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gstreamer/gst/gstbin.c
Wim Taymans 2d3e9f6438 gst/base/gstbasesink.c: Only error is an error. 
Original commit message from CVS:
* gst/base/gstbasesink.c: (gst_base_sink_change_state):
Only error is an error.

* gst/gstbin.c: (gst_bin_change_state):
Better debugging.

* gst/gstpad.c: (gst_pad_alloc_buffer), (gst_pad_chain):
Also call pad_block in pad alloc.

* gst/gstutils.c: (gst_flow_get_name):
Better debugging.
2005-09-30 08:00:12 +00:00

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/* GStreamer
*
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2004 Wim Taymans <wim@fluendo.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 for elements that contain other elements
*
* GstBin is the simplest of the container elements, allowing elements to
* become children of itself. Pads from the child elements can be ghosted to
* the bin, making the bin itself look transparently like any other element,
* allowing for deep nesting of predefined sub-pipelines.
*
* A new GstBin is created with gst_bin_new(). Use a #GstPipeline instead if you
* want to create a toplevel bin because a normal bin doesn't have a bus or
* handle clock distribution of its own.
*
* After the bin has been created you will typically add elements to it with
* gst_bin_add(). You can remove elements with gst_bin_remove().
*
* An element can be retrieved from a bin with gst_bin_get_by_name(), using the
* elements name. gst_bin_get_by_name_recurse_up() is mainly used for internal
* purposes and will query the parent bins when the element is not found in the
* current bin.
*
* An iterator of elements in a bin can be retrieved with
* gst_bin_iterate_elements(). Various other iterators exist to retrieve the
* elements in a bin.
*
* The "element_added" signal is fired whenever a new element is added to the
* bin. Likewise the "element_removed" signal is fired whenever an element is
* removed from the bin.
*
* gst_bin_unref() is used to destroy the bin.
*/
#include "gst_private.h"
#include "gstevent.h"
#include "gstbin.h"
#include "gstmarshal.h"
#include "gstxml.h"
#include "gstinfo.h"
#include "gsterror.h"
#include "gstindex.h"
#include "gstindexfactory.h"
#include "gstutils.h"
#include "gstchildproxy.h"
GST_DEBUG_CATEGORY_STATIC (bin_debug);
#define GST_CAT_DEFAULT bin_debug
#define GST_LOG_BIN_CONTENTS(bin, text) GST_LOG_OBJECT ((bin), \
text ": %d elements: %u PLAYING, %u PAUSED, %u READY, %u NULL, own state: %s", \
(bin)->numchildren, (guint) (bin)->child_states[3], \
(guint) (bin)->child_states[2], (bin)->child_states[1], \
(bin)->child_states[0], gst_element_state_get_name (GST_STATE (bin)))
static GstElementDetails gst_bin_details = GST_ELEMENT_DETAILS ("Generic bin",
"Generic/Bin",
"Simple container object",
"Erik Walthinsen <omega@cse.ogi.edu>," "Wim Taymans <wim@fluendo.com>");
GType _gst_bin_type = 0;
static void gst_bin_dispose (GObject * object);
static GstStateChangeReturn gst_bin_change_state (GstElement * element,
GstStateChange transition);
static GstStateChangeReturn gst_bin_get_state (GstElement * element,
GstState * state, GstState * pending, GTimeVal * timeout);
static gboolean gst_bin_add_func (GstBin * bin, GstElement * element);
static gboolean gst_bin_remove_func (GstBin * bin, GstElement * element);
#ifndef GST_DISABLE_INDEX
static void gst_bin_set_index_func (GstElement * element, GstIndex * index);
#endif
static GstClock *gst_bin_provide_clock_func (GstElement * element);
static void gst_bin_set_clock_func (GstElement * element, GstClock * clock);
static gboolean gst_bin_send_event (GstElement * element, GstEvent * event);
static GstBusSyncReply bin_bus_handler (GstBus * bus,
GstMessage * message, GstBin * bin);
static gboolean gst_bin_query (GstElement * element, GstQuery * query);
#ifndef GST_DISABLE_LOADSAVE
static xmlNodePtr gst_bin_save_thyself (GstObject * object, xmlNodePtr parent);
static void gst_bin_restore_thyself (GstObject * object, xmlNodePtr self);
#endif
static gint bin_element_is_sink (GstElement * child, GstBin * bin);
/* Bin signals and args */
enum
{
ELEMENT_ADDED,
ELEMENT_REMOVED,
LAST_SIGNAL
};
enum
{
ARG_0
/* FILL ME */
};
static void gst_bin_base_init (gpointer g_class);
static void gst_bin_class_init (GstBinClass * klass);
static void gst_bin_init (GstBin * bin);
static void gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data);
static GstElementClass *parent_class = NULL;
static guint gst_bin_signals[LAST_SIGNAL] = { 0 };
/**
* gst_bin_get_type:
*
* Returns: the type of #GstBin
*/
GType
gst_bin_get_type (void)
{
if (!_gst_bin_type) {
static const GTypeInfo bin_info = {
sizeof (GstBinClass),
gst_bin_base_init,
NULL,
(GClassInitFunc) gst_bin_class_init,
NULL,
NULL,
sizeof (GstBin),
0,
(GInstanceInitFunc) gst_bin_init,
NULL
};
static const GInterfaceInfo child_proxy_info = {
gst_bin_child_proxy_init,
NULL,
NULL
};
_gst_bin_type =
g_type_register_static (GST_TYPE_ELEMENT, "GstBin", &bin_info, 0);
g_type_add_interface_static (_gst_bin_type, GST_TYPE_CHILD_PROXY,
&child_proxy_info);
GST_DEBUG_CATEGORY_INIT (bin_debug, "bin", GST_DEBUG_BOLD,
"debugging info for the 'bin' container element");
}
return _gst_bin_type;
}
static void
gst_bin_base_init (gpointer g_class)
{
GstElementClass *gstelement_class = GST_ELEMENT_CLASS (g_class);
gst_element_class_set_details (gstelement_class, &gst_bin_details);
}
static GstObject *
gst_bin_child_proxy_get_child_by_index (GstChildProxy * child_proxy,
guint index)
{
return g_list_nth_data (GST_BIN (child_proxy)->children, index);
}
guint
gst_bin_child_proxy_get_children_count (GstChildProxy * child_proxy)
{
return GST_BIN (child_proxy)->numchildren;
}
static void
gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data)
{
GstChildProxyInterface *iface = g_iface;
iface->get_children_count = gst_bin_child_proxy_get_children_count;
iface->get_child_by_index = gst_bin_child_proxy_get_child_by_index;
}
static void
gst_bin_class_init (GstBinClass * klass)
{
GObjectClass *gobject_class;
GstObjectClass *gstobject_class;
GstElementClass *gstelement_class;
gobject_class = (GObjectClass *) klass;
gstobject_class = (GstObjectClass *) klass;
gstelement_class = (GstElementClass *) klass;
parent_class = g_type_class_peek_parent (klass);
/**
* GstBin::element-added:
* @bin: the object which emitted the signal.
