[gst-devel] Meta-plugins: a proposal

[Erik Walthinsen]

On Sat, 17 Mar 2001, Thomas Nyberg wrote:

> If one would use a common standard to assign types to each plugin, an
> audiosink might be "Audio/Sink", and an echo-filter might be "Audio/Filter"
> (using anything but text for this, seem to have some resistance :)
>
> Then one could simply do a
> gst_factory_get_me_my_list_of_nice_plugins_matching_my_type("Audio/Filter")
> and then retrieve the list.
We already have this capability, called the plugin's 'class'.  When you
run the editor and get the dialog to add a new element, the hierarchy is
generated from that element class.  This hierarchy is not quite clean
right now, having evolved poorly, but a week ago there were some
suggestions as to how to fix it.

Then we just need to add functions to query based on these classes.  The
audio case is simplified by the fact that an element should not be
instanitiatable if it cannot acquire the resources it needs.  This would
mean adding a field to each elementfactory stating whether it can be
created or not, and adding code to the plugins that need external
resources to let them check before they create the elementfactory.
Otherwise, they simply fail at instantiation time somehow.  That needs to
be speced out and implemented all the way through, of course.

      Erik Walthinsen <omega at temple-baptist.com> - System Administrator
        __
       /  \                GStreamer - The only way to stream!
      |    | M E G A        ***** http://gstreamer.net/ *****
      _\  /_