/* 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 and element that can contain other elements * * #GstBin is an element that can contain other #GstElement, allowing them to be * managed as a group. * Pads from the child elements can be ghosted to the bin, see #GstGhostPad. * This makes the bin look like any other elements and enables creation of * higher-level abstraction elements. * * 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. * * gst_object_unref() is used to drop your reference to the bin. * * The #GstBin::element-added signal is fired whenever a new element is added to * the bin. Likewise the #GstBin::element-removed signal is fired whenever an * element is removed from the bin. * * Notes * * A #GstBin internally intercepts every #GstMessage posted by its children and * implements the following default behaviour for each of them: * * * GST_MESSAGE_EOS * This message is only posted by sinks in the PLAYING * state. If all sinks posted the EOS message, this bin will post and EOS * message upwards. * * * GST_MESSAGE_SEGMENT_START * just collected and never forwarded upwards. * The messages are used to decide when all elements have completed playback * of their segment. * * * GST_MESSAGE_SEGMENT_DONE * Is posted by #GstBin when all elements that posted * a SEGMENT_START have posted a SEGMENT_DONE. * * * GST_MESSAGE_DURATION * Is posted by an element that detected a change * in the stream duration. The default bin behaviour is to clear any * cached duration values so that the next duration query will perform * a full duration recalculation. The duration change is posted to the * application so that it can refetch the new duration with a duration * query. Note that these messages can be posted before the bin is * prerolled, in which case the duration query might fail. * * * * GST_MESSAGE_CLOCK_LOST * This message is posted by an element when it * can no longer provide a clock. The default bin behaviour is to * check if the lost clock was the one provided by the bin. If so and * the bin is currently in the PLAYING state, the message is forwarded to * the bin parent. * This message is also generated when a clock provider is removed from * the bin. If this message is received by the application, it should * PAUSE the pipeline and set it back to PLAYING to force a new clock * distribution. * * * * GST_MESSAGE_CLOCK_PROVIDE * This message is generated when an element * can provide a clock. This mostly happens when a new clock * provider is added to the bin. The default behaviour of the bin is to * mark the currently selected clock as dirty, which will perform a clock * recalculation the next time the bin is asked to provide a clock. * This message is never sent tot the application but is forwarded to * the parent of the bin. * * * * OTHERS * posted upwards. * * * * * A #GstBin implements the following default behaviour for answering to a * #GstQuery: * * * GST_QUERY_DURATION * If the query has been asked before with the same format * and the bin is a toplevel bin (ie. has no parent), * use the cached previous value. If no previous value was cached, the * query is sent to all sink elements in the bin and the MAXIMUM of all * values is returned. If the bin is a toplevel bin the value is cached. * If no sinks are available in the bin, the query fails. * * * * GST_QUERY_POSITION * The query is sent to all sink elements in the bin and the * MAXIMUM of all values is returned. If no sinks are available in the bin, * the query fails. * * * * OTHERS * the query is forwarded to all sink elements, the result * of the first sink that answers the query successfully is returned. If no * sink is in the bin, the query fails. * * * * A #GstBin will by default forward any event sent to it to all sink elements. * If all the sinks return TRUE, the bin will also return TRUE, else FALSE is * returned. If no sinks are in the bin, the event handler will return TRUE. * * * * * Last reviewed on 2006-04-28 (0.10.6) */ #include "gst_private.h" #include "gstevent.h" #include "gstbin.h" #include "gstmarshal.h" #include "gstinfo.h" #include "gsterror.h" #include "gstindex.h" #include "gstindexfactory.h" #include "gstutils.h" #include "gstchildproxy.h" /* latency is by default enabled now. * live-preroll and no-live-preroll in the environment var GST_COMPAT * to enables or disable it respectively. */ static gboolean enable_latency = TRUE; GST_DEBUG_CATEGORY_STATIC (bin_debug); #define GST_CAT_DEFAULT bin_debug /* a bin is toplevel if it has no parent or when it is configured to behave like * a toplevel bin */ #define BIN_IS_TOPLEVEL(bin) ((GST_OBJECT_PARENT (bin) == NULL) || bin->priv->asynchandling) #define GST_BIN_GET_PRIVATE(obj) \ (G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_BIN, GstBinPrivate)) struct _GstBinPrivate { gboolean asynchandling; /* if we get an ASYNC_DONE message from ourselves, this means that the * subclass will simulate ASYNC behaviour without having ASYNC children. When * such an ASYNC_DONE message is posted while we are doing a state change, we * have to process the message after finishing the state change even when no * child returned GST_STATE_CHANGE_ASYNC. */ gboolean pending_async_done; guint32 structure_cookie; /* cached index */ GstIndex *index; /* forward messages from our children */ gboolean message_forward; }; typedef struct { GstBin *bin; guint32 cookie; GstState pending; } BinContinueData; static void gst_bin_dispose (GObject * object); static void gst_bin_set_property (GObject * object, guint prop_id, const GValue * value, GParamSpec * pspec); static void gst_bin_get_property (GObject * object, guint prop_id, GValue * value, GParamSpec * pspec); static GstStateChangeReturn gst_bin_change_state_func (GstElement * element, GstStateChange transition); static GstStateChangeReturn gst_bin_get_state_func (GstElement * element, GstState * state, GstState * pending, GstClockTime timeout); static void bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret, gboolean flag_pending); static void bin_handle_async_start (GstBin * bin, gboolean new_base_time); static void bin_push_state_continue (BinContinueData * data); static gboolean gst_bin_add_func (GstBin * bin, GstElement * element); static gboolean gst_bin_remove_func (GstBin * bin, GstElement * element); static void gst_bin_set_index_func (GstElement * element, GstIndex * index); static GstIndex *gst_bin_get_index_func (GstElement * element); static GstClock *gst_bin_provide_clock_func (GstElement * element); static gboolean gst_bin_set_clock_func (GstElement * element, GstClock * clock); static void gst_bin_handle_message_func (GstBin * bin, GstMessage * message); 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); static gboolean gst_bin_do_latency_func (GstBin * bin); static void bin_remove_messages (GstBin * bin, GstObject * src, GstMessageType types); static void gst_bin_continue_func (BinContinueData * data); static gint bin_element_is_sink (GstElement * child, GstBin * bin); static gint bin_element_is_src (GstElement * child, GstBin * bin); static GstIterator *gst_bin_sort_iterator_new (GstBin * bin); /* Bin signals and properties */ enum { ELEMENT_ADDED, ELEMENT_REMOVED, DO_LATENCY, LAST_SIGNAL }; #define DEFAULT_ASYNC_HANDLING FALSE #define DEFAULT_MESSAGE_FORWARD FALSE enum { PROP_0, PROP_ASYNC_HANDLING, PROP_MESSAGE_FORWARD, PROP_LAST }; static void gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data); static guint gst_bin_signals[LAST_SIGNAL] = { 0 }; #define _do_init \ { \ const gchar *compat; \ static const GInterfaceInfo iface_info = { \ gst_bin_child_proxy_init, \ NULL, \ NULL}; \ \ g_type_add_interface_static (g_define_type_id, GST_TYPE_CHILD_PROXY, &iface_info); \ \ GST_DEBUG_CATEGORY_INIT (bin_debug, "bin", GST_DEBUG_BOLD, \ "debugging info for the 'bin' container element"); \ \ /* compatibility stuff */ \ compat = g_getenv ("GST_COMPAT"); \ if (compat != NULL) { \ if (strstr (compat, "no-live-preroll")) \ enable_latency = FALSE; \ else if (strstr (compat, "live-preroll")) \ enable_latency = TRUE; \ } \ } #define gst_bin_parent_class parent_class G_DEFINE_TYPE_WITH_CODE (GstBin, gst_bin, GST_TYPE_ELEMENT, _do_init); 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_OBJECT_LOCK (bin); if ((res = g_list_nth_data (bin->children, index))) gst_object_ref (res); GST_OBJECT_UNLOCK (bin); return res; } static guint gst_bin_child_proxy_get_children_count (GstChildProxy * child_proxy) { guint num; GstBin *bin; bin = GST_BIN_CAST (child_proxy); GST_OBJECT_LOCK (bin); num = bin->numchildren; GST_OBJECT_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 gboolean _gst_boolean_accumulator (GSignalInvocationHint * ihint, GValue * return_accu, const GValue * handler_return, gpointer dummy) { gboolean myboolean; myboolean = g_value_get_boolean (handler_return); if (!(ihint->run_type & G_SIGNAL_RUN_CLEANUP)) g_value_set_boolean (return_accu, myboolean); GST_DEBUG ("invocation %d, %d", ihint->run_type, myboolean); /* stop emission */ return FALSE; } static void gst_bin_class_init (GstBinClass * klass) { GObjectClass *gobject_class; GstObjectClass *gstobject_class; GstElementClass *gstelement_class; GError *err; gobject_class = (GObjectClass *) klass; gstobject_class = (GstObjectClass *) klass; gstelement_class = (GstElementClass *) klass; g_type_class_add_private (klass, sizeof (GstBinPrivate)); gobject_class->set_property = gst_bin_set_property; gobject_class->get_property = gst_bin_get_property; /** * GstBin:async-handling * * If set to #TRUE, the bin will handle asynchronous state changes. * This should be used only if the bin subclass is modifying the state * of its children on its own. * * Since: 0.10.13 */ g_object_class_install_property (gobject_class, PROP_ASYNC_HANDLING, g_param_spec_boolean ("async-handling", "Async Handling", "The bin will handle Asynchronous state changes", DEFAULT_ASYNC_HANDLING, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); /** * GstBin::element-added: * @bin: the #GstBin * @element: the #GstElement that was added to the bin * * Will be emitted after the element was added to the 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 #GstBin * @element: the #GstElement that was removed from the bin * * Will be emitted after the element was removed from the 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); /** * GstBin::do-latency: * @bin: the #GstBin * * Will be emitted when the bin needs to perform latency calculations. This * signal is only emited for toplevel bins or when async-handling is * enabled. * * Only one signal handler is invoked. If no signals are connected, the * default handler is invoked, which will query and distribute the lowest * possible latency to all sinks. * * Connect to this signal if the default latency calculations are not * sufficient, like when you need different latencies for different sinks in * the same pipeline. * * Since: 0.10.22 */ gst_bin_signals[DO_LATENCY] = g_signal_new ("do-latency", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstBinClass, do_latency), _gst_boolean_accumulator, NULL, gst_marshal_BOOLEAN__VOID, G_TYPE_BOOLEAN, 