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 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          * Constructor
  87          *
  88          * @param string $file
  89          */
  90         function Exif( $file ) {
  91                 /**
  92                  * Page numbers here refer to pages in the EXIF 2.2 standard
  93                  *
  94                  * @link http://exif.org/Exif2-2.PDF The Exif 2.2 specification
  95                  */
  96                 $this->mExifTags = array(
  97                         # TIFF Rev. 6.0 Attribute Information (p22)
  98                         'tiff' => array(
  99                                 # Tags relating to image structure
 100                                 'structure' => array(
 101                                         'ImageWidth' => MW_EXIF_SHORT.','.MW_EXIF_LONG,         # Image width
 102                                         'ImageLength' => MW_EXIF_SHORT.','.MW_EXIF_LONG,        # Image height
 103                                         'BitsPerSample' => MW_EXIF_SHORT,                       # Number of bits per component
 104                                         # "When a primary image is JPEG compressed, this designation is not"
 105                                         # "necessary and is omitted." (p23)
 106                                         'Compression' => MW_EXIF_SHORT,                         # Compression scheme #p23
 107                                         'PhotometricInterpretation' => MW_EXIF_SHORT,           # Pixel composition #p23
 108                                         'Orientation' => MW_EXIF_SHORT,                         # Orientation of image #p24
 109                                         'SamplesPerPixel' => MW_EXIF_SHORT,                     # Number of components
 110                                         'PlanarConfiguration' => MW_EXIF_SHORT,                 # Image data arrangement #p24
 111                                         'YCbCrSubSampling' => MW_EXIF_SHORT,                    # Subsampling ratio of Y to C #p24
 112                                         'YCbCrPositioning' => MW_EXIF_SHORT,                    # Y and C positioning #p24-25
 113                                         'XResolution' => MW_EXIF_RATIONAL,                      # Image resolution in width direction
 114                                         'YResolution' => MW_EXIF_RATIONAL,                      # Image resolution in height direction
 115                                         'ResolutionUnit' => MW_EXIF_SHORT,                      # Unit of X and Y resolution #(p26)
 116                                 ),
 117
 118                                 # Tags relating to recording offset
 119                                 'offset' => array(
 120                                         'StripOffsets' => MW_EXIF_SHORT.','.MW_EXIF_LONG,                       # Image data location
 121                                         'RowsPerStrip' => MW_EXIF_SHORT.','.MW_EXIF_LONG,                       # Number of rows per strip
 122                                         'StripByteCounts' => MW_EXIF_SHORT.','.MW_EXIF_LONG,                    # Bytes per compressed strip
 123                                         'JPEGInterchangeFormat' => MW_EXIF_SHORT.','.MW_EXIF_LONG,              # Offset to JPEG SOI
 124                                         'JPEGInterchangeFormatLength' => MW_EXIF_SHORT.','.MW_EXIF_LONG,        # Bytes of JPEG data
 125                                 ),
 126
 127                                 # Tags relating to image data characteristics
 128                                 'characteristics' => array(
 129                                         'TransferFunction' => MW_EXIF_SHORT,            # Transfer function
 130                                         'WhitePoint' => MW_EXIF_RATIONAL,               # White point chromaticity
 131                                         'PrimaryChromaticities' => MW_EXIF_RATIONAL,    # Chromaticities of primarities
 132                                         'YCbCrCoefficients' => MW_EXIF_RATIONAL,        # Color space transformation matrix coefficients #p27
 133                                         'ReferenceBlackWhite' => MW_EXIF_RATIONAL       # Pair of black and white reference values
 134                                 ),
 135
 136                                 # Other tags
 137                                 'other' => array(
 138                                         'DateTime' => MW_EXIF_ASCII,            # File change date and time
 139                                         'ImageDescription' => MW_EXIF_ASCII,    # Image title
 140                                         'Make' => MW_EXIF_ASCII,                # Image input equipment manufacturer
 141                                         'Model' => MW_EXIF_ASCII,               # Image input equipment model
 142                                         'Software' => MW_EXIF_ASCII,            # Software used
 143                                         'Artist' => MW_EXIF_ASCII,              # Person who created the image
 144                                         'Copyright' => MW_EXIF_ASCII,           # Copyright holder
 145                                 ),
 146                         ),
 147
