Snowmix

http://snowmix.sourceforge.net

It is a Live Video Mixer which uses the GStreamer Pipeline in its backend. It allows for a scriptable creation/mixing of overlays on video.

DeltaShaper uses Snowmix to overlay generated payload frames in the background video. Due to the erroneous interaction that GStreamer had with Skype, the output of Snowmix is fed to another FFMPEG pipeline which is then used to deliver Skype-readable video to our v4l2 loopback device.