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
121 'Width' => Exif
::SHORT_OR_LONG
, # Image width
122 'Height' => Exif
::SHORT_OR_LONG
, # Image height
125 # TIFF Rev. 6.0 Attribute Information (p22)
127 # Tags relating to image structure
128 'ImageWidth' => Exif
::SHORT_OR_LONG
, # Image width
129 'ImageLength' => Exif
::SHORT_OR_LONG
, # Image height
130 'BitsPerSample' => [ Exif
::SHORT
, 3 ], # Number of bits per component
131 # "When a primary image is JPEG compressed, this designation is not"
132 # "necessary and is omitted." (p23)
133 'Compression' => Exif
::SHORT
, # Compression scheme #p23
134 'PhotometricInterpretation' => Exif
::SHORT
, # Pixel composition #p23
135 'Orientation' => Exif
::SHORT
, # Orientation of image #p24
136 'SamplesPerPixel' => Exif
::SHORT
, # Number of components
137 'PlanarConfiguration' => Exif
::SHORT
, # Image data arrangement #p24
138 'YCbCrSubSampling' => [ Exif
::SHORT
, 2 ], # Subsampling ratio of Y to C #p24
139 'YCbCrPositioning' => Exif
::SHORT
, # Y and C positioning #p24-25
140 'XResolution' => Exif
::RATIONAL
, # Image resolution in width direction
141 'YResolution' => Exif
::RATIONAL
, # Image resolution in height direction
142 'ResolutionUnit' => Exif
::SHORT
, # Unit of X and Y resolution #(p26)
144 # Tags relating to recording offset
145 'StripOffsets' => Exif
::SHORT_OR_LONG
, # Image data location
146 'RowsPerStrip' => Exif
::SHORT_OR_LONG
, # Number of rows per strip
147 'StripByteCounts' => Exif
::SHORT_OR_LONG
, # Bytes per compressed strip
148 'JPEGInterchangeFormat' => Exif
::SHORT_OR_LONG
, # Offset to JPEG SOI
149 'JPEGInterchangeFormatLength' => Exif
::SHORT_OR_LONG
, # Bytes of JPEG data
151 # Tags relating to image data characteristics
152 'TransferFunction' => Exif
::IGNORE
, # Transfer function
153 'WhitePoint' => [ Exif
::RATIONAL
, 2 ], # White point chromaticity
154 'PrimaryChromaticities' => [ Exif
::RATIONAL
, 6 ], # Chromaticities of primarities
155 # Color space transformation matrix coefficients #p27
156 'YCbCrCoefficients' => [ Exif
::RATIONAL
, 3 ],
157 'ReferenceBlackWhite' => [ Exif
::RATIONAL
, 6 ], # Pair of black and white reference values
160 'DateTime' => Exif
::ASCII
, # File change date and time
161 'ImageDescription' => Exif
::ASCII
, # Image title
162 'Make' => Exif
::ASCII
, # Image input equipment manufacturer
163 'Model' => Exif
::ASCII
, # Image input equipment model
164 'Software' => Exif
::ASCII
, # Software used
165 'Artist' => Exif
::ASCII
, # Person who created the image
166 'Copyright' => Exif
::ASCII
, # Copyright holder
169 # Exif IFD Attribute Information (p30-31)
171 # @todo NOTE: Nonexistence of this field is taken to mean nonconformance
172 # to the Exif 2.1 AND 2.2 standards
173 'ExifVersion' => Exif
::UNDEFINED
, # Exif version
174 'FlashPixVersion' => Exif
::UNDEFINED
, # Supported Flashpix version #p32
176 # Tags relating to Image Data Characteristics
177 'ColorSpace' => Exif
::SHORT
, # Color space information #p32
179 # Tags relating to image configuration
180 'ComponentsConfiguration' => Exif
::UNDEFINED
, # Meaning of each component #p33
181 'CompressedBitsPerPixel' => Exif
::RATIONAL
, # Image compression mode
182 'PixelYDimension' => Exif
::SHORT_OR_LONG
, # Valid image height
183 'PixelXDimension' => Exif
::SHORT_OR_LONG
, # Valid image width
