/*
* $Id$
*
* Copyright 2009 by Nigel Kerr.
*
* The contents of this file are subject to the Mozilla Public License Version 1.1
* (the "License"); you may not use this file except in compliance with the License.
* You may obtain a copy of the License at http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the License.
*
* The Original Code is 'iText, a free JAVA-PDF library'.
*
* The Initial Developer of the Original Code is Bruno Lowagie. Portions created by
* the Initial Developer are Copyright (C) 1999-2009 by Bruno Lowagie.
* All Rights Reserved.
* Co-Developer of the code is Paulo Soares. Portions created by the Co-Developer
* are Copyright (C) 2000-2009 by Paulo Soares. All Rights Reserved.
*
* Contributor(s): all the names of the contributors are added in the source code
* where applicable.
*
* Alternatively, the contents of this file may be used under the terms of the
* LGPL license (the "GNU LIBRARY GENERAL PUBLIC LICENSE"), in which case the
* provisions of LGPL are applicable instead of those above. If you wish to
* allow use of your version of this file only under the terms of the LGPL
* License and not to allow others to use your version of this file under
* the MPL, indicate your decision by deleting the provisions above and
* replace them with the notice and other provisions required by the LGPL.
* If you do not delete the provisions above, a recipient may use your version
* of this file under either the MPL or the GNU LIBRARY GENERAL PUBLIC LICENSE.
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the MPL as stated above or under the terms of the GNU
* Library General Public License as published by the Free Software Foundation;
* either version 2 of the License, or any later version.
*
* This library is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU Library general Public License for more
* details.
*
* If you didn't download this code from the following link, you should check if
* you aren't using an obsolete version:
* http://www.lowagie.com/iText/
*/
package com.lowagie.text.pdf.codec;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Iterator;
import java.util.SortedMap;
import java.util.SortedSet;
import java.util.TreeMap;
import java.util.TreeSet;
import com.lowagie.text.error_messages.MessageLocalization;
import com.lowagie.text.pdf.RandomAccessFileOrArray;
/**
* Class to read a JBIG2 file at a basic level: understand all the segments,
* understand what segments belong to which pages, how many pages there are,
* what the width and height of each page is, and global segments if there
* are any. Or: the minimum required to be able to take a normal sequential
* or random-access organized file, and be able to embed JBIG2 pages as images
* in a PDF.
*
* TODO: the indeterminate-segment-size value of dataLength, else?
*
* @since 2.1.5
*/
public class JBIG2SegmentReader {
public static final int SYMBOL_DICTIONARY = 0; //see 7.4.2.
public static final int INTERMEDIATE_TEXT_REGION = 4; //see 7.4.3.
public static final int IMMEDIATE_TEXT_REGION = 6; //see 7.4.3.
public static final int IMMEDIATE_LOSSLESS_TEXT_REGION = 7; //see 7.4.3.
public static final int PATTERN_DICTIONARY = 16; //see 7.4.4.
public static final int INTERMEDIATE_HALFTONE_REGION = 20; //see 7.4.5.
public static final int IMMEDIATE_HALFTONE_REGION = 22; //see 7.4.5.
public static final int IMMEDIATE_LOSSLESS_HALFTONE_REGION = 23; //see 7.4.5.
public static final int INTERMEDIATE_GENERIC_REGION = 36; //see 7.4.6.
public static final int IMMEDIATE_GENERIC_REGION = 38; //see 7.4.6.
public static final int IMMEDIATE_LOSSLESS_GENERIC_REGION = 39; //see 7.4.6.
public static final int INTERMEDIATE_GENERIC_REFINEMENT_REGION = 40; //see 7.4.7.
public static final int IMMEDIATE_GENERIC_REFINEMENT_REGION = 42; //see 7.4.7.
public static final int IMMEDIATE_LOSSLESS_GENERIC_REFINEMENT_REGION = 43; //see 7.4.7.
public static final int PAGE_INFORMATION = 48; //see 7.4.8.
public static final int END_OF_PAGE = 49; //see 7.4.9.
