Recommended buffer size frame. If the embedded info * flag is set then this indicates that an ID3 tag with the maximum size * described in buffer size may occur in the audio stream. In such case the tag * should reside between two MPEG frames, if the audio is MPEG encoded. If the * position of the next tag is known, offset to next tag may be used. The offset * is calculated from the end of tag in which this frame resides to the first * byte of the header in the next. This field may be omitted. Embedded tags are * generally not recommended since this could render unpredictable behaviour * from present software/hardware. * * For applications like streaming audio it might be an idea to embed tags into * the audio stream though. If the clients connects to individual connections * like HTTP and there is a possibility to begin every transmission with a tag, * then this tag should include a recommended buffer size frame. If the client * is connected to a arbitrary point in the stream, such as radio or multicast, * then the recommended buffer size frame should be included in every tag. * * The buffer size should be kept to a minimum. There may only be one "RBUF" * frame in each tag. * * @package php-reader * @subpackage ID3 * @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 $Rev$ */ final class ID3_Frame_RBUF extends ID3_Frame { /** * A flag to denote that an ID3 tag with the maximum size described in buffer * size may occur in the audio stream. */ const EMBEDDED = 0x1; /** @var integer */ private $_size; /** @var integer */ private $_flags; /** @var integer */ private $_offset; /** * Constructs the class with given parameters and parses object related data. * * @param Reader $reader The reader object. */ public function __construct($reader) { parent::__construct($reader); $this->_size = Transform::fromInt32BE(substr($this->_data, 0, 3)); $this->_flags = substr($this->_data, 3, 1); $this->_offset = Transform::fromInt32BE(substr($this->_data, 4, 4)); } /** * Returns the buffer size. * * @return integer */ public function getSize() { return $this->_size; } /** * Checks whether or not the flag is set. Returns true if the flag * is set, false otherwise. * * @param integer $flag The flag to query. * @return boolean */ public function hasFlag($flag) { return ($this->_flags & $flag) == $flag; } /** * Returns the offset to next tag. * * @return integer */ public function getOffset() { return $this->_size; } }