0, G_TYPE_NONE); /** * GstBin:message-forward * * Forward all children messages, even those that would normally be filtered by * the bin. This can be interesting when one wants to be notified of the EOS * state of individual elements, for example. * * The messages are converted to an ELEMENT message with the bin as the * source. The structure of the message is named 'GstBinForwarded' and contains * a field named 'message' of type GST_TYPE_MESSAGE that contains the original * forwarded message. * * Since: 0.10.31 */ g_object_class_install_property (gobject_class, PROP_MESSAGE_FORWARD, g_param_spec_boolean ("message-forward", "Message Forward", "Forwards all children messages", DEFAULT_MESSAGE_FORWARD, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); gobject_class->dispose = gst_bin_dispose; gst_element_class_set_metadata (gstelement_class, "Generic bin", "Generic/Bin", "Simple container object", "Erik Walthinsen ," "Wim Taymans "); gstelement_class->change_state = GST_DEBUG_FUNCPTR (gst_bin_change_state_func); gstelement_class->get_state = GST_DEBUG_FUNCPTR (gst_bin_get_state_func); gstelement_class->get_index = GST_DEBUG_FUNCPTR (gst_bin_get_index_func); gstelement_class->set_index = GST_DEBUG_FUNCPTR (gst_bin_set_index_func); 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); klass->handle_message = GST_DEBUG_FUNCPTR (gst_bin_handle_message_func); klass->do_latency = GST_DEBUG_FUNCPTR (gst_bin_do_latency_func); GST_DEBUG ("creating bin thread pool"); err = NULL; klass->pool = g_thread_pool_new ((GFunc) gst_bin_continue_func, NULL, -1, FALSE, &err); if (err != NULL) { g_critical ("could alloc threadpool %s", err->message); } } static void gst_bin_init (GstBin * bin) { GstBus *bus; bin->numchildren = 0; bin->children = NULL; bin->children_cookie = 0; bin->messages = NULL; bin->provided_clock = NULL; bin->clock_dirty = FALSE; /* Set up a bus for listening to child elements */ bus = g_object_new (GST_TYPE_BUS, "enable-async", FALSE, NULL); bin->child_bus = bus; GST_DEBUG_OBJECT (bin, "using bus %" GST_PTR_FORMAT " to listen to children", bus); gst_bus_set_sync_handler (bus, (GstBusSyncHandler) bin_bus_handler, bin); bin->priv = GST_BIN_GET_PRIVATE (bin); bin->priv->asynchandling = DEFAULT_ASYNC_HANDLING; bin->priv->structure_cookie = 0; bin->priv->message_forward = DEFAULT_MESSAGE_FORWARD; } static void gst_bin_dispose (GObject * object) { GstBin *bin = GST_BIN_CAST (object); GstBus **child_bus_p = &bin->child_bus; GstClock **provided_clock_p = &bin->provided_clock; GstElement **clock_provider_p = &bin->clock_provider; GstIndex **index_p = &bin->priv->index; GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object, "dispose"); GST_OBJECT_LOCK (object); gst_object_replace ((GstObject **) child_bus_p, NULL); gst_object_replace ((GstObject **) provided_clock_p, NULL); gst_object_replace ((GstObject **) clock_provider_p, NULL); gst_object_replace ((GstObject **) index_p, NULL); bin_remove_messages (bin, NULL, GST_MESSAGE_ANY); GST_OBJECT_UNLOCK (object); 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); } /** * gst_bin_new: * @name: the name of the new bin * * Creates a new bin with the given name. * * Returns: (transfer full): a new #GstBin */ GstElement * gst_bin_new (const gchar * name) { return gst_element_factory_make ("bin", name); } static void gst_bin_set_property (GObject * object, guint prop_id, const GValue * value, GParamSpec * pspec) { GstBin *gstbin; gstbin = GST_BIN_CAST (object); switch (prop_id) { case PROP_ASYNC_HANDLING: GST_OBJECT_LOCK (gstbin); gstbin->priv->asynchandling = g_value_get_boolean (value); GST_OBJECT_UNLOCK (gstbin); break; case PROP_MESSAGE_FORWARD: GST_OBJECT_LOCK (gstbin); gstbin->priv->message_forward = g_value_get_boolean (value); GST_OBJECT_UNLOCK (gstbin); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } static void gst_bin_get_property (GObject * object, guint prop_id, GValue * value, GParamSpec * pspec) { GstBin *gstbin; gstbin = GST_BIN_CAST (object); switch (prop_id) { case PROP_ASYNC_HANDLING: GST_OBJECT_LOCK (gstbin); g_value_set_boolean (value, gstbin->priv->asynchandling); GST_OBJECT_UNLOCK (gstbin); break; case PROP_MESSAGE_FORWARD: GST_OBJECT_LOCK (gstbin); g_value_set_boolean (value, gstbin->priv->message_forward); GST_OBJECT_UNLOCK (gstbin); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } /* return the cached index */ static GstIndex * gst_bin_get_index_func (GstElement * element) { GstBin *bin; GstIndex *result; bin = GST_BIN_CAST (element); GST_OBJECT_LOCK (bin); if ((result = bin->priv->index)) gst_object_ref (result); GST_OBJECT_UNLOCK (bin); return result; } /* set the index on all elements in this bin * * MT safe */ static void gst_bin_set_index_func (GstElement * element, GstIndex * index) { GstBin *bin; gboolean done; GstIterator *it; GstIndex *old; bin = GST_BIN_CAST (element); GST_OBJECT_LOCK (bin); old = bin->priv->index; if (G_UNLIKELY (old == index)) goto was_set; if (index) gst_object_ref (index); bin->priv->index = index; GST_OBJECT_UNLOCK (bin); if (old) gst_object_unref (old); it = gst_bin_iterate_elements (bin); /* set the index on all elements in the bin */ done = FALSE; while (!done) { gpointer data; switch (gst_iterator_next (it, &data)) { case GST_ITERATOR_OK: { GstElement *child = GST_ELEMENT_CAST (data); GST_DEBUG_OBJECT (bin, "setting index on '%s'", GST_ELEMENT_NAME (child)); gst_element_set_index (child, index); gst_object_unref (child); break; } case GST_ITERATOR_RESYNC: GST_DEBUG_OBJECT (bin, "iterator doing resync"); gst_iterator_resync (it); break; default: case GST_ITERATOR_DONE: GST_DEBUG_OBJECT (bin, "iterator done"); done = TRUE; break; } } gst_iterator_free (it); return; was_set: { GST_DEBUG_OBJECT (bin, "index was already set"); GST_OBJECT_UNLOCK (bin); return; } } /* set the clock on all elements in this bin * * MT safe */ static gboolean gst_bin_set_clock_func (GstElement * element, GstClock * clock) { GstBin *bin; gboolean done; GstIterator *it; gboolean res = TRUE; bin = GST_BIN_CAST (element); it = gst_bin_iterate_elements (bin); done = FALSE; while (!done) { gpointer data; switch (gst_iterator_next (it, &data)) { case GST_ITERATOR_OK: { GstElement *child = GST_ELEMENT_CAST (data); res &= gst_element_set_clock (child, clock); gst_object_unref (child); break; } case GST_ITERATOR_RESYNC: GST_DEBUG_OBJECT (bin, "iterator doing resync"); gst_iterator_resync (it); res = TRUE; break; default: case GST_ITERATOR_DONE: GST_DEBUG_OBJECT (bin, "iterator done"); done = TRUE; break; } } gst_iterator_free (it); return res; } /* 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. * * We loop the elements in state order and pick the last clock we can * get. This makes sure we get a clock from the source. * * MT safe */ static GstClock * gst_bin_provide_clock_func (GstElement * element) { GstClock *result = NULL; GstElement *provider = NULL; GstBin *bin; GstIterator *it; gpointer val; GstClock **provided_clock_p; GstElement **clock_provider_p; bin = GST_BIN_CAST (element); GST_OBJECT_LOCK (bin); if (!bin->clock_dirty) goto not_dirty; GST_DEBUG_OBJECT (bin, "finding new clock"); it = gst_bin_sort_iterator_new (bin); while (it->next (it, &val) == GST_ITERATOR_OK) { GstElement *child = GST_ELEMENT_CAST (val); GstClock *clock; clock = gst_element_provide_clock (child); if (clock) { GST_DEBUG_OBJECT (bin, "found candidate clock %p by element %s", clock, GST_ELEMENT_NAME (child)); if (result) { gst_object_unref (result); gst_object_unref (provider); } result = clock; provider = child; } else { gst_object_unref (child); } } provided_clock_p = &bin->provided_clock; clock_provider_p = &bin->clock_provider; gst_object_replace ((GstObject **) provided_clock_p, (GstObject *) result); gst_object_replace ((GstObject **) clock_provider_p, (GstObject *) provider); bin->clock_dirty = FALSE; GST_DEBUG_OBJECT (bin, "provided new clock %" GST_PTR_FORMAT " by provider %" GST_PTR_FORMAT, result, provider); /* Provider is not being returned to caller, just the result */ if (provider) gst_object_unref (provider); GST_OBJECT_UNLOCK (bin); gst_iterator_free (it); return result; not_dirty: { if ((result = bin->provided_clock)) gst_object_ref (result); GST_DEBUG_OBJECT (bin, "returning old clock %p", result); GST_OBJECT_UNLOCK (bin); return result; } } /* * functions for manipulating cached messages */ typedef struct { GstObject *src; GstMessageType types; } MessageFind; /* check if a message is of given src and type */ static gint message_check (GstMessage * message, MessageFind * target) { gboolean eq = TRUE; if (target->src) eq &= GST_MESSAGE_SRC (message) == target->src; if (target->types) eq &= (GST_MESSAGE_TYPE (message) & target->types) != 0; GST_LOG ("looking at message %p: %d", message, eq); return (eq ? 0 : 1); } static GList * find_message (GstBin * bin, GstObject * src, GstMessageType types) { GList *result; MessageFind find; find.src = src; find.types = types; result = g_list_find_custom (bin->messages, &find, (GCompareFunc) message_check); if (result) { GST_DEBUG_OBJECT (bin, "we found a message %p from %s matching types %08x", result->data, GST_OBJECT_NAME (GST_MESSAGE_CAST (result->data)->src), types); } else { GST_DEBUG_OBJECT (bin, "no message found matching types %08x", types); #ifndef GST_DISABLE_GST_DEBUG { guint i; for (i = 0; i < 32; i++) if (types & (1 << i)) GST_DEBUG_OBJECT (bin, " %s", gst_message_type_get_name (1 << i)); } #endif } return result; } /* with LOCK, returns TRUE if message had a valid SRC, takes ownership of * the message. * * A message that is cached and has the same SRC and type is replaced * by the given message. */ static gboolean bin_replace_message (GstBin * bin, GstMessage * message, GstMessageType types) { GList *previous; GstObject *src; gboolean res = TRUE; if ((src = GST_MESSAGE_SRC (message))) { /* first find the previous message posted by this element */ if ((previous = find_message (bin, src, types))) { GstMessage *previous_msg; /* if we found a previous message, replace it */ previous_msg = previous->data; previous->data = message; GST_DEBUG_OBJECT (bin, "replace old message %s from %s with %s message", GST_MESSAGE_TYPE_NAME (previous_msg), GST_ELEMENT_NAME (src), GST_MESSAGE_TYPE_NAME (message)); gst_message_unref (previous_msg); } else { /* keep new message */ bin->messages = g_list_prepend (bin->messages, message); GST_DEBUG_OBJECT (bin, "got new message %p, %s from %s", message, GST_MESSAGE_TYPE_NAME (message), GST_ELEMENT_NAME (src)); } } else { GST_DEBUG_OBJECT (bin, "got message %s from (NULL), not processing", GST_MESSAGE_TYPE_NAME (message)); res = FALSE; gst_message_unref (message); } return res; } /* with LOCK. Remove all messages of given types */ static void bin_remove_messages (GstBin * bin, GstObject * src, GstMessageType types) { MessageFind find; GList *walk, *next; find.src = src; find.types = types; for (walk = bin->messages; walk; walk = next) { GstMessage *message = (GstMessage *) walk->data; next = g_list_next (walk); if (message_check (message, &find) == 0) { GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message), "deleting message %p of types 0x%08x", message, types); bin->messages = g_list_delete_link (bin->messages, walk); gst_message_unref (message); } else { GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message), "not deleting message %p of type 0x%08x", message, GST_MESSAGE_TYPE (message)); } } } /* Check if the bin is EOS. We do this by scanning all sinks and * checking if they posted an EOS message. * * 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) { /* check if element posted EOS */ if (find_message (bin, GST_OBJECT_CAST (element), GST_MESSAGE_EOS)) { GST_DEBUG ("sink '%s' posted EOS", GST_ELEMENT_NAME (element)); } else { GST_DEBUG ("sink '%s' did not post EOS yet", GST_ELEMENT_NAME (element)); result = FALSE; break; } } } 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); } /* vmethod that adds an element to a bin * * MT safe */ static gboolean gst_bin_add_func (GstBin * bin, GstElement * element) { gchar *elem_name; GstIterator *it; gboolean is_sink, is_source; GstMessage *clock_message = NULL, *async_message = NULL; GstStateChangeReturn ret; GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element)); /* 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_OBJECT_LOCK (element); elem_name = g_strdup (GST_ELEMENT_NAME (element)); is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK); is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SOURCE); GST_OBJECT_UNLOCK (element); GST_OBJECT_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 (is_sink) { GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was sink", elem_name); GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_IS_SINK); } if (is_source) { GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was source", elem_name); GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_IS_SOURCE); } if (gst_element_provides_clock (element)) { GST_DEBUG_OBJECT (bin, "element \"%s\" can provide a clock", elem_name); clock_message = gst_message_new_clock_provide (GST_OBJECT_CAST (element), NULL, TRUE); } bin->children = g_list_prepend (bin->children, element); bin->numchildren++; bin->children_cookie++; bin->priv->structure_cookie++; /* distribute the bus */ gst_element_set_bus (element, bin->child_bus); /* propagate the current base_time, start_time and clock */ gst_element_set_base_time (element, GST_ELEMENT_CAST (bin)->base_time); gst_element_set_start_time (element, GST_ELEMENT_START_TIME (bin)); /* it's possible that the element did not accept the clock but * that is not important right now. When the pipeline goes to PLAYING, * a new clock will be selected */ gst_element_set_clock (element, GST_ELEMENT_CLOCK (bin)); /* set the cached index on the children */ if (bin->priv->index) gst_element_set_index (element, bin->priv->index); ret = GST_STATE_RETURN (bin); /* no need to update the state if we are in error */ if (ret == GST_STATE_CHANGE_FAILURE) goto no_state_recalc; /* update the bin state, the new element could have been an ASYNC or * NO_PREROLL element */ ret = GST_STATE_RETURN (element); GST_DEBUG_OBJECT (bin, "added %s element", gst_element_state_change_return_get_name (ret)); switch (ret) { case GST_STATE_CHANGE_ASYNC: { /* create message to track this aync element when it posts an async-done * message */ async_message = gst_message_new_async_start (GST_OBJECT_CAST (element), FALSE); break; } case GST_STATE_CHANGE_NO_PREROLL: /* ignore all async elements we might have and commit our state */ bin_handle_async_done (bin, ret, FALSE); break; case GST_STATE_CHANGE_FAILURE: break; default: break; } no_state_recalc: GST_OBJECT_UNLOCK (bin); /* post the messages on the bus of the element so that the bin can handle * them */ if (clock_message) gst_element_post_message (GST_ELEMENT_CAST (element), clock_message); if (async_message) gst_element_post_message (GST_ELEMENT_CAST (element), async_message); /* 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 (bin, gst_bin_signals[ELEMENT_ADDED], 0, element); gst_child_proxy_child_added ((GstObject *) bin, (GstObject *) element); return TRUE; /* ERROR handling here */ adding_itself: { GST_OBJECT_LOCK (bin); g_warning ("Cannot add bin '%s' to itself", GST_ELEMENT_NAME (bin)); GST_OBJECT_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_OBJECT_UNLOCK (bin); g_free (elem_name); return FALSE; } had_parent: { g_warning ("Element '%s' already has parent", elem_name); GST_OBJECT_UNLOCK (bin); g_free (elem_name); return FALSE; } } /** * gst_bin_add: * @bin: a #GstBin * @element: (transfer full): the #GstElement to add * * 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. * * * When you add an element to an already-running pipeline, you will have to * take care to set the state of the newly-added element to the desired * state (usually PLAYING or PAUSED, same you set the pipeline to originally) * with gst_element_set_state(), or use gst_element_sync_state_with_parent(). * The bin or pipeline will not take care of this for you. * * * MT safe. * * Returns: TRUE if the element could be added, FALSE if * 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_STR_NULL (GST_ELEMENT_NAME (element)), GST_STR_NULL (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; gboolean is_sink, is_source, othersink, othersource, found; GstMessage *clock_message = NULL; GstClock **provided_clock_p; GstElement **clock_provider_p; GList *walk, *next; gboolean other_async, this_async, have_no_preroll; GstStateChangeReturn ret; GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element)); GST_OBJECT_LOCK (element); /* Check if the element is already being removed and immediately * return */ if (G_UNLIKELY (GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_UNPARENTING))) goto already_removing; GST_OBJECT_FLAG_SET (element, GST_ELEMENT_UNPARENTING); /* grab element name so we can print it */ elem_name = g_strdup (GST_ELEMENT_NAME (element)); is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK); is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SOURCE); GST_OBJECT_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_OBJECT_LOCK (bin); found = FALSE; othersink = FALSE; othersource = FALSE; have_no_preroll = FALSE; /* iterate the elements, we collect which ones are async and no_preroll. We * also remove the element when we find it. */ for (walk = bin->children; walk; walk = next) { GstElement *child = GST_ELEMENT_CAST (walk->data); next = g_list_next (walk); if (child == element) { found = TRUE; /* remove the element */ bin->children = g_list_delete_link (bin->children, walk); } else { gboolean child_sink, child_source; GST_OBJECT_LOCK (child); child_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SINK); child_source = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SOURCE); /* when we remove a sink, check if there are other sinks. */ if (is_sink && !othersink && child_sink) othersink = TRUE; if (is_source && !othersource && child_source) othersource = TRUE; /* check if we have NO_PREROLL children */ if (GST_STATE_RETURN (child) == GST_STATE_CHANGE_NO_PREROLL) have_no_preroll = TRUE; GST_OBJECT_UNLOCK (child); } } /* the element must have been in the bin's list of children */ if (G_UNLIKELY (!found)) goto not_in_bin; /* we now removed the element from the list of elements, increment the cookie * so that others can detect a change in the children list. */ bin->numchildren--; bin->children_cookie++; bin->priv->structure_cookie++; if (is_sink && !othersink) { /* we're not a sink anymore */ GST_DEBUG_OBJECT (bin, "we removed the last sink"); GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_IS_SINK); } if (is_source && !othersource) { /* we're not a source anymore */ GST_DEBUG_OBJECT (bin, "we removed the last source"); GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_IS_SOURCE); } /* if the clock provider for this element is removed, we lost * the clock as well, we need to inform the parent of this * so that it can select a new clock */ if (bin->clock_provider == element) { GST_DEBUG_OBJECT (bin, "element \"%s\" provided the clock", elem_name); bin->clock_dirty = TRUE; clock_message = gst_message_new_clock_lost (GST_OBJECT_CAST (bin), bin->provided_clock); provided_clock_p = &bin->provided_clock; clock_provider_p = &bin->clock_provider; gst_object_replace ((GstObject **) provided_clock_p, NULL); gst_object_replace ((GstObject **) clock_provider_p, NULL); } /* remove messages for the element, if there was a pending ASYNC_START * message we must see if removing the element caused the bin to lose its * async state. */ this_async = FALSE; other_async = FALSE; for (walk = bin->messages; walk; walk = next) { GstMessage *message = (GstMessage *) walk->data; GstElement *src = GST_ELEMENT_CAST (GST_MESSAGE_SRC (message)); gboolean remove; next = g_list_next (walk); remove = FALSE; switch (GST_MESSAGE_TYPE (message)) { case GST_MESSAGE_ASYNC_START: if (src == element) this_async = TRUE; else other_async = TRUE; GST_DEBUG_OBJECT (src, "looking at message %p", message); break; case GST_MESSAGE_STRUCTURE_CHANGE: { GstElement *owner; GST_DEBUG_OBJECT (src, "looking at structure change message %p", message); /* it's unlikely that this message is still in the list of messages * because this would mean that a link/unlink is busy in another thread * while we remove the element. We still have to remove the message * because we might not receive the done message anymore when the element * is removed from the bin. */ gst_message_parse_structure_change (message, NULL, &owner, NULL); if (owner == element) remove = TRUE; break; } default: break; } if (src == element) remove = TRUE; if (remove) { /* delete all message types */ GST_DEBUG_OBJECT (src, "deleting message %p of element \"%s\"", message, elem_name); bin->messages = g_list_delete_link (bin->messages, walk); gst_message_unref (message); } } /* get last return */ ret = GST_STATE_RETURN (bin); /* no need to update the state if we are in error */ if (ret == GST_STATE_CHANGE_FAILURE) goto no_state_recalc; if (!other_async && this_async) { /* all other elements were not async and we removed the async one, * handle the async-done case because we are not async anymore now. */ GST_DEBUG_OBJECT (bin, "we removed the last async element, have no_preroll %d", have_no_preroll); /* the current state return of the bin depends on if there are no_preroll * elements in the pipeline or not */ if (have_no_preroll) ret = GST_STATE_CHANGE_NO_PREROLL; else ret = GST_STATE_CHANGE_SUCCESS; bin_handle_async_done (bin, ret, FALSE); } else { GST_DEBUG_OBJECT (bin, "recalc state preroll: %d, other async: %d, this async %d", have_no_preroll, other_async, this_async); if (have_no_preroll) { ret = GST_STATE_CHANGE_NO_PREROLL; } else if (other_async) { /* there are other async elements and we were not doing an async state * change, change our pending state and go async */ if (GST_STATE_PENDING (bin) == GST_STATE_VOID_PENDING) { GST_STATE_NEXT (bin) = GST_STATE (bin); GST_STATE_PENDING (bin) = GST_STATE (bin); } ret = GST_STATE_CHANGE_ASYNC; } GST_STATE_RETURN (bin) = ret; } no_state_recalc: GST_OBJECT_UNLOCK (bin); if (clock_message) gst_element_post_message (GST_ELEMENT_CAST (bin), clock_message); GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "removed child \"%s\"", elem_name); g_free (elem_name); gst_element_set_bus (element, NULL); /* Clear the clock we provided to the element */ gst_element_set_clock (element, NULL); /* 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_OBJECT_LOCK (element); GST_OBJECT_FLAG_UNSET (element, GST_ELEMENT_UNPARENTING); GST_OBJECT_UNLOCK (element); g_signal_emit (bin, gst_bin_signals[ELEMENT_REMOVED], 0, element); gst_child_proxy_child_removed ((GstObject *) bin, (GstObject *) 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_OBJECT_UNLOCK (bin); g_free (elem_name); return FALSE; } already_removing: { GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "already removing child"); GST_OBJECT_UNLOCK (element); return FALSE; } } /** * gst_bin_remove: * @bin: a #GstBin * @element: (transfer none): the #GstElement to remove * * Removes the element from the 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 if * 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: a #GstBin * * Gets an iterator for the elements in this bin. * * Each element yielded by the iterator will have its refcount increased, so * unref after use. * * MT safe. Caller owns returned value. * * Returns: (transfer full): a #GstIterator of #GstElement, or NULL */ GstIterator * gst_bin_iterate_elements (GstBin * bin) { GstIterator *result; g_return_val_if_fail (GST_IS_BIN (bin), NULL); GST_OBJECT_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_OBJECT_GET_LOCK (bin), &bin->children_cookie, &bin->children, bin, (GstIteratorItemFunction) iterate_child, (GstIteratorDisposeFunction) gst_object_unref); GST_OBJECT_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_CAST (child)); gst_iterator_push (it, other); } return GST_ITERATOR_ITEM_PASS; } /** * gst_bin_iterate_recurse: * @bin: a #GstBin * * Gets an iterator for the elements in this bin. * This iterator recurses into GstBin children. * * Each element yielded by the iterator will have its refcount increased, so * unref after use. * * MT safe. Caller owns returned value. * * Returns: (transfer full): a #GstIterator of #GstElement, or NULL */ GstIterator * gst_bin_iterate_recurse (GstBin * bin) { GstIterator *result; g_return_val_if_fail (GST_IS_BIN (bin), NULL); GST_OBJECT_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_OBJECT_GET_LOCK (bin), &bin->children_cookie, &bin->children, bin, (GstIteratorItemFunction) iterate_child_recurse, (GstIteratorDisposeFunction) gst_object_unref); GST_OBJECT_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 and flag safely. */ GST_OBJECT_LOCK (child); is_sink = GST_OBJECT_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_OBJECT_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 (child); return 1; } } /** * gst_bin_iterate_sinks: * @bin: a #GstBin * * Gets an iterator for all elements in the bin that have the * #GST_ELEMENT_IS_SINK flag set. * * Each element yielded by the iterator will have its refcount increased, so * unref after use. * * MT safe. Caller owns returned value. * * Returns: (transfer full): a #GstIterator of #GstElement, or NULL */ 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; } /* returns 0 when TRUE because this is a GCompareFunc */ /* MT safe */ static gint bin_element_is_src (GstElement * child, GstBin * bin) { gboolean is_src; /* we lock the child here for the remainder of the function to * get its name and other info safely. */ GST_OBJECT_LOCK (child); is_src = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SOURCE); GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "child %s %s src", GST_OBJECT_NAME (child), is_src ? "is" : "is not"); GST_OBJECT_UNLOCK (child); return is_src ? 0 : 1; } static gint src_iterator_filter (GstElement * child, GstBin * bin) { if (bin_element_is_src (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 (child); return 1; } } /** * gst_bin_iterate_sources: * @bin: a #GstBin * * Gets an iterator for all elements in the bin that have the * #GST_ELEMENT_IS_SOURCE flag set. * * Each element yielded by the iterator will have its refcount increased, so * unref after use. * * MT safe. Caller owns returned value. * * Returns: (transfer full): a #GstIterator of #GstElement, or NULL */ GstIterator * gst_bin_iterate_sources (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) src_iterator_filter, bin); return result; } /* * MT safe */ static GstStateChangeReturn gst_bin_get_state_func (GstElement * element, GstState * state, GstState * pending, GstClockTime timeout) { GstStateChangeReturn ret; GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "getting state"); ret = GST_ELEMENT_CLASS (parent_class)->get_state (element, state, pending, timeout); 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; /* hashtable with element dependencies */ gboolean dirty; /* we detected structure change */ } 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_OBJECT (bit->bin, "adding '%s' to queue", GST_ELEMENT_NAME (element)); gst_object_ref (element); g_queue_push_tail (bit->queue, element); HASH_SET_DEGREE (bit, element, -1); } static void remove_from_queue (GstBinSortIterator * bit, GstElement * element) { GList *find; if ((find = g_queue_find (bit->queue, element))) { GST_DEBUG_OBJECT (bit->bin, "removing '%s' from queue", GST_ELEMENT_NAME (element)); g_queue_delete_link (bit->queue, find); gst_object_unref (element); } else { GST_DEBUG_OBJECT (bit->bin, "unable to remove '%s' from queue", GST_ELEMENT_NAME (element)); } } /* 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. Since we only look at the SINK flag of the * element, it is possible that we add non-sinks to the queue. These will be * removed from the queue again when we can prove that it provides data for some * other element. */ static void reset_degree (GstElement * element, GstBinSortIterator * bit) { gboolean is_sink; /* sinks are added right away */ GST_OBJECT_LOCK (element); is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK); GST_OBJECT_UNLOCK (element); if (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 a 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_OBJECT_LOCK (element); /* don't touch degree if element has no sinkpads */ 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 *pad, *peer; pad = GST_PAD_CAST (pads->data); /* we're iterating over the sinkpads, check if it's busy in a link/unlink */ if (G_UNLIKELY (find_message (bit->bin, GST_OBJECT_CAST (pad), GST_MESSAGE_STRUCTURE_CHANGE))) { /* mark the iterator as dirty because we won't be updating the degree * of the peer parent now. This would result in the 'loop detected' * later on because the peer parent element could become the best next * element with a degree > 0. We will simply continue our state * changes and we'll eventually resync when the unlink completed and * the iterator cookie is updated. */ bit->dirty = TRUE; continue; } if ((peer = gst_pad_get_peer (pad))) { GstElement *peer_element; if ((peer_element = gst_pad_get_parent_element (peer))) { GST_OBJECT_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); /* check to see if we added an element as sink that was not really a * sink because it was connected to some other element. */ if (old_deg == -1) { remove_from_queue (bit, peer_element); old_deg = 0; } new_deg = old_deg + bit->mode; GST_DEBUG_OBJECT (bit->bin, "change element %s, degree %d->%d, linked to %s", GST_ELEMENT_NAME (peer_element), old_deg, new_deg, GST_ELEMENT_NAME (element)); /* update degree, it is possible that an element was in 0 and * reaches -1 here. This would mean that the element had no sinkpads * but became linked while the state change was happening. We will * resync on this with the structure change message. */ 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_OBJECT_UNLOCK (peer_element); gst_object_unref (peer_element); } gst_object_unref (peer); } } } if (!linked) { GST_DEBUG_OBJECT (bit->bin, "element %s not linked on any sinkpads", GST_ELEMENT_NAME (element)); } GST_OBJECT_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) { GstBin *bin = bit->bin; /* empty queue, we have to find a next best element */ if (g_queue_is_empty (bit->queue)) { GstElement *best; bit->best = NULL; bit->best_deg = G_MAXINT; g_list_foreach (bin->children, (GFunc) find_element, bit); if ((best = bit->best)) { /* when we detected an unlink, don't warn because our degrees might be * screwed up. We will resync later */ if (bit->best_deg != 0 && !bit->dirty) { /* we don't fail on this one yet */ GST_WARNING_OBJECT (bin, "loop dected in graph"); g_warning ("loop detected in the graph of bin '%s'!!", GST_ELEMENT_NAME (bin)); } /* best unhandled element, schedule as next element */ GST_DEBUG_OBJECT (bin, "queue empty, next best: %s", GST_ELEMENT_NAME (best)); gst_object_ref (best); HASH_SET_DEGREE (bit, best, -1); *result = best; } else { GST_DEBUG_OBJECT (bin, "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_OBJECT (bin, "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) { GstBin *bin = bit->bin; GST_DEBUG_OBJECT (bin, "resync"); bit->dirty = FALSE; clear_queue (bit->queue); /* reset degrees */ g_list_foreach (bin->children, (GFunc) reset_degree, bit); /* calc degrees, incrementing */ bit->mode = 1; g_list_foreach (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) { GstBin *bin = bit->bin; GST_DEBUG_OBJECT (bin, "free"); clear_queue (bit->queue); g_queue_free (bit->queue); g_hash_table_destroy (bit->hash); gst_object_unref (bin); g_free (bit); } /* should be called with the bin LOCK held */ static GstIterator * gst_bin_sort_iterator_new (GstBin * bin) { GstBinSortIterator *result; /* we don't need an ItemFunction because we ref the items in the _next * method already */ result = (GstBinSortIterator *) gst_iterator_new (sizeof (GstBinSortIterator), GST_TYPE_ELEMENT, GST_OBJECT_GET_LOCK (bin), &bin->priv->structure_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); gst_object_ref (bin); result->bin = bin; gst_bin_sort_iterator_resync (result); return (GstIterator *) result; } /** * gst_bin_iterate_sorted: * @bin: a #GstBin * * Gets 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 and for clock selection. * * Each element yielded by the iterator will have its refcount increased, so * unref after use. * * MT safe. Caller owns returned value. * * Returns: (transfer full): a #GstIterator of #GstElement, or NULL */ GstIterator * gst_bin_iterate_sorted (GstBin * bin) { GstIterator *result; g_return_val_if_fail (GST_IS_BIN (bin), NULL); GST_OBJECT_LOCK (bin); result = gst_bin_sort_iterator_new (bin); GST_OBJECT_UNLOCK (bin); return result; } static GstStateChangeReturn gst_bin_element_set_state (GstBin * bin, GstElement * element, GstClockTime base_time, GstClockTime start_time, GstState current, GstState next) { GstStateChangeReturn ret; GstState pending, child_current, child_pending; gboolean locked; GList *found; GST_STATE_LOCK (element); GST_OBJECT_LOCK (element); /* set base_time and start time on child */ GST_ELEMENT_START_TIME (element) = start_time; element->base_time = base_time; /* peel off the locked flag */ locked = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_LOCKED_STATE); /* Get the previous set_state result to preserve NO_PREROLL and ASYNC */ ret = GST_STATE_RETURN (element); child_current = GST_STATE (element); child_pending = GST_STATE_PENDING (element); GST_OBJECT_UNLOCK (element); /* skip locked elements */ if (G_UNLIKELY (locked)) goto locked; /* if the element was no preroll, just start changing the state regardless * if it had async elements (in the case of a bin) because they won't preroll * anyway. */ if (G_UNLIKELY (ret == GST_STATE_CHANGE_NO_PREROLL)) { GST_DEBUG_OBJECT (element, "element is NO_PREROLL, ignore async elements"); goto no_preroll; } GST_OBJECT_LOCK (bin); pending = GST_STATE_PENDING (bin); /* Try not to change the state of elements that are already in the state we're * going to */ if (!