StackedNto16

function StackedNto16(clip c, int n)
{
    Assert(8 <= n <= 15, "StackedNto16: bitdepth should be in range 8-15")
    h = c.Height / 2
    msb = c.Crop(0,0,0,-h)
    lsb = c.Crop(0,h,0,0)
    shamt = string(16-n)
     
    msb16 = (n != 8) ? msb.mt_lutxy(lsb, "x " + shamt + " << y 8 " + shamt + " - >> +", v=3, u=3) : lsb
    lsb16 = (n != 8) ? lsb.mt_lut("x " + shamt + " << 255 &u", v=3, u=3) : msb
    return StackVertical(msb16, lsb16)
}

function InterleavedToStacked(clip c, int bitdepth)
{
    c.SeparateColumns(2)
    lsb = SelectEven()
    msb = SelectOdd()

    StackVertical(msb, lsb)
    StackedNto16(bitdepth)
}