org.jpedal.jbig2.decoders.ArithmeticDecoder Maven / Gradle / Ivy
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/**
* ===========================================
* Java Pdf Extraction Decoding Access Library
* ===========================================
*
* Project Info: http://www.jpedal.org
* (C) Copyright 1997-2008, IDRsolutions and Contributors.
* Main Developer: Simon Barnett
*
* This file is part of JPedal
*
* Copyright (c) 2008, IDRsolutions
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of the IDRsolutions nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY IDRsolutions ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL IDRsolutions BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Other JBIG2 image decoding implementations include
* jbig2dec (http://jbig2dec.sourceforge.net/)
* xpdf (http://www.foolabs.com/xpdf/)
*
* The final draft JBIG2 specification can be found at http://www.jpeg.org/public/fcd14492.pdf
*
* All three of the above resources were used in the writing of this software, with methodologies,
* processes and inspiration taken from all three.
*
* ---------------
* ArithmeticDecoder.java
* ---------------
*/
package org.jpedal.jbig2.decoders;
import java.io.IOException;
import org.jpedal.jbig2.io.StreamReader;
import org.jpedal.jbig2.util.BinaryOperation;
public class ArithmeticDecoder {
private StreamReader reader;
public ArithmeticDecoderStats genericRegionStats, refinementRegionStats;
public ArithmeticDecoderStats iadhStats, iadwStats, iaexStats, iaaiStats, iadtStats, iaitStats, iafsStats, iadsStats, iardxStats, iardyStats,
iardwStats, iardhStats, iariStats, iaidStats;
int contextSize[] = { 16, 13, 10, 10 }, referredToContextSize[] = { 13, 10 };
long buffer0, buffer1;
long c, a;
long previous;
int counter;
private ArithmeticDecoder() {}
public ArithmeticDecoder(StreamReader reader) {
this.reader = reader;
this.genericRegionStats = new ArithmeticDecoderStats(1 << 1);
this.refinementRegionStats = new ArithmeticDecoderStats(1 << 1);
this.iadhStats = new ArithmeticDecoderStats(1 << 9);
this.iadwStats = new ArithmeticDecoderStats(1 << 9);
this.iaexStats = new ArithmeticDecoderStats(1 << 9);
this.iaaiStats = new ArithmeticDecoderStats(1 << 9);
this.iadtStats = new ArithmeticDecoderStats(1 << 9);
this.iaitStats = new ArithmeticDecoderStats(1 << 9);
this.iafsStats = new ArithmeticDecoderStats(1 << 9);
this.iadsStats = new ArithmeticDecoderStats(1 << 9);
this.iardxStats = new ArithmeticDecoderStats(1 << 9);
this.iardyStats = new ArithmeticDecoderStats(1 << 9);
this.iardwStats = new ArithmeticDecoderStats(1 << 9);
this.iardhStats = new ArithmeticDecoderStats(1 << 9);
this.iariStats = new ArithmeticDecoderStats(1 << 9);
this.iaidStats = new ArithmeticDecoderStats(1 << 1);
}
public void resetIntStats(int symbolCodeLength) {
this.iadhStats.reset();
this.iadwStats.reset();
this.iaexStats.reset();
this.iaaiStats.reset();
this.iadtStats.reset();
this.iaitStats.reset();
this.iafsStats.reset();
this.iadsStats.reset();
this.iardxStats.reset();
this.iardyStats.reset();
this.iardwStats.reset();
this.iardhStats.reset();
this.iariStats.reset();
if (this.iaidStats.getContextSize() == 1 << (symbolCodeLength + 1)) {
this.iaidStats.reset();
}
else {
this.iaidStats = new ArithmeticDecoderStats(1 << (symbolCodeLength + 1));
