gstreamer_core/gst/gstevent.c
changeset 16 8e837d1bf446
parent 0 0e761a78d257
child 30 7e817e7e631c
--- a/gstreamer_core/gst/gstevent.c	Wed Mar 24 17:58:42 2010 -0500
+++ b/gstreamer_core/gst/gstevent.c	Wed Mar 24 18:04:17 2010 -0500
@@ -83,9 +83,10 @@
 #include "gstevent.h"
 #include "gstenumtypes.h"
 #include "gstutils.h"
+#include "gstquark.h"
 
-static void gst_event_init (GTypeInstance * instance, gpointer g_class);
-static void gst_event_class_init (gpointer g_class, gpointer class_data);
+#define GST_EVENT_SEQNUM(e) ((GstEvent*)e)->abidata.seqnum
+
 static void gst_event_finalize (GstEvent * event);
 static GstEvent *_gst_event_copy (GstEvent * event);
 
@@ -200,62 +201,31 @@
 
   return ret;
 }
-#ifdef __SYMBIAN32__
-EXPORT_C
-#endif
 
-
-GType
-gst_event_get_type (void)
-{
-  static GType _gst_event_type = 0;
-  int i;
-
-  if (G_UNLIKELY (_gst_event_type == 0)) {
-    static const GTypeInfo event_info = {
-      sizeof (GstEventClass),
-      NULL,
-      NULL,
-      gst_event_class_init,
-      NULL,
-      NULL,
-      sizeof (GstEvent),
-      0,
-      gst_event_init,
-      NULL
-    };
-
-    _gst_event_type = g_type_register_static (GST_TYPE_MINI_OBJECT,
-        "GstEvent", &event_info, 0);
-
-    for (i = 0; event_quarks[i].name; i++) {
-      event_quarks[i].quark = g_quark_from_static_string (event_quarks[i].name);
-    }
-  }
-
-  return _gst_event_type;
+#define _do_init \
+{ \
+  gint i; \
+  \
+  for (i = 0; event_quarks[i].name; i++) { \
+    event_quarks[i].quark = g_quark_from_static_string (event_quarks[i].name); \
+  } \
 }
 
-static void
-gst_event_class_init (gpointer g_class, gpointer class_data)
-{
-  GstEventClass *event_class = GST_EVENT_CLASS (g_class);
+G_DEFINE_TYPE_WITH_CODE (GstEvent, gst_event, GST_TYPE_MINI_OBJECT, _do_init);
 
-  parent_class = g_type_class_peek_parent (g_class);
+static void
+gst_event_class_init (GstEventClass * klass)
+{
+  parent_class = g_type_class_peek_parent (klass);
 
-  event_class->mini_object_class.copy =
-      (GstMiniObjectCopyFunction) _gst_event_copy;
-  event_class->mini_object_class.finalize =
+  klass->mini_object_class.copy = (GstMiniObjectCopyFunction) _gst_event_copy;
+  klass->mini_object_class.finalize =
       (GstMiniObjectFinalizeFunction) gst_event_finalize;
 }
 
 static void
-gst_event_init (GTypeInstance * instance, gpointer g_class)
+gst_event_init (GstEvent * event)
 {
-  GstEvent *event;
-
-  event = GST_EVENT (instance);
-
   GST_EVENT_TIMESTAMP (event) = GST_CLOCK_TIME_NONE;
 }
 
