includes/Exif.php

   1 <?php
   2 if ( !defined( 'MEDIAWIKI' ) ) die();
   3 /**
   4  * @package MediaWiki
   5  * @subpackage Metadata
   6  *
   7  * @author Ævar Arnfjörð Bjarmason <avarab@gmail.com>
   8  * @copyright Copyright © 2005, Ævar Arnfjörð Bjarmason
   9  * @license http://www.gnu.org/copyleft/gpl.html GNU General Public License
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License along
  22  * with this program; if not, write to the Free Software Foundation, Inc.,
  23  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  24  * http://www.gnu.org/copyleft/gpl.html
  25  *
  26  * @link http://exif.org/Exif2-2.PDF The Exif 2.2 specification
  27  * @bug 1555, 1947
  28  */
  29
  30 /**#@+
  31  * Exif tag type definition
  32  */
  33 define('MW_EXIF_BYTE', 1);              # An 8-bit (1-byte) unsigned integer.
  34 define('MW_EXIF_ASCII', 2);             # An 8-bit byte containing one 7-bit ASCII code. The final byte is terminated with NULL.
  35 define('MW_EXIF_SHORT', 3);             # A 16-bit (2-byte) unsigned integer.
  36 define('MW_EXIF_LONG', 4);              # A 32-bit (4-byte) unsigned integer.
  37 define('MW_EXIF_RATIONAL', 5);          # Two LONGs. The first LONG is the numerator and the second LONG expresses the denominator
  38 define('MW_EXIF_UNDEFINED', 7);         # An 8-bit byte that can take any value depending on the field definition
  39 define('MW_EXIF_SLONG', 9);             # A 32-bit (4-byte) signed integer (2's complement notation),
  40 define('MW_EXIF_SRATIONAL', 10);        # Two SLONGs. The first SLONG is the numerator and the second SLONG is the denominator.
  41 /**#@-*/
  42
  43
  44 /**
  45  * @package MediaWiki
  46  * @subpackage Metadata
  47  */
  48 class Exif {
  49         /**#@+
  50          * @var array
  51          * @access private
  52          */
  53
  54         /**
  55          * Exif tags grouped by category, the tagname itself is the key and the type
  56          * is the value, in the case of more than one possible value type they are
  57          * seperated by commas.
  58          */
  59         var $mExifTags;
  60
  61         /**
  62          * A one dimentional array of all Exif tags
  63          */
  64         var $mFlatExifTags;
  65
  66         /**
  67          * The raw Exif data returned by exif_read_data()
  68          */
  69         var $mRawExifData;
  70
  71         /**
  72          * A Filtered version of $mRawExifData that has been pruned of invalid
  73          * tags and tags that contain content they shouldn't contain according
  74          * to the Exif specification
  75          */
  76         var $mFilteredExifData;
  77
  78         /**
  79          * Filtered and formatted Exif data, see FormatExif::getFormattedData()
  80          */
  81         var $mFormattedExifData;
  82
  83         /**#@-*/
  84
  85         /**#@+
  86          * @var string
  87          * @access private
  88          */
  89
  90         /**
  91          * The file being processed
  92          */
  93         var $file;
  94
  95         /**
  96          * The basename of the file being processed
  97          */
  98         var $basename;
  99
 100         /**
 101          * The private log to log to
 102          */
 103         var $log = 'exif';
 104
 105         /**#@-*/
 106
 107         /**
 108          * Constructor
 109          *
 110          * @param string $file
 111          */
 112         function Exif( $file ) {
 113                 /**
 114                  * Page numbers here refer to pages in the EXIF 2.2 standard
 115                  *
 116                  * @link http://exif.org/Exif2-2.PDF The Exif 2.2 specification
 117                  */
 118                 $this->mExifTags = array(
 119                         # TIFF Rev. 6.0 Attribute Information (p22)
 120                         'tiff' => array(
 121                                 # Tags relating to image structure
 122                                 'structure' => array(
 123                                         'ImageWidth' => MW_EXIF_SHORT.','.MW_EXIF_LONG,         # Image width
 124                                         'ImageLength' => MW_EXIF_SHORT.','.MW_EXIF_LONG,        # Image height
 125                                         'BitsPerSample' => MW_EXIF_SHORT,                       # Number of bits per component
 126                                         # "When a primary image is JPEG compressed, this designation is not"
 127                                         # "necessary and is omitted." (p23)
 128                                         'Compression' => MW_EXIF_SHORT,                         # Compression scheme #p23
 129                                         'PhotometricInterpretation' => MW_EXIF_SHORT,           # Pixel composition #p23
 130                                         'Orientation' => MW_EXIF_SHORT,                         # Orientation of image #p24
 131                                         'SamplesPerPixel' => MW_EXIF_SHORT,                     # Number of components
 132                                         'PlanarConfiguration' => MW_EXIF_SHORT,                 # Image data arrangement #p24
 133                                         'YCbCrSubSampling' => MW_EXIF_SHORT,                    # Subsampling ratio of Y to C #p24
