GstElementFactory

GstElementFactory — Create GstElements from a factory

Synopsis

#include <gst/gst.h>

                    GstElementFactory;
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_metadata    (GstElementFactory *factory,
                                                         const gchar *key);
gchar **            gst_element_factory_get_metadata_keys
                                                        (GstElementFactory *factory);
guint               gst_element_factory_get_num_pad_templates
                                                        (GstElementFactory *factory);
GstURIType          gst_element_factory_get_uri_type    (GstElementFactory *factory);
gboolean            gst_element_factory_has_interface   (GstElementFactory *factory,
                                                         const gchar *interfacename);
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_all_caps
                                                        (GstElementFactory *factory,
                                                         const GstCaps *caps);
gboolean            gst_element_factory_can_src_all_caps
                                                        (GstElementFactory *factory,
                                                         const GstCaps *caps);
gboolean            gst_element_factory_can_sink_any_caps
                                                        (GstElementFactory *factory,
                                                         const GstCaps *caps);
gboolean            gst_element_factory_can_src_any_caps
                                                        (GstElementFactory *factory,
                                                         const GstCaps *caps);
const GList *       gst_element_factory_get_static_pad_templates
                                                        (GstElementFactory *factory);
typedef             GstElementFactoryListType;
#define             GST_ELEMENT_FACTORY_TYPE_ANY
#define             GST_ELEMENT_FACTORY_TYPE_AUDIOVIDEO_SINKS
#define             GST_ELEMENT_FACTORY_TYPE_AUDIO_ENCODER
#define             GST_ELEMENT_FACTORY_TYPE_DECODABLE
#define             GST_ELEMENT_FACTORY_TYPE_DECODER
#define             GST_ELEMENT_FACTORY_TYPE_DEMUXER
#define             GST_ELEMENT_FACTORY_TYPE_DEPAYLOADER
#define             GST_ELEMENT_FACTORY_TYPE_ENCODER
#define             GST_ELEMENT_FACTORY_TYPE_FORMATTER
#define             GST_ELEMENT_FACTORY_TYPE_MAX_ELEMENTS
#define             GST_ELEMENT_FACTORY_TYPE_MEDIA_AUDIO
#define             GST_ELEMENT_FACTORY_TYPE_MEDIA_IMAGE
#define             GST_ELEMENT_FACTORY_TYPE_MEDIA_METADATA
#define             GST_ELEMENT_FACTORY_TYPE_MEDIA_SUBTITLE
#define             GST_ELEMENT_FACTORY_TYPE_MEDIA_VIDEO
#define             GST_ELEMENT_FACTORY_TYPE_MEDIA_ANY
#define             GST_ELEMENT_FACTORY_TYPE_MUXER
#define             GST_ELEMENT_FACTORY_TYPE_PARSER
#define             GST_ELEMENT_FACTORY_TYPE_PAYLOADER
#define             GST_ELEMENT_FACTORY_TYPE_SINK
#define             GST_ELEMENT_FACTORY_TYPE_SRC
#define             GST_ELEMENT_FACTORY_TYPE_VIDEO_ENCODER
GList *             gst_element_factory_list_filter     (GList *list,
                                                         const GstCaps *caps,
                                                         GstPadDirection direction,
                                                         gboolean subsetonly);
GList *             gst_element_factory_list_get_elements
                                                        (GstElementFactoryListType type,
                                                         GstRank minrank);
gboolean            gst_element_factory_list_is_type    (GstElementFactory *factory,
                                                         GstElementFactoryListType type);

Object Hierarchy

  GObject
   +----GInitiallyUnowned
         +----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

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#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.

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 :

 GstPlugin to register the element with, or NULL for a static element. [allow-none]

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 of factory to find

Returns :

 GstElementFactory if found, NULL otherwise. [transfer full]

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 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_metadata ()

const gchar *       gst_element_factory_get_metadata    (GstElementFactory *factory,
                                                         const gchar *key);

Get the metadata on factory with key.

factory :

 a GstElementFactory

key :

 a key

Returns :

 the metadata with key on factory or NULL when there was no metadata with the given key.

gst_element_factory_get_metadata_keys ()

gchar **            gst_element_factory_get_metadata_keys
                                                        (GstElementFactory *factory);

Get the available keys for the metadata on factory.

factory :

 a GstElementFactory

Returns :

 a NULL-terminated array of key strings, or NULL when there is no metadata. Free with g_strfreev() when no longer needed. [transfer full][element-type utf8][array zero-terminated=1]

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 :

 a GstElementFactory

Returns :

 the number of pad_templates

gst_element_factory_get_uri_type ()

GstURIType          gst_element_factory_get_uri_type    (GstElementFactory *factory);

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

factory :

 a GstElementFactory

Returns :

 type of URIs this element supports

gst_element_factory_has_interface ()

gboolean            gst_element_factory_has_interface   (GstElementFactory *factory,
                                                         const gchar *interfacename);

Check if factory implements the interface with name interfacename.

factory :

 a GstElementFactory

interfacename :

 an interface name

Returns :

 TRUE when factory implement the interface.

