includes/Exif.php

   1 <?php
   2 if ( !defined( 'MEDIAWIKI' ) ) die();
   3 /**
   4  * @package MediaWiki
   5  * @subpackage Metadata
   6  *
   7  * @author Ævar Arnfjörð Bjarmason <avarab@gmail.com>
   8  * @copyright Copyright © 2005, Ævar Arnfjörð Bjarmason
   9  * @license http://www.gnu.org/copyleft/gpl.html GNU General Public License
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License along
  22  * with this program; if not, write to the Free Software Foundation, Inc.,
  23  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  24  * http://www.gnu.org/copyleft/gpl.html
  25  *
  26  * @link http://exif.org/Exif2-2.PDF The Exif 2.2 specification
  27  * @bug 1555, 1947
  28  */
  29
  30 /**#@+
  31  * Exif tag type definition
  32  */
  33 define('MW_EXIF_BYTE', 1);              # An 8-bit unsigned integer.
  34 define('MW_EXIF_ASCII', 2);             # An 8-bit byte containing one 7-bit ASCII code. The final byte is terminated with NULL.
  35 define('MW_EXIF_SHORT', 3);             # A 16-bit (2-byte) unsigned integer.
  36 define('MW_EXIF_LONG', 4);              # A 32-bit (4-byte) unsigned integer.
  37 define('MW_EXIF_RATIONAL', 5);          # Two LONGs. The first LONG is the numerator and the second LONG expresses the denominator
  38 define('MW_EXIF_UNDEFINED', 7);         # An 8-bit byte that can take any value depending on the field definition
  39 define('MW_EXIF_SLONG', 9);             # A 32-bit (4-byte) signed integer (2's complement notation),
  40 define('MW_EXIF_SRATIONAL', 10);        # Two SLONGs. The first SLONG is the numerator and the second SLONG is the denominator.
  41 /**#@-*/
  42
  43
  44 /**
  45  * @package MediaWiki
  46  * @subpackage Metadata
  47  */
  48 class Exif {
  49         /**#@+
  50          * @var array
  51          * @access private
  52          */
  53
  54         /**
  55          * Exif tags grouped by category, the tagname itself is the key and the type
  56          * is the value, in the case of more than one possible value type they are
  57          * seperated by commas.
  58          */
  59         var $mExifTags;
  60
  61         /**
  62          * A one dimentional array of all Exif tags
  63          */
  64         var $mFlatExifTags;
  65
  66         /**
  67          * The raw Exif data returned by exif_read_data()
  68          */
  69         var $mRawExifData;
  70
  71         /**
  72          * A Filtered version of $mRawExifData that has been pruned of invalid
  73          * tags and tags that contain content they shouldn't contain according
  74          * to the Exif specification
  75          */
  76         var $mFilteredExifData;
  77
  78         /**
  79          * Filtered and formatted Exif data, see FormatExif::getFormattedData()
  80          */
  81         var $mFormattedExifData;
  82
  83         /**#@-*/
  84
  85         /**
  86          * Constructor
  87          *
  88          * @param string $file
  89          */
  90         function Exif( $file ) {
  91                 /**
  92                  * Page numbers here refer to pages in the EXIF 2.2 standard
  93                  *
  94                  * @link http://exif.org/Exif2-2.PDF The Exif 2.2 specification
  95                  */
  96                 $this->mExifTags = array(
  97                         # TIFF Rev. 6.0 Attribute Information (p22)
  98                         'tiff' => array(
  99                                 # Tags relating to image structure
 100                                 'structure' => array(
 101                                         'ImageWidth' => MW_EXIF_SHORT.','.MW_EXIF_LONG,         # Image width
 102                                         'ImageLength' => MW_EXIF_SHORT.','.MW_EXIF_LONG,        # Image height
 103                                         'BitsPerSample' => MW_EXIF_SHORT,                       # Number of bits per component
 104                                         # "When a primary image is JPEG compressed, this designation is not"
 105                                         # "necessary and is omitted." (p23)
 106                                         'Compression' => MW_EXIF_SHORT,                         # Compression scheme #p23
 107                                         'PhotometricInterpretation' => MW_EXIF_SHORT,           # Pixel composition #p23
 108                                         'Orientation' => MW_EXIF_SHORT,                         # Orientation of image #p24
 109                                         'SamplesPerPixel' => MW_EXIF_SHORT,                     # Number of components
 110                                         'PlanarConfiguration' => MW_EXIF_SHORT,                 # Image data arrangement #p24
 111                                         'YCbCrSubSampling' => MW_EXIF_SHORT,                    # Subsampling ratio of Y to C #p24
 112                                         'YCbCrPositioning' => MW_EXIF_SHORT,                    # Y and C positioning #p24-25
 113                                         'XResolution' => MW_EXIF_RATIONAL,                      # Image resolution in width direction
 114                                         'YResolution' => MW_EXIF_RATIONAL,                      # Image resolution in height direction
 115                                         'ResolutionUnit' => MW_EXIF_SHORT,                      # Unit of X and Y resolution #(p26)
 116                                 ),
 117
 118                                 # Tags relating to recording offset
 119                                 'offset' => array(
 120                                         'StripOffsets' => MW_EXIF_SHORT.','.MW_EXIF_LONG,                       # Image data location
 121                                         'RowsPerStrip' => MW_EXIF_SHORT.','.MW_EXIF_LONG,                       # Number of rows per strip
 122                                         'StripByteCounts' => MW_EXIF_SHORT.','.MW_EXIF_LONG,                    # Bytes per compressed strip
