GESTimeline

GESTimeline — Multimedia timeline

Functions

Properties

Signals

Types and Values

Object Hierarchy

    GObject
    ╰── GInitiallyUnowned
        ╰── GstObject
            ╰── GstElement
                ╰── GstBin
                    ╰── GESTimeline

Implemented Interfaces

GESTimeline implements GstChildProxy, GESExtractable and GESMetaContainer.

Includes

#include <ges/ges.h>

Description

GESTimeline is the central object for any multimedia timeline.

Contains a list of GESLayer which users should use to arrange the various clips through time.

The output type is determined by the GESTrack that are set on the GESTimeline.

To save/load a timeline, you can use the ges_timeline_load_from_uri() and ges_timeline_save_to_uri() methods to use the default format. If you wish

Note that any change you make in the timeline will not actually be taken into account until you call the ges_timeline_commit method.

Functions

ges_timeline_new ()

GESTimeline *
ges_timeline_new (void);

Creates a new empty GESTimeline.

Returns

The new timeline.


ges_timeline_new_audio_video ()

GESTimeline *
ges_timeline_new_audio_video (void);

Creates a new GESTimeline containing a raw audio and a raw video track.

Returns

The newly created GESTimeline.


ges_timeline_new_from_uri ()

GESTimeline *
ges_timeline_new_from_uri (const gchar *uri,
                           GError **error);

Creates a timeline from the given URI.

Parameters

uri

the URI to load from

 

error

An error to be set in case something wrong happens or NULL.

[out][allow-none]

Returns

A new timeline if the uri was loaded successfully, or NULL if the uri could not be loaded


ges_timeline_add_layer ()

gboolean
ges_timeline_add_layer (GESTimeline *timeline,
                        GESLayer *layer);

Add the layer to the timeline. The reference to the layer will be stolen by the timeline .

Parameters

timeline

a GESTimeline

 

layer

the GESLayer to add

 

Returns

TRUE if the layer was properly added, else FALSE.


ges_timeline_append_layer ()

GESLayer *
ges_timeline_append_layer (GESTimeline *timeline);

Append a newly created GESLayer to timeline Note that you do not own any reference to the returned layer.

Parameters

timeline

a GESTimeline

 

Returns

The newly created GESLayer, or the last (empty) GESLayer of timeline .

[transfer none]


ges_timeline_remove_layer ()

gboolean
ges_timeline_remove_layer (GESTimeline *timeline,
                           GESLayer *layer);

Removes the layer from the timeline. The reference that the timeline holds on the layer will be dropped. If you wish to use the layer after calling this method, you need to take a reference before calling.

Parameters

timeline

a GESTimeline

 

layer

the GESLayer to remove

 

Returns

TRUE if the layer was properly removed, else FALSE.


ges_timeline_add_track ()

gboolean
ges_timeline_add_track (GESTimeline *timeline,
                        GESTrack *track);

Add a track to the timeline. The reference to the track will be stolen by the pipeline.

Parameters

timeline

a GESTimeline

 

track

the GESTrack to add

 

Returns

TRUE if the track was properly added, else FALSE.


ges_timeline_remove_track ()

gboolean
ges_timeline_remove_track (GESTimeline *timeline,
                           GESTrack *track);

Remove the track from the timeline . The reference stolen when adding the track will be removed. If you wish to use the track after calling this function you must ensure that you have a reference to it.

Parameters

timeline

a GESTimeline

 

track

the GESTrack to remove

 

Returns

TRUE if the track was properly removed, else FALSE.


ges_timeline_load_from_uri ()

gboolean
ges_timeline_load_from_uri (GESTimeline *timeline,
                            const gchar *uri,
                            GError **error);

Loads the contents of URI into the given timeline.

Parameters

timeline

an empty GESTimeline into which to load the formatter

 

uri

The URI to load from

 

error

An error to be set in case something wrong happens or NULL.

[out][allow-none]

Returns

TRUE if the timeline was loaded successfully, or FALSE if the uri could not be loaded.


ges_timeline_save_to_uri ()

gboolean
ges_timeline_save_to_uri (GESTimeline *timeline,
                          const gchar *uri,
                          GESAsset *formatter_asset,
                          gboolean overwrite,
                          GError **error);

Saves the timeline to the given location

Parameters

timeline

a GESTimeline

 

uri

The location to save to

 

formatter_asset

The formatter asset to use or NULL. If NULL, will try to save in the same format as the one from which the timeline as been loaded or default to the formatter with highest rank.

[allow-none]

overwrite

TRUE to overwrite file if it exists

 

error

An error to be set in case something wrong happens or NULL.

[out][allow-none]

Returns

TRUE if the timeline was successfully saved to the given location, else FALSE.


ges_timeline_commit ()

gboolean
ges_timeline_commit (GESTimeline *timeline);

Commit all the pending changes of the clips contained in the timeline .

