Image_XMP Class Reference

getID3() by James Heinrich info@.nosp@m.geti.nosp@m.d3.or.nosp@m.g // More...

Collaboration diagram for Image_XMP:

Public Member Functions
	isValid ()
	Returns the status of XMP parsing during instantiation. More...
	getAllTags ()
	Get a copy of all XMP tags extracted from the image. More...
	_get_jpeg_header_data ($filename)
	Reads all the JPEG header segments from an JPEG image file into an array. More...
	_get_XMP_text ($filename)
	Retrieves XMP information from an APP1 JPEG segment and returns the raw XML text as a string. More...
	read_XMP_array_from_text ($xmltext)
	Parses a string containing XMP data (XML), and returns an array which contains all the XMP (XML) information. More...
	__construct ($sFilename)
	Constructor. More...

Data Fields
	$_sFilename = null
	$_aXMP = array()
	$_bXMPParse = false

Detailed Description

getID3() by James Heinrich info@.nosp@m.geti.nosp@m.d3.or.nosp@m.g //

Definition at line 34 of file module.tag.xmp.php.

Constructor & Destructor Documentation

__construct()

Image_XMP::__construct

(

$sFilename

)

Constructor.

Parameters

string

- Name of the image file to access and extract XMP information from.

Definition at line 402 of file module.tag.xmp.php.

        {
                $this->_sFilename = $sFilename;
 
                if (is_file($this->_sFilename))
                {
                        // Get XMP data
                        $xmp_data = $this->_get_XMP_text($sFilename);
                        if ($xmp_data)
                        {
                                $this->_aXMP = $this->read_XMP_array_from_text($xmp_data);
                                $this->_bXMPParse = true;
                        }
                }
        }

References _get_XMP_text(), and read_XMP_array_from_text().

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Member Function Documentation

_get_jpeg_header_data()

Image_XMP::_get_jpeg_header_data

(

$filename

)

Reads all the JPEG header segments from an JPEG image file into an array.

Parameters

string

$filename

- the filename of the JPEG file to read

Returns

array $headerdata - Array of JPEG header segments

boolean FALSE - if headers could not be read

Definition at line 87 of file module.tag.xmp.php.

        {
                // prevent refresh from aborting file operations and hosing file
                ignore_user_abort(true);
 
                // Attempt to open the jpeg file - the at symbol supresses the error message about
                // not being able to open files. The file_exists would have been used, but it
                // does not work with files fetched over http or ftp.
                if (is_readable($filename) && is_file($filename) && ($filehnd = fopen($filename, 'rb'))) {
                        // great
                } else {
                        return false;
                }
 
                // Read the first two characters
                $data = fread($filehnd, 2);
 
                // Check that the first two characters are 0xFF 0xD8  (SOI - Start of image)
                if ($data != "\xFF\xD8")
                {
                        // No SOI (FF D8) at start of file - This probably isn't a JPEG file - close file and return;
                        echo '<p>This probably is not a JPEG file</p>'."\n";
                        fclose($filehnd);
                        return false;
                }
 
                // Read the third character
                $data = fread($filehnd, 2);
 
                // Check that the third character is 0xFF (Start of first segment header)
                if ($data{0} != "\xFF")
                {
                        // NO FF found - close file and return - JPEG is probably corrupted
                        fclose($filehnd);
                        return false;
                }
 
                // Flag that we havent yet hit the compressed image data
                $hit_compressed_image_data = false;
 
                // Cycle through the file until, one of: 1) an EOI (End of image) marker is hit,
                //                                       2) we have hit the compressed image data (no more headers are allowed after data)
                //                                       3) or end of file is hit
 
                while (($data{1} != "\xD9") && (!$hit_compressed_image_data) && (!feof($filehnd)))
                {
                        // Found a segment to look at.
                        // Check that the segment marker is not a Restart marker - restart markers don't have size or data after them
                        if ((ord($data{1}) < 0xD0) || (ord($data{1}) > 0xD7))
                        {
                                // Segment isn't a Restart marker
                                // Read the next two bytes (size)
                                $sizestr = fread($filehnd, 2);
 
                                // convert the size bytes to an integer
                                $decodedsize = unpack('nsize', $sizestr);
 
                                // Save the start position of the data
                                $segdatastart = ftell($filehnd);
 
                                // Read the segment data with length indicated by the previously read size
                                $segdata = fread($filehnd, $decodedsize['size'] - 2);
 
                                // Store the segment information in the output array
                                $headerdata[] = array(
                                        'SegType'      => ord($data{1}),
                                        'SegName'      => $GLOBALS['JPEG_Segment_Names'][ord($data{1})],
                                        'SegDataStart' => $segdatastart,
                                        'SegData'      => $segdata,
                                );
                        }
 