@@ -277,7 +247,7 @@
     gst_structure_free (event->structure);
   }
 
-  GST_MINI_OBJECT_CLASS (parent_class)->finalize (GST_MINI_OBJECT (event));
+/*   GST_MINI_OBJECT_CLASS (parent_class)->finalize (GST_MINI_OBJECT (event)); */
 }
 
 static GstEvent *
@@ -289,6 +259,7 @@
 
   GST_EVENT_TYPE (copy) = GST_EVENT_TYPE (event);
   GST_EVENT_TIMESTAMP (copy) = GST_EVENT_TIMESTAMP (event);
+  GST_EVENT_SEQNUM (copy) = GST_EVENT_SEQNUM (event);
 
   if (GST_EVENT_SRC (event)) {
     GST_EVENT_SRC (copy) = gst_object_ref (GST_EVENT_SRC (event));
@@ -314,6 +285,7 @@
   event->type = type;
   event->src = NULL;
   event->structure = NULL;
+  GST_EVENT_SEQNUM (event) = gst_util_seqnum_next ();
 
   return event;
 }
@@ -383,6 +355,95 @@
 }
 
 /**
+ * gst_event_has_name:
+ * @event: The #GstEvent.
+ * @name: name to check
+ *
+ * Checks if @event has the given @name. This function is usually used to
+ * check the name of a custom event.
+ *
+ * Returns: %TRUE if @name matches the name of the event structure.
+ *
+ * Since: 0.10.20
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+gboolean
+gst_event_has_name (GstEvent * event, const gchar * name)
+{
+  g_return_val_if_fail (GST_IS_EVENT (event), FALSE);
+
+  if (event->structure == NULL)
+    return FALSE;
+
+  return gst_structure_has_name (event->structure, name);
+}
+
+/**
+ * gst_event_get_seqnum:
+ * @event: A #GstEvent.
+ *
+ * Retrieve the sequence number of a event.
+ *
+ * Events have ever-incrementing sequence numbers, which may also be set
+ * explicitly via gst_event_set_seqnum(). Sequence numbers are typically used to
+ * indicate that a event corresponds to some other set of events or messages,
+ * for example an EOS event corresponding to a SEEK event. It is considered good
+ * practice to make this correspondence when possible, though it is not
+ * required.
+ *
+ * Note that events and messages share the same sequence number incrementor;
+ * two events or messages will never not have the same sequence number unless
+ * that correspondence was made explicitly.
+ *
+ * Returns: The event's sequence number.
+ *
+ * MT safe.
+ *
+ * Since: 0.10.22
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+guint32
+gst_event_get_seqnum (GstEvent * event)
+{
+  g_return_val_if_fail (GST_IS_EVENT (event), -1);
+
+  return GST_EVENT_SEQNUM (event);
+}
+
+/**
+ * gst_event_set_seqnum:
+ * @event: A #GstEvent.
+ * @seqnum: A sequence number.
+ *
+ * Set the sequence number of a event.
+ *
+ * This function might be called by the creator of a event to indicate that the
+ * event relates to other events or messages. See gst_event_get_seqnum() for
+ * more information.
+ *
+ * MT safe.
+ *
+ * Since: 0.10.22
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+void
+gst_event_set_seqnum (GstEvent * event, guint32 seqnum)
+{
+  g_return_if_fail (GST_IS_EVENT (event));
+
+  GST_EVENT_SEQNUM (event) = seqnum;
+}
+
+/**
  * gst_event_new_flush_start:
  *
  * Allocate a new flush start event. The flush start event can be sent
@@ -541,7 +602,8 @@
  * The newsegment event marks the range of buffers to be processed. All
  * data not within the segment range is not to be processed. This can be
  * used intelligently by plugins to apply more efficient methods of skipping
- * unneeded data.
+ * unneeded data. The valid range is expressed with the @start and @stop
+ * values.
  *
  * The position value of the segment is used in conjunction with the start
  * value to convert the buffer timestamps into the stream time. This is 
@@ -572,11 +634,15 @@
 #ifdef __SYMBIAN32__
 EXPORT_C
 #endif
+
 GstEvent *
 gst_event_new_new_segment_full (gboolean update, gdouble rate,
     gdouble applied_rate, GstFormat format, gint64 start, gint64 stop,
     gint64 position)
 {
+  GstEvent *event;
+  GstStructure *structure;
+
   g_return_val_if_fail (rate != 0.0, NULL);
   g_return_val_if_fail (applied_rate != 0.0, NULL);
 
