X-Git-Url: http://review.tizen.org/git/?a=blobdiff_plain;f=gst%2Fgstobject.c;h=3aa20c44351ad0924ba840c6028c6b94009b8358;hb=dac5966da6a0f53d0443dfa1ac239289028c415d;hp=50c4c25a5b4c4703164ba8822c507166a1dc3e17;hpb=31b70ea701fe72aa3c91caa307953b5a5619db50;p=platform%2Fupstream%2Fgstreamer.git

diff --git a/gst/gstobject.c b/gst/gstobject.c
index 50c4c25..3aa20c4 100644
--- a/gst/gstobject.c
+++ b/gst/gstobject.c
@@ -17,85 +17,77 @@
  *
  * You should have received a copy of the GNU Library General Public
  * License along with this library; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 02111-1307, USA.
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
  */
 
 /**
  * SECTION:gstobject
+ * @title: GstObject
  * @short_description: Base class for the GStreamer object hierarchy
  *
  * #GstObject provides a root for the object hierarchy tree filed in by the
  * GStreamer library.  It is currently a thin wrapper on top of
- * #GObject. It is an abstract class that is not very usable on its own.
+ * #GInitiallyUnowned. It is an abstract class that is not very usable on its own.
  *
  * #GstObject gives us basic refcounting, parenting functionality and locking.
- * Most of the function are just extended for special GStreamer needs and can be
+ * Most of the functions are just extended for special GStreamer needs and can be
  * found under the same name in the base class of #GstObject which is #GObject
  * (e.g. g_object_ref() becomes gst_object_ref()).
  *
- * The most interesting difference between #GstObject and #GObject is the
- * "floating" reference count. A #GObject is created with a reference count of
- * 1, owned by the creator of the #GObject. (The owner of a reference is the
- * code section that has the right to call gst_object_unref() in order to
- * remove that reference.) A #GstObject is created with a reference count of 1
- * also, but it isn't owned by anyone; Instead, the initial reference count
- * of a #GstObject is "floating". The floating reference can be removed by
- * anyone at any time, by calling gst_object_sink().  gst_object_sink() does
- * nothing if an object is already sunk (has no floating reference).
- *
- * When you add a #GstElement to its parent container, the parent container will
- * do this:
- * <informalexample>
- * <programlisting>
- *   gst_object_ref (GST_OBJECT (child_element));
- *   gst_object_sink (GST_OBJECT (child_element));
- * </programlisting>
- * </informalexample>
- * This means that the container now owns a reference to the child element
- * (since it called gst_object_ref()), and the child element has no floating
- * reference.
- *
- * The purpose of the floating reference is to keep the child element alive
- * until you add it to a parent container, which then manages the lifetime of
- * the object itself:
- * <informalexample>
- * <programlisting>
- *    element = gst_element_factory_make (factoryname, name);
- *    // element has one floating reference to keep it alive
- *    gst_bin_add (GST_BIN (bin), element);
- *    // element has one non-floating reference owned by the container
- * </programlisting>
- * </informalexample>
- *
- * Another effect of this is, that calling gst_object_unref() on a bin object,
- * will also destoy all the #GstElement objects in it. The same is true for
- * calling gst_bin_remove().
- *
- * Special care has to be taken for all methods that gst_object_sink() an object
- * since if the caller of those functions had a floating reference to the object,
- * the object reference is now invalid.
+ * Since #GstObject derives from #GInitiallyUnowned, it also inherits the
+ * floating reference. Be aware that functions such as gst_bin_add() and
+ * gst_element_add_pad() take ownership of the floating reference.
  *
  * In contrast to #GObject instances, #GstObject adds a name property. The functions
  * gst_object_set_name() and gst_object_get_name() are used to set/get the name
  * of the object.
  *
- * Last reviewed on 2005-11-09 (0.9.4)
+ * ## controlled properties
+ *
+ * Controlled properties offers a lightweight way to adjust gobject properties
+ * over stream-time. It works by using time-stamped value pairs that are queued
+ * for element-properties. At run-time the elements continuously pull value
+ * changes for the current stream-time.
+ *
+ * What needs to be changed in a #GstElement?
+ * Very little - it is just two steps to make a plugin controllable!
+ *
+ *   * mark gobject-properties paramspecs that make sense to be controlled,
+ *     by GST_PARAM_CONTROLLABLE.
+ *
+ *   * when processing data (get, chain, loop function) at the beginning call
+ *     gst_object_sync_values(element,timestamp).
+ *     This will make the controller update all GObject properties that are
+ *     under its control with the current values based on the timestamp.
+ *
+ * What needs to be done in applications? Again it's not a lot to change.
+ *
+ *   * create a #GstControlSource.
+ *     csource = gst_interpolation_control_source_new ();
+ *     g_object_set (csource, "mode", GST_INTERPOLATION_MODE_LINEAR, NULL);
+ *
+ *   * Attach the #GstControlSource on the controller to a property.
+ *     gst_object_add_control_binding (object, gst_direct_control_binding_new (object, "prop1", csource));
+ *
+ *   * Set the control values
+ *     gst_timed_value_control_source_set ((GstTimedValueControlSource *)csource,0 * GST_SECOND, value1);
+ *     gst_timed_value_control_source_set ((GstTimedValueControlSource *)csource,1 * GST_SECOND, value2);
+ *
+ *   * start your pipeline
  */
 
