includes/Exif.php

   1 <?php
   2 /**
   3  * @package MediaWiki
   4  * @subpackage Metadata
   5  *
   6  * @author Ævar Arnfjörð Bjarmason <avarab@gmail.com>
   7  * @copyright Copyright © 2005, Ævar Arnfjörð Bjarmason
   8  * @license http://www.gnu.org/copyleft/gpl.html GNU General Public License
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License along
  21  * with this program; if not, write to the Free Software Foundation, Inc.,
  22  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  23  * http://www.gnu.org/copyleft/gpl.html
  24  *
  25  * @link http://exif.org/Exif2-2.PDF The Exif 2.2 specification
  26  * @bug 1555, 1947
  27  */
  28
  29 /**
  30  * @package MediaWiki
  31  * @subpackage Metadata
  32  */
  33 class Exif {
  34         //@{
  35         /* @var array
  36          * @private
  37          */
  38
  39         /**#@+
  40          * Exif tag type definition
  41          */
  42         const BYTE      = 1;    # An 8-bit (1-byte) unsigned integer.
  43         const ASCII     = 2;    # An 8-bit byte containing one 7-bit ASCII code. The final byte is terminated with NULL.
  44         const SHORT     = 3;    # A 16-bit (2-byte) unsigned integer.
  45         const LONG      = 4;    # A 32-bit (4-byte) unsigned integer.
  46         const RATIONAL  = 5;    # Two LONGs. The first LONG is the numerator and the second LONG expresses the denominator
  47         const UNDEFINED = 7;    # An 8-bit byte that can take any value depending on the field definition
  48         const SLONG     = 9;    # A 32-bit (4-byte) signed integer (2's complement notation),
  49         const SRATIONAL = 10;   # Two SLONGs. The first SLONG is the numerator and the second SLONG is the denominator.
  50
  51         /**
  52          * Exif tags grouped by category, the tagname itself is the key and the type
  53          * is the value, in the case of more than one possible value type they are
  54          * seperated by commas.
  55          */
  56         var $mExifTags;
  57
  58         /**
  59          * A one dimentional array of all Exif tags
  60          */
  61         var $mFlatExifTags;
  62
  63         /**
  64          * The raw Exif data returned by exif_read_data()
  65          */
  66         var $mRawExifData;
  67
  68         /**
  69          * A Filtered version of $mRawExifData that has been pruned of invalid
  70          * tags and tags that contain content they shouldn't contain according
  71          * to the Exif specification
  72          */
  73         var $mFilteredExifData;
  74
  75         /**
  76          * Filtered and formatted Exif data, see FormatExif::getFormattedData()
  77          */
  78         var $mFormattedExifData;
  79
  80         //@}
  81
  82         //@{
  83         /* @var string
  84          * @private
  85          */
  86
  87         /**
  88          * The file being processed
  89          */
  90         var $file;
  91
  92         /**
  93          * The basename of the file being processed
  94          */
  95         var $basename;
  96
  97         /**
  98          * The private log to log to
  99          */
 100         var $log = 'exif';
 101
 102         //@}
 103
 104         /**
 105          * Constructor
 106          *
 107          * @param $file String: filename.
 108          */
 109         function Exif( $file ) {
 110                 /**
 111                  * Page numbers here refer to pages in the EXIF 2.2 standard
 112                  *
 113                  * @link http://exif.org/Exif2-2.PDF The Exif 2.2 specification
 114                  */
 115                 $this->mExifTags = array(
 116                         # TIFF Rev. 6.0 Attribute Information (p22)
 117                         'tiff' => array(
 118                                 # Tags relating to image structure
 119                                 'structure' => array(
 120                                         'ImageWidth' => Exif::SHORT.','.Exif::LONG,             # Image width
 121                                         'ImageLength' => Exif::SHORT.','.Exif::LONG,    # Image height
 122                                         'BitsPerSample' => Exif::SHORT,                 # Number of bits per component
 123                                         # "When a primary image is JPEG compressed, this designation is not"
 124                                         # "necessary and is omitted." (p23)
 125                                         'Compression' => Exif::SHORT,                           # Compression scheme #p23
 126                                         'PhotometricInterpretation' => Exif::SHORT,             # Pixel composition #p23
 127                                         'Orientation' => Exif::SHORT,                           # Orientation of image #p24
 128                                         'SamplesPerPixel' => Exif::SHORT,                       # Number of components
 129                                         'PlanarConfiguration' => Exif::SHORT,                   # Image data arrangement #p24
 130                                         'YCbCrSubSampling' => Exif::SHORT,                      # Subsampling ratio of Y to C #p24
 131                                         'YCbCrPositioning' => Exif::SHORT,                      # Y and C positioning #p24-25
 132                                         'XResolution' => Exif::RATIONAL,                        # Image resolution in width direction
 133                                         'YResolution' => Exif::RATIONAL,                        # Image resolution in height direction
 134                                         'ResolutionUnit' => Exif::SHORT,                        # Unit of X and Y resolution #(p26)
 135                                 ),
 136
 137                                 # Tags relating to recording offset
 138                                 'offset' => array(
 139                                         'StripOffsets' => Exif::SHORT.','.Exif::LONG,                   # Image data location
 140                                         'RowsPerStrip' => Exif::SHORT.','.Exif::LONG,                   # Number of rows per strip
 141                                         'StripByteCounts' => Exif::SHORT.','.Exif::LONG,                        # Bytes per compressed strip
 142                                         'JPEGInterchangeFormat' => Exif::SHORT.','.Exif::LONG,          # Offset to JPEG SOI
 143                                         'JPEGInterchangeFormatLength' => Exif::SHORT.','.Exif::LONG,    # Bytes of JPEG data
 144                                 ),
 145
 146                                 # Tags relating to image data characteristics
 147                                 'characteristics' => array(
 148                                         'TransferFunction' => Exif::SHORT,              # Transfer function
 149                                         'WhitePoint' => Exif::RATIONAL,         # White point chromaticity
