GstTypefind

GstTypeFind

gst_type_find_get_length

guint64
gst_type_find_get_length (GstTypeFind * find)

Get the length of the data stream.

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

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_empty_simple

gst_type_find_suggest_empty_simple (GstTypeFind * find,
                                    guint probability,
                                    const char* media_type)

If a GstTypeFindFunction calls this function it suggests caps of the given media_type with the given probability.

This function is similar to gst_type_find_suggest_simple, but uses a GstCaps with no fields.

Since : 1.20

gst_type_find_suggest_simple

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_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.

GST_TYPE_FIND_REGISTER

#define GST_TYPE_FIND_REGISTER(t_f, plugin) G_PASTE(gst_type_find_register_, t_f) (plugin)

This macro can be used to register a type find into a GstPlugin. This method will be usually called in the plugin init function but can also be called with a NULL plugin.

Since : 1.20

GST_TYPE_FIND_REGISTER_DECLARE

#define GST_TYPE_FIND_REGISTER_DECLARE(t_f) \
G_BEGIN_DECLS \
gboolean G_PASTE(gst_type_find_register_, t_f) (GstPlugin * plugin); \
G_END_DECLS

This macro can be used to declare a new type find. It has to be used in combination with GST_TYPE_FIND_REGISTER_DEFINE macro and must be placed outside any block to declare the type find registration function.

Since : 1.20

GST_TYPE_FIND_REGISTER_DEFINE

#define GST_TYPE_FIND_REGISTER_DEFINE(t_f, t_f_n, r, func, extensions, possible_caps, data, data_notify) \
G_BEGIN_DECLS \
gboolean G_PASTE (gst_type_find_register_, t_f) (GstPlugin * plugin) \
{ \
  return gst_type_find_register (plugin, t_f_n, r, func, extensions, possible_caps, data, data_notify); \
} \
G_END_DECLS

A convenience macro to define the entry point of a type find gst_type_find_register_*(GstPlugin* plugin).

Since : 1.20

GST_TYPE_FIND_REGISTER_DEFINE_CUSTOM

#define GST_TYPE_FIND_REGISTER_DEFINE_CUSTOM(type_find, register_func) \
G_BEGIN_DECLS \
gboolean G_PASTE (gst_type_find_register_, type_find) (GstPlugin * plugin) \
{ \
  return register_func (plugin); \
} \
G_END_DECLS

A convenience macro to define the entry point of a type find gst_type_find_register_*(GstPlugin* plugin) which uses register_func as the main registration method for the type find. As an example, you may define the type find named "custom-typefind" as following using type_find_register_custom:

GST_TYPE_FIND_REGISTER_DEFINE_CUSTOM (plugin, type_find_register_custom)

Since : 1.20

GstTypeFindProbability

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

GstTypeFindFunction

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

A function that will be called by typefinding.