gstreamer/gst/gstbin.c
Wim Taymans 1b4b1a5b1f bin: always mark pending_async_done
When we get an ASYNC_DONE message when a state change was busy, set the
pending_async_done flag so that after the state change completes, the bin can
check if all async elements are finished. Don't only do this for the bin itself
but for all elements.

This fixes some bins in bins that simulate async state changes by posting ASYNC
messages (such as sdpparse in uridecodebin/playbin2).
2009-04-09 11:51:43 +02:00

3645 lines
107 KiB
C

/* 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., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*
* MT safe.
*/
/**
* SECTION:gstbin
* @short_description: Base class and element that can contain other elements
*
* #GstBin is an element that can contain other #GstElement, allowing them to be
* managed as a group.
* Pads from the child elements can be ghosted to the bin, see #GstGhostPad.
* This makes the bin look like any other elements and enables creation of
* higher-level abstraction elements.
*
* A new #GstBin is created with gst_bin_new(). Use a #GstPipeline instead if you
* want to create a toplevel bin because a normal bin doesn't have a bus or
* handle clock distribution of its own.
*
* After the bin has been created you will typically add elements to it with
* gst_bin_add(). You can remove elements with gst_bin_remove().
*
* An element can be retrieved from a bin with gst_bin_get_by_name(), using the
* elements name. gst_bin_get_by_name_recurse_up() is mainly used for internal
* purposes and will query the parent bins when the element is not found in the
* current bin.
*
* An iterator of elements in a bin can be retrieved with
* gst_bin_iterate_elements(). Various other iterators exist to retrieve the
* elements in a bin.
*
* gst_object_unref() is used to drop your reference to the bin.
*
* The #GstBin::element-added signal is fired whenever a new element is added to
* the bin. Likewise the #GstBin::element-removed signal is fired whenever an
* element is removed from the bin.
*
* <refsect2><title>Notes</title>
* <para>
* A #GstBin internally intercepts every #GstMessage posted by its children and
* implements the following default behaviour for each of them:
* <variablelist>
* <varlistentry>
* <term>GST_MESSAGE_EOS</term>
* <listitem><para>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.</para></listitem>
* </varlistentry>
* <varlistentry>
* <term>GST_MESSAGE_SEGMENT_START</term>
* <listitem><para>just collected and never forwarded upwards.
* The messages are used to decide when all elements have completed playback
* of their segment.</para></listitem>
* </varlistentry>
* <varlistentry>
* <term>GST_MESSAGE_SEGMENT_DONE</term>
* <listitem><para> Is posted by #GstBin when all elements that posted
* a SEGMENT_START have posted a SEGMENT_DONE.</para></listitem>
* </varlistentry>
* <varlistentry>
* <term>GST_MESSAGE_DURATION</term>
* <listitem><para> 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.
* </para></listitem>
* </varlistentry>
* <varlistentry>
* <term>GST_MESSAGE_CLOCK_LOST</term>
* <listitem><para> 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.
* </para></listitem>
* </varlistentry>
* <varlistentry>
* <term>GST_MESSAGE_CLOCK_PROVIDE</term>
* <listitem><para> 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.
* </para></listitem>
* </varlistentry>
* <varlistentry>
* <term>OTHERS</term>
* <listitem><para> posted upwards.</para></listitem>
* </varlistentry>
* </variablelist>
*
*
* A #GstBin implements the following default behaviour for answering to a
* #GstQuery:
* <variablelist>
* <varlistentry>
* <term>GST_QUERY_DURATION</term>
* <listitem><para>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.
* </para></listitem>
* </varlistentry>
* <varlistentry>
* <term>GST_QUERY_POSITION</term>
* <listitem><para>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.
* </para></listitem>
* </varlistentry>
* <varlistentry>
* <term>OTHERS</term>
* <listitem><para>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.</para></listitem>
* </varlistentry>
* </variablelist>
*
* A #GstBin will by default forward any event sent to it to all sink elements.
* If all the sinks return TRUE, the bin will also return TRUE, else FALSE is
* returned. If no sinks are in the bin, the event handler will return TRUE.
*
* </para>
* </refsect2>
*
* Last reviewed on 2006-04-28 (0.10.6)
*/
#include "gst_private.h"
#include "gstevent.h"
#include "gstbin.h"
#include "gstmarshal.h"
#include "gstxml.h"
#include "gstinfo.h"
#include "gsterror.h"
#include "gstindex.h"
#include "gstindexfactory.h"
#include "gstutils.h"
#include "gstchildproxy.h"
/* enable for DURATION caching.
* FIXME currently too many elements don't update
* their duration when it changes so we return inaccurate values. */
#undef DURATION_CACHING
/* latency is by default enabled now.
* live-preroll and no-live-preroll in the environment var GST_COMPAT
* to enables or disable it respectively.
*/
static gboolean enable_latency = TRUE;
GST_DEBUG_CATEGORY_STATIC (bin_debug);
#define GST_CAT_DEFAULT bin_debug
/* a bin is toplevel if it has no parent or when it is configured to behave like
* a toplevel bin */
#define BIN_IS_TOPLEVEL(bin) ((GST_OBJECT_PARENT (bin) == NULL) || bin->priv->asynchandling)
#define GST_BIN_GET_PRIVATE(obj) \
(G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_BIN, GstBinPrivate))
struct _GstBinPrivate
{
gboolean asynchandling;
/* if we get an ASYNC_DONE message from ourselves, this means that the
* subclass will simulate ASYNC behaviour without having ASYNC children. When
* such an ASYNC_DONE message is posted while we are doing a state change, we
* have to process the message after finishing the state change even when no
* child returned GST_STATE_CHANGE_ASYNC. */
gboolean pending_async_done;
guint32 structure_cookie;
};
typedef struct
{
GstBin *bin;
guint32 cookie;
GstState pending;
} BinContinueData;
static void gst_bin_dispose (GObject * object);
static void gst_bin_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec);
static void gst_bin_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec);
static GstStateChangeReturn gst_bin_change_state_func (GstElement * element,
GstStateChange transition);
static GstStateChangeReturn gst_bin_get_state_func (GstElement * element,
GstState * state, GstState * pending, GstClockTime timeout);
static void bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret,
gboolean flag_pending);
static void bin_handle_async_start (GstBin * bin, gboolean new_base_time);
static void bin_push_state_continue (BinContinueData * data);
static gboolean gst_bin_add_func (GstBin * bin, GstElement * element);
static gboolean gst_bin_remove_func (GstBin * bin, GstElement * element);
static void gst_bin_set_index_func (GstElement * element, GstIndex * index);
static GstClock *gst_bin_provide_clock_func (GstElement * element);
static gboolean gst_bin_set_clock_func (GstElement * element, GstClock * clock);
static void gst_bin_handle_message_func (GstBin * bin, GstMessage * message);
static gboolean gst_bin_send_event (GstElement * element, GstEvent * event);
static GstBusSyncReply bin_bus_handler (GstBus * bus,
GstMessage * message, GstBin * bin);
static gboolean gst_bin_query (GstElement * element, GstQuery * query);
static gboolean gst_bin_do_latency_func (GstBin * bin);
#ifndef GST_DISABLE_LOADSAVE
static xmlNodePtr gst_bin_save_thyself (GstObject * object, xmlNodePtr parent);
static void gst_bin_restore_thyself (GstObject * object, xmlNodePtr self);
#endif
static void bin_remove_messages (GstBin * bin, GstObject * src,
GstMessageType types);
static void gst_bin_continue_func (BinContinueData * data);
static gint bin_element_is_sink (GstElement * child, GstBin * bin);
static gint bin_element_is_src (GstElement * child, GstBin * bin);
static GstIterator *gst_bin_sort_iterator_new (GstBin * bin);
/* Bin signals and properties */
enum
{
ELEMENT_ADDED,
ELEMENT_REMOVED,
DO_LATENCY,
LAST_SIGNAL
};
#define DEFAULT_ASYNC_HANDLING FALSE
enum
{
PROP_0,
PROP_ASYNC_HANDLING
/* FILL ME */
};
static void gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data);
static guint gst_bin_signals[LAST_SIGNAL] = { 0 };
#define _do_init(type) \
{ \
const gchar *compat; \
static const GInterfaceInfo iface_info = { \
gst_bin_child_proxy_init, \
NULL, \
NULL}; \
\
g_type_add_interface_static (type, GST_TYPE_CHILD_PROXY, &iface_info); \
\
GST_DEBUG_CATEGORY_INIT (bin_debug, "bin", GST_DEBUG_BOLD, \
"debugging info for the 'bin' container element"); \
\
/* compatibility stuff */ \
compat = g_getenv ("GST_COMPAT"); \
if (compat != NULL) { \
if (strstr (compat, "no-live-preroll")) \
enable_latency = FALSE; \
else if (strstr (compat, "live-preroll")) \
enable_latency = TRUE; \
} \
}
GST_BOILERPLATE_FULL (GstBin, gst_bin, GstElement, GST_TYPE_ELEMENT, _do_init);
static void
gst_bin_base_init (gpointer g_class)
{
GstElementClass *gstelement_class = GST_ELEMENT_CLASS (g_class);
gst_element_class_set_details_simple (gstelement_class, "Generic bin",
"Generic/Bin",
"Simple container object",
"Erik Walthinsen <omega@cse.ogi.edu>,"
"Wim Taymans <wim.taymans@gmail.com>");
}
static GstObject *
gst_bin_child_proxy_get_child_by_index (GstChildProxy * child_proxy,
guint index)
{
GstObject *res;
GstBin *bin;
bin = GST_BIN_CAST (child_proxy);
GST_OBJECT_LOCK (bin);
if ((res = g_list_nth_data (bin->children, index)))
gst_object_ref (res);
GST_OBJECT_UNLOCK (bin);
return res;
}
guint
gst_bin_child_proxy_get_children_count (GstChildProxy * child_proxy)
{
guint num;
GstBin *bin;
bin = GST_BIN_CAST (child_proxy);
GST_OBJECT_LOCK (bin);
num = bin->numchildren;
GST_OBJECT_UNLOCK (bin);
return num;
}
static void
gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data)
{
GstChildProxyInterface *iface = g_iface;
iface->get_children_count = gst_bin_child_proxy_get_children_count;
iface->get_child_by_index = gst_bin_child_proxy_get_child_by_index;
}
static gboolean
_gst_boolean_accumulator (GSignalInvocationHint * ihint,
GValue * return_accu, const GValue * handler_return, gpointer dummy)
{
gboolean myboolean;
myboolean = g_value_get_boolean (handler_return);
if (!(ihint->run_type & G_SIGNAL_RUN_CLEANUP))
g_value_set_boolean (return_accu, myboolean);
GST_DEBUG ("invocation %d, %d", ihint->run_type, myboolean);
/* stop emission */
return FALSE;
}
static void
gst_bin_class_init (GstBinClass * klass)
{
GObjectClass *gobject_class;
GstObjectClass *gstobject_class;
GstElementClass *gstelement_class;
GError *err;
gobject_class = (GObjectClass *) klass;
gstobject_class = (GstObjectClass *) klass;
gstelement_class = (GstElementClass *) klass;
g_type_class_add_private (klass, sizeof (GstBinPrivate));
gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_bin_set_property);
gobject_class->get_property = GST_DEBUG_FUNCPTR (gst_bin_get_property);
/**
* GstBin:async-handling
*
* If set to #TRUE, the bin will handle asynchronous state changes.
* This should be used only if the bin subclass is modifying the state
* of its children on its own.
*
* Since: 0.10.13
*/
g_object_class_install_property (gobject_class, PROP_ASYNC_HANDLING,
g_param_spec_boolean ("async-handling", "Async Handling",
"The bin will handle Asynchronous state changes",
DEFAULT_ASYNC_HANDLING, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
/**
* GstBin::element-added:
* @bin: the #GstBin
* @element: the #GstElement that was added to the bin
*
* Will be emitted after the element was added to the bin.
*/
gst_bin_signals[ELEMENT_ADDED] =
g_signal_new ("element-added", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_added), NULL,
NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);
/**
* GstBin::element-removed:
* @bin: the #GstBin
* @element: the #GstElement that was removed from the bin
*
* Will be emitted after the element was removed from the bin.
