audioclock: add methods for the internal offset

Add two methods for getting the unadjusted time of the clock and one for
adjusting an internal time. We will need these methods for correctly handling
the time after a gst_audio_clock_reset().

Add a debug category and some debug lines to the audio clock.

API: gst_audio_clock_get_time()
API: gst_audio_clock_adjust()
API: GST_AUDIO_CLOCK_CAST()

gst-libs/gst/audio/gstaudioclock.c

@@ -39,6 +39,9 @@
 
 #include "gstaudioclock.h"
 
+GST_DEBUG_CATEGORY_STATIC (gst_audio_clock_debug);
+#define GST_CAT_DEFAULT gst_audio_clock_debug
+
 static void gst_audio_clock_class_init (GstAudioClockClass * klass);
 static void gst_audio_clock_init (GstAudioClock * clock);
 
@@ -88,6 +91,9 @@ gst_audio_clock_class_init (GstAudioClockClass * klass)
   parent_class = g_type_class_peek_parent (klass);
 
   gstclock_class->get_internal_time = gst_audio_clock_get_internal_time;
+
+  GST_DEBUG_CATEGORY_INIT (gst_audio_clock_debug, "audioclock", 0,
+      "audioclock");
 }
 
 static void
@@ -136,10 +142,18 @@ gst_audio_clock_new (const gchar * name, GstAudioClockGetTimeFunc func,
 void
 gst_audio_clock_reset (GstAudioClock * clock, GstClockTime time)
 {
+  GstClockTimeDiff time_offset;
+
   if (clock->last_time >= time)
-    clock->abidata.ABI.time_offset = clock->last_time - time;
+    time_offset = clock->last_time - time;
   else
-    clock->abidata.ABI.time_offset = -(time - clock->last_time);
+    time_offset = -(time - clock->last_time);
+
+  clock->abidata.ABI.time_offset = time_offset;
+
+  GST_DEBUG_OBJECT (clock,
+      "reset clock to %" GST_TIME_FORMAT ", offset %" GST_TIME_FORMAT,
+      GST_TIME_ARGS (time), GST_TIME_ARGS (time_offset));
 }
 
 static GstClockTime
@@ -148,7 +162,7 @@ gst_audio_clock_get_internal_time (GstClock * clock)
   GstAudioClock *aclock;
   GstClockTime result;
 
-  aclock = GST_AUDIO_CLOCK (clock);
+  aclock = GST_AUDIO_CLOCK_CAST (clock);
 
   result = aclock->func (clock, aclock->user_data);
   if (result == GST_CLOCK_TIME_NONE)
@@ -159,3 +173,51 @@ gst_audio_clock_get_internal_time (GstClock * clock)
   }
   return result;
 }
+
+/**
+ * gst_audio_clock_get_time:
+ * @clock: a #GstAudioClock
+ *
+ * Report the time as returned by the #GstAudioClockGetTimeFunc without applying
+ * any offsets. 
+ *
+ * Returns: the time as reported by the time function of the audio clock
+ *
+ * Since: 0.10.23
+ */
+GstClockTime
+gst_audio_clock_get_time (GstClock * clock)
+{
+  GstAudioClock *aclock;
+  GstClockTime result;
+
+  aclock = GST_AUDIO_CLOCK_CAST (clock);
+
+  result = aclock->func (clock, aclock->user_data);
+
+  return result;
+}
+
+/**
+ * gst_audio_clock_adjust:
+ * @clock: a #GstAudioClock
+ * @time: a #GstClockTime
+ *
+ * Adjust @time with the internal offset of the audio clock.
+ *
+ * Returns: @time adjusted with the internal offset.
+ *
+ * Since: 0.10.23
+ */
+GstClockTime
+gst_audio_clock_adjust (GstClock * clock, GstClockTime time)
+{
+  GstAudioClock *aclock;
+  GstClockTime result;
+
+  aclock = GST_AUDIO_CLOCK_CAST (clock);
+
+  result = time + aclock->abidata.ABI.time_offset;
+
+  return result;
+}

gst-libs/gst/audio/gstaudioclock.h

@@ -23,6 +23,7 @@
 #ifndef __GST_AUDIO_CLOCK_H__
 #define __GST_AUDIO_CLOCK_H__
 
+#include <gst/gst.h>
 #include <gst/gstsystemclock.h>
 
 G_BEGIN_DECLS
@@ -37,6 +38,8 @@ G_BEGIN_DECLS
   (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_AUDIO_CLOCK))
 #define GST_IS_AUDIO_CLOCK_CLASS(klass) \
   (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_AUDIO_CLOCK))
+#define GST_AUDIO_CLOCK_CAST(obj) \
+  ((GstAudioClock*)(obj))
 
 typedef struct _GstAudioClock GstAudioClock;
 typedef struct _GstAudioClockClass GstAudioClockClass;
@@ -92,6 +95,9 @@ GstClock*       gst_audio_clock_new             (const gchar *name, GstAudioCloc
                                                  gpointer user_data);
 void            gst_audio_clock_reset           (GstAudioClock *clock, GstClockTime time);
 
+GstClockTime    gst_audio_clock_get_time        (GstClock * clock);
+GstClockTime    gst_audio_clock_adjust          (GstClock * clock, GstClockTime time);
+
 G_END_DECLS
 
 #endif /* __GST_AUDIO_CLOCK_H__ */

win32/common/libgstaudio.def

@@ -2,6 +2,8 @@ EXPORTS
 	gst_audio_buffer_clip
 	gst_audio_channel_position_get_type
 	gst_audio_check_channel_positions
+	gst_audio_clock_adjust
+	gst_audio_clock_get_time
 	gst_audio_clock_get_type
 	gst_audio_clock_new
 	gst_audio_clock_reset