 134                                         'YCbCrPositioning' => MW_EXIF_SHORT,                    # Y and C positioning #p24-25
 135                                         'XResolution' => MW_EXIF_RATIONAL,                      # Image resolution in width direction
 136                                         'YResolution' => MW_EXIF_RATIONAL,                      # Image resolution in height direction
 137                                         'ResolutionUnit' => MW_EXIF_SHORT,                      # Unit of X and Y resolution #(p26)
 138                                 ),
 139
 140                                 # Tags relating to recording offset
 141                                 'offset' => array(
 142                                         'StripOffsets' => MW_EXIF_SHORT.','.MW_EXIF_LONG,                       # Image data location
 143                                         'RowsPerStrip' => MW_EXIF_SHORT.','.MW_EXIF_LONG,                       # Number of rows per strip
 144                                         'StripByteCounts' => MW_EXIF_SHORT.','.MW_EXIF_LONG,                    # Bytes per compressed strip
 145                                         'JPEGInterchangeFormat' => MW_EXIF_SHORT.','.MW_EXIF_LONG,              # Offset to JPEG SOI
 146                                         'JPEGInterchangeFormatLength' => MW_EXIF_SHORT.','.MW_EXIF_LONG,        # Bytes of JPEG data
 147                                 ),
 148
 149                                 # Tags relating to image data characteristics
 150                                 'characteristics' => array(
 151                                         'TransferFunction' => MW_EXIF_SHORT,            # Transfer function
 152                                         'WhitePoint' => MW_EXIF_RATIONAL,               # White point chromaticity
 153                                         'PrimaryChromaticities' => MW_EXIF_RATIONAL,    # Chromaticities of primarities
 154                                         'YCbCrCoefficients' => MW_EXIF_RATIONAL,        # Color space transformation matrix coefficients #p27
 155                                         'ReferenceBlackWhite' => MW_EXIF_RATIONAL       # Pair of black and white reference values
 156                                 ),
 157
 158                                 # Other tags
 159                                 'other' => array(
 160                                         'DateTime' => MW_EXIF_ASCII,            # File change date and time
 161                                         'ImageDescription' => MW_EXIF_ASCII,    # Image title
 162                                         'Make' => MW_EXIF_ASCII,                # Image input equipment manufacturer
 163                                         'Model' => MW_EXIF_ASCII,               # Image input equipment model
 164                                         'Software' => MW_EXIF_ASCII,            # Software used
 165                                         'Artist' => MW_EXIF_ASCII,              # Person who created the image
 166                                         'Copyright' => MW_EXIF_ASCII,           # Copyright holder
 167                                 ),
 168                         ),
 169
 170                         # Exif IFD Attribute Information (p30-31)
 171                         'exif' => array(
 172                                 # Tags relating to version
 173                                 'version' => array(
 174                                         # TODO: NOTE: Nonexistence of this field is taken to mean nonconformance
 175                                         # to the EXIF 2.1 AND 2.2 standards
 176                                         'ExifVersion' => MW_EXIF_UNDEFINED,     # Exif version
 177                                         'FlashpixVersion' => MW_EXIF_UNDEFINED, # Supported Flashpix version #p32
 178                                 ),
 179
 180                                 # Tags relating to Image Data Characteristics
 181                                 'characteristics' => array(
 182                                         'ColorSpace' => MW_EXIF_SHORT,          # Color space information #p32
 183                                 ),
 184
 185                                 # Tags relating to image configuration
 186                                 'configuration' => array(
 187                                         'ComponentsConfiguration' => MW_EXIF_UNDEFINED,         # Meaning of each component #p33
 188                                         'CompressedBitsPerPixel' => MW_EXIF_RATIONAL,           # Image compression mode
 189                                         'PixelYDimension' => MW_EXIF_SHORT.','.MW_EXIF_LONG,    # Valid image width
 190                                         'PixelXDimension' => MW_EXIF_SHORT.','.MW_EXIF_LONG,    # Valind image height
 191                                 ),
 192
 193                                 # Tags relating to related user information
 194                                 'user' => array(
 195                                         'MakerNote' => MW_EXIF_UNDEFINED,                       # Manufacturer notes
 196                                         'UserComment' => MW_EXIF_UNDEFINED,                     # User comments #p34
 197                                 ),
 198
 199                                 # Tags relating to related file information
 200                                 'related' => array(