 #include "gst_private.h"
 #include "glib-compat-private.h"
 
 #include "gstobject.h"
-#include "gstmarshal.h"
+#include "gstclock.h"
+#include "gstcontrolbinding.h"
+#include "gstcontrolsource.h"
 #include "gstinfo.h"
+#include "gstparamspecs.h"
 #include "gstutils.h"
 
-#ifndef GST_DISABLE_TRACE
-#include "gsttrace.h"
-static GstAllocTrace *_gst_object_trace;
-#endif
-
 #define DEBUG_REFCOUNT
 
 /* Object signals and args */
@@ -144,28 +136,39 @@ static GParamSpec *properties[PROP_LAST];
 G_DEFINE_ABSTRACT_TYPE (GstObject, gst_object, G_TYPE_INITIALLY_UNOWNED);
 
 static void
+gst_object_constructed (GObject * object)
+{
+  GST_TRACER_OBJECT_CREATED (GST_OBJECT_CAST (object));
+
+  ((GObjectClass *) gst_object_parent_class)->constructed (object);
+}
+
+static void
 gst_object_class_init (GstObjectClass * klass)
 {
   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
 
-#ifndef GST_DISABLE_TRACE
-  _gst_object_trace = gst_alloc_trace_register (g_type_name (GST_TYPE_OBJECT));
-#endif
-
   gobject_class->set_property = gst_object_set_property;
   gobject_class->get_property = gst_object_get_property;
 
   properties[PROP_NAME] =
       g_param_spec_string ("name", "Name", "The name of the object", NULL,
       G_PARAM_READWRITE | G_PARAM_CONSTRUCT | G_PARAM_STATIC_STRINGS);
-  g_object_class_install_property (gobject_class, PROP_NAME,
-      properties[PROP_NAME]);
 
+  /**
+   * GstObject:parent:
+   *
+   * The parent of the object. Please note, that when changing the 'parent'
+   * property, we don't emit #GObject::notify and #GstObject::deep-notify
+   * signals due to locking issues. In some cases one can use
+   * #GstBin::element-added or #GstBin::element-removed signals on the parent to
+   * achieve a similar effect.
+   */
   properties[PROP_PARENT] =
       g_param_spec_object ("parent", "Parent", "The parent of the object",
       GST_TYPE_OBJECT, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);
-  g_object_class_install_property (gobject_class, PROP_PARENT,
-      properties[PROP_PARENT]);
+
+  g_object_class_install_properties (gobject_class, PROP_LAST, properties);
 
