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/*
* $Id: JBIG2SegmentReader.java 3714 2009-02-20 21:04:16Z xlv $
*
* 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.aowagie.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.aowagie.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
*/
class JBIG2SegmentReader {
private static final int PAGE_INFORMATION = 48; //see 7.4.8.
private static final int END_OF_PAGE = 49; //see 7.4.9.
private static final int END_OF_FILE = 51; //see 7.4.11.
private final SortedMap segments = new TreeMap();
private final SortedMap pages = new TreeMap();
private final SortedSet globals = new TreeSet();
private final 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
*/
private static class JBIG2Segment implements Comparable {
private final int segmentNumber;
private long dataLength = -1;
private int page = -1;
private int[] referredToSegmentNumbers = null;
private boolean[] segmentRetentionFlags = null;
private int type = -1;
private boolean deferredNonRetain = false;
private int countOfReferredToSegments = -1;
private byte[] data = null;
private byte[] headerData = null;
private boolean page_association_size = false;
private int page_association_offset = -1;
private JBIG2Segment(final int segment_number) {
this.segmentNumber = segment_number;
}
// for the globals treeset
@Override
public int compareTo(final Object o) {
return this.compareTo((JBIG2Segment)o);
}
private int compareTo(final JBIG2Segment s) {
return this.segmentNumber - s.segmentNumber;
}
}
/**
* Inner class that holds information about a JBIG2 page.
* @since 2.1.5
*/
public static class JBIG2Page {
private final JBIG2SegmentReader sr;
private final SortedMap segs = new TreeMap();
int pageBitmapWidth = -1;
int pageBitmapHeight = -1;
private JBIG2Page(final int page, final JBIG2SegmentReader sr) {
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(final boolean for_embedding) throws IOException {
final ByteArrayOutputStream os = new ByteArrayOutputStream();
for (final Iterator i = this.segs.keySet().iterator(); i.hasNext(); ) {
final Integer sn = (Integer) i.next();
final JBIG2Segment s = (JBIG2Segment) this.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
final 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();
}
private void addSegment(final JBIG2Segment s) {
this.segs.put(Integer.valueOf(s.segmentNumber), s);
}
}
public JBIG2SegmentReader(final RandomAccessFileOrArray ra ) throws IOException {
this.ra = ra;
}
private static byte[] copyByteArray(final byte[] b) {
final 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("already attempted a read() on this Jbig2 File");
}
this.read = true;
readFileHeader();
// Annex D
if ( this.sequential ) {
// D.1
do {
final JBIG2Segment tmp = readHeader();
readSegment(tmp);
this.segments.put(Integer.valueOf(tmp.segmentNumber), tmp);
} while ( this.ra.getFilePointer() < this.ra.length() );
} else {
// D.2
JBIG2Segment tmp;
do {
tmp = readHeader();
this.segments.put(Integer.valueOf(tmp.segmentNumber), tmp);
} while ( tmp.type != END_OF_FILE );
final Iterator segs = this.segments.keySet().iterator();
while ( segs.hasNext() ) {
readSegment((JBIG2Segment)this.segments.get(segs.next()));
}
}
}
private void readSegment(final JBIG2Segment s) throws IOException {
final int ptr = this.ra.getFilePointer();
if ( s.dataLength == 0xffffffffl ) {
// TODO figure this bit out, 7.2.7
return;
}
final byte[] data = new byte[(int)s.dataLength];
this.ra.read(data);
s.data = data;
if ( s.type == PAGE_INFORMATION ) {
final int last = this.ra.getFilePointer();
this.ra.seek(ptr);
final int page_bitmap_width = this.ra.readInt();
final int page_bitmap_height = this.ra.readInt();
this.ra.seek(last);
final JBIG2Page p = (JBIG2Page)this.pages.get(Integer.valueOf(s.page));
if ( p == null ) {
throw new IllegalStateException("referring to widht/height of page we havent seen yet? " + s.page);
}
p.pageBitmapWidth = page_bitmap_width;
