STATE_H_L_R2;
                                state[j-1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_D_DR_R1|STATE_H_R_R2;
                            }
                        }
                        else {
                            csj |= STATE_VISITED_R2;
                        }
                    }
                    state[j] = csj;
                }
                // Do half bottom of column
                if (sheight < 3) continue;
                j += sscanw;
                csj = state[j];
                // If any of the two samples is not significant and has a
                // non-zero context (i.e. some neighbor is significant) we can
                // not skip them
                if ((((~csj) & (csj<<2)) & SIG_MASK_R1R2) != 0) {
                    k = sk+(dscanw<<1);
                    // Scan first row
                    if ((csj & (STATE_SIG_R1|STATE_NZ_CTXT_R1)) ==
                        STATE_NZ_CTXT_R1) {
                        // Use zero coding
                        if (bin.readBit() != 0) {
                            // Became significant
                            // Use sign coding
                            sym = bin.readBit();
                            // Update data
                            data[k] = (sym<<31) | setmask;
                            // Update state information (significant bit,
                            // visited bit, neighbor significant bit of
                            // neighbors, non zero context of neighbors, sign
                            // of neighbors)
                            state[j+off_ul] |=
                                STATE_NZ_CTXT_R2|STATE_D_DR_R2;
                            state[j+off_ur] |=
                                STATE_NZ_CTXT_R2|STATE_D_DL_R2;
                            // Update sign state information of neighbors
                            if (sym != 0) {
                                csj |= STATE_SIG_R1|STATE_VISITED_R1|
                                    STATE_NZ_CTXT_R2|
                                    STATE_V_U_R2|STATE_V_U_SIGN_R2;
                                state[j-sscanw] |= STATE_NZ_CTXT_R2|
                                    STATE_V_D_R2|STATE_V_D_SIGN_R2;
                                state[j+1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_H_L_R1|STATE_H_L_SIGN_R1|
                                    STATE_D_UL_R2;
                                state[j-1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_H_R_R1|STATE_H_R_SIGN_R1|
                                    STATE_D_UR_R2;
                            }
                            else {
                                csj |= STATE_SIG_R1|STATE_VISITED_R1|
                                    STATE_NZ_CTXT_R2|STATE_V_U_R2;
                                state[j-sscanw] |= STATE_NZ_CTXT_R2|
                                    STATE_V_D_R2;
                                state[j+1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_H_L_R1|STATE_D_UL_R2;
                                state[j-1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_H_R_R1|STATE_D_UR_R2;
                            }
                        }
                        else {
                            csj |= STATE_VISITED_R1;
                        }
                    }
                    if (sheight < 4) {
                        state[j] = csj;
                        continue;
                    }
                    // Scan second row
                    if ((csj & (STATE_SIG_R2|STATE_NZ_CTXT_R2)) ==
                        STATE_NZ_CTXT_R2) {
                        k += dscanw;
                        // Use zero coding
                        if (bin.readBit() != 0) {
                            // Became significant
                            // Use sign coding
                            sym = bin.readBit();
                            // Update data
                            data[k] = (sym<<31) | setmask;
                            // Update state information (significant bit,
                            // visited bit, neighbor significant bit of
                            // neighbors, non zero context of neighbors, sign
                            // of neighbors)
                            state[j+off_dl] |= STATE_NZ_CTXT_R1|STATE_D_UR_R1;
                            state[j+off_dr] |= STATE_NZ_CTXT_R1|STATE_D_UL_R1;
                            // Update sign state information of neighbors
                            if (sym != 0) {
                                csj |= STATE_SIG_R2|STATE_VISITED_R2|
                                    STATE_NZ_CTXT_R1|
                                    STATE_V_D_R1|STATE_V_D_SIGN_R1;
                                state[j+sscanw] |= STATE_NZ_CTXT_R1|
                                    STATE_V_U_R1|STATE_V_U_SIGN_R1;
                                state[j+1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_D_DL_R1|
                                    STATE_H_L_R2|STATE_H_L_SIGN_R2;
                                state[j-1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_D_DR_R1|
                                    STATE_H_R_R2|STATE_H_R_SIGN_R2;
                            }
                            else {
                                csj |= STATE_SIG_R2|STATE_VISITED_R2|
                                    STATE_NZ_CTXT_R1|STATE_V_D_R1;
                                state[j+sscanw] |= STATE_NZ_CTXT_R1|
                                    STATE_V_U_R1;
                                state[j+1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_D_DL_R1|STATE_H_L_R2;
                                state[j-1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_D_DR_R1|STATE_H_R_R2;
                            }
                        }
                        else {
                            csj |= STATE_VISITED_R2;
                        }
                    }
                    state[j] = csj;
                }
            }
        }

        error = false;

        // Check the byte padding if the pass is terminated
        if (isterm) {
            error = bin.checkBytePadding();
        }

