GstPluginFeature

GstPluginFeature — Base class for contents of a GstPlugin

Functions

Types and Values

Object Hierarchy

    GObject
    ╰── GInitiallyUnowned
        ╰── GstObject
            ╰── GstPluginFeature
                ├── GstElementFactory
                ╰── GstTypeFindFactory

Includes

#include <gst/gst.h>

Description

This is a base class for anything that can be added to a GstPlugin.

Functions

GstPluginFeatureFilter ()

gboolean
(*GstPluginFeatureFilter) (GstPluginFeature *feature,
                           gpointer user_data);

A function that can be used with e.g. gst_registry_feature_filter() to get a list of pluginfeature that match certain criteria.

Parameters

feature

the pluginfeature to check

 

user_data

the user_data that has been passed on e.g. gst_registry_feature_filter()

 

Returns

TRUE for a positive match, FALSE otherwise


gst_plugin_feature_set_rank ()

void
gst_plugin_feature_set_rank (GstPluginFeature *feature,
                             guint rank);

Specifies a rank for a plugin feature, so that autoplugging uses the most appropriate feature.

Parameters

feature

feature to rank

 

rank

rank value - higher number means more priority rank

 

gst_plugin_feature_set_name()

#define                 gst_plugin_feature_set_name(feature,name) gst_object_set_name(GST_OBJECT_CAST(feature),name)

Sets the name of the plugin feature, getting rid of the old name if there was one.

Parameters

feature

a GstPluginFeature to set the name of.

 

name

the new name

 

gst_plugin_feature_get_rank ()

guint
gst_plugin_feature_get_rank (GstPluginFeature *feature);

Gets the rank of a plugin feature.

Parameters

feature

a feature

 

Returns

The rank of the feature


gst_plugin_feature_get_name()

#define                 gst_plugin_feature_get_name(feature)      GST_OBJECT_NAME(feature)

Returns the name of feature . For a nameless plugin feature, this returns NULL.

Parameters

feature

a GstPluginFeature to get the name of feature .

 

Returns

the name of feature . MT safe.

[transfer none]


gst_plugin_feature_get_plugin ()

GstPlugin *
gst_plugin_feature_get_plugin (GstPluginFeature *feature);

Get the plugin that provides this feature.

Parameters

feature

a feature

 

Returns

the plugin that provides this feature, or NULL. Unref with gst_object_unref() when no longer needed.

[transfer full]


gst_plugin_feature_get_plugin_name ()

const gchar *
gst_plugin_feature_get_plugin_name (GstPluginFeature *feature);

Get the name of the plugin that provides this feature.

Parameters

feature

a feature

 

Returns

the name of the plugin that provides this feature, or NULL if the feature is not associated with a plugin.

Since 1.2.0


gst_plugin_feature_load ()

GstPluginFeature *
gst_plugin_feature_load (GstPluginFeature *feature);

Loads the plugin containing feature if it's not already loaded. feature is unaffected; use the return value instead.

Normally this function is used like this:

1
2
3
4
5
6
GstPluginFeature *loaded_feature;

loaded_feature = gst_plugin_feature_load (feature);
// presumably, we're no longer interested in the potentially-unloaded feature
gst_object_unref (feature);
feature = loaded_feature;

Parameters

feature

the plugin feature to check.

[transfer none]

Returns

a reference to the loaded feature, or NULL on error.

[transfer full]


gst_plugin_feature_list_copy ()

GList *
gst_plugin_feature_list_copy (GList *list);

Copies the list of features. Caller should call gst_plugin_feature_list_free when done with the list.

Parameters

list

list of GstPluginFeature.

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

Returns

a copy of list , with each feature's reference count incremented.

[transfer full][element-type Gst.PluginFeature]


gst_plugin_feature_list_free ()

void
gst_plugin_feature_list_free (GList *list);

Unrefs each member of list , then frees the list.

Parameters

list

list of GstPluginFeature.

[transfer full][element-type Gst.PluginFeature]

GST_PLUGIN_FEATURE_LIST_DEBUG()

#define GST_PLUGIN_FEATURE_LIST_DEBUG(list) gst_plugin_feature_list_debug(list)

Debug the plugin feature names in list .

Parameters

list

a GList of plugin features.

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

gst_plugin_feature_check_version ()

gboolean
gst_plugin_feature_check_version (GstPluginFeature *feature,
                                  guint min_major,
                                  guint min_minor,
                                  guint min_micro);

Checks whether the given plugin feature is at least the required version

Parameters

feature

a feature

 

min_major

minimum required major version

 

min_minor

minimum required minor version

 

min_micro

minimum required micro version

 

Returns

TRUE if the plugin feature has at least the required version, otherwise FALSE.


gst_plugin_feature_rank_compare_func ()

gint
gst_plugin_feature_rank_compare_func (gconstpointer p1,
                                      gconstpointer p2);

Compares the two given GstPluginFeature instances. This function can be used as a GCompareFunc when sorting by rank and then by name.

Parameters

Returns

negative value if the rank of p1 > the rank of p2 or the ranks are equal but the name of p1 comes before the name of p2; zero if the rank and names are equal; positive value if the rank of p1 < the rank of p2 or the ranks are equal but the name of p2 comes before the name of p1

Types and Values

GstPluginFeature

typedef struct _GstPluginFeature GstPluginFeature;

Opaque GstPluginFeature structure.


enum GstRank

Element priority ranks. Defines the order in which the autoplugger (or similar rank-picking mechanisms, such as e.g. gst_element_make_from_uri()) will choose this element over an alternative one with the same function.

These constants serve as a rough guidance for defining the rank of a GstPluginFeature. Any value is valid, including values bigger than GST_RANK_PRIMARY .

Members

GST_RANK_NONE

will be chosen last or not at all

 

GST_RANK_MARGINAL

unlikely to be chosen

 

GST_RANK_SECONDARY

likely to be chosen

 

GST_RANK_PRIMARY

will be chosen first

 

See Also

GstPlugin