Animations using ffmpeg

Partially stolen from Joshua Burrow

# concatenate individual frames (images) to a video
ffmpeg -i img%03d.png -c:v libx264 -vf fps=25 -y out.mp4

# concatenate videos (list.txt: "file 'video.mp4'" for each video)
ffmpeg -safe 0 -f concat -i list.txt -c copy -y out.mp4