gstreamer/gst/gstpipeline.c
Nate Bogdanowicz 25c6490109 gstpipeline: fix failed assertion caused by seeking pipeline with NULL clock
Under certain GST_STATE_CHANGED_PAUSED_TO_PLAYING transitions, a pipeline with
a NULL clock will fail an assertion due to an unchecked call to gst_object_ref().
This is fixed by simply adding a check and only ref-ing if the clock is not NULL.

https://bugzilla.gnome.org/show_bug.cgi?id=693065
2013-02-05 14:28:36 +01:00

841 lines
26 KiB
C

/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2004,2005 Wim Taymans <wim@fluendo.com>
*
* gstpipeline.c: Overall pipeline management element
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/**
* SECTION:gstpipeline
* @short_description: Top-level bin with clocking and bus management
functionality.
* @see_also: #GstElement, #GstBin, #GstClock, #GstBus
*
* A #GstPipeline is a special #GstBin used as the toplevel container for
* the filter graph. The #GstPipeline will manage the selection and
* distribution of a global #GstClock as well as provide a #GstBus to the
* application.
*
* gst_pipeline_new() is used to create a pipeline. when you are done with
* the pipeline, use gst_object_unref() to free its resources including all
* added #GstElement objects (if not otherwise referenced).
*
* Elements are added and removed from the pipeline using the #GstBin
* methods like gst_bin_add() and gst_bin_remove() (see #GstBin).
*
* Before changing the state of the #GstPipeline (see #GstElement) a #GstBus
* can be retrieved with gst_pipeline_get_bus(). This bus can then be
* used to receive #GstMessage from the elements in the pipeline.
*
* By default, a #GstPipeline will automatically flush the pending #GstBus
* messages when going to the NULL state to ensure that no circular
* references exist when no messages are read from the #GstBus. This
* behaviour can be changed with gst_pipeline_set_auto_flush_bus().
*
* When the #GstPipeline performs the PAUSED to PLAYING state change it will
* select a clock for the elements. The clock selection algorithm will by
* default select a clock provided by an element that is most upstream
* (closest to the source). For live pipelines (ones that return
* #GST_STATE_CHANGE_NO_PREROLL from the gst_element_set_state() call) this
* will select the clock provided by the live source. For normal pipelines
* this will select a clock provided by the sinks (most likely the audio
* sink). If no element provides a clock, a default #GstSystemClock is used.
*
* The clock selection can be controlled with the gst_pipeline_use_clock()
* method, which will enforce a given clock on the pipeline. With
* gst_pipeline_auto_clock() the default clock selection algorithm can be
* restored.
*
* A #GstPipeline maintains a running time for the elements. The running
* time is defined as the difference between the current clock time and
* the base time. When the pipeline goes to READY or a flushing seek is
* performed on it, the running time is reset to 0. When the pipeline is
* set from PLAYING to PAUSED, the current clock time is sampled and used to
* configure the base time for the elements when the pipeline is set
* to PLAYING again. The effect is that the running time (as the difference
* between the clock time and the base time) will count how much time was spent
* in the PLAYING state. This default behaviour can be changed with the
* gst_element_set_start_time() method.
