includes/Exif.php

   1 <?php
   2 /**
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation; either version 2 of the License, or
   6  * (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  16  * http://www.gnu.org/copyleft/gpl.html
  17  *
  18  * @ingroup Media
  19  * @author Ævar Arnfjörð Bjarmason <avarab@gmail.com>
  20  * @copyright Copyright © 2005, Ævar Arnfjörð Bjarmason, 2009 Brent Garber
  21  * @license http://www.gnu.org/copyleft/gpl.html GNU General Public License
  22  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 specification
  23  * @file
  24  */
  25
  26 /**
  27  * @todo document (e.g. one-sentence class-overview description)
  28  * @ingroup Media
  29  */
  30 class Exif {
  31
  32         const BYTE      = 1;    //!< An 8-bit (1-byte) unsigned integer.
  33         const ASCII     = 2;    //!< An 8-bit byte containing one 7-bit ASCII code. The final byte is terminated with NULL.
  34         const SHORT     = 3;    //!< A 16-bit (2-byte) unsigned integer.
  35         const LONG      = 4;    //!< A 32-bit (4-byte) unsigned integer.
  36         const RATIONAL  = 5;    //!< Two LONGs. The first LONG is the numerator and the second LONG expresses the denominator
  37         const UNDEFINED = 7;    //!< An 8-bit byte that can take any value depending on the field definition
  38         const SLONG     = 9;    //!< A 32-bit (4-byte) signed integer (2's complement notation),
  39         const SRATIONAL = 10;   //!< Two SLONGs. The first SLONG is the numerator and the second SLONG is the denominator.
  40
  41         //@{
  42         /* @var array
  43          * @private
  44          */
  45
  46         /**
  47          * Exif tags grouped by category, the tagname itself is the key and the type
  48          * is the value, in the case of more than one possible value type they are
  49          * separated by commas.
  50          */
  51         var $mExifTags;
  52
  53         /**
  54          * The raw Exif data returned by exif_read_data()
  55          */
  56         var $mRawExifData;
  57
  58         /**
  59          * A Filtered version of $mRawExifData that has been pruned of invalid
  60          * tags and tags that contain content they shouldn't contain according
  61          * to the Exif specification
  62          */
  63         var $mFilteredExifData;
  64
  65         /**
  66          * Filtered and formatted Exif data, see FormatExif::getFormattedData()
  67          */
  68         var $mFormattedExifData;
  69
  70         //@}
  71
  72         //@{
  73         /* @var string
  74          * @private
  75          */
  76
  77         /**
  78          * The file being processed
  79          */
  80         var $file;
  81
  82         /**
  83          * The basename of the file being processed
  84          */
  85         var $basename;
  86
  87         /**
  88          * The private log to log to, e.g. 'exif'
  89          */
  90         var $log = false;
  91
  92         //@}
  93
  94         /**
  95          * Constructor
  96          *
  97          * @param $file String: filename.
  98          */
  99         function __construct( $file ) {
 100                 /**
 101                  * Page numbers here refer to pages in the EXIF 2.2 standard
 102                  *
 103                  * @link http://exif.org/Exif2-2.PDF The Exif 2.2 specification
 104                  */
 105                 $this->mExifTags = array(
 106                         # TIFF Rev. 6.0 Attribute Information (p22)
 107                         'IFD0' => array(
 108                                 # Tags relating to image structure
 109                                 'ImageWidth' => Exif::SHORT.','.Exif::LONG,             # Image width
 110                                 'ImageLength' => Exif::SHORT.','.Exif::LONG,            # Image height
 111                                 'BitsPerSample' => array( Exif::SHORT, 3 ),             # Number of bits per component
 112                                 # "When a primary image is JPEG compressed, this designation is not"
 113                                 # "necessary and is omitted." (p23)
 114                                 'Compression' => Exif::SHORT,                           # Compression scheme #p23
 115                                 'PhotometricInterpretation' => Exif::SHORT,             # Pixel composition #p23
 116                                 'Orientation' => Exif::SHORT,                           # Orientation of image #p24
 117                                 'SamplesPerPixel' => Exif::SHORT,                       # Number of components
 118                                 'PlanarConfiguration' => Exif::SHORT,                   # Image data arrangement #p24
 119                                 'YCbCrSubSampling' => array( Exif::SHORT, 2),           # Subsampling ratio of Y to C #p24
 120                                 'YCbCrPositioning' => Exif::SHORT,                      # Y and C positioning #p24-25
 121                                 'XResolution' => Exif::RATIONAL,                        # Image resolution in width direction
 122                                 'YResolution' => Exif::RATIONAL,                        # Image resolution in height direction
 123                                 'ResolutionUnit' => Exif::SHORT,                        # Unit of X and Y resolution #(p26)
 124
 125                                 # Tags relating to recording offset
 126                                 'StripOffsets' => Exif::SHORT.','.Exif::LONG,                   # Image data location
 127                                 'RowsPerStrip' => Exif::SHORT.','.Exif::LONG,                   # Number of rows per strip
 128                                 'StripByteCounts' => Exif::SHORT.','.Exif::LONG,                # Bytes per compressed strip
 129                                 'JPEGInterchangeFormat' => Exif::SHORT.','.Exif::LONG,          # Offset to JPEG SOI
 130                                 'JPEGInterchangeFormatLength' => Exif::SHORT.','.Exif::LONG,    # Bytes of JPEG data
 131
 132                                 # Tags relating to image data characteristics
 133                                 'TransferFunction' => Exif::SHORT,                      # Transfer function
 134                                 'WhitePoint' => array( Exif::RATIONAL, 2),              # White point chromaticity
 135                                 'PrimaryChromaticities' => array( Exif::RATIONAL, 6),   # Chromaticities of primarities
 136                                 'YCbCrCoefficients' => array( Exif::RATIONAL, 3),       # Color space transformation matrix coefficients #p27
 137                                 'ReferenceBlackWhite' => array( Exif::RATIONAL, 6),     # Pair of black and white reference values
 138
 139                                 # Other tags
 140                                 'DateTime' => Exif::ASCII,                              # File change date and time
 141                                 'ImageDescription' => Exif::ASCII,                      # Image title
 142                                 'Make' => Exif::ASCII,                                  # Image input equipment manufacturer
 143                                 'Model' => Exif::ASCII,                                 # Image input equipment model
 144                                 'Software' => Exif::ASCII,                              # Software used
 145                                 'Artist' => Exif::ASCII,                                # Person who created the image
 146                                 'Copyright' => Exif::ASCII,                             # Copyright holder
