includes/Exif.php

   1 <?php
   2 /**
   3  * @addtogroup Media
   4  *
   5  * @author Ævar Arnfjörð Bjarmason <avarab@gmail.com>
   6  * @copyright Copyright © 2005, Ævar Arnfjörð Bjarmason
   7  * @license http://www.gnu.org/copyleft/gpl.html GNU General Public License
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write to the Free Software Foundation, Inc.,
  21  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  22  * http://www.gnu.org/copyleft/gpl.html
  23  *
  24  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 specification
  25  */
  26
  27 /**
  28  * @todo document (e.g. one-sentence class-overview description)
  29  * @addtogroup Media
  30  */
  31 class Exif {
  32         //@{
  33         /* @var array
  34          * @private
  35          */
  36
  37         /**#@+
  38          * Exif tag type definition
  39          */
  40         const BYTE      = 1;    # An 8-bit (1-byte) unsigned integer.
  41         const ASCII     = 2;    # An 8-bit byte containing one 7-bit ASCII code. The final byte is terminated with NULL.
  42         const SHORT     = 3;    # A 16-bit (2-byte) unsigned integer.
  43         const LONG      = 4;    # A 32-bit (4-byte) unsigned integer.
  44         const RATIONAL  = 5;    # Two LONGs. The first LONG is the numerator and the second LONG expresses the denominator
  45         const UNDEFINED = 7;    # An 8-bit byte that can take any value depending on the field definition
  46         const SLONG     = 9;    # A 32-bit (4-byte) signed integer (2's complement notation),
  47         const SRATIONAL = 10;   # Two SLONGs. The first SLONG is the numerator and the second SLONG is the denominator.
  48
  49         /**
  50          * Exif tags grouped by category, the tagname itself is the key and the type
  51          * is the value, in the case of more than one possible value type they are
  52          * seperated by commas.
  53          */
  54         var $mExifTags;
  55
  56         /**
  57          * A one dimentional array of all Exif tags
  58          */
  59         var $mFlatExifTags;
  60
  61         /**
  62          * The raw Exif data returned by exif_read_data()
  63          */
  64         var $mRawExifData;
  65
  66         /**
  67          * A Filtered version of $mRawExifData that has been pruned of invalid
  68          * tags and tags that contain content they shouldn't contain according
  69          * to the Exif specification
  70          */
  71         var $mFilteredExifData;
  72
  73         /**
  74          * Filtered and formatted Exif data, see FormatExif::getFormattedData()
  75          */
  76         var $mFormattedExifData;
  77
  78         //@}
  79
  80         //@{
  81         /* @var string
  82          * @private
  83          */
  84
  85         /**
  86          * The file being processed
  87          */
  88         var $file;
  89
  90         /**
  91          * The basename of the file being processed
  92          */
  93         var $basename;
  94
  95         /**
  96          * The private log to log to, e.g. 'exif'
  97          */
  98         var $log = false;
  99
 100         //@}
 101
 102         /**
 103          * Constructor
 104          *
 105          * @param $file String: filename.
 106          */
 107         function __construct( $file ) {
 108                 /**
 109                  * Page numbers here refer to pages in the EXIF 2.2 standard
 110                  *
 111                  * @link http://exif.org/Exif2-2.PDF The Exif 2.2 specification
 112                  */
 113                 $this->mExifTags = array(
 114                         # TIFF Rev. 6.0 Attribute Information (p22)
 115                         'tiff' => array(
 116                                 # Tags relating to image structure
 117                                 'structure' => array(
 118                                         'ImageWidth' => Exif::SHORT.','.Exif::LONG,             # Image width
 119                                         'ImageLength' => Exif::SHORT.','.Exif::LONG,    # Image height
 120                                         'BitsPerSample' => Exif::SHORT,                 # Number of bits per component
 121                                         # "When a primary image is JPEG compressed, this designation is not"
 122                                         # "necessary and is omitted." (p23)
 123                                         'Compression' => Exif::SHORT,                           # Compression scheme #p23
 124                                         'PhotometricInterpretation' => Exif::SHORT,             # Pixel composition #p23
 125                                         'Orientation' => Exif::SHORT,                           # Orientation of image #p24
 126                                         'SamplesPerPixel' => Exif::SHORT,                       # Number of components
 127                                         'PlanarConfiguration' => Exif::SHORT,                   # Image data arrangement #p24
 128                                         'YCbCrSubSampling' => Exif::SHORT,                      # Subsampling ratio of Y to C #p24
 129                                         'YCbCrPositioning' => Exif::SHORT,                      # Y and C positioning #p24-25
 130                                         'XResolution' => Exif::RATIONAL,                        # Image resolution in width direction
 131                                         'YResolution' => Exif::RATIONAL,                        # Image resolution in height direction
 132                                         'ResolutionUnit' => Exif::SHORT,                        # Unit of X and Y resolution #(p26)
 133                                 ),
 134
 135                                 # Tags relating to recording offset
 136                                 'offset' => array(
 137                                         'StripOffsets' => Exif::SHORT.','.Exif::LONG,                   # Image data location
 138                                         'RowsPerStrip' => Exif::SHORT.','.Exif::LONG,                   # Number of rows per strip
 139                                         'StripByteCounts' => Exif::SHORT.','.Exif::LONG,                        # Bytes per compressed strip
 140                                         'JPEGInterchangeFormat' => Exif::SHORT.','.Exif::LONG,          # Offset to JPEG SOI
 141                                         'JPEGInterchangeFormatLength' => Exif::SHORT.','.Exif::LONG,    # Bytes of JPEG data
 142                                 ),
 143
 144                                 # Tags relating to image data characteristics
 145                                 'characteristics' => array(
 146                                         'TransferFunction' => Exif::SHORT,              # Transfer function
 147                                         'WhitePoint' => Exif::RATIONAL,         # White point chromaticity