*/
gst_bin_signals[ELEMENT_REMOVED] =
g_signal_new ("element-removed", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_removed), NULL,
NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);
/**
* GstBin::do-latency:
* @bin: the #GstBin
*
* Will be emitted when the bin needs to perform latency calculations. This
* signal is only emited for toplevel bins or when async-handling is
* enabled.
*
* Only one signal handler is invoked. If no signals are connected, the
* default handler is invoked, which will query and distribute the lowest
* possible latency to all sinks.
*
* Connect to this signal if the default latency calculations are not
* sufficient, like when you need different latencies for different sinks in
* the same pipeline.
*
* Since: 0.10.22
*/
gst_bin_signals[DO_LATENCY] =
g_signal_new ("do-latency", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstBinClass, do_latency),
_gst_boolean_accumulator, NULL, gst_marshal_BOOLEAN__VOID,
G_TYPE_BOOLEAN, 0, G_TYPE_NONE);
gobject_class->dispose = GST_DEBUG_FUNCPTR (gst_bin_dispose);
#ifndef GST_DISABLE_LOADSAVE
gstobject_class->save_thyself = GST_DEBUG_FUNCPTR (gst_bin_save_thyself);
gstobject_class->restore_thyself =
GST_DEBUG_FUNCPTR (gst_bin_restore_thyself);
#endif
gstelement_class->change_state =
GST_DEBUG_FUNCPTR (gst_bin_change_state_func);
gstelement_class->get_state = GST_DEBUG_FUNCPTR (gst_bin_get_state_func);
gstelement_class->set_index = GST_DEBUG_FUNCPTR (gst_bin_set_index_func);
gstelement_class->provide_clock =
GST_DEBUG_FUNCPTR (gst_bin_provide_clock_func);
gstelement_class->set_clock = GST_DEBUG_FUNCPTR (gst_bin_set_clock_func);
gstelement_class->send_event = GST_DEBUG_FUNCPTR (gst_bin_send_event);
gstelement_class->query = GST_DEBUG_FUNCPTR (gst_bin_query);
klass->add_element = GST_DEBUG_FUNCPTR (gst_bin_add_func);
klass->remove_element = GST_DEBUG_FUNCPTR (gst_bin_remove_func);
klass->handle_message = GST_DEBUG_FUNCPTR (gst_bin_handle_message_func);
klass->do_latency = GST_DEBUG_FUNCPTR (gst_bin_do_latency_func);
GST_DEBUG ("creating bin thread pool");
err = NULL;
klass->pool =
g_thread_pool_new ((GFunc) gst_bin_continue_func, NULL, -1, FALSE, &err);
if (err != NULL) {
g_critical ("could alloc threadpool %s", err->message);
}
}
static void
gst_bin_init (GstBin * bin, GstBinClass * klass)
{
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 = gst_bus_new ();
bin->child_bus = bus;
GST_DEBUG_OBJECT (bin, "using bus %" GST_PTR_FORMAT " to listen to children",
bus);
gst_bus_set_sync_handler (bus, (GstBusSyncHandler) bin_bus_handler, bin);
bin->priv = GST_BIN_GET_PRIVATE (bin);
bin->priv->asynchandling = DEFAULT_ASYNC_HANDLING;
bin->priv->structure_cookie = 0;
}
static void
gst_bin_dispose (GObject * object)
{
GstBin *bin = GST_BIN (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, "dispose");
GST_OBJECT_LOCK (object);
gst_object_replace ((GstObject **) child_bus_p, NULL);
gst_object_replace ((GstObject **) provided_clock_p, NULL);
gst_object_replace ((GstObject **) clock_provider_p, NULL);
bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
GST_OBJECT_UNLOCK (object);
while (bin->children) {
gst_bin_remove (bin, GST_ELEMENT_CAST (bin->children->data));
}
if (G_UNLIKELY (bin->children != NULL)) {
g_critical ("could not remove elements from bin %s",
GST_STR_NULL (GST_OBJECT_NAME (object)));
}
G_OBJECT_CLASS (parent_class)->dispose (object);
}
/**
* gst_bin_new:
* @name: the name of the new bin
*
* Creates a new bin with the given name.
*
* Returns: 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 (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;
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 (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;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
/* 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;
bin = GST_BIN (element);
it = gst_bin_iterate_elements (bin);
done = FALSE;
while (!done) {
gpointer data;
switch (gst_iterator_next (it, &data)) {
case GST_ITERATOR_OK:
{
GstElement *child = GST_ELEMENT_CAST (data);
GST_DEBUG_OBJECT (bin, "setting index on %s", GST_ELEMENT_NAME (child));
gst_element_set_index (child, index);
gst_object_unref (child);
break;
}
case GST_ITERATOR_RESYNC:
GST_DEBUG_OBJECT (bin, "iterator doing resync");
gst_iterator_resync (it);
break;
default:
case GST_ITERATOR_DONE:
GST_DEBUG_OBJECT (bin, "iterator done");
done = TRUE;
break;
}
}
gst_iterator_free (it);
}
/* set the clock on all elements in this bin
*
* MT safe
*/
static gboolean
gst_bin_set_clock_func (GstElement * element, GstClock * clock)
{
GstBin *bin;
gboolean done;
GstIterator *it;
gboolean res = TRUE;
bin = GST_BIN (element);
it = gst_bin_iterate_elements (bin);
done = FALSE;
while (!done) {
gpointer data;
switch (gst_iterator_next (it, &data)) {
case GST_ITERATOR_OK:
{
GstElement *child = GST_ELEMENT_CAST (data);
res &= gst_element_set_clock (child, clock);
gst_object_unref (child);
break;
}
case GST_ITERATOR_RESYNC:
GST_DEBUG_OBJECT (bin, "iterator doing resync");
gst_iterator_resync (it);
res = TRUE;
break;
default:
case GST_ITERATOR_DONE:
GST_DEBUG_OBJECT (bin, "iterator done");
done = TRUE;
break;
}
}
gst_iterator_free (it);
return res;
}
/* get the clock for this bin by asking all of the children in this bin
*
* The ref of the returned clock in increased so unref after usage.
*
* We loop the elements in state order and pick the last clock we can
* get. This makes sure we get a clock from the source.
*
* MT safe
*/
static GstClock *
gst_bin_provide_clock_func (GstElement * element)
{
GstClock *result = NULL;
GstElement *provider = NULL;
GstBin *bin;
GstIterator *it;
gpointer val;
GstClock **provided_clock_p;
GstElement **clock_provider_p;
bin = GST_BIN (element);
GST_OBJECT_LOCK (bin);
if (!bin->clock_dirty)
goto not_dirty;
GST_DEBUG_OBJECT (bin, "finding new clock");
it = gst_bin_sort_iterator_new (bin);
while (it->next (it, &val) == GST_ITERATOR_OK) {
GstElement *child = GST_ELEMENT_CAST (val);
GstClock *clock;
clock = gst_element_provide_clock (child);
if (clock) {
GST_DEBUG_OBJECT (bin, "found candidate clock %p by element %s",
clock, GST_ELEMENT_NAME (child));
if (result) {
gst_object_unref (result);
gst_object_unref (provider);
}
result = clock;
provider = child;
} else {
gst_object_unref (child);
}
}
provided_clock_p = &bin->provided_clock;
clock_provider_p = &bin->clock_provider;
gst_object_replace ((GstObject **) provided_clock_p, (GstObject *) result);
gst_object_replace ((GstObject **) clock_provider_p, (GstObject *) provider);
bin->clock_dirty = FALSE;
GST_DEBUG_OBJECT (bin,
"provided new clock %" GST_PTR_FORMAT " by provider %" GST_PTR_FORMAT,
result, provider);
/* Provider is not being returned to caller, just the result */
if (provider)
gst_object_unref (provider);
GST_OBJECT_UNLOCK (bin);
gst_iterator_free (it);
return result;
not_dirty:
{
if ((result = bin->provided_clock))
gst_object_ref (result);
GST_DEBUG_OBJECT (bin, "returning old clock %p", result);
GST_OBJECT_UNLOCK (bin);
return result;
}
}
/*
* functions for manipulating cached messages
*/
typedef struct
{
GstObject *src;
GstMessageType types;
} MessageFind;
/* check if a message is of given src and type */
static gint
message_check (GstMessage * message, MessageFind * target)
{
gboolean eq = TRUE;
if (target->src)
eq &= GST_MESSAGE_SRC (message) == target->src;
if (target->types)
eq &= (GST_MESSAGE_TYPE (message) & target->types) != 0;
GST_LOG ("looking at message %p: %d", message, eq);
return (eq ? 0 : 1);
}
static GList *
find_message (GstBin * bin, GstObject * src, GstMessageType types)
{
GList *result;
MessageFind find;
find.src = src;
find.types = types;
result = g_list_find_custom (bin->messages, &find,
(GCompareFunc) message_check);
if (result) {
GST_DEBUG_OBJECT (bin, "we found a message %p from %s matching types %08x",
result->data, GST_OBJECT_NAME (GST_MESSAGE_CAST (result->data)->src),
types);
} else {
GST_DEBUG_OBJECT (bin, "no message found matching types %08x", types);
#ifndef GST_DISABLE_GST_DEBUG
{
guint i;
for (i = 0; i < 32; i++)
if (types & (1 << i))
GST_DEBUG_OBJECT (bin, " %s", gst_message_type_get_name (1 << i));
}
#endif
}
return result;
}
/* with LOCK, returns TRUE if message had a valid SRC, takes ownership of
* the message.
*
* A message that is cached and has the same SRC and type is replaced
* by the given message.
*/
static gboolean
bin_replace_message (GstBin * bin, GstMessage * message, GstMessageType types)
{
GList *previous;
GstObject *src;
gboolean res = TRUE;
const gchar *name;
name = GST_MESSAGE_TYPE_NAME (message);
if ((src = GST_MESSAGE_SRC (message))) {
/* first find the previous message posted by this element */
if ((previous = find_message (bin, src, types))) {
/* if we found a previous message, replace it */
gst_message_unref (previous->data);
previous->data = message;
GST_DEBUG_OBJECT (bin, "replace old message %s from %s",
name, GST_ELEMENT_NAME (src));
} else {
/* keep new message */
bin->messages = g_list_prepend (bin->messages, message);
GST_DEBUG_OBJECT (bin, "got new message %p, %s from %s",
message, name, GST_ELEMENT_NAME (src));
}
} else {
GST_DEBUG_OBJECT (bin, "got message %s from (NULL), not processing", name);
res = FALSE;
gst_message_unref (message);
}
return res;
}
/* with LOCK. Remove all messages of given types */
static void
bin_remove_messages (GstBin * bin, GstObject * src, GstMessageType types)
{
MessageFind find;
GList *walk, *next;
find.src = src;
find.types = types;
for (walk = bin->messages; walk; walk = next) {
GstMessage *message = (GstMessage *) walk->data;
next = g_list_next (walk);
if (message_check (message, &find) == 0) {
GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
"deleting message %p of types 0x%08x", message, types);
bin->messages = g_list_delete_link (bin->messages, walk);
gst_message_unref (message);
} else {
GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
"not deleting message %p of type 0x%08x", message,
GST_MESSAGE_TYPE (message));
}
}
}
/* Check if the bin is EOS. We do this by scanning all sinks and
* checking if they posted an EOS message.
