[gst-devel] Use of GstElementFactory::klass property

Edward Hervey bilboed at gmail.com
Tue Feb 28 05:47:04 CET 2006

Hi all,

GstElementFactory has this, seamingly, very useful property called
klass. The only documentation about it however is lost somewhere in
the description of the GstElementDetails structure:
"gchar *klass; 	 type of element, as hierarchy"

The problem is two-fold:
1/ There isn't any established standard of which klass you should put
a ElementFactory in and what the meaning of every class hierarchy
means. Very problematic for an application to do any kind of filtering
on types of elements it would need (like listing video effects (and
not transformations like scaling, colorspace conversion,...)).

2/ There are inconsistencies in the already available klasses:
 _ Codec/Depayr vs Codec/Payloader . Should the first one be Codec/Depayloader ?
 _ Src/Audio vs Source/Audio (alsasrc is in the first one, all the
other audio sources in the second one)
 _ Filter/Effect/Video vs Filter/Video vs Filter/Editor/Video vs
Filter/Converter/Video (WHICH one does what ???)

The proposition is to first document properly every class hierarchy
somewhere (What should go in every (sub-)level, what's the policy on
creating new (sub-)levels, ....). This is useful both for application
and plugin developers, so I guess it should go in the ADM.

  Any comments ?


Edward Hervey
Junior developer / Fluendo S.L.

More information about the gstreamer-devel mailing list