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gstreamer/gst/gstelement.c
Wim Taymans d31c5ea1f6 gst/gstcaps.c: Make _static_caps_get() refcounting sane. 
Original commit message from CVS:
* gst/gstcaps.c: (gst_static_caps_get), (gst_caps_to_string):
Make _static_caps_get() refcounting sane.

* gst/gstelement.c: (gst_element_set_state):
Add g_return_val_if_fail() to protect against segfaults.
2005-08-22 14:35:42 +00:00

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/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2004 Wim Taymans <wim@fluendo.com>
*
* gstelement.c: The base element, all elements derive from this
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include "gst_private.h"
#include <glib.h>
#include <stdarg.h>
#include <gobject/gvaluecollector.h>
#include "gstelement.h"
#include "gstbus.h"
#include "gstmarshal.h"
#include "gsterror.h"
#include "gstevent.h"
#include "gstutils.h"
#include "gstinfo.h"
#include "gst-i18n-lib.h"
/* Element signals and args */
enum
{
STATE_CHANGE,
NEW_PAD,
PAD_REMOVED,
NO_MORE_PADS,
/* add more above */
LAST_SIGNAL
};
enum
{
ARG_0
/* FILL ME */
};
extern void __gst_element_details_clear (GstElementDetails * dp);
extern void __gst_element_details_copy (GstElementDetails * dest,
const GstElementDetails * src);
static void gst_element_class_init (GstElementClass * klass);
static void gst_element_init (GstElement * element);
static void gst_element_base_class_init (gpointer g_class);
static void gst_element_base_class_finalize (gpointer g_class);
static void gst_element_dispose (GObject * object);
static void gst_element_finalize (GObject * object);
static GstElementStateReturn gst_element_change_state (GstElement * element);
static GstElementStateReturn gst_element_get_state_func (GstElement * element,
GstElementState * state, GstElementState * pending, GTimeVal * timeout);
static void gst_element_set_bus_func (GstElement * element, GstBus * bus);
#ifndef GST_DISABLE_LOADSAVE
static xmlNodePtr gst_element_save_thyself (GstObject * object,
xmlNodePtr parent);
static void gst_element_restore_thyself (GstObject * parent, xmlNodePtr self);
#endif
GType _gst_element_type = 0;
static GstObjectClass *parent_class = NULL;
static guint gst_element_signals[LAST_SIGNAL] = { 0 };
GType
gst_element_get_type (void)
{
if (!_gst_element_type) {
static const GTypeInfo element_info = {
sizeof (GstElementClass),
gst_element_base_class_init,
gst_element_base_class_finalize,
(GClassInitFunc) gst_element_class_init,
NULL,
NULL,
sizeof (GstElement),
0,
(GInstanceInitFunc) gst_element_init,
NULL
};
_gst_element_type = g_type_register_static (GST_TYPE_OBJECT, "GstElement",
&element_info, G_TYPE_FLAG_ABSTRACT);
}
return _gst_element_type;
}
static void
gst_element_class_init (GstElementClass * klass)
{
GObjectClass *gobject_class;
GstObjectClass *gstobject_class;
gobject_class = (GObjectClass *) klass;
gstobject_class = (GstObjectClass *) klass;
parent_class = g_type_class_ref (GST_TYPE_OBJECT);
/**
* GstElement::state-changed:
* @gstelement: the object which received the signal
* @old_state: the GST_STATE_XXX before the change
* @new_state: the GST_STATE_XXX after the change
*
* the #GstElementState of the element has been changed
*/
gst_element_signals[STATE_CHANGE] =
g_signal_new ("state-changed", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstElementClass, state_changed), NULL,
NULL, gst_marshal_VOID__INT_INT, G_TYPE_NONE, 2, G_TYPE_INT, G_TYPE_INT);
/**
* GstElement::pad-added:
* @gstelement: the object which received the signal
* @new_pad: the pad that has been added
*
* a new #GstPad has been added to the element
*/
gst_element_signals[NEW_PAD] =
g_signal_new ("pad-added", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (GstElementClass, pad_added), NULL, NULL,
gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, G_TYPE_OBJECT);
/**
* GstElement::pad-removed:
* @gstelement: the object which received the signal
* @old_pad: the pad that has been removed
*
* a #GstPad has been removed from the element
*/
gst_element_signals[PAD_REMOVED] =
g_signal_new ("pad-removed", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (GstElementClass, pad_removed), NULL, NULL,
gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, G_TYPE_OBJECT);
/**
* GstElement::no-more-pads:
* @gstelement: the object which received the signal
*
* This signals that the element will not generate more dynamic pads.
*/
gst_element_signals[NO_MORE_PADS] =
g_signal_new ("no-more-pads", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstElementClass, no_more_pads), NULL,
NULL, gst_marshal_VOID__VOID, G_TYPE_NONE, 0);
gobject_class->dispose = GST_DEBUG_FUNCPTR (gst_element_dispose);
gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_element_finalize);
#ifndef GST_DISABLE_LOADSAVE
gstobject_class->save_thyself = GST_DEBUG_FUNCPTR (gst_element_save_thyself);
gstobject_class->restore_thyself =
GST_DEBUG_FUNCPTR (gst_element_restore_thyself);
#endif
klass->change_state = GST_DEBUG_FUNCPTR (gst_element_change_state);
klass->get_state = GST_DEBUG_FUNCPTR (gst_element_get_state_func);
klass->set_bus = GST_DEBUG_FUNCPTR (gst_element_set_bus_func);
klass->numpadtemplates = 0;
klass->elementfactory = NULL;
}
static void
gst_element_base_class_init (gpointer g_class)
{
GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
memset (&element_class->details, 0, sizeof (GstElementDetails));
element_class->padtemplates = NULL;
}
static void
gst_element_base_class_finalize (gpointer g_class)
{
GstElementClass *klass = GST_ELEMENT_CLASS (g_class);
g_list_foreach (klass->padtemplates, (GFunc) gst_object_unref, NULL);
g_list_free (klass->padtemplates);
__gst_element_details_clear (&klass->details);
}
static void
gst_element_init (GstElement * element)
{
element->current_state = GST_STATE_NULL;
element->pending_state = GST_STATE_VOID_PENDING;
element->state_lock = g_mutex_new ();
element->state_cond = g_cond_new ();
}
/**
* gst_element_default_error:
* @object: a #GObject that signalled the error.
* @orig: the #GstObject that initiated the error.
* @error: the GError.
* @debug: an additional debug information string, or NULL.
*
* A default error signal callback to attach to an element.
* The user data passed to the g_signal_connect is ignored.
*
* The default handler will simply print the error string using g_print.
*
* MT safe.
*/
void
gst_element_default_error (GObject * object, GstObject * source, GError * error,
gchar * debug)
{
gchar *name = gst_object_get_path_string (source);
g_print (_("ERROR: from element %s: %s\n"), name, error->message);
if (debug)
g_print (_("Additional debug info:\n%s\n"), debug);
g_free (name);
}
/**
* gst_element_release_request_pad:
* @element: a #GstElement to release the request pad of.
* @pad: the #GstPad to release.
*
* Makes the element free the previously requested pad as obtained
* with gst_element_get_request_pad().
*
* MT safe.
*/
void
gst_element_release_request_pad (GstElement * element, GstPad * pad)
{
GstElementClass *oclass;
g_return_if_fail (GST_IS_ELEMENT (element));
g_return_if_fail (GST_IS_PAD (pad));
oclass = GST_ELEMENT_GET_CLASS (element);
if (oclass->release_pad)
(oclass->release_pad) (element, pad);
else
gst_element_remove_pad (element, pad);
}
/**
* gst_element_requires_clock:
* @element: a #GstElement to query
*
* Query if the element requires a clock.
