blob: dcdc2f2b66e007939a54dd5e2d3cd070ff055983 [file] [log] [blame]
/* GStreamer
*
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2004 Wim Taymans <wim.taymans@gmail.com>
*
* 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., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*
* MT safe.
*/
/**
* SECTION:gstbin
* @title: 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_CHANGED: 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
* (#GST_EVENT_TYPE_DOWNSTREAM) or source (#GST_EVENT_TYPE_UPSTREAM) elements
* depending on the event type.
* If all the elements return %TRUE, the bin will also return %TRUE, else %FALSE
* is returned. If no elements of the required type are in the bin, the event
* handler will return %TRUE.
*
*/
#include "gst_private.h"
#include "gstevent.h"
#include "gstbin.h"
#include "gstinfo.h"
#include "gsterror.h"
#include "gstutils.h"
#include "gstchildproxy.h"
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;
#if 0
/* cached index */
GstIndex *index;
#endif
/* forward messages from our children */
gboolean message_forward;
gboolean posted_eos;
gboolean posted_playing;
GstElementFlags suppressed_flags;
};
typedef struct
{
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 gboolean gst_bin_post_message (GstElement * element, GstMessage * msg);
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, GstClockTime running_time);
static void bin_handle_async_start (GstBin * bin);
static void bin_push_state_continue (GstBin * bin, BinContinueData * data);
static void bin_do_eos (GstBin * bin);
static gboolean gst_bin_add_func (GstBin * bin, GstElement * element);
static gboolean gst_bin_remove_func (GstBin * bin, GstElement * element);
static void gst_bin_deep_element_added_func (GstBin * bin, GstBin * sub_bin,
GstElement * element);
static void gst_bin_deep_element_removed_func (GstBin * bin, GstBin * sub_bin,
GstElement * element);
static void gst_bin_update_context (GstBin * bin, GstContext * context);
static void gst_bin_update_context_unlocked (GstBin * bin,
GstContext * context);
#if 0
static void gst_bin_set_index_func (GstElement * element, GstIndex * index);
static GstIndex *gst_bin_get_index_func (GstElement * element);
#endif
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 void gst_bin_set_context (GstElement * element, GstContext * context);
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 (GstBin * bin, 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,
DEEP_ELEMENT_ADDED,
DEEP_ELEMENT_REMOVED,
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 \
{ \
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"); \
\
}
#define gst_bin_parent_class parent_class
G_DEFINE_TYPE_WITH_CODE (GstBin, gst_bin, GST_TYPE_ELEMENT, _do_init);
static GObject *
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 (GObject *) 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;
GstElementClass *gstelement_class;
gobject_class = (GObjectClass *) 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.
*/
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, g_cclosure_marshal_generic, 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, g_cclosure_marshal_generic, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);
/**
* GstBin::deep-element-added:
* @bin: the #GstBin
* @sub_bin: the #GstBin the element was added to
* @element: the #GstElement that was added to @sub_bin
*
* Will be emitted after the element was added to sub_bin.
*
* Since: 1.10
*/
gst_bin_signals[DEEP_ELEMENT_ADDED] =
g_signal_new ("deep-element-added", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, deep_element_added),
NULL, NULL, g_cclosure_marshal_generic, G_TYPE_NONE, 2, GST_TYPE_BIN,
GST_TYPE_ELEMENT);
/**
* GstBin::deep-element-removed:
* @bin: the #GstBin
* @sub_bin: the #GstBin the element was removed from
* @element: the #GstElement that was removed from @sub_bin
*
* Will be emitted after the element was removed from sub_bin.
*
* Since: 1.10
*/
gst_bin_signals[DEEP_ELEMENT_REMOVED] =
g_signal_new ("deep-element-removed", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, deep_element_removed),
NULL, NULL, g_cclosure_marshal_generic, G_TYPE_NONE, 2, GST_TYPE_BIN,
GST_TYPE_ELEMENT);
/**
* GstBin::do-latency:
* @bin: the #GstBin
*
* Will be emitted when the bin needs to perform latency calculations. This
* signal is only emitted 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.
*/
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, g_cclosure_marshal_generic,
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.
