Cmake errors when configuring blender to compile

I found this guide on how to build blender https://blog.machinimatrix.org/building-blender/ but when I follow it, I get errors when doing the configuration and generation, so no solution is generated to build. I noticed in my configuration, all the OSL stuff was not set, so I fixed that, but the FFMPEG_DIR is not set either. But no matter how many times I point it to the ffmpeg directory under my lib/win64_vc12 directory, it continues to say it can’t find the directory. Is there a better guide I should use to compile that will show whatever steps I’m missing?