   /**
    * GstObject::deep-notify:
@@ -181,7 +184,7 @@ gst_object_class_init (GstObjectClass * klass)
       g_signal_new ("deep-notify", G_TYPE_FROM_CLASS (klass),
       G_SIGNAL_RUN_FIRST | G_SIGNAL_NO_RECURSE | G_SIGNAL_DETAILED |
       G_SIGNAL_NO_HOOKS, G_STRUCT_OFFSET (GstObjectClass, deep_notify), NULL,
-      NULL, gst_marshal_VOID__OBJECT_PARAM, G_TYPE_NONE, 2, GST_TYPE_OBJECT,
+      NULL, g_cclosure_marshal_generic, G_TYPE_NONE, 2, GST_TYPE_OBJECT,
       G_TYPE_PARAM);
 
   klass->path_string_separator = "/";
@@ -190,6 +193,7 @@ gst_object_class_init (GstObjectClass * klass)
   gobject_class->dispatch_properties_changed
       = GST_DEBUG_FUNCPTR (gst_object_dispatch_properties_changed);
 
+  gobject_class->constructed = gst_object_constructed;
   gobject_class->dispose = gst_object_dispose;
   gobject_class->finalize = gst_object_finalize;
 }
@@ -197,21 +201,20 @@ gst_object_class_init (GstObjectClass * klass)
 static void
 gst_object_init (GstObject * object)
 {
-  object->lock = g_mutex_new ();
+  g_mutex_init (&object->lock);
   object->parent = NULL;
   object->name = NULL;
   GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p new", object);
 
-#ifndef GST_DISABLE_TRACE
-  gst_alloc_trace_new (_gst_object_trace, object);
-#endif
-
   object->flags = 0;
+
+  object->control_rate = 100 * GST_MSECOND;
+  object->last_sync = GST_CLOCK_TIME_NONE;
 }
 
 /**
  * gst_object_ref:
- * @object: a #GstObject to reference
+ * @object: (type Gst.Object): a #GstObject to reference
  *
  * Increments the reference count on @object. This function
  * does not take the lock on @object because it relies on
@@ -221,13 +224,14 @@ gst_object_init (GstObject * object)
  * constructs like :
  *  result = gst_object_ref (object->parent);
  *
- * Returns: (transfer full): A pointer to @object
+ * Returns: (transfer full) (type Gst.Object): A pointer to @object
  */
 gpointer
 gst_object_ref (gpointer object)
 {
   g_return_val_if_fail (object != NULL, NULL);
 
+  GST_TRACER_OBJECT_REFFED (object, ((GObject *) object)->ref_count + 1);
 #ifdef DEBUG_REFCOUNT
   GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p ref %d->%d", object,
       ((GObject *) object)->ref_count, ((GObject *) object)->ref_count + 1);
@@ -239,7 +243,7 @@ gst_object_ref (gpointer object)
 
 /**
  * gst_object_unref:
- * @object: a #GstObject to unreference
+ * @object: (type Gst.Object): a #GstObject to unreference
  *
  * Decrements the reference count on @object.  If reference count hits
  * zero, destroy @object. This function does not take the lock
@@ -254,6 +258,7 @@ gst_object_unref (gpointer object)
   g_return_if_fail (object != NULL);
   g_return_if_fail (((GObject *) object)->ref_count > 0);
 
+  GST_TRACER_OBJECT_UNREFFED (object, ((GObject *) object)->ref_count - 1);
 #ifdef DEBUG_REFCOUNT
   GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p unref %d->%d", object,
       ((GObject *) object)->ref_count, ((GObject *) object)->ref_count - 1);
@@ -262,7 +267,7 @@ gst_object_unref (gpointer object)
 }
 
 /**
- * gst_object_ref_sink:
+ * gst_object_ref_sink: (skip)
  * @object: a #GstObject to sink
  *
  * Increase the reference count of @object, and possibly remove the floating
@@ -273,6 +278,9 @@ gst_object_unref (gpointer object)
  * the floating flag while leaving the reference count unchanged. If the object
  * is not floating, then this call adds a new normal reference increasing the
  * reference count by one.
+ *
+ * For more background on "floating references" please see the #GObject
+ * documentation.
  */
 gpointer
 gst_object_ref_sink (gpointer object)
@@ -288,18 +296,42 @@ gst_object_ref_sink (gpointer object)
 }
 