185 # Tags relating to related user information
186 'MakerNote' => Exif
::IGNORE
, # Manufacturer notes
187 'UserComment' => Exif
::UNDEFINED
, # User comments #p34
189 # Tags relating to related file information
190 'RelatedSoundFile' => Exif
::ASCII
, # Related audio file
192 # Tags relating to date and time
193 'DateTimeOriginal' => Exif
::ASCII
, # Date and time of original data generation #p36
194 'DateTimeDigitized' => Exif
::ASCII
, # Date and time of original data generation
195 'SubSecTime' => Exif
::ASCII
, # DateTime subseconds
196 'SubSecTimeOriginal' => Exif
::ASCII
, # DateTimeOriginal subseconds
197 'SubSecTimeDigitized' => Exif
::ASCII
, # DateTimeDigitized subseconds
199 # Tags relating to picture-taking conditions (p31)
200 'ExposureTime' => Exif
::RATIONAL
, # Exposure time
201 'FNumber' => Exif
::RATIONAL
, # F Number
202 'ExposureProgram' => Exif
::SHORT
, # Exposure Program #p38
203 'SpectralSensitivity' => Exif
::ASCII
, # Spectral sensitivity
204 'ISOSpeedRatings' => Exif
::SHORT
, # ISO speed rating
205 'OECF' => Exif
::IGNORE
,
206 # Optoelectronic conversion factor. Note: We don't have support for this atm.
207 'ShutterSpeedValue' => Exif
::SRATIONAL
, # Shutter speed
208 'ApertureValue' => Exif
::RATIONAL
, # Aperture
209 'BrightnessValue' => Exif
::SRATIONAL
, # Brightness
210 'ExposureBiasValue' => Exif
::SRATIONAL
, # Exposure bias
211 'MaxApertureValue' => Exif
::RATIONAL
, # Maximum land aperture
212 'SubjectDistance' => Exif
::RATIONAL
, # Subject distance
213 'MeteringMode' => Exif
::SHORT
, # Metering mode #p40
214 'LightSource' => Exif
::SHORT
, # Light source #p40-41
215 'Flash' => Exif
::SHORT
, # Flash #p41-42
216 'FocalLength' => Exif
::RATIONAL
, # Lens focal length
217 'SubjectArea' => [ Exif
::SHORT
, 4 ], # Subject area
218 'FlashEnergy' => Exif
::RATIONAL
, # Flash energy
219 'SpatialFrequencyResponse' => Exif
::IGNORE
, # Spatial frequency response. Not supported atm.
220 'FocalPlaneXResolution' => Exif
::RATIONAL
, # Focal plane X resolution
221 'FocalPlaneYResolution' => Exif
::RATIONAL
, # Focal plane Y resolution
222 'FocalPlaneResolutionUnit' => Exif
::SHORT
, # Focal plane resolution unit #p46
223 'SubjectLocation' => [ Exif
::SHORT
, 2 ], # Subject location
224 'ExposureIndex' => Exif
::RATIONAL
, # Exposure index
225 'SensingMethod' => Exif
::SHORT
, # Sensing method #p46
226 'FileSource' => Exif
::UNDEFINED
, # File source #p47
227 'SceneType' => Exif
::UNDEFINED
, # Scene type #p47
228 'CFAPattern' => Exif
::IGNORE
, # CFA pattern. not supported atm.
229 'CustomRendered' => Exif
::SHORT
, # Custom image processing #p48
230 'ExposureMode' => Exif
::SHORT
, # Exposure mode #p48
231 'WhiteBalance' => Exif
::SHORT
, # White Balance #p49
232 'DigitalZoomRatio' => Exif
::RATIONAL
, # Digital zoom ration
233 'FocalLengthIn35mmFilm' => Exif
::SHORT
, # Focal length in 35 mm film
234 'SceneCaptureType' => Exif
::SHORT
, # Scene capture type #p49
235 'GainControl' => Exif
::SHORT
, # Scene control #p49-50
236 'Contrast' => Exif
::SHORT
, # Contrast #p50
237 'Saturation' => Exif
::SHORT
, # Saturation #p50
238 'Sharpness' => Exif
::SHORT
, # Sharpness #p50
239 'DeviceSettingDescription' => Exif
::IGNORE
,
240 # Device settings description. This could maybe be supported. Need to find an
241 # example file that uses this to see if it has stuff of interest in it.
