gstreamer_core/gst/gstpipeline.c
changeset 0 0e761a78d257
child 8 4a7fac7dd34a
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gstreamer_core/gst/gstpipeline.c	Thu Dec 17 08:53:32 2009 +0200
@@ -0,0 +1,952 @@
+/* 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. It will also implement a default behavour for managing
+ * seek events (see gst_element_seek()).
+ *
+ * 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 stream time for the elements. The stream
+ * 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 stream 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. This default behaviour can be changed with the
+ * gst_pipeline_set_new_stream_time() method.
+ *
+ * When sending a flushing seek event to a GstPipeline (see
+ * gst_element_seek()), it will make sure that the pipeline is properly
+ * PAUSED and resumed as well as set the new stream time to 0 when the
+ * seek succeeded.
+ *
+ * Last reviewed on 2006-03-12 (0.10.5)
+ */
+
+#include "gst_private.h"
+#include "gsterror.h"
+#include "gst-i18n-lib.h"
+
+#include "gstpipeline.h"
+#include "gstinfo.h"
+#include "gstsystemclock.h"
+
+#ifdef __SYMBIAN32__
+#include <glib_global.h>
+#endif
+
+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*/
+  gboolean update_stream_time;
+  gboolean update_clock;
+};
+
+
+static void gst_pipeline_base_init (gpointer g_class);
+static void gst_pipeline_class_init (gpointer g_class, gpointer class_data);
+static void gst_pipeline_init (GTypeInstance * instance, gpointer g_class);
+
+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 GstBinClass *parent_class = NULL;
+
+/* static guint gst_pipeline_signals[LAST_SIGNAL] = { 0 }; */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+
+GType
+gst_pipeline_get_type (void)
+{
+  static GType pipeline_type = 0;
+
+  if (G_UNLIKELY (pipeline_type == 0)) {
+    static const GTypeInfo pipeline_info = {
+      sizeof (GstPipelineClass),
+      gst_pipeline_base_init,
+      NULL,
+      (GClassInitFunc) gst_pipeline_class_init,
+      NULL,
+      NULL,
+      sizeof (GstPipeline),
+      0,
+      gst_pipeline_init,
+      NULL
+    };
+
+    pipeline_type =
+        g_type_register_static (GST_TYPE_BIN, "GstPipeline", &pipeline_info, 0);
+
+    GST_DEBUG_CATEGORY_INIT (pipeline_debug, "pipeline", GST_DEBUG_BOLD,
+        "debugging info for the 'pipeline' container element");
+  }
+  return pipeline_type;
+}
+
+static void
+gst_pipeline_base_init (gpointer g_class)
+{
+  GstElementClass *gstelement_class = GST_ELEMENT_CLASS (g_class);
+
+  gst_element_class_set_details_simple (gstelement_class, "Pipeline object",
+      "Generic/Bin",
+      "Complete pipeline object",
+      "Erik Walthinsen <omega@cse.ogi.edu>, Wim Taymans <wim@fluendo.com>");
+}
+
+static void
+gst_pipeline_class_init (gpointer g_class, gpointer class_data)
+{
+  GObjectClass *gobject_class = G_OBJECT_CLASS (g_class);
+  GstElementClass *gstelement_class = GST_ELEMENT_CLASS (g_class);
+  GstBinClass *gstbin_class = GST_BIN_CLASS (g_class);
+  GstPipelineClass *klass = GST_PIPELINE_CLASS (g_class);
+
+  parent_class = g_type_class_peek_parent (klass);
+
+  g_type_class_add_private (klass, sizeof (GstPipelinePrivate));
+
+  gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_pipeline_set_property);
+  gobject_class->get_property = GST_DEBUG_FUNCPTR (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.
+   *
+   * Since: 0.10.5
+   **/
+  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));
+
+  /**
+   * 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.
+   *
+   * Since: 0.10.4
+   **/
+  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));
+
+  gobject_class->dispose = GST_DEBUG_FUNCPTR (gst_pipeline_dispose);
+
+  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 (GTypeInstance * instance, gpointer g_class)
+{
+  GstPipeline *pipeline = GST_PIPELINE (instance);
+  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 stream time to 0 */
+static void
+reset_stream_time (GstPipeline * pipeline)
+{
+  GST_OBJECT_LOCK (pipeline);
+  if (pipeline->stream_time != GST_CLOCK_TIME_NONE) {
+    GST_DEBUG_OBJECT (pipeline, "reset stream_time to 0");
+    pipeline->stream_time = 0;
+    pipeline->priv->update_stream_time = TRUE;
+  } else {
+    GST_DEBUG_OBJECT (pipeline, "application asked to not reset stream_time");
+  }
+  GST_OBJECT_UNLOCK (pipeline);
+}
+
+/**
+ * gst_pipeline_new:
+ * @name: name of new pipeline
+ *
+ * Create a new pipeline with the given name.
