public static function audioCodingModeLookup($acmod) {
    // array(channel configuration, # channels (not incl LFE), channel order)
    static $audioCodingModeLookup = array (
      0 => array('channel_config'=>'1+1', 'num_channels'=>2, 'channel_order'=>'Ch1,Ch2'),
      1 => array('channel_config'=>'1/0', 'num_channels'=>1, 'channel_order'=>'C'),
      2 => array('channel_config'=>'2/0', 'num_channels'=>2, 'channel_order'=>'L,R'),
      3 => array('channel_config'=>'3/0', 'num_channels'=>3, 'channel_order'=>'L,C,R'),
      4 => array('channel_config'=>'2/1', 'num_channels'=>3, 'channel_order'=>'L,R,S'),
      5 => array('channel_config'=>'3/1', 'num_channels'=>4, 'channel_order'=>'L,C,R,S'),
      6 => array('channel_config'=>'2/2', 'num_channels'=>4, 'channel_order'=>'L,R,SL,SR'),
      7 => array('channel_config'=>'3/2', 'num_channels'=>5, 'channel_order'=>'L,C,R,SL,SR'),
    );
    return (isset($audioCodingModeLookup[$acmod]) ? $audioCodingModeLookup[$acmod] : false);
  }