2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2000 Wim Taymans <wtay@chello.be>
4 * 2005 Wim Taymans <wim@fluendo.com>
6 * gstobject.c: Fundamental class used for all of GStreamer
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Library General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Library General Public License for more details.
18 * You should have received a copy of the GNU Library General Public
19 * License along with this library; if not, write to the
20 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
21 * Boston, MA 02111-1307, USA.
26 * @short_description: Base class for the GStreamer object hierarchy
28 * #GstObject provides a root for the object hierarchy tree filed in by the
29 * GStreamer library. It is currently a thin wrapper on top of
30 * #GInitiallyUnowned. It is an abstract class that is not very usable on its own.
32 * #GstObject gives us basic refcounting, parenting functionality and locking.
33 * Most of the function are just extended for special GStreamer needs and can be
34 * found under the same name in the base class of #GstObject which is #GObject
35 * (e.g. g_object_ref() becomes gst_object_ref()).
37 * Since #GstObject dereives from #GInitiallyUnowned, it also inherits the
38 * floating reference. Be aware that functions such as gst_bin_add() and
39 * gst_element_add_pad() take ownership of the floating reference.
41 * In contrast to #GObject instances, #GstObject adds a name property. The functions
42 * gst_object_set_name() and gst_object_get_name() are used to set/get the name
46 * <title>controlled properties</title>
48 * Controlled properties offers a lightweight way to adjust gobject
49 * properties over stream-time. It works by using time-stamped value pairs that
50 * are queued for element-properties. At run-time the elements continously pull
51 * values changes for the current stream-time.
53 * What needs to be changed in a #GstElement?
54 * Very little - it is just two steps to make a plugin controllable!
57 * mark gobject-properties paramspecs that make sense to be controlled,
58 * by GST_PARAM_CONTROLLABLE.
61 * when processing data (get, chain, loop function) at the beginning call
62 * gst_object_sync_values(element,timestamp).
63 * This will made the controller to update all gobject properties that are under
64 * control with the current values based on timestamp.
68 * What needs to be done in applications?
69 * Again its not a lot to change.
72 * first put some properties under control, by calling
73 * gst_object_control_properties (object, "prop1", "prop2",...);
76 * create a #GstControlSource.
77 * csource = gst_interpolation_control_source_new ();
78 * g_object_set (csource, "mode", GST_INTERPOLATION_MODE_LINEAR, NULL);
81 * Attach the #GstControlSource on the controller to a property.
82 * gst_object_add_control_binding (object, gst_direct_control_binding_new (objetct, "prop1", csource));
85 * Set the control values
86 * gst_timed_value_control_source_set ((GstTimedValueControlSource *)csource,0 * GST_SECOND, value1);
87 * gst_timed_value_control_source_set ((GstTimedValueControlSource *)csource,1 * GST_SECOND, value2);
96 * Last reviewed on 2012-03-29 (0.11.3)
99 #include "gst_private.h"
100 #include "glib-compat-private.h"
102 #include "gstobject.h"
103 #include "gstclock.h"
104 #include "gstcontrolbinding.h"
105 #include "gstcontrolsource.h"
107 #include "gstparamspecs.h"
108 #include "gstutils.h"
110 #ifndef GST_DISABLE_TRACE
111 #include "gsttrace.h"
112 static GstAllocTrace *_gst_object_trace;
115 #define DEBUG_REFCOUNT
117 /* Object signals and args */
138 /* maps type name quark => count */
139 static GData *object_name_counts = NULL;
141 G_LOCK_DEFINE_STATIC (object_name_mutex);
143 static void gst_object_set_property (GObject * object, guint prop_id,
144 const GValue * value, GParamSpec * pspec);
145 static void gst_object_get_property (GObject * object, guint prop_id,
146 GValue * value, GParamSpec * pspec);
148 static void gst_object_dispatch_properties_changed (GObject * object,
149 guint n_pspecs, GParamSpec ** pspecs);
151 static void gst_object_dispose (GObject * object);
152 static void gst_object_finalize (GObject * object);
154 static gboolean gst_object_set_name_default (GstObject * object);
156 static guint gst_object_signals[LAST_SIGNAL] = { 0 };
158 static GParamSpec *properties[PROP_LAST];
160 G_DEFINE_ABSTRACT_TYPE (GstObject, gst_object, G_TYPE_INITIALLY_UNOWNED);
163 gst_object_class_init (GstObjectClass * klass)
165 GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
167 #ifndef GST_DISABLE_TRACE
169 _gst_alloc_trace_register (g_type_name (GST_TYPE_OBJECT), -2);
172 gobject_class->set_property = gst_object_set_property;
173 gobject_class->get_property = gst_object_get_property;
175 properties[PROP_NAME] =
176 g_param_spec_string ("name", "Name", "The name of the object", NULL,
177 G_PARAM_READWRITE | G_PARAM_CONSTRUCT | G_PARAM_STATIC_STRINGS);
179 properties[PROP_PARENT] =
180 g_param_spec_object ("parent", "Parent", "The parent of the object",
181 GST_TYPE_OBJECT, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);
183 g_object_class_install_properties (gobject_class, PROP_LAST, properties);
186 * GstObject::deep-notify:
187 * @gstobject: a #GstObject
188 * @prop_object: the object that originated the signal
189 * @prop: the property that changed
191 * The deep notify signal is used to be notified of property changes. It is
192 * typically attached to the toplevel bin to receive notifications from all
193 * the elements contained in that bin.
