414 lines
10 KiB
PHP
414 lines
10 KiB
PHP
<?php
|
||
/**
|
||
* DjVu image handler.
|
||
*
|
||
* Copyright © 2006 Brion Vibber <brion@pobox.com>
|
||
* https://www.mediawiki.org/
|
||
*
|
||
* This program is free software; you can redistribute it and/or modify
|
||
* it under the terms of the GNU General Public License as published by
|
||
* the Free Software Foundation; either version 2 of the License, or
|
||
* (at your option) any later version.
|
||
*
|
||
* This program 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 General Public License for more details.
|
||
*
|
||
* You should have received a copy of the GNU General Public License along
|
||
* with this program; if not, write to the Free Software Foundation, Inc.,
|
||
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
|
||
* http://www.gnu.org/copyleft/gpl.html
|
||
*
|
||
* @file
|
||
* @ingroup Media
|
||
*/
|
||
|
||
use MediaWiki\Shell\Shell;
|
||
|
||
/**
|
||
* Support for detecting/validating DjVu image files and getting
|
||
* some basic file metadata (resolution etc)
|
||
*
|
||
* File format docs are available in source package for DjVuLibre:
|
||
* http://djvulibre.djvuzone.org/
|
||
*
|
||
* @ingroup Media
|
||
*/
|
||
class DjVuImage {
|
||
|
||
/**
|
||
* Memory limit for the DjVu description software
|
||
*/
|
||
private const DJVUTXT_MEMORY_LIMIT = 300000;
|
||
|
||
/** @var string */
|
||
private $mFilename;
|
||
|
||
/**
|
||
* @param string $filename The DjVu file name.
|
||
*/
|
||
public function __construct( $filename ) {
|
||
$this->mFilename = $filename;
|
||
}
|
||
|
||
/**
|
||
* Check if the given file is indeed a valid DjVu image file
|
||
* @return bool
|
||
*/
|
||
public function isValid() {
|
||
$info = $this->getInfo();
|
||
|
||
return $info !== false;
|
||
}
|
||
|
||
/**
|
||
* Return width and height
|
||
* @return array An array with "width" and "height" keys, or an empty array on failure.
|
||
*/
|
||
public function getImageSize() {
|
||
$data = $this->getInfo();
|
||
|
||
if ( $data !== false ) {
|
||
return [
|
||
'width' => $data['width'],
|
||
'height' => $data['height']
|
||
];
|
||
} else {
|
||
return [];
|
||
}
|
||
}
|
||
|
||
// ---------
|
||
|
||
/**
|
||
* For debugging; dump the IFF chunk structure
|
||
*/
|
||
public function dump() {
|
||
$file = fopen( $this->mFilename, 'rb' );
|
||
$header = fread( $file, 12 );
|
||
$arr = unpack( 'a4magic/a4chunk/NchunkLength', $header );
|
||
$chunk = $arr['chunk'];
|
||
$chunkLength = $arr['chunkLength'];
|
||
echo "$chunk $chunkLength\n";
|
||
$this->dumpForm( $file, $chunkLength, 1 );
|
||
fclose( $file );
|
||
}
|
||
|
||
private function dumpForm( $file, $length, $indent ) {
|
||
$start = ftell( $file );
|
||
$secondary = fread( $file, 4 );
|
||
echo str_repeat( ' ', $indent * 4 ) . "($secondary)\n";
|
||
while ( ftell( $file ) - $start < $length ) {
|
||
$chunkHeader = fread( $file, 8 );
|
||
if ( $chunkHeader == '' ) {
|
||
break;
|
||
}
|
||
$arr = unpack( 'a4chunk/NchunkLength', $chunkHeader );
|
||
$chunk = $arr['chunk'];
|
||
$chunkLength = $arr['chunkLength'];
|
||
echo str_repeat( ' ', $indent * 4 ) . "$chunk $chunkLength\n";
|
||
|
||
if ( $chunk == 'FORM' ) {
|
||
$this->dumpForm( $file, $chunkLength, $indent + 1 );
|
||