*
* call with bin LOCK */
static gboolean
is_eos (GstBin * bin)
{
gboolean result;
GList *walk;
result = TRUE;
for (walk = bin->children; walk; walk = g_list_next (walk)) {
GstElement *element;
element = GST_ELEMENT_CAST (walk->data);
if (bin_element_is_sink (element, bin) == 0) {
/* check if element posted EOS */
if (find_message (bin, GST_OBJECT_CAST (element), GST_MESSAGE_EOS)) {
GST_DEBUG ("sink '%s' posted EOS", GST_ELEMENT_NAME (element));
} else {
GST_DEBUG ("sink '%s' did not post EOS yet",
GST_ELEMENT_NAME (element));
result = FALSE;
break;
}
}
}
return result;
}
static void
unlink_pads (GstPad * pad)
{
GstPad *peer;
if ((peer = gst_pad_get_peer (pad))) {
if (gst_pad_get_direction (pad) == GST_PAD_SRC)
gst_pad_unlink (pad, peer);
else
gst_pad_unlink (peer, pad);
gst_object_unref (peer);
}
gst_object_unref (pad);
}
/* vmethod that adds an element to a bin
*
* MT safe
*/
static gboolean
gst_bin_add_func (GstBin * bin, GstElement * element)
{
gchar *elem_name;
GstIterator *it;
gboolean is_sink;
GstMessage *clock_message = NULL, *async_message = NULL;
GstStateChangeReturn ret;
GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
/* we obviously can't add ourself to ourself */
if (G_UNLIKELY (GST_ELEMENT_CAST (element) == GST_ELEMENT_CAST (bin)))
goto adding_itself;
/* get the element name to make sure it is unique in this bin. */
GST_OBJECT_LOCK (element);
elem_name = g_strdup (GST_ELEMENT_NAME (element));
is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK);
GST_OBJECT_UNLOCK (element);
GST_OBJECT_LOCK (bin);
/* then check to see if the element's name is already taken in the bin,
* we can safely take the lock here. This check is probably bogus because
* you can safely change the element name after this check and before setting
* the object parent. The window is very small though... */
if (G_UNLIKELY (!gst_object_check_uniqueness (bin->children, elem_name)))
goto duplicate_name;
/* set the element's parent and add the element to the bin's list of children */
if (G_UNLIKELY (!gst_object_set_parent (GST_OBJECT_CAST (element),
GST_OBJECT_CAST (bin))))
goto had_parent;
/* if we add a sink we become a sink */
if (is_sink) {
GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was sink",
elem_name);
GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_IS_SINK);
}
if (gst_element_provides_clock (element)) {
GST_DEBUG_OBJECT (bin, "element \"%s\" can provide a clock", elem_name);
clock_message =
gst_message_new_clock_provide (GST_OBJECT_CAST (element), NULL, TRUE);
}
bin->children = g_list_prepend (bin->children, element);
bin->numchildren++;
bin->children_cookie++;
bin->priv->structure_cookie++;
/* distribute the bus */
gst_element_set_bus (element, bin->child_bus);
/* propagate the current base_time and clock */
gst_element_set_base_time (element, GST_ELEMENT (bin)->base_time);
/* 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));
ret = GST_STATE_RETURN (bin);
/* no need to update the state if we are in error */
if (ret == GST_STATE_CHANGE_FAILURE)
goto no_state_recalc;
/* update the bin state, the new element could have been an ASYNC or
* NO_PREROLL element */
ret = GST_STATE_RETURN (element);
GST_DEBUG_OBJECT (bin, "added %s element",
gst_element_state_change_return_get_name (ret));
switch (ret) {
case GST_STATE_CHANGE_ASYNC:
{
/* create message to track this aync element when it posts an async-done
* message */
async_message =
gst_message_new_async_start (GST_OBJECT_CAST (element), FALSE);
break;
}
case GST_STATE_CHANGE_NO_PREROLL:
/* ignore all async elements we might have and commit our state */
bin_handle_async_done (bin, ret, FALSE);
break;
case GST_STATE_CHANGE_FAILURE:
break;
default:
break;
}
no_state_recalc:
GST_OBJECT_UNLOCK (bin);
/* post the messages on the bus of the element so that the bin can handle
* them */
if (clock_message)
gst_element_post_message (GST_ELEMENT_CAST (element), clock_message);
if (async_message)
gst_element_post_message (GST_ELEMENT_CAST (element), async_message);
/* unlink all linked pads */
it = gst_element_iterate_pads (element);
gst_iterator_foreach (it, (GFunc) unlink_pads, element);
gst_iterator_free (it);
GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "added element \"%s\"",
elem_name);
g_free (elem_name);
g_signal_emit (G_OBJECT (bin), gst_bin_signals[ELEMENT_ADDED], 0, element);
return TRUE;
/* ERROR handling here */
adding_itself:
{
GST_OBJECT_LOCK (bin);
g_warning ("Cannot add bin %s to itself", GST_ELEMENT_NAME (bin));
GST_OBJECT_UNLOCK (bin);
return FALSE;
}
duplicate_name:
{
g_warning ("Name %s is not unique in bin %s, not adding",
elem_name, GST_ELEMENT_NAME (bin));
GST_OBJECT_UNLOCK (bin);
g_free (elem_name);
return FALSE;
}
had_parent:
{
g_warning ("Element %s already has parent", elem_name);
GST_OBJECT_UNLOCK (bin);
g_free (elem_name);
return FALSE;
}
}
/**
* gst_bin_add:
* @bin: a #GstBin
* @element: 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.
*
* MT safe.
*
* Returns: TRUE if the element could be added, FALSE if
* the bin does not want to accept the element.
*/
gboolean
gst_bin_add (GstBin * bin, GstElement * element)
{
GstBinClass *bclass;
gboolean result;
g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
bclass = GST_BIN_GET_CLASS (bin);
if (G_UNLIKELY (bclass->add_element == NULL))
goto no_function;
GST_CAT_DEBUG (GST_CAT_PARENTAGE, "adding element %s to bin %s",
GST_STR_NULL (GST_ELEMENT_NAME (element)),
GST_STR_NULL (GST_ELEMENT_NAME (bin)));
result = bclass->add_element (bin, element);
return result;
/* ERROR handling */
no_function:
{
g_warning ("adding elements to bin %s is not supported",
GST_ELEMENT_NAME (bin));
return FALSE;
}
}
/* remove an element from the bin
*
* MT safe
*/
static gboolean
gst_bin_remove_func (GstBin * bin, GstElement * element)
{
gchar *elem_name;
GstIterator *it;
gboolean is_sink, othersink, found;
GstMessage *clock_message = NULL;
GList *walk, *next;
gboolean other_async, this_async, have_no_preroll;
GstStateChangeReturn ret;
GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
GST_OBJECT_LOCK (element);
/* Check if the element is already being removed and immediately
* return */
if (G_UNLIKELY (GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_UNPARENTING)))
goto already_removing;
GST_OBJECT_FLAG_SET (element, GST_ELEMENT_UNPARENTING);
/* grab element name so we can print it */
elem_name = g_strdup (GST_ELEMENT_NAME (element));
is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK);
GST_OBJECT_UNLOCK (element);
/* unlink all linked pads */
it = gst_element_iterate_pads (element);
gst_iterator_foreach (it, (GFunc) unlink_pads, element);
gst_iterator_free (it);
GST_OBJECT_LOCK (bin);
found = FALSE;
othersink = FALSE;
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;
GST_OBJECT_LOCK (child);
child_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SINK);
/* when we remove a sink, check if there are other sinks. */
if (is_sink && !othersink && child_sink)
othersink = TRUE;
/* check if we have NO_PREROLL children */
if (GST_STATE_RETURN (child) == GST_STATE_CHANGE_NO_PREROLL)
have_no_preroll = TRUE;
GST_OBJECT_UNLOCK (child);
}
}
/* the element must have been in the bin's list of children */
if (G_UNLIKELY (!found))
goto not_in_bin;
/* we now removed the element from the list of elements, increment the cookie
* so that others can detect a change in the children list. */
bin->numchildren--;
bin->children_cookie++;
bin->priv->structure_cookie++;
if (is_sink && !othersink) {
/* we're not a sink anymore */
GST_DEBUG_OBJECT (bin, "we removed the last sink");
GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_IS_SINK);
}
/* if 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);
}
/* remove messages for the element, if there was a pending ASYNC_START
* message we must see if removing the element caused the bin to lose its
* async state. */
this_async = FALSE;
other_async = FALSE;
for (walk = bin->messages; walk; walk = next) {
GstMessage *message = (GstMessage *) walk->data;
GstElement *src = GST_ELEMENT_CAST (GST_MESSAGE_SRC (message));
gboolean remove;
next = g_list_next (walk);
remove = FALSE;
switch (GST_MESSAGE_TYPE (message)) {
case GST_MESSAGE_ASYNC_START:
if (src == element)
this_async = TRUE;
else
other_async = TRUE;
GST_DEBUG_OBJECT (src, "looking at message %p", message);
break;
case GST_MESSAGE_STRUCTURE_CHANGE:
{
GstElement *owner;
GST_DEBUG_OBJECT (src, "looking at structure change message %p",
message);
/* it's unlikely that this message is still in the list of messages
* because this would mean that a link/unlink is busy in another thread
* while we remove the element. We still have to remove the message
* because we might not receive the done message anymore when the element
* is removed from the bin. */
gst_message_parse_structure_change (message, NULL, &owner, NULL);
if (owner == element)
remove = TRUE;
break;
}
default:
break;
}
if (src == element)
remove = TRUE;
if (remove) {
/* delete all message types */
GST_DEBUG_OBJECT (src, "deleting message %p of element \"%s\"",
message, elem_name);
bin->messages = g_list_delete_link (bin->messages, walk);
gst_message_unref (message);
}
}
/* get last return */
ret = GST_STATE_RETURN (bin);
/* no need to update the state if we are in error */
if (ret == GST_STATE_CHANGE_FAILURE)
goto no_state_recalc;
if (!other_async && this_async) {
/* all other elements were not async and we removed the async one,
* handle the async-done case because we are not async anymore now. */
GST_DEBUG_OBJECT (bin,
"we removed the last async element, have no_preroll %d",
have_no_preroll);
/* the current state return of the bin depends on if there are no_preroll
* elements in the pipeline or not */
if (have_no_preroll)
ret = GST_STATE_CHANGE_NO_PREROLL;
else
ret = GST_STATE_CHANGE_SUCCESS;
bin_handle_async_done (bin, ret, FALSE);
} else {
GST_DEBUG_OBJECT (bin,
"recalc state preroll: %d, other async: %d, this async %d",
have_no_preroll, other_async, this_async);
if (have_no_preroll) {
ret = GST_STATE_CHANGE_NO_PREROLL;
} else if (other_async) {
/* there are other async elements and we were not doing an async state
* change, change our pending state and go async */
if (GST_STATE_PENDING (bin) == GST_STATE_VOID_PENDING) {
GST_STATE_NEXT (bin) = GST_STATE (bin);
GST_STATE_PENDING (bin) = GST_STATE (bin);
}
ret = GST_STATE_CHANGE_ASYNC;
}
GST_STATE_RETURN (bin) = ret;
}
no_state_recalc:
GST_OBJECT_UNLOCK (bin);
if (clock_message)
gst_element_post_message (GST_ELEMENT_CAST (bin), clock_message);
GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "removed child \"%s\"",
elem_name);
g_free (elem_name);
gst_element_set_bus (element, NULL);
/* Clear the clock we provided to the element */
gst_element_set_clock (element, NULL);
/* we ref here because after the _unparent() the element can be disposed
* and we still need it to reset the UNPARENTING flag and fire a signal. */
gst_object_ref (element);
gst_object_unparent (GST_OBJECT_CAST (element));
GST_OBJECT_LOCK (element);
GST_OBJECT_FLAG_UNSET (element, GST_ELEMENT_UNPARENTING);
GST_OBJECT_UNLOCK (element);
g_signal_emit (G_OBJECT (bin), gst_bin_signals[ELEMENT_REMOVED], 0, element);
/* element is really out of our control now */
gst_object_unref (element);
return TRUE;
/* ERROR handling */
not_in_bin:
{
g_warning ("Element %s is not in bin %s", elem_name,
GST_ELEMENT_NAME (bin));
GST_OBJECT_UNLOCK (bin);
g_free (elem_name);
return FALSE;
}
already_removing:
{
GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "already removing child");
GST_OBJECT_UNLOCK (element);
return FALSE;
}
}
/**
* gst_bin_remove:
* @bin: a #GstBin
* @element: the #GstElement to remove
*
* Removes the element from the bin, unparenting it as well.
* Unparenting the element means that the element will be dereferenced,
* so if the bin holds the only reference to the element, the element
* will be freed in the process of removing it from the bin. If you
* want the element to still exist after removing, you need to call
* gst_object_ref() before removing it from the bin.
*
* If the element's pads are linked to other pads, the pads will be unlinked
* before the element is removed from the bin.
*
* MT safe.
*
* Returns: TRUE if the element could be removed, FALSE if
* the bin does not want to remove the element.