195 gst_object_signals[DEEP_NOTIFY] =
196 g_signal_new ("deep-notify", G_TYPE_FROM_CLASS (klass),
197 G_SIGNAL_RUN_FIRST | G_SIGNAL_NO_RECURSE | G_SIGNAL_DETAILED |
198 G_SIGNAL_NO_HOOKS, G_STRUCT_OFFSET (GstObjectClass, deep_notify), NULL,
199 NULL, g_cclosure_marshal_generic, G_TYPE_NONE, 2, GST_TYPE_OBJECT,
202 klass->path_string_separator = "/";
204 /* see the comments at gst_object_dispatch_properties_changed */
205 gobject_class->dispatch_properties_changed
206 = GST_DEBUG_FUNCPTR (gst_object_dispatch_properties_changed);
208 gobject_class->dispose = gst_object_dispose;
209 gobject_class->finalize = gst_object_finalize;
213 gst_object_init (GstObject * object)
215 g_mutex_init (&object->lock);
216 object->parent = NULL;
218 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p new", object);
220 #ifndef GST_DISABLE_TRACE
221 _gst_alloc_trace_new (_gst_object_trace, object);
226 object->control_rate = 100 * GST_MSECOND;
227 object->last_sync = GST_CLOCK_TIME_NONE;
232 * @object: (type Gst.Object): a #GstObject to reference
234 * Increments the reference count on @object. This function
235 * does not take the lock on @object because it relies on
236 * atomic refcounting.
238 * This object returns the input parameter to ease writing
240 * result = gst_object_ref (object->parent);
242 * Returns: (transfer full) (type Gst.Object): A pointer to @object
245 gst_object_ref (gpointer object)
247 g_return_val_if_fail (object != NULL, NULL);
249 #ifdef DEBUG_REFCOUNT
250 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p ref %d->%d", object,
251 ((GObject *) object)->ref_count, ((GObject *) object)->ref_count + 1);
253 g_object_ref (object);
260 * @object: (type Gst.Object): a #GstObject to unreference
262 * Decrements the reference count on @object. If reference count hits
263 * zero, destroy @object. This function does not take the lock
264 * on @object as it relies on atomic refcounting.
266 * The unref method should never be called with the LOCK held since
267 * this might deadlock the dispose function.
270 gst_object_unref (gpointer object)
272 g_return_if_fail (object != NULL);
273 g_return_if_fail (((GObject *) object)->ref_count > 0);
275 #ifdef DEBUG_REFCOUNT
276 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p unref %d->%d", object,
277 ((GObject *) object)->ref_count, ((GObject *) object)->ref_count - 1);
279 g_object_unref (object);
283 * gst_object_ref_sink: (skip)
284 * @object: a #GstObject to sink
286 * Increase the reference count of @object, and possibly remove the floating
287 * reference, if @object has a floating reference.
289 * In other words, if the object is floating, then this call "assumes ownership"
290 * of the floating reference, converting it to a normal reference by clearing
291 * the floating flag while leaving the reference count unchanged. If the object
292 * is not floating, then this call adds a new normal reference increasing the
293 * reference count by one.
296 gst_object_ref_sink (gpointer object)
298 g_return_val_if_fail (object != NULL, NULL);
300 #ifdef DEBUG_REFCOUNT
301 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p ref_sink %d->%d",
302 object, ((GObject *) object)->ref_count,
303 ((GObject *) object)->ref_count + 1);
305 return g_object_ref_sink (object);
309 * gst_object_replace:
310 * @oldobj: (inout) (transfer full): pointer to a place of a #GstObject to
312 * @newobj: (transfer none): a new #GstObject
314 * Atomically modifies a pointer to point to a new object.
315 * The reference count of @oldobj is decreased and the reference count of
316 * @newobj is increased.
318 * Either @newobj and the value pointed to by @oldobj may be NULL.
