Sample Size Box contains the sample count and a table giving the * size in bytes of each sample. This allows the media data itself to be * unframed. The total number of samples in the media is always indicated in the * sample count. * * There are two variants of the sample size box. This variant permits smaller * than 32-bit size fields, to save space when the sizes are varying but small. * One of the boxes must be present; the {@link ISO14496_Box_STSZ another * variant} is preferred for maximum compatibility. * * @package php-reader * @subpackage ISO 14496 * @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: 92 $ */ final class ISO14496_Box_STZ2 extends ISO14496_Box_Full { /** @var Array */ private $_sampleSizeTable = array(); /** * Constructs the class with given parameters and reads box related data from * the ISO Base Media file. * * @param Reader $reader The reader object. */ public function __construct($reader, &$options = array()) { parent::__construct($reader, $options); $this->_reader->skip(3); $fieldSize = $this->_reader->readInt8(); $sampleCount = $this->_reader->readUInt32BE(); $data = $this->_reader->read ($this->getOffset() + $this->getSize() - $this->_reader->getOffset()); for ($i = 1; $i <= $sampleCount; $i++) { switch ($fieldSize) { case 4: $this->_sampleSizeTable[$i] = (($tmp = Transform::fromInt8($data[$i - 1])) >> 4) & 0xf; if ($i + 1 < $sampleCount) $this->_sampleSizeTable[$i++] = $tmp & 0xf; break; case 8: $this->_sampleSizeTable[$i] = Transform::fromInt8($data[$i - 1]); break; case 16: $this->_sampleSizeTable[$i] = Transform::fromUInt16BE(substr($data, ($i - 1) * 2, 2)); break; } } } /** * Returns an array of sample sizes specifying the size of a sample, indexed * by its number. * * @return Array */ public function getSampleSizeTable() { return $this->_sampleSizeTable; } }