includes/Exif.php

   1 <?php
   2 /**
   3  * Exif metadata reader
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @ingroup Media
  21  * @author Ævar Arnfjörð Bjarmason <avarab@gmail.com>
  22  * @copyright Copyright © 2005, Ævar Arnfjörð Bjarmason
  23  * @license http://www.gnu.org/copyleft/gpl.html GNU General Public License
  24  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 specification
  25  * @file
  26  */
  27
  28 /**
  29  * @todo document (e.g. one-sentence class-overview description)
  30  * @ingroup Media
  31  */
  32 class Exif {
  33
  34         const BYTE      = 1;    //!< An 8-bit (1-byte) unsigned integer.
  35         const ASCII     = 2;    //!< An 8-bit byte containing one 7-bit ASCII code. The final byte is terminated with NULL.
  36         const SHORT     = 3;    //!< A 16-bit (2-byte) unsigned integer.
  37         const LONG      = 4;    //!< A 32-bit (4-byte) unsigned integer.
  38         const RATIONAL  = 5;    //!< Two LONGs. The first LONG is the numerator and the second LONG expresses the denominator
  39         const UNDEFINED = 7;    //!< An 8-bit byte that can take any value depending on the field definition
  40         const SLONG     = 9;    //!< A 32-bit (4-byte) signed integer (2's complement notation),
  41         const SRATIONAL = 10;   //!< Two SLONGs. The first SLONG is the numerator and the second SLONG is the denominator.
  42
  43         //@{
  44         /* @var array
  45          * @private
  46          */
  47
  48         /**
  49          * Exif tags grouped by category, the tagname itself is the key and the type
  50          * is the value, in the case of more than one possible value type they are
  51          * separated by commas.
  52          */
  53         var $mExifTags;
  54
  55         /**
  56          * A one dimentional array of all Exif tags
  57          */
  58         var $mFlatExifTags;
  59
  60         /**
  61          * The raw Exif data returned by exif_read_data()
  62          */
  63         var $mRawExifData;
  64
  65         /**
  66          * A Filtered version of $mRawExifData that has been pruned of invalid
  67          * tags and tags that contain content they shouldn't contain according
  68          * to the Exif specification
  69          */
  70         var $mFilteredExifData;
  71
  72         /**
  73          * Filtered and formatted Exif data, see FormatExif::getFormattedData()
  74          */
  75         var $mFormattedExifData;
  76
  77         //@}
  78
  79         //@{
  80         /* @var string
  81          * @private
  82          */
  83
  84         /**
  85          * The file being processed
  86          */
  87         var $file;
  88
  89         /**
  90          * The basename of the file being processed
  91          */
  92         var $basename;
  93
  94         /**
  95          * The private log to log to, e.g. 'exif'
  96          */
  97         var $log = false;
  98
  99         //@}
 100
 101         /**
 102          * Constructor
 103          *
 104          * @param $file String: filename.
 105          */
 106         function __construct( $file ) {
 107                 /**
 108                  * Page numbers here refer to pages in the EXIF 2.2 standard
 109                  *
 110                  * @link http://exif.org/Exif2-2.PDF The Exif 2.2 specification
 111                  */
 112                 $this->mExifTags = array(
 113                         # TIFF Rev. 6.0 Attribute Information (p22)
 114                         'tiff' => array(
 115                                 # Tags relating to image structure
 116                                 'structure' => array(
 117                                         'ImageWidth' => Exif::SHORT.','.Exif::LONG,             # Image width
 118                                         'ImageLength' => Exif::SHORT.','.Exif::LONG,    # Image height
 119                                         'BitsPerSample' => Exif::SHORT,                 # Number of bits per component
 120                                         # "When a primary image is JPEG compressed, this designation is not"
 121                                         # "necessary and is omitted." (p23)
 122                                         'Compression' => Exif::SHORT,                           # Compression scheme #p23
 123                                         'PhotometricInterpretation' => Exif::SHORT,             # Pixel composition #p23
 124                                         'Orientation' => Exif::SHORT,                           # Orientation of image #p24
 125                                         'SamplesPerPixel' => Exif::SHORT,                       # Number of components
 126                                         'PlanarConfiguration' => Exif::SHORT,                   # Image data arrangement #p24
 127                                         'YCbCrSubSampling' => Exif::SHORT,                      # Subsampling ratio of Y to C #p24
 128                                         'YCbCrPositioning' => Exif::SHORT,                      # Y and C positioning #p24-25
 129                                         'XResolution' => Exif::RATIONAL,                        # Image resolution in width direction
 130                                         'YResolution' => Exif::RATIONAL,                        # Image resolution in height direction
 131                                         'ResolutionUnit' => Exif::SHORT,                        # Unit of X and Y resolution #(p26)
 132                                 ),
 133
 134                                 # Tags relating to recording offset
 135                                 'offset' => array(
 136                                         'StripOffsets' => Exif::SHORT.','.Exif::LONG,                   # Image data location
 137                                         'RowsPerStrip' => Exif::SHORT.','.Exif::LONG,                   # Number of rows per strip
 138                                         'StripByteCounts' => Exif::SHORT.','.Exif::LONG,                        # Bytes per compressed strip
 139                                         'JPEGInterchangeFormat' => Exif::SHORT.','.Exif::LONG,          # Offset to JPEG SOI
 140                                         'JPEGInterchangeFormatLength' => Exif::SHORT.','.Exif::LONG,    # Bytes of JPEG data
 141                                 ),
 142
 143                                 # Tags relating to image data characteristics
 144                                 'characteristics' => array(
 145                                         'TransferFunction' => Exif::SHORT,              # Transfer function
 146                                         'WhitePoint' => Exif::RATIONAL,         # White point chromaticity
 147                                         'PrimaryChromaticities' => Exif::RATIONAL,      # Chromaticities of primarities
 148                                         'YCbCrCoefficients' => Exif::RATIONAL,  # Color space transformation matrix coefficients #p27
