/* GStreamer * Copyright (C) 1999,2000 Erik Walthinsen * 2004 Wim Taymans * * gstelement.c: The base element, all elements derive from this * * 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. */ /** * SECTION:gstelement * @short_description: Abstract base class for all pipeline elements * @see_also: #GstElementFactory, #GstPad * * GstElement is the abstract base class needed to construct an element that * can be used in a GStreamer pipeline. Please refer to the plugin writers * guide for more information on creating #GstElement subclasses. * * The name of a #GstElement can be get with gst_element_get_name() and set with * gst_element_set_name(). For speed, GST_ELEMENT_NAME() can be used in the * core when using the appropriate locking. Do not use this in plug-ins or * applications in order to retain ABI compatibility. * * All elements have pads (of the type #GstPad). These pads link to pads on * other elements. #GstBuffer flow between these linked pads. * A #GstElement has a #GList of #GstPad structures for all their input (or sink) * and output (or source) pads. * Core and plug-in writers can add and remove pads with gst_element_add_pad() * and gst_element_remove_pad(). * * A pad of an element can be retrieved by name with gst_element_get_pad(). * An iterator of all pads can be retrieved with gst_element_iterate_pads(). * * Elements can be linked through their pads. * If the link is straightforward, use the gst_element_link() * convenience function to link two elements, or gst_element_link_many() * for more elements in a row. * Use gst_element_link_filtered() to link two elements constrained by * a specified set of #GstCaps. * For finer control, use gst_element_link_pads() and * gst_element_link_pads_filtered() to specify the pads to link on * each element by name. * * Each element has a state (see #GstState). You can get and set the state * of an element with gst_element_get_state() and gst_element_set_state(). * To get a string representation of a #GstState, use * gst_element_state_get_name(). * * You can get and set a #GstClock on an element using gst_element_get_clock() * and gst_element_set_clock(). * Some elements can provide a clock for the pipeline if * gst_element_provides_clock() returns %TRUE. With the * gst_element_provide_clock() method one can retrieve the clock provided by * such an element. * Not all elements require a clock to operate correctly. If * gst_element_requires_clock() returns %TRUE, a clock should be set on the * element with gst_element_set_clock(). * * Note that clock slection and distribution is normally handled by the * toplevel #GstPipeline so the clock functions are only to be used in very * specific situations. * * Last reviewed on 2009-05-21 (0.10.24) */ #include "gst_private.h" #include #include #include #include "gstelement.h" #include "gstenumtypes.h" #include "gstbus.h" #include "gstmarshal.h" #include "gsterror.h" #include "gstevent.h" #include "gstutils.h" #include "gstinfo.h" #include "gst-i18n-lib.h" /* Element signals and args */ enum { PAD_ADDED, PAD_REMOVED, NO_MORE_PADS, /* add more above */ LAST_SIGNAL }; enum { ARG_0 /* FILL ME */ }; extern void __gst_element_details_clear (GstElementDetails * dp); extern void __gst_element_details_copy (GstElementDetails * dest, const GstElementDetails * src); static void gst_element_class_init (GstElementClass * klass); static void gst_element_init (GstElement * element); static void gst_element_base_class_init (gpointer g_class); static void gst_element_base_class_finalize (gpointer g_class); static void gst_element_dispose (GObject * object); static void gst_element_finalize (GObject * object); static GstStateChangeReturn gst_element_change_state_func (GstElement * element, GstStateChange transition); static GstStateChangeReturn gst_element_get_state_func (GstElement * element, GstState * state, GstState * pending, GstClockTime timeout); static GstStateChangeReturn gst_element_set_state_func (GstElement * element, GstState state); static void gst_element_set_bus_func (GstElement * element, GstBus * bus); static gboolean gst_element_default_send_event (GstElement * element, GstEvent * event); static gboolean gst_element_default_query (GstElement * element, GstQuery * query); static GstPadTemplate * gst_element_class_get_request_pad_template (GstElementClass * element_class, const gchar * name); #ifndef GST_DISABLE_LOADSAVE static xmlNodePtr gst_element_save_thyself (GstObject * object, xmlNodePtr parent); static void gst_element_restore_thyself (GstObject * parent, xmlNodePtr self); #endif static GstObjectClass *parent_class = NULL; static guint gst_element_signals[LAST_SIGNAL] = { 0 }; GType gst_element_get_type (void) { static volatile gsize gst_element_type = 0; if (g_once_init_enter (&gst_element_type)) { GType _type; static const GTypeInfo element_info = { sizeof (GstElementClass), gst_element_base_class_init, gst_element_base_class_finalize, (GClassInitFunc) gst_element_class_init, NULL, NULL, sizeof (GstElement), 0, (GInstanceInitFunc) gst_element_init, NULL }; _type = g_type_register_static (GST_TYPE_OBJECT, "GstElement", &element_info, G_TYPE_FLAG_ABSTRACT); g_once_init_leave (&gst_element_type, _type); } return gst_element_type; } static void gst_element_class_init (GstElementClass * klass) { GObjectClass *gobject_class; GstObjectClass *gstobject_class; gobject_class = (GObjectClass *) klass; gstobject_class = (GstObjectClass *) klass; parent_class = g_type_class_peek_parent (klass); /** * GstElement::pad-added: * @gstelement: the object which received the signal * @new_pad: the pad that has been added * * a new #GstPad has been added to the element. */ gst_element_signals[PAD_ADDED] = g_signal_new ("pad-added", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstElementClass, pad_added), NULL, NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_PAD); /** * GstElement::pad-removed: * @gstelement: the object which received the signal * @old_pad: the pad that has been removed * * a #GstPad has been removed from the element */ gst_element_signals[PAD_REMOVED] = g_signal_new ("pad-removed", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstElementClass, pad_removed), NULL, NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_PAD); /** * GstElement::no-more-pads: * @gstelement: the object which received the signal * * This signals that the element will not generate more dynamic pads. */ gst_element_signals[NO_MORE_PADS] = g_signal_new ("no-more-pads", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstElementClass, no_more_pads), NULL, NULL, gst_marshal_VOID__VOID, G_TYPE_NONE, 0); gobject_class->dispose = GST_DEBUG_FUNCPTR (gst_element_dispose); gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_element_finalize); #ifndef GST_DISABLE_LOADSAVE gstobject_class->save_thyself = GST_DEBUG_FUNCPTR (gst_element_save_thyself); gstobject_class->restore_thyself = GST_DEBUG_FUNCPTR (gst_element_restore_thyself); #endif klass->change_state = GST_DEBUG_FUNCPTR (gst_element_change_state_func); klass->set_state = GST_DEBUG_FUNCPTR (gst_element_set_state_func); klass->get_state = GST_DEBUG_FUNCPTR (gst_element_get_state_func); klass->set_bus = GST_DEBUG_FUNCPTR (gst_element_set_bus_func); klass->query = GST_DEBUG_FUNCPTR (gst_element_default_query); klass->send_event = GST_DEBUG_FUNCPTR (gst_element_default_send_event); klass->numpadtemplates = 0; klass->elementfactory = NULL; } static void gst_element_base_class_init (gpointer g_class) { GstElementClass *element_class = GST_ELEMENT_CLASS (g_class); /* FIXME 0.11: Copy the element details and instead of clearing the * pad template list copy the list and increase the refcount of * the pad templates by one. * * This will make it possible to add pad templates and set element * details in the class_init functions and is the real GObject way * of doing things. * See http://bugzilla.gnome.org/show_bug.cgi?id=491501 */ memset (&element_class->details, 0, sizeof (GstElementDetails)); element_class->padtemplates = NULL; } static void gst_element_base_class_finalize (gpointer g_class) { GstElementClass *klass = GST_ELEMENT_CLASS (g_class); g_list_foreach (klass->padtemplates, (GFunc) gst_object_unref, NULL); g_list_free (klass->padtemplates); __gst_element_details_clear (&klass->details); } static void gst_element_init (GstElement * element) { GST_STATE (element) = GST_STATE_NULL; GST_STATE_TARGET (element) = GST_STATE_NULL; GST_STATE_NEXT (element) = GST_STATE_VOID_PENDING; GST_STATE_PENDING (element) = GST_STATE_VOID_PENDING; GST_STATE_RETURN (element) = GST_STATE_CHANGE_SUCCESS; element->state_lock = g_new0 (GStaticRecMutex, 1); g_static_rec_mutex_init (element->state_lock); element->state_cond = g_cond_new (); } /** * gst_element_default_error: * @object: a #GObject that signalled the error. * @orig: the #GstObject that initiated the error. * @error: the GError. * @debug: an additional debug information string, or %NULL. * * A default error signal callback to attach to an element. * The user data passed to the g_signal_connect is ignored. * * The default handler will simply print the error string using g_print. * * MT safe. */ void gst_element_default_error (GObject * object, GstObject * source, GError * error, gchar * debug) { gchar *name = gst_object_get_path_string (source); g_print (_("ERROR: from element %s: %s\n"), name, error->message); if (debug) g_print (_("Additional debug info:\n%s\n"), debug); g_free (name); } /** * gst_element_release_request_pad: * @element: a #GstElement to release the request pad of. * @pad: the #GstPad to release. * * Makes the element free the previously requested pad as obtained * with gst_element_get_request_pad(). * * MT safe. */ void gst_element_release_request_pad (GstElement * element, GstPad * pad) { GstElementClass *oclass; g_return_if_fail (GST_IS_ELEMENT (element)); g_return_if_fail (GST_IS_PAD (pad)); oclass = GST_ELEMENT_GET_CLASS (element); /* if the element implements a custom release function we call that, else we * simply remove the pad from the element */ if (oclass->release_pad) (oclass->release_pad) (element, pad); else