After doing Chromium for some time I'm back to Firefox/Waterfox as my primary browsers. Anyway, Chromium did have a built in multi-media blocker. Just disable all plugins. I don't know what you guys are using, but Stop AutoPlay seems to work.
Just thought I'd post because when I first tried to get it on mozilla, it showed it as discontinued by author. But it's still available for download from Softpedia:Stop AutoPlay Firefox Extension
You may want to try it before it's pulled down.
I've just started using it. One thing I noticed is download of audio files, like for radio shows that make podcast and mp3 of the show available, may be blocked also unless you add the site to the white list. (The links where you would normally "save link as" don't even show up if the files are blocked.)