/* GStreamer * * Copyright (C) 1999,2000 Erik Walthinsen * 2004 Wim Taymans * * gstbin.c: GstBin container object and support code * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Library General Public License for more details. * * 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. * * MT safe. */ /** * SECTION:gstbin * @short_description: Base class for elements that contain other elements * * GstBin is the simplest of the container elements, allowing elements to * become children of itself. Pads from the child elements can be ghosted to * the bin, making the bin itself look transparently like any other element, * allowing for deep nesting of predefined sub-pipelines. * * A new GstBin is created with gst_bin_new(). Use a #GstPipeline instead if you * want to create a toplevel bin because a normal bin doesn't have a bus or * handle clock distribution of its own. * * After the bin has been created you will typically add elements to it with * gst_bin_add(). You can remove elements with gst_bin_remove(). * * An element can be retrieved from a bin with gst_bin_get_by_name(), using the * elements name. gst_bin_get_by_name_recurse_up() is mainly used for internal * purposes and will query the parent bins when the element is not found in the * current bin. * * An iterator of elements in a bin can be retrieved with * gst_bin_iterate_elements(). Various other iterators exist to retrieve the * elements in a bin. * * The "element_added" signal is fired whenever a new element is added to the * bin. Likewise the "element_removed" signal is fired whenever an element is * removed from the bin. * * gst_bin_unref() is used to destroy the bin. */ #include "gst_private.h" #include "gstevent.h" #include "gstbin.h" #include "gstmarshal.h" #include "gstxml.h" #include "gstinfo.h" #include "gsterror.h" #include "gstindex.h" #include "gstindexfactory.h" #include "gstutils.h" #include "gstchildproxy.h" GST_DEBUG_CATEGORY_STATIC (bin_debug); #define GST_CAT_DEFAULT bin_debug #define GST_LOG_BIN_CONTENTS(bin, text) GST_LOG_OBJECT ((bin), \ text ": %d elements: %u PLAYING, %u PAUSED, %u READY, %u NULL, own state: %s", \ (bin)->numchildren, (guint) (bin)->child_states[3], \ (guint) (bin)->child_states[2], (bin)->child_states[1], \ (bin)->child_states[0], gst_element_state_get_name (GST_STATE (bin))) static GstElementDetails gst_bin_details = GST_ELEMENT_DETAILS ("Generic bin", "Generic/Bin", "Simple container object", "Erik Walthinsen ," "Wim Taymans "); GType _gst_bin_type = 0; static void gst_bin_dispose (GObject * object); static GstStateChangeReturn gst_bin_change_state (GstElement * element, GstStateChange transition); static GstStateChangeReturn gst_bin_get_state (GstElement * element, GstState * state, GstState * pending, GTimeVal * timeout); static gboolean gst_bin_add_func (GstBin * bin, GstElement * element); static gboolean gst_bin_remove_func (GstBin * bin, GstElement * element); #ifndef GST_DISABLE_INDEX static void gst_bin_set_index_func (GstElement * element, GstIndex * index); #endif static GstClock *gst_bin_provide_clock_func (GstElement * element); static void gst_bin_set_clock_func (GstElement * element, GstClock * clock); static gboolean gst_bin_send_event (GstElement * element, GstEvent * event); static GstBusSyncReply bin_bus_handler (GstBus * bus, GstMessage * message, GstBin * bin); static gboolean gst_bin_query (GstElement * element, GstQuery * query); #ifndef GST_DISABLE_LOADSAVE static xmlNodePtr gst_bin_save_thyself (GstObject * object, xmlNodePtr parent); static void gst_bin_restore_thyself (GstObject * object, xmlNodePtr self); #endif static gint bin_element_is_sink (GstElement * child, GstBin * bin); /* Bin signals and properties */ enum { ELEMENT_ADDED, ELEMENT_REMOVED, LAST_SIGNAL }; enum { PROP_0 /* FILL ME */ }; static void gst_bin_base_init (gpointer g_class); static void gst_bin_class_init (GstBinClass * klass); static void gst_bin_init (GstBin * bin); static void gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data); static GstElementClass *parent_class = NULL; static guint gst_bin_signals[LAST_SIGNAL] = { 0 }; /** * gst_bin_get_type: * * Returns: the type of #GstBin */ GType gst_bin_get_type (void) { if (!_gst_bin_type) { static const GTypeInfo bin_info = { sizeof (GstBinClass), gst_bin_base_init, NULL, (GClassInitFunc) gst_bin_class_init, NULL, NULL, sizeof (GstBin), 0, (GInstanceInitFunc) gst_bin_init, NULL }; static const GInterfaceInfo child_proxy_info = { gst_bin_child_proxy_init, NULL, NULL }; _gst_bin_type = g_type_register_static (GST_TYPE_ELEMENT, "GstBin", &bin_info, 0); g_type_add_interface_static (_gst_bin_type, GST_TYPE_CHILD_PROXY, &child_proxy_info); GST_DEBUG_CATEGORY_INIT (bin_debug, "bin", GST_DEBUG_BOLD, "debugging info for the 'bin' container element"); } return _gst_bin_type; } static void gst_bin_base_init (gpointer g_class) { GstElementClass *gstelement_class = GST_ELEMENT_CLASS (g_class); gst_element_class_set_details (gstelement_class, &gst_bin_details); } static GstObject * gst_bin_child_proxy_get_child_by_index (GstChildProxy * child_proxy, guint index) { GstObject *res; GstBin *bin; bin = GST_BIN_CAST (child_proxy); GST_LOCK (bin); if ((res = g_list_nth_data (bin->children, index))) gst_object_ref (res); GST_UNLOCK (bin); return res; } guint gst_bin_child_proxy_get_children_count (GstChildProxy * child_proxy) { guint num; GstBin *bin; bin = GST_BIN_CAST (child_proxy); GST_LOCK (bin); num = bin->numchildren; GST_UNLOCK (bin); return num; } static void gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data) { GstChildProxyInterface *iface = g_iface; iface->get_children_count = gst_bin_child_proxy_get_children_count; iface->get_child_by_index = gst_bin_child_proxy_get_child_by_index; } static void gst_bin_class_init (GstBinClass * klass) { GObjectClass *gobject_class; GstObjectClass *gstobject_class; GstElementClass *gstelement_class; gobject_class = (GObjectClass *) klass; gstobject_class = (GstObjectClass *) klass; gstelement_class = (GstElementClass *) klass; parent_class = g_type_class_peek_parent (klass); /** * GstBin::element-added: * @bin: the object which emitted the signal. * @element: the element that was added to the bin * * Will be emitted if a new element was removed/added to this bin. */ gst_bin_signals[ELEMENT_ADDED] = g_signal_new ("element-added", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_added), NULL, NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_ELEMENT); /** * GstBin::element-removed: * @bin: the object which emitted the signal. * @element: the element that was removed from the bin * * Will be emitted if an element was removed from this bin. */ gst_bin_signals[ELEMENT_REMOVED] = g_signal_new ("element-removed", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_removed), NULL, NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_ELEMENT); gobject_class->dispose = GST_DEBUG_FUNCPTR (gst_bin_dispose); #ifndef GST_DISABLE_LOADSAVE gstobject_class->save_thyself = GST_DEBUG_FUNCPTR (gst_bin_save_thyself); gstobject_class->restore_thyself = GST_DEBUG_FUNCPTR (gst_bin_restore_thyself); #endif gstelement_class->change_state = GST_DEBUG_FUNCPTR (gst_bin_change_state); gstelement_class->get_state = GST_DEBUG_FUNCPTR (gst_bin_get_state); #ifndef GST_DISABLE_INDEX gstelement_class->set_index = GST_DEBUG_FUNCPTR (gst_bin_set_index_func); #endif gstelement_class->provide_clock = GST_DEBUG_FUNCPTR (gst_bin_provide_clock_func); gstelement_class->set_clock = GST_DEBUG_FUNCPTR (gst_bin_set_clock_func); gstelement_class->send_event = GST_DEBUG_FUNCPTR (gst_bin_send_event); gstelement_class->query = GST_DEBUG_FUNCPTR (gst_bin_query); klass->add_element = GST_DEBUG_FUNCPTR (gst_bin_add_func); klass->remove_element = GST_DEBUG_FUNCPTR (gst_bin_remove_func); } static void gst_bin_init (GstBin * bin) { GstBus *bus; bin->numchildren = 0; bin->children = NULL; bin->children_cookie = 0; bin->eosed = NULL; /* Set up a bus for listening to child elements */ bus = g_object_new (gst_bus_get_type (), NULL); bin->child_bus = bus; gst_bus_set_sync_handler (bus, (GstBusSyncHandler) bin_bus_handler, bin); } /** * gst_bin_new: * @name: name of new bin * * Create a new bin with given name. * * Returns: new bin */ GstElement * gst_bin_new (const gchar * name) { return gst_element_factory_make ("bin", name); } /* set the index on all elements in this bin * * MT safe */ #ifndef GST_DISABLE_INDEX static void gst_bin_set_index_func (GstElement * element, GstIndex * index) { GstBin *bin; GList *children; bin = GST_BIN (element); GST_LOCK (bin); for (children = bin->children; children; children = g_list_next (children)) { GstElement *child = GST_ELEMENT (children->data); gst_element_set_index (child, index); } GST_UNLOCK (bin); } #endif /* set the clock on all elements in this bin * * MT safe */ static void gst_bin_set_clock_func (GstElement * element, GstClock * clock) { GList *children; GstBin *bin; bin = GST_BIN (element); GST_LOCK (bin); for (children = bin->children; children; children = g_list_next (children)) { GstElement *child = GST_ELEMENT (children->data); gst_element_set_clock (child, clock); } GST_UNLOCK (bin); } /* get the clock for this bin by asking all of the children in this bin * * The ref of the returned clock in increased so unref after usage. * * MT safe * * FIXME, clock selection is not correct here. */ static GstClock * gst_bin_provide_clock_func (GstElement * element) { GstClock *result = NULL; GstBin *bin; GList *children; bin = GST_BIN (element); GST_LOCK (bin); for (children = bin->children; children; children = g_list_next (children)) { GstElement *child = GST_ELEMENT (children->data); result = gst_element_provide_clock (child); if (result) break; } GST_UNLOCK (bin); return result; } /* Check if the bin is EOS. We do this by scanning all sinks and * checking if they posted EOS. * * call with bin LOCK */ static gboolean is_eos (GstBin * bin) { gboolean result; GList *walk; result = TRUE; for (walk = bin->children; walk; walk = g_list_next (walk)) { GstElement *element; element = GST_ELEMENT_CAST (walk->data); if (bin_element_is_sink (element, bin) == 0) { if (!g_list_find (bin->eosed, element)) { GST_DEBUG ("element did not post EOS yet"); result = FALSE; break; } else { GST_DEBUG ("element posted EOS"); } } } return result; } static void unlink_pads (GstPad * pad) { GstPad *peer; if ((peer = gst_pad_get_peer (pad))) { if (gst_pad_get_direction (pad) == GST_PAD_SRC) gst_pad_unlink (pad, peer); else gst_pad_unlink (peer, pad); gst_object_unref (peer); } gst_object_unref (pad); } /* add an element to this bin * * MT safe */ static gboolean gst_bin_add_func (GstBin * bin, GstElement * element) { gchar *elem_name; GstIterator *it; /* we obviously can't add ourself to ourself */ if (G_UNLIKELY (GST_ELEMENT_CAST (element) == GST_ELEMENT_CAST (bin))) goto adding_itself; /* get the element name to make sure it is unique in this bin. */ GST_LOCK (element); elem_name = g_strdup (GST_ELEMENT_NAME (element)); GST_UNLOCK (element); GST_LOCK (bin); /* then check to see if the element's name is already taken in the bin, * we can safely take the lock here. This check is probably bogus because * you can safely change the element name after this check and before setting * the object parent. The window is very small though... */ if (G_UNLIKELY (!gst_object_check_uniqueness (bin->children, elem_name))) goto duplicate_name; /* set the element's parent and add the element to the bin's list of children */ if (G_UNLIKELY (!gst_object_set_parent (GST_OBJECT_CAST (element), GST_OBJECT_CAST (bin)))) goto had_parent; /* if we add a sink we become a sink */ if (GST_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK)) { GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was