*/
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_static_metadata (gstelement_class, "Generic bin",
"Generic/Bin",
"Simple container object",
"Erik Walthinsen <omega@cse.ogi.edu>,"
"Wim Taymans <wim.taymans@gmail.com>");
gstelement_class->change_state =
GST_DEBUG_FUNCPTR (gst_bin_change_state_func);
gstelement_class->post_message = GST_DEBUG_FUNCPTR (gst_bin_post_message);
gstelement_class->get_state = GST_DEBUG_FUNCPTR (gst_bin_get_state_func);
#if 0
gstelement_class->get_index = GST_DEBUG_FUNCPTR (gst_bin_get_index_func);
gstelement_class->set_index = GST_DEBUG_FUNCPTR (gst_bin_set_index_func);
#endif
gstelement_class->provide_clock =
GST_DEBUG_FUNCPTR (gst_bin_provide_clock_func);
gstelement_class->set_clock = GST_DEBUG_FUNCPTR (gst_bin_set_clock_func);
gstelement_class->send_event = GST_DEBUG_FUNCPTR (gst_bin_send_event);
gstelement_class->query = GST_DEBUG_FUNCPTR (gst_bin_query);
gstelement_class->set_context = GST_DEBUG_FUNCPTR (gst_bin_set_context);
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->deep_element_added = gst_bin_deep_element_added_func;
klass->deep_element_removed = gst_bin_deep_element_removed_func;
klass->do_latency = GST_DEBUG_FUNCPTR (gst_bin_do_latency_func);
}
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);
gst_object_ref_sink (bus);
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,
NULL);
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;
GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object, "%p dispose", object);
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);
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: (allow-none): the name of the new bin
*
* Creates a new bin with the given name.
*
* Returns: (transfer floating): 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;
}
}
#if 0
/* 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;
GValue data = { 0, };
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) {
switch (gst_iterator_next (it, &data)) {
case GST_ITERATOR_OK:
{
GstElement *child = g_value_get_object (&data);
GST_DEBUG_OBJECT (bin, "setting index on '%s'",
GST_ELEMENT_NAME (child));
gst_element_set_index (child, index);
g_value_reset (&data);
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;
}
}
g_value_unset (&data);
gst_iterator_free (it);
return;
was_set:
{
GST_DEBUG_OBJECT (bin, "index was already set");
GST_OBJECT_UNLOCK (bin);
return;
}
}
#endif
/* 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;
GValue data = { 0, };
bin = GST_BIN_CAST (element);
it = gst_bin_iterate_elements (bin);
done = FALSE;
while (!done) {
switch (gst_iterator_next (it, &data)) {
case GST_ITERATOR_OK:
{
GstElement *child = g_value_get_object (&data);
res &= gst_element_set_clock (child, clock);
g_value_reset (&data);
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;
}
}
g_value_unset (&data);
gst_iterator_free (it);
if (res)
res = GST_ELEMENT_CLASS (parent_class)->set_clock (element, clock);
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;
gboolean done;
GValue val = { 0, };
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);
GST_OBJECT_UNLOCK (bin);
done = FALSE;
while (!done) {
switch (gst_iterator_next (it, &val)) {
case GST_ITERATOR_OK:
{
GstElement *child = g_value_get_object (&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 = gst_object_ref (child);
}
g_value_reset (&val);
break;
}
case GST_ITERATOR_RESYNC:
gst_iterator_resync (it);
break;
default:
case GST_ITERATOR_DONE:
done = TRUE;
break;
}
}
g_value_unset (&val);
gst_iterator_free (it);
GST_OBJECT_LOCK (bin);
if (!bin->clock_dirty) {
if (provider)
gst_object_unref (provider);
if (result)
gst_object_unref (result);
result = NULL;
goto not_dirty;
}
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);
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 & (1U << i))
GST_DEBUG_OBJECT (bin, " %s", gst_message_type_get_name (1U << 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 type %s (types 0x%08x)", message,
GST_MESSAGE_TYPE_NAME (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, guint32 * seqnum)
{
gboolean result;
gint n_eos = 0;
GList *walk, *msgs;
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 ((msgs =
find_message (bin, GST_OBJECT_CAST (element), GST_MESSAGE_EOS))) {
GST_DEBUG ("sink '%s' posted EOS", GST_ELEMENT_NAME (element));
*seqnum = gst_message_get_seqnum (GST_MESSAGE_CAST (msgs->data));
n_eos++;
} else {
GST_DEBUG ("sink '%s' did not post EOS yet",
GST_ELEMENT_NAME (element));
result = FALSE;
break;
}
}
}
/* FIXME: Some tests (e.g. elements/capsfilter) use
* pipelines with a dangling sinkpad but no sink element.
* These tests assume that no EOS message is ever
* posted on the bus so let's keep that behaviour.
* In valid pipelines this doesn't make a difference.
*/
return result && n_eos > 0;
}
/* Check if the bin is STREAM_START. We do this by scanning all sinks and
* checking if they posted an STREAM_START message.
