ges: add some g-i annotations according to documentation

Mainly (transfer xxx) and (nullable). Also fix some typo.

https://bugzilla.gnome.org/show_bug.cgi?id=766459

ges/ges-asset.c

@@ -477,7 +477,7 @@ _gtask_return_true (GTask * task, gpointer udata)
  *
  * Looks for asset with specified id in cache and it's completely loaded.
  *
- * Returns: (transfer none): The #GESAsset found or %NULL
+ * Returns: (transfer none) (nullable): The #GESAsset found or %NULL
  */
 GESAsset *
 ges_asset_cache_lookup (GType extractable_type, const gchar * id)
@@ -770,7 +770,7 @@ ges_asset_list_proxies (GESAsset * asset)
  * ges_asset_get_proxy:
  * @asset: The #GESAsset to get currenlty used proxy
  *
- * Returns: (transfer none): The proxy in use for @asset
+ * Returns: (transfer none) (nullable): The proxy in use for @asset
  */
 GESAsset *
 ges_asset_get_proxy (GESAsset * asset)
@@ -788,7 +788,7 @@ ges_asset_get_proxy (GESAsset * asset)
  * ges_asset_get_proxy_target:
  * @proxy: The #GESAsset from which to get the the asset it proxies.
  *
- * Returns: (transfer none): The #GESAsset that is proxied by @proxy
+ * Returns: (transfer none) (nullable): The #GESAsset that is proxied by @proxy
  */
 GESAsset *
 ges_asset_get_proxy_target (GESAsset * proxy)
@@ -1283,8 +1283,8 @@ ges_list_assets (GType filter)
  * ges_asset_get_error:
  * @self: The asset to retrieve the error from
  *
- * Returns: (transfer none): The #GError of the asset or %NULL if the asset was
- * loaded without issue
+ * Returns: (transfer none) (nullable): The #GError of the asset or %NULL if
+ * the asset was loaded without issue
  *
  * Since: 1.8
  */

ges/ges-audio-test-source.c

@@ -183,7 +183,7 @@ ges_audio_test_source_get_freq (GESAudioTestSource * self)
 /**
  * ges_audio_test_source_get_volume:
  * @self: a #GESAudioTestSource
- * 
+ *
  * Get the current volume of @self.
  *
  * Returns: The current volume of @self
@@ -203,7 +203,7 @@ ges_audio_test_source_get_volume (GESAudioTestSource * self)
  *
  * Creates a new #GESAudioTestSource.
  *
- * Returns: The newly created #GESAudioTestSource.
+ * Returns: (transfer floating) (nullable): The newly created #GESAudioTestSource.
  */
 GESAudioTestSource *
 ges_audio_test_source_new (void)

ges/ges-audio-track.c

@@ -114,7 +114,7 @@ ges_audio_track_class_init (GESAudioTrackClass * klass)
  * Creates a new #GESAudioTrack of type #GES_TRACK_TYPE_AUDIO and with generic
  * raw audio caps ("audio/x-raw");
  *
- * Returns: A new #GESTrack
+ * Returns: (transfer floating): A new #GESTrack
  */
 GESAudioTrack *
 ges_audio_track_new (void)

ges/ges-audio-transition.c

@@ -287,7 +287,7 @@ ges_audio_transition_duration_changed (GESTrackElement * track_element,
  *
  * Creates a new #GESAudioTransition.
  *
- * Returns: The newly created #GESAudioTransition.
+ * Returns: (transfer floating): The newly created #GESAudioTransition.
  */
 GESAudioTransition *
 ges_audio_transition_new (void)

ges/ges-audio-uri-source.c

@@ -185,8 +185,8 @@ ges_audio_uri_source_init (GESAudioUriSource * self)
  *
  * Creates a new #GESAudioUriSource for the provided @uri.
  *
- * Returns: The newly created #GESAudioUriSource, or %NULL if there was an
- * error.
+ * Returns: (transfer floating) (nullable): The newly created
+ * #GESAudioUriSource, or %NULL if there was an error.
  */
 GESAudioUriSource *
 ges_audio_uri_source_new (gchar * uri)

