I have a ceiling mounted projector and a blue ray player I'd like to connect via HDMI. however - I have 4 coax cables above the projector, running to the wall plate behind the blue ray. Can I split the HDMI cable into 4 RCA/BNC runs and then "remux" them back into an HDMI cable at the projector?
It sounds like your projector is using component video and you want to connect it to your Blu Ray with an HDMI cable. That won't work. Component is analog and HDMI is a digital connection they are incompatible. In order to do that you'd have to run it through some type of analog to digital conversion box first.