 147                         ),
 148
 149                         # Exif IFD Attribute Information (p30-31)
 150                         'EXIF' => array(
 151                                 # TODO: NOTE: Nonexistence of this field is taken to mean nonconformance
 152                                 # to the EXIF 2.1 AND 2.2 standards
 153                                 'ExifVersion' => array( Exif::UNDEFINED, 4 ),           # Exif version
 154                                 'FlashPixVersion' => array( Exif::UNDEFINED, 4 ),       # Supported Flashpix version #p32
 155
 156                                 # Tags relating to Image Data Characteristics
 157                                 'ColorSpace' => Exif::SHORT,                            # Color space information #p32
 158
 159                                 # Tags relating to image configuration
 160                                 'ComponentsConfiguration' => array( Exif::UNDEFINED, 1),        # Meaning of each component #p33
 161                                 'CompressedBitsPerPixel' => Exif::RATIONAL,                     # Image compression mode
 162                                 'PixelYDimension' => Exif::SHORT.','.Exif::LONG,                # Valid image width
 163                                 'PixelXDimension' => Exif::SHORT.','.Exif::LONG,                # Valid image height
 164
 165                                 # Tags relating to related user information
 166                                 'MakerNote' => Exif::UNDEFINED,                         # Manufacturer notes
 167                                 'UserComment' => Exif::UNDEFINED,                       # User comments #p34
 168
 169                                 # Tags relating to related file information
 170                                 'RelatedSoundFile' => Exif::ASCII,                      # Related audio file
 171
 172                                 # Tags relating to date and time
 173                                 'DateTimeOriginal' => Exif::ASCII,                      # Date and time of original data generation #p36
 174                                 'DateTimeDigitized' => Exif::ASCII,                     # Date and time of original data generation
 175                                 'SubSecTime' => Exif::ASCII,                            # DateTime subseconds
 176                                 'SubSecTimeOriginal' => Exif::ASCII,                    # DateTimeOriginal subseconds
 177                                 'SubSecTimeDigitized' => Exif::ASCII,                   # DateTimeDigitized subseconds
 178
 179                                 # Tags relating to picture-taking conditions (p31)
 180                                 'ExposureTime' => Exif::RATIONAL,                       # Exposure time
 181                                 'FNumber' => Exif::RATIONAL,                            # F Number
 182                                 'ExposureProgram' => Exif::SHORT,                       # Exposure Program #p38
 183                                 'SpectralSensitivity' => Exif::ASCII,                   # Spectral sensitivity
 184                                 'ISOSpeedRatings' => Exif::SHORT,                       # ISO speed rating
 185                                 'OECF' => Exif::UNDEFINED,                              # Optoelectronic conversion factor
 186                                 'ShutterSpeedValue' => Exif::SRATIONAL,                 # Shutter speed
 187                                 'ApertureValue' => Exif::RATIONAL,                      # Aperture
 188                                 'BrightnessValue' => Exif::SRATIONAL,                   # Brightness
 189                                 'ExposureBiasValue' => Exif::SRATIONAL,                 # Exposure bias
 190                                 'MaxApertureValue' => Exif::RATIONAL,                   # Maximum land aperture
 191                                 'SubjectDistance' => Exif::RATIONAL,                    # Subject distance
 192                                 'MeteringMode' => Exif::SHORT,                          # Metering mode #p40
 193                                 'LightSource' => Exif::SHORT,                           # Light source #p40-41
 194                                 'Flash' => Exif::SHORT,                                 # Flash #p41-42
 195                                 'FocalLength' => Exif::RATIONAL,                        # Lens focal length
 196                                 'SubjectArea' => array( Exif::SHORT, 4 ),               # Subject area
 197                                 'FlashEnergy' => Exif::RATIONAL,                        # Flash energy
 198                                 'SpatialFrequencyResponse' => Exif::UNDEFINED,          # Spatial frequency response
 199                                 'FocalPlaneXResolution' => Exif::RATIONAL,              # Focal plane X resolution
 200                                 'FocalPlaneYResolution' => Exif::RATIONAL,              # Focal plane Y resolution
 201                                 'FocalPlaneResolutionUnit' => Exif::SHORT,              # Focal plane resolution unit #p46
 202                                 'SubjectLocation' => array( Exif::SHORT, 2),            # Subject location
 203                                 'ExposureIndex' => Exif::RATIONAL,                      # Exposure index
 204                                 'SensingMethod' => Exif::SHORT,                         # Sensing method #p46
 205                                 'FileSource' => Exif::UNDEFINED,                        # File source #p47
 206                                 'SceneType' => Exif::UNDEFINED,                         # Scene type #p47
 207                                 'CFAPattern' => Exif::UNDEFINED,                        # CFA pattern
 208                                 'CustomRendered' => Exif::SHORT,                        # Custom image processing #p48
 209                                 'ExposureMode' => Exif::SHORT,                          # Exposure mode #p48
 210                                 'WhiteBalance' => Exif::SHORT,                          # White Balance #p49
 211                                 'DigitalZoomRatio' => Exif::RATIONAL,                   # Digital zoom ration
 212                                 'FocalLengthIn35mmFilm' => Exif::SHORT,                 # Focal length in 35 mm film
 213                                 'SceneCaptureType' => Exif::SHORT,                      # Scene capture type #p49
 214                                 'GainControl' => Exif::RATIONAL,                        # Scene control #p49-50
 215                                 'Contrast' => Exif::SHORT,                              # Contrast #p50
 216                                 'Saturation' => Exif::SHORT,                            # Saturation #p50
 217                                 'Sharpness' => Exif::SHORT,                             # Sharpness #p50
 218                                 'DeviceSettingDescription' => Exif::UNDEFINED,          # Desice settings description
 219                                 'SubjectDistanceRange' => Exif::SHORT,                  # Subject distance range #p51
 220
 221                                 'ImageUniqueID' => Exif::ASCII,                         # Unique image ID
 222                         ),
 223
 224                         # GPS Attribute Information (p52)
 225                         'GPS' => array(
 226                                 'GPSVersionID' => array( Exif::BYTE, 4 ),               # GPS tag version