 148                                         'PrimaryChromaticities' => Exif::RATIONAL,      # Chromaticities of primarities
 149                                         'YCbCrCoefficients' => Exif::RATIONAL,  # Color space transformation matrix coefficients #p27
 150                                         'ReferenceBlackWhite' => Exif::RATIONAL # Pair of black and white reference values
 151                                 ),
 152
 153                                 # Other tags
 154                                 'other' => array(
 155                                         'DateTime' => Exif::ASCII,            # File change date and time
 156                                         'ImageDescription' => Exif::ASCII,    # Image title
 157                                         'Make' => Exif::ASCII,                # Image input equipment manufacturer
 158                                         'Model' => Exif::ASCII,               # Image input equipment model
 159                                         'Software' => Exif::ASCII,            # Software used
 160                                         'Artist' => Exif::ASCII,              # Person who created the image
 161                                         'Copyright' => Exif::ASCII,           # Copyright holder
 162                                 ),
 163                         ),
 164
 165                         # Exif IFD Attribute Information (p30-31)
 166                         'exif' => array(
 167                                 # Tags relating to version
 168                                 'version' => array(
 169                                         # TODO: NOTE: Nonexistence of this field is taken to mean nonconformance
 170                                         # to the EXIF 2.1 AND 2.2 standards
 171                                         'ExifVersion' => Exif::UNDEFINED,       # Exif version
 172                                         'FlashpixVersion' => Exif::UNDEFINED, # Supported Flashpix version #p32
 173                                 ),
 174
 175                                 # Tags relating to Image Data Characteristics
 176                                 'characteristics' => array(
 177                                         'ColorSpace' => Exif::SHORT,            # Color space information #p32
 178                                 ),
 179
 180                                 # Tags relating to image configuration
 181                                 'configuration' => array(
 182                                         'ComponentsConfiguration' => Exif::UNDEFINED,           # Meaning of each component #p33
 183                                         'CompressedBitsPerPixel' => Exif::RATIONAL,             # Image compression mode
 184                                         'PixelYDimension' => Exif::SHORT.','.Exif::LONG,        # Valid image width
 185                                         'PixelXDimension' => Exif::SHORT.','.Exif::LONG,        # Valind image height
 186                                 ),
 187
 188                                 # Tags relating to related user information
 189                                 'user' => array(
 190                                         'MakerNote' => Exif::UNDEFINED,                 # Manufacturer notes
 191                                         'UserComment' => Exif::UNDEFINED,                       # User comments #p34
 192                                 ),
 193
 194                                 # Tags relating to related file information
 195                                 'related' => array(
 196                                         'RelatedSoundFile' => Exif::ASCII,                      # Related audio file
 197                                 ),
 198
 199                                 # Tags relating to date and time
 200                                 'dateandtime' => array(
 201                                         'DateTimeOriginal' => Exif::ASCII,                      # Date and time of original data generation #p36
 202                                         'DateTimeDigitized' => Exif::ASCII,                     # Date and time of original data generation
 203                                         'SubSecTime' => Exif::ASCII,                            # DateTime subseconds
 204                                         'SubSecTimeOriginal' => Exif::ASCII,                    # DateTimeOriginal subseconds
 205                                         'SubSecTimeDigitized' => Exif::ASCII,                   # DateTimeDigitized subseconds
 206                                 ),
 207
 208                                 # Tags relating to picture-taking conditions (p31)
 209                                 'conditions' => array(
 210                                         'ExposureTime' => Exif::RATIONAL,                       # Exposure time
 211                                         'FNumber' => Exif::RATIONAL,                            # F Number
 212                                         'ExposureProgram' => Exif::SHORT,                       # Exposure Program #p38
 213                                         'SpectralSensitivity' => Exif::ASCII,                   # Spectral sensitivity
 214                                         'ISOSpeedRatings' => Exif::SHORT,                       # ISO speed rating
 215                                         'OECF' => Exif::UNDEFINED,                              # Optoelectronic conversion factor
 216                                         'ShutterSpeedValue' => Exif::SRATIONAL,         # Shutter speed
 217                                         'ApertureValue' => Exif::RATIONAL,                      # Aperture
 218                                         'BrightnessValue' => Exif::SRATIONAL,                   # Brightness
 219                                         'ExposureBiasValue' => Exif::SRATIONAL,         # Exposure bias
 220                                         'MaxApertureValue' => Exif::RATIONAL,                   # Maximum land aperture
 221                                         'SubjectDistance' => Exif::RATIONAL,                    # Subject distance
 222                                         'MeteringMode' => Exif::SHORT,                  # Metering mode #p40
 223                                         'LightSource' => Exif::SHORT,                           # Light source #p40-41
 224                                         'Flash' => Exif::SHORT,                         # Flash #p41-42
 225                                         'FocalLength' => Exif::RATIONAL,                        # Lens focal length
 226                                         'SubjectArea' => Exif::SHORT,                           # Subject area
 227                                         'FlashEnergy' => Exif::RATIONAL,                        # Flash energy
 228                                         'SpatialFrequencyResponse' => Exif::UNDEFINED,  # Spatial frequency response