 201                                         'RelatedSoundFile' => MW_EXIF_ASCII,                    # Related audio file
 202                                 ),
 203
 204                                 # Tags relating to date and time
 205                                 'dateandtime' => array(
 206                                         'DateTimeOriginal' => MW_EXIF_ASCII,                    # Date and time of original data generation #p36
 207                                         'DateTimeDigitized' => MW_EXIF_ASCII,                   # Date and time of original data generation
 208                                         'SubSecTime' => MW_EXIF_ASCII,                          # DateTime subseconds
 209                                         'SubSecTimeOriginal' => MW_EXIF_ASCII,                  # DateTimeOriginal subseconds
 210                                         'SubSecTimeDigitized' => MW_EXIF_ASCII,                 # DateTimeDigitized subseconds
 211                                 ),
 212
 213                                 # Tags relating to picture-taking conditions (p31)
 214                                 'conditions' => array(
 215                                         'ExposureTime' => MW_EXIF_RATIONAL,                     # Exposure time
 216                                         'FNumber' => MW_EXIF_RATIONAL,                          # F Number
 217                                         'ExposureProgram' => MW_EXIF_SHORT,                     # Exposure Program #p38
 218                                         'SpectralSensitivity' => MW_EXIF_ASCII,                 # Spectral sensitivity
 219                                         'ISOSpeedRatings' => MW_EXIF_SHORT,                     # ISO speed rating
 220                                         'OECF' => MW_EXIF_UNDEFINED,                            # Optoelectronic conversion factor
 221                                         'ShutterSpeedValue' => MW_EXIF_SRATIONAL,               # Shutter speed
 222                                         'ApertureValue' => MW_EXIF_RATIONAL,                    # Aperture
 223                                         'BrightnessValue' => MW_EXIF_SRATIONAL,                 # Brightness
 224                                         'ExposureBiasValue' => MW_EXIF_SRATIONAL,               # Exposure bias
 225                                         'MaxApertureValue' => MW_EXIF_RATIONAL,                 # Maximum land aperture
 226                                         'SubjectDistance' => MW_EXIF_RATIONAL,                  # Subject distance
 227                                         'MeteringMode' => MW_EXIF_SHORT,                        # Metering mode #p40
 228                                         'LightSource' => MW_EXIF_SHORT,                         # Light source #p40-41
 229                                         'Flash' => MW_EXIF_SHORT,                               # Flash #p41-42
 230                                         'FocalLength' => MW_EXIF_RATIONAL,                      # Lens focal length
 231                                         'SubjectArea' => MW_EXIF_SHORT,                         # Subject area
 232                                         'FlashEnergy' => MW_EXIF_RATIONAL,                      # Flash energy
 233                                         'SpatialFrequencyResponse' => MW_EXIF_UNDEFINED,        # Spatial frequency response
 234                                         'FocalPlaneXResolution' => MW_EXIF_RATIONAL,            # Focal plane X resolution
 235                                         'FocalPlaneYResolution' => MW_EXIF_RATIONAL,            # Focal plane Y resolution
 236                                         'FocalPlaneResolutionUnit' => MW_EXIF_SHORT,            # Focal plane resolution unit #p46
 237                                         'SubjectLocation' => MW_EXIF_SHORT,                     # Subject location
 238                                         'ExposureIndex' => MW_EXIF_RATIONAL,                    # Exposure index
 239                                         'SensingMethod' => MW_EXIF_SHORT,                       # Sensing method #p46
 240                                         'FileSource' => MW_EXIF_UNDEFINED,                      # File source #p47
 241                                         'SceneType' => MW_EXIF_UNDEFINED,                       # Scene type #p47
 242                                         'CFAPattern' => MW_EXIF_UNDEFINED,                      # CFA pattern
 243                                         'CustomRendered' => MW_EXIF_SHORT,                      # Custom image processing #p48
 244                                         'ExposureMode' => MW_EXIF_SHORT,                        # Exposure mode #p48
 245                                         'WhiteBalance' => MW_EXIF_SHORT,                        # White Balance #p49
 246                                         'DigitalZoomRatio' => MW_EXIF_RATIONAL,                 # Digital zoom ration
 247                                         'FocalLengthIn35mmFilm' => MW_EXIF_SHORT,               # Focal length in 35 mm film
 248                                         'SceneCaptureType' => MW_EXIF_SHORT,                    # Scene capture type #p49
 249                                         'GainControl' => MW_EXIF_RATIONAL,                      # Scene control #p49-50
