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Diffstat (limited to 'www/wiki/includes/media/Exif.php')
| -rw-r--r-- | www/wiki/includes/media/Exif.php | 858 |
1 files changed, 858 insertions, 0 deletions
diff --git a/www/wiki/includes/media/Exif.php b/www/wiki/includes/media/Exif.php new file mode 100644 index 00000000..70f8d5c0 --- /dev/null +++ b/www/wiki/includes/media/Exif.php @@ -0,0 +1,858 @@ +<?php +/** + * Extraction and validation of image metadata. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * http://www.gnu.org/copyleft/gpl.html + * + * @ingroup Media + * @author Ævar Arnfjörð Bjarmason <avarab@gmail.com> + * @copyright Copyright © 2005, Ævar Arnfjörð Bjarmason, 2009 Brent Garber + * @license http://www.gnu.org/copyleft/gpl.html GNU General Public License + * @see http://exif.org/Exif2-2.PDF The Exif 2.2 specification + * @file + */ + +/** + * Class to extract and validate Exif data from jpeg (and possibly tiff) files. + * @ingroup Media + */ +class Exif { + /** An 8-bit (1-byte) unsigned integer. */ + const BYTE = 1; + + /** An 8-bit byte containing one 7-bit ASCII code. + * The final byte is terminated with NULL. + */ + const ASCII = 2; + + /** A 16-bit (2-byte) unsigned integer. */ + const SHORT = 3; + + /** A 32-bit (4-byte) unsigned integer. */ + const LONG = 4; + + /** Two LONGs. The first LONG is the numerator and the second LONG expresses + * the denominator + */ + const RATIONAL = 5; + + /** A 16-bit (2-byte) or 32-bit (4-byte) unsigned integer. */ + const SHORT_OR_LONG = 6; + + /** An 8-bit byte that can take any value depending on the field definition */ + const UNDEFINED = 7; + + /** A 32-bit (4-byte) signed integer (2's complement notation), */ + const SLONG = 9; + + /** Two SLONGs. The first SLONG is the numerator and the second SLONG is + * the denominator. + */ + const SRATIONAL = 10; + + /** A fake value for things we don't want or don't support. */ + const IGNORE = -1; + + /** @var array Exif tags grouped by category, the tagname itself is the key + * and the type is the value, in the case of more than one possible value + * type they are separated by commas. + */ + private $mExifTags; + + /** @var array The raw Exif data returned by exif_read_data() */ + private $mRawExifData; + + /** @var array A Filtered version of $mRawExifData that has been pruned + * of invalid tags and tags that contain content they shouldn't contain + * according to the Exif specification + */ + private $mFilteredExifData; + + /** @var string The file being processed */ + private $file; + + /** @var string The basename of the file being processed */ + private $basename; + + /** @var string The private log to log to, e.g. 'exif' */ + private $log = false; + + /** @var string The byte order of the file. Needed because php's extension + * doesn't fully process some obscure props. + */ + private $byteOrder; + + /** + * @param string $file Filename. + * @param string $byteOrder Type of byte ordering either 'BE' (Big Endian) + * or 'LE' (Little Endian). Default ''. + * @throws MWException + * @todo FIXME: The following are broke: + * SubjectArea. Need to test the more obscure tags. + * DigitalZoomRatio = 0/0 is rejected. need to determine if that's valid. + * Possibly should treat 0/0 = 0. need to read exif spec on that. + */ + function __construct( $file, $byteOrder = '' ) { + /** + * Page numbers here refer to pages in the Exif 2.2 standard + * + * Note, Exif::UNDEFINED is treated as a string, not as an array of bytes + * so don't put a count parameter for any UNDEFINED values. + * + * @link http://exif.org/Exif2-2.PDF