gst_element_remove_pad (element, pad); } /** * gst_element_requires_clock: * @element: a #GstElement to query * * Query if the element requires a clock. * * Returns: %TRUE if the element requires a clock * * MT safe. */ gboolean gst_element_requires_clock (GstElement * element) { gboolean result; g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE); result = (GST_ELEMENT_GET_CLASS (element)->set_clock != NULL); return result; } /** * gst_element_provides_clock: * @element: a #GstElement to query * * Query if the element provides a clock. A #GstClock provided by an * element can be used as the global #GstClock for the pipeline. * An element that can provide a clock is only required to do so in the PAUSED * state, this means when it is fully negotiated and has allocated the resources * to operate the clock. * * Returns: %TRUE if the element provides a clock * * MT safe. */ gboolean gst_element_provides_clock (GstElement * element) { gboolean result; g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE); result = (GST_ELEMENT_GET_CLASS (element)->provide_clock != NULL); return result; } /** * gst_element_provide_clock: * @element: a #GstElement to query * * Get the clock provided by the given element. * An element is only required to provide a clock in the PAUSED * state. Some elements can provide a clock in other states. * * Returns: the GstClock provided by the element or %NULL * if no clock could be provided. Unref after usage. * * MT safe. */ GstClock * gst_element_provide_clock (GstElement * element) { GstClock *result = NULL; GstElementClass *oclass; g_return_val_if_fail (GST_IS_ELEMENT (element), NULL); oclass = GST_ELEMENT_GET_CLASS (element); if (oclass->provide_clock) result = oclass->provide_clock (element); return result; } /** * gst_element_set_clock: * @element: a #GstElement to set the clock for. * @clock: the #GstClock to set for the element. * * Sets the clock for the element. This function increases the * refcount on the clock. Any previously set clock on the object * is unreffed. * * Returns: %TRUE if the element accepted the clock. An element can refuse a * clock when it, for example, is not able to slave its internal clock to the * @clock or when it requires a specific clock to operate. * * MT safe. */ gboolean gst_element_set_clock (GstElement * element, GstClock * clock) { GstElementClass *oclass; gboolean res = TRUE; GstClock **clock_p; g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE); oclass = GST_ELEMENT_GET_CLASS (element); GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, element, "setting clock %p", clock); if (oclass->set_clock) res = oclass->set_clock (element, clock); if (res) { /* only update the clock pointer if the element accepted the clock */ GST_OBJECT_LOCK (element); clock_p = &element->clock; gst_object_replace ((GstObject **) clock_p, (GstObject *) clock); GST_OBJECT_UNLOCK (element); } return res; } /** * gst_element_get_clock: * @element: a #GstElement to get the clock of. * * Gets the currently configured clock of the element. This is the clock as was * last set with gst_element_set_clock(). * * Returns: the #GstClock of the element. unref after usage. * * MT safe. */ GstClock * gst_element_get_clock (GstElement * element) { GstClock *result; g_return_val_if_fail (GST_IS_ELEMENT (element), NULL); GST_OBJECT_LOCK (element); if ((result = element->clock)) gst_object_ref (result); GST_OBJECT_UNLOCK (element); return result; } /** * gst_element_set_base_time: * @element: a #GstElement. * @time: the base time to set. * * Set the base time of an element. See gst_element_get_base_time(). * * MT safe. */ void gst_element_set_base_time (GstElement * element, GstClockTime time) { GstClockTime old; g_return_if_fail (GST_IS_ELEMENT (element)); GST_OBJECT_LOCK (element); old = element->base_time; element->base_time = time; GST_OBJECT_UNLOCK (element); GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, element, "set base_time=%" GST_TIME_FORMAT ", old %" GST_TIME_FORMAT, GST_TIME_ARGS (time), GST_TIME_ARGS (old)); } /** * gst_element_get_base_time: * @element: a #GstElement. * * Returns the base time of the element. The base time is the * absolute time of the clock when this element was last put to * PLAYING. Subtracting the base time from the clock time gives * the running time of the element. * * Returns: the base time of the element. * * MT safe. */ GstClockTime gst_element_get_base_time (GstElement * element) { GstClockTime result; g_return_val_if_fail (GST_IS_ELEMENT (element), GST_CLOCK_TIME_NONE); GST_OBJECT_LOCK (element); result = element->base_time; GST_OBJECT_UNLOCK (element); return result; } /** * gst_element_is_indexable: * @element: a #GstElement. * * Queries if the element can be indexed. * * Returns: TRUE if the element can be indexed. * * MT safe. */ gboolean gst_element_is_indexable (GstElement * element) { gboolean result; g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE); result = (GST_ELEMENT_GET_CLASS (element)->set_index != NULL); return result; } /** * gst_element_set_index: * @element: a #GstElement. * @index: a #GstIndex. * * Set @index on the element. The refcount of the index * will be increased, any previously set index is unreffed. * * MT safe. */ void gst_element_set_index (GstElement * element, GstIndex * index) { GstElementClass *oclass; g_return_if_fail (GST_IS_ELEMENT (element)); g_return_if_fail (GST_IS_INDEX (index)); oclass = GST_ELEMENT_GET_CLASS (element); if (oclass->set_index) oclass->set_index (element, index); } /** * gst_element_get_index: * @element: a #GstElement. * * Gets the index from the element. * * Returns: a #GstIndex or %NULL when no index was set on the * element. unref after usage. * * MT safe. */ GstIndex * gst_element_get_index (GstElement * element) { GstElementClass *oclass; GstIndex *result = NULL; g_return_val_if_fail (GST_IS_ELEMENT (element), NULL); oclass = GST_ELEMENT_GET_CLASS (element); if (oclass->get_index) result = oclass->get_index (element); return result; } /** * gst_element_add_pad: * @element: a #GstElement to add the pad to. * @pad: the #GstPad to add to the element. * * Adds a pad (link point) to @element. @pad's parent will be set to @element; * see gst_object_set_parent() for refcounting information. * * Pads are not automatically activated so elements should perform the needed * steps to activate the pad in case this pad is added in the PAUSED or PLAYING * state. See gst_pad_set_active() for more information about activating pads. * * The pad and the element should be unlocked when calling this function. * * This function will emit the #GstElement::pad-added signal on the element. * * Returns: %TRUE if the pad could be added. This function can fail when * a pad with the same name already existed or the pad already had another * parent. * * MT safe. */ gboolean gst_element_add_pad (GstElement * element, GstPad * pad) { gchar *pad_name; gboolean flushing; g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE); g_return_val_if_fail (GST_IS_PAD (pad), FALSE); /* locking pad to look at the name */ GST_OBJECT_LOCK (pad); pad_name = g_strdup (GST_PAD_NAME (pad)); GST_CAT_INFO_OBJECT (GST_CAT_ELEMENT_PADS, element, "adding pad '%s'", GST_STR_NULL (pad_name)); flushing = GST_PAD_IS_FLUSHING (pad); GST_OBJECT_UNLOCK (pad); /* then check to see if there's already a pad by that name here */ GST_OBJECT_LOCK (element); if (G_UNLIKELY (!gst_object_check_uniqueness (element->pads, pad_name))) goto name_exists; /* try to set the pad's parent */ if (G_UNLIKELY (!gst_object_set_parent (GST_OBJECT_CAST (pad), GST_OBJECT_CAST (element)))) goto had_parent; /* check for flushing pads */ if (flushing && (GST_STATE (element) > GST_STATE_READY || GST_STATE_NEXT (element) == GST_STATE_PAUSED)) { g_warning ("adding flushing pad '%s' to running element '%s'", GST_STR_NULL (pad_name), GST_ELEMENT_NAME (element)); /* unset flushing */ GST_OBJECT_LOCK (pad); GST_PAD_UNSET_FLUSHING (pad); GST_OBJECT_UNLOCK (pad); } g_free (pad_name); /* add it to the list */ switch (gst_pad_get_direction (pad)) { case GST_PAD_SRC: element->srcpads = g_list_prepend (element->srcpads, pad); element->numsrcpads++; break; case GST_PAD_SINK: element->sinkpads = g_list_prepend (element->sinkpads, pad); element->numsinkpads++; break; default: goto no_direction; } element->pads = g_list_prepend (element->pads, pad); element->numpads++; element->pads_cookie++; GST_OBJECT_UNLOCK (element); /* emit the PAD_ADDED signal */ g_signal_emit (element, gst_element_signals[PAD_ADDED], 0, pad); return TRUE; /* ERROR cases */ name_exists: { g_critical ("Padname %s is not unique in element %s, not adding", pad_name, GST_ELEMENT_NAME (element)); GST_OBJECT_UNLOCK (element); g_free (pad_name); return FALSE; } had_parent: { g_critical ("Pad %s already has parent when trying to add to element %s", pad_name, GST_ELEMENT_NAME (element)); GST_OBJECT_UNLOCK (element); g_free (pad_name); return FALSE; } no_direction: { GST_OBJECT_LOCK (pad); g_critical ("Trying to add pad %s to element %s, but it has no direction", GST_OBJECT_NAME (pad), GST_ELEMENT_NAME (element)); GST_OBJECT_UNLOCK (pad); GST_OBJECT_UNLOCK (element); return FALSE; } } /** * gst_element_remove_pad: * @element: a #GstElement to remove pad from. * @pad: the #GstPad to remove from the element. * * Removes @pad from @element. @pad will be destroyed if it has not been * referenced elsewhere using gst_object_unparent(). * * This function is used by plugin developers and should not be used * by applications. Pads that were dynamically requested from elements * with gst_element_get_request_pad() should be released with the * gst_element_release_request_pad() function instead. * * Pads are not automatically deactivated so elements should perform the needed * steps to deactivate the pad in case this pad is removed in the PAUSED or * PLAYING state. See gst_pad_set_active() for more information about * deactivating pads. * * The pad and the element should be unlocked when calling this function. * * This function will emit the #GstElement::pad-removed signal on the