 148                         # Exif IFD Attribute Information (p30-31)
 149                         'exif' => array(
 150                                 # Tags relating to version
 151                                 'version' => array(
 152                                         # TODO: NOTE: Nonexistence of this field is taken to mean nonconformance
 153                                         # to the EXIF 2.1 AND 2.2 standards
 154                                         'ExifVersion' => MW_EXIF_UNDEFINED,     # Exif version
 155                                         'FlashpixVersion' => MW_EXIF_UNDEFINED, # Supported Flashpix version #p32
 156                                 ),
 157
 158                                 # Tags relating to Image Data Characteristics
 159                                 'characteristics' => array(
 160                                         'ColorSpace' => MW_EXIF_SHORT,          # Color space information #p32
 161                                 ),
 162
 163                                 # Tags relating to image configuration
 164                                 'configuration' => array(
 165                                         'ComponentsConfiguration' => MW_EXIF_UNDEFINED,         # Meaning of each component #p33
 166                                         'CompressedBitsPerPixel' => MW_EXIF_RATIONAL,           # Image compression mode
 167                                         'PixelYDimension' => MW_EXIF_SHORT.','.MW_EXIF_LONG,    # Valid image width
 168                                         'PixelXDimension' => MW_EXIF_SHORT.','.MW_EXIF_LONG,    # Valind image height
 169                                 ),
 170
 171                                 # Tags relating to related user information
 172                                 'user' => array(
 173                                         'MakerNote' => MW_EXIF_UNDEFINED,                       # Manufacturer notes
 174                                         'UserComment' => MW_EXIF_UNDEFINED,                     # User comments #p34
 175                                 ),
 176
 177                                 # Tags relating to related file information
 178                                 'related' => array(
 179                                         'RelatedSoundFile' => MW_EXIF_ASCII,                    # Related audio file
 180                                 ),
 181
 182                                 # Tags relating to date and time
 183                                 'dateandtime' => array(
 184                                         'DateTimeOriginal' => MW_EXIF_ASCII,                    # Date and time of original data generation #p36
 185                                         'DateTimeDigitized' => MW_EXIF_ASCII,                   # Date and time of original data generation
 186                                         'SubSecTime' => MW_EXIF_ASCII,                          # DateTime subseconds
 187                                         'SubSecTimeOriginal' => MW_EXIF_ASCII,                  # DateTimeOriginal subseconds
 188                                         'SubSecTimeDigitized' => MW_EXIF_ASCII,                 # DateTimeDigitized subseconds
 189                                 ),
 190
 191                                 # Tags relating to picture-taking conditions (p31)
 192                                 'conditions' => array(
 193                                         'ExposureTime' => MW_EXIF_RATIONAL,                     # Exposure time
 194                                         'FNumber' => MW_EXIF_RATIONAL,                          # F Number
 195                                         'ExposureProgram' => MW_EXIF_SHORT,                     # Exposure Program #p38
 196                                         'SpectralSensitivity' => MW_EXIF_ASCII,                 # Spectral sensitivity
 197                                         'ISOSpeedRatings' => MW_EXIF_SHORT,                     # ISO speed rating
 198                                         'OECF' => MW_EXIF_UNDEFINED,                            # Optoelectronic conversion factor
 199                                         'ShutterSpeedValue' => MW_EXIF_SRATIONAL,               # Shutter speed
 200                                         'ApertureValue' => MW_EXIF_RATIONAL,                    # Aperture
 201                                         'BrightnessValue' => MW_EXIF_SRATIONAL,                 # Brightness
 202                                         'ExposureBiasValue' => MW_EXIF_SRATIONAL,               # Exposure bias
 203                                         'MaxApertureValue' => MW_EXIF_RATIONAL,                 # Maximum land aperture
 204                                         'SubjectDistance' => MW_EXIF_RATIONAL,                  # Subject distance
 205                                         'MeteringMode' => MW_EXIF_SHORT,                        # Metering mode #p40
 206                                         'LightSource' => MW_EXIF_SHORT,                         # Light source #p40-41
 207                                         'Flash' => MW_EXIF_SHORT,                               # Flash #p41-42
 208                                         'FocalLength' => MW_EXIF_RATIONAL,                      # Lens focal length
