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 MW_EXIF_BYTE      = 1;    # An 8-bit (1-byte) unsigned integer.
  43         const MW_EXIF_ASCII     = 2;    # An 8-bit byte containing one 7-bit ASCII code. The final byte is terminated with NULL.
  44         const MW_EXIF_SHORT     = 3;    # A 16-bit (2-byte) unsigned integer.
  45         const MW_EXIF_LONG      = 4;    # A 32-bit (4-byte) unsigned integer.
  46         const MW_EXIF_RATIONAL  = 5;    # Two LONGs. The first LONG is the numerator and the second LONG expresses the denominator
  47         const MW_EXIF_UNDEFINED = 7;    # An 8-bit byte that can take any value depending on the field definition
  48         const MW_EXIF_SLONG     = 9;    # A 32-bit (4-byte) signed integer (2's complement notation),
  49         const MW_EXIF_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::MW_EXIF_SHORT.','.Exif::MW_EXIF_LONG,             # Image width
 121                                         'ImageLength' => Exif::MW_EXIF_SHORT.','.Exif::MW_EXIF_LONG,    # Image height
 122                                         'BitsPerSample' => Exif::MW_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::MW_EXIF_SHORT,                           # Compression scheme #p23
 126                                         'PhotometricInterpretation' => Exif::MW_EXIF_SHORT,             # Pixel composition #p23
 127                                         'Orientation' => Exif::MW_EXIF_SHORT,                           # Orientation of image #p24
 128                                         'SamplesPerPixel' => Exif::MW_EXIF_SHORT,                       # Number of components
 129                                         'PlanarConfiguration' => Exif::MW_EXIF_SHORT,                   # Image data arrangement #p24
 130                                         'YCbCrSubSampling' => Exif::MW_EXIF_SHORT,                      # Subsampling ratio of Y to C #p24
 131                                         'YCbCrPositioning' => Exif::MW_EXIF_SHORT,                      # Y and C positioning #p24-25
 132                                         'XResolution' => Exif::MW_EXIF_RATIONAL,                        # Image resolution in width direction
 133                                         'YResolution' => Exif::MW_EXIF_RATIONAL,                        # Image resolution in height direction
 134                                         'ResolutionUnit' => Exif::MW_EXIF_SHORT,                        # Unit of X and Y resolution #(p26)
 135                                 ),
 136
 137                                 # Tags relating to recording offset
 138                                 'offset' => array(
 139                                         'StripOffsets' => Exif::MW_EXIF_SHORT.','.Exif::MW_EXIF_LONG,                   # Image data location
 140                                         'RowsPerStrip' => Exif::MW_EXIF_SHORT.','.Exif::MW_EXIF_LONG,                   # Number of rows per strip
 141                                         'StripByteCounts' => Exif::MW_EXIF_SHORT.','.Exif::MW_EXIF_LONG,                        # Bytes per compressed strip
 142                                         'JPEGInterchangeFormat' => Exif::MW_EXIF_SHORT.','.Exif::MW_EXIF_LONG,          # Offset to JPEG SOI
 143                                         'JPEGInterchangeFormatLength' => Exif::MW_EXIF_SHORT.','.Exif::MW_EXIF_LONG,    # Bytes of JPEG data
 144                                 ),
 145
 146                                 # Tags relating to image data characteristics
 147                                 'characteristics' => array(
 148                                         'TransferFunction' => Exif::MW_EXIF_SHORT,              # Transfer function
 149                                         'WhitePoint' => Exif::MW_EXIF_RATIONAL,         # White point chromaticity
 150                                         'PrimaryChromaticities' => Exif::MW_EXIF_RATIONAL,      # Chromaticities of primarities
 151                                         'YCbCrCoefficients' => Exif::MW_EXIF_RATIONAL,  # Color space transformation matrix coefficients #p27
 152                                         'ReferenceBlackWhite' => Exif::MW_EXIF_RATIONAL # Pair of black and white reference values
 153                                 ),
 154
 155                                 # Other tags
 156                                 'other' => array(
 157                                         'DateTime' => Exif::MW_EXIF_ASCII,            # File change date and time
 158                                         'ImageDescription' => Exif::MW_EXIF_ASCII,    # Image title
 159                                         'Make' => Exif::MW_EXIF_ASCII,                # Image input equipment manufacturer
 160                                         'Model' => Exif::MW_EXIF_ASCII,               # Image input equipment model
 161                                         'Software' => Exif::MW_EXIF_ASCII,            # Software used
 162                                         'Artist' => Exif::MW_EXIF_ASCII,              # Person who created the image
 163                                         'Copyright' => Exif::MW_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::MW_EXIF_UNDEFINED,       # Exif version
 174                                         'FlashpixVersion' => Exif::MW_EXIF_UNDEFINED, # Supported Flashpix version #p32
 175                                 ),
 176
 177                                 # Tags relating to Image Data Characteristics
 178                                 'characteristics' => array(
