Re: gstreamermm option group does not init

[Marcus Brinkmann <marcus brinkmann ruhr-uni-bochum de>]

At Thu, 19 Jun 2008 13:31:03 +0200,
Murray Cumming <murrayc murrayc com> wrote:
> > >     Returns a Glib::OptionGroup with GStreamer's argument specifications.
> > > 
> > >     The group is set up to use standard GOption callbacks, so when using
> > >     this group in combination with GOption parsing methods, all argument
> > >     parsing and initialization is automated.
> > >     ...
> > > 
> > > If you read carefully, I think you'll see that the word `initialization' 
> > > refers to argument initialization and not gstreamermm initialization.  
> > 
> > I respectfully disagree.  I think it is pretty clear that
> > "initialization" in the gstreamer documentation of
> > gst_init_get_option_group to mean gstreamer itself.
> 
> Does gstreamer require any initialization? For instance, do you need to
> call any init() function when not using GOption? If not, then it's
> unlikely that the documentation means this.

You need to call gst_init(&argc, &argv) or gst_init_check(&argc, &argv)
if not using GOption.

> Note that we probably can hook into the GOption stuff if necessary.

I think that would be best.  It must be possible, the question is what
is the simplest solution.  How about something like this:

class GstOptionGroup : public Glib::OptionGroup
{
  GstOptionGroup (GOptionGroup* castitem)
    : Glib::OptionGroup (castitem) { }

  virtual on_pre_parse (OptionContext& context, OptionGroup& group)
    {
      Glib::OptionGroup::on_pre_parse (context, group);
      init_pre ();  /* Appropriate refactorization of Gst::init() */
    }

  virtual on_post_parse (OptionContext& context, OptionGroup& group)
    {
      Glib::OptionGroup::on_post_parse (context, group);
      init_post ();  /* Appropriate refactorization of Gst::init() */
    }
};


Glib::OptionGroup Gst::get_option_group()
{
  return GstOptionGroup (gst_init_get_option_group());
}


Thanks,
Marcus