sink", elem_name); GST_FLAG_SET (bin, GST_ELEMENT_IS_SINK); } bin->children = g_list_prepend (bin->children, element); bin->numchildren++; bin->children_cookie++; /* distribute the bus */ gst_element_set_bus (element, bin->child_bus); /* propagate the current base time and clock */ GST_DEBUG_OBJECT (element, "setting base time %" GST_TIME_FORMAT, GST_TIME_ARGS (GST_ELEMENT (bin)->base_time)); gst_element_set_base_time (element, GST_ELEMENT (bin)->base_time); GST_DEBUG_OBJECT (element, "setting clock %p", GST_ELEMENT_CLOCK (bin)); gst_element_set_clock (element, GST_ELEMENT_CLOCK (bin)); GST_UNLOCK (bin); /* unlink all linked pads */ it = gst_element_iterate_pads (element); gst_iterator_foreach (it, (GFunc) unlink_pads, element); gst_iterator_free (it); GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "added element \"%s\"", elem_name); g_free (elem_name); g_signal_emit (G_OBJECT (bin), gst_bin_signals[ELEMENT_ADDED], 0, element); return TRUE; /* ERROR handling here */ adding_itself: { GST_LOCK (bin); g_warning ("Cannot add bin %s to itself", GST_ELEMENT_NAME (bin)); GST_UNLOCK (bin); return FALSE; } duplicate_name: { g_warning ("Name %s is not unique in bin %s, not adding", elem_name, GST_ELEMENT_NAME (bin)); GST_UNLOCK (bin); g_free (elem_name); return FALSE; } had_parent: { g_warning ("Element %s already has parent", elem_name); GST_UNLOCK (bin); g_free (elem_name); return FALSE; } } /** * gst_bin_add: * @bin: #GstBin to add element to * @element: #GstElement to add to bin * * Adds the given element to the bin. Sets the element's parent, and thus * takes ownership of the element. An element can only be added to one bin. * * If the element's pads are linked to other pads, the pads will be unlinked * before the element is added to the bin. * * MT safe. * * Returns: TRUE if the element could be added, FALSE on wrong parameters or * the bin does not want to accept the element. */ gboolean gst_bin_add (GstBin * bin, GstElement * element) { GstBinClass *bclass; gboolean result; g_return_val_if_fail (GST_IS_BIN (bin), FALSE); g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE); bclass = GST_BIN_GET_CLASS (bin); if (G_UNLIKELY (bclass->add_element == NULL)) goto no_function; GST_CAT_DEBUG (GST_CAT_PARENTAGE, "adding element %s to bin %s", GST_ELEMENT_NAME (element), GST_ELEMENT_NAME (bin)); result = bclass->add_element (bin, element); return result; /* ERROR handling */ no_function: { g_warning ("adding elements to bin %s is not supported", GST_ELEMENT_NAME (bin)); return FALSE; } } /* remove an element from the bin * * MT safe */ static gboolean gst_bin_remove_func (GstBin * bin, GstElement * element) { gchar *elem_name; GstIterator *it; GST_LOCK (element); /* Check if the element is already being removed and immediately * return */ if (G_UNLIKELY (GST_FLAG_IS_SET (element, GST_ELEMENT_UNPARENTING))) goto already_removing; GST_FLAG_SET (element, GST_ELEMENT_UNPARENTING); /* grab element name so we can print it */ elem_name = g_strdup (GST_ELEMENT_NAME (element)); GST_UNLOCK (element); /* unlink all linked pads */ it = gst_element_iterate_pads (element); gst_iterator_foreach (it, (GFunc) unlink_pads, element); gst_iterator_free (it); GST_LOCK (bin); /* the element must be in the bin's list of children */ if (G_UNLIKELY (g_list_find (bin->children, element) == NULL)) goto not_in_bin; /* now remove the element from the list of elements */ bin->children = g_list_remove (bin->children, element); bin->numchildren--; bin->children_cookie++; /* check if we removed a sink */ if (GST_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK)) { GList *other_sink; /* check if we removed the last sink */ other_sink = g_list_find_custom (bin->children, bin, (GCompareFunc) bin_element_is_sink); if (!other_sink) { /* yups, we're not a sink anymore */ GST_FLAG_UNSET (bin, GST_ELEMENT_IS_SINK); } } GST_UNLOCK (bin); GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "removed child \"%s\"", elem_name); g_free (elem_name); gst_element_set_bus (element, NULL); /* unlock any waiters for the state change. It is possible that * we are waiting for an ASYNC state change on this element. The * element cannot be added to another bin yet as it is not yet * unparented. */ GST_STATE_LOCK (element); GST_STATE_BROADCAST (element); GST_STATE_UNLOCK (element); /* we ref here because after the _unparent() the element can be disposed * and we still need it to reset the UNPARENTING flag and fire a signal. */ gst_object_ref (element); gst_object_unparent (GST_OBJECT_CAST (element)); GST_LOCK (element); GST_FLAG_UNSET (element, GST_ELEMENT_UNPARENTING); GST_UNLOCK (element); g_signal_emit (G_OBJECT (bin), gst_bin_signals[ELEMENT_REMOVED], 0, element); /* element is really out of our control now */ gst_object_unref (element); return TRUE; /* ERROR handling */ not_in_bin: { g_warning ("Element %s is not in bin %s", elem_name, GST_ELEMENT_NAME (bin)); GST_UNLOCK (bin); g_free (elem_name); return FALSE; } already_removing: { GST_UNLOCK (element); return FALSE; } } /** * gst_bin_remove: * @bin: #GstBin to remove element from * @element: #GstElement to remove * * Remove the element from its associated bin, unparenting it as well. * Unparenting the element means that the element will be dereferenced, * so if the bin holds the only reference to the element, the element * will be freed in the process of removing it from the bin. If you * want the element to still exist after removing, you need to call * gst_object_ref() before removing it from the bin. * * If the element's pads are linked to other pads, the pads will be unlinked * before the element is removed from the bin. * * MT safe. * * Returns: TRUE if the element could be removed, FALSE on wrong parameters or * the bin does not want to remove the element. */ gboolean gst_bin_remove (GstBin * bin, GstElement * element) { GstBinClass *bclass; gboolean result; g_return_val_if_fail (GST_IS_BIN (bin), FALSE); g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE); bclass = GST_BIN_GET_CLASS (bin); if (G_UNLIKELY (bclass->remove_element == NULL)) goto no_function; GST_CAT_DEBUG (GST_CAT_PARENTAGE, "removing element %s from bin %s", GST_ELEMENT_NAME (element), GST_ELEMENT_NAME (bin)); result = bclass->remove_element (bin, element); return result; /* ERROR handling */ no_function: { g_warning ("removing elements from bin %s is not supported", GST_ELEMENT_NAME (bin)); return FALSE; } } static GstIteratorItem iterate_child (GstIterator * it, GstElement * child) { gst_object_ref (child); return GST_ITERATOR_ITEM_PASS; } /** * gst_bin_iterate_elements: * @bin: #Gstbin to iterate the elements of * * Get an iterator for the elements in this bin. * Each element will have its refcount increased, so unref * after use. * * MT safe. * * Returns: a #GstIterator of #GstElements. gst_iterator_free after * use. returns NULL when passing bad parameters. */ GstIterator * gst_bin_iterate_elements (GstBin * bin) { GstIterator *result; g_return_val_if_fail (GST_IS_BIN (bin), NULL); GST_LOCK (bin); /* add ref because the iterator refs the bin. When the iterator * is freed it will unref the bin again using the provided dispose * function. */ gst_object_ref (bin); result = gst_iterator_new_list (GST_TYPE_ELEMENT, GST_GET_LOCK (bin), &bin->children_cookie, &bin->children, bin, (GstIteratorItemFunction) iterate_child, (GstIteratorDisposeFunction) gst_object_unref); GST_UNLOCK (bin); return result; } static GstIteratorItem iterate_child_recurse (GstIterator * it, GstElement * child) { gst_object_ref (child); if (GST_IS_BIN (child)) { GstIterator *other = gst_bin_iterate_recurse (GST_BIN (child)); gst_iterator_push (it, other); } return GST_ITERATOR_ITEM_PASS; } /** * gst_bin_iterate_recurse: * @bin: #Gstbin to iterate the elements of * * Get an iterator for the elements in this bin. * Each element will have its refcount increased, so unref * after use. This iterator recurses into GstBin children. * * MT safe. * * Returns: a #GstIterator of #GstElements. gst_iterator_free after * use. returns NULL when passing bad parameters. */ GstIterator * gst_bin_iterate_recurse (GstBin * bin) { GstIterator *result; g_return_val_if_fail (GST_IS_BIN (bin), NULL); GST_LOCK (bin); /* add ref because the iterator refs the bin. When the iterator * is freed it will unref the bin again using the provided dispose * function. */ gst_object_ref (bin); result = gst_iterator_new_list (GST_TYPE_ELEMENT, GST_GET_LOCK (bin), &bin->children_cookie, &bin->children, bin, (GstIteratorItemFunction) iterate_child_recurse, (GstIteratorDisposeFunction) gst_object_unref); GST_UNLOCK (bin); return result; } /* returns 0 when TRUE because this is a GCompareFunc */ /* MT safe */ static gint bin_element_is_sink (GstElement * child, GstBin * bin) { gboolean is_sink; /* we lock the child here for the remainder of the function to * get its name safely. */ GST_LOCK (child); is_sink = GST_FLAG_IS_SET (child, GST_ELEMENT_IS_SINK); GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "child %s %s sink", GST_OBJECT_NAME (child), is_sink ? "is" : "is not"); GST_UNLOCK (child); return is_sink ? 0 : 1; } static gint sink_iterator_filter (GstElement * child, GstBin * bin) { if (bin_element_is_sink (child, bin) == 0) { /* returns 0 because this is a GCompareFunc */ return 0; } else { /* child carries a ref from gst_bin_iterate_elements -- drop if not passing through */ gst_object_unref ((GstObject *) child); return 1; } } /** * gst_bin_iterate_sinks: * @bin: #Gstbin to iterate on * * Get an iterator for the sink elements in this bin. * Each element will have its refcount increased, so unref * after use. * * The sink elements are those without any linked srcpads. * * MT safe. * * Returns: a #GstIterator of #GstElements. gst_iterator_free after use. */ GstIterator * gst_bin_iterate_sinks (GstBin * bin) { GstIterator *children; GstIterator *result; g_return_val_if_fail (GST_IS_BIN (bin), NULL); children = gst_bin_iterate_elements (bin); result = gst_iterator_filter (children, (GCompareFunc) sink_iterator_filter, bin); return result; } /* 2 phases: * 1) check state of all children with 0 timeout to find ERROR and * NO_PREROLL elements. return if found. * 2) perform full blocking wait with requested timeout. * * 2) cannot be performed when 1) returns results as the sinks might * not be able to complete the state change making 2) block forever. * * MT safe */ static GstStateChangeReturn gst_bin_get_state (GstElement * element, GstState * state, GstState * pending, GTimeVal * timeout) { GstBin *bin = GST_BIN (element); GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS; GList *children; guint32 children_cookie; gboolean have_no_preroll; GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "getting state"); /* lock bin, no element can be added or removed between going into * the quick scan and the blocking wait. */ GST_LOCK (bin); restart: have_no_preroll = FALSE; /* first we need to poll with a non zero timeout to make sure we don't block * on the sinks when we have NO_PREROLL elements. This is why we do * a quick check if there are still NO_PREROLL elements. We also * catch the error elements this way. */ { GTimeVal tv; gboolean have_async = FALSE; GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "checking for NO_PREROLL"); /* use 0 timeout so we don't block on the sinks */ GST_TIME_TO_TIMEVAL (0, tv); children = bin->children; children_cookie = bin->children_cookie; while (children) { GstElement *child = GST_ELEMENT_CAST (children->data); gst_object_ref (child); /* now we release the lock to enter a non blocking wait. We * release the lock anyway since we can. */ GST_UNLOCK (bin); ret = gst_element_get_state (child, NULL, NULL, &tv); gst_object_unref (child); /* now grab the lock to iterate to the next child */ GST_LOCK (bin); if (G_UNLIKELY (children_cookie != bin->children_cookie)) { /* child added/removed during state change, restart. We need * to restart with the quick check as a no-preroll element could * have been added here and we don't want to block on sinks then.