TypeFindFactory

These functions allow querying information about registered typefind functions. How to create and register these functions is described in the section <link linkend="gstreamer-Writing-typefind-functions"> "Writing typefind functions"</link>.

The following 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.

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 &gt;= 0 &amp;&amp; offset + size &lt;= find->size) {
return find->data + offset;
}
return NULL;
}
static void
my_suggest (gpointer data, guint probability, GstCaps *caps)
{
MyTypeFind *find = (MyTypeFind *) data;
if (probability &gt; find->probability) {
find->probability = probability;
gst_caps_replace (&amp;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, &amp;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, &amp;gst_find);
}
g_list_free (type_list);
return find.caps;
};

class TypeFindFactory : PluginFeature {

protected

GstTypeFindFactory* gstTypeFindFactory;

GstTypeFindFactory* getTypeFindFactoryStruct(bool transferOwnership);

void* getStruct();

this(GstTypeFindFactory* gstTypeFindFactory, bool ownedRef);

static GType getType();

static ListG getList();

void callFunction(TypeFind find);

Caps getCaps();

string[] getExtensions();

bool hasFunction();

}

Constructors

this this(GstTypeFindFactory* gstTypeFindFactory, bool ownedRef): Sets our main struct and passes it to the parent class.

Members

Functions

callFunction void callFunction(TypeFind find): Calls the GstTypeFindFunction associated with this factory.
getCaps Caps getCaps(): Gets the gstreamer.Caps associated with a typefind factory.
getExtensions string[] getExtensions(): Gets the extensions associated with a gstreamer.TypeFindFactory The returned array should not be changed. If you need to change stuff in it, you should copy it using g_strdupv(). This function may return NULL to indicate a 0-length list.
getStruct void* getStruct(): the main Gtk struct as a void*
getTypeFindFactoryStruct GstTypeFindFactory* getTypeFindFactoryStruct(bool transferOwnership): Get the main Gtk struct
hasFunction bool hasFunction(): Check whether the factory has a typefind function. Typefind factories without typefind functions are a last-effort fallback mechanism to e.g. assume a certain media type based on the file extension.

Static functions

getList ListG getList(): Gets the list of all registered typefind factories. You must free the list using Plugin.featureListFree.
getType GType getType()

Variables

gstTypeFindFactory GstTypeFindFactory* gstTypeFindFactory;: the main Gtk struct

Inherited Members

From PluginFeature

gstPluginFeature GstPluginFeature* gstPluginFeature;: the main Gtk struct
getPluginFeatureStruct GstPluginFeature* getPluginFeatureStruct(bool transferOwnership): Get the main Gtk struct
getStruct void* getStruct(): the main Gtk struct as a void*
getType GType getType()
listCopy ListG listCopy(ListG list): Copies the list of features. Caller should call gst_plugin_feature_list_free when done with the list.
listDebug void listDebug(ListG list): Debug the plugin feature names in list.
listFree void listFree(ListG list): Unrefs each member of list, then frees the list.
rankCompareFunc int rankCompareFunc(void* p1, void* p2): Compares the two given gstreamer.PluginFeature instances. This function can be used as a GCompareFunc when sorting by rank and then by name.
checkVersion bool checkVersion(uint minMajor, uint minMinor, uint minMicro): Checks whether the given plugin feature is at least the required version
getPlugin Plugin getPlugin(): Get the plugin that provides this feature.
getPluginName string getPluginName(): Get the name of the plugin that provides this feature.
getRank uint getRank(): Gets the rank of a plugin feature.
load PluginFeature load(): Loads the plugin containing feature if it's not already loaded. feature is unaffected; use the return value instead.
setRank void setRank(uint rank): Specifies a rank for a plugin feature, so that autoplugging uses the most appropriate feature.

gstreamer TypeFindFactory classes

TypeFindFactory