NTSC_TV_LINES_PER_FRAME
v_offset = ((int)(v_total * h_total) * 2 * tv_dac->v_pos) / (int)(NTSC_TV_LINES_PER_FRAME);
vert_space = const_ptr->ver_total * 2 * 10000 / NTSC_TV_LINES_PER_FRAME;
tmp /= NTSC_TV_LINES_PER_FRAME;