gstreamer/gst/gstplugin.h

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/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
*
* gstplugin.h: Header for plugin subsystem
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#ifndef __GST_PLUGIN_H__
#define __GST_PLUGIN_H__
#include <gst/gstconfig.h>
#include <time.h> /* time_t */
#include <sys/types.h> /* off_t */
#include <sys/stat.h> /* off_t */
#include <gmodule.h>
#include <gst/gstobject.h>
#include <gst/gstmacros.h>
G_BEGIN_DECLS
typedef struct _GstPlugin GstPlugin;
typedef struct _GstPluginClass GstPluginClass;
typedef struct _GstPluginDesc GstPluginDesc;
/**
* gst_plugin_error_quark:
*
* Get the error quark.
*
* Returns: The error quark used in GError messages
*/
GQuark gst_plugin_error_quark (void);
/**
* GST_PLUGIN_ERROR:
*
* The error message category quark
*/
#define GST_PLUGIN_ERROR gst_plugin_error_quark ()
/**
* GstPluginError:
* @GST_PLUGIN_ERROR_MODULE: The plugin could not be loaded
* @GST_PLUGIN_ERROR_DEPENDENCIES: The plugin has unresolved dependencies
* @GST_PLUGIN_ERROR_NAME_MISMATCH: The plugin has already be loaded from a different file
*
* The plugin loading errors
*/
typedef enum
{
GST_PLUGIN_ERROR_MODULE,
GST_PLUGIN_ERROR_DEPENDENCIES,
GST_PLUGIN_ERROR_NAME_MISMATCH
} GstPluginError;
typedef enum
{
GST_PLUGIN_FLAG_CACHED = (1<<0)
} GstPluginFlags;
/**
* GstPluginInitFunc:
* @plugin: The plugin object that can be used to register #GstPluginFeatures for this plugin.
*
* A plugin should provide a pointer to a function of this type in the
* plugin_desc struct.
* This function will be called by the loader at startup.
*
* Returns: %TRUE if plugin initialised successfully
*/
typedef gboolean (*GstPluginInitFunc) (GstPlugin *plugin);
/**
* GstPluginDesc:
* @major_version: the major version number of core that plugin was compiled for
* @minor_version: the minor version number of core that plugin was compiled for
* @name: a unique name of the plugin
* @description: description of plugin
* @plugin_init: pointer to the init function of this plugin.
* @version: version of the plugin
* @license: effective license of plugin
* @source: source module plugin belongs to
* @package: shipped package plugin belongs to
* @origin: URL to provider of plugin
* @_gst_reserved: private, for later expansion
*
*
* A plugins should export a variable of this type called plugin_desc. This plugin
* loaded will use this variable to initialize the plugin.
*/
struct _GstPluginDesc {
gint major_version;
gint minor_version;
gchar *name;
gchar *description;
GstPluginInitFunc plugin_init;
gchar *version;
gchar *license;
gchar *source;
gchar *package;
gchar *origin;
gpointer _gst_reserved[GST_PADDING];
};
#define GST_TYPE_PLUGIN (gst_plugin_get_type())
#define GST_IS_PLUGIN(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_PLUGIN))
#define GST_IS_PLUGIN_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_PLUGIN))
#define GST_PLUGIN_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_PLUGIN, GstPluginClass))
#define GST_PLUGIN(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_PLUGIN, GstPlugin))
#define GST_PLUGIN_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_PLUGIN, GstPluginClass))
#define GST_PLUGIN_CAST(obj) ((GstPlugin*)(obj))
/**
* GstPlugin:
*
* The plugin object
*/
struct _GstPlugin {
GstObject object;
/*< private >*/
GstPluginDesc desc;
GstPluginDesc *orig_desc;
unsigned int flags;
gchar * filename;
gchar * basename; /* base name (non-dir part) of plugin path */
GModule * module; /* contains the module if plugin is loaded */
off_t file_size;
time_t file_mtime;
gboolean registered; /* TRUE when the registry has seen a filename
* that matches the plugin's basename */
gpointer _gst_reserved[GST_PADDING];
};
struct _GstPluginClass {
GstObjectClass object_class;
/*< private >*/
gpointer _gst_reserved[GST_PADDING];
};
/**
* GST_PLUGIN_DEFINE:
* @major: major version number of the gstreamer-core that plugin was compiled for
* @minor: minor version number of the gstreamer-core that plugin was compiled for
* @name: short, but unique name of the plugin
* @description: information about the purpose of the plugin
* @init: function pointer to the plugin_init method with the signature of <code>static gboolean plugin_init (GstPlugin * plugin)</code>.