element. * * Returns: %TRUE if the pad could be removed. Can return %FALSE if the * pad does not belong to the provided element. * * MT safe. */ gboolean gst_element_remove_pad (GstElement * element, GstPad * pad) { GstPad *peer; g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE); g_return_val_if_fail (GST_IS_PAD (pad), FALSE); /* locking pad to look at the name and parent */ GST_OBJECT_LOCK (pad); GST_CAT_INFO_OBJECT (GST_CAT_ELEMENT_PADS, element, "removing pad '%s'", GST_STR_NULL (GST_PAD_NAME (pad))); if (G_UNLIKELY (GST_PAD_PARENT (pad) != element)) goto not_our_pad; GST_OBJECT_UNLOCK (pad); /* unlink */ if ((peer = gst_pad_get_peer (pad))) { /* window for MT unsafeness, someone else could unlink here * and then we call unlink with wrong pads. The unlink * function would catch this and safely return failed. */ if (GST_PAD_IS_SRC (pad)) gst_pad_unlink (pad, peer); else gst_pad_unlink (peer, pad); gst_object_unref (peer); } GST_OBJECT_LOCK (element); /* remove it from the list */ switch (gst_pad_get_direction (pad)) { case GST_PAD_SRC: element->srcpads = g_list_remove (element->srcpads, pad); element->numsrcpads--; break; case GST_PAD_SINK: element->sinkpads = g_list_remove (element->sinkpads, pad); element->numsinkpads--; break; default: g_critical ("Removing pad without direction???"); break; } element->pads = g_list_remove (element->pads, pad); element->numpads--; element->pads_cookie++; GST_OBJECT_UNLOCK (element); /* emit the PAD_REMOVED signal before unparenting and losing the last ref. */ g_signal_emit (element, gst_element_signals[PAD_REMOVED], 0, pad); gst_object_unparent (GST_OBJECT_CAST (pad)); return TRUE; /* ERRORS */ not_our_pad: { /* FIXME, locking order? */ GST_OBJECT_LOCK (element); g_critical ("Padname %s:%s does not belong to element %s when removing", GST_DEBUG_PAD_NAME (pad), GST_ELEMENT_NAME (element)); GST_OBJECT_UNLOCK (element); GST_OBJECT_UNLOCK (pad); return FALSE; } } /** * gst_element_no_more_pads: * @element: a #GstElement * * Use this function to signal that the element does not expect any more pads * to show up in the current pipeline. This function should be called whenever * pads have been added by the element itself. Elements with #GST_PAD_SOMETIMES * pad templates use this in combination with autopluggers to figure out that * the element is done initializing its pads. * * This function emits the #GstElement::no-more-pads signal. * * MT safe. */ void gst_element_no_more_pads (GstElement * element) { g_return_if_fail (GST_IS_ELEMENT (element)); g_signal_emit (element, gst_element_signals[NO_MORE_PADS], 0); } static gint pad_compare_name (GstPad * pad1, const gchar * name) { gint result; GST_OBJECT_LOCK (pad1); result = strcmp (GST_PAD_NAME (pad1), name); GST_OBJECT_UNLOCK (pad1); return result; } /** * gst_element_get_static_pad: * @element: a #GstElement to find a static pad of. * @name: the name of the static #GstPad to retrieve. * * Retrieves a pad from @element by name. This version only retrieves * already-existing (i.e. 'static') pads. * * Returns: the requested #GstPad if found, otherwise %NULL. unref after * usage. * * MT safe. */ GstPad * gst_element_get_static_pad (GstElement * element, const gchar * name) { GList *find; GstPad *result = NULL; g_return_val_if_fail (GST_IS_ELEMENT (element), NULL); g_return_val_if_fail (name != NULL, NULL); GST_OBJECT_LOCK (element); find = g_list_find_custom (element->pads, name, (GCompareFunc) pad_compare_name); if (find) { result = GST_PAD_CAST (find->data); gst_object_ref (result); } if (result == NULL) { GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "no such pad '%s' in element \"%s\"", name, GST_ELEMENT_NAME (element)); } else { GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "found pad %s:%s", GST_ELEMENT_NAME (element), name); } GST_OBJECT_UNLOCK (element); return result; } static GstPad * gst_element_request_pad (GstElement * element, GstPadTemplate * templ, const gchar * name) { GstPad *newpad = NULL; GstElementClass *oclass; oclass = GST_ELEMENT_GET_CLASS (element); if (oclass->request_new_pad) newpad = (oclass->request_new_pad) (element, templ, name); if (newpad) gst_object_ref (newpad); return newpad; } /** * gst_element_get_request_pad: * @element: a #GstElement to find a request pad of. * @name: the name of the request #GstPad to retrieve. * * Retrieves a pad from the element by name. This version only retrieves * request pads. The pad should be released with * gst_element_release_request_pad(). * * Returns: requested #GstPad if found, otherwise %NULL. Release after usage. */ GstPad * gst_element_get_request_pad (GstElement * element, const gchar * name) { GstPadTemplate *templ = NULL; GstPad *pad; const gchar *req_name = NULL; gboolean templ_found = FALSE; GList *list; gint n; const gchar *data; gchar *str, *endptr = NULL; GstElementClass *class; g_return_val_if_fail (GST_IS_ELEMENT (element), NULL); g_return_val_if_fail (name != NULL, NULL); class = GST_ELEMENT_GET_CLASS (element); /* if the name contains a %, we assume it's the complete template name. Get * the template and try to get a pad */ if (strstr (name, "%")) { templ = gst_element_class_get_request_pad_template (class, name); req_name = NULL; if (templ) templ_found = TRUE; } else { /* there is no % in the name, try to find a matching template */ list = gst_element_class_get_pad_template_list (class); while (!templ_found && list) { templ = (GstPadTemplate *) list->data; if (templ->presence == GST_PAD_REQUEST) { GST_CAT_DEBUG (GST_CAT_PADS, "comparing %s to %s", name, templ->name_template); /* see if we find an exact match */ if (strcmp (name, templ->name_template) == 0) { templ_found = TRUE; req_name = name; break; } /* Because of sanity checks in gst_pad_template_new(), we know that %s and %d, occurring at the end of the name_template, are the only possibilities. */ else if ((str = strchr (templ->name_template, '%')) && strncmp (templ->name_template, name, str - templ->name_template) == 0 && strlen (name) > str - templ->name_template) { data = name + (str - templ->name_template); if (*(str + 1) == 'd') { /* it's an int */ n = (gint) strtol (data, &endptr, 10); if (endptr && *endptr == '\0') { templ_found = TRUE; req_name = name; break; } } else { /* it's a string */ templ_found = TRUE; req_name = name; break; } } } list = list->next; } } if (!templ_found) return NULL; pad = gst_element_request_pad (element, templ, req_name); return pad; } /** * gst_element_get_pad: * @element: a #GstElement. * @name: the name of the pad to retrieve. * * Retrieves a pad from @element by name. Tries gst_element_get_static_pad() * first, then gst_element_get_request_pad(). * * Deprecated: This function is deprecated as it's unclear if the reference * to the result pad should be released with gst_object_unref() in case of a static pad * or gst_element_release_request_pad() in case of a request pad. * Use gst_element_get_static_pad() or gst_element_get_request_pad() instead. * * Returns: the #GstPad if found, otherwise %NULL. Unref or Release after usage, * depending on the type of the pad. */ #ifndef GST_REMOVE_DEPRECATED GstPad * gst_element_get_pad (GstElement * element, const gchar * name) { GstPad *pad; g_return_val_if_fail (GST_IS_ELEMENT (element), NULL); g_return_val_if_fail (name != NULL, NULL); pad = gst_element_get_static_pad (element, name); if (!pad) pad = gst_element_get_request_pad (element, name); return pad; } #endif /* GST_REMOVE_DEPRECATED */ static GstIteratorItem iterate_pad (GstIterator * it, GstPad * pad) { gst_object_ref (pad); return GST_ITERATOR_ITEM_PASS; } static GstIterator * gst_element_iterate_pad_list (GstElement * element, GList ** padlist) { GstIterator *result; GST_OBJECT_LOCK (element); gst_object_ref (element); result = gst_iterator_new_list (GST_TYPE_PAD, GST_OBJECT_GET_LOCK (element), &element->pads_cookie, padlist, element, (GstIteratorItemFunction) iterate_pad, (GstIteratorDisposeFunction) gst_object_unref); GST_OBJECT_UNLOCK (element); return result; } /** * gst_element_iterate_pads: * @element: a #GstElement to iterate pads of. * * Retrieves an iterattor of @element's pads. The iterator should * be freed after usage. * * Returns: the #GstIterator of #GstPad. Unref each pad after use. * * MT safe. */ GstIterator * gst_element_iterate_pads (GstElement * element) { g_return_val_if_fail (GST_IS_ELEMENT (element), NULL); return gst_element_iterate_pad_list (element, &element->pads); } /** * gst_element_iterate_src_pads: * @element: a #GstElement. * * Retrieves an iterator of @element's source pads. * * Returns: the #GstIterator of #GstPad. Unref each pad after use. * * MT safe. */ GstIterator * gst_element_iterate_src_pads (GstElement * element) { g_return_val_if_fail (GST_IS_ELEMENT (element), NULL); return gst_element_iterate_pad_list (element, &element->srcpads); } /** * gst_element_iterate_sink_pads: * @element: a #GstElement. * * Retrieves an iterator of @element's sink pads. * * Returns: the #GstIterator of #GstPad. Unref each pad after use. * * MT safe. */ GstIterator * gst_element_iterate_sink_pads (GstElement * element) { g_return_val_if_fail (GST_IS_ELEMENT (element), NULL); return gst_element_iterate_pad_list (element, &element->sinkpads); } /** * gst_element_class_add_pad_template: * @klass: the #GstElementClass to add the pad template to. * @templ: a #GstPadTemplate to add to the element class. * * Adds a padtemplate to an element class. This is mainly used in the _base_init * functions of classes. */ void gst_element_class_add_pad_template (GstElementClass * klass, GstPadTemplate * templ) { g_return_if_fail (GST_IS_ELEMENT_CLASS (klass)); g_return_if_fail (GST_IS_PAD_TEMPLATE (templ)); /* FIXME 0.11: allow replacing the pad templates by * calling this with the same name as an already existing pad * template. For this we _must_ _not_ ref the added pad template * a second time and _must_ document that this function takes * ownership of the pad template. Otherwise we will leak pad templates * or the caller unref's the pad template and it disappears */ /* avoid registering pad templates with the same name */ g_return_if_fail (gst_element_class_get_pad_template (klass, templ->name_template) == NULL); klass->padtemplates = g_list_append (klass->padtemplates, gst_object_ref (templ)); klass->numpadtemplates++; } /** * gst_element_class_set_details: * @klass: class to set details for * @details: details to set * * Sets the detailed information for a #GstElementClass. * This function is for use in _base_init functions only. * * The @details are copied. */ void gst_element_class_set_details (GstElementClass * klass, const GstElementDetails * details) { g_return_if_fail (GST_IS_ELEMENT_CLASS (klass)); g_return_if_fail (GST_IS_ELEMENT_DETAILS (details)); __gst_element_details_copy (&klass->details, details); } /** * gst_element_class_set_details_simple: * @klass: class to set details for * @longname: The long English name of the element. E.g. "File Sink" * @classification: String describing the type of element, as an unordered list * separated with slashes ('/'). See draft-klass.txt of the design docs * for more details and common types. E.g: "Sink/File" * @description: Sentence describing the purpose of the element. * E.g: "Write stream to a file" * @author: Name and contact details of the author(s). Use \n to separate * multiple author details. E.g: "Joe Bloggs <joe.blogs at foo.com>" * * Sets the detailed information for a #GstElementClass. Simpler version of * gst_element_class_set_details() that generates less linker overhead. * This function is for use in _base_init functions only. * * The detail parameter strings are copied into the #GstElementDetails for * the element class. * * Since: 0.10.14 */ void gst_element_class_set_details_simple (GstElementClass * klass, const gchar * longname, const gchar * classification, const gchar * description, const gchar * author) { const GstElementDetails details = GST_ELEMENT_DETAILS ((gchar *) longname, (gchar *) classification, (gchar *) description, (gchar *) author); g_return_if_fail (GST_IS_ELEMENT_CLASS (klass)); __gst_element_details_copy (&klass->details, &details); } /** * gst_element_class_get_pad_template_list: * @element_class: a #GstElementClass to get pad templates of. * * Retrieves a list of the pad templates associated with @element_class. The * list must not be modified by the calling code. * If you use this function in the #GInstanceInitFunc of an object class * that has subclasses, make sure to pass the g_class parameter of the * #GInstanceInitFunc here. * * Returns: the #GList of padtemplates. */ GList * gst_element_class_get_pad_template_list (GstElementClass * element_class) { g_return_val_if_fail (GST_IS_ELEMENT_CLASS (element_class), NULL); return element_class->padtemplates; } /** * gst_element_class_get_pad_template: * @element_class: a #GstElementClass to get the pad template of. * @name: the name of the #GstPadTemplate to get. * * Retrieves a padtemplate from @element_class with the given name. * If you use this function in the #GInstanceInitFunc of an object class * that has subclasses, make sure to pass the g_class parameter of the * #GInstanceInitFunc here. * * Returns: the #GstPadTemplate with the given name, or %NULL if none was found. * No unreferencing is necessary. */ GstPadTemplate * gst_element_class_get_pad_template (GstElementClass * element_class, const gchar * name) { GList *padlist; g_return_val_if_fail (GST_IS_ELEMENT_CLASS (element_class), NULL); g_return_val_if_fail (name != NULL, NULL); padlist = gst_element_class_get_pad_template_list (element_class); while (padlist) { GstPadTemplate *padtempl = (GstPadTemplate *) padlist->data; if (strcmp (padtempl->name_template, name) == 0) return padtempl; padlist = g_list_next (padlist); } return NULL; } static GstPadTemplate * gst_element_class_get_request_pad_template (GstElementClass * element_class, const gchar * name) { GstPadTemplate *tmpl; tmpl = gst_element_class_get_pad_template (element_class, name); if (tmpl != NULL && tmpl->presence == GST_PAD_REQUEST) return tmpl; return NULL; } /* get a random pad on element of the given direction. * The pad is random in a sense that it is the first pad that is (optionaly) linked. */ static GstPad * gst_element_get_random_pad (GstElement * element, gboolean need_linked, GstPadDirection dir) { GstPad *result = NULL; GList *pads; GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "getting a random pad"); switch (dir) { case GST_PAD_SRC: GST_OBJECT_LOCK (element); pads = element->srcpads; break; case GST_PAD_SINK: GST_OBJECT_LOCK (element); pads = element->sinkpads; break; default: goto wrong_direction; } for (; pads; pads = g_list_next (pads)) { GstPad *pad = GST_PAD_CAST (pads->data); GST_OBJECT_LOCK (pad); GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "checking pad %s:%s", GST_DEBUG_PAD_NAME (pad)); if (need_linked && !GST_PAD_IS_LINKED (pad)) { /* if we require a linked pad, and it is not linked, continue the * search */ GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "pad %s:%s is not linked", GST_DEBUG_PAD_NAME (pad)); GST_OBJECT_UNLOCK (pad); continue; } else { /* found a pad, stop search */ GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "found pad %s:%s", GST_DEBUG_PAD_NAME (pad)); GST_OBJECT_UNLOCK (pad); result = pad; break; } } if (result) gst_object_ref (result); GST_OBJECT_UNLOCK (element); return result; /* ERROR handling */ wrong_direction: { g_warning ("unknown pad direction %d", dir); return NULL; } } static gboolean gst_element_default_send_event (GstElement * element, GstEvent * event) { gboolean result = FALSE; GstPad *pad; pad = GST_EVENT_IS_DOWNSTREAM (event) ? gst_element_get_random_pad (element, TRUE, GST_PAD_SRC) : gst_element_get_random_pad (element, TRUE, GST_PAD_SINK); if (pad) { GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "pushing %s event to random %s pad %s:%s", GST_EVENT_TYPE_NAME (event), (GST_PAD_DIRECTION (pad) == GST_PAD_SRC ? "src" : "sink"), GST_DEBUG_PAD_NAME (pad)); result = gst_pad_push_event (pad, event); gst_object_unref (pad); } else { GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "can't send %s event on element %s", GST_EVENT_TYPE_NAME (event), GST_ELEMENT_NAME (element)); } return result; } /** * gst_element_send_event: * @element: a #GstElement to send the event to. * @event: the #GstEvent to send to the element. * * Sends an event to an element. If the element doesn't implement an * event handler, the event will be pushed on a random linked sink pad for * upstream events or a random linked source pad for downstream events. * * This function takes owership of the provided event so you should * gst_event_ref() it if you want to reuse the event after this call. * * Returns: %TRUE if the event was handled. * * MT safe. */ gboolean gst_element_send_event (GstElement * element, GstEvent * event) { GstElementClass *oclass; gboolean result = FALSE; g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE); g_return_val_if_fail (event != NULL, FALSE); oclass = GST_ELEMENT_GET_CLASS (element); GST_STATE_LOCK (element); if (oclass->send_event) { GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "send %s event on element %s", GST_EVENT_TYPE_NAME (event), GST_ELEMENT_NAME (element)); result = oclass->send_event (element, event); } else { result = gst_element_default_send_event (element, event); } GST_STATE_UNLOCK (element); return result; } /** * gst_element_seek: * @element: a #GstElement to send the event to. * @rate: The new playback rate * @format: The format of the seek values * @flags: The optional seek flags. * @cur_type: The type and flags for the new current position * @cur: The value of the new current position * @stop_type: The type and flags for the new stop position * @stop: The value of the new stop position * * Sends a seek event to an element. See gst_event_new_seek() for the details of * the parameters. The seek event is sent to the element using * gst_element_send_event(). * * Returns: %TRUE if the event was handled. * * MT safe. */ gboolean gst_element_seek (GstElement * element, gdouble rate, GstFormat format, GstSeekFlags flags, GstSeekType cur_type, gint64 cur, GstSeekType stop_type, gint64 stop) { GstEvent *event; gboolean result; g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE); event = gst_event_new_seek (rate, format, flags, cur_type, cur, stop_type, stop); result = gst_element_send_event (element, event); return result; } /** * gst_element_get_query_types: * @element: a #GstElement to query * * Get an array of query types from the element. * If the element doesn't implement a query types function, * the query will be forwarded to the peer of a random linked sink pad. * * Returns: An array of #GstQueryType elements that should not * be freed or modified. * * MT safe. */ const GstQueryType * gst_element_get_query_types (GstElement * element) { GstElementClass *oclass; const GstQueryType *result = NULL; g_return_val_if_fail (GST_IS_ELEMENT (element), NULL); oclass = GST_ELEMENT_GET_CLASS (element); if (oclass->get_query_types) { result = oclass->get_query_types (element); } else { GstPad *pad = gst_element_get_random_pad (element, TRUE, GST_PAD_SINK); if (pad) { GstPad *peer = gst_pad_get_peer (pad); if (peer) { result = gst_pad_get_query_types (peer); gst_object_unref (peer); } gst_object_unref (pad); } } return result; } static gboolean gst_element_default_query (GstElement * element, GstQuery * query) { gboolean result = FALSE; GstPad *pad; pad = gst_element_get_random_pad (element, FALSE, GST_PAD_SRC); if (pad) { result = gst_pad_query (pad, query); gst_object_unref (pad); } else { pad = gst_element_get_random_pad (element, TRUE, GST_PAD_SINK); if (pad) { GstPad *peer = gst_pad_get_peer (pad); if (peer) { result = gst_pad_query (peer, query); gst_object_unref (peer); } gst_object_unref (pad); } } return result; } /** * gst_element_query: * @element: a #GstElement to perform the query on. * @query: the #GstQuery. * * Performs a query on the given element. * * For elements that don't implement a query handler, this function * forwards the query to a random srcpad or to the peer of a * random linked sinkpad of this element. * * Returns: