SlackBuildsOrg/multimedia/gst0-plugins-base

GStreamer Base Plug-ins is a well-groomed and well-maintained
collection of GStreamer plug-ins and elements, spanning the range of
possible types of elements one would want to write for GStreamer.
It also contains helper libraries and base classes useful for
writing elements. A wide range of video and audio decoders, encoders,
and filters are included.