3 * Extraction and validation of image metadata.
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
18 * http://www.gnu.org/copyleft/gpl.html
21 * @author Ævar Arnfjörð Bjarmason <avarab@gmail.com>
22 * @copyright Copyright © 2005, Ævar Arnfjörð Bjarmason, 2009 Brent Garber
23 * @license http://www.gnu.org/copyleft/gpl.html GNU General Public License
24 * @see http://exif.org/Exif2-2.PDF The Exif 2.2 specification
29 * Class to extract and validate Exif data from jpeg (and possibly tiff) files.
33 /** An 8-bit (1-byte) unsigned integer. */
36 /** An 8-bit byte containing one 7-bit ASCII code.
37 * The final byte is terminated with NULL.
41 /** A 16-bit (2-byte) unsigned integer. */
44 /** A 32-bit (4-byte) unsigned integer. */
47 /** Two LONGs. The first LONG is the numerator and the second LONG expresses
52 /** A 16-bit (2-byte) or 32-bit (4-byte) unsigned integer. */
53 const SHORT_OR_LONG
= 6;
55 /** An 8-bit byte that can take any value depending on the field definition */
58 /** A 32-bit (4-byte) signed integer (2's complement notation), */
61 /** Two SLONGs. The first SLONG is the numerator and the second SLONG is
66 /** A fake value for things we don't want or don't support. */
69 /** @var array Exif tags grouped by category, the tagname itself is the key
70 * and the type is the value, in the case of more than one possible value
71 * type they are separated by commas.
75 /** @var array The raw Exif data returned by exif_read_data() */
76 private $mRawExifData;
78 /** @var array A Filtered version of $mRawExifData that has been pruned
79 * of invalid tags and tags that contain content they shouldn't contain
80 * according to the Exif specification
82 private $mFilteredExifData;
84 /** @var string The file being processed */
87 /** @var string The basename of the file being processed */
90 /** @var string The private log to log to, e.g. 'exif' */
93 /** @var string The byte order of the file. Needed because php's extension
94 * doesn't fully process some obscure props.
101 * @param string $file Filename.
102 * @param string $byteOrder Type of byte ordering either 'BE' (Big Endian)
103 * or 'LE' (Little Endian). Default ''.
104 * @throws MWException
105 * @todo FIXME: The following are broke:
106 * SubjectArea. Need to test the more obscure tags.
107 * DigitalZoomRatio = 0/0 is rejected. need to determine if that's valid.
108 * Possibly should treat 0/0 = 0. need to read exif spec on that.
110 function __construct( $file, $byteOrder = '' ) {
112 * Page numbers here refer to pages in the Exif 2.2 standard
114 * Note, Exif::UNDEFINED is treated as a string, not as an array of bytes
115 * so don't put a count parameter for any UNDEFINED values.
117 * @link http://exif.org/Exif2-2.PDF The Exif 2.2 specification
120 # TIFF Rev. 6.0 Attribute Information (p22)
122 # Tags relating to image structure
123 'ImageWidth' => Exif
::SHORT_OR_LONG
, # Image width
124 'ImageLength' => Exif
::SHORT_OR_LONG
, # Image height
125 'BitsPerSample' => [ Exif
::SHORT
, 3 ], # Number of bits per component
126 # "When a primary image is JPEG compressed, this designation is not"
127 # "necessary and is omitted." (p23)
128 'Compression' => Exif
::SHORT
, # Compression scheme #p23
129 'PhotometricInterpretation' => Exif
::SHORT
, # Pixel composition #p23
130 'Orientation' => Exif
::SHORT
, # Orientation of image #p24
131 'SamplesPerPixel' => Exif
::SHORT
, # Number of components
132 'PlanarConfiguration' => Exif
::SHORT
, # Image data arrangement #p24
133 'YCbCrSubSampling' => [ Exif
::SHORT