}
}
public void resetGenericStats(int template, ArithmeticDecoderStats previousStats) {
int size = this.contextSize[template];
if (previousStats != null && previousStats.getContextSize() == size) {
if (this.genericRegionStats.getContextSize() == size) {
this.genericRegionStats.overwrite(previousStats);
}
else {
this.genericRegionStats = previousStats.copy();
}
}
else {
if (this.genericRegionStats.getContextSize() == size) {
this.genericRegionStats.reset();
}
else {
this.genericRegionStats = new ArithmeticDecoderStats(1 << size);
}
}
}
public void resetRefinementStats(int template, ArithmeticDecoderStats previousStats) {
int size = this.referredToContextSize[template];
if (previousStats != null && previousStats.getContextSize() == size) {
if (this.refinementRegionStats.getContextSize() == size) {
this.refinementRegionStats.overwrite(previousStats);
}
else {
this.refinementRegionStats = previousStats.copy();
}
}
else {
if (this.refinementRegionStats.getContextSize() == size) {
this.refinementRegionStats.reset();
}
else {
this.refinementRegionStats = new ArithmeticDecoderStats(1 << size);
}
}
}
public void start() throws IOException {
this.buffer0 = this.reader.readByte();
this.buffer1 = this.reader.readByte();
this.c = BinaryOperation.bit32ShiftL((this.buffer0 ^ 0xff), 16);
readByte();
this.c = BinaryOperation.bit32ShiftL(this.c, 7);
this.counter -= 7;
this.a = 0x80000000l;
}
public DecodeIntResult decodeInt(ArithmeticDecoderStats stats) throws IOException {
long value;
this.previous = 1;
int s = decodeIntBit(stats);
if (decodeIntBit(stats) != 0) {
if (decodeIntBit(stats) != 0) {
if (decodeIntBit(stats) != 0) {
if (decodeIntBit(stats) != 0) {
if (decodeIntBit(stats) != 0) {
value = 0;
for (int i = 0; i < 32; i++) {
value = BinaryOperation.bit32ShiftL(value, 1) | decodeIntBit(stats);
}
value += 4436;
}
else {
value = 0;
for (int i = 0; i < 12; i++) {
value = BinaryOperation.bit32ShiftL(value, 1) | decodeIntBit(stats);
}
value += 340;
}
}
else {
value = 0;
for (int i = 0; i < 8; i++) {
value = BinaryOperation.bit32ShiftL(value, 1) | decodeIntBit(stats);
}
value += 84;
}
}
else {
value = 0;
for (int i = 0; i < 6; i++) {
value = BinaryOperation.bit32ShiftL(value, 1) | decodeIntBit(stats);
}
value += 20;
}
}
else {
value = decodeIntBit(stats);
value = BinaryOperation.bit32ShiftL(value, 1) | decodeIntBit(stats);
value = BinaryOperation.bit32ShiftL(value, 1) | decodeIntBit(stats);
value = BinaryOperation.bit32ShiftL(value, 1) | decodeIntBit(stats);
value += 4;
}
}
else {
value = decodeIntBit(stats);
value = BinaryOperation.bit32ShiftL(value, 1) | decodeIntBit(stats);
}
int decodedInt;
if (s != 0) {
if (value == 0) {
return new DecodeIntResult((int) value, false);
}
decodedInt = (int) -value;
}
else {
decodedInt = (int) value;
}
return new DecodeIntResult(decodedInt, true);
}
public long decodeIAID(long codeLen, ArithmeticDecoderStats stats) throws IOException {
this.previous = 1;
for (long i = 0; i < codeLen; i++) {
int bit = decodeBit(this.previous, stats);
this.previous = BinaryOperation.bit32ShiftL(this.previous, 1) | bit;
}
return this.previous - (1 << codeLen);
}
public int decodeBit(long context, ArithmeticDecoderStats stats) throws IOException {
int iCX = BinaryOperation.bit8Shift(stats.getContextCodingTableValue((int) context), 1, BinaryOperation.RIGHT_SHIFT);