The Exif 2.2 specification + */ + $this->mExifTags = [ + # TIFF Rev. 6.0 Attribute Information (p22) + 'IFD0' => [ + # Tags relating to image structure + 'ImageWidth' => self::SHORT_OR_LONG, # Image width + 'ImageLength' => self::SHORT_OR_LONG, # Image height + 'BitsPerSample' => [ self::SHORT, 3 ], # Number of bits per component + # "When a primary image is JPEG compressed, this designation is not" + # "necessary and is omitted." (p23) + 'Compression' => self::SHORT, # Compression scheme #p23 + 'PhotometricInterpretation' => self::SHORT, # Pixel composition #p23 + 'Orientation' => self::SHORT, # Orientation of image #p24 + 'SamplesPerPixel' => self::SHORT, # Number of components + 'PlanarConfiguration' => self::SHORT, # Image data arrangement #p24 + 'YCbCrSubSampling' => [ self::SHORT, 2 ], # Subsampling ratio of Y to C #p24 + 'YCbCrPositioning' => self::SHORT, # Y and C positioning #p24-25 + 'XResolution' => self::RATIONAL, # Image resolution in width direction + 'YResolution' => self::RATIONAL, # Image resolution in height direction + 'ResolutionUnit' => self::SHORT, # Unit of X and Y resolution #(p26) + + # Tags relating to recording offset + 'StripOffsets' => self::SHORT_OR_LONG, # Image data location + 'RowsPerStrip' => self::SHORT_OR_LONG, # Number of rows per strip + 'StripByteCounts' => self::SHORT_OR_LONG, # Bytes per compressed strip + 'JPEGInterchangeFormat' => self::SHORT_OR_LONG, # Offset to JPEG SOI + 'JPEGInterchangeFormatLength' => self::SHORT_OR_LONG, # Bytes of JPEG data + + # Tags relating to image data characteristics + 'TransferFunction' => self::IGNORE, # Transfer function + 'WhitePoint' => [ self::RATIONAL, 2 ], # White point chromaticity + 'PrimaryChromaticities' => [ self::RATIONAL, 6 ], # Chromaticities of primarities + # Color space transformation matrix coefficients #p27 + 'YCbCrCoefficients' => [ self::RATIONAL, 3 ], + 'ReferenceBlackWhite' => [ self::RATIONAL, 6 ], # Pair of black and white reference values + + # Other tags + 'DateTime' => self::ASCII, # File change date and time + 'ImageDescription' => self::ASCII, # Image title + 'Make' => self::ASCII, # Image input equipment manufacturer + 'Model' => self::ASCII, # Image input equipment model + 'Software' => self::ASCII, # Software used + 'Artist' => self::ASCII, # Person who created the image + 'Copyright' => self::ASCII, # Copyright holder + ], + + # Exif IFD Attribute Information (p30-31) + 'EXIF' => [ + # @todo NOTE: Nonexistence of this field is taken to mean nonconformance + # to the Exif 2.1 AND 2.2 standards + 'ExifVersion' => self::UNDEFINED, # Exif version + 'FlashPixVersion' => self::UNDEFINED, # Supported Flashpix version #p32 + + # Tags relating to Image Data Characteristics + 'ColorSpace' => self::SHORT, # Color space information #p32 + + # Tags relating to image configuration + 'ComponentsConfiguration' => self::UNDEFINED, # Meaning of each component #p33 + 'CompressedBitsPerPixel' => self::RATIONAL, # Image compression mode + 'PixelYDimension' => self::SHORT_OR_LONG, # Valid image height + 'PixelXDimension' => self::SHORT_OR_LONG, # Valid image width + + # Tags relating to related user information + 'MakerNote' => self::IGNORE, # Manufacturer notes + 'UserComment' => self::UNDEFINED, # User comments #p34 + + # Tags relating to related file information + 'RelatedSoundFile' => self::ASCII, # Related audio file + + # Tags relating to date and time + 'DateTimeOriginal' => self::ASCII, # Date and time of original data generation #p36 + 'DateTimeDigitized' => self::ASCII, # Date and time of original data generation + 