*
* call with bin LOCK */
static gboolean
is_stream_start (GstBin * bin, guint32 * seqnum, gboolean * have_group_id,
guint * group_id)
{
gboolean result;
GList *walk, *msgs;
guint tmp_group_id;
gboolean first = TRUE, same_group_id = TRUE;
*have_group_id = TRUE;
*group_id = 0;
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 STREAM_START */
if ((msgs =
find_message (bin, GST_OBJECT_CAST (element),
GST_MESSAGE_STREAM_START))) {
GST_DEBUG ("sink '%s' posted STREAM_START", GST_ELEMENT_NAME (element));
*seqnum = gst_message_get_seqnum (GST_MESSAGE_CAST (msgs->data));
if (gst_message_parse_group_id (GST_MESSAGE_CAST (msgs->data),
&tmp_group_id)) {
if (first) {
first = FALSE;
*group_id = tmp_group_id;
} else {
if (tmp_group_id != *group_id)
same_group_id = FALSE;
}
} else {
*have_group_id = FALSE;
}
} else {
GST_DEBUG ("sink '%s' did not post STREAM_START yet",
GST_ELEMENT_NAME (element));
result = FALSE;
break;
}
}
}
/* If all have a group_id we only consider this stream started
* if all group ids were the same and all sinks posted a stream-start
* message */
if (*have_group_id)
return same_group_id && result;
/* otherwise consider this stream started after all sinks
* have reported stream-start for backward compatibility.
* FIXME 2.0: This should go away! */
return result;
}
static void
unlink_pads (const GValue * item, gpointer user_data)
{
GstPad *pad;
GstPad *peer;
pad = g_value_get_object (item);
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);
}
}
static void
bin_deep_iterator_foreach (const GValue * item, gpointer user_data)
{
GQueue *queue = user_data;
g_queue_push_tail (queue, g_value_dup_object (item));
}
static void
gst_bin_do_deep_add_remove (GstBin * bin, gint sig_id, const gchar * sig_name,
GstElement * element)
{
g_signal_emit (bin, sig_id, 0, bin, element);
/* When removing a bin, emit deep-element-* for everything in the bin too */
if (GST_IS_BIN (element)) {
GstIterator *it;
GstIteratorResult ires;
GQueue elements = G_QUEUE_INIT;
GST_LOG_OBJECT (bin, "Recursing into bin %" GST_PTR_FORMAT " for %s",
element, sig_name);
it = gst_bin_iterate_recurse (GST_BIN_CAST (element));
do {
ires = gst_iterator_foreach (it, bin_deep_iterator_foreach, &elements);
if (ires != GST_ITERATOR_DONE) {
g_queue_foreach (&elements, (GFunc) g_object_unref, NULL);
g_queue_clear (&elements);
}
if (ires == GST_ITERATOR_RESYNC)
gst_iterator_resync (it);
} while (ires == GST_ITERATOR_RESYNC);
if (ires != GST_ITERATOR_ERROR) {
GstElement *e;
while ((e = g_queue_pop_head (&elements))) {
GstObject *parent = gst_object_get_parent (GST_OBJECT_CAST (e));
GST_LOG_OBJECT (bin, "calling %s for element %" GST_PTR_FORMAT
" in bin %" GST_PTR_FORMAT, sig_name, e, parent);
g_signal_emit (bin, sig_id, 0, parent, e);
gst_object_unref (parent);
g_object_unref (e);
}
}
gst_iterator_free (it);
}
}
/* 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, provides_clock, requires_clock;
GstMessage *clock_message = NULL, *async_message = NULL;
GstStateChangeReturn ret;
GList *l, *elem_contexts, *need_context_messages;
GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
/* we obviously can't add ourself to ourself */
if (G_UNLIKELY (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_FLAG_SINK);
is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SOURCE);
provides_clock =
GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
requires_clock =
GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
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 && !(bin->priv->suppressed_flags & GST_ELEMENT_FLAG_SINK)) {
GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was sink",
elem_name);
GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_SINK);
}
if (is_source && !(bin->priv->suppressed_flags & GST_ELEMENT_FLAG_SOURCE)) {
GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was source",
elem_name);
GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_SOURCE);
}
if (provides_clock
&& !(bin->priv->suppressed_flags & GST_ELEMENT_FLAG_PROVIDE_CLOCK)) {
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);
GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
}
if (requires_clock
&& !(bin->priv->suppressed_flags & GST_ELEMENT_FLAG_REQUIRE_CLOCK)) {
GST_DEBUG_OBJECT (bin, "element \"%s\" requires a clock", elem_name);
GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
}
bin->children = g_list_prepend (bin->children, element);
bin->numchildren++;
bin->children_cookie++;
if (!GST_BIN_IS_NO_RESYNC (bin))
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));
/* get the element's list of contexts before propagating our own */