, 2 ], # Subsampling ratio of Y to C #p24
134 'YCbCrPositioning' => Exif
::SHORT
, # Y and C positioning #p24-25
135 'XResolution' => Exif
::RATIONAL
, # Image resolution in width direction
136 'YResolution' => Exif
::RATIONAL
, # Image resolution in height direction
137 'ResolutionUnit' => Exif
::SHORT
, # Unit of X and Y resolution #(p26)
139 # Tags relating to recording offset
140 'StripOffsets' => Exif
::SHORT_OR_LONG
, # Image data location
141 'RowsPerStrip' => Exif
::SHORT_OR_LONG
, # Number of rows per strip
142 'StripByteCounts' => Exif
::SHORT_OR_LONG
, # Bytes per compressed strip
143 'JPEGInterchangeFormat' => Exif
::SHORT_OR_LONG
, # Offset to JPEG SOI
144 'JPEGInterchangeFormatLength' => Exif
::SHORT_OR_LONG
, # Bytes of JPEG data
146 # Tags relating to image data characteristics
147 'TransferFunction' => Exif
::IGNORE
, # Transfer function
148 'WhitePoint' => [ Exif
::RATIONAL
, 2 ], # White point chromaticity
149 'PrimaryChromaticities' => [ Exif
::RATIONAL
, 6 ], # Chromaticities of primarities
150 # Color space transformation matrix coefficients #p27
151 'YCbCrCoefficients' => [ Exif
::RATIONAL
, 3 ],
152 'ReferenceBlackWhite' => [ Exif
::RATIONAL
, 6 ], # Pair of black and white reference values
155 'DateTime' => Exif
::ASCII
, # File change date and time
156 'ImageDescription' => Exif
::ASCII
, # Image title
157 'Make' => Exif
::ASCII
, # Image input equipment manufacturer
158 'Model' => Exif
::ASCII
, # Image input equipment model
159 'Software' => Exif
::ASCII
, # Software used
160 'Artist' => Exif
::ASCII
, # Person who created the image
161 'Copyright' => Exif
::ASCII
, # Copyright holder
164 # Exif IFD Attribute Information (p30-31)
166 # @todo NOTE: Nonexistence of this field is taken to mean nonconformance
167 # to the Exif 2.1 AND 2.2 standards
168 'ExifVersion' => Exif
::UNDEFINED
, # Exif version
169 'FlashPixVersion' => Exif
::UNDEFINED
, # Supported Flashpix version #p32
171 # Tags relating to Image Data Characteristics
172 'ColorSpace' => Exif
::SHORT
, # Color space information #p32
174 # Tags relating to image configuration
175 'ComponentsConfiguration' => Exif
::UNDEFINED
, # Meaning of each component #p33
176 'CompressedBitsPerPixel' => Exif
::RATIONAL
, # Image compression mode
177 'PixelYDimension' => Exif
::SHORT_OR_LONG
, # Valid image height
178 'PixelXDimension' => Exif
::SHORT_OR_LONG
, # Valid image width
180 # Tags relating to related user information
181 'MakerNote' => Exif
::IGNORE
, # Manufacturer notes
182 'UserComment' => Exif
::UNDEFINED
, # User comments #p34
184 # Tags relating to related file information
185 'RelatedSoundFile' => Exif
::ASCII
, # Related audio file
187 # Tags relating to date and time
188 'DateTimeOriginal' => Exif
::ASCII
, # Date and time of original data generation #p36
189 'DateTimeDigitized' => Exif
::ASCII
, # Date and time of original data generation
190 'SubSecTime' => Exif
::ASCII
, # DateTime subseconds
191 'SubSecTimeOriginal' => Exif
::ASCII
, # DateTimeOriginal subseconds
192 'SubSecTimeDigitized' => Exif
::ASCII
, # DateTimeDigitized subseconds
194 # Tags relating to picture-taking conditions (p31)
195 'ExposureTime' => Exif
::RATIONAL
, # Exposure time
196 'FNumber' => Exif
::RATIONAL
, # F Number
197 'ExposureProgram' => Exif
::SHORT
, # Exposure Program #p38
198 'SpectralSensitivity' => Exif
::ASCII
, # Spectral sensitivity
199 'ISOSpeedRatings' => Exif
::SHORT
, # ISO speed rating
200 'OECF' => Exif
::IGNORE
,
201 # Optoelectronic conversion factor. Note: We don't have support for this atm.