*
* Returns: TRUE if the element requires a clock
*
* MT safe.
*/
gboolean
gst_element_requires_clock (GstElement * element)
{
gboolean result = FALSE;
g_return_val_if_fail (GST_IS_ELEMENT (element), result);
result = (GST_ELEMENT_GET_CLASS (element)->set_clock != NULL);
return result;
}
/**
* gst_element_provides_clock:
* @element: a #GstElement to query
*
* Query if the element provides a clock.
*
* Returns: TRUE if the element provides a clock
*
* MT safe.
*/
gboolean
gst_element_provides_clock (GstElement * element)
{
gboolean result = FALSE;
g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
result = (GST_ELEMENT_GET_CLASS (element)->get_clock != NULL);
return result;
}
/**
* gst_element_set_clock:
* @element: a #GstElement to set the clock for.
* @clock: the #GstClock to set for the element.
*
* Sets the clock for the element. This function increases the
* refcount on the clock. Any previously set clock on the object
* is unreffed.
*
* MT safe.
*/
void
gst_element_set_clock (GstElement * element, GstClock * clock)
{
GstElementClass *oclass;
g_return_if_fail (GST_IS_ELEMENT (element));
oclass = GST_ELEMENT_GET_CLASS (element);
if (oclass->set_clock)
oclass->set_clock (element, clock);
GST_LOCK (element);
gst_object_replace ((GstObject **) & element->clock, (GstObject *) clock);
GST_UNLOCK (element);
}
/**
* gst_element_get_clock:
* @element: a #GstElement to get the clock of.
*
* Gets the clock of the element. If the element provides a clock,
* this function will return this clock. For elements that do not
* provide a clock, this function returns NULL.
*
* Returns: the #GstClock of the element. unref after usage.
*
* MT safe.
*/
GstClock *
gst_element_get_clock (GstElement * element)
{
GstElementClass *oclass;
g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
oclass = GST_ELEMENT_GET_CLASS (element);
if (oclass->get_clock)
return oclass->get_clock (element);
return NULL;
}
/**
* gst_element_set_base_time:
* @element: a #GstElement.
* @time: the base time to set.
*
* Set the base time of an element. See @gst_element_get_base_time().
*
* MT safe.
*/
void
gst_element_set_base_time (GstElement * element, GstClockTime time)
{
g_return_if_fail (GST_IS_ELEMENT (element));
GST_LOCK (element);
element->base_time = time;
GST_UNLOCK (element);
}
/**
* gst_element_get_base_time:
* @element: a #GstElement.
*
* Returns the base time of the element. The base time is the
* absolute time of the clock when this element was last put to
* PLAYING. Substracting the base time from the clock time gives
* the stream time of the element.
*
* Returns: the base time of the element.
*
* MT safe.
*/
GstClockTime
gst_element_get_base_time (GstElement * element)
{
GstClockTime result;
g_return_val_if_fail (GST_IS_ELEMENT (element), GST_CLOCK_TIME_NONE);
GST_LOCK (element);
result = element->base_time;
GST_UNLOCK (element);
return result;
}
#ifndef GST_DISABLE_INDEX
/**
* gst_element_is_indexable:
* @element: a #GstElement.
*
* Queries if the element can be indexed.
*
* Returns: TRUE if the element can be indexed.
*
* MT safe.
*/
gboolean
gst_element_is_indexable (GstElement * element)
{
gboolean result = FALSE;
g_return_val_if_fail (GST_IS_ELEMENT (element), result);
result = (GST_ELEMENT_GET_CLASS (element)->set_index != NULL);
return result;
}
/**
* gst_element_set_index:
* @element: a #GstElement.
* @index: a #GstIndex.
*
* Set the specified GstIndex on the element.
*
* MT safe.
*/
void
gst_element_set_index (GstElement * element, GstIndex * index)
{
GstElementClass *oclass;
g_return_if_fail (GST_IS_ELEMENT (element));
g_return_if_fail (GST_IS_INDEX (index));
oclass = GST_ELEMENT_GET_CLASS (element);
if (oclass->set_index)
oclass->set_index (element, index);
}
/**
* gst_element_get_index:
* @element: a #GstElement.
*
* Gets the index from the element.
*
* Returns: a #GstIndex or NULL when no index was set on the
* element. unref after usage.
*
* MT safe.
*/
GstIndex *
gst_element_get_index (GstElement * element)
{
GstElementClass *oclass;
g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
oclass = GST_ELEMENT_GET_CLASS (element);
if (oclass->get_index)
return oclass->get_index (element);
return NULL;
}
#endif
/**
* gst_element_add_pad:
* @element: a #GstElement to add the pad to.
* @pad: the #GstPad to add to the element.
*
* Adds a pad (link point) to @element. @pad's parent will be set to @element;
* see gst_object_set_parent() for refcounting information.
*
* Pads are not automatically activated so elements should perform the needed
* steps to activate the pad.
*
* The pad and the element should be unlocked when calling this function.
*
* Returns: TRUE if the pad could be added. This function can fail when
* passing bad arguments or when a pad with the same name already existed.
*
* MT safe.
*/
gboolean
gst_element_add_pad (GstElement * element, GstPad * pad)
{
gchar *pad_name;
g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
/* locking pad to look at the name */
GST_LOCK (pad);
pad_name = g_strdup (GST_PAD_NAME (pad));
GST_CAT_INFO_OBJECT (GST_CAT_ELEMENT_PADS, element, "adding pad '%s'",
GST_STR_NULL (pad_name));
GST_UNLOCK (pad);
/* then check to see if there's already a pad by that name here */
GST_LOCK (element);
if (G_UNLIKELY (!gst_object_check_uniqueness (element->pads, pad_name)))
goto name_exists;
/* try to set the pad's parent */
if (G_UNLIKELY (!gst_object_set_parent (GST_OBJECT_CAST (pad),
GST_OBJECT_CAST (element))))
goto had_parent;
g_free (pad_name);
/* add it to the list */
switch (gst_pad_get_direction (pad)) {
case GST_PAD_SRC:
element->srcpads = g_list_prepend (element->srcpads, pad);
element->numsrcpads++;
break;
case GST_PAD_SINK:
element->sinkpads = g_list_prepend (element->sinkpads, pad);
element->numsinkpads++;
break;
default:
goto no_direction;
}
element->pads = g_list_prepend (element->pads, pad);
element->numpads++;
element->pads_cookie++;
GST_UNLOCK (element);
/* emit the NEW_PAD signal */
g_signal_emit (G_OBJECT (element), gst_element_signals[NEW_PAD], 0, pad);
return TRUE;
/* ERROR cases */
name_exists:
{
g_critical ("Padname %s is not unique in element %s, not adding",
pad_name, GST_ELEMENT_NAME (element));
GST_UNLOCK (element);
g_free (pad_name);
return FALSE;
}
had_parent:
{
g_critical
("Pad %s already has parent when trying to add to element %s",
pad_name, GST_ELEMENT_NAME (element));
GST_UNLOCK (element);
g_free (pad_name);
return FALSE;
}
no_direction:
{
GST_LOCK (pad);
g_critical
("Trying to add pad %s to element %s, but it has no direction",
GST_OBJECT_NAME (pad), GST_ELEMENT_NAME (element));
GST_UNLOCK (pad);
GST_UNLOCK (element);
return FALSE;
}
}
/**
* gst_element_remove_pad:
* @element: a #GstElement to remove pad from.
* @pad: the #GstPad to remove from the element.
*
* Removes @pad from @element. @pad will be destroyed if it has not been
* referenced elsewhere.