public static final int END_OF_STRIPE = 50; //see 7.4.10.
public static final int END_OF_FILE = 51; //see 7.4.11.
public static final int PROFILES = 52; //see 7.4.12.
public static final int TABLES = 53; //see 7.4.13.
public static final int EXTENSION = 62; //see 7.4.14.
private final SortedMap segments = new TreeMap();
private final SortedMap pages = new TreeMap();
private final SortedSet globals = new TreeSet();
private RandomAccessFileOrArray ra;
private boolean sequential;
private boolean number_of_pages_known;
private int number_of_pages = -1;
private boolean read = false;
/**
* Inner class that holds information about a JBIG2 segment.
* @since 2.1.5
*/
public static class JBIG2Segment implements Comparable {
public final int segmentNumber;
public long dataLength = -1;
public int page = -1;
public int[] referredToSegmentNumbers = null;
public boolean[] segmentRetentionFlags = null;
public int type = -1;
public boolean deferredNonRetain = false;
public int countOfReferredToSegments = -1;
public byte[] data = null;
public byte[] headerData = null;
public boolean page_association_size = false;
public int page_association_offset = -1;
public JBIG2Segment(int segment_number) {
this.segmentNumber = segment_number;
}
// for the globals treeset
public int compareTo(Object o) {
return this.compareTo((JBIG2Segment)o);
}
public int compareTo(JBIG2Segment s) {
return this.segmentNumber - s.segmentNumber;
}
}
/**
* Inner class that holds information about a JBIG2 page.
* @since 2.1.5
*/
public static class JBIG2Page {
public final int page;
private final JBIG2SegmentReader sr;
private final SortedMap segs = new TreeMap();
public int pageBitmapWidth = -1;
public int pageBitmapHeight = -1;
public JBIG2Page(int page, JBIG2SegmentReader sr) {
this.page = page;
this.sr = sr;
}
/**
* return as a single byte array the header-data for each segment in segment number
* order, EMBEDDED organization, but i am putting the needed segments in SEQUENTIAL organization.
* if for_embedding, skip the segment types that are known to be not for acrobat.
* @param for_embedding
* @return a byte array
* @throws IOException
*/
public byte[] getData(boolean for_embedding) throws IOException {
ByteArrayOutputStream os = new ByteArrayOutputStream();
for (Iterator i = segs.keySet().iterator(); i.hasNext(); ) {
Integer sn = (Integer) i.next();
JBIG2Segment s = (JBIG2Segment) segs.get(sn);
// pdf reference 1.4, section 3.3.6 JBIG2Decode Filter
// D.3 Embedded organisation
if ( for_embedding &&
( s.type == END_OF_FILE || s.type == END_OF_PAGE ) ) {
continue;
}
if ( for_embedding ) {
// change the page association to page 1
byte[] headerData_emb = copyByteArray(s.headerData);
if ( s.page_association_size ) {
headerData_emb[s.page_association_offset] = 0x0;
headerData_emb[s.page_association_offset+1] = 0x0;
headerData_emb[s.page_association_offset+2] = 0x0;
headerData_emb[s.page_association_offset+3] = 0x1;
} else {
headerData_emb[s.page_association_offset] = 0x1;
}
os.write(headerData_emb);
} else {
os.write(s.headerData);
}
os.write(s.data);
}
os.close();
return os.toByteArray();
}
public void addSegment(JBIG2Segment s) {
segs.put(new Integer(s.segmentNumber), s);
}
}
public JBIG2SegmentReader(RandomAccessFileOrArray ra ) throws IOException {
this.ra = ra;
}
public static byte[] copyByteArray(byte[] b) {
byte[] bc = new byte[b.length];
System.arraycopy(b, 0, bc, 0, b.length);
return bc;
}
public void read() throws IOException {
if ( this.read ) {
throw new IllegalStateException(MessageLocalization.getComposedMessage("already.attempted.a.read.on.this.jbig2.file"));
}
this.read = true;
readFileHeader();
// Annex D
if ( this.sequential ) {
// D.1
do {
JBIG2Segment tmp = readHeader();
readSegment(tmp);
segments.put(new Integer(tmp.segmentNumber), tmp);
} while ( this.ra.getFilePointer() < this.ra.length() );
} else {
// D.2
JBIG2Segment tmp;
do {