242 'SubjectDistanceRange' => Exif
::SHORT
, # Subject distance range #p51
244 'ImageUniqueID' => Exif
::ASCII
, # Unique image ID
247 # GPS Attribute Information (p52)
249 'GPSVersion' => Exif
::UNDEFINED
,
250 # Should be an array of 4 Exif::BYTE's. However php treats it as an undefined
251 # Note exif standard calls this GPSVersionID, but php doesn't like the id suffix
252 'GPSLatitudeRef' => Exif
::ASCII
, # North or South Latitude #p52-53
253 'GPSLatitude' => [ Exif
::RATIONAL
, 3 ], # Latitude
254 'GPSLongitudeRef' => Exif
::ASCII
, # East or West Longitude #p53
255 'GPSLongitude' => [ Exif
::RATIONAL
, 3 ], # Longitude
256 'GPSAltitudeRef' => Exif
::UNDEFINED
,
257 # Altitude reference. Note, the exif standard says this should be an EXIF::Byte,
258 # but php seems to disagree.
259 'GPSAltitude' => Exif
::RATIONAL
, # Altitude
260 'GPSTimeStamp' => [ Exif
::RATIONAL
, 3 ], # GPS time (atomic clock)
261 'GPSSatellites' => Exif
::ASCII
, # Satellites used for measurement
262 'GPSStatus' => Exif
::ASCII
, # Receiver status #p54
263 'GPSMeasureMode' => Exif
::ASCII
, # Measurement mode #p54-55
264 'GPSDOP' => Exif
::RATIONAL
, # Measurement precision
265 'GPSSpeedRef' => Exif
::ASCII
, # Speed unit #p55
266 'GPSSpeed' => Exif
::RATIONAL
, # Speed of GPS receiver
267 'GPSTrackRef' => Exif
::ASCII
, # Reference for direction of movement #p55
268 'GPSTrack' => Exif
::RATIONAL
, # Direction of movement
269 'GPSImgDirectionRef' => Exif
::ASCII
, # Reference for direction of image #p56
270 'GPSImgDirection' => Exif
::RATIONAL
, # Direction of image
271 'GPSMapDatum' => Exif
::ASCII
, # Geodetic survey data used
272 'GPSDestLatitudeRef' => Exif
::ASCII
, # Reference for latitude of destination #p56
273 'GPSDestLatitude' => [ Exif
::RATIONAL
, 3 ], # Latitude destination
274 'GPSDestLongitudeRef' => Exif
::ASCII
, # Reference for longitude of destination #p57
275 'GPSDestLongitude' => [ Exif
::RATIONAL
, 3 ], # Longitude of destination
276 'GPSDestBearingRef' => Exif
::ASCII
, # Reference for bearing of destination #p57
277 'GPSDestBearing' => Exif
::RATIONAL
, # Bearing of destination
278 'GPSDestDistanceRef' => Exif
::ASCII
, # Reference for distance to destination #p57-58
279 'GPSDestDistance' => Exif
::RATIONAL
, # Distance to destination
280 'GPSProcessingMethod' => Exif
::UNDEFINED
, # Name of GPS processing method
281 'GPSAreaInformation' => Exif
::UNDEFINED
, # Name of GPS area
282 'GPSDateStamp' => Exif
::ASCII
, # GPS date
283 'GPSDifferential' => Exif
::SHORT
, # GPS differential correction
288 $this->basename
= wfBaseName( $this->file
);
289 if ( $byteOrder === 'BE' ||
$byteOrder === 'LE' ) {
290 $this->byteOrder
= $byteOrder;
292 // Only give a warning for b/c, since originally we didn't
293 // require this. The number of things affected by this is
295 wfWarn( 'Exif class did not have byte order specified. ' .
296 'Some properties may be decoded incorrectly.' );
297 $this->byteOrder
= 'BE'; // BE seems about twice as popular as LE in jpg's.
300 $this->debugFile( $this->basename
, __FUNCTION__
, true );
301 if ( function_exists( 'exif_read_data' ) ) {
302 MediaWiki\
suppressWarnings();
303 $data = exif_read_data( $this->file
, 0, true );
304 MediaWiki\restoreWarnings
();
306 throw new MWException( "Internal error: exif_read_data not present. " .