TRUE if the query could be performed. * * MT safe. */ gboolean gst_element_query (GstElement * element, GstQuery * query) { GstElementClass *oclass; gboolean result = FALSE; g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE); g_return_val_if_fail (query != NULL, FALSE); oclass = GST_ELEMENT_GET_CLASS (element); if (oclass->query) { GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "send query on element %s", GST_ELEMENT_NAME (element)); result = oclass->query (element, query); } else { result = gst_element_default_query (element, query); } return result; } /** * gst_element_post_message: * @element: a #GstElement posting the message * @message: a #GstMessage to post * * Post a message on the element's #GstBus. This function takes ownership of the * message; if you want to access the message after this call, you should add an * additional reference before calling. * * Returns: %TRUE if the message was successfully posted. The function returns * %FALSE if the element did not have a bus. * * MT safe. */ gboolean gst_element_post_message (GstElement * element, GstMessage * message) { GstBus *bus; gboolean result = FALSE; g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE); g_return_val_if_fail (message != NULL, FALSE); GST_OBJECT_LOCK (element); bus = element->bus; if (G_UNLIKELY (bus == NULL)) goto no_bus; gst_object_ref (bus); GST_OBJECT_UNLOCK (element); /* we release the element lock when posting the message so that any * (synchronous) message handlers can operate on the element */ result = gst_bus_post (bus, message); gst_object_unref (bus); return result; /* ERRORS */ no_bus: { GST_CAT_DEBUG_OBJECT (GST_CAT_MESSAGE, element, "not posting message %p: no bus", message); GST_OBJECT_UNLOCK (element); gst_message_unref (message); return FALSE; } } /** * _gst_element_error_printf: * @format: the printf-like format to use, or %NULL * * This function is only used internally by the gst_element_error() macro. * * Returns: a newly allocated string, or %NULL if the format was %NULL or "" * * MT safe. */ gchar * _gst_element_error_printf (const gchar * format, ...) { va_list args; gchar *buffer; if (format == NULL) return NULL; if (format[0] == 0) return NULL; va_start (args, format); buffer = g_strdup_vprintf (format, args); va_end (args); return buffer; } /** * gst_element_message_full: * @element: a #GstElement to send message from * @type: the #GstMessageType * @domain: the GStreamer GError domain this message belongs to * @code: the GError code belonging to the domain * @text: an allocated text string to be used as a replacement for the * default message connected to code, or %NULL * @debug: an allocated debug message to be used as a replacement for the * default debugging information, or %NULL * @file: the source code file where the error was generated * @function: the source code function where the error was generated * @line: the source code line where the error was generated * * Post an error, warning or info message on the bus from inside an element. * * @type must be of #GST_MESSAGE_ERROR, #GST_MESSAGE_WARNING or * #GST_MESSAGE_INFO. * * MT safe. */ void gst_element_message_full (GstElement * element, GstMessageType type, GQuark domain, gint code, gchar * text, gchar * debug, const gchar * file, const gchar * function, gint line) { GError *gerror = NULL; gchar *name; gchar *sent_text; gchar *sent_debug; gboolean has_debug = TRUE; GstMessage *message = NULL; /* checks */ GST_CAT_DEBUG_OBJECT (GST_CAT_MESSAGE, element, "start"); g_return_if_fail (GST_IS_ELEMENT (element)); g_return_if_fail ((type == GST_MESSAGE_ERROR) || (type == GST_MESSAGE_WARNING) || (type == GST_MESSAGE_INFO)); /* check if we send the given text or the default error text */ if ((text == NULL) || (text[0] == 0)) { /* text could have come from g_strdup_printf (""); */ g_free (text); sent_text = gst_error_get_message (domain, code); } else sent_text = text; /* construct a sent_debug with extra information from source */ if ((debug == NULL) || (debug[0] == 0)) { /* debug could have come from g_strdup_printf (""); */ has_debug = FALSE; } name = gst_object_get_path_string (GST_OBJECT_CAST (element)); if (has_debug) sent_debug = g_strdup_printf ("%s(%d): %s (): %s:\n%s", file, line, function, name, debug); else sent_debug = g_strdup_printf ("%s(%d): %s (): %s", file, line, function, name); g_free (name); g_free (debug); /* create gerror and post message */ GST_CAT_INFO_OBJECT (GST_CAT_ERROR_SYSTEM, element, "posting message: %s", sent_text); gerror = g_error_new_literal (domain, code, sent_text); switch (type) { case GST_MESSAGE_ERROR: message = gst_message_new_error (GST_OBJECT_CAST (element), gerror, sent_debug); break; case GST_MESSAGE_WARNING: message = gst_message_new_warning (GST_OBJECT_CAST (element), gerror, sent_debug); break; case GST_MESSAGE_INFO: message = gst_message_new_info (GST_OBJECT_CAST (element), gerror, sent_debug); break; default: g_assert_not_reached (); break; } gst_element_post_message (element, message); GST_CAT_INFO_OBJECT (GST_CAT_ERROR_SYSTEM, element, "posted %s message: %s", (type == GST_MESSAGE_ERROR ? "error" : "warning"), sent_text); /* cleanup */ g_error_free (gerror); g_free (sent_debug); g_free (sent_text); } /** * gst_element_is_locked_state: * @element: a #GstElement. * * Checks if the state of an element is locked. * If the state of an element is locked, state changes of the parent don't * affect the element. * This way you can leave currently unused elements inside bins. Just lock their * state before changing the state from #GST_STATE_NULL. * * MT safe. * * Returns: TRUE, if the element's state is locked. */ gboolean gst_element_is_locked_state (GstElement * element) { gboolean result; g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE); GST_OBJECT_LOCK (element); result = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_LOCKED_STATE); GST_OBJECT_UNLOCK (element); return result; } /** * gst_element_set_locked_state: * @element: a #GstElement * @locked_state: TRUE to lock the element's state * * Locks the state of an element, so state changes of the parent don't affect * this element anymore. * * MT safe. * * Returns: TRUE if the state was changed, FALSE if bad parameters were given * or the elements state-locking needed no change. */ gboolean gst_element_set_locked_state (GstElement * element, gboolean locked_state) { gboolean old; g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE); GST_OBJECT_LOCK (element); old = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_LOCKED_STATE); if (G_UNLIKELY (old == locked_state)) goto was_ok; if (locked_state) { GST_CAT_DEBUG (GST_CAT_STATES, "locking state of element %s", GST_ELEMENT_NAME (element)); GST_OBJECT_FLAG_SET (element, GST_ELEMENT_LOCKED_STATE); } else { GST_CAT_DEBUG (GST_CAT_STATES, "unlocking state of element %s", GST_ELEMENT_NAME (element)); GST_OBJECT_FLAG_UNSET (element, GST_ELEMENT_LOCKED_STATE); } GST_OBJECT_UNLOCK (element); return TRUE; was_ok: { GST_CAT_DEBUG (GST_CAT_STATES, "elements %s was already in locked state %d", GST_ELEMENT_NAME (element), old); GST_OBJECT_UNLOCK (element); return FALSE; } } /** * gst_element_sync_state_with_parent: * @element: a #GstElement. * * Tries to change the state of the element to the same as its parent. * If this function returns FALSE, the state of element is undefined. * * Returns: TRUE, if the element's state could be synced to the parent's state. * * MT safe. */ gboolean gst_element_sync_state_with_parent (GstElement * element) { GstElement *parent; GstState target; GstStateChangeReturn ret; g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE); if ((parent = GST_ELEMENT_CAST (gst_element_get_parent (element)))) { GstState parent_current, parent_pending; GST_OBJECT_LOCK (parent); parent_current = GST_STATE (parent); parent_pending = GST_STATE_PENDING (parent); GST_OBJECT_UNLOCK (parent); /* set to pending if there is one, else we set it to the current state of * the parent */ if (parent_pending != GST_STATE_VOID_PENDING) target = parent_pending; else target = parent_current; GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "syncing state (%s) to parent %s %s (%s, %s)", gst_element_state_get_name (GST_STATE (element)), GST_ELEMENT_NAME (parent), gst_element_state_get_name (target), gst_element_state_get_name (parent_current), gst_element_state_get_name (parent_pending)); ret = gst_element_set_state (element, target); if (ret == GST_STATE_CHANGE_FAILURE) goto failed; gst_object_unref (parent); return TRUE; } else { GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "element has no parent"); } return FALSE; /* ERROR */ failed: { GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "syncing state failed (%s)", gst_element_state_change_return_get_name (ret)); gst_object_unref (parent); return FALSE; } } /* MT safe */ static GstStateChangeReturn gst_element_get_state_func (GstElement * element, GstState * state, GstState * pending, GstClockTime timeout) { GstStateChangeReturn ret = GST_STATE_CHANGE_FAILURE; GstState old_pending; GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "getting state, timeout %" GST_TIME_FORMAT, GST_TIME_ARGS (timeout)); GST_OBJECT_LOCK (element); ret = GST_STATE_RETURN (element); GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "RETURN is %s", gst_element_state_change_return_get_name (ret)); /* we got an error, report immediatly */ if (ret == GST_STATE_CHANGE_FAILURE) goto done; /* we got no_preroll, report immediatly */ if (ret == GST_STATE_CHANGE_NO_PREROLL) goto done; /* no need to wait async if we are not async */ if (ret != GST_STATE_CHANGE_ASYNC) goto done; old_pending = GST_STATE_PENDING (element); if (old_pending != GST_STATE_VOID_PENDING) { GTimeVal *timeval, abstimeout; guint32 cookie; if (timeout != GST_CLOCK_TIME_NONE) { glong add = timeout / 1000; if (add == 0) goto done; /* make timeout absolute */ g_get_current_time (&abstimeout); g_time_val_add (&abstimeout, add); timeval = &abstimeout; } else { timeval = NULL; } /* get cookie to dected state change during waiting */ cookie = element->state_cookie; GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "waiting for element to commit state"); /* we have a pending state change, wait for it to complete */ if (!GST_STATE_TIMED_WAIT (element, timeval)) { GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "timed out"); /* timeout triggered */ ret = GST_STATE_CHANGE_ASYNC; } else { if (cookie != element->state_cookie) goto interrupted; /* could be success or failure */ if (old_pending == GST_STATE (element)) { GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "got success"); ret = GST_STATE_CHANGE_SUCCESS; } else { GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "got failure"); ret = GST_STATE_CHANGE_FAILURE; } } /* if nothing is pending anymore we can return SUCCESS */ if (GST_STATE_PENDING (element) == GST_STATE_VOID_PENDING) { GST_CAT_LOG_OBJECT (GST_CAT_STATES, element, "nothing pending"); ret = GST_STATE_CHANGE_SUCCESS; } } done: if (state) *state = GST_STATE (element); if (pending) *pending = GST_STATE_PENDING (element); GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "state current: %s, pending: %s, result: %s", gst_element_state_get_name (GST_STATE (element)), gst_element_state_get_name (GST_STATE_PENDING (element)), gst_element_state_change_return_get_name (ret)); GST_OBJECT_UNLOCK (element); return ret; interrupted: { if (state) *state = GST_STATE_VOID_PENDING; if (pending) *pending = GST_STATE_VOID_PENDING; GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "interruped"); GST_OBJECT_UNLOCK (element); return GST_STATE_CHANGE_FAILURE; } } /** * gst_element_get_state: * @element: a #GstElement to get the state of. * @state: a pointer to #GstState to hold the state. Can be %NULL. * @pending: a pointer to #GstState to hold the pending state. * Can be %NULL. * @timeout: a #GstClockTime to specify the timeout for an async * state change or %GST_CLOCK_TIME_NONE for infinite timeout. * * Gets the state of the element. * * For elements that performed an ASYNC state change, as reported by * gst_element_set_state(), this function will block up to the * specified timeout value for the state change to complete. * If the element completes the state change or goes into * an error, this function returns immediately with a return value of * %GST_STATE_CHANGE_SUCCESS or %GST_STATE_CHANGE_FAILURE respectively. * * For elements that did not return %GST_STATE_CHANGE_ASYNC, this function * returns the current and pending state immediately. * * This function returns %GST_STATE_CHANGE_NO_PREROLL if the element * successfully changed its state but is not able to provide data yet. * This mostly happens for live sources that only produce data in the PLAYING * state. While the state change return is equivalent to * %GST_STATE_CHANGE_SUCCESS, it is returned to the application to signal that * some sink elements might not be able to complete their state change because * an element is not producing data to complete the preroll. When setting the * element to playing, the preroll will complete and playback will start. * * Returns: %GST_STATE_CHANGE_SUCCESS if the element has no more pending state * and the last state change succeeded, %GST_STATE_CHANGE_ASYNC if the * element is still performing a state change or * %GST_STATE_CHANGE_FAILURE if the last state change failed. * * MT safe. */ GstStateChangeReturn gst_element_get_state (GstElement * element, GstState * state, GstState * pending, GstClockTime timeout) { GstElementClass *oclass; GstStateChangeReturn result = GST_STATE_CHANGE_FAILURE; g_return_val_if_fail (GST_IS_ELEMENT (element), GST_STATE_CHANGE_FAILURE); oclass = GST_ELEMENT_GET_CLASS (element); if (oclass->get_state) result = (oclass->get_state) (element, state, pending, timeout); return result; } /** * gst_element_abort_state: * @element: a #GstElement to abort the state of. * * Abort the state change of the element. This function is used * by elements that do asynchronous state changes and find out * something is wrong. * * This function should be called with the STATE_LOCK held. * * MT safe. */ void gst_element_abort_state (GstElement * element) { GstState pending; #ifndef GST_DISABLE_GST_DEBUG GstState old_state; #endif g_return_if_fail (GST_IS_ELEMENT (element)); GST_OBJECT_LOCK (element); pending = GST_STATE_PENDING (element); if (pending == GST_STATE_VOID_PENDING || GST_STATE_RETURN (element) == GST_STATE_CHANGE_FAILURE) goto nothing_aborted; #ifndef GST_DISABLE_GST_DEBUG old_state = GST_STATE (element); GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "aborting state from %s to %s", gst_element_state_get_name (old_state), gst_element_state_get_name (pending)); #endif /* flag error */ GST_STATE_RETURN (element) = GST_STATE_CHANGE_FAILURE; GST_STATE_BROADCAST (element); GST_OBJECT_UNLOCK (element); return; nothing_aborted: { GST_OBJECT_UNLOCK (element); return; } } /** * gst_element_continue_state: * @element: a #GstElement to continue the state change of. * @ret: The previous state return value * * Commit the state change of the element and proceed to the next * pending state if any. This function is used * by elements that do asynchronous state changes. * The core will normally call this method automatically when an * element returned %GST_STATE_CHANGE_SUCCESS from the state change function. * * If after calling this method the element still has not reached * the pending state, the next state change is performed. * * This method is used internally and should normally not be called by plugins * or applications. * * Returns: The result of the commit state change. * * MT safe. */ GstStateChangeReturn gst_element_continue_state (GstElement * element, GstStateChangeReturn ret) { GstStateChangeReturn old_ret; GstState old_state, old_next; GstState current, next, pending; GstMessage *message; GstStateChange transition; GST_OBJECT_LOCK (element); old_ret = GST_STATE_RETURN (element); GST_STATE_RETURN (element) = ret; pending = GST_STATE_PENDING (element); /* check if there is something to commit */ if (pending == GST_STATE_VOID_PENDING) goto nothing_pending; old_state = GST_STATE (element); /* this is the state we should go to next */ old_next = GST_STATE_NEXT (element); /* update current state */ current = GST_STATE (element) = old_next; /* see if we reached the final state */ if (pending == current) goto complete; next = GST_STATE_GET_NEXT (current, pending); transition = (GstStateChange) GST_STATE_TRANSITION (current, next); GST_STATE_NEXT (element) = next; /* mark busy */ GST_STATE_RETURN (element) = GST_STATE_CHANGE_ASYNC; GST_OBJECT_UNLOCK (element); GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "committing state from %s to %s, pending %s", gst_element_state_get_name (old_state), gst_element_state_get_name (old_next), gst_element_state_get_name (pending)); message = gst_message_new_state_changed (GST_OBJECT_CAST (element), old_state, old_next, pending); gst_element_post_message (element, message); GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "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)); ret = gst_element_change_state (element, transition); return ret; nothing_pending: { GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "nothing pending"); GST_OBJECT_UNLOCK (element); return ret; } complete: { GST_STATE_PENDING (element) = GST_STATE_VOID_PENDING; GST_STATE_NEXT (element) = GST_STATE_VOID_PENDING; GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "completed state change to %s", gst_element_state_get_name (pending)); GST_OBJECT_UNLOCK (element); /* don't post silly messages with the same state. This can happen * when an element state is changed to what it already was. For bins * this can be the result of a lost state, which we check with the * previous return value. * We do signal the cond though as a _get_state() might be blocking * on it. */ if (old_state != old_next || old_ret == GST_STATE_CHANGE_ASYNC) { GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "posting state-changed %s to %s", gst_element_state_get_name (old_state), gst_element_state_get_name (old_next)); message = gst_message_new_state_changed (GST_OBJECT_CAST (element), old_state, old_next, GST_STATE_VOID_PENDING); gst_element_post_message (element, message); } GST_STATE_BROADCAST (element); return ret; } } /** * gst_element_lost_state_full: * @element: a #GstElement the state is lost of * @new_base_time: if a new base time should be distributed * * Brings the element to the lost state. The current state of the * element is copied to the pending state so that any call to * gst_element_get_state() will return %GST_STATE_CHANGE_ASYNC. * * An ASYNC_START message is posted with indication to distribute a new * base_time to the element when @new_base_time is %TRUE. * If the element was PLAYING, it will go to PAUSED. The element * will be restored to its PLAYING state by the parent pipeline when it * prerolls again. * * This is mostly used for elements that lost their preroll buffer * in the %GST_STATE_PAUSED or %GST_STATE_PLAYING state after a flush, * they will go to their pending state again when a new preroll buffer is * queued. This function can only be called when the element is currently * not in error or an async state change. * * This function is used internally and should normally not be called from * plugins or applications. * * MT safe. * * Since: 0.10.24 */ void gst_element_lost_state_full (GstElement * element, gboolean new_base_time) { GstState old_state, new_state; GstMessage *message; g_return_if_fail (GST_IS_ELEMENT (element)); GST_OBJECT_LOCK (element); if (GST_STATE_RETURN (element) == GST_STATE_CHANGE_FAILURE) goto nothing_lost; if (GST_STATE_PENDING (element) != GST_STATE_VOID_PENDING) goto only_async_start; old_state = GST_STATE (element); /* when we were PLAYING, the new state is PAUSED. We will also not * automatically go to PLAYING but let the parent bin(s) set us to PLAYING * when we preroll. */ if (old_state > GST_STATE_PAUSED) new_state = GST_STATE_PAUSED; else new_state = old_state; GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "lost state of %s to %s", gst_element_state_get_name (old_state), gst_element_state_get_name (new_state)); GST_STATE (element) = new_state; GST_STATE_NEXT (element) = new_state; GST_STATE_PENDING (element) = new_state; GST_STATE_RETURN (element) = GST_STATE_CHANGE_ASYNC; GST_OBJECT_UNLOCK (element); message = gst_message_new_state_changed (GST_OBJECT_CAST (element), new_state, new_state, new_state); gst_element_post_message (element, message); message = gst_message_new_async_start (GST_OBJECT_CAST (element), new_base_time); gst_element_post_message (element, message); return; nothing_lost: { GST_OBJECT_UNLOCK (element); return; } only_async_start: { GST_OBJECT_UNLOCK (element); message = gst_message_new_async_start (GST_OBJECT_CAST (element), TRUE); gst_element_post_message (element, message); return; } } /** * gst_element_lost_state: * @element: a #GstElement the state is lost of * * Brings the element to the lost state. This function calls * gst_element_lost_state_full() with the new_base_time set to %TRUE. * * This function is used internally and should normally not be called from * plugins or applications. * * MT safe. */ void gst_element_lost_state (GstElement * element) { gst_element_lost_state_full (element, TRUE); } /** * gst_element_set_state: * @element: a #GstElement to change state of. * @state: the element's new #GstState. * * Sets the state of the element. This function will try to set the * requested state by going through all the intermediary states and calling * the class's state change function for each. * * This function can return #GST_STATE_CHANGE_ASYNC, in which case the * element will perform the remainder of the state change asynchronously in * another thread. * An application can use gst_element_get_state() to wait for the completion * of the state change or it can wait for a state change message on the bus. * * State changes to %GST_STATE_READY or %GST_STATE_NULL never return * #GST_STATE_CHANGE_ASYNC. * * Returns: Result of the state change using #GstStateChangeReturn. * * MT safe. */ GstStateChangeReturn gst_element_set_state (GstElement * element, GstState state) { GstElementClass *oclass; GstStateChangeReturn result = GST_STATE_CHANGE_FAILURE; g_return_val_if_fail (GST_IS_ELEMENT (element), GST_STATE_CHANGE_FAILURE); oclass = GST_ELEMENT_GET_CLASS (element); if (oclass->set_state) result = (oclass->set_state) (element, state); return result; } /* * default set state function, calculates the next state based * on current state and calls the change_state function */ static GstStateChangeReturn gst_element_set_state_func (GstElement * element, GstState state) { GstState current, next, old_pending; GstStateChangeReturn ret; GstStateChange transition; GstStateChangeReturn old_ret; g_return_val_if_fail (GST_IS_ELEMENT (element), GST_STATE_CHANGE_FAILURE); GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "set_state to %s", gst_element_state_get_name (state)); /* state lock is taken to protect the set_state() and get_state() * procedures, it does not lock any variables. */ GST_STATE_LOCK (element); /* now calculate how to get to the new state */ GST_OBJECT_LOCK (element); old_ret = GST_STATE_RETURN (element); /* previous state change returned an error, remove all pending * and next states */ if (old_ret == GST_STATE_CHANGE_FAILURE) { GST_STATE_NEXT (element) = GST_STATE_VOID_PENDING; GST_STATE_PENDING (element) = GST_STATE_VOID_PENDING; GST_STATE_RETURN (element) = GST_STATE_CHANGE_SUCCESS; } current = GST_STATE (element); next = GST_STATE_NEXT (element); old_pending = GST_STATE_PENDING (element); /* this is the (new) state we should go to. TARGET is the last state we set on * the element. */ if (state != GST_STATE_TARGET (element)) { GST_STATE_TARGET (element) = state; /* increment state cookie so that we can track each state change. We only do * this if this is actually a new state change. */ element->state_cookie++; } GST_STATE_PENDING (element) = state; GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "current %s, old_pending %s, next %s, old return %s", gst_element_state_get_name (current), gst_element_state_get_name (old_pending), gst_element_state_get_name (next), gst_element_state_change_return_get_name (old_ret)); /* if the element was busy doing a state change, we just update the * target state, it'll get to it async then. */ if (old_pending != GST_STATE_VOID_PENDING) { /* upwards state change will happen ASYNC */ if (old_pending <= state) goto was_busy; /* element is going to this state already */ else if (next == state) goto was_busy; /* element was performing an ASYNC upward state change and * we request to go downward again. Start from the next pending * state then. */ else if (next > state && GST_STATE_RETURN (element) == GST_STATE_CHANGE_ASYNC) { current = next; } } next = GST_STATE_GET_NEXT (current, state); /* now we store the next state */ GST_STATE_NEXT (element) = next; /* mark busy, we need to check that there is actually a state change * to be done else we could accidentally override SUCCESS/NO_PREROLL and * the default element change_state function has no way to know what the * old value was... could consider this a FIXME...*/ if (current != next) GST_STATE_RETURN (element) = GST_STATE_CHANGE_ASYNC; transition = (GstStateChange) GST_STATE_TRANSITION (current, next); GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "%s: setting state from %s to %s", (next != state ? "intermediate" : "final"), gst_element_state_get_name (current), gst_element_state_get_name (next)); /* now signal any waiters, they will error since the cookie was incremented */ GST_STATE_BROADCAST (element); GST_OBJECT_UNLOCK (element); ret = gst_element_change_state (element, transition); GST_STATE_UNLOCK (element); GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "returned %s", gst_element_state_change_return_get_name (ret)); return ret; was_busy: { GST_STATE_RETURN (element) = GST_STATE_CHANGE_ASYNC; GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "element was busy with async state change"); GST_OBJECT_UNLOCK (element); GST_STATE_UNLOCK (element); return GST_STATE_CHANGE_ASYNC; } } /** * gst_element_change_state: * @element: a #GstElement * @transition: the requested transition * * Perform @transition on @element. * * This function must be called with STATE_LOCK held and is mainly used * internally. * * Returns: the #GstStateChangeReturn of the state transition. */ GstStateChangeReturn gst_element_change_state (GstElement * element, GstStateChange transition) { GstElementClass *oclass; GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS; oclass = GST_ELEMENT_GET_CLASS (element); /* call the state change function so it can set the state */ if (oclass->change_state) ret = (oclass->change_state) (element, transition); else ret = GST_STATE_CHANGE_FAILURE; switch (ret) { case GST_STATE_CHANGE_FAILURE: GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "have FAILURE change_state return"); /* state change failure */ gst_element_abort_state (element); break; case GST_STATE_CHANGE_ASYNC: { GstState target; GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "element will change state ASYNC"); target = GST_STATE_TARGET (element); if (target > GST_STATE_READY) goto async; /* else we just continue the state change downwards */ GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "forcing commit state %s <= %s", gst_element_state_get_name (target), gst_element_state_get_name (GST_STATE_READY)); ret = gst_element_continue_state (element, GST_STATE_CHANGE_SUCCESS); break; } case GST_STATE_CHANGE_SUCCESS: GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "element changed state SUCCESS"); /* we can commit the state now which will proceeed to * the next state */ ret = gst_element_continue_state (element, ret); break; case GST_STATE_CHANGE_NO_PREROLL: GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "element changed state NO_PREROLL"); /* we can commit the state now which will proceeed to * the next state */ ret = gst_element_continue_state (element, ret); break; default: goto invalid_return; } GST_CAT_LOG_OBJECT (GST_CAT_STATES, element, "exit state change %d", ret); return ret; async: GST_CAT_LOG_OBJECT (GST_CAT_STATES, element, "exit async state change %d", ret); return ret; /* ERROR */ invalid_return: { GST_OBJECT_LOCK (element); /* somebody added a GST_STATE_ and forgot to do stuff here ! */ g_critical ("%s: unknown return value %d from a state change function", GST_ELEMENT_NAME (element), ret); /* we are in error now */ ret = GST_STATE_CHANGE_FAILURE; GST_STATE_RETURN (element) = ret; GST_OBJECT_UNLOCK (element); return ret; } } /* gst_iterator_fold functions for pads_activate * Note how we don't stop the iterator when we fail an activation. This is * probably a FIXME since when one pad activation fails, we don't want to * continue our state change. */ static gboolean activate_pads (GstPad * pad, GValue * ret, gboolean * active) { if (!gst_pad_set_active (pad, *active)) g_value_set_boolean (ret, FALSE); /* unref the object that was reffed for us by _fold */ gst_object_unref (pad); return TRUE; } /* set the caps on the pad to NULL */ static gboolean clear_caps (GstPad * pad, GValue * ret, gboolean * active) { gst_pad_set_caps (pad, NULL); gst_object_unref (pad); return TRUE; } /* returns false on error or early cutout (will never happen because the fold * function always returns TRUE, see FIXME above) of the fold, true if all * pads in @iter were (de)activated successfully. */ static gboolean iterator_activate_fold_with_resync (GstIterator * iter, GstIteratorFoldFunction func, 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, func, &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 * * Pads are activated from source pads to sinkpads. */ static gboolean gst_element_pads_activate (GstElement * element, gboolean active) { GstIterator *iter; gboolean res; GST_CAT_DEBUG_OBJECT (GST_CAT_ELEMENT_PADS, element, "pads_activate with active %d", active); iter = gst_element_iterate_src_pads (element); res = iterator_activate_fold_with_resync (iter, (GstIteratorFoldFunction) activate_pads, &active); gst_iterator_free (iter); if (G_UNLIKELY (!res)) goto