 179                                         'ColorSpace' => Exif::MW_EXIF_SHORT,            # Color space information #p32
 180                                 ),
 181
 182                                 # Tags relating to image configuration
 183                                 'configuration' => array(
 184                                         'ComponentsConfiguration' => Exif::MW_EXIF_UNDEFINED,           # Meaning of each component #p33
 185                                         'CompressedBitsPerPixel' => Exif::MW_EXIF_RATIONAL,             # Image compression mode
 186                                         'PixelYDimension' => Exif::MW_EXIF_SHORT.','.Exif::MW_EXIF_LONG,        # Valid image width
 187                                         'PixelXDimension' => Exif::MW_EXIF_SHORT.','.Exif::MW_EXIF_LONG,        # Valind image height
 188                                 ),
 189
 190                                 # Tags relating to related user information
 191                                 'user' => array(
 192                                         'MakerNote' => Exif::MW_EXIF_UNDEFINED,                 # Manufacturer notes
 193                                         'UserComment' => Exif::MW_EXIF_UNDEFINED,                       # User comments #p34
 194                                 ),
 195
 196                                 # Tags relating to related file information
 197                                 'related' => array(
 198                                         'RelatedSoundFile' => Exif::MW_EXIF_ASCII,                      # Related audio file
 199                                 ),
 200
 201                                 # Tags relating to date and time
 202                                 'dateandtime' => array(
 203                                         'DateTimeOriginal' => Exif::MW_EXIF_ASCII,                      # Date and time of original data generation #p36
 204                                         'DateTimeDigitized' => Exif::MW_EXIF_ASCII,                     # Date and time of original data generation
 205                                         'SubSecTime' => Exif::MW_EXIF_ASCII,                            # DateTime subseconds
 206                                         'SubSecTimeOriginal' => Exif::MW_EXIF_ASCII,                    # DateTimeOriginal subseconds
 207                                         'SubSecTimeDigitized' => Exif::MW_EXIF_ASCII,                   # DateTimeDigitized subseconds
 208                                 ),
 209
 210                                 # Tags relating to picture-taking conditions (p31)
 211                                 'conditions' => array(
 212                                         'ExposureTime' => Exif::MW_EXIF_RATIONAL,                       # Exposure time
 213                                         'FNumber' => Exif::MW_EXIF_RATIONAL,                            # F Number
 214                                         'ExposureProgram' => Exif::MW_EXIF_SHORT,                       # Exposure Program #p38
 215                                         'SpectralSensitivity' => Exif::MW_EXIF_ASCII,                   # Spectral sensitivity
 216                                         'ISOSpeedRatings' => Exif::MW_EXIF_SHORT,                       # ISO speed rating
 217                                         'OECF' => Exif::MW_EXIF_UNDEFINED,                              # Optoelectronic conversion factor
 218                                         'ShutterSpeedValue' => Exif::MW_EXIF_SRATIONAL,         # Shutter speed
 219                                         'ApertureValue' => Exif::MW_EXIF_RATIONAL,                      # Aperture
 220                                         'BrightnessValue' => Exif::MW_EXIF_SRATIONAL,                   # Brightness
 221                                         'ExposureBiasValue' => Exif::MW_EXIF_SRATIONAL,         # Exposure bias
 222                                         'MaxApertureValue' => Exif::MW_EXIF_RATIONAL,                   # Maximum land aperture
 223                                         'SubjectDistance' => Exif::MW_EXIF_RATIONAL,                    # Subject distance
 224                                         'MeteringMode' => Exif::MW_EXIF_SHORT,                  # Metering mode #p40
 225                                         'LightSource' => Exif::MW_EXIF_SHORT,                           # Light source #p40-41
 226                                         'Flash' => Exif::MW_EXIF_SHORT,                         # Flash #p41-42
 227                                         'FocalLength' => Exif::MW_EXIF_RATIONAL,                        # Lens focal length
 228                                         'SubjectArea' => Exif::MW_EXIF_SHORT,                           # Subject area
 229                                         'FlashEnergy' => Exif::MW_EXIF_RATIONAL,                        # Flash energy
 230                                         'SpatialFrequencyResponse' => Exif::MW_EXIF_UNDEFINED,  # Spatial frequency response
 231                                         'FocalPlaneXResolution' => Exif::MW_EXIF_RATIONAL,              # Focal plane X resolution
 232                                         'FocalPlaneYResolution' => Exif::MW_EXIF_RATIONAL,              # Focal plane Y resolution
 233                                         'FocalPlaneResolutionUnit' => Exif::MW_EXIF_SHORT,              # Focal plane resolution unit #p46
 234                                         'SubjectLocation' => Exif::MW_EXIF_SHORT,                       # Subject location
 235                                         'ExposureIndex' => Exif::MW_EXIF_RATIONAL,                      # Exposure index
