if you want to give it a try.. download them:
gstplugins support a wide range of audio + video codecs
install instructions:
download it, unpack it, put it in /usr/lib/gstreamer-0.10/
so:
mkdir /tmp/gst
cd /tmp/gst
wget http://pkgsrc.sartek.net/gst/gstplugins.tar.gz
gtar xf gstplugins.tar.gz
pfexec cp gstplugins/* /usr/lib/gstreamer-0.10/
cd
rm -r /tmp/gst