 /**
+ * gst_clear_object: (skip)
+ * @object_ptr: a pointer to a #GstObject reference
+ *
+ * Clears a reference to a #GstObject.
+ *
+ * @object_ptr must not be %NULL.
+ *
+ * If the reference is %NULL then this function does nothing.
+ * Otherwise, the reference count of the object is decreased using
+ * gst_object_unref() and the pointer is set to %NULL.
+ *
+ * A macro is also included that allows this function to be used without
+ * pointer casts.
+ *
+ * Since: 1.16
+ **/
+#undef gst_clear_object
+void
+gst_clear_object (GstObject ** object_ptr)
+{
+  g_clear_pointer (object_ptr, gst_object_unref);
+}
+
+/**
  * gst_object_replace:
- * @oldobj: (inout) (transfer full): pointer to a place of a #GstObject to
- *     replace
- * @newobj: (transfer none): a new #GstObject
+ * @oldobj: (inout) (transfer full) (nullable): pointer to a place of
+ *     a #GstObject to replace
+ * @newobj: (transfer none) (allow-none): a new #GstObject
  *
  * Atomically modifies a pointer to point to a new object.
  * The reference count of @oldobj is decreased and the reference count of
  * @newobj is increased.
  *
- * Either @newobj and the value pointed to by @oldobj may be NULL.
+ * Either @newobj and the value pointed to by @oldobj may be %NULL.
  *
- * Returns: TRUE if @newobj was different from @oldobj
+ * Returns: %TRUE if @newobj was different from @oldobj
  */
 gboolean
 gst_object_replace (GstObject ** oldobj, GstObject * newobj)
@@ -322,7 +354,7 @@ gst_object_replace (GstObject ** oldobj, GstObject * newobj)
     return FALSE;
 
   if (newobj)
-    g_object_ref (newobj);
+    gst_object_ref (newobj);
 
   while (G_UNLIKELY (!g_atomic_pointer_compare_and_exchange ((gpointer *)
               oldobj, oldptr, newobj))) {
@@ -332,7 +364,7 @@ gst_object_replace (GstObject ** oldobj, GstObject * newobj)
   }
 
   if (oldptr)
-    g_object_unref (oldptr);
+    gst_object_unref (oldptr);
 
   return oldptr != newobj;
 }
@@ -342,9 +374,10 @@ gst_object_replace (GstObject ** oldobj, GstObject * newobj)
 static void
 gst_object_dispose (GObject * object)
 {
+  GstObject *self = (GstObject *) object;
   GstObject *parent;
 
-  GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "dispose");
+  GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p dispose", object);
 
   GST_OBJECT_LOCK (object);
   if ((parent = GST_OBJECT_PARENT (object)))
@@ -352,6 +385,16 @@ gst_object_dispose (GObject * object)
   GST_OBJECT_PARENT (object) = NULL;
   GST_OBJECT_UNLOCK (object);
 
+  if (self->control_bindings) {
+    GList *node;
+
+    for (node = self->control_bindings; node; node = g_list_next (node)) {
+      gst_object_unparent (node->data);
+    }
+    g_list_free (self->control_bindings);
+    self->control_bindings = NULL;
+  }
+
   ((GObjectClass *) gst_object_parent_class)->dispose (object);
 
   return;
@@ -376,16 +419,14 @@ gst_object_finalize (GObject * object)
 {
   GstObject *gstobject = GST_OBJECT_CAST (object);
 
-  GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "finalize");
+  GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p finalize", object);
 
   g_signal_handlers_destroy (object);
 
   g_free (gstobject->name);
-  g_mutex_free (gstobject->lock);
+  g_mutex_clear (&gstobject->lock);
 
-#ifndef GST_DISABLE_TRACE
-  gst_alloc_trace_free (_gst_object_trace, object);
-#endif
+  GST_TRACER_OBJECT_DESTROYED (gstobject);
 