} else {
|
||
fseek( $file, $chunkLength, SEEK_CUR );
|
||
if ( $chunkLength & 1 ) {
|
||
// Padding byte between chunks
|
||
fseek( $file, 1, SEEK_CUR );
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
private function getInfo() {
|
||
Wikimedia\suppressWarnings();
|
||
$file = fopen( $this->mFilename, 'rb' );
|
||
Wikimedia\restoreWarnings();
|
||
if ( $file === false ) {
|
||
wfDebug( __METHOD__ . ": missing or failed file read" );
|
||
|
||
return false;
|
||
}
|
||
|
||
$header = fread( $file, 16 );
|
||
$info = false;
|
||
|
||
if ( strlen( $header ) < 16 ) {
|
||
wfDebug( __METHOD__ . ": too short file header" );
|
||
} else {
|
||
$arr = unpack( 'a4magic/a4form/NformLength/a4subtype', $header );
|
||
|
||
$subtype = $arr['subtype'];
|
||
if ( $arr['magic'] != 'AT&T' ) {
|
||
wfDebug( __METHOD__ . ": not a DjVu file" );
|
||
} elseif ( $subtype == 'DJVU' ) {
|
||
// Single-page document
|
||
$info = $this->getPageInfo( $file );
|
||
} elseif ( $subtype == 'DJVM' ) {
|
||
// Multi-page document
|
||
$info = $this->getMultiPageInfo( $file, $arr['formLength'] );
|
||
} else {
|
||
wfDebug( __METHOD__ . ": unrecognized DJVU file type '{$arr['subtype']}'" );
|
||
}
|
||
}
|
||
fclose( $file );
|
||
|
||
return $info;
|
||
}
|
||
|
||
private function readChunk( $file ) {
|
||
$header = fread( $file, 8 );
|
||
if ( strlen( $header ) < 8 ) {
|
||
return [ false, 0 ];
|
||
} else {
|
||
$arr = unpack( 'a4chunk/Nlength', $header );
|
||
|
||
return [ $arr['chunk'], $arr['length'] ];
|
||
}
|
||
}
|
||
|
||
private function skipChunk( $file, $chunkLength ) {
|
||
fseek( $file, $chunkLength, SEEK_CUR );
|
||
|
||
if ( ( $chunkLength & 1 ) && !feof( $file ) ) {
|
||
// padding byte
|
||
fseek( $file, 1, SEEK_CUR );
|
||
}
|
||
}
|
||
|
||
private function getMultiPageInfo( $file, $formLength ) {
|
||
// For now, we'll just look for the first page in the file
|
||
// and report its information, hoping others are the same size.
|
||
$start = ftell( $file );
|
||
do {
|
||
list( $chunk, $length ) = $this->readChunk( $file );
|
||
if ( !$chunk ) {
|
||
break;
|
||
}
|
||
|
||
if ( $chunk == 'FORM' ) {
|
||
$subtype = fread( $file, 4 );
|
||
if ( $subtype == 'DJVU' ) {
|
||
wfDebug( __METHOD__ . ": found first subpage" );
|
||
|
||
return $this->getPageInfo( $file );
|
||
}
|
||
$this->skipChunk( $file, $length - 4 );
|
||
} else {
|
||
wfDebug( __METHOD__ . ": skipping '$chunk' chunk" );
|
||
$this->skipChunk( $file, $length );
|
||
}
|
||
} while ( $length != 0 && !feof( $file ) && ftell( $file ) - $start < $formLength );
|
||
|
||
wfDebug( __METHOD__ . ": multi-page DJVU file contained no pages" );
|
||
|
||
return false;
|
||
}
|
||
|
||
private function getPageInfo( $file ) {
|
||
list( $chunk, $length ) = $this->readChunk( $file );
|
||
if ( $chunk != 'INFO' ) {
|
||
wfDebug( __METHOD__ . ": expected INFO chunk, got '$chunk'" );
|
||
|
||
return false;
|
||
}
|
||
|
||
if ( $length < 9 ) {
|
||
wfDebug( __METHOD__ . ": INFO should be 9 or 10 bytes, found $length" );
|
||
|
||
return false;
|
||
}
|
||
$data = fread( $file, $length );
|
||
if ( strlen( $data ) < $length ) {
|
||
wfDebug( __METHOD__ . ": INFO chunk cut off" );
|
||
|
||
return false;
|
||
}
|
||
|
||
$arr = unpack(
|
||
'nwidth/' .
