Do not download Xvid codec from any website other then its original. Most websites offering streaming movies will have advertisements that look like streaming movies and demand you to download something before it will play.
The simple fact is that it isn't a video and no movies require you to download Xvid anymore.
If you infact want to watch streaming videos I do have a website for you to go to -
http://www.tubeplus.me
It looked like a crappy site to me at first but when I checked it out the videos are real and the only issue that I have is putlocker being a slow host.
Divx videos are also high in data size so you may want to avoid that as well.