GstTypeFindFunction ()

void
(*GstTypeFindFunction) (GstTypeFind *find,
                        gpointer user_data);

A function that will be called by typefinding.

gst_type_find_peek ()

const guint8 *
gst_type_find_peek (GstTypeFind *find,
                    gint64 offset,
                    guint size);

Returns the size bytes of the stream to identify beginning at offset. If offset is a positive number, the offset is relative to the beginning of the stream, if offset is a negative number the offset is relative to the end of the stream. The returned memory is valid until the typefinding function returns and must not be freed.

gst_type_find_suggest ()

void
gst_type_find_suggest (GstTypeFind *find,
                       guint probability,
                       GstCaps *caps);

If a GstTypeFindFunction calls this function it suggests the caps with the given probability. A GstTypeFindFunction may supply different suggestions in one call. It is up to the caller of the GstTypeFindFunction to interpret these values.

gst_type_find_suggest_simple ()

void
gst_type_find_suggest_simple (GstTypeFind *find,
                              guint probability,
                              const char *media_type,
                              const char *fieldname,
                              ...);

If a GstTypeFindFunction calls this function it suggests the caps with the given probability. A GstTypeFindFunction may supply different suggestions in one call. It is up to the caller of the GstTypeFindFunction to interpret these values.

This function is similar to gst_type_find_suggest(), only that instead of passing a GstCaps argument you can create the caps on the fly in the same way as you can with gst_caps_new_simple().

Make sure you terminate the list of arguments with a NULL argument and that the values passed have the correct type (in terms of width in bytes when passed to the vararg function - this applies particularly to gdouble and guint64 arguments).

gst_type_find_get_length ()

guint64
gst_type_find_get_length (GstTypeFind *find);

Get the length of the data stream.

gst_type_find_register ()

gboolean
gst_type_find_register (GstPlugin *plugin,
                        const gchar *name,
                        guint rank,
                        GstTypeFindFunction func,
                        const gchar *extensions,
                        GstCaps *possible_caps,
                        gpointer data,
                        GDestroyNotify data_notify);

Registers a new typefind function to be used for typefinding. After registering this function will be available for typefinding. This function is typically called during an element's plugin initialization.

struct GstTypeFind

struct GstTypeFind {
  /* private to the caller of the typefind function */
  const guint8 *  (* peek)       (gpointer         data,
                                  gint64           offset,
                                  guint            size);

  void            (* suggest)    (gpointer         data,
                                  guint            probability,
                                  GstCaps         *caps);

  gpointer         data;

  /* optional */
  guint64         (* get_length) (gpointer data);
};

Object that stores typefind callbacks. To use with GstTypeFindFactory.

enum GstTypeFindProbability

The probability of the typefind function. Higher values have more certainty in doing a reliable typefind.