IPTC.php

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<?php
use Wikimedia\AtEase\AtEase;
 
class IPTC {
    public static function parse( $rawData ) {
        $parsed = iptcparse( $rawData );
        $data = [];
        if ( !is_array( $parsed ) ) {
            return $data;
        }
 
        $c = '';
        // charset info contained in tag 1:90.
        if ( isset( $parsed['1#090'] ) && isset( $parsed['1#090'][0] ) ) {
            $c = self::getCharset( $parsed['1#090'][0] );
            if ( $c === false ) {
                // Unknown charset. refuse to parse.
                // note: There is a different between
                // unknown and no charset specified.
                return [];
            }
            unset( $parsed['1#090'] );
        }
 
        foreach ( $parsed as $tag => $val ) {
            if ( isset( $val[0] ) && trim( $val[0] ) == '' ) {
                wfDebugLog( 'iptc', "IPTC tag $tag had only whitespace as its value." );
                continue;
            }
            switch ( $tag ) {
                case '2#120': /*IPTC caption. mapped with exif ImageDescription*/
                    $data['ImageDescription'] = self::convIPTC( $val, $c );
                    break;
                case '2#116': /* copyright. Mapped with exif copyright */
                    $data['Copyright'] = self::convIPTC( $val, $c );
                    break;
                case '2#080': /* byline. Mapped with exif Artist */
                    /* merge with byline title (2:85)
                     * like how exif does it with
                     * Title, person. Not sure if this is best
                     * approach since we no longer have the two fields
                     * separate. each byline title entry corresponds to a
                     * specific byline. */
 
                    $bylines = self::convIPTC( $val, $c );
                    if ( isset( $parsed['2#085'] ) ) {
                        $titles = self::convIPTC( $parsed['2#085'], $c );
                    } else {
                        $titles = [];
                    }
 
                    $titleCount = count( $titles );
                    for ( $i = 0; $i < $titleCount; $i++ ) {
                        if ( isset( $bylines[$i] ) ) {
                            // theoretically this should always be set
                            // but doesn't hurt to be careful.
                            $bylines[$i] = $titles[$i] . ', ' . $bylines[$i];
                        }
                    }
                    $data['Artist'] = $bylines;
                    break;
                case '2#025': /* keywords */
                    $data['Keywords'] = self::convIPTC( $val, $c );
                    break;
                case '2#101': /* Country (shown) */
                    $data['CountryDest'] = self::convIPTC( $val, $c );
                    break;
                case '2#095': /* state/province (shown) */
                    $data['ProvinceOrStateDest'] = self::convIPTC( $val, $c );
                    break;
                case '2#090': /* city (Shown) */
                    $data['CityDest'] = self::convIPTC( $val, $c );
                    break;
                case '2#092': /* sublocation (shown) */
                    $data['SublocationDest'] = self::convIPTC( $val, $c );
                    break;
                case '2#005': /* object name/title */
                    $data['ObjectName'] = self::convIPTC( $val, $c );
                    break;
                case '2#040': /* special instructions */
                    $data['SpecialInstructions'] = self::convIPTC( $val, $c );
                    break;
                case '2#105': /* headline */
                    $data['Headline'] = self::convIPTC( $val, $c );
                    break;
                case '2#110': /* credit */
                    /*"Identifies the provider of the objectdata,
                     * not necessarily the owner/creator". */
                    $data['Credit'] = self::convIPTC( $val, $c );
                    break;
                case '2#115': /* source */
                    /* "Identifies the original owner of the intellectual content of the
                     *objectdata. This could be an agency, a member of an agency or
                     *an individual." */
                    $data['Source'] = self::convIPTC( $val, $c );
                    break;
 
                case '2#007': /* edit status (lead, correction, etc) */
                    $data['EditStatus'] = self::convIPTC( $val, $c );
                    break;
                case '2#015': /* category. deprecated. max 3 letters in theory, often more */
                    $data['iimCategory'] = self::convIPTC( $val, $c );
                    break;
                case '2#020': /* category. deprecated. */
                    $data['iimSupplementalCategory'] = self::convIPTC( $val, $c );
                    break;
                case '2#010': /*urgency (1-8. 1 most, 5 normal, 8 low priority)*/
                    $data['Urgency'] = self::convIPTC( $val, $c );
                    break;
                case '2#022':
                    /* "Identifies objectdata that recurs often and predictably...
                     * Example: Euroweather" */
                    $data['FixtureIdentifier'] = self::convIPTC( $val, $c );
                    break;
                case '2#026':
                    /* Content location code (iso 3166 + some custom things)
                     * ex: TUR (for turkey), XUN (for UN), XSP (outer space)
                     * See wikipedia article on iso 3166 and appendix D of iim std. */
                    $data['LocationDestCode'] = self::convIPTC( $val, $c );
                    break;
                case '2#027':
                    /* Content location name. Full printable name
                     * of location of photo. */
                    $data['LocationDest'] = self::convIPTC( $val, $c );
                    break;
                case '2#065':
                    /* Originating Program.
                     * Combine with Program version (2:70) if present.
                     */
                    $software = self::convIPTC( $val, $c );
 