When changes happen in a timeline, they are not directly executed in the non-linear engine. Call this method once you are done with a set of changes and want it to be executed.

The GESTimeline::commited signal will be emitted when the (possibly updated) GstPipeline is ready to output data again, except if the state of the timeline was GST_STATE_READY or GST_STATE_NULL.

Note that all the pending changes will automatically be executed when the timeline goes from GST_STATE_READY to GST_STATE_PAUSED, which usually is triggered by corresponding state changes in a containing GESPipeline.

You should not try to change the state of the timeline, seek it or add tracks to it during a commit operation, that is between a call to this function and after receiving the GESTimeline::commited signal.

See ges_timeline_commit_sync if you don't want to bother with waiting for the signal.

Parameters

timeline

a GESTimeline

 

Returns

TRUE if pending changes were commited or FALSE if nothing needed to be commited


ges_timeline_commit_sync ()

gboolean
ges_timeline_commit_sync (GESTimeline *timeline);

Commit all the pending changes of the GESClips contained in the timeline .

Will return once the update is complete, that is when the (possibly updated) GstPipeline is ready to output data again, or if the state of the timeline was GST_STATE_READY or GST_STATE_NULL.

This function will wait for any pending state change of the timeline by calling gst_element_get_state with a GST_CLOCK_TIME_NONE timeout, you should not try to change the state from another thread before this function has returned.

See ges_timeline_commit for more information.

Parameters

timeline

a GESTimeline

 

Returns

TRUE if pending changes were commited or FALSE if nothing needed to be commited


ges_timeline_get_tracks ()

GList *
ges_timeline_get_tracks (GESTimeline *timeline);

Returns the list of GESTrack used by the Timeline.

Parameters

timeline

a GESTimeline

 

Returns

A list of GESTrack. The caller should unref each track once he is done with them.

[transfer full][element-type GESTrack]


ges_timeline_get_layer ()

GESLayer *
ges_timeline_get_layer (GESTimeline *timeline,
                        guint priority);

Retrieve the layer with priority as a priority

Parameters

timeline

The GESTimeline to retrive a layer from

 

priority

The priority of the layer to find

 

Returns

A GESLayer or NULL if no layer with priority was found

Since 1.6


ges_timeline_get_layers ()

GList *
ges_timeline_get_layers (GESTimeline *timeline);

Get the list of GESLayer present in the Timeline.

Parameters

timeline

a GESTimeline

 

Returns

the list of GESLayer present in the Timeline sorted by priority. The caller should unref each Layer once he is done with them.

[transfer full][element-type GESLayer]


ges_timeline_get_track_for_pad ()

GESTrack *
ges_timeline_get_track_for_pad (GESTimeline *timeline,
                                GstPad *pad);

Search the GESTrack corresponding to the given timeline 's pad .

Parameters

timeline

The GESTimeline

 

pad

The GstPad

 

Returns

The corresponding GESTrack if it is found, or NULL if there is an error.

[transfer none]


ges_timeline_get_pad_for_track ()

GstPad *
ges_timeline_get_pad_for_track (GESTimeline *timeline,
                                GESTrack *track);

Search the GstPad corresponding to the given timeline 's track .

Parameters

timeline

The GESTimeline

 

track

The GESTrack

 

Returns

The corresponding GstPad if it is found, or NULL if there is an error.

[transfer none]


ges_timeline_get_duration ()

GstClockTime
ges_timeline_get_duration (GESTimeline *timeline);

Get the current duration of timeline

Parameters

timeline

a GESTimeline

 

Returns

The current duration of timeline


ges_timeline_get_project()

#define ges_timeline_get_project(obj) (GES_PROJECT (ges_extractable_get_asset (GES_EXTRACTABLE(obj))))

Helper macro to retrieve the project from which a GESTimeline as been extracted

Parameters

obj

The GESTimeline from which to retrieve the project

 

ges_timeline_get_auto_transition ()

gboolean
ges_timeline_get_auto_transition (GESTimeline *timeline);

Gets whether transitions are automatically added when objects overlap or not.

Parameters

timeline

a GESTimeline

 

Returns

TRUE if transitions are automatically added, else FALSE.


ges_timeline_set_auto_transition ()

void
ges_timeline_set_auto_transition (GESTimeline *timeline,
                                  gboolean auto_transition);

Sets the layer to the given auto_transition . See the documentation of the property auto_transition for more information.

Parameters

timeline

a GESLayer

 

auto_transition

whether the auto_transition is active

 

ges_timeline_get_snapping_distance ()

GstClockTime
ges_timeline_get_snapping_distance (GESTimeline *timeline);

Gets the configured snapping distance of the timeline. See the documentation of the property snapping_distance for more information.