 149                                         'ReferenceBlackWhite' => Exif::RATIONAL # Pair of black and white reference values
 150                                 ),
 151
 152                                 # Other tags
 153                                 'other' => array(
 154                                         'DateTime' => Exif::ASCII,            # File change date and time
 155                                         'ImageDescription' => Exif::ASCII,    # Image title
 156                                         'Make' => Exif::ASCII,                # Image input equipment manufacturer
 157                                         'Model' => Exif::ASCII,               # Image input equipment model
 158                                         'Software' => Exif::ASCII,            # Software used
 159                                         'Artist' => Exif::ASCII,              # Person who created the image
 160                                         'Copyright' => Exif::ASCII,           # Copyright holder
 161                                 ),
 162                         ),
 163
 164                         # Exif IFD Attribute Information (p30-31)
 165                         'exif' => array(
 166                                 # Tags relating to version
 167                                 'version' => array(
 168                                         # TODO: NOTE: Nonexistence of this field is taken to mean nonconformance
 169                                         # to the EXIF 2.1 AND 2.2 standards
 170                                         'ExifVersion' => Exif::UNDEFINED,       # Exif version
 171                                         'FlashpixVersion' => Exif::UNDEFINED, # Supported Flashpix version #p32
 172                                 ),
 173
 174                                 # Tags relating to Image Data Characteristics
 175                                 'characteristics' => array(
 176                                         'ColorSpace' => Exif::SHORT,            # Color space information #p32
 177                                 ),
 178
 179                                 # Tags relating to image configuration
 180                                 'configuration' => array(
 181                                         'ComponentsConfiguration' => Exif::UNDEFINED,           # Meaning of each component #p33
 182                                         'CompressedBitsPerPixel' => Exif::RATIONAL,             # Image compression mode
 183                                         'PixelYDimension' => Exif::SHORT.','.Exif::LONG,        # Valid image width
 184                                         'PixelXDimension' => Exif::SHORT.','.Exif::LONG,        # Valind image height
 185                                 ),
 186
 187                                 # Tags relating to related user information
 188                                 'user' => array(
 189                                         'MakerNote' => Exif::UNDEFINED,                 # Manufacturer notes
 190                                         'UserComment' => Exif::UNDEFINED,                       # User comments #p34
 191                                 ),
 192
 193                                 # Tags relating to related file information
 194                                 'related' => array(
 195                                         'RelatedSoundFile' => Exif::ASCII,                      # Related audio file
 196                                 ),
 197
 198                                 # Tags relating to date and time
 199                                 'dateandtime' => array(
 200                                         'DateTimeOriginal' => Exif::ASCII,                      # Date and time of original data generation #p36
 201                                         'DateTimeDigitized' => Exif::ASCII,                     # Date and time of original data generation
 202                                         'SubSecTime' => Exif::ASCII,                            # DateTime subseconds
 203                                         'SubSecTimeOriginal' => Exif::ASCII,                    # DateTimeOriginal subseconds
 204                                         'SubSecTimeDigitized' => Exif::ASCII,                   # DateTimeDigitized subseconds
 205                                 ),
 206
 207                                 # Tags relating to picture-taking conditions (p31)
 208                                 'conditions' => array(
 209                                         'ExposureTime' => Exif::RATIONAL,                       # Exposure time
 210                                         'FNumber' => Exif::RATIONAL,                            # F Number
 211                                         'ExposureProgram' => Exif::SHORT,                       # Exposure Program #p38
 212                                         'SpectralSensitivity' => Exif::ASCII,                   # Spectral sensitivity
 213                                         'ISOSpeedRatings' => Exif::SHORT,                       # ISO speed rating
 214                                         'OECF' => Exif::UNDEFINED,                              # Optoelectronic conversion factor
 215                                         'ShutterSpeedValue' => Exif::SRATIONAL,         # Shutter speed
 216                                         'ApertureValue' => Exif::RATIONAL,                      # Aperture
 217                                         'BrightnessValue' => Exif::SRATIONAL,                   # Brightness
 218                                         'ExposureBiasValue' => Exif::SRATIONAL,         # Exposure bias
 219                                         'MaxApertureValue' => Exif::RATIONAL,                   # Maximum land aperture
 220                                         'SubjectDistance' => Exif::RATIONAL,                    # Subject distance
 221                                         'MeteringMode' => Exif::SHORT,                  # Metering mode #p40
 222                                         'LightSource' => Exif::SHORT,                           # Light source #p40-41
 223                                         'Flash' => Exif::SHORT,                         # Flash #p41-42
 224                                         'FocalLength' => Exif::RATIONAL,                        # Lens focal length
 225                                         'SubjectArea' => Exif::SHORT,                           # Subject area
 226                                         'FlashEnergy' => Exif::RATIONAL,                        # Flash energy
 227                                         'SpatialFrequencyResponse' => Exif::UNDEFINED,  # Spatial frequency response
 228                                         'FocalPlaneXResolution' => Exif::RATIONAL,              # Focal plane X resolution
 229                                         'FocalPlaneYResolution' => Exif::RATIONAL,              # Focal plane Y resolution