*/
gboolean
gst_bin_remove (GstBin * bin, GstElement * element)
{
GstBinClass *bclass;
gboolean result;
g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
bclass = GST_BIN_GET_CLASS (bin);
if (G_UNLIKELY (bclass->remove_element == NULL))
goto no_function;
GST_CAT_DEBUG (GST_CAT_PARENTAGE, "removing element %s from bin %s",
GST_ELEMENT_NAME (element), GST_ELEMENT_NAME (bin));
result = bclass->remove_element (bin, element);
return result;
/* ERROR handling */
no_function:
{
g_warning ("removing elements from bin %s is not supported",
GST_ELEMENT_NAME (bin));
return FALSE;
}
}
static GstIteratorItem
iterate_child (GstIterator * it, GstElement * child)
{
gst_object_ref (child);
return GST_ITERATOR_ITEM_PASS;
}
/**
* gst_bin_iterate_elements:
* @bin: a #GstBin
*
* Gets an iterator for the elements in this bin.
*
* Each element yielded by the iterator will have its refcount increased, so
* unref after use.
*
* MT safe. Caller owns returned value.
*
* Returns: a #GstIterator of #GstElement, or NULL
*/
GstIterator *
gst_bin_iterate_elements (GstBin * bin)
{
GstIterator *result;
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
GST_OBJECT_LOCK (bin);
/* add ref because the iterator refs the bin. When the iterator
* is freed it will unref the bin again using the provided dispose
* function. */
gst_object_ref (bin);
result = gst_iterator_new_list (GST_TYPE_ELEMENT,
GST_OBJECT_GET_LOCK (bin),
&bin->children_cookie,
&bin->children,
bin,
(GstIteratorItemFunction) iterate_child,
(GstIteratorDisposeFunction) gst_object_unref);
GST_OBJECT_UNLOCK (bin);
return result;
}
static GstIteratorItem
iterate_child_recurse (GstIterator * it, GstElement * child)
{
gst_object_ref (child);
if (GST_IS_BIN (child)) {
GstIterator *other = gst_bin_iterate_recurse (GST_BIN (child));
gst_iterator_push (it, other);
}
return GST_ITERATOR_ITEM_PASS;
}
/**
* gst_bin_iterate_recurse:
* @bin: a #GstBin
*
* Gets an iterator for the elements in this bin.
* This iterator recurses into GstBin children.
*
* Each element yielded by the iterator will have its refcount increased, so
* unref after use.
*
* MT safe. Caller owns returned value.
*
* Returns: a #GstIterator of #GstElement, or NULL
*/
GstIterator *
gst_bin_iterate_recurse (GstBin * bin)
{
GstIterator *result;
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
GST_OBJECT_LOCK (bin);
/* add ref because the iterator refs the bin. When the iterator
* is freed it will unref the bin again using the provided dispose
* function. */
gst_object_ref (bin);
result = gst_iterator_new_list (GST_TYPE_ELEMENT,
GST_OBJECT_GET_LOCK (bin),
&bin->children_cookie,
&bin->children,
bin,
(GstIteratorItemFunction) iterate_child_recurse,
(GstIteratorDisposeFunction) gst_object_unref);
GST_OBJECT_UNLOCK (bin);
return result;
}
/* returns 0 when TRUE because this is a GCompareFunc */
/* MT safe */
static gint
bin_element_is_sink (GstElement * child, GstBin * bin)
{
gboolean is_sink;
/* we lock the child here for the remainder of the function to
* get its name and flag safely. */
GST_OBJECT_LOCK (child);
is_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SINK);
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
"child %s %s sink", GST_OBJECT_NAME (child), is_sink ? "is" : "is not");
GST_OBJECT_UNLOCK (child);
return is_sink ? 0 : 1;
}
static gint
sink_iterator_filter (GstElement * child, GstBin * bin)
{
if (bin_element_is_sink (child, bin) == 0) {
/* returns 0 because this is a GCompareFunc */
return 0;
} else {
/* child carries a ref from gst_bin_iterate_elements -- drop if not passing
through */
gst_object_unref (child);
return 1;
}
}
/**
* gst_bin_iterate_sinks:
* @bin: a #GstBin
*
* Gets an iterator for all elements in the bin that have the
* #GST_ELEMENT_IS_SINK flag set.
*
* Each element yielded by the iterator will have its refcount increased, so
* unref after use.
*
* MT safe. Caller owns returned value.
*
* Returns: a #GstIterator of #GstElement, or NULL
*/
GstIterator *
gst_bin_iterate_sinks (GstBin * bin)
{
GstIterator *children;
GstIterator *result;
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
children = gst_bin_iterate_elements (bin);
result = gst_iterator_filter (children,
(GCompareFunc) sink_iterator_filter, bin);
return result;
}
/* returns 0 when TRUE because this is a GCompareFunc */
/* MT safe */
static gint
bin_element_is_src (GstElement * child, GstBin * bin)
{
gboolean is_src = FALSE;
/* we lock the child here for the remainder of the function to
* get its name and flag safely. */
GST_OBJECT_LOCK (child);
if (!GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SINK) &&
!child->numsinkpads) {
is_src = TRUE;
}
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
"child %s %s src", GST_OBJECT_NAME (child), is_src ? "is" : "is not");
GST_OBJECT_UNLOCK (child);
return is_src ? 0 : 1;
}
static gint
src_iterator_filter (GstElement * child, GstBin * bin)
{
if (bin_element_is_src (child, bin) == 0) {
/* returns 0 because this is a GCompareFunc */
return 0;
} else {
/* child carries a ref from gst_bin_iterate_elements -- drop if not passing
through */
gst_object_unref (child);
return 1;
}
}
/**
* gst_bin_iterate_sources:
* @bin: a #GstBin
*
* Gets an iterator for all elements in the bin that have no sinkpads and have
* the #GST_ELEMENT_IS_SINK flag unset.
*
* Each element yielded by the iterator will have its refcount increased, so
* unref after use.
*
* MT safe. Caller owns returned value.
*
* Returns: a #GstIterator of #GstElement, or NULL
*/
GstIterator *
gst_bin_iterate_sources (GstBin * bin)
{
GstIterator *children;
GstIterator *result;
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
children = gst_bin_iterate_elements (bin);
result = gst_iterator_filter (children,
(GCompareFunc) src_iterator_filter, bin);
return result;
}
/*
* MT safe
*/
static GstStateChangeReturn
gst_bin_get_state_func (GstElement * element, GstState * state,
GstState * pending, GstClockTime timeout)
{
GstStateChangeReturn ret;
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "getting state");
ret = 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 */
} GstBinSortIterator;
/* we add and subtract 1 to make sure we don't confuse NULL and 0 */
#define HASH_SET_DEGREE(bit, elem, deg) \
g_hash_table_replace (bit->hash, elem, GINT_TO_POINTER(deg+1))
#define HASH_GET_DEGREE(bit, elem) \
(GPOINTER_TO_INT(g_hash_table_lookup (bit->hash, elem))-1)
/* add element to queue of next elements in the iterator.
* We push at the tail to give higher priority elements a
* chance first */
static void
add_to_queue (GstBinSortIterator * bit, GstElement * element)
{
GST_DEBUG_OBJECT (bit->bin, "adding '%s' to queue",
GST_ELEMENT_NAME (element));
gst_object_ref (element);
g_queue_push_tail (bit->queue, element);
HASH_SET_DEGREE (bit, element, -1);
}
static void
remove_from_queue (GstBinSortIterator * bit, GstElement * element)
{
GList *find;
if ((find = g_queue_find (bit->queue, element))) {
GST_DEBUG_OBJECT (bit->bin, "removing '%s' from queue",
GST_ELEMENT_NAME (element));
g_queue_delete_link (bit->queue, find);
gst_object_unref (element);
} else {
GST_DEBUG_OBJECT (bit->bin, "unable to remove '%s' from queue",
GST_ELEMENT_NAME (element));
}
}
/* clear the queue, unref all objects as we took a ref when
* we added them to the queue */
static void
clear_queue (GQueue * queue)
{
gpointer p;
while ((p = g_queue_pop_head (queue)))
gst_object_unref (p);
}
/* set all degrees to 0. Elements marked as a sink are
* added to the queue immediatly. Since we only look at the SINK flag of the
* element, it is possible that we add non-sinks to the queue. These will be
* removed from the queue again when we can prove that it provides data for some
* other element. */
static void
reset_degree (GstElement * element, GstBinSortIterator * bit)
{
gboolean is_sink;
/* sinks are added right away */
GST_OBJECT_LOCK (element);
is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK);
GST_OBJECT_UNLOCK (element);
if (is_sink) {
add_to_queue (bit, element);
} else {
/* others are marked with 0 and handled when sinks are done */
HASH_SET_DEGREE (bit, element, 0);
}
}
/* adjust the degree of all elements connected to the given
* element. If a degree of an element drops to 0, it is
* added to the queue of elements to schedule next.
*
* We have to make sure not to cross the bin boundary this element
* belongs to.
*/
static void
update_degree (GstElement * element, GstBinSortIterator * bit)
{
gboolean linked = FALSE;
GST_OBJECT_LOCK (element);
/* don't touch degree if element has no sinkpads */
if (element->numsinkpads != 0) {
/* loop over all sinkpads, decrement degree for all connected
* elements in this bin */
GList *pads;
for (pads = element->sinkpads; pads; pads = g_list_next (pads)) {
GstPad *pad, *peer;
pad = GST_PAD_CAST (pads->data);
if ((peer = gst_pad_get_peer (pad))) {
GstElement *peer_element;
/* we're iterating over the sinkpads, this is the peer and thus the
* srcpad, check if it's busy in a link/unlink */
if (G_UNLIKELY (find_message (bit->bin, GST_OBJECT_CAST (peer),
GST_MESSAGE_STRUCTURE_CHANGE))) {
gst_object_unref (peer);
continue;
}
if ((peer_element = gst_pad_get_parent_element (peer))) {
GST_OBJECT_LOCK (peer_element);
/* check that we don't go outside of this bin */
if (GST_OBJECT_CAST (peer_element)->parent ==
GST_OBJECT_CAST (bit->bin)) {
gint old_deg, new_deg;
old_deg = HASH_GET_DEGREE (bit, peer_element);
/* check to see if we added an element as sink that was not really a
* sink because it was connected to some other element. */
if (old_deg == -1) {
remove_from_queue (bit, peer_element);
old_deg = 0;
}
new_deg = old_deg + bit->mode;
GST_DEBUG_OBJECT (bit->bin,
"change element %s, degree %d->%d, linked to %s",
GST_ELEMENT_NAME (peer_element), old_deg, new_deg,
GST_ELEMENT_NAME (element));
/* update degree, it is possible that an element was in 0 and
* reaches -1 here. This would mean that the element had no sinkpads
* but became linked while the state change was happening. We will
* resync on this with the structure change message. */
if (new_deg == 0) {
/* degree hit 0, add to queue */
add_to_queue (bit, peer_element);
} else {
HASH_SET_DEGREE (bit, peer_element, new_deg);
}
linked = TRUE;
}
GST_OBJECT_UNLOCK (peer_element);
gst_object_unref (peer_element);
}
gst_object_unref (peer);
}
}
}
if (!linked) {
GST_DEBUG_OBJECT (bit->bin, "element %s not linked on any sinkpads",
GST_ELEMENT_NAME (element));
}
GST_OBJECT_UNLOCK (element);
}
/* find the next best element not handled yet. This is the one
* with the lowest non-negative degree */
static void
find_element (GstElement * element, GstBinSortIterator * bit)
{
gint degree;
/* element is already handled */
if ((degree = HASH_GET_DEGREE (bit, element)) < 0)
return;
/* first element or element with smaller degree */
if (bit->best == NULL || bit->best_deg > degree) {
bit->best = element;
bit->best_deg = degree;
}
}
/* get next element in iterator. the returned element has the
* refcount increased */
static GstIteratorResult
gst_bin_sort_iterator_next (GstBinSortIterator * bit, gpointer * result)
{
GstBin *bin = bit->bin;
/* empty queue, we have to find a next best element */
if (g_queue_is_empty (bit->queue)) {
GstElement *best;
bit->best = NULL;
bit->best_deg = G_MAXINT;
g_list_foreach (bin->children, (GFunc) find_element, bit);
if ((best = bit->best)) {
if (bit->best_deg != 0) {
/* we don't fail on this one yet */
GST_WARNING_OBJECT (bin, "loop dected in graph");
g_warning ("loop detected in the graph of bin %s!!",
GST_ELEMENT_NAME (bin));
}
/* best unhandled element, schedule as next element */
GST_DEBUG_OBJECT (bin, "queue empty, next best: %s",
GST_ELEMENT_NAME (best));
gst_object_ref (best);
HASH_SET_DEGREE (bit, best, -1);
*result = best;
} else {
GST_DEBUG_OBJECT (bin, "queue empty, elements exhausted");
/* no more unhandled elements, we are done */
return GST_ITERATOR_DONE;
}
} else {
/* everything added to the queue got reffed */
*result = g_queue_pop_head (bit->queue);
}
GST_DEBUG_OBJECT (bin, "queue head gives %s", GST_ELEMENT_NAME (*result));
/* update degrees of linked elements */
update_degree (GST_ELEMENT_CAST (*result), bit);
return GST_ITERATOR_OK;
}
/* clear queues, recalculate the degrees and restart. */
static void
gst_bin_sort_iterator_resync (GstBinSortIterator * bit)
{
GstBin *bin = bit->bin;
GST_DEBUG_OBJECT (bin, "resync");
clear_queue (bit->queue);
/* reset degrees */
g_list_foreach (bin->children, (GFunc) reset_degree, bit);
/* calc degrees, incrementing */
bit->mode = 1;
g_list_foreach (bin->children, (GFunc) update_degree, bit);
/* for the rest of the function we decrement the degrees */
bit->mode = -1;
}
/* clear queues, unref bin and free iterator. */
static void
gst_bin_sort_iterator_free (GstBinSortIterator * bit)
{
GstBin *bin = bit->bin;
GST_DEBUG_OBJECT (bin, "free");
clear_queue (bit->queue);
g_queue_free (bit->queue);
g_hash_table_destroy (bit->hash);
gst_object_unref (bin);
g_free (bit);
}
/* should be called with the bin LOCK held */
static GstIterator *
gst_bin_sort_iterator_new (GstBin * bin)
{
GstBinSortIterator *result;
/* we don't need an ItemFunction because we ref the items in the _next
* method already */
result = (GstBinSortIterator *)
gst_iterator_new (sizeof (GstBinSortIterator),
GST_TYPE_ELEMENT,
GST_OBJECT_GET_LOCK (bin),
&bin->priv->structure_cookie,
(GstIteratorNextFunction) gst_bin_sort_iterator_next,
(GstIteratorItemFunction) NULL,
(GstIteratorResyncFunction) gst_bin_sort_iterator_resync,
(GstIteratorFreeFunction) gst_bin_sort_iterator_free);
result->queue = g_queue_new ();
result->hash = g_hash_table_new (NULL, NULL);
gst_object_ref (bin);
result->bin = bin;
gst_bin_sort_iterator_resync (result);
return (GstIterator *) result;
}
/**
* gst_bin_iterate_sorted:
* @bin: a #GstBin
*
* Gets an iterator for the elements in this bin in topologically
* sorted order. This means that the elements are returned from
* the most downstream elements (sinks) to the sources.