*
* Last reviewed on 2012-03-29 (0.11.3)
*/
#include "gst_private.h"
#include "gsterror.h"
#include "gst-i18n-lib.h"
#include "gstpipeline.h"
#include "gstinfo.h"
#include "gstsystemclock.h"
#include "gstutils.h"
GST_DEBUG_CATEGORY_STATIC (pipeline_debug);
#define GST_CAT_DEFAULT pipeline_debug
/* Pipeline signals and args */
enum
{
/* FILL ME */
LAST_SIGNAL
};
#define DEFAULT_DELAY 0
#define DEFAULT_AUTO_FLUSH_BUS TRUE
enum
{
PROP_0,
PROP_DELAY,
PROP_AUTO_FLUSH_BUS
};
#define GST_PIPELINE_GET_PRIVATE(obj) \
(G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_PIPELINE, GstPipelinePrivate))
struct _GstPipelinePrivate
{
/* with LOCK */
gboolean auto_flush_bus;
/* when we need to update stream_time or clock when going back to
* PLAYING*/
GstClockTime last_start_time;
gboolean update_clock;
};
static void gst_pipeline_dispose (GObject * object);
static void gst_pipeline_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec);
static void gst_pipeline_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec);
static GstClock *gst_pipeline_provide_clock_func (GstElement * element);
static GstStateChangeReturn gst_pipeline_change_state (GstElement * element,
GstStateChange transition);
static void gst_pipeline_handle_message (GstBin * bin, GstMessage * message);
/* static guint gst_pipeline_signals[LAST_SIGNAL] = { 0 }; */
#define _do_init \
{ \
GST_DEBUG_CATEGORY_INIT (pipeline_debug, "pipeline", GST_DEBUG_BOLD, \
"debugging info for the 'pipeline' container element"); \
}
#define gst_pipeline_parent_class parent_class
G_DEFINE_TYPE_WITH_CODE (GstPipeline, gst_pipeline, GST_TYPE_BIN, _do_init);
static void
gst_pipeline_class_init (GstPipelineClass * klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
GstElementClass *gstelement_class = GST_ELEMENT_CLASS (klass);
GstBinClass *gstbin_class = GST_BIN_CLASS (klass);
g_type_class_add_private (klass, sizeof (GstPipelinePrivate));
gobject_class->set_property = gst_pipeline_set_property;
gobject_class->get_property = gst_pipeline_get_property;
/**
* GstPipeline:delay:
*
* The expected delay needed for elements to spin up to the
* PLAYING state expressed in nanoseconds.
* see gst_pipeline_set_delay() for more information on this option.
**/
g_object_class_install_property (gobject_class, PROP_DELAY,
g_param_spec_uint64 ("delay", "Delay",
"Expected delay needed for elements "
"to spin up to PLAYING in nanoseconds", 0, G_MAXUINT64, DEFAULT_DELAY,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
/**
* GstPipeline:auto-flush-bus:
*
* Whether or not to automatically flush all messages on the
* pipeline's bus when going from READY to NULL state. Please see
* gst_pipeline_set_auto_flush_bus() for more information on this option.
**/
g_object_class_install_property (gobject_class, PROP_AUTO_FLUSH_BUS,
g_param_spec_boolean ("auto-flush-bus", "Auto Flush Bus",
"Whether to automatically flush the pipeline's bus when going "
"from READY into NULL state", DEFAULT_AUTO_FLUSH_BUS,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
gobject_class->dispose = gst_pipeline_dispose;
gst_element_class_set_static_metadata (gstelement_class, "Pipeline object",
"Generic/Bin",
"Complete pipeline object",
"Erik Walthinsen <omega@cse.ogi.edu>, Wim Taymans <wim@fluendo.com>");
gstelement_class->change_state =
GST_DEBUG_FUNCPTR (gst_pipeline_change_state);
gstelement_class->provide_clock =
GST_DEBUG_FUNCPTR (gst_pipeline_provide_clock_func);
gstbin_class->handle_message =
GST_DEBUG_FUNCPTR (gst_pipeline_handle_message);
