<?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 {
const BYTE = 1; //!< An 8-bit (1-byte) unsigned integer.
const ASCII = 2; //!< An 8-bit byte containing one 7-bit ASCII code. The final byte is terminated with NULL.
const SHORT = 3; //!< A 16-bit (2-byte) unsigned integer.
const LONG = 4; //!< A 32-bit (4-byte) unsigned integer.
const RATIONAL = 5; //!< Two LONGs. The first LONG is the numerator and the second LONG expresses the denominator
const SHORT_OR_LONG = 6; //!< A 16-bit (2-byte) or 32-bit (4-byte) unsigned integer.
const UNDEFINED = 7; //!< An 8-bit byte that can take any value depending on the field definition
const SLONG = 9; //!< A 32-bit (4-byte) signed integer (2's complement notation),
const SRATIONAL = 10; //!< Two SLONGs. The first SLONG is the numerator and the second SLONG is the denominator.
const IGNORE = -1; // A fake value for things we don't want or don't support.
//@{
/* @var array
* @private
*/
/**
* 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.
*/
var $mExifTags;
/**
* The raw Exif data returned by exif_read_data()
*/
var $mRawExifData;
/**
* 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
*/
var $mFilteredExifData;
/**
* Filtered and formatted Exif data, see FormatMetadata::getFormattedData()
*/
var $mFormattedExifData;
//@}
//@{
/* @var string
* @private
*/
/**
* The file being processed
*/
var $file;
/**
* The basename of the file being processed
*/
var $basename;
/**
* The private log to log to, e.g. 'exif'
*/
var $log = false;
/**
* The byte order of the file. Needed because php's
* extension doesn't fully process some obscure props.
*/
private $byteOrder;
//@}
/**
* Constructor
*
* @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 = array(
# TIFF Rev. 6.0 Attribute Information (p22)
'IFD0' => array(
# Tags relating to image structure
'ImageWidth' => Exif::SHORT_OR_LONG, # Image width
'ImageLength' => Exif::SHORT_OR_LONG, # Image height
'BitsPerSample' => array( Exif::SHORT, 3 ), # Number of bits per component
# "When a primary image is JPEG compressed, this designation is not"
# "necessary and is omitted." (p23)
'Compression' => Exif::SHORT, # Compression scheme #p23
'PhotometricInterpretation' => Exif::SHORT, # Pixel composition #p23
'Orientation' => Exif::SHORT, # Orientation of image #p24
'SamplesPerPixel' => Exif::SHORT, # Number of components
'PlanarConfiguration' => Exif::SHORT, # Image data arrangement #p24
'YCbCrSubSampling' => array( Exif::SHORT, 2 ), # Subsampling ratio of Y to C #p24
'YCbCrPositioning' => Exif::SHORT, # Y and C positioning #p24-25
'XResolution' => Exif::RATIONAL, # Image resolution in width direction
'YResolution' => Exif::RATIONAL, # Image resolution in height direction
'ResolutionUnit' => Exif::SHORT, # Unit of X and Y resolution #(p26)
# Tags relating to recording offset
'StripOffsets' => Exif::SHORT_OR_LONG, # Image data location
'RowsPerStrip' => Exif::SHORT_OR_LONG, # Number of rows per strip
'StripByteCounts' => Exif::SHORT_OR_LONG, # Bytes per compressed strip
'JPEGInterchangeFormat' => Exif::SHORT_OR_LONG, # Offset to JPEG SOI
'JPEGInterchangeFormatLength' => Exif::SHORT_OR_LONG, # Bytes of JPEG data
# Tags relating to image data characteristics
'TransferFunction' => Exif::IGNORE, # Transfer function
'WhitePoint' => array( Exif::RATIONAL, 2 ), # White point chromaticity
'PrimaryChromaticities' => array( Exif::RATIONAL, 6 ), # Chromaticities of primarities
'YCbCrCoefficients' => array( Exif::RATIONAL, 3 ), # Color space transformation matrix coefficients #p27
