Snowmix is a leading Free and Open Source Video Mixer. Snowmix is a very fast and flexible command line tool with a small ressource footprint for dynamically mixing live audio and video feeds.
You can build the image runing the build script or by pulling the image from docker hub.
Once the container is up, it will be running the minimal ini file in order to wait for futher commands.
Keep in mind to expose the 9999 port to allow netcat to comunicate with the container.