DVR dash cam help needed please.

[jason8]

Hi all
Another day another issue with my Android head unit install.
I have just fitted one, its a HuiFei 8" model S06 (I believe). I've fitted a reverse cam (Bluetooth version) which works about 80% of the time, the other 20% is 'no signal'. That's by the buy at the moment, it works at least..
My headache is the dash cam for a DVR. I purchased what is essentially another reverse camera without the guides in the picture and positioned it front and centre on the dash. The camera does actually work, I tried it on the reverse cam circuit, looks pretty good picture. However, when I connect it as I think it should be, no joy. I have 12v from the amp feed (no amp just the reverse camera powered from it also). Then I have a video cable (yellow phono) connected to video IN. I have video IN, video 1 OUT and video 2 OUT. Logical is video in? Doesn't work on any of them anyway..
There is a red flying cable from each yellow phonograph but I think this is only required if using the cam as a reverse to send a trigger voltage to the 'reverse' feed on the head unit to force rear view mode?
I note in the manual (if you can call it that) that it says for the DVR "you can use any USB camera".
I don't think this is strictly true and I don't really want a full webcam size camera on my dash. I did however try my webcam into the USB port which gives me pink and grey noise bars on the screen in DVR mode. My webcam is however a 720p model and I suspect that because its HD its incompatible?
Do I really need to use a webcam and if so I guess a 480tvl model is what I will have to use?
That's all the info I can give, if anyone's still reading and can offer me up anything I'd be very grateful.
Thanks for getting this far ;)