I suspect that you just need an RCA to f or RCA to bnc adaptor... the BT video input is for baseband video , not rf... the outputs from a dvd player should work fine.
http://www.amazon.com/C2G-Cables-Go-...=rca+to+f+type
http://www.amazon.com/Monoprice-BNC-...rds=rca+to+bnc
jr