                    if ( count( $software ) !== 1 ) {
                        // according to iim standard this cannot have multiple values
                        // so if there is more than one, something weird is happening,
                        // and we skip it.
                        wfDebugLog( 'iptc', 'IPTC: Wrong count on 2:65 Software field' );
                        break;
                    }
 
                    if ( isset( $parsed['2#070'] ) ) {
                        // if a version is set for the software.
                        $softwareVersion = self::convIPTC( $parsed['2#070'], $c );
                        unset( $parsed['2#070'] );
                        $data['Software'] = [ [ $software[0], $softwareVersion[0] ] ];
                    } else {
                        $data['Software'] = $software;
                    }
                    break;
                case '2#075':
                    /* Object cycle.
                     * a for morning (am), p for evening, b for both */
                    $data['ObjectCycle'] = self::convIPTC( $val, $c );
                    break;
                case '2#100':
                    /* Country/Primary location code.
                     * "Indicates the code of the country/primary location where the
                     * intellectual property of the objectdata was created"
                     * unclear how this differs from 2#026
                     */
                    $data['CountryCodeDest'] = self::convIPTC( $val, $c );
                    break;
                case '2#103':
                    /* original transmission ref.
                     * "A code representing the location of original transmission ac-
                     * cording to practises of the provider."
                     */
                    $data['OriginalTransmissionRef'] = self::convIPTC( $val, $c );
                    break;
                case '2#118': /*contact*/
                    $data['Contact'] = self::convIPTC( $val, $c );
                    break;
                case '2#122':
                    /* Writer/Editor
                     * "Identification of the name of the person involved in the writing,
                     * editing or correcting the objectdata or caption/abstract."
                     */
                    $data['Writer'] = self::convIPTC( $val, $c );
                    break;
                case '2#135': /* lang code */
                    $data['LanguageCode'] = self::convIPTC( $val, $c );
                    break;
 
                // Start date stuff.
                // It doesn't accept incomplete dates even though they are valid
                // according to spec.
                // Should potentially store timezone as well.
                case '2#055':
                    // Date created (not date digitized).
                    // Maps to exif DateTimeOriginal
                    $time = $parsed['2#060'] ?? [];
                    $timestamp = self::timeHelper( $val, $time, $c );
                    if ( $timestamp ) {
                        $data['DateTimeOriginal'] = $timestamp;
                    }
                    break;
 
                case '2#062':
                    // Date converted to digital representation.
                    // Maps to exif DateTimeDigitized
                    $time = $parsed['2#063'] ?? [];
                    $timestamp = self::timeHelper( $val, $time, $c );
                    if ( $timestamp ) {
                        $data['DateTimeDigitized'] = $timestamp;
                    }
                    break;
 
                case '2#030':
                    // Date released.
                    $time = $parsed['2#035'] ?? [];
                    $timestamp = self::timeHelper( $val, $time, $c );
                    if ( $timestamp ) {
                        $data['DateTimeReleased'] = $timestamp;
                    }
                    break;
 
                case '2#037':
                    // Date expires.
                    $time = $parsed['2#038'] ?? [];
                    $timestamp = self::timeHelper( $val, $time, $c );
                    if ( $timestamp ) {
                        $data['DateTimeExpires'] = $timestamp;
                    }
                    break;
 
                case '2#000': /* iim version */
                    // unlike other tags, this is a 2-byte binary number.
                    // technically this is required if there is iptc data
                    // but in practise it isn't always there.
                    if ( strlen( $val[0] ) === 2 ) {
                        // if is just to be paranoid.
                        $versionValue = ord( substr( $val[0], 0, 1 ) ) * 256;
                        $versionValue += ord( substr( $val[0], 1, 1 ) );
                        $data['iimVersion'] = $versionValue;
                    }
                    break;
 
                case '2#004':
                    // IntellectualGenere.
                    // first 4 characters are an id code
                    // That we're not really interested in.
 