 236                                         'SensingMethod' => Exif::MW_EXIF_SHORT,                 # Sensing method #p46
 237                                         'FileSource' => Exif::MW_EXIF_UNDEFINED,                        # File source #p47
 238                                         'SceneType' => Exif::MW_EXIF_UNDEFINED,                 # Scene type #p47
 239                                         'CFAPattern' => Exif::MW_EXIF_UNDEFINED,                        # CFA pattern
 240                                         'CustomRendered' => Exif::MW_EXIF_SHORT,                        # Custom image processing #p48
 241                                         'ExposureMode' => Exif::MW_EXIF_SHORT,                  # Exposure mode #p48
 242                                         'WhiteBalance' => Exif::MW_EXIF_SHORT,                  # White Balance #p49
 243                                         'DigitalZoomRatio' => Exif::MW_EXIF_RATIONAL,                   # Digital zoom ration
 244                                         'FocalLengthIn35mmFilm' => Exif::MW_EXIF_SHORT,         # Focal length in 35 mm film
 245                                         'SceneCaptureType' => Exif::MW_EXIF_SHORT,                      # Scene capture type #p49
 246                                         'GainControl' => Exif::MW_EXIF_RATIONAL,                        # Scene control #p49-50
 247                                         'Contrast' => Exif::MW_EXIF_SHORT,                              # Contrast #p50
 248                                         'Saturation' => Exif::MW_EXIF_SHORT,                            # Saturation #p50
 249                                         'Sharpness' => Exif::MW_EXIF_SHORT,                             # Sharpness #p50
 250                                         'DeviceSettingDescription' => Exif::MW_EXIF_UNDEFINED,  # Desice settings description
 251                                         'SubjectDistanceRange' => Exif::MW_EXIF_SHORT,          # Subject distance range #p51
 252                                 ),
 253
 254                                 'other' => array(
 255                                         'ImageUniqueID' => Exif::MW_EXIF_ASCII, # Unique image ID
 256                                 ),
 257                         ),
 258
 259                         # GPS Attribute Information (p52)
 260                         'gps' => array(
 261                                 'GPSVersionID' => Exif::MW_EXIF_BYTE,                   # GPS tag version
 262                                 'GPSLatitudeRef' => Exif::MW_EXIF_ASCII,                # North or South Latitude #p52-53
 263                                 'GPSLatitude' => Exif::MW_EXIF_RATIONAL,                # Latitude
 264                                 'GPSLongitudeRef' => Exif::MW_EXIF_ASCII,               # East or West Longitude #p53
 265                                 'GPSLongitude' => Exif::MW_EXIF_RATIONAL,               # Longitude
 266                                 'GPSAltitudeRef' => Exif::MW_EXIF_BYTE,         # Altitude reference
 267                                 'GPSAltitude' => Exif::MW_EXIF_RATIONAL,                # Altitude
 268                                 'GPSTimeStamp' => Exif::MW_EXIF_RATIONAL,               # GPS time (atomic clock)
 269                                 'GPSSatellites' => Exif::MW_EXIF_ASCII,         # Satellites used for measurement
 270                                 'GPSStatus' => Exif::MW_EXIF_ASCII,                     # Receiver status #p54
 271                                 'GPSMeasureMode' => Exif::MW_EXIF_ASCII,                # Measurement mode #p54-55
 272                                 'GPSDOP' => Exif::MW_EXIF_RATIONAL,                     # Measurement precision
 273                                 'GPSSpeedRef' => Exif::MW_EXIF_ASCII,                   # Speed unit #p55
 274                                 'GPSSpeed' => Exif::MW_EXIF_RATIONAL,                   # Speed of GPS receiver
 275                                 'GPSTrackRef' => Exif::MW_EXIF_ASCII,                   # Reference for direction of movement #p55
 276                                 'GPSTrack' => Exif::MW_EXIF_RATIONAL,                   # Direction of movement
 277                                 'GPSImgDirectionRef' => Exif::MW_EXIF_ASCII,            # Reference for direction of image #p56
 278                                 'GPSImgDirection' => Exif::MW_EXIF_RATIONAL,            # Direction of image
 279                                 'GPSMapDatum' => Exif::MW_EXIF_ASCII,                   # Geodetic survey data used
 280                                 'GPSDestLatitudeRef' => Exif::MW_EXIF_ASCII,            # Reference for latitude of destination #p56
 281                                 'GPSDestLatitude' => Exif::MW_EXIF_RATIONAL,            # Latitude destination
 282                                 'GPSDestLongitudeRef' => Exif::MW_EXIF_ASCII,           # Reference for longitude of destination #p57
 283                                 'GPSDestLongitude' => Exif::MW_EXIF_RATIONAL,           # Longitude of destination
 284                                 'GPSDestBearingRef' => Exif::MW_EXIF_ASCII,             # Reference for bearing of destination #p57
 285                                 'GPSDestBearing' => Exif::MW_EXIF_RATIONAL,             # Bearing of destination
 286                                 'GPSDestDistanceRef' => Exif::MW_EXIF_ASCII,            # Reference for distance to destination #p57-58