 227                                 'GPSLatitudeRef' => Exif::ASCII,                        # North or South Latitude #p52-53
 228                                 'GPSLatitude' => array( Exif::RATIONAL, 3 ),            # Latitude
 229                                 'GPSLongitudeRef' => Exif::ASCII,                       # East or West Longitude #p53
 230                                 'GPSLongitude' => array( Exif::RATIONAL, 3),            # Longitude
 231                                 'GPSAltitudeRef' => Exif::BYTE,                         # Altitude reference
 232                                 'GPSAltitude' => Exif::RATIONAL,                        # Altitude
 233                                 'GPSTimeStamp' => array( Exif::RATIONAL, 3),            # GPS time (atomic clock)
 234                                 'GPSSatellites' => Exif::ASCII,                         # Satellites used for measurement
 235                                 'GPSStatus' => Exif::ASCII,                             # Receiver status #p54
 236                                 'GPSMeasureMode' => Exif::ASCII,                        # Measurement mode #p54-55
 237                                 'GPSDOP' => Exif::RATIONAL,                             # Measurement precision
 238                                 'GPSSpeedRef' => Exif::ASCII,                           # Speed unit #p55
 239                                 'GPSSpeed' => Exif::RATIONAL,                           # Speed of GPS receiver
 240                                 'GPSTrackRef' => Exif::ASCII,                           # Reference for direction of movement #p55
 241                                 'GPSTrack' => Exif::RATIONAL,                           # Direction of movement
 242                                 'GPSImgDirectionRef' => Exif::ASCII,                    # Reference for direction of image #p56
 243                                 'GPSImgDirection' => Exif::RATIONAL,                    # Direction of image
 244                                 'GPSMapDatum' => Exif::ASCII,                           # Geodetic survey data used
 245                                 'GPSDestLatitudeRef' => Exif::ASCII,                    # Reference for latitude of destination #p56
 246                                 'GPSDestLatitude' => array( Exif::RATIONAL, 3 ),        # Latitude destination
 247                                 'GPSDestLongitudeRef' => Exif::ASCII,                   # Reference for longitude of destination #p57
 248                                 'GPSDestLongitude' => array( Exif::RATIONAL, 3 ),       # Longitude of destination
 249                                 'GPSDestBearingRef' => Exif::ASCII,                     # Reference for bearing of destination #p57
 250                                 'GPSDestBearing' => Exif::RATIONAL,                     # Bearing of destination
 251                                 'GPSDestDistanceRef' => Exif::ASCII,                    # Reference for distance to destination #p57-58
 252                                 'GPSDestDistance' => Exif::RATIONAL,                    # Distance to destination
 253                                 'GPSProcessingMethod' => Exif::UNDEFINED,               # Name of GPS processing method
 254                                 'GPSAreaInformation' => Exif::UNDEFINED,                # Name of GPS area
 255                                 'GPSDateStamp' => Exif::ASCII,                          # GPS date
 256                                 'GPSDifferential' => Exif::SHORT,                       # GPS differential correction
 257                         ),
 258                 );
 259
 260                 $this->file = $file;
 261                 $this->basename = wfBaseName( $this->file );
 262
 263                 $this->debugFile( $this->basename, __FUNCTION__, true );
 264                 wfSuppressWarnings();
 265                 $data = exif_read_data( $this->file, 0, true );
 266                 wfRestoreWarnings();
 267                 /**
 268                  * exif_read_data() will return false on invalid input, such as
 269                  * when somebody uploads a file called something.jpeg
 270                  * containing random gibberish.
 271                  */
 272                 $this->mRawExifData = $data ? $data : array();
 273                 $this->makeFilteredData();
 274                 $this->makeFormattedData();
 275                 $this->debugFile( __FUNCTION__, false );
 276         }
 277
 278         /**
 279          * Make $this->mFilteredExifData
 280          */
 281         function makeFilteredData() {
 282                 $this->mFilteredExifData = $this->mRawExifData;
 283
 284                 foreach( array_keys( $this->mFilteredExifData ) as $section ) {
 285                         if ( !in_array( $section, array_keys( $this->mExifTags ) ) ) {
 286                                 $this->debug( $section , __FUNCTION__, "'$section' is not a valid Exif section" );
 287                                 unset( $this->mFilteredExifData[$section] );
 288                                 continue;
 289                         }
 290
 291                         foreach( array_keys( $this->mFilteredExifData[$section] ) as $tag ) {
 292                                 if ( !in_array( $tag, array_keys( $this->mExifTags[$section] ) ) ) {
 293                                         $this->debug( $tag, __FUNCTION__, "'$tag' is not a valid tag in '$section'" );
 294                                         unset( $this->mFilteredExifData[$section][$tag] );
 295                                         continue;
 296                                 }
 297                                 $value = $this->mFilteredExifData[$section][$tag];
 298                                 if( !$this->validate( $section, $tag, $value ) ) {
 299                                         $this->debug( $value, __FUNCTION__, "'$tag' contained invalid data" );
 300                                         unset( $this->mFilteredExifData[$section][$tag] );
 301                                 }
 302                         }
 303                 }
 304         }
 305
 306         /**
 307          * @todo document
 308          */
 309         function makeFormattedData( ) {
 310                 $format = new FormatExif( $this->getFilteredData() );
 311                 $this->mFormattedExifData = $format->getFormattedData();
 312         }
 313         /**#@-*/
 314
 315         /**#@+
 316          * @return array
 317          */
 318         /**
 319          * Get $this->mRawExifData
 320          */
 321         function getData() {
 322                 return $this->mRawExifData;
 323         }
 324
 325         /**
 326          * Get $this->mFilteredExifData
 327          */
 328         function getFilteredData() {
 329                 return $this->mFilteredExifData;
 330         }
 331
 332         /**
 333          * Get $this->mFormattedExifData
 334          */
 335         function getFormattedData() {
 336                 return $this->mFormattedExifData;
 337         }
 338         /**#@-*/
 339
 340         /**
 341          * The version of the output format
 342          *
 343          * Before the actual metadata information is saved in the database we
 344          * strip some of it since we don't want to save things like thumbnails
 345          * which usually accompany Exif data. This value gets saved in the
 346          * database along with the actual Exif data, and if the version in the
 347          * database doesn't equal the value returned by this function the Exif
 348          * data is regenerated.