elem_contexts = gst_element_get_contexts (element);
for (l = GST_ELEMENT_CAST (bin)->contexts; l; l = l->next)
gst_element_set_context (element, l->data);
need_context_messages = NULL;
for (l = elem_contexts; l; l = l->next) {
GstContext *replacement, *context = l->data;
const gchar *context_type;
context_type = gst_context_get_context_type (context);
/* we already set this context above? */
replacement =
gst_element_get_context_unlocked (GST_ELEMENT (bin), context_type);
if (replacement) {
gst_context_unref (replacement);
} else {
GstMessage *msg;
GstStructure *s;
/* ask our parent for the context */
msg = gst_message_new_need_context (GST_OBJECT_CAST (bin), context_type);
s = (GstStructure *) gst_message_get_structure (msg);
gst_structure_set (s, "bin.old.context", GST_TYPE_CONTEXT, context, NULL);
need_context_messages = g_list_prepend (need_context_messages, msg);
}
}
#if 0
/* set the cached index on the children */
if (bin->priv->index)
gst_element_set_index (element, bin->priv->index);
#endif
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));
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, GST_CLOCK_TIME_NONE);
break;
case GST_STATE_CHANGE_FAILURE:
break;
default:
break;
}
no_state_recalc:
GST_OBJECT_UNLOCK (bin);
for (l = need_context_messages; l; l = l->next) {
GstMessage *msg = l->data;
GstStructure *s;
const gchar *context_type;
GstContext *replacement, *context;
gst_message_parse_context_type (msg, &context_type);
GST_LOG_OBJECT (bin, "asking parent for context type: %s "
"from %" GST_PTR_FORMAT, context_type, element);
s = (GstStructure *) gst_message_get_structure (msg);
gst_structure_get (s, "bin.old.context", GST_TYPE_CONTEXT, &context, NULL);
gst_structure_remove_field (s, "bin.old.context");
/* Keep the msg around while we still need access to the context_type */
gst_element_post_message (GST_ELEMENT_CAST (bin), gst_message_ref (msg));
/* lock to avoid losing a potential write */
GST_OBJECT_LOCK (bin);
replacement =
gst_element_get_context_unlocked (GST_ELEMENT_CAST (bin), context_type);
gst_message_unref (msg);
if (replacement) {
/* we got the context set from GstElement::set_context */
gst_context_unref (replacement);
GST_OBJECT_UNLOCK (bin);
} else {
/* Propagate the element's context upwards */
GST_LOG_OBJECT (bin, "propagating existing context type: %s %p "
"from %" GST_PTR_FORMAT, context_type, context, element);
gst_bin_update_context_unlocked (bin, context);
msg =
gst_message_new_have_context (GST_OBJECT_CAST (bin),
gst_context_ref (context));
GST_OBJECT_UNLOCK (bin);
gst_element_post_message (GST_ELEMENT_CAST (bin), msg);
}
gst_context_unref (context);
}
g_list_free_full (elem_contexts, (GDestroyNotify) gst_context_unref);
g_list_free (need_context_messages);
/* post the messages on the bus of the element so that the bin can handle
* them */
if (clock_message)
gst_element_post_message (element, clock_message);
if (async_message)
gst_element_post_message (element, async_message);
/* unlink all linked pads */
it = gst_element_iterate_pads (element);
while (gst_iterator_foreach (it, (GstIteratorForeachFunction) unlink_pads,
NULL) == GST_ITERATOR_RESYNC)
gst_iterator_resync (it);
gst_iterator_free (it);
GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "added element \"%s\"",
elem_name);
g_signal_emit (bin, gst_bin_signals[ELEMENT_ADDED], 0, element);
gst_child_proxy_child_added ((GstChildProxy *) bin, (GObject *) element,
elem_name);
gst_bin_do_deep_add_remove (bin, gst_bin_signals[DEEP_ELEMENT_ADDED],
"deep-element-added", element);
g_free (elem_name);
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);
gst_object_ref_sink (element);
gst_object_unref (element);
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);
gst_object_ref_sink (element);
gst_object_unref (element);
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_set_suppressed_flags:
* @bin: a #GstBin
* @flags: the #GstElementFlags to suppress
*
* Suppress the given flags on the bin. #GstElementFlags of a
* child element are propagated when it is added to the bin.
* When suppressed flags are set, those specified flags will
* not be propagated to the bin.
*
* MT safe.
*
* Since: 1.10
*/
void
gst_bin_set_suppressed_flags (GstBin * bin, GstElementFlags flags)
{
g_return_if_fail (GST_IS_BIN (bin));
GST_OBJECT_LOCK (bin);
bin->priv->suppressed_flags = bin->priv->suppressed_flags | flags;
GST_OBJECT_UNLOCK (bin);
GST_DEBUG_OBJECT (bin, "Set suppressed flags(0x%x) to bin '%s'", flags,
GST_ELEMENT_NAME (bin));
}
/**
* gst_bin_get_suppressed_flags:
* @bin: a #GstBin
*
* Return the suppressed flags of the bin.