320 * Returns: TRUE if @newobj was different from @oldobj
323 gst_object_replace (GstObject ** oldobj, GstObject * newobj)
327 g_return_val_if_fail (oldobj != NULL, FALSE);
329 #ifdef DEBUG_REFCOUNT
330 GST_CAT_TRACE (GST_CAT_REFCOUNTING, "replace %p %s (%d) with %p %s (%d)",
331 *oldobj, *oldobj ? GST_STR_NULL (GST_OBJECT_NAME (*oldobj)) : "(NONE)",
332 *oldobj ? G_OBJECT (*oldobj)->ref_count : 0,
333 newobj, newobj ? GST_STR_NULL (GST_OBJECT_NAME (newobj)) : "(NONE)",
334 newobj ? G_OBJECT (newobj)->ref_count : 0);
337 oldptr = g_atomic_pointer_get ((gpointer *) oldobj);
339 if (G_UNLIKELY (oldptr == newobj))
343 gst_object_ref (newobj);
345 while (G_UNLIKELY (!g_atomic_pointer_compare_and_exchange ((gpointer *)
346 oldobj, oldptr, newobj))) {
347 oldptr = g_atomic_pointer_get ((gpointer *) oldobj);
348 if (G_UNLIKELY (oldptr == newobj))
353 gst_object_unref (oldptr);
355 return oldptr != newobj;
358 /* dispose is called when the object has to release all links
359 * to other objects */
361 gst_object_dispose (GObject * object)
363 GstObject *self = (GstObject *) object;
366 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "dispose");
368 GST_OBJECT_LOCK (object);
369 if ((parent = GST_OBJECT_PARENT (object)))
371 GST_OBJECT_PARENT (object) = NULL;
372 GST_OBJECT_UNLOCK (object);
374 if (self->control_bindings) {
377 for (node = self->control_bindings; node; node = g_list_next (node)) {
378 gst_object_unparent (node->data);
380 g_list_free (self->control_bindings);
381 self->control_bindings = NULL;
384 ((GObjectClass *) gst_object_parent_class)->dispose (object);
391 g_critical ("\nTrying to dispose object \"%s\", but it still has a "
392 "parent \"%s\".\nYou need to let the parent manage the "
393 "object instead of unreffing the object directly.\n",
394 GST_OBJECT_NAME (object), GST_OBJECT_NAME (parent));
395 GST_OBJECT_UNLOCK (object);
396 /* ref the object again to revive it in this error case */
397 gst_object_ref (object);
402 /* finalize is called when the object has to free its resources */
404 gst_object_finalize (GObject * object)
406 GstObject *gstobject = GST_OBJECT_CAST (object);
408 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "finalize");
410 g_signal_handlers_destroy (object);
412 g_free (gstobject->name);
413 g_mutex_clear (&gstobject->lock);
415 #ifndef GST_DISABLE_TRACE
416 _gst_alloc_trace_free (_gst_object_trace, object);
419 ((GObjectClass *) gst_object_parent_class)->finalize (object);
422 /* Changing a GObject property of a GstObject will result in "deep-notify"
423 * signals being emitted by the object itself, as well as in each parent
424 * object. This is so that an application can connect a listener to the
425 * top-level bin to catch property-change notifications for all contained
431 gst_object_dispatch_properties_changed (GObject * object,
432 guint n_pspecs, GParamSpec ** pspecs)
434 GstObject *gst_object, *parent, *old_parent;
436 #ifndef GST_DISABLE_GST_DEBUG
438 const gchar *debug_name;
441 /* do the standard dispatching */
443 gst_object_parent_class)->dispatch_properties_changed (object, n_pspecs,
446 gst_object = GST_OBJECT_CAST (object);
447 #ifndef GST_DISABLE_GST_DEBUG
448 if (G_UNLIKELY (_gst_debug_min >= GST_LEVEL_LOG)) {
449 name = gst_object_get_name (gst_object);
450 debug_name = GST_STR_NULL (name);
455 /* now let the parent dispatch those, too */
456 parent = gst_object_get_parent (gst_object);
458 for (i = 0; i < n_pspecs; i++) {
459 GST_CAT_LOG_OBJECT (GST_CAT_PROPERTIES, parent,
460 "deep notification from %s (%s)", debug_name, pspecs[i]->name);
462 g_signal_emit (parent, gst_object_signals[DEEP_NOTIFY],
463 g_quark_from_string (pspecs[i]->name), gst_object, pspecs[i]);
467 parent = gst_object_get_parent (old_parent);
468 gst_object_unref (old_parent);
470 #ifndef GST_DISABLE_GST_DEBUG
476 * gst_object_default_deep_notify:
477 * @object: the #GObject that signalled the notify.
478 * @orig: a #GstObject that initiated the notify.
479 * @pspec: a #GParamSpec of the property.
480 * @excluded_props: (array zero-terminated=1) (element-type gchar*)
481 * (allow-none): a set of user-specified properties to exclude or
482 * NULL to show all changes.