'SubSecTime' => self::ASCII, # DateTime subseconds + 'SubSecTimeOriginal' => self::ASCII, # DateTimeOriginal subseconds + 'SubSecTimeDigitized' => self::ASCII, # DateTimeDigitized subseconds + + # Tags relating to picture-taking conditions (p31) + 'ExposureTime' => self::RATIONAL, # Exposure time + 'FNumber' => self::RATIONAL, # F Number + 'ExposureProgram' => self::SHORT, # Exposure Program #p38 + 'SpectralSensitivity' => self::ASCII, # Spectral sensitivity + 'ISOSpeedRatings' => self::SHORT, # ISO speed rating + 'OECF' => self::IGNORE, + # Optoelectronic conversion factor. Note: We don't have support for this atm. + 'ShutterSpeedValue' => self::SRATIONAL, # Shutter speed + 'ApertureValue' => self::RATIONAL, # Aperture + 'BrightnessValue' => self::SRATIONAL, # Brightness + 'ExposureBiasValue' => self::SRATIONAL, # Exposure bias + 'MaxApertureValue' => self::RATIONAL, # Maximum land aperture + 'SubjectDistance' => self::RATIONAL, # Subject distance + 'MeteringMode' => self::SHORT, # Metering mode #p40 + 'LightSource' => self::SHORT, # Light source #p40-41 + 'Flash' => self::SHORT, # Flash #p41-42 + 'FocalLength' => self::RATIONAL, # Lens focal length + 'SubjectArea' => [ self::SHORT, 4 ], # Subject area + 'FlashEnergy' => self::RATIONAL, # Flash energy + 'SpatialFrequencyResponse' => self::IGNORE, # Spatial frequency response. Not supported atm. + 'FocalPlaneXResolution' => self::RATIONAL, # Focal plane X resolution + 'FocalPlaneYResolution' => self::RATIONAL, # Focal plane Y resolution + 'FocalPlaneResolutionUnit' => self::SHORT, # Focal plane resolution unit #p46 + 'SubjectLocation' => [ self::SHORT, 2 ], # Subject location + 'ExposureIndex' => self::RATIONAL, # Exposure index + 'SensingMethod' => self::SHORT, # Sensing method #p46 + 'FileSource' => self::UNDEFINED, # File source #p47 + 'SceneType' => self::UNDEFINED, # Scene type #p47 + 'CFAPattern' => self::IGNORE, # CFA pattern. not supported atm. + 'CustomRendered' => self::SHORT, # Custom image processing #p48 + 'ExposureMode' => self::SHORT, # Exposure mode #p48 + 'WhiteBalance' => self::SHORT, # White Balance #p49 + 'DigitalZoomRatio' => self::RATIONAL, # Digital zoom ration + 'FocalLengthIn35mmFilm' => self::SHORT, # Focal length in 35 mm film + 'SceneCaptureType' => self::SHORT, # Scene capture type #p49 + 'GainControl' => self::SHORT, # Scene control #p49-50 + 'Contrast' => self::SHORT, # Contrast #p50 + 'Saturation' => self::SHORT, # Saturation #p50 + 'Sharpness' => self::SHORT, # Sharpness #p50 + 'DeviceSettingDescription' => self::IGNORE, + # Device settings description. This could maybe be supported. Need to find an + # example file that uses this to see if it has stuff of interest in it. + 'SubjectDistanceRange' => self::SHORT, # Subject distance range #p51 + + 'ImageUniqueID' => self::ASCII, # Unique image ID + ], + + # GPS Attribute Information (p52) + 'GPS' => [ + 'GPSVersion' => self::UNDEFINED, + # Should be an array of 4 Exif::BYTE's. However php treats it as an undefined + # Note exif standard calls this GPSVersionID, but php doesn't like the id suffix + 'GPSLatitudeRef' => self::ASCII, # North or South Latitude #p52-53 + 'GPSLatitude' => [ self::RATIONAL, 3 ], # Latitude + 'GPSLongitudeRef' => self::ASCII, # East or West Longitude #p53 + 'GPSLongitude' => [ self::RATIONAL, 3 ], # Longitude + 'GPSAltitudeRef' => self::UNDEFINED, + # Altitude reference. Note, the exif standard says this should be an EXIF::Byte, + # but php seems to disagree. + 'GPSAltitude' => self::RATIONAL, # Altitude + 'GPSTimeStamp' => [ self::RATIONAL, 3 ], # GPS time (atomic clock) + 