*
* Returns: TRUE if the pad could be removed. Can return FALSE if the
* pad is not belonging to the provided element or when wrong parameters
* are passed to this function.
*
* MT safe.
*/
gboolean
gst_element_remove_pad (GstElement * element, GstPad * pad)
{
GstPad *peer;
g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
/* locking pad to look at the name and parent */
GST_LOCK (pad);
GST_CAT_INFO_OBJECT (GST_CAT_ELEMENT_PADS, element, "removing pad '%s'",
GST_STR_NULL (GST_PAD_NAME (pad)));
if (G_UNLIKELY (GST_PAD_PARENT (pad) != element))
goto not_our_pad;
GST_UNLOCK (pad);
/* unlink */
if ((peer = gst_pad_get_peer (pad))) {
/* window for MT unsafeness, someone else could unlink here
* and then we call unlink with wrong pads. The unlink
* function would catch this and safely return failed. */
if (GST_PAD_IS_SRC (pad))
gst_pad_unlink (pad, peer);
else
gst_pad_unlink (peer, pad);
gst_object_unref (peer);
}
GST_LOCK (element);
/* remove it from the list */
switch (gst_pad_get_direction (pad)) {
case GST_PAD_SRC:
element->srcpads = g_list_remove (element->srcpads, pad);
element->numsrcpads--;
break;
case GST_PAD_SINK:
element->sinkpads = g_list_remove (element->sinkpads, pad);
element->numsinkpads--;
break;
default:
g_critical ("Removing pad without direction???");
break;
}
element->pads = g_list_remove (element->pads, pad);
element->numpads--;
element->pads_cookie++;
GST_UNLOCK (element);
g_signal_emit (G_OBJECT (element), gst_element_signals[PAD_REMOVED], 0, pad);
gst_object_unparent (GST_OBJECT (pad));
return TRUE;
not_our_pad:
{
/* FIXME, locking order? */
GST_LOCK (element);
g_critical ("Padname %s:%s does not belong to element %s when removing",
GST_ELEMENT_NAME (GST_PAD_PARENT (pad)), GST_PAD_NAME (pad),
GST_ELEMENT_NAME (element));
GST_UNLOCK (element);
GST_UNLOCK (pad);
return FALSE;
}
}
/**
* gst_element_no_more_pads:
* @element: a #GstElement
*
* Use this function to signal that the element does not expect any more pads
* to show up in the current pipeline. This function should be called whenever
* pads have been added by the element itself. Elements with GST_PAD_SOMETIMES
* pad templates use this in combination with autopluggers to figure out that
* the element is done initializing its pads.
*
* MT safe.
*/
void
gst_element_no_more_pads (GstElement * element)
{
g_return_if_fail (GST_IS_ELEMENT (element));
g_signal_emit (element, gst_element_signals[NO_MORE_PADS], 0);
}
static gint
pad_compare_name (GstPad * pad1, const gchar * name)
{
gint result;
GST_LOCK (pad1);
result = strcmp (GST_PAD_NAME (pad1), name);
GST_UNLOCK (pad1);
return result;
}
/**
* gst_element_get_static_pad:
* @element: a #GstElement to find a static pad of.
* @name: the name of the static #GstPad to retrieve.
*
* Retrieves a pad from @element by name. This version only retrieves
* already-existing (i.e. 'static') pads.
*
* Returns: the requested #GstPad if found, otherwise NULL. unref after
* usage.
*
* MT safe.
*/
GstPad *
gst_element_get_static_pad (GstElement * element, const gchar * name)
{
GList *find;
GstPad *result = NULL;
g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
g_return_val_if_fail (name != NULL, NULL);
GST_LOCK (element);
find =
g_list_find_custom (element->pads, name, (GCompareFunc) pad_compare_name);
if (find) {
result = GST_PAD_CAST (find->data);
gst_object_ref (result);
}
if (result == NULL) {
GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "no such pad '%s' in element \"%s\"",
name, GST_ELEMENT_NAME (element));
} else {
GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "found pad %s:%s",
GST_ELEMENT_NAME (element), name);
}
GST_UNLOCK (element);
return result;
}
static GstPad *
gst_element_request_pad (GstElement * element, GstPadTemplate * templ,
const gchar * name)
{
GstPad *newpad = NULL;
GstElementClass *oclass;
oclass = GST_ELEMENT_GET_CLASS (element);
if (oclass->request_new_pad)
newpad = (oclass->request_new_pad) (element, templ, name);
if (newpad)
gst_object_ref (newpad);
return newpad;
}
/**
* gst_element_get_request_pad:
* @element: a #GstElement to find a request pad of.
* @name: the name of the request #GstPad to retrieve.
*
* Retrieves a pad from the element by name. This version only retrieves
* request pads.
*
* Returns: requested #GstPad if found, otherwise NULL. Unref after usage.
*/
GstPad *
gst_element_get_request_pad (GstElement * element, const gchar * name)
{
GstPadTemplate *templ = NULL;
GstPad *pad;
const gchar *req_name = NULL;
gboolean templ_found = FALSE;
GList *list;
gint n;
const gchar *data;
gchar *str, *endptr = NULL;
GstElementClass *class;
g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
g_return_val_if_fail (name != NULL, NULL);
class = GST_ELEMENT_GET_CLASS (element);
if (strstr (name, "%")) {
templ = gst_element_class_get_pad_template (class, name);
req_name = NULL;
if (templ)
templ_found = TRUE;
} else {
list = gst_element_class_get_pad_template_list (class);
while (!templ_found && list) {
templ = (GstPadTemplate *) list->data;
if (templ->presence == GST_PAD_REQUEST) {
/* Because of sanity checks in gst_pad_template_new(), we know that %s
and %d, occurring at the end of the name_template, are the only
possibilities. */
GST_CAT_DEBUG (GST_CAT_PADS, "comparing %s to %s", name,
templ->name_template);
if ((str = strchr (templ->name_template, '%'))
&& strncmp (templ->name_template, name,
str - templ->name_template) == 0
&& strlen (name) > str - templ->name_template) {
data = name + (str - templ->name_template);
if (*(str + 1) == 'd') {
/* it's an int */
n = (gint) strtol (data, &endptr, 10);
if (endptr && *endptr == '\0') {
templ_found = TRUE;
req_name = name;
break;
}
} else {
/* it's a string */
templ_found = TRUE;
req_name = name;
break;
}
}
}
list = list->next;
}
}
if (!templ_found)
return NULL;
pad = gst_element_request_pad (element, templ, req_name);
return pad;
}
/**
* gst_element_get_pad:
* @element: a #GstElement.
* @name: the name of the pad to retrieve.
*
* Retrieves a pad from @element by name. Tries gst_element_get_static_pad()
* first, then gst_element_get_request_pad().
*
* Returns: the #GstPad if found, otherwise %NULL. Unref after usage.
*/
GstPad *
gst_element_get_pad (GstElement * element, const gchar * name)
{
GstPad *pad;
g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
g_return_val_if_fail (name != NULL, NULL);
pad = gst_element_get_static_pad (element, name);
if (!pad)
pad = gst_element_get_request_pad (element, name);
return pad;
}
GstIteratorItem
iterate_pad (GstIterator * it, GstPad * pad)
{
gst_object_ref (pad);
return GST_ITERATOR_ITEM_PASS;
}
/**
* gst_element_iterate_pads:
* @element: a #GstElement to iterate pads of.
*
* Retrieves an iterattor of @element's pads.
*
* Returns: the #GstIterator of #GstPad. Unref each pad after use.
*
* MT safe.