484 * A default deep_notify signal callback for an object. The user data
485 * should contain a pointer to an array of strings that should be excluded
486 * from the notify. The default handler will print the new value of the property
489 * MT safe. This function grabs and releases @object's LOCK for getting its
493 gst_object_default_deep_notify (GObject * object, GstObject * orig,
494 GParamSpec * pspec, gchar ** excluded_props)
496 GValue value = { 0, }; /* the important thing is that value.type = 0 */
500 if (pspec->flags & G_PARAM_READABLE) {
501 /* let's not print these out for excluded properties... */
502 while (excluded_props != NULL && *excluded_props != NULL) {
503 if (strcmp (pspec->name, *excluded_props) == 0)
507 g_value_init (&value, pspec->value_type);
508 g_object_get_property (G_OBJECT (orig), pspec->name, &value);
510 if (G_VALUE_HOLDS_STRING (&value))
511 str = g_value_dup_string (&value);
513 str = gst_value_serialize (&value);
514 name = gst_object_get_path_string (orig);
515 g_print ("%s: %s = %s\n", name, pspec->name, str);
518 g_value_unset (&value);
520 name = gst_object_get_path_string (orig);
521 g_warning ("Parameter %s not readable in %s.", pspec->name, name);
527 gst_object_set_name_default (GstObject * object)
529 const gchar *type_name;
535 /* to ensure guaranteed uniqueness across threads, only one thread
536 * may ever assign a name */
537 G_LOCK (object_name_mutex);
539 if (!object_name_counts) {
540 g_datalist_init (&object_name_counts);
543 q = g_type_qname (G_OBJECT_TYPE (object));
544 count = GPOINTER_TO_INT (g_datalist_id_get_data (&object_name_counts, q));
545 g_datalist_id_set_data (&object_name_counts, q, GINT_TO_POINTER (count + 1));
547 G_UNLOCK (object_name_mutex);
549 /* GstFooSink -> foosink<N> */
550 type_name = g_quark_to_string (q);
551 if (strncmp (type_name, "Gst", 3) == 0)
553 /* give the 20th "queue" element and the first "queue2" different names */
554 l = strlen (type_name);
555 if (l > 0 && g_ascii_isdigit (type_name[l - 1])) {
556 name = g_strdup_printf ("%s-%d", type_name, count);
558 name = g_strdup_printf ("%s%d", type_name, count);
562 for (i = 0; i < l; i++)
563 name[i] = g_ascii_tolower (name[i]);
565 GST_OBJECT_LOCK (object);
566 if (G_UNLIKELY (object->parent != NULL))
569 g_free (object->name);
572 GST_OBJECT_UNLOCK (object);
579 GST_WARNING ("parented objects can't be renamed");
580 GST_OBJECT_UNLOCK (object);
586 * gst_object_set_name:
587 * @object: a #GstObject
588 * @name: new name of object
590 * Sets the name of @object, or gives @object a guaranteed unique
591 * name (if @name is NULL).
592 * This function makes a copy of the provided name, so the caller
593 * retains ownership of the name it sent.
595 * Returns: TRUE if the name could be set. Since Objects that have
596 * a parent cannot be renamed, this function returns FALSE in those
599 * MT safe. This function grabs and releases @object's LOCK.
602 gst_object_set_name (GstObject * object, const gchar * name)
606 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
608 GST_OBJECT_LOCK (object);
610 /* parented objects cannot be renamed */
611 if (G_UNLIKELY (object->parent != NULL))
615 g_free (object->name);
616 object->name = g_strdup (name);
617 GST_OBJECT_UNLOCK (object);
620 GST_OBJECT_UNLOCK (object);
621 result = gst_object_set_name_default (object);
623 /* FIXME-0.11: this misses a g_object_notify (object, "name"); unless called
624 * from gst_object_set_property.
625 * Ideally remove such custom setters (or make it static).
632 GST_WARNING ("parented objects can't be renamed");
633 GST_OBJECT_UNLOCK (object);
639 * gst_object_get_name:
640 * @object: a #GstObject
642 * Returns a copy of the name of @object.
643 * Caller should g_free() the return value after usage.
644 * For a nameless object, this returns NULL, which you can safely g_free()
647 * Free-function: g_free
649 * Returns: (transfer full): the name of @object. g_free() after usage.
651 * MT safe. This function grabs and releases @object's LOCK.
654 gst_object_get_name (GstObject * object)
656 gchar *result = NULL;
658 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
660 GST_OBJECT_LOCK (object);
661 result = g_strdup (object->name);
662 GST_OBJECT_UNLOCK (object);
668 * gst_object_set_parent:
669 * @object: a #GstObject
670 * @parent: new parent of object
672 * Sets the parent of @object to @parent. The object's reference count will
673 * be incremented, and any floating reference will be removed (see gst_object_ref_sink()).
675 * Returns: TRUE if @parent could be set or FALSE when @object
676 * already had a parent or @object and @parent are the same.
678 * MT safe. Grabs and releases @object's LOCK.