int mpsCX = stats.getContextCodingTableValue((int) context) & 1;
int qe = this.qeTable[iCX];
this.a -= qe;
int bit;
if (this.c < this.a) {
if ((this.a & 0x80000000) != 0) {
bit = mpsCX;
}
else {
if (this.a < qe) {
bit = 1 - mpsCX;
if (this.switchTable[iCX] != 0) {
stats.setContextCodingTableValue((int) context, (this.nlpsTable[iCX] << 1) | (1 - mpsCX));
}
else {
stats.setContextCodingTableValue((int) context, (this.nlpsTable[iCX] << 1) | mpsCX);
}
}
else {
bit = mpsCX;
stats.setContextCodingTableValue((int) context, (this.nmpsTable[iCX] << 1) | mpsCX);
}
do {
if (this.counter == 0) {
readByte();
}
this.a = BinaryOperation.bit32ShiftL(this.a, 1);
this.c = BinaryOperation.bit32ShiftL(this.c, 1);
this.counter--;
}
while ((this.a & 0x80000000) == 0);
}
}
else {
this.c -= this.a;
if (this.a < qe) {
bit = mpsCX;
stats.setContextCodingTableValue((int) context, (this.nmpsTable[iCX] << 1) | mpsCX);
}
else {
bit = 1 - mpsCX;
if (this.switchTable[iCX] != 0) {
stats.setContextCodingTableValue((int) context, (this.nlpsTable[iCX] << 1) | (1 - mpsCX));
}
else {
stats.setContextCodingTableValue((int) context, (this.nlpsTable[iCX] << 1) | mpsCX);
}
}
this.a = qe;
do {
if (this.counter == 0) {
readByte();
}
this.a = BinaryOperation.bit32ShiftL(this.a, 1);
this.c = BinaryOperation.bit32ShiftL(this.c, 1);
this.counter--;
}
while ((this.a & 0x80000000) == 0);
}
return bit;
}
private void readByte() throws IOException {
if (this.buffer0 == 0xff) {
if (this.buffer1 > 0x8f) {
this.counter = 8;
}
else {
this.buffer0 = this.buffer1;
this.buffer1 = this.reader.readByte();
this.c = this.c + 0xfe00 - (BinaryOperation.bit32ShiftL(this.buffer0, 9));
this.counter = 7;
}
}
else {
this.buffer0 = this.buffer1;
this.buffer1 = this.reader.readByte();
this.c = this.c + 0xff00 - (BinaryOperation.bit32ShiftL(this.buffer0, 8));
this.counter = 8;
}
}
private int decodeIntBit(ArithmeticDecoderStats stats) throws IOException {
int bit;
bit = decodeBit(this.previous, stats);
if (this.previous < 0x100) {
this.previous = BinaryOperation.bit32ShiftL(this.previous, 1) | bit;
}
else {
this.previous = (((BinaryOperation.bit32ShiftL(this.previous, 1)) | bit) & 0x1ff) | 0x100;
}
return bit;
}
int qeTable[] = { 0x56010000, 0x34010000, 0x18010000, 0x0AC10000, 0x05210000, 0x02210000, 0x56010000, 0x54010000, 0x48010000, 0x38010000,
0x30010000, 0x24010000, 0x1C010000, 0x16010000, 0x56010000, 0x54010000, 0x51010000, 0x48010000, 0x38010000, 0x34010000, 0x30010000,
0x28010000, 0x24010000, 0x22010000, 0x1C010000, 0x18010000, 0x16010000, 0x14010000, 0x12010000, 0x11010000, 0x0AC10000, 0x09C10000,
0x08A10000, 0x05210000, 0x04410000, 0x02A10000, 0x02210000, 0x01410000, 0x01110000, 0x00850000, 0x00490000, 0x00250000, 0x00150000,
0x00090000, 0x00050000, 0x00010000, 0x56010000 };
int nmpsTable[] = { 1, 2, 3, 4, 5, 38, 7, 8, 9, 10, 11, 12, 13, 29, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33,
34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 45, 46 };
int nlpsTable[] = { 1, 6, 9, 12, 29, 33, 6, 14, 14, 14, 17, 18, 20, 21, 14, 14, 15, 16, 17, 18, 19, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29,
30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 46 };
int switchTable[] = { 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0 };
}