Hello. I have followed the guide and was able to successfully build a 64 bit version of VLC player for Windows.
https://wiki.videolan.org/Win32Compile/
I had to disable libavcodec as it would only fetch 56.6 and needed 57, and I nearly lost my mind trying to get this (no luck even with getting ffmpeg installed.. whatever).
Anyway, I built the NSIS installer, and it installs fine, but never shows up in FireFox 64 bit. Confirmed I am using 64 bit version of FireFox 47, and that the installer has the option to install the FF plugin.
What could be wrong?