 230                                         'FocalPlaneResolutionUnit' => Exif::SHORT,              # Focal plane resolution unit #p46
 231                                         'SubjectLocation' => Exif::SHORT,                       # Subject location
 232                                         'ExposureIndex' => Exif::RATIONAL,                      # Exposure index
 233                                         'SensingMethod' => Exif::SHORT,                 # Sensing method #p46
 234                                         'FileSource' => Exif::UNDEFINED,                        # File source #p47
 235                                         'SceneType' => Exif::UNDEFINED,                 # Scene type #p47
 236                                         'CFAPattern' => Exif::UNDEFINED,                        # CFA pattern
 237                                         'CustomRendered' => Exif::SHORT,                        # Custom image processing #p48
 238                                         'ExposureMode' => Exif::SHORT,                  # Exposure mode #p48
 239                                         'WhiteBalance' => Exif::SHORT,                  # White Balance #p49
 240                                         'DigitalZoomRatio' => Exif::RATIONAL,                   # Digital zoom ration
 241                                         'FocalLengthIn35mmFilm' => Exif::SHORT,         # Focal length in 35 mm film
 242                                         'SceneCaptureType' => Exif::SHORT,                      # Scene capture type #p49
 243                                         'GainControl' => Exif::RATIONAL,                        # Scene control #p49-50
 244                                         'Contrast' => Exif::SHORT,                              # Contrast #p50
 245                                         'Saturation' => Exif::SHORT,                            # Saturation #p50
 246                                         'Sharpness' => Exif::SHORT,                             # Sharpness #p50
 247                                         'DeviceSettingDescription' => Exif::UNDEFINED,  # Desice settings description
 248                                         'SubjectDistanceRange' => Exif::SHORT,          # Subject distance range #p51
 249                                 ),
 250
 251                                 'other' => array(
 252                                         'ImageUniqueID' => Exif::ASCII, # Unique image ID
 253                                 ),
 254                         ),
 255
 256                         # GPS Attribute Information (p52)
 257                         'gps' => array(
 258                                 'GPSVersionID' => Exif::BYTE,                   # GPS tag version
 259                                 'GPSLatitudeRef' => Exif::ASCII,                # North or South Latitude #p52-53
 260                                 'GPSLatitude' => Exif::RATIONAL,                # Latitude
 261                                 'GPSLongitudeRef' => Exif::ASCII,               # East or West Longitude #p53
 262                                 'GPSLongitude' => Exif::RATIONAL,               # Longitude
 263                                 'GPSAltitudeRef' => Exif::BYTE,         # Altitude reference
 264                                 'GPSAltitude' => Exif::RATIONAL,                # Altitude
 265                                 'GPSTimeStamp' => Exif::RATIONAL,               # GPS time (atomic clock)
 266                                 'GPSSatellites' => Exif::ASCII,         # Satellites used for measurement
 267                                 'GPSStatus' => Exif::ASCII,                     # Receiver status #p54
 268                                 'GPSMeasureMode' => Exif::ASCII,                # Measurement mode #p54-55
 269                                 'GPSDOP' => Exif::RATIONAL,                     # Measurement precision
 270                                 'GPSSpeedRef' => Exif::ASCII,                   # Speed unit #p55
 271                                 'GPSSpeed' => Exif::RATIONAL,                   # Speed of GPS receiver
 272                                 'GPSTrackRef' => Exif::ASCII,                   # Reference for direction of movement #p55
 273                                 'GPSTrack' => Exif::RATIONAL,                   # Direction of movement
 274                                 'GPSImgDirectionRef' => Exif::ASCII,            # Reference for direction of image #p56
 275                                 'GPSImgDirection' => Exif::RATIONAL,            # Direction of image
 276                                 'GPSMapDatum' => Exif::ASCII,                   # Geodetic survey data used
 277                                 'GPSDestLatitudeRef' => Exif::ASCII,            # Reference for latitude of destination #p56
 278                                 'GPSDestLatitude' => Exif::RATIONAL,            # Latitude destination
 279                                 'GPSDestLongitudeRef' => Exif::ASCII,           # Reference for longitude of destination #p57
 280                                 'GPSDestLongitude' => Exif::RATIONAL,           # Longitude of destination
 281                                 'GPSDestBearingRef' => Exif::ASCII,             # Reference for bearing of destination #p57
 282                                 'GPSDestBearing' => Exif::RATIONAL,             # Bearing of destination
 283                                 'GPSDestDistanceRef' => Exif::ASCII,            # Reference for distance to destination #p57-58
 284                                 'GPSDestDistance' => Exif::RATIONAL,            # Distance to destination
 285                                 'GPSProcessingMethod' => Exif::UNDEFINED,       # Name of GPS processing method
 286                                 'GPSAreaInformation' => Exif::UNDEFINED,        # Name of GPS area
 287                                 'GPSDateStamp' => Exif::ASCII,          # GPS date
 288                                 'GPSDifferential' => Exif::SHORT,               # GPS differential correction
 289                         ),
 290                 );
 291
 292                 $this->file = $file;
 293                 $this->basename = wfBaseName( $this->file );
 294
 295                 $this->makeFlatExifTags();
 296
 297                 $this->debugFile( $this->basename, __FUNCTION__, true );
 298                 if( function_exists( 'exif_read_data' ) ) {
 299                         wfSuppressWarnings();
 300                         $data = exif_read_data( $this->file );
 301                         wfRestoreWarnings();
 302                 } else {
 303                         throw new MWException( "Internal error: exif_read_data not present. \$wgShowEXIF may be incorrectly set or not checked by an extension." );
 304                 }
 305                 /**
 306                  * exif_read_data() will return false on invalid input, such as
 307                  * when somebody uploads a file called something.jpeg
 308                  * containing random gibberish.