* @element: the element that was added to the bin
*
* Will be emitted if a new element was removed/added to this bin.
*/
gst_bin_signals[ELEMENT_ADDED] =
g_signal_new ("element-added", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_added), NULL,
NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);
/**
* GstBin::element-removed:
* @bin: the object which emitted the signal.
* @element: the element that was removed from the bin
*
* Will be emitted if an element was removed from this bin.
*/
gst_bin_signals[ELEMENT_REMOVED] =
g_signal_new ("element-removed", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_removed), NULL,
NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);
gobject_class->dispose = GST_DEBUG_FUNCPTR (gst_bin_dispose);
#ifndef GST_DISABLE_LOADSAVE
gstobject_class->save_thyself = GST_DEBUG_FUNCPTR (gst_bin_save_thyself);
gstobject_class->restore_thyself =
GST_DEBUG_FUNCPTR (gst_bin_restore_thyself);
#endif
gstelement_class->change_state = GST_DEBUG_FUNCPTR (gst_bin_change_state);
gstelement_class->get_state = GST_DEBUG_FUNCPTR (gst_bin_get_state);
#ifndef GST_DISABLE_INDEX
gstelement_class->set_index = GST_DEBUG_FUNCPTR (gst_bin_set_index_func);
#endif
gstelement_class->provide_clock =
GST_DEBUG_FUNCPTR (gst_bin_provide_clock_func);
gstelement_class->set_clock = GST_DEBUG_FUNCPTR (gst_bin_set_clock_func);
gstelement_class->send_event = GST_DEBUG_FUNCPTR (gst_bin_send_event);
gstelement_class->query = GST_DEBUG_FUNCPTR (gst_bin_query);
klass->add_element = GST_DEBUG_FUNCPTR (gst_bin_add_func);
klass->remove_element = GST_DEBUG_FUNCPTR (gst_bin_remove_func);
}
static void
gst_bin_init (GstBin * bin)
{
GstBus *bus;
bin->numchildren = 0;
bin->children = NULL;
bin->children_cookie = 0;
bin->eosed = NULL;
/* Set up a bus for listening to child elements */
bus = g_object_new (gst_bus_get_type (), NULL);
bin->child_bus = bus;
gst_bus_set_sync_handler (bus, (GstBusSyncHandler) bin_bus_handler, bin);
}
/**
* gst_bin_new:
* @name: name of new bin
*
* Create a new bin with given name.
*
* Returns: new bin
*/
GstElement *
gst_bin_new (const gchar * name)
{
return gst_element_factory_make ("bin", name);
}
/* set the index on all elements in this bin
*
* MT safe
*/
#ifndef GST_DISABLE_INDEX
static void
gst_bin_set_index_func (GstElement * element, GstIndex * index)
{
GstBin *bin;
GList *children;
bin = GST_BIN (element);
GST_LOCK (bin);
for (children = bin->children; children; children = g_list_next (children)) {
GstElement *child = GST_ELEMENT (children->data);
gst_element_set_index (child, index);
}
GST_UNLOCK (bin);
}
#endif
/* set the clock on all elements in this bin
*
* MT safe
*/
static void
gst_bin_set_clock_func (GstElement * element, GstClock * clock)
{
GList *children;
GstBin *bin;
bin = GST_BIN (element);
GST_LOCK (bin);
for (children = bin->children; children; children = g_list_next (children)) {
GstElement *child = GST_ELEMENT (children->data);
gst_element_set_clock (child, clock);
}
GST_UNLOCK (bin);
}
/* get the clock for this bin by asking all of the children in this bin
*
* The ref of the returned clock in increased so unref after usage.
*
* MT safe
*
* FIXME, clock selection is not correct here.
*/
static GstClock *
gst_bin_provide_clock_func (GstElement * element)
{
GstClock *result = NULL;
GstBin *bin;
GList *children;
bin = GST_BIN (element);
GST_LOCK (bin);
for (children = bin->children; children; children = g_list_next (children)) {
GstElement *child = GST_ELEMENT (children->data);
result = gst_element_provide_clock (child);
if (result)
break;
}
GST_UNLOCK (bin);
return result;
}
static gboolean
is_eos (GstBin * bin)
{
GstIterator *sinks;
gboolean result = TRUE;
gboolean done = FALSE;
sinks = gst_bin_iterate_sinks (bin);
while (!done) {
gpointer data;
switch (gst_iterator_next (sinks, &data)) {
case GST_ITERATOR_OK:
{
GstElement *element = GST_ELEMENT (data);
GList *eosed;
gchar *name;
name = gst_element_get_name (element);
eosed = g_list_find (bin->eosed, element);
if (!eosed) {
GST_DEBUG ("element %s did not post EOS yet", name);
result = FALSE;
done = TRUE;
} else {
GST_DEBUG ("element %s posted EOS", name);
}
g_free (name);
gst_object_unref (element);
break;
}
case GST_ITERATOR_RESYNC:
result = TRUE;
gst_iterator_resync (sinks);
break;
case GST_ITERATOR_DONE:
done = TRUE;
break;
default:
g_assert_not_reached ();
break;
}
}
gst_iterator_free (sinks);
return result;
}
static void
unlink_pads (GstPad * pad)
{
GstPad *peer;
if ((peer = gst_pad_get_peer (pad))) {
if (gst_pad_get_direction (pad) == GST_PAD_SRC)
gst_pad_unlink (pad, peer);
else
gst_pad_unlink (peer, pad);
gst_object_unref (peer);
}
gst_object_unref (pad);
}
/* add an element to this bin
*
* MT safe
*/
static gboolean
gst_bin_add_func (GstBin * bin, GstElement * element)
{
gchar *elem_name;
GstIterator *it;
/* we obviously can't add ourself to ourself */
if (G_UNLIKELY (GST_ELEMENT_CAST (element) == GST_ELEMENT_CAST (bin)))
goto adding_itself;
/* get the element name to make sure it is unique in this bin. */
GST_LOCK (element);
elem_name = g_strdup (GST_ELEMENT_NAME (element));
GST_UNLOCK (element);
GST_LOCK (bin);
/* then check to see if the element's name is already taken in the bin,
* we can safely take the lock here. This check is probably bogus because
* you can safely change the element name after this check and before setting
* the object parent. The window is very small though... */