'GPSSatellites' => self::ASCII, # Satellites used for measurement + 'GPSStatus' => self::ASCII, # Receiver status #p54 + 'GPSMeasureMode' => self::ASCII, # Measurement mode #p54-55 + 'GPSDOP' => self::RATIONAL, # Measurement precision + 'GPSSpeedRef' => self::ASCII, # Speed unit #p55 + 'GPSSpeed' => self::RATIONAL, # Speed of GPS receiver + 'GPSTrackRef' => self::ASCII, # Reference for direction of movement #p55 + 'GPSTrack' => self::RATIONAL, # Direction of movement + 'GPSImgDirectionRef' => self::ASCII, # Reference for direction of image #p56 + 'GPSImgDirection' => self::RATIONAL, # Direction of image + 'GPSMapDatum' => self::ASCII, # Geodetic survey data used + 'GPSDestLatitudeRef' => self::ASCII, # Reference for latitude of destination #p56 + 'GPSDestLatitude' => [ self::RATIONAL, 3 ], # Latitude destination + 'GPSDestLongitudeRef' => self::ASCII, # Reference for longitude of destination #p57 + 'GPSDestLongitude' => [ self::RATIONAL, 3 ], # Longitude of destination + 'GPSDestBearingRef' => self::ASCII, # Reference for bearing of destination #p57 + 'GPSDestBearing' => self::RATIONAL, # Bearing of destination + 'GPSDestDistanceRef' => self::ASCII, # Reference for distance to destination #p57-58 + 'GPSDestDistance' => self::RATIONAL, # Distance to destination + 'GPSProcessingMethod' => self::UNDEFINED, # Name of GPS processing method + 'GPSAreaInformation' => self::UNDEFINED, # Name of GPS area + 'GPSDateStamp' => self::ASCII, # GPS date + 'GPSDifferential' => self::SHORT, # GPS differential correction + ], + ]; + + $this->file = $file; + $this->basename = wfBaseName( $this->file ); + if ( $byteOrder === 'BE' || $byteOrder === 'LE' ) { + $this->byteOrder = $byteOrder; + } else { + // Only give a warning for b/c, since originally we didn't + // require this. The number of things affected by this is + // rather small. + wfWarn( 'Exif class did not have byte order specified. ' . + 'Some properties may be decoded incorrectly.' ); + $this->byteOrder = 'BE'; // BE seems about twice as popular as LE in jpg's. + } + + $this->debugFile( $this->basename, __FUNCTION__, true ); + if ( function_exists( 'exif_read_data' ) ) { + Wikimedia\suppressWarnings(); + $data = exif_read_data( $this->file, 0, true ); + Wikimedia\restoreWarnings(); + } else { + throw new MWException( "Internal error: exif_read_data not present. " . + "\$wgShowEXIF may be incorrectly set or not checked by an extension." ); + } + /** + * exif_read_data() will return false on invalid input, such as + * when somebody uploads a file called something.jpeg + * containing random gibberish. + */ + $this->mRawExifData = $data ?: []; + $this->makeFilteredData(); + $this->collapseData(); + $this->debugFile( __FUNCTION__, false ); + } + + /** + * Make $this->mFilteredExifData + */ + function makeFilteredData() { + $this->mFilteredExifData = []; + + foreach ( array_keys( $this->mRawExifData ) as $section ) { + if ( !array_key_exists( $section, $this->mExifTags ) ) { + $this->debug( $section, __FUNCTION__, "'$section' is not a valid Exif section" ); + continue; + } + + foreach ( array_keys( $this->mRawExifData[$section] ) as $tag ) { + if ( !array_key_exists( $tag, $this->mExifTags[$section] ) ) { + $this->debug( $tag, __FUNCTION__, "'$tag' is not a valid tag in '$section'" ); + continue; + } + + $this->mFilteredExifData[$tag] = $this->mRawExifData[$section][$tag]; + // This is ok, as the tags in the different sections do not conflict. + // except in computed and thumbnail section, which we don't use. + + $value = $this->mRawExifData[$section][$tag]; + if ( !