gst-plugins-farsight contains Farsight plugins for the GStreamer
Farsight is an effort to create a framework to deal with all known 
audio/video conferencing protocols for use by applications such as 
instant messaging. These applications are able to use Farsight for 
all their Audio/Video conferencing needs without having to worry 
about any of the lower level streaming and NAT traversal issues.  

This requires libjingle and openjpeg, and can optionally use gsm
and libmimic.
