Do this:
0. Shockwave Flash plugins (Gnash/Lightspark/Flash) must be disabled from
Abrowser's Add-ons Manager
1. Go to the video site you want to play (e.g.
http://video.golem.de/games/10750/metro-last-light-test-fazit.html)
2. In the place where video should appear, there is a title of the video and
just above a tiny little piece of an actual image. Right-click on it, and
select View Background Image
3. Modify the URL of the image by replacing teaser with files, then rename
the filename from QUALITY-HEIGHT-TITLE-AUTHOR-pic.jpg to
TITLE-DEFINITION*.EXT*.
DEFINITION - should be sd or hd
EXT - should be mp4 or flv
This way, you will be able to watch videos right from your web browser.