getid3_dts::channelArrangementLookup

			3  => '(L+R) + (L-R) (sum-difference)',
			4  => 'LT + RT (left and right total)',
			5  => 'C + L + R',
			6  => 'L + R + S',
			7  => 'C + L + R + S',
			8  => 'L + R + SL + SR',
			9  => 'C + L + R + SL + SR',
			10 => 'CL + CR + L + R + SL + SR',
			11 => 'C + L + R+ LR + RR + OV',
			12 => 'CF + CR + LF + RF + LR + RR',
			13 => 'CL + C + CR + L + R + SL + SR',
			14 => 'CL + CR + L + R + SL1 + SL2 + SR1 + SR2',
			15 => 'CL + C+ CR + L + R + SL + S + SR',
		);
		return (isset($lookup[$index]) ? $lookup[$index] : 'user-defined');
	}

	/**
	 * @param int $index
	 * @param int $version
	 *