 123                                         'JPEGInterchangeFormat' => MW_EXIF_SHORT.','.MW_EXIF_LONG,              # Offset to JPEG SOI
 124                                         'JPEGInterchangeFormatLength' => MW_EXIF_SHORT.','.MW_EXIF_LONG,        # Bytes of JPEG data
 125                                 ),
 126
 127                                 # Tags relating to image data characteristics
 128                                 'characteristics' => array(
 129                                         'TransferFunction' => MW_EXIF_SHORT,            # Transfer function
 130                                         'WhitePoint' => MW_EXIF_RATIONAL,               # White point chromaticity
 131                                         'PrimaryChromaticities' => MW_EXIF_RATIONAL,    # Chromaticities of primarities
 132                                         'YCbCrCoefficients' => MW_EXIF_RATIONAL,        # Color space transformation matrix coefficients #p27
 133                                         'ReferenceBlackWhite' => MW_EXIF_RATIONAL       # Pair of black and white reference values
 134                                 ),
 135
 136                                 # Other tags
 137                                 'other' => array(
 138                                         'DateTime' => MW_EXIF_ASCII,            # File change date and time
 139                                         'ImageDescription' => MW_EXIF_ASCII,    # Image title
 140                                         'Make' => MW_EXIF_ASCII,                # Image input equipment manufacturer
 141                                         'Model' => MW_EXIF_ASCII,               # Image input equipment model
 142                                         'Software' => MW_EXIF_ASCII,            # Software used
 143                                         'Artist' => MW_EXIF_ASCII,              # Person who created the image
 144                                         'Copyright' => MW_EXIF_ASCII,           # Copyright holder
 145                                 ),
 146                         ),
 147
 148                         # Exif IFD Attribute Information (p30-31)
 149                         'exif' => array(
 150                                 # Tags relating to version
 151                                 'version' => array(
 152                                         # TODO: NOTE: Nonexistence of this field is taken to mean nonconformance
 153                                         # to the EXIF 2.1 AND 2.2 standards
 154                                         'ExifVersion' => MW_EXIF_UNDEFINED,     # Exif version
 155                                         'FlashpixVersion' => MW_EXIF_UNDEFINED, # Supported Flashpix version #p32
 156                                 ),
 157
 158                                 # Tags relating to Image Data Characteristics
 159                                 'characteristics' => array(
 160                                         'ColorSpace' => MW_EXIF_SHORT,          # Color space information #p32
 161                                 ),
 162
 163                                 # Tags relating to image configuration
 164                                 'configuration' => array(
 165                                         'ComponentsConfiguration' => MW_EXIF_UNDEFINED,         # Meaning of each component #p33
 166                                         'CompressedBitsPerPixel' => MW_EXIF_RATIONAL,           # Image compression mode
 167                                         'PixelYDimension' => MW_EXIF_SHORT.','.MW_EXIF_LONG,    # Valid image width
 168                                         'PixelXDimension' => MW_EXIF_SHORT.','.MW_EXIF_LONG,    # Valind image height
 169                                 ),
 170
 171                                 # Tags relating to related user information
 172                                 'user' => array(
 173                                         'MakerNote' => MW_EXIF_UNDEFINED,                       # Manufacturer notes
 174                                         'UserComment' => MW_EXIF_UNDEFINED,                     # User comments #p34
 175                                 ),
 176
 177                                 # Tags relating to related file information
 178                                 'related' => array(
 179                                         'RelatedSoundFile' => MW_EXIF_ASCII,                    # Related audio file
 180                                 ),
 181
 182                                 # Tags relating to date and time
 183                                 'dateandtime' => array(
 184                                         'DateTimeOriginal' => MW_EXIF_ASCII,                    # Date and time of original data generation #p36
 185                                         'DateTimeDigitized' => MW_EXIF_ASCII,                   # Date and time of original data generation
 186                                         'SubSecTime' => MW_EXIF_ASCII,                          # DateTime subseconds
 187                                         'SubSecTimeOriginal' => MW_EXIF_ASCII,                  # DateTimeOriginal subseconds
 188                                         'SubSecTimeDigitized' => MW_EXIF_ASCII,                 # DateTimeDigitized subseconds
 189                                 ),
 190
 191                                 # Tags relating to picture-taking conditions (p31)
 192                                 'conditions' => array(
 193                                         'ExposureTime' => MW_EXIF_RATIONAL,                     # Exposure time
 194                                         'FNumber' => MW_EXIF_RATIONAL,                          # F Number
 195                                         'ExposureProgram' => MW_EXIF_SHORT,                     # Exposure Program #p38
 196                                         'SpectralSensitivity' => MW_EXIF_ASCII,                 # Spectral sensitivity
 197                                         'ISOSpeedRatings' => MW_EXIF_SHORT,                     # ISO speed rating
