includes/media/BitmapMetadataHandler.php

   1 <?php
   2 /**
   3 Class to deal with reconciling and extracting metadata from bitmap images.
   4 This is meant to comply with http://www.metadataworkinggroup.org/pdf/mwg_guidance.pdf
   5
   6 This sort of acts as an intermediary between MediaHandler::getMetadata
   7 and the various metadata extractors.
   8
   9 @todo other image formats.
  10 */
  11 class BitmapMetadataHandler {
  12
  13         private $metadata = Array();
  14         private $metaPriority = Array(
  15                 20 => Array( 'other' ),
  16                 40 => Array( 'native' ),
  17                 60 => Array( 'iptc-good-hash', 'iptc-no-hash' ),
  18                 70 => Array( 'xmp-deprecated' ),
  19                 80 => Array( 'xmp-general' ),
  20                 90 => Array( 'xmp-exif' ),
  21                 100 => Array( 'iptc-bad-hash' ),
  22                 120 => Array( 'exif' ),
  23         );
  24         private $iptcType = 'iptc-no-hash';
  25
  26         /**
  27         * This does the photoshop image resource app13 block
  28         * of interest, IPTC-IIM metadata is stored here.
  29         *
  30         * Mostly just calls doPSIR and doIPTC
  31         *
  32         * @param String $app13 String containing app13 block from jpeg file
  33         */
  34         private function doApp13 ( $app13 ) {
  35                 $this->iptcType = JpegMetadataExtractor::doPSIR( $app13 );
  36
  37                 $iptc = IPTC::parse( $app13 );
  38                 $this->addMetadata( $iptc, $this->iptcType );
  39         }
  40
  41
  42         /** get exif info using exif class.
  43         * Basically what used to be in BitmapHandler::getMetadata().
  44         * Just calls stuff in the Exif class.
  45         */
  46         function getExif ( $filename ) {
  47                 if ( file_exists( $filename ) ) {
  48                         $exif = new Exif( $filename );
  49                         $data = $exif->getFilteredData();
  50                         if ( $data ) {
  51                                 $this->addMetadata( $data, 'exif' );
  52                         }
  53                 }
  54         }
  55         /** Add misc metadata. Warning: atm if the metadata category
  56         * doesn't have a priority, it will be silently discarded.
  57         *
  58         * @param Array $metaArray array of metadata values
  59         * @param string $type type. defaults to other. if two things have the same type they're merged
  60         */
  61         function addMetadata ( $metaArray, $type = 'other' ) {
  62                 if ( isset( $this->metadata[$type] ) ) {
  63                         /* merge with old data */
  64                         $metaArray = $metaArray + $this->metadata[$type];
  65                 }
  66
  67                 $this->metadata[$type] = $metaArray;
  68         }
  69
  70         /**
  71         * Merge together the various types of metadata
  72         * the different types have different priorites,
  73         * and are merged in order.
  74         *
  75         * This function is generally called by the media handlers' getMetadata()
  76         *
  77         * @return Array metadata array
  78         */
  79         function getMetadataArray () {
  80                 // this seems a bit ugly... This is all so its merged in right order
  81                 // based on the MWG recomendation.
  82                 $temp = Array();
  83                 krsort( $this->metaPriority );
  84                 foreach ( $this->metaPriority as $pri ) {
  85                         foreach ( $pri as $type ) {
  86                                 if ( isset( $this->metadata[$type] ) ) {
  87                                         // Do some special casing for multilingual values.
  88                                         // Don't discard translations if also as a simple value.
  89                                         foreach ( $this->metadata[$type] as $itemName => $item ) {
  90                                                 if ( is_array( $item ) && isset( $item['_type'] ) && $item['_type'] === 'lang' ) {
  91                                                         if ( isset( $temp[$itemName] ) && !is_array( $temp[$itemName] ) ) {
  92                                                                 $default = $temp[$itemName];
  93                                                                 $temp[$itemName] = $item;
  94                                                                 $temp[$itemName]['x-default'] = $default;
  95                                                                 unset( $this->metadata[$type][$itemName] );
  96                                                         }
  97                                                 }
  98                                         }
  99
 100                                         $temp = $temp + $this->metadata[$type];
 101                                 }
 102                         }
 103                 }
 104                 return $temp;
 105         }
 106
 107         /** Main entry point for jpeg's.
