Yes the black wire are normally the ground wire.
I think the brand are unknown to most of us in here, the kind of rear camera, which just appear to be for reversing, confuse me a bit.
Generally it is advised against using the rear camera in 2 channel dashcams for reversing, first of all the cameras are often aimed different, a reversing camera very much aimed down so you can see everything behind the car and / or installed very low on the fender for instance.
Where as a rear cashcam are best mounted up high like the front camera and aimed horizontal, so for instance in a sedan, well the boot of the car would obscure what is directly behind the car, and just seeing the asphalt you probably wound before you are 2 M behind the car.
so a sedan with a rear dashcam in the window, a small child could easy sit behind the car,,,,,, this actually happened here in Denmark this past summer, a guy "killed" his friends child.
Also rear cameras in dual channel dashcams, they almost always do not have guide or distance markings in the footage, of course these are not absolutely needed, you can probably do fine without as after all reversing are a gentle procedure.
Anso reversing cameras are mirrored as its more natural when you look at a screen while reversing, but this do mean a license plate the camera see are miorrored too, so harder to read.
Normal dashcams like yours appare to be are just low resolution and most often connect to the entertainment system up front, so when you put the car in reverse the camera get power and start to transmit its AV signal, the head unit then detect that and automatic switch to the reversing camera, and when done and you go to neutral or forward gear the camera in the back go out and your head unit change back to the radio or what ever you had going before you reversed.
The fact your camera seem to be bundled with a dashcam is uncommon, though probably also not unique, just not the way " normal" dashcams we usually talk about in here are made.
You may have noticed many work vans have a reversing camera way up on the roof, but aimed down very much, so even if it is very wide angle it probably do not see very far out back, like you would want a dashcam to do, so its a pure reversing solution.
Now most dashcams can actually also reverse / mirror the rear camera, but we dont want that as we want to easy be able to read a captured plate.
Proper reversing cameras, often sold with a cheap 7" LCD screen, can be had pretty cheap, i am considering that as my old body are not as flexible as it use to be