        // Return error condition
        return error;
    }

    /**
     * Performs the magnitude refinement pass on the specified data and
     * bit-plane. It decodes the samples which are significant and which do not
     * have the "visited" state bit turned on, using the MR primitive. The
     * "visited" state bit is not mofified for any samples.
     *
     * <P>This method also checks for segmentation markers if those are
     * present and returns true if an error is detected, or false
     * otherwise. If an error is detected it means that the bit stream contains
     * some erroneous bit that have led to the decoding of incorrect
     * data. This data affects the whole last decoded bit-plane (i.e. 'bp'). If
     * 'true' is returned the 'conceal' method should be called and no more
     * passes should be decoded for this code-block's bit stream.
     *
     * @param cblk The code-block data to decode
     *
     * @param mq The MQ-decoder to use
     *
     * @param bp The bit-plane to decode
     *
     * @param state The state information for the code-block
     *
     * @param isterm If this pass has been terminated. If the pass has been
     * terminated it can be used to check error resilience.
     *
     * @return True if an error was detected in the bit stream, false otherwise.
     * */
    private boolean magRefPass(DataBlk cblk, MQDecoder mq, int bp,
                               int state[], boolean isterm) {
        int j,sj;        // The state index for line and stripe
        int k,sk;        // The data index for line and stripe
        int dscanw;      // The data scan-width
        int sscanw;      // The state scan-width
        int jstep;       // Stripe to stripe step for 'sj'
        int kstep;       // Stripe to stripe step for 'sk'
        int stopsk;      // The loop limit on the variable sk
        int csj;         // Local copy (i.e. cached) of 'state[j]'
        int setmask;     // The mask to set lower bit-planes to 1/2 approximation
        int resetmask;   // The mask to reset approximation bit-planes
        int sym;         // The symbol to decode
        int data[];      // The data buffer
        int s;           // The stripe index
        int nstripes;    // The number of stripes in the code-block
        int sheight;     // Height of the current stripe
        boolean error;   // The error condition

        // Initialize local variables
        dscanw = cblk.scanw;
        sscanw = cblk.w+2;
        jstep = sscanw*STRIPE_HEIGHT/2-cblk.w;
        kstep = dscanw*STRIPE_HEIGHT-cblk.w;
        setmask = (1<<bp)>>1;
        resetmask = (-1)<<(bp+1);
        data = (int[]) cblk.getData();
        nstripes = (cblk.h+STRIPE_HEIGHT-1)/STRIPE_HEIGHT;

        // Decode stripe by stripe
        sk = cblk.offset;
        sj = sscanw+1;
        for (s = nstripes-1; s >= 0; s--, sk+=kstep, sj+=jstep) {
            sheight = (s != 0) ? STRIPE_HEIGHT :
                cblk.h-(nstripes-1)*STRIPE_HEIGHT;
            stopsk = sk+cblk.w;
            // Scan by set of 1 stripe column at a time
            for (; sk < stopsk; sk++, sj++) {
                // Do half top of column
                j = sj;
                csj = state[j];
                // If any of the two samples is significant and not yet
                // visited in the current bit-plane we can not skip them
                if ((((csj >>> 1) & (~csj)) & VSTD_MASK_R1R2) != 0) {
                    k = sk;
                    // Scan first row
                    if ((csj & (STATE_SIG_R1|STATE_VISITED_R1)) ==
                        STATE_SIG_R1) {
                        // Use MR primitive
                        sym = mq.decodeSymbol(MR_LUT[csj&MR_MASK]);
                        // Update the data
                        data[k] &= resetmask;
                        data[k] |= (sym<<bp)|setmask;
                        // Update the STATE_PREV_MR bit
                        csj |= STATE_PREV_MR_R1;
                    }
                    if (sheight < 2) {
                        state[j] = csj;
                        continue;
                    }
                    // Scan second row
                    if ((csj & (STATE_SIG_R2|STATE_VISITED_R2)) ==
                        STATE_SIG_R2) {
                        k += dscanw;
                        // Use MR primitive
                        sym = mq.decodeSymbol(MR_LUT[(csj>>>STATE_SEP)&
                                                    MR_MASK]);
                        // Update the data
                        data[k] &= resetmask;
                        data[k] |= (sym<<bp)|setmask;
                        // Update the STATE_PREV_MR bit
                        csj |= STATE_PREV_MR_R2;
                    }
                    state[j] = csj;
                }
                // Do half bottom of column
                if (sheight < 3) continue;
                j += sscanw;
                csj = state[j];
                // If any of the two samples is significant and not yet
                // visited in the current bit-plane we can not skip them
                if ((((csj >>> 1) & (~csj)) & VSTD_MASK_R1R2) != 0) {
                    k = sk+(dscanw<<1);
                    // Scan first row
                    if ((csj & (STATE_SIG_R1|STATE_VISITED_R1)) ==
                        STATE_SIG_R1) {
                        // Use MR primitive
                        sym = mq.decodeSymbol(MR_LUT[csj&MR_MASK]);
                        // Update the data
                        data[k] &= resetmask;
                        data[k] |= (sym<<bp)|setmask;
                        // Update the STATE_PREV_MR bit
                        csj |= STATE_PREV_MR_R1;
                    }
                    if (sheight < 4) {
                        state[j] = csj;
                        continue;
                    }
                    // Scan second row
                    if ((state[j] & (STATE_SIG_R2|STATE_VISITED_R2)) ==
                        STATE_SIG_R2) {
                        k += dscanw;
                        // Use MR primitive
                        sym = mq.decodeSymbol(MR_LUT[(csj>>>STATE_SEP)&
                                                    MR_MASK]);
                        // Update the data
                        data[k] &= resetmask;
                        data[k] |= (sym<<bp)|setmask;
                        // Update the STATE_PREV_MR bit
                        csj |= STATE_PREV_MR_R2;
                    }
                    state[j] = csj;
                }
            }
        }

