c_gst_meta_register

Undocumented in source but is binding to C. You might be able to learn more by searching the web for its name.
__gshared extern (C)
GstMetaInfo* function(GType api, gchar* impl, gsize size, GstMetaInitFunction initFunc, GstMetaFreeFunction freeFunc, GstMetaTransformFunction transformFunc) c_gst_meta_register;

Meta