   ((GObjectClass *) gst_object_parent_class)->finalize (object);
 }
@@ -416,7 +457,7 @@ gst_object_dispatch_properties_changed (GObject * object,
 
   gst_object = GST_OBJECT_CAST (object);
 #ifndef GST_DISABLE_GST_DEBUG
-  if (G_UNLIKELY (__gst_debug_min >= GST_LEVEL_LOG)) {
+  if (G_UNLIKELY (_gst_debug_min >= GST_LEVEL_LOG)) {
     name = gst_object_get_name (gst_object);
     debug_name = GST_STR_NULL (name);
   } else
@@ -448,9 +489,9 @@ gst_object_dispatch_properties_changed (GObject * object,
  * @object: the #GObject that signalled the notify.
  * @orig: a #GstObject that initiated the notify.
  * @pspec: a #GParamSpec of the property.
- * @excluded_props: (array zero-terminated=1) (element-type gchar*)
- *     (allow-none):a set of user-specified properties to exclude or
- *     NULL to show all changes.
+ * @excluded_props: (array zero-terminated=1) (element-type gchar*) (allow-none):
+ *     a set of user-specified properties to exclude or %NULL to show
+ *     all changes.
  *
  * A default deep_notify signal callback for an object. The user data
  * should contain a pointer to an array of strings that should be excluded
@@ -478,19 +519,10 @@ gst_object_default_deep_notify (GObject * object, GstObject * orig,
     g_value_init (&value, pspec->value_type);
     g_object_get_property (G_OBJECT (orig), pspec->name, &value);
 
-    /* FIXME: handle flags */
-    if (G_IS_PARAM_SPEC_ENUM (pspec)) {
-      GEnumValue *enum_value;
-      GEnumClass *klass = G_ENUM_CLASS (g_type_class_ref (pspec->value_type));
-
-      enum_value = g_enum_get_value (klass, g_value_get_enum (&value));
-
-      str = g_strdup_printf ("%s (%d)", enum_value->value_nick,
-          enum_value->value);
-      g_type_class_unref (klass);
-    } else {
-      str = g_strdup_value_contents (&value);
-    }
+    if (G_VALUE_HOLDS_STRING (&value))
+      str = g_value_dup_string (&value);
+    else
+      str = gst_value_serialize (&value);
     name = gst_object_get_path_string (orig);
     g_print ("%s: %s = %s\n", name, pspec->name, str);
     g_free (name);
@@ -530,7 +562,14 @@ gst_object_set_name_default (GstObject * object)
   type_name = g_quark_to_string (q);
   if (strncmp (type_name, "Gst", 3) == 0)
     type_name += 3;
-  name = g_strdup_printf ("%s%d", type_name, count);
+  /* give the 20th "queue" element and the first "queue2" different names */
+  l = strlen (type_name);
+  if (l > 0 && g_ascii_isdigit (type_name[l - 1])) {
+    name = g_strdup_printf ("%s-%d", type_name, count);
+  } else {
+    name = g_strdup_printf ("%s%d", type_name, count);
+  }
+
   l = strlen (name);
   for (i = 0; i < l; i++)
     name[i] = g_ascii_tolower (name[i]);
@@ -558,15 +597,15 @@ had_parent:
 /**
  * gst_object_set_name:
  * @object: a #GstObject
- * @name:   new name of object
+ * @name: (allow-none): new name of object
  *
  * Sets the name of @object, or gives @object a guaranteed unique
- * name (if @name is NULL).
+ * name (if @name is %NULL).
  * This function makes a copy of the provided name, so the caller
  * retains ownership of the name it sent.
  *
- * Returns: TRUE if the name could be set. Since Objects that have
- * a parent cannot be renamed, this function returns FALSE in those
+ * Returns: %TRUE if the name could be set. Since Objects that have
+ * a parent cannot be renamed, this function returns %FALSE in those
  * cases.
  *
  * MT safe.  This function grabs and releases @object's LOCK.
@@ -593,10 +632,8 @@ gst_object_set_name (GstObject * object, const gchar * name)
     GST_OBJECT_UNLOCK (object);
     result = gst_object_set_name_default (object);
   }
-  /* FIXME-0.11: this misses a g_object_notify (object, "name"); unless called
-   * from gst_object_set_property.
-   * Ideally remove such custom setters (or make it static).
-   */
+
+  g_object_notify (G_OBJECT (object), "name");
   return result;
 