(next == GST_STATE_PLAYING || child_pending != GST_STATE_VOID_PENDING || (child_pending == GST_STATE_VOID_PENDING && ((pending > child_current && next > child_current) || (pending < child_current && next < child_current))))) goto unneeded; /* the element was busy with an upwards async state change, we must wait for * an ASYNC_DONE message before we attemp to change the state. */ if ((found = find_message (bin, GST_OBJECT_CAST (element), GST_MESSAGE_ASYNC_START))) { #ifndef GST_DISABLE_GST_DEBUG GstMessage *message = GST_MESSAGE_CAST (found->data); GST_DEBUG_OBJECT (element, "element message %p, %s async busy", message, GST_ELEMENT_NAME (GST_MESSAGE_SRC (message))); #endif /* only wait for upward state changes */ if (next > current) { /* We found an async element check if we can force its state to change or * if we have to wait for it to preroll. */ if (G_UNLIKELY (!enable_latency)) { g_warning ("Future versions of GStreamer will wait for element \"%s\"\n" "\tto preroll in order to perform correct latency calculations.\n" "\tPlease verify that the application continues to work correctly by\n" "\tsetting the environment variable GST_COMPAT to a value containing\n" "\tthe string 'live-preroll'.", GST_ELEMENT_NAME (element)); goto no_latency; } goto was_busy; } } no_latency: GST_OBJECT_UNLOCK (bin); no_preroll: GST_DEBUG_OBJECT (bin, "setting element %s to %s, base_time %" GST_TIME_FORMAT, GST_ELEMENT_NAME (element), gst_element_state_get_name (next), GST_TIME_ARGS (base_time)); /* change state */ ret = gst_element_set_state (element, next); GST_STATE_UNLOCK (element); return ret; locked: { GST_DEBUG_OBJECT (element, "element is locked, return previous return %s", gst_element_state_change_return_get_name (ret)); GST_STATE_UNLOCK (element); return ret; } was_busy: { GST_DEBUG_OBJECT (element, "element was busy, delaying state change"); GST_OBJECT_UNLOCK (bin); GST_STATE_UNLOCK (element); return GST_STATE_CHANGE_ASYNC; } unneeded: { GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "skipping transition from %s to %s, since bin pending" " is %s : last change state return follows", gst_element_state_get_name (child_current), gst_element_state_get_name (next), gst_element_state_get_name (pending)); GST_OBJECT_UNLOCK (bin); GST_STATE_UNLOCK (element); return ret; } } /* gst_iterator_fold functions for pads_activate * Stop the iterator if activating one pad failed. */ static gboolean activate_pads (GstPad * pad, GValue * ret, gboolean * active) { gboolean cont = TRUE; if (!(cont = gst_pad_set_active (pad, *active))) g_value_set_boolean (ret, FALSE); else if (!*active) gst_pad_set_caps (pad, NULL); /* unref the object that was reffed for us by _fold */ gst_object_unref (pad); return cont; } /* returns false on error or early cutout of the fold, true if all * pads in @iter were (de)activated successfully. */ static gboolean iterator_activate_fold_with_resync (GstIterator * iter, gpointer user_data) { GstIteratorResult ires; GValue ret = { 0 }; /* no need to unset this later, it's just a boolean */ g_value_init (&ret, G_TYPE_BOOLEAN); g_value_set_boolean (&ret, TRUE); while (1) { ires = gst_iterator_fold (iter, (GstIteratorFoldFunction) activate_pads, &ret, user_data); switch (ires) { case GST_ITERATOR_RESYNC: /* need to reset the result again */ g_value_set_boolean (&ret, TRUE); gst_iterator_resync (iter); break; case GST_ITERATOR_DONE: /* all pads iterated, return collected value */ goto done; default: /* iterator returned _ERROR or premature end with _OK, * mark an error and exit */ g_value_set_boolean (&ret, FALSE); goto done; } } done: /* return collected value */ return g_value_get_boolean (&ret); } /* is called with STATE_LOCK */ static gboolean gst_bin_src_pads_activate (GstBin * bin, gboolean active) { GstIterator *iter; gboolean fold_ok; GST_DEBUG_OBJECT (bin, "src_pads_activate with active %d", active); iter = gst_element_iterate_src_pads ((GstElement *) bin); fold_ok = iterator_activate_fold_with_resync (iter, &active); gst_iterator_free (iter); if (G_UNLIKELY (!fold_ok)) goto failed; GST_DEBUG_OBJECT (bin, "pads_activate successful"); return TRUE; /* ERRORS */ failed: { GST_DEBUG_OBJECT (bin, "source pads_activate failed"); return FALSE; } } /** * gst_bin_recalculate_latency: * @bin: a #GstBin * * Query @bin for the current latency using and reconfigures this latency to all the * elements with a LATENCY event. * * This method is typically called on the pipeline when a #GST_MESSAGE_LATENCY * is posted on the bus. * * This function simply emits the 'do-latency' signal so any custom latency * calculations will be performed. * * Returns: %TRUE if the latency could be queried and reconfigured. * * Since: 0.10.22. */ gboolean gst_bin_recalculate_latency (GstBin * bin) { gboolean res; g_signal_emit (bin, gst_bin_signals[DO_LATENCY], 0, &res); GST_DEBUG_OBJECT (bin, "latency returned %d", res); return res; } static gboolean gst_bin_do_latency_func (GstBin * bin) { GstQuery *query; GstElement *element; GstClockTime min_latency, max_latency; gboolean res; g_return_val_if_fail (GST_IS_BIN (bin), FALSE); element = GST_ELEMENT_CAST (bin); GST_DEBUG_OBJECT (element, "querying latency"); query = gst_query_new_latency (); if ((res = gst_element_query (element, query))) { gboolean live; gst_query_parse_latency (query, &live, &min_latency, &max_latency); GST_DEBUG_OBJECT (element, "got min latency %" GST_TIME_FORMAT ", max latency %" GST_TIME_FORMAT ", live %d", GST_TIME_ARGS (min_latency), GST_TIME_ARGS (max_latency), live); if (max_latency < min_latency) { /* this is an impossible situation, some parts of the pipeline might not * work correctly. We post a warning for now. */ GST_ELEMENT_WARNING (element, CORE, CLOCK, (NULL), ("Impossible to configure latency: max %" GST_TIME_FORMAT " < min %" GST_TIME_FORMAT ". Add queues or other buffering elements.", GST_TIME_ARGS (max_latency), GST_TIME_ARGS (min_latency))); } /* configure latency on elements */ res = gst_element_send_event (element, gst_event_new_latency (min_latency)); if (res) { GST_INFO_OBJECT (element, "configured latency of %" GST_TIME_FORMAT, GST_TIME_ARGS (min_latency)); } else { GST_WARNING_OBJECT (element, "did not really configure latency of %" GST_TIME_FORMAT, GST_TIME_ARGS (min_latency)); } } else { /* this is not a real problem, we just don't configure any latency. */ GST_WARNING_OBJECT (element, "failed to query latency"); } gst_query_unref (query); return res; } static GstStateChangeReturn gst_bin_change_state_func (GstElement * element, GstStateChange transition) { GstBin *bin; GstStateChangeReturn ret; GstState current, next; gboolean have_async; gboolean have_no_preroll; GstClockTime base_time, start_time; GstIterator *it; gboolean done; /* we don't need to take the STATE_LOCK, it is already taken */ current = (GstState) GST_STATE_TRANSITION_CURRENT (transition); next = (GstState) GST_STATE_TRANSITION_NEXT (transition); GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "changing state of children from %s to %s", gst_element_state_get_name (current), gst_element_state_get_name (next)); bin = GST_BIN_CAST (element); switch (next) { case GST_STATE_PLAYING: { gboolean toplevel; GST_OBJECT_LOCK (bin); toplevel = BIN_IS_TOPLEVEL (bin); GST_OBJECT_UNLOCK (bin); if (toplevel) gst_bin_recalculate_latency (bin); break; } case GST_STATE_PAUSED: /* Clear EOS list on next PAUSED */ GST_OBJECT_LOCK (bin); GST_DEBUG_OBJECT (element, "clearing EOS elements"); bin_remove_messages (bin, NULL, GST_MESSAGE_EOS); GST_OBJECT_UNLOCK (bin); if (current == GST_STATE_READY) if (!(gst_bin_src_pads_activate (bin, TRUE))) goto activate_failure; break; case GST_STATE_READY: /* Clear message list on next READY */ GST_OBJECT_LOCK (bin); GST_DEBUG_OBJECT (element, "clearing all cached messages"); bin_remove_messages (bin, NULL, GST_MESSAGE_ANY); GST_OBJECT_UNLOCK (bin); if (current == GST_STATE_PAUSED) if (!(gst_bin_src_pads_activate (bin, FALSE))) goto activate_failure; break; case GST_STATE_NULL: if (current == GST_STATE_READY) if (!(gst_bin_src_pads_activate (bin, FALSE))) goto activate_failure; break; default: break; } /* this flag is used to make the async state changes return immediatly. We * don't want them to interfere with this state change */ GST_OBJECT_LOCK (bin); bin->polling = TRUE; GST_OBJECT_UNLOCK (bin); /* iterate in state change order */ it = gst_bin_iterate_sorted (bin); /* mark if we've seen an ASYNC element in the bin when we did a state change. * Note how we don't reset this value when a resync happens, the reason being * that the async element posted ASYNC_START and we want to post ASYNC_DONE * even after a resync when the async element is gone */ have_async = FALSE; restart: /* take base_time */ base_time = gst_element_get_base_time (element); start_time = gst_element_get_start_time (element); 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 state and base_time now */ ret = gst_bin_element_set_state (bin, child, base_time, start_time, current, next); 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), next, gst_element_state_get_name (next)); break; case GST_STATE_CHANGE_ASYNC: { GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "child '%s' is changing state asynchronously to %s", GST_ELEMENT_NAME (child), gst_element_state_get_name (next)); have_async = TRUE; break; } case GST_STATE_CHANGE_FAILURE:{ GstObject *parent; GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "child '%s' failed to go to state %d(%s)", GST_ELEMENT_NAME (child), next, gst_element_state_get_name (next)); /* Only fail if the child is still inside * this bin. It might've been removed already * because of the error by the bin subclass * to ignore the error. */ parent = gst_object_get_parent (GST_OBJECT_CAST (child)); if (parent == GST_OBJECT_CAST (element)) { /* element is still in bin, really error now */ gst_object_unref (child); gst_object_unref (parent); goto done; } /* child removed from bin, let the resync code redo the state * change */ GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "child '%s' was removed from the bin", GST_ELEMENT_NAME (child)); if (parent) gst_object_unref (parent); break; } 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), next, gst_element_state_get_name (next)); 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; default: case GST_ITERATOR_DONE: GST_CAT_DEBUG (GST_CAT_STATES, "iterator done"); done = TRUE; break; } } ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition); if (G_UNLIKELY (ret == GST_STATE_CHANGE_FAILURE)) goto done; if (have_no_preroll) { GST_CAT_DEBUG (GST_CAT_STATES, "we have NO_PREROLL elements %s -> NO_PREROLL", gst_element_state_change_return_get_name (ret)); ret = GST_STATE_CHANGE_NO_PREROLL; } else if (have_async) { GST_CAT_DEBUG (GST_CAT_STATES, "we have ASYNC elements %s -> ASYNC", gst_element_state_change_return_get_name (ret)); ret = GST_STATE_CHANGE_ASYNC; } done: gst_iterator_free (it); GST_OBJECT_LOCK (bin); bin->polling = FALSE; /* it's possible that we did not get ASYNC from the children while the bin is * simulating ASYNC behaviour by posting an ASYNC_DONE message on the bus with * itself as the source. In that case we still want to check if the state * change completed. */ if (ret != GST_STATE_CHANGE_ASYNC && !bin->priv->pending_async_done) { /* no element returned ASYNC and there are no pending async_done messages, * we can just complete. */ GST_DEBUG_OBJECT (bin, "no async elements"); goto state_end; } /* when we get here an ASYNC element was found */ if (GST_STATE_TARGET (bin) <= GST_STATE_READY) { /* we ignore ASYNC state changes when we go to READY or NULL */ GST_DEBUG_OBJECT (bin, "target state %s <= READY", gst_element_state_get_name (GST_STATE_TARGET (bin))); goto state_end; } GST_DEBUG_OBJECT (bin, "check async elements"); /* check if all elements managed to commit their state already */ if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) { /* nothing found, remove all old ASYNC_DONE messages. This can happen when * all the elements commited their state while we were doing the state * change. We will still return ASYNC for consistency but we commit the * state already so that a _get_state() will return immediatly. */ bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE); GST_DEBUG_OBJECT (bin, "async elements commited"); bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, FALSE); } state_end: bin->priv->pending_async_done = FALSE; GST_OBJECT_UNLOCK (bin); GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "done changing bin's state from %s to %s, now in %s, ret %s", gst_element_state_get_name (current), gst_element_state_get_name (next), gst_element_state_get_name (GST_STATE (element)), gst_element_state_change_return_get_name (ret)); return ret; /* ERRORS */ activate_failure: { GST_CAT_WARNING_OBJECT (GST_CAT_STATES, element, "failure (de)activating src pads"); return GST_STATE_CHANGE_FAILURE; } } /* * This function is a utility event handler for seek events. * It will send the event to all sinks or sources depending on the * event-direction. * * 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_CAST (element); GstIterator *iter; gboolean res = TRUE; gboolean done = FALSE; if (GST_EVENT_IS_DOWNSTREAM (event)) { iter = gst_bin_iterate_sources (bin); GST_DEBUG_OBJECT (bin, "Sending %s event to src children", GST_EVENT_TYPE_NAME (event)); } else { iter = gst_bin_iterate_sinks (bin); GST_DEBUG_OBJECT (bin, "Sending %s event to sink children", GST_EVENT_TYPE_NAME (event)); } while (!done) { gpointer data; switch (gst_iterator_next (iter, &data)) { case GST_ITERATOR_OK: { GstElement *child; gst_event_ref (event); child = GST_ELEMENT_CAST (data); res &= gst_element_send_event (child, event); gst_object_unref (child); break; } case GST_ITERATOR_RESYNC: gst_iterator_resync (iter); res = TRUE; break; case GST_ITERATOR_DONE: done = TRUE; break; case GST_ITERATOR_ERROR: g_assert_not_reached (); break; } } gst_iterator_free (iter); gst_event_unref (event); return res; } /* this is the function called by the threadpool. When async elements commit * their state, this function will attempt to bring the bin to the next state. */ static void gst_bin_continue_func (BinContinueData * data) { GstBin *bin; GstState current, next, pending; GstStateChange transition; bin = data->bin; pending = data->pending; GST_DEBUG_OBJECT (bin, "waiting for state lock"); GST_STATE_LOCK (bin); GST_DEBUG_OBJECT (bin, "doing state continue"); GST_OBJECT_LOCK (bin); /* if a new state change happened after this thread was scheduled, we return * immediatly. */ if (data->cookie != GST_ELEMENT_CAST (bin)->state_cookie) goto interrupted; current = GST_STATE (bin); next = GST_STATE_GET_NEXT (current, pending); transition = (GstStateChange) GST_STATE_TRANSITION (current, next); GST_STATE_NEXT (bin) = next; GST_STATE_PENDING (bin) = pending; /* mark busy */ GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC; GST_OBJECT_UNLOCK (bin); GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin, "continue state change %s to %s, final %s", gst_element_state_get_name (current), gst_element_state_get_name (next), gst_element_state_get_name (pending)); gst_element_change_state (GST_ELEMENT_CAST (bin), transition); GST_STATE_UNLOCK (bin); GST_DEBUG_OBJECT (bin, "state continue done"); gst_object_unref (bin); g_slice_free (BinContinueData, data); return; interrupted: { GST_OBJECT_UNLOCK (bin); GST_STATE_UNLOCK (bin); GST_DEBUG_OBJECT (bin, "state continue aborted due to intervening change"); gst_object_unref (bin); g_slice_free (BinContinueData, data); return; } } static GstBusSyncReply bin_bus_handler (GstBus * bus, GstMessage * message, GstBin * bin) { GstBinClass *bclass; bclass = GST_BIN_GET_CLASS (bin); if (bclass->handle_message) bclass->handle_message (bin, message); else gst_message_unref (message); return GST_BUS_DROP; } static void bin_push_state_continue (BinContinueData * data) { GstBinClass *klass; GstBin *bin; /* ref was taken */ bin = data->bin; klass = GST_BIN_GET_CLASS (bin); GST_DEBUG_OBJECT (bin, "pushing continue on thread pool"); g_thread_pool_push (klass->pool, data, NULL); } /* an element started an async state change, if we were not busy with a state * change, we perform a lost state. * This function is called with the OBJECT lock. */ static void bin_handle_async_start (GstBin * bin, gboolean new_base_time) { GstState old_state, new_state; gboolean toplevel; GstMessage *amessage = NULL; if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE) goto had_error; /* get our toplevel state */ toplevel = BIN_IS_TOPLEVEL (bin); /* prepare an ASYNC_START message, we always post the start message even if we * are busy with a state change or when we are NO_PREROLL. */ if (!toplevel) /* non toplevel bin, prepare async-start for the parent */ amessage = gst_message_new_async_start (GST_OBJECT_CAST (bin), new_base_time); if (bin->polling || GST_STATE_PENDING (bin) != GST_STATE_VOID_PENDING) goto was_busy; /* async starts are ignored when we are NO_PREROLL */ if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_NO_PREROLL) goto was_no_preroll; old_state = GST_STATE (bin); /* when we PLAYING we go back to PAUSED, when preroll happens, we go back to * PLAYING after optionally redistributing the base_time. */ if (old_state > GST_STATE_PAUSED) new_state = GST_STATE_PAUSED; else new_state = old_state; GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "lost state of %s, new %s", gst_element_state_get_name (old_state), gst_element_state_get_name (new_state)); GST_STATE (bin) = new_state; GST_STATE_NEXT (bin) = new_state; GST_STATE_PENDING (bin) = new_state; GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC; GST_OBJECT_UNLOCK (bin); /* post message */ gst_element_post_message (GST_ELEMENT_CAST (bin), gst_message_new_state_changed (GST_OBJECT_CAST (bin), new_state, new_state, new_state)); post_start: if (amessage) { /* post our ASYNC_START. */ GST_DEBUG_OBJECT (bin, "posting ASYNC_START to parent"); gst_element_post_message (GST_ELEMENT_CAST (bin), amessage); } GST_OBJECT_LOCK (bin); return; had_error: { GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error"); return; } was_busy: { GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy"); GST_OBJECT_UNLOCK (bin); goto post_start; } was_no_preroll: { GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "ignoring, we are NO_PREROLL"); GST_OBJECT_UNLOCK (bin); goto post_start; } } /* this function is called when there are no more async elements in the bin. We * post a state changed message and an ASYNC_DONE message. * This function is called with the OBJECT lock. */ static void bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret, gboolean flag_pending) { GstState current, pending, target; GstStateChangeReturn old_ret; GstState old_state, old_next; gboolean toplevel; GstMessage *smessage = NULL, *amessage = NULL; BinContinueData *cont = NULL; if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE) goto had_error; pending = GST_STATE_PENDING (bin); if (bin->polling) goto was_busy; /* check if there is something to commit */ if (pending == GST_STATE_VOID_PENDING) goto nothing_pending; old_ret = GST_STATE_RETURN (bin); GST_STATE_RETURN (bin) = ret; /* move to the next target state */ target = GST_STATE_TARGET (bin); pending = GST_STATE_PENDING (bin) = target; amessage = gst_message_new_async_done (GST_OBJECT_CAST (bin)); old_state = GST_STATE (bin); /* this is the state we should go to next */ old_next = GST_STATE_NEXT (bin); if (old_next != GST_STATE_PLAYING) { GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin, "committing state from %s to %s, old pending %s", gst_element_state_get_name (old_state), gst_element_state_get_name (old_next), gst_element_state_get_name (pending)); /* update current state */ current = GST_STATE (bin) = old_next; } else { GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin, "setting state from %s to %s, pending %s", gst_element_state_get_name (old_state), gst_element_state_get_name (old_state), gst_element_state_get_name (pending)); current = old_state; } /* get our toplevel state */ toplevel = BIN_IS_TOPLEVEL (bin); /* see if we reached the final state. If we are not toplevel, we also have to * stop here, the parent will continue our state. */ if ((pending == current) || !toplevel) { GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin, "completed state change, pending VOID"); /* mark VOID pending */ pending = GST_STATE_VOID_PENDING; GST_STATE_PENDING (bin) = pending; GST_STATE_NEXT (bin) = GST_STATE_VOID_PENDING; } else { GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin, "continue state change, pending %s", gst_element_state_get_name (pending)); cont = g_slice_new (BinContinueData); /* ref to the bin */ cont->bin = gst_object_ref (bin); /* cookie to detect concurrent state change */ cont->cookie = GST_ELEMENT_CAST (bin)->state_cookie; /* pending target state */ cont->pending = pending; /* mark busy */ GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC; GST_STATE_NEXT (bin) = GST_STATE_GET_NEXT (old_state, pending); } if (old_next != GST_STATE_PLAYING) { if (old_state != old_next || old_ret == GST_STATE_CHANGE_ASYNC) { smessage = gst_message_new_state_changed (GST_OBJECT_CAST (bin), old_state, old_next, pending); } } GST_OBJECT_UNLOCK (bin); if (smessage) { GST_DEBUG_OBJECT (bin, "posting state change message"); gst_element_post_message (GST_ELEMENT_CAST (bin), smessage); } if (amessage) { /* post our combined ASYNC_DONE when all is ASYNC_DONE. */ GST_DEBUG_OBJECT (bin, "posting ASYNC_DONE to parent"); gst_element_post_message (GST_ELEMENT_CAST (bin), amessage); } GST_OBJECT_LOCK (bin); if (cont) { /* toplevel, start continue state */ GST_DEBUG_OBJECT (bin, "all async-done, starting state continue"); bin_push_state_continue (cont); } else { GST_DEBUG_OBJECT (bin, "state change complete"); GST_STATE_BROADCAST (bin); } return; had_error: { GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error"); return; } was_busy: { GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy"); /* if we were busy with a state change and we are requested to flag a * pending async done, we do so here */ if (flag_pending) bin->priv->pending_async_done = TRUE; return; } nothing_pending: { GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin, "nothing pending"); return; } } /* must be called with the object lock. This function releases the lock to post * the message. */ static void bin_do_message_forward (GstBin * bin, GstMessage * message) { if (bin->priv->message_forward) { GstMessage *forwarded; GST_DEBUG_OBJECT (bin, "pass %s message upward", GST_MESSAGE_TYPE_NAME (message)); GST_OBJECT_UNLOCK (bin); /* we need to convert these messages to element messages so that our parent * bin can easily ignore them and so that the application can easily * distinguish between the internally forwarded and the real messages. */ forwarded = gst_message_new_element (GST_OBJECT_CAST (bin), gst_structure_new ("GstBinForwarded", "message", GST_TYPE_MESSAGE, message, NULL)); gst_element_post_message (GST_ELEMENT_CAST (bin), forwarded); GST_OBJECT_LOCK (bin); } } /* handle child messages: * * This method is called synchronously when a child posts a message on * the internal bus. * * GST_MESSAGE_EOS: This message is only posted by sinks * in the PLAYING state. If all sinks posted the EOS message, post * one upwards. * * GST_MESSAGE_STATE_DIRTY: Deprecated * * GST_MESSAGE_SEGMENT_START: just collect, never forward upwards. If an * element posts segment_start twice, only the last message is kept. * * GST_MESSAGE_SEGMENT_DONE: replace SEGMENT_START message from same poster * with the segment_done message. If there are no more segment_start * messages, post segment_done message upwards. * * GST_MESSAGE_DURATION: remove all previously cached duration messages. * Whenever someone performs a duration query on the bin, we store the * result so we can answer it quicker the next time. Any element that * changes its duration marks our cached values invalid. * This message is also posted upwards. This is currently disabled * because too many elements don't post DURATION messages when the * duration changes. * * GST_MESSAGE_CLOCK_LOST: This message is posted by an element when it * can no longer provide a clock. The default bin behaviour is to * check if the lost clock was the one provided by the bin. If so and * we are currently in the PLAYING state, we forward the message to * our parent. * This message is also generated when we remove a clock provider from * a bin. If this message is received by the application, it should * PAUSE the pipeline and set it back to PLAYING to force a new clock * and a new base_time distribution. * * GST_MESSAGE_CLOCK_PROVIDE: This message is generated when an element * can provide a clock. This mostly happens when we add a new clock * provider to the bin. The default behaviour of the bin is to mark the * currently selected clock as dirty, which will perform a clock * recalculation the next time we are asked to provide a clock. * This message is never sent to the application but is forwarded to * the parent. * * GST_MESSAGE_ASYNC_START: Create an internal ELEMENT message that stores * the state of the element and the fact that the element will need a * new base_time. This message is not forwarded to the application. * * GST_MESSAGE_ASYNC_DONE: Find the internal ELEMENT message we kept for the * element when it posted ASYNC_START. If all elements are done, post a * ASYNC_DONE message to the parent. * * OTHER: post upwards. */ static void gst_bin_handle_message_func (GstBin * bin, GstMessage * message) { GstObject *src; GstMessageType type; GstMessage *tmessage; guint32 seqnum; src = GST_MESSAGE_SRC (message); type = GST_MESSAGE_TYPE (message); GST_DEBUG_OBJECT (bin, "[msg %p] handling child %s message of type %s", message, src ? GST_ELEMENT_NAME (src) : "(NULL)", GST_MESSAGE_TYPE_NAME (message)); switch (type) { case GST_MESSAGE_ERROR: { GST_OBJECT_LOCK (bin); /* flag error */ GST_DEBUG_OBJECT (bin, "got ERROR message, unlocking state change"); GST_STATE_RETURN (bin) = GST_STATE_CHANGE_FAILURE; GST_STATE_BROADCAST (bin); GST_OBJECT_UNLOCK (bin); goto forward; } case GST_MESSAGE_EOS: { gboolean eos; /* collect all eos messages from the children */ GST_OBJECT_LOCK (bin); bin_do_message_forward (bin, message); /* ref message for future use */ gst_message_ref (message); bin_replace_message (bin, message, GST_MESSAGE_EOS); eos = is_eos (bin); GST_OBJECT_UNLOCK (bin); /* if we are completely EOS, we forward an EOS message */ if (eos) { seqnum = gst_message_get_seqnum (message); tmessage = gst_message_new_eos (GST_OBJECT_CAST (bin)); gst_message_set_seqnum (tmessage, seqnum); GST_DEBUG_OBJECT (bin, "all sinks posted EOS, posting seqnum #%" G_GUINT32_FORMAT, seqnum); gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage); } gst_message_unref (message); break; } case GST_MESSAGE_STATE_DIRTY: { GST_WARNING_OBJECT (bin, "received deprecated STATE_DIRTY message"); /* free message */ gst_message_unref (message); break; } case GST_MESSAGE_SEGMENT_START:{ gboolean post = FALSE; GstFormat format; gint64 position; gst_message_parse_segment_start (message, &format, &position); seqnum = gst_message_get_seqnum (message); GST_OBJECT_LOCK (bin); bin_do_message_forward (bin, message); /* if this is the first segment-start, post to parent but not to the * application */ if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START) && (GST_OBJECT_PARENT (bin) != NULL)) { post = TRUE; } /* replace any previous segment_start message from this source * with the new segment start message */ bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START); GST_OBJECT_UNLOCK (bin); if (post) { tmessage = gst_message_new_segment_start (GST_OBJECT_CAST (bin), format, position); gst_message_set_seqnum (tmessage, seqnum); /* post segment start with initial format and position. */ GST_DEBUG_OBJECT (bin, "posting SEGMENT_START (%u) bus message: %p", seqnum, message); gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage); } break; } case GST_MESSAGE_SEGMENT_DONE: { gboolean post = FALSE; GstFormat format; gint64 position; gst_message_parse_segment_done (message, &format, &position); seqnum = gst_message_get_seqnum (message); GST_OBJECT_LOCK (bin); bin_do_message_forward (bin, message); bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START); /* if there are no more segment_start messages, everybody posted * a segment_done and we can post one on the bus. */ /* we don't care who still has a pending segment start */ if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START)) { /* nothing found */ post = TRUE; /* remove all old segment_done messages */ bin_remove_messages (bin, NULL, GST_MESSAGE_SEGMENT_DONE); } GST_OBJECT_UNLOCK (bin); if (post) { tmessage = gst_message_new_segment_done (GST_OBJECT_CAST (bin), format, position); gst_message_set_seqnum (tmessage, seqnum); /* post segment done with latest format and position. */ GST_DEBUG_OBJECT (bin, "posting SEGMENT_DONE (%u) bus message: %p", seqnum, message); gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage); } break; } case GST_MESSAGE_DURATION: { /* remove all cached duration messages, next time somebody asks * for duration, we will recalculate. */ GST_OBJECT_LOCK (bin); bin_remove_messages (bin, NULL, GST_MESSAGE_DURATION); GST_OBJECT_UNLOCK (bin); goto forward; } case GST_MESSAGE_CLOCK_LOST: { GstClock **provided_clock_p; GstElement **clock_provider_p; gboolean playing, provided, forward; GstClock *clock; gst_message_parse_clock_lost (message, &clock); GST_OBJECT_LOCK (bin); bin->clock_dirty = TRUE; /* if we lost the clock that we provided, post to parent but * only if we are PLAYING. */ provided = (clock == bin->provided_clock); playing = (GST_STATE (bin) == GST_STATE_PLAYING); forward = playing & provided; if (provided) { GST_DEBUG_OBJECT (bin, "Lost clock %" GST_PTR_FORMAT " provided by %" GST_PTR_FORMAT, bin->provided_clock, bin->clock_provider); provided_clock_p = &bin->provided_clock; clock_provider_p = &bin->clock_provider; gst_object_replace ((GstObject **) provided_clock_p, NULL); gst_object_replace ((GstObject **) clock_provider_p, NULL); } GST_DEBUG_OBJECT (bin, "provided %d, playing %d, forward %d", provided, playing, forward); GST_OBJECT_UNLOCK (bin); if (forward) goto forward; /* free message */ gst_message_unref (message); break; } case GST_MESSAGE_CLOCK_PROVIDE: { gboolean forward; GST_OBJECT_LOCK (bin); bin->clock_dirty = TRUE; /* a new clock is available, post to parent but not * to the application */ forward = GST_OBJECT_PARENT (bin) != NULL; GST_OBJECT_UNLOCK (bin); if (forward) goto forward; /* free message */ gst_message_unref (message); break; } case GST_MESSAGE_ASYNC_START: { gboolean new_base_time; GstState target; GST_DEBUG_OBJECT (bin, "ASYNC_START message %p, %s", message, src ? GST_OBJECT_NAME (src) : "(NULL)"); gst_message_parse_async_start (message, &new_base_time); GST_OBJECT_LOCK (bin); bin_do_message_forward (bin, message); /* we ignore the message if we are going to <= READY */ if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY) goto ignore_start_message; /* takes ownership of the message */ bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START); bin_handle_async_start (bin, new_base_time); GST_OBJECT_UNLOCK (bin); break; ignore_start_message: { GST_DEBUG_OBJECT (bin, "ignoring message, target %s", gst_element_state_get_name (target)); GST_OBJECT_UNLOCK (bin); gst_message_unref (message); break; } } case GST_MESSAGE_ASYNC_DONE: { GstState target; GST_DEBUG_OBJECT (bin, "ASYNC_DONE message %p, %s", message, src ? GST_OBJECT_NAME (src) : "(NULL)"); GST_OBJECT_LOCK (bin); bin_do_message_forward (bin, message); /* ignore messages if we are shutting down */ if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY) goto ignore_done_message; bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START); /* if there are no more ASYNC_START messages, everybody posted * a ASYNC_DONE and we can post one on the bus. When checking, we * don't care who still has a pending