You should look at this thread on raspberrypi.org. It helped us alot last year when we had a similar issue with mjpg-streamer.
https://www.raspberrypi.org/forums/v...ic.php?t=45178
The way we ended up getting it working last year was by using this fork of mjpg-streamer. It has an opencv input plugin which should allow for lower latency streaming of your opencv output.
https://github.com/robotpy/mjpg-streamer
I haven't looked much into it, but the new Camera Server library made by WPILib seems very promising for streaming opencv.
https://github.com/wpilibsuite/cscore