@@ -589,9 +655,10 @@
         GST_TIME_ARGS (stop), GST_TIME_ARGS (position));
   } else {
     GST_CAT_INFO (GST_CAT_EVENT,
-        "creating newsegment update %d, rate %lf, format %d, "
+        "creating newsegment update %d, rate %lf, format %s, "
         "start %" G_GINT64_FORMAT ", stop %" G_GINT64_FORMAT ", position %"
-        G_GINT64_FORMAT, update, rate, format, start, stop, position);
+        G_GINT64_FORMAT, update, rate, gst_format_get_name (format), start,
+        stop, position);
   }
 
   g_return_val_if_fail (position != -1, NULL);
@@ -599,15 +666,17 @@
   if (stop != -1)
     g_return_val_if_fail (start <= stop, NULL);
 
-  return gst_event_new_custom (GST_EVENT_NEWSEGMENT,
-      gst_structure_new ("GstEventNewsegment",
-          "update", G_TYPE_BOOLEAN, update,
-          "rate", G_TYPE_DOUBLE, rate,
-          "applied_rate", G_TYPE_DOUBLE, applied_rate,
-          "format", GST_TYPE_FORMAT, format,
-          "start", G_TYPE_INT64, start,
-          "stop", G_TYPE_INT64, stop,
-          "position", G_TYPE_INT64, position, NULL));
+  structure = gst_structure_id_new (GST_QUARK (EVENT_NEWSEGMENT),
+      GST_QUARK (UPDATE), G_TYPE_BOOLEAN, update,
+      GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
+      GST_QUARK (APPLIED_RATE), G_TYPE_DOUBLE, applied_rate,
+      GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
+      GST_QUARK (START), G_TYPE_INT64, start,
+      GST_QUARK (STOP), G_TYPE_INT64, stop,
+      GST_QUARK (POSITION), G_TYPE_INT64, position, NULL);
+  event = gst_event_new_custom (GST_EVENT_NEWSEGMENT, structure);
+
+  return event;
 }
 
 /**
@@ -644,27 +713,37 @@
   structure = gst_event_get_structure (event);
   if (G_LIKELY (update))
     *update =
-        g_value_get_boolean (gst_structure_get_value (structure, "update"));
+        g_value_get_boolean (gst_structure_id_get_value (structure,
+            GST_QUARK (UPDATE)));
   if (G_LIKELY (rate))
-    *rate = g_value_get_double (gst_structure_get_value (structure, "rate"));
+    *rate =
+        g_value_get_double (gst_structure_id_get_value (structure,
+            GST_QUARK (RATE)));
   if (G_LIKELY (applied_rate))
     *applied_rate =
-        g_value_get_double (gst_structure_get_value (structure,
-            "applied_rate"));
+        g_value_get_double (gst_structure_id_get_value (structure,
+            GST_QUARK (APPLIED_RATE)));
   if (G_LIKELY (format))
-    *format = g_value_get_enum (gst_structure_get_value (structure, "format"));
+    *format =
+        g_value_get_enum (gst_structure_id_get_value (structure,
+            GST_QUARK (FORMAT)));
   if (G_LIKELY (start))
-    *start = g_value_get_int64 (gst_structure_get_value (structure, "start"));
+    *start =
+        g_value_get_int64 (gst_structure_id_get_value (structure,
+            GST_QUARK (START)));
   if (G_LIKELY (stop))
-    *stop = g_value_get_int64 (gst_structure_get_value (structure, "stop"));
+    *stop =
+        g_value_get_int64 (gst_structure_id_get_value (structure,
+            GST_QUARK (STOP)));
   if (G_LIKELY (position))
     *position =
-        g_value_get_int64 (gst_structure_get_value (structure, "position"));
+        g_value_get_int64 (gst_structure_id_get_value (structure,
+            GST_QUARK (POSITION)));
 }
 