 349          *
 350          * @return int
 351          */
 352         public static function version() {
 353                 return 2; // We don't need no bloddy constants!
 354         }
 355
 356         /**#@+
 357          * Validates if a tag value is of the type it should be according to the Exif spec
 358          *
 359          * @private
 360          *
 361          * @param $in Mixed: the input value to check
 362          * @return bool
 363          */
 364         function isByte( $in ) {
 365                 if ( !is_array( $in ) && sprintf('%d', $in) == $in && $in >= 0 && $in <= 255 ) {
 366                         $this->debug( $in, __FUNCTION__, true );
 367                         return true;
 368                 } else {
 369                         $this->debug( $in, __FUNCTION__, false );
 370                         return false;
 371                 }
 372         }
 373
 374         function isASCII( $in ) {
 375                 if ( is_array( $in ) ) {
 376                         return false;
 377                 }
 378
 379                 if ( preg_match( "/[^\x0a\x20-\x7e]/", $in ) ) {
 380                         $this->debug( $in, __FUNCTION__, 'found a character not in our whitelist' );
 381                         return false;
 382                 }
 383
 384                 if ( preg_match( '/^\s*$/', $in ) ) {
 385                         $this->debug( $in, __FUNCTION__, 'input consisted solely of whitespace' );
 386                         return false;
 387                 }
 388
 389                 return true;
 390         }
 391
 392         function isShort( $in ) {
 393                 if ( !is_array( $in ) && sprintf('%d', $in) == $in && $in >= 0 && $in <= 65536 ) {
 394                         $this->debug( $in, __FUNCTION__, true );
 395                         return true;
 396                 } else {
 397                         $this->debug( $in, __FUNCTION__, false );
 398                         return false;
 399                 }
 400         }
 401
 402         function isLong( $in ) {
 403                 if ( !is_array( $in ) && sprintf('%d', $in) == $in && $in >= 0 && $in <= 4294967296 ) {
 404                         $this->debug( $in, __FUNCTION__, true );
 405                         return true;
 406                 } else {
 407                         $this->debug( $in, __FUNCTION__, false );
 408                         return false;
 409                 }
 410         }
 411
 412         function isRational( $in ) {
 413                 $m = array();
 414                 if ( !is_array( $in ) && @preg_match( '/^(\d+)\/(\d+[1-9]|[1-9]\d*)$/', $in, $m ) ) { # Avoid division by zero
 415                         return $this->isLong( $m[1] ) && $this->isLong( $m[2] );
 416                 } else {
 417                         $this->debug( $in, __FUNCTION__, 'fed a non-fraction value' );
 418                         return false;
 419                 }
 420         }
 421
 422         function isUndefined( $in ) {
 423                 if ( !is_array( $in ) && preg_match( '/^\d{4}$/', $in ) ) { // Allow ExifVersion and FlashpixVersion
 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 isSlong( $in ) {
 433                 if ( $this->isLong( abs( $in ) ) ) {
 434                         $this->debug( $in, __FUNCTION__, true );
 435                         return true;
 436                 } else {
 437                         $this->debug( $in, __FUNCTION__, false );
 438                         return false;
 439                 }
 440         }
 441
 442         function isSrational( $in ) {
 443                 $m = array();
 444                 if ( !is_array( $in ) && preg_match( '/^(\d+)\/(\d+[1-9]|[1-9]\d*)$/', $in, $m ) ) { # Avoid division by zero
 445                         return $this->isSlong( $m[0] ) && $this->isSlong( $m[1] );
 446                 } else {
 447                         $this->debug( $in, __FUNCTION__, 'fed a non-fraction value' );
 448                         return false;
 449                 }
 450         }
 451         /**#@-*/
 452
 453         /**
 454          * Validates if a tag has a legal value according to the Exif spec
 455          *
 456          * @private
 457          * @param $section String: section where tag is located.
 458          * @param $tag String: the tag to check.
 459          * @param $val Mixed: the value of the tag.
 460          * @param $recursive Boolean: true if called recursively for array types.
