I was wondering if someone could point me in the right direction or give me an idea as to how feasible this is.
I want to have a simple graphic overlay onto a MIPI CSI video that is then encoded to h264 and streamed over the network. Something like a PNG with alpha that can be dynamically updated by application. I would prefer this to all be hardware accelerated to minimize power consumption and allow a low cost single core processor to be used. The application is to draw boxes over objects detected in an environment from a radar sensor (no image detection going on, camera is fixed in location)
I've tried to prototype this on a raspberry broadcom board and the h264 encoding and streaming works great with low cpu usage and low latency but any attempt to add a graphic overlay involves the cpu which quickly throttles everything.