Build FFMpeg on Windows 10 (using MinGW/MSYS2)

Greetings! I need a working build of FFMpeg on Windows 10, using the MinGW compiler, including many of the popular codec libraries (h.264, h.265, libvorbis, libtheora, libpng, libopenjpeg, libtiff, and libvpx). The end result should be both an executable of [login to view URL] and a /bin/ folder full of DLL's for each library, including libavformat, libavcodec, and the other FFmpeg libraries that are compatible with Windows 10. *** CRITICAL IMPORTANT POINT *** We must use an install of Qt 5.4.2 (built with and includes MinGW: [login to view URL]). It is critical that the Qt 5.4.2 version of MinGW be used as the compiler and linker, since they have a special build of MinGW, and I'm using that compiler on other parts of my project. I've had some success with MSYS2, and using the included Qt 5.4.2 version of MinGW as the compiler, but I just don't have the time to figure out all the small details and get everything working. *** The Deliverables: *** 1) A script of some kind, that kicks off the entire build process, and all the commands used to configure and build everything. This way, I can update the source code of these projects in the future, and re-build everything without too much headache. =) 2) A working version of FFmpeg that can be used transcode videos into the following formats without any crashes: A) WEBM (libvorbis & libvpx) B) MP4 (libx264, ac3) C) OGG (libtheora, libvorbis) D) MP4 (mpeg4, libmp3lame) E) AVI (mpeg2video, mp2) F) MOV (libx264, ac3) 3) The shared DLLs which can be linked to another project I'm working on, and the associated header files (which should be available after building and installing into the various MSYS2 folders /bin/ /lib/ /include/, etc...)