import vapoursynth as vs

core = vs.get_core()

def make_gray_lines(width, height):
    white_clip = core.std.BlankClip(width=width, height=1, format=vs.GRAY8, color=255)
    black_clip = core.std.BlankClip(width=width, height=1, format=vs.GRAY8, color=0)
    line_source = []
    for line in range(height):
        if (line % 8 == 0) or (line % 8 == 7):
            line_source.append(white_clip)
        else:
            line_source.append(black_clip)
    return core.std.StackVertical(line_source)

def make_gray_grid(width, height):
    h_lines = make_gray_lines(width, height)
    v_lines = core.std.Transpose(make_gray_lines(height, width))
    return core.std.Expr([h_lines, v_lines], expr='x y max')

def make_grid(width, height):
    return core.std.ShufflePlanes([make_gray_grid(width, height), make_gray_grid(width // 2, height // 2)], planes=[0, 0, 0], colorfamily=vs.YUV)

make_grid(640, 480).set_output()