 198                                         'OECF' => MW_EXIF_UNDEFINED,                            # Optoelectronic conversion factor
 199                                         'ShutterSpeedValue' => MW_EXIF_SRATIONAL,               # Shutter speed
 200                                         'ApertureValue' => MW_EXIF_RATIONAL,                    # Aperture
 201                                         'BrightnessValue' => MW_EXIF_SRATIONAL,                 # Brightness
 202                                         'ExposureBiasValue' => MW_EXIF_SRATIONAL,               # Exposure bias
 203                                         'MaxApertureValue' => MW_EXIF_RATIONAL,                 # Maximum land aperture
 204                                         'SubjectDistance' => MW_EXIF_RATIONAL,                  # Subject distance
 205                                         'MeteringMode' => MW_EXIF_SHORT,                        # Metering mode #p40
 206                                         'LightSource' => MW_EXIF_SHORT,                         # Light source #p40-41
 207                                         'Flash' => MW_EXIF_SHORT,                               # Flash #p41-42
 208                                         'FocalLength' => MW_EXIF_RATIONAL,                      # Lens focal length
 209                                         'SubjectArea' => MW_EXIF_SHORT,                         # Subject area
 210                                         'FlashEnergy' => MW_EXIF_RATIONAL,                      # Flash energy
 211                                         'SpatialFrequencyResponse' => MW_EXIF_UNDEFINED,        # Spatial frequency response
 212                                         'FocalPlaneXResolution' => MW_EXIF_RATIONAL,            # Focal plane X resolution
 213                                         'FocalPlaneYResolution' => MW_EXIF_RATIONAL,            # Focal plane Y resolution
 214                                         'FocalPlaneResolutionUnit' => MW_EXIF_SHORT,            # Focal plane resolution unit #p46
 215                                         'SubjectLocation' => MW_EXIF_SHORT,                     # Subject location
 216                                         'ExposureIndex' => MW_EXIF_RATIONAL,                    # Exposure index
 217                                         'SensingMethod' => MW_EXIF_SHORT,                       # Sensing method #p46
 218                                         'FileSource' => MW_EXIF_UNDEFINED,                      # File source #p47
 219                                         'SceneType' => MW_EXIF_UNDEFINED,                       # Scene type #p47
 220                                         'CFAPattern' => MW_EXIF_UNDEFINED,                      # CFA pattern
 221                                         'CustomRendered' => MW_EXIF_SHORT,                      # Custom image processing #p48
 222                                         'ExposureMode' => MW_EXIF_SHORT,                        # Exposure mode #p48
 223                                         'WhiteBalance' => MW_EXIF_SHORT,                        # White Balance #p49
 224                                         'DigitalZoomRatio' => MW_EXIF_RATIONAL,                 # Digital zoom ration
 225                                         'FocalLengthIn35mmFilm' => MW_EXIF_SHORT,               # Focal length in 35 mm film
 226                                         'SceneCaptureType' => MW_EXIF_SHORT,                    # Scene capture type #p49
 227                                         'GainControl' => MW_EXIF_RATIONAL,                      # Scene control #p49-50
 228                                         'Contrast' => MW_EXIF_SHORT,                            # Contrast #p50
 229                                         'Saturation' => MW_EXIF_SHORT,                          # Saturation #p50
 230                                         'Sharpness' => MW_EXIF_SHORT,                           # Sharpness #p50
 231                                         'DeviceSettingDescription' => MW_EXIF_UNDEFINED,        # Desice settings description
 232                                         'SubjectDistanceRange' => MW_EXIF_SHORT,                # Subject distance range #p51
 233                                 ),
 234
 235                                 'other' => array(
 236                                         'ImageUniqueID' => MW_EXIF_ASCII,       # Unique image ID
 237                                 ),
 238                         ),
 239
 240                         # GPS Attribute Information (p52)
 241                         'gps' => array(
 242                                 'GPSVersionID' => MW_EXIF_BYTE,                 # GPS tag version
 243                                 'GPSLatitudeRef' => MW_EXIF_ASCII,              # North or South Latitude #p52-53
 244                                 'GPSLatitude' => MW_EXIF_RATIONAL,              # Latitude
 245                                 'GPSLongitudeRef' => MW_EXIF_ASCII,             # East or West Longitude #p53
 246                                 'GPSLongitude' => MW_EXIF_RATIONAL,             # Longitude
 247                                 'GPSAltitudeRef' => MW_EXIF_BYTE,               # Altitude reference
 248                                 'GPSAltitude' => MW_EXIF_RATIONAL,              # Altitude
 249                                 'GPSTimeStamp' => MW_EXIF_RATIONAL,             # GPS time (atomic clock)
 250                                 'GPSSatellites' => MW_EXIF_ASCII,               # Satellites used for measurement
 251                                 'GPSStatus' => MW_EXIF_ASCII,                   # Receiver status #p54
 252                                 'GPSMeasureMode' => MW_EXIF_ASCII,              # Measurement mode #p54-55
 253                                 'GPSDOP' => MW_EXIF_RATIONAL,                   # Measurement precision
 254                                 'GPSSpeedRef' => MW_EXIF_ASCII,                 # Speed unit #p55