$this->validate( $section, $tag, $value ) ) { + $this->debug( $value, __FUNCTION__, "'$tag' contained invalid data" ); + unset( $this->mFilteredExifData[$tag] ); + } + } + } + } + + /** + * Collapse some fields together. + * This converts some fields from exif form, to a more friendly form. + * For example GPS latitude to a single number. + * + * The rationale behind this is that we're storing data, not presenting to the user + * For example a longitude is a single number describing how far away you are from + * the prime meridian. Well it might be nice to split it up into minutes and seconds + * for the user, it doesn't really make sense to split a single number into 4 parts + * for storage. (degrees, minutes, second, direction vs single floating point number). + * + * Other things this might do (not really sure if they make sense or not): + * Dates -> mediawiki date format. + * convert values that can be in different units to be in one standardized unit. + * + * As an alternative approach, some of this could be done in the validate phase + * if we make up our own types like Exif::DATE. + */ + function collapseData() { + $this->exifGPStoNumber( 'GPSLatitude' ); + $this->exifGPStoNumber( 'GPSDestLatitude' ); + $this->exifGPStoNumber( 'GPSLongitude' ); + $this->exifGPStoNumber( 'GPSDestLongitude' ); + + if ( isset( $this->mFilteredExifData['GPSAltitude'] ) + && isset( $this->mFilteredExifData['GPSAltitudeRef'] ) + ) { + // We know altitude data is a <num>/<denom> from the validation + // functions ran earlier. But multiplying such a string by -1 + // doesn't work well, so convert. + list( $num, $denom ) = explode( '/', $this->mFilteredExifData['GPSAltitude'] ); + $this->mFilteredExifData['GPSAltitude'] = $num / $denom; + + if ( $this->mFilteredExifData['GPSAltitudeRef'] === "\1" ) { + $this->mFilteredExifData['GPSAltitude'] *= -1; + } + unset( $this->mFilteredExifData['GPSAltitudeRef'] ); + } + + $this->exifPropToOrd( 'FileSource' ); + $this->exifPropToOrd( 'SceneType' ); + + $this->charCodeString( 'UserComment' ); + $this->charCodeString( 'GPSProcessingMethod' ); + $this->charCodeString( 'GPSAreaInformation' ); + + // ComponentsConfiguration should really be an array instead of a string... + // This turns a string of binary numbers into an array of numbers. + + if ( isset( $this->mFilteredExifData['ComponentsConfiguration'] ) ) { + $val = $this->mFilteredExifData['ComponentsConfiguration']; + $ccVals = []; + + $strLen = strlen( $val ); + for ( $i = 0; $i < $strLen; $i++ ) { + $ccVals[$i] = ord( substr( $val, $i, 1 ) ); + } + $ccVals['_type'] = 'ol'; // this is for formatting later. + $this->mFilteredExifData['ComponentsConfiguration'] = $ccVals; + } + + // GPSVersion(ID) is treated as the wrong type by php exif support. + // Go through each byte turning it into a version string. + // For example: "\x02\x02\x00\x00" -> "2.2.0.0" + + // Also change exif tag name from GPSVersion (what php exif thinks it is) + // to GPSVersionID (what the exif standard thinks it is). + + if ( isset( $this->mFilteredExifData['GPSVersion'] ) ) { + $val = $this->mFilteredExifData['GPSVersion']; + $newVal = ''; + + $strLen = strlen( $val ); + for ( $i = 0; $i < $strLen; $i++ ) { + if ( $i !== 0 ) { + $newVal .= '.'; + } + $newVal .= ord( substr( $val, $i, 1 ) ); + } + + if ( $this->byteOrder === 'LE' ) { + // Need to reverse the string + $newVal2 = ''; + for ( $i = strlen( $newVal ) - 1; $i >= 0; $i-- ) { + $newVal2 .