I am trying to use everything I already have on my shelves to keep the cost as low as possible, and because I do not want to wait for spare parts I would have to order on some asian country, with delivery delays of around a month. 
Here is the idea : I want to use two raspberry pi zero linked together by a usb cable, one being a usb gadget connected to the other. The video streaming between both will be entirely managed by usb virtual network interfaces and routed through iptables.  The usb hub will also host an android smartphone using its usb tethering mode to use the same network and be able to watch the images streamed by both raspberry pis.