GstElementFactory

GstElementFactory — Create GstElements from a factory

Synopsis


#include <gst/gst.h>


            GstElementFactory;
            GstElementDetails;
#define     GST_ELEMENT_DETAILS             (longname,klass,description,author)
#define     GST_IS_ELEMENT_DETAILS          (details)
gboolean    gst_element_register            (GstPlugin *plugin,
                                             const gchar *name,
                                             guint rank,
                                             GType type);
GstElementFactory* gst_element_factory_find (const gchar *name);
GType       gst_element_factory_get_element_type
                                            (GstElementFactory *factory);
const gchar* gst_element_factory_get_longname
                                            (GstElementFactory *factory);
const gchar* gst_element_factory_get_klass  (GstElementFactory *factory);
const gchar* gst_element_factory_get_description
                                            (GstElementFactory *factory);
const gchar* gst_element_factory_get_author (GstElementFactory *factory);
guint       gst_element_factory_get_num_pad_templates
                                            (GstElementFactory *factory);
gint        gst_element_factory_get_uri_type
                                            (GstElementFactory *factory);
gchar**     gst_element_factory_get_uri_protocols
                                            (GstElementFactory *factory);
GstElement* gst_element_factory_create      (GstElementFactory *factory,
                                             const gchar *name);
GstElement* gst_element_factory_make        (const gchar *factoryname,
                                             const gchar *name);
gboolean    gst_element_factory_can_sink_caps
                                            (GstElementFactory *factory,
                                             const GstCaps *caps);
gboolean    gst_element_factory_can_src_caps
                                            (GstElementFactory *factory,
                                             const GstCaps *caps);
const GList* gst_element_factory_get_static_pad_templates
                                            (GstElementFactory *factory);


Object Hierarchy


  GObject
   +----GstObject
         +----GstPluginFeature
               +----GstElementFactory

Description

GstElementFactory is used to create instances of elements. A GstElementfactory can be added to a GstPlugin as it is also a GstPluginFeature.

Use the gst_element_factory_find() and gst_element_factory_create() functions to create element instances or use gst_element_factory_make() as a convenient shortcut.

The following code example shows you how to create a GstFileSrc element.

Example 6. Using an element factory

  include <gst/gst.h>
  GstElement *src;
  GstElementFactory *srcfactory;
  gst_init(&argc,&argv);
  srcfactory = gst_element_factory_find("filesrc");
  g_return_if_fail(srcfactory != NULL);
  src = gst_element_factory_create(srcfactory,"src");
  g_return_if_fail(src != NULL);
  ...

Last reviewed on 2005-11-23 (0.9.5)

Details

GstElementFactory

typedef struct _GstElementFactory GstElementFactory;

The opaque GstElementFactory data structure.


GstElementDetails

typedef struct {
  gchar *longname;
  gchar *klass;
  gchar *description;
  gchar *author;
} GstElementDetails;

This struct defines the public information about a GstElement. It contains meta-data about the element that is mostly for the benefit of editors.

The klass member can be used by applications to filter elements based on functionality.

gchar *longname;gcharlongname long, english name long, english name gchar *klass;gcharklass type of element, as an unordered list separated with slashes ('/') type of element, as an unordered list separated with slashes ('/') gchar *description;gchardescription what the element is about what the element is about gchar *author;gcharauthor who wrote this thing? who wrote this thing?
gchar *longname; long, english name
gchar *klass; type of element, as an unordered list separated with slashes ('/')
gchar *description; what the element is about
gchar *author; who wrote this thing?

GST_ELEMENT_DETAILS()

#define     GST_ELEMENT_DETAILS(longname,klass,description,author)

Macro to initialize GstElementDetails.

longname :longname long, english name long, english name klass :klass type of element, as hierarchy type of element, as hierarchy description :description what the element is about what the element is about author :author who wrote this thing? who wrote this thing?
longname : long, english name
klass : type of element, as hierarchy
description : what the element is about
author : who wrote this thing?

GST_IS_ELEMENT_DETAILS()

#define     GST_IS_ELEMENT_DETAILS(details)

Tests if element details are initialized.

details :details the GstElementDetails to check the GstElementDetails to check GstElementDetailsGstElementDetails
details : the GstElementDetails to check

gst_element_register ()

gboolean    gst_element_register            (GstPlugin *plugin,
                                             const gchar *name,
                                             guint rank,
                                             GType type);

Create a new elementfactory capable of instantiating objects of the type and add the factory to plugin.

plugin :plugin GstPlugin to register the element with GstPlugin to register the element with GstPluginGstPluginname :name name of elements of this type name of elements of this type rank :rank rank of element (higher rank means more importance when autoplugging) rank of element (higher rank means more importance when autoplugging) type :type GType of element to register GType of element to register Returns :Returns TRUE, if the registering succeeded, FALSE on error TRUE, if the registering succeeded, FALSE on error
plugin : GstPlugin to register the element with
name : name of elements of this type
rank : rank of element (higher rank means more importance when autoplugging)
type : GType of element to register
Returns : TRUE, if the registering succeeded, FALSE on error

gst_element_factory_find ()

GstElementFactory* gst_element_factory_find (const gchar *name);

Search for an element factory of the given name. Refs the returned element factory; caller is responsible for unreffing.

name :name name of factory to find name of factory to find Returns :Returns GstElementFactory if found, NULL otherwise GstElementFactory if found, NULL otherwise GstElementFactoryGstElementFactory
name : name of factory to find
Returns : GstElementFactory if found, NULL otherwise

gst_element_factory_get_element_type ()

GType       gst_element_factory_get_element_type
                                            (GstElementFactory *factory);