|
||
'nheight/' .
|
||
'Cminor/' .
|
||
'Cmajor/' .
|
||
'vresolution/' .
|
||
'Cgamma', $data );
|
||
|
||
# Newer files have rotation info in byte 10, but we don't use it yet.
|
||
|
||
return [
|
||
'width' => $arr['width'],
|
||
'height' => $arr['height'],
|
||
'version' => "{$arr['major']}.{$arr['minor']}",
|
||
'resolution' => $arr['resolution'],
|
||
'gamma' => $arr['gamma'] / 10.0 ];
|
||
}
|
||
|
||
/**
|
||
* Return an XML string describing the DjVu image
|
||
* @return string|null|false
|
||
*/
|
||
public function retrieveMetaData() {
|
||
global $wgDjvuDump, $wgDjvuTxt;
|
||
|
||
if ( !$this->isValid() ) {
|
||
return false;
|
||
}
|
||
|
||
if ( isset( $wgDjvuDump ) ) {
|
||
# djvudump is faster than djvutoxml (now abandoned) as of version 3.5
|
||
# https://sourceforge.net/p/djvu/bugs/71/
|
||
$cmd = Shell::escape( $wgDjvuDump ) . ' ' . Shell::escape( $this->mFilename );
|
||
$dump = wfShellExec( $cmd );
|
||
$xml = $this->convertDumpToXML( $dump );
|
||
} else {
|
||
$xml = null;
|
||
}
|
||
# Text layer
|
||
if ( isset( $wgDjvuTxt ) ) {
|
||
$cmd = Shell::escape( $wgDjvuTxt ) . ' --detail=page ' . Shell::escape( $this->mFilename );
|
||
wfDebug( __METHOD__ . ": $cmd" );
|
||
$retval = '';
|
||
$txt = wfShellExec( $cmd, $retval, [], [ 'memory' => self::DJVUTXT_MEMORY_LIMIT ] );
|
||
if ( $retval == 0 ) {
|
||
# Strip some control characters
|
||
# Ignore carriage returns
|
||
$txt = preg_replace( "/\\\\013/", "", $txt );
|
||
# Replace runs of OCR region separators with a single extra line break
|
||
$txt = preg_replace( "/(?:\\\\(035|037))+/", "\n", $txt );
|
||
|
||
$reg = <<<EOR
|
||
/\(page\s[\d-]*\s[\d-]*\s[\d-]*\s[\d-]*\s*"
|
||
((?> # Text to match is composed of atoms of either:
|
||
\\\\. # - any escaped character
|
||
| # - any character different from " and \
|
||
[^"\\\\]+
|
||
)*?)
|
||
"\s*\)
|
||
| # Or page can be empty ; in this case, djvutxt dumps ()
|
||
\(\s*()\)/sx
|
||
EOR;
|
||
$txt = preg_replace_callback( $reg, [ $this, 'pageTextCallback' ], $txt );
|
||
$txt = "<DjVuTxt>\n<HEAD></HEAD>\n<BODY>\n" . $txt . "</BODY>\n</DjVuTxt>\n";
|
||
$xml = preg_replace( "/<DjVuXML>/", "<mw-djvu><DjVuXML>", $xml, 1 ) .
|
||
$txt .