202 'ShutterSpeedValue' => Exif
::SRATIONAL
, # Shutter speed
203 'ApertureValue' => Exif
::RATIONAL
, # Aperture
204 'BrightnessValue' => Exif
::SRATIONAL
, # Brightness
205 'ExposureBiasValue' => Exif
::SRATIONAL
, # Exposure bias
206 'MaxApertureValue' => Exif
::RATIONAL
, # Maximum land aperture
207 'SubjectDistance' => Exif
::RATIONAL
, # Subject distance
208 'MeteringMode' => Exif
::SHORT
, # Metering mode #p40
209 'LightSource' => Exif
::SHORT
, # Light source #p40-41
210 'Flash' => Exif
::SHORT
, # Flash #p41-42
211 'FocalLength' => Exif
::RATIONAL
, # Lens focal length
212 'SubjectArea' => [ Exif
::SHORT
, 4 ], # Subject area
213 'FlashEnergy' => Exif
::RATIONAL
, # Flash energy
214 'SpatialFrequencyResponse' => Exif
::IGNORE
, # Spatial frequency response. Not supported atm.
215 'FocalPlaneXResolution' => Exif
::RATIONAL
, # Focal plane X resolution
216 'FocalPlaneYResolution' => Exif
::RATIONAL
, # Focal plane Y resolution
217 'FocalPlaneResolutionUnit' => Exif
::SHORT
, # Focal plane resolution unit #p46
218 'SubjectLocation' => [ Exif
::SHORT
, 2 ], # Subject location
219 'ExposureIndex' => Exif
::RATIONAL
, # Exposure index
220 'SensingMethod' => Exif
::SHORT
, # Sensing method #p46
221 'FileSource' => Exif
::UNDEFINED
, # File source #p47
222 'SceneType' => Exif
::UNDEFINED
, # Scene type #p47
223 'CFAPattern' => Exif
::IGNORE
, # CFA pattern. not supported atm.
224 'CustomRendered' => Exif
::SHORT
, # Custom image processing #p48
225 'ExposureMode' => Exif
::SHORT
, # Exposure mode #p48
226 'WhiteBalance' => Exif
::SHORT
, # White Balance #p49
227 'DigitalZoomRatio' => Exif
::RATIONAL
, # Digital zoom ration
228 'FocalLengthIn35mmFilm' => Exif
::SHORT
, # Focal length in 35 mm film
229 'SceneCaptureType' => Exif
::SHORT
, # Scene capture type #p49
230 'GainControl' => Exif
::SHORT
, # Scene control #p49-50
231 'Contrast' => Exif
::SHORT
, # Contrast #p50
232 'Saturation' => Exif
::SHORT
, # Saturation #p50
233 'Sharpness' => Exif
::SHORT
, # Sharpness #p50
234 'DeviceSettingDescription' => Exif
::IGNORE
,
235 # Device settings description. This could maybe be supported. Need to find an
236 # example file that uses this to see if it has stuff of interest in it.
237 'SubjectDistanceRange' => Exif
::SHORT
, # Subject distance range #p51
239 'ImageUniqueID' => Exif
::ASCII
, # Unique image ID
242 # GPS Attribute Information (p52)
244 'GPSVersion' => Exif
::UNDEFINED
,
245 # Should be an array of 4 Exif::BYTE's. However php treats it as an undefined
246 # Note exif standard calls this GPSVersionID, but php doesn't like the id suffix
247 'GPSLatitudeRef' => Exif
::ASCII
, # North or South Latitude #p52-53
248 'GPSLatitude' => [ Exif
::RATIONAL
, 3 ], # Latitude
249 'GPSLongitudeRef' => Exif
::ASCII
, # East or West Longitude #p53
250 'GPSLongitude' => [ Exif
::RATIONAL
, 3 ], # Longitude
251 'GPSAltitudeRef' => Exif
::UNDEFINED
,
252 # Altitude reference. Note, the exif standard says this should be an EXIF::Byte,
253 # but php seems to disagree.