 255                                 'GPSSpeed' => MW_EXIF_RATIONAL,                 # Speed of GPS receiver
 256                                 'GPSTrackRef' => MW_EXIF_ASCII,                 # Reference for direction of movement #p55
 257                                 'GPSTrack' => MW_EXIF_RATIONAL,                 # Direction of movement
 258                                 'GPSImgDirectionRef' => MW_EXIF_ASCII,          # Reference for direction of image #p56
 259                                 'GPSImgDirection' => MW_EXIF_RATIONAL,          # Direction of image
 260                                 'GPSMapDatum' => MW_EXIF_ASCII,                 # Geodetic survey data used
 261                                 'GPSDestLatitudeRef' => MW_EXIF_ASCII,          # Reference for latitude of destination #p56
 262                                 'GPSDestLatitude' => MW_EXIF_RATIONAL,          # Latitude destination
 263                                 'GPSDestLongitudeRef' => MW_EXIF_ASCII,         # Reference for longitude of destination #p57
 264                                 'GPSDestLongitude' => MW_EXIF_RATIONAL,         # Longitude of destination
 265                                 'GPSDestBearingRef' => MW_EXIF_ASCII,           # Reference for bearing of destination #p57
 266                                 'GPSDestBearing' => MW_EXIF_RATIONAL,           # Bearing of destination
 267                                 'GPSDestDistanceRef' => MW_EXIF_ASCII,          # Reference for distance to destination #p57-58
 268                                 'GPSDestDistance' => MW_EXIF_RATIONAL,          # Distance to destination
 269                                 'GPSProcessingMethod' => MW_EXIF_UNDEFINED,     # Name of GPS processing method
 270                                 'GPSAreaInformation' => MW_EXIF_UNDEFINED,      # Name of GPS area
 271                                 'GPSDateStamp' => MW_EXIF_ASCII,                # GPS date
 272                                 'GPSDifferential' => MW_EXIF_SHORT,             # GPS differential correction
 273                         ),
 274                 );
 275
 276                 $this->makeFlatExifTags();
 277                 wfSuppressWarnings();
 278                 $this->mRawExifData = exif_read_data( $file );
 279                 wfRestoreWarnings();
 280                 $this->makeFilteredData();
 281                 $this->makeFormattedData();
 282         }
 283
 284         /**#@+
 285          * @access private
 286          */
 287         /**
 288          * Generate a flat list of the exif tags
 289          */
 290         function makeFlatExifTags() {
 291                 $this->extractTags( $this->mExifTags );
 292         }
 293
 294         /**
 295          * A recursing extractor function used by makeFlatExifTags()
 296          *
 297          * Note: This used to use an array_walk function, but it made PHP5
 298          * segfault, see `cvs diff -u -r 1.4 -r 1.5 Exif.php`
 299          */
 300         function extractTags( &$tagset ) {
 301                 foreach( $tagset as $key => $val ) {
 302                         if( is_array( $val ) ) {
 303                                 $this->extractTags( $val );
 304                         } else {
 305                                 $this->mFlatExifTags[$key] = $val;
 306                         }
 307                 }
 308         }
 309
 310         /**
 311          * Make $this->mFilteredExifData
 312          */
 313         function makeFilteredData() {
 314                 $this->mFilteredExifData = $this->mRawExifData;
 315
 316                 foreach( $this->mFilteredExifData as $k => $v ) {
 317                         if ( !in_array( $k, array_keys( $this->mFlatExifTags ) ) ) {
 318                                 $this->debug( $v, __FUNCTION__, "'$k' is not a valid Exif tag" );
 319                                 unset( $this->mFilteredExifData[$k] );
 320                         }
 321                 }
 322
 323                 foreach( $this->mFilteredExifData as $k => $v ) {
 324                         if ( !$this->validate($k, $v) ) {
 325                                 $this->debug( $v, __FUNCTION__, "'$k' contained invalid data" );
 326                                 unset( $this->mFilteredExifData[$k] );
 327                         }
 328                 }
 329         }
 330
 331         function makeFormattedData( $data = null ) {
 332                 $format = new FormatExif( $this->getFilteredData() );
 333                 $this->mFormattedExifData = $format->getFormattedData();
 334         }
 335         /**#@-*/
 336
 337         /**#@+
 338          * @return array
 339          */
 340         /**
 341          * Get $this->mRawExifData
 342          */
 343         function getData() {
 344                 return $this->mRawExifData;
 345         }
 346
 347         /**
 348          * Get $this->mFilteredExifData
 349          */
 350         function getFilteredData() {
 351                 return $this->mFilteredExifData;
 352         }
 353
 354         /**
 355          * Get $this->mFormattedExifData
 356          */
 357         function getFormattedData() {
 358                 return $this->mFormattedExifData;
 359         }
 360         /**#@-*/
 361
 362         /**
 363          * The version of the output format
 364          *
 365          * Before the actual metadata information is saved in the database we
 366          * strip some of it since we don't want to save things like thumbnails
 367          * which usually accompany Exif data. This value gets saved in the
 368          * database along with the actual Exif data, and if the version in the
 369          * database doesn't equal the value returned by this function the Exif
 370          * data is regenerated.
 371          *
 372          * @return int
 373          */
 374         function version() {
 375                 return 1; // We don't need no bloddy constants!
