GESTrackElement: GStreamer Editing Services 1.10.4 Reference Manual

## GESTrackElement GESTrackElement — Base Class for objects contained in a GESTrack |

## Functions

gboolean | ges_track_element_set_active ()
GESTrack * | ges_track_element_get_track ()
GstElement * | ges_track_element_get_nleobject ()
GstElement * | ges_track_element_get_gnlobject ()
GstElement * | ges_track_element_get_element ()
gboolean | ges_track_element_is_active ()
gboolean | ges_track_element_lookup_child ()
GParamSpec ** | ges_track_element_list_children_properties ()
gboolean | ges_track_element_set_child_property ()
void | ges_track_element_set_child_properties ()
void | ges_track_element_set_child_property_valist ()
void | ges_track_element_set_child_property_by_pspec ()
gboolean | ges_track_element_get_child_property ()
void | ges_track_element_get_child_properties ()
void | ges_track_element_get_child_property_valist ()
void | ges_track_element_get_child_property_by_pspec ()
gboolean | ges_track_element_edit ()
gboolean | ges_track_element_set_control_source ()
GstControlBinding * | ges_track_element_get_control_binding ()
GHashTable * | ges_track_element_get_all_control_bindings ()
gboolean | ges_track_element_remove_control_binding ()

## Properties

gboolean | active | Read / Write
GESTrack * | track | Read
GESTrackType | track-type | Read / Write / Construct

## Signals

void | control-binding-added | Run First
void | control-binding-removed | Run First

## Types and Values

| GESTrackElement
| GESTrackElementClass

## Object Hierarchy

        GObject
        ╰── GInitiallyUnowned
            ╰── GESTimelineElement
                ╰── GESTrackElement
                    ├── GESSource
                    ╰── GESOperation

## Implemented Interfaces

GESTrackElement implements GESExtractable and GESMetaContainer.

## Includes

    #include <ges/ges.h>

## Description

GESTrackElement is the Base Class for any object that can be contained in a GESTrack.

It contains the basic information as to the location of the object within its container, like the start position, the inpoint, the duration and the priority.

## Functions

### ges_track_element_set_active ()

    gboolean
    ges_track_element_set_active (GESTrackElement *object,
                                  gboolean active);

Sets the usage of the `object` . If `active` is `TRUE`, the object will be used for playback and rendering, else it will be ignored.

#### Parameters

object | a GESTrackElement |
active | visibility |

#### Returns

`TRUE` if the property was toggled, else `FALSE`

### ges_track_element_get_track ()

    GESTrack *
    ges_track_element_get_track (GESTrackElement *object);

Get the GESTrack to which this object belongs.

#### Parameters

object | a GESTrackElement |

#### Returns

The GESTrack to which this object belongs. Can be `NULL` if it is not in any track.

[transfer none][nullable]

### ges_track_element_get_nleobject ()

    GstElement *
    ges_track_element_get_nleobject (GESTrackElement *object);

Get the GNonLin object this object is controlling.

#### Parameters

object | a GESTrackElement |

#### Returns

the GNonLin object this object is controlling.

[transfer none]

Since: 1.6

### ges_track_element_get_gnlobject ()

    GstElement *
    ges_track_element_get_gnlobject (GESTrackElement *object);

`ges_track_element_get_gnlobject` is deprecated and should not be used in newly-written code.

use ges_track_element_get_nleobject instead.

Get the NleObject object this object is controlling.

#### Parameters

object | a GESTrackElement |

#### Returns

the NleObject object this object is controlling.

[transfer none]

### ges_track_element_get_element ()

    GstElement *
    ges_track_element_get_element (GESTrackElement *object);

Get the GstElement this track element is controlling within GNonLin.

#### Parameters

object | a GESTrackElement |

#### Returns

the GstElement this track element is controlling within GNonLin.

[transfer none]

### ges_track_element_is_active ()

    gboolean
    ges_track_element_is_active (GESTrackElement *object);

Lets you know if `object` will be used for playback and rendering, or not.

#### Parameters

object | a GESTrackElement |

#### Returns

`TRUE` if `object` is active, `FALSE` otherwize

### ges_track_element_lookup_child ()

    gboolean
    ges_track_element_lookup_child (GESTrackElement *object,
                                    const gchar *prop_name,
                                    GstElement **element,
                                    GParamSpec **pspec);

`ges_track_element_lookup_child` is deprecated and should not be used in newly-written code.

