There were a bunch of people experimenting with using RaspberryPis for low latency drone FPV video. Turns out for some use cases WiFi in it's standard config is a big part of the "getting below a few hundred milliseconds latency" problem. (Note: trying for low latency on 1080p video is making life harder for yourself too. If you don't _need_ 2 megapixel frames, go smaller. 720 or 600 lines might be fine. Drone FPV often uses 525 line analog video.)
These days most drone people just blow money on the new-ish DJI digital video stuff (which works on non-DJI drones). It's pretty spectacular, but it's over a grand (in AUD) worth of gear so for now I'm sticking with my old analog video gear.
I've got a setup I built based on this: https://befinitiv.wordpress.com/wifibroadcast-analog-like-tr... that's well below 100ms if latency. It's still not as good as analog video for fast drones though.
These days most drone people just blow money on the new-ish DJI digital video stuff (which works on non-DJI drones). It's pretty spectacular, but it's over a grand (in AUD) worth of gear so for now I'm sticking with my old analog video gear.