if (G_UNLIKELY (!gst_object_check_uniqueness (bin->children, elem_name)))
goto duplicate_name;
/* set the element's parent and add the element to the bin's list of children */
if (G_UNLIKELY (!gst_object_set_parent (GST_OBJECT_CAST (element),
GST_OBJECT_CAST (bin))))
goto had_parent;
/* if we add a sink we become a sink */
if (GST_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK)) {
GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was sink",
elem_name);
GST_FLAG_SET (bin, GST_ELEMENT_IS_SINK);
}
bin->children = g_list_prepend (bin->children, element);
bin->numchildren++;
bin->children_cookie++;
/* distribute the bus */
gst_element_set_bus (element, bin->child_bus);
/* propagate the current base time and clock */
gst_element_set_base_time (element, GST_ELEMENT (bin)->base_time);
gst_element_set_clock (element, GST_ELEMENT_CLOCK (bin));
GST_UNLOCK (bin);
/* unlink all linked pads */
it = gst_element_iterate_pads (element);
gst_iterator_foreach (it, (GFunc) unlink_pads, element);
gst_iterator_free (it);
GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "added element \"%s\"",
elem_name);
g_free (elem_name);
g_signal_emit (G_OBJECT (bin), gst_bin_signals[ELEMENT_ADDED], 0, element);
return TRUE;
/* ERROR handling here */
adding_itself:
{
GST_LOCK (bin);
g_warning ("Cannot add bin %s to itself", GST_ELEMENT_NAME (bin));
GST_UNLOCK (bin);
return FALSE;
}
duplicate_name:
{
g_warning ("Name %s is not unique in bin %s, not adding",
elem_name, GST_ELEMENT_NAME (bin));
GST_UNLOCK (bin);
g_free (elem_name);
return FALSE;
}
had_parent:
{
g_warning ("Element %s already has parent", elem_name);
GST_UNLOCK (bin);
g_free (elem_name);
return FALSE;
}
}
/**
* gst_bin_add:
* @bin: #GstBin to add element to
* @element: #GstElement to add to bin
*
* Adds the given element to the bin. Sets the element's parent, and thus
* takes ownership of the element. An element can only be added to one bin.
*
* If the element's pads are linked to other pads, the pads will be unlinked
* before the element is added to the bin.
*
* MT safe.
*
* Returns: TRUE if the element could be added, FALSE on wrong parameters or
* the bin does not want to accept the element.
*/
gboolean
gst_bin_add (GstBin * bin, GstElement * element)
{
GstBinClass *bclass;
gboolean result;
g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
bclass = GST_BIN_GET_CLASS (bin);
if (G_UNLIKELY (bclass->add_element == NULL))
goto no_function;
GST_CAT_DEBUG (GST_CAT_PARENTAGE, "adding element %s to bin %s",
GST_ELEMENT_NAME (element), GST_ELEMENT_NAME (bin));
result = bclass->add_element (bin, element);
return result;
/* ERROR handling */
no_function:
{
g_warning ("adding elements to bin %s is not supported",
GST_ELEMENT_NAME (bin));
return FALSE;
}
}
/* remove an element from the bin
*
* MT safe
*/
static gboolean
gst_bin_remove_func (GstBin * bin, GstElement * element)
{
gchar *elem_name;
GstIterator *it;
GST_LOCK (element);
/* Check if the element is already being removed and immediately
* return */
if (G_UNLIKELY (GST_FLAG_IS_SET (element, GST_ELEMENT_UNPARENTING)))
goto already_removing;
GST_FLAG_SET (element, GST_ELEMENT_UNPARENTING);
/* grab element name so we can print it */
elem_name = g_strdup (GST_ELEMENT_NAME (element));
GST_UNLOCK (element);
/* unlink all linked pads */
it = gst_element_iterate_pads (element);
gst_iterator_foreach (it, (GFunc) unlink_pads, element);
gst_iterator_free (it);
GST_LOCK (bin);
/* the element must be in the bin's list of children */
if (G_UNLIKELY (g_list_find (bin->children, element) == NULL))
goto not_in_bin;
/* now remove the element from the list of elements */
bin->children = g_list_remove (bin->children, element);
bin->numchildren--;
bin->children_cookie++;
/* check if we removed a sink */
if (GST_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK)) {
GList *other_sink;
/* check if we removed the last sink */
other_sink = g_list_find_custom (bin->children,
bin, (GCompareFunc) bin_element_is_sink);
if (!other_sink) {
/* yups, we're not a sink anymore */
GST_FLAG_UNSET (bin, GST_ELEMENT_IS_SINK);
}
}
GST_UNLOCK (bin);
GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "removed child \"%s\"",
elem_name);
g_free (elem_name);
gst_element_set_bus (element, NULL);
/* unlock any waiters for the state change. It is possible that
* we are waiting for an ASYNC state change on this element. The
* element cannot be added to another bin yet as it is not yet
* unparented. */
GST_STATE_LOCK (element);
GST_STATE_BROADCAST (element);
GST_STATE_UNLOCK (element);
/* we ref here because after the _unparent() the element can be disposed
* and we still need it to reset the UNPARENTING flag and fire a signal. */
gst_object_ref (element);
gst_object_unparent (GST_OBJECT_CAST (element));
GST_LOCK (element);
GST_FLAG_UNSET (element, GST_ELEMENT_UNPARENTING);
GST_UNLOCK (element);
g_signal_emit (G_OBJECT (bin), gst_bin_signals[ELEMENT_REMOVED], 0, element);
/* element is really out of our control now */
gst_object_unref (element);
return TRUE;
/* ERROR handling */
not_in_bin:
{
g_warning ("Element %s is not in bin %s", elem_name,
GST_ELEMENT_NAME (bin));
GST_UNLOCK (bin);
g_free (elem_name);
return FALSE;
}
already_removing:
{
GST_UNLOCK (element);
return FALSE;
}
}
/**
* gst_bin_remove:
* @bin: #GstBin to remove element from
* @element: #GstElement to remove
*
* Remove the element from its associated bin, unparenting it as well.