 250                                         'Contrast' => MW_EXIF_SHORT,                            # Contrast #p50
 251                                         'Saturation' => MW_EXIF_SHORT,                          # Saturation #p50
 252                                         'Sharpness' => MW_EXIF_SHORT,                           # Sharpness #p50
 253                                         'DeviceSettingDescription' => MW_EXIF_UNDEFINED,        # Desice settings description
 254                                         'SubjectDistanceRange' => MW_EXIF_SHORT,                # Subject distance range #p51
 255                                 ),
 256
 257                                 'other' => array(
 258                                         'ImageUniqueID' => MW_EXIF_ASCII,       # Unique image ID
 259                                 ),
 260                         ),
 261
 262                         # GPS Attribute Information (p52)
 263                         'gps' => array(
 264                                 'GPSVersionID' => MW_EXIF_BYTE,                 # GPS tag version
 265                                 'GPSLatitudeRef' => MW_EXIF_ASCII,              # North or South Latitude #p52-53
 266                                 'GPSLatitude' => MW_EXIF_RATIONAL,              # Latitude
 267                                 'GPSLongitudeRef' => MW_EXIF_ASCII,             # East or West Longitude #p53
 268                                 'GPSLongitude' => MW_EXIF_RATIONAL,             # Longitude
 269                                 'GPSAltitudeRef' => MW_EXIF_BYTE,               # Altitude reference
 270                                 'GPSAltitude' => MW_EXIF_RATIONAL,              # Altitude
 271                                 'GPSTimeStamp' => MW_EXIF_RATIONAL,             # GPS time (atomic clock)
 272                                 'GPSSatellites' => MW_EXIF_ASCII,               # Satellites used for measurement
 273                                 'GPSStatus' => MW_EXIF_ASCII,                   # Receiver status #p54
 274                                 'GPSMeasureMode' => MW_EXIF_ASCII,              # Measurement mode #p54-55
 275                                 'GPSDOP' => MW_EXIF_RATIONAL,                   # Measurement precision
 276                                 'GPSSpeedRef' => MW_EXIF_ASCII,                 # Speed unit #p55
 277                                 'GPSSpeed' => MW_EXIF_RATIONAL,                 # Speed of GPS receiver
 278                                 'GPSTrackRef' => MW_EXIF_ASCII,                 # Reference for direction of movement #p55
 279                                 'GPSTrack' => MW_EXIF_RATIONAL,                 # Direction of movement
 280                                 'GPSImgDirectionRef' => MW_EXIF_ASCII,          # Reference for direction of image #p56
 281                                 'GPSImgDirection' => MW_EXIF_RATIONAL,          # Direction of image
 282                                 'GPSMapDatum' => MW_EXIF_ASCII,                 # Geodetic survey data used
 283                                 'GPSDestLatitudeRef' => MW_EXIF_ASCII,          # Reference for latitude of destination #p56
 284                                 'GPSDestLatitude' => MW_EXIF_RATIONAL,          # Latitude destination
 285                                 'GPSDestLongitudeRef' => MW_EXIF_ASCII,         # Reference for longitude of destination #p57
 286                                 'GPSDestLongitude' => MW_EXIF_RATIONAL,         # Longitude of destination
 287                                 'GPSDestBearingRef' => MW_EXIF_ASCII,           # Reference for bearing of destination #p57
 288                                 'GPSDestBearing' => MW_EXIF_RATIONAL,           # Bearing of destination
 289                                 'GPSDestDistanceRef' => MW_EXIF_ASCII,          # Reference for distance to destination #p57-58
 290                                 'GPSDestDistance' => MW_EXIF_RATIONAL,          # Distance to destination
 291                                 'GPSProcessingMethod' => MW_EXIF_UNDEFINED,     # Name of GPS processing method
 292                                 'GPSAreaInformation' => MW_EXIF_UNDEFINED,      # Name of GPS area
 293                                 'GPSDateStamp' => MW_EXIF_ASCII,                # GPS date
 294                                 'GPSDifferential' => MW_EXIF_SHORT,             # GPS differential correction
 295                         ),
 296                 );
 297
 298                 $this->file = $file;
 299                 $this->basename = basename( $this->file );
 300
 301                 $this->makeFlatExifTags();
 302
 303                 $this->debugFile( $this->basename, __FUNCTION__, true );
 304                 wfSuppressWarnings();
 305                 $data = exif_read_data( $this->file );
 306                 wfRestoreWarnings();
 307                 /**
 308                  * exif_read_data() will return false on invalid input, such as
 309                  * when somebody uploads a file called something.jpeg
 310                  * containing random gibberish.
 311                  */
 312                 $this->mRawExifData = $data ? $data : array();
 313
 314                 $this->makeFilteredData();
 315                 $this->makeFormattedData();
 316