 229                                         'FocalPlaneXResolution' => Exif::RATIONAL,              # Focal plane X resolution
 230                                         'FocalPlaneYResolution' => Exif::RATIONAL,              # Focal plane Y resolution
 231                                         'FocalPlaneResolutionUnit' => Exif::SHORT,              # Focal plane resolution unit #p46
 232                                         'SubjectLocation' => Exif::SHORT,                       # Subject location
 233                                         'ExposureIndex' => Exif::RATIONAL,                      # Exposure index
 234                                         'SensingMethod' => Exif::SHORT,                 # Sensing method #p46
 235                                         'FileSource' => Exif::UNDEFINED,                        # File source #p47
 236                                         'SceneType' => Exif::UNDEFINED,                 # Scene type #p47
 237                                         'CFAPattern' => Exif::UNDEFINED,                        # CFA pattern
 238                                         'CustomRendered' => Exif::SHORT,                        # Custom image processing #p48
 239                                         'ExposureMode' => Exif::SHORT,                  # Exposure mode #p48
 240                                         'WhiteBalance' => Exif::SHORT,                  # White Balance #p49
 241                                         'DigitalZoomRatio' => Exif::RATIONAL,                   # Digital zoom ration
 242                                         'FocalLengthIn35mmFilm' => Exif::SHORT,         # Focal length in 35 mm film
 243                                         'SceneCaptureType' => Exif::SHORT,                      # Scene capture type #p49
 244                                         'GainControl' => Exif::RATIONAL,                        # Scene control #p49-50
 245                                         'Contrast' => Exif::SHORT,                              # Contrast #p50
 246                                         'Saturation' => Exif::SHORT,                            # Saturation #p50
 247                                         'Sharpness' => Exif::SHORT,                             # Sharpness #p50
 248                                         'DeviceSettingDescription' => Exif::UNDEFINED,  # Desice settings description
 249                                         'SubjectDistanceRange' => Exif::SHORT,          # Subject distance range #p51
 250                                 ),
 251
 252                                 'other' => array(
 253                                         'ImageUniqueID' => Exif::ASCII, # Unique image ID
 254                                 ),
 255                         ),
 256
 257                         # GPS Attribute Information (p52)
 258                         'gps' => array(
 259                                 'GPSVersionID' => Exif::BYTE,                   # GPS tag version
 260                                 'GPSLatitudeRef' => Exif::ASCII,                # North or South Latitude #p52-53
 261                                 'GPSLatitude' => Exif::RATIONAL,                # Latitude
 262                                 'GPSLongitudeRef' => Exif::ASCII,               # East or West Longitude #p53
 263                                 'GPSLongitude' => Exif::RATIONAL,               # Longitude
 264                                 'GPSAltitudeRef' => Exif::BYTE,         # Altitude reference
 265                                 'GPSAltitude' => Exif::RATIONAL,                # Altitude
 266                                 'GPSTimeStamp' => Exif::RATIONAL,               # GPS time (atomic clock)
 267                                 'GPSSatellites' => Exif::ASCII,         # Satellites used for measurement
 268                                 'GPSStatus' => Exif::ASCII,                     # Receiver status #p54
 269                                 'GPSMeasureMode' => Exif::ASCII,                # Measurement mode #p54-55
 270                                 'GPSDOP' => Exif::RATIONAL,                     # Measurement precision
 271                                 'GPSSpeedRef' => Exif::ASCII,                   # Speed unit #p55
 272                                 'GPSSpeed' => Exif::RATIONAL,                   # Speed of GPS receiver
 273                                 'GPSTrackRef' => Exif::ASCII,                   # Reference for direction of movement #p55
 274                                 'GPSTrack' => Exif::RATIONAL,                   # Direction of movement
 275                                 'GPSImgDirectionRef' => Exif::ASCII,            # Reference for direction of image #p56
 276                                 'GPSImgDirection' => Exif::RATIONAL,            # Direction of image
 277                                 'GPSMapDatum' => Exif::ASCII,                   # Geodetic survey data used
 278                                 'GPSDestLatitudeRef' => Exif::ASCII,            # Reference for latitude of destination #p56
 279                                 'GPSDestLatitude' => Exif::RATIONAL,            # Latitude destination
 280                                 'GPSDestLongitudeRef' => Exif::ASCII,           # Reference for longitude of destination #p57
 281                                 'GPSDestLongitude' => Exif::RATIONAL,           # Longitude of destination
 282                                 'GPSDestBearingRef' => Exif::ASCII,             # Reference for bearing of destination #p57
 283                                 'GPSDestBearing' => Exif::RATIONAL,             # Bearing of destination
 284                                 'GPSDestDistanceRef' => Exif::ASCII,            # Reference for distance to destination #p57-58
 285                                 'GPSDestDistance' => Exif::RATIONAL,            # Distance to destination
 286                                 'GPSProcessingMethod' => Exif::UNDEFINED,       # Name of GPS processing method
 287                                 'GPSAreaInformation' => Exif::UNDEFINED,        # Name of GPS area
 288                                 'GPSDateStamp' => Exif::ASCII,          # GPS date
 289                                 'GPSDifferential' => Exif::SHORT,               # GPS differential correction
 290                         ),
 291                 );
 292
 293                 $this->file = $file;
 294                 $this->basename = wfBaseName( $this->file );
 295
 296                 $this->makeFlatExifTags();
 297
 298                 $this->debugFile( $this->basename, __FUNCTION__, true );
 299                 wfSuppressWarnings();
 300                 $data = exif_read_data( $this->file );
 301                 wfRestoreWarnings();
 302                 /**
 303                  * exif_read_data() will return false on invalid input, such as
 304                  * when somebody uploads a file called something.jpeg
 305                  * containing random gibberish.