 209                                         'SubjectArea' => MW_EXIF_SHORT,                         # Subject area
 210                                         'FlashEnergy' => MW_EXIF_RATIONAL,                      # Flash energy
 211                                         'SpatialFrequencyResponse' => MW_EXIF_UNDEFINED,        # Spatial frequency response
 212                                         'FocalPlaneXResolution' => MW_EXIF_RATIONAL,            # Focal plane X resolution
 213                                         'FocalPlaneYResolution' => MW_EXIF_RATIONAL,            # Focal plane Y resolution
 214                                         'FocalPlaneResolutionUnit' => MW_EXIF_SHORT,            # Focal plane resolution unit #p46
 215                                         'SubjectLocation' => MW_EXIF_SHORT,                     # Subject location
 216                                         'ExposureIndex' => MW_EXIF_RATIONAL,                    # Exposure index
 217                                         'SensingMethod' => MW_EXIF_SHORT,                       # Sensing method #p46
 218                                         'FileSource' => MW_EXIF_UNDEFINED,                      # File source #p47
 219                                         'SceneType' => MW_EXIF_UNDEFINED,                       # Scene type #p47
 220                                         'CFAPattern' => MW_EXIF_UNDEFINED,                      # CFA pattern
 221                                         'CustomRendered' => MW_EXIF_SHORT,                      # Custom image processing #p48
 222                                         'ExposureMode' => MW_EXIF_SHORT,                        # Exposure mode #p48
 223                                         'WhiteBalance' => MW_EXIF_SHORT,                        # White Balance #p49
 224                                         'DigitalZoomRatio' => MW_EXIF_RATIONAL,                 # Digital zoom ration
 225                                         'FocalLengthIn35mmFilm' => MW_EXIF_SHORT,               # Focal length in 35 mm film
 226                                         'SceneCaptureType' => MW_EXIF_SHORT,                    # Scene capture type #p49
 227                                         'GainControl' => MW_EXIF_RATIONAL,                      # Scene control #p49-50
 228                                         'Contrast' => MW_EXIF_SHORT,                            # Contrast #p50
 229                                         'Saturation' => MW_EXIF_SHORT,                          # Saturation #p50
 230                                         'Sharpness' => MW_EXIF_SHORT,                           # Sharpness #p50
 231                                         'DeviceSettingDescription' => MW_EXIF_UNDEFINED,        # Desice settings description
 232                                         'SubjectDistanceRange' => MW_EXIF_SHORT,                # Subject distance range #p51
 233                                 ),
 234
 235                                 'other' => array(
 236                                         'ImageUniqueID' => MW_EXIF_ASCII,       # Unique image ID
 237                                 ),
 238                         ),
 239
 240                         # GPS Attribute Information (p52)
 241                         'gps' => array(
 242                                 'GPSVersionID' => MW_EXIF_BYTE,                 # GPS tag version
 243                                 'GPSLatitudeRef' => MW_EXIF_ASCII,              # North or South Latitude #p52-53
 244                                 'GPSLatitude' => MW_EXIF_RATIONAL,              # Latitude
 245                                 'GPSLongitudeRef' => MW_EXIF_ASCII,             # East or West Longitude #p53
 246                                 'GPSLongitude' => MW_EXIF_RATIONAL,             # Longitude
 247                                 'GPSAltitudeRef' => MW_EXIF_BYTE,               # Altitude reference
 248                                 'GPSAltitude' => MW_EXIF_RATIONAL,              # Altitude
 249                                 'GPSTimeStamp' => MW_EXIF_RATIONAL,             # GPS time (atomic clock)
 250                                 'GPSSatellites' => MW_EXIF_ASCII,               # Satellites used for measurement
 251                                 'GPSStatus' => MW_EXIF_ASCII,                   # Receiver status #p54
 252                                 'GPSMeasureMode' => MW_EXIF_ASCII,              # Measurement mode #p54-55
 253                                 'GPSDOP' => MW_EXIF_RATIONAL,                   # Measurement precision
 254                                 'GPSSpeedRef' => MW_EXIF_ASCII,                 # Speed unit #p55
 255                                 'GPSSpeed' => MW_EXIF_RATIONAL,                 # Speed of GPS receiver
 256                                 'GPSTrackRef' => MW_EXIF_ASCII,                 # Reference for direction of movement #p55
 257                                 'GPSTrack' => MW_EXIF_RATIONAL,                 # Direction of movement
 258                                 'GPSImgDirectionRef' => MW_EXIF_ASCII,          # Reference for direction of image #p56
 259                                 'GPSImgDirection' => MW_EXIF_RATIONAL,          # Direction of image
 260                                 'GPSMapDatum' => MW_EXIF_ASCII,                 # Geodetic survey data used