        error = false;

        // Check the error resilient termination
        if (isterm && (options & OPT_PRED_TERM) != 0) {
            error = mq.checkPredTerm();
        }

        // Reset the MQ context states if we need to
        if ((options & OPT_RESET_MQ) != 0) {
            mq.resetCtxts();
        }

        // Return error condition
        return error;
    }

    /**
     * Performs the magnitude refinement pass on the specified data and
     * bit-plane. It decodes the samples which are significant and which do not
     * have the "visited" state bit turned on, using the MR primitive. The
     * "visited" state bit is not mofified for any samples.
     *
     * <P>This method bypasses the arithmetic coder and reads "raw" symbols
     * from the bit stream.
     *
     * <P>This method also checks for segmentation markers if those are
     * present and returns true if an error is detected, or false
     * otherwise. If an error is detected it measn that the bit stream contains
     * some erroneous bit that have led to the decoding of incorrect
     * data. This data affects the whole last decoded bit-plane (i.e. 'bp'). If
     * 'true' is returned the 'conceal' method should be called and no more
     * passes should be decoded for this code-block's bit stream.
     *
     * @param cblk The code-block data to decode
     *
     * @param bin The raw bit based input
     *
     * @param bp The bit-plane to decode
     *
     * @param state The state information for the code-block
     *
     * @param isterm If this pass has been terminated. If the pass has been
     * terminated it can be used to check error resilience.
     *
     * @return True if an error was detected in the bit stream, false otherwise.
     * */
    private boolean rawMagRefPass(DataBlk cblk, ByteToBitInput bin, int bp,
                                  int state[], boolean isterm) {
        int j,sj;        // The state index for line and stripe
        int k,sk;        // The data index for line and stripe
        int dscanw;      // The data scan-width
        int sscanw;      // The state scan-width
        int jstep;       // Stripe to stripe step for 'sj'
        int kstep;       // Stripe to stripe step for 'sk'
        int stopsk;      // The loop limit on the variable sk
        int csj;         // Local copy (i.e. cached) of 'state[j]'
        int setmask;     // The mask to set lower bit-planes to 1/2 approximation
        int resetmask;   // The mask to reset approximation bit-planes
        int sym;         // The symbol to decode
        int data[];      // The data buffer
        int s;           // The stripe index
        int nstripes;    // The number of stripes in the code-block
        int sheight;     // Height of the current stripe
        boolean error;   // The error condition

        // Initialize local variables
        dscanw = cblk.scanw;
        sscanw = cblk.w+2;
        jstep = sscanw*STRIPE_HEIGHT/2-cblk.w;
        kstep = dscanw*STRIPE_HEIGHT-cblk.w;
        setmask = (1<<bp)>>1;
        resetmask = (-1)<<(bp+1);
        data = (int[]) cblk.getData();
        nstripes = (cblk.h+STRIPE_HEIGHT-1)/STRIPE_HEIGHT;

