SUM_IN_F_C
sum = mixer->sums[SUM_IN_F_C*CHN_NUM];
sum = mixer->sums[SUM_IN_F_C*CHN_NUM+1];
sum = mixer->sums[SUM_IN_F_C*CHN_NUM];
sum = mixer->sums[SUM_IN_F_C*CHN_NUM+1];
sum = mixer->sums[SUM_IN_F_C*CHN_NUM];
sum = mixer->sums[SUM_IN_F_C*CHN_NUM+1];
sum = mixer->sums[SUM_IN_F_C*CHN_NUM];
sum = mixer->sums[SUM_IN_F_C*CHN_NUM+1];
sum = mixer->sums[SUM_IN_F_C*CHN_NUM];
sum = mixer->sums[SUM_IN_F_C*CHN_NUM+1];
sum_c = mixer->sums[SUM_IN_F_C*CHN_NUM+i];