There is a "quite simple" Portfile patch that makes mpv work on the older systems here <https://trac.macports.org/ticket/60116>.
mpv has an active macos version, and the objective-c and SDK requirements advance fairly quickly. but the fallback x11 version works OK, if you can live with it. making the newer objective-c compatible with older SDKs is a bigger project -- I just don't have it in me. Building against a newer SDK and deploying on older systems to get the macOS version is a better bet -- I don't know how much support is written into mpv for that with my quick look. Anyway, macports doesn't have much support for that yet, although who knows what the future may hold in that regard? Best, Ken
