@gemlog Wow, you did put it to good use!
I'm pretty sure you can do that with ffmpeg too, but it's been years since I tried that. I know ImageMagick is a great tool, but… you know, the learning curve — when you do you best not to touch something that looks too versatile and powerful, but also complex. I think I got into ffmpeg when clipping videos with avidemux got too repetitive and not precise enough, I was like "This thing just makes previews and spawns ffmpeg, why don't I do this myself?"