307 "\$wgShowEXIF may be incorrectly set or not checked by an extension." );
310 * exif_read_data() will return false on invalid input, such as
311 * when somebody uploads a file called something.jpeg
312 * containing random gibberish.
314 $this->mRawExifData
= $data ?
: [];
315 $this->makeFilteredData();
316 $this->collapseData();
317 $this->debugFile( __FUNCTION__
, false );
321 * Make $this->mFilteredExifData
323 function makeFilteredData() {
324 $this->mFilteredExifData
= [];
326 foreach ( array_keys( $this->mRawExifData
) as $section ) {
327 if ( !array_key_exists( $section, $this->mExifTags
) ) {
328 $this->debug( $section, __FUNCTION__
, "'$section' is not a valid Exif section" );
332 foreach ( array_keys( $this->mRawExifData
[$section] ) as $tag ) {
333 if ( !array_key_exists( $tag, $this->mExifTags
[$section] ) ) {
334 $this->debug( $tag, __FUNCTION__
, "'$tag' is not a valid tag in '$section'" );
338 $this->mFilteredExifData
[$tag] = $this->mRawExifData
[$section][$tag];
339 // This is ok, as the tags in the different sections do not conflict.
340 // except in computed and thumbnail section, which we don't use.
342 $value = $this->mRawExifData
[$section][$tag];
343 if ( !$this->validate( $section, $tag, $value ) ) {
344 $this->debug( $value, __FUNCTION__
, "'$tag' contained invalid data" );
345 unset( $this->mFilteredExifData
[$tag] );
352 * Collapse some fields together.
353 * This converts some fields from exif form, to a more friendly form.
354 * For example GPS latitude to a single number.
356 * The rationale behind this is that we're storing data, not presenting to the user
357 * For example a longitude is a single number describing how far away you are from
358 * the prime meridian. Well it might be nice to split it up into minutes and seconds
359 * for the user, it doesn't really make sense to split a single number into 4 parts
360 * for storage. (degrees, minutes, second, direction vs single floating point number).
362 * Other things this might do (not really sure if they make sense or not):
363 * Dates -> mediawiki date format.
364 * convert values that can be in different units to be in one standardized unit.
366 * As an alternative approach, some of this could be done in the validate phase
367 * if we make up our own types like Exif::DATE.
369 function collapseData() {
371 $this->exifGPStoNumber( 'GPSLatitude' );
372 $this->exifGPStoNumber( 'GPSDestLatitude' );
373 $this->exifGPStoNumber( 'GPSLongitude' );
374 $this->exifGPStoNumber( 'GPSDestLongitude' );
376 if ( isset( $this->mFilteredExifData
['GPSAltitude'] )
377 && isset( $this->mFilteredExifData
['GPSAltitudeRef'] )
379 // We know altitude data is a <num>/<denom> from the validation
380 // functions ran earlier. But multiplying such a string by -1
381 // doesn't work well, so convert.
382 list( $num, $denom ) = explode( '/', $this->mFilteredExifData
['GPSAltitude'] );
383 $this->mFilteredExifData
['GPSAltitude'] = $num / $denom;
385 if ( $this->mFilteredExifData
['GPSAltitudeRef'] === "\1" ) {
386 $this->mFilteredExifData
['GPSAltitude'] *= -1;
388 unset( $this->mFilteredExifData
['GPSAltitudeRef'] );
391 $this->exifPropToOrd( 'FileSource' );
392 $this->exifPropToOrd( 'SceneType' );
394 $this->charCodeString( 'UserComment' );
395 $this->charCodeString( 'GPSProcessingMethod' );
396 $this->charCodeString( 'GPSAreaInformation' );
398 // ComponentsConfiguration should really be an array instead of a string...
399 // This turns a string of binary numbers into an array of numbers.
401 if ( isset( $this->mFilteredExifData
['ComponentsConfiguration'] ) ) {
402 $val = $this->mFilteredExifData
['ComponentsConfiguration'];
405 $strLen = strlen( $val );
406 for ( $i = 0; $i < $strLen; $i++
) {
407 $ccVals[$i] = ord( substr( $val, $i, 1 ) );
409 $ccVals['_type'] = 'ol'; // this is for formatting later.
