element: add start_time field an methods

Add a start_time field and some methods. The start_time will contain the
running_time of when the element last went to paused. This time can be user to
report the position in PAUSED but also to do more correct clipping and
stepping later.

docs/gst/gstreamer-sections.txt

@@ -482,6 +482,7 @@ GST_ELEMENT_PARENT
 GST_ELEMENT_BUS
 GST_ELEMENT_CLOCK
 GST_ELEMENT_PADS
+GST_ELEMENT_START_TIME
 GST_ELEMENT_ERROR
 GST_ELEMENT_WARNING
 GST_ELEMENT_INFO
@@ -523,6 +524,8 @@ gst_element_link_filtered
 <SUBSECTION element-properties>
 gst_element_set_base_time
 gst_element_get_base_time
+gst_element_set_start_time
+gst_element_get_start_time
 gst_element_set_bus
 gst_element_get_bus
 gst_element_get_factory

gst/gstelement.c

@@ -530,6 +530,62 @@ gst_element_get_base_time (GstElement * element)
   return result;
 }
 
+/**
+ * gst_element_set_start_time:
+ * @element: a #GstElement.
+ * @time: the base time to set.
+ *
+ * Set the start time of an element. See gst_element_get_start_time().
+ *
+ * MT safe.
+ *
+ * Since: 0.10.24
+ */
+void
+gst_element_set_start_time (GstElement * element, GstClockTime time)
+{
+  GstClockTime old;
+
+  g_return_if_fail (GST_IS_ELEMENT (element));
+
+  GST_OBJECT_LOCK (element);
+  old = GST_ELEMENT_START_TIME (element);
+  GST_ELEMENT_START_TIME (element) = time;
+  GST_OBJECT_UNLOCK (element);
+
+  GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, element,
+      "set start_time=%" GST_TIME_FORMAT ", old %" GST_TIME_FORMAT,
+      GST_TIME_ARGS (time), GST_TIME_ARGS (old));
+}
+
+/**
+ * gst_element_get_start_time:
+ * @element: a #GstElement.
+ *
+ * Returns the start time of the element. The start time is the
+ * running time of the clock when this element was last put to
+ * PAUSED. 
+ *
+ * MT safe.
+ *
+ * Returns: the start time of the element.
+ *
+ * Since: 0.10.24
+ */
+GstClockTime
+gst_element_get_start_time (GstElement * element)
+{
+  GstClockTime result;
+
+  g_return_val_if_fail (GST_IS_ELEMENT (element), GST_CLOCK_TIME_NONE);
+
+  GST_OBJECT_LOCK (element);
+  result = GST_ELEMENT_START_TIME (element);
+  GST_OBJECT_UNLOCK (element);
+
+  return result;
+}
+
 /**
  * gst_element_is_indexable:
  * @element: a #GstElement.

gst/gstelement.h

@@ -262,6 +262,17 @@ typedef enum
  */
 #define GST_ELEMENT_PADS(elem)			(GST_ELEMENT_CAST(elem)->pads)
 
+/**
+ * GST_ELEMENT_START_TIME:
+ * @elem: a #GstElement to return the start time for.
+ *
+ * This macro returns the start_time of the @elem. The start_time is the
+ * running_time of the pipeline when the element went to PAUSED.
+ *
+ * Since: 0.10.24
+ */
+#define GST_ELEMENT_START_TIME(elem)		(GST_ELEMENT_CAST(elem)->abidata.ABI.start_time)
+
 /**
  * GST_ELEMENT_ERROR:
  * @el:     the element that generates the error
@@ -441,6 +452,8 @@ struct _GstElement
     struct {
       /* state set by application */
       GstState              target_state;
+      /* running time of the last PAUSED state */
+      GstClockTime          start_time;
     } ABI;
     /* adding + 0 to mark ABI change to be undone later */
     gpointer _gst_reserved[GST_PADDING + 0];
@@ -586,6 +599,8 @@ GstClock*		gst_element_get_clock		(GstElement *element);
 gboolean		gst_element_set_clock		(GstElement *element, GstClock *clock);
 void			gst_element_set_base_time	(GstElement *element, GstClockTime time);
 GstClockTime		gst_element_get_base_time	(GstElement *element);
+void			gst_element_set_start_time	(GstElement *element, GstClockTime time);
+GstClockTime		gst_element_get_start_time	(GstElement *element);
 
 /* indexes */
 gboolean		gst_element_is_indexable	(GstElement *element);

win32/common/libgstreamer.def

@@ -291,6 +291,7 @@ EXPORTS
 	gst_element_get_pad
 	gst_element_get_query_types
 	gst_element_get_request_pad
+	gst_element_get_start_time
 	gst_element_get_state
 	gst_element_get_static_pad
 	gst_element_get_type
@@ -330,6 +331,7 @@ EXPORTS
 	gst_element_set_clock
 	gst_element_set_index
 	gst_element_set_locked_state
+	gst_element_set_start_time
 	gst_element_set_state
 	gst_element_state_change_return_get_name
 	gst_element_state_get_name