681 gst_object_set_parent (GstObject * object, GstObject * parent)
683 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
684 g_return_val_if_fail (GST_IS_OBJECT (parent), FALSE);
685 g_return_val_if_fail (object != parent, FALSE);
687 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object,
688 "set parent (ref and sink)");
690 GST_OBJECT_LOCK (object);
691 if (G_UNLIKELY (object->parent != NULL))
694 object->parent = parent;
695 gst_object_ref_sink (object);
696 GST_OBJECT_UNLOCK (object);
698 /* FIXME, this does not work, the deep notify takes the lock from the parent
699 * object and deadlocks when the parent holds its lock when calling this
700 * function (like _element_add_pad()) */
701 /* g_object_notify_by_pspec ((GObject *)object, properties[PROP_PARENT]); */
708 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object,
709 "set parent failed, object already had a parent");
710 GST_OBJECT_UNLOCK (object);
716 * gst_object_get_parent:
717 * @object: a #GstObject
719 * Returns the parent of @object. This function increases the refcount
720 * of the parent object so you should gst_object_unref() it after usage.
722 * Returns: (transfer full): parent of @object, this can be NULL if @object
723 * has no parent. unref after usage.
725 * MT safe. Grabs and releases @object's LOCK.
728 gst_object_get_parent (GstObject * object)
730 GstObject *result = NULL;
732 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
734 GST_OBJECT_LOCK (object);
735 result = object->parent;
736 if (G_LIKELY (result))
737 gst_object_ref (result);
738 GST_OBJECT_UNLOCK (object);
744 * gst_object_unparent:
745 * @object: a #GstObject to unparent
747 * Clear the parent of @object, removing the associated reference.
748 * This function decreases the refcount of @object.
750 * MT safe. Grabs and releases @object's lock.
753 gst_object_unparent (GstObject * object)
757 g_return_if_fail (GST_IS_OBJECT (object));
759 GST_OBJECT_LOCK (object);
760 parent = object->parent;
762 if (G_LIKELY (parent != NULL)) {
763 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "unparent");
764 object->parent = NULL;
765 GST_OBJECT_UNLOCK (object);
767 /* g_object_notify_by_pspec ((GObject *)object, properties[PROP_PARENT]); */
769 gst_object_unref (object);
771 GST_OBJECT_UNLOCK (object);
776 * gst_object_has_ancestor:
777 * @object: a #GstObject to check
778 * @ancestor: a #GstObject to check as ancestor
780 * Check if @object has an ancestor @ancestor somewhere up in
781 * the hierarchy. One can e.g. check if a #GstElement is inside a #GstPipeline.
783 * Returns: TRUE if @ancestor is an ancestor of @object.
785 * MT safe. Grabs and releases @object's locks.
788 gst_object_has_ancestor (GstObject * object, GstObject * ancestor)
790 GstObject *parent, *tmp;
792 if (!ancestor || !object)
795 parent = gst_object_ref (object);
797 if (parent == ancestor) {
798 gst_object_unref (parent);
802 tmp = gst_object_get_parent (parent);
803 gst_object_unref (parent);
811 * gst_object_check_uniqueness:
812 * @list: (transfer none) (element-type Gst.Object): a list of #GstObject to
814 * @name: the name to search for
816 * Checks to see if there is any object named @name in @list. This function
817 * does not do any locking of any kind. You might want to protect the
818 * provided list with the lock of the owner of the list. This function
819 * will lock each #GstObject in the list to compare the name, so be
820 * carefull when passing a list with a locked object.
822 * Returns: TRUE if a #GstObject named @name does not appear in @list,
825 * MT safe. Grabs and releases the LOCK of each object in the list.
828 gst_object_check_uniqueness (GList * list, const gchar * name)
830 gboolean result = TRUE;
832 g_return_val_if_fail (name != NULL, FALSE);
834 for (; list; list = g_list_next (list)) {
838 child = GST_OBJECT_CAST (list->data);
840 GST_OBJECT_LOCK (child);
841 eq = strcmp (GST_OBJECT_NAME (child), name) == 0;
842 GST_OBJECT_UNLOCK (child);
844 if (G_UNLIKELY (eq)) {
854 gst_object_set_property (GObject * object, guint prop_id,
855 const GValue * value, GParamSpec * pspec)
857 GstObject *gstobject;
859 gstobject = GST_OBJECT_CAST (object);
863 gst_object_set_name (gstobject, g_value_get_string (value));
866 gst_object_set_parent (gstobject, g_value_get_object (value));
869 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
875 gst_object_get_property (GObject * object, guint prop_id,
876 GValue * value, GParamSpec * pspec)
878 GstObject *gstobject;
880 gstobject = GST_OBJECT_CAST (object);
884 g_value_take_string (value, gst_object_get_name (gstobject));
887 g_value_take_object (value, gst_object_get_parent (gstobject));
890 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
896 * gst_object_get_path_string:
897 * @object: a #GstObject
899 * Generates a string describing the path of @object in
900 * the object hierarchy. Only useful (or used) for debugging.
902 * Free-function: g_free
904 * Returns: (transfer full): a string describing the path of @object. You must
905 * g_free() the string after usage.