                    // This prop is weird, since it's
                    // allowed to have multiple values
                    // in iim 4.1, but not in the XMP
                    // stuff. We're going to just
                    // extract the first value.
                    $con = self::convIPTC( $val, $c );
                    if ( strlen( $con[0] ) < 5 ) {
                        wfDebugLog( 'iptc', 'IPTC: '
                            . '2:04 too short. '
                            . 'Ignoring.' );
                        break;
                    }
                    $extracted = substr( $con[0], 4 );
                    $data['IntellectualGenre'] = $extracted;
                    break;
 
                case '2#012':
                    // Subject News code - this is a compound field
                    // at the moment we only extract the subject news
                    // code, which is an 8 digit (ascii) number
                    // describing the subject matter of the content.
                    $codes = self::convIPTC( $val, $c );
                    foreach ( $codes as $ic ) {
                        $fields = explode( ':', $ic, 3 );
 
                        if ( count( $fields ) < 2 || $fields[0] !== 'IPTC' ) {
                            wfDebugLog( 'IPTC', 'IPTC: '
                                . 'Invalid 2:12 - ' . $ic );
                            break;
                        }
                        $data['SubjectNewsCode'] = $fields[1];
                    }
                    break;
 
                // purposely does not do 2:125, 2:130, 2:131,
                // 2:47, 2:50, 2:45, 2:42, 2:8, 2:3
                // 2:200, 2:201, 2:202
                // or the audio stuff (2:150 to 2:154)
 
                case '2#070':
                case '2#060':
                case '2#063':
                case '2#085':
                case '2#038':
                case '2#035':
                    // ignore. Handled elsewhere.
                    break;
 
                default:
                    wfDebugLog( 'iptc', "Unsupported iptc tag: $tag. Value: " . implode( ',', $val ) );
                    break;
            }
        }
 
        return $data;
    }
 
    private static function timeHelper( $date, $time, $charset ) {
        if ( count( $date ) === 1 ) {
            // the standard says this should always be 1
            // just double checking.
            [ $date ] = self::convIPTC( $date, $charset );
        } else {
            return null;
        }
 
        if ( count( $time ) === 1 ) {
            [ $time ] = self::convIPTC( $time, $charset );
            $dateOnly = false;
        } else {
            $time = '000000+0000'; // placeholder
            $dateOnly = true;
        }
 
        if ( !( preg_match( '/\d\d\d\d\d\d[-+]\d\d\d\d/', $time )
            && preg_match( '/\d\d\d\d\d\d\d\d/', $date )
            && substr( $date, 0, 4 ) !== '0000'
            && substr( $date, 4, 2 ) !== '00'
            && substr( $date, 6, 2 ) !== '00'
        ) ) {
            // something wrong.
            // Note, this rejects some valid dates according to iptc spec
            // for example: the date 00000400 means the photo was taken in
            // April, but the year and day is unknown. We don't process these
            // types of incomplete dates atm.
            wfDebugLog( 'iptc', "IPTC: invalid time ( $time ) or date ( $date )" );
 
            return null;
        }
 
        $unixTS = wfTimestamp( TS_UNIX, $date . substr( $time, 0, 6 ) );
        if ( $unixTS === false ) {
            wfDebugLog( 'iptc', "IPTC: can't convert date to TS_UNIX: $date $time." );
 
            return null;
        }
 
        $tz = ( (int)substr( $time, 7, 2 ) * 60 * 60 )
            + ( (int)substr( $time, 9, 2 ) * 60 );
 
        if ( substr( $time, 6, 1 ) === '-' ) {
            $tz = -$tz;
        }
 
        $finalTimestamp = wfTimestamp( TS_EXIF, (int)$unixTS + $tz );
        if ( $finalTimestamp === false ) {
            wfDebugLog( 'iptc', "IPTC: can't make final timestamp. Date: " . ( (int)$unixTS + $tz ) );
 
            return null;
        }
        if ( $dateOnly ) {
            // return the date only
            return substr( $finalTimestamp, 0, 10 );
        }
        return $finalTimestamp;
    }
 
    private static function convIPTC( $data, $charset ) {
        if ( is_array( $data ) ) {
            foreach ( $data as &$val ) {
                $val = self::convIPTCHelper( $val, $charset );
            }
        } else {
            $data = self::convIPTCHelper( $data, $charset );
        }
 
        return $data;
    }
 
    private static function convIPTCHelper( $data, $charset ) {
        if ( $charset ) {
            AtEase::suppressWarnings();
            $data = iconv( $charset, "UTF-8//IGNORE", $data );
            AtEase::restoreWarnings();
            if ( $data === false ) {
                $data = "";
                wfDebugLog( 'iptc', __METHOD__ . " Error converting iptc data charset $charset to utf-8" );
            }
        } else {
            // treat as utf-8 if is valid utf-8. otherwise pretend its windows-1252
            // most of the time if there is no 1:90 tag, it is either ascii, latin1, or utf-8
            $oldData = $data;
            UtfNormal\Validator::quickIsNFCVerify( $data ); // make $data valid utf-8
            if ( $data === $oldData ) {
                return $data; // if validation didn't change $data
            }
            return self::convIPTCHelper( $oldData, 'Windows-1252' );
        }
 
        return trim( $data );
    }
 
    public static function getCharset( $tag ) {
        // According to iim standard, charset is defined by the tag 1:90.
        // in which there are iso 2022 escape sequences to specify the character set.
        // the iim standard seems to encourage that all necessary escape sequences are
        // in the 1:90 tag, but says it doesn't have to be.
 