'ReferenceBlackWhite' => array( Exif::RATIONAL, 6 ), # Pair of black and white reference values
# Other tags
'DateTime' => Exif::ASCII, # File change date and time
'ImageDescription' => Exif::ASCII, # Image title
'Make' => Exif::ASCII, # Image input equipment manufacturer
'Model' => Exif::ASCII, # Image input equipment model
'Software' => Exif::ASCII, # Software used
'Artist' => Exif::ASCII, # Person who created the image
'Copyright' => Exif::ASCII, # Copyright holder
),
# Exif IFD Attribute Information (p30-31)
'EXIF' => array(
# TODO: NOTE: Nonexistence of this field is taken to mean nonconformance
# to the Exif 2.1 AND 2.2 standards
'ExifVersion' => Exif::UNDEFINED, # Exif version
'FlashPixVersion' => Exif::UNDEFINED, # Supported Flashpix version #p32
# Tags relating to Image Data Characteristics
'ColorSpace' => Exif::SHORT, # Color space information #p32
# Tags relating to image configuration
'ComponentsConfiguration' => Exif::UNDEFINED, # Meaning of each component #p33
'CompressedBitsPerPixel' => Exif::RATIONAL, # Image compression mode
'PixelYDimension' => Exif::SHORT_OR_LONG, # Valid image width
'PixelXDimension' => Exif::SHORT_OR_LONG, # Valid image height
# Tags relating to related user information
'MakerNote' => Exif::IGNORE, # Manufacturer notes
'UserComment' => Exif::UNDEFINED, # User comments #p34
# Tags relating to related file information
'RelatedSoundFile' => Exif::ASCII, # Related audio file
# Tags relating to date and time
'DateTimeOriginal' => Exif::ASCII, # Date and time of original data generation #p36
'DateTimeDigitized' => Exif::ASCII, # Date and time of original data generation
'SubSecTime' => Exif::ASCII, # DateTime subseconds
'SubSecTimeOriginal' => Exif::ASCII, # DateTimeOriginal subseconds
'SubSecTimeDigitized' => Exif::ASCII, # DateTimeDigitized subseconds
# Tags relating to picture-taking conditions (p31)
'ExposureTime' => Exif::RATIONAL, # Exposure time
'FNumber' => Exif::RATIONAL, # F Number
'ExposureProgram' => Exif::SHORT, # Exposure Program #p38
'SpectralSensitivity' => Exif::ASCII, # Spectral sensitivity
'ISOSpeedRatings' => Exif::SHORT, # ISO speed rating
'OECF' => Exif::IGNORE,
# Optoelectronic conversion factor. Note: We don't have support for this atm.
'ShutterSpeedValue' => Exif::SRATIONAL, # Shutter speed
'ApertureValue' => Exif::RATIONAL, # Aperture
'BrightnessValue' => Exif::SRATIONAL, # Brightness
'ExposureBiasValue' => Exif::SRATIONAL, # Exposure bias
'MaxApertureValue' => Exif::RATIONAL, # Maximum land aperture
'SubjectDistance' => Exif::RATIONAL, # Subject distance
'MeteringMode' => Exif::SHORT, # Metering mode #p40
'LightSource' => Exif::SHORT, # Light source #p40-41
'Flash' => Exif::SHORT, # Flash #p41-42
'FocalLength' => Exif::RATIONAL, # Lens focal length
'SubjectArea' => array( Exif::SHORT, 4 ), # Subject area
'FlashEnergy' => Exif::RATIONAL, # Flash energy
'SpatialFrequencyResponse' => Exif::IGNORE, # Spatial frequency response. Not supported atm.
'FocalPlaneXResolution' => Exif::RATIONAL, # Focal plane X resolution
'FocalPlaneYResolution' => Exif::RATIONAL, # Focal plane Y resolution
'FocalPlaneResolutionUnit' => Exif::SHORT, # Focal plane resolution unit #p46
'SubjectLocation' => array( Exif::SHORT, 2 ), # Subject location
'ExposureIndex' => Exif::RATIONAL, # Exposure index
'SensingMethod' => Exif::SHORT, # Sensing method #p46
'FileSource' => Exif::UNDEFINED, # File source #p47
'SceneType' => Exif::UNDEFINED, # Scene type #p47
'CFAPattern' => Exif::IGNORE, # CFA pattern. not supported atm.
