gst/gsttypefind.h

   1 /* GStreamer
   2  * Copyright (C) 2003 Benjamin Otte <in7y118@public.uni-hamburg.de>
   3  *
   4  * gsttypefind.h: typefinding subsystem
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Library General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Library General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Library General Public
  17  * License along with this library; if not, write to the
  18  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19  * Boston, MA 02111-1307, USA.
  20  */
  21
  22
  23 #ifndef __GST_TYPE_FIND_H__
  24 #define __GST_TYPE_FIND_H__
  25
  26 #include <gst/gstcaps.h>
  27 #include <gst/gstplugin.h>
  28 #include <gst/gstpluginfeature.h>
  29
  30 G_BEGIN_DECLS
  31
  32 typedef struct _GstTypeFind GstTypeFind;
  33
  34 /**
  35  * GstTypeFindFunction:
  36  * @find: A #GstTypeFind structure
  37  * @data: optionnal data to pass to the function
  38  *
  39  * A function that will be called by typefinding.
  40  */
  41 typedef void (* GstTypeFindFunction) (GstTypeFind *find, gpointer data);
  42
  43 typedef enum {
  44   GST_TYPE_FIND_MINIMUM = 1,
  45   GST_TYPE_FIND_POSSIBLE = 50,
  46   GST_TYPE_FIND_LIKELY = 80,
  47   GST_TYPE_FIND_NEARLY_CERTAIN = 99,
  48   GST_TYPE_FIND_MAXIMUM = 100
  49 } GstTypeFindProbability;
  50
  51 /**
  52  * GstTypeFind:
  53  * @peek: Method to peek data.
  54  * @suggest: Method to suggest #GstCaps with a given probability.
  55  * @data: The data used by the caller of the typefinding function.
  56  * @get_length: Returns the length of current data.
  57  *
  58  * Object that stores typefind callbacks. To use with #GstTypeFindFactory.
  59  */
  60 struct _GstTypeFind {
  61   /* private to the caller of the typefind function */
  62   guint8 *      (* peek)        (gpointer               data,
  63                                  gint64                 offset,
  64                                  guint                  size);
  65   void          (* suggest)     (gpointer               data,
  66                                  guint                  probability,
  67                                  const GstCaps *        caps);
  68
  69   gpointer      data;
  70
  71   /* optional */
  72   guint64       (* get_length)  (gpointer               data);
  73
  74   /* <private> */
  75   gpointer _gst_reserved[GST_PADDING];
  76 };
  77
  78 /* typefind function interface */
  79 guint8 *        gst_type_find_peek                      (GstTypeFind *          find,
  80                                                          gint64                 offset,
  81                                                          guint                  size);
  82 void            gst_type_find_suggest                   (GstTypeFind *          find,
  83                                                          guint                  probability,
  84                                                          const GstCaps *        caps);
  85 guint64         gst_type_find_get_length                (GstTypeFind *          find);
  86
  87 /* registration interface */
  88 gboolean        gst_type_find_register                  (GstPlugin *            plugin,
  89                                                          const gchar *          name,
  90                                                          guint                  rank,
  91                                                          GstTypeFindFunction    func,
  92                                                          gchar **               extensions,
  93                                                          const GstCaps *        possible_caps,
  94                                                          gpointer               data);
  95
  96 G_END_DECLS
  97
  98 #endif /* __GST_TYPE_FIND_H__ */