San Francisco-based Mux, a provider of performance analytics for video developers and media publishers, announced it has raised $2.8 million in seed-stage funding. Investors include SV Angel, Lowercase Capital, Susa Ventures, Liquid 2 Ventures, Advancit Capital, Y Combinator and individual investors, including Stripe co-founders John and Patrick Collison, Parse founder Ilya Sukhar, and Heroku founder James Lindenbaum. In addition, Mux has joined Heavybit, a San Francisco membership organization founded by Lindenbaum and which helps developers bring their product to market.