+ *
+ * Returns: newly created GstPipeline
+ *
+ * MT safe.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+GstElement *
+gst_pipeline_new (const gchar * name)
+{
+  return gst_element_factory_make ("pipeline", name);
+}
+
+/* MT safe */
+static GstStateChangeReturn
+gst_pipeline_change_state (GstElement * element, GstStateChange transition)
+{
+  GstStateChangeReturn result = GST_STATE_CHANGE_SUCCESS;
+  GstPipeline *pipeline = GST_PIPELINE (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 new_base_time;
+      GstClockTime start_time, stream_time, delay;
+      gboolean new_clock, update_stream_time, 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);
+      stream_time = pipeline->stream_time;
+      update_stream_time = pipeline->priv->update_stream_time;
+      update_clock = pipeline->priv->update_clock;
+      pipeline->priv->update_stream_time = FALSE;
+      pipeline->priv->update_clock = FALSE;
+      delay = pipeline->delay;
+      GST_OBJECT_UNLOCK (element);
+
+      /* stream time changed, either with a PAUSED or a flush, we need to check
+       * if there is a new clock & update the base time */
+      if (update_stream_time) {
+        GST_DEBUG_OBJECT (pipeline, "Need to update stream_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.");
+          clock = gst_object_ref (cur_clock);
+        }
+
+        new_clock = (clock != cur_clock);
+
+        if (clock) {
+          start_time = gst_clock_get_time (clock);
+        } else {
+          GST_DEBUG ("no clock, using base time of NONE");
+          start_time = GST_CLOCK_TIME_NONE;
+          new_base_time = GST_CLOCK_TIME_NONE;
+        }
+
+        if (new_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 (stream_time != GST_CLOCK_TIME_NONE
+            && start_time != GST_CLOCK_TIME_NONE) {
+          new_base_time = start_time - stream_time + delay;
+          GST_DEBUG_OBJECT (element,
+              "stream_time=%" GST_TIME_FORMAT ", now=%" GST_TIME_FORMAT
+              ", base_time %" GST_TIME_FORMAT,
+              GST_TIME_ARGS (stream_time), GST_TIME_ARGS (start_time),
+              GST_TIME_ARGS (new_base_time));
+        } else
+          new_base_time = GST_CLOCK_TIME_NONE;
+
+        if (new_base_time != GST_CLOCK_TIME_NONE)
+          gst_element_set_base_time (element, new_base_time);
+        else
+          GST_DEBUG_OBJECT (pipeline,
+              "NOT adjusting base_time because stream_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:
+      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:
+    {
+      reset_stream_time (pipeline);
+      break;
+    }
+    case GST_STATE_CHANGE_PAUSED_TO_PLAYING:
+      break;
+    case GST_STATE_CHANGE_PLAYING_TO_PAUSED:
+      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 stream time */
+        if (pipeline->stream_time != GST_CLOCK_TIME_NONE) {
+          pipeline->stream_time = now - element->base_time;
+          /* we went to PAUSED, when going to PLAYING select clock and new
+           * base_time */
+          pipeline->priv->update_stream_time = TRUE;
+          pipeline->priv->update_clock = TRUE;
+        }
+
+        GST_DEBUG_OBJECT (element,
+            "stream_time=%" GST_TIME_FORMAT ", now=%" GST_TIME_FORMAT
+            ", base_time %" GST_TIME_FORMAT,
+            GST_TIME_ARGS (pipeline->stream_time), GST_TIME_ARGS (now),
+            GST_TIME_ARGS (element->base_time));
+      }
+      GST_OBJECT_UNLOCK (element);
+      break;
+    case GST_STATE_CHANGE_PAUSED_TO_READY:
+      break;
+    case GST_STATE_CHANGE_READY_TO_NULL:
+      GST_OBJECT_LOCK (element);
+      if (element->bus) {
+        if (pipeline->priv->auto_flush_bus) {
+          gst_bus_set_flushing (element->bus, TRUE);
+        } else {
+          GST_INFO_OBJECT (element, "not flushing bus, auto-flushing disabled");
+        }
+      }
+      GST_OBJECT_UNLOCK (element);
+      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;
+  }
+}
+
+static void
+gst_pipeline_handle_message (GstBin * bin, GstMessage * message)
+{
+  GstPipeline *pipeline = GST_PIPELINE_CAST (bin);
+
+  switch (GST_MESSAGE_TYPE (message)) {
+    case GST_MESSAGE_ASYNC_START:
+    {
+      gboolean new_base_time;
+
+      gst_message_parse_async_start (message, &new_base_time);
+
+      /* reset our stream time if we need to distribute a new base_time to the
+       * children. */
+      if (new_base_time)
+        reset_stream_time (pipeline);
+
+      break;
+    }
+    default:
+      break;
+  }
+  GST_BIN_CLASS (parent_class)->handle_message (bin, message);
+}
+
+/**
+ * gst_pipeline_get_bus:
+ * @pipeline: a #GstPipeline
+ *
+ * Gets the #GstBus of @pipeline.