}
static void
gst_pipeline_init (GstPipeline * pipeline)
{
GstBus *bus;
pipeline->priv = GST_PIPELINE_GET_PRIVATE (pipeline);
/* set default property values */
pipeline->priv->auto_flush_bus = DEFAULT_AUTO_FLUSH_BUS;
pipeline->delay = DEFAULT_DELAY;
/* create and set a default bus */
bus = gst_bus_new ();
#if 0
/* FIXME, disabled for 0.10.5 release as it caused to many regressions */
/* Start our bus in flushing if appropriate */
if (pipeline->priv->auto_flush_bus)
gst_bus_set_flushing (bus, TRUE);
#endif
gst_element_set_bus (GST_ELEMENT_CAST (pipeline), bus);
GST_DEBUG_OBJECT (pipeline, "set bus %" GST_PTR_FORMAT " on pipeline", bus);
gst_object_unref (bus);
}
static void
gst_pipeline_dispose (GObject * object)
{
GstPipeline *pipeline = GST_PIPELINE (object);
GstClock **clock_p = &pipeline->fixed_clock;
GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, pipeline, "dispose");
/* clear and unref any fixed clock */
gst_object_replace ((GstObject **) clock_p, NULL);
G_OBJECT_CLASS (parent_class)->dispose (object);
}
static void
gst_pipeline_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstPipeline *pipeline = GST_PIPELINE (object);
switch (prop_id) {
case PROP_DELAY:
gst_pipeline_set_delay (pipeline, g_value_get_uint64 (value));
break;
case PROP_AUTO_FLUSH_BUS:
gst_pipeline_set_auto_flush_bus (pipeline, g_value_get_boolean (value));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_pipeline_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec)
{
GstPipeline *pipeline = GST_PIPELINE (object);
switch (prop_id) {
case PROP_DELAY:
g_value_set_uint64 (value, gst_pipeline_get_delay (pipeline));
break;
case PROP_AUTO_FLUSH_BUS:
g_value_set_boolean (value, gst_pipeline_get_auto_flush_bus (pipeline));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
/* set the start_time to 0, this will cause us to select a new base_time and
* make the running_time start from 0 again. */
static void
reset_start_time (GstPipeline * pipeline, GstClockTime start_time)
{
GST_OBJECT_LOCK (pipeline);
if (GST_ELEMENT_START_TIME (pipeline) != GST_CLOCK_TIME_NONE) {
GST_DEBUG_OBJECT (pipeline, "reset start_time to 0");
GST_ELEMENT_START_TIME (pipeline) = start_time;
pipeline->priv->last_start_time = -1;
} else {
GST_DEBUG_OBJECT (pipeline, "application asked to not reset stream_time");
}
GST_OBJECT_UNLOCK (pipeline);
}
/**
* gst_pipeline_new:
* @name: (allow-none): name of new pipeline
*
* Create a new pipeline with the given name.
*
* Returns: (transfer floating): newly created GstPipeline
*
* MT safe.
*/
GstElement *
gst_pipeline_new (const gchar * name)
{
return gst_element_factory_make ("pipeline", name);
}
/* takes a snapshot of the running_time of the pipeline and store this as the
* element start_time. This is the time we will set as the running_time of the
* pipeline when we go to PLAYING next. */
static void
pipeline_update_start_time (GstElement * element)
{
GstPipeline *pipeline = GST_PIPELINE_CAST (element);
GstClock *clock;
GST_OBJECT_LOCK (element);
if ((clock = element->clock)) {
GstClockTime now;
gst_object_ref (clock);
GST_OBJECT_UNLOCK (element);
/* calculate the time when we stopped */
now = gst_clock_get_time (clock);
gst_object_unref (clock);
GST_OBJECT_LOCK (element);
/* store the current running time */
if (GST_ELEMENT_START_TIME (pipeline) != GST_CLOCK_TIME_NONE) {
if (now != GST_CLOCK_TIME_NONE)
GST_ELEMENT_START_TIME (pipeline) = now - element->base_time;
else
GST_WARNING_OBJECT (element,
"Clock %s returned invalid time, can't calculate "