 376         }
 377
 378         /**#@+
 379          * Validates if a tag value is of the type it should be according to the Exif spec
 380          *
 381          * @access private
 382          *
 383          * @param mixed $in The input value to check
 384          * @return bool
 385          */
 386         function isByte( $in ) {
 387                 if ( sprintf('%d', $in) == $in && $in >= 0 && $in <= 255 ) {
 388                         $this->debug( $in, __FUNCTION__, true );
 389                         return true;
 390                 } else {
 391                         $this->debug( $in, __FUNCTION__, false );
 392                         return false;
 393                 }
 394         }
 395
 396         function isASCII( $in ) {
 397                 if ( preg_match( "/[^\x0a\x20-\x7e]/", $in ) ) {
 398                         $this->debug( $in, __FUNCTION__, 'found a character not in our whitelist' );
 399                         return false;
 400                 }
 401
 402                 if ( preg_match( "/^\s*$/", $in ) ) {
 403                         $this->debug( $in, __FUNCTION__, 'input consisted solely of whitespace' );
 404                         return false;
 405                 }
 406
 407                 if ( strlen($in) > 1024 ) { // TODO: This might not be according to the spec
 408                         $this->debug( $in, __FUNCTION__, 'input was too long' );
 409                         return false;
 410                 }
 411
 412                 return true;
 413         }
 414
 415         function isShort( $in ) {
 416                 if ( sprintf('%d', $in) == $in && $in >= 0 && $in <= 65536 ) {
 417                         $this->debug( $in, __FUNCTION__, true );
 418                         return true;
 419                 } else {
 420                         $this->debug( $in, __FUNCTION__, false );
 421                         return false;
 422                 }
 423         }
 424
 425         function isLong( $in ) {
 426                 if ( sprintf('%d', $in) == $in && $in >= 0 && $in <= 4294967296 ) {
 427                         $this->debug( $in, __FUNCTION__, true );
 428                         return true;
 429                 } else {
 430                         $this->debug( $in, __FUNCTION__, false );
 431                         return false;
 432                 }
 433         }
 434
 435         function isRational( $in ) {
 436                 if ( @preg_match( "/^(\d+)\/(\d+[1-9]|[1-9]\d*)$/", $in, $m ) ) { # Avoid division by zero
 437                         return $this->isLong( $m[1] ) && $this->isLong( $m[2] );
 438                 } else {
 439                         $this->debug( $in, __FUNCTION__, 'fed a non-fraction value' );
 440                         return false;
 441                 }
 442         }
 443
 444         function isUndefined( $in ) {
 445                 if ( preg_match( "/^\d{4}$/", $in ) ) { // Allow ExifVersion and FlashpixVersion
 446                         $this->debug( $in, __FUNCTION__, true );
 447                         return true;
 448                 } else {
 449                         $this->debug( $in, __FUNCTION__, false );
 450                         return false;
 451                 }
 452         }
 453
 454         function isSlong( $in ) {
 455                 if ( $this->isLong( abs( $in ) ) ) {
 456                         $this->debug( $in, __FUNCTION__, true );
 457                         return true;
 458                 } else {
 459                         $this->debug( $in, __FUNCTION__, false );
 460                         return false;
 461                 }
 462         }
 463
 464         function isSrational( $in ) {
 465                 if ( preg_match( "/^(\d+)\/(\d+[1-9]|[1-9]\d*)$/", $in, $m ) ) { # Avoid division by zero
 466                         return $this->isSlong( $m[0] ) && $this->isSlong( $m[1] );
 467                 } else {
 468                         $this->debug( $in, __FUNCTION__, 'fed a non-fraction value' );
 469                         return false;
 470                 }
 471         }
 472         /**#@-*/
 473
 474         /**
 475          * Validates if a tag has a legal value according to the Exif spec
 476          *
 477          * @access private
 478          *
 479          * @param string $tag The tag to check
 480          * @param mixed  $val The value of the tag
 481          * @return bool
 482          */
 483         function validate( $tag, $val ) {
 484                 $debug = "tag is '$tag'";
 485                 // Fucks up if not typecast
 486                 switch( (string)$this->mFlatExifTags[$tag] ) {
 487                         case (string)MW_EXIF_BYTE:
 488                                 $this->debug( $val, __FUNCTION__, $debug );
 489                                 return $this->isByte( $val );
 490                         case (string)MW_EXIF_ASCII:
 491                                 $this->debug( $val, __FUNCTION__, $debug );
 492                                 return $this->isASCII( $val );
 493                         case (string)MW_EXIF_SHORT:
 494                                 $this->debug( $val, __FUNCTION__, $debug );
 495                                 return $this->isShort( $val );
 496                         case (string)MW_EXIF_LONG:
 497                                 $this->debug( $val, __FUNCTION__, $debug );
 498                                 return $this->isLong( $val );
 499                         case (string)MW_EXIF_RATIONAL:
 500                                 $this->debug( $val, __FUNCTION__, $debug );
 501                                 return $this->isRational( $val );
 502                         case (string)MW_EXIF_UNDEFINED:
 503                                 $this->debug( $val, __FUNCTION__, $debug );
 504                                 return $this->isUndefined( $val );
 505                         case (string)MW_EXIF_SLONG:
 506                                 $this->debug( $val, __FUNCTION__, $debug );
 507                                 return $this->isSlong( $val );
 508                         case (string)MW_EXIF_SRATIONAL:
 509                                 $this->debug( $val, __FUNCTION__, $debug );
 510                                 return $this->isSrational( $val );
 511                         case (string)MW_EXIF_SHORT.','.MW_EXIF_LONG:
 512                                 $this->debug( $val, __FUNCTION__, $debug );
 513                                 return $this->isShort( $val ) || $this->isLong( $val );
 514                         default:
 515                                 $this->debug( $val, __FUNCTION__, "The tag '$tag' is unknown" );
 516                                 return false;
 517                 }
 518         }
 519
 520         /**
 521          * Conviniance function for debugging output
 522          *
 523          * @access private
 524          *
 525          * @param mixed $in
 526          * @param string $fname
 527          * @param mixed $action
 528          */
 529          function debug( $in, $fname, $action = null ) {
 530                 $type = gettype( $in );
 531                 $class = ucfirst( __CLASS__ );
 532                 if ( $type === 'array' )
 533                         $in = print_r( $in, true );
 534
 535                 if ( $action === true )