*/
GstIterator *
gst_element_iterate_pads (GstElement * element)
{
GstIterator *result;
g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
GST_LOCK (element);
gst_object_ref (element);
result = gst_iterator_new_list (GST_GET_LOCK (element),
&element->pads_cookie,
&element->pads,
element,
(GstIteratorItemFunction) iterate_pad,
(GstIteratorDisposeFunction) gst_object_unref);
GST_UNLOCK (element);
return result;
}
static gint
direction_filter (gconstpointer pad, gconstpointer direction)
{
if (GST_PAD_DIRECTION (pad) == GPOINTER_TO_INT (direction)) {
/* pass the ref through */
return 0;
} else {
/* unref */
/* FIXME: this is very stupid */
gst_object_unref (GST_OBJECT_CAST (pad));
return 1;
}
}
/**
* gst_element_iterate_src_pads:
* @element: a #GstElement.
*
* Retrieves an iterator of @element's source pads.
*
* Returns: the #GstIterator of #GstPad. Unref each pad after use.
*
* MT safe.
*/
GstIterator *
gst_element_iterate_src_pads (GstElement * element)
{
g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
return gst_iterator_filter (gst_element_iterate_pads (element),
direction_filter, GINT_TO_POINTER (GST_PAD_SRC));
}
/**
* gst_element_iterate_sink_pads:
* @element: a #GstElement.
*
* Retrieves an iterator of @element's sink pads.
*
* Returns: the #GstIterator of #GstPad. Unref each pad after use.
*
* MT safe.
*/
GstIterator *
gst_element_iterate_sink_pads (GstElement * element)
{
g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
return gst_iterator_filter (gst_element_iterate_pads (element),
direction_filter, GINT_TO_POINTER (GST_PAD_SINK));
}
/**
* gst_element_class_add_pad_template:
* @klass: the #GstElementClass to add the pad template to.
* @templ: a #GstPadTemplate to add to the element class.
*
* Adds a padtemplate to an element class. This is mainly used in the _base_init
* functions of classes.
*/
void
gst_element_class_add_pad_template (GstElementClass * klass,
GstPadTemplate * templ)
{
g_return_if_fail (GST_IS_ELEMENT_CLASS (klass));
g_return_if_fail (GST_IS_PAD_TEMPLATE (templ));
/* avoid registering pad templates with the same name */
g_return_if_fail (gst_element_class_get_pad_template (klass,
templ->name_template) == NULL);
klass->padtemplates = g_list_append (klass->padtemplates,
gst_object_ref (templ));
klass->numpadtemplates++;
}
/**
* gst_element_class_set_details:
* @klass: class to set details for
* @details: details to set
*
* Sets the detailed information for a #GstElementClass.
* <note>This function is for use in _base_init functions only.</note>
*/
void
gst_element_class_set_details (GstElementClass * klass,
const GstElementDetails * details)
{
g_return_if_fail (GST_IS_ELEMENT_CLASS (klass));
g_return_if_fail (GST_IS_ELEMENT_DETAILS (details));
__gst_element_details_copy (&klass->details, details);
}
/**
* gst_element_class_get_pad_template_list:
* @element_class: a #GstElementClass to get pad templates of.
*
* Retrieves a list of the pad templates associated with @element_class. The
* list must not be modified by the calling code.
* <note>If you use this function in the #GInstanceInitFunc of an object class
* that has subclasses, make sure to pass the g_class parameter of the
* #GInstanceInitFunc here.</note>
*
* Returns: the #GList of padtemplates.
*/
GList *
gst_element_class_get_pad_template_list (GstElementClass * element_class)
{
g_return_val_if_fail (GST_IS_ELEMENT_CLASS (element_class), NULL);
return element_class->padtemplates;
}
/**
* gst_element_class_get_pad_template:
* @element_class: a #GstElementClass to get the pad template of.
* @name: the name of the #GstPadTemplate to get.
*
* Retrieves a padtemplate from @element_class with the given name.
* <note>If you use this function in the #GInstanceInitFunc of an object class
* that has subclasses, make sure to pass the g_class parameter of the
* #GInstanceInitFunc here.</note>
*
* Returns: the #GstPadTemplate with the given name, or NULL if none was found.
* No unreferencing is necessary.
*/
GstPadTemplate *
gst_element_class_get_pad_template (GstElementClass * element_class,
const gchar * name)
{
GList *padlist;
g_return_val_if_fail (GST_IS_ELEMENT_CLASS (element_class), NULL);
g_return_val_if_fail (name != NULL, NULL);
padlist = gst_element_class_get_pad_template_list (element_class);
while (padlist) {
GstPadTemplate *padtempl = (GstPadTemplate *) padlist->data;
if (strcmp (padtempl->name_template, name) == 0)
return padtempl;
padlist = g_list_next (padlist);
}
return NULL;
}
static GstPad *
gst_element_get_random_pad (GstElement * element, GstPadDirection dir)
{
GstPad *result = NULL;
GList *pads;
GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "getting a random pad");
switch (dir) {
case GST_PAD_SRC:
GST_LOCK (element);
pads = element->srcpads;
break;
case GST_PAD_SINK:
GST_LOCK (element);
pads = element->sinkpads;
break;
default:
goto wrong_direction;
}
for (; pads; pads = g_list_next (pads)) {
GstPad *pad = GST_PAD (pads->data);
GST_LOCK (pad);
GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "checking pad %s:%s",
GST_DEBUG_PAD_NAME (pad));
if (GST_PAD_IS_LINKED (pad)) {
GST_UNLOCK (pad);
result = pad;
break;
} else {
GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "pad %s:%s is not linked",
GST_DEBUG_PAD_NAME (pad));
}
GST_UNLOCK (pad);
}
if (result)
gst_object_ref (result);
GST_UNLOCK (element);
return result;
/* ERROR handling */
wrong_direction:
{
g_warning ("unknown pad direction %d", dir);
return NULL;
}
}
/**
* gst_element_send_event:
* @element: a #GstElement to send the event to.
* @event: the #GstEvent to send to the element.
*
* Sends an event to an element. If the element doesn't
* implement an event handler, the event will be forwarded
* to a random sink pad. This function takes owership of the
* provided event so you should _ref it if you want to reuse
* the event after this call.
*
* Returns: TRUE if the event was handled.
*
* MT safe.
*/
gboolean
gst_element_send_event (GstElement * element, GstEvent * event)
{
GstElementClass *oclass;
gboolean result = FALSE;
g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
g_return_val_if_fail (event != NULL, FALSE);
oclass = GST_ELEMENT_GET_CLASS (element);
if (oclass->send_event) {
result = oclass->send_event (element, event);
} else {
GstPad *pad = gst_element_get_random_pad (element, GST_PAD_SINK);
if (pad) {
GstPad *peer = gst_pad_get_peer (pad);
if (peer) {
GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
"sending event to random pad %s:%s", GST_DEBUG_PAD_NAME (pad));
result = gst_pad_send_event (peer, event);
gst_object_unref (peer);
}
gst_object_unref (pad);
}
}
GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "can't send event on element %s",
GST_ELEMENT_NAME (element));
return result;
}
/**
* gst_element_seek:
* @element: a #GstElement to send the event to.
* @seek_method: the method to use for seeking (GST_SEEK_METHOD_*).
* @seek_format: the #GstFormat to use for seeking (GST_FORMAT_*).
* @seek_flags: the flags to use for seeking (GST_SEEK_FLAG_*).
* @offset: the offset to seek to (in the given seek_format).
*
* Sends a seek event to an element.
*
* Returns: TRUE if the event was handled.
*
* MT safe.
*/
gboolean
gst_element_seek (GstElement * element, gdouble rate, GstFormat format,
GstSeekFlags flags, GstSeekType cur_type, gint64 cur,
GstSeekType stop_type, gint64 stop)
{
GstEvent *event;
gboolean result;
g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
event =
gst_event_new_seek (rate, format, flags, cur_type, cur, stop_type, stop);
result = gst_element_send_event (element, event);
return result;
}
/**
* gst_element_get_query_types:
* @element: a #GstElement to query
*
* Get an array of query types from the element.