* Unparenting the element means that the element will be dereferenced,
* so if the bin holds the only reference to the element, the element
* will be freed in the process of removing it from the bin. If you
* want the element to still exist after removing, you need to call
* gst_object_ref() before removing it from the bin.
*
* If the element's pads are linked to other pads, the pads will be unlinked
* before the element is removed from the bin.
*
* MT safe.
*
* Returns: TRUE if the element could be removed, FALSE on wrong parameters or
* the bin does not want to remove the element.
*/
gboolean
gst_bin_remove (GstBin * bin, GstElement * element)
{
GstBinClass *bclass;
gboolean result;
g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
bclass = GST_BIN_GET_CLASS (bin);
if (G_UNLIKELY (bclass->remove_element == NULL))
goto no_function;
GST_CAT_DEBUG (GST_CAT_PARENTAGE, "removing element %s from bin %s",
GST_ELEMENT_NAME (element), GST_ELEMENT_NAME (bin));
result = bclass->remove_element (bin, element);
return result;
/* ERROR handling */
no_function:
{
g_warning ("removing elements from bin %s is not supported",
GST_ELEMENT_NAME (bin));
return FALSE;
}
}
static GstIteratorItem
iterate_child (GstIterator * it, GstElement * child)
{
gst_object_ref (child);
return GST_ITERATOR_ITEM_PASS;
}
/**
* gst_bin_iterate_elements:
* @bin: #Gstbin to iterate the elements of
*
* Get an iterator for the elements in this bin.
* Each element will have its refcount increased, so unref
* after use.
*
* MT safe.
*
* Returns: a #GstIterator of #GstElements. gst_iterator_free after
* use. returns NULL when passing bad parameters.
*/
GstIterator *
gst_bin_iterate_elements (GstBin * bin)
{
GstIterator *result;
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
GST_LOCK (bin);
/* add ref because the iterator refs the bin. When the iterator
* is freed it will unref the bin again using the provided dispose
* function. */
gst_object_ref (bin);
result = gst_iterator_new_list (GST_GET_LOCK (bin),
&bin->children_cookie,
&bin->children,
bin,
(GstIteratorItemFunction) iterate_child,
(GstIteratorDisposeFunction) gst_object_unref);
GST_UNLOCK (bin);
return result;
}
static GstIteratorItem
iterate_child_recurse (GstIterator * it, GstElement * child)
{
gst_object_ref (child);
if (GST_IS_BIN (child)) {
GstIterator *other = gst_bin_iterate_recurse (GST_BIN (child));
gst_iterator_push (it, other);
}
return GST_ITERATOR_ITEM_PASS;
}
/**
* gst_bin_iterate_recurse:
* @bin: #Gstbin to iterate the elements of
*
* Get an iterator for the elements in this bin.
* Each element will have its refcount increased, so unref
* after use. This iterator recurses into GstBin children.
*
* MT safe.
*
* Returns: a #GstIterator of #GstElements. gst_iterator_free after
* use. returns NULL when passing bad parameters.
*/
GstIterator *
gst_bin_iterate_recurse (GstBin * bin)
{
GstIterator *result;
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
GST_LOCK (bin);
/* add ref because the iterator refs the bin. When the iterator
* is freed it will unref the bin again using the provided dispose
* function. */
gst_object_ref (bin);
result = gst_iterator_new_list (GST_GET_LOCK (bin),
&bin->children_cookie,
&bin->children,
bin,
(GstIteratorItemFunction) iterate_child_recurse,
(GstIteratorDisposeFunction) gst_object_unref);
GST_UNLOCK (bin);
return result;
}
/* returns 0 when TRUE because this is a GCompareFunc */
/* MT safe */
static gint
bin_element_is_sink (GstElement * child, GstBin * bin)
{
gboolean is_sink;
/* we lock the child here for the remainder of the function to
* get its name safely. */
GST_LOCK (child);
is_sink = GST_FLAG_IS_SET (child, GST_ELEMENT_IS_SINK);
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
"child %s %s sink", GST_OBJECT_NAME (child), is_sink ? "is" : "is not");
GST_UNLOCK (child);
return is_sink ? 0 : 1;
}
static gint
sink_iterator_filter (GstElement * child, GstBin * bin)
{
if (bin_element_is_sink (child, bin) == 0) {
/* returns 0 because this is a GCompareFunc */
return 0;
} else {
/* child carries a ref from gst_bin_iterate_elements -- drop if not passing
through */
gst_object_unref ((GstObject *) child);
return 1;
}
}
/**
* gst_bin_iterate_sinks:
* @bin: #Gstbin to iterate on
*
* Get an iterator for the sink elements in this bin.
* Each element will have its refcount increased, so unref
* after use.
*
* The sink elements are those without any linked srcpads.
*
* MT safe.
*
* Returns: a #GstIterator of #GstElements. gst_iterator_free after use.
*/
GstIterator *
gst_bin_iterate_sinks (GstBin * bin)
{
GstIterator *children;
GstIterator *result;
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
children = gst_bin_iterate_elements (bin);
result = gst_iterator_filter (children,
(GCompareFunc) sink_iterator_filter, bin);
return result;
}
/* 2 phases:
* 1) check state of all children with 0 timeout to find ERROR and
* NO_PREROLL elements. return if found.
* 2) perform full blocking wait with requested timeout.
*
* 2) cannot be performed when 1) returns results as the sinks might
* not be able to complete the state change making 2) block forever.
