@Jerry, lots of questions, I don't think many people have the knowledge to answer them, but I will try to point you in the right direction as best as I can.
Solo camera: What camera are you using?
The 3DR Solo shipped with two different cameras afaik, are you using the GoPro or the SiteScan camera R10C?
- For the GoPro video pipeline, you can check out this link
- for the R10C you are on your own, I don't think 3DR or Sony made that API available.
I would like to point out that both cameras are controlled by the SoloLink (i.MX6) companion computer, and control/streaming happens there, here's a brief architecture overview diagram for how the Solo works.
QGC & Mission Planner: I'm not sure about the current compatibility with either control station, but you should be able to connect to udp 14550 on 10.1.1.10 (here's a guide on how to connect to Solo)
I think you should probably be asking your questions to the Open Solo community, this is the best link I could find for them https://github.com/OpenSolo/documentation