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>Chapter 14. Plugins</H1
><P
>
All plugins should implement one function, <CODE
CLASS="function"
>plugin_init</CODE
>,
that creates all the element factories and registers all the type
definitions contained in the plugin.
Without this function, a plugin cannot be registered.
</P
><P
>
The plugins are maintained in the plugin system. Optionally, the
type definitions and the element factories can be saved into an XML
representation so that the plugin system does not have to load all
available plugins in order to know their definition.
</P
><P
>
The basic plugin structure has the following fields:
</P
><PRE
CLASS="programlisting"
> typedef struct _GstPlugin GstPlugin;
struct _GstPlugin {
gchar *name; /* name of the plugin */
gchar *longname; /* long name of plugin */
gchar *filename; /* filename it came from */
GList *types; /* list of types provided */
gint numtypes;
GList *elements; /* list of elements provided */
gint numelements;
GList *autopluggers; /* list of autopluggers provided */
gint numautopluggers;
gboolean loaded; /* if the plugin is in memory */
};
</PRE
><P
>
You can query a <CODE
CLASS="classname"
>GList</CODE
> of available plugins with the
function <CODE
CLASS="function"
>gst_plugin_get_list</CODE
> as this example shows:
</P
><PRE
CLASS="programlisting"
> GList *plugins;
plugins = gst_plugin_get_list ();
while (plugins) {
GstPlugin *plugin = (GstPlugin *)plugins->data;
g_print ("plugin: %s\n", gst_plugin_get_name (plugin));
plugins = g_list_next (plugins);
}
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