410 $this->mFilteredExifData
['ComponentsConfiguration'] = $ccVals;
413 // GPSVersion(ID) is treated as the wrong type by php exif support.
414 // Go through each byte turning it into a version string.
415 // For example: "\x02\x02\x00\x00" -> "2.2.0.0"
417 // Also change exif tag name from GPSVersion (what php exif thinks it is)
418 // to GPSVersionID (what the exif standard thinks it is).
420 if ( isset( $this->mFilteredExifData
['GPSVersion'] ) ) {
421 $val = $this->mFilteredExifData
['GPSVersion'];
424 $strLen = strlen( $val );
425 for ( $i = 0; $i < $strLen; $i++
) {
429 $newVal .= ord( substr( $val, $i, 1 ) );
432 if ( $this->byteOrder
=== 'LE' ) {
433 // Need to reverse the string
435 for ( $i = strlen( $newVal ) - 1; $i >= 0; $i-- ) {
436 $newVal2 .= substr( $newVal, $i, 1 );
438 $this->mFilteredExifData
['GPSVersionID'] = $newVal2;
440 $this->mFilteredExifData
['GPSVersionID'] = $newVal;
442 unset( $this->mFilteredExifData
['GPSVersion'] );
447 * Do userComment tags and similar. See pg. 34 of exif standard.
448 * basically first 8 bytes is charset, rest is value.
449 * This has not been tested on any shift-JIS strings.
450 * @param string $prop Prop name
452 private function charCodeString( $prop ) {
453 if ( isset( $this->mFilteredExifData
[$prop] ) ) {
455 if ( strlen( $this->mFilteredExifData
[$prop] ) <= 8 ) {
456 // invalid. Must be at least 9 bytes long.
458 $this->debug( $this->mFilteredExifData
[$prop], __FUNCTION__
, false );
459 unset( $this->mFilteredExifData
[$prop] );
463 $charCode = substr( $this->mFilteredExifData
[$prop], 0, 8 );
464 $val = substr( $this->mFilteredExifData
[$prop], 8 );
466 switch ( $charCode ) {
467 case "\x4A\x49\x53\x00\x00\x00\x00\x00":
469 $charset = "Shift-JIS";
472 $charset = "UTF-16" . $this->byteOrder
;
474 default: // ascii or undefined.
479 MediaWiki\
suppressWarnings();
480 $val = iconv( $charset, 'UTF-8//IGNORE', $val );
481 MediaWiki\restoreWarnings
();
483 // if valid utf-8, assume that, otherwise assume windows-1252
485 UtfNormal\Validator
::quickIsNFCVerify( $valCopy ); // validates $valCopy.
486 if ( $valCopy !== $val ) {
487 MediaWiki\
suppressWarnings();
488 $val = iconv( 'Windows-1252', 'UTF-8//IGNORE', $val );
489 MediaWiki\restoreWarnings
();
493 // trim and check to make sure not only whitespace.
495 if ( strlen( $val ) === 0 ) {
497 $this->debug( $this->mFilteredExifData
[$prop], __FUNCTION__
, "$prop: Is only whitespace" );
498 unset( $this->mFilteredExifData
[$prop] );
504 $this->mFilteredExifData
[$prop] = $val;
509 * Convert an Exif::UNDEFINED from a raw binary string
510 * to its value. This is sometimes needed depending on
511 * the type of UNDEFINED field
512 * @param string $prop Name of property
514 private function exifPropToOrd( $prop ) {
515 if ( isset( $this->mFilteredExifData
[$prop] ) ) {
516 $this->mFilteredExifData
[$prop] = ord( $this->mFilteredExifData
[$prop] );
521 * Convert gps in exif form to a single floating point number
522 * for example 10 degress 20`40`` S -> -10.34444
523 * @param string $prop A GPS coordinate exif tag name (like GPSLongitude)
525 private function exifGPStoNumber( $prop ) {
526 $loc =& $this->mFilteredExifData
[$prop];
527 $dir =& $this->mFilteredExifData
[$prop . 'Ref'];
530 if ( isset( $loc ) && isset( $dir )
531 && ( $dir === 'N' ||
$dir === 'S' ||
$dir === 'E' ||
$dir === 'W' )
533 list( $num, $denom ) = explode( '/', $loc[0] );
534 $res = $num / $denom;
535 list( $num, $denom ) = explode( '/', $loc[1] );
536 $res +
= ( $num / $denom ) * ( 1 / 60 );
537 list( $num, $denom ) = explode( '/', $loc[2] );
538 $res +
= ( $num / $denom ) * ( 1 / 3600 );
540 if ( $dir === 'S' ||
$dir === 'W' ) {
541 $res *= -1; // make negative
545 // update the exif records.