Use ges_timeline_element_lookup_child

Looks up which `element` and `pspec` would be effected by the given `name` . If various contained elements have this property name you will get the first one, unless you specify the class name in `name` .

#### Parameters

object | object to lookup the property in |
prop_name | name of the property to look up. You can specify the name of the class as such: "ClassName::property-name", to guarantee that you get the proper GParamSpec in case various GstElement-s contain the same property name. If you don't do so, you will get the first element found, having this property and the and the corresponding GParamSpec. |
element | pointer to a GstElement that takes the real object to set property on. | [out][allow-none][transfer full]
pspec | pointer to take the GParamSpec describing the property. | [out][allow-none][transfer full]

#### Returns

TRUE if `element` and `pspec` could be found. FALSE otherwise. In that case the values for `pspec` and `element` are not modified. Unref `element` after usage.

### ges_track_element_list_children_properties ()

    GParamSpec **
    ges_track_element_list_children_properties
                                   (GESTrackElement *object,
                                    guint *n_properties);

`ges_track_element_list_children_properties` is deprecated and should not be used in newly-written code.

Use ges_timeline_element_list_children_properties

Gets an array of GParamSpec* for all configurable properties of the children of `object` .

#### Parameters

object | The GESTrackElement to get the list of children properties from |
n_properties | return location for the length of the returned array. | [out]

#### Returns

an array of GParamSpec* which should be freed after use or `NULL` if something went wrong.

[transfer full][array length=n_properties]

### ges_track_element_set_child_property ()

    gboolean
    ges_track_element_set_child_property (GESTrackElement *object,
                                          const gchar *property_name,
                                          GValue *value);

### ges_track_element_set_child_properties ()

    void
    ges_track_element_set_child_properties
                                   (GESTrackElement *object,
                                    const gchar *first_property_name,
                                    ...);

### ges_track_element_set_child_property_valist ()

    void
    ges_track_element_set_child_property_valist
                                   (GESTrackElement *object,
                                    const gchar *first_property_name,
                                    va_list var_args);

### ges_track_element_set_child_property_by_pspec ()

    void
    ges_track_element_set_child_property_by_pspec
                                   (GESTrackElement *object,
                                    GParamSpec *pspec,
                                    GValue *value);

### ges_track_element_get_child_property ()

    gboolean
    ges_track_element_get_child_property (GESTrackElement *object,
                                          const gchar *property_name,
                                          GValue *value);

### ges_track_element_get_child_properties ()

    void
    ges_track_element_get_child_properties
                                   (GESTrackElement *object,
                                    const gchar *first_property_name,
                                    ...);

### ges_track_element_get_child_property_valist ()

    void
    ges_track_element_get_child_property_valist
                                   (GESTrackElement *object,
                                    const gchar *first_property_name,
                                    va_list var_args);

### ges_track_element_get_child_property_by_pspec ()

    void
    ges_track_element_get_child_property_by_pspec
                                   (GESTrackElement *object,
                                    GParamSpec *pspec,
                                    GValue *value);

### ges_track_element_edit ()

    gboolean
    ges_track_element_edit (GESTrackElement *object,
                            GList *layers,
                            GESEditMode mode,
                            GESEdge edge,
                            guint64 position);

Edit `object` in the different exisiting GESEditMode modes. In the case of slide, and roll, you need to specify a GESEdge

#### Parameters

object | the GESTrackElement to edit |
layers | The layers you want the edit to happen in, `NULL` means that the edition is done in all the GESLayers contained in the current timeline. FIXME: This is not implemented yet. | [element-type GESLayer]
mode | The GESEditMode in which the editition will happen. |
edge | The GESEdge the edit should happen on. |
position | The position at which to edit `object` (in nanosecond) |

#### Returns

`TRUE` if the object as been edited properly, `FALSE` if an error occured

### ges_track_element_set_control_source ()

    gboolean
    ges_track_element_set_control_source (GESTrackElement *object,
                                          GstControlSource *source,
                                          const gchar *property_name,
                                          const gchar *binding_type);

Creates a GstControlBinding and adds it to the GstElement concerned by the property. Use the same syntax as ges_track_element_lookup_child for the property name.

#### Parameters

object | the GESTrackElement on which to set a control binding |
source | the GstControlSource to set on the binding. |
property_name | The name of the property to control. |
binding_type | The type of binding to create. Only "direct" is available for now. |

#### Returns

`TRUE` if the binding could be created and added, `FALSE` if an error occured

### ges_track_element_get_control_binding ()

    GstControlBinding *
    ges_track_element_get_control_binding (GESTrackElement *object,
                                           const gchar *property_name);

Looks up the various controlled properties for that GESTrackElement, and returns the GstControlBinding which controls `property_name` .

