last = col_hi[last as usize].read_sym(br, trees)?;
let lo = self.tree.read_sym(br, trees)?;
let val = Self::cvt_color(lo, last, new_bink);
last = col_hi[last as usize].read_sym(br, trees)?;
let lo = self.tree.read_sym(br, trees)?;
let val = Self::cvt_color(lo, last, new_bink);