My projector has a single RG-6 cable with RCA terminals running to it from the console space in the front of the room. I wanted the cable to be hidden as much as possible and I didn't run an HDMI connection because I couldn't find a way to terminate HDMI terminals on unterminated stock HDMI cable, which is how I did with RG-6 and RCA terminals. Currently, I output the video signal out of an older model DVD player, which has a single RCA output. The video quality is good and the projection size on the wall is 98# in diameter.
However, I would like to buy a streaming video box, such as Roku HD, so that I can stream movies and music from YouTube and Netflix onto my home theater system. I ruled out Apple TV as it only has HDMI out. Roku HD has HDMI, which I can use for audio, but it also has three composite ports.
My question is: can I either just use one of those three ports to connect to the single wire projector connection or can I somehow convert the signal by using all the three and then some kind of adapter? If not, what are my options for streaming with this kind of video connection setup?