 309                  */
 310                 $this->mRawExifData = $data ? $data : array();
 311
 312                 $this->makeFilteredData();
 313                 $this->makeFormattedData();
 314
 315                 $this->debugFile( __FUNCTION__, false );
 316         }
 317
 318         /**#@+
 319          * @private
 320          */
 321         /**
 322          * Generate a flat list of the exif tags
 323          */
 324         function makeFlatExifTags() {
 325                 $this->extractTags( $this->mExifTags );
 326         }
 327
 328         /**
 329          * A recursing extractor function used by makeFlatExifTags()
 330          *
 331          * Note: This used to use an array_walk function, but it made PHP5
 332          * segfault, see `cvs diff -u -r 1.4 -r 1.5 Exif.php`
 333          */
 334         function extractTags( &$tagset ) {
 335                 foreach( $tagset as $key => $val ) {
 336                         if( is_array( $val ) ) {
 337                                 $this->extractTags( $val );
 338                         } else {
 339                                 $this->mFlatExifTags[$key] = $val;
 340                         }
 341                 }
 342         }
 343
 344         /**
 345          * Make $this->mFilteredExifData
 346          */
 347         function makeFilteredData() {
 348                 $this->mFilteredExifData = $this->mRawExifData;
 349
 350                 foreach( $this->mFilteredExifData as $k => $v ) {
 351                         if ( !in_array( $k, array_keys( $this->mFlatExifTags ) ) ) {
 352                                 $this->debug( $v, __FUNCTION__, "'$k' is not a valid Exif tag" );
 353                                 unset( $this->mFilteredExifData[$k] );
 354                         }
 355                 }
 356
 357                 foreach( $this->mFilteredExifData as $k => $v ) {
 358                         if ( !$this->validate($k, $v) ) {
 359                                 $this->debug( $v, __FUNCTION__, "'$k' contained invalid data" );
 360                                 unset( $this->mFilteredExifData[$k] );
 361                         }
 362                 }
 363         }
 364
 365         /**
 366          * @todo document
 367          */
 368         function makeFormattedData( ) {
 369                 $format = new FormatExif( $this->getFilteredData() );
 370                 $this->mFormattedExifData = $format->getFormattedData();
 371         }
 372         /**#@-*/
 373
 374         /**#@+
 375          * @return array
 376          */
 377         /**
 378          * Get $this->mRawExifData
 379          */
 380         function getData() {
 381                 return $this->mRawExifData;
 382         }
 383
 384         /**
 385          * Get $this->mFilteredExifData
 386          */
 387         function getFilteredData() {
 388                 return $this->mFilteredExifData;
 389         }
 390
 391         /**
 392          * Get $this->mFormattedExifData
 393          */
 394         function getFormattedData() {
 395                 return $this->mFormattedExifData;
 396         }
 397         /**#@-*/
 398
 399         /**
 400          * The version of the output format
 401          *
 402          * Before the actual metadata information is saved in the database we
 403          * strip some of it since we don't want to save things like thumbnails
 404          * which usually accompany Exif data. This value gets saved in the
 405          * database along with the actual Exif data, and if the version in the
 406          * database doesn't equal the value returned by this function the Exif
 407          * data is regenerated.
 408          *
 409          * @return int
 410          */
 411         public static function version() {
 412                 return 1; // We don't need no bloddy constants!
 413         }
 414
 415         /**#@+
 416          * Validates if a tag value is of the type it should be according to the Exif spec
 417          *
 418          * @private
 419          *
 420          * @param $in Mixed: the input value to check
 421          * @return bool
 422          */
 423         function isByte( $in ) {
 424                 if ( !is_array( $in ) && sprintf('%d', $in) == $in && $in >= 0 && $in <= 255 ) {
 425                         $this->debug( $in, __FUNCTION__, true );
 426                         return true;
 427                 } else {
 428                         $this->debug( $in, __FUNCTION__, false );
 429                         return false;
 430                 }
 431         }
 432
 433         function isASCII( $in ) {
 434                 if ( is_array( $in ) ) {
 435                         return false;
 436                 }
 437
 438                 if ( preg_match( "/[^\x0a\x20-\x7e]/", $in ) ) {
 439                         $this->debug( $in, __FUNCTION__, 'found a character not in our whitelist' );
 440                         return false;
 441                 }
 442
 443                 if ( preg_match( '/^\s*$/', $in ) ) {
 444                         $this->debug( $in, __FUNCTION__, 'input consisted solely of whitespace' );
 445                         return false;
 446                 }
 447
 448                 return true;
 449         }
 450
 451         function isShort( $in ) {
 452                 if ( !is_array( $in ) && sprintf('%d', $in) == $in && $in >= 0 && $in <= 65536 ) {
 453                         $this->debug( $in, __FUNCTION__, true );
 454                         return true;
 455                 } else {
 456                         $this->debug( $in, __FUNCTION__, false );
 457                         return false;
 458                 }
 459         }
 460
 461         function isLong( $in ) {
 462                 if ( !is_array( $in ) && sprintf('%d', $in) == $in && $in >= 0 && $in <= 4294967296 ) {
 463                         $this->debug( $in, __FUNCTION__, true );
 464                         return true;
 465                 } else {
 466                         $this->debug( $in, __FUNCTION__, false );
 467                         return false;
 468                 }
 469         }
 470
 471         function isRational( $in ) {
 472                 $m = array();
 473                 if ( !is_array( $in ) && @preg_match( '/^(\d+)\/(\d+[1-9]|[1-9]\d*)$/', $in, $m ) ) { # Avoid division by zero
 474                         return $this->isLong( $m[1] ) && $this->isLong( $m[2] );
 475                 } else {
 476                         $this->debug( $in, __FUNCTION__, 'fed a non-fraction value' );
 477                         return false;
 478                 }
 479         }
 480
 481         function isUndefined( $in ) {
 482                 if ( !is_array( $in ) && preg_match( '/^\d{4}$/', $in ) ) { // Allow ExifVersion and FlashpixVersion
 483                         $this->debug( $in, __FUNCTION__, true );
 484                         return true;
 485                 } else {
 486                         $this->debug( $in, __FUNCTION__, false );
 487                         return false;
 488                 }
 489         }
 490
 491         function isSlong( $in ) {
 492                 if ( $this->isLong( abs( $in ) ) ) {
 493                         $this->debug( $in, __FUNCTION__, true );
 494                         return true;
 495                 } else {
 496                         $this->debug( $in, __FUNCTION__, false );
 497                         return false;
 498                 }
 499         }
 500
 501         function isSrational( $in ) {
 502                 $m = array();
 503                 if ( !is_array( $in ) && preg_match( '/^(\d+)\/(\d+[1-9]|[1-9]\d*)$/', $in, $m ) ) { # Avoid division by zero
 504                         return $this->isSlong( $m[0] ) && $this->isSlong( $m[1] );
 505                 } else {
 506                         $this->debug( $in, __FUNCTION__, 'fed a non-fraction value' );
 507                         return false;
 508                 }
 509         }
 510         /**#@-*/
 511
 512         /**
 513          * Validates if a tag has a legal value according to the Exif spec
 514          *
 515          * @private
 516          *
 517          * @param $tag String: the tag to check.