*
* MT safe.
*
* Returns: the bin's suppressed #GstElementFlags.
*
* Since: 1.10
*/
GstElementFlags
gst_bin_get_suppressed_flags (GstBin * bin)
{
GstElementFlags res;
g_return_val_if_fail (GST_IS_BIN (bin), 0);
GST_OBJECT_LOCK (bin);
res = bin->priv->suppressed_flags;
GST_OBJECT_UNLOCK (bin);
return res;
}
/* signal vfunc, will be called when a new element was added */
static void
gst_bin_deep_element_added_func (GstBin * bin, GstBin * sub_bin,
GstElement * child)
{
GstBin *parent_bin;
parent_bin = (GstBin *) gst_object_get_parent (GST_OBJECT_CAST (bin));
if (parent_bin == NULL) {
GST_LOG_OBJECT (bin, "no parent, reached top-level");
return;
}
GST_LOG_OBJECT (parent_bin, "emitting deep-element-added for element "
"%" GST_PTR_FORMAT " which has just been added to %" GST_PTR_FORMAT,
child, sub_bin);
g_signal_emit (parent_bin, gst_bin_signals[DEEP_ELEMENT_ADDED], 0, sub_bin,
child);
gst_object_unref (parent_bin);
}
/* signal vfunc, will be called when an element was removed */
static void
gst_bin_deep_element_removed_func (GstBin * bin, GstBin * sub_bin,
GstElement * child)
{
GstBin *parent_bin;
parent_bin = (GstBin *) gst_object_get_parent (GST_OBJECT_CAST (bin));
if (parent_bin == NULL) {
GST_LOG_OBJECT (bin, "no parent, reached top-level");
return;
}
GST_LOG_OBJECT (parent_bin, "emitting deep-element-removed for element "
"%" GST_PTR_FORMAT " which has just been removed from %" GST_PTR_FORMAT,
sub_bin, child);
g_signal_emit (parent_bin, gst_bin_signals[DEEP_ELEMENT_REMOVED], 0, sub_bin,
child);
gst_object_unref (parent_bin);
}
/**
* gst_bin_add:
* @bin: a #GstBin
* @element: (transfer floating): 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);
g_return_val_if_fail (GST_ELEMENT_CAST (bin) != 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)));
GST_TRACER_BIN_ADD_PRE (bin, element);
result = bclass->add_element (bin, element);
GST_TRACER_BIN_ADD_POST (bin, element, result);
return result;
/* ERROR handling */
no_function:
{
g_warning ("adding elements to bin '%s' is not supported",
GST_ELEMENT_NAME (bin));
gst_object_ref_sink (element);
gst_object_unref (element);
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, provides_clock, requires_clock;
gboolean othersink, othersource, otherprovider, otherrequirer, 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));
/* we obviously can't remove ourself from ourself */
if (G_UNLIKELY (element == GST_ELEMENT_CAST (bin)))
goto removing_itself;
GST_OBJECT_LOCK (bin);
GST_OBJECT_LOCK (element);
elem_name = g_strdup (GST_ELEMENT_NAME (element));
if (GST_OBJECT_PARENT (element) != GST_OBJECT_CAST (bin))
goto not_in_bin;
/* remove the parent ref */
GST_OBJECT_PARENT (element) = NULL;
/* grab element name so we can print it */
is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SINK);
is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SOURCE);
provides_clock =
GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
requires_clock =
GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
GST_OBJECT_UNLOCK (element);
found = FALSE;
othersink = FALSE;
othersource = FALSE;
otherprovider = FALSE;
otherrequirer = 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, child_provider, child_requirer;
GST_OBJECT_LOCK (child);
child_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SINK);
child_source = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SOURCE);
child_provider =
GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
child_requirer =
GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
/* 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;
if (provides_clock && !otherprovider && child_provider)
otherprovider = TRUE;
if (requires_clock && !otherrequirer && child_requirer)
otherrequirer = 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++;
if (!GST_BIN_IS_NO_RESYNC (bin))
bin->priv->structure_cookie++;
if (is_sink && !othersink
&& !(bin->priv->suppressed_flags & GST_ELEMENT_FLAG_SINK)) {
/* we're not a sink anymore */
GST_DEBUG_OBJECT (bin, "we removed the last sink");
GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_SINK);