254 'GPSAltitude' => Exif
::RATIONAL
, # Altitude
255 'GPSTimeStamp' => [ Exif
::RATIONAL
, 3 ], # GPS time (atomic clock)
256 'GPSSatellites' => Exif
::ASCII
, # Satellites used for measurement
257 'GPSStatus' => Exif
::ASCII
, # Receiver status #p54
258 'GPSMeasureMode' => Exif
::ASCII
, # Measurement mode #p54-55
259 'GPSDOP' => Exif
::RATIONAL
, # Measurement precision
260 'GPSSpeedRef' => Exif
::ASCII
, # Speed unit #p55
261 'GPSSpeed' => Exif
::RATIONAL
, # Speed of GPS receiver
262 'GPSTrackRef' => Exif
::ASCII
, # Reference for direction of movement #p55
263 'GPSTrack' => Exif
::RATIONAL
, # Direction of movement
264 'GPSImgDirectionRef' => Exif
::ASCII
, # Reference for direction of image #p56
265 'GPSImgDirection' => Exif
::RATIONAL
, # Direction of image
266 'GPSMapDatum' => Exif
::ASCII
, # Geodetic survey data used
267 'GPSDestLatitudeRef' => Exif
::ASCII
, # Reference for latitude of destination #p56
268 'GPSDestLatitude' => [ Exif
::RATIONAL
, 3 ], # Latitude destination
269 'GPSDestLongitudeRef' => Exif
::ASCII
, # Reference for longitude of destination #p57
270 'GPSDestLongitude' => [ Exif
::RATIONAL
, 3 ], # Longitude of destination
271 'GPSDestBearingRef' => Exif
::ASCII
, # Reference for bearing of destination #p57
272 'GPSDestBearing' => Exif
::RATIONAL
, # Bearing of destination
273 'GPSDestDistanceRef' => Exif
::ASCII
, # Reference for distance to destination #p57-58
274 'GPSDestDistance' => Exif
::RATIONAL
, # Distance to destination
275 'GPSProcessingMethod' => Exif
::UNDEFINED
, # Name of GPS processing method
276 'GPSAreaInformation' => Exif
::UNDEFINED
, # Name of GPS area
277 'GPSDateStamp' => Exif
::ASCII
, # GPS date
278 'GPSDifferential' => Exif
::SHORT
, # GPS differential correction
283 $this->basename
= wfBaseName( $this->file
);
284 if ( $byteOrder === 'BE' ||
$byteOrder === 'LE' ) {
285 $this->byteOrder
= $byteOrder;
287 // Only give a warning for b/c, since originally we didn't
288 // require this. The number of things affected by this is
290 wfWarn( 'Exif class did not have byte order specified. ' .
291 'Some properties may be decoded incorrectly.' );
292 $this->byteOrder
= 'BE'; // BE seems about twice as popular as LE in jpg's.
295 $this->debugFile( $this->basename
, __FUNCTION__
, true );
296 if ( function_exists( 'exif_read_data' ) ) {
297 MediaWiki\
suppressWarnings();
298 $data = exif_read_data( $this->file
, 0, true );
299 MediaWiki\restoreWarnings
();
301 throw new MWException( "Internal error: exif_read_data not present. " .
302 "\$wgShowEXIF may be incorrectly set or not checked by an extension." );
305 * exif_read_data() will return false on invalid input, such as
306 * when somebody uploads a file called something.jpeg
307 * containing random gibberish.
309 $this->mRawExifData
= $data ?