tmp = readHeader();
segments.put(new Integer(tmp.segmentNumber), tmp);
} while ( tmp.type != END_OF_FILE );
Iterator segs = segments.keySet().iterator();
while ( segs.hasNext() ) {
readSegment((JBIG2Segment)segments.get(segs.next()));
}
}
}
void readSegment(JBIG2Segment s) throws IOException {
int ptr = ra.getFilePointer();
if ( s.dataLength == 0xffffffffl ) {
// TODO figure this bit out, 7.2.7
return;
}
byte[] data = new byte[(int)s.dataLength];
ra.read(data);
s.data = data;
if ( s.type == PAGE_INFORMATION ) {
int last = ra.getFilePointer();
ra.seek(ptr);
int page_bitmap_width = ra.readInt();
int page_bitmap_height = ra.readInt();
ra.seek(last);
JBIG2Page p = (JBIG2Page)pages.get(new Integer(s.page));
if ( p == null ) {
throw new IllegalStateException(MessageLocalization.getComposedMessage("referring.to.widht.height.of.page.we.havent.seen.yet.1", s.page));
}
p.pageBitmapWidth = page_bitmap_width;
p.pageBitmapHeight = page_bitmap_height;
}
}
JBIG2Segment readHeader() throws IOException {
int ptr = ra.getFilePointer();
// 7.2.1
int segment_number = ra.readInt();
JBIG2Segment s = new JBIG2Segment(segment_number);
// 7.2.3
int segment_header_flags = ra.read();
boolean deferred_non_retain = (( segment_header_flags & 0x80 ) == 0x80);
s.deferredNonRetain = deferred_non_retain;
boolean page_association_size = (( segment_header_flags & 0x40 ) == 0x40);
int segment_type = ( segment_header_flags & 0x3f );
s.type = segment_type;
//7.2.4
int referred_to_byte0 = ra.read();
int count_of_referred_to_segments = (referred_to_byte0 & 0xE0) >> 5;
int[] referred_to_segment_numbers = null;
boolean[] segment_retention_flags = null;
if ( count_of_referred_to_segments == 7 ) {
// at least five bytes
ra.seek(ra.getFilePointer() - 1);
count_of_referred_to_segments = ( ra.readInt() & 0x1fffffff );
segment_retention_flags = new boolean[count_of_referred_to_segments+1];
int i = 0;
int referred_to_current_byte = 0;
do {
int j = i % 8;
if ( j == 0) {
referred_to_current_byte = ra.read();
}
segment_retention_flags[i] = (((( 0x1 << j ) & referred_to_current_byte) >> j) == 0x1);
i++;
} while ( i <= count_of_referred_to_segments );
} else if ( count_of_referred_to_segments <= 4 ) {
// only one byte
segment_retention_flags = new boolean[count_of_referred_to_segments+1];
referred_to_byte0 &= 0x1f;
for ( int i = 0; i <= count_of_referred_to_segments; i++ ) {
segment_retention_flags[i] = (((( 0x1 << i ) & referred_to_byte0) >> i) == 0x1);
}
} else if ( count_of_referred_to_segments == 5 || count_of_referred_to_segments == 6 ) {
throw new IllegalStateException(MessageLocalization.getComposedMessage("count.of.referred.to.segments.had.bad.value.in.header.for.segment.1.starting.at.2", String.valueOf(segment_number), String.valueOf(ptr)));
}
s.segmentRetentionFlags = segment_retention_flags;
s.countOfReferredToSegments = count_of_referred_to_segments;
// 7.2.5
referred_to_segment_numbers = new int[count_of_referred_to_segments+1];
for ( int i = 1; i <= count_of_referred_to_segments; i++ ) {
if ( segment_number <= 256 ) {
referred_to_segment_numbers[i] = ra.read();
} else if ( segment_number <= 65536 ) {
referred_to_segment_numbers[i] = ra.readUnsignedShort();
} else {
referred_to_segment_numbers[i] = (int)ra.readUnsignedInt(); // TODO wtf ack
}
}
s.referredToSegmentNumbers = referred_to_segment_numbers;
// 7.2.6
int segment_page_association;
int page_association_offset = ra.getFilePointer() - ptr;
if ( page_association_size ) {
segment_page_association = ra.readInt();
} else {
segment_page_association = ra.read();
}
if ( segment_page_association < 0 ) {
throw new IllegalStateException(MessageLocalization.getComposedMessage("page.1.invalid.for.segment.2.starting.at.3", String.valueOf(segment_page_association), String.valueOf(segment_number), String.valueOf(ptr)));
}
s.page = segment_page_association;
// so we can change the page association at embedding time.