"running_time when going to the PAUSED state",
GST_OBJECT_NAME (clock));
/* we went to PAUSED, when going to PLAYING select clock and new
* base_time */
pipeline->priv->update_clock = TRUE;
}
GST_DEBUG_OBJECT (element,
"start_time=%" GST_TIME_FORMAT ", now=%" GST_TIME_FORMAT
", base_time %" GST_TIME_FORMAT,
GST_TIME_ARGS (GST_ELEMENT_START_TIME (pipeline)),
GST_TIME_ARGS (now), GST_TIME_ARGS (element->base_time));
}
GST_OBJECT_UNLOCK (element);
}
/* MT safe */
static GstStateChangeReturn
gst_pipeline_change_state (GstElement * element, GstStateChange transition)
{
GstStateChangeReturn result = GST_STATE_CHANGE_SUCCESS;
GstPipeline *pipeline = GST_PIPELINE_CAST (element);
GstClock *clock;
switch (transition) {
case GST_STATE_CHANGE_NULL_TO_READY:
GST_OBJECT_LOCK (element);
if (element->bus)
gst_bus_set_flushing (element->bus, FALSE);
GST_OBJECT_UNLOCK (element);
break;
case GST_STATE_CHANGE_READY_TO_PAUSED:
GST_OBJECT_LOCK (element);
pipeline->priv->update_clock = TRUE;
GST_OBJECT_UNLOCK (element);
break;
case GST_STATE_CHANGE_PAUSED_TO_PLAYING:
{
GstClockTime now, start_time, last_start_time, delay;
gboolean update_clock;
GstClock *cur_clock;
GST_DEBUG_OBJECT (element, "selecting clock and base_time");
GST_OBJECT_LOCK (element);
cur_clock = element->clock;
if (cur_clock)
gst_object_ref (cur_clock);
/* get the desired running_time of the first buffer aka the start_time */
start_time = GST_ELEMENT_START_TIME (pipeline);
last_start_time = pipeline->priv->last_start_time;
pipeline->priv->last_start_time = start_time;
/* see if we need to update the clock */
update_clock = pipeline->priv->update_clock;
pipeline->priv->update_clock = FALSE;
delay = pipeline->delay;
GST_OBJECT_UNLOCK (element);
/* running time changed, either with a PAUSED or a flush, we need to check
* if there is a new clock & update the base time */
/* only do this for top-level, however */
if (GST_OBJECT_PARENT (element) == NULL &&
(update_clock || last_start_time != start_time)) {
GST_DEBUG_OBJECT (pipeline, "Need to update start_time");
/* when going to PLAYING, select a clock when needed. If we just got
* flushed, we don't reselect the clock. */
if (update_clock) {
GST_DEBUG_OBJECT (pipeline, "Need to update clock.");
clock = gst_element_provide_clock (element);
} else {
GST_DEBUG_OBJECT (pipeline,
"Don't need to update clock, using old clock.");
/* only try to ref if cur_clock is not NULL */
if (cur_clock)
gst_object_ref (cur_clock);
clock = cur_clock;
}
if (clock) {
now = gst_clock_get_time (clock);
} else {
GST_DEBUG_OBJECT (pipeline, "no clock, using base time of NONE");
now = GST_CLOCK_TIME_NONE;
}
if (clock != cur_clock) {
/* now distribute the clock (which could be NULL). If some
* element refuses the clock, this will return FALSE and
* we effectively fail the state change. */
if (!gst_element_set_clock (element, clock))
goto invalid_clock;
/* if we selected and distributed a new clock, let the app
* know about it */
gst_element_post_message (element,
gst_message_new_new_clock (GST_OBJECT_CAST (element), clock));
}
if (clock)
gst_object_unref (clock);
if (start_time != GST_CLOCK_TIME_NONE && now != GST_CLOCK_TIME_NONE) {
GstClockTime new_base_time = now - start_time + delay;
GST_DEBUG_OBJECT (element,
"start_time=%" GST_TIME_FORMAT ", now=%" GST_TIME_FORMAT
", base_time %" GST_TIME_FORMAT,
GST_TIME_ARGS (start_time), GST_TIME_ARGS (now),
GST_TIME_ARGS (new_base_time));
gst_element_set_base_time (element, new_base_time);
} else {
GST_DEBUG_OBJECT (pipeline,