* @version: full version string (e.g. VERSION from config.h)
* @license: under which licence the package has been released, e.g. GPL, LGPL.
* @package: the package-name (e.g. PACKAGE_NAME from config.h)
* @origin: a description from where the package comes from (e.g. the homepage URL)
*
* This macro needs to be used to define the entry point and meta data of a
* plugin. One would use this macro to export a plugin, so that it can be used
* by other applications
*/
#define GST_PLUGIN_DEFINE(major,minor,name,description,init,version,license,package,origin) \
GST_PLUGIN_EXPORT GstPluginDesc gst_plugin_desc = { \
major, \
minor, \
name, \
description, \
init, \
version, \
license, \
PACKAGE, \
package, \
origin, \
GST_PADDING_INIT \
};
/**
* GST_PLUGIN_DEFINE_STATIC:
* @major: major version number of the gstreamer-core that plugin was compiled for
* @minor: minor version number of the gstreamer-core that plugin was compiled for
* @name: short, but unique name of the plugin
* @description: information about the purpose of the plugin
* @init: function pointer to the plugin_init method with the signature of <code>static gboolean plugin_init (GstPlugin * plugin)</code>.
* @version: full version string (e.g. VERSION from config.h)
* @license: under which licence the package has been released, e.g. GPL, LGPL.
* @package: the package-name (e.g. PACKAGE_NAME from config.h)
* @origin: a description from where the package comes from (e.g. the homepage URL)
*
* This macro needs to be used to define the entry point and meta data of a
* local plugin. One would use this macro to define a local plugin that can only
* be used by the own application.
*/
#define GST_PLUGIN_DEFINE_STATIC(major,minor,name,description,init,version,license,package,origin) \
static void GST_GNUC_CONSTRUCTOR \
_gst_plugin_static_init__ ##init (void) \
{ \
static GstPluginDesc plugin_desc_ = { \
major, \
minor, \
name, \
description, \
init, \
version, \
license, \
PACKAGE, \
package, \
origin, \
GST_PADDING_INIT \
}; \
_gst_plugin_register_static (&plugin_desc_); \
}
/**
* GST_LICENSE_UNKNOWN:
*
* To be used in GST_PLUGIN_DEFINE or GST_PLUGIN_DEFINE_STATIC if usure about
* the licence.
*/
#define GST_LICENSE_UNKNOWN "unknown"
/* function for filters */
/**
* GstPluginFilter:
* @plugin: the plugin to check
* @user_data: the user_data that has been passed on e.g. gst_registry_plugin_filter()
*
* A function that can be used with e.g. gst_registry_plugin_filter()
* to get a list of plugins that match certain criteria.
*
* Returns: TRUE for a positive match, FALSE otherwise
*/
typedef gboolean (*GstPluginFilter) (GstPlugin *plugin,
gpointer user_data);
GType gst_plugin_get_type (void);
void _gst_plugin_initialize (void);
void _gst_plugin_register_static (GstPluginDesc *desc);
G_CONST_RETURN gchar* gst_plugin_get_name (GstPlugin *plugin);
G_CONST_RETURN gchar* gst_plugin_get_description (GstPlugin *plugin);
G_CONST_RETURN gchar* gst_plugin_get_filename (GstPlugin *plugin);
G_CONST_RETURN gchar* gst_plugin_get_version (GstPlugin *plugin);
G_CONST_RETURN gchar* gst_plugin_get_license (GstPlugin *plugin);
G_CONST_RETURN gchar* gst_plugin_get_source (GstPlugin *plugin);
G_CONST_RETURN gchar* gst_plugin_get_package (GstPlugin *plugin);
G_CONST_RETURN gchar* gst_plugin_get_origin (GstPlugin *plugin);
GModule * gst_plugin_get_module (GstPlugin *plugin);
gboolean gst_plugin_is_loaded (GstPlugin *plugin);
gboolean gst_plugin_name_filter (GstPlugin *plugin, const gchar *name);
GstPlugin * gst_plugin_load_file (const gchar *filename, GError** error);
GstPlugin * gst_plugin_load (GstPlugin *plugin);
GstPlugin * gst_plugin_load_by_name (const gchar *name);
void gst_plugin_list_free (GList *list);
G_END_DECLS
#endif /* __GST_PLUGIN_H__ */