 518          * @param $val Mixed: the value of the tag.
 519          * @return bool
 520          */
 521         function validate( $tag, $val ) {
 522                 $debug = "tag is '$tag'";
 523                 // Does not work if not typecast
 524                 switch( (string)$this->mFlatExifTags[$tag] ) {
 525                         case (string)Exif::BYTE:
 526                                 $this->debug( $val, __FUNCTION__, $debug );
 527                                 return $this->isByte( $val );
 528                         case (string)Exif::ASCII:
 529                                 $this->debug( $val, __FUNCTION__, $debug );
 530                                 return $this->isASCII( $val );
 531                         case (string)Exif::SHORT:
 532                                 $this->debug( $val, __FUNCTION__, $debug );
 533                                 return $this->isShort( $val );
 534                         case (string)Exif::LONG:
 535                                 $this->debug( $val, __FUNCTION__, $debug );
 536                                 return $this->isLong( $val );
 537                         case (string)Exif::RATIONAL:
 538                                 $this->debug( $val, __FUNCTION__, $debug );
 539                                 return $this->isRational( $val );
 540                         case (string)Exif::UNDEFINED:
 541                                 $this->debug( $val, __FUNCTION__, $debug );
 542                                 return $this->isUndefined( $val );
 543                         case (string)Exif::SLONG:
 544                                 $this->debug( $val, __FUNCTION__, $debug );
 545                                 return $this->isSlong( $val );
 546                         case (string)Exif::SRATIONAL:
 547                                 $this->debug( $val, __FUNCTION__, $debug );
 548                                 return $this->isSrational( $val );
 549                         case (string)Exif::SHORT.','.Exif::LONG:
 550                                 $this->debug( $val, __FUNCTION__, $debug );
 551                                 return $this->isShort( $val ) || $this->isLong( $val );
 552                         default:
 553                                 $this->debug( $val, __FUNCTION__, "The tag '$tag' is unknown" );
 554                                 return false;
 555                 }
 556         }
 557
 558         /**
 559          * Convenience function for debugging output
 560          *
 561          * @private
 562          *
 563          * @param $in Mixed:
 564          * @param $fname String:
 565          * @param $action Mixed: , default NULL.
 566          */
 567         function debug( $in, $fname, $action = null ) {
 568                 if ( !$this->log ) {
 569                         return;
 570                 }
 571                 $type = gettype( $in );
 572                 $class = ucfirst( __CLASS__ );
 573                 if ( $type === 'array' )
 574                         $in = print_r( $in, true );
 575
 576                 if ( $action === true )
 577                         wfDebugLog( $this->log, "$class::$fname: accepted: '$in' (type: $type)\n");
 578                 elseif ( $action === false )
 579                         wfDebugLog( $this->log, "$class::$fname: rejected: '$in' (type: $type)\n");
 580                 elseif ( $action === null )
 581                         wfDebugLog( $this->log, "$class::$fname: input was: '$in' (type: $type)\n");
 582                 else
 583                         wfDebugLog( $this->log, "$class::$fname: $action (type: $type; content: '$in')\n");
 584         }
 585
 586         /**
 587          * Convenience function for debugging output
 588          *
 589          * @private
 590          *
 591          * @param $fname String: the name of the function calling this function
 592          * @param $io Boolean: Specify whether we're beginning or ending
 593          */
 594         function debugFile( $fname, $io ) {
 595                 if ( !$this->log ) {
 596                         return;
 597                 }
 598                 $class = ucfirst( __CLASS__ );
 599                 if ( $io ) {
 600                         wfDebugLog( $this->log, "$class::$fname: begin processing: '{$this->basename}'\n" );
 601                 } else {
 602                         wfDebugLog( $this->log, "$class::$fname: end processing: '{$this->basename}'\n" );
 603                 }
 604         }
 605
 606 }
 607
 608 /**
 609  * @todo document (e.g. one-sentence class-overview description)
 610  * @ingroup Media
 611  */
 612 class FormatExif {
 613         /**
 614          * The Exif data to format
 615          *
 616          * @var array
 617          * @private
 618          */
 619         var $mExif;
 620
 621         /**
 622          * Constructor
 623          *
 624          * @param $exif Array: the Exif data to format ( as returned by
 625          *                    Exif::getFilteredData() )
 626          */
 627         function __construct( $exif ) {
 628                 $this->mExif = $exif;
 629         }
 630
 631         /**
 632          * Numbers given by Exif user agents are often magical, that is they
 633          * should be replaced by a detailed explanation depending on their
 634          * value which most of the time are plain integers. This function
 635          * formats Exif values into human readable form.
