Maybe you could try Videostream for Google Chromecast.  You can get it from Chrome web store, but i haven't test it yet.

I don't think chromecast has  codec built in, it is just to stream from a website or app that supports chromecast.  

And yes Videostream can play RMVB and stream to chromecast

Icy today, schools are closed again.  

Oh.  So you stay at home also?

good morning all....

so boss said videostream can play RMVB? where to obtain this program? google site?

ben, yeah.  but the road is all cleared I think.  they should have opened late instead of closing the whole day.  Too caution.

flora, yeah.. Videostream is a Chrome extension, and can only stream to Chromecast.

I see.

I want to stream other format video files easily.  So i got a 4TB WD with WD TV to stream video on my TV.  Please easy to setup.