+ *
+ * Returns: a #GstBus, unref after usage.
+ *
+ * MT safe.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+GstBus *
+gst_pipeline_get_bus (GstPipeline * pipeline)
+{
+  return gst_element_get_bus (GST_ELEMENT (pipeline));
+}
+
+/**
+ * gst_pipeline_set_new_stream_time:
+ * @pipeline: a #GstPipeline
+ * @time: the new stream time to set
+ *
+ * Set the new stream time of @pipeline to @time. The stream time is used to
+ * set the base time on the elements (see gst_element_set_base_time())
+ * in the PAUSED->PLAYING state transition.
+ *
+ * Setting @time to #GST_CLOCK_TIME_NONE will disable the pipeline's management
+ * of element base time. The application will then be responsible for
+ * performing base time distribution. This is sometimes useful if you want to
+ * synchronize capture from multiple pipelines, and you can also ensure that the
+ * pipelines have the same clock.
+ *
+ * MT safe.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+void
+gst_pipeline_set_new_stream_time (GstPipeline * pipeline, GstClockTime time)
+{
+  g_return_if_fail (GST_IS_PIPELINE (pipeline));
+
+  GST_OBJECT_LOCK (pipeline);
+  pipeline->stream_time = time;
+  pipeline->priv->update_stream_time = TRUE;
+  GST_OBJECT_UNLOCK (pipeline);
+
+  GST_DEBUG_OBJECT (pipeline, "set new stream_time to %" GST_TIME_FORMAT,
+      GST_TIME_ARGS (time));
+
+  if (time == GST_CLOCK_TIME_NONE)
+    GST_DEBUG_OBJECT (pipeline, "told not to adjust base_time");
+}
+
+/**
+ * gst_pipeline_get_last_stream_time:
+ * @pipeline: a #GstPipeline
+ *
+ * Gets the last stream time of @pipeline. If the pipeline is PLAYING,
+ * the returned time is the stream time used to configure the element's
+ * base time in the PAUSED->PLAYING state. If the pipeline is PAUSED, the
+ * returned time is the stream time when the pipeline was paused.
+ *
+ * This function returns #GST_CLOCK_TIME_NONE if the pipeline was
+ * configured to not handle the management of the element's base time
+ * (see gst_pipeline_set_new_stream_time()).
+ *
+ * Returns: a #GstClockTime.
+ *
+ * MT safe.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+GstClockTime
+gst_pipeline_get_last_stream_time (GstPipeline * pipeline)
+{
+  GstClockTime result;
+
+  g_return_val_if_fail (GST_IS_PIPELINE (pipeline), GST_CLOCK_TIME_NONE);
+
+  GST_OBJECT_LOCK (pipeline);
+  result = pipeline->stream_time;
+  GST_OBJECT_UNLOCK (pipeline);
+
+  return result;
+}
+
+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: a #GstClock, unref after usage.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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 (pipeline));
+}
+
+
+/**
+ * gst_pipeline_use_clock:
+ * @pipeline: a #GstPipeline
+ * @clock: 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.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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: 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.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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 (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.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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.
+ *
+ * Since: 0.10.5
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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.
+ *
+ * Since: 0.10.5
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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.
+ *
+ * Since: 0.10.4
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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.
+ *
+ * Since: 0.10.4
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+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;
+}