 461          * @return bool
 462          */
 463         function validate( $section, $tag, $val, $recursive = false ) {
 464                 $debug = "tag is '$tag'";
 465                 $etype = $this->mExifTags[$section][$tag];
 466                 $ecount = 1;
 467                 if( is_array( $etype ) ) {
 468                         list( $etype, $ecount ) = $etype;
 469                         if ( $recursive )
 470                                 $ecount = 1; // checking individual elements
 471                 }
 472                 $count = count( $val );
 473                 if( $ecount != $count ) {
 474                         $this->debug( $val, __FUNCTION__, "Expected $ecount elements for $tag but got $count" );
 475                         return false;
 476                 }
 477                 if( $count > 1 ) {
 478                         foreach( $val as $v ) {
 479                                 if( !$this->validate( $section, $tag, $v, true ) ) {
 480                                         return false;
 481                                 }
 482                         }
 483                         return true;
 484                 }
 485                 // Does not work if not typecast
 486                 switch( (string)$etype ) {
 487                         case (string)Exif::BYTE:
 488                                 $this->debug( $val, __FUNCTION__, $debug );
 489                                 return $this->isByte( $val );
 490                         case (string)Exif::ASCII:
 491                                 $this->debug( $val, __FUNCTION__, $debug );
 492                                 return $this->isASCII( $val );
 493                         case (string)Exif::SHORT:
 494                                 $this->debug( $val, __FUNCTION__, $debug );
 495                                 return $this->isShort( $val );
 496                         case (string)Exif::LONG:
 497                                 $this->debug( $val, __FUNCTION__, $debug );
 498                                 return $this->isLong( $val );
 499                         case (string)Exif::RATIONAL:
 500                                 $this->debug( $val, __FUNCTION__, $debug );
 501                                 return $this->isRational( $val );
 502                         case (string)Exif::UNDEFINED:
 503                                 $this->debug( $val, __FUNCTION__, $debug );
 504                                 return $this->isUndefined( $val );
 505                         case (string)Exif::SLONG:
 506                                 $this->debug( $val, __FUNCTION__, $debug );
 507                                 return $this->isSlong( $val );
 508                         case (string)Exif::SRATIONAL:
 509                                 $this->debug( $val, __FUNCTION__, $debug );
 510                                 return $this->isSrational( $val );
 511                         case (string)Exif::SHORT.','.Exif::LONG:
 512                                 $this->debug( $val, __FUNCTION__, $debug );
 513                                 return $this->isShort( $val ) || $this->isLong( $val );
 514                         default:
 515                                 $this->debug( $val, __FUNCTION__, "The tag '$tag' is unknown" );
 516                                 return false;
 517                 }
 518         }
 519
 520         /**
 521          * Convenience function for debugging output
 522          *
 523          * @private
 524          *
 525          * @param $in Mixed:
 526          * @param $fname String:
 527          * @param $action Mixed: , default NULL.
 528          */
 529         function debug( $in, $fname, $action = NULL ) {
 530                 if ( !$this->log ) {
 531                         return;
 532                 }
 533                 $type = gettype( $in );
 534                 $class = ucfirst( __CLASS__ );
 535                 if ( $type === 'array' )
 536                         $in = print_r( $in, true );
 537
 538                 if ( $action === true )
 539                         wfDebugLog( $this->log, "$class::$fname: accepted: '$in' (type: $type)\n");
 540                 elseif ( $action === false )
 541                         wfDebugLog( $this->log, "$class::$fname: rejected: '$in' (type: $type)\n");
 542                 elseif ( $action === null )
 543                         wfDebugLog( $this->log, "$class::$fname: input was: '$in' (type: $type)\n");
 544                 else
 545                         wfDebugLog( $this->log, "$class::$fname: $action (type: $type; content: '$in')\n");
 546         }
 547
 548         /**
 549          * Convenience function for debugging output
 550          *
 551          * @private
 552          *
 553          * @param $fname String: the name of the function calling this function
 554          * @param $io Boolean: Specify whether we're beginning or ending
 555          */
 556         function debugFile( $fname, $io ) {
 557                 if ( !$this->log ) {
 558                         return;
 559                 }
 560                 $class = ucfirst( __CLASS__ );
 561                 if ( $io ) {
 562                         wfDebugLog( $this->log, "$class::$fname: begin processing: '{$this->basename}'\n" );
 563                 } else {
 564                         wfDebugLog( $this->log, "$class::$fname: end processing: '{$this->basename}'\n" );
 565                 }
 566         }
 567
 568 }
 569
 570 /**
 571  * @todo document (e.g. one-sentence class-overview description)
 572  * @ingroup Media
 573  */
 574 class FormatExif {
 575         /**
 576          * The Exif data to format
 577          *
 578          * @var array
 579          * @private
 580          */
 581         var $mExif;
 582
 583         /**
 584          * Constructor
 585          *
 586          * @param $exif Array: the Exif data to format ( as returned by
 587          *                    Exif::getFilteredData() )
 588          */
 589         function FormatExif( $exif ) {
 590                 $this->mExif = $exif;
 591         }
 592
 593         /**
 594          * Numbers given by Exif user agents are often magical, that is they
 595          * should be replaced by a detailed explanation depending on their
 596          * value which most of the time are plain integers. This function
 597          * formats Exif values into human readable form.
 598          *
 599          * @return array
 600          */
 601         function getFormattedData() {
 602                 global $wgLang;
 603
 604                 $sections =& $this->mExif;
 605
 606                 $resolutionunit = !isset( $sections['IFD0']['ResolutionUnit'] ) || $sections['IFD0']['ResolutionUnit'] == 2 ? 2 : 3;
 607                 unset( $sections['IFD0']['ResolutionUnit'] );
 608
 609                 foreach( $sections as $section => &$tags ) {
 610                 foreach( $tags as $tag => $val ) {
 611                         switch( $tag ) {
 612                         case 'Compression':
 613                                 switch( $val ) {
 614                                 case 1: case 6:
 615                                         $tags[$tag] = $this->msg( $tag, $val );
 616                                         break;
 617                                 default:
 618                                         $tags[$tag] = $val;
 619                                         break;
 620                                 }
 621                                 break;
 622
 623                         case 'PhotometricInterpretation':
 624                                 switch( $val ) {
 625                                 case 2: case 6:
 626                                         $tags[$tag] = $this->msg( $tag, $val );
 627                                         break;
 628                                 default:
 629                                         $tags[$tag] = $val;
 630                                         break;
 631                                 }
 632                                 break;
 633
 634                         case 'Orientation':
 635                                 switch( $val ) {
 636                                 case 1: case 2: case 3: case 4: case 5: case 6: case 7: case 8:
 637                                         $tags[$tag] = $this->msg( $tag, $val );
 638                                         break;
 639                                 default:
 640                                         $tags[$tag] = $val;
 641                                         break;
 642                                 }
 643                                 break;
 644
 645                         case 'PlanarConfiguration':
 646                                 switch( $val ) {
 647                                 case 1: case 2:
 648                                         $tags[$tag] = $this->msg( $tag, $val );
 649                                         break;
 650                                 default:
 651                                         $tags[$tag] = $val;
 652                                         break;
 653                                 }
 654                                 break;
 655
 656                         // TODO: YCbCrSubSampling
 657                         // TODO: YCbCrPositioning
 658
 659                         case 'XResolution':
 660                         case 'YResolution':
 661                                 switch( $resolutionunit ) {
