+
+/* controller helper functions */
+
+/*
+ * gst_object_find_control_binding:
+ * @self: the gobject to search for a property in
+ * @name: the gobject property name to look for
+ *
+ * Searches the list of properties under control.
+ *
+ * Returns: a #GstControlBinding or %NULL if the property is not being
+ * controlled.
+ */
+static GstControlBinding *
+gst_object_find_control_binding (GstObject * self, const gchar * name)
+{
+ GstControlBinding *binding;
+ GList *node;
+
+ for (node = self->control_bindings; node; node = g_list_next (node)) {
+ binding = node->data;
+ /* FIXME: eventually use GQuark to speed it up */
+ if (!strcmp (binding->name, name)) {
+ GST_DEBUG_OBJECT (self, "found control binding for property '%s'", name);
+ return binding;
+ }
+ }
+ GST_DEBUG_OBJECT (self, "controller does not manage property '%s'", name);
+
+ return NULL;
+}
+
+/* controller functions */
+
+/**
+ * gst_object_suggest_next_sync:
+ * @object: the object that has controlled properties
+ *
+ * Returns a suggestion for timestamps where buffers should be split
+ * to get best controller results.
+ *
+ * Returns: Returns the suggested timestamp or %GST_CLOCK_TIME_NONE
+ * if no control-rate was set.
+ */
+GstClockTime
+gst_object_suggest_next_sync (GstObject * object)
+{
+ GstClockTime ret;
+
+ g_return_val_if_fail (GST_IS_OBJECT (object), GST_CLOCK_TIME_NONE);
+ g_return_val_if_fail (object->control_rate != GST_CLOCK_TIME_NONE,
+ GST_CLOCK_TIME_NONE);
+
+ GST_OBJECT_LOCK (object);
+
+ /* TODO: Implement more logic, depending on interpolation mode and control
+ * points
+ * FIXME: we need playback direction
+ */
+ ret = object->last_sync + object->control_rate;
+
+ GST_OBJECT_UNLOCK (object);
+
+ return ret;
+}
+
+/**
+ * gst_object_sync_values:
+ * @object: the object that has controlled properties
+ * @timestamp: the time that should be processed
+ *
+ * Sets the properties of the object, according to the #GstControlSources that
+ * (maybe) handle them and for the given timestamp.
+ *
+ * If this function fails, it is most likely the application developers fault.
+ * Most probably the control sources are not setup correctly.
+ *
+ * Returns: %TRUE if the controller values could be applied to the object
+ * properties, %FALSE otherwise
+ */
+gboolean
+gst_object_sync_values (GstObject * object, GstClockTime timestamp)
+{
+ GList *node;
+ gboolean ret = TRUE;
+
+ g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
+ g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), FALSE);
+
+ GST_LOG_OBJECT (object, "sync_values");
+ if (!object->control_bindings)
+ return TRUE;
+
+ /* FIXME: this deadlocks */
+ /* GST_OBJECT_LOCK (object); */
+ g_object_freeze_notify ((GObject *) object);
+ for (node = object->control_bindings; node; node = g_list_next (node)) {
+ ret &= gst_control_binding_sync_values ((GstControlBinding *) node->data,
+ object, timestamp, object->last_sync);
+ }
+ object->last_sync = timestamp;
+ g_object_thaw_notify ((GObject *) object);
+ /* GST_OBJECT_UNLOCK (object); */
+
+ return ret;
+}
+
+
+/**
+ * gst_object_has_active_control_bindings:
+ * @object: the object that has controlled properties
+ *
+ * Check if the @object has an active controlled properties.
+ *
+ * Returns: %TRUE if the object has active controlled properties
+ */
+gboolean
+gst_object_has_active_control_bindings (GstObject * object)
+{
+ gboolean res = FALSE;
+ GList *node;
+
+ g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
+
+ GST_OBJECT_LOCK (object);
+ for (node = object->control_bindings; node; node = g_list_next (node)) {
+ res |= !gst_control_binding_is_disabled ((GstControlBinding *) node->data);
+ }
+ GST_OBJECT_UNLOCK (object);
+ return res;
+}
+
+/**
+ * gst_object_set_control_bindings_disabled:
+ * @object: the object that has controlled properties
+ * @disabled: boolean that specifies whether to disable the controller
+ * or not.
+ *
+ * This function is used to disable all controlled properties of the @object for
+ * some time, i.e. gst_object_sync_values() will do nothing.