        // Decode stripe by stripe
        sk = cblk.offset;
        sj = sscanw+1;
        for (s = nstripes-1; s >= 0; s--, sk+=kstep, sj+=jstep) {
            sheight = (s != 0) ? STRIPE_HEIGHT :
                cblk.h-(nstripes-1)*STRIPE_HEIGHT;
            stopsk = sk+cblk.w;
            // Scan by set of 1 stripe column at a time
            for (; sk < stopsk; sk++, sj++) {
                // Do half top of column
                j = sj;
                csj = state[j];
                // If any of the two samples is significant and not yet
                // visited in the current bit-plane we can not skip them
                if ((((csj >>> 1) & (~csj)) & VSTD_MASK_R1R2) != 0) {
                    k = sk;
                    // Scan first row
                    if ((csj & (STATE_SIG_R1|STATE_VISITED_R1)) ==
                        STATE_SIG_R1) {
                        // Read raw bit (no MR primative)
                        sym = bin.readBit();
                        // Update the data
                        data[k] &= resetmask;
                        data[k] |= (sym<<bp)|setmask;
                        // No need to set STATE_PREV_MR_R1 since all magnitude
                        // refinement passes to follow are "raw"
                    }
                    if (sheight < 2) continue;
                    // Scan second row
                    if ((csj & (STATE_SIG_R2|STATE_VISITED_R2)) ==
                        STATE_SIG_R2) {
                        k += dscanw;
                        // Read raw bit (no MR primative)
                        sym = bin.readBit();
                        // Update the data
                        data[k] &= resetmask;
                        data[k] |= (sym<<bp)|setmask;
                        // No need to set STATE_PREV_MR_R1 since all magnitude
                        // refinement passes to follow are "raw"
                    }
                }
                // Do half bottom of column
                if (sheight < 3) continue;
                j += sscanw;
                csj = state[j];
                // If any of the two samples is significant and not yet
                // visited in the current bit-plane we can not skip them
                if ((((csj >>> 1) & (~csj)) & VSTD_MASK_R1R2) != 0) {
                    k = sk+(dscanw<<1);
                    // Scan first row
                    if ((csj & (STATE_SIG_R1|STATE_VISITED_R1)) ==
                        STATE_SIG_R1) {
                        // Read raw bit (no MR primative)
                        sym = bin.readBit();
                        // Update the data
                        data[k] &= resetmask;
                        data[k] |= (sym<<bp)|setmask;
                        // No need to set STATE_PREV_MR_R1 since all magnitude
                        // refinement passes to follow are "raw"
                    }
                    if (sheight < 4) continue;
                    // Scan second row
                    if ((state[j] & (STATE_SIG_R2|STATE_VISITED_R2)) ==
                        STATE_SIG_R2) {
                        k += dscanw;
                        // Read raw bit (no MR primative)
                        sym = bin.readBit();
                        // Update the data
                        data[k] &= resetmask;
                        data[k] |= (sym<<bp)|setmask;
                        // No need to set STATE_PREV_MR_R1 since all magnitude
                        // refinement passes to follow are "raw"
                    }
                }
            }
        }

        error = false;

        // Check the byte padding if the pass is terminated
        if (isterm && (options & OPT_PRED_TERM)!=0 ) {
            error = bin.checkBytePadding();
        }

        // Return error condition
        return error;
    }

    /**
     * Performs the cleanup pass on the specified data and bit-plane. It
     * decodes all insignificant samples which have its "visited" state bit
     * off, using the ZC, SC, and RLC primitives. It toggles the "visited"
     * state bit to 0 (off) for all samples in the code-block.
     *
     * <P>This method also checks for segmentation markers if those are
     * present and returns true if an error is detected, or false
     * otherwise. If an error is detected it measn that the bit stream
     * contains some erroneous bit that have led to the decoding of incorrect
     * data. This data affects the whole last decoded bit-plane
     * (i.e. 'bp'). If 'true' is returned the 'conceal' method should be
     * called and no more passes should be decoded for this code-block's bit
     * stream.
     *
     * @param cblk The code-block data to code
     *
     * @param mq The MQ-coder to use
     *
     * @param bp The bit-plane to decode
     *
     * @param state The state information for the code-block
     *
     * @param zc_lut The ZC lookup table to use in ZC.
     *
     * @param isterm If this pass has been terminated. If the pass has been
     * terminated it can be used to check error resilience.
     *
     * @return True if an error was detected in the bit stream, false
     * otherwise.
     * */
    private boolean cleanuppass(DataBlk cblk, MQDecoder mq, int bp,
                                int state[], int zc_lut[], boolean isterm) {
        int j,sj;        // The state index for line and stripe
        int k,sk;        // The data index for line and stripe
        int dscanw;      // The data scan-width
        int sscanw;      // The state scan-width
        int jstep;       // Stripe to stripe step for 'sj'
        int kstep;       // Stripe to stripe step for 'sk'
        int stopsk;      // The loop limit on the variable sk
        int csj;         // Local copy (i.e. cached) of 'state[j]'
        int setmask;     // The mask to set current and lower bit-planes to 1/2
                         // approximation
        int sym;         // The decoded symbol
        int rlclen;      // Length of RLC
        int ctxt;        // The context to use
        int data[];      // The data buffer
        int s;           // The stripe index
        boolean causal;  // Flag to indicate if stripe-causal context
                         // formation is to be used
        int nstripes;    // The number of stripes in the code-block
        int sheight;     // Height of the current stripe
        int off_ul,off_ur,off_dr,off_dl; // offsets
        boolean error;   // The error condition

        // Initialize local variables
        dscanw = cblk.scanw;
        sscanw = cblk.w+2;
        jstep = sscanw*STRIPE_HEIGHT/2-cblk.w;
        kstep = dscanw*STRIPE_HEIGHT-cblk.w;
        setmask = (3<<bp)>>1;
        data = (int[]) cblk.getData();
        nstripes = (cblk.h+STRIPE_HEIGHT-1)/STRIPE_HEIGHT;
        causal = (options & OPT_VERT_STR_CAUSAL) != 0;

