diff -r 000000000000 -r 0e761a78d257 gst_plugins_base/gst-libs/gst/audio/gstaudioclock.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gst_plugins_base/gst-libs/gst/audio/gstaudioclock.c	Thu Dec 17 08:53:32 2009 +0200
@@ -0,0 +1,146 @@
+/* GStreamer
+ * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
+ *                    2000 Wim Taymans <wtay@chello.be>
+ *
+ * audioclock.c: Clock for use by audio plugins
+ *
+ * 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:gstaudioclock
+ * @short_description: Helper object for implementing audio clocks
+ * @see_also: #GstBaseAudioSink, #GstSystemClock
+ *
+ * #GstAudioClock makes it easy for elements to implement a #GstClock, they
+ * simply need to provide a function that returns the current clock time.
+ *
+ * This object is internally used to implement the clock in #GstBaseAudioSink.
+ *
+ * Last reviewed on 2006-09-27 (0.10.12)
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "gstaudioclock.h"
+
+static void gst_audio_clock_class_init (GstAudioClockClass * klass);
+static void gst_audio_clock_init (GstAudioClock * clock);
+
+static GstClockTime gst_audio_clock_get_internal_time (GstClock * clock);
+
+static GstSystemClockClass *parent_class = NULL;
+
+/* static guint gst_audio_clock_signals[LAST_SIGNAL] = { 0 }; */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+
+GType
+gst_audio_clock_get_type (void)
+{
+  static GType clock_type = 0;
+
+  if (!clock_type) {
+    static const GTypeInfo clock_info = {
+      sizeof (GstAudioClockClass),
+      NULL,
+      NULL,
+      (GClassInitFunc) gst_audio_clock_class_init,
+      NULL,
+      NULL,
+      sizeof (GstAudioClock),
+      4,
+      (GInstanceInitFunc) gst_audio_clock_init,
+      NULL
+    };
+
+    clock_type = g_type_register_static (GST_TYPE_SYSTEM_CLOCK, "GstAudioClock",
+        &clock_info, 0);
+  }
+  return clock_type;
+}
+
+
+static void
+gst_audio_clock_class_init (GstAudioClockClass * klass)
+{
+  GObjectClass *gobject_class;
+  GstObjectClass *gstobject_class;
+  GstClockClass *gstclock_class;
+
+  gobject_class = (GObjectClass *) klass;
+  gstobject_class = (GstObjectClass *) klass;
+  gstclock_class = (GstClockClass *) klass;
+
+  parent_class = g_type_class_peek_parent (klass);
+
+  gstclock_class->get_internal_time = gst_audio_clock_get_internal_time;
+}
+
+static void
+gst_audio_clock_init (GstAudioClock * clock)
+{
+  clock->last_time = 0;
+  GST_OBJECT_FLAG_SET (clock, GST_CLOCK_FLAG_CAN_SET_MASTER);
+}
+
+/**
+ * gst_audio_clock_new:
+ * @name: the name of the clock
+ * @func: a function
+ * @user_data: user data
+ *
+ * Create a new #GstAudioClock instance. Whenever the clock time should be
+ * calculated it will call @func with @user_data. When @func returns
+ * #GST_CLOCK_TIME_NONE, the clock will return the last reported time.
+ *
+ * Returns: a new #GstAudioClock casted to a #GstClock.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+GstClock *
+gst_audio_clock_new (gchar * name, GstAudioClockGetTimeFunc func,
+    gpointer user_data)
+{
+  GstAudioClock *aclock =
+      GST_AUDIO_CLOCK (g_object_new (GST_TYPE_AUDIO_CLOCK, "name", name, NULL));
+
+  aclock->func = func;
+  aclock->user_data = user_data;
+
+  return (GstClock *) aclock;
+}
+
+static GstClockTime
+gst_audio_clock_get_internal_time (GstClock * clock)
+{
+  GstAudioClock *aclock = GST_AUDIO_CLOCK (clock);
+  GstClockTime result;
+
+  result = aclock->func (clock, aclock->user_data);
+  if (result == GST_CLOCK_TIME_NONE)
+    result = aclock->last_time;
+  else
+    aclock->last_time = result;
+
+  return result;
+}