 636          *
 637          * @return array
 638          */
 639         function getFormattedData() {
 640                 global $wgLang;
 641
 642                 $tags =& $this->mExif;
 643
 644                 $resolutionunit = !isset( $tags['ResolutionUnit'] ) || $tags['ResolutionUnit'] == 2 ? 2 : 3;
 645                 unset( $tags['ResolutionUnit'] );
 646
 647                 foreach( $tags as $tag => $val ) {
 648                         switch( $tag ) {
 649                         case 'Compression':
 650                                 switch( $val ) {
 651                                 case 1: case 6:
 652                                         $tags[$tag] = $this->msg( $tag, $val );
 653                                         break;
 654                                 default:
 655                                         $tags[$tag] = $val;
 656                                         break;
 657                                 }
 658                                 break;
 659
 660                         case 'PhotometricInterpretation':
 661                                 switch( $val ) {
 662                                 case 2: case 6:
 663                                         $tags[$tag] = $this->msg( $tag, $val );
 664                                         break;
 665                                 default:
 666                                         $tags[$tag] = $val;
 667                                         break;
 668                                 }
 669                                 break;
 670
 671                         case 'Orientation':
 672                                 switch( $val ) {
 673                                 case 1: case 2: case 3: case 4: case 5: case 6: case 7: case 8:
 674                                         $tags[$tag] = $this->msg( $tag, $val );
 675                                         break;
 676                                 default:
 677                                         $tags[$tag] = $val;
 678                                         break;
 679                                 }
 680                                 break;
 681
 682                         case 'PlanarConfiguration':
 683                                 switch( $val ) {
 684                                 case 1: case 2:
 685                                         $tags[$tag] = $this->msg( $tag, $val );
 686                                         break;
 687                                 default:
 688                                         $tags[$tag] = $val;
 689                                         break;
 690                                 }
 691                                 break;
 692
 693                         // TODO: YCbCrSubSampling
 694                         // TODO: YCbCrPositioning
 695
 696                         case 'XResolution':
 697                         case 'YResolution':
 698                                 switch( $resolutionunit ) {
 699                                         case 2:
 700                                                 $tags[$tag] = $this->msg( 'XYResolution', 'i', $this->formatNum( $val ) );
 701                                                 break;
 702                                         case 3:
 703                                                 $this->msg( 'XYResolution', 'c', $this->formatNum( $val ) );
 704                                                 break;
 705                                         default:
 706                                                 $tags[$tag] = $val;
 707                                                 break;
 708                                 }
 709                                 break;
 710
 711                         // TODO: YCbCrCoefficients  #p27 (see annex E)
 712                         case 'ExifVersion': case 'FlashpixVersion':
 713                                 $tags[$tag] = "$val"/100;
 714                                 break;
 715
 716                         case 'ColorSpace':
 717                                 switch( $val ) {
 718                                 case 1: case 'FFFF.H':
 719                                         $tags[$tag] = $this->msg( $tag, $val );
 720                                         break;
 721                                 default:
 722                                         $tags[$tag] = $val;
 723                                         break;
 724                                 }
 725                                 break;
 726
 727                         case 'ComponentsConfiguration':
 728                                 switch( $val ) {
 729                                 case 0: case 1: case 2: case 3: case 4: case 5: case 6:
 730                                         $tags[$tag] = $this->msg( $tag, $val );
 731                                         break;
 732                                 default:
 733                                         $tags[$tag] = $val;
 734                                         break;
 735                                 }
 736                                 break;
 737
 738                         case 'DateTime':
 739                         case 'DateTimeOriginal':
 740                         case 'DateTimeDigitized':
 741                                 if( $val == '0000:00:00 00:00:00' ) {
 742                                         $tags[$tag] = wfMsg('exif-unknowndate');
 743                                 } elseif( preg_match( '/^(?:\d{4}):(?:\d\d):(?:\d\d) (?:\d\d):(?:\d\d):(?:\d\d)$/', $val ) ) {
 744                                         $tags[$tag] = $wgLang->timeanddate( wfTimestamp(TS_MW, $val) );
 745                                 }
 746                                 break;
 747
 748                         case 'ExposureProgram':
 749                                 switch( $val ) {
 750                                 case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7: case 8:
 751                                         $tags[$tag] = $this->msg( $tag, $val );
 752                                         break;
 753                                 default:
 754                                         $tags[$tag] = $val;
 755                                         break;
 756                                 }
 757                                 break;
 758
 759                         case 'SubjectDistance':
 760                                 $tags[$tag] = $this->msg( $tag, '', $this->formatNum( $val ) );
 761                                 break;
 762
 763                         case 'MeteringMode':
 764                                 switch( $val ) {
 765                                 case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7: case 255:
 766                                         $tags[$tag] = $this->msg( $tag, $val );
 767                                         break;
 768                                 default:
 769                                         $tags[$tag] = $val;
 770                                         break;
 771                                 }
 772                                 break;
 773
 774                         case 'LightSource':
 775                                 switch( $val ) {
 776                                 case 0: case 1: case 2: case 3: case 4: case 9: case 10: case 11:
 777                                 case 12: case 13: case 14: case 15: case 17: case 18: case 19: case 20:
 778                                 case 21: case 22: case 23: case 24: case 255:
 779                                         $tags[$tag] = $this->msg( $tag, $val );
 780                                         break;
 781                                 default:
 782                                         $tags[$tag] = $val;
 783                                         break;
 784                                 }
 785                                 break;
 786
 787                         case 'Flash':
 788                                 $flashDecode = array(
 789                                         'fired'    => $val & bindec( '00000001' ),
 790                                         'return'   => ($val & bindec( '00000110' )) >> 1,
 791                                         'mode'     => ($val & bindec( '00011000' )) >> 3,
 792                                         'function' => ($val & bindec( '00100000' )) >> 5,
 793                                         'redeye'   => ($val & bindec( '01000000' )) >> 6,
 794 //                                      'reserved' => ($val & bindec( '10000000' )) >> 7,
 795                                 );
 796
 797                                 # We do not need to handle unknown values since all are used.
 798                                 foreach( $flashDecode as $subTag => $subValue ) {
 799                                         # We do not need any message for zeroed values.