 261                                 'GPSDestLatitudeRef' => MW_EXIF_ASCII,          # Reference for latitude of destination #p56
 262                                 'GPSDestLatitude' => MW_EXIF_RATIONAL,          # Latitude destination
 263                                 'GPSDestLongitudeRef' => MW_EXIF_ASCII,         # Reference for longitude of destination #p57
 264                                 'GPSDestLongitude' => MW_EXIF_RATIONAL,         # Longitude of destination
 265                                 'GPSDestBearingRef' => MW_EXIF_ASCII,           # Reference for bearing of destination #p57
 266                                 'GPSDestBearing' => MW_EXIF_RATIONAL,           # Bearing of destination
 267                                 'GPSDestDistanceRef' => MW_EXIF_ASCII,          # Reference for distance to destination #p57-58
 268                                 'GPSDestDistance' => MW_EXIF_RATIONAL,          # Distance to destination
 269                                 'GPSProcessingMethod' => MW_EXIF_UNDEFINED,     # Name of GPS processing method
 270                                 'GPSAreaInformation' => MW_EXIF_UNDEFINED,      # Name of GPS area
 271                                 'GPSDateStamp' => MW_EXIF_ASCII,                # GPS date
 272                                 'GPSDifferential' => MW_EXIF_SHORT,             # GPS differential correction
 273                         ),
 274                 );
 275
 276                 $this->makeFlatExifTags();
 277                 wfSuppressWarnings();
 278                 $this->mRawExifData = exif_read_data( $file );
 279                 wfRestoreWarnings();
 280                 $this->makeFilteredData();
 281                 $this->makeFormattedData();
 282         }
 283
 284         /**#@+
 285          * @access private
 286          */
 287         /**
 288          * Generate a flat list of the exif tags
 289          */
 290         function makeFlatExifTags() {
 291                 $this->extractTags( $this->mExifTags );
 292         }
 293
 294         /**
 295          * A recursing extractor function used by makeFlatExifTags()
 296          *
 297          * Note: This used to use an array_walk function, but it made PHP5
 298          * segfault, see `cvs diff -u -r 1.4 -r 1.5 Exif.php`
 299          */
 300         function extractTags( &$tagset ) {
 301                 foreach( $tagset as $key => $val ) {
 302                         if( is_array( $val ) ) {
 303                                 $this->extractTags( $val );
 304                         } else {
 305                                 $this->mFlatExifTags[$key] = $val;
 306                         }
 307                 }
 308         }
 309
 310         /**
 311          * Make $this->mFilteredExifData
 312          */
 313         function makeFilteredData() {
 314                 $this->mFilteredExifData = $this->mRawExifData;
 315
 316                 foreach( $this->mFilteredExifData as $k => $v ) {
 317                         if ( !in_array( $k, array_keys( $this->mFlatExifTags ) ) ) {
 318                                 $this->debug( $v, __FUNCTION__, "'$k' is not a valid Exif tag" );
 319                                 unset( $this->mFilteredExifData[$k] );
 320                         }
 321                 }
 322
 323                 foreach( $this->mFilteredExifData as $k => $v ) {
 324                         if ( !$this->validate($k, $v) ) {
 325                                 $this->debug( $v, __FUNCTION__, "'$k' contained invalid data" );
 326                                 unset( $this->mFilteredExifData[$k] );
 327                         }
 328                 }
 329         }
 330
 331         function makeFormattedData( $data = null ) {
 332                 $format = new FormatExif( $this->getFilteredData() );
 333                 $this->mFormattedExifData = $format->getFormattedData();
 334         }
 335         /**#@-*/
 336
 337         /**#@+
 338          * @return array
 339          */
 340         /**
 341          * Get $this->mRawExifData
 342          */
 343         function getData() {
 344                 return $this->mRawExifData;
 345         }
 346
 347         /**
 348          * Get $this->mFilteredExifData
 349          */
 350         function getFilteredData() {
 351                 return $this->mFilteredExifData;
 352         }
 353
 354         /**
 355          * Get $this->mFormattedExifData
 356          */
 357         function getFormattedData() {
 358                 return $this->mFormattedExifData;
 359         }
 360         /**#@-*/
 361
 362         /**
 363          * The version of the output format
 364          *
 365          * Before the actual metadata information is saved in the database we
 366          * strip some of it since we don't want to save things like thumbnails
 367          * which usually accompany Exif data. This value gets saved in the
 368          * database along with the actual Exif data, and if the version in the
 369          * database doesn't equal the value returned by this function the Exif
 370          * data is regenerated.
 371          *
 372          * @return int
 373          */
 374         function version() {
 375                 return 1; // We don't need no bloddy constants!