907 * MT safe. Grabs and releases the #GstObject's LOCK for all objects
911 gst_object_get_path_string (GstObject * object)
916 gchar *prevpath, *path;
917 const gchar *typename;
919 const gchar *separator;
921 /* ref object before adding to list */
922 gst_object_ref (object);
923 parentage = g_slist_prepend (NULL, object);
925 path = g_strdup ("");
927 /* first walk the object hierarchy to build a list of the parents,
928 * be carefull here with refcounting. */
930 if (GST_IS_OBJECT (object)) {
931 parent = gst_object_get_parent (object);
932 /* add parents to list, refcount remains increased while
933 * we handle the object */
935 parentage = g_slist_prepend (parentage, parent);
940 } while (object != NULL);
942 /* then walk the parent list and print them out. we need to
943 * decrease the refcounting on each element after we handled
945 for (parents = parentage; parents; parents = g_slist_next (parents)) {
946 if (G_IS_OBJECT (parents->data)) {
947 typename = G_OBJECT_TYPE_NAME (parents->data);
951 if (GST_IS_OBJECT (parents->data)) {
952 GstObject *item = GST_OBJECT_CAST (parents->data);
953 GstObjectClass *oclass = GST_OBJECT_GET_CLASS (item);
954 gchar *objname = gst_object_get_name (item);
956 component = g_strdup_printf ("%s:%s", typename, objname);
957 separator = oclass->path_string_separator;
959 gst_object_unref (item);
963 component = g_strdup_printf ("%s:%p", typename, parents->data);
965 component = g_strdup_printf ("%p", parents->data);
971 path = g_strjoin (separator, prevpath, component, NULL);
976 g_slist_free (parentage);
981 /* controller helper functions */
984 * gst_object_find_control_binding:
985 * @self: the gobject to search for a property in
986 * @name: the gobject property name to look for
988 * Searches the list of properties under control.
990 * Returns: a #GstControlBinding or %NULL if the property is not being
993 static GstControlBinding *
994 gst_object_find_control_binding (GstObject * self, const gchar * name)
996 GstControlBinding *binding;
999 for (node = self->control_bindings; node; node = g_list_next (node)) {
1000 binding = node->data;
1001 /* FIXME: eventually use GQuark to speed it up */
1002 if (!strcmp (binding->name, name)) {
1003 GST_DEBUG_OBJECT (self, "found control binding for property '%s'", name);
1007 GST_DEBUG_OBJECT (self, "controller does not manage property '%s'", name);
1012 /* controller functions */
1015 * gst_object_suggest_next_sync:
1016 * @object: the object that has controlled properties
1018 * Returns a suggestion for timestamps where buffers should be split
1019 * to get best controller results.
1021 * Returns: Returns the suggested timestamp or %GST_CLOCK_TIME_NONE
1022 * if no control-rate was set.
1025 gst_object_suggest_next_sync (GstObject * object)
1029 g_return_val_if_fail (GST_IS_OBJECT (object), GST_CLOCK_TIME_NONE);
1030 g_return_val_if_fail (object->control_rate != GST_CLOCK_TIME_NONE,
1031 GST_CLOCK_TIME_NONE);
1033 GST_OBJECT_LOCK (object);
1035 /* TODO: Implement more logic, depending on interpolation mode and control
1037 * FIXME: we need playback direction
1039 ret = object->last_sync + object->control_rate;
1041 GST_OBJECT_UNLOCK (object);
1047 * gst_object_sync_values:
1048 * @object: the object that has controlled properties
1049 * @timestamp: the time that should be processed
1051 * Sets the properties of the object, according to the #GstControlSources that
1052 * (maybe) handle them and for the given timestamp.
1054 * If this function fails, it is most likely the application developers fault.
1055 * Most probably the control sources are not setup correctly.
1057 * Returns: %TRUE if the controller values could be applied to the object
1058 * properties, %FALSE otherwise
1061 gst_object_sync_values (GstObject * object, GstClockTime timestamp)
1064 gboolean ret = TRUE;
1066 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
1067 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), FALSE);
1069 GST_LOG_OBJECT (object, "sync_values");
1070 if (!object->control_bindings)
1073 /* FIXME: this deadlocks */
1074 /* GST_OBJECT_LOCK (object); */
1075 g_object_freeze_notify ((GObject *) object);
1076 for (node = object->control_bindings; node; node = g_list_next (node)) {
1077 ret &= gst_control_binding_sync_values ((GstControlBinding *) node->data,
1078 object, timestamp, object->last_sync);
1080 object->last_sync = timestamp;
1081 g_object_thaw_notify ((GObject *) object);
1082 /* GST_OBJECT_UNLOCK (object); */
1089 * gst_object_has_active_control_bindings:
1090 * @object: the object that has controlled properties
1092 * Check if the @object has an active controlled properties.