ges/ges-clip.c

@@ -824,8 +824,8 @@ ges_clip_init (GESClip * self)
  * keep a reference to the newly created trackelement, you therefore need to
  * call @ges_container_remove when you are done with it.
  *
- * Returns: (transfer none): A #GESTrackElement. Returns NULL if the #GESTrackElement could not
- * be created.
+ * Returns: (transfer none) (nullable): A #GESTrackElement. Returns NULL if
+ * the #GESTrackElement could not be created.
  */
 GESTrackElement *
 ges_clip_create_track_element (GESClip * clip, GESTrackType type)
@@ -1053,8 +1053,8 @@ ges_clip_move_to_layer (GESClip * clip, GESLayer * layer)
  * Note: If many objects match, then the one with the highest priority will be
  * returned.
  *
- * Returns: (transfer full): The #GESTrackElement used by @track, else %NULL,
- * Unref after usage
+ * Returns: (transfer full) (nullable): The #GESTrackElement used by @track,
+ * else %NULL. Unref after usage
  */
 
 GESTrackElement *
@@ -1090,7 +1090,7 @@ ges_clip_find_track_element (GESClip * clip, GESTrack * track, GType type)
  *
  * Get the #GESLayer to which this clip belongs.
  *
- * Returns: (transfer full): The #GESLayer where this @clip is being
+ * Returns: (transfer full) (nullable): The #GESLayer where this @clip is being
  * used, or %NULL if it is not used on any layer. The caller should unref it
  * usage.
  */
@@ -1265,8 +1265,8 @@ ges_clip_set_top_effect_index (GESClip * clip, GESBaseEffect * effect,
  * property must be registered using @ges_effect_class_register_rate_property;
  * for the 'pitch' plugin, this is already done.
  *
- * Returns: (transfer none): The newly created #GESClip resulting from the
- * splitting
+ * Returns: (transfer none) (nullable): The newly created #GESClip resulting
+ * from the splitting or %NULL if the clip can't be split.
  */
 GESClip *
 ges_clip_split (GESClip * clip, guint64 position)

ges/ges-effect-clip.c

@@ -176,7 +176,7 @@ _create_track_element (GESClip * self, GESTrackType type)
  *
  * Creates a new #GESEffectClip from the description of the bin.
  *
- * Returns: a newly created #GESEffectClip, or
+ * Returns: (transfer floating) (nullable): a newly created #GESEffectClip, or
  * %NULL if something went wrong.
  */
 GESEffectClip *

ges/ges-effect.c

@@ -257,7 +257,7 @@ ges_effect_create_element (GESTrackElement * object)
  * #ges_asset_request (GES_TYPE_EFFECT, "audio your ! bin ! description", NULL);
  * and extract that asset to be in full control.
  *
- * Returns: a newly created #GESEffect, or %NULL if something went
+ * Returns: (nullable): a newly created #GESEffect, or %NULL if something went
  * wrong.
  */
 GESEffect *

ges/ges-extractable.c

@@ -83,7 +83,8 @@ ges_extractable_default_init (GESExtractableInterface * iface)
  *
  * Method for getting an asset from a #GESExtractable
  *
- * Returns: (transfer none): The #GESAsset or %NULL if none has been set
+ * Returns: (transfer none) (nullable): The #GESAsset or %NULL if none has
+ * been set
  */
 GESAsset *
 ges_extractable_get_asset (GESExtractable * self)
@@ -212,8 +213,8 @@ ges_extractable_type_get_asset_type (GType type)
  *
  * Check if @id is valid for @type
  *
- * Returns: (transfer full): A newly allocated string containing the actuall
- * ID (after some processing) or %NULL if the ID is wrong.
+ * Returns: (transfer full) (nullable): A newly allocated string containing
+ * the actual ID (after some processing) or %NULL if the ID is wrong.
  */
 gchar *
 ges_extractable_type_check_id (GType type, const gchar * id, GError ** error)

ges/ges-group.c

@@ -791,7 +791,7 @@ ges_group_init (GESGroup * self)
  * together, it is recommanded to use the #ges_container_group method so the
  * proper subclass is selected.
  *
- * Returns: The new empty group.
+ * Returns: (transfer floating): The new empty group.
  */
 GESGroup *
 ges_group_new (void)

