let np1 = sfilter(p3, p2, p1, np0, q0, RV40_DITHER_L[dmode + i], fmode != 0, lims);
let nq1 = sfilter( p0, nq0, q1, q2, q3, RV40_DITHER_R[dmode + i], fmode != 0, lims);
let np1 = sfilter(p3, p2, p1, np0, q0, RV40_DITHER_L[dmode + i], fmode != 0, lims);
let nq1 = sfilter( p0, nq0, q1, q2, q3, RV40_DITHER_R[dmode + i], fmode != 0, lims);