This is really hard to fix, x11 is just terrible at cleaning up windows after they close. slop has lots of precautions to keep it from appearing in screenshots though.
maim shouldn't suffer from it.
Yeah you're right. My bad, I've changed the readme to reflect that. I did mean commandline screenshot utilities, but I was completely unaware that GUI screenshooters have the ability regardless (because I don't use any of them).
make && sudo make install would do the trick (For both slop and maim), but you should try to see if you can get your package manager to install it somehow.
For example Arch Linux has slop and maim in the AUR. I'll add an install section to the README.md
ffmpeg and slop work together nicely to record your desktop (record-my-desktop is great too), but I don't know of anything that streams the recordings.
Hey thanks! I appreciate it, I put quite a bit of work making sure their purpose was clear so people wouldn't just label it as another drop in an ocean of screenshot utilities.