Snowmix
Video mixer for mixing live and recorded video and audio feeds
...It supports animation of video, images and texts through native commands changing scale, placement, transparency and rotation. Animation and actions can also be controlled through native scripting and an embedded Tcl and/or Python interpreter. Snowmix is designed for control over low bandwidth links and can work as a standalone CLI based program. Control over both CLI and a TCP connections.
Input and outputs can be done through GStreamer pipelines or the GStreamer shmsrc/shmsink API.
Supported for Ubuntu, Mint, Debian, Fedora, Mageia, Manjaro, MX Linux and OpenSUSE (macOS/OS X is partly supported).
...