src_failed; iter = gst_element_iterate_sink_pads (element); res = iterator_activate_fold_with_resync (iter, (GstIteratorFoldFunction) activate_pads, &active); gst_iterator_free (iter); if (G_UNLIKELY (!res)) goto sink_failed; if (!active) { /* clear the caps on all pads, this should never fail */ iter = gst_element_iterate_pads (element); res = iterator_activate_fold_with_resync (iter, (GstIteratorFoldFunction) clear_caps, &active); gst_iterator_free (iter); if (G_UNLIKELY (!res)) goto caps_failed; } GST_CAT_DEBUG_OBJECT (GST_CAT_ELEMENT_PADS, element, "pads_activate successful"); return TRUE; /* ERRORS */ src_failed: { GST_CAT_DEBUG_OBJECT (GST_CAT_ELEMENT_PADS, element, "source pads_activate failed"); return FALSE; } sink_failed: { GST_CAT_DEBUG_OBJECT (GST_CAT_ELEMENT_PADS, element, "sink pads_activate failed"); return FALSE; } caps_failed: { GST_CAT_DEBUG_OBJECT (GST_CAT_ELEMENT_PADS, element, "failed to clear caps on pads"); return FALSE; } } /* is called with STATE_LOCK */ static GstStateChangeReturn gst_element_change_state_func (GstElement * element, GstStateChange transition) { GstState state, next; GstStateChangeReturn result = GST_STATE_CHANGE_SUCCESS; g_return_val_if_fail (GST_IS_ELEMENT (element), GST_STATE_CHANGE_FAILURE); state = (GstState) GST_STATE_TRANSITION_CURRENT (transition); next = GST_STATE_TRANSITION_NEXT (transition); /* if the element already is in the given state, we just return success */ if (next == GST_STATE_VOID_PENDING || state == next) goto was_ok; GST_CAT_LOG_OBJECT (GST_CAT_STATES, element, "default handler tries setting state from %s to %s (%04x)", gst_element_state_get_name (state), gst_element_state_get_name (next), transition); switch (transition) { case GST_STATE_CHANGE_NULL_TO_READY: break; case GST_STATE_CHANGE_READY_TO_PAUSED: if (!gst_element_pads_activate (element, TRUE)) { result = GST_STATE_CHANGE_FAILURE; } break; case GST_STATE_CHANGE_PAUSED_TO_PLAYING: break; case GST_STATE_CHANGE_PLAYING_TO_PAUSED: break; case GST_STATE_CHANGE_PAUSED_TO_READY: case GST_STATE_CHANGE_READY_TO_NULL: /* deactivate pads in both cases, since they are activated on ready->paused but the element might not have made it to paused */ if (!gst_element_pads_activate (element, FALSE)) { result = GST_STATE_CHANGE_FAILURE; } else { gst_element_set_base_time (element, 0); } break; default: /* this will catch real but unhandled state changes; * can only be caused by: * - a new state was added * - somehow the element was asked to jump across an intermediate state */ g_warning ("Unhandled state change from %s to %s", gst_element_state_get_name (state), gst_element_state_get_name (next)); break; } return result; was_ok: { GST_OBJECT_LOCK (element); result = GST_STATE_RETURN (element); GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "element is already in the %s state", gst_element_state_get_name (state)); GST_OBJECT_UNLOCK (element); return result; } } /** * gst_element_get_factory: * @element: a #GstElement to request the element factory of. * * Retrieves the factory that was used to create this element. * * Returns: the #GstElementFactory used for creating this element. * no refcounting is needed. */ GstElementFactory * gst_element_get_factory (GstElement * element) { g_return_val_if_fail (GST_IS_ELEMENT (element), NULL); return GST_ELEMENT_GET_CLASS (element)->elementfactory; } static void gst_element_dispose (GObject * object) { GstElement *element = GST_ELEMENT (object); GstClock **clock_p; GstBus **bus_p; GST_CAT_INFO_OBJECT (GST_CAT_REFCOUNTING, element, "dispose"); if (GST_STATE (element) != GST_STATE_NULL) goto not_null; GST_CAT_DEBUG_OBJECT (GST_CAT_ELEMENT_PADS, element, "removing %d pads", g_list_length (element->pads)); /* first we break all our links with the outside */ while (element->pads && element->pads->data) { /* don't call _remove_pad with NULL */ gst_element_remove_pad (element, GST_PAD_CAST (element->pads->data)); } if (G_UNLIKELY (element->pads != 0)) { g_critical ("could not remove pads from element %s", GST_STR_NULL (GST_OBJECT_NAME (object))); } GST_OBJECT_LOCK (element); clock_p = &element->clock; bus_p = &element->bus; gst_object_replace ((GstObject **) clock_p, NULL); gst_object_replace ((GstObject **) bus_p, NULL); GST_OBJECT_UNLOCK (element); GST_CAT_INFO_OBJECT (GST_CAT_REFCOUNTING, element, "parent class dispose"); G_OBJECT_CLASS (parent_class)->dispose (object); return; /* ERRORS */ not_null: { g_critical ("\nTrying to dispose element %s, but it is not in the NULL state.\n" "You need to explicitly set elements to the NULL state before\n" "dropping the final reference, to allow them to clean up.\n", GST_OBJECT_NAME (element)); return; } } static void gst_element_finalize (GObject * object) { GstElement *element = GST_ELEMENT (object); GST_CAT_INFO_OBJECT (GST_CAT_REFCOUNTING, element, "finalize"); GST_STATE_LOCK (element); if (element->state_cond) g_cond_free (element->state_cond); element->state_cond = NULL; GST_STATE_UNLOCK (element); g_static_rec_mutex_free (element->state_lock); g_free (element->state_lock); element->state_lock = NULL; GST_CAT_INFO_OBJECT (GST_CAT_REFCOUNTING, element, "finalize parent"); G_OBJECT_CLASS (parent_class)->finalize (object); } #ifndef GST_DISABLE_LOADSAVE /** * gst_element_save_thyself: * @element: a #GstElement to save. * @parent: the xml parent node. * * Saves the element as part of the given XML structure. * * Returns: the new #xmlNodePtr. */ static xmlNodePtr gst_element_save_thyself (GstObject * object, xmlNodePtr parent) { GList *pads; GstElementClass *oclass; GParamSpec **specs, *spec; guint nspecs; guint i; GValue value = { 0, }; GstElement *element; g_return_val_if_fail (GST_IS_ELEMENT (object), parent); element = GST_ELEMENT (object); oclass = GST_ELEMENT_GET_CLASS (element); xmlNewChild (parent, NULL, (xmlChar *) "name", (xmlChar *) GST_ELEMENT_NAME (element)); if (oclass->elementfactory != NULL) { GstElementFactory *factory = (GstElementFactory *) oclass->elementfactory; xmlNewChild (parent, NULL, (xmlChar *) "type", (xmlChar *) GST_PLUGIN_FEATURE (factory)->name); } /* params */ specs = g_object_class_list_properties (G_OBJECT_GET_CLASS (object), &nspecs); for (i = 0; i < nspecs; i++) { spec = specs[i]; if (spec->flags & G_PARAM_READABLE) { xmlNodePtr param; char *contents; g_value_init (&value, G_PARAM_SPEC_VALUE_TYPE (spec)); g_object_get_property (G_OBJECT (element), spec->name, &value); param = xmlNewChild (parent, NULL, (xmlChar *) "param", NULL); xmlNewChild (param, NULL, (xmlChar *) "name", (xmlChar *) spec->name); if (G_IS_PARAM_SPEC_STRING (spec)) contents = g_value_dup_string (&value); else if (G_IS_PARAM_SPEC_ENUM (spec)) contents = g_strdup_printf ("%d", g_value_get_enum (&value)); else if (G_IS_PARAM_SPEC_INT64 (spec)) contents = g_strdup_printf ("%" G_GINT64_FORMAT, g_value_get_int64 (&value)); else contents = g_strdup_value_contents (&value); xmlNewChild (param, NULL, (xmlChar *) "value", (xmlChar *) contents); g_free (contents); g_value_unset (&value); } } g_free (specs); pads = g_list_last (GST_ELEMENT_PADS (element)); while (pads) { GstPad *pad = GST_PAD_CAST (pads->data); /* figure out if it's a direct pad or a ghostpad */ if (GST_ELEMENT (GST_OBJECT_PARENT (pad)) == element) { xmlNodePtr padtag = xmlNewChild (parent, NULL, (xmlChar *) "pad", NULL); gst_object_save_thyself (GST_OBJECT_CAST (pad), padtag); } pads = g_list_previous (pads); } return parent; } static void gst_element_restore_thyself (GstObject * object, xmlNodePtr self) { xmlNodePtr children; GstElement *element; gchar *name = NULL; gchar *value = NULL; element = GST_ELEMENT (object); g_return_if_fail (element != NULL); /* parameters */ children = self->xmlChildrenNode; while (children) { if (!strcmp ((char *) children->name, "param")) { xmlNodePtr child = children->xmlChildrenNode; while (child) { if (!strcmp ((char *) child->name, "name")) { name = (gchar *) xmlNodeGetContent (child); } else if (!strcmp ((char *) child->name, "value")) { value = (gchar *) xmlNodeGetContent (child); } child = child->next; } /* FIXME: can this just be g_object_set ? */ gst_util_set_object_arg (G_OBJECT (element), name, value); /* g_object_set (G_OBJECT (element), name, value, NULL); */ g_free (name); g_free (value); } children = children->next; } /* pads */ children = self->xmlChildrenNode; while (children) { if (!strcmp ((char *) children->name, "pad")) { gst_pad_load_and_link (children, GST_OBJECT_CAST (element)); } children = children->next; } if (GST_OBJECT_CLASS (parent_class)->restore_thyself) (GST_OBJECT_CLASS (parent_class)->restore_thyself) (object, self); } #endif /* GST_DISABLE_LOADSAVE */ static void gst_element_set_bus_func (GstElement * element, GstBus * bus) { GstBus **bus_p; g_return_if_fail (GST_IS_ELEMENT (element)); GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, element, "setting bus to %p", bus); GST_OBJECT_LOCK (element); bus_p = &GST_ELEMENT_BUS (element); gst_object_replace ((GstObject **) bus_p, GST_OBJECT_CAST (bus)); GST_OBJECT_UNLOCK (element); } /** * gst_element_set_bus: * @element: a #GstElement to set the bus of. * @bus: the #GstBus to set. * * Sets the bus of the element. Increases the refcount on the bus. * For internal use only, unless you're testing elements. * * MT safe. */ void gst_element_set_bus (GstElement * element, GstBus * bus) { GstElementClass *oclass; g_return_if_fail (GST_IS_ELEMENT (element)); oclass = GST_ELEMENT_GET_CLASS (element); if (oclass->set_bus) oclass->set_bus (element, bus); } /** * gst_element_get_bus: * @element: a #GstElement to get the bus of. * * Returns the bus of the element. Note that only a #GstPipeline will provide a * bus for the application. * * Returns: the element's #GstBus. unref after usage. * * MT safe. */ GstBus * gst_element_get_bus (GstElement * element) { GstBus *result = NULL; g_return_val_if_fail (GST_IS_ELEMENT (element), result); GST_OBJECT_LOCK (element); if ((result = GST_ELEMENT_BUS (element))) gst_object_ref (result); GST_OBJECT_UNLOCK (element); GST_CAT_DEBUG_OBJECT (GST_CAT_BUS, element, "got bus %" GST_PTR_FORMAT, result); return result; }