 287                                 'GPSDestDistance' => Exif::MW_EXIF_RATIONAL,            # Distance to destination
 288                                 'GPSProcessingMethod' => Exif::MW_EXIF_UNDEFINED,       # Name of GPS processing method
 289                                 'GPSAreaInformation' => Exif::MW_EXIF_UNDEFINED,        # Name of GPS area
 290                                 'GPSDateStamp' => Exif::MW_EXIF_ASCII,          # GPS date
 291                                 'GPSDifferential' => Exif::MW_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 ( 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 ( preg_match( "/[^\x0a\x20-\x7e]/", $in ) ) {
 434                         $this->debug( $in, __FUNCTION__, 'found a character not in our whitelist' );
 435                         return false;
 436                 }
 437
 438                 if ( preg_match( "/^\s*$/", $in ) ) {
 439                         $this->debug( $in, __FUNCTION__, 'input consisted solely of whitespace' );
 440                         return false;
 441                 }
 442
 443                 return true;
 444         }
 445
 446         function isShort( $in ) {
 447                 if ( sprintf('%d', $in) == $in && $in >= 0 && $in <= 65536 ) {
 448                         $this->debug( $in, __FUNCTION__, true );
 449                         return true;
 450                 } else {
 451                         $this->debug( $in, __FUNCTION__, false );
 452                         return false;
 453                 }
 454         }
 455
 456         function isLong( $in ) {
 457                 if ( sprintf('%d', $in) == $in && $in >= 0 && $in <= 4294967296 ) {
 458                         $this->debug( $in, __FUNCTION__, true );
 459                         return true;
 460                 } else {
 461                         $this->debug( $in, __FUNCTION__, false );
 462                         return false;
 463                 }
 464         }
 465
 466         function isRational( $in ) {
 467                 if ( @preg_match( "/^(\d+)\/(\d+[1-9]|[1-9]\d*)$/", $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( $in ) {
 476                 if ( preg_match( "/^\d{4}$/", $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( $in ) {
 496                 if ( preg_match( "/^(\d+)\/(\d+[1-9]|[1-9]\d*)$/", $in, $m ) ) { # Avoid division by zero
 497                         return $this->isSlong( $m[0] ) && $this->isSlong( $m[1] );
 498                 } else {
 499                         $this->debug( $in, __FUNCTION__, 'fed a non-fraction value' );
 500                         return false;
 501                 }
 502         }
 503         /**#@-*/
 504
 505         /**
 506          * Validates if a tag has a legal value according to the Exif spec
 507          *
 508          * @private
 509          *
 510          * @param $tag String: the tag to check.
 511          * @param $val Mixed: the value of the tag.
 512          * @return bool
 513          */
 514         function validate( $tag, $val ) {
 515                 $debug = "tag is '$tag'";
 516                 // Fucks up if not typecast
 517                 switch( (string)$this->mFlatExifTags[$tag] ) {
 518                         case (string)Exif::MW_EXIF_BYTE:
 519                                 $this->debug( $val, __FUNCTION__, $debug );
 520                                 return $this->isByte( $val );
 521                         case (string)Exif::MW_EXIF_ASCII:
 522                                 $this->debug( $val, __FUNCTION__, $debug );
 523                                 return $this->isASCII( $val );
 524                         case (string)Exif::MW_EXIF_SHORT:
 525                                 $this->debug( $val, __FUNCTION__, $debug );
 526                                 return $this->isShort( $val );
 527                         case (string)Exif::MW_EXIF_LONG:
 528                                 $this->debug( $val, __FUNCTION__, $debug );
 529                                 return $this->isLong( $val );
 530                         case (string)Exif::MW_EXIF_RATIONAL:
 531                                 $this->debug( $val, __FUNCTION__, $debug );
 532                                 return $this->isRational( $val );
 533                         case (string)Exif::MW_EXIF_UNDEFINED:
 534                                 $this->debug( $val, __FUNCTION__, $debug );
 535                                 return $this->isUndefined( $val );
 536                         case (string)Exif::MW_EXIF_SLONG:
 537                                 $this->debug( $val, __FUNCTION__, $debug );
 538                                 return $this->isSlong( $val );
 539                         case (string)Exif::MW_EXIF_SRATIONAL:
 540                                 $this->debug( $val, __FUNCTION__, $debug );
 541                                 return $this->isSrational( $val );
 542                         case (string)Exif::MW_EXIF_SHORT.','.Exif::MW_EXIF_LONG:
 543                                 $this->debug( $val, __FUNCTION__, $debug );
 544                                 return $this->isShort( $val ) || $this->isLong( $val );
 545                         default:
 546                                 $this->debug( $val, __FUNCTION__, "The tag '$tag' is unknown" );
 547                                 return false;
 548                 }
 549         }
 550
 551         /**
 552          * Conviniance function for debugging output
 553          *
 554          * @private
 555          *
 556          * @param $in Mixed:
 557          * @param $fname String:
 558          * @param $action Mixed: , default NULL.
