ENVY24HT_REC_BUFUNIT
unit = ENVY24HT_REC_BUFUNIT / 4;
bsize = ch->blk * 4 / ENVY24HT_REC_BUFUNIT;
ch->blk *= ENVY24HT_REC_BUFUNIT / 4;
bsize = ch->blk * 4 / ENVY24HT_REC_BUFUNIT;
sc->rsize = ENVY24HT_REC_BUFUNIT * ENVY24HT_SAMPLE_NUM;