First, install gource. It seems to work best on Windows.
Preview the generated movie:
gource --load-config .gource.conf
Create a video file:
gource --load-config .gource.conf -o - | ffmpeg -y -r 60 -f image2pipe -vcodec ppm -i - -vcodec libx264 -preset veryslow -pix_fmt yuv420p -threads 0 -bf 0 -crf 18 git-town.mp4