 559          */
 560          function debug( $in, $fname, $action = NULL ) {
 561                 $type = gettype( $in );
 562                 $class = ucfirst( __CLASS__ );
 563                 if ( $type === 'array' )
 564                         $in = print_r( $in, true );
 565
 566                 if ( $action === true )
 567                         wfDebugLog( $this->log, "$class::$fname: accepted: '$in' (type: $type)\n");
 568                 elseif ( $action === false )
 569                         wfDebugLog( $this->log, "$class::$fname: rejected: '$in' (type: $type)\n");
 570                 elseif ( $action === null )
 571                         wfDebugLog( $this->log, "$class::$fname: input was: '$in' (type: $type)\n");
 572                 else
 573                         wfDebugLog( $this->log, "$class::$fname: $action (type: $type; content: '$in')\n");
 574         }
 575
 576         /**
 577          * Conviniance function for debugging output
 578          *
 579          * @private
 580          *
 581          * @param $fname String: the name of the function calling this function
 582          * @param $io Boolean: Specify whether we're beginning or ending
 583          */
 584         function debugFile( $fname, $io ) {
 585                 $class = ucfirst( __CLASS__ );
 586                 if ( $io ) {
 587                         wfDebugLog( $this->log, "$class::$fname: begin processing: '{$this->basename}'\n" );
 588                 } else {
 589                         wfDebugLog( $this->log, "$class::$fname: end processing: '{$this->basename}'\n" );
 590                 }
 591         }
 592
 593 }
 594
 595 /**
 596  * @package MediaWiki
 597  * @subpackage Metadata
 598  */
 599 class FormatExif {
 600         /**
 601          * The Exif data to format
 602          *
 603          * @var array
 604          * @private
 605          */
 606         var $mExif;
 607
 608         /**
 609          * Constructor
 610          *
 611          * @param $exif Array: the Exif data to format ( as returned by
 612          *                    Exif::getFilteredData() )
 613          */
 614         function FormatExif( $exif ) {
 615                 $this->mExif = $exif;
 616         }
 617
 618         /**
 619          * Numbers given by Exif user agents are often magical, that is they
 620          * should be replaced by a detailed explanation depending on their
 621          * value which most of the time are plain integers. This function
 622          * formats Exif values into human readable form.
 623          *
 624          * @return array
 625          */
 626         function getFormattedData() {
 627                 global $wgLang;
 628
 629                 $tags =& $this->mExif;
 630
 631                 $resolutionunit = !isset( $tags['ResolutionUnit'] ) || $tags['ResolutionUnit'] == 2 ? 2 : 3;
 632                 unset( $tags['ResolutionUnit'] );
 633
 634                 foreach( $tags as $tag => $val ) {
 635                         switch( $tag ) {
 636                         case 'Compression':
 637                                 switch( $val ) {
 638                                 case 1: case 6:
 639                                         $tags[$tag] = $this->msg( $tag, $val );
 640                                         break;
 641                                 default:
 642                                         $tags[$tag] = $val;
 643                                         break;
 644                                 }
 645                                 break;
 646
 647                         case 'PhotometricInterpretation':
 648                                 switch( $val ) {
 649                                 case 2: case 6:
 650                                         $tags[$tag] = $this->msg( $tag, $val );
 651                                         break;
 652                                 default:
 653                                         $tags[$tag] = $val;
 654                                         break;
 655                                 }
 656                                 break;
 657
 658                         case 'Orientation':
 659                                 switch( $val ) {
 660                                 case 1: case 2: case 3: case 4: case 5: case 6: case 7: case 8:
 661                                         $tags[$tag] = $this->msg( $tag, $val );
 662                                         break;
 663                                 default:
 664                                         $tags[$tag] = $val;
 665                                         break;
 666                                 }
 667                                 break;
 668
 669                         case 'PlanarConfiguration':
 670                                 switch( $val ) {
 671                                 case 1: case 2:
 672                                         $tags[$tag] = $this->msg( $tag, $val );
 673                                         break;
 674                                 default:
 675                                         $tags[$tag] = $val;
 676                                         break;
 677                                 }
 678                                 break;
 679
 680                         // TODO: YCbCrSubSampling
 681                         // TODO: YCbCrPositioning
 682
 683                         case 'XResolution':
 684                         case 'YResolution':
 685                                 switch( $resolutionunit ) {
 686                                         case 2:
 687                                                 $tags[$tag] = $this->msg( 'XYResolution', 'i', $this->formatNum( $val ) );
 688                                                 break;
 689                                         case 3:
 690                                                 $this->msg( 'XYResolution', 'c', $this->formatNum( $val ) );
 691                                                 break;
 692                                         default:
 693                                                 $tags[$tag] = $val;
 694                                                 break;
 695                                 }
 696                                 break;
 697
 698                         // TODO: YCbCrCoefficients  #p27 (see annex E)
 699                         case 'ExifVersion': case 'FlashpixVersion':
 700                                 $tags[$tag] = "$val"/100;
 701                                 break;
 702
 703                         case 'ColorSpace':
 704                                 switch( $val ) {
 705                                 case 1: case 'FFFF.H':
 706                                         $tags[$tag] = $this->msg( $tag, $val );
 707                                         break;
 708                                 default:
 709                                         $tags[$tag] = $val;
 710                                         break;
 711                                 }
 712                                 break;
 713
 714                         case 'ComponentsConfiguration':
 715                                 switch( $val ) {