* If the element doesn't implement a query types function,
* the query will be forwarded to a random sink pad.
*
* Returns: An array of #GstQueryType elements that should not
* be freed or modified.
*
* MT safe.
*/
const GstQueryType *
gst_element_get_query_types (GstElement * element)
{
GstElementClass *oclass;
const GstQueryType *result = NULL;
g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
oclass = GST_ELEMENT_GET_CLASS (element);
if (oclass->get_query_types) {
result = oclass->get_query_types (element);
} else {
GstPad *pad = gst_element_get_random_pad (element, GST_PAD_SINK);
if (pad) {
GstPad *peer = gst_pad_get_peer (pad);
if (peer) {
result = gst_pad_get_query_types (peer);
gst_object_unref (peer);
}
gst_object_unref (pad);
}
}
return result;
}
/**
* gst_element_query:
* @element: a #GstElement to perform the query on.
* @query: the #GstQuery.
*
* Performs a query on the given element. If the format is set
* to GST_FORMAT_DEFAULT and this function returns TRUE, the
* format pointer will hold the default format.
* For element that don't implement a query handler, this function
* forwards the query to a random usable sinkpad of this element.
*
* Returns: TRUE if the query could be performed.
*
* MT safe.
*/
gboolean
gst_element_query (GstElement * element, GstQuery * query)
{
GstElementClass *oclass;
gboolean result = FALSE;
g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
g_return_val_if_fail (query != NULL, FALSE);
oclass = GST_ELEMENT_GET_CLASS (element);
if (oclass->query) {
result = oclass->query (element, query);
} else {
GstPad *pad = gst_element_get_random_pad (element, GST_PAD_SRC);
if (pad) {
result = gst_pad_query (pad, query);
gst_object_unref (pad);
} else {
pad = gst_element_get_random_pad (element, GST_PAD_SINK);
if (pad) {
GstPad *peer = gst_pad_get_peer (pad);
if (peer) {
result = gst_pad_query (peer, query);
gst_object_unref (peer);
}
gst_object_unref (pad);
}
}
}
return result;
}
/**
* gst_element_post_message:
* @element: a #GstElement posting the message
* @message: a #GstMessage to post
*
* Post a message on the element's #GstBus.
*
* Returns: TRUE if the message was successfully posted.
*
* MT safe.
*/
gboolean
gst_element_post_message (GstElement * element, GstMessage * message)
{
GstBus *bus;
gboolean result = FALSE;
GST_DEBUG ("posting message %p ...", message);
g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
g_return_val_if_fail (message != NULL, FALSE);
GST_LOCK (element);
bus = element->bus;
if (G_UNLIKELY (bus == NULL)) {
GST_DEBUG ("... but I won't because I have no bus");
GST_UNLOCK (element);
gst_message_unref (message);
return FALSE;
}
gst_object_ref (bus);
GST_DEBUG ("... on bus %" GST_PTR_FORMAT, bus);
GST_UNLOCK (element);
result = gst_bus_post (bus, message);
gst_object_unref (bus);
return result;
}
/**
* _gst_element_error_printf:
* @format: the printf-like format to use, or NULL
*
* This function is only used internally by the #gst_element_error macro.
*
* Returns: a newly allocated string, or NULL if the format was NULL or ""
*
* MT safe.
*/
gchar *
_gst_element_error_printf (const gchar * format, ...)
{
va_list args;
gchar *buffer;
if (format == NULL)
return NULL;
if (format[0] == 0)
return NULL;
va_start (args, format);
buffer = g_strdup_vprintf (format, args);
va_end (args);
return buffer;
}
/**
* gst_element_message_full:
* @element: a #GstElement to send message from
* @type: the #GstMessageType
* @domain: the GStreamer GError domain this message belongs to
* @code: the GError code belonging to the domain
* @text: an allocated text string to be used as a replacement for the
* default message connected to code, or NULL
* @debug: an allocated debug message to be used as a replacement for the
* default debugging information, or NULL
* @file: the source code file where the error was generated
* @function: the source code function where the error was generated
* @line: the source code line where the error was generated
*
* Post an error or warning message on the bus from inside an element.
*
* MT safe.
*/
void gst_element_message_full
(GstElement * element, GstMessageType type,
GQuark domain, gint code, gchar * text,
gchar * debug, const gchar * file, const gchar * function, gint line)
{
GError *gerror = NULL;
gchar *name;
gchar *sent_text;
gchar *sent_debug;
GstMessage *message = NULL;
/* checks */
GST_DEBUG ("start");
g_return_if_fail (GST_IS_ELEMENT (element));
g_return_if_fail ((type == GST_MESSAGE_ERROR) ||
(type == GST_MESSAGE_WARNING));
/* check if we send the given text or the default error text */
if ((text == NULL) || (text[0] == 0)) {
/* text could have come from g_strdup_printf (""); */
g_free (text);
sent_text = gst_error_get_message (domain, code);
} else
sent_text = text;
/* construct a sent_debug with extra information from source */
if ((debug == NULL) || (debug[0] == 0)) {
/* debug could have come from g_strdup_printf (""); */
sent_debug = NULL;
} else {
name = gst_object_get_path_string (GST_OBJECT (element));
sent_debug = g_strdup_printf ("%s(%d): %s: %s:\n%s",
file, line, function, name, debug ? debug : "");
g_free (name);
}
g_free (debug);
/* create gerror and post message */
GST_CAT_INFO_OBJECT (GST_CAT_ERROR_SYSTEM, element, "posting message: %s",
sent_text);
gerror = g_error_new_literal (domain, code, sent_text);
if (type == GST_MESSAGE_ERROR) {
message = gst_message_new_error (GST_OBJECT (element), gerror, sent_debug);
} else if (type == GST_MESSAGE_WARNING) {
message = gst_message_new_warning (GST_OBJECT (element), gerror,
sent_debug);
} else {
g_assert_not_reached ();
}
gst_element_post_message (element, message);
GST_CAT_INFO_OBJECT (GST_CAT_ERROR_SYSTEM, element, "posted message: %s",
sent_text);
/* cleanup */
g_error_free (gerror);
g_free (sent_debug);
g_free (sent_text);
}
/**
* gst_element_is_locked_state:
* @element: a #GstElement.
*
* Checks if the state of an element is locked.
* If the state of an element is locked, state changes of the parent don't
* affect the element.
* This way you can leave currently unused elements inside bins. Just lock their
* state before changing the state from #GST_STATE_NULL.
*
* Returns: TRUE, if the element's state is locked.
*
* MT safe.
*/
gboolean
gst_element_is_locked_state (GstElement * element)
{
gboolean result = FALSE;
g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
GST_LOCK (element);
result = GST_FLAG_IS_SET (element, GST_ELEMENT_LOCKED_STATE);
GST_UNLOCK (element);
return result;
}
/**
* gst_element_set_locked_state:
* @element: a #GstElement
* @locked_state: TRUE to lock the element's state
*
* Locks the state of an element, so state changes of the parent don't affect
* this element anymore.
*
* Returns: TRUE if the state was changed, FALSE if bad params were given or
* the element was already in the correct state.
*
* MT safe.