: [];
310 $this->makeFilteredData();
311 $this->collapseData();
312 $this->debugFile( __FUNCTION__
, false );
316 * Make $this->mFilteredExifData
318 function makeFilteredData() {
319 $this->mFilteredExifData
= [];
321 foreach ( array_keys( $this->mRawExifData
) as $section ) {
322 if ( !array_key_exists( $section, $this->mExifTags
) ) {
323 $this->debug( $section, __FUNCTION__
, "'$section' is not a valid Exif section" );
327 foreach ( array_keys( $this->mRawExifData
[$section] ) as $tag ) {
328 if ( !array_key_exists( $tag, $this->mExifTags
[$section] ) ) {
329 $this->debug( $tag, __FUNCTION__
, "'$tag' is not a valid tag in '$section'" );
333 $this->mFilteredExifData
[$tag] = $this->mRawExifData
[$section][$tag];
334 // This is ok, as the tags in the different sections do not conflict.
335 // except in computed and thumbnail section, which we don't use.
337 $value = $this->mRawExifData
[$section][$tag];
338 if ( !$this->validate( $section, $tag, $value ) ) {
339 $this->debug( $value, __FUNCTION__
, "'$tag' contained invalid data" );
340 unset( $this->mFilteredExifData
[$tag] );
347 * Collapse some fields together.
348 * This converts some fields from exif form, to a more friendly form.
349 * For example GPS latitude to a single number.
351 * The rationale behind this is that we're storing data, not presenting to the user
352 * For example a longitude is a single number describing how far away you are from
353 * the prime meridian. Well it might be nice to split it up into minutes and seconds
354 * for the user, it doesn't really make sense to split a single number into 4 parts
355 * for storage. (degrees, minutes, second, direction vs single floating point number).
357 * Other things this might do (not really sure if they make sense or not):
358 * Dates -> mediawiki date format.
359 * convert values that can be in different units to be in one standardized unit.
361 * As an alternative approach, some of this could be done in the validate phase
362 * if we make up our own types like Exif::DATE.
364 function collapseData() {
365 $this->exifGPStoNumber( 'GPSLatitude' );
366 $this->exifGPStoNumber( 'GPSDestLatitude' );
367 $this->exifGPStoNumber( 'GPSLongitude' );
368 $this->exifGPStoNumber( 'GPSDestLongitude' );
370 if ( isset( $this->mFilteredExifData
['GPSAltitude'] )
371 && isset( $this->mFilteredExifData
['GPSAltitudeRef'] )
373 // We know altitude data is a <num>/<denom> from the validation
374 // functions ran earlier. But multiplying such a string by -1
375 // doesn't work well, so convert.
376 list( $num, $denom ) = explode( '/', $this->mFilteredExifData
['GPSAltitude'] );
377 $this->mFilteredExifData
['GPSAltitude'] = $num / $denom;
379 if ( $this->mFilteredExifData
['GPSAltitudeRef'] === "\1" ) {
380 $this->mFilteredExifData
['GPSAltitude'] *= -1;
382 unset( $this->mFilteredExifData
['GPSAltitudeRef'] );
385 $this->exifPropToOrd( 'FileSource' );
386 $this->exifPropToOrd( 'SceneType' );
388 $this->charCodeString( 'UserComment' );
389 $this->charCodeString( 'GPSProcessingMethod' );
390 $this->charCodeString( 'GPSAreaInformation' );
392 // ComponentsConfiguration should really be an array instead of a string...
393 // This turns a string of binary numbers into an array of numbers.
395 if ( isset( $this->mFilteredExifData
['ComponentsConfiguration'] ) ) {
396 $val = $this->mFilteredExifData
['ComponentsConfiguration'];
399 $strLen = strlen( $val );
400 for ( $i = 0; $i < $strLen; $i++
) {
401 $ccVals[$i] = ord( substr( $val, $i, 1 ) );
403 $ccVals['_type'] = 'ol'; // this is for formatting later.
404 $this->mFilteredExifData
['ComponentsConfiguration'] = $ccVals;
407 // GPSVersion(ID) is treated as the wrong type by php exif support.
408 // Go through each byte turning it into a version string.
409 // For example: "\x02\x02\x00\x00" -> "2.2.0.0"
411 // Also change exif tag name from GPSVersion (what php exif thinks it is)
412 // to GPSVersionID (what the exif standard thinks it is).