 150                                         'PrimaryChromaticities' => Exif::RATIONAL,      # Chromaticities of primarities
 151                                         'YCbCrCoefficients' => Exif::RATIONAL,  # Color space transformation matrix coefficients #p27
 152                                         'ReferenceBlackWhite' => Exif::RATIONAL # Pair of black and white reference values
 153                                 ),
 154
 155                                 # Other tags
 156                                 'other' => array(
 157                                         'DateTime' => Exif::ASCII,            # File change date and time
 158                                         'ImageDescription' => Exif::ASCII,    # Image title
 159                                         'Make' => Exif::ASCII,                # Image input equipment manufacturer
 160                                         'Model' => Exif::ASCII,               # Image input equipment model
 161                                         'Software' => Exif::ASCII,            # Software used
 162                                         'Artist' => Exif::ASCII,              # Person who created the image
 163                                         'Copyright' => Exif::ASCII,           # Copyright holder
 164                                 ),
 165                         ),
 166
 167                         # Exif IFD Attribute Information (p30-31)
 168                         'exif' => array(
 169                                 # Tags relating to version
 170                                 'version' => array(
 171                                         # TODO: NOTE: Nonexistence of this field is taken to mean nonconformance
 172                                         # to the EXIF 2.1 AND 2.2 standards
 173                                         'ExifVersion' => Exif::UNDEFINED,       # Exif version
 174                                         'FlashpixVersion' => Exif::UNDEFINED, # Supported Flashpix version #p32
 175                                 ),
 176
 177                                 # Tags relating to Image Data Characteristics
 178                                 'characteristics' => array(
 179                                         'ColorSpace' => Exif::SHORT,            # Color space information #p32
 180                                 ),
 181
 182                                 # Tags relating to image configuration
 183                                 'configuration' => array(
 184                                         'ComponentsConfiguration' => Exif::UNDEFINED,           # Meaning of each component #p33
 185                                         'CompressedBitsPerPixel' => Exif::RATIONAL,             # Image compression mode
 186                                         'PixelYDimension' => Exif::SHORT.','.Exif::LONG,        # Valid image width
 187                                         'PixelXDimension' => Exif::SHORT.','.Exif::LONG,        # Valind image height
 188                                 ),
 189
 190                                 # Tags relating to related user information
 191                                 'user' => array(
 192                                         'MakerNote' => Exif::UNDEFINED,                 # Manufacturer notes
 193                                         'UserComment' => Exif::UNDEFINED,                       # User comments #p34
 194                                 ),
 195
 196                                 # Tags relating to related file information
 197                                 'related' => array(
 198                                         'RelatedSoundFile' => Exif::ASCII,                      # Related audio file
 199                                 ),
 200
 201                                 # Tags relating to date and time
 202                                 'dateandtime' => array(
 203                                         'DateTimeOriginal' => Exif::ASCII,                      # Date and time of original data generation #p36
 204                                         'DateTimeDigitized' => Exif::ASCII,                     # Date and time of original data generation
 205                                         'SubSecTime' => Exif::ASCII,                            # DateTime subseconds
 206                                         'SubSecTimeOriginal' => Exif::ASCII,                    # DateTimeOriginal subseconds
 207                                         'SubSecTimeDigitized' => Exif::ASCII,                   # DateTimeDigitized subseconds
 208                                 ),
 209
 210                                 # Tags relating to picture-taking conditions (p31)
 211                                 'conditions' => array(
 212                                         'ExposureTime' => Exif::RATIONAL,                       # Exposure time
 213                                         'FNumber' => Exif::RATIONAL,                            # F Number
 214                                         'ExposureProgram' => Exif::SHORT,                       # Exposure Program #p38
 215                                         'SpectralSensitivity' => Exif::ASCII,                   # Spectral sensitivity
 216                                         'ISOSpeedRatings' => Exif::SHORT,                       # ISO speed rating
 217                                         'OECF' => Exif::UNDEFINED,                              # Optoelectronic conversion factor
 218                                         'ShutterSpeedValue' => Exif::SRATIONAL,         # Shutter speed
 219                                         'ApertureValue' => Exif::RATIONAL,                      # Aperture
 220                                         'BrightnessValue' => Exif::SRATIONAL,                   # Brightness
 221                                         'ExposureBiasValue' => Exif::SRATIONAL,         # Exposure bias
 222                                         'MaxApertureValue' => Exif::RATIONAL,                   # Maximum land aperture
 223                                         'SubjectDistance' => Exif::RATIONAL,                    # Subject distance
 224                                         'MeteringMode' => Exif::SHORT,                  # Metering mode #p40
 225                                         'LightSource' => Exif::SHORT,                           # Light source #p40-41
 226                                         'Flash' => Exif::SHORT,                         # Flash #p41-42
 227                                         'FocalLength' => Exif::RATIONAL,                        # Lens focal length
 228                                         'SubjectArea' => Exif::SHORT,                           # Subject area
 229                                         'FlashEnergy' => Exif::RATIONAL,                        # Flash energy
 230                                         'SpatialFrequencyResponse' => Exif::UNDEFINED,  # Spatial frequency response
