gboolean gst_control_source_get_value_array (GstControlSource *self, GstClockTime timestamp,
GstClockTime interval, guint n_values,
gdouble *values);
gboolean gst_control_source_get_value_array (GstControlSource *self, GstClockTime timestamp,
GstClockTime interval, guint n_values,
gdouble *values);