I've recently bought an Eachine Pro DVR which I want to add to my trusty FatShark Attitude v2 goggles.
Wiring the DVR to be able to record video is easy: just solder the DVR's video input wire to the receiver module's output. However this DVR also has a video output, to which it can display its own OSD and menus, or replay recorded footage.
I'd like to take advantage of these features, which means I need to wire that output back into the goggles somehow.
As far as I know, Fatshark's own builtin DVR in their later models also has an in-goggle OSD and video replay, and apparently it's wired right into the module's video feed such that its output gets intermixed with the original signal and the menus look transparent unless you turn off the module. Does that mean it's okay for me to wire the DVR's output directly to the module's output (essentially shorting it with its own input pin)?
Or do I have to somehow splice the DVR into the signal path, so that the goggles will see only the DVR's output at their input? Is such a splice going to degrade the latency of my goggles if I do? If I do the splicing, what's the best way of going about it? I'm good enough at soldering to cut traces and solder tiny wires to them, but I'd rather not do that if I can avoid it.