 231                                         'FocalPlaneXResolution' => Exif::RATIONAL,              # Focal plane X resolution
 232                                         'FocalPlaneYResolution' => Exif::RATIONAL,              # Focal plane Y resolution
 233                                         'FocalPlaneResolutionUnit' => Exif::SHORT,              # Focal plane resolution unit #p46
 234                                         'SubjectLocation' => Exif::SHORT,                       # Subject location
 235                                         'ExposureIndex' => Exif::RATIONAL,                      # Exposure index
 236                                         'SensingMethod' => Exif::SHORT,                 # Sensing method #p46
 237                                         'FileSource' => Exif::UNDEFINED,                        # File source #p47
 238                                         'SceneType' => Exif::UNDEFINED,                 # Scene type #p47
 239                                         'CFAPattern' => Exif::UNDEFINED,                        # CFA pattern
 240                                         'CustomRendered' => Exif::SHORT,                        # Custom image processing #p48
 241                                         'ExposureMode' => Exif::SHORT,                  # Exposure mode #p48
 242                                         'WhiteBalance' => Exif::SHORT,                  # White Balance #p49
 243                                         'DigitalZoomRatio' => Exif::RATIONAL,                   # Digital zoom ration
 244                                         'FocalLengthIn35mmFilm' => Exif::SHORT,         # Focal length in 35 mm film
 245                                         'SceneCaptureType' => Exif::SHORT,                      # Scene capture type #p49
 246                                         'GainControl' => Exif::RATIONAL,                        # Scene control #p49-50
 247                                         'Contrast' => Exif::SHORT,                              # Contrast #p50
 248                                         'Saturation' => Exif::SHORT,                            # Saturation #p50
 249                                         'Sharpness' => Exif::SHORT,                             # Sharpness #p50
 250                                         'DeviceSettingDescription' => Exif::UNDEFINED,  # Desice settings description
 251                                         'SubjectDistanceRange' => Exif::SHORT,          # Subject distance range #p51
 252                                 ),
 253
 254                                 'other' => array(
 255                                         'ImageUniqueID' => Exif::ASCII, # Unique image ID
 256                                 ),
 257                         ),
 258
 259                         # GPS Attribute Information (p52)
 260                         'gps' => array(
 261                                 'GPSVersionID' => Exif::BYTE,                   # GPS tag version
 262                                 'GPSLatitudeRef' => Exif::ASCII,                # North or South Latitude #p52-53
 263                                 'GPSLatitude' => Exif::RATIONAL,                # Latitude
 264                                 'GPSLongitudeRef' => Exif::ASCII,               # East or West Longitude #p53
 265                                 'GPSLongitude' => Exif::RATIONAL,               # Longitude
 266                                 'GPSAltitudeRef' => Exif::BYTE,         # Altitude reference
 267                                 'GPSAltitude' => Exif::RATIONAL,                # Altitude
 268                                 'GPSTimeStamp' => Exif::RATIONAL,               # GPS time (atomic clock)
 269                                 'GPSSatellites' => Exif::ASCII,         # Satellites used for measurement
 270                                 'GPSStatus' => Exif::ASCII,                     # Receiver status #p54
 271                                 'GPSMeasureMode' => Exif::ASCII,                # Measurement mode #p54-55
 272                                 'GPSDOP' => Exif::RATIONAL,                     # Measurement precision
 273                                 'GPSSpeedRef' => Exif::ASCII,                   # Speed unit #p55
 274                                 'GPSSpeed' => Exif::RATIONAL,                   # Speed of GPS receiver
 275                                 'GPSTrackRef' => Exif::ASCII,                   # Reference for direction of movement #p55
 276                                 'GPSTrack' => Exif::RATIONAL,                   # Direction of movement
 277                                 'GPSImgDirectionRef' => Exif::ASCII,            # Reference for direction of image #p56
 278                                 'GPSImgDirection' => Exif::RATIONAL,            # Direction of image
 279                                 'GPSMapDatum' => Exif::ASCII,                   # Geodetic survey data used
 280                                 'GPSDestLatitudeRef' => Exif::ASCII,            # Reference for latitude of destination #p56
 281                                 'GPSDestLatitude' => Exif::RATIONAL,            # Latitude destination
 282                                 'GPSDestLongitudeRef' => Exif::ASCII,           # Reference for longitude of destination #p57
 283                                 'GPSDestLongitude' => Exif::RATIONAL,           # Longitude of destination
 284                                 'GPSDestBearingRef' => Exif::ASCII,             # Reference for bearing of destination #p57
 285                                 'GPSDestBearing' => Exif::RATIONAL,             # Bearing of destination
 286                                 'GPSDestDistanceRef' => Exif::ASCII,            # Reference for distance to destination #p57-58
 287                                 'GPSDestDistance' => Exif::RATIONAL,            # Distance to destination
 288                                 'GPSProcessingMethod' => Exif::UNDEFINED,       # Name of GPS processing method
 289                                 'GPSAreaInformation' => Exif::UNDEFINED,        # Name of GPS area
 290                                 'GPSDateStamp' => Exif::ASCII,          # GPS date
 291                                 'GPSDifferential' => Exif::SHORT,               # GPS differential correction
 292                         ),
 293                 );
 294
 295                 $this->file = $file;
 296                 $this->basename = basename( $this->file );
 297
 298                 $this->makeFlatExifTags();
 299
 300                 $this->debugFile( $this->basename, __FUNCTION__, true );
 301                 wfSuppressWarnings();
 302                 $data = exif_read_data( $this->file );
 303                 wfRestoreWarnings();
 304                 /**
 305                  * exif_read_data() will return false on invalid input, such as
 306                  * when somebody uploads a file called something.jpeg
 307                  * containing random gibberish.