 /**
  * gst_event_new_tag:
- * @taglist: metadata list
+ * @taglist: metadata list. The event will take ownership of @taglist.
  *
  * Generates a metadata tag event from the given @taglist.
  *
@@ -726,17 +805,22 @@
 gst_event_new_buffer_size (GstFormat format, gint64 minsize,
     gint64 maxsize, gboolean async)
 {
+  GstEvent *event;
+  GstStructure *structure;
+
   GST_CAT_INFO (GST_CAT_EVENT,
-      "creating buffersize format %d, minsize %" G_GINT64_FORMAT
-      ", maxsize %" G_GINT64_FORMAT ", async %d", format,
+      "creating buffersize format %s, minsize %" G_GINT64_FORMAT
+      ", maxsize %" G_GINT64_FORMAT ", async %d", gst_format_get_name (format),
       minsize, maxsize, async);
 
-  return gst_event_new_custom (GST_EVENT_BUFFERSIZE,
-      gst_structure_new ("GstEventBufferSize",
-          "format", GST_TYPE_FORMAT, format,
-          "minsize", G_TYPE_INT64, minsize,
-          "maxsize", G_TYPE_INT64, maxsize,
-          "async", G_TYPE_BOOLEAN, async, NULL));
+  structure = gst_structure_id_new (GST_QUARK (EVENT_BUFFER_SIZE),
+      GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
+      GST_QUARK (MINSIZE), G_TYPE_INT64, minsize,
+      GST_QUARK (MAXSIZE), G_TYPE_INT64, maxsize,
+      GST_QUARK (ASYNC), G_TYPE_BOOLEAN, async, NULL);
+  event = gst_event_new_custom (GST_EVENT_BUFFERSIZE, structure);
+
+  return event;
 }
 
 /**
@@ -764,15 +848,21 @@
 
   structure = gst_event_get_structure (event);
   if (format)
-    *format = g_value_get_enum (gst_structure_get_value (structure, "format"));
+    *format =
+        g_value_get_enum (gst_structure_id_get_value (structure,
+            GST_QUARK (FORMAT)));
   if (minsize)
     *minsize =
-        g_value_get_int64 (gst_structure_get_value (structure, "minsize"));
+        g_value_get_int64 (gst_structure_id_get_value (structure,
+            GST_QUARK (MINSIZE)));
   if (maxsize)
     *maxsize =
-        g_value_get_int64 (gst_structure_get_value (structure, "maxsize"));
+        g_value_get_int64 (gst_structure_id_get_value (structure,
+            GST_QUARK (MAXSIZE)));
   if (async)
-    *async = g_value_get_boolean (gst_structure_get_value (structure, "async"));
+    *async =
+        g_value_get_boolean (gst_structure_id_get_value (structure,
+            GST_QUARK (ASYNC)));
 }
 
 /**
@@ -809,7 +899,8 @@
  * The upstream element can use the @diff and @timestamp values to decide
  * whether to process more buffers. For possitive @diff, all buffers with
  * timestamp <= @timestamp + @diff will certainly arrive late in the sink
- * as well. 
+ * as well. A (negative) @diff value so that @timestamp + @diff would yield a
+ * result smaller than 0 is not allowed.
  *
  * The application can use general event probes to intercept the QoS
  * event and implement custom application specific QoS handling.
@@ -824,16 +915,24 @@
 gst_event_new_qos (gdouble proportion, GstClockTimeDiff diff,
     GstClockTime timestamp)
 {
+  GstEvent *event;
+  GstStructure *structure;
+
+  /* diff must be positive or timestamp + diff must be positive */
+  g_return_val_if_fail (diff >= 0 || -diff <= timestamp, NULL);
+
   GST_CAT_INFO (GST_CAT_EVENT,
       "creating qos proportion %lf, diff %" G_GINT64_FORMAT
       ", timestamp %" GST_TIME_FORMAT, proportion,
       diff, GST_TIME_ARGS (timestamp));
 