 376         }
 377
 378         /**#@+
 379          * Validates if a tag value is of the type it should be according to the Exif spec
 380          *
 381          * @access private
 382          *
 383          * @param mixed $in The input value to check
 384          * @return bool
 385          */
 386         function isByte( $in ) {
 387                 if ( sprintf('%d', $in) == $in && $in >= 0 && $in <= 255 ) {
 388                         $this->debug( $in, __FUNCTION__, true );
 389                         return true;
 390                 } else {
 391                         $this->debug( $in, __FUNCTION__, false );
 392                         return false;
 393                 }
 394         }
 395
 396         function isASCII( $in ) {
 397                 if ( preg_match( "/[^\x0a\x20-\x7e]/", $in ) ) {
 398                         $this->debug( $in, __FUNCTION__, 'found a character not in our whitelist' );
 399                         return false;
 400                 }
 401
 402                 if ( preg_match( "/^\s*$/", $in ) ) {
 403                         $this->debug( $in, __FUNCTION__, 'input consisted solely of whitespace' );
 404                         return false;
 405                 }
 406
 407                 return true;
 408         }
 409
 410         function isShort( $in ) {
 411                 if ( sprintf('%d', $in) == $in && $in >= 0 && $in <= 65536 ) {
 412                         $this->debug( $in, __FUNCTION__, true );
 413                         return true;
 414                 } else {
 415                         $this->debug( $in, __FUNCTION__, false );
 416                         return false;
 417                 }
 418         }
 419
 420         function isLong( $in ) {
 421                 if ( sprintf('%d', $in) == $in && $in >= 0 && $in <= 4294967296 ) {
 422                         $this->debug( $in, __FUNCTION__, true );
 423                         return true;
 424                 } else {
 425                         $this->debug( $in, __FUNCTION__, false );
 426                         return false;
 427                 }
 428         }
 429
 430         function isRational( $in ) {
 431                 if ( @preg_match( "/^(\d+)\/(\d+[1-9]|[1-9]\d*)$/", $in, $m ) ) { # Avoid division by zero
 432                         return $this->isLong( $m[1] ) && $this->isLong( $m[2] );
 433                 } else {
 434                         $this->debug( $in, __FUNCTION__, 'fed a non-fraction value' );
 435                         return false;
 436                 }
 437         }
 438
 439         function isUndefined( $in ) {
 440                 if ( preg_match( "/^\d{4}$/", $in ) ) { // Allow ExifVersion and FlashpixVersion
 441                         $this->debug( $in, __FUNCTION__, true );
 442                         return true;
 443                 } else {
 444                         $this->debug( $in, __FUNCTION__, false );
 445                         return false;
 446                 }
 447         }
 448
 449         function isSlong( $in ) {
 450                 if ( $this->isLong( abs( $in ) ) ) {
 451                         $this->debug( $in, __FUNCTION__, true );
 452                         return true;
 453                 } else {
 454                         $this->debug( $in, __FUNCTION__, false );
 455                         return false;
 456                 }
 457         }
 458
 459         function isSrational( $in ) {
 460                 if ( preg_match( "/^(\d+)\/(\d+[1-9]|[1-9]\d*)$/", $in, $m ) ) { # Avoid division by zero
 461                         return $this->isSlong( $m[0] ) && $this->isSlong( $m[1] );
 462                 } else {
 463                         $this->debug( $in, __FUNCTION__, 'fed a non-fraction value' );
 464                         return false;
 465                 }
 466         }
 467         /**#@-*/
 468
 469         /**
 470          * Validates if a tag has a legal value according to the Exif spec
 471          *
 472          * @access private
 473          *
 474          * @param string $tag The tag to check
 475          * @param mixed  $val The value of the tag
 476          * @return bool
 477          */
 478         function validate( $tag, $val ) {
 479                 $debug = "tag is '$tag'";
 480                 // Fucks up if not typecast
 481                 switch( (string)$this->mFlatExifTags[$tag] ) {
 482                         case (string)MW_EXIF_BYTE:
 483                                 $this->debug( $val, __FUNCTION__, $debug );
 484                                 return $this->isByte( $val );
 485                         case (string)MW_EXIF_ASCII:
 486                                 $this->debug( $val, __FUNCTION__, $debug );
 487                                 return $this->isASCII( $val );
 488                         case (string)MW_EXIF_SHORT:
 489                                 $this->debug( $val, __FUNCTION__, $debug );
 490                                 return $this->isShort( $val );
 491                         case (string)MW_EXIF_LONG:
 492                                 $this->debug( $val, __FUNCTION__, $debug );
 493                                 return $this->isLong( $val );
 494                         case (string)MW_EXIF_RATIONAL:
 495                                 $this->debug( $val, __FUNCTION__, $debug );
 496                                 return $this->isRational( $val );
 497                         case (string)MW_EXIF_UNDEFINED:
 498                                 $this->debug( $val, __FUNCTION__, $debug );
 499                                 return $this->isUndefined( $val );
 500                         case (string)MW_EXIF_SLONG:
 501                                 $this->debug( $val, __FUNCTION__, $debug );
 502                                 return $this->isSlong( $val );
 503                         case (string)MW_EXIF_SRATIONAL:
 504                                 $this->debug( $val, __FUNCTION__, $debug );
 505                                 return $this->isSrational( $val );
 506                         case (string)MW_EXIF_SHORT.','.MW_EXIF_LONG:
 507                                 $this->debug( $val, __FUNCTION__, $debug );
 508                                 return $this->isShort( $val ) || $this->isLong( $val );
 509                         default:
 510                                 $this->debug( $val, __FUNCTION__, "The tag '$tag' is unknown" );
 511                                 return false;
 512                 }
 513         }
 514
 515         /**
 516          * Conviniance function for debugging output
 517          *
 518          * @access private
 519          *
 520          * @param mixed $in
 521          * @param string $fname
 522          * @param mixed $action
 523          */
 524          function debug( $in, $fname, $action = null ) {