                        // If this is a SOS (Start Of Scan) segment, then there is no more header data - the compressed image data follows
                        if ($data{1} == "\xDA")
                        {
                                // Flag that we have hit the compressed image data - exit loop as no more headers available.
                                $hit_compressed_image_data = true;
                        }
                        else
                        {
                                // Not an SOS - Read the next two bytes - should be the segment marker for the next segment
                                $data = fread($filehnd, 2);
 
                                // Check that the first byte of the two is 0xFF as it should be for a marker
                                if ($data{0} != "\xFF")
                                {
                                        // NO FF found - close file and return - JPEG is probably corrupted
                                        fclose($filehnd);
                                        return false;
                                }
                        }
                }
 
                // Close File
                fclose($filehnd);
                // Alow the user to abort from now on
                ignore_user_abort(false);
 
                // Return the header data retrieved
                return $headerdata;
        }

References $data, $filename, and $GLOBALS.

Referenced by _get_XMP_text().

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_get_XMP_text()

Image_XMP::_get_XMP_text

(

$filename

)

Retrieves XMP information from an APP1 JPEG segment and returns the raw XML text as a string.

Parameters

string

$filename

- the filename of the JPEG file to read

Returns

string $xmp_data - the string of raw XML text

boolean FALSE - if an APP 1 XMP segment could not be found, or if an error occured

Definition at line 197 of file module.tag.xmp.php.

        {
                //Get JPEG header data
                $jpeg_header_data = $this->_get_jpeg_header_data($filename);
 
                //Cycle through the header segments
                for ($i = 0; $i < count($jpeg_header_data); $i++)
                {
                        // If we find an APP1 header,
                        if (strcmp($jpeg_header_data[$i]['SegName'], 'APP1') == 0)
                        {
                                // And if it has the Adobe XMP/RDF label (http://ns.adobe.com/xap/1.0/\x00) ,
                                if (strncmp($jpeg_header_data[$i]['SegData'], 'http://ns.adobe.com/xap/1.0/'."\x00", 29) == 0)
                                {
                                        // Found a XMP/RDF block
                                        // Return the XMP text
                                        $xmp_data = substr($jpeg_header_data[$i]['SegData'], 29);
 
                                        return trim($xmp_data); // trim() should not be neccesary, but some files found in the wild with null-terminated block (known samples from Apple Aperture) causes problems elsewhere (see http://www.getid3.org/phpBB3/viewtopic.php?f=4&t=1153)
                                }
                        }
                }
                return false;
        }

References $filename, $i, and _get_jpeg_header_data().

Referenced by __construct().

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getAllTags()

Image_XMP::getAllTags

(

)

Get a copy of all XMP tags extracted from the image.

Returns

array - An array of XMP fields as it extracted by the XMPparse() function

Definition at line 75 of file module.tag.xmp.php.

        {
                return $this->_aXMP;
        }

References $_aXMP.

isValid()

Image_XMP::isValid

(

)

Returns the status of XMP parsing during instantiation.

You'll normally want to call this method before trying to get XMP fields.

Returns

boolean Returns true if an APP1 segment was found to contain XMP metadata.

Definition at line 65 of file module.tag.xmp.php.

        {
                return $this->_bXMPParse;
        }

References $_bXMPParse.

read_XMP_array_from_text()

Image_XMP::read_XMP_array_from_text

(

$xmltext

)

Parses a string containing XMP data (XML), and returns an array which contains all the XMP (XML) information.

Parameters

string

$xml_text

- a string containing the XMP data (XML) to be parsed

Returns

array $xmp_array - an array containing all xmp details retrieved.

boolean FALSE - couldn't parse the XMP data

Definition at line 230 of file module.tag.xmp.php.

        {
                // Check if there actually is any text to parse
                if (trim($xmltext) == '')
                {
                        return false;
                }
 
                // Create an instance of a xml parser to parse the XML text
                $xml_parser = xml_parser_create('UTF-8');
 
                // Change: Fixed problem that caused the whitespace (especially newlines) to be destroyed when converting xml text to an xml array, as of revision 1.10
 
                // We would like to remove unneccessary white space, but this will also
                // remove things like newlines (
) in the XML values, so white space
                // will have to be removed later
                if (xml_parser_set_option($xml_parser, XML_OPTION_SKIP_WHITE, 0) == false)
                {
                        // Error setting case folding - destroy the parser and return
                        xml_parser_free($xml_parser);
                        return false;
                }
 
                // to use XML code correctly we have to turn case folding
                // (uppercasing) off. XML is case sensitive and upper
                // casing is in reality XML standards violation
                if (xml_parser_set_option($xml_parser, XML_OPTION_CASE_FOLDING, 0) == false)
                {
                        // Error setting case folding - destroy the parser and return
                        xml_parser_free($xml_parser);
                        return false;
                }
 
                // Parse the XML text into a array structure
                if (xml_parse_into_struct($xml_parser, $xmltext, $values, $tags) == 0)
                {
                        // Error Parsing XML - destroy the parser and return
                        xml_parser_free($xml_parser);
                        return false;
                }
 
                // Destroy the xml parser
                xml_parser_free($xml_parser);
 
                // Clear the output array
                $xmp_array = array();
 
                // The XMP data has now been parsed into an array ...
 