 108         *
 109         * @param string $file filename (with full path)
 110         * @return metadata result array.
 111         * @throws MWException on invalid file.
 112         */
 113         static function Jpeg ( $filename ) {
 114                 $showXMP = function_exists( 'xml_parser_create_ns' );
 115                 $meta = new self();
 116                 $meta->getExif( $filename );
 117
 118                 $seg = JpegMetadataExtractor::segmentSplitter( $filename );
 119                 if ( isset( $seg['COM'] ) && isset( $seg['COM'][0] ) ) {
 120                         $meta->addMetadata( Array( 'JPEGFileComment' => $seg['COM'] ), 'native' );
 121                 }
 122                 if ( isset( $seg['PSIR'] ) ) {
 123                         $meta->doApp13( $seg['PSIR'] );
 124                 }
 125                 if ( isset( $seg['XMP'] ) && $showXMP ) {
 126                         $xmp = new XMPReader();
 127                         $xmp->parse( $seg['XMP'] );
 128                         foreach ( $seg['XMP_ext'] as $xmpExt ) {
 129                                 /* Support for extended xmp in jpeg files
 130                                  * is not well tested and a bit fragile.
 131                                  */
 132                                 $xmp->parseExtended( $xmpExt );
 133
 134                         }
 135                         $res = $xmp->getResults();
 136                         foreach ( $res as $type => $array ) {
 137                                 $meta->addMetadata( $array, $type );
 138                         }
 139                 }
 140                 return $meta->getMetadataArray();
 141         }
 142         /** Entry point for png
 143         * At some point in the future this might
 144         * merge the png various tEXt chunks to that
 145         * are interesting, but for now it only does XMP
 146         *
 147         * @param $filename String full path to file
 148         * @return Array Array for storage in img_metadata.
 149         */
 150         static public function PNG ( $filename ) {
 151                 $showXMP = function_exists( 'xml_parser_create_ns' );
 152
 153                 $meta = new self();
 154                 $array = PNGMetadataExtractor::getMetadata( $filename );
 155                 if ( isset( $array['text']['xmp']['x-default'] ) && $array['text']['xmp']['x-default'] !== '' && $showXMP ) {
 156                         $xmp = new XMPReader();
 157                         $xmp->parse( $array['text']['xmp']['x-default'] );
 158                         $xmpRes = $xmp->getResults();
 159                         foreach ( $xmpRes as $type => $xmpSection ) {
 160                                 $meta->addMetadata( $xmpSection, $type );
 161                         }
 162                 }
 163                 unset( $array['text']['xmp'] );
 164                 $meta->addMetadata( $array['text'], 'native' );
 165                 unset( $array['text'] );
 166                 $array['metadata'] = $meta->getMetadataArray();
 167                 $array['metadata']['_MW_PNG_VERSION'] = PNGMetadataExtractor::VERSION;
 168                 return $array;
 169         }
 170
 171         /** function for gif images.
 172          *
 173          * They don't really have native metadata, so just merges together
 174          * XMP and image comment.
 175          *
 176          * @param $filename full path to file
 177          * @return Array metadata array
 178          */
 179         static public function GIF ( $filename ) {
 180
 181                 $meta = new self();
 182                 $baseArray = GIFMetadataExtractor::getMetadata( $filename );
 183
 184                 if ( count( $baseArray['comment'] ) > 0 ) {
 185                         $meta->addMetadata( array( 'GIFFileComment' => $baseArray['comment'] ), 'native' );
 186                 }
 187
 188                 if ( $baseArray['xmp'] !== '' && function_exists( 'xml_parser_create_ns' ) ) {
 189                         $xmp = new XMPReader();
 190                         $xmp->parse( $baseArray['xmp'] );
 191                         $xmpRes = $xmp->getResults();
 192                         foreach ( $xmpRes as $type => $xmpSection ) {
 193                                 $meta->addMetadata( $xmpSection, $type );
 194                         }
 195
 196                 }
 197
 198                 unset( $baseArray['comment'] );
 199                 unset( $baseArray['xmp'] );
 200
 201                 $baseArray['metadata'] = $meta->getMetadataArray();
 202                 $baseArray['metadata']['_MW_GIF_VERSION'] = GIFMetadataExtractor::VERSION;
 203                 return $baseArray;
 204         }
 205
 206 }