"NOT adjusting base_time because start_time is NONE");
}
} else {
GST_DEBUG_OBJECT (pipeline,
"NOT adjusting base_time because we selected one before");
}
if (cur_clock)
gst_object_unref (cur_clock);
break;
}
case GST_STATE_CHANGE_PLAYING_TO_PAUSED:
{
/* we take a start_time snapshot before calling the children state changes
* so that they know about when the pipeline PAUSED. */
pipeline_update_start_time (element);
break;
}
case GST_STATE_CHANGE_PAUSED_TO_READY:
case GST_STATE_CHANGE_READY_TO_NULL:
break;
}
result = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
switch (transition) {
case GST_STATE_CHANGE_NULL_TO_READY:
break;
case GST_STATE_CHANGE_READY_TO_PAUSED:
{
/* READY to PAUSED starts running_time from 0 */
reset_start_time (pipeline, 0);
break;
}
case GST_STATE_CHANGE_PAUSED_TO_PLAYING:
break;
case GST_STATE_CHANGE_PLAYING_TO_PAUSED:
{
/* Take a new snapshot of the start_time after calling the state change on
* all children. This will be the running_time of the pipeline when we go
* back to PLAYING */
pipeline_update_start_time (element);
break;
}
case GST_STATE_CHANGE_PAUSED_TO_READY:
break;
case GST_STATE_CHANGE_READY_TO_NULL:
{
GstBus *bus;
gboolean auto_flush;
/* grab some stuff before we release the lock to flush out the bus */
GST_OBJECT_LOCK (element);
if ((bus = element->bus))
gst_object_ref (bus);
auto_flush = pipeline->priv->auto_flush_bus;
GST_OBJECT_UNLOCK (element);
if (bus) {
if (auto_flush) {
gst_bus_set_flushing (bus, TRUE);
} else {
GST_INFO_OBJECT (element, "not flushing bus, auto-flushing disabled");
}
gst_object_unref (bus);
}
break;
}
}
return result;
/* ERRORS */
invalid_clock:
{
/* we generate this error when the selected clock was not
* accepted by some element */
GST_ELEMENT_ERROR (pipeline, CORE, CLOCK,
(_("Selected clock cannot be used in pipeline.")),
("Pipeline cannot operate with selected clock"));
GST_DEBUG_OBJECT (pipeline,
"Pipeline cannot operate with selected clock %p", clock);
if (clock)
gst_object_unref (clock);
return GST_STATE_CHANGE_FAILURE;
}
}
/* intercept the bus messages from our children. We watch for the ASYNC_START
* message with is posted by the elements (sinks) that require a reset of the
* running_time after a flush. ASYNC_START also brings the pipeline back into
* the PAUSED, pending PAUSED state. When the ASYNC_DONE message is received the
* pipeline will redistribute the new base_time and will bring the elements back
* to the desired state of the pipeline. */
static void
gst_pipeline_handle_message (GstBin * bin, GstMessage * message)
{
GstPipeline *pipeline = GST_PIPELINE_CAST (bin);
switch (GST_MESSAGE_TYPE (message)) {
case GST_MESSAGE_RESET_TIME:
{
GstClockTime running_time;
gst_message_parse_reset_time (message, &running_time);
/* reset our running time if we need to distribute a new base_time to the
* children. */
reset_start_time (pipeline, running_time);
break;
}
case GST_MESSAGE_CLOCK_LOST:
{
GstClock *clock;
gst_message_parse_clock_lost (message, &clock);
GST_OBJECT_LOCK (bin);
if (clock == GST_ELEMENT_CAST (bin)->clock) {
GST_DEBUG_OBJECT (bin, "Used clock '%s' got lost",
GST_OBJECT_NAME (clock));
pipeline->priv->update_clock = TRUE;
}
GST_OBJECT_UNLOCK (bin);
}
default:
break;
}
GST_BIN_CLASS (parent_class)->handle_message (bin, message);
}
/**
* gst_pipeline_get_bus:
* @pipeline: a #GstPipeline
*
* Gets the #GstBus of @pipeline. The bus allows applications to receive
* #GstMessage packets.
*
* Returns: (transfer full): a #GstBus, unref after usage.
*
* MT safe.