'CustomRendered' => Exif::SHORT, # Custom image processing #p48
'ExposureMode' => Exif::SHORT, # Exposure mode #p48
'WhiteBalance' => Exif::SHORT, # White Balance #p49
'DigitalZoomRatio' => Exif::RATIONAL, # Digital zoom ration
'FocalLengthIn35mmFilm' => Exif::SHORT, # Focal length in 35 mm film
'SceneCaptureType' => Exif::SHORT, # Scene capture type #p49
'GainControl' => Exif::SHORT, # Scene control #p49-50
'Contrast' => Exif::SHORT, # Contrast #p50
'Saturation' => Exif::SHORT, # Saturation #p50
'Sharpness' => Exif::SHORT, # Sharpness #p50
'DeviceSettingDescription' => Exif::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' => Exif::SHORT, # Subject distance range #p51
'ImageUniqueID' => Exif::ASCII, # Unique image ID
),
# GPS Attribute Information (p52)
'GPS' => array(
'GPSVersion' => Exif::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' => Exif::ASCII, # North or South Latitude #p52-53
'GPSLatitude' => array( Exif::RATIONAL, 3 ), # Latitude
'GPSLongitudeRef' => Exif::ASCII, # East or West Longitude #p53
'GPSLongitude' => array( Exif::RATIONAL, 3 ), # Longitude
'GPSAltitudeRef' => Exif::UNDEFINED,
# Altitude reference. Note, the exif standard says this should be an EXIF::Byte,
# but php seems to disagree.
'GPSAltitude' => Exif::RATIONAL, # Altitude
'GPSTimeStamp' => array( Exif::RATIONAL, 3 ), # GPS time (atomic clock)
'GPSSatellites' => Exif::ASCII, # Satellites used for measurement
'GPSStatus' => Exif::ASCII, # Receiver status #p54
'GPSMeasureMode' => Exif::ASCII, # Measurement mode #p54-55
'GPSDOP' => Exif::RATIONAL, # Measurement precision
'GPSSpeedRef' => Exif::ASCII, # Speed unit #p55
'GPSSpeed' => Exif::RATIONAL, # Speed of GPS receiver
'GPSTrackRef' => Exif::ASCII, # Reference for direction of movement #p55
'GPSTrack' => Exif::RATIONAL, # Direction of movement
'GPSImgDirectionRef' => Exif::ASCII, # Reference for direction of image #p56
'GPSImgDirection' => Exif::RATIONAL, # Direction of image
'GPSMapDatum' => Exif::ASCII, # Geodetic survey data used
'GPSDestLatitudeRef' => Exif::ASCII, # Reference for latitude of destination #p56
'GPSDestLatitude' => array( Exif::RATIONAL, 3 ), # Latitude destination
'GPSDestLongitudeRef' => Exif::ASCII, # Reference for longitude of destination #p57
'GPSDestLongitude' => array( Exif::RATIONAL, 3 ), # Longitude of destination
'GPSDestBearingRef' => Exif::ASCII, # Reference for bearing of destination #p57
'GPSDestBearing' => Exif::RATIONAL, # Bearing of destination
'GPSDestDistanceRef' => Exif::ASCII, # Reference for distance to destination #p57-58
'GPSDestDistance' => Exif::RATIONAL, # Distance to destination
'GPSProcessingMethod' => Exif::UNDEFINED, # Name of GPS processing method
'GPSAreaInformation' => Exif::UNDEFINED, # Name of GPS area
'GPSDateStamp' => Exif::ASCII, # GPS date
'GPSDifferential' => Exif::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' ) ) {
wfSuppressWarnings();
$data = exif_read_data( $this->file, 0, true );
wfRestoreWarnings();
} 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 ? $data : array();
$this->makeFilteredData();
$this->collapseData();
$this->debugFile( __FUNCTION__, false );
}
/**
* Make $this->mFilteredExifData
*/
function makeFilteredData() {
$this->mFilteredExifData = Array();
foreach ( array_keys( $this->mRawExifData ) as $section ) {
if ( !in_array( $section, array_keys( $this->mExifTags ) ) ) {
$this->debug( $section, __FUNCTION__, "'$section' is not a valid Exif section" );
continue;
}
foreach ( array_keys( $this->mRawExifData[$section] ) as $tag ) {
if ( !in_array( $tag, array_keys( $this->mExifTags[$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 = array();
for ( $i = 0; $i < strlen( $val ); $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 = '';
for ( $i = 0; $i < strlen( $val ); $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;
}
// This could possibly check to see if iconv is really installed
// or if we're using the compatibility wrapper in globalFunctions.php
if ( $charset ) {
wfSuppressWarnings();
$val = iconv( $charset, 'UTF-8//IGNORE', $val );
wfRestoreWarnings();
} else {
// if valid utf-8, assume that, otherwise assume windows-1252
$valCopy = $val;
UtfNormal::quickIsNFCVerify( $valCopy ); //validates $valCopy.
if ( $valCopy !== $val ) {
wfSuppressWarnings();
$val = iconv( 'Windows-1252', 'UTF-8//IGNORE', $val );
wfRestoreWarnings();
}
}
//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'] );
}
}
/**
* Use FormatMetadata to create formatted values for display to user
* (is this ever used?)
