GstElementFactory

GstElementFactory — Create GstElements from a factory

Functions

gboolean gst_element_register ()
GstElementFactory * gst_element_factory_find ()
GType gst_element_factory_get_element_type ()
const gchar * gst_element_factory_get_metadata ()
gchar ** gst_element_factory_get_metadata_keys ()
guint gst_element_factory_get_num_pad_templates ()
GstURIType gst_element_factory_get_uri_type ()
const gchar * const * gst_element_factory_get_uri_protocols ()
gboolean gst_element_factory_has_interface ()
GstElement * gst_element_factory_create ()
GstElement * gst_element_factory_make ()
gboolean gst_element_factory_can_sink_all_caps ()
gboolean gst_element_factory_can_src_all_caps ()
gboolean gst_element_factory_can_sink_any_caps ()
gboolean gst_element_factory_can_src_any_caps ()
const GList * gst_element_factory_get_static_pad_templates ()
#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_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 * gst_element_factory_list_get_elements ()
gboolean gst_element_factory_list_is_type ()

Types and Values

Object Hierarchy

    GObject
    ╰── GInitiallyUnowned
        ╰── GstObject
            ╰── GstPluginFeature
                ╰── GstElementFactory

Includes

#include <gst/gst.h>

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)

Functions

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 .

Parameters

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.

Parameters

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().

Parameters

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 .

Parameters

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 .

Parameters

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.

Parameters

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.

Parameters

factory

a GstElementFactory

 

Returns

type of URIs this element supports


gst_element_factory_get_uri_protocols ()

const gchar * const *
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.

Parameters

factory

a GstElementFactory

 

Returns

the supported protocols or NULL.

[transfer none][array zero-terminated=1]


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 .

Parameters

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.

Parameters

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.

Parameters

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.

Parameters

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.

Parameters

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.

Parameters

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.

Parameters

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.

Parameters

factory

a GstElementFactory

 

Returns

the static pad templates.

[transfer none][element-type Gst.StaticPadTemplate]


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_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.

Parameters

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.

Parameters

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.

Parameters

Returns

TRUE if factory is of type .

Types and Values

GstElementFactory

typedef struct _GstElementFactory GstElementFactory;

The opaque GstElementFactory data structure.


GstElementFactoryListType

typedef guint64 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

See Also

GstElement, GstPlugin, GstPluginFeature, GstPadTemplate.