The media-autobuild_suite (brief: MABS) supports building ffmpeg in a regularly updates MSYS2/MinGW environment now also with vmaf for the Win64 target platform (a Win32 build failed due to "invalid EMMS intrinsics", is that intended, may that change?).
Another video developer asked me to confirm a memory leak he found, and indeed, once I managed to get ffmpeg built with libvmaf enabled, while comparing two similar videos I noticed a continuously increasing memory consumption.
I hope you can discover whether the reason is within this library or in the ffmpeg interface instead.

The media-autobuild_suite (brief: MABS) supports building ffmpeg in a regularly updates MSYS2/MinGW environment now also with vmaf for the Win64 target platform (a Win32 build failed due to "invalid EMMS intrinsics", is that intended, may that change?).
Another video developer asked me to confirm a memory leak he found, and indeed, once I managed to get ffmpeg built with libvmaf enabled, while comparing two similar videos I noticed a continuously increasing memory consumption.
I hope you can discover whether the reason is within this library or in the ffmpeg interface instead.