Thanks for the heads-up, Greg. I changed the PPA. I also added some links that I think may be helpful. 

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A call to anyone reading this: I'm not working on Linux right now, so I'm a bit out of touch with what works or doesn't work on the various distros. Help us improve the wiki page that Greg mentioned: Installing FFmpeg. Post your comments here. Or add your section directly to the page. (I'll come around and tidy up if it's needed.)