-  return gst_event_new_custom (GST_EVENT_QOS,
-      gst_structure_new ("GstEventQOS",
-          "proportion", G_TYPE_DOUBLE, proportion,
-          "diff", G_TYPE_INT64, diff,
-          "timestamp", G_TYPE_UINT64, timestamp, NULL));
+  structure = gst_structure_id_new (GST_QUARK (EVENT_QOS),
+      GST_QUARK (PROPORTION), G_TYPE_DOUBLE, proportion,
+      GST_QUARK (DIFF), G_TYPE_INT64, diff,
+      GST_QUARK (TIMESTAMP), G_TYPE_UINT64, timestamp, NULL);
+  event = gst_event_new_custom (GST_EVENT_QOS, structure);
+
+  return event;
 }
 
 /**
@@ -862,12 +961,16 @@
   structure = gst_event_get_structure (event);
   if (proportion)
     *proportion =
-        g_value_get_double (gst_structure_get_value (structure, "proportion"));
+        g_value_get_double (gst_structure_id_get_value (structure,
+            GST_QUARK (PROPORTION)));
   if (diff)
-    *diff = g_value_get_int64 (gst_structure_get_value (structure, "diff"));
+    *diff =
+        g_value_get_int64 (gst_structure_id_get_value (structure,
+            GST_QUARK (DIFF)));
   if (timestamp)
     *timestamp =
-        g_value_get_uint64 (gst_structure_get_value (structure, "timestamp"));
+        g_value_get_uint64 (gst_structure_id_get_value (structure,
+            GST_QUARK (TIMESTAMP)));
 }
 
 /**
@@ -896,9 +999,9 @@
  * configured playback segment can be queried with #GST_QUERY_SEGMENT. 
  *
  * @start_type and @stop_type specify how to adjust the currently configured 
- * start and stop fields in @segment. Adjustments can be made relative or
- * absolute to the last configured values. A type of #GST_SEEK_TYPE_NONE means
- * that the position should not be updated.
+ * start and stop fields in playback segment. Adjustments can be made relative
+ * or absolute to the last configured values. A type of #GST_SEEK_TYPE_NONE
+ * means that the position should not be updated.
  *
  * When the rate is positive and @start has been updated, playback will start
  * from the newly configured start position. 
@@ -910,17 +1013,22 @@
  * It is not possible to seek relative to the current playback position, to do
  * this, PAUSE the pipeline, query the current playback position with
  * #GST_QUERY_POSITION and update the playback segment current position with a
- * #GST_SEEK_TYPE_SET to the desired position.
+ * #GST_SEEK_TYPE_SET to the desired position. 
  *
  * Returns: A new seek event.
  */
+
 #ifdef __SYMBIAN32__
 EXPORT_C
 #endif
+
 GstEvent *
 gst_event_new_seek (gdouble rate, GstFormat format, GstSeekFlags flags,
     GstSeekType start_type, gint64 start, GstSeekType stop_type, gint64 stop)
 {
+  GstEvent *event;
+  GstStructure *structure;
+
   g_return_val_if_fail (rate != 0.0, NULL);
 
   if (format == GST_FORMAT_TIME) {
@@ -932,20 +1040,24 @@
         stop_type, GST_TIME_ARGS (stop));
   } else {
     GST_CAT_INFO (GST_CAT_EVENT,
-        "creating seek rate %lf, format %d, flags %d, "
+        "creating seek rate %lf, format %s, flags %d, "
         "start_type %d, start %" G_GINT64_FORMAT ", "
         "stop_type %d, stop %" G_GINT64_FORMAT,
-        rate, format, flags, start_type, start, stop_type, stop);
+        rate, gst_format_get_name (format), flags, start_type, start, stop_type,
+        stop);
   }
 
