Simple Index Object. Additionally, the instances of the Simple
* Index Object shall be ordered by stream number.
*
* Index entries in the Simple Index Object are in terms of
* Presentation Times. The corresponding Packet Number field
* values (of the Index Entry, see below) indicate the packet number of
* the ASF Data Packet with the closest past key frame. Note that for
* video streams that contain both key frames and non-key frames, the Packet
* Number field will always point to the closest past key frame.
*
* @package php-reader
* @subpackage ASF
* @author Sven Vollbehr
* @copyright Copyright (c) 2008 The PHP Reader Project Workgroup
* @license http://code.google.com/p/php-reader/wiki/License New BSD License
* @version $Rev: 108 $
*/
final class ASF_Object_SimpleIndex extends ASF_Object
{
/** @var string */
private $_fileId;
/** @var integer */
private $_indexEntryTimeInterval;
/** @var integer */
private $_maximumPacketCount;
/** @var Array */
private $_indexEntries = 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, &$options = array())
{
parent::__construct($reader, $options);
$this->_fileId = $this->_reader->readGUID();
$this->_indexEntryTimeInterval = $this->_reader->readInt64LE();
$this->_maximumPacketCount = $this->_reader->readUInt32LE();
$indexEntriesCount = $this->_reader->readUInt32LE();
for ($i = 0; $i < $indexEntriesCount; $i++) {
$this->_indexEntries[] = array
("packetNumber" => $this->_reader->readUInt32LE(),
"packetCount" => $this->_reader->readUInt16LE());
}
}
/**
* Returns the unique identifier for this ASF file. The value of this field
* should be changed every time the file is modified in any way. The value of
* this field may be set to 0 or set to be identical to the value of the
* File ID field of the Data Object and the Header
* Object.
*
* @return string
*/
public function getFileId() { return $this->_fileId; }
/**
* Returns the time interval between each index entry in 100-nanosecond units.
* The most common value is 10000000, to indicate that the index entries are
* in 1-second intervals, though other values can be used as well.
*
* @return integer
*/
public function getIndexEntryTimeInterval()
{
return $this->_indexEntryTimeInterval;
}
/**
* Returns the maximum Packet Count value of all Index Entries.
*
* @return integer
*/
public function getMaximumPacketCount() { return $this->_maximumPacketCount; }
/**
* Returns an array of index entries. Each entry consists of the following
* keys.
*
* o packetNumber -- Specifies the number of the Data Packet associated
* with this index entry. Note that for video streams that contain both
* key frames and non-key frames, this field will always point to the
* closest key frame prior to the time interval.
*
* o packetCount -- Specifies the number of Data Packets to send at
* this index entry. If a video key frame has been fragmented into two
* Data Packets, the value of this field will be equal to 2.
*
* @return Array
*/
public function getIndexEntries() { return $this->_indexEntries; }
}