The guy works at Hooli, which is suppose to be like Google, but has entrepreneurial aspirations so he develops something, shows it to a couple of co-workers and now the boss of Hooli has to buy it from him?
If you work for a big company, they own whatever you do, while you're under their employment, even if he did it on his own time.
Unlikely too that a new codec wouldn't be subject to patent disputes. Or that he'd develop it while his goal was something else. More likely, he'd use an existing codec if his idea was about searching for copyrights.