        // This is in need of more testing probably. This is definitely not complete.
        // however reading the docs of some other iptc software, it appears that most iptc software
        // only recognizes utf-8. If 1:90 tag is not present content is
        // usually ascii or iso-8859-1 (and sometimes utf-8), but no guarantee.
 
        // This also won't work if there are more than one escape sequence in the 1:90 tag
        // or if something is put in the G2, or G3 charsets, etc. It will only reliably recognize utf-8.
 
        // This is just going through the charsets mentioned in appendix C of the iim standard.
 
        //  \x1b = ESC.
        switch ( $tag ) {
            case "\x1b%G": // utf-8
            // Also call things that are compatible with utf-8, utf-8 (e.g. ascii)
            case "\x1b(B": // ascii
            case "\x1b(@": // iso-646-IRV (ascii in latest version, $ different in older version)
                $c = 'UTF-8';
                break;
            case "\x1b(A": // like ascii, but british.
                $c = 'ISO646-GB';
                break;
            case "\x1b(C": // some obscure sweedish/finland encoding
                $c = 'ISO-IR-8-1';
                break;
            case "\x1b(D":
                $c = 'ISO-IR-8-2';
                break;
            case "\x1b(E": // some obscure danish/norway encoding
                $c = 'ISO-IR-9-1';
                break;
            case "\x1b(F":
                $c = 'ISO-IR-9-2';
                break;
            case "\x1b(G":
                $c = 'SEN_850200_B'; // aka iso 646-SE; ascii-like
                break;
            case "\x1b(I":
                $c = "ISO646-IT";
                break;
            case "\x1b(L":
                $c = "ISO646-PT";
                break;
            case "\x1b(Z":
                $c = "ISO646-ES";
                break;
            case "\x1b([":
                $c = "GREEK7-OLD";
                break;
            case "\x1b(K":
                $c = "ISO646-DE";
                break;
            case "\x1b(N": // crylic
                $c = "ISO_5427";
                break;
            case "\x1b(`": // iso646-NO
                $c = "NS_4551-1";
                break;
            case "\x1b(f": // iso646-FR
                $c = "NF_Z_62-010";
                break;
            case "\x1b(g":
                $c = "PT2"; // iso646-PT2
                break;
            case "\x1b(h":
                $c = "ES2";
                break;
            case "\x1b(i": // iso646-HU
                $c = "MSZ_7795.3";
                break;
            case "\x1b(w":
                $c = "CSA_Z243.4-1985-1";
                break;
            case "\x1b(x":
                $c = "CSA_Z243.4-1985-2";
                break;
            case "\x1b\$(B":
            case "\x1b\$B":
            case "\x1b&@\x1b\$B":
            case "\x1b&@\x1b\$(B":
                $c = "JIS_C6226-1983";
                break;
            case "\x1b-A": // iso-8859-1. at least for the high code characters.
            case "\x1b(@\x1b-A":
            case "\x1b(B\x1b-A":
                $c = 'ISO-8859-1';
                break;
            case "\x1b-B": // iso-8859-2. at least for the high code characters.
                $c = 'ISO-8859-2';
                break;
            case "\x1b-C": // iso-8859-3. at least for the high code characters.
                $c = 'ISO-8859-3';
                break;
            case "\x1b-D": // iso-8859-4. at least for the high code characters.
                $c = 'ISO-8859-4';
                break;
            case "\x1b-E": // iso-8859-5. at least for the high code characters.
                $c = 'ISO-8859-5';
                break;
            case "\x1b-F": // iso-8859-6. at least for the high code characters.
                $c = 'ISO-8859-6';
                break;
            case "\x1b-G": // iso-8859-7. at least for the high code characters.
                $c = 'ISO-8859-7';
                break;
            case "\x1b-H": // iso-8859-8. at least for the high code characters.
                $c = 'ISO-8859-8';
                break;
            case "\x1b-I": // CSN_369103. at least for the high code characters.
                $c = 'CSN_369103';
                break;
            default:
                wfDebugLog( 'iptc', __METHOD__ . ': Unknown charset in iptc 1:90: ' . bin2hex( $tag ) );
                // at this point just give up and refuse to parse iptc?
                $c = false;
        }
        return $c;
    }
}