According to mpv.srsfckn.biz smplayer doesn't support mpv

[JanH]

[rvm]

The latest development versions include support for mpv. You only need to install SMPlayer and check yourself.

Maybe the guy from that site would prefer a better support by using libmpv instead of using the old slave mode, I already explained my reasons in and my intention is to use their API in a future version.

About the "quality" of the code, I'm not a professional developer, I'm developing SMPlayer for fun. And I make a lot of mistakes for sure. I reckon some parts of the code are a mess, with a lot of hacks to work around bugs and oddities in mplayer/mpv and support older versions as well. But anyway the code wasn't designed to look good or intended to be used by other people for other applications. The users of SMPlayer don't care about the "quality" of the code, as long as it works. And it works.