}
if (is_source && !othersource
&& !(bin->priv->suppressed_flags & GST_ELEMENT_FLAG_SOURCE)) {
/* we're not a source anymore */
GST_DEBUG_OBJECT (bin, "we removed the last source");
GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_SOURCE);
}
if (provides_clock && !otherprovider
&& !(bin->priv->suppressed_flags & GST_ELEMENT_FLAG_PROVIDE_CLOCK)) {
/* we're not a clock provider anymore */
GST_DEBUG_OBJECT (bin, "we removed the last clock provider");
GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
}
if (requires_clock && !otherrequirer
&& !(bin->priv->suppressed_flags & GST_ELEMENT_FLAG_REQUIRE_CLOCK)) {
/* we're not a clock requirer anymore */
GST_DEBUG_OBJECT (bin, "we removed the last clock requirer");
GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
}
/* 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, GST_CLOCK_TIME_NONE);
} 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:
/* clear bus */
gst_element_set_bus (element, NULL);
/* Clear the clock we provided to the element */
gst_element_set_clock (element, NULL);
GST_OBJECT_UNLOCK (bin);
if (clock_message)
gst_element_post_message (GST_ELEMENT_CAST (bin), clock_message);
/* unlink all linked pads */
it = gst_element_iterate_pads (element);
while (gst_iterator_foreach (it, (GstIteratorForeachFunction) unlink_pads,
NULL) == GST_ITERATOR_RESYNC)
gst_iterator_resync (it);
gst_iterator_free (it);
GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "removed child \"%s\"",
elem_name);
g_signal_emit (bin, gst_bin_signals[ELEMENT_REMOVED], 0, element);
gst_child_proxy_child_removed ((GstChildProxy *) bin, (GObject *) element,
elem_name);
gst_bin_do_deep_add_remove (bin, gst_bin_signals[DEEP_ELEMENT_REMOVED],
"deep-element-removed", element);
g_free (elem_name);
/* element is really out of our control now */
gst_object_unref (element);
return TRUE;
/* ERROR handling */
removing_itself:
{
GST_OBJECT_LOCK (bin);
g_warning ("Cannot remove bin '%s' from itself", GST_ELEMENT_NAME (bin));
GST_OBJECT_UNLOCK (bin);
return FALSE;
}
not_in_bin:
{
g_warning ("Element '%s' is not in bin '%s'", elem_name,
GST_ELEMENT_NAME (bin));
GST_OBJECT_UNLOCK (element);
GST_OBJECT_UNLOCK (bin);
g_free (elem_name);
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);
g_return_val_if_fail (GST_ELEMENT_CAST (bin) != 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));
GST_TRACER_BIN_REMOVE_PRE (bin, element);
result = bclass->remove_element (bin, element);
GST_TRACER_BIN_REMOVE_POST (bin, result);
return result;
/* ERROR handling */
no_function:
{
g_warning ("removing elements from bin '%s' is not supported",
GST_ELEMENT_NAME (bin));
return FALSE;
}
}
/**
* gst_bin_iterate_elements:
* @bin: a #GstBin
*
* Gets an iterator for the elements in this bin.
*
* MT safe. Caller owns returned value.
*
* Returns: (transfer full) (nullable): 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);
result = gst_iterator_new_list (GST_TYPE_ELEMENT,
GST_OBJECT_GET_LOCK (bin),
&bin->children_cookie, &bin->children, (GObject *) bin, NULL);
GST_OBJECT_UNLOCK (bin);
return result;
}
static GstIteratorItem
iterate_child_recurse (GstIterator * it, const GValue * item)
{
GstElement *child = g_value_get_object (item);
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.
*
* MT safe. Caller owns returned value.
*
* Returns: (transfer full) (nullable): 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);
result = gst_iterator_new_list (GST_TYPE_ELEMENT,
GST_OBJECT_GET_LOCK (bin),
&bin->children_cookie,
&bin->children,
(GObject *) bin, (GstIteratorItemFunction) iterate_child_recurse);
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_FLAG_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 (const GValue * vchild, GValue * vbin)
{
GstBin *bin = g_value_get_object (vbin);
GstElement *child = g_value_get_object (vchild);
return (bin_element_is_sink (child, bin));
}
/**
* gst_bin_iterate_sinks:
* @bin: a #GstBin
*
* Gets an iterator for all elements in the bin that have the
* #GST_ELEMENT_FLAG_SINK flag set.
*
* MT safe. Caller owns returned value.