s.page_association_size = page_association_size;
s.page_association_offset = page_association_offset;
if ( segment_page_association > 0 && ! pages.containsKey(new Integer(segment_page_association)) ) {
pages.put(new Integer(segment_page_association), new JBIG2Page(segment_page_association, this));
}
if ( segment_page_association > 0 ) {
((JBIG2Page)pages.get(new Integer(segment_page_association))).addSegment(s);
} else {
globals.add(s);
}
// 7.2.7
long segment_data_length = ra.readUnsignedInt();
// TODO the 0xffffffff value that might be here, and how to understand those afflicted segments
s.dataLength = segment_data_length;
int end_ptr = ra.getFilePointer();
ra.seek(ptr);
byte[] header_data = new byte[end_ptr - ptr];
ra.read(header_data);
s.headerData = header_data;
return s;
}
void readFileHeader() throws IOException {
ra.seek(0);
byte[] idstring = new byte[8];
ra.read(idstring);
byte[] refidstring = {(byte)0x97, 0x4A, 0x42, 0x32, 0x0D, 0x0A, 0x1A, 0x0A};
for ( int i = 0; i < idstring.length; i++ ) {
if ( idstring[i] != refidstring[i] ) {
throw new IllegalStateException(MessageLocalization.getComposedMessage("file.header.idstring.not.good.at.byte.1", i));
}
}
int fileheaderflags = ra.read();
this.sequential = (( fileheaderflags & 0x1 ) == 0x1);
this.number_of_pages_known = (( fileheaderflags & 0x2) == 0x0);
if ( (fileheaderflags & 0xfc) != 0x0 ) {
throw new IllegalStateException(MessageLocalization.getComposedMessage("file.header.flags.bits.2.7.not.0"));
}
if ( this.number_of_pages_known ) {
this.number_of_pages = ra.readInt();
}
}
public int numberOfPages() {
return pages.size();
}
public int getPageHeight(int i) {
return ((JBIG2Page)pages.get(new Integer(i))).pageBitmapHeight;
}
public int getPageWidth(int i) {
return ((JBIG2Page)pages.get(new Integer(i))).pageBitmapWidth;
}
public JBIG2Page getPage(int page) {
return (JBIG2Page)pages.get(new Integer(page));
}
public byte[] getGlobal(boolean for_embedding) {
ByteArrayOutputStream os = new ByteArrayOutputStream();
try {
for (Iterator gitr = globals.iterator(); gitr.hasNext();) {
JBIG2Segment s = (JBIG2Segment)gitr.next();
if ( for_embedding &&
( s.type == END_OF_FILE || s.type == END_OF_PAGE ) ) {
continue;
}
os.write(s.headerData);
os.write(s.data);
}
os.close();
} catch (IOException e) {
e.printStackTrace();
}
if ( os.size() <= 0 ) {
return null;
}
return os.toByteArray();
}
public String toString() {
if ( this.read ) {
return "Jbig2SegmentReader: number of pages: " + this.numberOfPages();
} else {
return "Jbig2SegmentReader in indeterminate state.";
}
}
}