 662                                         case 2:
 663                                                 $tags[$tag] = $this->msg( 'XYResolution', 'i', $this->formatNum( $val ) );
 664                                                 break;
 665                                         case 3:
 666                                                 $this->msg( 'XYResolution', 'c', $this->formatNum( $val ) );
 667                                                 break;
 668                                         default:
 669                                                 $tags[$tag] = $val;
 670                                                 break;
 671                                 }
 672                                 break;
 673
 674                         // TODO: YCbCrCoefficients  #p27 (see annex E)
 675                         case 'ExifVersion': case 'FlashPixVersion':
 676                                 $tags[$tag] = "$val"/100;
 677                                 break;
 678
 679                         case 'ColorSpace':
 680                                 switch( $val ) {
 681                                 case 1: case 'FFFF.H':
 682                                         $tags[$tag] = $this->msg( $tag, $val );
 683                                         break;
 684                                 default:
 685                                         $tags[$tag] = $val;
 686                                         break;
 687                                 }
 688                                 break;
 689
 690                         case 'ComponentsConfiguration':
 691                                 switch( $val ) {
 692                                 case 0: case 1: case 2: case 3: case 4: case 5: case 6:
 693                                         $tags[$tag] = $this->msg( $tag, $val );
 694                                         break;
 695                                 default:
 696                                         $tags[$tag] = $val;
 697                                         break;
 698                                 }
 699                                 break;
 700
 701                         case 'DateTime':
 702                         case 'DateTimeOriginal':
 703                         case 'DateTimeDigitized':
 704                                 if( $val == '0000:00:00 00:00:00' ) {
 705                                         $tags[$tag] = wfMsg('exif-unknowndate');
 706                                 } elseif( preg_match( '/^(?:\d{4}):(?:\d\d):(?:\d\d) (?:\d\d):(?:\d\d):(?:\d\d)$/', $val ) ) {
 707                                         $tags[$tag] = $wgLang->timeanddate( wfTimestamp(TS_MW, $val) );
 708                                 }
 709                                 break;
 710
 711                         case 'ExposureProgram':
 712                                 switch( $val ) {
 713                                 case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7: case 8:
 714                                         $tags[$tag] = $this->msg( $tag, $val );
 715                                         break;
 716                                 default:
 717                                         $tags[$tag] = $val;
 718                                         break;
 719                                 }
 720                                 break;
 721
 722                         case 'SubjectDistance':
 723                                 $tags[$tag] = $this->msg( $tag, '', $this->formatNum( $val ) );
 724                                 break;
 725
 726                         case 'MeteringMode':
 727                                 switch( $val ) {
 728                                 case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7: case 255:
 729                                         $tags[$tag] = $this->msg( $tag, $val );
 730                                         break;
 731                                 default:
 732                                         $tags[$tag] = $val;
 733                                         break;
 734                                 }
 735                                 break;
 736
 737                         case 'LightSource':
 738                                 switch( $val ) {
 739                                 case 0: case 1: case 2: case 3: case 4: case 9: case 10: case 11:
 740                                 case 12: case 13: case 14: case 15: case 17: case 18: case 19: case 20:
 741                                 case 21: case 22: case 23: case 24: case 255:
 742                                         $tags[$tag] = $this->msg( $tag, $val );
 743                                         break;
 744                                 default:
 745                                         $tags[$tag] = $val;
 746                                         break;
 747                                 }
 748                                 break;
 749
 750                         case 'Flash':
 751                                 $flashDecode = array(
 752                                         'fired'    => $val & bindec( '00000001' ),
 753                                         'return'   => ($val & bindec( '00000110' )) >> 1,
 754                                         'mode'     => ($val & bindec( '00011000' )) >> 3,
 755                                         'function' => ($val & bindec( '00100000' )) >> 5,
 756                                         'redeye'   => ($val & bindec( '01000000' )) >> 6,
 757 //                                      'reserved' => ($val & bindec( '10000000' )) >> 7,
 758                                 );
 759
 760                                 # We do not need to handle unknown values since all are used.
 761                                 foreach( $flashDecode as $subTag => $subValue ) {
 762                                         # We do not need any message for zeroed values.
 763                                         if( $subTag != 'fired' && $subValue == 0) {
 764                                                 continue;
 765                                         }
 766                                         $fullTag = $tag . '-' . $subTag ;
 767                                         $flashMsgs[] = $this->msg( $fullTag, $subValue );
 768                                 }
 769                                 $tags[$tag] = $wgLang->commaList( $flashMsgs );
 770                         break;
 771
 772                         case 'FocalPlaneResolutionUnit':
 773                                 switch( $val ) {
 774                                 case 2:
 775                                         $tags[$tag] = $this->msg( $tag, $val );
 776                                         break;
 777                                 default:
 778                                         $tags[$tag] = $val;
 779                                         break;
 780                                 }
 781                                 break;
 782
 783                         case 'SensingMethod':
 784                                 switch( $val ) {
 785                                 case 1: case 2: case 3: case 4: case 5: case 7: case 8:
 786                                         $tags[$tag] = $this->msg( $tag, $val );
 787                                         break;
 788                                 default:
 789                                         $tags[$tag] = $val;
 790                                         break;
 791                                 }
 792                                 break;
 793
 794                         case 'FileSource':
 795                                 switch( $val ) {
 796                                 case 3:
 797                                         $tags[$tag] = $this->msg( $tag, $val );
 798                                         break;
 799                                 default:
 800                                         $tags[$tag] = $val;
 801                                         break;
 802                                 }
 803                                 break;
 804
 805                         case 'SceneType':
 806                                 switch( $val ) {
 807                                 case 1:
 808                                         $tags[$tag] = $this->msg( $tag, $val );
 809                                         break;
 810                                 default:
 811                                         $tags[$tag] = $val;
 812                                         break;
 813                                 }
 814                                 break;
 815
 816                         case 'CustomRendered':
 817                                 switch( $val ) {
 818                                 case 0: case 1:
 819                                         $tags[$tag] = $this->msg( $tag, $val );
 820                                         break;
 821                                 default:
 822                                         $tags[$tag] = $val;
 823                                         break;
 824                                 }
 825                                 break;
 826
 827                         case 'ExposureMode':
 828                                 switch( $val ) {
 829                                 case 0: case 1: case 2:
 830                                         $tags[$tag] = $this->msg( $tag, $val );
 831                                         break;
 832                                 default:
 833                                         $tags[$tag] = $val;
 834                                         break;
 835                                 }
 836                                 break;
 837
 838                         case 'WhiteBalance':
 839                                 switch( $val ) {
 840                                 case 0: case 1:
 841                                         $tags[$tag] = $this->msg( $tag, $val );
 842                                         break;
 843                                 default:
 844                                         $tags[$tag] = $val;
 845                                         break;
 846                                 }
 847                                 break;
 848
 849                         case 'SceneCaptureType':
 850                                 switch( $val ) {
 851                                 case 0: case 1: case 2: case 3:
 852                                         $tags[$tag] = $this->msg( $tag, $val );
 853                                         break;
 854                                 default:
 855                                         $tags[$tag] = $val;
 856                                         break;
 857                                 }
 858                                 break;
 859
 860                         case 'GainControl':
 861                                 switch( $val ) {
 862                                 case 0: case 1: case 2: case 3: case 4:
 863                                         $tags[$tag] = $this->msg( $tag, $val );
 864                                         break;
 865                                 default:
 866                                         $tags[$tag] = $val;
 867                                         break;
 868                                 }
 869                                 break;
 870
 871                         case 'Contrast':
 872                                 switch( $val ) {
 873                                 case 0: case 1: case 2:
 874                                         $tags[$tag] = $this->msg( $tag, $val );
 875                                         break;
 876                                 default:
 877                                         $tags[$tag] = $val;
 878                                         break;
 879                                 }
 880                                 break;
 881
 882                         case 'Saturation':
 883                                 switch( $val ) {
 884                                 case 0: case 1: case 2:
 885                                         $tags[$tag] = $this->msg( $tag, $val );
 886                                         break;
 887                                 default:
 888                                         $tags[$tag] = $val;
 889                                         break;
 890                                 }
 891                                 break;
 892
 893                         case 'Sharpness':
 894                                 switch( $val ) {
 895                                 case 0: case 1: case 2:
 896                                         $tags[$tag] = $this->msg( $tag, $val );
 897                                         break;
 898                                 default:
 899                                         $tags[$tag] = $val;
 900                                         break;
 901                                 }
 902                                 break;
 903
 904                         case 'SubjectDistanceRange':
 905                                 switch( $val ) {
 906                                 case 0: case 1: case 2: case 3:
 907                                         $tags[$tag] = $this->msg( $tag, $val );
 908                                         break;
 909                                 default:
 910                                         $tags[$tag] = $val;
 911                                         break;
 912                                 }
 913                                 break;
 914
 915                         case 'GPSLatitudeRef':
 916                         case 'GPSDestLatitudeRef':
 917                                 switch( $val ) {
 918                                 case 'N': case 'S':
 919                                         $tags[$tag] = $this->msg( 'GPSLatitude', $val );
 920                                         break;
 921                                 default:
 922                                         $tags[$tag] = $val;
 923                                         break;
 924                                 }
 925                                 break;
 926
 927                         case 'GPSLongitudeRef':
 928                         case 'GPSDestLongitudeRef':
 929                                 switch( $val ) {
 930                                 case 'E': case 'W':
 931                                         $tags[$tag] = $this->msg( 'GPSLongitude', $val );
 932                                         break;
 933                                 default:
 934                                         $tags[$tag] = $val;
 935                                         break;
 936                                 }
 937                                 break;
 938
 939                         case 'GPSAltitudeRef':
 940                                 switch( $val ) {
 941                                 case 0: case 1:
 942                                         $tags[$tag] = $this->msg( 'GPSAltitude', $val );
 943                                         break;
 944                                 default:
 945                                         $tags[$tag] = $val;
 946                                         break;
 947                                 }
 948                                 break;
 949
 950                         case 'GPSLatitude':
 951                         case 'GPSDestLatitude':
 952                         case 'GPSLongitude':
 953                         case 'GPSDestLongitude':
 954                                 $tags[$tag] = $this->formatCoords( $val );
 955                                 break;
 956
 957                         case 'GPSStatus':
 958                                 switch( $val ) {
 959                                 case 'A': case 'V':
 960                                         $tags[$tag] = $this->msg( $tag, $val );
 961                                         break;
 962                                 default:
 963                                         $tags[$tag] = $val;
 964                                         break;
 965                                 }
 966                                 break;
 967
 968                         case 'GPSMeasureMode':
 969                                 switch( $val ) {
 970                                 case 2: case 3:
 971                                         $tags[$tag] = $this->msg( $tag, $val );
 972                                         break;
 973                                 default:
 974                                         $tags[$tag] = $val;
 975                                         break;
 976                                 }
 977                                 break;
 978
 979                         case 'GPSSpeedRef':
 980                                 switch( $val ) {
 981                                 case 'K': case 'M': case 'N':
 982                                         $tags[$tag] = $this->msg( 'GPSSpeed', $val );
 983                                         break;
 984                                 default:
 985                                         $tags[$tag] = $val;
 986                                         break;
 987                                 }
 988                                 break;
 989
 990                         case 'GPSDestDistanceRef':
 991                                 switch( $val ) {
 992                                 case 'K': case 'M': case 'N':
 993                                         $tags[$tag] = $this->msg( 'GPSDestDistance', $val );
 994                                         break;
 995                                 default:
 996                                         $tags[$tag] = $val;
 997                                         break;
 998                                 }
 999                                 break;
1000
1001                         case 'GPSTrackRef':
1002                         case 'GPSImgDirectionRef':
1003                         case 'GPSDestBearingRef':
1004                                 switch( $val ) {
1005                                 case 'T': case 'M':
1006                                         $tags[$tag] = $this->msg( 'GPSDirection', $val );
1007                                         break;
1008                                 default:
1009                                         $tags[$tag] = $val;
1010                                         break;
1011                                 }
1012                                 break;
1013
1014                         case 'GPSDateStamp':
1015                                 $tags[$tag] = $wgLang->date( substr( $val, 0, 4 ) . substr( $val, 5, 2 ) . substr( $val, 8, 2 ) . '000000' );
1016                                 break;
1017
1018                         // This is not in the Exif standard, just a special
1019                         // case for our purposes which enables wikis to wikify
1020                         // the make, model and software name to link to their articles.