        // Pre-calculate offsets in 'state' for diagonal neighbors
        off_ul = -sscanw-1;  // up-left
        off_ur =  -sscanw+1; // up-right
        off_dr = sscanw+1;   // down-right
        off_dl = sscanw-1;   // down-left

        // Decode stripe by stripe
        sk = cblk.offset;
        sj = sscanw+1;
        for (s = nstripes-1; s >= 0; s--, sk+=kstep, sj+=jstep) {
            sheight = (s != 0) ? STRIPE_HEIGHT :
                cblk.h-(nstripes-1)*STRIPE_HEIGHT;
            stopsk = sk+cblk.w;
            // Scan by set of 1 stripe column at a time
            for (; sk < stopsk; sk++, sj++) {
                // Start column
                j = sj;
                csj = state[j];
            top_half:
                {
                    // Check for RLC: if all samples are not significant, not
                    // visited and do not have a non-zero context, and column is
                    // full height, we do RLC.
                    if (csj == 0 && state[j+sscanw] == 0 &&
                        sheight == STRIPE_HEIGHT) {
                        if (mq.decodeSymbol(RLC_CTXT) != 0) {
                            // run-length is significant, decode length
                            rlclen = mq.decodeSymbol(UNIF_CTXT)<<1;
                            rlclen |= mq.decodeSymbol(UNIF_CTXT);
                            // Set 'k' and 'j' accordingly
                            k = sk+rlclen*dscanw;
                            if (rlclen > 1) {
                                j += sscanw;
                                csj = state[j];
                            }
                        }
                        else { // RLC is insignificant
                            // Goto next column
                            continue;
                        }
                        // We just decoded the length of a significant RLC
                        // and a sample became significant
                        // Use sign coding
                        if ((rlclen&0x01) == 0) {
                            // Sample that became significant is first row of
                            // its column half
                            ctxt = SC_LUT[(csj>>SC_SHIFT_R1)&SC_MASK];
                            sym = mq.decodeSymbol(ctxt & SC_LUT_MASK) ^
                                (ctxt>>>SC_SPRED_SHIFT);
                            // Update the data
                            data[k] = (sym<<31) | setmask;
                            // Update state information (significant bit,
                            // visited bit, neighbor significant bit of
                            // neighbors, non zero context of neighbors, sign
                            // of neighbors)
                            if (rlclen != 0 || !causal) {
                                // If in causal mode do not change
                                // contexts of previous stripe.
                                state[j+off_ul] |=
                                    STATE_NZ_CTXT_R2|STATE_D_DR_R2;
                                state[j+off_ur] |=
                                    STATE_NZ_CTXT_R2|STATE_D_DL_R2;
                            }
                            // Update sign state information of neighbors
                            if (sym != 0) {
                                csj |= STATE_SIG_R1|STATE_VISITED_R1|
                                    STATE_NZ_CTXT_R2|
                                    STATE_V_U_R2|STATE_V_U_SIGN_R2;
                                if (rlclen != 0 || !causal) {
                                    // If in causal mode do not change
                                    // contexts of previous stripe.
                                    state[j-sscanw] |= STATE_NZ_CTXT_R2|
                                        STATE_V_D_R2|STATE_V_D_SIGN_R2;
                                }
                                state[j+1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_H_L_R1|STATE_H_L_SIGN_R1|
                                    STATE_D_UL_R2;
                                state[j-1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_H_R_R1|STATE_H_R_SIGN_R1|
                                    STATE_D_UR_R2;
                            }
                            else {
                                csj |= STATE_SIG_R1|STATE_VISITED_R1|
                                    STATE_NZ_CTXT_R2|STATE_V_U_R2;
                                if (rlclen != 0 || !causal) {
                                    // If in causal mode do not change
                                    // contexts of previous stripe.
                                    state[j-sscanw] |= STATE_NZ_CTXT_R2|
                                        STATE_V_D_R2;
                                }
                                state[j+1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_H_L_R1|STATE_D_UL_R2;
                                state[j-1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_H_R_R1|STATE_D_UR_R2;
                            }
                            // Changes to csj are saved later
                            if ((rlclen>>1) != 0) {
                                // Sample that became significant is in
                                // bottom half of column => jump to bottom
                                // half
                                break top_half;
                            }
                            // Otherwise sample that became significant is in
                            // top half of column => continue on top half
                        }
                        else {
                            // Sample that became significant is second row of
                            // its column half
                            ctxt = SC_LUT[(csj>>SC_SHIFT_R2)&SC_MASK];
                            sym = mq.decodeSymbol(ctxt & SC_LUT_MASK) ^
                                (ctxt>>>SC_SPRED_SHIFT);
                            // Update the data
                            data[k] = (sym<<31) | setmask;
                            // Update state information (significant bit,
                            // neighbor significant bit of neighbors,
                            // non zero context of neighbors, sign of neighbors)
                            state[j+off_dl] |= STATE_NZ_CTXT_R1|STATE_D_UR_R1;
                            state[j+off_dr] |= STATE_NZ_CTXT_R1|STATE_D_UL_R1;
                            // Update sign state information of neighbors
                            if (sym != 0) {
                                csj |= STATE_SIG_R2|STATE_NZ_CTXT_R1|
                                    STATE_V_D_R1|STATE_V_D_SIGN_R1;
                                state[j+sscanw] |= STATE_NZ_CTXT_R1|
                                    STATE_V_U_R1|STATE_V_U_SIGN_R1;
                                state[j+1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_D_DL_R1|
                                    STATE_H_L_R2|STATE_H_L_SIGN_R2;
                                state[j-1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_D_DR_R1|
                                    STATE_H_R_R2|STATE_H_R_SIGN_R2;
                            }
                            else {
                                csj |= STATE_SIG_R2|STATE_NZ_CTXT_R1|
                                    STATE_V_D_R1;