Get the GType for elements managed by this factory. The type can only be retrieved if the element factory is loaded, which can be assured with gst_plugin_feature_load().

factory :factory factory to get managed GType from factory to get managed GType from GTypeGTypeReturns :Returns the GType for elements managed by this factory or 0 if the factory is not loaded. the GType for elements managed by this factory or 0 if the factory is not loaded. GTypeGType
factory : factory to get managed GType from
Returns : the GType for elements managed by this factory or 0 if the factory is not loaded.

gst_element_factory_get_longname ()

const gchar* gst_element_factory_get_longname
                                            (GstElementFactory *factory);

Gets the longname for this factory

factory :factory a GstElementFactory a GstElementFactory GstElementFactoryGstElementFactoryReturns :Returns the longname the longname
factory : a GstElementFactory
Returns : the longname

gst_element_factory_get_klass ()

const gchar* gst_element_factory_get_klass  (GstElementFactory *factory);

Gets the class for this factory.

factory :factory a GstElementFactory a GstElementFactory GstElementFactoryGstElementFactoryReturns :Returns the class the class
factory : a GstElementFactory
Returns : the class

gst_element_factory_get_description ()

const gchar* gst_element_factory_get_description
                                            (GstElementFactory *factory);

Gets the description for this factory.

factory :factory a GstElementFactory a GstElementFactory GstElementFactoryGstElementFactoryReturns :Returns the description the description
factory : a GstElementFactory
Returns : the description

gst_element_factory_get_author ()

const gchar* gst_element_factory_get_author (GstElementFactory *factory);

Gets the author for this factory.

factory :factory a GstElementFactory a GstElementFactory GstElementFactoryGstElementFactoryReturns :Returns the author the author
factory : a GstElementFactory
Returns : the author

gst_element_factory_get_num_pad_templates ()

guint       gst_element_factory_get_num_pad_templates
                                            (GstElementFactory *factory);

Gets the number of pad_templates in this factory.

factory :factory a GstElementFactory a GstElementFactory GstElementFactoryGstElementFactoryReturns :Returns the number of pad_templates the number of pad_templates
factory : a GstElementFactory
Returns : the number of pad_templates

gst_element_factory_get_uri_type ()

gint        gst_element_factory_get_uri_type
                                            (GstElementFactory *factory);

Gets the type of URIs the element supports or GST_URI_UNKNOWN if none.

factory :factory a GstElementFactory a GstElementFactory GstElementFactoryGstElementFactoryReturns :Returns type of URIs this element supports type of URIs this element supports
factory : a GstElementFactory
Returns : type of URIs this element supports

gst_element_factory_get_uri_protocols ()

gchar**     gst_element_factory_get_uri_protocols
                                            (GstElementFactory *factory);

Gets a NULL-terminated array of protocols this element supports or NULL if no protocols are supported. You may not change the contents of the returned array, as it is still owned by the element factory. Use g_strdupv() to make a copy of the protocol string array if you need to.

factory :factory a GstElementFactory a GstElementFactory GstElementFactoryGstElementFactoryReturns :Returns the supported protocols or NULL the supported protocols or NULL
factory : a GstElementFactory
Returns : the supported protocols or NULL

gst_element_factory_create ()

GstElement* gst_element_factory_create      (GstElementFactory *factory,
                                             const gchar *name);

Create a new element of the type defined by the given elementfactory. It will be given the name supplied, since all elements require a name as their first argument.

factory :factory factory to instantiate factory to instantiate name :name name of new element name of new element Returns :Returns new GstElement or NULL if the element couldn't be created new GstElement or NULL if the element couldn't be created GstElementGstElement
factory : factory to instantiate
name : name of new element
Returns : new GstElement or NULL if the element couldn't be created

gst_element_factory_make ()

GstElement* gst_element_factory_make        (const gchar *factoryname,
                                             const gchar *name);

Create a new element of the type defined by the given element factory. If name is NULL, then the element will receive a guaranteed unique name, consisting of the element factory name and a number. If name is given, it will be given the name supplied.

factoryname :factoryname a named factory to instantiate a named factory to instantiate name :name name of new element name of new element Returns :Returns new GstElement or NULL if unable to create element new GstElement or NULL if unable to create element GstElementGstElement
factoryname : a named factory to instantiate
name : name of new element
Returns : new GstElement or NULL if unable to create element

gst_element_factory_can_sink_caps ()

gboolean    gst_element_factory_can_sink_caps
                                            (GstElementFactory *factory,
                                             const GstCaps *caps);

Checks if the factory can sink the given capability.

factory :factory factory to query factory to query caps :caps the caps to check the caps to check Returns :Returns true if it can sink the capabilities true if it can sink the capabilities
factory : factory to query
caps : the caps to check
Returns : true if it can sink the capabilities

gst_element_factory_can_src_caps ()

gboolean    gst_element_factory_can_src_caps
                                            (GstElementFactory *factory,
                                             const GstCaps *caps);

Checks if the factory can source the given capability.

factory :factory factory to query factory to query caps :caps the caps to check the caps to check Returns :Returns true if it can src the capabilities true if it can src the capabilities
factory : factory to query
caps : the caps to check
Returns : true if it can src the capabilities

gst_element_factory_get_static_pad_templates ()

const GList* gst_element_factory_get_static_pad_templates
                                            (GstElementFactory *factory);

Gets the GList of padtemplates for this factory.

factory :factory a GstElementFactory a GstElementFactory GstElementFactoryGstElementFactoryReturns :Returns the padtemplates the padtemplates
factory : a GstElementFactory
Returns : the padtemplates

See Also

GstElement, GstPlugin, GstPluginFeature, GstPadTemplate.