 308                  */
 309                 $this->mRawExifData = $data ? $data : array();
 310
 311                 $this->makeFilteredData();
 312                 $this->makeFormattedData();
 313
 314                 $this->debugFile( __FUNCTION__, false );
 315         }
 316
 317         /**#@+
 318          * @private
 319          */
 320         /**
 321          * Generate a flat list of the exif tags
 322          */
 323         function makeFlatExifTags() {
 324                 $this->extractTags( $this->mExifTags );
 325         }
 326
 327         /**
 328          * A recursing extractor function used by makeFlatExifTags()
 329          *
 330          * Note: This used to use an array_walk function, but it made PHP5
 331          * segfault, see `cvs diff -u -r 1.4 -r 1.5 Exif.php`
 332          */
 333         function extractTags( &$tagset ) {
 334                 foreach( $tagset as $key => $val ) {
 335                         if( is_array( $val ) ) {
 336                                 $this->extractTags( $val );
 337                         } else {
 338                                 $this->mFlatExifTags[$key] = $val;
 339                         }
 340                 }
 341         }
 342
 343         /**
 344          * Make $this->mFilteredExifData
 345          */
 346         function makeFilteredData() {
 347                 $this->mFilteredExifData = $this->mRawExifData;
 348
 349                 foreach( $this->mFilteredExifData as $k => $v ) {
 350                         if ( !in_array( $k, array_keys( $this->mFlatExifTags ) ) ) {
 351                                 $this->debug( $v, __FUNCTION__, "'$k' is not a valid Exif tag" );
 352                                 unset( $this->mFilteredExifData[$k] );
 353                         }
 354                 }
 355
 356                 foreach( $this->mFilteredExifData as $k => $v ) {
 357                         if ( !$this->validate($k, $v) ) {
 358                                 $this->debug( $v, __FUNCTION__, "'$k' contained invalid data" );
 359                                 unset( $this->mFilteredExifData[$k] );
 360                         }
 361                 }
 362         }
 363
 364         /**
 365          * @todo document
 366          */
 367         function makeFormattedData( ) {
 368                 $format = new FormatExif( $this->getFilteredData() );
 369                 $this->mFormattedExifData = $format->getFormattedData();
 370         }
 371         /**#@-*/
 372
 373         /**#@+
 374          * @return array
 375          */
 376         /**
 377          * Get $this->mRawExifData
 378          */
 379         function getData() {
 380                 return $this->mRawExifData;
 381         }
 382
 383         /**
 384          * Get $this->mFilteredExifData
 385          */
 386         function getFilteredData() {
 387                 return $this->mFilteredExifData;
 388         }
 389
 390         /**
 391          * Get $this->mFormattedExifData
 392          */
 393         function getFormattedData() {
 394                 return $this->mFormattedExifData;
 395         }
 396         /**#@-*/
 397
 398         /**
 399          * The version of the output format
 400          *
 401          * Before the actual metadata information is saved in the database we
 402          * strip some of it since we don't want to save things like thumbnails
 403          * which usually accompany Exif data. This value gets saved in the
 404          * database along with the actual Exif data, and if the version in the
 405          * database doesn't equal the value returned by this function the Exif
 406          * data is regenerated.
 407          *
 408          * @return int
 409          */
 410         function version() {
 411                 return 1; // We don't need no bloddy constants!