 317                 $this->debugFile( __FUNCTION__, false );
 318         }
 319
 320         /**#@+
 321          * @access private
 322          */
 323         /**
 324          * Generate a flat list of the exif tags
 325          */
 326         function makeFlatExifTags() {
 327                 $this->extractTags( $this->mExifTags );
 328         }
 329
 330         /**
 331          * A recursing extractor function used by makeFlatExifTags()
 332          *
 333          * Note: This used to use an array_walk function, but it made PHP5
 334          * segfault, see `cvs diff -u -r 1.4 -r 1.5 Exif.php`
 335          */
 336         function extractTags( &$tagset ) {
 337                 foreach( $tagset as $key => $val ) {
 338                         if( is_array( $val ) ) {
 339                                 $this->extractTags( $val );
 340                         } else {
 341                                 $this->mFlatExifTags[$key] = $val;
 342                         }
 343                 }
 344         }
 345
 346         /**
 347          * Make $this->mFilteredExifData
 348          */
 349         function makeFilteredData() {
 350                 $this->mFilteredExifData = $this->mRawExifData;
 351
 352                 foreach( $this->mFilteredExifData as $k => $v ) {
 353                         if ( !in_array( $k, array_keys( $this->mFlatExifTags ) ) ) {
 354                                 $this->debug( $v, __FUNCTION__, "'$k' is not a valid Exif tag" );
 355                                 unset( $this->mFilteredExifData[$k] );
 356                         }
 357                 }
 358
 359                 foreach( $this->mFilteredExifData as $k => $v ) {
 360                         if ( !$this->validate($k, $v) ) {
 361                                 $this->debug( $v, __FUNCTION__, "'$k' contained invalid data" );
 362                                 unset( $this->mFilteredExifData[$k] );
 363                         }
 364                 }
 365         }
 366
 367         function makeFormattedData( $data = null ) {
 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          * @access private
 418          *
 419          * @param mixed $in 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          * @access private
 509          *
 510          * @param string $tag The tag to check
 511          * @param mixed  $val 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)MW_EXIF_BYTE:
 519                                 $this->debug( $val, __FUNCTION__, $debug );
 520                                 return $this->isByte( $val );
 521                         case (string)MW_EXIF_ASCII:
 522                                 $this->debug( $val, __FUNCTION__, $debug );
 523                                 return $this->isASCII( $val );
 524                         case (string)MW_EXIF_SHORT:
 525                                 $this->debug( $val, __FUNCTION__, $debug );
 526                                 return $this->isShort( $val );
 527                         case (string)MW_EXIF_LONG:
 528                                 $this->debug( $val, __FUNCTION__, $debug );
 529                                 return $this->isLong( $val );
 530                         case (string)MW_EXIF_RATIONAL:
 531                                 $this->debug( $val, __FUNCTION__, $debug );
 532                                 return $this->isRational( $val );
 533                         case (string)MW_EXIF_UNDEFINED:
 534                                 $this->debug( $val, __FUNCTION__, $debug );
 535                                 return $this->isUndefined( $val );
 536                         case (string)MW_EXIF_SLONG:
 537                                 $this->debug( $val, __FUNCTION__, $debug );
 538                                 return $this->isSlong( $val );
 539                         case (string)MW_EXIF_SRATIONAL:
 540                                 $this->debug( $val, __FUNCTION__, $debug );
 541                                 return $this->isSrational( $val );
 542                         case (string)MW_EXIF_SHORT.','.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          * @access private
 555          *
 556          * @param mixed $in
 557          * @param string $fname
 558          * @param mixed $action
 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          * @access private
 580          *
 581          * @param string $basename The name of the file being processed
 582          * @paran string $fname The name of the function calling this function
 583          * @param bool $bool $io Specify whether we're beginning or ending
 584          */
 585         function debugFile( $fname, $io ) {
 586                 $class = ucfirst( __CLASS__ );
 587                 if ( $io )
 588                         wfDebugLog( $this->log, "$class::$fname: begin processing: '{$this->basename}'\n" );
 589                 else
 590                         wfDebugLog( $this->log, "$class::$fname: end processing: '{$this->basename}'\n" );
 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          * @access private
 605          */
 606         var $mExif;
 607
 608         /**
 609          * Constructor
 610          *
 611          * @param array $exif 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                                 $tags[$tag] = $wgLang->timeanddate( wfTimestamp(TS_MW, $val) );