1021                         case 'Make':
1022                         case 'Model':
1023                         case 'Software':
1024                                 $tags[$tag] = $this->msg( $tag, '', $val );
1025                                 break;
1026
1027                         case 'ExposureTime':
1028                                 // Show the pretty fraction as well as decimal version
1029                                 $tags[$tag] = wfMsg( 'exif-exposuretime-format',
1030                                         $this->formatFraction( $val ), $this->formatNum( $val ) );
1031                                 break;
1032
1033                         case 'FNumber':
1034                                 $tags[$tag] = wfMsg( 'exif-fnumber-format',
1035                                         $this->formatNum( $val ) );
1036                                 break;
1037
1038                         case 'FocalLength':
1039                                 $tags[$tag] = wfMsg( 'exif-focallength-format',
1040                                         $this->formatNum( $val ) );
1041                                 break;
1042
1043                         default:
1044                                 $tags[$tag] = $this->formatNum( $val );
1045                                 break;
1046                         }
1047                 }
1048                 }
1049
1050                 return $this->mExif;
1051         }
1052
1053         /**
1054          * Convenience function for getFormattedData()
1055          *
1056          * @private
1057          *
1058          * @param $tag String: the tag name to pass on
1059          * @param $val String: the value of the tag
1060          * @param $arg String: an argument to pass ($1)
1061          * @return string A wfMsg of "exif-$tag-$val" in lower case
1062          */
1063         function msg( $tag, $val, $arg = null ) {
1064                 global $wgContLang;
1065
1066                 if ($val === '')
1067                         $val = 'value';
1068                 return wfMsg( $wgContLang->lc( "exif-$tag-$val" ), $arg );
1069         }
1070
1071         /**
1072          * Format a number, convert numbers from fractions into floating point
1073          * numbers, joins arrays of numbers with commas.
1074          *
1075          * @private
1076          *
1077          * @param $num Mixed: the value to format
1078          * @return mixed A floating point number or whatever we were fed
1079          */
1080         function formatNum( $num ) {
1081                 global $wgLang;
1082                 $m = array();
1083                 if( is_array($num) ) {
1084                         $out = array();
1085                         foreach( $num as $number ) {
1086                                 $out[] = $this->formatNum($number);
1087                         }
1088                         return $wgLang->commaList( $out );
1089                 }
1090                 if ( preg_match( '/^(\d+)\/(\d+)$/', $num, $m ) )
1091                         return $m[2] != 0 ? $m[1] / $m[2] : $num;
1092                 else
1093                         return $num;
1094         }
1095
1096         /**
1097          * Format a rational number, reducing fractions
1098          *
1099          * @private
1100          *
1101          * @param $num Mixed: the value to format
1102          * @return mixed A floating point number or whatever we were fed
1103          */
1104         function formatFraction( $num ) {
1105                 $m = array();
1106                 if ( preg_match( '/^(\d+)\/(\d+)$/', $num, $m ) ) {
1107                         $numerator = intval( $m[1] );
1108                         $denominator = intval( $m[2] );
1109                         $gcd = $this->gcd( $numerator, $denominator );
1110                         if( $gcd != 0 ) {
1111                                 // 0 shouldn't happen! ;)
1112                                 return $numerator / $gcd . '/' . $denominator / $gcd;
1113                         }
1114                 }
1115                 return $this->formatNum( $num );
1116         }
1117
1118         /**
1119          * Calculate the greatest common divisor of two integers.
1120          *
1121          * @param $a Integer: FIXME
1122          * @param $b Integer: FIXME
1123          * @return int
1124          * @private
1125          */
1126         function gcd( $a, $b ) {
1127                 /*
1128                         // http://en.wikipedia.org/wiki/Euclidean_algorithm
1129                         // Recursive form would be:
1130                         if( $b == 0 )
1131                                 return $a;
1132                         else
1133                                 return gcd( $b, $a % $b );
1134                 */
1135                 while( $b != 0 ) {
1136                         $remainder = $a % $b;
1137
1138                         // tail recursion...
1139                         $a = $b;
1140                         $b = $remainder;
1141                 }
1142                 return $a;
1143         }
1144
1145         /**
1146          * Format a coordinate value, convert numbers from fractions
1147          * into floating point numbers, .
1148          *
1149          * @private
1150          *
1151          * @param $coords Array: degrees, minutes and seconds
1152          * @param $ref String: reference direction (N/S/E/W), optional
1153          * @return mixed A floating point number or whatever we were fed
1154          */
1155         function formatCoords( $coords, $ref = null ) {
1156                 list($deg, $min, $sec) = $coords;
1157                 $deg = $this->formatNum($deg);
1158                 $min = $this->formatNum($min);
1159                 $sec = $this->formatNum($sec);
1160                 $out = $deg . "°";
1161                 if ($min) $out .= " " . $min . "'";
1162                 if ($sec) $out .= " " . $sec . '"';
1163                 if ($ref) $out .= " " . $ref;
1164                 return $out;
1165         }
1166
1167 }
1168
1169 /**
1170  * MW 1.6 compatibility
1171  */
1172 define( 'MW_EXIF_BYTE', Exif::BYTE );
1173 define( 'MW_EXIF_ASCII', Exif::ASCII );
1174 define( 'MW_EXIF_SHORT', Exif::SHORT );
1175 define( 'MW_EXIF_LONG', Exif::LONG );
1176 define( 'MW_EXIF_RATIONAL', Exif::RATIONAL );
1177 define( 'MW_EXIF_UNDEFINED', Exif::UNDEFINED );
1178 define( 'MW_EXIF_SLONG', Exif::SLONG );
1179 define( 'MW_EXIF_SRATIONAL', Exif::SRATIONAL );