 306                  */
 307                 $this->mRawExifData = $data ? $data : array();
 308
 309                 $this->makeFilteredData();
 310                 $this->makeFormattedData();
 311
 312                 $this->debugFile( __FUNCTION__, false );
 313         }
 314
 315         /**#@+
 316          * @private
 317          */
 318         /**
 319          * Generate a flat list of the exif tags
 320          */
 321         function makeFlatExifTags() {
 322                 $this->extractTags( $this->mExifTags );
 323         }
 324
 325         /**
 326          * A recursing extractor function used by makeFlatExifTags()
 327          *
 328          * Note: This used to use an array_walk function, but it made PHP5
 329          * segfault, see `cvs diff -u -r 1.4 -r 1.5 Exif.php`
 330          */
 331         function extractTags( &$tagset ) {
 332                 foreach( $tagset as $key => $val ) {
 333                         if( is_array( $val ) ) {
 334                                 $this->extractTags( $val );
 335                         } else {
 336                                 $this->mFlatExifTags[$key] = $val;
 337                         }
 338                 }
 339         }
 340
 341         /**
 342          * Make $this->mFilteredExifData
 343          */
 344         function makeFilteredData() {
 345                 $this->mFilteredExifData = $this->mRawExifData;
 346
 347                 foreach( $this->mFilteredExifData as $k => $v ) {
 348                         if ( !in_array( $k, array_keys( $this->mFlatExifTags ) ) ) {
 349                                 $this->debug( $v, __FUNCTION__, "'$k' is not a valid Exif tag" );
 350                                 unset( $this->mFilteredExifData[$k] );
 351                         }
 352                 }
 353
 354                 foreach( $this->mFilteredExifData as $k => $v ) {
 355                         if ( !$this->validate($k, $v) ) {
 356                                 $this->debug( $v, __FUNCTION__, "'$k' contained invalid data" );
 357                                 unset( $this->mFilteredExifData[$k] );
 358                         }
 359                 }
 360         }
 361
 362         /**
 363          * @todo document
 364          */
 365         function makeFormattedData( ) {
 366                 $format = new FormatExif( $this->getFilteredData() );
 367                 $this->mFormattedExifData = $format->getFormattedData();
 368         }
 369         /**#@-*/
 370
 371         /**#@+
 372          * @return array
 373          */
 374         /**
 375          * Get $this->mRawExifData
 376          */
 377         function getData() {
 378                 return $this->mRawExifData;
 379         }
 380
 381         /**
 382          * Get $this->mFilteredExifData
 383          */
 384         function getFilteredData() {
 385                 return $this->mFilteredExifData;
 386         }
 387
 388         /**
 389          * Get $this->mFormattedExifData
 390          */
 391         function getFormattedData() {
 392                 return $this->mFormattedExifData;
 393         }
 394         /**#@-*/
 395
 396         /**
 397          * The version of the output format
 398          *
 399          * Before the actual metadata information is saved in the database we
 400          * strip some of it since we don't want to save things like thumbnails
 401          * which usually accompany Exif data. This value gets saved in the
 402          * database along with the actual Exif data, and if the version in the
 403          * database doesn't equal the value returned by this function the Exif
 404          * data is regenerated.
 405          *
 406          * @return int
 407          */
 408         public static function version() {
 409                 return 1; // We don't need no bloddy constants!
 410         }
 411
 412         /**#@+
 413          * Validates if a tag value is of the type it should be according to the Exif spec
 414          *
 415          * @private
 416          *
 417          * @param $in Mixed: the input value to check
 418          * @return bool
 419          */
 420         function isByte( $in ) {
 421                 if ( !is_array( $in ) && sprintf('%d', $in) == $in && $in >= 0 && $in <= 255 ) {
 422                         $this->debug( $in, __FUNCTION__, true );
 423                         return true;
 424                 } else {
 425                         $this->debug( $in, __FUNCTION__, false );
 426                         return false;
 427                 }
 428         }
 429
 430         function isASCII( $in ) {
 431                 if ( is_array( $in ) ) {
 432                         return false;
 433                 }
 434
 435                 if ( preg_match( "/[^\x0a\x20-\x7e]/", $in ) ) {
 436                         $this->debug( $in, __FUNCTION__, 'found a character not in our whitelist' );
 437                         return false;
 438                 }
 439
 440                 if ( preg_match( '/^\s*$/', $in ) ) {
 441                         $this->debug( $in, __FUNCTION__, 'input consisted solely of whitespace' );
 442                         return false;
 443                 }
 444
 445                 return true;
 446         }
 447
 448         function isShort( $in ) {
 449                 if ( !is_array( $in ) && sprintf('%d', $in) == $in && $in >= 0 && $in <= 65536 ) {
 450                         $this->debug( $in, __FUNCTION__, true );
 451                         return true;
 452                 } else {
 453                         $this->debug( $in, __FUNCTION__, false );
 454                         return false;
 455                 }
 456         }
 457
 458         function isLong( $in ) {
 459                 if ( !is_array( $in ) && sprintf('%d', $in) == $in && $in >= 0 && $in <= 4294967296 ) {
 460                         $this->debug( $in, __FUNCTION__, true );
 461                         return true;
 462                 } else {
 463                         $this->debug( $in, __FUNCTION__, false );
 464                         return false;
 465                 }
 466         }
 467
 468         function isRational( $in ) {
 469                 $m = array();
 470                 if ( !is_array( $in ) && @preg_match( '/^(\d+)\/(\d+[1-9]|[1-9]\d*)$/', $in, $m ) ) { # Avoid division by zero
 471                         return $this->isLong( $m[1] ) && $this->isLong( $m[2] );
 472                 } else {
 473                         $this->debug( $in, __FUNCTION__, 'fed a non-fraction value' );
 474                         return false;
 475                 }
 476         }
 477
 478         function isUndefined( $in ) {
 479                 if ( !is_array( $in ) && preg_match( '/^\d{4}$/', $in ) ) { // Allow ExifVersion and FlashpixVersion
 480                         $this->debug( $in, __FUNCTION__, true );
 481                         return true;
 482                 } else {
 483                         $this->debug( $in, __FUNCTION__, false );
 484                         return false;
 485                 }
 486         }
 487
 488         function isSlong( $in ) {
 489                 if ( $this->isLong( abs( $in ) ) ) {
 490                         $this->debug( $in, __FUNCTION__, true );
 491                         return true;
 492                 } else {
 493                         $this->debug( $in, __FUNCTION__, false );
 494                         return false;
 495                 }
 496         }
 497
 498         function isSrational( $in ) {
 499                 $m = array();
 500                 if ( !is_array( $in ) && preg_match( '/^(\d+)\/(\d+[1-9]|[1-9]\d*)$/', $in, $m ) ) { # Avoid division by zero
 501                         return $this->isSlong( $m[0] ) && $this->isSlong( $m[1] );
 502                 } else {
 503                         $this->debug( $in, __FUNCTION__, 'fed a non-fraction value' );
 504                         return false;
 505                 }
 506         }
 507         /**#@-*/
 508
 509         /**
 510          * Validates if a tag has a legal value according to the Exif spec
 511          *
 512          * @private
 513          *
 514          * @param $tag String: the tag to check.
