"Safety cam" is a term which I find hard to digest. If it were a device which emitted a force field and kept others at a safe distance, that would be ideal. Perhaps if drivers think you have one fitted they would be more likely to play nice. Maybe even a prominent fake one with an attention getting LED might do the job.
I did buy a bike cam once, with a view to recording my more interesting rides. Fortunately it was quite cheap but there seems to be trade off between image quality and battery life. If you invest in a more up market one, you might get a better balance but to me at least, the potential benefit of recording the one in a million scrotes who might invade your space versus worrying about battery life, charging, vibration damage, how waterproof it might be, remembering to take it off when parked in case it gets nicked, and so on just spoiled the spontaneity of my ride.
If you have a commute that makes you feel like a WWII fighter pilot then the feeling of security it can give might well be worthwhile. Or you could just buy one of those signs that says "camera on board". You'll never forget to charge it, it will be waterproof, it has no electronics to go wrong, and unless it actually vibrates loose and falls off, it will keep on working. The main drawback is that the kind of inattentive driver who doesn't see you is also unlikely to see your sticker.
Perhaps for those more fond of gadgets than I am, a camera is worthwhile, but despite the advice of those who use them here, you will probably go through a few, becoming your own expert, before you find the ideal one for you. But beware, for some this sort of thing can be addictive, and before you know it you might become another Cycling Mikey!