+ */
+void
+gst_object_set_control_bindings_disabled (GstObject * object, gboolean disabled)
+{
+ GList *node;
+
+ g_return_if_fail (GST_IS_OBJECT (object));
+
+ GST_OBJECT_LOCK (object);
+ for (node = object->control_bindings; node; node = g_list_next (node)) {
+ gst_control_binding_set_disabled ((GstControlBinding *) node->data,
+ disabled);
+ }
+ GST_OBJECT_UNLOCK (object);
+}
+
+/**
+ * gst_object_set_control_binding_disabled:
+ * @object: the object that has controlled properties
+ * @property_name: property to disable
+ * @disabled: boolean that specifies whether to disable the controller
+ * or not.
+ *
+ * This function is used to disable the #GstController on a property for
+ * some time, i.e. gst_controller_sync_values() will do nothing for the
+ * property.
+ */
+void
+gst_object_set_control_binding_disabled (GstObject * object,
+ const gchar * property_name, gboolean disabled)
+{
+ GstControlBinding *binding;
+
+ g_return_if_fail (GST_IS_OBJECT (object));
+ g_return_if_fail (property_name);
+
+ GST_OBJECT_LOCK (object);
+ if ((binding = gst_object_find_control_binding (object, property_name))) {
+ gst_control_binding_set_disabled (binding, disabled);
+ }
+ GST_OBJECT_UNLOCK (object);
+}
+
+
+/**
+ * gst_object_add_control_binding:
+ * @object: the controller object
+ * @binding: (transfer full): the #GstControlBinding that should be used
+ *
+ * Sets the #GstControlBinding. If there already was a #GstControlBinding
+ * for this property it will be replaced.
+ * The @object will take ownership of the @binding.
+ *
+ * Returns: %FALSE if the given @binding has not been setup for this object or
+ * %TRUE otherwise.
+ */
+gboolean
+gst_object_add_control_binding (GstObject * object, GstControlBinding * binding)
+{
+ GstControlBinding *old;
+
+ g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
+ g_return_val_if_fail (GST_IS_CONTROL_BINDING (binding), FALSE);
+ //g_return_val_if_fail (g_type_is_a (binding->pspec->owner_type,
+ // G_OBJECT_TYPE (object)), FALSE);
+
+ GST_OBJECT_LOCK (object);
+ if ((old = gst_object_find_control_binding (object, binding->name))) {
+ GST_DEBUG_OBJECT (object, "controlled property %s removed", old->name);
+ object->control_bindings = g_list_remove (object->control_bindings, old);
+ gst_object_unparent (GST_OBJECT_CAST (old));
+ }
+ object->control_bindings = g_list_prepend (object->control_bindings, binding);
+ gst_object_set_parent (GST_OBJECT_CAST (binding), object);
+ GST_DEBUG_OBJECT (object, "controlled property %s added", binding->name);
+ GST_OBJECT_UNLOCK (object);
+
+ return TRUE;
+}
+
+/**
+ * gst_object_get_control_binding:
+ * @object: the object
+ * @property_name: name of the property
+ *
+ * Gets the corresponding #GstControlBinding for the property. This should be
+ * unreferenced again after use.
+ *
+ * Returns: (transfer full): the #GstControlBinding for @property_name or %NULL if
+ * the property is not controlled.
+ */
+GstControlBinding *
+gst_object_get_control_binding (GstObject * object, const gchar * property_name)
+{
+ GstControlBinding *binding;
+
+ g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
+ g_return_val_if_fail (property_name, NULL);
+
+ GST_OBJECT_LOCK (object);
+ if ((binding = gst_object_find_control_binding (object, property_name))) {
+ g_object_ref (binding);
+ }
+ GST_OBJECT_UNLOCK (object);
+
+ return binding;
+}
+
+/**
+ * gst_object_remove_control_binding:
+ * @object: the object
+ * @binding: the binding
+ *
+ * Removes the corresponding #GstControlBinding. If it was the
+ * last ref of the binding, it will be disposed.
+ *
+ * Returns: %TRUE if the binding could be removed.