*
* @deprecated since 1.18
*/
function makeFormattedData() {
wfDeprecated( __METHOD__, '1.18' );
$this->mFormattedExifData = FormatMetadata::getFormattedData(
$this->mFilteredExifData );
}
/**#@-*/
/**#@+
* @return array
*/
/**
* Get $this->mRawExifData
* @return array
*/
function getData() {
return $this->mRawExifData;
}
/**
* Get $this->mFilteredExifData
*/
function getFilteredData() {
return $this->mFilteredExifData;
}
/**
* Get $this->mFormattedExifData
*
* This returns the data for display to user.
* Its unclear if this is ever used.
*
* @deprecated since 1.18
*/
function getFormattedData() {
wfDeprecated( __METHOD__, '1.18' );
if ( !$this->mFormattedExifData ) {
$this->makeFormattedData();
}
return $this->mFormattedExifData;
}
/**#@-*/
/**
* 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
*
* @private
*
* @param $in Mixed: 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 $in
* @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 $in
* @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 $in
* @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 $in
* @return bool
*/
private function isRational( $in ) {
$m = array();
if ( !is_array( $in ) && preg_match( '/^(\d+)\/(\d+[1-9]|[1-9]\d*)$/', $in, $m ) ) { # Avoid division by zero
return $this->isLong( $m[1] ) && $this->isLong( $m[2] );
} else {
$this->debug( $in, __FUNCTION__, 'fed a non-fraction value' );
return false;
}
}
/**
* @param $in
* @return bool
*/
private function isUndefined( $in ) {
$this->debug( $in, __FUNCTION__, true );
return true;
}
/**
* @param $in
* @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 $in
* @return bool
*/
private function isSrational( $in ) {
$m = array();
if ( !is_array( $in ) && preg_match( '/^(-?\d+)\/(\d+[1-9]|[1-9]\d*)$/', $in, $m ) ) { # Avoid division by zero
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
*
* @private
* @param string $section section where tag is located.
* @param string $tag the tag to check.
* @param $val Mixed: the value of the tag.
* @param $recursive Boolean: 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 = count( $val );
if ( $ecount != $count ) {
$this->debug( $val, __FUNCTION__, "Expected $ecount elements for $tag but got $count" );
return false;
}
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)Exif::BYTE:
$this->debug( $val, __FUNCTION__, $debug );
return $this->isByte( $val );
case (string)Exif::ASCII:
$this->debug( $val, __FUNCTION__, $debug );
return $this->isASCII( $val );
case (string)Exif::SHORT:
$this->debug( $val, __FUNCTION__, $debug );
return $this->isShort( $val );
case (string)Exif::LONG:
$this->debug( $val, __FUNCTION__, $debug );
return $this->isLong( $val );
case (string)Exif::RATIONAL:
$this->debug( $val, __FUNCTION__, $debug );
return $this->isRational( $val );
case (string)Exif::SHORT_OR_LONG:
$this->debug( $val, __FUNCTION__, $debug );
return $this->isShort( $val ) || $this->isLong( $val );
case (string)Exif::UNDEFINED:
$this->debug( $val, __FUNCTION__, $debug );
return $this->isUndefined( $val );
case (string)Exif::SLONG:
$this->debug( $val, __FUNCTION__, $debug );
return $this->isSlong( $val );
case (string)Exif::SRATIONAL:
$this->debug( $val, __FUNCTION__, $debug );
return $this->isSrational( $val );
case (string)Exif::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
*
* @private
*
* @param $in Mixed:
* @param $fname String:
* @param $action Mixed: , 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)\n" );
} elseif ( $action === false ) {
wfDebugLog( $this->log, "$class::$fname: rejected: '$in' (type: $type)\n" );
} elseif ( $action === null ) {
wfDebugLog( $this->log, "$class::$fname: input was: '$in' (type: $type)\n" );
} else {
wfDebugLog( $this->log, "$class::$fname: $action (type: $type; content: '$in')\n" );
}
}
/**
* Convenience function for debugging output
*
* @private
*
* @param string $fname the name of the function calling this function
* @param $io Boolean: 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}'\n" );
} else {
wfDebugLog( $this->log, "$class::$fname: end processing: '{$this->basename}'\n" );
}
}
}