 729                                 break;
 730
 731                         case 'ExposureProgram':
 732                                 switch( $val ) {
 733                                 case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7: case 8:
 734                                         $tags[$tag] = $this->msg( $tag, $val );
 735                                         break;
 736                                 default:
 737                                         $tags[$tag] = $val;
 738                                         break;
 739                                 }
 740                                 break;
 741
 742                         case 'SubjectDistance':
 743                                 $tags[$tag] = $this->msg( $tag, '', $this->formatNum( $val ) );
 744                                 break;
 745
 746                         case 'MeteringMode':
 747                                 switch( $val ) {
 748                                 case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7: case 255:
 749                                         $tags[$tag] = $this->msg( $tag, $val );
 750                                         break;
 751                                 default:
 752                                         $tags[$tag] = $val;
 753                                         break;
 754                                 }
 755                                 break;
 756
 757                         case 'LightSource':
 758                                 switch( $val ) {
 759                                 case 0: case 1: case 2: case 3: case 4: case 9: case 10: case 11:
 760                                 case 12: case 13: case 14: case 15: case 17: case 18: case 19: case 20:
 761                                 case 21: case 22: case 23: case 24: case 255:
 762                                         $tags[$tag] = $this->msg( $tag, $val );
 763                                         break;
 764                                 default:
 765                                         $tags[$tag] = $val;
 766                                         break;
 767                                 }
 768                                 break;
 769
 770                         // TODO: Flash
 771                         case 'FocalPlaneResolutionUnit':
 772                                 switch( $val ) {
 773                                 case 2:
 774                                         $tags[$tag] = $this->msg( $tag, $val );
 775                                         break;
 776                                 default:
 777                                         $tags[$tag] = $val;
 778                                         break;
 779                                 }
 780                                 break;
 781
 782                         case 'SensingMethod':
 783                                 switch( $val ) {
 784                                 case 1: case 2: case 3: case 4: case 5: case 7: case 8:
 785                                         $tags[$tag] = $this->msg( $tag, $val );
 786                                         break;
 787                                 default:
 788                                         $tags[$tag] = $val;
 789                                         break;
 790                                 }
 791                                 break;
 792
 793                         case 'FileSource':
 794                                 switch( $val ) {
 795                                 case 3:
 796                                         $tags[$tag] = $this->msg( $tag, $val );
 797                                         break;
 798                                 default:
 799                                         $tags[$tag] = $val;
 800                                         break;
 801                                 }
 802                                 break;
 803
 804                         case 'SceneType':
 805                                 switch( $val ) {
 806                                 case 1:
 807                                         $tags[$tag] = $this->msg( $tag, $val );
 808                                         break;
 809                                 default:
 810                                         $tags[$tag] = $val;
 811                                         break;
 812                                 }
 813                                 break;
 814
 815                         case 'CustomRendered':
 816                                 switch( $val ) {
 817                                 case 0: case 1:
 818                                         $tags[$tag] = $this->msg( $tag, $val );
 819                                         break;
 820                                 default:
 821                                         $tags[$tag] = $val;
 822                                         break;
 823                                 }
 824                                 break;
 825
 826                         case 'ExposureMode':
 827                                 switch( $val ) {
 828                                 case 0: case 1: case 2:
 829                                         $tags[$tag] = $this->msg( $tag, $val );
 830                                         break;
 831                                 default:
 832                                         $tags[$tag] = $val;
