diff --git a/gst/gstbuffer.c b/gst/gstbuffer.c
index 37d4bf89ef..41bfe37cbf 100644
--- a/gst/gstbuffer.c
+++ b/gst/gstbuffer.c
@@ -138,6 +138,7 @@ struct _GstMetaItem
 
 #define GST_BUFFER_MEM_MAX         16
 
+#define GST_BUFFER_SLICE_SIZE(b)   (((GstBufferImpl *)(b))->slice_size)
 #define GST_BUFFER_MEM_LEN(b)      (((GstBufferImpl *)(b))->len)
 #define GST_BUFFER_MEM_ARRAY(b)    (((GstBufferImpl *)(b))->mem)
 #define GST_BUFFER_MEM_PTR(b,i)    (((GstBufferImpl *)(b))->mem[i])
@@ -148,6 +149,8 @@ typedef struct
 {
   GstBuffer buffer;
 
+  gsize slice_size;
+
   /* the memory blocks */
   guint len;
   GstMemory *mem[GST_BUFFER_MEM_MAX];
@@ -505,7 +508,7 @@ _gst_buffer_free (GstBuffer * buffer)
 
   /* get the size, when unreffing the memory, we could also unref the buffer
    * itself */
-  msize = GST_MINI_OBJECT_SIZE (buffer);
+  msize = GST_BUFFER_SLICE_SIZE (buffer);
 
   /* free our memory */
   len = GST_BUFFER_MEM_LEN (buffer);
@@ -522,7 +525,7 @@ _gst_buffer_free (GstBuffer * buffer)
 static void
 gst_buffer_init (GstBufferImpl * buffer, gsize size)
 {
-  gst_mini_object_init (GST_MINI_OBJECT_CAST (buffer), _gst_buffer_type, size);
+  gst_mini_object_init (GST_MINI_OBJECT_CAST (buffer), _gst_buffer_type);
 
   buffer->buffer.mini_object.copy =
       (GstMiniObjectCopyFunction) _gst_buffer_copy;
@@ -531,6 +534,8 @@ gst_buffer_init (GstBufferImpl * buffer, gsize size)
   buffer->buffer.mini_object.free =
       (GstMiniObjectFreeFunction) _gst_buffer_free;
 
+  GST_BUFFER_SLICE_SIZE (buffer) = size;
+
   GST_BUFFER (buffer)->pool = NULL;
   GST_BUFFER_PTS (buffer) = GST_CLOCK_TIME_NONE;
   GST_BUFFER_DTS (buffer) = GST_CLOCK_TIME_NONE;
diff --git a/gst/gstbufferlist.c b/gst/gstbufferlist.c
index f3e047eb3d..0e1cd7577c 100644
--- a/gst/gstbufferlist.c
+++ b/gst/gstbufferlist.c
@@ -54,6 +54,8 @@ struct _GstBufferList
 {
   GstMiniObject mini_object;
 
+  gsize slice_size;
+
   GArray *array;
 };
 
@@ -97,18 +99,19 @@ _gst_buffer_list_free (GstBufferList * list)
     gst_buffer_unref (g_array_index (list->array, GstBuffer *, i));
   g_array_free (list->array, TRUE);
 
-  g_slice_free1 (GST_MINI_OBJECT_SIZE (list), list);
+  g_slice_free1 (list->slice_size, list);
 }
 
 static void
 gst_buffer_list_init (GstBufferList * list, gsize size, guint asize)
 {
-  gst_mini_object_init (GST_MINI_OBJECT_CAST (list), _gst_buffer_list_type,
-      size);
+  gst_mini_object_init (GST_MINI_OBJECT_CAST (list), _gst_buffer_list_type);
 
   list->mini_object.copy = (GstMiniObjectCopyFunction) _gst_buffer_list_copy;
   list->mini_object.free = (GstMiniObjectFreeFunction) _gst_buffer_list_free;
 
+  list->slice_size = size;
+
   list->array = g_array_sized_new (FALSE, FALSE, sizeof (GstBuffer *), asize);
 
   GST_LOG ("init %p", list);
diff --git a/gst/gstcaps.c b/gst/gstcaps.c
index ec95ed5891..68ed8c84d4 100644
--- a/gst/gstcaps.c
+++ b/gst/gstcaps.c
@@ -75,9 +75,12 @@ typedef struct _GstCapsImpl
 {
   GstCaps caps;
 
+  gsize slice_size;
+
   GPtrArray *array;
 } GstCapsImpl;
 
+#define GST_CAPS_SLICE_SIZE(c) (((GstCapsImpl *)(c))->slice_size)
 #define GST_CAPS_ARRAY(c) (((GstCapsImpl *)(c))->array)
 