414 if ( isset( $this->mFilteredExifData
['GPSVersion'] ) ) {
415 $val = $this->mFilteredExifData
['GPSVersion'];
418 $strLen = strlen( $val );
419 for ( $i = 0; $i < $strLen; $i++
) {
423 $newVal .= ord( substr( $val, $i, 1 ) );
426 if ( $this->byteOrder
=== 'LE' ) {
427 // Need to reverse the string
429 for ( $i = strlen( $newVal ) - 1; $i >= 0; $i-- ) {
430 $newVal2 .= substr( $newVal, $i, 1 );
432 $this->mFilteredExifData
['GPSVersionID'] = $newVal2;
434 $this->mFilteredExifData
['GPSVersionID'] = $newVal;
436 unset( $this->mFilteredExifData
['GPSVersion'] );
441 * Do userComment tags and similar. See pg. 34 of exif standard.
442 * basically first 8 bytes is charset, rest is value.
443 * This has not been tested on any shift-JIS strings.
444 * @param string $prop Prop name
446 private function charCodeString( $prop ) {
447 if ( isset( $this->mFilteredExifData
[$prop] ) ) {
448 if ( strlen( $this->mFilteredExifData
[$prop] ) <= 8 ) {
449 // invalid. Must be at least 9 bytes long.
451 $this->debug( $this->mFilteredExifData
[$prop], __FUNCTION__
, false );
452 unset( $this->mFilteredExifData
[$prop] );
456 $charCode = substr( $this->mFilteredExifData
[$prop], 0, 8 );
457 $val = substr( $this->mFilteredExifData
[$prop], 8 );
459 switch ( $charCode ) {
460 case "\x4A\x49\x53\x00\x00\x00\x00\x00":
462 $charset = "Shift-JIS";
465 $charset = "UTF-16" . $this->byteOrder
;
467 default: // ascii or undefined.
472 MediaWiki\
suppressWarnings();
473 $val = iconv( $charset, 'UTF-8//IGNORE', $val );
474 MediaWiki\restoreWarnings
();
476 // if valid utf-8, assume that, otherwise assume windows-1252
478 UtfNormal\Validator
::quickIsNFCVerify( $valCopy ); // validates $valCopy.
479 if ( $valCopy !== $val ) {
480 MediaWiki\
suppressWarnings();
481 $val = iconv( 'Windows-1252', 'UTF-8//IGNORE', $val );
482 MediaWiki\restoreWarnings
();
486 // trim and check to make sure not only whitespace.
488 if ( strlen( $val ) === 0 ) {
490 $this->debug( $this->mFilteredExifData
[$prop], __FUNCTION__
, "$prop: Is only whitespace" );
491 unset( $this->mFilteredExifData
[$prop] );
497 $this->mFilteredExifData
[$prop] = $val;
502 * Convert an Exif::UNDEFINED from a raw binary string
503 * to its value. This is sometimes needed depending on
504 * the type of UNDEFINED field
505 * @param string $prop Name of property
507 private function exifPropToOrd( $prop ) {
508 if ( isset( $this->mFilteredExifData
[$prop] ) ) {
509 $this->mFilteredExifData
[$prop] = ord( $this->mFilteredExifData
[$prop] );
514 * Convert gps in exif form to a single floating point number
515 * for example 10 degress 20`40`` S -> -10.34444
516 * @param string $prop A GPS coordinate exif tag name (like GPSLongitude)
518 private function exifGPStoNumber( $prop ) {
519 $loc =& $this->mFilteredExifData
[$prop];
520 $dir =& $this->mFilteredExifData
[$prop . 'Ref'];
523 if ( isset( $loc ) && isset( $dir )
524 && ( $dir === 'N' ||
$dir === 'S' ||
$dir === 'E' ||
$dir === 'W' )
526 list( $num, $denom ) = explode( '/', $loc[0] );
527 $res = $num / $denom;
528 list( $num, $denom ) = explode( '/', $loc[1] );
529 $res +
= ( $num / $denom ) * ( 1 / 60 );
530 list( $num, $denom ) = explode( '/', $loc[2] );
531 $res +
= ( $num / $denom ) * ( 1 / 3600 );
533 if ( $dir === 'S' ||
$dir === 'W' ) {
534 $res *= -1; // make negative
538 // update the exif records.