   /* error */
@@ -614,12 +651,13 @@ had_parent:
  *
  * Returns a copy of the name of @object.
  * Caller should g_free() the return value after usage.
- * For a nameless object, this returns NULL, which you can safely g_free()
+ * For a nameless object, this returns %NULL, which you can safely g_free()
  * as well.
  *
  * Free-function: g_free
  *
- * Returns: (transfer full): the name of @object. g_free() after usage.
+ * Returns: (transfer full) (nullable): the name of @object. g_free()
+ * after usage.
  *
  * MT safe. This function grabs and releases @object's LOCK.
  */
@@ -639,13 +677,13 @@ gst_object_get_name (GstObject * object)
 
 /**
  * gst_object_set_parent:
- * @object: a #GstObject
+ * @object: (transfer floating): a #GstObject
  * @parent: new parent of object
  *
  * Sets the parent of @object to @parent. The object's reference count will
  * be incremented, and any floating reference will be removed (see gst_object_ref_sink()).
  *
- * Returns: TRUE if @parent could be set or FALSE when @object
+ * Returns: %TRUE if @parent could be set or %FALSE when @object
  * already had a parent or @object and @parent are the same.
  *
  * MT safe. Grabs and releases @object's LOCK.
@@ -665,12 +703,14 @@ gst_object_set_parent (GstObject * object, GstObject * parent)
     goto had_parent;
 
   object->parent = parent;
-  g_object_ref_sink (object);
+  gst_object_ref_sink (object);
   GST_OBJECT_UNLOCK (object);
 
-  /* FIXME, this does not work, the deep notify takes the lock from the parent
-   * object and deadlocks when the parent holds its lock when calling this
-   * function (like _element_add_pad()) */
+  /* FIXME-2.0: this does not work, the deep notify takes the lock from the
+   * parent object and deadlocks when the parent holds its lock when calling
+   * this function (like _element_add_pad()), we need to use a GRecMutex
+   * for locking the parent instead.
+   */
   /* g_object_notify_by_pspec ((GObject *)object, properties[PROP_PARENT]); */
 
   return TRUE;
@@ -680,6 +720,8 @@ had_parent:
   {
     GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object,
         "set parent failed, object already had a parent");
+    gst_object_ref_sink (object);
+    gst_object_unref (object);
     GST_OBJECT_UNLOCK (object);
     return FALSE;
   }
@@ -692,8 +734,8 @@ had_parent:
  * Returns the parent of @object. This function increases the refcount
  * of the parent object so you should gst_object_unref() it after usage.
  *
- * Returns: (transfer full): parent of @object, this can be NULL if @object
- *   has no parent. unref after usage.
+ * Returns: (transfer full) (nullable): parent of @object, this can be
+ *   %NULL if @object has no parent. unref after usage.
  *
  * MT safe. Grabs and releases @object's LOCK.
  */
@@ -746,19 +788,47 @@ gst_object_unparent (GstObject * object)
 }
 
 /**
- * gst_object_has_ancestor:
+ * gst_object_has_as_parent:
+ * @object: a #GstObject to check
+ * @parent: a #GstObject to check as parent
+ *
+ * Check if @parent is the parent of @object.
+ * E.g. a #GstElement can check if it owns a given #GstPad.
+ *
+ * Returns: %FALSE if either @object or @parent is %NULL. %TRUE if @parent is
+ *          the parent of @object. Otherwise %FALSE.
+ *
+ * MT safe. Grabs and releases @object's locks.
+ * Since: 1.6
+ */
+gboolean
+gst_object_has_as_parent (GstObject * object, GstObject * parent)
+{
+  gboolean result = FALSE;
+
+  if (G_LIKELY (GST_IS_OBJECT (object) && GST_IS_OBJECT (parent))) {
+    GST_OBJECT_LOCK (object);
+    result = GST_OBJECT_PARENT (object) == parent;
+    GST_OBJECT_UNLOCK (object);
+  }
+
+  return result;
+}
+
+/**
+ * gst_object_has_as_ancestor:
  * @object: a #GstObject to check
  * @ancestor: a #GstObject to check as ancestor
  *
  * Check if @object has an ancestor @ancestor somewhere up in
  * the hierarchy. One can e.g. check if a #GstElement is inside a #GstPipeline.
  *
- * Returns: TRUE if @ancestor is an ancestor of @object.
+ * Returns: %TRUE if @ancestor is an ancestor of @object.
  *
  * MT safe. Grabs and releases @object's locks.
  */
 gboolean
-gst_object_has_ancestor (GstObject * object, GstObject * ancestor)
+gst_object_has_as_ancestor (GstObject * object, GstObject * ancestor)
 {
   GstObject *parent, *tmp;
 
