I went through it and there's still some ugly hackery involved on Windows. These are technical issues (e.g. how ffmpeg is compiled via MinGW), but they make it

I went through it and there's still some ugly hackery involved on Windows. These are technical issues (e.g. how ffmpeg is compiled via MinGW), but they make it complicated to generate a non-branded, psuedo-official build. That said, all the pieces you need (minus the closed-source plugins) appear to be in the repository and can be built and compared against an official release. It could definitely be made easier, but would require some non-trivial engineering to do so.