*/
GstBus *
gst_pipeline_get_bus (GstPipeline * pipeline)
{
return gst_element_get_bus (GST_ELEMENT_CAST (pipeline));
}
static GstClock *
gst_pipeline_provide_clock_func (GstElement * element)
{
GstClock *clock = NULL;
GstPipeline *pipeline = GST_PIPELINE (element);
/* if we have a fixed clock, use that one */
GST_OBJECT_LOCK (pipeline);
if (GST_OBJECT_FLAG_IS_SET (pipeline, GST_PIPELINE_FLAG_FIXED_CLOCK)) {
clock = pipeline->fixed_clock;
if (clock)
gst_object_ref (clock);
GST_OBJECT_UNLOCK (pipeline);
GST_CAT_DEBUG (GST_CAT_CLOCK, "pipeline using fixed clock %p (%s)",
clock, clock ? GST_STR_NULL (GST_OBJECT_NAME (clock)) : "-");
} else {
GST_OBJECT_UNLOCK (pipeline);
/* let the parent bin select a clock */
clock =
GST_ELEMENT_CLASS (parent_class)->provide_clock (GST_ELEMENT
(pipeline));
/* no clock, use a system clock */
if (!clock) {
clock = gst_system_clock_obtain ();
GST_CAT_DEBUG (GST_CAT_CLOCK, "pipeline obtained system clock: %p (%s)",
clock, clock ? GST_STR_NULL (GST_OBJECT_NAME (clock)) : "-");
} else {
GST_CAT_DEBUG (GST_CAT_CLOCK, "pipeline obtained clock: %p (%s)",
clock, clock ? GST_STR_NULL (GST_OBJECT_NAME (clock)) : "-");
}
}
return clock;
}
/**
* gst_pipeline_get_clock:
* @pipeline: a #GstPipeline
*
* Gets the current clock used by @pipeline.
*
* Returns: (transfer full): a #GstClock, unref after usage.
*/
GstClock *
gst_pipeline_get_clock (GstPipeline * pipeline)
{
g_return_val_if_fail (GST_IS_PIPELINE (pipeline), NULL);
return gst_pipeline_provide_clock_func (GST_ELEMENT_CAST (pipeline));
}
/**
* gst_pipeline_use_clock:
* @pipeline: a #GstPipeline
* @clock: (transfer none): the clock to use
*
* Force @pipeline to use the given @clock. The pipeline will
* always use the given clock even if new clock providers are added
* to this pipeline.
*
* If @clock is NULL all clocking will be disabled which will make
* the pipeline run as fast as possible.
*
* MT safe.
*/
void
gst_pipeline_use_clock (GstPipeline * pipeline, GstClock * clock)
{
GstClock **clock_p;
g_return_if_fail (GST_IS_PIPELINE (pipeline));
GST_OBJECT_LOCK (pipeline);
GST_OBJECT_FLAG_SET (pipeline, GST_PIPELINE_FLAG_FIXED_CLOCK);
clock_p = &pipeline->fixed_clock;
gst_object_replace ((GstObject **) clock_p, (GstObject *) clock);
GST_OBJECT_UNLOCK (pipeline);
GST_CAT_DEBUG (GST_CAT_CLOCK, "pipeline using fixed clock %p (%s)", clock,
(clock ? GST_OBJECT_NAME (clock) : "nil"));
}
/**
* gst_pipeline_set_clock:
* @pipeline: a #GstPipeline
* @clock: (transfer none): the clock to set
*
* Set the clock for @pipeline. The clock will be distributed
* to all the elements managed by the pipeline.
*
* Returns: TRUE if the clock could be set on the pipeline. FALSE if
* some element did not accept the clock.
*
* MT safe.
*/
gboolean
gst_pipeline_set_clock (GstPipeline * pipeline, GstClock * clock)
{
g_return_val_if_fail (pipeline != NULL, FALSE);
g_return_val_if_fail (GST_IS_PIPELINE (pipeline), FALSE);
return
GST_ELEMENT_CLASS (parent_class)->set_clock (GST_ELEMENT_CAST (pipeline),
clock);
}
/**
* gst_pipeline_auto_clock:
* @pipeline: a #GstPipeline
*
* Let @pipeline select a clock automatically. This is the default
* behaviour.
*
* Use this function if you previous forced a fixed clock with
* gst_pipeline_use_clock() and want to restore the default
* pipeline clock selection algorithm.