#### Parameters

object | the GESTrackElement in which to lookup the bindings. |
property_name | The property_name to which the binding is associated. |

#### Returns

the GstControlBinding associated with `property_name` , or `NULL` if that property is not controlled.

[transfer none][nullable]

### ges_track_element_get_all_control_bindings ()

    GHashTable *
    ges_track_element_get_all_control_bindings
                                   (GESTrackElement *trackelement);

#### Parameters

trackelement | The TrackElement from which to get all set bindings |

#### Returns

A GHashTable containing all property_name: GstControlBinding.

[element-type gchar* GstControlBinding][transfer none]

### ges_track_element_remove_control_binding ()

    gboolean
    ges_track_element_remove_control_binding
                                   (GESTrackElement *object,
                                    const gchar *property_name);

Removes a GstControlBinding from `object` .

#### Parameters

object | the GESTrackElement on which to set a control binding |
property_name | The name of the property to control. |

#### Returns

`TRUE` if the binding could be removed, `FALSE` if an error occured

## Types and Values

### GESTrackElement

    typedef struct _GESTrackElement GESTrackElement;

The GESTrackElement base class.

### GESTrackElementClass

    typedef struct {
      /* virtual methods for subclasses */
      const gchar  *nleobject_factorytype;
      GstElement*  (*create_gnl_object)        (GESTrackElement * object);
      GstElement*  (*create_element)           (GESTrackElement * object);

      void (*active_changed)       (GESTrackElement *object, gboolean active);

      /* virtual methods for subclasses */
      GParamSpec** (*list_children_properties) (GESTrackElement * object,
                  guint *n_properties);
      gboolean (*lookup_child)                 (GESTrackElement *object,
                                                const gchar *prop_name,
                                                GstElement **element,
                                                GParamSpec **pspec);
    } GESTrackElementClass;

Subclasses can override the `create_gnl_object` method to override what type of GNonLin object will be created.

#### Members

const gchar *`nleobject_factorytype`; | name of the GNonLin GStElementFactory type to use. |
`create_gnl_object` () | method to create the GNonLin container object. |
`create_element` () | method to return the GstElement to put in the nleobject. |
`active_changed` () | active property of nleobject has changed |
`list_children_properties` () | method to get children properties that user could like to configure. The default implementation will create an object of type `nleobject_factorytype` and call `create_element` . DeprecatedUse: GESTimelineElement.list_children_properties instead |
`lookup_child` () | method letting subclasses look for a child, overriding the simple standard behaviour. This vmethod can be used for example in the case where you want the name of a child property to be 'overriden'. A good example of where it is usefull is the GESTitleSource where we have a videotestsrc which has a 'foreground-color' property that is used in the TitleSource to set the background color of the title, in that case, this method has been overriden so that we tweak the name passed has parametter to rename "background" to "foreground-backend" making our API understandable. Deprecated: use GESTimelineElement.lookup_child instead |

## Property Details

### The `“active”` property

      “active”                   gboolean

Whether the object should be taken into account in the GESTrack output. If FALSE, then its contents will not be used in the resulting track.

Flags: Read / Write

Default value: TRUE

### The `“track”` property

      “track”                    GESTrack *

The track the object is in.

Flags: Read

### The `“track-type”` property

      “track-type”               GESTrackType

The track type of the object.

Flags: Read / Write / Construct

Default value: GES_TRACK_TYPE_UNKNOWN

## Signal Details

### The `“control-binding-added”` signal

    void
    user_function (GESTrackElement   *track_element,
                   GstControlBinding *control_binding,
                   gpointer           user_data)

The control-binding-added signal is emitted each time a control binding is added for a child property of `track_element`

#### Parameters

track_element | a GESTrackElement |
control_binding | the GstControlBinding that has been added |
user_data | user data set when the signal handler was connected. |

Flags: Run First

### The `“control-binding-removed”` signal

    void
    user_function (GESTrackElement   *track_element,
                   GstControlBinding *control_binding,
                   gpointer           user_data)

The control-binding-removed signal is emitted each time a control binding is removed for a child property of `track_element`

#### Parameters

track_element | a GESTrackElement |
control_binding | the GstControlBinding that has been removed |
user_data | user data set when the signal handler was connected. |

Flags: Run First