*
* This function is used internally to perform the state changes
* of the bin elements and for clock selection.
*
* Each element yielded by the iterator will have its refcount increased, so
* unref after use.
*
* MT safe. Caller owns returned value.
*
* Returns: 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, GstState current, GstState next)
{
GstStateChangeReturn ret;
gboolean locked;
GList *found;
/* set base_time on child */
gst_element_set_base_time (element, base_time);
GST_STATE_LOCK (element);
/* peel off the locked flag */
GST_OBJECT_LOCK (element);
locked = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_LOCKED_STATE);
/* get previous state return */
ret = GST_STATE_RETURN (element);
GST_OBJECT_UNLOCK (element);
/* skip locked elements */
if (G_UNLIKELY (locked))
goto locked;
/* if the element was no preroll, just start changing the state regardless
* if it had async elements (in the case of a bin) because they won't preroll
* anyway. */
if (G_UNLIKELY (ret == GST_STATE_CHANGE_NO_PREROLL)) {
GST_DEBUG_OBJECT (element, "element is NO_PREROLL, ignore async elements");
goto no_preroll;
}
GST_OBJECT_LOCK (bin);
/* the element was busy with an upwards async state change, we must wait for
* an ASYNC_DONE message before we attemp to change the state. */
if ((found =
find_message (bin, GST_OBJECT_CAST (element),
GST_MESSAGE_ASYNC_START))) {
#ifndef GST_DISABLE_GST_DEBUG
GstMessage *message = GST_MESSAGE_CAST (found->data);
GST_DEBUG_OBJECT (element, "element message %p, %s async busy",
message, GST_ELEMENT_NAME (GST_MESSAGE_SRC (message)));
#endif
/* only wait for upward state changes */
if (next > current) {
/* We found an async element check if we can force its state to change or
* if we have to wait for it to preroll. */
if (G_UNLIKELY (!enable_latency)) {
g_warning ("Future versions of GStreamer will wait for element \"%s\"\n"
"\tto preroll in order to perform correct latency calculations.\n"
"\tPlease verify that the application continues to work correctly by\n"
"\tsetting the environment variable GST_COMPAT to a value containing\n"
"\tthe string 'live-preroll'.", GST_ELEMENT_NAME (element));
goto no_latency;
}
goto was_busy;
}
}
no_latency:
GST_OBJECT_UNLOCK (bin);
no_preroll:
GST_DEBUG_OBJECT (bin,
"setting element %s to %s, base_time %" GST_TIME_FORMAT,
GST_ELEMENT_NAME (element), gst_element_state_get_name (next),
GST_TIME_ARGS (base_time));
/* change state */
ret = gst_element_set_state (element, next);
GST_STATE_UNLOCK (element);
return ret;
locked:
{
GST_DEBUG_OBJECT (element,
"element is locked, return previous return %s",
gst_element_state_change_return_get_name (ret));
GST_STATE_UNLOCK (element);
return ret;
}
was_busy:
{
GST_DEBUG_OBJECT (element, "element was busy, delaying state change");
GST_OBJECT_UNLOCK (bin);
GST_STATE_UNLOCK (element);
return GST_STATE_CHANGE_ASYNC;
}
}
/* 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);
else if (!*active)
gst_pad_set_caps (pad, NULL);
/* unref the object that was reffed for us by _fold */
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, gpointer user_data)
{
GstIteratorResult ires;
GValue ret = { 0 };
/* no need to unset this later, it's just a boolean */
g_value_init (&ret, G_TYPE_BOOLEAN);
g_value_set_boolean (&ret, TRUE);
while (1) {
ires = gst_iterator_fold (iter, (GstIteratorFoldFunction) activate_pads,
&ret, user_data);
switch (ires) {
case GST_ITERATOR_RESYNC:
/* need to reset the result again */
g_value_set_boolean (&ret, TRUE);
gst_iterator_resync (iter);
break;
case GST_ITERATOR_DONE:
/* all pads iterated, return collected value */
goto done;
default:
/* iterator returned _ERROR or premature end with _OK,
* mark an error and exit */
g_value_set_boolean (&ret, FALSE);
goto done;
}
}
done:
/* return collected value */
return g_value_get_boolean (&ret);
}
/* is called with STATE_LOCK
*/
static gboolean
gst_bin_src_pads_activate (GstBin * bin, gboolean active)
{
GstIterator *iter;
gboolean fold_ok;
GST_DEBUG_OBJECT (bin, "src_pads_activate with active %d", active);
iter = gst_element_iterate_src_pads ((GstElement *) bin);
fold_ok = iterator_activate_fold_with_resync (iter, &active);
gst_iterator_free (iter);
if (G_UNLIKELY (!fold_ok))
goto failed;
GST_DEBUG_OBJECT (bin, "pads_activate successful");
return TRUE;
/* ERRORS */
failed:
{
GST_DEBUG_OBJECT (bin, "source pads_activate failed");
return FALSE;
}
}
/**
* gst_bin_recalculate_latency:
* @bin: a #GstBin
*
* Query @bin for the current latency using and reconfigures this latency to all the
* elements with a LATENCY event.
*
* This method is typically called on the pipeline when a #GST_MESSAGE_LATENCY
* is posted on the bus.
*
* This function simply emits the 'do-latency' signal so any custom latency
* calculations will be performed.
*
* Returns: %TRUE if the latency could be queried and reconfigured.
*
* Since: 0.10.22.
*/
gboolean
gst_bin_recalculate_latency (GstBin * bin)
{
gboolean res;
g_signal_emit (G_OBJECT (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,
"failed to configure latency of %" GST_TIME_FORMAT,
GST_TIME_ARGS (min_latency));
GST_ELEMENT_WARNING (element, CORE, CLOCK, (NULL),
("Failed to configure latency of %" GST_TIME_FORMAT,
GST_TIME_ARGS (min_latency)));
}
} else {
/* this is not a real problem, we just don't configure any latency. */
GST_WARNING_OBJECT (element, "failed to query latency");
}
gst_query_unref (query);
return res;
}
static GstStateChangeReturn
gst_bin_change_state_func (GstElement * element, GstStateChange transition)
{
GstBin *bin;
GstStateChangeReturn ret;
GstState current, next;
gboolean have_async;
gboolean have_no_preroll;
GstClockTime base_time;
GstIterator *it;
gboolean done;
/* we don't need to take the STATE_LOCK, it is already taken */
current = (GstState) GST_STATE_TRANSITION_CURRENT (transition);
next = (GstState) GST_STATE_TRANSITION_NEXT (transition);
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
"changing state of children from %s to %s",
gst_element_state_get_name (current), gst_element_state_get_name (next));
bin = GST_BIN_CAST (element);
switch (next) {
case GST_STATE_PLAYING:
{
gboolean toplevel;
GST_OBJECT_LOCK (bin);
toplevel = BIN_IS_TOPLEVEL (bin);
GST_OBJECT_UNLOCK (bin);
if (toplevel)
gst_bin_recalculate_latency (bin);
break;
}
case GST_STATE_PAUSED:
/* Clear EOS list on next PAUSED */
GST_OBJECT_LOCK (bin);
GST_DEBUG_OBJECT (element, "clearing EOS elements");
bin_remove_messages (bin, NULL, GST_MESSAGE_EOS);
GST_OBJECT_UNLOCK (bin);
if (current == GST_STATE_READY)
if (!(gst_bin_src_pads_activate (bin, TRUE)))
goto activate_failure;
break;
case GST_STATE_READY:
/* Clear message list on next READY */
GST_OBJECT_LOCK (bin);
GST_DEBUG_OBJECT (element, "clearing all cached messages");
bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
GST_OBJECT_UNLOCK (bin);
if (current == GST_STATE_PAUSED)
if (!(gst_bin_src_pads_activate (bin, FALSE)))
goto activate_failure;
break;
case GST_STATE_NULL:
if (current == GST_STATE_READY)
if (!(gst_bin_src_pads_activate (bin, FALSE)))
goto activate_failure;
break;
default:
break;
}
/* this flag is used to make the async state changes return immediatly. We
* don't want them to interfere with this state change */
GST_OBJECT_LOCK (bin);
bin->polling = TRUE;
GST_OBJECT_UNLOCK (bin);
/* iterate in state change order */
it = gst_bin_iterate_sorted (bin);
/* mark if we've seen an ASYNC element in the bin when we did a state change.
