I have upgraded my binary distribution of open source multimedia utilities to include a proper installer, not just an archive. This distribution is for Windows 64 bit only, and is tested on Windows 10.
These are usually very recent compilations of best-in-class open source programs for multimedia conversion, manipulation and exchange. Within this bundle are extremely full versions of: FFmpeg, SoX, x265, x264, x262, the Fraunhofer AAC encoder (including HE-AAC and HE-AAC2), the mpv player, LAME, GraphicsMagick, MP4Box, DCP-o-matic and many others. Many of these are world-standard programs, very actively maintained, and in constant use by broadcasters and multi-media companies on every continent.
These are all open source and free (as in both beer and speech), so you are welcome to download and use them, and much else beside, without any consideration beyond obeying the legal licences accompanying them. The licence usually forbids you from withholding the source code if you modify anything, and this is a very important rule that you must obey. If you just use the binary programs, you need probably not worry about anything else.
The source code for my compilation is available from GitHub, and the README file is fairly up-to-date. It contains information about other packages you will need to make some of these run (a Perl and a Python interpreter, for example).
GitHub source: https://github.com/Warblefly/MultimediaTools-mingw-w64
Binary distribution (download and run this installer): http://gallery.johnwarburton.net/MultimediaTools-mingw-w64-Open-source.exe