 525                 $type = gettype( $in );
 526                 $class = ucfirst( __CLASS__ );
 527                 if ( $type === 'array' )
 528                         $in = print_r( $in, true );
 529
 530                 if ( $action === true )
 531                         wfDebug( "$class::$fname: accepted: '$in' (type: $type)\n");
 532                 elseif ( $action === false )
 533                         wfDebug( "$class::$fname: rejected: '$in' (type: $type)\n");
 534                 elseif ( $action === null )
 535                         wfDebug( "$class::$fname: input was: '$in' (type: $type)\n");
 536                 else
 537                         wfDebug( "$class::$fname: $action (type: $type; content: '$in')\n");
 538         }
 539
 540 }
 541
 542 /**
 543  * @package MediaWiki
 544  * @subpackage Metadata
 545  */
 546 class FormatExif {
 547         /**
 548          * The Exif data to format
 549          *
 550          * @var array
 551          * @access private
 552          */
 553         var $mExif;
 554
 555         /**
 556          * Constructor
 557          *
 558          * @param array $exif The Exif data to format ( as returned by
 559          *                    Exif::getFilteredData() )
 560          */
 561         function FormatExif( $exif ) {
 562                 $this->mExif = $exif;
 563         }
 564
 565         /**
 566          * Numbers given by Exif user agents are often magical, that is they
 567          * should be replaced by a detailed explanation depending on their
 568          * value which most of the time are plain integers. This function
 569          * formats Exif values into human readable form.
 570          *
 571          * @return array
 572          */
 573         function getFormattedData() {
 574                 global $wgLang;
 575
 576                 $tags =& $this->mExif;
 577
 578                 $resolutionunit = !isset( $tags['ResolutionUnit'] ) || $tags['ResolutionUnit'] == 2 ? 2 : 3;
 579                 unset( $tags['ResolutionUnit'] );
 580
 581                 foreach( $tags as $tag => $val ) {
 582                         switch( $tag ) {
 583                         case 'Compression':
 584                                 switch( $val ) {
 585                                 case 1: case 6:
 586                                         $tags[$tag] = $this->msg( $tag, $val );
 587                                         break;
 588                                 default:
 589                                         $tags[$tag] = $val;
 590                                         break;
 591                                 }
 592                                 break;
 593
 594                         case 'PhotometricInterpretation':
 595                                 switch( $val ) {
 596                                 case 2: case 6:
 597                                         $tags[$tag] = $this->msg( $tag, $val );
 598                                         break;
 599                                 default:
 600                                         $tags[$tag] = $val;
 601                                         break;
 602                                 }
 603                                 break;
 604
 605                         case 'Orientation':
 606                                 switch( $val ) {
 607                                 case 1: case 2: case 3: case 4: case 5: case 6: case 7: case 8:
 608                                         $tags[$tag] = $this->msg( $tag, $val );
 609                                         break;
 610                                 default:
 611                                         $tags[$tag] = $val;
 612                                         break;
 613                                 }
 614                                 break;
 615
 616                         case 'PlanarConfiguration':
 617                                 switch( $val ) {
 618                                 case 1: case 2:
 619                                         $tags[$tag] = $this->msg( $tag, $val );
 620                                         break;
 621                                 default:
 622                                         $tags[$tag] = $val;
 623                                         break;
 624                                 }
 625                                 break;
 626
 627                         // TODO: YCbCrSubSampling
 628                         // TODO: YCbCrPositioning
 629
 630                         case 'XResolution':
 631                         case 'YResolution':
 632                                 switch( $resolutionunit ) {
 633                                         case 2:
 634                                                 $tags[$tag] = $this->msg( 'XYResolution', 'i', $this->formatNum( $val ) );
 635                                                 break;
 636                                         case 3:
 637                                                 $this->msg( 'XYResolution', 'c', $this->formatNum( $val ) );
 638                                                 break;
 639                                         default:
 640                                                 $tags[$tag] = $val;
 641                                                 break;
 642                                 }
 643                                 break;
 644
 645                         // TODO: YCbCrCoefficients  #p27 (see annex E)
 646                         case 'ExifVersion': case 'FlashpixVersion':
 647                                 $tags[$tag] = "$val"/100;
 648                                 break;
 649
 650                         case 'ColorSpace':
 651                                 switch( $val ) {
 652                                 case 1: case 'FFFF.H':
 653                                         $tags[$tag] = $this->msg( $tag, $val );
 654                                         break;
 655                                 default:
 656                                         $tags[$tag] = $val;
 657                                         break;
 658                                 }
 659                                 break;
 660
 661                         case 'ComponentsConfiguration':
 662                                 switch( $val ) {
 663                                 case 0: case 1: case 2: case 3: case 4: case 5: case 6:
 664                                         $tags[$tag] = $this->msg( $tag, $val );
 665                                         break;
 666                                 default:
 667                                         $tags[$tag] = $val;
 668                                         break;
 669                                 }
 670                                 break;
 671
 672                         case 'DateTime':
 673                         case 'DateTimeOriginal':