*/
gboolean
gst_element_set_locked_state (GstElement * element, gboolean locked_state)
{
gboolean old;
g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
GST_LOCK (element);
old = GST_FLAG_IS_SET (element, GST_ELEMENT_LOCKED_STATE);
if (G_UNLIKELY (old == locked_state))
goto was_ok;
if (locked_state) {
GST_CAT_DEBUG (GST_CAT_STATES, "locking state of element %s",
GST_ELEMENT_NAME (element));
GST_FLAG_SET (element, GST_ELEMENT_LOCKED_STATE);
} else {
GST_CAT_DEBUG (GST_CAT_STATES, "unlocking state of element %s",
GST_ELEMENT_NAME (element));
GST_FLAG_UNSET (element, GST_ELEMENT_LOCKED_STATE);
}
GST_UNLOCK (element);
return TRUE;
was_ok:
GST_UNLOCK (element);
return FALSE;
}
/**
* gst_element_sync_state_with_parent:
* @element: a #GstElement.
*
* Tries to change the state of the element to the same as its parent.
* If this function returns FALSE, the state of element is undefined.
*
* Returns: TRUE, if the element's state could be synced to the parent's state.
*/
gboolean
gst_element_sync_state_with_parent (GstElement * element)
{
GstElement *parent;
g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
parent = GST_ELEMENT (GST_ELEMENT_PARENT (element));
g_return_val_if_fail (GST_IS_BIN (parent), FALSE);
GST_CAT_DEBUG (GST_CAT_STATES, "syncing state of element %s (%s) to %s (%s)",
GST_ELEMENT_NAME (element),
gst_element_state_get_name (GST_STATE (element)),
GST_ELEMENT_NAME (parent),
gst_element_state_get_name (GST_STATE (parent)));
if (gst_element_set_state (element, GST_STATE (parent)) == GST_STATE_FAILURE) {
return FALSE;
}
return TRUE;
}
/* MT safe */
static GstElementStateReturn
gst_element_get_state_func (GstElement * element,
GstElementState * state, GstElementState * pending, GTimeVal * timeout)
{
GstElementStateReturn ret = GST_STATE_FAILURE;
GstElementState old_pending;
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "getting state");
GST_STATE_LOCK (element);
/* we got an error, report immediatly */
if (GST_STATE_NO_PREROLL (element)) {
ret = GST_STATE_NO_PREROLL;
goto done;
}
/* we got an error, report immediatly */
if (GST_STATE_ERROR (element)) {
ret = GST_STATE_FAILURE;
goto done;
}
old_pending = GST_STATE_PENDING (element);
if (old_pending != GST_STATE_VOID_PENDING) {
GTimeVal *timeval, abstimeout;
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "wait for pending");
if (timeout) {
/* make timeout absolute */
g_get_current_time (&abstimeout);
g_time_val_add (&abstimeout,
timeout->tv_sec * G_USEC_PER_SEC + timeout->tv_usec);
timeval = &abstimeout;
} else {
timeval = NULL;
}
/* we have a pending state change, wait for it to complete */
if (!GST_STATE_TIMED_WAIT (element, timeval)) {
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "timeout");
/* timeout triggered */
ret = GST_STATE_ASYNC;
} else {
/* could be success or failure */
if (old_pending == GST_STATE (element)) {
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "got success");
ret = GST_STATE_SUCCESS;
} else {
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "got failure");
ret = GST_STATE_FAILURE;
}
}
}
/* if nothing is pending anymore we can return SUCCESS */
if (GST_STATE_PENDING (element) == GST_STATE_VOID_PENDING) {
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "nothing pending");
ret = GST_STATE_SUCCESS;
}
done:
if (state)
*state = GST_STATE (element);
if (pending)
*pending = GST_STATE_PENDING (element);
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 (element);
return ret;
}
/**
* gst_element_get_state:
* @element: a #GstElement to get the state of.
* @state: a pointer to #GstElementState to hold the state. Can be NULL.
* @pending: a pointer to #GstElementState to hold the pending state.
* Can be NULL.
* @timeout: a #GTimeVal to specify the timeout for an async
* state change or NULL for infinite timeout.
*
* Gets the state of the element.
*
* For elements that performed an ASYNC state change, as reported by
* #gst_element_set_state(), this function will block up to the
* specified timeout value for the state change to complete.
* If the element completes the state change or goes into
* an error, this function returns immediatly with a return value of
* GST_STATE_SUCCESS or GST_STATE_FAILURE respectively.
*
* Returns: GST_STATE_SUCCESS if the element has no more pending state and
* the last state change succeeded, GST_STATE_ASYNC
* if the element is still performing a state change or
* GST_STATE_FAILURE if the last state change failed.
*
* MT safe.
*/
GstElementStateReturn
gst_element_get_state (GstElement * element,
GstElementState * state, GstElementState * pending, GTimeVal * timeout)
{
GstElementClass *oclass;
GstElementStateReturn result = GST_STATE_FAILURE;
g_return_val_if_fail (GST_IS_ELEMENT (element), GST_STATE_FAILURE);
oclass = GST_ELEMENT_GET_CLASS (element);
if (oclass->get_state)
result = (oclass->get_state) (element, state, pending, timeout);
return result;
}
/**
* gst_element_abort_state:
* @element: a #GstElement to abort the state of.
*
* Abort the state change of the element. This function is used
* by elements that do asynchronous state changes and find out
* something is wrong.
*
* This function should be called with the STATE_LOCK held.
*
* MT safe.
*/
void
gst_element_abort_state (GstElement * element)
{
GstElementState pending;
g_return_if_fail (GST_IS_ELEMENT (element));
pending = GST_STATE_PENDING (element);
if (pending != GST_STATE_VOID_PENDING && !GST_STATE_ERROR (element)) {
#ifndef GST_DISABLE_GST_DEBUG
GstElementState old_state = GST_STATE (element);
#endif
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
"aborting state from %s to %s", gst_element_state_get_name (old_state),
gst_element_state_get_name (pending));
/* flag error */
GST_STATE_ERROR (element) = TRUE;
GST_STATE_BROADCAST (element);
}
}
/**
* gst_element_commit_state:
* @element: a #GstElement to commit the state of.
*
* Commit the state change of the element. This function is used
* by elements that do asynchronous state changes.
*
* This function can only be called with the STATE_LOCK held.
*
* MT safe.
*/
void
gst_element_commit_state (GstElement * element)
{
GstElementState pending;
GstMessage *message;
g_return_if_fail (GST_IS_ELEMENT (element));
pending = GST_STATE_PENDING (element);
if (pending != GST_STATE_VOID_PENDING) {
GstElementState old_state = GST_STATE (element);
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
"commiting state from %s to %s", gst_element_state_get_name (old_state),
gst_element_state_get_name (pending));
GST_STATE (element) = pending;
GST_STATE_PENDING (element) = GST_STATE_VOID_PENDING;
GST_STATE_ERROR (element) = FALSE;
g_signal_emit (G_OBJECT (element), gst_element_signals[STATE_CHANGE],
0, old_state, pending);
message = gst_message_new_state_changed (GST_OBJECT (element),
old_state, pending);
gst_element_post_message (element, message);
GST_STATE_BROADCAST (element);
}
}
/**
* gst_element_lost_state:
* @element: a #GstElement the state is lost of
*
* Brings the element to the lost state. The current state of the
* element is copied to the pending state so that any call to
* #gst_element_get_state() will return ASYNC.
* This is mostly used for elements that lost their preroll buffer
* in the PAUSED state after a flush, they become PAUSED again
* if a new preroll buffer is queued.
* This function can only be called when the element is currently
* not in error or an async state change.
*
* This function can only be called with the STATE_LOCK held.
*
* MT safe.
*/
void
gst_element_lost_state (GstElement * element)
{
g_return_if_fail (GST_IS_ELEMENT (element));
if (GST_STATE_PENDING (element) == GST_STATE_VOID_PENDING &&
!GST_STATE_ERROR (element)) {
GstElementState current_state = GST_STATE (element);
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
"lost state of %s", gst_element_state_get_name (current_state));
GST_STATE_PENDING (element) = current_state;
GST_STATE_ERROR (element) = FALSE;
}
}
/**
* gst_element_set_state:
* @element: a #GstElement to change state of.