*/ goto restart; } switch (ret) { /* report FAILURE immediatly */ case GST_STATE_CHANGE_FAILURE: goto done; case GST_STATE_CHANGE_NO_PREROLL: /* we have to continue scanning as there might be * ERRORS too */ have_no_preroll = TRUE; break; case GST_STATE_CHANGE_ASYNC: have_async = TRUE; break; default: break; } children = g_list_next (children); } /* if we get here, we have no FAILURES, check for any NO_PREROLL * elements then. */ if (have_no_preroll) { ret = GST_STATE_CHANGE_NO_PREROLL; goto done; } /* if we get here, no NO_PREROLL elements are in the pipeline */ GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "no NO_PREROLL elements"); /* if no ASYNC elements exist we don't even have to poll with a * timeout again */ if (!have_async) { ret = GST_STATE_CHANGE_SUCCESS; goto done; } } /* next we poll all children for their state to see if one of them * is still busy with its state change. We did not release the bin lock * yet so the elements are the same as the ones from the quick scan. */ children = bin->children; children_cookie = bin->children_cookie; while (children) { GstElement *child = GST_ELEMENT_CAST (children->data); gst_object_ref (child); /* now we release the lock to enter the potentialy blocking wait */ GST_UNLOCK (bin); /* ret is ASYNC if some child is still performing the state change * ater the timeout. */ ret = gst_element_get_state (child, NULL, NULL, timeout); gst_object_unref (child); /* now grab the lock to iterate to the next child */ GST_LOCK (bin); if (G_UNLIKELY (children_cookie != bin->children_cookie)) { /* child added/removed during state change, restart. We need * to restart with the quick check as a no-preroll element could * have been added here and we don't want to block on sinks then.*/ goto restart; } switch (ret) { case GST_STATE_CHANGE_SUCCESS: break; case GST_STATE_CHANGE_FAILURE: case GST_STATE_CHANGE_NO_PREROLL: /* report FAILURE and NO_PREROLL immediatly */ goto done; case GST_STATE_CHANGE_ASYNC: goto done; default: g_assert_not_reached (); } children = g_list_next (children); } /* if we got here, all elements can do preroll */ have_no_preroll = FALSE; done: GST_UNLOCK (bin); /* now we can take the state lock, it is possible that new elements * are added now and we still report the old state. No problem though as * the return is still consistent, the effect is as if the element was * added after this function completed. */ GST_STATE_LOCK (bin); switch (ret) { case GST_STATE_CHANGE_SUCCESS: /* we can commit the state */ gst_element_commit_state (element); break; case GST_STATE_CHANGE_FAILURE: /* some element failed, abort the state change */ gst_element_abort_state (element); break; default: /* other cases are just passed along */ break; } /* and report the state if needed */ if (state) *state = GST_STATE (element); if (pending) *pending = GST_STATE_PENDING (element); GST_STATE_NO_PREROLL (element) = have_no_preroll; GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "state current: %s, pending: %s, error: %d, no_preroll: %d, result: %d", gst_element_state_get_name (GST_STATE (element)), gst_element_state_get_name (GST_STATE_PENDING (element)), GST_STATE_ERROR (element), GST_STATE_NO_PREROLL (element), ret); GST_STATE_UNLOCK (bin); return ret; } /*********************************************** * Topologically sorted iterator * see http://en.wikipedia.org/wiki/Topological_sorting * * For each element in the graph, an entry is kept in a HashTable * with its number of srcpad connections (degree). * We then change state of all elements without dependencies * (degree 0) and decrement the degree of all elements connected * on the sinkpads. When an element reaches degree 0, its state is * changed next. * When all elements are handled the algorithm stops. */ typedef struct _GstBinSortIterator { GstIterator it; GQueue *queue; /* elements queued for state change */ GstBin *bin; /* bin we iterate */ gint mode; /* adding or removing dependency */ GstElement *best; /* next element with least dependencies */ gint best_deg; /* best degree */ GHashTable *hash; /* has table with element dependencies */ } GstBinSortIterator; /* we add and subtract 1 to make sure we don't confuse NULL and 0 */ #define HASH_SET_DEGREE(bit, elem, deg) \ g_hash_table_replace (bit->hash, elem, GINT_TO_POINTER(deg+1)) #define HASH_GET_DEGREE(bit, elem) \ (GPOINTER_TO_INT(g_hash_table_lookup (bit->hash, elem))-1) /* add element to queue of next elements in the iterator. * We push at the tail to give higher priority elements a * chance first */ static void add_to_queue (GstBinSortIterator * bit, GstElement * element) { GST_DEBUG ("%s add to queue", GST_ELEMENT_NAME (element)); gst_object_ref (element); g_queue_push_tail (bit->queue, element); HASH_SET_DEGREE (bit, element, -1); } /* clear the queue, unref all objects as we took a ref when * we added them to the queue */ static void clear_queue (GQueue * queue) { gpointer p; while ((p = g_queue_pop_head (queue))) gst_object_unref (p); } /* set all degrees to 0. Elements marked as a sink are * added to the queue immediatly. */ static void reset_degree (GstElement * element, GstBinSortIterator * bit) { /* sinks are added right away */ if (GST_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK)) { add_to_queue (bit, element); } else { /* others are marked with 0 and handled when sinks are done */ HASH_SET_DEGREE (bit, element, 0); } } /* adjust the degree of all elements connected to the given * element. If an degree of an element drops to 0, it is * added to the queue