summaryrefslogtreecommitdiff
path: root/includes/media/DjVuImage.php
diff options
context:
space:
mode:
Diffstat (limited to 'includes/media/DjVuImage.php')
-rw-r--r--includes/media/DjVuImage.php379
1 files changed, 379 insertions, 0 deletions
diff --git a/includes/media/DjVuImage.php b/includes/media/DjVuImage.php
new file mode 100644
index 00000000..80b7408c
--- /dev/null
+++ b/includes/media/DjVuImage.php
@@ -0,0 +1,379 @@
+<?php
+/**
+ * DjVu image handler
+ *
+ * Copyright © 2006 Brion Vibber <brion@pobox.com>
+ * http://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
+ */
+
+/**
+ * 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 {
+ 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 data in the style of getimagesize()
+ * @return array or false on failure
+ */
+ public function getImageSize() {
+ $data = $this->getInfo();
+
+ if( $data !== false ) {
+ $width = $data['width'];
+ $height = $data['height'];
+
+ return array( $width, $height, 'DjVu',
+ "width=\"$width\" height=\"$height\"" );
+ }
+ return false;
+ }
+
+ // ---------
+
+ /**
+ * For debugging; dump the IFF chunk structure
+ */
+ function dump() {
+ $file = fopen( $this->mFilename, 'rb' );
+ $header = fread( $file, 12 );
+ // @todo FIXME: Would be good to replace this extract() call with something that explicitly initializes local variables.
+ extract( unpack( 'a4magic/a4chunk/NchunkLength', $header ) );
+ echo "$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;
+ }
+ // @todo FIXME: Would be good to replace this extract() call with something that explicitly initializes local variables.
+ extract( unpack( 'a4chunk/NchunkLength', $chunkHeader ) );
+ 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 == 1 ) {
+ // Padding byte between chunks
+ fseek( $file, 1, SEEK_CUR );
+ }
+ }
+ }
+ }
+
+ function getInfo() {
+ wfSuppressWarnings();
+ $file = fopen( $this->mFilename, 'rb' );
+ wfRestoreWarnings();
+ if( $file === false ) {
+ wfDebug( __METHOD__ . ": missing or failed file read\n" );
+ return false;
+ }
+
+ $header = fread( $file, 16 );
+ $info = false;
+
+ if( strlen( $header ) < 16 ) {
+ wfDebug( __METHOD__ . ": too short file header\n" );
+ } else {
+ // @todo FIXME: Would be good to replace this extract() call with something that explicitly initializes local variables.
+ extract( unpack( 'a4magic/a4form/NformLength/a4subtype', $header ) );
+
+ if( $magic != 'AT&T' ) {
+ wfDebug( __METHOD__ . ": not a DjVu file\n" );
+ } elseif( $subtype == 'DJVU' ) {
+ // Single-page document
+ $info = $this->getPageInfo( $file, $formLength );
+ } elseif( $subtype == 'DJVM' ) {
+ // Multi-page document
+ $info = $this->getMultiPageInfo( $file, $formLength );
+ } else {
+ wfDebug( __METHOD__ . ": unrecognized DJVU file type '$formType'\n" );
+ }
+ }
+ fclose( $file );
+ return $info;
+ }
+
+ private function readChunk( $file ) {
+ $header = fread( $file, 8 );
+ if( strlen( $header ) < 8 ) {
+ return array( false, 0 );
+ } else {
+ // @todo FIXME: Would be good to replace this extract() call with something that explicitly initializes local variables.
+ extract( unpack( 'a4chunk/Nlength', $header ) );
+ return array( $chunk, $length );
+ }
+ }
+
+ private function skipChunk( $file, $chunkLength ) {
+ fseek( $file, $chunkLength, SEEK_CUR );
+
+ if( $chunkLength & 0x01 == 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\n" );
+ return $this->getPageInfo( $file, $length );
+ }
+ $this->skipChunk( $file, $length - 4 );
+ } else {
+ wfDebug( __METHOD__ . ": skipping '$chunk' chunk\n" );
+ $this->skipChunk( $file, $length );
+ }
+ } while( $length != 0 && !feof( $file ) && ftell( $file ) - $start < $formLength );
+
+ wfDebug( __METHOD__ . ": multi-page DJVU file contained no pages\n" );
+ return false;
+ }
+
+ private function getPageInfo( $file, $formLength ) {
+ list( $chunk, $length ) = $this->readChunk( $file );
+ if( $chunk != 'INFO' ) {
+ wfDebug( __METHOD__ . ": expected INFO chunk, got '$chunk'\n" );
+ return false;
+ }
+
+ if( $length < 9 ) {
+ wfDebug( __METHOD__ . ": INFO should be 9 or 10 bytes, found $length\n" );
+ return false;
+ }
+ $data = fread( $file, $length );
+ if( strlen( $data ) < $length ) {
+ wfDebug( __METHOD__ . ": INFO chunk cut off\n" );
+ return false;
+ }
+
+ // @todo FIXME: Would be good to replace this extract() call with something that explicitly initializes local variables.
