Interface CEC over HDMI

I want to turn on the TV and switch to the appropriate input when my PC wake from sleep. I found this previous thread for implementing most of it.

But then I found this ir2cec adapter that seems to accept input over a 3.5mm coaxial cable.

Would it be correct to assume it is piping signals directly over the CEC line? That way I can hook a 3.5mm cable to GPIO of an arduino board?