@@ -781,6 +851,28 @@ gst_object_has_ancestor (GstObject * object, GstObject * ancestor)
 }
 
 /**
+ * gst_object_has_ancestor:
+ * @object: a #GstObject to check
+ * @ancestor: a #GstObject to check as ancestor
+ *
+ * Check if @object has an ancestor @ancestor somewhere up in
+ * the hierarchy. One can e.g. check if a #GstElement is inside a #GstPipeline.
+ *
+ * Returns: %TRUE if @ancestor is an ancestor of @object.
+ *
+ * Deprecated: Use gst_object_has_as_ancestor() instead.
+ *
+ * MT safe. Grabs and releases @object's locks.
+ */
+#ifndef GST_REMOVE_DEPRECATED
+gboolean
+gst_object_has_ancestor (GstObject * object, GstObject * ancestor)
+{
+  return gst_object_has_as_ancestor (object, ancestor);
+}
+#endif
+
+/**
  * gst_object_check_uniqueness:
  * @list: (transfer none) (element-type Gst.Object): a list of #GstObject to
  *      check through
@@ -790,10 +882,10 @@ gst_object_has_ancestor (GstObject * object, GstObject * ancestor)
  * does not do any locking of any kind. You might want to protect the
  * provided list with the lock of the owner of the list. This function
  * will lock each #GstObject in the list to compare the name, so be
- * carefull when passing a list with a locked object.
+ * careful when passing a list with a locked object.
  *
- * Returns: TRUE if a #GstObject named @name does not appear in @list,
- * FALSE if it does.
+ * Returns: %TRUE if a #GstObject named @name does not appear in @list,
+ * %FALSE if it does.
  *
  * MT safe. Grabs and releases the LOCK of each object in the list.
  */
@@ -898,7 +990,7 @@ gst_object_get_path_string (GstObject * object)
   path = g_strdup ("");
 
   /* first walk the object hierarchy to build a list of the parents,
-   * be carefull here with refcounting. */
+   * be careful here with refcounting. */
   do {
     if (GST_IS_OBJECT (object)) {
       parent = gst_object_get_parent (object);
@@ -950,3 +1042,448 @@ gst_object_get_path_string (GstObject * object)
 
   return path;
 }
+
+/* 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: (nullable): 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 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 control bindings on a property for
+ * some time, i.e. gst_object_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 floating): the #GstControlBinding that should be used
+ *
+ * Attach the #GstControlBinding to the object. If there already was a
+ * #GstControlBinding for this property it will be replaced.
+ *
+ * The object's reference count will be incremented, and any floating
+ * reference will be removed (see gst_object_ref_sink())
+ *
+ * Returns: %FALSE if the given @binding has not been setup for this object or
+ * has been setup for a non suitable property, %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 (binding->pspec, 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) (nullable): 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))) {
+    gst_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: (nullable): 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: (skip)
+ * @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 controlled 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.
+ *
+ * The values are unboxed and ready to be used. The similar function
+ * gst_object_get_g_value_array() returns the array as #GValues and is
+ * better suites for bindings.
+ *
+ * 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,
+    gpointer 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_g_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 length=n_values): array to put control-values in
+ *
+ * Gets a number of #GValues for the given controlled property starting at the
+ * requested time. The array @values need to hold enough space for @n_values of
+ * #GValue.
+ *
+ * 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_g_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_g_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() in between. 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() in between. 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;
+}