org.jpedal.jbig2.decoders.ArithmeticDecoder Maven / Gradle / Ivy
/**
* ===========================================
* 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;
genericRegionStats = new ArithmeticDecoderStats(1 << 1);
refinementRegionStats = new ArithmeticDecoderStats(1 << 1);
iadhStats = new ArithmeticDecoderStats(1 << 9);
iadwStats = new ArithmeticDecoderStats(1 << 9);
iaexStats = new ArithmeticDecoderStats(1 << 9);
iaaiStats = new ArithmeticDecoderStats(1 << 9);
iadtStats = new ArithmeticDecoderStats(1 << 9);
iaitStats = new ArithmeticDecoderStats(1 << 9);
iafsStats = new ArithmeticDecoderStats(1 << 9);
iadsStats = new ArithmeticDecoderStats(1 << 9);
iardxStats = new ArithmeticDecoderStats(1 << 9);
iardyStats = new ArithmeticDecoderStats(1 << 9);
iardwStats = new ArithmeticDecoderStats(1 << 9);
iardhStats = new ArithmeticDecoderStats(1 << 9);
iariStats = new ArithmeticDecoderStats(1 << 9);
iaidStats = new ArithmeticDecoderStats(1 << 1);
}
public void resetIntStats(int symbolCodeLength) {
iadhStats.reset();
iadwStats.reset();
iaexStats.reset();
iaaiStats.reset();
iadtStats.reset();
iaitStats.reset();
iafsStats.reset();
iadsStats.reset();
iardxStats.reset();
iardyStats.reset();
iardwStats.reset();
iardhStats.reset();
iariStats.reset();
if (iaidStats.getContextSize() == 1 << (symbolCodeLength + 1)) {
iaidStats.reset();
} else {
iaidStats = new ArithmeticDecoderStats(1 << (symbolCodeLength + 1));
}
}
public void resetGenericStats(int template, ArithmeticDecoderStats previousStats) {
int size = contextSize[template];
if (previousStats != null && previousStats.getContextSize() == size) {
if (genericRegionStats.getContextSize() == size) {
genericRegionStats.overwrite(previousStats);
} else {
genericRegionStats = previousStats.copy();
}
} else {
if (genericRegionStats.getContextSize() == size) {
genericRegionStats.reset();
} else {
genericRegionStats = new ArithmeticDecoderStats(1 << size);
}
}
}
public void resetRefinementStats(int template, ArithmeticDecoderStats previousStats) {
int size = referredToContextSize[template];
if (previousStats != null && previousStats.getContextSize() == size) {
if (refinementRegionStats.getContextSize() == size) {
refinementRegionStats.overwrite(previousStats);
} else {
refinementRegionStats = previousStats.copy();
}
} else {
if (refinementRegionStats.getContextSize() == size) {
refinementRegionStats.reset();
} else {
refinementRegionStats = new ArithmeticDecoderStats(1 << size);
}
}
}
public void start() throws IOException {
buffer0 = reader.readByte();
buffer1 = reader.readByte();
c = BinaryOperation.bit32Shift((buffer0 ^ 0xff), 16, BinaryOperation.LEFT_SHIFT);
readByte();
c = BinaryOperation.bit32Shift(c, 7, BinaryOperation.LEFT_SHIFT);
counter -= 7;
a = 0x80000000l;
}
public DecodeIntResult decodeInt(ArithmeticDecoderStats stats) throws IOException {
long value;
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.bit32Shift(value, 1, BinaryOperation.LEFT_SHIFT) | decodeIntBit(stats);
}
value += 4436;
} else {
value = 0;
for (int i = 0; i < 12; i++) {
value = BinaryOperation.bit32Shift(value, 1, BinaryOperation.LEFT_SHIFT) | decodeIntBit(stats);