                                state[j+sscanw] |= STATE_NZ_CTXT_R1|
                                    STATE_V_U_R1;
                                state[j+1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_D_DL_R1|STATE_H_L_R2;
                                state[j-1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_D_DR_R1|STATE_H_R_R2;
                            }
                            // Save changes to csj
                            state[j] = csj;
                            if ((rlclen>>1) != 0) {
                                // Sample that became significant is in bottom
                                // half of column => we're done with this
                                // column
                                continue;
                            }
                            // Otherwise sample that became significant is in
                            // top half of column => we're done with top
                            // column
                            j += sscanw;
                            csj = state[j];
                            break top_half;
                        }
                    }
                    // Do half top of column
                    // If any of the two samples is not significant and has
                    // not been visited in the current bit-plane we can not
                    // skip them
                    if ((((csj>>1)|csj) & VSTD_MASK_R1R2) != VSTD_MASK_R1R2) {
                        k = sk;
                        // Scan first row
                        if ((csj & (STATE_SIG_R1|STATE_VISITED_R1)) == 0) {
                            // Use zero coding
                            if (mq.decodeSymbol(zc_lut[csj&ZC_MASK]) != 0) {
                                // Became significant
                                // Use sign coding
                                ctxt = SC_LUT[(csj>>>SC_SHIFT_R1)&SC_MASK];
                                sym = mq.decodeSymbol(ctxt & SC_LUT_MASK) ^
                                    (ctxt>>>SC_SPRED_SHIFT);
                                // Update the data
                                data[k] = (sym<<31) | setmask;
                                // Update state information (significant bit,
                                // visited bit, neighbor significant bit of
                                // neighbors, non zero context of neighbors,
                                // sign of neighbors)
                                if (!causal) {
                                    // If in causal mode do not change
                                    // contexts of previous stripe.
                                    state[j+off_ul] |=
                                        STATE_NZ_CTXT_R2|STATE_D_DR_R2;
                                    state[j+off_ur] |=
                                        STATE_NZ_CTXT_R2|STATE_D_DL_R2;
                                }
                                // Update sign state information of neighbors
                                if (sym != 0) {
                                    csj |= STATE_SIG_R1|STATE_VISITED_R1|
                                        STATE_NZ_CTXT_R2|
                                        STATE_V_U_R2|STATE_V_U_SIGN_R2;
                                    if (!causal) {
                                        // If in causal mode do not change
                                        // contexts of previous stripe.
                                        state[j-sscanw] |= STATE_NZ_CTXT_R2|
                                            STATE_V_D_R2|STATE_V_D_SIGN_R2;
                                    }
                                    state[j+1] |=
                                        STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                        STATE_H_L_R1|STATE_H_L_SIGN_R1|
                                        STATE_D_UL_R2;
                                    state[j-1] |=
                                        STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                        STATE_H_R_R1|STATE_H_R_SIGN_R1|
                                        STATE_D_UR_R2;
                                }
                                else {
                                    csj |= STATE_SIG_R1|STATE_VISITED_R1|
                                        STATE_NZ_CTXT_R2|STATE_V_U_R2;
                                    if (!causal) {
                                        // If in causal mode do not change
                                        // contexts of previous stripe.
                                        state[j-sscanw] |= STATE_NZ_CTXT_R2|
                                            STATE_V_D_R2;
                                    }
                                    state[j+1] |=
                                        STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                        STATE_H_L_R1|STATE_D_UL_R2;
                                    state[j-1] |=
                                        STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                        STATE_H_R_R1|STATE_D_UR_R2;
                                }
                            }
                        }
                        if (sheight < 2) {
                            csj &= ~(STATE_VISITED_R1|STATE_VISITED_R2);
                            state[j] = csj;
                            continue;
                        }
                        // Scan second row
                        if ((csj & (STATE_SIG_R2|STATE_VISITED_R2)) == 0) {
                            k += dscanw;
                            // Use zero coding
                            if (mq.decodeSymbol(zc_lut[(csj>>>STATE_SEP)&
                                                      ZC_MASK]) != 0) {
                                // Became significant
                                // Use sign coding
                                ctxt = SC_LUT[(csj>>>SC_SHIFT_R2)&SC_MASK];
                                sym = mq.decodeSymbol(ctxt & SC_LUT_MASK) ^
                                    (ctxt>>>SC_SPRED_SHIFT);
                                // Update the data
                                data[k] = (sym<<31) | setmask;
                                // Update state information (significant bit,
                                // visited bit, neighbor significant bit of
                                // neighbors, non zero context of neighbors,
                                // sign of neighbors)
                                state[j+off_dl] |=
                                    STATE_NZ_CTXT_R1|STATE_D_UR_R1;
                                state[j+off_dr] |=
                                    STATE_NZ_CTXT_R1|STATE_D_UL_R1;
                                // Update sign state information of neighbors
                                if (sym != 0) {
                                    csj |= STATE_SIG_R2|STATE_VISITED_R2|
                                        STATE_NZ_CTXT_R1|
                                        STATE_V_D_R1|STATE_V_D_SIGN_R1;
                                    state[j+sscanw] |= STATE_NZ_CTXT_R1|
                                        STATE_V_U_R1|STATE_V_U_SIGN_R1;
                                    state[j+1] |=
                                        STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                        STATE_D_DL_R1|