 412         }
 413
 414         /**#@+
 415          * Validates if a tag value is of the type it should be according to the Exif spec
 416          *
 417          * @private
 418          *
 419          * @param $in Mixed: the input value to check
 420          * @return bool
 421          */
 422         function isByte( $in ) {
 423                 if ( !is_array( $in ) && sprintf('%d', $in) == $in && $in >= 0 && $in <= 255 ) {
 424                         $this->debug( $in, __FUNCTION__, true );
 425                         return true;
 426                 } else {
 427                         $this->debug( $in, __FUNCTION__, false );
 428                         return false;
 429                 }
 430         }
 431
 432         function isASCII( $in ) {
 433                 if ( is_array( $in ) ) {
 434                         return false;
 435                 }
 436
 437                 if ( preg_match( "/[^\x0a\x20-\x7e]/", $in ) ) {
 438                         $this->debug( $in, __FUNCTION__, 'found a character not in our whitelist' );
 439                         return false;
 440                 }
 441
 442                 if ( preg_match( "/^\s*$/", $in ) ) {
 443                         $this->debug( $in, __FUNCTION__, 'input consisted solely of whitespace' );
 444                         return false;
 445                 }
 446
 447                 return true;
 448         }
 449
 450         function isShort( $in ) {
 451                 if ( !is_array( $in ) && sprintf('%d', $in) == $in && $in >= 0 && $in <= 65536 ) {
 452                         $this->debug( $in, __FUNCTION__, true );
 453                         return true;
 454                 } else {
 455                         $this->debug( $in, __FUNCTION__, false );
 456                         return false;
 457                 }
 458         }
 459
 460         function isLong( $in ) {
 461                 if ( !is_array( $in ) && sprintf('%d', $in) == $in && $in >= 0 && $in <= 4294967296 ) {
 462                         $this->debug( $in, __FUNCTION__, true );
 463                         return true;
 464                 } else {
 465                         $this->debug( $in, __FUNCTION__, false );
 466                         return false;
 467                 }
 468         }
 469
 470         function isRational( $in ) {
 471                 if ( !is_array( $in ) && @preg_match( "/^(\d+)\/(\d+[1-9]|[1-9]\d*)$/", $in, $m ) ) { # Avoid division by zero
 472                         return $this->isLong( $m[1] ) && $this->isLong( $m[2] );
 473                 } else {
 474                         $this->debug( $in, __FUNCTION__, 'fed a non-fraction value' );
 475                         return false;
 476                 }
 477         }
 478
 479         function isUndefined( $in ) {
 480                 if ( !is_array( $in ) && preg_match( "/^\d{4}$/", $in ) ) { // Allow ExifVersion and FlashpixVersion
 481                         $this->debug( $in, __FUNCTION__, true );
 482                         return true;
 483                 } else {
 484                         $this->debug( $in, __FUNCTION__, false );
 485                         return false;
 486                 }
 487         }
 488
 489         function isSlong( $in ) {
 490                 if ( $this->isLong( abs( $in ) ) ) {
 491                         $this->debug( $in, __FUNCTION__, true );
 492                         return true;
 493                 } else {
 494                         $this->debug( $in, __FUNCTION__, false );
 495                         return false;
 496                 }
 497         }
 498
 499         function isSrational( $in ) {
 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                 $type = gettype( $in );
 566                 $class = ucfirst( __CLASS__ );
 567                 if ( $type === 'array' )
 568                         $in = print_r( $in, true );
 569
 570                 if ( $action === true )
 571                         wfDebugLog( $this->log, "$class::$fname: accepted: '$in' (type: $type)\n");
 572                 elseif ( $action === false )
 573                         wfDebugLog( $this->log, "$class::$fname: rejected: '$in' (type: $type)\n");
 574                 elseif ( $action === null )
 575                         wfDebugLog( $this->log, "$class::$fname: input was: '$in' (type: $type)\n");
 576                 else
 577                         wfDebugLog( $this->log, "$class::$fname: $action (type: $type; content: '$in')\n");
 578         }
 579
 580         /**
 581          * Convenience function for debugging output
 582          *
 583          * @private
 584          *
 585          * @param $fname String: the name of the function calling this function
 586          * @param $io Boolean: Specify whether we're beginning or ending
 587          */
 588         function debugFile( $fname, $io ) {
 589                 $class = ucfirst( __CLASS__ );
 590                 if ( $io ) {
 591                         wfDebugLog( $this->log, "$class::$fname: begin processing: '{$this->basename}'\n" );
 592                 } else {
 593                         wfDebugLog( $this->log, "$class::$fname: end processing: '{$this->basename}'\n" );
 594                 }
 595         }
 596
 597 }
 598
 599 /**
 600  * @package MediaWiki
 601  * @subpackage Metadata
 602  */
 603 class FormatExif {
 604         /**
 605          * The Exif data to format
 606          *
 607          * @var array
 608          * @private
 609          */
 610         var $mExif;
 611
 612         /**
 613          * Constructor
 614          *
 615          * @param $exif Array: the Exif data to format ( as returned by
 616          *                    Exif::getFilteredData() )
 617          */
 618         function FormatExif( $exif ) {
 619                 $this->mExif = $exif;
 620         }
 621
 622         /**
 623          * Numbers given by Exif user agents are often magical, that is they
 624          * should be replaced by a detailed explanation depending on their
 625          * value which most of the time are plain integers. This function
 626          * formats Exif values into human readable form.