ges/ges-image-source.c

@@ -181,7 +181,7 @@ ges_image_source_init (GESImageSource * self)
  *
  * Creates a new #GESImageSource for the provided @uri.
  *
- * Returns: A new #GESImageSource.
+ * Returns: (transfer floating): A new #GESImageSource.
  */
 GESImageSource *
 ges_image_source_new (gchar * uri)

ges/ges-layer.c

@@ -502,7 +502,7 @@ ges_layer_is_empty (GESLayer * layer)
  * are constructed, you should connect to the container::child-added signal which
  * is emited right after those elements are ready to be used.
  *
- * Returns: TRUE if the clip was properly added to the layer, or FALSE
+ * Returns: %TRUE if the clip was properly added to the layer, or %FALSE
  * if the @layer refuses to add the clip.
  */
 gboolean
@@ -662,7 +662,7 @@ ges_layer_add_asset (GESLayer * layer,
  *
  * Creates a new #GESLayer.
  *
- * Returns: A new #GESLayer
+ * Returns: (transfer floating): A new #GESLayer
  */
 GESLayer *
 ges_layer_new (void)
@@ -676,7 +676,7 @@ ges_layer_new (void)
  *
  * Get the #GESTimeline in which #GESLayer currently is.
  *
- * Returns: (transfer none):  the #GESTimeline in which #GESLayer
+ * Returns: (transfer none) (nullable): the #GESTimeline in which #GESLayer
  * currently is or %NULL if not in any timeline yet.
  */
 GESTimeline *

ges/ges-meta-container.c

@@ -426,8 +426,8 @@ ges_meta_container_set_meta (GESMetaContainer * container,
  *
  * Serializes a meta container to a string.
  *
- * Returns: a newly-allocated string, or NULL in case of an error. The
- *    string must be freed with g_free() when no longer needed.
+ * Returns: (nullable): a newly-allocated string, or NULL in case of an error.
+ * The string must be freed with g_free() when no longer needed.
  */
 gchar *
 ges_meta_container_metas_to_string (GESMetaContainer * container)

ges/ges-multi-file-source.c

@@ -261,7 +261,7 @@ ges_multi_file_source_init (GESMultiFileSource * self)
  *
  * Creates a new #GESMultiFileSource for the provided @uri.
  *
- * Returns: A new #GESMultiFileSource.
+ * Returns: (transfer floating): A new #GESMultiFileSource.
  */
 GESMultiFileSource *
 ges_multi_file_source_new (gchar * uri)

ges/ges-pipeline.c

@@ -401,7 +401,7 @@ no_encodebin:
  *
  * Creates a new conveninence #GESPipeline.
  *
- * Returns: the new #GESPipeline.
+ * Returns: (transfer floating): the new #GESPipeline.
  */
 GESPipeline *
 ges_pipeline_new (void)
@@ -921,7 +921,7 @@ _unlink_track (GESPipeline * self, GESTrack * track)
 /**
  * ges_pipeline_set_timeline:
  * @pipeline: a #GESPipeline
- * @timeline: the #GESTimeline to set on the @pipeline.
+ * @timeline: (transfer full): the #GESTimeline to set on the @pipeline.
  *
  * Sets the timeline to use in this pipeline.
  *
@@ -1196,7 +1196,7 @@ ges_pipeline_set_mode (GESPipeline * pipeline, GESPipelineFlags mode)
  * is currently used by the sink. This information can be retrieve from caps
  * associated with the buffer.
  *
- * Returns: (transfer full): a #GstSample or %NULL
+ * Returns: (transfer full) (nullable): a #GstSample or %NULL
  */
 
 GstSample *
@@ -1284,11 +1284,11 @@ ges_pipeline_save_thumbnail (GESPipeline * self, int width, int
  * and height. If -1 is specified for either dimension, it will be left at
  * native size. You can retreive this information from the caps associated
  * with the buffer.
- * 
+ *
  * The caller is responsible for unreffing the returned sample with
  * #gst_sample_unref.
  *
- * Returns: (transfer full): a #GstSample or %NULL
+ * Returns: (transfer full) (nullable): a #GstSample or %NULL
  */
 