540 if ( $res !== false ) { // using !== as $res could potentially be 0
541 $this->mFilteredExifData
[$prop] = $res;
542 unset( $this->mFilteredExifData
[$prop . 'Ref'] );
543 } else { // if invalid
544 unset( $this->mFilteredExifData
[$prop] );
545 unset( $this->mFilteredExifData
[$prop . 'Ref'] );
555 * Get $this->mRawExifData
559 return $this->mRawExifData
;
563 * Get $this->mFilteredExifData
566 function getFilteredData() {
567 return $this->mFilteredExifData
;
573 * The version of the output format
575 * Before the actual metadata information is saved in the database we
576 * strip some of it since we don't want to save things like thumbnails
577 * which usually accompany Exif data. This value gets saved in the
578 * database along with the actual Exif data, and if the version in the
579 * database doesn't equal the value returned by this function the Exif
580 * data is regenerated.
584 public static function version() {
585 return 2; // We don't need no bloddy constants!
589 * Validates if a tag value is of the type it should be according to the Exif spec
591 * @param mixed $in The input value to check
594 private function isByte( $in ) {
595 if ( !is_array( $in ) && sprintf( '%d', $in ) == $in && $in >= 0 && $in <= 255 ) {
596 $this->debug( $in, __FUNCTION__
, true );
600 $this->debug( $in, __FUNCTION__
, false );
607 * @param mixed $in The input value to check
610 private function isASCII( $in ) {
611 if ( is_array( $in ) ) {
615 if ( preg_match( "/[^\x0a\x20-\x7e]/", $in ) ) {
616 $this->debug( $in, __FUNCTION__
, 'found a character not in our whitelist' );
621 if ( preg_match( '/^\s*$/', $in ) ) {
622 $this->debug( $in, __FUNCTION__
, 'input consisted solely of whitespace' );
631 * @param mixed $in The input value to check
634 private function isShort( $in ) {
635 if ( !is_array( $in ) && sprintf( '%d', $in ) == $in && $in >= 0 && $in <= 65536 ) {
636 $this->debug( $in, __FUNCTION__
, true );
640 $this->debug( $in, __FUNCTION__
, false );
647 * @param mixed $in The input value to check
650 private function isLong( $in ) {
651 if ( !is_array( $in ) && sprintf( '%d', $in ) == $in && $in >= 0 && $in <= 4294967296 ) {
652 $this->debug( $in, __FUNCTION__
, true );
656 $this->debug( $in, __FUNCTION__
, false );
663 * @param mixed $in The input value to check
666 private function isRational( $in ) {
669 # Avoid division by zero
670 if ( !is_array( $in )
671 && preg_match( '/^(\d+)\/(\d+[1-9]|[1-9]\d*)$/', $in, $m )
673 return $this->isLong( $m[1] ) && $this->isLong( $m[2] );
675 $this->debug( $in, __FUNCTION__
, 'fed a non-fraction value' );
682 * @param mixed $in The input value to check
685 private function isUndefined( $in ) {
686 $this->debug( $in, __FUNCTION__
, true );
692 * @param mixed $in The input value to check
695 private function isSlong( $in ) {
696 if ( $this->isLong( abs( $in ) ) ) {
697 $this->debug( $in, __FUNCTION__
, true );
701 $this->debug( $in, __FUNCTION__
, false );
708 * @param mixed $in The input value to check
711 private function isSrational( $in ) {
714 # Avoid division by zero
715 if ( !is_array( $in ) &&
716 preg_match( '/^(-?\d+)\/(\d+[1-9]|[1-9]\d*)$/', $in, $m )
718 return $this->isSlong( $m[0] ) && $this->isSlong( $m[1] );
720 $this->debug( $in, __FUNCTION__
, 'fed a non-fraction value' );
729 * Validates if a tag has a legal value according to the Exif spec
731 * @param string $section Section where tag is located.