 627          *
 628          * @return array
 629          */
 630         function getFormattedData() {
 631                 global $wgLang;
 632
 633                 $tags =& $this->mExif;
 634
 635                 $resolutionunit = !isset( $tags['ResolutionUnit'] ) || $tags['ResolutionUnit'] == 2 ? 2 : 3;
 636                 unset( $tags['ResolutionUnit'] );
 637
 638                 foreach( $tags as $tag => $val ) {
 639                         switch( $tag ) {
 640                         case 'Compression':
 641                                 switch( $val ) {
 642                                 case 1: case 6:
 643                                         $tags[$tag] = $this->msg( $tag, $val );
 644                                         break;
 645                                 default:
 646                                         $tags[$tag] = $val;
 647                                         break;
 648                                 }
 649                                 break;
 650
 651                         case 'PhotometricInterpretation':
 652                                 switch( $val ) {
 653                                 case 2: case 6:
 654                                         $tags[$tag] = $this->msg( $tag, $val );
 655                                         break;
 656                                 default:
 657                                         $tags[$tag] = $val;
 658                                         break;
 659                                 }
 660                                 break;
 661
 662                         case 'Orientation':
 663                                 switch( $val ) {
 664                                 case 1: case 2: case 3: case 4: case 5: case 6: case 7: case 8:
 665                                         $tags[$tag] = $this->msg( $tag, $val );
 666                                         break;
 667                                 default:
 668                                         $tags[$tag] = $val;
 669                                         break;
 670                                 }
 671                                 break;
 672
 673                         case 'PlanarConfiguration':
 674                                 switch( $val ) {
 675                                 case 1: case 2:
 676                                         $tags[$tag] = $this->msg( $tag, $val );
 677                                         break;
 678                                 default:
 679                                         $tags[$tag] = $val;
 680                                         break;
 681                                 }
 682                                 break;
 683
 684                         // TODO: YCbCrSubSampling
 685                         // TODO: YCbCrPositioning
 686
 687                         case 'XResolution':
 688                         case 'YResolution':
 689                                 switch( $resolutionunit ) {
 690                                         case 2:
 691                                                 $tags[$tag] = $this->msg( 'XYResolution', 'i', $this->formatNum( $val ) );
 692                                                 break;
 693                                         case 3:
 694                                                 $this->msg( 'XYResolution', 'c', $this->formatNum( $val ) );
 695                                                 break;
 696                                         default:
 697                                                 $tags[$tag] = $val;
 698                                                 break;
 699                                 }
 700                                 break;
 701
 702                         // TODO: YCbCrCoefficients  #p27 (see annex E)
 703                         case 'ExifVersion': case 'FlashpixVersion':
 704                                 $tags[$tag] = "$val"/100;
 705                                 break;
 706
 707                         case 'ColorSpace':
 708                                 switch( $val ) {
 709                                 case 1: case 'FFFF.H':
 710                                         $tags[$tag] = $this->msg( $tag, $val );
 711                                         break;
 712                                 default:
 713                                         $tags[$tag] = $val;
 714                                         break;
 715                                 }
 716                                 break;
 717
 718                         case 'ComponentsConfiguration':
 719                                 switch( $val ) {
 720                                 case 0: case 1: case 2: case 3: case 4: case 5: case 6:
 721                                         $tags[$tag] = $this->msg( $tag, $val );
 722                                         break;
 723                                 default:
 724                                         $tags[$tag] = $val;
 725                                         break;
 726                                 }
 727                                 break;
 728
 729                         case 'DateTime':
 730                         case 'DateTimeOriginal':
 731                         case 'DateTimeDigitized':
 732                                 if( preg_match( "/^(\d{4}):(\d\d):(\d\d) (\d\d):(\d\d):(\d\d)$/", $val ) ) {
 733                                         $tags[$tag] = $wgLang->timeanddate( wfTimestamp(TS_MW, $val) );
 734                                 }
 735                                 break;
 736
 737                         case 'ExposureProgram':
 738                                 switch( $val ) {
 739                                 case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7: case 8:
 740                                         $tags[$tag] = $this->msg( $tag, $val );
 741                                         break;
 742                                 default:
 743                                         $tags[$tag] = $val;
 744                                         break;
 745                                 }
 746                                 break;
 747
 748                         case 'SubjectDistance':
 749                                 $tags[$tag] = $this->msg( $tag, '', $this->formatNum( $val ) );
 750                                 break;
 751
 752                         case 'MeteringMode':
 753                                 switch( $val ) {
 754                                 case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7: case 255:
 755                                         $tags[$tag] = $this->msg( $tag, $val );
 756                                         break;
 757                                 default:
 758                                         $tags[$tag] = $val;
 759                                         break;
 760                                 }
 761                                 break;
 762
 763                         case 'LightSource':
 764                                 switch( $val ) {
 765                                 case 0: case 1: case 2: case 3: case 4: case 9: case 10: case 11:
 766                                 case 12: case 13: case 14: case 15: case 17: case 18: case 19: case 20:
 767                                 case 21: case 22: case 23: case 24: case 255:
 768                                         $tags[$tag] = $this->msg( $tag, $val );
 769                                         break;
 770                                 default:
 771                                         $tags[$tag] = $val;
 772                                         break;
 773                                 }
 774                                 break;
 775
 776                         // TODO: Flash
 777                         case 'FocalPlaneResolutionUnit':
 778                                 switch( $val ) {
 779                                 case 2:
 780                                         $tags[$tag] = $this->msg( $tag, $val );
 781                                         break;
 782                                 default:
 783                                         $tags[$tag] = $val;
 784                                         break;
 785                                 }
 786                                 break;
 787
 788                         case 'SensingMethod':
 789                                 switch( $val ) {
 790                                 case 1: case 2: case 3: case 4: case 5: case 7: case 8:
 791                                         $tags[$tag] = $this->msg( $tag, $val );
 792                                         break;
 793                                 default:
 794                                         $tags[$tag] = $val;
 795                                         break;
 796                                 }
 797                                 break;
 798
 799                         case 'FileSource':
 800                                 switch( $val ) {
 801                                 case 3:
 802                                         $tags[$tag] = $this->msg( $tag, $val );
 803                                         break;
 804                                 default:
 805                                         $tags[$tag] = $val;
 806                                         break;
 807                                 }
 808                                 break;
 809
 810                         case 'SceneType':