 515          * @param $val Mixed: the value of the tag.
 516          * @return bool
 517          */
 518         function validate( $tag, $val ) {
 519                 $debug = "tag is '$tag'";
 520                 // Does not work if not typecast
 521                 switch( (string)$this->mFlatExifTags[$tag] ) {
 522                         case (string)Exif::BYTE:
 523                                 $this->debug( $val, __FUNCTION__, $debug );
 524                                 return $this->isByte( $val );
 525                         case (string)Exif::ASCII:
 526                                 $this->debug( $val, __FUNCTION__, $debug );
 527                                 return $this->isASCII( $val );
 528                         case (string)Exif::SHORT:
 529                                 $this->debug( $val, __FUNCTION__, $debug );
 530                                 return $this->isShort( $val );
 531                         case (string)Exif::LONG:
 532                                 $this->debug( $val, __FUNCTION__, $debug );
 533                                 return $this->isLong( $val );
 534                         case (string)Exif::RATIONAL:
 535                                 $this->debug( $val, __FUNCTION__, $debug );
 536                                 return $this->isRational( $val );
 537                         case (string)Exif::UNDEFINED:
 538                                 $this->debug( $val, __FUNCTION__, $debug );
 539                                 return $this->isUndefined( $val );
 540                         case (string)Exif::SLONG:
 541                                 $this->debug( $val, __FUNCTION__, $debug );
 542                                 return $this->isSlong( $val );
 543                         case (string)Exif::SRATIONAL:
 544                                 $this->debug( $val, __FUNCTION__, $debug );
 545                                 return $this->isSrational( $val );
 546                         case (string)Exif::SHORT.','.Exif::LONG:
 547                                 $this->debug( $val, __FUNCTION__, $debug );
 548                                 return $this->isShort( $val ) || $this->isLong( $val );
 549                         default:
 550                                 $this->debug( $val, __FUNCTION__, "The tag '$tag' is unknown" );
 551                                 return false;
 552                 }
 553         }
 554
 555         /**
 556          * Convenience function for debugging output
 557          *
 558          * @private
 559          *
 560          * @param $in Mixed:
 561          * @param $fname String:
 562          * @param $action Mixed: , default NULL.
 563          */
 564         function debug( $in, $fname, $action = NULL ) {
 565                 if ( !$this->log ) {
 566                         return;
 567                 }
 568                 $type = gettype( $in );
 569                 $class = ucfirst( __CLASS__ );
 570                 if ( $type === 'array' )
 571                         $in = print_r( $in, true );
 572
 573                 if ( $action === true )
 574                         wfDebugLog( $this->log, "$class::$fname: accepted: '$in' (type: $type)\n");
 575                 elseif ( $action === false )
 576                         wfDebugLog( $this->log, "$class::$fname: rejected: '$in' (type: $type)\n");
 577                 elseif ( $action === null )
 578                         wfDebugLog( $this->log, "$class::$fname: input was: '$in' (type: $type)\n");
 579                 else
 580                         wfDebugLog( $this->log, "$class::$fname: $action (type: $type; content: '$in')\n");
 581         }
 582
 583         /**
 584          * Convenience function for debugging output
 585          *
 586          * @private
 587          *
 588          * @param $fname String: the name of the function calling this function
 589          * @param $io Boolean: Specify whether we're beginning or ending
 590          */
 591         function debugFile( $fname, $io ) {
 592                 if ( !$this->log ) {
 593                         return;
 594                 }
 595                 $class = ucfirst( __CLASS__ );
 596                 if ( $io ) {
 597                         wfDebugLog( $this->log, "$class::$fname: begin processing: '{$this->basename}'\n" );
 598                 } else {
 599                         wfDebugLog( $this->log, "$class::$fname: end processing: '{$this->basename}'\n" );
 600                 }
 601         }
 602
 603 }
 604
 605 /**
 606  * @todo document (e.g. one-sentence class-overview description)
 607  * @addtogroup Media
 608  */
 609 class FormatExif {
 610         /**
 611          * The Exif data to format
 612          *
 613          * @var array
 614          * @private
 615          */
 616         var $mExif;
 617
 618         /**
 619          * Constructor
 620          *
 621          * @param $exif Array: the Exif data to format ( as returned by
 622          *                    Exif::getFilteredData() )
 623          */
 624         function FormatExif( $exif ) {
 625                 $this->mExif = $exif;
 626         }
 627
 628         /**
 629          * Numbers given by Exif user agents are often magical, that is they
 630          * should be replaced by a detailed explanation depending on their
 631          * value which most of the time are plain integers. This function
 632          * formats Exif values into human readable form.