of elements to schedule next. * * We have to make sure not to cross the bin boundary this element * belongs to. */ static void update_degree (GstElement * element, GstBinSortIterator * bit) { gboolean linked = FALSE; GST_LOCK (element); /* don't touch degree if element has no sourcepads */ if (element->numsinkpads != 0) { /* loop over all sinkpads, decrement degree for all connected * elements in this bin */ GList *pads; for (pads = element->sinkpads; pads; pads = g_list_next (pads)) { GstPad *peer; if ((peer = gst_pad_get_peer (GST_PAD_CAST (pads->data)))) { GstElement *peer_element; if ((peer_element = gst_pad_get_parent_element (peer))) { GST_LOCK (peer_element); /* check that we don't go outside of this bin */ if (GST_OBJECT_CAST (peer_element)->parent == GST_OBJECT_CAST (bit->bin)) { gint old_deg, new_deg; old_deg = HASH_GET_DEGREE (bit, peer_element); new_deg = old_deg + bit->mode; GST_DEBUG ("change element %s, degree %d->%d, linked to %s", GST_ELEMENT_NAME (peer_element), old_deg, new_deg, GST_ELEMENT_NAME (element)); /* update degree */ if (new_deg == 0) { /* degree hit 0, add to queue */ add_to_queue (bit, peer_element); } else { HASH_SET_DEGREE (bit, peer_element, new_deg); } linked = TRUE; } GST_UNLOCK (peer_element); gst_object_unref (peer_element); } gst_object_unref (peer); } } } if (!linked) { GST_DEBUG ("element %s not linked on any sinkpads", GST_ELEMENT_NAME (element)); } GST_UNLOCK (element); } /* find the next best element not handled yet. This is the one * with the lowest non-negative degree */ static void find_element (GstElement * element, GstBinSortIterator * bit) { gint degree; /* element is already handled */ if ((degree = HASH_GET_DEGREE (bit, element)) < 0) return; /* first element or element with smaller degree */ if (bit->best == NULL || bit->best_deg > degree) { bit->best = element; bit->best_deg = degree; } } /* get next element in iterator. the returned element has the * refcount increased */ static GstIteratorResult gst_bin_sort_iterator_next (GstBinSortIterator * bit, gpointer * result) { /* empty queue, we have to find a next best element */ if (g_queue_is_empty (bit->queue)) { bit->best = NULL; bit->best_deg = G_MAXINT; g_list_foreach (bit->bin->children, (GFunc) find_element, bit); if (bit->best) { if (bit->best_deg != 0) { /* we don't fail on this one yet */ g_warning ("loop detected in the graph !!"); } /* best unhandled element, schedule as next element */ GST_DEBUG ("queue empty, next best: %s", GST_ELEMENT_NAME (bit->best)); gst_object_ref (bit->best); HASH_SET_DEGREE (bit, bit->best, -1); *result = bit->best; } else { GST_DEBUG ("queue empty, elements exhausted"); /* no more unhandled elements, we are done */ return GST_ITERATOR_DONE; } } else { /* everything added to the queue got reffed */ *result = g_queue_pop_head (bit->queue); } GST_DEBUG ("queue head gives %s", GST_ELEMENT_NAME (*result)); /* update degrees of linked elements */ update_degree (GST_ELEMENT_CAST (*result), bit); return GST_ITERATOR_OK; } /* clear queues, recalculate the degrees and restart. */ static void gst_bin_sort_iterator_resync (GstBinSortIterator * bit) { clear_queue (bit->queue); /* reset degrees */ g_list_foreach (bit->bin->children, (GFunc) reset_degree, bit); /* calc degrees, incrementing */ bit->mode = 1; g_list_foreach (bit->bin->children, (GFunc) update_degree, bit); /* for the rest of the function we decrement the degrees */ bit->mode = -1; } /* clear queues, unref bin and free iterator. */ static void gst_bin_sort_iterator_free (GstBinSortIterator * bit) { clear_queue (bit->queue); g_queue_free (bit->queue); g_hash_table_destroy (bit->hash); gst_object_unref (bit->bin); g_free (bit); } /** * gst_bin_iterate_sorted: * @bin: #Gstbin to iterate on * * Get an iterator for the elements in this bin in topologically * sorted order. This means that the elements are returned from * the most downstream elements (sinks) to the sources. * * This function is used internally to perform the state changes * of the bin elements. * * Each element will have its refcount increased, so unref * after use. * * MT safe. * * Returns: a #GstIterator of #GstElements. gst_iterator_free after use. */ GstIterator * gst_bin_iterate_sorted (GstBin * bin) { GstBinSortIterator *result; g_return_val_if_fail (GST_IS_BIN (bin), NULL); GST_LOCK (bin); gst_object_ref (bin); /* we don't need a NextFunction because we ref the items in the _next * method already */ result = (GstBinSortIterator *) gst_iterator_new (GST_TYPE_ELEMENT, sizeof (GstBinSortIterator), GST_GET_LOCK (bin), &bin->children_cookie, (GstIteratorNextFunction) gst_bin_sort_iterator_next, (GstIteratorItemFunction) NULL, (GstIteratorResyncFunction) gst_bin_sort_iterator_resync, (GstIteratorFreeFunction) gst_bin_sort_iterator_free); result->queue = g_queue_new (); result->hash = g_hash_table_new (NULL, NULL); result->bin = bin; gst_bin_sort_iterator_resync (result); GST_UNLOCK (bin); return (GstIterator *) result; } static GstStateChangeReturn gst_bin_element_set_state (GstBin * bin, GstElement * element, GstState pending) { GstStateChangeReturn ret; gboolean locked; /* peel off the locked flag */ GST_LOCK (element); locked = GST_FLAG_IS_SET (element, GST_ELEMENT_LOCKED_STATE); GST_UNLOCK (element); /* skip locked elements */ if (G_UNLIKELY (locked)) { ret = GST_STATE_CHANGE_SUCCESS; goto done; } /* change state */ ret = gst_element_set_state (element, pending); done: return ret; } static GstStateChangeReturn gst_bin_change_state (GstElement * element, GstStateChange transition) { GstBin *bin; GstStateChangeReturn ret; GstState old_state, pending; gboolean have_async; gboolean have_no_preroll; GstClockTime base_time; GstIterator *it; gboolean done; /* we don't need to take the STATE_LOCK, it is already taken */ old_state = GST_STATE (element); pending = GST_STATE_PENDING (element); GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "changing state of children from %s to %s", gst_element_state_get_name (old_state), gst_element_state_get_name (pending)); if (pending == GST_STATE_VOID_PENDING) return GST_STATE_CHANGE_SUCCESS; bin = GST_BIN_CAST (element); /* Clear eosed element list on -> PAUSED */ if (transition == GST_STATE_CHANGE_READY_TO_PAUSED || transition == GST_STATE_CHANGE_PLAYING_TO_PAUSED) { GST_LOCK (bin); g_list_free (bin->eosed); bin->eosed = NULL; GST_UNLOCK (bin); } /* iterate in state change order */ it = gst_bin_iterate_sorted (bin); restart: /* take base time */ base_time = gst_element_get_base_time (element); have_async = FALSE; have_no_preroll = FALSE; done = FALSE; while (!done) { gpointer data; switch (gst_iterator_next (it, &data)) { case GST_ITERATOR_OK: { GstElement *child; child = GST_ELEMENT_CAST (data); /* set base time on element */ gst_element_set_base_time (child, base_time); /* set state now */ ret = gst_bin_element_set_state (bin, child, pending); switch (ret) { case GST_STATE_CHANGE_SUCCESS: GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "child '%s' changed state to %d(%s) successfully", GST_ELEMENT_NAME (child), pending, gst_element_state_get_name (pending)); break; case GST_STATE_CHANGE_ASYNC: GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "child '%s' is changing state asynchronously", GST_ELEMENT_NAME (child)); have_async = TRUE; break; case GST_STATE_CHANGE_FAILURE: GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "child '%s' failed to go to state %d(%s)", GST_ELEMENT_NAME (child), pending, gst_element_state_get_name (pending)); gst_object_unref (child); goto done; case GST_STATE_CHANGE_NO_PREROLL: GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "child '%s' changed state to %d(%s) successfully without preroll", GST_ELEMENT_NAME (child), pending, gst_element_state_get_name (pending)); have_no_preroll = TRUE; break; default: g_assert_not_reached (); break; } gst_object_unref (child); break; } case GST_ITERATOR_RESYNC: GST_CAT_DEBUG (GST_CAT_STATES, "iterator doing resync"); gst_iterator_resync (it); goto restart; break; default: case GST_ITERATOR_DONE: GST_CAT_DEBUG (GST_CAT_STATES, "iterator done"); done = TRUE; break; } } if (have_no_preroll) { ret = GST_STATE_CHANGE_NO_PREROLL; } else if (have_async) { ret = GST_STATE_CHANGE_ASYNC; } else { ret = parent_class->change_state (element, transition); } done: gst_iterator_free (it); GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "done changing bin's state from %s to %s, now in %s, ret %d", gst_element_state_get_name (old_state), gst_element_state_get_name (pending), gst_element_state_get_name (GST_STATE (element)), ret); return ret; } static void gst_bin_dispose (GObject * object) { GstBin *bin = GST_BIN (object); GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object, "dispose"); g_list_free (bin->eosed); bin->eosed = NULL; gst_object_unref (bin->child_bus); bin->child_bus = NULL; while (bin->children) { gst_bin_remove (bin, GST_ELEMENT_CAST (bin->children->data)); } if (G_UNLIKELY (bin->children != NULL)) { g_critical ("could not remove elements from bin %s", GST_STR_NULL (GST_OBJECT_NAME (object))); } G_OBJECT_CLASS (parent_class)->dispose (object); } /* * This function is a utility event handler for seek events. * It will send the event to all sinks. * Applications are free to override this behaviour and * implement their own seek handler, but this will work for * pretty much all cases in practice. */ static gboolean gst_bin_send_event (GstElement * element, GstEvent * event) { GstBin *bin = GST_BIN (element); GstIterator *iter; gboolean res = TRUE; gboolean done = FALSE; iter = gst_bin_iterate_sinks (bin); GST_DEBUG_OBJECT (bin, "Sending event to sink children"); while (!done) { gpointer data; switch (gst_iterator_next (iter, &data)) { case GST_ITERATOR_OK: { GstElement *sink; gst_event_ref (event); sink = GST_ELEMENT_CAST (data); res &= gst_element_send_event (sink, event); gst_object_unref (sink); break; } case GST_ITERATOR_RESYNC: gst_iterator_resync (iter); res = TRUE; break; default: case GST_ITERATOR_DONE: done = TRUE; break; } } gst_iterator_free (iter); gst_event_unref (event); return res; } static GstBusSyncReply bin_bus_handler (GstBus * bus, GstMessage * message, GstBin * bin) { GST_DEBUG_OBJECT (bin, "[msg %p] handling child message of type %s", message, gst_message_type_get_name (GST_MESSAGE_TYPE (message))); switch (GST_MESSAGE_TYPE (message)) { case GST_MESSAGE_EOS:{ GstObject *src = GST_MESSAGE_SRC (message); if (src) { gchar *name; gboolean eos; name = gst_object_get_name (src); GST_DEBUG_OBJECT (bin, "got EOS message from %s", name); g_free (name); /* collect all eos messages from the children */ GST_LOCK (bin); bin->eosed = g_list_prepend (bin->eosed, src); eos = is_eos (bin); GST_UNLOCK (bin); /* if we are completely EOS, we forward an EOS message */ if (eos) { GST_DEBUG_OBJECT (bin, "all sinks posted EOS"); gst_element_post_message (GST_ELEMENT_CAST (bin), gst_message_new_eos (GST_OBJECT_CAST (bin))); } } else { GST_DEBUG_OBJECT (bin, "got EOS message from (NULL), not processing"); } /* we drop all EOS messages */ gst_message_unref (message); break; } default: /* Send all other messages upward */ GST_DEBUG_OBJECT (bin, "posting message upward"); gst_element_post_message (GST_ELEMENT_CAST (bin), message); break; } return GST_BUS_DROP; } static gboolean gst_bin_query (GstElement * element, GstQuery * query) { GstBin *bin = GST_BIN (element); GstIterator *iter; gboolean res = FALSE, done = FALSE; iter = gst_bin_iterate_sinks (bin); GST_DEBUG_OBJECT (bin, "Sending event to sink children"); while (!