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GStreamer 0.10 Core Reference Manual | ![]() |
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#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 g_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.
factory : |
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.
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.
factory : |
A GstTypeFindFactory |
find : |
A properly setup GstTypeFind entry. The get_data and suggest_type members must be set. |