https://blog.wongcw.com/2020/10/17/analogue%e6%98%8e%e5%b9%b4%e5%b0%87%e6%8e%a8%e5%87%ba%e8%a4%87%e5%8f%a4%e9%81%8a%e6%88%b2%e6%a9%9fduo-%e5%85%bc%e5%ae%b9%e5%a4%9a%e7%a8%ae%e8%88%8a%e5%b9%b3%e5%8f%b0/