ASYNC_START */ if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) { /* nothing found, remove all old ASYNC_DONE messages */ bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE); GST_DEBUG_OBJECT (bin, "async elements commited"); /* when we get an async done message when a state change was busy, we * need to set the pending_done flag so that at the end of the state * change we can see if we need to verify pending async elements, hence * the TRUE argument here. */ bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, TRUE); } else { GST_DEBUG_OBJECT (bin, "there are more async elements pending"); } GST_OBJECT_UNLOCK (bin); break; ignore_done_message: { GST_DEBUG_OBJECT (bin, "ignoring message, target %s", gst_element_state_get_name (target)); GST_OBJECT_UNLOCK (bin); gst_message_unref (message); break; } } case GST_MESSAGE_STRUCTURE_CHANGE: { gboolean busy; gst_message_parse_structure_change (message, NULL, NULL, &busy); GST_OBJECT_LOCK (bin); if (busy) { /* while the pad is busy, avoid following it when doing state changes. * Don't update the cookie yet, we will do that after the structure * change finished and we are ready to inspect the new updated * structure. */ bin_replace_message (bin, message, GST_MESSAGE_STRUCTURE_CHANGE); message = NULL; } else { /* a pad link/unlink ended, signal the state change iterator that we * need to resync by updating the structure_cookie. */ bin_remove_messages (bin, GST_MESSAGE_SRC (message), GST_MESSAGE_STRUCTURE_CHANGE); bin->priv->structure_cookie++; } GST_OBJECT_UNLOCK (bin); if (message) gst_message_unref (message); break; } default: goto forward; } return; forward: { /* Send all other messages upward */ GST_DEBUG_OBJECT (bin, "posting message upward"); gst_element_post_message (GST_ELEMENT_CAST (bin), message); return; } } /* generic struct passed to all query fold methods */ typedef struct { GstQuery *query; gint64 min; gint64 max; gboolean live; } QueryFold; typedef void (*QueryInitFunction) (GstBin * bin, QueryFold * fold); typedef void (*QueryDoneFunction) (GstBin * bin, QueryFold * fold); /* for duration/position we collect all durations/positions and take * the MAX of all valid results */ static void bin_query_min_max_init (GstBin * bin, QueryFold * fold) { fold->min = 0; fold->max = -1; fold->live = FALSE; } static gboolean bin_query_duration_fold (GstElement * item, GValue * ret, QueryFold * fold) { if (gst_element_query (item, fold->query)) { gint64 duration; g_value_set_boolean (ret, TRUE); gst_query_parse_duration (fold->query, NULL, &duration); GST_DEBUG_OBJECT (item, "got duration %" G_GINT64_FORMAT, duration); if (duration > fold->max) fold->max = duration; } gst_object_unref (item); return TRUE; } static void bin_query_duration_done (GstBin * bin, QueryFold * fold) { GstFormat format; gst_query_parse_duration (fold->query, &format, NULL); /* store max in query result */ gst_query_set_duration (fold->query, format, fold->max); GST_DEBUG_OBJECT (bin, "max duration %" G_GINT64_FORMAT, fold->max); /* and cache now */ GST_OBJECT_LOCK (bin); bin->messages = g_list_prepend (bin->messages, gst_message_new_duration (GST_OBJECT_CAST (bin), format, fold->max)); GST_OBJECT_UNLOCK (bin); } static gboolean bin_query_position_fold (GstElement * item, GValue * ret, QueryFold * fold) { if (gst_element_query (item, fold->query)) { gint64 position; g_value_set_boolean (ret, TRUE); gst_query_parse_position (fold->query, NULL, &position); GST_DEBUG_OBJECT (item, "got position %" G_GINT64_FORMAT, position); if (position > fold->max) fold->max = position; } gst_object_unref (item); return TRUE; } static void bin_query_position_done (GstBin * bin, QueryFold * fold) { GstFormat format; gst_query_parse_position (fold->query, &format, NULL); /* store max in query result */ gst_query_set_position (fold->query, format, fold->max); GST_DEBUG_OBJECT (bin, "max position %" G_GINT64_FORMAT, fold->max); } static gboolean bin_query_latency_fold (GstElement * item, GValue * ret, QueryFold * fold) { if (gst_element_query (item, fold->query)) { GstClockTime min, max; gboolean live; gst_query_parse_latency (fold->query, &live, &min, &max); GST_DEBUG_OBJECT (item, "got latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT ", live %d", GST_TIME_ARGS (min), GST_TIME_ARGS (max), live); /* for the combined latency we collect the MAX of all min latencies and * the MIN of all max latencies */ if (live) { if (min > fold->min) fold->min = min; if (fold->max == -1) fold->max = max; else if (max < fold->max) fold->max = max; if (fold->live == FALSE) fold->live = live; } } else { g_value_set_boolean (ret, FALSE); GST_DEBUG_OBJECT (item, "failed query"); } gst_object_unref (item); return TRUE; } static void bin_query_latency_done (GstBin * bin, QueryFold * fold) { /* store max in query result */ gst_query_set_latency (fold->query, fold->live, fold->min, fold->max); GST_DEBUG_OBJECT (bin, "latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT ", live %d", GST_TIME_ARGS (fold->min), GST_TIME_ARGS (fold->max), fold->live); } /* generic fold, return first valid result */ static gboolean bin_query_generic_fold (GstElement * item, GValue * ret, QueryFold * fold) { gboolean res; if ((res = gst_element_query (item, fold->query))) { g_value_set_boolean (ret, TRUE); GST_DEBUG_OBJECT (item, "answered query %p", fold->query); } gst_object_unref (item); /* and stop as soon as we have a valid result */ return !res; } static gboolean gst_bin_query (GstElement * element, GstQuery * query) { GstBin *bin = GST_BIN_CAST (element); GstIterator *iter; gboolean res = FALSE; GstIteratorFoldFunction fold_func; QueryInitFunction fold_init = NULL; QueryDoneFunction fold_done = NULL; QueryFold fold_data; GValue ret = { 0 }; switch (GST_QUERY_TYPE (query)) { case GST_QUERY_DURATION: { GList *cached; GstFormat qformat; gst_query_parse_duration (query, &qformat, NULL); /* find cached duration query */ GST_OBJECT_LOCK (bin); for (cached = bin->messages; cached; cached = g_list_next (cached)) { GstMessage *message = (GstMessage *) cached->data; if (GST_MESSAGE_TYPE (message) == GST_MESSAGE_DURATION && GST_MESSAGE_SRC (message) == GST_OBJECT_CAST (bin)) { GstFormat format; gint64 duration; gst_message_parse_duration (message, &format, &duration); /* if cached same format, copy duration in query result */ if (format == qformat) { GST_DEBUG_OBJECT (bin, "return cached duration %" G_GINT64_FORMAT, duration); GST_OBJECT_UNLOCK (bin); gst_query_set_duration (query, qformat, duration); res = TRUE; goto exit; } } } GST_OBJECT_UNLOCK (bin); /* no cached value found, iterate and collect durations */ fold_func = (GstIteratorFoldFunction) bin_query_duration_fold; fold_init = bin_query_min_max_init; fold_done = bin_query_duration_done; break; } case GST_QUERY_POSITION: { fold_func = (GstIteratorFoldFunction) bin_query_position_fold; fold_init = bin_query_min_max_init; fold_done = bin_query_position_done; break; } case GST_QUERY_LATENCY: { fold_func = (GstIteratorFoldFunction) bin_query_latency_fold; fold_init = bin_query_min_max_init; fold_done = bin_query_latency_done; res = TRUE; break; } default: fold_func = (GstIteratorFoldFunction) bin_query_generic_fold; break; } fold_data.query = query; /* set the result of the query to FALSE initially */ g_value_init (&ret, G_TYPE_BOOLEAN); g_value_set_boolean (&ret, res); iter = gst_bin_iterate_sinks (bin); GST_DEBUG_OBJECT (bin, "Sending query %p (type %s) to sink children", query, GST_QUERY_TYPE_NAME (query)); if (fold_init) fold_init (bin, &fold_data); while (TRUE) { GstIteratorResult ires; ires = gst_iterator_fold (iter, fold_func, &ret, &fold_data); switch (ires) { case GST_ITERATOR_RESYNC: gst_iterator_resync (iter); if (fold_init) fold_init (bin, &fold_data); g_value_set_boolean (&ret, res); break; case GST_ITERATOR_OK: case GST_ITERATOR_DONE: res = g_value_get_boolean (&ret); if (fold_done != NULL && res) fold_done (bin, &fold_data); goto done; default: res = FALSE; goto done; } } done: gst_iterator_free (iter); exit: GST_DEBUG_OBJECT (bin, "query %p result %d", query, res); return res; } static gint compare_name (GstElement * element, const gchar * name) { gint eq; GST_OBJECT_LOCK (element); eq = strcmp (GST_ELEMENT_NAME (element), name); GST_OBJECT_UNLOCK (element); if (eq != 0) { gst_object_unref (element); } return eq; } /** * gst_bin_get_by_name: * @bin: a #GstBin * @name: the element name to search for * * Gets the element with the given name from a bin. This * function recurses into child bins. * * Returns NULL if no element with the given name is found in the bin. * * MT safe. Caller owns returned reference. * * Returns: (transfer full): the #GstElement with the given name, or NULL */ GstElement * gst_bin_get_by_name (GstBin * bin, const gchar * name) { GstIterator *children; gpointer 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: a #GstBin * @name: the element name to search for * * Gets the element with the given name from this bin. If the * element is not found, a recursion is performed on the parent bin. * * Returns NULL if: * - no element with the given name is found in the bin * * MT safe. Caller owns returned reference. * * Returns: (transfer full): the #GstElement with the given name, or NULL */ 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) { GType interface_type = (GType) interface; gint ret; if (G_TYPE_CHECK_INSTANCE_TYPE (element, interface_type)) { 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: a #GstBin * @iface: the #GType of an interface * * Looks for an 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(). This function recurses into child bins. * * MT safe. Caller owns returned reference. * * Returns: (transfer full): A #GstElement inside the bin implementing the interface */ GstElement * gst_bin_get_by_interface (GstBin * bin, GType iface) { GstIterator *children; gpointer result; g_return_val_if_fail (GST_IS_BIN (bin), NULL); g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL); children = gst_bin_iterate_recurse (bin); result = gst_iterator_find_custom (children, (GCompareFunc) compare_interface, (gpointer) iface); gst_iterator_free (children); return GST_ELEMENT_CAST (result); } /** * gst_bin_iterate_all_by_interface: * @bin: a #GstBin * @iface: the #GType of an 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 inside child bins. The iterator will yield a series * of #GstElement that should be unreffed after use. * * Each element yielded by the iterator will have its refcount increased, so * unref after use. * * MT safe. Caller owns returned value. * * Returns: (transfer full): a #GstIterator of #GstElement for all elements * in the bin implementing the given interface, or NULL */ GstIterator * gst_bin_iterate_all_by_interface (GstBin * bin, GType iface) { GstIterator *children; GstIterator *result; g_return_val_if_fail (GST_IS_BIN (bin), NULL); g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL); children = gst_bin_iterate_recurse (bin); result = gst_iterator_filter (children, (GCompareFunc) compare_interface, (gpointer) iface); return result; }