 633          *
 634          * @return array
 635          */
 636         function getFormattedData() {
 637                 global $wgLang;
 638
 639                 $tags =& $this->mExif;
 640
 641                 $resolutionunit = !isset( $tags['ResolutionUnit'] ) || $tags['ResolutionUnit'] == 2 ? 2 : 3;
 642                 unset( $tags['ResolutionUnit'] );
 643
 644                 foreach( $tags as $tag => $val ) {
 645                         switch( $tag ) {
 646                         case 'Compression':
 647                                 switch( $val ) {
 648                                 case 1: case 6:
 649                                         $tags[$tag] = $this->msg( $tag, $val );
 650                                         break;
 651                                 default:
 652                                         $tags[$tag] = $val;
 653                                         break;
 654                                 }
 655                                 break;
 656
 657                         case 'PhotometricInterpretation':
 658                                 switch( $val ) {
 659                                 case 2: case 6:
 660                                         $tags[$tag] = $this->msg( $tag, $val );
 661                                         break;
 662                                 default:
 663                                         $tags[$tag] = $val;
 664                                         break;
 665                                 }
 666                                 break;
 667
 668                         case 'Orientation':
 669                                 switch( $val ) {
 670                                 case 1: case 2: case 3: case 4: case 5: case 6: case 7: case 8:
 671                                         $tags[$tag] = $this->msg( $tag, $val );
 672                                         break;
 673                                 default:
 674                                         $tags[$tag] = $val;
 675                                         break;
 676                                 }
 677                                 break;
 678
 679                         case 'PlanarConfiguration':
 680                                 switch( $val ) {
 681                                 case 1: case 2:
 682                                         $tags[$tag] = $this->msg( $tag, $val );
 683                                         break;
 684                                 default:
 685                                         $tags[$tag] = $val;
 686                                         break;
 687                                 }
 688                                 break;
 689
 690                         // TODO: YCbCrSubSampling
 691                         // TODO: YCbCrPositioning
 692
 693                         case 'XResolution':
 694                         case 'YResolution':
 695                                 switch( $resolutionunit ) {
 696                                         case 2:
 697                                                 $tags[$tag] = $this->msg( 'XYResolution', 'i', $this->formatNum( $val ) );
 698                                                 break;
 699                                         case 3:
 700                                                 $this->msg( 'XYResolution', 'c', $this->formatNum( $val ) );
 701                                                 break;
 702                                         default:
 703                                                 $tags[$tag] = $val;
 704                                                 break;
 705                                 }
 706                                 break;
 707
 708                         // TODO: YCbCrCoefficients  #p27 (see annex E)
 709                         case 'ExifVersion': case 'FlashpixVersion':
 710                                 $tags[$tag] = "$val"/100;
 711                                 break;
 712
 713                         case 'ColorSpace':
 714                                 switch( $val ) {
 715                                 case 1: case 'FFFF.H':
 716                                         $tags[$tag] = $this->msg( $tag, $val );
 717                                         break;
 718                                 default:
 719                                         $tags[$tag] = $val;
 720                                         break;
 721                                 }
 722                                 break;
 723
 724                         case 'ComponentsConfiguration':
 725                                 switch( $val ) {
 726                                 case 0: case 1: case 2: case 3: case 4: case 5: case 6:
 727                                         $tags[$tag] = $this->msg( $tag, $val );
 728                                         break;
 729                                 default:
 730                                         $tags[$tag] = $val;
 731                                         break;
 732                                 }
 733                                 break;
 734
 735                         case 'DateTime':
 736                         case 'DateTimeOriginal':
 737                         case 'DateTimeDigitized':
 738                                 if( $val == '0000:00:00 00:00:00' ) {
 739                                         $tags[$tag] = wfMsg('exif-unknowndate');
 740                                 } elseif( preg_match( '/^(?:\d{4}):(?:\d\d):(?:\d\d) (?:\d\d):(?:\d\d):(?:\d\d)$/', $val ) ) {
 741                                         $tags[$tag] = $wgLang->timeanddate( wfTimestamp(TS_MW, $val) );
 742                                 }
 743                                 break;
 744
 745                         case 'ExposureProgram':
 746                                 switch( $val ) {
 747                                 case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7: case 8:
 748                                         $tags[$tag] = $this->msg( $tag, $val );
 749                                         break;
 750                                 default:
 751                                         $tags[$tag] = $val;
 752                                         break;
 753                                 }
 754                                 break;
 755
 756                         case 'SubjectDistance':
 757                                 $tags[$tag] = $this->msg( $tag, '', $this->formatNum( $val ) );
 758                                 break;
 759
 760                         case 'MeteringMode':
 761                                 switch( $val ) {
 762                                 case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7: case 255:
 763                                         $tags[$tag] = $this->msg( $tag, $val );
 764                                         break;
 765                                 default:
 766                                         $tags[$tag] = $val;
 767                                         break;
 768                                 }
 769                                 break;
 770
 771                         case 'LightSource':
 772                                 switch( $val ) {
 773                                 case 0: case 1: case 2: case 3: case 4: case 9: case 10: case 11:
 774                                 case 12: case 13: case 14: case 15: case 17: case 18: case 19: case 20:
 775                                 case 21: case 22: case 23: case 24: case 255:
 776                                         $tags[$tag] = $this->msg( $tag, $val );
 777                                         break;
 778                                 default:
 779                                         $tags[$tag] = $val;
 780                                         break;
 781                                 }
 782                                 break;
 783
 784                         // TODO: Flash
 785                         case 'FocalPlaneResolutionUnit':
 786                                 switch( $val ) {
 787                                 case 2:
 788                                         $tags[$tag] = $this->msg( $tag, $val );
 789                                         break;
 790                                 default:
 791                                         $tags[$tag] = $val;
 792                                         break;
 793                                 }
 794                                 break;
 795
 796                         case 'SensingMethod':
 797                                 switch( $val ) {
 798                                 case 1: case 2: case 3: case 4: case 5: case 7: case 8:
 799                                         $tags[$tag] = $this->msg( $tag, $val );
 800                                         break;
 801                                 default:
 802                                         $tags[$tag] = $val;
 803                                         break;
 804                                 }
 805                                 break;
 806
 807                         case 'FileSource':
 808                                 switch( $val ) {
 809                                 case 3:
 810                                         $tags[$tag] = $this->msg( $tag, $val );
 811                                         break;
 812                                 default:
 813                                         $tags[$tag] = $val;
 814                                         break;
 815                                 }
 816                                 break;