 GstSample *

ges/ges-project.c

@@ -732,7 +732,7 @@ ges_project_create_asset (GESProject * project, const gchar * id,
  * "asset-added" signal to get the asset when it finally gets added to
  * @project
  *
- * Returns: (transfer full): The newly created #GESAsset
+ * Returns: (transfer full) (nullable): The newly created #GESAsset or %NULL.
  */
 GESAsset *
 ges_project_create_asset_sync (GESProject * project, const gchar * id,

ges/ges-test-clip.c

@@ -358,8 +358,8 @@ ges_test_clip_create_track_element (GESClip * clip, GESTrackType type)
  *
  * Creates a new #GESTestClip.
  *
- * Returns: The newly created #GESTestClip, or NULL if there was an
- * error.
+ * Returns: (transfer floating) (nullable): The newly created #GESTestClip,
+ * or %NULL if there was an error.
  */
 GESTestClip *
 ges_test_clip_new (void)
@@ -379,8 +379,8 @@ ges_test_clip_new (void)
  *
  * Creates a new #GESTestClip for the provided @nick.
  *
- * Returns: The newly created #GESTestClip, or NULL if there was an
- * error.
+ * Returns: (transfer floating) (nullable): The newly created #GESTestClip,
+ * or %NULL if there was an error.
  */
 GESTestClip *
 ges_test_clip_new_for_nick (gchar * nick)

ges/ges-text-overlay-clip.c

@@ -38,7 +38,6 @@ G_DEFINE_TYPE (GESTextOverlayClip, ges_text_overlay_clip,
 #define DEFAULT_PROP_FONT_DESC "Serif 36"
 #define DEFAULT_PROP_VALIGNMENT GES_TEXT_VALIGN_BASELINE
 #define DEFAULT_PROP_HALIGNMENT GES_TEXT_HALIGN_CENTER
-#
 
 struct _GESTextOverlayClipPrivate
 {
@@ -583,8 +582,8 @@ ges_text_overlay_clip_create_track_element (GESClip * clip, GESTrackType type)
  *
  * Creates a new #GESTextOverlayClip
  *
- * Returns: The newly created #GESTextOverlayClip, or NULL if there was an
- * error.
+ * Returns: (transfer floating) (nullable): The newly created
+ * #GESTextOverlayClip, or %NULL if there was an error.
  */
 GESTextOverlayClip *
 ges_text_overlay_clip_new (void)

ges/ges-text-overlay.c

@@ -425,8 +425,8 @@ ges_text_overlay_get_ypos (GESTextOverlay * self)
  *
  * Creates a new #GESTextOverlay.
  *
- * Returns: The newly created #GESTextOverlay or %NULL if something went
- * wrong.
+ * Returns: (transfer floating) (nullable): The newly created #GESTextOverlay or
+ * %NULL if something went wrong.
  */
 GESTextOverlay *
 ges_text_overlay_new (void)

ges/ges-timeline-element.c

@@ -553,8 +553,8 @@ had_parent:
  * Returns the parent of @self. This function increases the refcount
  * of the parent object so you should gst_object_unref() it after usage.
  *
- * Returns: (transfer full): parent of @self, this can be %NULL if @self
- *   has no parent. unref after usage.
+ * Returns: (transfer full) (nullable): parent of @self, this can be %NULL if
+ * @self has no parent. unref after usage.
  */
 GESTimelineElement *
 ges_timeline_element_get_parent (GESTimelineElement * self)
@@ -629,8 +629,8 @@ had_timeline:
  * Returns the timeline of @self. This function increases the refcount
  * of the timeline so you should gst_object_unref() it after usage.
  *
- * Returns: (transfer full): timeline of @self, this can be %NULL if @self
- *   has no timeline. unref after usage.
+ * Returns: (transfer full) (nullable): timeline of @self, this can be %NULL if
+ * @self has no timeline. unref after usage.
  */
 GESTimeline *
 ges_timeline_element_get_timeline (GESTimelineElement * self)