*
* MT safe
*/
static GstStateChangeReturn
gst_bin_get_state (GstElement * element, GstState * state,
GstState * pending, GTimeVal * timeout)
{
GstBin *bin = GST_BIN (element);
GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS;
GList *children;
guint32 children_cookie;
gboolean have_no_preroll;
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "getting state");
/* lock bin, no element can be added or removed between going into
* the quick scan and the blocking wait. */
GST_LOCK (bin);
restart:
have_no_preroll = FALSE;
/* first we need to poll with a non zero timeout to make sure we don't block
* on the sinks when we have NO_PREROLL elements. This is why we do
* a quick check if there are still NO_PREROLL elements. We also
* catch the error elements this way. */
{
GTimeVal tv;
gboolean have_async = FALSE;
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "checking for NO_PREROLL");
/* use 0 timeout so we don't block on the sinks */
GST_TIME_TO_TIMEVAL (0, tv);
children = bin->children;
children_cookie = bin->children_cookie;
while (children) {
GstElement *child = GST_ELEMENT_CAST (children->data);
gst_object_ref (child);
/* now we release the lock to enter a non blocking wait. We
* release the lock anyway since we can. */
GST_UNLOCK (bin);
ret = gst_element_get_state (child, NULL, NULL, &tv);
gst_object_unref (child);
/* now grab the lock to iterate to the next child */
GST_LOCK (bin);
if (G_UNLIKELY (children_cookie != bin->children_cookie)) {
/* child added/removed during state change, restart. We need
* to restart with the quick check as a no-preroll element could
* have been added here and we don't want to block on sinks then.*/
goto restart;
}
switch (ret) {
/* report FAILURE immediatly */
case GST_STATE_CHANGE_FAILURE:
goto done;
case GST_STATE_CHANGE_NO_PREROLL:
/* we have to continue scanning as there might be
* ERRORS too */
have_no_preroll = TRUE;
break;
case GST_STATE_CHANGE_ASYNC:
have_async = TRUE;
break;
default:
break;
}
children = g_list_next (children);
}
/* if we get here, we have no FAILURES, check for any NO_PREROLL
* elements then. */
if (have_no_preroll) {
ret = GST_STATE_CHANGE_NO_PREROLL;
goto done;
}
/* if we get here, no NO_PREROLL elements are in the pipeline */
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "no NO_PREROLL elements");
/* if no ASYNC elements exist we don't even have to poll with a
* timeout again */
if (!have_async) {
ret = GST_STATE_CHANGE_SUCCESS;
goto done;
}
}
/* next we poll all children for their state to see if one of them
* is still busy with its state change. We did not release the bin lock
* yet so the elements are the same as the ones from the quick scan. */
children = bin->children;
children_cookie = bin->children_cookie;
while (children) {
GstElement *child = GST_ELEMENT_CAST (children->data);
gst_object_ref (child);
/* now we release the lock to enter the potentialy blocking wait */
GST_UNLOCK (bin);
/* ret is ASYNC if some child is still performing the state change
* ater the timeout. */
ret = gst_element_get_state (child, NULL, NULL, timeout);
gst_object_unref (child);
/* now grab the lock to iterate to the next child */
GST_LOCK (bin);
if (G_UNLIKELY (children_cookie != bin->children_cookie)) {
/* child added/removed during state change, restart. We need
* to restart with the quick check as a no-preroll element could
* have been added here and we don't want to block on sinks then.*/
goto restart;
}
switch (ret) {
case GST_STATE_CHANGE_SUCCESS:
break;
case GST_STATE_CHANGE_FAILURE:
case GST_STATE_CHANGE_NO_PREROLL:
/* report FAILURE and NO_PREROLL immediatly */
goto done;
case GST_STATE_CHANGE_ASYNC:
goto done;
default:
g_assert_not_reached ();
}
children = g_list_next (children);
}
/* if we got here, all elements can do preroll */
have_no_preroll = FALSE;
done:
GST_UNLOCK (bin);
/* now we can take the state lock, it is possible that new elements
* are added now and we still report the old state. No problem though as
* the return is still consistent, the effect is as if the element was
* added after this function completed. */
GST_STATE_LOCK (bin);
switch (ret) {
case GST_STATE_CHANGE_SUCCESS:
/* we can commit the state */
gst_element_commit_state (element);
break;
case GST_STATE_CHANGE_FAILURE:
/* some element failed, abort the state change */
gst_element_abort_state (element);
break;
default:
/* other cases are just passed along */
break;
}
/* and report the state if needed */
if (state)
*state = GST_STATE (element);
if (pending)
*pending = GST_STATE_PENDING (element);
GST_STATE_NO_PREROLL (element) = have_no_preroll;
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
"state current: %s, pending: %s, error: %d, no_preroll: %d, result: %d",
gst_element_state_get_name (GST_STATE (element)),
gst_element_state_get_name (GST_STATE_PENDING (element)),
GST_STATE_ERROR (element), GST_STATE_NO_PREROLL (element), ret);
GST_STATE_UNLOCK (bin);
return ret;
}
/***********************************************
* Topologically sorted iterator
* see http://en.wikipedia.org/wiki/Topological_sorting
*
* For each element in the graph, an entry is kept in a HashTable
* with its number of srcpad connections (degree).
* We then change state of all elements without dependencies
* (degree 0) and decrement the degree of all elements connected
* on the sinkpads. When an element reaches degree 0, its state is
* changed next.
* When all elements are handled the algorithm stops.
*/
typedef struct _GstBinSortIterator
{
GstIterator it;
GQueue *queue; /* elements queued for state change */
GstBin *bin; /* bin we iterate */
gint mode; /* adding or removing dependency */
GstElement *best; /* next element with least dependencies */
gint best_deg; /* best degree */
GHashTable *hash; /* has table with element dependencies */
} GstBinSortIterator;
/* we add and subtract 1 to make sure we don't confuse NULL and 0 */
#define HASH_SET_DEGREE(bit, elem, deg) \
g_hash_table_replace (bit->hash, elem, GINT_TO_POINTER(deg+1))
#define HASH_GET_DEGREE(bit, elem) \
(GPOINTER_TO_INT(g_hash_table_lookup (bit->hash, elem))-1)
/* add element to queue of next elements in the iterator.
* We push at the tail to give higher priority elements a
* chance first */
static void
add_to_queue (GstBinSortIterator * bit, GstElement * element)
{
GST_DEBUG ("%s add to queue", GST_ELEMENT_NAME (element));
gst_object_ref (element);
g_queue_push_tail (bit->queue, element);
HASH_SET_DEGREE (bit, element, -1);
}
/* clear the queue, unref all objects as we took a ref when
* we added them to the queue */
static void
clear_queue (GQueue * queue)
{
gpointer p;
while ((p = g_queue_pop_head (queue)))
gst_object_unref (p);
}
/* set all degrees to 0. Elements marked as a sink are
* added to the queue immediatly. */
static void
reset_degree (GstElement * element, GstBinSortIterator * bit)
{
/* sinks are added right away */
if (GST_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK)) {
add_to_queue (bit, element);
} else {
/* others are marked with 0 and handled when sinks are done */
HASH_SET_DEGREE (bit, element, 0);
}
}
/* adjust the degree of all elements connected to the given
* element. If an degree of an element drops to 0, it is
* added to the queue of elements to schedule next.
*
* We have to make sure not to cross the bin boundary this element
* belongs to.