*
* MT safe.
*/
void
gst_pipeline_auto_clock (GstPipeline * pipeline)
{
GstClock **clock_p;
g_return_if_fail (pipeline != NULL);
g_return_if_fail (GST_IS_PIPELINE (pipeline));
GST_OBJECT_LOCK (pipeline);
GST_OBJECT_FLAG_UNSET (pipeline, GST_PIPELINE_FLAG_FIXED_CLOCK);
clock_p = &pipeline->fixed_clock;
gst_object_replace ((GstObject **) clock_p, NULL);
GST_OBJECT_UNLOCK (pipeline);
GST_CAT_DEBUG (GST_CAT_CLOCK, "pipeline using automatic clock");
}
/**
* gst_pipeline_set_delay:
* @pipeline: a #GstPipeline
* @delay: the delay
*
* Set the expected delay needed for all elements to perform the
* PAUSED to PLAYING state change. @delay will be added to the
* base time of the elements so that they wait an additional @delay
* amount of time before starting to process buffers and cannot be
* #GST_CLOCK_TIME_NONE.
*
* This option is used for tuning purposes and should normally not be
* used.
*
* MT safe.
*/
void
gst_pipeline_set_delay (GstPipeline * pipeline, GstClockTime delay)
{
g_return_if_fail (GST_IS_PIPELINE (pipeline));
g_return_if_fail (delay != GST_CLOCK_TIME_NONE);
GST_OBJECT_LOCK (pipeline);
pipeline->delay = delay;
GST_OBJECT_UNLOCK (pipeline);
}
/**
* gst_pipeline_get_delay:
* @pipeline: a #GstPipeline
*
* Get the configured delay (see gst_pipeline_set_delay()).
*
* Returns: The configured delay.
*
* MT safe.
*/
GstClockTime
gst_pipeline_get_delay (GstPipeline * pipeline)
{
GstClockTime res;
g_return_val_if_fail (GST_IS_PIPELINE (pipeline), GST_CLOCK_TIME_NONE);
GST_OBJECT_LOCK (pipeline);
res = pipeline->delay;
GST_OBJECT_UNLOCK (pipeline);
return res;
}
/**
* gst_pipeline_set_auto_flush_bus:
* @pipeline: a #GstPipeline
* @auto_flush: whether or not to automatically flush the bus when
* the pipeline goes from READY to NULL state
*
* Usually, when a pipeline goes from READY to NULL state, it automatically
* flushes all pending messages on the bus, which is done for refcounting
* purposes, to break circular references.
*
* This means that applications that update state using (async) bus messages
* (e.g. do certain things when a pipeline goes from PAUSED to READY) might
* not get to see messages when the pipeline is shut down, because they might
* be flushed before they can be dispatched in the main thread. This behaviour
* can be disabled using this function.
*
* It is important that all messages on the bus are handled when the
* automatic flushing is disabled else memory leaks will be introduced.
*
* MT safe.
*/
void
gst_pipeline_set_auto_flush_bus (GstPipeline * pipeline, gboolean auto_flush)
{
g_return_if_fail (GST_IS_PIPELINE (pipeline));
GST_OBJECT_LOCK (pipeline);
pipeline->priv->auto_flush_bus = auto_flush;
GST_OBJECT_UNLOCK (pipeline);
}
/**
* gst_pipeline_get_auto_flush_bus:
* @pipeline: a #GstPipeline
*
* Check if @pipeline will automatically flush messages when going to
* the NULL state.
*
* Returns: whether the pipeline will automatically flush its bus when
* going from READY to NULL state or not.
*
* MT safe.
*/
gboolean
gst_pipeline_get_auto_flush_bus (GstPipeline * pipeline)
{
gboolean res;
g_return_val_if_fail (GST_IS_PIPELINE (pipeline), FALSE);
GST_OBJECT_LOCK (pipeline);
res = pipeline->priv->auto_flush_bus;
GST_OBJECT_UNLOCK (pipeline);
return res;
}