* @state: the element's new #GstElementState.
*
* Sets the state of the element. This function will try to set the
* requested state by going through all the intermediary states and calling
* the class's state change function for each.
*
* Returns: Result of the state change using #GstElementStateReturn.
*
* MT safe.
*/
GstElementStateReturn
gst_element_set_state (GstElement * element, GstElementState state)
{
GstElementClass *oclass;
GstElementState current;
GstElementStateReturn return_val = GST_STATE_SUCCESS;
GstElementStateReturn ret;
GstElementState pending;
GTimeVal tv;
g_return_val_if_fail (GST_IS_ELEMENT (element), GST_STATE_FAILURE);
/* get current element state, need to call the method so that
* we call the virtual method and subclasses can implement their
* own algorithms */
GST_TIME_TO_TIMEVAL (0, tv);
ret = gst_element_get_state (element, &current, &pending, &tv);
/* get the element state lock */
GST_STATE_LOCK (element);
/* this is the state we should go to */
GST_STATE_FINAL (element) = state;
if (ret == GST_STATE_ASYNC) {
gst_element_commit_state (element);
gst_element_lost_state (element);
}
/* start with the current state */
current = GST_STATE (element);
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "setting state from %s to %s",
gst_element_state_get_name (current), gst_element_state_get_name (state));
oclass = GST_ELEMENT_GET_CLASS (element);
/* We always perform at least one state change, even if the
* current state is equal to the required state. This is needed
* for bins that sync their children. */
do {
GstElementState pending;
/* calculate the pending state */
if (current < state)
pending = current << 1;
else if (current > state)
pending = current >> 1;
else
pending = current;
/* set the pending state variable */
GST_STATE_PENDING (element) = pending;
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
"%s: setting state from %s to %s",
(pending != state ? "intermediate" : "final"),
gst_element_state_get_name (current),
gst_element_state_get_name (pending));
/* call the state change function so it can set the state */
if (oclass->change_state)
return_val = (oclass->change_state) (element);
else
return_val = GST_STATE_FAILURE;
/* clear the error and preroll flag, we need to do that after
* calling the virtual change_state function so that it can use the
* old previous value. */
GST_STATE_ERROR (element) = FALSE;
GST_STATE_NO_PREROLL (element) = FALSE;
switch (return_val) {
case GST_STATE_FAILURE:
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
"have failed change_state return");
/* state change failure exits the loop */
gst_element_abort_state (element);
goto exit;
case GST_STATE_ASYNC:
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
"element will change state async");
/* an async state change exits the loop, we can only
* go to the next state change when this one completes. */
goto exit;
case GST_STATE_SUCCESS:
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
"element changed state successfully");
/* we can commit the state now and proceed to the next state */
gst_element_commit_state (element);
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "commited state");
break;
case GST_STATE_NO_PREROLL:
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
"element changed state successfully and can't preroll");
/* we can commit the state now and proceed to the next state */
gst_element_commit_state (element);
GST_STATE_NO_PREROLL (element) = TRUE;
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "commited state");
break;
default:
goto invalid_return;
}
/* get the current state of the element and see if we need to do more
* state changes */
current = GST_STATE (element);
}
while (current != state);
exit:
GST_STATE_FINAL (element) = GST_STATE_VOID_PENDING;
GST_STATE_UNLOCK (element);
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "exit state change");
return return_val;
/* ERROR */
invalid_return:
{
GST_STATE_FINAL (element) = GST_STATE_VOID_PENDING;
GST_STATE_UNLOCK (element);
/* somebody added a GST_STATE_ and forgot to do stuff here ! */
g_critical ("unknown return value %d from a state change function",
return_val);
return GST_STATE_FAILURE;
}
}
/* gst_iterator_fold functions for pads_activate */
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);
gst_object_unref (pad);
return TRUE;
}
/* returns false on error or early cutout of the fold, true otherwise */
static gboolean
iterator_fold_with_resync (GstIterator * iter, GstIteratorFoldFunction func,
GValue * ret, gpointer user_data)
{
GstIteratorResult ires;
gboolean res = TRUE;
while (1) {
ires = gst_iterator_fold (iter, func, ret, user_data);
switch (ires) {
case GST_ITERATOR_RESYNC:
gst_iterator_resync (iter);
break;
case GST_ITERATOR_DONE:
res = TRUE;
goto done;
default:
res = FALSE;
goto done;
}
}
done:
return res;
}
/* is called with STATE_LOCK
*/
static gboolean
gst_element_pads_activate (GstElement * element, gboolean active)
{
GValue ret = { 0, };
GstIterator *iter;
gboolean fold_ok;
/* no need to unset this later, it's just a boolean */
g_value_init (&ret, G_TYPE_BOOLEAN);
g_value_set_boolean (&ret, TRUE);
iter = gst_element_iterate_src_pads (element);
fold_ok = iterator_fold_with_resync
(iter, (GstIteratorFoldFunction) activate_pads, &ret, &active);
gst_iterator_free (iter);
if (!fold_ok || !g_value_get_boolean (&ret))
return FALSE;
iter = gst_element_iterate_sink_pads (element);
fold_ok = iterator_fold_with_resync
(iter, (GstIteratorFoldFunction) activate_pads, &ret, &active);
gst_iterator_free (iter);
if (!fold_ok || !g_value_get_boolean (&ret))
return FALSE;
return TRUE;
}
/* is called with STATE_LOCK */
static GstElementStateReturn
gst_element_change_state (GstElement * element)
{
GstElementState old_state;
gint old_pending, old_transition;
GstElementStateReturn result = GST_STATE_SUCCESS;
g_return_val_if_fail (GST_IS_ELEMENT (element), GST_STATE_FAILURE);
old_state = GST_STATE (element);
old_pending = GST_STATE_PENDING (element);
old_transition = GST_STATE_TRANSITION (element);
/* if the element already is in the given state, we just return success */
if (old_pending == GST_STATE_VOID_PENDING ||
old_state == GST_STATE_PENDING (element)) {
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
"element is already in the %s state",
gst_element_state_get_name (old_state));
if (GST_STATE_NO_PREROLL (element))
return GST_STATE_NO_PREROLL;
else
return GST_STATE_SUCCESS;
}
GST_CAT_LOG_OBJECT (GST_CAT_STATES, element,
"default handler tries setting state from %s to %s (%04x)",
gst_element_state_get_name (old_state),
gst_element_state_get_name (old_pending), old_transition);
switch (old_transition) {
case GST_STATE_NULL_TO_READY:
break;
case GST_STATE_READY_TO_PAUSED:
if (!gst_element_pads_activate (element, TRUE)) {
result = GST_STATE_FAILURE;
}
break;
case GST_STATE_PAUSED_TO_PLAYING:
break;
case GST_STATE_PLAYING_TO_PAUSED:
break;
case GST_STATE_PAUSED_TO_READY:
case GST_STATE_READY_TO_NULL:
/* deactivate pads in both cases, since they are activated on
ready->paused but the element might not have made it to paused */
if (!gst_element_pads_activate (element, FALSE)) {
result = GST_STATE_FAILURE;
} else {
GST_LOCK (element);
element->base_time = 0;
GST_UNLOCK (element);
}
break;
default:
/* this will catch real but unhandled state changes;
* can only be caused by:
* - a new state was added
* - somehow the element was asked to jump across an intermediate state
*/
g_warning ("Unhandled state change from %s to %s",
gst_element_state_get_name (old_state),
gst_element_state_get_name (old_pending));
break;
}
return result;
}
/**
* gst_element_get_factory:
* @element: a #GstElement to request the element factory of.