 536                         wfDebug( "$class::$fname: accepted: '$in' (type: $type)\n");
 537                 elseif ( $action === false )
 538                         wfDebug( "$class::$fname: rejected: '$in' (type: $type)\n");
 539                 elseif ( $action === null )
 540                         wfDebug( "$class::$fname: input was: '$in' (type: $type)\n");
 541                 else
 542                         wfDebug( "$class::$fname: $action (type: $type; content: '$in')\n");
 543         }
 544
 545 }
 546
 547 /**
 548  * @package MediaWiki
 549  * @subpackage Metadata
 550  */
 551 class FormatExif {
 552         /**
 553          * The Exif data to format
 554          *
 555          * @var array
 556          * @access private
 557          */
 558         var $mExif;
 559
 560         /**
 561          * Constructor
 562          *
 563          * @param array $exif The Exif data to format ( as returned by
 564          *                    Exif::getFilteredData() )
 565          */
 566         function FormatExif( $exif ) {
 567                 $this->mExif = $exif;
 568         }
 569
 570         /**
 571          * Numbers given by Exif user agents are often magical, that is they
 572          * should be replaced by a detailed explanation depending on their
 573          * value which most of the time are plain integers. This function
 574          * formats Exif values into human readable form.
 575          *
 576          * @return array
 577          */
 578         function getFormattedData() {
 579                 global $wgLang;
 580
 581                 $tags =& $this->mExif;
 582
 583                 $resolutionunit = !isset( $tags['ResolutionUnit'] ) || $tags['ResolutionUnit'] == 2 ? 2 : 3;
 584                 unset( $tags['ResolutionUnit'] );
 585
 586                 foreach( $tags as $tag => $val ) {
 587                         switch( $tag ) {
 588                         case 'Compression':
 589                                 switch( $val ) {
 590                                 case 1: case 6:
 591                                         $tags[$tag] = $this->msg( $tag, $val );
 592                                         break;
 593                                 default:
 594                                         $tags[$tag] = $val;
 595                                         break;
 596                                 }
 597                                 break;
 598
 599                         case 'PhotometricInterpretation':
 600                                 switch( $val ) {
 601                                 case 2: case 6:
 602                                         $tags[$tag] = $this->msg( $tag, $val );
 603                                         break;
 604                                 default:
 605                                         $tags[$tag] = $val;
 606                                         break;
 607                                 }
 608                                 break;
 609
 610                         case 'Orientation':
 611                                 switch( $val ) {
 612                                 case 1: case 2: case 3: case 4: case 5: case 6: case 7: case 8:
 613                                         $tags[$tag] = $this->msg( $tag, $val );
 614                                         break;
 615                                 default:
 616                                         $tags[$tag] = $val;
 617                                         break;
 618                                 }
 619                                 break;
 620
 621                         case 'PlanarConfiguration':
 622                                 switch( $val ) {
 623                                 case 1: case 2:
 624                                         $tags[$tag] = $this->msg( $tag, $val );
 625                                         break;
 626                                 default:
 627                                         $tags[$tag] = $val;
 628                                         break;
 629                                 }
 630                                 break;
 631
 632                         // TODO: YCbCrSubSampling
 633                         // TODO: YCbCrPositioning
 634
 635                         case 'XResolution':
 636                         case 'YResolution':
 637                                 switch( $resolutionunit ) {
 638                                         case 2:
 639                                                 $tags[$tag] = $this->msg( 'XYResolution', 'i', $this->formatNum( $val ) );
 640                                                 break;
 641                                         case 3:
 642                                                 $this->msg( 'XYResolution', 'c', $this->formatNum( $val ) );
 643                                                 break;
 644                                         default:
 645                                                 $tags[$tag] = $val;
 646                                                 break;
 647                                 }
 648                                 break;
 649
 650                         // TODO: YCbCrCoefficients  #p27 (see annex E)
 651                         case 'ExifVersion': case 'FlashpixVersion':
 652                                 $tags[$tag] = "$val"/100;
 653                                 break;
 654
 655                         case 'ColorSpace':
 656                                 switch( $val ) {
 657                                 case 1: case 'FFFF.H':
 658                                         $tags[$tag] = $this->msg( $tag, $val );
 659                                         break;
 660                                 default:
 661                                         $tags[$tag] = $val;
 662                                         break;
 663                                 }
 664                                 break;
 665
 666                         case 'ComponentsConfiguration':
 667                                 switch( $val ) {
 668                                 case 0: case 1: case 2: case 3: case 4: case 5: case 6:
 669                                         $tags[$tag] = $this->msg( $tag, $val );
 670                                         break;
 671                                 default:
 672                                         $tags[$tag] = $val;
 673                                         break;
 674                                 }
 675                                 break;
 676
 677                         case 'DateTime':
 678                         case 'DateTimeOriginal':
 679                         case 'DateTimeDigitized':
 680                                 $tags[$tag] = $wgLang->timeanddate( wfTimestamp(TS_MW, $val) );
 681                                 break;
 682
 683                         case 'ExposureProgram':
 684                                 switch( $val ) {
 685                                 case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7: case 8:
 686                                         $tags[$tag] = $this->msg( $tag, $val );
 687                                         break;
 688                                 default:
 689                                         $tags[$tag] = $val;
 690                                         break;