1094 * Returns: %TRUE if the object has active controlled properties
1097 gst_object_has_active_control_bindings (GstObject * object)
1099 gboolean res = FALSE;
1102 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
1104 GST_OBJECT_LOCK (object);
1105 for (node = object->control_bindings; node; node = g_list_next (node)) {
1106 res |= !gst_control_binding_is_disabled ((GstControlBinding *) node->data);
1108 GST_OBJECT_UNLOCK (object);
1113 * gst_object_set_control_bindings_disabled:
1114 * @object: the object that has controlled properties
1115 * @disabled: boolean that specifies whether to disable the controller
1118 * This function is used to disable all controlled properties of the @object for
1119 * some time, i.e. gst_object_sync_values() will do nothing.
1122 gst_object_set_control_bindings_disabled (GstObject * object, gboolean disabled)
1126 g_return_if_fail (GST_IS_OBJECT (object));
1128 GST_OBJECT_LOCK (object);
1129 for (node = object->control_bindings; node; node = g_list_next (node)) {
1130 gst_control_binding_set_disabled ((GstControlBinding *) node->data,
1133 GST_OBJECT_UNLOCK (object);
1137 * gst_object_set_control_binding_disabled:
1138 * @object: the object that has controlled properties
1139 * @property_name: property to disable
1140 * @disabled: boolean that specifies whether to disable the controller
1143 * This function is used to disable the #GstController on a property for
1144 * some time, i.e. gst_controller_sync_values() will do nothing for the
1148 gst_object_set_control_binding_disabled (GstObject * object,
1149 const gchar * property_name, gboolean disabled)
1151 GstControlBinding *binding;
1153 g_return_if_fail (GST_IS_OBJECT (object));
1154 g_return_if_fail (property_name);
1156 GST_OBJECT_LOCK (object);
1157 if ((binding = gst_object_find_control_binding (object, property_name))) {
1158 gst_control_binding_set_disabled (binding, disabled);
1160 GST_OBJECT_UNLOCK (object);
1165 * gst_object_add_control_binding:
1166 * @object: the controller object
1167 * @binding: (transfer full): the #GstControlBinding that should be used
1169 * Sets the #GstControlBinding. If there already was a #GstControlBinding
1170 * for this property it will be replaced.
1171 * The @object will take ownership of the @binding.
1173 * Returns: %FALSE if the given @binding has not been setup for this object or
1177 gst_object_add_control_binding (GstObject * object, GstControlBinding * binding)
1179 GstControlBinding *old;
1181 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
1182 g_return_val_if_fail (GST_IS_CONTROL_BINDING (binding), FALSE);
1183 //g_return_val_if_fail (g_type_is_a (binding->pspec->owner_type,
1184 // G_OBJECT_TYPE (object)), FALSE);
1186 GST_OBJECT_LOCK (object);
1187 if ((old = gst_object_find_control_binding (object, binding->name))) {
1188 GST_DEBUG_OBJECT (object, "controlled property %s removed", old->name);
1189 object->control_bindings = g_list_remove (object->control_bindings, old);
1190 gst_object_unparent (GST_OBJECT_CAST (old));
1192 object->control_bindings = g_list_prepend (object->control_bindings, binding);
1193 gst_object_set_parent (GST_OBJECT_CAST (binding), object);
1194 GST_DEBUG_OBJECT (object, "controlled property %s added", binding->name);
1195 GST_OBJECT_UNLOCK (object);
1201 * gst_object_get_control_binding:
1202 * @object: the object
1203 * @property_name: name of the property
1205 * Gets the corresponding #GstControlBinding for the property. This should be
1206 * unreferenced again after use.
1208 * Returns: (transfer full): the #GstControlBinding for @property_name or %NULL if
1209 * the property is not controlled.
1212 gst_object_get_control_binding (GstObject * object, const gchar * property_name)
1214 GstControlBinding *binding;
1216 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
1217 g_return_val_if_fail (property_name, NULL);
1219 GST_OBJECT_LOCK (object);
1220 if ((binding = gst_object_find_control_binding (object, property_name))) {
1221 gst_object_ref (binding);
1223 GST_OBJECT_UNLOCK (object);
1229 * gst_object_remove_control_binding:
1230 * @object: the object
1231 * @binding: the binding
1233 * Removes the corresponding #GstControlBinding. If it was the
1234 * last ref of the binding, it will be disposed.
1236 * Returns: %TRUE if the binding could be removed.
1239 gst_object_remove_control_binding (GstObject * object,
1240 GstControlBinding * binding)
1243 gboolean ret = FALSE;
1245 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
1246 g_return_val_if_fail (GST_IS_CONTROL_BINDING (binding), FALSE);
1248 GST_OBJECT_LOCK (object);
1249 if ((node = g_list_find (object->control_bindings, binding))) {
1250 GST_DEBUG_OBJECT (object, "controlled property %s removed", binding->name);
1251 object->control_bindings =
1252 g_list_delete_link (object->control_bindings, node);
1253 gst_object_unparent (GST_OBJECT_CAST (binding));
1256 GST_OBJECT_UNLOCK (object);
1262 * gst_object_get_value:
1263 * @object: the object that has controlled properties
1264 * @property_name: the name of the property to get
1265 * @timestamp: the time the control-change should be read from
1267 * Gets the value for the given controlled property at the requested time.