*
* Returns: (transfer full) (nullable): a #GstIterator of #GstElement,
* or %NULL
*/
GstIterator *
gst_bin_iterate_sinks (GstBin * bin)
{
GstIterator *children;
GstIterator *result;
GValue vbin = { 0, };
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
g_value_init (&vbin, GST_TYPE_BIN);
g_value_set_object (&vbin, bin);
children = gst_bin_iterate_elements (bin);
result = gst_iterator_filter (children,
(GCompareFunc) sink_iterator_filter, &vbin);
g_value_unset (&vbin);
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_FLAG_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 (const GValue * vchild, GValue * vbin)
{
GstBin *bin = g_value_get_object (vbin);
GstElement *child = g_value_get_object (vchild);
return (bin_element_is_src (child, bin));
}
/**
* gst_bin_iterate_sources:
* @bin: a #GstBin
*
* Gets an iterator for all elements in the bin that have the
* #GST_ELEMENT_FLAG_SOURCE flag set.
*
* MT safe. Caller owns returned value.
*
* Returns: (transfer full) (nullable): a #GstIterator of #GstElement,
* or %NULL
*/
GstIterator *
gst_bin_iterate_sources (GstBin * bin)
{
GstIterator *children;
GstIterator *result;
GValue vbin = { 0, };
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
g_value_init (&vbin, GST_TYPE_BIN);
g_value_set_object (&vbin, bin);
children = gst_bin_iterate_elements (bin);
result = gst_iterator_filter (children,
(GCompareFunc) src_iterator_filter, &vbin);
g_value_unset (&vbin);
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;
static void
copy_to_queue (gpointer data, gpointer user_data)
{
GstElement *element = data;
GQueue *queue = user_data;
gst_object_ref (element);
g_queue_push_tail (queue, element);
}
static void
gst_bin_sort_iterator_copy (const GstBinSortIterator * it,
GstBinSortIterator * copy)
{
GHashTableIter iter;
gpointer key, value;
g_queue_init (&copy->queue);
g_queue_foreach ((GQueue *) & it->queue, copy_to_queue, &copy->queue);
copy->bin = gst_object_ref (it->bin);
if (it->best)
copy->best = gst_object_ref (it->best);
copy->hash = g_hash_table_new (NULL, NULL);
g_hash_table_iter_init (&iter, it->hash);
while (g_hash_table_iter_next (&iter, &key, &value))
g_hash_table_insert (copy->hash, key, value);
}
/* 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 immediately. 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_FLAG_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;
} else if (bit->best_deg == degree
&& GST_OBJECT_FLAG_IS_SET (bit->best, GST_ELEMENT_FLAG_SOURCE)
&& !GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SOURCE)) {
/* If two elements have the same degree, we want to ensure we
* return non-source elements first. */
bit->best = element;
}
}
/* get next element in iterator. */
static GstIteratorResult
gst_bin_sort_iterator_next (GstBinSortIterator * bit, GValue * result)
{
GstElement *best;
GstBin *bin = bit->bin;
/* empty queue, we have to find a next best element */
if (g_queue_is_empty (&bit->queue)) {
bit->best = NULL;
bit->best_deg = G_MAXINT;
g_list_foreach (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));
HASH_SET_DEGREE (bit, best, -1);
g_value_set_object (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 */
best = g_queue_pop_head (&bit->queue);
g_value_set_object (result, best);
gst_object_unref (best);
}
GST_DEBUG_OBJECT (bin, "queue head gives %s", GST_ELEMENT_NAME (best));
/* update degrees of linked elements */
update_degree (best, 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_hash_table_destroy (bit->hash);
gst_object_unref (bin);
}
/* 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,
(GstIteratorCopyFunction) gst_bin_sort_iterator_copy,
(GstIteratorNextFunction) gst_bin_sort_iterator_next,
(GstIteratorItemFunction) NULL,
(GstIteratorResyncFunction) gst_bin_sort_iterator_resync,
(GstIteratorFreeFunction) gst_bin_sort_iterator_free);
g_queue_init (&result->queue);
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.
*
* MT safe. Caller owns returned value.