 691                                 }
 692                                 break;
 693
 694                         case 'SubjectDistance':
 695                                 $tags[$tag] = $this->msg( $tag, '', $this->formatNum( $val ) );
 696                                 break;
 697
 698                         case 'MeteringMode':
 699                                 switch( $val ) {
 700                                 case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7: case 255:
 701                                         $tags[$tag] = $this->msg( $tag, $val );
 702                                         break;
 703                                 default:
 704                                         $tags[$tag] = $val;
 705                                         break;
 706                                 }
 707                                 break;
 708
 709                         case 'LightSource':
 710                                 switch( $val ) {
 711                                 case 0: case 1: case 2: case 3: case 4: case 9: case 10: case 11:
 712                                 case 12: case 13: case 14: case 15: case 17: case 18: case 19: case 20:
 713                                 case 21: case 22: case 23: case 24: case 255:
 714                                         $tags[$tag] = $this->msg( $tag, $val );
 715                                         break;
 716                                 default:
 717                                         $tags[$tag] = $val;
 718                                         break;
 719                                 }
 720                                 break;
 721
 722                         // TODO: Flash
 723                         case 'FocalPlaneResolutionUnit':
 724                                 switch( $val ) {
 725                                 case 2:
 726                                         $tags[$tag] = $this->msg( $tag, $val );
 727                                         break;
 728                                 default:
 729                                         $tags[$tag] = $val;
 730                                         break;
 731                                 }
 732                                 break;
 733
 734                         case 'SensingMethod':
 735                                 switch( $val ) {
 736                                 case 1: case 2: case 3: case 4: case 5: case 7: case 8:
 737                                         $tags[$tag] = $this->msg( $tag, $val );
 738                                         break;
 739                                 default:
 740                                         $tags[$tag] = $val;
 741                                         break;
 742                                 }
 743                                 break;
 744
 745                         case 'FileSource':
 746                                 switch( $val ) {
 747                                 case 3:
 748                                         $tags[$tag] = $this->msg( $tag, $val );
 749                                         break;
 750                                 default:
 751                                         $tags[$tag] = $val;
 752                                         break;
 753                                 }
 754                                 break;
 755
 756                         case 'SceneType':
 757                                 switch( $val ) {
 758                                 case 1:
 759                                         $tags[$tag] = $this->msg( $tag, $val );
 760                                         break;
 761                                 default:
 762                                         $tags[$tag] = $val;
 763                                         break;
 764                                 }
 765                                 break;
 766
 767                         case 'CustomRendered':
 768                                 switch( $val ) {
 769                                 case 0: case 1:
 770                                         $tags[$tag] = $this->msg( $tag, $val );
 771                                         break;
 772                                 default:
 773                                         $tags[$tag] = $val;
 774                                         break;
 775                                 }
 776                                 break;
 777
 778                         case 'ExposureMode':
 779                                 switch( $val ) {
 780                                 case 0: case 1: case 2:
 781                                         $tags[$tag] = $this->msg( $tag, $val );
 782                                         break;
 783                                 default:
 784                                         $tags[$tag] = $val;
 785                                         break;
 786                                 }
 787                                 break;
 788
 789                         case 'WhiteBalance':
 790                                 switch( $val ) {
 791                                 case 0: case 1:
 792                                         $tags[$tag] = $this->msg( $tag, $val );
 793                                         break;
 794                                 default:
 795                                         $tags[$tag] = $val;
 796                                         break;
 797                                 }
 798                                 break;
 799
 800                         case 'SceneCaptureType':
 801                                 switch( $val ) {
 802                                 case 0: case 1: case 2: case 3:
 803                                         $tags[$tag] = $this->msg( $tag, $val );
 804                                         break;
 805                                 default:
 806                                         $tags[$tag] = $val;
 807                                         break;
 808                                 }
 809                                 break;
 810
 811                         case 'GainControl':
 812                                 switch( $val ) {
 813                                 case 0: case 1: case 2: case 3: case 4:
 814                                         $tags[$tag] = $this->msg( $tag, $val );
 815                                         break;
 816                                 default:
 817                                         $tags[$tag] = $val;
 818                                         break;
 819                                 }
 820                                 break;
 821
 822                         case 'Contrast':
 823                                 switch( $val ) {
 824                                 case 0: case 1: case 2:
 825                                         $tags[$tag] = $this->msg( $tag, $val );
 826                                         break;
 827                                 default:
 828                                         $tags[$tag] = $val;
 829                                         break;
 830                                 }
 831                                 break;
 832
 833                         case 'Saturation':
 834                                 switch( $val ) {
 835                                 case 0: case 1: case 2:
 836                                         $tags[$tag] = $this->msg( $tag, $val );
 837                                         break;
 838                                 default:
 839                                         $tags[$tag] = $val;
 840                                         break;
 841                                 }
 842                                 break;
 843
 844                         case 'Sharpness':
 845                                 switch( $val ) {
 846                                 case 0: case 1: case 2:
 847                                         $tags[$tag] = $this->msg( $tag, $val );
 848                                         break;
 849                                 default:
 850                                         $tags[$tag] = $val;
 851                                         break;
 852                                 }
 853                                 break;
 854
 855                         case 'SubjectDistanceRange':
 856                                 switch( $val ) {
 857                                 case 0: case 1: case 2: case 3:
 858                                         $tags[$tag] = $this->msg( $tag, $val );
 859                                         break;
 860                                 default:
 861                                         $tags[$tag] = $val;
 862                                         break;
 863                                 }
 864                                 break;
 865
 866                         case 'GPSLatitudeRef':
 867                         case 'GPSDestLatitudeRef':
 868                                 switch( $val ) {
 869                                 case 'N': case 'S':
 870                                         $tags[$tag] = $this->msg( 'GPSLatitude', $val );
 871                                         break;
 872                                 default:
 873                                         $tags[$tag] = $val;
 874                                         break;
 875                                 }
 876                                 break;
 877
 878                         case 'GPSLongitudeRef':
 879                         case 'GPSDestLongitudeRef':
 880                                 switch( $val ) {
 881                                 case 'E': case 'W':
 882                                         $tags[$tag] = $this->msg( 'GPSLongitude', $val );
 883                                         break;
 884                                 default:
 885                                         $tags[$tag] = $val;
 886                                         break;
 887                                 }
 888                                 break;
 889
 890                         case 'GPSStatus':
 891                                 switch( $val ) {
 892                                 case 'A': case 'V':
 893                                         $tags[$tag] = $this->msg( $tag, $val );
 894                                         break;
 895                                 default:
 896                                         $tags[$tag] = $val;
 897                                         break;
 898                                 }
 899                                 break;
 900
 901                         case 'GPSMeasureMode':
 902                                 switch( $val ) {
 903                                 case 2: case 3:
 904                                         $tags[$tag] = $this->msg( $tag, $val );
 905                                         break;
 906                                 default:
 907                                         $tags[$tag] = $val;
 908                                         break;
 909                                 }
 910                                 break;
 911
 912                         case 'GPSSpeedRef':
 913                         case 'GPSDestDistanceRef':
 914                                 switch( $val ) {
 915                                 case 'K': case 'M': case 'N':
 916                                         $tags[$tag] = $this->msg( 'GPSSpeed', $val );
 917                                         break;
 918                                 default:
 919                                         $tags[$tag] = $val;
 920                                         break;
 921                                 }
 922                                 break;
 923
 924                         case 'GPSTrackRef':
 925                         case 'GPSImgDirectionRef':
 926                         case 'GPSDestBearingRef':
 927                                 switch( $val ) {
 928                                 case 'T': case 'M':
 929                                         $tags[$tag] = $this->msg( 'GPSDirection', $val );
 930                                         break;
 931                                 default:
 932                                         $tags[$tag] = $val;
 933                                         break;
 934                                 }
 935                                 break;
 936
 937                         case 'GPSDateStamp':
 938                                 $tags[$tag] = $wgLang->date( substr( $val, 0, 4 ) . substr( $val, 5, 2 ) . substr( $val, 8, 2 ) . '000000' );
 939                                 break;
 940
 941                         // This is not in the Exif standard, just a special
 942                         // case for our purposes which enables wikis to wikify
 943                         // the make, model and software name to link to their articles.
 944                         case 'Make':
 945                         case 'Model':
 946                         case 'Software':
 947                                 $tags[$tag] = $this->msg( $tag, '', $val );
 948                                 break;
 949                         default:
 950                                 $tags[$tag] = $this->formatNum( $val );
 951                                 break;
 952                         }
 953                 }
 954
 955                 return $tags;
 956         }
 957
 958         /**
 959          * Conviniance function for getFormattedData()
 960          *
 961          * @access private
 962          *
 963          * @param string $tag The tag name to pass on
 964          * @param string $val The value of the tag
 965          * @param string $arg An argument to pass ($1)
 966          * @return string A wfMsg of "exif-$tag-$val" in lower case
 967          */
 968         function msg( $tag, $val, $arg = null ) {
 969                 if ($val === '')
 970                         $val = 'value';
 971                 return wfMsg( strtolower( "exif-$tag-$val" ), $arg );
 972         }
 973
 974         /**
 975          * Format a number, convert numbers from fractions into floating point
 976          * numbers
 977          *
 978          * @access private
 979          *
 980          * @param mixed $num The value to format
 981          * @return mixed A floating point number or whatever we were fed
 982          */
 983         function formatNum( $num ) {
 984                 if ( preg_match( '/^(\d+)\/(\d+)$/', $num, $m ) )
 985                         return $m[2] != 0 ? $m[1] / $m[2] : $num;
 986                 else
 987                         return $num;
 988         }
 989 }