+ extract( unpack(
+ 'nwidth/' .
+ 'nheight/' .
+ 'Cminor/' .
+ 'Cmajor/' .
+ 'vresolution/' .
+ 'Cgamma', $data ) );
+ # Newer files have rotation info in byte 10, but we don't use it yet.
+
+ return array(
+ 'width' => $width,
+ 'height' => $height,
+ 'version' => "$major.$minor",
+ 'resolution' => $resolution,
+ 'gamma' => $gamma / 10.0 );
+ }
+
+ /**
+ * Return an XML string describing the DjVu image
+ * @return string
+ */
+ function retrieveMetaData() {
+ global $wgDjvuToXML, $wgDjvuDump, $wgDjvuTxt;
+ wfProfileIn( __METHOD__ );
+
+ if ( isset( $wgDjvuDump ) ) {
+ # djvudump is faster as of version 3.5
+ # http://sourceforge.net/tracker/index.php?func=detail&aid=1704049&group_id=32953&atid=406583
+ wfProfileIn( 'djvudump' );
+ $cmd = wfEscapeShellArg( $wgDjvuDump ) . ' ' . wfEscapeShellArg( $this->mFilename );
+ $dump = wfShellExec( $cmd );
+ $xml = $this->convertDumpToXML( $dump );
+ wfProfileOut( 'djvudump' );
+ } elseif ( isset( $wgDjvuToXML ) ) {
+ wfProfileIn( 'djvutoxml' );
+ $cmd = wfEscapeShellArg( $wgDjvuToXML ) . ' --without-anno --without-text ' .
+ wfEscapeShellArg( $this->mFilename );
+ $xml = wfShellExec( $cmd );
+ wfProfileOut( 'djvutoxml' );
+ } else {
+ $xml = null;
+ }
+ # Text layer
+ if ( isset( $wgDjvuTxt ) ) {
+ wfProfileIn( 'djvutxt' );
+ $cmd = wfEscapeShellArg( $wgDjvuTxt ) . ' --detail=page ' . wfEscapeShellArg( $this->mFilename ) ;
+ wfDebug( __METHOD__.": $cmd\n" );
+ $retval = '';
+ $txt = wfShellExec( $cmd, $retval );
+ wfProfileOut( 'djvutxt' );
+ if( $retval == 0) {
+ # Strip some control characters
+ $txt = preg_replace( "/[\013\035\037]/", "", $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, array( $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 );
+ $xml = $xml . $txt. '</mw-djvu>' ;
+ }
+ }
+ wfProfileOut( __METHOD__ );
+ return $xml;
+ }
+
+ function pageTextCallback( $matches ) {
+ # Get rid of invalid UTF-8, strip control characters
+ return '<PAGE value="' . htmlspecialchars( UtfNormal::cleanUp( $matches[1] ) ) . '" />';
+ }
+
+ /**
+ * Hack to temporarily work around djvutoxml bug
+ */
+ 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!\n" );
+ 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;
+ }
+
+ 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',
+ array(
+ #'data' => '',
+ #'type' => 'image/x.djvu',
+ 'height' => $m[2],
+ 'width' => $m[1],
+ #'usemap' => '',
+ ),
+ "\n" .
+ Xml::element( 'PARAM', array( 'name' => 'DPI', 'value' => $m[3] ) ) . "\n" .
+ Xml::element( 'PARAM', array( 'name' => 'GAMMA', 'value' => $m[4] ) ) . "\n"
+ ) . "\n";
+ return true;
+ }
+ $line = strtok( "\n" );
+ }
+ # Not found
+ return false;
+ }
+}
generated by cgit v1.2.2 (git 2.25.0) at 2024-04-18 23:02:16 +0000