AMFStream

		return (isset($lookup[$id]) ? $lookup[$id] : false);
	}
}

class AMFStream
{
	/**
	 * @var string
	 */
	public $bytes;

	/**
	 * @var int
	 */
	public $pos;

	/**
	 * @param string $bytes
	 */
	public function __construct(&$bytes) {
		$this->bytes =& $bytes;
		$this->pos = 0;
	}

	/**
	 * @return int
	 */
	public function readByte() { //  8-bit
		return ord(substr($this->bytes, $this->pos++, 1));
	}

	/**
	 * @return int
	 */
	public function readInt() { // 16-bit
		return ($this->readByte() << 8) + $this->readByte();
	}

	/**
	 * @return int
	 */
	public function readLong() { // 32-bit
		return ($this->readByte() << 24) + ($this->readByte() << 16) + ($this->readByte() << 8) + $this->readByte();
	}

	/**
	 * @return float|false
	 */
	public function readDouble() {
		return getid3_lib::BigEndian2Float($this->read(8));
	}

	/**
	 * @return string
	 */
	public function readUTF() {
		$length = $this->readInt();
		return $this->read($length);
	}

	/**
	 * @return string
	 */
	public function readLongUTF() {
		$length = $this->readLong();
		return $this->read($length);
	}

	/**
	 * @param int $length
	 *
	 * @return string
	 */
	public function read($length) {
		$val = substr($this->bytes, $this->pos, $length);
		$this->pos += $length;
		return $val;
	}

	/**
	 * @return int
	 */
	public function peekByte() {
		$pos = $this->pos;
		$val = $this->readByte();
		$this->pos = $pos;
		return $val;
	}

	/**
	 * @return int
	 */
	public function peekInt() {
		$pos = $this->pos;
		$val = $this->readInt();
		$this->pos = $pos;
		return $val;
	}

	/**
	 * @return int
	 */
	public function peekLong() {
		$pos = $this->pos;
		$val = $this->readLong();
		$this->pos = $pos;
		return $val;
	}

	/**
	 * @return float|false
	 */
	public function peekDouble() {
		$pos = $this->pos;
		$val = $this->readDouble();
		$this->pos = $pos;
		return $val;
	}

	/**
	 * @return string
	 */
	public function peekUTF() {
		$pos = $this->pos;
		$val = $this->readUTF();
		$this->pos = $pos;
		return $val;
	}

	/**
	 * @return string
	 */
	public function peekLongUTF() {
		$pos = $this->pos;
		$val = $this->readLongUTF();