547 if ( $res !== false ) { // using !== as $res could potentially be 0
548 $this->mFilteredExifData
[$prop] = $res;
549 unset( $this->mFilteredExifData
[$prop . 'Ref'] );
550 } else { // if invalid
551 unset( $this->mFilteredExifData
[$prop] );
552 unset( $this->mFilteredExifData
[$prop . 'Ref'] );
562 * Get $this->mRawExifData
566 return $this->mRawExifData
;
570 * Get $this->mFilteredExifData
573 function getFilteredData() {
574 return $this->mFilteredExifData
;
580 * The version of the output format
582 * Before the actual metadata information is saved in the database we
583 * strip some of it since we don't want to save things like thumbnails
584 * which usually accompany Exif data. This value gets saved in the
585 * database along with the actual Exif data, and if the version in the
586 * database doesn't equal the value returned by this function the Exif
587 * data is regenerated.
591 public static function version() {
592 return 2; // We don't need no bloddy constants!
596 * Validates if a tag value is of the type it should be according to the Exif spec
598 * @param mixed $in The input value to check
601 private function isByte( $in ) {
602 if ( !is_array( $in ) && sprintf( '%d', $in ) == $in && $in >= 0 && $in <= 255 ) {
603 $this->debug( $in, __FUNCTION__
, true );
607 $this->debug( $in, __FUNCTION__
, false );
614 * @param mixed $in The input value to check
617 private function isASCII( $in ) {
618 if ( is_array( $in ) ) {
622 if ( preg_match( "/[^\x0a\x20-\x7e]/", $in ) ) {
623 $this->debug( $in, __FUNCTION__
, 'found a character not in our whitelist' );
628 if ( preg_match( '/^\s*$/', $in ) ) {
629 $this->debug( $in, __FUNCTION__
, 'input consisted solely of whitespace' );
638 * @param mixed $in The input value to check
641 private function isShort( $in ) {
642 if ( !is_array( $in ) && sprintf( '%d', $in ) == $in && $in >= 0 && $in <= 65536 ) {
643 $this->debug( $in, __FUNCTION__
, true );
647 $this->debug( $in, __FUNCTION__
, false );
654 * @param mixed $in The input value to check
657 private function isLong( $in ) {
658 if ( !is_array( $in ) && sprintf( '%d', $in ) == $in && $in >= 0 && $in <= 4294967296 ) {
659 $this->debug( $in, __FUNCTION__
, true );
663 $this->debug( $in, __FUNCTION__
, false );
670 * @param mixed $in The input value to check
673 private function isRational( $in ) {
676 # Avoid division by zero
677 if ( !is_array( $in )
678 && preg_match( '/^(\d+)\/(\d+[1-9]|[1-9]\d*)$/', $in, $m )
680 return $this->isLong( $m[1] ) && $this->isLong( $m[2] );
682 $this->debug( $in, __FUNCTION__
, 'fed a non-fraction value' );
689 * @param mixed $in The input value to check
692 private function isUndefined( $in ) {
693 $this->debug( $in, __FUNCTION__
, true );
699 * @param mixed $in The input value to check
702 private function isSlong( $in ) {
703 if ( $this->isLong( abs( $in ) ) ) {
704 $this->debug( $in, __FUNCTION__
, true );
708 $this->debug( $in, __FUNCTION__
, false );
715 * @param mixed $in The input value to check
718 private function isSrational( $in ) {
721 # Avoid division by zero
722 if ( !is_array( $in ) &&
723 preg_match( '/^(-?\d+)\/(\d+[1-9]|[1-9]\d*)$/', $in, $m )
725 return $this->isSlong( $m[0] ) && $this->isSlong( $m[1] );
727 $this->debug( $in, __FUNCTION__
, 'fed a non-fraction value' );
736 * Validates if a tag has a legal value according to the Exif spec
738 * @param string $section Section where tag is located.