+ */
+gboolean
+gst_object_remove_control_binding (GstObject * object,
+ GstControlBinding * binding)
+{
+ GList *node;
+ gboolean ret = FALSE;
+
+ g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
+ g_return_val_if_fail (GST_IS_CONTROL_BINDING (binding), FALSE);
+
+ GST_OBJECT_LOCK (object);
+ if ((node = g_list_find (object->control_bindings, binding))) {
+ GST_DEBUG_OBJECT (object, "controlled property %s removed", binding->name);
+ object->control_bindings =
+ g_list_delete_link (object->control_bindings, node);
+ gst_object_unparent (GST_OBJECT_CAST (binding));
+ ret = TRUE;
+ }
+ GST_OBJECT_UNLOCK (object);
+
+ return ret;
+}
+
+/**
+ * gst_object_get_value:
+ * @object: the object that has controlled properties
+ * @property_name: the name of the property to get
+ * @timestamp: the time the control-change should be read from
+ *
+ * Gets the value for the given controlled property at the requested time.
+ *
+ * Returns: the GValue of the property at the given time, or %NULL if the
+ * property isn't controlled.
+ */
+GValue *
+gst_object_get_value (GstObject * object, const gchar * property_name,
+ GstClockTime timestamp)
+{
+ GstControlBinding *binding;
+ GValue *val = NULL;
+
+ g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
+ g_return_val_if_fail (property_name, NULL);
+ g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), NULL);
+
+ GST_OBJECT_LOCK (object);
+ if ((binding = gst_object_find_control_binding (object, property_name))) {
+ val = gst_control_binding_get_value (binding, timestamp);
+ }
+ GST_OBJECT_UNLOCK (object);
+
+ return val;
+}
+
+/**
+ * gst_object_get_value_array:
+ * @object: the object that has controlled properties
+ * @property_name: the name of the property to get
+ * @timestamp: the time that should be processed
+ * @interval: the time spacing between subsequent values
+ * @n_values: the number of values
+ * @values: array to put control-values in
+ *
+ * Gets a number of values for the given controllered property starting at the
+ * requested time. The array @values need to hold enough space for @n_values of
+ * the same type as the objects property's type.
+ *
+ * This function is useful if one wants to e.g. draw a graph of the control
+ * curve or apply a control curve sample by sample.
+ *
+ * Returns: %TRUE if the given array could be filled, %FALSE otherwise
+ */
+gboolean
+gst_object_get_value_array (GstObject * object, const gchar * property_name,
+ GstClockTime timestamp, GstClockTime interval, guint n_values,
+ GValue * values)
+{
+ gboolean res = FALSE;
+ GstControlBinding *binding;
+
+ g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
+ g_return_val_if_fail (property_name, FALSE);
+ g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), FALSE);
+ g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (interval), FALSE);
+ g_return_val_if_fail (values, FALSE);
+
+ GST_OBJECT_LOCK (object);
+ if ((binding = gst_object_find_control_binding (object, property_name))) {
+ res = gst_control_binding_get_value_array (binding, timestamp, interval,
+ n_values, values);
+ }
+ GST_OBJECT_UNLOCK (object);
+ return res;
+}
+
+
+/**
+ * gst_object_get_control_rate:
+ * @object: the object that has controlled properties
+ *
+ * Obtain the control-rate for this @object. Audio processing #GstElement
+ * objects will use this rate to sub-divide their processing loop and call
+ * gst_object_sync_values() inbetween. The length of the processing segment
+ * should be up to @control-rate nanoseconds.
+ *
+ * If the @object is not under property control, this will return
+ * %GST_CLOCK_TIME_NONE. This allows the element to avoid the sub-dividing.
+ *
+ * The control-rate is not expected to change if the element is in
+ * %GST_STATE_PAUSED or %GST_STATE_PLAYING.
+ *
+ * Returns: the control rate in nanoseconds
+ */
+GstClockTime
+gst_object_get_control_rate (GstObject * object)
+{
+ g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
+
+ return object->control_rate;
+}
+
+/**
+ * gst_object_set_control_rate:
+ * @object: the object that has controlled properties
+ * @control_rate: the new control-rate in nanoseconds.
+ *
+ * Change the control-rate for this @object. Audio processing #GstElement
+ * objects will use this rate to sub-divide their processing loop and call
+ * gst_object_sync_values() inbetween. The length of the processing segment
+ * should be up to @control-rate nanoseconds.
+ *
+ * The control-rate should not change if the element is in %GST_STATE_PAUSED or
+ * %GST_STATE_PLAYING.
+ */
+void
+gst_object_set_control_rate (GstObject * object, GstClockTime control_rate)
+{
+ g_return_if_fail (GST_IS_OBJECT (object));
+
+ object->control_rate = control_rate;
+}