GStreamer Base Classes

GstAdapter - object to splice and merge buffers to desired size
GstBaseSrc - Base class for getrange based source elements
GstBaseSink - Base class for sink elements
GstBaseTransform - Base class for simple tranform filters
GstCollectPads - manages a set of pads that operate in collect mode
GstPushSrc - Base class for push based source elements

libgstbase-0.9.so provides some base classes to be extended by elements.