>So how is this good for anyone but John? If you think this kind of stuff doesn't happen and all this kind of advancements are public domain anyway, you are wrong. There are many niche fields where competing advantage comes from technical excellence and understanding couple of key things better than your competition.

This is good for society, because society gets more competitive labor markets and more competitive video-encoding markets. This encourages the spread of high-quality products and technical knowledge at low prices.

Remember: companies exist to supply a product efficiently. You are not entitled to get rich by rentiering on ideas.

If you want to keep John from working for a competitor, just agree to pay him his salary for two years after he stops working for you, while he goes on vacation around the world. The amount of competition and poaching you want to avoid should be priced in terms of years of salary you're willing to pay in exchange for non-labor.