-  return gst_event_new_custom (GST_EVENT_SEEK,
-      gst_structure_new ("GstEventSeek", "rate", G_TYPE_DOUBLE, rate,
-          "format", GST_TYPE_FORMAT, format,
-          "flags", GST_TYPE_SEEK_FLAGS, flags,
-          "cur_type", GST_TYPE_SEEK_TYPE, start_type,
-          "cur", G_TYPE_INT64, start,
-          "stop_type", GST_TYPE_SEEK_TYPE, stop_type,
-          "stop", G_TYPE_INT64, stop, NULL));
+  structure = gst_structure_id_new (GST_QUARK (EVENT_SEEK),
+      GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
+      GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
+      GST_QUARK (FLAGS), GST_TYPE_SEEK_FLAGS, flags,
+      GST_QUARK (CUR_TYPE), GST_TYPE_SEEK_TYPE, start_type,
+      GST_QUARK (CUR), G_TYPE_INT64, start,
+      GST_QUARK (STOP_TYPE), GST_TYPE_SEEK_TYPE, stop_type,
+      GST_QUARK (STOP), G_TYPE_INT64, stop, NULL);
+  event = gst_event_new_custom (GST_EVENT_SEEK, structure);
+
+  return event;
 }
 
 /**
@@ -977,26 +1089,39 @@
 
   structure = gst_event_get_structure (event);
   if (rate)
-    *rate = g_value_get_double (gst_structure_get_value (structure, "rate"));
+    *rate =
+        g_value_get_double (gst_structure_id_get_value (structure,
+            GST_QUARK (RATE)));
   if (format)
-    *format = g_value_get_enum (gst_structure_get_value (structure, "format"));
+    *format =
+        g_value_get_enum (gst_structure_id_get_value (structure,
+            GST_QUARK (FORMAT)));
   if (flags)
-    *flags = g_value_get_flags (gst_structure_get_value (structure, "flags"));
+    *flags =
+        g_value_get_flags (gst_structure_id_get_value (structure,
+            GST_QUARK (FLAGS)));
   if (start_type)
     *start_type =
-        g_value_get_enum (gst_structure_get_value (structure, "cur_type"));
+        g_value_get_enum (gst_structure_id_get_value (structure,
+            GST_QUARK (CUR_TYPE)));
   if (start)
-    *start = g_value_get_int64 (gst_structure_get_value (structure, "cur"));
+    *start =
+        g_value_get_int64 (gst_structure_id_get_value (structure,
+            GST_QUARK (CUR)));
   if (stop_type)
     *stop_type =
-        g_value_get_enum (gst_structure_get_value (structure, "stop_type"));
+        g_value_get_enum (gst_structure_id_get_value (structure,
+            GST_QUARK (STOP_TYPE)));
   if (stop)
-    *stop = g_value_get_int64 (gst_structure_get_value (structure, "stop"));
+    *stop =
+        g_value_get_int64 (gst_structure_id_get_value (structure,
+            GST_QUARK (STOP)));
 }
 
 /**
  * gst_event_new_navigation:
- * @structure: description of the event
+ * @structure: description of the event. The event will take ownership of the
+ *     structure.
  *
  * Create a new navigation event from the given description.
  *
@@ -1020,7 +1145,7 @@
  *
  * Create a new latency event. The event is sent upstream from the sinks and
  * notifies elements that they should add an additional @latency to the
- * timestamps before synchronising against the clock.
+ * running time before synchronising against the clock.
  *
  * The latency is mostly used in live sinks and is always expressed in
  * the time format.
@@ -1036,12 +1161,17 @@
 GstEvent *
 gst_event_new_latency (GstClockTime latency)
 {
+  GstEvent *event;
+  GstStructure *structure;
+
   GST_CAT_INFO (GST_CAT_EVENT,
       "creating latency event %" GST_TIME_FORMAT, GST_TIME_ARGS (latency));
 