 833                                         break;
 834                                 }
 835                                 break;
 836
 837                         case 'WhiteBalance':
 838                                 switch( $val ) {
 839                                 case 0: case 1:
 840                                         $tags[$tag] = $this->msg( $tag, $val );
 841                                         break;
 842                                 default:
 843                                         $tags[$tag] = $val;
 844                                         break;
 845                                 }
 846                                 break;
 847
 848                         case 'SceneCaptureType':
 849                                 switch( $val ) {
 850                                 case 0: case 1: case 2: case 3:
 851                                         $tags[$tag] = $this->msg( $tag, $val );
 852                                         break;
 853                                 default:
 854                                         $tags[$tag] = $val;
 855                                         break;
 856                                 }
 857                                 break;
 858
 859                         case 'GainControl':
 860                                 switch( $val ) {
 861                                 case 0: case 1: case 2: case 3: case 4:
 862                                         $tags[$tag] = $this->msg( $tag, $val );
 863                                         break;
 864                                 default:
 865                                         $tags[$tag] = $val;
 866                                         break;
 867                                 }
 868                                 break;
 869
 870                         case 'Contrast':
 871                                 switch( $val ) {
 872                                 case 0: case 1: case 2:
 873                                         $tags[$tag] = $this->msg( $tag, $val );
 874                                         break;
 875                                 default:
 876                                         $tags[$tag] = $val;
 877                                         break;
 878                                 }
 879                                 break;
 880
 881                         case 'Saturation':
 882                                 switch( $val ) {
 883                                 case 0: case 1: case 2:
 884                                         $tags[$tag] = $this->msg( $tag, $val );
 885                                         break;
 886                                 default:
 887                                         $tags[$tag] = $val;
 888                                         break;
 889                                 }
 890                                 break;
 891
 892                         case 'Sharpness':
 893                                 switch( $val ) {
 894                                 case 0: case 1: case 2:
 895                                         $tags[$tag] = $this->msg( $tag, $val );
 896                                         break;
 897                                 default:
 898                                         $tags[$tag] = $val;
 899                                         break;
 900                                 }
 901                                 break;
 902
 903                         case 'SubjectDistanceRange':
 904                                 switch( $val ) {
 905                                 case 0: case 1: case 2: case 3:
 906                                         $tags[$tag] = $this->msg( $tag, $val );
 907                                         break;
 908                                 default:
 909                                         $tags[$tag] = $val;
 910                                         break;
 911                                 }
 912                                 break;
 913
 914                         case 'GPSLatitudeRef':
 915                         case 'GPSDestLatitudeRef':
 916                                 switch( $val ) {
 917                                 case 'N': case 'S':
 918                                         $tags[$tag] = $this->msg( 'GPSLatitude', $val );
 919                                         break;
 920                                 default:
 921                                         $tags[$tag] = $val;
 922                                         break;
 923                                 }
 924                                 break;
 925
 926                         case 'GPSLongitudeRef':
 927                         case 'GPSDestLongitudeRef':
 928                                 switch( $val ) {
 929                                 case 'E': case 'W':
 930                                         $tags[$tag] = $this->msg( 'GPSLongitude', $val );
 931                                         break;
 932                                 default:
 933                                         $tags[$tag] = $val;
 934                                         break;
 935                                 }
 936                                 break;
 937
 938                         case 'GPSStatus':
 939                                 switch( $val ) {
 940                                 case 'A': case 'V':
