|  |  |  | GStreamer 0.10 Core Reference Manual |  | 
|---|---|---|---|---|
#include <gst/gst.h>
                    GstTypeFindFactory;
GList*              gst_type_find_factory_get_list      (void);
gchar**             gst_type_find_factory_get_extensions
                                                        (GstTypeFindFactory *factory);
GstCaps*            gst_type_find_factory_get_caps      (GstTypeFindFactory *factory);
void                gst_type_find_factory_call_function (GstTypeFindFactory *factory,
                                                         GstTypeFind *find);
These functions allow querying informations about registered typefind functions. How to create and register these functions is described in the section "Writing typefind functions".
Example 14. how to write a simple typefinder
  typedef struct {
    guint8 *data;
    guint size;
    guint probability;
    GstCaps *data;
  } MyTypeFind;
  static void
  my_peek (gpointer data, gint64 offset, guint size)
  {
    MyTypeFind *find = (MyTypeFind *) data;
    if (offset >= 0 && offset + size <= find->size) {
      return find->data + offset;
    }
    return NULL;
  }
  static void
  my_suggest (gpointer data, guint probability, GstCaps *caps)
  {
    MyTypeFind *find = (MyTypeFind *) data;
    if (probability > find->probability) {
      find->probability = probability;
      gst_caps_replace (&find->caps, caps);
    }
  }
  static GstCaps *
  find_type (guint8 *data, guint size)
  {
    GList *walk, *type_list;
    MyTypeFind find = {data, size, 0, NULL};
    GstTypeFind gst_find = {my_peek, my_suggest, &find, };
    walk = type_list = gst_type_find_factory_get_list ();
    while (walk) {
      GstTypeFindFactory *factory = GST_TYPE_FIND_FACTORY (walk->data);
      walk = g_list_next (walk)
      gst_type_find_factory_call_function (factory, &gst_find);
    }
    g_list_free (type_list);
    return find.caps;
  };
  
The above example shows how to write a very simple typefinder that identifies the given data. You can get quite a bit more complicated than that though.
Last reviewed on 2005-11-09 (0.9.4)
typedef struct _GstTypeFindFactory GstTypeFindFactory;
Object that stores information about a typefind function.
GList* gst_type_find_factory_get_list (void);
Gets the list of all registered typefind factories. You must free the list using gst_plugin_feature_list_free.
| Returns : | the list of all registered GstTypeFindFactory. | 
gchar**             gst_type_find_factory_get_extensions
                                                        (GstTypeFindFactory *factory);
Gets the extensions associated with a GstTypeFindFactory. The returned
array should not be changed. If you need to change stuff in it, you should
copy it using g_stdupv().  This function may return NULL to indicate
a 0-length list.
| 
 | A GstTypeFindFactory | 
| Returns : | a NULL-terminated array of extensions associated with this factory | 
GstCaps* gst_type_find_factory_get_caps (GstTypeFindFactory *factory);
Gets the GstCaps associated with a typefind factory.
| 
 | A GstTypeFindFactory | 
| Returns : | The GstCaps associated with this factory | 
void gst_type_find_factory_call_function (GstTypeFindFactory *factory, GstTypeFind *find);
Calls the GstTypeFindFunction associated with this factory.
| 
 | A GstTypeFindFactory | 
| 
 | A properly setup GstTypeFind entry. The get_data and suggest_type members must be set. |