|
||
'</mw-djvu>';
|
||
}
|
||
}
|
||
|
||
return $xml;
|
||
}
|
||
|
||
private function pageTextCallback( $matches ) {
|
||
# Get rid of invalid UTF-8, strip control characters
|
||
$val = htmlspecialchars( UtfNormal\Validator::cleanUp( stripcslashes( $matches[1] ) ) );
|
||
$val = str_replace( [ "\n", '<27>' ], [ ' ', '' ], $val );
|
||
return '<PAGE value="' . $val . '" />';
|
||
}
|
||
|
||
/**
|
||
* Hack to temporarily work around djvutoxml bug
|
||
* @param string $dump
|
||
* @return string|false
|
||
*/
|
||
private function convertDumpToXML( $dump ) {
|
||
if ( strval( $dump ) == '' ) {
|
||
return false;
|
||
}
|
||
|
||
$xml = <<<EOT
|
||
<?xml version="1.0" ?>
|
||
<!DOCTYPE DjVuXML PUBLIC "-//W3C//DTD DjVuXML 1.1//EN" "pubtext/DjVuXML-s.dtd">
|
||
<DjVuXML>
|
||
<HEAD></HEAD>
|
||
<BODY>
|
||
EOT;
|
||
|
||
$dump = str_replace( "\r", '', $dump );
|
||
$line = strtok( $dump, "\n" );
|
||
$m = false;
|
||
$good = false;
|
||
if ( preg_match( '/^( *)FORM:DJVU/', $line, $m ) ) {
|
||
# Single-page
|
||
if ( $this->parseFormDjvu( $line, $xml ) ) {
|
||
$good = true;
|
||
} else {
|
||
return false;
|
||
}
|
||
} elseif ( preg_match( '/^( *)FORM:DJVM/', $line, $m ) ) {
|
||
# Multi-page
|
||
$parentLevel = strlen( $m[1] );
|
||
# Find DIRM
|
||
$line = strtok( "\n" );
|
||
while ( $line !== false ) {
|
||
$childLevel = strspn( $line, ' ' );
|
||
if ( $childLevel <= $parentLevel ) {
|
||
# End of chunk
|
||
break;
|
||
}
|
||
|
||
if ( preg_match( '/^ *DIRM.*indirect/', $line ) ) {
|
||
wfDebug( "Indirect multi-page DjVu document, bad for server!" );
|
||
|
||
return false;
|
||
}
|
||
if ( preg_match( '/^ *FORM:DJVU/', $line ) ) {
|
||
# Found page
|
||
if ( $this->parseFormDjvu( $line, $xml ) ) {
|
||
$good = true;
|
||
} else {
|
||
return false;
|
||
}
|
||
}
|
||
$line = strtok( "\n" );
|
||
}
|
||
}
|
||
if ( !$good ) {
|
||
return false;
|
||
}
|
||
|
||
$xml .= "</BODY>\n</DjVuXML>\n";
|
||
|
||
return $xml;
|
||
}
|
||
|
||
private function parseFormDjvu( $line, &$xml ) {
|
||
$parentLevel = strspn( $line, ' ' );
|
||
$line = strtok( "\n" );
|
||
|
||
# Find INFO
|
||
while ( $line !== false ) {
|
||
$childLevel = strspn( $line, ' ' );
|
||
if ( $childLevel <= $parentLevel ) {
|
||
# End of chunk
|
||
break;
|
||
}
|
||
|
||
if ( preg_match(
|
||
'/^ *INFO *\[\d*\] *DjVu *(\d+)x(\d+), *\w*, *(\d+) *dpi, *gamma=([0-9.-]+)/',
|
||
$line,
|
||
$m
|
||
) ) {
|
||
$xml .= Xml::tags(
|
||
'OBJECT',
|
||
[
|
||
# 'data' => '',
|
||
# 'type' => 'image/x.djvu',
|
||
'height' => $m[2],
|
||
'width' => $m[1],
|
||
# 'usemap' => '',
|
||
],
|
||
"\n" .
|
||
Xml::element( 'PARAM', [ 'name' => 'DPI', 'value' => $m[3] ] ) . "\n" .
|
||
Xml::element( 'PARAM', [ 'name' => 'GAMMA', 'value' => $m[4] ] ) . "\n"
|
||
) . "\n";
|
||
|
||
return true;
|
||
}
|
||
$line = strtok( "\n" );
|
||
}
|
||
|
||
# Not found
|
||
return false;
|
||
}
|
||
}
|