*/
static void
update_degree (GstElement * element, GstBinSortIterator * bit)
{
gboolean linked = FALSE;
GST_LOCK (element);
/* don't touch degree is element has no sourcepads */
if (element->numsinkpads != 0) {
/* loop over all sinkpads, decrement degree for all connected
* elements in this bin */
GList *pads;
for (pads = element->sinkpads; pads; pads = g_list_next (pads)) {
GstPad *peer;
if ((peer = gst_pad_get_peer (GST_PAD_CAST (pads->data)))) {
GstElement *peer_element;
if ((peer_element = gst_pad_get_parent_element (peer))) {
GST_LOCK (peer_element);
if (GST_OBJECT_CAST (peer_element)->parent ==
GST_OBJECT_CAST (bit->bin)) {
gint old_deg, new_deg;
old_deg = HASH_GET_DEGREE (bit, peer_element);
new_deg = old_deg + bit->mode;
GST_DEBUG ("change element %s, degree %d->%d, linked to %s",
GST_ELEMENT_NAME (peer_element),
old_deg, new_deg, GST_ELEMENT_NAME (element));
/* update degree */
if (new_deg == 0) {
/* degree hit 0, add to queue */
add_to_queue (bit, peer_element);
} else {
HASH_SET_DEGREE (bit, peer_element, new_deg);
}
linked = TRUE;
}
GST_UNLOCK (peer_element);
gst_object_unref (peer_element);
}
gst_object_unref (peer);
}
}
}
if (!linked) {
GST_DEBUG ("element %s not linked to anything", GST_ELEMENT_NAME (element));
}
GST_UNLOCK (element);
}
/* find the next best element not handled yet. This is the one
* with the lowest non-negative degree */
static void
find_element (GstElement * element, GstBinSortIterator * bit)
{
gint degree;
/* element is already handled */
if ((degree = HASH_GET_DEGREE (bit, element)) < 0)
return;
/* first element or element with smaller degree */
if (bit->best == NULL || bit->best_deg > degree) {
bit->best = element;
bit->best_deg = degree;
}
}
/* get next element in iterator. the returned element has the
* refcount increased */
static GstIteratorResult
gst_bin_sort_iterator_next (GstBinSortIterator * bit, gpointer * result)
{
/* empty queue, we have to find a next best element */
if (g_queue_is_empty (bit->queue)) {
bit->best = NULL;
bit->best_deg = G_MAXINT;
g_list_foreach (bit->bin->children, (GFunc) find_element, bit);
if (bit->best) {
if (bit->best_deg != 0) {
/* we don't fail on this one yet */
g_warning ("loop detected in the graph !!");
}
/* best unhandled element, schedule as next element */
GST_DEBUG ("queue empty, next best: %s", GST_ELEMENT_NAME (bit->best));
gst_object_ref (bit->best);
HASH_SET_DEGREE (bit, bit->best, -1);
*result = bit->best;
} else {
GST_DEBUG ("queue empty, elements exhausted");
/* no more unhandled elements, we are done */
return GST_ITERATOR_DONE;
}
} else {
/* everything added to the queue got reffed */
*result = g_queue_pop_head (bit->queue);
}
GST_DEBUG ("queue head gives %s", GST_ELEMENT_NAME (*result));
/* update degrees of linked elements */
update_degree (GST_ELEMENT_CAST (*result), bit);
return GST_ITERATOR_OK;
}
/* clear queues, recalculate the degrees and restart. */
static void
gst_bin_sort_iterator_resync (GstBinSortIterator * bit)
{
clear_queue (bit->queue);
/* reset degrees */
g_list_foreach (bit->bin->children, (GFunc) reset_degree, bit);
/* calc degrees, incrementing */
bit->mode = 1;
g_list_foreach (bit->bin->children, (GFunc) update_degree, bit);
/* for the rest of the function we decrement the degrees */
bit->mode = -1;
}
/* clear queues, unref bin and free iterator. */
static void
gst_bin_sort_iterator_free (GstBinSortIterator * bit)
{
clear_queue (bit->queue);
g_queue_free (bit->queue);
g_hash_table_destroy (bit->hash);
gst_object_unref (bit->bin);
g_free (bit);
}
/**
* gst_bin_iterate_sorted:
* @bin: #Gstbin to iterate on
*
* Get an iterator for the elements in this bin in topologically
* sorted order. This means that the elements are returned from
* the most downstream elements (sinks) to the sources.
*
* This function is used internally to perform the state changes
* of the bin elements.
*
* Each element will have its refcount increased, so unref
* after use.
*
* MT safe.
*
* Returns: a #GstIterator of #GstElements. gst_iterator_free after use.
*/
GstIterator *
gst_bin_iterate_sorted (GstBin * bin)
{
GstBinSortIterator *result;
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
GST_LOCK (bin);
gst_object_ref (bin);
/* we don't need a NextFunction because we ref the items in the _next
* method already */
result = (GstBinSortIterator *)
gst_iterator_new (sizeof (GstBinSortIterator),
GST_GET_LOCK (bin),
&bin->children_cookie,
(GstIteratorNextFunction) gst_bin_sort_iterator_next,
(GstIteratorItemFunction) NULL,
(GstIteratorResyncFunction) gst_bin_sort_iterator_resync,
(GstIteratorFreeFunction) gst_bin_sort_iterator_free);
result->queue = g_queue_new ();
result->hash = g_hash_table_new (NULL, NULL);
result->bin = bin;
gst_bin_sort_iterator_resync (result);
GST_UNLOCK (bin);
return (GstIterator *) result;
}
static GstStateChangeReturn
gst_bin_element_set_state (GstBin * bin, GstElement * element, GstState pending)
{
GstStateChangeReturn ret;
gboolean locked;
/* peel off the locked flag */
GST_LOCK (element);
locked = GST_FLAG_IS_SET (element, GST_ELEMENT_LOCKED_STATE);
GST_UNLOCK (element);
/* skip locked elements */
if (G_UNLIKELY (locked)) {
ret = GST_STATE_CHANGE_SUCCESS;
goto done;
}
/* change state */
ret = gst_element_set_state (element, pending);
done:
return ret;
}
static GstStateChangeReturn
gst_bin_change_state (GstElement * element, GstStateChange transition)
{
GstBin *bin;
GstStateChangeReturn ret;
GstState old_state, pending;
gboolean have_async;
gboolean have_no_preroll;
GstClockTime base_time;
GstIterator *it;
gboolean done;
/* we don't need to take the STATE_LOCK, it is already taken */
old_state = GST_STATE (element);
pending = GST_STATE_PENDING (element);
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
"changing state of children from %s to %s",
gst_element_state_get_name (old_state),
gst_element_state_get_name (pending));
if (pending == GST_STATE_VOID_PENDING)
return GST_STATE_CHANGE_SUCCESS;
bin = GST_BIN_CAST (element);
