GStreamer 1.0 Core Reference Manual: GstElementFactory

## 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

| GstElementFactory
typedef | GstElementFactoryListType
#define | GST_ELEMENT_FACTORY_TYPE_DECODABLE

## 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

factory | a GstElementFactory |
type | a GstElementFactoryListType |

#### 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.