* Note how we don't reset this value when a resync happens, the reason being
* that the async element posted ASYNC_START and we want to post ASYNC_DONE
* even after a resync when the async element is gone */
have_async = FALSE;
restart:
/* take base_time */
base_time = gst_element_get_base_time (element);
have_no_preroll = FALSE;
done = FALSE;
while (!done) {
gpointer data;
switch (gst_iterator_next (it, &data)) {
case GST_ITERATOR_OK:
{
GstElement *child;
child = GST_ELEMENT_CAST (data);
/* set state and base_time now */
ret = gst_bin_element_set_state (bin, child, base_time, current, next);
switch (ret) {
case GST_STATE_CHANGE_SUCCESS:
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
"child '%s' changed state to %d(%s) successfully",
GST_ELEMENT_NAME (child), next,
gst_element_state_get_name (next));
break;
case GST_STATE_CHANGE_ASYNC:
{
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
"child '%s' is changing state asynchronously to %s",
GST_ELEMENT_NAME (child), gst_element_state_get_name (next));
have_async = TRUE;
break;
}
case GST_STATE_CHANGE_FAILURE:
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
"child '%s' failed to go to state %d(%s)",
GST_ELEMENT_NAME (child),
next, gst_element_state_get_name (next));
gst_object_unref (child);
goto done;
case GST_STATE_CHANGE_NO_PREROLL:
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
"child '%s' changed state to %d(%s) successfully without preroll",
GST_ELEMENT_NAME (child), next,
gst_element_state_get_name (next));
have_no_preroll = TRUE;
break;
default:
g_assert_not_reached ();
break;
}
gst_object_unref (child);
break;
}
case GST_ITERATOR_RESYNC:
GST_CAT_DEBUG (GST_CAT_STATES, "iterator doing resync");
gst_iterator_resync (it);
goto restart;
default:
case GST_ITERATOR_DONE:
GST_CAT_DEBUG (GST_CAT_STATES, "iterator done");
done = TRUE;
break;
}
}
ret = parent_class->change_state (element, transition);
if (G_UNLIKELY (ret == GST_STATE_CHANGE_FAILURE))
goto done;
if (have_no_preroll) {
ret = GST_STATE_CHANGE_NO_PREROLL;
} else if (have_async) {
ret = GST_STATE_CHANGE_ASYNC;
}
done:
gst_iterator_free (it);
GST_OBJECT_LOCK (bin);
bin->polling = FALSE;
/* it's possible that we did not get ASYNC form the children while the bin is
* simulating ASYNC behaviour by posting an ASYNC_DONE message on the bus with
* itself as the source. In that case we still want to check if the state
* change completed. */
if (ret != GST_STATE_CHANGE_ASYNC && !bin->priv->pending_async_done) {
/* no element returned ASYNC, we can just complete. */
GST_DEBUG_OBJECT (bin, "no async elements");
goto state_end;
}
/* when we get here an ASYNC element was found */
if (GST_STATE_TARGET (bin) <= GST_STATE_READY) {
/* we ignore ASYNC state changes when we go to READY or NULL */
GST_DEBUG_OBJECT (bin, "target state %s <= READY",
gst_element_state_get_name (GST_STATE_TARGET (bin)));
goto state_end;
}
GST_DEBUG_OBJECT (bin, "check async elements");
/* check if all elements managed to commit their state already */
if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
/* nothing found, remove all old ASYNC_DONE messages. This can happen when
* all the elements commited their state while we were doing the state
* change. We will still return ASYNC for consistency but we commit the
* state already so that a _get_state() will return immediatly. */
bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
GST_DEBUG_OBJECT (bin, "async elements commited");
bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, FALSE);
}
state_end:
bin->priv->pending_async_done = FALSE;
GST_OBJECT_UNLOCK (bin);
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
"done changing bin's state from %s to %s, now in %s, ret %s",
gst_element_state_get_name (current),
gst_element_state_get_name (next),
gst_element_state_get_name (GST_STATE (element)),
gst_element_state_change_return_get_name (ret));
return ret;
/* ERRORS */
activate_failure:
{
GST_CAT_WARNING_OBJECT (GST_CAT_STATES, element,
"failure (de)activating src pads");
return GST_STATE_CHANGE_FAILURE;
}
}
/*
* This function is a utility event handler for seek events.
* It will send the event to all sinks or sources depending on the
* event-direction.
*
* Applications are free to override this behaviour and
* implement their own seek handler, but this will work for
* pretty much all cases in practice.
*/
static gboolean
gst_bin_send_event (GstElement * element, GstEvent * event)
{
GstBin *bin = GST_BIN (element);
GstIterator *iter;
gboolean res = TRUE;
gboolean done = FALSE;
if (GST_EVENT_IS_DOWNSTREAM (event)) {
iter = gst_bin_iterate_sources (bin);
GST_DEBUG_OBJECT (bin, "Sending %s event to src children",
GST_EVENT_TYPE_NAME (event));
} else {
iter = gst_bin_iterate_sinks (bin);
GST_DEBUG_OBJECT (bin, "Sending %s event to sink children",
GST_EVENT_TYPE_NAME (event));
}
while (!done) {
gpointer data;
switch (gst_iterator_next (iter, &data)) {
case GST_ITERATOR_OK:
{
GstElement *child;
gst_event_ref (event);
child = GST_ELEMENT_CAST (data);
res &= gst_element_send_event (child, event);
gst_object_unref (child);
break;
}
case GST_ITERATOR_RESYNC:
gst_iterator_resync (iter);
res = TRUE;
break;
case GST_ITERATOR_DONE:
done = TRUE;
break;
case GST_ITERATOR_ERROR:
g_assert_not_reached ();
break;
}
}
gst_iterator_free (iter);
gst_event_unref (event);
return res;
}
/* this is the function called by the threadpool. When async elements commit
* their state, this function will attempt to bring the bin to the next state.
*/
static void
gst_bin_continue_func (BinContinueData * data)
{
GstBin *bin;
GstState current, next, pending;
GstStateChange transition;
bin = data->bin;
pending = data->pending;
GST_DEBUG_OBJECT (bin, "waiting for state lock");
GST_STATE_LOCK (bin);
GST_DEBUG_OBJECT (bin, "doing state continue");
GST_OBJECT_LOCK (bin);
/* if a new state change happened after this thread was scheduled, we return
* immediatly. */
if (data->cookie != GST_ELEMENT_CAST (bin)->state_cookie)
goto interrupted;
current = GST_STATE (bin);
next = GST_STATE_GET_NEXT (current, pending);
transition = (GstStateChange) GST_STATE_TRANSITION (current, next);
GST_STATE_NEXT (bin) = next;
/* mark busy */
GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
GST_OBJECT_UNLOCK (bin);
GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
"continue state change %s to %s, final %s",
gst_element_state_get_name (current),
gst_element_state_get_name (next), gst_element_state_get_name (pending));
gst_element_change_state (GST_ELEMENT_CAST (bin), transition);
GST_STATE_UNLOCK (bin);
GST_DEBUG_OBJECT (bin, "state continue done");
gst_object_unref (bin);
g_free (data);
return;
interrupted:
{
GST_OBJECT_UNLOCK (bin);
GST_STATE_UNLOCK (bin);
GST_DEBUG_OBJECT (bin, "state continue aborted due to intervening change");
gst_object_unref (bin);
g_free (data);
return;
}
}
static GstBusSyncReply
bin_bus_handler (GstBus * bus, GstMessage * message, GstBin * bin)
{
GstBinClass *bclass;
bclass = GST_BIN_GET_CLASS (bin);
if (bclass->handle_message)
bclass->handle_message (bin, message);
else
gst_message_unref (message);
return GST_BUS_DROP;
}
static void
bin_push_state_continue (BinContinueData * data)
{
GstBinClass *klass;
GstBin *bin;
/* ref was taken */
bin = data->bin;
klass = GST_BIN_GET_CLASS (bin);
GST_DEBUG_OBJECT (bin, "pushing continue on thread pool");
g_thread_pool_push (klass->pool, data, NULL);
}
/* an element started an async state change, if we were not busy with a state
* change, we perform a lost state.
* This function is called with the OBJECT lock.
*/
static void
bin_handle_async_start (GstBin * bin, gboolean new_base_time)
{
GstState old_state, new_state;
gboolean toplevel;
GstMessage *amessage = NULL;
if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
goto had_error;
/* get our toplevel state */
toplevel = BIN_IS_TOPLEVEL (bin);
/* prepare an ASYNC_START message, we always post the start message even if we
* are busy with a state change or when we are NO_PREROLL. */
if (!toplevel)
/* non toplevel bin, prepare async-start for the parent */
amessage =
gst_message_new_async_start (GST_OBJECT_CAST (bin), new_base_time);
if (bin->polling || GST_STATE_PENDING (bin) != GST_STATE_VOID_PENDING)
goto was_busy;
/* async starts are ignored when we are NO_PREROLL */
if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_NO_PREROLL)
goto was_no_preroll;
old_state = GST_STATE (bin);
/* when we PLAYING we go back to PAUSED, when preroll happens, we go back to
* PLAYING after optionally redistributing the base_time. */
if (old_state > GST_STATE_PAUSED)
new_state = GST_STATE_PAUSED;
else
new_state = old_state;
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
"lost state of %s, new %s", gst_element_state_get_name (old_state),
gst_element_state_get_name (new_state));
GST_STATE (bin) = new_state;
GST_STATE_NEXT (bin) = new_state;
GST_STATE_PENDING (bin) = new_state;
GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
GST_OBJECT_UNLOCK (bin);
/* post message */
gst_element_post_message (GST_ELEMENT_CAST (bin),
gst_message_new_state_changed (GST_OBJECT_CAST (bin),
new_state, new_state, new_state));
post_start:
if (amessage) {
/* post our ASYNC_START. */
GST_DEBUG_OBJECT (bin, "posting ASYNC_START to parent");
gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
}
GST_OBJECT_LOCK (bin);
return;
had_error:
{
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
return;
}
was_busy:
{
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
GST_OBJECT_UNLOCK (bin);
goto post_start;
}
was_no_preroll:
{
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "ignoring, we are NO_PREROLL");
GST_OBJECT_UNLOCK (bin);
goto post_start;
}
}
/* this function is called when there are no more async elements in the bin. We
* post a state changed message and an ASYNC_DONE message.
* This function is called with the OBJECT lock.
*/
static void
bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret,
gboolean flag_pending)
{
GstState current, pending, target;
GstStateChangeReturn old_ret;
GstState old_state, old_next;
gboolean toplevel;
GstMessage *smessage = NULL, *amessage = NULL;
BinContinueData *cont = NULL;
if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
goto had_error;
pending = GST_STATE_PENDING (bin);
if (bin->polling)
goto was_busy;
/* check if there is something to commit */
if (pending == GST_STATE_VOID_PENDING)
goto nothing_pending;
old_ret = GST_STATE_RETURN (bin);
GST_STATE_RETURN (bin) = ret;
/* move to the next target state */
target = GST_STATE_TARGET (bin);
pending = GST_STATE_PENDING (bin) = target;
amessage = gst_message_new_async_done (GST_OBJECT_CAST (bin));
old_state = GST_STATE (bin);
/* this is the state we should go to next */
old_next = GST_STATE_NEXT (bin);
if (old_next != GST_STATE_PLAYING) {
GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
"committing state from %s to %s, old pending %s",
gst_element_state_get_name (old_state),
gst_element_state_get_name (old_next),
gst_element_state_get_name (pending));
/* update current state */
current = GST_STATE (bin) = old_next;
} else {
current = old_state;
}
/* get our toplevel state */
toplevel = BIN_IS_TOPLEVEL (bin);
/* see if we reached the final state. If we are not toplevel, we also have to
* stop here, the parent will continue our state. */
if ((pending == current) || !toplevel) {
GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
"completed state change, pending VOID");
/* mark VOID pending */
pending = GST_STATE_VOID_PENDING;
GST_STATE_PENDING (bin) = pending;
GST_STATE_NEXT (bin) = GST_STATE_VOID_PENDING;
} else {
GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
"continue state change, pending %s",
gst_element_state_get_name (pending));
cont = g_new0 (BinContinueData, 1);
/* ref to the bin */
cont->bin = gst_object_ref (bin);
/* cookie to detect concurrent state change */
cont->cookie = GST_ELEMENT_CAST (bin)->state_cookie;
/* pending target state */
cont->pending = pending;
/* mark busy */
GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
GST_STATE_NEXT (bin) = pending;
}
if (old_next != GST_STATE_PLAYING) {
if (old_state != old_next || old_ret == GST_STATE_CHANGE_ASYNC) {
smessage = gst_message_new_state_changed (GST_OBJECT_CAST (bin),
old_state, old_next, pending);
}
}
GST_OBJECT_UNLOCK (bin);
if (smessage) {
GST_DEBUG_OBJECT (bin, "posting state change message");
gst_element_post_message (GST_ELEMENT_CAST (bin), smessage);
}
if (amessage) {
/* post our combined ASYNC_DONE when all is ASYNC_DONE. */
GST_DEBUG_OBJECT (bin, "posting ASYNC_DONE to parent");
gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
}
GST_OBJECT_LOCK (bin);
if (cont) {
/* toplevel, start continue state */
GST_DEBUG_OBJECT (bin, "all async-done, starting state continue");
bin_push_state_continue (cont);
} else {
GST_DEBUG_OBJECT (bin, "state change complete");
GST_STATE_BROADCAST (bin);
}
return;
had_error:
{
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
return;
}
was_busy:
{
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
/* if we were busy with a state change and we are requested to flag a
* pending async done, we do so here */
if (flag_pending)
bin->priv->pending_async_done = TRUE;
return;
}
nothing_pending:
{
GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin, "nothing pending");
return;
}
}
/* handle child messages:
*
* This method is called synchronously when a child posts a message on
* the internal bus.