                                        STATE_H_L_R2|STATE_H_L_SIGN_R2;
                                    state[j-1] |=
                                        STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                        STATE_D_DR_R1|
                                        STATE_H_R_R2|STATE_H_R_SIGN_R2;
                                }
                                else {
                                    csj |= STATE_SIG_R2|STATE_VISITED_R2|
                                        STATE_NZ_CTXT_R1|STATE_V_D_R1;
                                    state[j+sscanw] |= STATE_NZ_CTXT_R1|
                                        STATE_V_U_R1;
                                    state[j+1] |=
                                        STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                        STATE_D_DL_R1|STATE_H_L_R2;
                                    state[j-1] |=
                                        STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                        STATE_D_DR_R1|STATE_H_R_R2;
                                }
                            }
                        }
                    }
                    csj &= ~(STATE_VISITED_R1|STATE_VISITED_R2);
                    state[j] = csj;
                    // Do half bottom of column
                    if (sheight < 3) continue;
                    j += sscanw;
                    csj = state[j];
                } // end of 'top_half' block
                // If any of the two samples is not significant and has
                // not been visited in the current bit-plane we can not
                // skip them
                if ((((csj>>1)|csj) & VSTD_MASK_R1R2) != VSTD_MASK_R1R2) {
                    k = sk+(dscanw<<1);
                    // Scan first row
                    if ((csj & (STATE_SIG_R1|STATE_VISITED_R1)) == 0) {
                        // Use zero coding
                        if (mq.decodeSymbol(zc_lut[csj&ZC_MASK]) != 0) {
                            // Became significant
                            // Use sign coding
                            ctxt = SC_LUT[(csj>>SC_SHIFT_R1)&SC_MASK];
                            sym = mq.decodeSymbol(ctxt & SC_LUT_MASK) ^
                                (ctxt>>>SC_SPRED_SHIFT);
                            // Update the data
                            data[k] = (sym<<31) | setmask;
                            // Update state information (significant bit,
                            // visited bit, neighbor significant bit of
                            // neighbors, non zero context of neighbors,
                            // sign of neighbors)
                            state[j+off_ul] |=
                                STATE_NZ_CTXT_R2|STATE_D_DR_R2;
                            state[j+off_ur] |=
                                STATE_NZ_CTXT_R2|STATE_D_DL_R2;
                            // Update sign state information of neighbors
                            if (sym != 0) {
                                csj |= STATE_SIG_R1|STATE_VISITED_R1|
                                    STATE_NZ_CTXT_R2|
                                    STATE_V_U_R2|STATE_V_U_SIGN_R2;
                                state[j-sscanw] |= STATE_NZ_CTXT_R2|
                                    STATE_V_D_R2|STATE_V_D_SIGN_R2;
                                state[j+1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_H_L_R1|STATE_H_L_SIGN_R1|
                                    STATE_D_UL_R2;
                                state[j-1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_H_R_R1|STATE_H_R_SIGN_R1|
                                    STATE_D_UR_R2;
                            }
                            else {
                                csj |= STATE_SIG_R1|STATE_VISITED_R1|
                                    STATE_NZ_CTXT_R2|STATE_V_U_R2;
                                state[j-sscanw] |= STATE_NZ_CTXT_R2|
                                    STATE_V_D_R2;
                                state[j+1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_H_L_R1|STATE_D_UL_R2;
                                state[j-1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_H_R_R1|STATE_D_UR_R2;
                            }
                        }
                    }
                    if (sheight < 4) {
                        csj &= ~(STATE_VISITED_R1|STATE_VISITED_R2);
                        state[j] = csj;
                        continue;
                    }
                    // Scan second row
                    if ((csj & (STATE_SIG_R2|STATE_VISITED_R2)) == 0) {
                        k += dscanw;
                        // Use zero coding
                        if (mq.decodeSymbol(zc_lut[(csj>>>STATE_SEP)&
                                                  ZC_MASK]) != 0) {
                            // Became significant
                            // Use sign coding
                            ctxt = SC_LUT[(csj>>>SC_SHIFT_R2)&SC_MASK];
                            sym = mq.decodeSymbol(ctxt & SC_LUT_MASK) ^
                                (ctxt>>>SC_SPRED_SHIFT);
                            // Update the data
                            data[k] = (sym<<31) | setmask;
                            // Update state information (significant bit,
                            // visited bit, neighbor significant bit of
                            // neighbors, non zero context of neighbors,
                            // sign of neighbors)
                            state[j+off_dl] |=
                                STATE_NZ_CTXT_R1|STATE_D_UR_R1;
                            state[j+off_dr] |=
                                STATE_NZ_CTXT_R1|STATE_D_UL_R1;
                            // Update sign state information of neighbors
                            if (sym != 0) {
                                csj |= STATE_SIG_R2|STATE_VISITED_R2|
                                    STATE_NZ_CTXT_R1|
                                    STATE_V_D_R1|STATE_V_D_SIGN_R1;
                                state[j+sscanw] |= STATE_NZ_CTXT_R1|
                                    STATE_V_U_R1|STATE_V_U_SIGN_R1;
                                state[j+1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_D_DL_R1|
                                    STATE_H_L_R2|STATE_H_L_SIGN_R2;
                                state[j-1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_D_DR_R1|
                                    STATE_H_R_R2|STATE_H_R_SIGN_R2;
                            }
                            else {
                                csj |= STATE_SIG_R2|STATE_VISITED_R2|
                                    STATE_NZ_CTXT_R1|STATE_V_D_R1;
                                state[j+sscanw] |= STATE_NZ_CTXT_R1|
                                    STATE_V_U_R1;
                                state[j+1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_D_DL_R1|STATE_H_L_R2;
                                state[j-1] |=
                                    STATE_NZ_CTXT_R1|STATE_NZ_CTXT_R2|
                                    STATE_D_DR_R1|STATE_H_R_R2;
                            }
                        }
                    }
                }
                csj &= ~(STATE_VISITED_R1|STATE_VISITED_R2);
                state[j] = csj;
            }
        }