 817
 818                         case 'SceneType':
 819                                 switch( $val ) {
 820                                 case 1:
 821                                         $tags[$tag] = $this->msg( $tag, $val );
 822                                         break;
 823                                 default:
 824                                         $tags[$tag] = $val;
 825                                         break;
 826                                 }
 827                                 break;
 828
 829                         case 'CustomRendered':
 830                                 switch( $val ) {
 831                                 case 0: case 1:
 832                                         $tags[$tag] = $this->msg( $tag, $val );
 833                                         break;
 834                                 default:
 835                                         $tags[$tag] = $val;
 836                                         break;
 837                                 }
 838                                 break;
 839
 840                         case 'ExposureMode':
 841                                 switch( $val ) {
 842                                 case 0: case 1: case 2:
 843                                         $tags[$tag] = $this->msg( $tag, $val );
 844                                         break;
 845                                 default:
 846                                         $tags[$tag] = $val;
 847                                         break;
 848                                 }
 849                                 break;
 850
 851                         case 'WhiteBalance':
 852                                 switch( $val ) {
 853                                 case 0: case 1:
 854                                         $tags[$tag] = $this->msg( $tag, $val );
 855                                         break;
 856                                 default:
 857                                         $tags[$tag] = $val;
 858                                         break;
 859                                 }
 860                                 break;
 861
 862                         case 'SceneCaptureType':
 863                                 switch( $val ) {
 864                                 case 0: case 1: case 2: case 3:
 865                                         $tags[$tag] = $this->msg( $tag, $val );
 866                                         break;
 867                                 default:
 868                                         $tags[$tag] = $val;
 869                                         break;
 870                                 }
 871                                 break;
 872
 873                         case 'GainControl':
 874                                 switch( $val ) {
 875                                 case 0: case 1: case 2: case 3: case 4:
 876                                         $tags[$tag] = $this->msg( $tag, $val );
 877                                         break;
 878                                 default:
 879                                         $tags[$tag] = $val;
 880                                         break;
 881                                 }
 882                                 break;
 883
 884                         case 'Contrast':
 885                                 switch( $val ) {
 886                                 case 0: case 1: case 2:
 887                                         $tags[$tag] = $this->msg( $tag, $val );
 888                                         break;
 889                                 default:
 890                                         $tags[$tag] = $val;
 891                                         break;
 892                                 }
 893                                 break;
 894
 895                         case 'Saturation':
 896                                 switch( $val ) {
 897                                 case 0: case 1: case 2:
 898                                         $tags[$tag] = $this->msg( $tag, $val );
 899                                         break;
 900                                 default:
 901                                         $tags[$tag] = $val;
 902                                         break;
 903                                 }
 904                                 break;
 905
 906                         case 'Sharpness':
 907                                 switch( $val ) {
 908                                 case 0: case 1: case 2:
 909                                         $tags[$tag] = $this->msg( $tag, $val );
 910                                         break;
 911                                 default:
 912                                         $tags[$tag] = $val;
 913                                         break;
 914                                 }
 915                                 break;
 916
 917                         case 'SubjectDistanceRange':
 918                                 switch( $val ) {
 919                                 case 0: case 1: case 2: case 3:
 920                                         $tags[$tag] = $this->msg( $tag, $val );
 921                                         break;
 922                                 default:
 923                                         $tags[$tag] = $val;
 924                                         break;
 925                                 }
 926                                 break;
 927
 928                         case 'GPSLatitudeRef':
 929                         case 'GPSDestLatitudeRef':
 930                                 switch( $val ) {
 931                                 case 'N': case 'S':
 932                                         $tags[$tag] = $this->msg( 'GPSLatitude', $val );
 933                                         break;
 934                                 default:
 935                                         $tags[$tag] = $val;
 936                                         break;
 937                                 }
 938                                 break;
 939
 940                         case 'GPSLongitudeRef':
 941                         case 'GPSDestLongitudeRef':
 942                                 switch( $val ) {
 943                                 case 'E': case 'W':
 944                                         $tags[$tag] = $this->msg( 'GPSLongitude', $val );
 945                                         break;
 946                                 default:
 947                                         $tags[$tag] = $val;
 948                                         break;
 949                                 }
 950                                 break;
 951
 952                         case 'GPSStatus':
 953                                 switch( $val ) {
 954                                 case 'A': case 'V':
 955                                         $tags[$tag] = $this->msg( $tag, $val );
 956                                         break;
 957                                 default:
 958                                         $tags[$tag] = $val;
 959                                         break;
 960                                 }
 961                                 break;
 962
 963                         case 'GPSMeasureMode':
 964                                 switch( $val ) {
 965                                 case 2: case 3:
 966                                         $tags[$tag] = $this->msg( $tag, $val );
 967                                         break;
 968                                 default:
 969                                         $tags[$tag] = $val;
 970                                         break;
 971                                 }
 972                                 break;
 973
 974                         case 'GPSSpeedRef':
 975                         case 'GPSDestDistanceRef':
 976                                 switch( $val ) {
 977                                 case 'K': case 'M': case 'N':
 978                                         $tags[$tag] = $this->msg( 'GPSSpeed', $val );
 979                                         break;
 980                                 default:
 981                                         $tags[$tag] = $val;
 982                                         break;
 983                                 }
 984                                 break;
 985
 986                         case 'GPSTrackRef':
 987                         case 'GPSImgDirectionRef':
 988                         case 'GPSDestBearingRef':
 989                                 switch( $val ) {
 990                                 case 'T': case 'M':
 991                                         $tags[$tag] = $this->msg( 'GPSDirection', $val );
 992                                         break;
 993                                 default:
 994                                         $tags[$tag] = $val;
 995                                         break;
 996                                 }
 997                                 break;
 998
 999                         case 'GPSDateStamp':
1000                                 $tags[$tag] = $wgLang->date( substr( $val, 0, 4 ) . substr( $val, 5, 2 ) . substr( $val, 8, 2 ) . '000000' );
1001                                 break;
1002
1003                         // This is not in the Exif standard, just a special
1004                         // case for our purposes which enables wikis to wikify
1005                         // the make, model and software name to link to their articles.