Parameters

timeline

a GESTimeline

 

Returns

The snapping_distance property of the timeline


ges_timeline_set_snapping_distance ()

void
ges_timeline_set_snapping_distance (GESTimeline *timeline,
                                    GstClockTime snapping_distance);

Sets the snapping_distance of the timeline. See the documentation of the property snapping_distance for more information.

Parameters

timeline

a GESLayer

 

snapping_distance

whether the snapping_distance is active

 

ges_timeline_get_element ()

GESTimelineElement *
ges_timeline_get_element (GESTimeline *timeline,
                          const gchar *name);

Gets a GESTimelineElement contained in the timeline

Parameters

timeline

a GESTimeline

 

Returns

The GESTimelineElement or NULL if not found.

[transfer full]


ges_timeline_is_empty ()

gboolean
ges_timeline_is_empty (GESTimeline *timeline);

Check whether a GESTimelineElement is empty or not

Parameters

timeline

a GESTimeline

 

Returns

TRUE if the timeline is empty FALSE otherwize

Types and Values

GESTimeline

typedef struct {
  /* <readonly> */
  GList *layers;
  GList *tracks;
} GESTimeline;

Members

GList *layers;

A list of GESLayer sorted by priority NOTE: Do not modify.

[element-type GES.Layer]

GList *tracks;

A list of GESTrack sorted by priority NOTE: Do not modify.

[element-type GES.Track]

Property Details

The “auto-transition” property

  “auto-transition”          gboolean

Sets whether transitions are added automagically when clips overlap.

Flags: Read / Write

Default value: FALSE


The “duration” property

  “duration”                 guint64

Current duration (in nanoseconds) of the GESTimeline

Flags: Read

Default value: 18446744073709551615


The “snapping-distance” property

  “snapping-distance”        guint64

Distance (in nanoseconds) from which a moving object will snap with it neighboors. 0 means no snapping.

Flags: Read / Write

Default value: 0

Signal Details

The “commited” signal

void
user_function (GESTimeline *timeline,
               gpointer     user_data)

This signal will be emitted once the changes initiated by ges_timeline_commit have been executed in the backend. Use ges_timeline_commit_sync if you don't need to do anything in the meantime.

Parameters

timeline

the GESTimeline

 

user_data

user data set when the signal handler was connected.

 

Flags: Run Last


The “layer-added” signal

void
user_function (GESTimeline *timeline,
               GESLayer    *layer,
               gpointer     user_data)

Will be emitted after the layer was added to the timeline.

Parameters

timeline

the GESTimeline

 

layer

the GESLayer that was added to the timeline

 

user_data

user data set when the signal handler was connected.

 

Flags: Run First


The “layer-removed” signal

void
user_function (GESTimeline *timeline,
               GESLayer    *layer,
               gpointer     user_data)

Will be emitted after the layer was removed from the timeline.

Parameters

timeline

the GESTimeline

 

layer

the GESLayer that was removed from the timeline

 

user_data

user data set when the signal handler was connected.

 

Flags: Run First


The “select-tracks-for-object” signal

GPtrArray*
user_function (GESTimeline     *timeline,
               GESClip         *clip,
               GESTrackElement *track-element,
               gpointer         user_data)

Parameters

timeline

the GESTimeline

 

clip

The GESClip on which track -element will land

 

track-element

The GESTrackElement for which to choose the tracks it should land into

 

user_data

user data set when the signal handler was connected.

 

Returns

a GPtrArray of GESTrack-s where that object should be added.

[transfer full][element-type GESTrack]

Flags: Run Last


The “snapping-ended” signal

void
user_function (GESTimeline     *gestimeline,
               GESTrackElement *arg1,
               GESTrackElement *arg2,
               guint64          arg3,
               gpointer         user_data)

Flags: Run Last


The “snapping-started” signal

void
user_function (GESTimeline     *gestimeline,
               GESTrackElement *arg1,
               GESTrackElement *arg2,
               guint64          arg3,
               gpointer         user_data)

Flags: Run Last


The “track-added” signal

void
user_function (GESTimeline *timeline,
               GESTrack    *track,
               gpointer     user_data)

Will be emitted after the track was added to the timeline.

Parameters

timeline

the GESTimeline

 

track

the GESTrack that was added to the timeline

 

user_data

user data set when the signal handler was connected.

 

Flags: Run First


The “track-removed” signal

void
user_function (GESTimeline *timeline,
               GESTrack    *track,
               gpointer     user_data)

Will be emitted after the track was removed from the timeline.

Parameters

timeline

the GESTimeline

 

track

the GESTrack that was removed from the timeline

 

user_data

user data set when the signal handler was connected.

 

Flags: Run First