 800                                         if( $subTag != 'fired' && $subValue == 0) {
 801                                                 continue;
 802                                         }
 803                                         $fullTag = $tag . '-' . $subTag ;
 804                                         $flashMsgs[] = $this->msg( $fullTag, $subValue );
 805                                 }
 806                                 $tags[$tag] = $wgLang->commaList( $flashMsgs );
 807                         break;
 808
 809                         case 'FocalPlaneResolutionUnit':
 810                                 switch( $val ) {
 811                                 case 2:
 812                                         $tags[$tag] = $this->msg( $tag, $val );
 813                                         break;
 814                                 default:
 815                                         $tags[$tag] = $val;
 816                                         break;
 817                                 }
 818                                 break;
 819
 820                         case 'SensingMethod':
 821                                 switch( $val ) {
 822                                 case 1: case 2: case 3: case 4: case 5: case 7: case 8:
 823                                         $tags[$tag] = $this->msg( $tag, $val );
 824                                         break;
 825                                 default:
 826                                         $tags[$tag] = $val;
 827                                         break;
 828                                 }
 829                                 break;
 830
 831                         case 'FileSource':
 832                                 switch( $val ) {
 833                                 case 3:
 834                                         $tags[$tag] = $this->msg( $tag, $val );
 835                                         break;
 836                                 default:
 837                                         $tags[$tag] = $val;
 838                                         break;
 839                                 }
 840                                 break;
 841
 842                         case 'SceneType':
 843                                 switch( $val ) {
 844                                 case 1:
 845                                         $tags[$tag] = $this->msg( $tag, $val );
 846                                         break;
 847                                 default:
 848                                         $tags[$tag] = $val;
 849                                         break;
 850                                 }
 851                                 break;
 852
 853                         case 'CustomRendered':
 854                                 switch( $val ) {
 855                                 case 0: case 1:
 856                                         $tags[$tag] = $this->msg( $tag, $val );
 857                                         break;
 858                                 default:
 859                                         $tags[$tag] = $val;
 860                                         break;
 861                                 }
 862                                 break;
 863
 864                         case 'ExposureMode':
 865                                 switch( $val ) {
 866                                 case 0: case 1: case 2:
 867                                         $tags[$tag] = $this->msg( $tag, $val );
 868                                         break;
 869                                 default:
 870                                         $tags[$tag] = $val;
 871                                         break;
 872                                 }
 873                                 break;
 874
 875                         case 'WhiteBalance':
 876                                 switch( $val ) {
 877                                 case 0: case 1:
 878                                         $tags[$tag] = $this->msg( $tag, $val );
 879                                         break;
 880                                 default:
 881                                         $tags[$tag] = $val;
 882                                         break;
 883                                 }
 884                                 break;
 885
 886                         case 'SceneCaptureType':
 887                                 switch( $val ) {
 888                                 case 0: case 1: case 2: case 3:
 889                                         $tags[$tag] = $this->msg( $tag, $val );
 890                                         break;
 891                                 default:
 892                                         $tags[$tag] = $val;
 893                                         break;
 894                                 }
 895                                 break;
 896
 897                         case 'GainControl':
 898                                 switch( $val ) {
 899                                 case 0: case 1: case 2: case 3: case 4:
 900                                         $tags[$tag] = $this->msg( $tag, $val );
 901                                         break;
 902                                 default:
 903                                         $tags[$tag] = $val;
 904                                         break;
 905                                 }
 906                                 break;
 907
 908                         case 'Contrast':
 909                                 switch( $val ) {
 910                                 case 0: case 1: case 2:
 911                                         $tags[$tag] = $this->msg( $tag, $val );
 912                                         break;
 913                                 default:
 914                                         $tags[$tag] = $val;
 915                                         break;
 916                                 }
 917                                 break;
 918
 919                         case 'Saturation':
 920                                 switch( $val ) {
 921                                 case 0: case 1: case 2:
 922                                         $tags[$tag] = $this->msg( $tag, $val );
 923                                         break;
 924                                 default:
 925                                         $tags[$tag] = $val;
 926                                         break;
 927                                 }
 928                                 break;
 929
 930                         case 'Sharpness':
 931                                 switch( $val ) {
 932                                 case 0: case 1: case 2:
 933                                         $tags[$tag] = $this->msg( $tag, $val );
 934                                         break;
 935                                 default:
 936                                         $tags[$tag] = $val;
 937                                         break;
 938                                 }
 939                                 break;
 940
 941                         case 'SubjectDistanceRange':
 942                                 switch( $val ) {
 943                                 case 0: case 1: case 2: case 3:
 944                                         $tags[$tag] = $this->msg( $tag, $val );
 945                                         break;
 946                                 default:
 947                                         $tags[$tag] = $val;
 948                                         break;
 949                                 }
 950                                 break;
 951
 952                         case 'GPSLatitudeRef':
 953                         case 'GPSDestLatitudeRef':
 954                                 switch( $val ) {
 955                                 case 'N': case 'S':
 956                                         $tags[$tag] = $this->msg( 'GPSLatitude', $val );
 957                                         break;
 958                                 default:
 959                                         $tags[$tag] = $val;
 960                                         break;
 961                                 }
 962                                 break;
 963
 964                         case 'GPSLongitudeRef':
 965                         case 'GPSDestLongitudeRef':
 966                                 switch( $val ) {
 967                                 case 'E': case 'W':
 968                                         $tags[$tag] = $this->msg( 'GPSLongitude', $val );
 969                                         break;
 970                                 default:
 971                                         $tags[$tag] = $val;
 972                                         break;
 973                                 }
 974                                 break;
 975
 976                         case 'GPSStatus':
 977                                 switch( $val ) {
 978                                 case 'A': case 'V':
 979                                         $tags[$tag] = $this->msg( $tag, $val );
 980                                         break;
 981                                 default:
 982                                         $tags[$tag] = $val;
 983                                         break;
 984                                 }
 985                                 break;
 986
 987                         case 'GPSMeasureMode':
 988                                 switch( $val ) {
 989                                 case 2: case 3:
 990                                         $tags[$tag] = $this->msg( $tag, $val );
 991                                         break;
 992                                 default:
 993                                         $tags[$tag] = $val;
 994                                         break;
 995                                 }
 996                                 break;
 997
 998                         case 'GPSSpeedRef':
 999                         case 'GPSDestDistanceRef':
1000                                 switch( $val ) {
1001                                 case 'K': case 'M': case 'N':
1002                                         $tags[$tag] = $this->msg( 'GPSSpeed', $val );
1003                                         break;
1004                                 default:
1005                                         $tags[$tag] = $val;
1006                                         break;
1007                                 }
1008                                 break;
1009
1010                         case 'GPSTrackRef':
1011                         case 'GPSImgDirectionRef':
1012                         case 'GPSDestBearingRef':
1013                                 switch( $val ) {
1014                                 case 'T': case 'M':
1015                                         $tags[$tag] = $this->msg( 'GPSDirection', $val );
1016                                         break;
1017                                 default:
1018                                         $tags[$tag] = $val;
1019                                         break;
1020                                 }
1021                                 break;
1022
1023                         case 'GPSDateStamp':
1024                                 $tags[$tag] = $wgLang->date( substr( $val, 0, 4 ) . substr( $val, 5, 2 ) . substr( $val, 8, 2 ) . '000000' );
1025                                 break;
1026
1027                         // This is not in the Exif standard, just a special
1028                         // case for our purposes which enables wikis to wikify
1029                         // the make, model and software name to link to their articles.
