Which video format allows concatenation simply by joining files?
cat out1.mp4 ou2.mp4 >out.mp4
These videos are created from images using ffmpeg:
ffmpeg -loop 1 -f image2 -i image.png -s 640x480 -vcodec libx264 -t 30 -y out.mp4
If you can give me a running example it'd be great.