*
* GST_MESSAGE_EOS: This message is only posted by sinks
* in the PLAYING state. If all sinks posted the EOS message, post
* one upwards.
*
* GST_MESSAGE_STATE_DIRTY: Deprecated
*
* GST_MESSAGE_SEGMENT_START: just collect, never forward upwards. If an
* element posts segment_start twice, only the last message is kept.
*
* GST_MESSAGE_SEGMENT_DONE: replace SEGMENT_START message from same poster
* with the segment_done message. If there are no more segment_start
* messages, post segment_done message upwards.
*
* GST_MESSAGE_DURATION: remove all previously cached duration messages.
* Whenever someone performs a duration query on the bin, we store the
* result so we can answer it quicker the next time. Any element that
* changes its duration marks our cached values invalid.
* This message is also posted upwards. This is currently disabled
* because too many elements don't post DURATION messages when the
* duration changes.
*
* GST_MESSAGE_CLOCK_LOST: This message is posted by an element when it
* can no longer provide a clock. The default bin behaviour is to
* check if the lost clock was the one provided by the bin. If so and
* we are currently in the PLAYING state, we forward the message to
* our parent.
* This message is also generated when we remove a clock provider from
* a bin. If this message is received by the application, it should
* PAUSE the pipeline and set it back to PLAYING to force a new clock
* and a new base_time distribution.
*
* GST_MESSAGE_CLOCK_PROVIDE: This message is generated when an element
* can provide a clock. This mostly happens when we add a new clock
* provider to the bin. The default behaviour of the bin is to mark the
* currently selected clock as dirty, which will perform a clock
* recalculation the next time we are asked to provide a clock.
* This message is never sent to the application but is forwarded to
* the parent.
*
* GST_MESSAGE_ASYNC_START: Create an internal ELEMENT message that stores
* the state of the element and the fact that the element will need a
* new base_time. This message is not forwarded to the application.
*
* GST_MESSAGE_ASYNC_DONE: Find the internal ELEMENT message we kept for the
* element when it posted ASYNC_START. If all elements are done, post a
* ASYNC_DONE message to the parent.
*
* OTHER: post upwards.
*/
static void
gst_bin_handle_message_func (GstBin * bin, GstMessage * message)
{
GstObject *src;
GstMessageType type;
GstMessage *tmessage;
guint32 seqnum;
src = GST_MESSAGE_SRC (message);
type = GST_MESSAGE_TYPE (message);
GST_DEBUG_OBJECT (bin, "[msg %p] handling child %s message of type %s",
message, src ? GST_ELEMENT_NAME (src) : "(NULL)",
GST_MESSAGE_TYPE_NAME (message));
switch (type) {
case GST_MESSAGE_EOS:
{
gboolean eos;
/* collect all eos messages from the children */
GST_OBJECT_LOCK (bin);
bin_replace_message (bin, message, GST_MESSAGE_EOS);
eos = is_eos (bin);
GST_OBJECT_UNLOCK (bin);
/* if we are completely EOS, we forward an EOS message */
if (eos) {
seqnum = gst_message_get_seqnum (message);
tmessage = gst_message_new_eos (GST_OBJECT_CAST (bin));
gst_message_set_seqnum (tmessage, seqnum);
GST_DEBUG_OBJECT (bin,
"all sinks posted EOS, posting seqnum #%" G_GUINT32_FORMAT, seqnum);
gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
}
break;
}
case GST_MESSAGE_STATE_DIRTY:
{
GST_WARNING_OBJECT (bin, "received deprecated STATE_DIRTY message");
/* free message */
gst_message_unref (message);
break;
}
case GST_MESSAGE_SEGMENT_START:{
gboolean post = FALSE;
GstFormat format;
gint64 position;
gst_message_parse_segment_start (message, &format, &position);
seqnum = gst_message_get_seqnum (message);
GST_OBJECT_LOCK (bin);
/* if this is the first segment-start, post to parent but not to the
* application */
if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START) &&
(GST_OBJECT_PARENT (bin) != NULL)) {
post = TRUE;
}
/* replace any previous segment_start message from this source
* with the new segment start message */
bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
GST_OBJECT_UNLOCK (bin);
if (post) {
tmessage = gst_message_new_segment_start (GST_OBJECT_CAST (bin),
format, position);
gst_message_set_seqnum (tmessage, seqnum);
/* post segment start with initial format and position. */
GST_DEBUG_OBJECT (bin, "posting SEGMENT_START (%u) bus message: %p",
seqnum, message);
gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
}
break;
}
case GST_MESSAGE_SEGMENT_DONE:
{
gboolean post = FALSE;
GstFormat format;
gint64 position;
gst_message_parse_segment_done (message, &format, &position);
seqnum = gst_message_get_seqnum (message);
GST_OBJECT_LOCK (bin);
bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
/* if there are no more segment_start messages, everybody posted
* a segment_done and we can post one on the bus. */
/* we don't care who still has a pending segment start */
if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START)) {
/* nothing found */
post = TRUE;
/* remove all old segment_done messages */
bin_remove_messages (bin, NULL, GST_MESSAGE_SEGMENT_DONE);
}
GST_OBJECT_UNLOCK (bin);
if (post) {
tmessage = gst_message_new_segment_done (GST_OBJECT_CAST (bin),
format, position);
gst_message_set_seqnum (tmessage, seqnum);
/* post segment done with latest format and position. */
GST_DEBUG_OBJECT (bin, "posting SEGMENT_DONE (%u) bus message: %p",
seqnum, message);
gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
}
break;
}
case GST_MESSAGE_DURATION:
{
/* remove all cached duration messages, next time somebody asks
* for duration, we will recalculate. */
GST_OBJECT_LOCK (bin);
bin_remove_messages (bin, NULL, GST_MESSAGE_DURATION);
GST_OBJECT_UNLOCK (bin);
goto forward;
}
case GST_MESSAGE_CLOCK_LOST:
{
GstClock **provided_clock_p;
GstElement **clock_provider_p;
gboolean playing, provided, forward;
GstClock *clock;
gst_message_parse_clock_lost (message, &clock);
GST_OBJECT_LOCK (bin);
bin->clock_dirty = TRUE;
/* if we lost the clock that we provided, post to parent but
* only if we are PLAYING. */
provided = (clock == bin->provided_clock);
playing = (GST_STATE (bin) == GST_STATE_PLAYING);
forward = playing & provided;
if (provided) {
GST_DEBUG_OBJECT (bin,
"Lost clock %" GST_PTR_FORMAT " provided by %" GST_PTR_FORMAT,
bin->provided_clock, bin->clock_provider);
provided_clock_p = &bin->provided_clock;
clock_provider_p = &bin->clock_provider;
gst_object_replace ((GstObject **) provided_clock_p, NULL);
gst_object_replace ((GstObject **) clock_provider_p, NULL);
}
GST_DEBUG_OBJECT (bin, "provided %d, playing %d, forward %d",
provided, playing, forward);
GST_OBJECT_UNLOCK (bin);
if (forward)
goto forward;
/* free message */
gst_message_unref (message);
break;
}
case GST_MESSAGE_CLOCK_PROVIDE:
{
gboolean forward;
GST_OBJECT_LOCK (bin);
bin->clock_dirty = TRUE;
/* a new clock is available, post to parent but not
* to the application */
forward = GST_OBJECT_PARENT (bin) != NULL;
GST_OBJECT_UNLOCK (bin);
if (forward)
goto forward;
/* free message */
gst_message_unref (message);
break;
}
case GST_MESSAGE_ASYNC_START:
{
gboolean new_base_time;
GstState target;
GST_DEBUG_OBJECT (bin, "ASYNC_START message %p, %s", message,
src ? GST_OBJECT_NAME (src) : "(NULL)");
gst_message_parse_async_start (message, &new_base_time);
GST_OBJECT_LOCK (bin);
/* we ignore the message if we are going to <= READY */
target = GST_STATE_TARGET (bin);
if (target <= GST_STATE_READY)
goto ignore_start_message;
/* takes ownership of the message */
bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
bin_handle_async_start (bin, new_base_time);
GST_OBJECT_UNLOCK (bin);
break;
ignore_start_message:
{
GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
gst_element_state_get_name (target));
GST_OBJECT_UNLOCK (bin);
gst_message_unref (message);
break;
}
}
case GST_MESSAGE_ASYNC_DONE:
{
GstState target;
GST_DEBUG_OBJECT (bin, "ASYNC_DONE message %p, %s", message,
src ? GST_OBJECT_NAME (src) : "(NULL)");
GST_OBJECT_LOCK (bin);
target = GST_STATE_TARGET (bin);
/* ignore messages if we are shutting down */
if (target <= GST_STATE_READY)
goto ignore_done_message;
bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
/* if there are no more ASYNC_START messages, everybody posted
* a ASYNC_DONE and we can post one on the bus. When checking, we
* don't care who still has a pending ASYNC_START */
if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
/* nothing found, remove all old ASYNC_DONE messages */
bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
GST_DEBUG_OBJECT (bin, "async elements commited");
/* when we get an async done message when a state change was busy, we
* need to set the pending_done flag so that at the end of the state
* change we can see if we need to verify pending async elements, hence
* the TRUE argument here. */
bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, TRUE);
} else {
GST_DEBUG_OBJECT (bin, "there are more async elements pending");
}
GST_OBJECT_UNLOCK (bin);
break;
ignore_done_message:
{
GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
gst_element_state_get_name (target));
GST_OBJECT_UNLOCK (bin);
gst_message_unref (message);
break;
}
}
case GST_MESSAGE_STRUCTURE_CHANGE:
{
gboolean busy;
gst_message_parse_structure_change (message, NULL, NULL, &busy);
GST_OBJECT_LOCK (bin);
if (busy) {
/* while the pad is busy, avoid following it when doing state changes.
