Does the video iPod only connect with Tivo or any DVR?

This cable from Apple sends audio & video signal out to any device with Composite Video and Audio inputs. You must also turn on the Video Out option in the iPod Video Settings area.

No, it does not. Moving from Tivo out requires first moving it to a computer through Tivo supported means - they exist but I don't know anything about them. Once on the computer, the file must be converted to iPod compatible size & format.

This Search result from looking for "tivo AND convert" should give you some more information on the topic.