Metadata Object permits authors to store stream-based metadata in
* a file. This object supports the same types of metadata information as the
* Extended Content Description Object except that it also allows a
* stream number to be specified.
*
* @package php-reader
* @subpackage ASF
* @author Sven Vollbehr
* @copyright Copyright (c) 2008-2009 The PHP Reader Project Workgroup
* @license http://code.google.com/p/php-reader/wiki/License New BSD License
* @version $Rev$
*/
final class ASF_Object_Metadata extends ASF_Object
{
/** @var Array */
private $_descriptionRecords = array();
/**
* Constructs the class with given parameters and reads object related data
* from the ASF file.
*
* @param Reader $reader The reader object.
* @param Array $options The options array.
*/
public function __construct($reader = null, &$options = array())
{
parent::__construct($reader, $options);
if ($reader === null)
return;
$descriptionRecordsCount = $this->_reader->readUInt16LE();
for ($i = 0; $i < $descriptionRecordsCount; $i++) {
$this->_reader->skip(2);
$descriptionRecord = array("streamNumber" => $this->_reader->readUInt16LE());
$nameLength = $this->_reader->readUInt16LE();
$dataType = $this->_reader->readUInt16LE();
$dataLength = $this->_reader->readUInt32LE();
$descriptionRecord["name"] = iconv
("utf-16le", $this->getOption("encoding"),
$this->_reader->readString16LE($nameLength));
switch ($dataType) {
case 0: // Unicode string
$descriptionRecord["data"] = iconv
("utf-16le", $this->getOption("encoding"),
$this->_reader->readString16LE($dataLength));
break;
case 1: // BYTE array
$descriptionRecord["data"] = $this->_reader->read($dataLength);
break;
case 2: // BOOL
$descriptionRecord["data"] = $this->_reader->readUInt16LE() == 1;
break;
case 3: // DWORD
$descriptionRecord["data"] = $this->_reader->readUInt32LE();
break;
case 4: // QWORD
$descriptionRecord["data"] = $this->_reader->readInt64LE();
break;
case 5: // WORD
$descriptionRecord["data"] = $this->_reader->readUInt16LE();
break;
}
$this->_descriptionRecords[] = $descriptionRecord;
}
}
/**
* Returns the array of description records. Each record consists of the
* following keys.
*
* o streamNumber -- Specifies the stream number. Valid values are between
* 1 and 127.
*
* o name -- Specifies the name that uniquely identifies the attribute being
* described. Names are case-sensitive.
*
* o data -- Specifies the actual metadata being stored.
*
* @return Array
*/
public function getDescriptionRecords() { return $this->_descriptionRecords; }
/**
* Sets the array of description records. Each record must consist of the
* following keys.
*
* o streamNumber -- Specifies the stream number. Valid values are between
* 1 and 127.
*
* o name -- Specifies the name that uniquely identifies the attribute being
* described. Names are case-sensitive.
*
* o data -- Specifies the actual metadata being stored.
*
* @param Array $descriptionRecords The array of description records.
*/
public function setDescriptionRecords($descriptionRecords)
{
$this->_descriptionRecords = $descriptionRecords;
}
/**
* Returns the whether the object is required to be present, or whether
* minimum cardinality is 1.
*
* @return boolean
*/
public function isMandatory() { return false; }
/**
* Returns whether multiple instances of this object can be present, or
* whether maximum cardinality is greater than 1.
*
* @return boolean
*/
public function isMultiple() { return false; }
/**
* Returns the object data with headers.
*
* @return string
*/
public function __toString()
{
$data = Transform::toUInt16LE
($descriptionRecordsCount = count($this->_descriptionRecords));
for ($i = 0; $i < $descriptionRecordsCount; $i++) {
$data .= Transform::toUInt16LE(0) .
Transform::toUInt16LE($this->_descriptionRecords[$i]["streamNumber"]) .
Transform::toUInt16LE(strlen($name = iconv
($this->getOption("encoding"), "utf-16le",
$this->_descriptionRecords[$i]["name"]) . "\0\0"));
if (is_string($this->_descriptionRecords[$i]["data"])) {
/* There is no way to distinguish byte arrays from unicode strings and
* hence the need for a list of fields of type byte array */
static $byteArray = array (
""
); // TODO: Add to the list if you encounter one
if (in_array($name, $byteArray))
$data .= Transform::toUInt16LE(1) . Transform::toUInt32LE
(strlen($this->_descriptionRecords[$i]["data"])) . $name .
$this->_descriptionRecords[$i]["data"];
else {
$value = iconv
($this->getOption("encoding"), "utf-16le",
$this->_descriptionRecords[$i]["data"]);
$value = ($value ? $value . "\0\0" : "");
$data .= Transform::toUInt16LE(0) .
Transform::toUInt32LE(strlen($value)) . $name .
Transform::toString16LE($value);
}
}
else if (is_bool($this->_descriptionRecords[$i]["data"])) {
$data .= Transform::toUInt16LE(2) . Transform::toUInt32LE(2) . $name .
Transform::toUInt16LE($this->_descriptionRecords[$i]["data"] ? 1 : 0);
}
else if (is_int($this->_descriptionRecords[$i]["data"])) {
$data .= Transform::toUInt16LE(3) . Transform::toUInt32LE(4) . $name .
Transform::toUInt32LE($this->_descriptionRecords[$i]["data"]);
}
else if (is_float($this->_descriptionRecords[$i]["data"])) {
$data .= Transform::toUInt16LE(4) . Transform::toUInt32LE(8) . $name .
Transform::toInt64LE($this->_descriptionRecords[$i]["data"]);
}
else {
// Invalid value and there is nothing to be done so cause a fatal error
require_once("ASF/Exception.php");
throw new ASF_Exception("Invalid data type");
}
}
$this->setSize(24 /* for header */ + strlen($data));
return
Transform::toGUID($this->getIdentifier()) .
Transform::toInt64LE($this->getSize()) . $data;
}
}