(I use Linux KNOPPIX (distro 7.0.2, ver 3.3.7) on hard drive.)

I download videos of TV programs from the 60s and 70s (mainly from youtube). I copy the youtube URL then paste it into www.keepvid.com to download it (usually .mp4 format).

Having now got dozens of such video files (and growing) on my hard drive, I'd like to organise them. WHAT I'D LIKE TO DO IS:

1. Say I find a new vid (of a TV prog) on youtube (or another site), and I'm about to download it. It's possible that I've WATCHED IT BEFORE but have forgotten.

2. So is there software out there that I can run which will do the following:

3. Check for me if I've ALREADY WATCHED the vid that I'm about to download. At the moment, once I've watched a vid on my hard drive, I move the file to another directory called "Watched". But this of course doesn't alert me in the immediate way that I want.
   .
   It would crudely suffice, if the software told me AFTER I've downloaded the vid, if I've ALREADY WATCHED it (ie if it's already in my "Watched" directory, or perhaps in a "watched" list). I sometimes alter the filename of the original video file on hard drive, so this might spoil a comparison.

4. If the software alerts me to the fact that I've already watched the vid (preferably BEFORE I download it), then this will allow me to confidently download only new vids that I haven't watched before, and save me duplicating my effort.

I'd be most grateful if anyone can suggest such a piece of software, or an alternative solution.

I'll be honest, I avoid software that infringes your privacy and control - you know, software that automatically does things behind your back, like upgrades itself over the internet, puts things on your hard drive that you didn't ask for, or sends information from your hard drive to websites.