question: private void decodeChannelMap ( int [ ] [ ] layoutMap , int layoutMapOffset , int type , int n ) { while ( n -- != 0 ) { int synEle ; switch ( type ) { case AAC_CHANNEL_FRONT : case AAC_CHANNEL_BACK : case AAC_CHANNEL_SIDE : synEle = br . read1 ( ) ; break ; case AAC_CHANNEL_CC : br . skip ( 1 ) ; synEle = TYPE_CCE ; break ; case AAC_CHANNEL_LFE : synEle = TYPE_LFE ; break ; default : log . error ( String . format ( "decodeChannelMap invalid type %d" , type ) ) ; return ; } layoutMap [ layoutMapOffset ] [ 0 ] = synEle ; layoutMap [ layoutMapOffset ] [ 1 ] = br . read ( 4 ) ; layoutMap [ layoutMapOffset ] [ 2 ] = type ; layoutMapOffset ++ ; } }
target:  Decode an array of 4 bit element IDs, optionally interleaved with a stereo/mono switching bit.