* Don't update the cookie yet, we will do that after the structure
* change finished and we are ready to inspect the new updated
* structure. */
bin_replace_message (bin, message, GST_MESSAGE_STRUCTURE_CHANGE);
message = NULL;
} else {
/* a pad link/unlink ended, signal the state change iterator that we
* need to resync by updating the structure_cookie. */
bin_remove_messages (bin, GST_MESSAGE_SRC (message),
GST_MESSAGE_STRUCTURE_CHANGE);
bin->priv->structure_cookie++;
}
GST_OBJECT_UNLOCK (bin);
if (message)
gst_message_unref (message);
break;
}
default:
goto forward;
}
return;
forward:
{
/* Send all other messages upward */
GST_DEBUG_OBJECT (bin, "posting message upward");
gst_element_post_message (GST_ELEMENT_CAST (bin), message);
return;
}
}
/* generic struct passed to all query fold methods */
typedef struct
{
GstQuery *query;
gint64 min;
gint64 max;
gboolean live;
} QueryFold;
typedef void (*QueryInitFunction) (GstBin * bin, QueryFold * fold);
typedef void (*QueryDoneFunction) (GstBin * bin, QueryFold * fold);
/* for duration/position we collect all durations/positions and take
* the MAX of all valid results */
static void
bin_query_min_max_init (GstBin * bin, QueryFold * fold)
{
fold->min = 0;
fold->max = -1;
fold->live = FALSE;
}
static gboolean
bin_query_duration_fold (GstElement * item, GValue * ret, QueryFold * fold)
{
if (gst_element_query (item, fold->query)) {
gint64 duration;
g_value_set_boolean (ret, TRUE);
gst_query_parse_duration (fold->query, NULL, &duration);
GST_DEBUG_OBJECT (item, "got duration %" G_GINT64_FORMAT, duration);
if (duration > fold->max)
fold->max = duration;
}
gst_object_unref (item);
return TRUE;
}
static void
bin_query_duration_done (GstBin * bin, QueryFold * fold)
{
GstFormat format;
gst_query_parse_duration (fold->query, &format, NULL);
/* store max in query result */
gst_query_set_duration (fold->query, format, fold->max);
GST_DEBUG_OBJECT (bin, "max duration %" G_GINT64_FORMAT, fold->max);
#ifdef DURATION_CACHING
/* and cache now */
GST_OBJECT_LOCK (bin);
bin->messages = g_list_prepend (bin->messages,
gst_message_new_duration (GST_OBJECT_CAST (bin), format, fold->max));
GST_OBJECT_UNLOCK (bin);
#endif
}
static gboolean
bin_query_position_fold (GstElement * item, GValue * ret, QueryFold * fold)
{
if (gst_element_query (item, fold->query)) {
gint64 position;
g_value_set_boolean (ret, TRUE);
gst_query_parse_position (fold->query, NULL, &position);
GST_DEBUG_OBJECT (item, "got position %" G_GINT64_FORMAT, position);
if (position > fold->max)
fold->max = position;
}
gst_object_unref (item);
return TRUE;
}
static void
bin_query_position_done (GstBin * bin, QueryFold * fold)
{
GstFormat format;
gst_query_parse_position (fold->query, &format, NULL);
/* store max in query result */
gst_query_set_position (fold->query, format, fold->max);
GST_DEBUG_OBJECT (bin, "max position %" G_GINT64_FORMAT, fold->max);
}
static gboolean
bin_query_latency_fold (GstElement * item, GValue * ret, QueryFold * fold)
{
if (gst_element_query (item, fold->query)) {
GstClockTime min, max;
gboolean live;
gst_query_parse_latency (fold->query, &live, &min, &max);
GST_DEBUG_OBJECT (item,
"got latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
", live %d", GST_TIME_ARGS (min), GST_TIME_ARGS (max), live);
/* for the combined latency we collect the MAX of all min latencies and
* the MIN of all max latencies */
if (live) {
if (min > fold->min)
fold->min = min;
if (fold->max == -1)
fold->max = max;
else if (max < fold->max)
fold->max = max;
if (fold->live == FALSE)
fold->live = live;
}
} else {
g_value_set_boolean (ret, FALSE);
GST_DEBUG_OBJECT (item, "failed query");
}
gst_object_unref (item);
return TRUE;
}
static void
bin_query_latency_done (GstBin * bin, QueryFold * fold)
{
/* store max in query result */
gst_query_set_latency (fold->query, fold->live, fold->min, fold->max);
GST_DEBUG_OBJECT (bin,
"latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
", live %d", GST_TIME_ARGS (fold->min), GST_TIME_ARGS (fold->max),
fold->live);
}
/* generic fold, return first valid result */
static gboolean
bin_query_generic_fold (GstElement * item, GValue * ret, QueryFold * fold)
{
gboolean res;
if ((res = gst_element_query (item, fold->query))) {
g_value_set_boolean (ret, TRUE);
GST_DEBUG_OBJECT (item, "answered query %p", fold->query);
}
gst_object_unref (item);
/* and stop as soon as we have a valid result */
return !res;
}
static gboolean
gst_bin_query (GstElement * element, GstQuery * query)
{
GstBin *bin = GST_BIN (element);
GstIterator *iter;
gboolean res = FALSE;
GstIteratorFoldFunction fold_func;
QueryInitFunction fold_init = NULL;
QueryDoneFunction fold_done = NULL;
QueryFold fold_data;
GValue ret = { 0 };
switch (GST_QUERY_TYPE (query)) {
case GST_QUERY_DURATION:
{
#ifdef DURATION_CACHING
GList *cached;
GstFormat qformat;
gst_query_parse_duration (query, &qformat, NULL);
/* find cached duration query */
GST_OBJECT_LOCK (bin);
for (cached = bin->messages; cached; cached = g_list_next (cached)) {
GstMessage *message = (GstMessage *) cached->data;
if (GST_MESSAGE_TYPE (message) == GST_MESSAGE_DURATION &&
GST_MESSAGE_SRC (message) == GST_OBJECT_CAST (bin)) {
GstFormat format;
gint64 duration;
gst_message_parse_duration (message, &format, &duration);
/* if cached same format, copy duration in query result */
if (format == qformat) {
GST_DEBUG_OBJECT (bin, "return cached duration %" G_GINT64_FORMAT,
duration);
GST_OBJECT_UNLOCK (bin);
gst_query_set_duration (query, qformat, duration);
res = TRUE;
goto exit;
}
}
}
GST_OBJECT_UNLOCK (bin);
#endif
/* no cached value found, iterate and collect durations */
fold_func = (GstIteratorFoldFunction) bin_query_duration_fold;
fold_init = bin_query_min_max_init;
fold_done = bin_query_duration_done;
break;
}
case GST_QUERY_POSITION:
{
fold_func = (GstIteratorFoldFunction) bin_query_position_fold;
fold_init = bin_query_min_max_init;
fold_done = bin_query_position_done;
break;
}
case GST_QUERY_LATENCY:
{
fold_func = (GstIteratorFoldFunction) bin_query_latency_fold;
fold_init = bin_query_min_max_init;
fold_done = bin_query_latency_done;
res = TRUE;
break;
}
default:
fold_func = (GstIteratorFoldFunction) bin_query_generic_fold;
break;
}
fold_data.query = query;
/* set the result of the query to FALSE initially */
g_value_init (&ret, G_TYPE_BOOLEAN);
g_value_set_boolean (&ret, res);
iter = gst_bin_iterate_sinks (bin);
GST_DEBUG_OBJECT (bin, "Sending query %p (type %s) to sink children",
query, GST_QUERY_TYPE_NAME (query));
if (fold_init)
fold_init (bin, &fold_data);
while (TRUE) {
GstIteratorResult ires;
ires = gst_iterator_fold (iter, fold_func, &ret, &fold_data);
switch (ires) {
case GST_ITERATOR_RESYNC:
gst_iterator_resync (iter);
if (fold_init)
fold_init (bin, &fold_data);
g_value_set_boolean (&ret, res);
break;
case GST_ITERATOR_OK:
case GST_ITERATOR_DONE:
res = g_value_get_boolean (&ret);
if (fold_done != NULL && res)
fold_done (bin, &fold_data);
goto done;
default:
res = FALSE;
goto done;
}
}
done:
gst_iterator_free (iter);
#ifdef DURATION_CACHING
exit:
#endif
GST_DEBUG_OBJECT (bin, "query %p result %d", query, res);
return res;
}
static gint
compare_name (GstElement * element, const gchar * name)
{
gint eq;
GST_OBJECT_LOCK (element);
eq = strcmp (GST_ELEMENT_NAME (element), name);
GST_OBJECT_UNLOCK (element);
if (eq != 0) {
gst_object_unref (element);
}
return eq;
}
/**
* gst_bin_get_by_name:
* @bin: a #GstBin
* @name: the element name to search for
*
* Gets the element with the given name from a bin. This
* function recurses into child bins.
*
* Returns NULL if no element with the given name is found in the bin.
*
* MT safe. Caller owns returned reference.
*
* Returns: the #GstElement with the given name, or NULL
*/
GstElement *
gst_bin_get_by_name (GstBin * bin, const gchar * name)
{
GstIterator *children;
GstIterator *result;
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
GST_CAT_INFO (GST_CAT_PARENTAGE, "[%s]: looking up child element %s",
GST_ELEMENT_NAME (bin), name);
children = gst_bin_iterate_recurse (bin);
result = gst_iterator_find_custom (children,
(GCompareFunc) compare_name, (gpointer) name);
gst_iterator_free (children);
return GST_ELEMENT_CAST (result);
}
/**
* gst_bin_get_by_name_recurse_up:
* @bin: a #GstBin
* @name: the element name to search for
*
* Gets the element with the given name from this bin. If the
* element is not found, a recursion is performed on the parent bin.
*
* Returns NULL if:
* - no element with the given name is found in the bin
*
* MT safe. Caller owns returned reference.
*
* Returns: the #GstElement with the given name, or NULL
*/
GstElement *
gst_bin_get_by_name_recurse_up (GstBin * bin, const gchar * name)
{
GstElement *result;
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
g_return_val_if_fail (name != NULL, NULL);
result = gst_bin_get_by_name (bin, name);
if (!result) {
GstObject *parent;
parent = gst_object_get_parent (GST_OBJECT_CAST (bin));
if (parent) {
if (GST_IS_BIN (parent)) {
result = gst_bin_get_by_name_recurse_up (GST_BIN_CAST (parent), name);
}
gst_object_unref (parent);
}
}
return result;
}
static gint
compare_interface (GstElement * element, gpointer interface)
{
GType interface_type = (GType) interface;
gint ret;
if (G_TYPE_CHECK_INSTANCE_TYPE (element, interface_type)) {
ret = 0;
} else {
/* we did not find the element, need to release the ref
* added by the iterator */
gst_object_unref (element);
ret = 1;
}
return ret;
}
/**
* gst_bin_get_by_interface:
* @bin: a #GstBin
* @iface: the #GType of an interface
*
* Looks for an element inside the bin that implements the given
* interface. If such an element is found, it returns the element.
* You can cast this element to the given interface afterwards. If you want
* all elements that implement the interface, use
* gst_bin_iterate_all_by_interface(). This function recurses into child bins.
*
* MT safe. Caller owns returned reference.
*
* Returns: A #GstElement inside the bin implementing the interface
*/
GstElement *
gst_bin_get_by_interface (GstBin * bin, GType iface)
{
GstIterator *children;
gpointer result;
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
children = gst_bin_iterate_recurse (bin);
result = gst_iterator_find_custom (children, (GCompareFunc) compare_interface,
(gpointer) iface);
gst_iterator_free (children);
return GST_ELEMENT_CAST (result);
}
/**
* gst_bin_iterate_all_by_interface:
* @bin: a #GstBin
* @iface: the #GType of an interface
*
* Looks for all elements inside the bin that implements the given
* interface. You can safely cast all returned elements to the given interface.
* The function recurses inside child bins. The iterator will yield a series
* of #GstElement that should be unreffed after use.
*
* Each element yielded by the iterator will have its refcount increased, so
* unref after use.
*
* MT safe. Caller owns returned value.
*
* Returns: a #GstIterator of #GstElement for all elements in the bin
* implementing the given interface, or NULL
*/
GstIterator *
gst_bin_iterate_all_by_interface (GstBin * bin, GType iface)
{
GstIterator *children;
GstIterator *result;
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
children = gst_bin_iterate_recurse (bin);
result = gst_iterator_filter (children, (GCompareFunc) compare_interface,
(gpointer) iface);
return result;
}
#ifndef GST_DISABLE_LOADSAVE
static xmlNodePtr
gst_bin_save_thyself (GstObject * object, xmlNodePtr parent)
{
GstBin *bin = GST_BIN (object);
xmlNodePtr childlist, elementnode;
GList *children;
GstElement *child;
if (GST_OBJECT_CLASS (parent_class)->save_thyself)
GST_OBJECT_CLASS (parent_class)->save_thyself (GST_OBJECT (bin), parent);
childlist = xmlNewChild (parent, NULL, (xmlChar *) "children", NULL);
GST_CAT_INFO (GST_CAT_XML, "[%s]: saving %d children",
GST_ELEMENT_NAME (bin), bin->numchildren);
children = bin->children;
while (children) {
child = GST_ELEMENT (children->data);
elementnode = xmlNewChild (childlist, NULL, (xmlChar *) "element", NULL);
gst_object_save_thyself (GST_OBJECT (child), elementnode);
children = g_list_next (children);
}
return childlist;
}
static void
gst_bin_restore_thyself (GstObject * object, xmlNodePtr self)
{
GstBin *bin = GST_BIN (object);
xmlNodePtr field = self->xmlChildrenNode;
xmlNodePtr childlist;
while (field) {
if (!strcmp ((char *) field->name, "children")) {
GST_CAT_INFO (GST_CAT_XML, "[%s]: loading children",
GST_ELEMENT_NAME (object));
childlist = field->xmlChildrenNode;
while (childlist) {
if (!strcmp ((char *) childlist->name, "element")) {
/* gst_xml_make_element will gst_bin_add() the element to ourself */
gst_xml_make_element (childlist, GST_OBJECT (bin));
}
childlist = childlist->next;
}
}
field = field->next;
}
if (GST_OBJECT_CLASS (parent_class)->restore_thyself)
(GST_OBJECT_CLASS (parent_class)->restore_thyself) (object, self);
}
#endif /* GST_DISABLE_LOADSAVE */