= substr( $newVal, $i, 1 ); + } + $this->mFilteredExifData['GPSVersionID'] = $newVal2; + } else { + $this->mFilteredExifData['GPSVersionID'] = $newVal; + } + unset( $this->mFilteredExifData['GPSVersion'] ); + } + } + + /** + * Do userComment tags and similar. See pg. 34 of exif standard. + * basically first 8 bytes is charset, rest is value. + * This has not been tested on any shift-JIS strings. + * @param string $prop Prop name + */ + private function charCodeString( $prop ) { + if ( isset( $this->mFilteredExifData[$prop] ) ) { + if ( strlen( $this->mFilteredExifData[$prop] ) <= 8 ) { + // invalid. Must be at least 9 bytes long. + + $this->debug( $this->mFilteredExifData[$prop], __FUNCTION__, false ); + unset( $this->mFilteredExifData[$prop] ); + + return; + } + $charCode = substr( $this->mFilteredExifData[$prop], 0, 8 ); + $val = substr( $this->mFilteredExifData[$prop], 8 ); + + switch ( $charCode ) { + case "\x4A\x49\x53\x00\x00\x00\x00\x00": + // JIS + $charset = "Shift-JIS"; + break; + case "UNICODE\x00": + $charset = "UTF-16" . $this->byteOrder; + break; + default: // ascii or undefined. + $charset = ""; + break; + } + if ( $charset ) { + Wikimedia\suppressWarnings(); + $val = iconv( $charset, 'UTF-8//IGNORE', $val ); + Wikimedia\restoreWarnings(); + } else { + // if valid utf-8, assume that, otherwise assume windows-1252 + $valCopy = $val; + UtfNormal\Validator::quickIsNFCVerify( $valCopy ); // validates $valCopy. + if ( $valCopy !== $val ) { + Wikimedia\suppressWarnings(); + $val = iconv( 'Windows-1252', 'UTF-8//IGNORE', $val ); + Wikimedia\restoreWarnings(); + } + } + + // trim and check to make sure not only whitespace. + $val = trim( $val ); + if ( strlen( $val ) === 0 ) { + // only whitespace. + $this->debug( $this->mFilteredExifData[$prop], __FUNCTION__, "$prop: Is only whitespace" ); + unset( $this->mFilteredExifData[$prop] ); + + return; + } + + // all's good. + $this->mFilteredExifData[$prop] = $val; + } + } + + /** + * Convert an Exif::UNDEFINED from a raw binary string + * to its value. This is sometimes needed depending on + * the type of UNDEFINED field + * @param string $prop Name of property + */ + private function exifPropToOrd( $prop ) { + if ( isset( $this->mFilteredExifData[$prop] ) ) { + $this->mFilteredExifData[$prop] = ord( $this->mFilteredExifData[$prop] ); + } + } + + /** + * Convert gps in exif form to a single floating point number + * for example 10 degress 20`40`` S -> -10.34444 + * @param string $prop A GPS coordinate exif tag name (like GPSLongitude) + */ + private function exifGPStoNumber( $prop ) { + $loc =& $this->mFilteredExifData[$prop]; + $dir =& $this->mFilteredExifData[$prop . 'Ref']; + $res = false; + + if ( isset( $loc ) && isset( $dir ) + && ( $dir === 'N' || $dir === 'S' || $dir === 'E' || $dir === 'W' ) + ) { + list( $num, $denom ) = explode( '/', $loc[0] ); + $res = $num / $denom; + list( $num, $denom ) = explode( '/', $loc[1] ); + $res += ( $num / $denom ) * ( 1 / 60 ); + list( $num, $denom ) = explode( '/', $loc[2] ); + $res += ( $num / $denom ) * ( 1 / 3600 ); + + if ( $dir === 'S' || $dir === 'W' ) { + $res *= -1; // make negative + } + } + + // update the exif records. + + if ( $res !== false ) { // using !== as $res could potentially be 0 + $this->mFilteredExifData[$prop] = $res; + unset( $this->mFilteredExifData[$prop . 'Ref'] ); + } else { // if invalid + unset( $this->mFilteredExifData[$prop] ); + unset( $this->mFilteredExifData[$prop . 