/* Clear eosed element list on READY-> PAUSED */
if (transition == GST_STATE_CHANGE_READY_TO_PAUSED) {
g_list_free (bin->eosed);
bin->eosed = NULL;
}
/* iterate in state change order */
it = gst_bin_iterate_sorted (bin);
restart:
/* take base time */
base_time = element->base_time;
have_async = FALSE;
have_no_preroll = FALSE;
done = FALSE;
while (!done) {
gpointer data;
switch (gst_iterator_next (it, &data)) {
case GST_ITERATOR_OK:
{
GstElement *element;
element = GST_ELEMENT_CAST (data);
/* set base time on element */
gst_element_set_base_time (element, base_time);
/* set state now */
ret = gst_bin_element_set_state (bin, element, pending);
switch (ret) {
case GST_STATE_CHANGE_SUCCESS:
GST_CAT_DEBUG (GST_CAT_STATES,
"child '%s' changed state to %d(%s) successfully",
GST_ELEMENT_NAME (element), pending,
gst_element_state_get_name (pending));
break;
case GST_STATE_CHANGE_ASYNC:
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
"child '%s' is changing state asynchronously",
GST_ELEMENT_NAME (element));
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 (element),
pending, gst_element_state_get_name (pending));
gst_object_unref (element);
goto done;
case GST_STATE_CHANGE_NO_PREROLL:
GST_CAT_DEBUG (GST_CAT_STATES,
"child '%s' changed state to %d(%s) successfully without preroll",
GST_ELEMENT_NAME (element), pending,
gst_element_state_get_name (pending));
have_no_preroll = TRUE;
break;
default:
g_assert_not_reached ();
break;
}
gst_object_unref (element);
break;
}
case GST_ITERATOR_RESYNC:
GST_CAT_DEBUG (GST_CAT_STATES, "iterator doing resync");
gst_iterator_resync (it);
goto restart;
break;
default:
case GST_ITERATOR_DONE:
GST_CAT_DEBUG (GST_CAT_STATES, "iterator done");
done = TRUE;
break;
}
}
if (have_no_preroll) {
ret = GST_STATE_CHANGE_NO_PREROLL;
} else if (have_async) {
ret = GST_STATE_CHANGE_ASYNC;
} else {
ret = parent_class->change_state (element, transition);
}
done:
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
"done changing bin's state from %s to %s, now in %s, ret %d",
gst_element_state_get_name (old_state),
gst_element_state_get_name (pending),
gst_element_state_get_name (GST_STATE (element)), ret);
gst_iterator_free (it);
return ret;
}
static void
gst_bin_dispose (GObject * object)
{
GstBin *bin = GST_BIN (object);
GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object, "dispose");
g_list_free (bin->eosed);
bin->eosed = NULL;
gst_object_unref (bin->child_bus);
bin->child_bus = NULL;
while (bin->children) {
gst_bin_remove (bin, GST_ELEMENT (bin->children->data));
}
if (G_UNLIKELY (bin->children != NULL)) {
g_critical ("could not remove elements from bin %s",
GST_STR_NULL (GST_OBJECT_NAME (object)));
}
G_OBJECT_CLASS (parent_class)->dispose (object);
}
/*
* This function is a utility event handler for seek events.
* It will send the event to all sinks.
* Applications are free to override this behaviour and
* implement their own seek handler, but this will work for
* pretty much all cases in practice.
*/
static gboolean
gst_bin_send_event (GstElement * element, GstEvent * event)
{
GstBin *bin = GST_BIN (element);
GstIterator *iter;
gboolean res = TRUE;
gboolean done = FALSE;
iter = gst_bin_iterate_sinks (bin);
GST_DEBUG_OBJECT (bin, "Sending event to sink children");
while (!done) {
gpointer data;
switch (gst_iterator_next (iter, &data)) {
case GST_ITERATOR_OK:
{
GstElement *sink;
gst_event_ref (event);
sink = GST_ELEMENT_CAST (data);
res &= gst_element_send_event (sink, event);
gst_object_unref (sink);
break;
}
case GST_ITERATOR_RESYNC:
gst_iterator_resync (iter);
res = TRUE;
break;
default:
case GST_ITERATOR_DONE:
done = TRUE;
break;
}
}
gst_iterator_free (iter);
gst_event_unref (event);
return res;
}
static GstBusSyncReply
bin_bus_handler (GstBus * bus, GstMessage * message, GstBin * bin)
{
GST_DEBUG_OBJECT (bin, "[msg %p] handling child message of type %s",
message, gst_message_type_get_name (GST_MESSAGE_TYPE (message)));
switch (GST_MESSAGE_TYPE (message)) {
case GST_MESSAGE_EOS:{
GstObject *src = GST_MESSAGE_SRC (message);
if (src) {
gchar *name;
name = gst_object_get_name (src);
GST_DEBUG_OBJECT (bin, "got EOS message from %s", name);
g_free (name);
/* collect all eos messages from the children */
GST_LOCK (bin->child_bus);
bin->eosed = g_list_prepend (bin->eosed, src);
GST_UNLOCK (bin->child_bus);
/* if we are completely EOS, we forward an EOS message */
if (is_eos (bin)) {
GST_DEBUG_OBJECT (bin, "all sinks posted EOS");
gst_element_post_message (GST_ELEMENT (bin),
gst_message_new_eos (GST_OBJECT (bin)));
}
} else {
GST_DEBUG_OBJECT (bin, "got EOS message from (NULL), not processing");
}
/* we drop all EOS messages */
gst_message_unref (message);
break;
}
default:
/* Send all other messages upward */
GST_DEBUG_OBJECT (bin, "posting message upward");
gst_element_post_message (GST_ELEMENT (bin), message);
break;
}
return GST_BUS_DROP;
}
static gboolean
gst_bin_query (GstElement * element, GstQuery * query)
{
GstBin *bin = GST_BIN (element);
GstIterator *iter;
gboolean res = FALSE, done = FALSE;
iter = gst_bin_iterate_sinks (bin);
GST_DEBUG_OBJECT (bin, "Sending event to sink children");
while (!(res || done)) {
gpointer data;
switch (gst_iterator_next (iter, &data)) {
case GST_ITERATOR_OK:
{
GstElement *sink;
sink = GST_ELEMENT_CAST (data);
res = gst_element_query (sink, query);
gst_object_unref (sink);
break;
}
case GST_ITERATOR_RESYNC:
gst_iterator_resync (iter);
break;
default:
case GST_ITERATOR_DONE:
done = TRUE;
break;
}
}
gst_iterator_free (iter);
return res;
}
static gint
compare_name (GstElement * element, const gchar * name)
{
gint eq;
GST_LOCK (element);
eq = strcmp (GST_ELEMENT_NAME (element), name);
GST_UNLOCK (element);
if (eq != 0) {
gst_object_unref (element);
}
return eq;
}
/**
* gst_bin_get_by_name:
* @bin: #Gstbin to search
* @name: the element name to search for
*
* Get the element with the given name from this bin. This
* function recurses into subbins.