p.pageBitmapHeight = page_bitmap_height;
}
}
private JBIG2Segment readHeader() throws IOException {
final int ptr = this.ra.getFilePointer();
// 7.2.1
final int segment_number = this.ra.readInt();
final JBIG2Segment s = new JBIG2Segment(segment_number);
// 7.2.3
final int segment_header_flags = this.ra.read();
final boolean deferred_non_retain = ( segment_header_flags & 0x80 ) == 0x80;
s.deferredNonRetain = deferred_non_retain;
final boolean page_association_size = ( segment_header_flags & 0x40 ) == 0x40;
final int segment_type = segment_header_flags & 0x3f;
s.type = segment_type;
//7.2.4
int referred_to_byte0 = this.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
this.ra.seek(this.ra.getFilePointer() - 1);
count_of_referred_to_segments = this.ra.readInt() & 0x1fffffff;
segment_retention_flags = new boolean[count_of_referred_to_segments+1];
int i = 0;
int referred_to_current_byte = 0;
do {
final int j = i % 8;
if ( j == 0) {
referred_to_current_byte = this.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("count of referred-to segments had bad value in header for segment " + segment_number + " starting at " + 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] = this.ra.read();
} else if ( segment_number <= 65536 ) {
referred_to_segment_numbers[i] = this.ra.readUnsignedShort();
} else {
referred_to_segment_numbers[i] = (int)this.ra.readUnsignedInt(); // TODO wtf ack
}
}
s.referredToSegmentNumbers = referred_to_segment_numbers;
// 7.2.6
int segment_page_association;
final int page_association_offset = this.ra.getFilePointer() - ptr;
if ( page_association_size ) {
segment_page_association = this.ra.readInt();
} else {
segment_page_association = this.ra.read();
}
if ( segment_page_association < 0 ) {
throw new IllegalStateException("page " + segment_page_association + " invalid for segment " + segment_number + " starting at " + 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 && ! this.pages.containsKey(Integer.valueOf(segment_page_association)) ) {
this.pages.put(Integer.valueOf(segment_page_association), new JBIG2Page(segment_page_association, this));
}
if ( segment_page_association > 0 ) {
((JBIG2Page)this.pages.get(Integer.valueOf(segment_page_association))).addSegment(s);
} else {
this.globals.add(s);
}
// 7.2.7
final long segment_data_length = this.ra.readUnsignedInt();
// TODO the 0xffffffff value that might be here, and how to understand those afflicted segments
s.dataLength = segment_data_length;
final int end_ptr = this.ra.getFilePointer();
this.ra.seek(ptr);
final byte[] header_data = new byte[end_ptr - ptr];
this.ra.read(header_data);
s.headerData = header_data;
return s;
}
private void readFileHeader() throws IOException {
this.ra.seek(0);
final byte[] idstring = new byte[8];
this.ra.read(idstring);
final 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("file header idstring not good at byte " + i);
}
}
final int fileheaderflags = this.ra.read();
this.sequential = ( fileheaderflags & 0x1 ) == 0x1;
this.number_of_pages_known = ( fileheaderflags & 0x2) == 0x0;
if ( (fileheaderflags & 0xfc) != 0x0 ) {
throw new IllegalStateException("file header flags bits 2-7 not 0");
}
if ( this.number_of_pages_known ) {
this.number_of_pages = this.ra.readInt();
}
}
private int numberOfPages() {
return this.pages.size();
}
JBIG2Page getPage(final int page) {
return (JBIG2Page)this.pages.get(Integer.valueOf(page));
}
byte[] getGlobal(final boolean for_embedding) {
final ByteArrayOutputStream os = new ByteArrayOutputStream();
try {
for (final Iterator gitr = this.globals.iterator(); gitr.hasNext();) {
final 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 (final IOException e) {
e.printStackTrace();
}
if ( os.size() <= 0 ) {
return null;
}
return os.toByteArray();
}
@Override
public String toString() {
if ( this.read ) {
return "Jbig2SegmentReader: number of pages: " + this.numberOfPages();
} else {
return "Jbig2SegmentReader in indeterminate state.";
}
}
}