        // Decode segment marker if we need to
        if ((options & OPT_SEG_SYMBOLS) != 0) {
            sym = mq.decodeSymbol(UNIF_CTXT)<<3;
            sym |= mq.decodeSymbol(UNIF_CTXT)<<2;
            sym |= mq.decodeSymbol(UNIF_CTXT)<<1;
            sym |= mq.decodeSymbol(UNIF_CTXT);
            // Set error condition accordingly
            error = sym != SEG_SYMBOL;
        }
        else { // We can not detect any errors
            error = false;
        }

        // Check the error resilient termination
        if (isterm && (options & OPT_PRED_TERM) != 0) {
            error = mq.checkPredTerm();
        }

        // Reset the MQ context states if we need to
        if ((options & OPT_RESET_MQ) != 0) {
            mq.resetCtxts();
        }

        // Return error condition
        return error;
    }

    /**
     * Conceals decoding errors detected in the last bit-plane. The
     * concealement resets the state of the decoded data to what it was before
     * the decoding of bit-plane 'bp' started. No more data should be decoded
     * after this method is called for this code-block's data to which it is
     * applied.
     *
     * @param cblk The code-block's data
     *
     * @param bp The last decoded bit-plane (which contains errors).
     * */
    private void conceal(DataBlk cblk, int bp) {
        int l;         // line index
        int k;         // array index
        int kmax;      // 'k' limit
        int dk;        // Value of data[k]
        int data[];    // the data array
        int setmask;   // Bitmask to set approximation to 1/2 of
                       // known interval on significant data
        int resetmask; // Bitmask to erase all the data from
                       // bit-plane 'bp'

        // Initialize masks
        setmask = 1<<bp;
        resetmask = (-1)<<(bp);

        // Get the data array
        data = (int[]) cblk.getData();

        // Visit each sample, apply the reset mask to it and add an
        // approximation if significant.
        for (l=cblk.h-1, k=cblk.offset; l>=0; l--) {
            for (kmax = k+cblk.w; k<kmax; k++) {
                dk = data[k];
                if ((dk & resetmask & 0x7FFFFFFF) != 0) {
                    // Something was decoded in previous bit-planes => set the
                    // approximation for previous bit-plane
                    data[k] = (dk&resetmask)|setmask;
                }
                else {
                    // Was insignificant in previous bit-planes = set to zero
                    data[k] = 0;
                }
            }
            k += cblk.scanw-cblk.w;
        }

    }
}