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 to instantiate

name :

 name of new element, or NULL to automatically create a unique name. [allow-none]

Returns :

 new GstElement or NULL if the element couldn't be created. [transfer floating]

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 :

 a named factory to instantiate

name :

 name of new element, or NULL to automatically create a unique name. [allow-none]

Returns :

 new GstElement or NULL if unable to create element. [transfer floating]

gst_element_factory_can_sink_all_caps ()

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

Checks if the factory can sink all possible capabilities.

factory :

 factory to query

caps :

 the caps to check

Returns :

 TRUE if the caps are fully compatible.

gst_element_factory_can_src_all_caps ()

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

Checks if the factory can src all possible capabilities.

factory :

 factory to query

caps :

 the caps to check

Returns :

 TRUE if the caps are fully compatible.

gst_element_factory_can_sink_any_caps ()

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

Checks if the factory can sink any possible capability.

factory :

 factory to query

caps :

 the caps to check

Returns :

 TRUE if the caps have a common subset.

gst_element_factory_can_src_any_caps ()

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

Checks if the factory can src any possible capability.

factory :

 factory to query

caps :

 the caps to check

Returns :

 TRUE if the caps have a common subset.

gst_element_factory_get_static_pad_templates ()

const GList *       gst_element_factory_get_static_pad_templates
                                                        (GstElementFactory *factory);

Gets the GList of GstStaticPadTemplate for this factory.

factory :

 a GstElementFactory

Returns :

 the static pad templates. [transfer none][element-type Gst.StaticPadTemplate]

GstElementFactoryListType

typedef guint64 GstElementFactoryListType;

GST_ELEMENT_FACTORY_TYPE_ANY

#define  GST_ELEMENT_FACTORY_TYPE_ANY ((G_GUINT64_CONSTANT (1) << 49) - 1)

Elements of any of the defined GST_ELEMENT_FACTORY_LIST types

Value: 562949953421311 Type: GstElementFactoryListType

GST_ELEMENT_FACTORY_TYPE_AUDIOVIDEO_SINKS

#define GST_ELEMENT_FACTORY_TYPE_AUDIOVIDEO_SINKS (GST_ELEMENT_FACTORY_TYPE_SINK | GST_ELEMENT_FACTORY_TYPE_MEDIA_AUDIO | GST_ELEMENT_FACTORY_TYPE_MEDIA_VIDEO | GST_ELEMENT_FACTORY_TYPE_MEDIA_IMAGE)

All sinks handling audio, video or image media types

Value: 3940649673949188 Type: GstElementFactoryListType

GST_ELEMENT_FACTORY_TYPE_AUDIO_ENCODER

#define GST_ELEMENT_FACTORY_TYPE_AUDIO_ENCODER (GST_ELEMENT_FACTORY_TYPE_ENCODER | GST_ELEMENT_FACTORY_TYPE_MEDIA_AUDIO)

All encoders handling audio media types

Value: 1125899906842626 Type: GstElementFactoryListType

GST_ELEMENT_FACTORY_TYPE_DECODABLE

#define             GST_ELEMENT_FACTORY_TYPE_DECODABLE

All elements used to 'decode' streams (decoders, demuxers, parsers, depayloaders)

Value: 353 Type: GstElementFactoryListType

GST_ELEMENT_FACTORY_TYPE_DECODER

#define  GST_ELEMENT_FACTORY_TYPE_DECODER        (G_GUINT64_CONSTANT (1) << 0)

GST_ELEMENT_FACTORY_TYPE_DEMUXER

#define  GST_ELEMENT_FACTORY_TYPE_DEMUXER        (G_GUINT64_CONSTANT (1) << 5)

GST_ELEMENT_FACTORY_TYPE_DEPAYLOADER

#define  GST_ELEMENT_FACTORY_TYPE_DEPAYLOADER    (G_GUINT64_CONSTANT (1) << 8)

GST_ELEMENT_FACTORY_TYPE_ENCODER

#define  GST_ELEMENT_FACTORY_TYPE_ENCODER        (G_GUINT64_CONSTANT (1) << 1)

GST_ELEMENT_FACTORY_TYPE_FORMATTER

#define  GST_ELEMENT_FACTORY_TYPE_FORMATTER      (G_GUINT64_CONSTANT (1) << 9)

GST_ELEMENT_FACTORY_TYPE_MAX_ELEMENTS

#define  GST_ELEMENT_FACTORY_TYPE_MAX_ELEMENTS   (G_GUINT64_CONSTANT (1) << 48)