 811                                 switch( $val ) {
 812                                 case 1:
 813                                         $tags[$tag] = $this->msg( $tag, $val );
 814                                         break;
 815                                 default:
 816                                         $tags[$tag] = $val;
 817                                         break;
 818                                 }
 819                                 break;
 820
 821                         case 'CustomRendered':
 822                                 switch( $val ) {
 823                                 case 0: case 1:
 824                                         $tags[$tag] = $this->msg( $tag, $val );
 825                                         break;
 826                                 default:
 827                                         $tags[$tag] = $val;
 828                                         break;
 829                                 }
 830                                 break;
 831
 832                         case 'ExposureMode':
 833                                 switch( $val ) {
 834                                 case 0: case 1: case 2:
 835                                         $tags[$tag] = $this->msg( $tag, $val );
 836                                         break;
 837                                 default:
 838                                         $tags[$tag] = $val;
 839                                         break;
 840                                 }
 841                                 break;
 842
 843                         case 'WhiteBalance':
 844                                 switch( $val ) {
 845                                 case 0: case 1:
 846                                         $tags[$tag] = $this->msg( $tag, $val );
 847                                         break;
 848                                 default:
 849                                         $tags[$tag] = $val;
 850                                         break;
 851                                 }
 852                                 break;
 853
 854                         case 'SceneCaptureType':
 855                                 switch( $val ) {
 856                                 case 0: case 1: case 2: case 3:
 857                                         $tags[$tag] = $this->msg( $tag, $val );
 858                                         break;
 859                                 default:
 860                                         $tags[$tag] = $val;
 861                                         break;
 862                                 }
 863                                 break;
 864
 865                         case 'GainControl':
 866                                 switch( $val ) {
 867                                 case 0: case 1: case 2: case 3: case 4:
 868                                         $tags[$tag] = $this->msg( $tag, $val );
 869                                         break;
 870                                 default:
 871                                         $tags[$tag] = $val;
 872                                         break;
 873                                 }
 874                                 break;
 875
 876                         case 'Contrast':
 877                                 switch( $val ) {
 878                                 case 0: case 1: case 2:
 879                                         $tags[$tag] = $this->msg( $tag, $val );
 880                                         break;
 881                                 default:
 882                                         $tags[$tag] = $val;
 883                                         break;
 884                                 }
 885                                 break;
 886
 887                         case 'Saturation':
 888                                 switch( $val ) {
 889                                 case 0: case 1: case 2:
 890                                         $tags[$tag] = $this->msg( $tag, $val );
 891                                         break;
 892                                 default:
 893                                         $tags[$tag] = $val;
 894                                         break;
 895                                 }
 896                                 break;
 897
 898                         case 'Sharpness':
 899                                 switch( $val ) {
 900                                 case 0: case 1: case 2:
 901                                         $tags[$tag] = $this->msg( $tag, $val );
 902                                         break;
 903                                 default:
 904                                         $tags[$tag] = $val;
 905                                         break;
 906                                 }
 907                                 break;
 908
 909                         case 'SubjectDistanceRange':
 910                                 switch( $val ) {
 911                                 case 0: case 1: case 2: case 3:
 912                                         $tags[$tag] = $this->msg( $tag, $val );
 913                                         break;
 914                                 default:
 915                                         $tags[$tag] = $val;
 916                                         break;
 917                                 }
 918                                 break;
 919
 920                         case 'GPSLatitudeRef':
 921                         case 'GPSDestLatitudeRef':
 922                                 switch( $val ) {
 923                                 case 'N': case 'S':
 924                                         $tags[$tag] = $this->msg( 'GPSLatitude', $val );
 925                                         break;
 926                                 default:
 927                                         $tags[$tag] = $val;
 928                                         break;
 929                                 }
 930                                 break;
 931
 932                         case 'GPSLongitudeRef':
 933                         case 'GPSDestLongitudeRef':
 934                                 switch( $val ) {
 935                                 case 'E': case 'W':
 936                                         $tags[$tag] = $this->msg( 'GPSLongitude', $val );
 937                                         break;
 938                                 default:
 939                                         $tags[$tag] = $val;
 940                                         break;
 941                                 }
 942                                 break;
 943
 944                         case 'GPSStatus':
 945                                 switch( $val ) {
 946                                 case 'A': case 'V':
 947                                         $tags[$tag] = $this->msg( $tag, $val );
 948                                         break;
 949                                 default:
 950                                         $tags[$tag] = $val;
 951                                         break;
 952                                 }
 953                                 break;
 954
 955                         case 'GPSMeasureMode':
 956                                 switch( $val ) {
 957                                 case 2: case 3:
 958                                         $tags[$tag] = $this->msg( $tag, $val );
 959                                         break;
 960                                 default:
 961                                         $tags[$tag] = $val;
 962                                         break;
 963                                 }
 964                                 break;
 965
 966                         case 'GPSSpeedRef':
 967                         case 'GPSDestDistanceRef':
 968                                 switch( $val ) {
 969                                 case 'K': case 'M': case 'N':
 970                                         $tags[$tag] = $this->msg( 'GPSSpeed', $val );
 971                                         break;
 972                                 default:
 973                                         $tags[$tag] = $val;
 974                                         break;
 975                                 }
 976                                 break;
 977
 978                         case 'GPSTrackRef':
 979                         case 'GPSImgDirectionRef':
 980                         case 'GPSDestBearingRef':
 981                                 switch( $val ) {
 982                                 case 'T': case 'M':
 983                                         $tags[$tag] = $this->msg( 'GPSDirection', $val );
 984                                         break;
 985                                 default:
 986                                         $tags[$tag] = $val;
 987                                         break;
 988                                 }
 989                                 break;
 990
 991                         case 'GPSDateStamp':
 992                                 $tags[$tag] = $wgLang->date( substr( $val, 0, 4 ) . substr( $val, 5, 2 ) . substr( $val, 8, 2 ) . '000000' );
 993                                 break;
 994
 995                         // This is not in the Exif standard, just a special
 996                         // case for our purposes which enables wikis to wikify
 997                         // the make, model and software name to link to their articles.
