How does the download-them-all plugin work?

I used the download-them-all plugin in mozilla to download the video on the page at a time. It is very good what he does.

But I could not understand how this is done on https sites?

At first I thought it would be a parsing of the html content of a web page, and then getting into these URLs.

I tried to do this in a separate python application with a url but could not do this. This should be a cookie session problem and everything else.

Is this possible only through the plugin? Can this be done with a web application such as a website where users give us a URL and we can act on this?