                // Cycle through each of the array elements
                $current_property = ''; // current property being processed
                $container_index = -1; // -1 = no container open, otherwise index of container content
                foreach ($values as $xml_elem)
                {
                        // Syntax and Class names
                        switch ($xml_elem['tag'])
                        {
                                case 'x:xmpmeta':
                                        // only defined attribute is x:xmptk written by Adobe XMP Toolkit; value is the version of the toolkit
                                        break;
 
                                case 'rdf:RDF':
                                        // required element immediately within x:xmpmeta; no data here
                                        break;
 
                                case 'rdf:Description':
                                        switch ($xml_elem['type'])
                                        {
                                                case 'open':
                                                case 'complete':
                                                        if (array_key_exists('attributes', $xml_elem))
                                                        {
                                                                // rdf:Description may contain wanted attributes
                                                                foreach (array_keys($xml_elem['attributes']) as $key)
                                                                {
                                                                        // Check whether we want this details from this attribute
//                                                                      if (in_array($key, $GLOBALS['XMP_tag_captions']))
                                                                        if (true)
                                                                        {
                                                                                // Attribute wanted
                                                                                $xmp_array[$key] = $xml_elem['attributes'][$key];
                                                                        }
                                                                }
                                                        }
                                                case 'cdata':
                                                case 'close':
                                                        break;
                                        }
 
                                case 'rdf:ID':
                                case 'rdf:nodeID':
                                        // Attributes are ignored
                                        break;
 
                                case 'rdf:li':
                                        // Property member
                                        if ($xml_elem['type'] == 'complete')
                                        {
                                                if (array_key_exists('attributes', $xml_elem))
                                                {
                                                        // If Lang Alt (language alternatives) then ensure we take the default language
                                                        if (isset($xml_elem['attributes']['xml:lang']) && ($xml_elem['attributes']['xml:lang'] != 'x-default'))
                                                        {
                                                                break;
                                                        }
                                                }
                                                if ($current_property != '')
                                                {
                                                        $xmp_array[$current_property][$container_index] = (isset($xml_elem['value']) ? $xml_elem['value'] : '');
                                                        $container_index += 1;
                                                }
                                        //else unidentified attribute!!
                                        }
                                        break;
 
                                case 'rdf:Seq':
                                case 'rdf:Bag':
                                case 'rdf:Alt':
                                        // Container found
                                        switch ($xml_elem['type'])
                                        {
                                                case 'open':
                                                        $container_index = 0;
                                                        break;
                                                case 'close':
                                                        $container_index = -1;
                                                        break;
                                                case 'cdata':
                                                        break;
                                        }
                                        break;
 
                                default:
                                        // Check whether we want the details from this attribute
//                                      if (in_array($xml_elem['tag'], $GLOBALS['XMP_tag_captions']))
                                        if (true)
                                        {
                                                switch ($xml_elem['type'])
                                                {
                                                        case 'open':
                                                                // open current element
                                                                $current_property = $xml_elem['tag'];
                                                                break;
 
                                                        case 'close':
                                                                // close current element
                                                                $current_property = '';
                                                                break;
 
                                                        case 'complete':
                                                                // store attribute value
                                                                $xmp_array[$xml_elem['tag']] = (isset($xml_elem['attributes']) ? $xml_elem['attributes'] : (isset($xml_elem['value']) ? $xml_elem['value'] : ''));
                                                                break;
 
                                                        case 'cdata':
                                                                // ignore
                                                                break;
                                                }
                                        }
                                        break;
                        }
 
                }
                return $xmp_array;
        }

References $key, $tags, and $values.

Referenced by __construct().

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Field Documentation

$_aXMP

Image_XMP::$_aXMP = array()

Definition at line 48 of file module.tag.xmp.php.

Referenced by getAllTags().

$_bXMPParse

Image_XMP::$_bXMPParse = false

Definition at line 55 of file module.tag.xmp.php.

Referenced by isValid().

$_sFilename

Image_XMP::$_sFilename = null

Definition at line 41 of file module.tag.xmp.php.

---

The documentation for this class was generated from the following file:

• libs/composer/vendor/james-heinrich/getid3/getid3/module.tag.xmp.php