How do you create jpg format video's?

I've always thought .jpg was non-animated, but I've recently found several animations in .jpg format.

1) The obvious question - how do you create .jpg video's directly in the fileformat (not using javascript, for example)?

2) It's both hard to find examples of more .j开发者_如何学编程pg format video's (unlike gif's, there aren't exactly archives of animated jpg's), so if you've found any notable .jpg video's not listed below, please also post them below!

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These are no jpgs. They are gif files just named jpg. You could see the file details to see they are gif. There are no animated jpgs.