'Ref'] ); + } + } + + /**#@-*/ + + /**#@+ + * @return array + */ + /** + * Get $this->mRawExifData + * @return array + */ + function getData() { + return $this->mRawExifData; + } + + /** + * Get $this->mFilteredExifData + * @return array + */ + function getFilteredData() { + return $this->mFilteredExifData; + } + + /**#@-*/ + + /** + * The version of the output format + * + * Before the actual metadata information is saved in the database we + * strip some of it since we don't want to save things like thumbnails + * which usually accompany Exif data. This value gets saved in the + * database along with the actual Exif data, and if the version in the + * database doesn't equal the value returned by this function the Exif + * data is regenerated. + * + * @return int + */ + public static function version() { + return 2; // We don't need no bloddy constants! + } + + /** + * Validates if a tag value is of the type it should be according to the Exif spec + * + * @param mixed $in The input value to check + * @return bool + */ + private function isByte( $in ) { + if ( !is_array( $in ) && sprintf( '%d', $in ) == $in && $in >= 0 && $in <= 255 ) { + $this->debug( $in, __FUNCTION__, true ); + + return true; + } else { + $this->debug( $in, __FUNCTION__, false ); + + return false; + } + } + + /** + * @param mixed $in The input value to check + * @return bool + */ + private function isASCII( $in ) { + if ( is_array( $in ) ) { + return false; + } + + if ( preg_match( "/[^\x0a\x20-\x7e]/", $in ) ) { + $this->debug( $in, __FUNCTION__, 'found a character not in our whitelist' ); + + return false; + } + + if ( preg_match( '/^\s*$/', $in ) ) { + $this->debug( $in, __FUNCTION__, 'input consisted solely of whitespace' ); + + return false; + } + + return true; + } + + /** + * @param mixed $in The input value to check + * @return bool + */ + private function isShort( $in ) { + if ( !is_array( $in ) && sprintf( '%d', $in ) == $in && $in >= 0 && $in <= 65536 ) { + $this->debug( $in, __FUNCTION__, true ); + + return true; + } else { + $this->debug( $in, __FUNCTION__, false ); + + return false; + } + } + + /** + * @param mixed $in The input value to check + * @return bool + */ + private function isLong( $in ) { + if ( !is_array( $in ) && sprintf( '%d', $in ) == $in && $in >= 0 && $in <= 4294967296 ) { + $this->debug( $in, __FUNCTION__, true ); + + return true; + } else { + $this->debug( $in, __FUNCTION__, false ); + + return false; + } + } + + /** + * @param mixed $in The input value to check + * @return bool + */ + private function isRational( $in ) { + $m = []; + + # Avoid division by zero + if ( !is_array( $in ) + && preg_match( '/^(\d+)\/(\d+[1-9]|[1-9]\d*)$/', $in, $m ) + ) { + return $this->isLong( $m[1] ) && $this->isLong( $m[2] ); + } else { + $this->debug( $in, __FUNCTION__, 'fed a non-fraction value' ); + + return false; + } + } + + /** + * @param mixed $in The input value to check + * @return bool + */ + private function isUndefined( $in ) { + $this->debug( $in, __FUNCTION__, true ); + + return true; + } + + /** + * @param mixed $in The input value to check + * @return bool + */ + private function isSlong( $in ) { + if ( $this->isLong( abs( $in ) ) ) { + $this->debug( $in, __FUNCTION__, true ); + + return true; + } else { + $this->debug( $in, __FUNCTION__, false ); + + return false; + } + } + + /** + * @param mixed $in The input value to check + * @return bool + */ + private function isSrational( $in ) { + $m = []; + + # Avoid division by zero + if ( !is_array( $in ) && + preg_match( '/^(-?