GST_ELEMENT_FACTORY_TYPE_MEDIA_AUDIO

#define  GST_ELEMENT_FACTORY_TYPE_MEDIA_AUDIO    (G_GUINT64_CONSTANT (1) << 50)

GST_ELEMENT_FACTORY_TYPE_MEDIA_IMAGE

#define  GST_ELEMENT_FACTORY_TYPE_MEDIA_IMAGE    (G_GUINT64_CONSTANT (1) << 51)

GST_ELEMENT_FACTORY_TYPE_MEDIA_METADATA

#define  GST_ELEMENT_FACTORY_TYPE_MEDIA_METADATA (G_GUINT64_CONSTANT (1) << 53)

GST_ELEMENT_FACTORY_TYPE_MEDIA_SUBTITLE

#define  GST_ELEMENT_FACTORY_TYPE_MEDIA_SUBTITLE (G_GUINT64_CONSTANT (1) << 52)

GST_ELEMENT_FACTORY_TYPE_MEDIA_VIDEO

#define  GST_ELEMENT_FACTORY_TYPE_MEDIA_VIDEO    (G_GUINT64_CONSTANT (1) << 49)

GST_ELEMENT_FACTORY_TYPE_MEDIA_ANY

#define GST_ELEMENT_FACTORY_TYPE_MEDIA_ANY (~G_GUINT64_CONSTANT (0) << 48)

Elements matching any of the defined GST_ELEMENT_FACTORY_TYPE_MEDIA types

Note: Do not use this if you wish to not filter against any of the defined media types. If you wish to do this, simply don't specify any GST_ELEMENT_FACTORY_TYPE_MEDIA flag.

Value: 18446462598732840960 Type: GstElementFactoryListType

GST_ELEMENT_FACTORY_TYPE_MUXER

#define  GST_ELEMENT_FACTORY_TYPE_MUXER          (G_GUINT64_CONSTANT (1) << 4)

GST_ELEMENT_FACTORY_TYPE_PARSER

#define  GST_ELEMENT_FACTORY_TYPE_PARSER         (G_GUINT64_CONSTANT (1) << 6)

GST_ELEMENT_FACTORY_TYPE_PAYLOADER

#define  GST_ELEMENT_FACTORY_TYPE_PAYLOADER      (G_GUINT64_CONSTANT (1) << 7)

GST_ELEMENT_FACTORY_TYPE_SINK

#define  GST_ELEMENT_FACTORY_TYPE_SINK           (G_GUINT64_CONSTANT (1) << 2)

GST_ELEMENT_FACTORY_TYPE_SRC

#define  GST_ELEMENT_FACTORY_TYPE_SRC            (G_GUINT64_CONSTANT (1) << 3)

GST_ELEMENT_FACTORY_TYPE_VIDEO_ENCODER

#define GST_ELEMENT_FACTORY_TYPE_VIDEO_ENCODER (GST_ELEMENT_FACTORY_TYPE_ENCODER | GST_ELEMENT_FACTORY_TYPE_MEDIA_VIDEO | GST_ELEMENT_FACTORY_TYPE_MEDIA_IMAGE)

All encoders handling video or image media types

Value: 2814749767106562 Type: GstElementFactoryListType

gst_element_factory_list_filter ()

GList *             gst_element_factory_list_filter     (GList *list,
                                                         const GstCaps *caps,
                                                         GstPadDirection direction,
                                                         gboolean subsetonly);

Filter out all the elementfactories in list that can handle caps in the given direction.

If subsetonly is TRUE, then only the elements whose pads templates are a complete superset of caps will be returned. Else any element whose pad templates caps can intersect with caps will be returned.

list :

 a GList of GstElementFactory to filter. [transfer none][element-type Gst.ElementFactory]

caps :

 a GstCaps

direction :

 a GstPadDirection to filter on

subsetonly :

 whether to filter on caps subsets or not.

Returns :

 a GList of GstElementFactory elements that match the given requisits. Use gst_plugin_feature_list_free after usage. [transfer full][element-type Gst.ElementFactory]

gst_element_factory_list_get_elements ()

GList *             gst_element_factory_list_get_elements
                                                        (GstElementFactoryListType type,
                                                         GstRank minrank);

Get a list of factories that match the given type. Only elements with a rank greater or equal to minrank will be returned. The list of factories is returned by decreasing rank.

type :

 a GstElementFactoryListType

minrank :

 Minimum rank

Returns :

 a GList of GstElementFactory elements. Use gst_plugin_feature_list_free() after usage. [transfer full][element-type Gst.ElementFactory]

gst_element_factory_list_is_type ()

gboolean            gst_element_factory_list_is_type    (GstElementFactory *factory,
                                                         GstElementFactoryListType type);

Check if factory is of the given types.

factory :

 a GstElementFactory

type :

 a GstElementFactoryListType

Returns :

 TRUE if factory is of type.

See Also

GstElement, GstPlugin, GstPluginFeature, GstPadTemplate.
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