 941                                         $tags[$tag] = $this->msg( $tag, $val );
 942                                         break;
 943                                 default:
 944                                         $tags[$tag] = $val;
 945                                         break;
 946                                 }
 947                                 break;
 948
 949                         case 'GPSMeasureMode':
 950                                 switch( $val ) {
 951                                 case 2: case 3:
 952                                         $tags[$tag] = $this->msg( $tag, $val );
 953                                         break;
 954                                 default:
 955                                         $tags[$tag] = $val;
 956                                         break;
 957                                 }
 958                                 break;
 959
 960                         case 'GPSSpeedRef':
 961                         case 'GPSDestDistanceRef':
 962                                 switch( $val ) {
 963                                 case 'K': case 'M': case 'N':
 964                                         $tags[$tag] = $this->msg( 'GPSSpeed', $val );
 965                                         break;
 966                                 default:
 967                                         $tags[$tag] = $val;
 968                                         break;
 969                                 }
 970                                 break;
 971
 972                         case 'GPSTrackRef':
 973                         case 'GPSImgDirectionRef':
 974                         case 'GPSDestBearingRef':
 975                                 switch( $val ) {
 976                                 case 'T': case 'M':
 977                                         $tags[$tag] = $this->msg( 'GPSDirection', $val );
 978                                         break;
 979                                 default:
 980                                         $tags[$tag] = $val;
 981                                         break;
 982                                 }
 983                                 break;
 984
 985                         case 'GPSDateStamp':
 986                                 $tags[$tag] = $wgLang->date( substr( $val, 0, 4 ) . substr( $val, 5, 2 ) . substr( $val, 8, 2 ) . '000000' );
 987                                 break;
 988
 989                         // This is not in the Exif standard, just a special
 990                         // case for our purposes which enables wikis to wikify
 991                         // the make, model and software name to link to their articles.
 992                         case 'Make':
 993                         case 'Model':
 994                         case 'Software':
 995                                 $tags[$tag] = $this->msg( $tag, '', $val );
 996                                 break;
 997
 998                         case 'ExposureTime':
 999                                 // Show the pretty fraction as well as decimal version
1000                                 $tags[$tag] = wfMsg( 'exif-exposuretime-format',
1001                                         $val, $this->formatNum( $val ) );
1002                                 break;
1003
1004                         case 'FNumber':
1005                                 $tags[$tag] = wfMsg( 'exif-fnumber-format',
1006                                         $this->formatNum( $val ) );
1007                                 break;
1008
1009                         case 'FocalLength':
1010                                 $tags[$tag] = wfMsg( 'exif-focallength-format',
1011                                         $this->formatNum( $val ) );
1012                                 break;
1013
1014                         default:
1015                                 $tags[$tag] = $this->formatNum( $val );
1016                                 break;
1017                         }
1018                 }
1019
1020                 return $tags;
1021         }
1022
1023         /**
1024          * Conviniance function for getFormattedData()
1025          *
1026          * @access private
1027          *
1028          * @param string $tag The tag name to pass on
1029          * @param string $val The value of the tag
1030          * @param string $arg An argument to pass ($1)
1031          * @return string A wfMsg of "exif-$tag-$val" in lower case
1032          */
1033         function msg( $tag, $val, $arg = null ) {
1034                 global $wgContLang;
1035
1036                 if ($val === '')
1037                         $val = 'value';
1038                 return wfMsg( $wgContLang->lc( "exif-$tag-$val" ), $arg );
1039         }
1040
1041         /**
1042          * Format a number, convert numbers from fractions into floating point
1043          * numbers
1044          *
1045          * @access private
1046          *
1047          * @param mixed $num The value to format
1048          * @return mixed A floating point number or whatever we were fed
1049          */
1050         function formatNum( $num ) {
1051                 if ( preg_match( '/^(\d+)\/(\d+)$/', $num, $m ) )
1052                         return $m[2] != 0 ? $m[1] / $m[2] : $num;
1053                 else
1054                         return $num;
1055         }
1056 }