}
value += 340;
}
} else {
value = 0;
for (int i = 0; i < 8; i++) {
value = BinaryOperation.bit32Shift(value, 1, BinaryOperation.LEFT_SHIFT) | decodeIntBit(stats);
}
value += 84;
}
} else {
value = 0;
for (int i = 0; i < 6; i++) {
value = BinaryOperation.bit32Shift(value, 1, BinaryOperation.LEFT_SHIFT) | decodeIntBit(stats);
}
value += 20;
}
} else {
value = decodeIntBit(stats);
value = BinaryOperation.bit32Shift(value, 1, BinaryOperation.LEFT_SHIFT) | decodeIntBit(stats);
value = BinaryOperation.bit32Shift(value, 1, BinaryOperation.LEFT_SHIFT) | decodeIntBit(stats);
value = BinaryOperation.bit32Shift(value, 1, BinaryOperation.LEFT_SHIFT) | decodeIntBit(stats);
value += 4;
}
} else {
value = decodeIntBit(stats);
value = BinaryOperation.bit32Shift(value, 1, BinaryOperation.LEFT_SHIFT) | 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 {
previous = 1;
for (long i = 0; i < codeLen; i++) {
int bit = decodeBit(previous, stats);
previous = BinaryOperation.bit32Shift(previous, 1, BinaryOperation.LEFT_SHIFT) | bit;
}
return 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 = qeTable[iCX];
a -= qe;
int bit;
if (c < a) {
if ((a & 0x80000000) != 0) {
bit = mpsCX;
} else {
if (a < qe) {
bit = 1 - mpsCX;
if (switchTable[iCX] != 0) {
stats.setContextCodingTableValue((int) context, (nlpsTable[iCX] << 1) | (1 - mpsCX));
} else {
stats.setContextCodingTableValue((int) context, (nlpsTable[iCX] << 1) | mpsCX);
}
} else {
bit = mpsCX;
stats.setContextCodingTableValue((int) context, (nmpsTable[iCX] << 1) | mpsCX);
}
do {
if (counter == 0) {
readByte();
}
a = BinaryOperation.bit32Shift(a, 1, BinaryOperation.LEFT_SHIFT);
c = BinaryOperation.bit32Shift(c, 1, BinaryOperation.LEFT_SHIFT);
counter--;
} while ((a & 0x80000000) == 0);
}
} else {
c -= a;
if (a < qe) {
bit = mpsCX;
stats.setContextCodingTableValue((int) context, (nmpsTable[iCX] << 1) | mpsCX);
} else {
bit = 1 - mpsCX;
if (switchTable[iCX] != 0) {
stats.setContextCodingTableValue((int) context, (nlpsTable[iCX] << 1) | (1 - mpsCX));
} else {
stats.setContextCodingTableValue((int) context, (nlpsTable[iCX] << 1) | mpsCX);
}
}
a = qe;
do {
if (counter == 0) {
readByte();
}
a = BinaryOperation.bit32Shift(a, 1, BinaryOperation.LEFT_SHIFT);
c = BinaryOperation.bit32Shift(c, 1, BinaryOperation.LEFT_SHIFT);
counter--;
} while ((a & 0x80000000) == 0);
}
return bit;
}
private void readByte() throws IOException {
if (buffer0 == 0xff) {
if (buffer1 > 0x8f) {
counter = 8;
} else {
buffer0 = buffer1;
buffer1 = reader.readByte();
c = c + 0xfe00 - (BinaryOperation.bit32Shift(buffer0, 9, BinaryOperation.LEFT_SHIFT));
counter = 7;
}
} else {
buffer0 = buffer1;
buffer1 = reader.readByte();
c = c + 0xff00 - (BinaryOperation.bit32Shift(buffer0, 8, BinaryOperation.LEFT_SHIFT));
counter = 8;
}
}
private int decodeIntBit(ArithmeticDecoderStats stats) throws IOException {
int bit;
bit = decodeBit(previous, stats);
if (previous < 0x100) {
previous = BinaryOperation.bit32Shift(previous, 1, BinaryOperation.LEFT_SHIFT) | bit;
} else {
previous = (((BinaryOperation.bit32Shift(previous, 1, BinaryOperation.LEFT_SHIFT)) | 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};
}