739 * @param string $tag The tag to check.
740 * @param mixed $val The value of the tag.
741 * @param bool $recursive True if called recursively for array types.
744 private function validate( $section, $tag, $val, $recursive = false ) {
745 $debug = "tag is '$tag'";
746 $etype = $this->mExifTags
[$section][$tag];
748 if ( is_array( $etype ) ) {
749 list( $etype, $ecount ) = $etype;
751 $ecount = 1; // checking individual elements
754 $count = count( $val );
755 if ( $ecount != $count ) {
756 $this->debug( $val, __FUNCTION__
, "Expected $ecount elements for $tag but got $count" );
761 foreach ( $val as $v ) {
762 if ( !$this->validate( $section, $tag, $v, true ) ) {
769 // Does not work if not typecast
770 switch ( (string)$etype ) {
771 case (string)Exif
::BYTE
:
772 $this->debug( $val, __FUNCTION__
, $debug );
774 return $this->isByte( $val );
775 case (string)Exif
::ASCII
:
776 $this->debug( $val, __FUNCTION__
, $debug );
778 return $this->isASCII( $val );
779 case (string)Exif
::SHORT
:
780 $this->debug( $val, __FUNCTION__
, $debug );
782 return $this->isShort( $val );
783 case (string)Exif
::LONG
:
784 $this->debug( $val, __FUNCTION__
, $debug );
786 return $this->isLong( $val );
787 case (string)Exif
::RATIONAL
:
788 $this->debug( $val, __FUNCTION__
, $debug );
790 return $this->isRational( $val );
791 case (string)Exif
::SHORT_OR_LONG
:
792 $this->debug( $val, __FUNCTION__
, $debug );
794 return $this->isShort( $val ) ||
$this->isLong( $val );
795 case (string)Exif
::UNDEFINED
:
796 $this->debug( $val, __FUNCTION__
, $debug );
798 return $this->isUndefined( $val );
799 case (string)Exif
::SLONG
:
800 $this->debug( $val, __FUNCTION__
, $debug );
802 return $this->isSlong( $val );
803 case (string)Exif
::SRATIONAL
:
804 $this->debug( $val, __FUNCTION__
, $debug );
806 return $this->isSrational( $val );
807 case (string)Exif
::IGNORE
:
808 $this->debug( $val, __FUNCTION__
, $debug );
812 $this->debug( $val, __FUNCTION__
, "The tag '$tag' is unknown" );
819 * Convenience function for debugging output
821 * @param mixed $in Arrays will be processed with print_r().
822 * @param string $fname Function name to log.
823 * @param string|bool|null $action Default null.
825 private function debug( $in, $fname, $action = null ) {
829 $type = gettype( $in );
830 $class = ucfirst( __CLASS__
);
831 if ( is_array( $in ) ) {
832 $in = print_r( $in, true );
835 if ( $action === true ) {
836 wfDebugLog( $this->log
, "$class::$fname: accepted: '$in' (type: $type)" );
837 } elseif ( $action === false ) {
838 wfDebugLog( $this->log
, "$class::$fname: rejected: '$in' (type: $type)" );
839 } elseif ( $action === null ) {
840 wfDebugLog( $this->log
, "$class::$fname: input was: '$in' (type: $type)" );
842 wfDebugLog( $this->log
, "$class::$fname: $action (type: $type; content: '$in')" );
847 * Convenience function for debugging output
849 * @param string $fname The name of the function calling this function
850 * @param bool $io Specify whether we're beginning or ending
852 private function debugFile( $fname, $io ) {
856 $class = ucfirst( __CLASS__
);
858 wfDebugLog( $this->log
, "$class::$fname: begin processing: '{$this->basename}'" );
860 wfDebugLog( $this->log
, "$class::$fname: end processing: '{$this->basename}'" );