XScreenSaver to mp4

To spontaneously record the xscreensaver hacks as video files. Thx to Albert Veli for giving me a clue, alexgran for a Debian-bullseye patch, and of course Jamie Zawinski for XScreenSaver.

• remember to disable other screensavers while you're recording xscreensaver-command -exit How to detect it was running, and re-activate it when we're done here?

• which hack? Get a list find /usr/lib/xscreensaver -type f -perm /001

Prerequisites

I built it on my Debian workstation; should be easy to find these.

• bash
• ffmpeg
• xdotool & xwininfo
• Xscreensaver by jwz, who'd remind you to compile from the latest sourcecode.

Usage

It's a bash script.

• record_xscreensaver.sh pong record five minutes (300s) of the pong screensaver
• duration=3600 record_xscreensaver.sh glmatrix -hexadecimal record one hour (3600s) of the glmatrix screensaver's hex mode

TODO

• better way of detecting the XScreenSaver window than assuming the window title will always have a particular substring. Too bad xdotool search --pid doesn't work.
• something that would work in Mac OSX