*
* Retrieves the factory that was used to create this element.
*
* Returns: the #GstElementFactory used for creating this element.
*/
GstElementFactory *
gst_element_get_factory (GstElement * element)
{
g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
return GST_ELEMENT_GET_CLASS (element)->elementfactory;
}
static void
gst_element_dispose (GObject * object)
{
GstElement *element = GST_ELEMENT (object);
GST_CAT_INFO_OBJECT (GST_CAT_REFCOUNTING, element, "dispose");
/* ref so we don't hit 0 again */
gst_object_ref (object);
/* first we break all our links with the outside */
while (element->pads) {
gst_element_remove_pad (element, GST_PAD_CAST (element->pads->data));
}
if (G_UNLIKELY (element->pads != 0)) {
g_critical ("could not remove pads from element %s",
GST_STR_NULL (GST_OBJECT_NAME (object)));
}
GST_LOCK (element);
gst_object_replace ((GstObject **) & element->clock, NULL);
GST_UNLOCK (element);
GST_CAT_INFO_OBJECT (GST_CAT_REFCOUNTING, element, "dispose parent");
G_OBJECT_CLASS (parent_class)->dispose (object);
}
static void
gst_element_finalize (GObject * object)
{
GstElement *element = GST_ELEMENT (object);
GST_CAT_INFO_OBJECT (GST_CAT_REFCOUNTING, element, "finalize");
GST_STATE_LOCK (element);
if (element->state_cond)
g_cond_free (element->state_cond);
element->state_cond = NULL;
GST_STATE_UNLOCK (element);
g_mutex_free (element->state_lock);
GST_CAT_INFO_OBJECT (GST_CAT_REFCOUNTING, element, "finalize parent");
G_OBJECT_CLASS (parent_class)->finalize (object);
}
#ifndef GST_DISABLE_LOADSAVE
/**
* gst_element_save_thyself:
* @element: a #GstElement to save.
* @parent: the xml parent node.
*
* Saves the element as part of the given XML structure.
*
* Returns: the new #xmlNodePtr.
*/
static xmlNodePtr
gst_element_save_thyself (GstObject * object, xmlNodePtr parent)
{
GList *pads;
GstElementClass *oclass;
GParamSpec **specs, *spec;
guint nspecs;
gint i;
GValue value = { 0, };
GstElement *element;
g_return_val_if_fail (GST_IS_ELEMENT (object), parent);
element = GST_ELEMENT (object);
oclass = GST_ELEMENT_GET_CLASS (element);
xmlNewChild (parent, NULL, (xmlChar *) "name",
(xmlChar *) GST_ELEMENT_NAME (element));
if (oclass->elementfactory != NULL) {
GstElementFactory *factory = (GstElementFactory *) oclass->elementfactory;
xmlNewChild (parent, NULL, (xmlChar *) "type",
(xmlChar *) GST_PLUGIN_FEATURE (factory)->name);
}
/* params */
specs = g_object_class_list_properties (G_OBJECT_GET_CLASS (object), &nspecs);
for (i = 0; i < nspecs; i++) {
spec = specs[i];
if (spec->flags & G_PARAM_READABLE) {
xmlNodePtr param;
char *contents;
g_value_init (&value, G_PARAM_SPEC_VALUE_TYPE (spec));
g_object_get_property (G_OBJECT (element), spec->name, &value);
param = xmlNewChild (parent, NULL, (xmlChar *) "param", NULL);
xmlNewChild (param, NULL, (xmlChar *) "name", (xmlChar *) spec->name);
if (G_IS_PARAM_SPEC_STRING (spec))
contents = g_value_dup_string (&value);
else if (G_IS_PARAM_SPEC_ENUM (spec))
contents = g_strdup_printf ("%d", g_value_get_enum (&value));
else if (G_IS_PARAM_SPEC_INT64 (spec))
contents = g_strdup_printf ("%" G_GINT64_FORMAT,
g_value_get_int64 (&value));
else
contents = g_strdup_value_contents (&value);
xmlNewChild (param, NULL, (xmlChar *) "value", (xmlChar *) contents);
g_free (contents);
g_value_unset (&value);
}
}
pads = GST_ELEMENT_PADS (element);
while (pads) {
GstPad *pad = GST_PAD (pads->data);
/* figure out if it's a direct pad or a ghostpad */
if (GST_ELEMENT (GST_OBJECT_PARENT (pad)) == element) {
xmlNodePtr padtag = xmlNewChild (parent, NULL, (xmlChar *) "pad", NULL);
gst_object_save_thyself (GST_OBJECT (pad), padtag);
}
pads = g_list_next (pads);
}
return parent;
}
static void
gst_element_restore_thyself (GstObject * object, xmlNodePtr self)
{
xmlNodePtr children;
GstElement *element;
gchar *name = NULL;
gchar *value = NULL;
element = GST_ELEMENT (object);
g_return_if_fail (element != NULL);
/* parameters */
children = self->xmlChildrenNode;
while (children) {
if (!strcmp ((char *) children->name, "param")) {
xmlNodePtr child = children->xmlChildrenNode;
while (child) {
if (!strcmp ((char *) child->name, "name")) {
name = (gchar *) xmlNodeGetContent (child);
} else if (!strcmp ((char *) child->name, "value")) {
value = (gchar *) xmlNodeGetContent (child);
}
child = child->next;
}
/* FIXME: can this just be g_object_set ? */
gst_util_set_object_arg (G_OBJECT (element), name, value);
/* g_object_set (G_OBJECT (element), name, value, NULL); */
g_free (name);
g_free (value);
}
children = children->next;
}
/* pads */
children = self->xmlChildrenNode;
while (children) {
if (!strcmp ((char *) children->name, "pad")) {
gst_pad_load_and_link (children, GST_OBJECT (element));
}
children = children->next;
}
if (GST_OBJECT_CLASS (parent_class)->restore_thyself)
(GST_OBJECT_CLASS (parent_class)->restore_thyself) (object, self);
}
#endif /* GST_DISABLE_LOADSAVE */
static void
gst_element_set_bus_func (GstElement * element, GstBus * bus)
{
g_return_if_fail (GST_IS_ELEMENT (element));
GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, element, "setting bus to %p", bus);
GST_LOCK (element);
gst_object_replace ((GstObject **) & GST_ELEMENT_BUS (element),
GST_OBJECT (bus));
GST_UNLOCK (element);
}
/**
* gst_element_set_bus:
* @element: a #GstElement to set the bus of.
* @bus: the #GstBus to set.
*
* Sets the bus of the element. For internal use only, unless you're
* testing elements.
*
* MT safe.
*/
void
gst_element_set_bus (GstElement * element, GstBus * bus)
{
GstElementClass *oclass;
g_return_if_fail (GST_IS_ELEMENT (element));
oclass = GST_ELEMENT_GET_CLASS (element);
if (oclass->set_bus)
oclass->set_bus (element, bus);
}
/**
* gst_element_get_bus:
* @element: a #GstElement to get the bus of.
*
* Returns the bus of the element.
*
* Returns: the element's #GstBus. unref after usage.
*
* MT safe.
*/
GstBus *
gst_element_get_bus (GstElement * element)
{
GstBus *result = NULL;
g_return_val_if_fail (GST_IS_ELEMENT (element), result);
GST_LOCK (element);
result = GST_ELEMENT_BUS (element);
gst_object_ref (result);
GST_UNLOCK (element);
GST_DEBUG_OBJECT (element, "got bus %" GST_PTR_FORMAT, result);
return result;
}
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