 716                                 case 0: case 1: case 2: case 3: case 4: case 5: case 6:
 717                                         $tags[$tag] = $this->msg( $tag, $val );
 718                                         break;
 719                                 default:
 720                                         $tags[$tag] = $val;
 721                                         break;
 722                                 }
 723                                 break;
 724
 725                         case 'DateTime':
 726                         case 'DateTimeOriginal':
 727                         case 'DateTimeDigitized':
 728                                 if( preg_match( "/^(\d{4}):(\d\d):(\d\d) (\d\d):(\d\d):(\d\d)$/", $val ) ) {
 729                                         $tags[$tag] = $wgLang->timeanddate( wfTimestamp(TS_MW, $val) );
 730                                 }
 731                                 break;
 732
 733                         case 'ExposureProgram':
 734                                 switch( $val ) {
 735                                 case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7: case 8:
 736                                         $tags[$tag] = $this->msg( $tag, $val );
 737                                         break;
 738                                 default:
 739                                         $tags[$tag] = $val;
 740                                         break;
 741                                 }
 742                                 break;
 743
 744                         case 'SubjectDistance':
 745                                 $tags[$tag] = $this->msg( $tag, '', $this->formatNum( $val ) );
 746                                 break;
 747
 748                         case 'MeteringMode':
 749                                 switch( $val ) {
 750                                 case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7: case 255:
 751                                         $tags[$tag] = $this->msg( $tag, $val );
 752                                         break;
 753                                 default:
 754                                         $tags[$tag] = $val;
 755                                         break;
 756                                 }
 757                                 break;
 758
 759                         case 'LightSource':
 760                                 switch( $val ) {
 761                                 case 0: case 1: case 2: case 3: case 4: case 9: case 10: case 11:
 762                                 case 12: case 13: case 14: case 15: case 17: case 18: case 19: case 20:
 763                                 case 21: case 22: case 23: case 24: case 255:
 764                                         $tags[$tag] = $this->msg( $tag, $val );
 765                                         break;
 766                                 default:
 767                                         $tags[$tag] = $val;
 768                                         break;
 769                                 }
 770                                 break;
 771
 772                         // TODO: Flash
 773                         case 'FocalPlaneResolutionUnit':
 774                                 switch( $val ) {
 775                                 case 2:
 776                                         $tags[$tag] = $this->msg( $tag, $val );
 777                                         break;
 778                                 default:
 779                                         $tags[$tag] = $val;
 780                                         break;
 781                                 }
 782                                 break;
 783
 784                         case 'SensingMethod':
 785                                 switch( $val ) {
 786                                 case 1: case 2: case 3: case 4: case 5: case 7: case 8:
 787                                         $tags[$tag] = $this->msg( $tag, $val );
 788                                         break;
 789                                 default:
 790                                         $tags[$tag] = $val;
 791                                         break;
 792                                 }
 793                                 break;
 794
 795                         case 'FileSource':
 796                                 switch( $val ) {
 797                                 case 3:
 798                                         $tags[$tag] = $this->msg( $tag, $val );
 799                                         break;
 800                                 default:
 801                                         $tags[$tag] = $val;
 802                                         break;
 803                                 }
 804                                 break;
 805
 806                         case 'SceneType':
 807                                 switch( $val ) {
 808                                 case 1:
 809                                         $tags[$tag] = $this->msg( $tag, $val );
 810                                         break;
 811                                 default:
 812                                         $tags[$tag] = $val;
 813                                         break;
 814                                 }
 815                                 break;
 816
 817                         case 'CustomRendered':
 818                                 switch( $val ) {
 819                                 case 0: case 1:
 820                                         $tags[$tag] = $this->msg( $tag, $val );
 821                                         break;
 822                                 default:
 823                                         $tags[$tag] = $val;
 824                                         break;
 825                                 }
 826                                 break;
 827
 828                         case 'ExposureMode':
 829                                 switch( $val ) {
 830                                 case 0: case 1: case 2:
 831                                         $tags[$tag] = $this->msg( $tag, $val );
 832                                         break;
 833                                 default:
 834                                         $tags[$tag] = $val;
 835                                         break;
 836                                 }
 837                                 break;
 838
 839                         case 'WhiteBalance':
 840                                 switch( $val ) {
 841                                 case 0: case 1:
 842                                         $tags[$tag] = $this->msg( $tag, $val );
 843                                         break;
 844                                 default:
 845                                         $tags[$tag] = $val;
 846                                         break;
 847                                 }
 848                                 break;
 849
 850                         case 'SceneCaptureType':
 851                                 switch( $val ) {
 852                                 case 0: case 1: case 2: case 3:
 853                                         $tags[$tag] = $this->msg( $tag, $val );