 674                         case 'DateTimeDigitized':
 675                                 $tags[$tag] = $wgLang->timeanddate( wfTimestamp(TS_MW, $val) );
 676                                 break;
 677
 678                         case 'ExposureProgram':
 679                                 switch( $val ) {
 680                                 case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7: case 8:
 681                                         $tags[$tag] = $this->msg( $tag, $val );
 682                                         break;
 683                                 default:
 684                                         $tags[$tag] = $val;
 685                                         break;
 686                                 }
 687                                 break;
 688
 689                         case 'SubjectDistance':
 690                                 $tags[$tag] = $this->msg( $tag, '', $this->formatNum( $val ) );
 691                                 break;
 692
 693                         case 'MeteringMode':
 694                                 switch( $val ) {
 695                                 case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7: case 255:
 696                                         $tags[$tag] = $this->msg( $tag, $val );
 697                                         break;
 698                                 default:
 699                                         $tags[$tag] = $val;
 700                                         break;
 701                                 }
 702                                 break;
 703
 704                         case 'LightSource':
 705                                 switch( $val ) {
 706                                 case 0: case 1: case 2: case 3: case 4: case 9: case 10: case 11:
 707                                 case 12: case 13: case 14: case 15: case 17: case 18: case 19: case 20:
 708                                 case 21: case 22: case 23: case 24: case 255:
 709                                         $tags[$tag] = $this->msg( $tag, $val );
 710                                         break;
 711                                 default:
 712                                         $tags[$tag] = $val;
 713                                         break;
 714                                 }
 715                                 break;
 716
 717                         // TODO: Flash
 718                         case 'FocalPlaneResolutionUnit':
 719                                 switch( $val ) {
 720                                 case 2:
 721                                         $tags[$tag] = $this->msg( $tag, $val );
 722                                         break;
 723                                 default:
 724                                         $tags[$tag] = $val;
 725                                         break;
 726                                 }
 727                                 break;
 728
 729                         case 'SensingMethod':
 730                                 switch( $val ) {
 731                                 case 1: case 2: case 3: case 4: case 5: case 7: case 8:
 732                                         $tags[$tag] = $this->msg( $tag, $val );
 733                                         break;
 734                                 default:
 735                                         $tags[$tag] = $val;
 736                                         break;
 737                                 }
 738                                 break;
 739
 740                         case 'FileSource':
 741                                 switch( $val ) {
 742                                 case 3:
 743                                         $tags[$tag] = $this->msg( $tag, $val );
 744                                         break;
 745                                 default:
 746                                         $tags[$tag] = $val;
 747                                         break;
 748                                 }
 749                                 break;
 750
 751                         case 'SceneType':
 752                                 switch( $val ) {
 753                                 case 1:
 754                                         $tags[$tag] = $this->msg( $tag, $val );
 755                                         break;
 756                                 default:
 757                                         $tags[$tag] = $val;
 758                                         break;
 759                                 }
 760                                 break;
 761
 762                         case 'CustomRendered':
 763                                 switch( $val ) {
 764                                 case 0: case 1:
 765                                         $tags[$tag] = $this->msg( $tag, $val );
 766                                         break;
 767                                 default:
 768                                         $tags[$tag] = $val;
 769                                         break;
 770                                 }
 771                                 break;
 772
 773                         case 'ExposureMode':
 774                                 switch( $val ) {
 775                                 case 0: case 1: 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 'WhiteBalance':
 785                                 switch( $val ) {
 786                                 case 0: case 1:
 787                                         $tags[$tag] = $this->msg( $tag, $val );
 788                                         break;
 789                                 default:
 790                                         $tags[$tag] = $val;
 791                                         break;
 792                                 }
 793                                 break;
 794
 795                         case 'SceneCaptureType':
 796                                 switch( $val ) {
 797                                 case 0: case 1: case 2: 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 'GainControl':
 807                                 switch( $val ) {
 808                                 case 0: case 1: case 2: case 3: case 4:
 809                                         $tags[$tag] = $this->msg( $tag, $val );
 810                                         break;
 811                                 default:
 812                                         $tags[$tag] = $val;
 813                                         break;
 814                                 }
 815                                 break;
 816
 817                         case 'Contrast':
 818                                 switch( $val ) {
 819                                 case 0: case 1: case 2:
 820                                         $tags[$tag] = $this->msg( $tag, $val );
