[Vala] vala and gstreamer plugins

[alberto colombo <a colombo kingston ac uk>]

Hello,

I've been playing with Vala and GStreamer to build a simple
application... smooth like a breeze :-) However, things get difficult
when I try to build a GStreamer plugin, i.e. and object derived from
Gst.Element.

The problem is that I need to put some code in the _base_init function
of my plugin [1]:

        static void
        gst_my_filter_base_init (gpointer klass)
        {
          GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
        
          static const GstElementDetails my_filter_details = {
                [..]
          };
        
          gst_element_class_set_details (element_class, &my_filter_details);
        }

but I can't find out how to do that in Vala. Similar problem when I
need to add a static pad template to my plugin Class [2]:

        static void
        gst_my_filter_base_init (gpointer klass)
        {
          GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
          [..]
        
          gst_element_class_add_pad_template (element_class,
                gst_static_pad_template_get (&src_factory));
          gst_element_class_add_pad_template (element_class,
                gst_static_pad_template_get (&sink_factory));
        }

In the gstreamer-0.10.vapi file, the add_pad_template is declared as:

        [CCode (cname = "gst_element_class_add_pad_template")]
        public class void add_pad_template (Gst.PadTemplate templ);
        
which looks correct, but what does the "class" modifier mean? In
practice, it behaves like a normal instance method, which is
not what I want...

Any help will be greatly appreciated. I'm using Vala 0.5.4.
Thanks in advance

alb
            
[1]
http://gstreamer.freedesktop.org/data/doc/gstreamer/head/pwg/html/section-boiler-details.html

[2]
http://gstreamer.freedesktop.org/data/doc/gstreamer/head/pwg/html/section-boiler-padtemplates.html

-- 
alberto colombo <a colombo kingston ac uk>

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