 998                         case 'Make':
 999                         case 'Model':
1000                         case 'Software':
1001                                 $tags[$tag] = $this->msg( $tag, '', $val );
1002                                 break;
1003
1004                         case 'ExposureTime':
1005                                 // Show the pretty fraction as well as decimal version
1006                                 $tags[$tag] = wfMsg( 'exif-exposuretime-format',
1007                                         $this->formatFraction( $val ), $this->formatNum( $val ) );
1008                                 break;
1009
1010                         case 'FNumber':
1011                                 $tags[$tag] = wfMsg( 'exif-fnumber-format',
1012                                         $this->formatNum( $val ) );
1013                                 break;
1014
1015                         case 'FocalLength':
1016                                 $tags[$tag] = wfMsg( 'exif-focallength-format',
1017                                         $this->formatNum( $val ) );
1018                                 break;
1019
1020                         default:
1021                                 $tags[$tag] = $this->formatNum( $val );
1022                                 break;
1023                         }
1024                 }
1025
1026                 return $tags;
1027         }
1028
1029         /**
1030          * Convenience function for getFormattedData()
1031          *
1032          * @private
1033          *
1034          * @param $tag String: the tag name to pass on
1035          * @param $val String: the value of the tag
1036          * @param $arg String: an argument to pass ($1)
1037          * @return string A wfMsg of "exif-$tag-$val" in lower case
1038          */
1039         function msg( $tag, $val, $arg = null ) {
1040                 global $wgContLang;
1041
1042                 if ($val === '')
1043                         $val = 'value';
1044                 return wfMsg( $wgContLang->lc( "exif-$tag-$val" ), $arg );
1045         }
1046
1047         /**
1048          * Format a number, convert numbers from fractions into floating point
1049          * numbers
1050          *
1051          * @private
1052          *
1053          * @param $num Mixed: the value to format
1054          * @return mixed A floating point number or whatever we were fed
1055          */
1056         function formatNum( $num ) {
1057                 if ( preg_match( '/^(\d+)\/(\d+)$/', $num, $m ) )
1058                         return $m[2] != 0 ? $m[1] / $m[2] : $num;
1059                 else
1060                         return $num;
1061         }
1062
1063         /**
1064          * Format a rational number, reducing fractions
1065          *
1066          * @private
1067          *
1068          * @param $num Mixed: the value to format
1069          * @return mixed A floating point number or whatever we were fed
1070          */
1071         function formatFraction( $num ) {
1072                 if ( preg_match( '/^(\d+)\/(\d+)$/', $num, $m ) ) {
1073                         $numerator = intval( $m[1] );
1074                         $denominator = intval( $m[2] );
1075                         $gcd = $this->gcd( $numerator, $denominator );
1076                         if( $gcd != 0 ) {
1077                                 // 0 shouldn't happen! ;)
1078                                 return $numerator / $gcd . '/' . $denominator / $gcd;
1079                         }
1080                 }
1081                 return $this->formatNum( $num );
1082         }
1083
1084         /**
1085          * Calculate the greatest common divisor of two integers.
1086          *
1087          * @param $a Integer: FIXME
1088          * @param $b Integer: FIXME
1089          * @return int
1090          * @private
1091          */
1092         function gcd( $a, $b ) {
1093                 /*
1094                         // http://en.wikipedia.org/wiki/Euclidean_algorithm
1095                         // Recursive form would be:
1096                         if( $b == 0 )
1097                                 return $a;
1098                         else
1099                                 return gcd( $b, $a % $b );
1100                 */
1101                 while( $b != 0 ) {
1102                         $remainder = $a % $b;
1103
1104                         // tail recursion...
1105                         $a = $b;
1106                         $b = $remainder;
1107                 }
1108                 return $a;
1109         }
1110 }
1111
1112 /**
1113  * MW 1.6 compatibility
1114  */
1115 define( 'MW_EXIF_BYTE', Exif::BYTE );
1116 define( 'MW_EXIF_ASCII', Exif::ASCII );
1117 define( 'MW_EXIF_SHORT', Exif::SHORT );
1118 define( 'MW_EXIF_LONG', Exif::LONG );
1119 define( 'MW_EXIF_RATIONAL', Exif::RATIONAL );
1120 define( 'MW_EXIF_UNDEFINED', Exif::UNDEFINED );
1121 define( 'MW_EXIF_SLONG', Exif::SLONG );
1122 define( 'MW_EXIF_SRATIONAL', Exif::SRATIONAL );
1123
1124 ?>