*
* Returns: (transfer full) (nullable): 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 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_ELEMENT_IS_LOCKED_STATE (element);
/* 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_CAT_INFO_OBJECT (GST_CAT_STATES, element,
"current %s pending %s, desired next %s",
gst_element_state_get_name (child_current),
gst_element_state_get_name (child_pending),
gst_element_state_get_name (next));
/* always recurse into bins so that we can set the base time */
if (GST_IS_BIN (element))
goto do_state;
/* Try not to change the state of elements that are already in the state we're
* going to */
if (child_current == next && child_pending == GST_STATE_VOID_PENDING) {
/* child is already at the requested state, return previous return. Note that
* if the child has a pending state to next, we will still call the
* set_state function */
goto unneeded;
} else if (next > current) {
/* upward state change */
if (child_pending == GST_STATE_VOID_PENDING) {
/* .. and the child is not busy doing anything */
if (child_current > next) {
/* .. and is already past the requested state, assume it got there
* without error */
ret = GST_STATE_CHANGE_SUCCESS;
goto unneeded;
}
} else if (child_pending > child_current) {
/* .. and the child is busy going upwards */
if (child_current >= next) {
/* .. and is already past the requested state, assume it got there
* without error */
ret = GST_STATE_CHANGE_SUCCESS;
goto unneeded;
}
} else {
/* .. and the child is busy going downwards */
if (child_current > next) {
/* .. and is already past the requested state, assume it got there
* without error */
ret = GST_STATE_CHANGE_SUCCESS;
goto unneeded;
}
}
} else if (next < current) {
/* downward state change */
if (child_pending == GST_STATE_VOID_PENDING) {
/* .. and the child is not busy doing anything */
if (child_current < next) {
/* .. and is already past the requested state, assume it got there
* without error */
ret = GST_STATE_CHANGE_SUCCESS;
goto unneeded;
}
} else if (child_pending < child_current) {
/* .. and the child is busy going downwards */
if (child_current <= next) {
/* .. and is already past the requested state, assume it got there
* without error */
ret = GST_STATE_CHANGE_SUCCESS;
goto unneeded;
}
} else {
/* .. and the child is busy going upwards */
if (child_current < next) {
/* .. and is already past the requested state, assume it got there
* without error */
ret = GST_STATE_CHANGE_SUCCESS;
goto unneeded;
}
}
}
do_state:
GST_OBJECT_LOCK (bin);
/* 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. */
goto was_busy;
}
}
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;
}
unneeded:
{
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
"skipping transition from %s to %s",
gst_element_state_get_name (child_current),
gst_element_state_get_name (next));
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;
}
}
/* gst_iterator_fold functions for pads_activate
* Stop the iterator if activating one pad failed, but only if that pad
* has not been removed from the element. */
static gboolean
activate_pads (const GValue * vpad, GValue * ret, gboolean * active)
{
GstPad *pad = g_value_get_object (vpad);
gboolean cont = TRUE;
if (!gst_pad_set_active (pad, *active)) {
if (GST_PAD_PARENT (pad) != NULL) {
cont = FALSE;
g_value_set_boolean (ret, FALSE);
}
}
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, "%s pads", active ? "activate" : "deactivate");
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, "pad %sactivation successful", active ? "" : "de");
return TRUE;
/* ERRORS */
failed:
{
GST_DEBUG_OBJECT (bin, "pad %sactivation failed", active ? "" : "de");
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.
*/
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 gboolean
gst_bin_post_message (GstElement * element, GstMessage * msg)
{
GstElementClass *pklass = (GstElementClass *) parent_class;
gboolean ret;
ret = pklass->post_message (element, gst_message_ref (msg));
if (GST_MESSAGE_TYPE (msg) == GST_MESSAGE_STATE_CHANGED &&
GST_MESSAGE_SRC (msg) == GST_OBJECT_CAST (element)) {
GstState newstate, pending;
gst_message_parse_state_changed (msg, NULL, &newstate, &pending);
if (newstate == GST_STATE_PLAYING && pending == GST_STATE_VOID_PENDING) {
GST_BIN_CAST (element)->priv->posted_playing = TRUE;
bin_do_eos (GST_BIN_CAST (element));
} else {
GST_BIN_CAST (element)->priv->posted_playing = FALSE;
}
}
gst_message_unref (msg);
return ret;
}
static void
reset_state (const GValue * data, gpointer user_data)
{
GstElement *e = g_value_get_object (data);
GstState state = GPOINTER_TO_INT (user_data);
if (gst_element_set_state (e, state) == GST_STATE_CHANGE_FAILURE)
GST_WARNING_OBJECT (e, "Failed to switch back down to %s",
gst_element_state_get_name (state));
}
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;
GValue data = { 0, };
/* 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, asynchandling;
GST_OBJECT_LOCK (bin);
toplevel = BIN_IS_TOPLEVEL (bin);
asynchandling = bin->priv->asynchandling;
GST_OBJECT_UNLOCK (bin);
if (toplevel)
gst_bin_recalculate_latency (bin);
if (asynchandling)
gst_element_post_message (element,
gst_message_new_latency (GST_OBJECT_CAST (element)));
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);
bin->priv->posted_eos = FALSE;
if (current == GST_STATE_READY)
bin_remove_messages (bin, NULL, GST_MESSAGE_STREAM_START);
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);
/* We might not have reached PAUSED yet due to async errors,
* make sure to always deactivate the pads nonetheless */
if (!(gst_bin_src_pads_activate (bin, FALSE)))
goto activate_failure;
break;
case GST_STATE_NULL:
/* Clear message list on next NULL */
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_READY) {
if (!(gst_bin_src_pads_activate (bin, FALSE)))
goto activate_failure;
}
break;