includes/Exif.php

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