1030                         case 'Make':
1031                         case 'Model':
1032                         case 'Software':
1033                                 $tags[$tag] = $this->msg( $tag, '', $val );
1034                                 break;
1035
1036                         case 'ExposureTime':
1037                                 // Show the pretty fraction as well as decimal version
1038                                 $tags[$tag] = wfMsg( 'exif-exposuretime-format',
1039                                         $this->formatFraction( $val ), $this->formatNum( $val ) );
1040                                 break;
1041
1042                         case 'FNumber':
1043                                 $tags[$tag] = wfMsg( 'exif-fnumber-format',
1044                                         $this->formatNum( $val ) );
1045                                 break;
1046
1047                         case 'FocalLength':
1048                                 $tags[$tag] = wfMsg( 'exif-focallength-format',
1049                                         $this->formatNum( $val ) );
1050                                 break;
1051
1052                         // Do not transform fields with pure text.
1053                         // For some languages the formatNum() conversion results to wrong output like
1054                         // foo,bar@example,com or foo٫bar@example٫com
1055                         case 'ImageDescription':
1056                         case 'Artist':
1057                         case 'Copyright':
1058                                 $tags[$tag] = htmlspecialchars( $val );
1059                                 break;
1060                         default:
1061                                 $tags[$tag] = $this->formatNum( $val );
1062                                 break;
1063                         }
1064                 }
1065
1066                 return $tags;
1067         }
1068
1069         /**
1070          * Convenience function for getFormattedData()
1071          *
1072          * @private
1073          *
1074          * @param $tag String: the tag name to pass on
1075          * @param $val String: the value of the tag
1076          * @param $arg String: an argument to pass ($1)
1077          * @return string A wfMsg of "exif-$tag-$val" in lower case
1078          */
1079         function msg( $tag, $val, $arg = null ) {
1080                 global $wgContLang;
1081
1082                 if ($val === '')
1083                         $val = 'value';
1084                 return wfMsg( $wgContLang->lc( "exif-$tag-$val" ), $arg );
1085         }
1086
1087         /**
1088          * Format a number, convert numbers from fractions into floating point
1089          * numbers
1090          *
1091          * @private
1092          *
1093          * @param $num Mixed: the value to format
1094          * @return mixed A floating point number or whatever we were fed
1095          */
1096         function formatNum( $num ) {
1097                 global $wgLang;
1098
1099                 $m = array();
1100                 if ( preg_match( '/^(\d+)\/(\d+)$/', $num, $m ) )
1101                         return $wgLang->formatNum( $m[2] != 0 ? $m[1] / $m[2] : $num );
1102                 else
1103                         return $wgLang->formatNum( $num );
1104         }
1105
1106         /**
1107          * Format a rational number, reducing fractions
1108          *
1109          * @private
1110          *
1111          * @param $num Mixed: the value to format
1112          * @return mixed A floating point number or whatever we were fed
1113          */
1114         function formatFraction( $num ) {
1115                 $m = array();
1116                 if ( preg_match( '/^(\d+)\/(\d+)$/', $num, $m ) ) {
1117                         $numerator = intval( $m[1] );
1118                         $denominator = intval( $m[2] );
1119                         $gcd = $this->gcd( $numerator, $denominator );
1120                         if( $gcd != 0 ) {
1121                                 // 0 shouldn't happen! ;)
1122                                 return $this->formatNum( $numerator / $gcd ) . '/' . $this->formatNum( $denominator / $gcd );
1123                         }
1124                 }
1125                 return $this->formatNum( $num );
1126         }
1127
1128         /**
1129          * Calculate the greatest common divisor of two integers.
1130          *
1131          * @param $a Integer: FIXME
1132          * @param $b Integer: FIXME
1133          * @return int
1134          * @private
1135          */
1136         function gcd( $a, $b ) {
1137                 /*
1138                         // http://en.wikipedia.org/wiki/Euclidean_algorithm
1139                         // Recursive form would be:
1140                         if( $b == 0 )
1141                                 return $a;
1142                         else
1143                                 return gcd( $b, $a % $b );
1144                 */
1145                 while( $b != 0 ) {
1146                         $remainder = $a % $b;
1147
1148                         // tail recursion...
1149                         $a = $b;
1150                         $b = $remainder;
1151                 }
1152                 return $a;
1153         }
1154 }