1269 * Returns: the GValue of the property at the given time, or %NULL if the
1270 * property isn't controlled.
1273 gst_object_get_value (GstObject * object, const gchar * property_name,
1274 GstClockTime timestamp)
1276 GstControlBinding *binding;
1279 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
1280 g_return_val_if_fail (property_name, NULL);
1281 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), NULL);
1283 GST_OBJECT_LOCK (object);
1284 if ((binding = gst_object_find_control_binding (object, property_name))) {
1285 val = gst_control_binding_get_value (binding, timestamp);
1287 GST_OBJECT_UNLOCK (object);
1293 * gst_object_get_value_array:
1294 * @object: the object that has controlled properties
1295 * @property_name: the name of the property to get
1296 * @timestamp: the time that should be processed
1297 * @interval: the time spacing between subsequent values
1298 * @n_values: the number of values
1299 * @values: array to put control-values in
1301 * Gets a number of values for the given controlled property starting at the
1302 * requested time. The array @values need to hold enough space for @n_values of
1303 * the same type as the objects property's type.
1305 * This function is useful if one wants to e.g. draw a graph of the control
1306 * curve or apply a control curve sample by sample.
1308 * The values are unboxed and ready to be used. The similar function
1309 * gst_object_get_g_value_array() returns the array as #GValues and is
1310 * better suites for bindings.
1312 * Returns: %TRUE if the given array could be filled, %FALSE otherwise
1315 gst_object_get_value_array (GstObject * object, const gchar * property_name,
1316 GstClockTime timestamp, GstClockTime interval, guint n_values,
1319 gboolean res = FALSE;
1320 GstControlBinding *binding;
1322 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
1323 g_return_val_if_fail (property_name, FALSE);
1324 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), FALSE);
1325 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (interval), FALSE);
1326 g_return_val_if_fail (values, FALSE);
1328 GST_OBJECT_LOCK (object);
1329 if ((binding = gst_object_find_control_binding (object, property_name))) {
1330 res = gst_control_binding_get_value_array (binding, timestamp, interval,
1333 GST_OBJECT_UNLOCK (object);
1338 * gst_object_get_g_value_array:
1339 * @object: the object that has controlled properties
1340 * @property_name: the name of the property to get
1341 * @timestamp: the time that should be processed
1342 * @interval: the time spacing between subsequent values
1343 * @n_values: the number of values
1344 * @values: array to put control-values in
1346 * Gets a number of #GValues for the given controlled property starting at the
1347 * requested time. The array @values need to hold enough space for @n_values of
1350 * This function is useful if one wants to e.g. draw a graph of the control
1351 * curve or apply a control curve sample by sample.
1353 * Returns: %TRUE if the given array could be filled, %FALSE otherwise
1356 gst_object_get_g_value_array (GstObject * object, const gchar * property_name,
1357 GstClockTime timestamp, GstClockTime interval, guint n_values,
1360 gboolean res = FALSE;
1361 GstControlBinding *binding;
1363 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
1364 g_return_val_if_fail (property_name, FALSE);
1365 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), FALSE);
1366 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (interval), FALSE);
1367 g_return_val_if_fail (values, FALSE);
1369 GST_OBJECT_LOCK (object);
1370 if ((binding = gst_object_find_control_binding (object, property_name))) {
1371 res = gst_control_binding_get_g_value_array (binding, timestamp, interval,
1374 GST_OBJECT_UNLOCK (object);
1380 * gst_object_get_control_rate:
1381 * @object: the object that has controlled properties
1383 * Obtain the control-rate for this @object. Audio processing #GstElement
1384 * objects will use this rate to sub-divide their processing loop and call
1385 * gst_object_sync_values() inbetween. The length of the processing segment
1386 * should be up to @control-rate nanoseconds.
1388 * If the @object is not under property control, this will return
1389 * %GST_CLOCK_TIME_NONE. This allows the element to avoid the sub-dividing.
1391 * The control-rate is not expected to change if the element is in
1392 * %GST_STATE_PAUSED or %GST_STATE_PLAYING.
1394 * Returns: the control rate in nanoseconds
1397 gst_object_get_control_rate (GstObject * object)
1399 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
1401 return object->control_rate;
1405 * gst_object_set_control_rate:
1406 * @object: the object that has controlled properties
1407 * @control_rate: the new control-rate in nanoseconds.
1409 * Change the control-rate for this @object. Audio processing #GstElement
1410 * objects will use this rate to sub-divide their processing loop and call
1411 * gst_object_sync_values() inbetween. The length of the processing segment
1412 * should be up to @control-rate nanoseconds.
1414 * The control-rate should not change if the element is in %GST_STATE_PAUSED or
1415 * %GST_STATE_PLAYING.
1418 gst_object_set_control_rate (GstObject * object, GstClockTime control_rate)
1420 g_return_if_fail (GST_IS_OBJECT (object));
1422 object->control_rate = control_rate;