getid3_ac3::serviceTypeLookup

	 *
	 * @return string|false
	 */
	public static function serviceTypeLookup($bsmod, $acmod) {
		static $serviceTypeLookup = array();
		if (empty($serviceTypeLookup)) {
			for ($i = 0; $i <= 7; $i++) {
				$serviceTypeLookup[0][$i] = 'main audio service: complete main (CM)';
				$serviceTypeLookup[1][$i] = 'main audio service: music and effects (ME)';
				$serviceTypeLookup[2][$i] = 'associated service: visually impaired (VI)';
				$serviceTypeLookup[3][$i] = 'associated service: hearing impaired (HI)';
				$serviceTypeLookup[4][$i] = 'associated service: dialogue (D)';
				$serviceTypeLookup[5][$i] = 'associated service: commentary (C)';
				$serviceTypeLookup[6][$i] = 'associated service: emergency (E)';
			}

			$serviceTypeLookup[7][1]      = 'associated service: voice over (VO)';
			for ($i = 2; $i <= 7; $i++) {
				$serviceTypeLookup[7][$i] = 'main audio service: karaoke';
			}