ENVY24_REC_BUFUNIT
unit = ENVY24_REC_BUFUNIT / 4;
bsize = ch->blk * 4 / ENVY24_REC_BUFUNIT;
ch->blk *= ENVY24_REC_BUFUNIT / 4;
bsize = ch->blk * 4 / ENVY24_REC_BUFUNIT;
sc->rsize = ENVY24_REC_BUFUNIT * ENVY24_SAMPLE_NUM;