1006                         case 'Make':
1007                         case 'Model':
1008                         case 'Software':
1009                                 $tags[$tag] = $this->msg( $tag, '', $val );
1010                                 break;
1011
1012                         case 'ExposureTime':
1013                                 // Show the pretty fraction as well as decimal version
1014                                 $tags[$tag] = wfMsg( 'exif-exposuretime-format',
1015                                         $this->formatFraction( $val ), $this->formatNum( $val ) );
1016                                 break;
1017
1018                         case 'FNumber':
1019                                 $tags[$tag] = wfMsg( 'exif-fnumber-format',
1020                                         $this->formatNum( $val ) );
1021                                 break;
1022
1023                         case 'FocalLength':
1024                                 $tags[$tag] = wfMsg( 'exif-focallength-format',
1025                                         $this->formatNum( $val ) );
1026                                 break;
1027
1028                         default:
1029                                 $tags[$tag] = $this->formatNum( $val );
1030                                 break;
1031                         }
1032                 }
1033
1034                 return $tags;
1035         }
1036
1037         /**
1038          * Convenience function for getFormattedData()
1039          *
1040          * @private
1041          *
1042          * @param $tag String: the tag name to pass on
1043          * @param $val String: the value of the tag
1044          * @param $arg String: an argument to pass ($1)
1045          * @return string A wfMsg of "exif-$tag-$val" in lower case
1046          */
1047         function msg( $tag, $val, $arg = null ) {
1048                 global $wgContLang;
1049
1050                 if ($val === '')
1051                         $val = 'value';
1052                 return wfMsg( $wgContLang->lc( "exif-$tag-$val" ), $arg );
1053         }
1054
1055         /**
1056          * Format a number, convert numbers from fractions into floating point
1057          * numbers
1058          *
1059          * @private
1060          *
1061          * @param $num Mixed: the value to format
1062          * @return mixed A floating point number or whatever we were fed
1063          */
1064         function formatNum( $num ) {
1065                 $m = array();
1066                 if ( preg_match( '/^(\d+)\/(\d+)$/', $num, $m ) )
1067                         return $m[2] != 0 ? $m[1] / $m[2] : $num;
1068                 else
1069                         return $num;
1070         }
1071
1072         /**
1073          * Format a rational number, reducing fractions
1074          *
1075          * @private
1076          *
1077          * @param $num Mixed: the value to format
1078          * @return mixed A floating point number or whatever we were fed
1079          */
1080         function formatFraction( $num ) {
1081                 $m = array();
1082                 if ( preg_match( '/^(\d+)\/(\d+)$/', $num, $m ) ) {
1083                         $numerator = intval( $m[1] );
1084                         $denominator = intval( $m[2] );
1085                         $gcd = $this->gcd( $numerator, $denominator );
1086                         if( $gcd != 0 ) {
1087                                 // 0 shouldn't happen! ;)
1088                                 return $numerator / $gcd . '/' . $denominator / $gcd;
1089                         }
1090                 }
1091                 return $this->formatNum( $num );
1092         }
1093
1094         /**
1095          * Calculate the greatest common divisor of two integers.
1096          *
1097          * @param $a Integer: FIXME
1098          * @param $b Integer: FIXME
1099          * @return int
1100          * @private
1101          */
1102         function gcd( $a, $b ) {
1103                 /*
1104                         // http://en.wikipedia.org/wiki/Euclidean_algorithm
1105                         // Recursive form would be:
1106                         if( $b == 0 )
1107                                 return $a;
1108                         else
1109                                 return gcd( $b, $a % $b );
1110                 */
1111                 while( $b != 0 ) {
1112                         $remainder = $a % $b;
1113
1114                         // tail recursion...
1115                         $a = $b;
1116                         $b = $remainder;
1117                 }
1118                 return $a;
1119         }
1120 }
1121
1122 /**
1123  * MW 1.6 compatibility
1124  */
1125 define( 'MW_EXIF_BYTE', Exif::BYTE );
1126 define( 'MW_EXIF_ASCII', Exif::ASCII );
1127 define( 'MW_EXIF_SHORT', Exif::SHORT );
1128 define( 'MW_EXIF_LONG', Exif::LONG );
1129 define( 'MW_EXIF_RATIONAL', Exif::RATIONAL );
1130 define( 'MW_EXIF_UNDEFINED', Exif::UNDEFINED );
1131 define( 'MW_EXIF_SLONG', Exif::SLONG );
1132 define( 'MW_EXIF_SRATIONAL', Exif::SRATIONAL );
1133
1134