732 * @param string $tag The tag to check.
733 * @param mixed $val The value of the tag.
734 * @param bool $recursive True if called recursively for array types.
737 private function validate( $section, $tag, $val, $recursive = false ) {
738 $debug = "tag is '$tag'";
739 $etype = $this->mExifTags
[$section][$tag];
741 if ( is_array( $etype ) ) {
742 list( $etype, $ecount ) = $etype;
744 $ecount = 1; // checking individual elements
747 $count = count( $val );
748 if ( $ecount != $count ) {
749 $this->debug( $val, __FUNCTION__
, "Expected $ecount elements for $tag but got $count" );
754 foreach ( $val as $v ) {
755 if ( !$this->validate( $section, $tag, $v, true ) ) {
762 // Does not work if not typecast
763 switch ( (string)$etype ) {
764 case (string)Exif
::BYTE
:
765 $this->debug( $val, __FUNCTION__
, $debug );
767 return $this->isByte( $val );
768 case (string)Exif
::ASCII
:
769 $this->debug( $val, __FUNCTION__
, $debug );
771 return $this->isASCII( $val );
772 case (string)Exif
::SHORT
:
773 $this->debug( $val, __FUNCTION__
, $debug );
775 return $this->isShort( $val );
776 case (string)Exif
::LONG
:
777 $this->debug( $val, __FUNCTION__
, $debug );
779 return $this->isLong( $val );
780 case (string)Exif
::RATIONAL
:
781 $this->debug( $val, __FUNCTION__
, $debug );
783 return $this->isRational( $val );
784 case (string)Exif
::SHORT_OR_LONG
:
785 $this->debug( $val, __FUNCTION__
, $debug );
787 return $this->isShort( $val ) ||
$this->isLong( $val );
788 case (string)Exif
::UNDEFINED
:
789 $this->debug( $val, __FUNCTION__
, $debug );
791 return $this->isUndefined( $val );
792 case (string)Exif
::SLONG
:
793 $this->debug( $val, __FUNCTION__
, $debug );
795 return $this->isSlong( $val );
796 case (string)Exif
::SRATIONAL
:
797 $this->debug( $val, __FUNCTION__
, $debug );
799 return $this->isSrational( $val );
800 case (string)Exif
::IGNORE
:
801 $this->debug( $val, __FUNCTION__
, $debug );
805 $this->debug( $val, __FUNCTION__
, "The tag '$tag' is unknown" );
812 * Convenience function for debugging output
814 * @param mixed $in Arrays will be processed with print_r().
815 * @param string $fname Function name to log.
816 * @param string|bool|null $action Default null.
818 private function debug( $in, $fname, $action = null ) {
822 $type = gettype( $in );
823 $class = ucfirst( __CLASS__
);
824 if ( is_array( $in ) ) {
825 $in = print_r( $in, true );
828 if ( $action === true ) {
829 wfDebugLog( $this->log
, "$class::$fname: accepted: '$in' (type: $type)" );
830 } elseif ( $action === false ) {
831 wfDebugLog( $this->log
, "$class::$fname: rejected: '$in' (type: $type)" );
832 } elseif ( $action === null ) {
833 wfDebugLog( $this->log
, "$class::$fname: input was: '$in' (type: $type)" );
835 wfDebugLog( $this->log
, "$class::$fname: $action (type: $type; content: '$in')" );
840 * Convenience function for debugging output
842 * @param string $fname The name of the function calling this function
843 * @param bool $io Specify whether we're beginning or ending
845 private function debugFile( $fname, $io ) {
849 $class = ucfirst( __CLASS__
);
851 wfDebugLog( $this->log
, "$class::$fname: begin processing: '{$this->basename}'" );
853 wfDebugLog( $this->log
, "$class::$fname: end processing: '{$this->basename}'" );