-  return gst_event_new_custom (GST_EVENT_LATENCY,
-      gst_structure_new ("GstEventLatency",
-          "latency", G_TYPE_UINT64, latency, NULL));
+  structure = gst_structure_id_new (GST_QUARK (EVENT_LATENCY),
+      GST_QUARK (LATENCY), G_TYPE_UINT64, latency, NULL);
+  event = gst_event_new_custom (GST_EVENT_LATENCY, structure);
+
+  return event;
 }
 
 /**
@@ -1068,5 +1198,101 @@
   structure = gst_event_get_structure (event);
   if (latency)
     *latency =
-        g_value_get_uint64 (gst_structure_get_value (structure, "latency"));
+        g_value_get_uint64 (gst_structure_id_get_value (structure,
+            GST_QUARK (LATENCY)));
 }
+
+/**
+ * gst_event_new_step:
+ * @format: the format of @amount
+ * @amount: the amount of data to step
+ * @rate: the step rate
+ * @flush: flushing steps
+ * @intermediate: intermediate steps
+ *
+ * Create a new step event. The purpose of the step event is to instruct a sink
+ * to skip @amount (expressed in @format) of media. It can be used to implement
+ * stepping through the video frame by frame or for doing fast trick modes.
+ *
+ * A rate of <= 0.0 is not allowed, pause the pipeline or reverse the playback
+ * direction of the pipeline to get the same effect.
+ *
+ * The @flush flag will clear any pending data in the pipeline before starting
+ * the step operation.
+ *
+ * The @intermediate flag instructs the pipeline that this step operation is
+ * part of a larger step operation.
+ *
+ * Returns: a new #GstEvent
+ *
+ * Since: 0.10.24
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+GstEvent *
+gst_event_new_step (GstFormat format, guint64 amount, gdouble rate,
+    gboolean flush, gboolean intermediate)
+{
+  GstEvent *event;
+  GstStructure *structure;
+
+  g_return_val_if_fail (rate > 0.0, NULL);
+
+  GST_CAT_INFO (GST_CAT_EVENT, "creating step event");
+
+  structure = gst_structure_id_new (GST_QUARK (EVENT_STEP),
+      GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
+      GST_QUARK (AMOUNT), G_TYPE_UINT64, amount,
+      GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
+      GST_QUARK (FLUSH), G_TYPE_BOOLEAN, flush,
+      GST_QUARK (INTERMEDIATE), G_TYPE_BOOLEAN, intermediate, NULL);
+  event = gst_event_new_custom (GST_EVENT_STEP, structure);
+
+  return event;
+}
+
+/**
+ * gst_event_parse_step:
+ * @event: The event to query
+ * @format: A pointer to store the format in.
+ * @amount: A pointer to store the amount in.
+ * @rate: A pointer to store the rate in.
+ * @flush: A pointer to store the flush boolean in.
+ * @intermediate: A pointer to store the intermediate boolean in.
+ *
+ * Parse the step event.
+ *
+ * Since: 0.10.24
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+void
+gst_event_parse_step (GstEvent * event, GstFormat * format, guint64 * amount,
+    gdouble * rate, gboolean * flush, gboolean * intermediate)
+{
+  const GstStructure *structure;
+
+  g_return_if_fail (GST_IS_EVENT (event));
+  g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STEP);
+
+  structure = gst_event_get_structure (event);
+  if (format)
+    *format = g_value_get_enum (gst_structure_id_get_value (structure,
+            GST_QUARK (FORMAT)));
+  if (amount)
+    *amount = g_value_get_uint64 (gst_structure_id_get_value (structure,
+            GST_QUARK (AMOUNT)));
+  if (rate)
+    *rate = g_value_get_double (gst_structure_id_get_value (structure,
+            GST_QUARK (RATE)));
+  if (flush)
+    *flush = g_value_get_boolean (gst_structure_id_get_value (structure,
+            GST_QUARK (FLUSH)));
+  if (intermediate)
+    *intermediate = g_value_get_boolean (gst_structure_id_get_value (structure,
+            GST_QUARK (INTERMEDIATE)));
+}