*
* MT safe.
*
* Returns: the element with the given name. Returns NULL if the
* element is not found or when bad parameters were given. Unref after
* use.
*/
GstElement *
gst_bin_get_by_name (GstBin * bin, const gchar * name)
{
GstIterator *children;
GstIterator *result;
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
GST_CAT_INFO (GST_CAT_PARENTAGE, "[%s]: looking up child element %s",
GST_ELEMENT_NAME (bin), name);
children = gst_bin_iterate_recurse (bin);
result = gst_iterator_find_custom (children,
(GCompareFunc) compare_name, (gpointer) name);
gst_iterator_free (children);
return GST_ELEMENT_CAST (result);
}
/**
* gst_bin_get_by_name_recurse_up:
* @bin: #Gstbin to search
* @name: the element name to search for
*
* MT safe.
*
* Get the element with the given name from this bin. If the
* element is not found, a recursion is performed on the parent bin.
*
* Returns: the element with the given name or NULL when the element
* was not found or bad parameters were given. Unref after use.
*/
GstElement *
gst_bin_get_by_name_recurse_up (GstBin * bin, const gchar * name)
{
GstElement *result;
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
g_return_val_if_fail (name != NULL, NULL);
result = gst_bin_get_by_name (bin, name);
if (!result) {
GstObject *parent;
parent = gst_object_get_parent (GST_OBJECT_CAST (bin));
if (parent) {
if (GST_IS_BIN (parent)) {
result = gst_bin_get_by_name_recurse_up (GST_BIN_CAST (parent), name);
}
gst_object_unref (parent);
}
}
return result;
}
static gint
compare_interface (GstElement * element, gpointer interface)
{
gint ret;
if (G_TYPE_CHECK_INSTANCE_TYPE (element, GPOINTER_TO_INT (interface))) {
ret = 0;
} else {
/* we did not find the element, need to release the ref
* added by the iterator */
gst_object_unref (element);
ret = 1;
}
return ret;
}
/**
* gst_bin_get_by_interface:
* @bin: bin to find element in
* @interface: interface to be implemented by interface
*
* Looks for the first element inside the bin that implements the given
* interface. If such an element is found, it returns the element. You can
* cast this element to the given interface afterwards.
* If you want all elements that implement the interface, use
* gst_bin_iterate_all_by_interface(). The function recurses inside bins.
*
* MT safe.
*
* Returns: An #GstElement inside the bin implementing the interface.
* Unref after use.
*/
GstElement *
gst_bin_get_by_interface (GstBin * bin, GType interface)
{
GstIterator *children;
GstIterator *result;
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
children = gst_bin_iterate_recurse (bin);
result = gst_iterator_find_custom (children, (GCompareFunc) compare_interface,
GINT_TO_POINTER (interface));
gst_iterator_free (children);
return GST_ELEMENT_CAST (result);
}
/**
* gst_bin_iterate_all_by_interface:
* @bin: bin to find elements in
* @interface: interface to be implemented by interface
*
* Looks for all elements inside the bin that implements the given
* interface. You can safely cast all returned elements to the given interface.
* The function recurses bins inside bins. The iterator will return a series
* of #GstElement that should be unreffed after use.
*
* MT safe.
*
* Returns: A #GstIterator for the elements inside the bin implementing the
* given interface.
*/
GstIterator *
gst_bin_iterate_all_by_interface (GstBin * bin, GType interface)
{
GstIterator *children;
GstIterator *result;
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
children = gst_bin_iterate_recurse (bin);
result = gst_iterator_filter (children, (GCompareFunc) compare_interface,
GINT_TO_POINTER (interface));
return result;
}
#ifndef GST_DISABLE_LOADSAVE
static xmlNodePtr
gst_bin_save_thyself (GstObject * object, xmlNodePtr parent)
{
GstBin *bin = GST_BIN (object);
xmlNodePtr childlist, elementnode;
GList *children;
GstElement *child;
if (GST_OBJECT_CLASS (parent_class)->save_thyself)
GST_OBJECT_CLASS (parent_class)->save_thyself (GST_OBJECT (bin), parent);
childlist = xmlNewChild (parent, NULL, (xmlChar *) "children", NULL);
GST_CAT_INFO (GST_CAT_XML, "[%s]: saving %d children",
GST_ELEMENT_NAME (bin), bin->numchildren);
children = bin->children;
while (children) {
child = GST_ELEMENT (children->data);
elementnode = xmlNewChild (childlist, NULL, (xmlChar *) "element", NULL);
gst_object_save_thyself (GST_OBJECT (child), elementnode);
children = g_list_next (children);
}
return childlist;
}
static void
gst_bin_restore_thyself (GstObject * object, xmlNodePtr self)
{
GstBin *bin = GST_BIN (object);
xmlNodePtr field = self->xmlChildrenNode;
xmlNodePtr childlist;
while (field) {
if (!strcmp ((char *) field->name, "children")) {
GST_CAT_INFO (GST_CAT_XML, "[%s]: loading children",
GST_ELEMENT_NAME (object));
childlist = field->xmlChildrenNode;
while (childlist) {
if (!strcmp ((char *) childlist->name, "element")) {
GstElement *element =
gst_xml_make_element (childlist, GST_OBJECT (bin));
/* it had to be parented to find the pads, now we ref and unparent so
* we can add it to the bin */
gst_object_ref (element);
gst_object_unparent (GST_OBJECT (element));
gst_bin_add (bin, element);
}
childlist = childlist->next;
}
}
field = field->next;
}
if (GST_OBJECT_CLASS (parent_class)->restore_thyself)
(GST_OBJECT_CLASS (parent_class)->restore_thyself) (object, self);
}
#endif /* GST_DISABLE_LOADSAVE */
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