 821                                         break;
 822                                 default:
 823                                         $tags[$tag] = $val;
 824                                         break;
 825                                 }
 826                                 break;
 827
 828                         case 'Saturation':
 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 'Sharpness':
 840                                 switch( $val ) {
 841                                 case 0: case 1: case 2:
 842                                         $tags[$tag] = $this->msg( $tag, $val );
 843                                         break;
 844                                 default:
 845                                         $tags[$tag] = $val;
 846                                         break;
 847                                 }
 848                                 break;
 849
 850                         case 'SubjectDistanceRange':
 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 'GPSLatitudeRef':
 862                         case 'GPSDestLatitudeRef':
 863                                 switch( $val ) {
 864                                 case 'N': case 'S':
 865                                         $tags[$tag] = $this->msg( 'GPSLatitude', $val );
 866                                         break;
 867                                 default:
 868                                         $tags[$tag] = $val;
 869                                         break;
 870                                 }
 871                                 break;
 872
 873                         case 'GPSLongitudeRef':
 874                         case 'GPSDestLongitudeRef':
 875                                 switch( $val ) {
 876                                 case 'E': case 'W':
 877                                         $tags[$tag] = $this->msg( 'GPSLongitude', $val );
 878                                         break;
 879                                 default:
 880                                         $tags[$tag] = $val;
 881                                         break;
 882                                 }
 883                                 break;
 884
 885                         case 'GPSStatus':
 886                                 switch( $val ) {
 887                                 case 'A': case 'V':
 888                                         $tags[$tag] = $this->msg( $tag, $val );
 889                                         break;
 890                                 default:
 891                                         $tags[$tag] = $val;
 892                                         break;
 893                                 }
 894                                 break;
 895
 896                         case 'GPSMeasureMode':
 897                                 switch( $val ) {
 898                                 case 2: case 3:
 899                                         $tags[$tag] = $this->msg( $tag, $val );
 900                                         break;
 901                                 default:
 902                                         $tags[$tag] = $val;
 903                                         break;
 904                                 }
 905                                 break;
 906
 907                         case 'GPSSpeedRef':
 908                         case 'GPSDestDistanceRef':
 909                                 switch( $val ) {
 910                                 case 'K': case 'M': case 'N':
 911                                         $tags[$tag] = $this->msg( 'GPSSpeed', $val );
 912                                         break;
 913                                 default:
 914                                         $tags[$tag] = $val;
 915                                         break;
 916                                 }
 917                                 break;
 918
 919                         case 'GPSTrackRef':
 920                         case 'GPSImgDirectionRef':
 921                         case 'GPSDestBearingRef':
 922                                 switch( $val ) {
 923                                 case 'T': case 'M':
 924                                         $tags[$tag] = $this->msg( 'GPSDirection', $val );
 925                                         break;
 926                                 default:
 927                                         $tags[$tag] = $val;
 928                                         break;
 929                                 }
 930                                 break;
 931
 932                         case 'GPSDateStamp':
 933                                 $tags[$tag] = $wgLang->date( substr( $val, 0, 4 ) . substr( $val, 5, 2 ) . substr( $val, 8, 2 ) . '000000' );
 934                                 break;
 935
 936                         // This is not in the Exif standard, just a special
 937                         // case for our purposes which enables wikis to wikify
 938                         // the make, model and software name to link to their articles.
 939                         case 'Make':
 940                         case 'Model':
 941                         case 'Software':
 942                                 $tags[$tag] = $this->msg( $tag, '', $val );
 943                                 break;
 944                         default:
 945                                 $tags[$tag] = $this->formatNum( $val );
 946                                 break;
 947                         }
 948                 }
 949
 950                 return $tags;
 951         }
 952
 953         /**
 954          * Conviniance function for getFormattedData()
 955          *
 956          * @access private
 957          *
 958          * @param string $tag The tag name to pass on
 959          * @param string $val The value of the tag
 960          * @param string $arg An argument to pass ($1)
 961          * @return string A wfMsg of "exif-$tag-$val" in lower case
 962          */
 963         function msg( $tag, $val, $arg = null ) {
 964                 if ($val === '')
 965                         $val = 'value';
 966                 return wfMsg( strtolower( "exif-$tag-$val" ), $arg );
 967         }
 968
 969         /**
 970          * Format a number, convert numbers from fractions into floating point
 971          * numbers
 972          *
 973          * @access private
 974          *
 975          * @param mixed $num The value to format
 976          * @return mixed A floating point number or whatever we were fed
 977          */
 978         function formatNum( $num ) {
 979                 if ( preg_match( '/^(\d+)\/(\d+)$/', $num, $m ) )
 980                         return $m[2] != 0 ? $m[1] / $m[2] : $num;
 981                 else
 982                         return $num;
 983         }
 984 }