\d+)\/(\d+[1-9]|[1-9]\d*)$/', $in, $m ) + ) { + return $this->isSlong( $m[0] ) && $this->isSlong( $m[1] ); + } else { + $this->debug( $in, __FUNCTION__, 'fed a non-fraction value' ); + + return false; + } + } + + /**#@-*/ + + /** + * Validates if a tag has a legal value according to the Exif spec + * + * @param string $section Section where tag is located. + * @param string $tag The tag to check. + * @param mixed $val The value of the tag. + * @param bool $recursive True if called recursively for array types. + * @return bool + */ + private function validate( $section, $tag, $val, $recursive = false ) { + $debug = "tag is '$tag'"; + $etype = $this->mExifTags[$section][$tag]; + $ecount = 1; + if ( is_array( $etype ) ) { + list( $etype, $ecount ) = $etype; + if ( $recursive ) { + $ecount = 1; // checking individual elements + } + } + + $count = 1; + if ( is_array( $val ) ) { + $count = count( $val ); + if ( $ecount != $count ) { + $this->debug( $val, __FUNCTION__, "Expected $ecount elements for $tag but got $count" ); + return false; + } + } + // If there are multiple values, recursively validate each of them. + if ( $count > 1 ) { + foreach ( $val as $v ) { + if ( !$this->validate( $section, $tag, $v, true ) ) { + return false; + } + } + + return true; + } + // Does not work if not typecast + switch ( (string)$etype ) { + case (string)self::BYTE: + $this->debug( $val, __FUNCTION__, $debug ); + + return $this->isByte( $val ); + case (string)self::ASCII: + $this->debug( $val, __FUNCTION__, $debug ); + + return $this->isASCII( $val ); + case (string)self::SHORT: + $this->debug( $val, __FUNCTION__, $debug ); + + return $this->isShort( $val ); + case (string)self::LONG: + $this->debug( $val, __FUNCTION__, $debug ); + + return $this->isLong( $val ); + case (string)self::RATIONAL: + $this->debug( $val, __FUNCTION__, $debug ); + + return $this->isRational( $val ); + case (string)self::SHORT_OR_LONG: + $this->debug( $val, __FUNCTION__, $debug ); + + return $this->isShort( $val ) || $this->isLong( $val ); + case (string)self::UNDEFINED: + $this->debug( $val, __FUNCTION__, $debug ); + + return $this->isUndefined( $val ); + case (string)self::SLONG: + $this->debug( $val, __FUNCTION__, $debug ); + + return $this->isSlong( $val ); + case (string)self::SRATIONAL: + $this->debug( $val, __FUNCTION__, $debug ); + + return $this->isSrational( $val ); + case (string)self::IGNORE: + $this->debug( $val, __FUNCTION__, $debug ); + + return false; + default: + $this->debug( $val, __FUNCTION__, "The tag '$tag' is unknown" ); + + return false; + } + } + + /** + * Convenience function for debugging output + * + * @param mixed $in Arrays will be processed with print_r(). + * @param string $fname Function name to log. + * @param string|bool|null $action Default null. + */ + private function debug( $in, $fname, $action = null ) { + if ( !$this->log ) { + return; + } + $type = gettype( $in ); + $class = ucfirst( __CLASS__ ); + if ( is_array( $in ) ) { + $in = print_r( $in, true ); + } + + if ( $action === true ) { + wfDebugLog( $this->log, "$class::$fname: accepted: '$in' (type: $type)" ); + } elseif ( $action === false ) { + wfDebugLog( $this->log, "$class::$fname: rejected: '$in' (type: $type)" ); + } elseif ( $action === null ) { + wfDebugLog( $this->log, "$class::$fname: input was: '$in' (type: $type)" ); + } else { + wfDebugLog( $this->log, "$class::$fname: $action (type: $type; content: '$in')" ); + } + } + + /** + * Convenience function for debugging output + * + * @param string $fname The name of the function calling this function + * @param bool $io Specify whether we're beginning or ending + */ + private function debugFile( $fname, $io ) { + if ( !$this->log ) { + return; + } + $class = ucfirst( __CLASS__ ); + if ( $io ) { + wfDebugLog( $this->log, "$class::$fname: begin processing: '{$this->basename}'" ); + } else { + wfDebugLog( $this->log, "$class::$fname: end processing: '{$this->basename}'" ); + } + } +} |