gstreamer/gst/gsttypefind.h

/* GStreamer
 * Copyright (C) 2003 Benjamin Otte <in7y118@public.uni-hamburg.de>
 *
 * gsttypefind.h: typefinding 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_TYPE_FIND_H__
#define __GST_TYPE_FIND_H__

#include <gst/gstbuffer.h>
#include <gst/gstcaps.h>
#include <gst/gstplugin.h>
#include <gst/gstpluginfeature.h>
#include <gst/gsttypes.h>

G_BEGIN_DECLS

#define GST_TYPE_TYPE_FIND_FACTORY                 (gst_type_find_factory_get_type())
#define GST_TYPE_FIND_FACTORY(obj)                 (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_TYPE_FIND_FACTORY, GstTypeFindFactory))
#define GST_IS_TYPE_FIND_FACTORY(obj)              (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_TYPE_FIND_FACTORY))
#define GST_TYPE_FIND_FACTORY_CLASS(klass)         (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_TYPE_FIND_FACTORY, GstTypeFindFactoryClass))
#define GST_IS_TYPE_FIND_FACTORY_CLASS(klass)      (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_TYPE_FIND_FACTORY))
#define GST_TYPE_FIND_FACTORY_GET_CLASS(obj)       (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_TYPE_FIND_FACTORY, GstTypeFindFactoryClass))

typedef struct _GstTypeFind GstTypeFind;
typedef struct _GstTypeFindFactory GstTypeFindFactory;
typedef struct _GstTypeFindFactoryClass GstTypeFindFactoryClass;

typedef void (* GstTypeFindFunction) (GstTypeFind *find, gpointer data);

typedef enum {
  GST_TYPE_FIND_MINIMUM = 1,
  GST_TYPE_FIND_POSSIBLE = 50,
  GST_TYPE_FIND_LIKELY = 80,
  GST_TYPE_FIND_NEARLY_CERTAIN = 99,
  GST_TYPE_FIND_MAXIMUM = 100,
} GstTypeFindProbability;

struct _GstTypeFind {
  /* private to the caller of the typefind function */
  guint8 *		(* peek)			(gpointer		data,
							 gint64	         	offset,
							 guint			size);
  void			(* suggest)			(gpointer		data,
							 guint			probability,
							 GstCaps *		caps);
  
  gpointer			data;
  
  /* optional */
  guint64		(* get_length)			(gpointer		data);

  /* <private> */
  GST_STRUCT_PADDING
};

struct _GstTypeFindFactory {
  GstPluginFeature		feature;
  /* <private> */

  GstTypeFindFunction		function;
  gchar **			extensions;
  GstCaps *			caps; /* FIXME: not yet saved in registry */
  
  gpointer			user_data;
    
  GST_OBJECT_PADDING
};
                                                                                                                                                                         
struct _GstTypeFindFactoryClass {
  GstPluginFeatureClass		parent;
  /* <private> */
    
  GST_CLASS_PADDING
};

/* typefind function interface */
guint8 *	gst_type_find_peek			(GstTypeFind *		find,
							 gint64			offset,
							 guint			size);
void		gst_type_find_suggest			(GstTypeFind *		find,
							 guint			probability,
							 GstCaps *		caps);
guint64		gst_type_find_get_length		(GstTypeFind *		find);

/* registration interface */
void      	gst_type_find_factory_register		(GstPlugin *		plugin,
							 const gchar *		name, 
							 guint			rank,
							 GstTypeFindFunction	func,
							 gchar **		extensions,
							 GstCaps *		possible_caps,
							 gpointer		data); 

/* typefinding interface */

GType           gst_type_find_factory_get_type		(void);
    
GList *		gst_type_find_factory_get_list		(void);

gchar **	gst_type_find_factory_get_extensions	(const GstTypeFindFactory *factory);
GstCaps *	gst_type_find_factory_get_caps	  	(const GstTypeFindFactory *factory);
void		gst_type_find_factory_call_function	(const GstTypeFindFactory *factory,
							 GstTypeFind *find);


G_END_DECLS

#endif /* __GST_TYPE_FIND_H__ */