 854                                         break;
 855                                 default:
 856                                         $tags[$tag] = $val;
 857                                         break;
 858                                 }
 859                                 break;
 860
 861                         case 'GainControl':
 862                                 switch( $val ) {
 863                                 case 0: case 1: case 2: case 3: case 4:
 864                                         $tags[$tag] = $this->msg( $tag, $val );
 865                                         break;
 866                                 default:
 867                                         $tags[$tag] = $val;
 868                                         break;
 869                                 }
 870                                 break;
 871
 872                         case 'Contrast':
 873                                 switch( $val ) {
 874                                 case 0: case 1: case 2:
 875                                         $tags[$tag] = $this->msg( $tag, $val );
 876                                         break;
 877                                 default:
 878                                         $tags[$tag] = $val;
 879                                         break;
 880                                 }
 881                                 break;
 882
 883                         case 'Saturation':
 884                                 switch( $val ) {
 885                                 case 0: case 1: case 2:
 886                                         $tags[$tag] = $this->msg( $tag, $val );
 887                                         break;
 888                                 default:
 889                                         $tags[$tag] = $val;
 890                                         break;
 891                                 }
 892                                 break;
 893
 894                         case 'Sharpness':
 895                                 switch( $val ) {
 896                                 case 0: case 1: case 2:
 897                                         $tags[$tag] = $this->msg( $tag, $val );
 898                                         break;
 899                                 default:
 900                                         $tags[$tag] = $val;
 901                                         break;
 902                                 }
 903                                 break;
 904
 905                         case 'SubjectDistanceRange':
 906                                 switch( $val ) {
 907                                 case 0: case 1: case 2: case 3:
 908                                         $tags[$tag] = $this->msg( $tag, $val );
 909                                         break;
 910                                 default:
 911                                         $tags[$tag] = $val;
 912                                         break;
 913                                 }
 914                                 break;
 915
 916                         case 'GPSLatitudeRef':
 917                         case 'GPSDestLatitudeRef':
 918                                 switch( $val ) {
 919                                 case 'N': case 'S':
 920                                         $tags[$tag] = $this->msg( 'GPSLatitude', $val );
 921                                         break;
 922                                 default:
 923                                         $tags[$tag] = $val;
 924                                         break;
 925                                 }
 926                                 break;
 927
 928                         case 'GPSLongitudeRef':
 929                         case 'GPSDestLongitudeRef':
 930                                 switch( $val ) {
 931                                 case 'E': case 'W':
 932                                         $tags[$tag] = $this->msg( 'GPSLongitude', $val );
 933                                         break;
 934                                 default:
 935                                         $tags[$tag] = $val;
 936                                         break;
 937                                 }
 938                                 break;
 939
 940                         case 'GPSStatus':
 941                                 switch( $val ) {
 942                                 case 'A': case 'V':
 943                                         $tags[$tag] = $this->msg( $tag, $val );
 944                                         break;
 945                                 default:
 946                                         $tags[$tag] = $val;
 947                                         break;
 948                                 }
 949                                 break;
 950
 951                         case 'GPSMeasureMode':
 952                                 switch( $val ) {
 953                                 case 2: case 3:
 954                                         $tags[$tag] = $this->msg( $tag, $val );
 955                                         break;
 956                                 default:
 957                                         $tags[$tag] = $val;
 958                                         break;
 959                                 }
 960                                 break;
 961
 962                         case 'GPSSpeedRef':
 963                         case 'GPSDestDistanceRef':
 964                                 switch( $val ) {
 965                                 case 'K': case 'M': case 'N':
 966                                         $tags[$tag] = $this->msg( 'GPSSpeed', $val );
 967                                         break;
 968                                 default:
 969                                         $tags[$tag] = $val;
 970                                         break;
 971                                 }
 972                                 break;
 973
 974                         case 'GPSTrackRef':
 975                         case 'GPSImgDirectionRef':
 976                         case 'GPSDestBearingRef':
 977                                 switch( $val ) {
 978                                 case 'T': case 'M':
 979                                         $tags[$tag] = $this->msg( 'GPSDirection', $val );
 980                                         break;
 981                                 default:
 982                                         $tags[$tag] = $val;
 983                                         break;
 984                                 }
 985                                 break;
 986
 987                         case 'GPSDateStamp':
 988                                 $tags[$tag] = $wgLang->date( substr( $val, 0, 4 ) . substr( $val, 5, 2 ) . substr( $val, 8, 2 ) . '000000' );
 989                                 break;
 990
 991                         // This is not in the Exif standard, just a special
 992                         // case for our purposes which enables wikis to wikify
 993                         // the make, model and software name to link to their articles.