(res || done)) { gpointer data; switch (gst_iterator_next (iter, &data)) { case GST_ITERATOR_OK: { GstElement *sink; sink = GST_ELEMENT_CAST (data); res = gst_element_query (sink, query); gst_object_unref (sink); break; } case GST_ITERATOR_RESYNC: gst_iterator_resync (iter); break; default: case GST_ITERATOR_DONE: done = TRUE; break; } } gst_iterator_free (iter); return res; } static gint compare_name (GstElement * element, const gchar * name) { gint eq; GST_LOCK (element); eq = strcmp (GST_ELEMENT_NAME (element), name); GST_UNLOCK (element); if (eq != 0) { gst_object_unref (element); } return eq; } /** * gst_bin_get_by_name: * @bin: #Gstbin to search * @name: the element name to search for * * Get the element with the given name from this bin. This * function recurses into subbins. * * MT safe. * * Returns: the element with the given name. Returns NULL if the * element is not found or when bad parameters were given. Unref after * use. */ GstElement * gst_bin_get_by_name (GstBin * bin, const gchar * name) { GstIterator *children; GstIterator *result; g_return_val_if_fail (GST_IS_BIN (bin), NULL); GST_CAT_INFO (GST_CAT_PARENTAGE, "[%s]: looking up child element %s", GST_ELEMENT_NAME (bin), name); children = gst_bin_iterate_recurse (bin); result = gst_iterator_find_custom (children, (GCompareFunc) compare_name, (gpointer) name); gst_iterator_free (children); return GST_ELEMENT_CAST (result); } /** * gst_bin_get_by_name_recurse_up: * @bin: #Gstbin to search * @name: the element name to search for * * MT safe. * * Get the element with the given name from this bin. If the * element is not found, a recursion is performed on the parent bin. * * Returns: the element with the given name or NULL when the element * was not found or bad parameters were given. Unref after use. */ GstElement * gst_bin_get_by_name_recurse_up (GstBin * bin, const gchar * name) { GstElement *result; g_return_val_if_fail (GST_IS_BIN (bin), NULL); g_return_val_if_fail (name != NULL, NULL); result = gst_bin_get_by_name (bin, name); if (!result) { GstObject *parent; parent = gst_object_get_parent (GST_OBJECT_CAST (bin)); if (parent) { if (GST_IS_BIN (parent)) { result = gst_bin_get_by_name_recurse_up (GST_BIN_CAST (parent), name); } gst_object_unref (parent); } } return result; } static gint compare_interface (GstElement * element, gpointer interface) { gint ret; if (G_TYPE_CHECK_INSTANCE_TYPE (element, GPOINTER_TO_INT (interface))) { ret = 0; } else { /* we did not find the element, need to release the ref * added by the iterator */ gst_object_unref (element); ret = 1; } return ret; } /** * gst_bin_get_by_interface: * @bin: bin to find element in * @interface: interface to be implemented by interface * * Looks for the first element inside the bin that implements the given * interface. If such an element is found, it returns the element. You can * cast this element to the given interface afterwards. * If you want all elements that implement the interface, use * gst_bin_iterate_all_by_interface(). The function recurses inside bins. * * MT safe. * * Returns: An #GstElement inside the bin implementing the interface. * Unref after use. */ GstElement * gst_bin_get_by_interface (GstBin * bin, GType interface) { GstIterator *children; GstIterator *result; g_return_val_if_fail (GST_IS_BIN (bin), NULL); children = gst_bin_iterate_recurse (bin); result = gst_iterator_find_custom (children, (GCompareFunc) compare_interface, GINT_TO_POINTER (interface)); gst_iterator_free (children); return GST_ELEMENT_CAST (result); } /** * gst_bin_iterate_all_by_interface: * @bin: bin to find elements in * @interface: interface to be implemented by interface * * Looks for all elements inside the bin that implements the given * interface. You can safely cast all returned elements to the given interface. * The function recurses bins inside bins. The iterator will return a series * of #GstElement that should be unreffed after use. * * MT safe. * * Returns: A #GstIterator for the elements inside the bin implementing the * given interface. */ GstIterator * gst_bin_iterate_all_by_interface (GstBin * bin, GType interface) { GstIterator *children; GstIterator *result; g_return_val_if_fail (GST_IS_BIN (bin), NULL); children = gst_bin_iterate_recurse (bin); result = gst_iterator_filter (children, (GCompareFunc) compare_interface, GINT_TO_POINTER (interface)); return result; } #ifndef GST_DISABLE_LOADSAVE static xmlNodePtr gst_bin_save_thyself (GstObject * object, xmlNodePtr parent) { GstBin *bin = GST_BIN (object); xmlNodePtr childlist, elementnode; GList *children; GstElement *child; if (GST_OBJECT_CLASS (parent_class)->save_thyself) GST_OBJECT_CLASS (parent_class)->save_thyself (GST_OBJECT (bin), parent); childlist = xmlNewChild (parent, NULL, (xmlChar *) "children", NULL); GST_CAT_INFO (GST_CAT_XML, "[%s]: saving %d children", GST_ELEMENT_NAME (bin), bin->numchildren); children = bin->children; while (children) { child = GST_ELEMENT (children->data); elementnode = xmlNewChild (childlist, NULL, (xmlChar *) "element", NULL); gst_object_save_thyself (GST_OBJECT (child), elementnode); children = g_list_next (children); } return childlist; } static void gst_bin_restore_thyself (GstObject * object, xmlNodePtr self) { GstBin *bin = GST_BIN (object); xmlNodePtr field = self->xmlChildrenNode; xmlNodePtr childlist; while (field) { if (!strcmp ((char *) field->name, "children")) { GST_CAT_INFO (GST_CAT_XML, "[%s]: loading children", GST_ELEMENT_NAME (object)); childlist = field->xmlChildrenNode; while (childlist) { if (!strcmp ((char *) childlist->name, "element")) { GstElement *element = gst_xml_make_element (childlist, GST_OBJECT (bin)); /* it had to be parented to find the pads, now we ref and unparent so * we can add it to the bin */ gst_object_ref (element); gst_object_unparent (GST_OBJECT (element)); gst_bin_add (bin, element); } childlist = childlist->next; } } field = field->next; } if (GST_OBJECT_CLASS (parent_class)->restore_thyself) (GST_OBJECT_CLASS (parent_class)->restore_thyself) (object, self); } #endif /* GST_DISABLE_LOADSAVE */