gst-plugins-libav : FFmpeg based gstreamer plugin ( http://gstreamer.freedesktop.org/modules/gst-libav.html )
live : Source-code libraries for standards-based RTP/RTCP/RTSP multimedia streaming, suitable for embedded and/or low-cost streaming applications ( http://www.live555.com/ )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a gmt
For Paludis use this rsync : rsync://gentoo.zugaina.org/gmt-portage
If you have a problem : ycarus(-at-)zugaina.org