 994                         case 'Make':
 995                         case 'Model':
 996                         case 'Software':
 997                                 $tags[$tag] = $this->msg( $tag, '', $val );
 998                                 break;
 999
1000                         case 'ExposureTime':
1001                                 // Show the pretty fraction as well as decimal version
1002                                 $tags[$tag] = wfMsg( 'exif-exposuretime-format',
1003                                         $this->formatFraction( $val ), $this->formatNum( $val ) );
1004                                 break;
1005
1006                         case 'FNumber':
1007                                 $tags[$tag] = wfMsg( 'exif-fnumber-format',
1008                                         $this->formatNum( $val ) );
1009                                 break;
1010
1011                         case 'FocalLength':
1012                                 $tags[$tag] = wfMsg( 'exif-focallength-format',
1013                                         $this->formatNum( $val ) );
1014                                 break;
1015
1016                         default:
1017                                 $tags[$tag] = $this->formatNum( $val );
1018                                 break;
1019                         }
1020                 }
1021
1022                 return $tags;
1023         }
1024
1025         /**
1026          * Conviniance function for getFormattedData()
1027          *
1028          * @private
1029          *
1030          * @param $tag String: the tag name to pass on
1031          * @param $val String: the value of the tag
1032          * @param $arg String: an argument to pass ($1)
1033          * @return string A wfMsg of "exif-$tag-$val" in lower case
1034          */
1035         function msg( $tag, $val, $arg = null ) {
1036                 global $wgContLang;
1037
1038                 if ($val === '')
1039                         $val = 'value';
1040                 return wfMsg( $wgContLang->lc( "exif-$tag-$val" ), $arg );
1041         }
1042
1043         /**
1044          * Format a number, convert numbers from fractions into floating point
1045          * numbers
1046          *
1047          * @private
1048          *
1049          * @param $num Mixed: the value to format
1050          * @return mixed A floating point number or whatever we were fed
1051          */
1052         function formatNum( $num ) {
1053                 if ( preg_match( '/^(\d+)\/(\d+)$/', $num, $m ) )
1054                         return $m[2] != 0 ? $m[1] / $m[2] : $num;
1055                 else
1056                         return $num;
1057         }
1058
1059         /**
1060          * Format a rational number, reducing fractions
1061          *
1062          * @private
1063          *
1064          * @param $num Mixed: the value to format
1065          * @return mixed A floating point number or whatever we were fed
1066          */
1067         function formatFraction( $num ) {
1068                 if ( preg_match( '/^(\d+)\/(\d+)$/', $num, $m ) ) {
1069                         $numerator = intval( $m[1] );
1070                         $denominator = intval( $m[2] );
1071                         $gcd = $this->gcd( $numerator, $denominator );
1072                         if( $gcd != 0 ) {
1073                                 // 0 shouldn't happen! ;)
1074                                 return $numerator / $gcd . '/' . $denominator / $gcd;
1075                         }
1076                 }
1077                 return $this->formatNum( $num );
1078         }
1079
1080         /**
1081          * Calculate the greatest common divisor of two integers.
1082          *
1083          * @param $a Integer: FIXME
1084          * @param $b Integer: FIXME
1085          * @return int
1086          * @private
1087          */
1088         function gcd( $a, $b ) {
1089                 /*
1090                         // http://en.wikipedia.org/wiki/Euclidean_algorithm
1091                         // Recursive form would be:
1092                         if( $b == 0 )
1093                                 return $a;
1094                         else
1095                                 return gcd( $b, $a % $b );
1096                 */
1097                 while( $b != 0 ) {
1098                         $remainder = $a % $b;
1099
1100                         // tail recursion...
1101                         $a = $b;
1102                         $b = $remainder;
1103                 }
1104                 return $a;
1105         }
1106 }
1107 ?>