PCM_CHANNEL_FC
ch_map[0] = PCM_CHANNEL_FC;
ch_map[2] = PCM_CHANNEL_FC;
ch_map[2] = PCM_CHANNEL_FC;
ch_map[3] = PCM_CHANNEL_FC;
ch_map[3] = PCM_CHANNEL_FC;
ch_map[0] = PCM_CHANNEL_FC;
ch_map[2] = PCM_CHANNEL_FC;