 #define GST_CAPS_LEN(c)   (GST_CAPS_ARRAY(c)->len)
@@ -179,18 +182,19 @@ _gst_caps_free (GstCaps * caps)
 #ifdef DEBUG_REFCOUNT
   GST_CAT_TRACE (GST_CAT_CAPS, "freeing caps %p", caps);
 #endif
-  g_slice_free1 (GST_MINI_OBJECT_SIZE (caps), caps);
+  g_slice_free1 (GST_CAPS_SLICE_SIZE (caps), caps);
 }
 
 static void
 gst_caps_init (GstCaps * caps, gsize size)
 {
-  gst_mini_object_init (GST_MINI_OBJECT_CAST (caps), _gst_caps_type, size);
+  gst_mini_object_init (GST_MINI_OBJECT_CAST (caps), _gst_caps_type);
 
   caps->mini_object.copy = (GstMiniObjectCopyFunction) _gst_caps_copy;
   caps->mini_object.dispose = NULL;
   caps->mini_object.free = (GstMiniObjectFreeFunction) _gst_caps_free;
 
+  GST_CAPS_SLICE_SIZE (caps) = size;
   /* the 32 has been determined by logging caps sizes in _gst_caps_free
    * but g_ptr_array uses 16 anyway if it expands once, so this does not help
    * in practice
diff --git a/gst/gstevent.c b/gst/gstevent.c
index 3ba388a8b7..c4359692bc 100644
--- a/gst/gstevent.c
+++ b/gst/gstevent.c
@@ -92,9 +92,12 @@ typedef struct
 {
   GstEvent event;
 
+  gsize slice_size;
+
   GstStructure *structure;
 } GstEventImpl;
 
+#define GST_EVENT_SLICE_SIZE(e) (((GstEventImpl *)(e))->slice_size)
 #define GST_EVENT_STRUCTURE(e)  (((GstEventImpl *)(e))->structure)
 
 typedef struct
@@ -229,7 +232,7 @@ _gst_event_free (GstEvent * event)
     gst_structure_free (s);
   }
 
-  g_slice_free1 (GST_MINI_OBJECT_SIZE (event), event);
+  g_slice_free1 (GST_EVENT_SLICE_SIZE (event), event);
 }
 
 static void gst_event_init (GstEventImpl * event, gsize size,
@@ -262,11 +265,13 @@ _gst_event_copy (GstEvent * event)
 static void
 gst_event_init (GstEventImpl * event, gsize size, GstEventType type)
 {
-  gst_mini_object_init (GST_MINI_OBJECT_CAST (event), _gst_event_type, size);
+  gst_mini_object_init (GST_MINI_OBJECT_CAST (event), _gst_event_type);
 
   event->event.mini_object.copy = (GstMiniObjectCopyFunction) _gst_event_copy;
   event->event.mini_object.free = (GstMiniObjectFreeFunction) _gst_event_free;
 
+  GST_EVENT_SLICE_SIZE (event) = size;
+
   GST_EVENT_TYPE (event) = type;
   GST_EVENT_TIMESTAMP (event) = GST_CLOCK_TIME_NONE;
   GST_EVENT_SEQNUM (event) = gst_util_seqnum_next ();
@@ -318,7 +323,7 @@ gst_event_new_custom (GstEventType type, GstStructure * structure)
   /* ERRORS */
 had_parent:
   {
-    g_slice_free1 (GST_MINI_OBJECT_SIZE (event), event);
+    g_slice_free1 (GST_EVENT_SLICE_SIZE (event), event);
     g_warning ("structure is already owned by another object");
     return NULL;
   }
diff --git a/gst/gstmemory.c b/gst/gstmemory.c
index 4bc4674138..bc392907e3 100644
--- a/gst/gstmemory.c
+++ b/gst/gstmemory.c
@@ -95,6 +95,8 @@ struct _GstAllocator
 {
   GstMiniObject mini_object;
 
+  gsize slice_size;
+
   GstMemoryInfo info;
 
   gpointer user_data;
@@ -105,6 +107,7 @@ struct _GstAllocator
 typedef struct
 {
   GstMemory mem;
+  gsize slice_size;
   guint8 *data;
   gpointer user_data;
   GDestroyNotify notify;
@@ -137,8 +140,7 @@ _default_mem_init (GstMemoryDefault * mem, GstMemoryFlags flags,
     gsize maxsize, gsize offset, gsize size, gsize align,
     gpointer user_data, GDestroyNotify notify)
 {
-  gst_mini_object_init (GST_MINI_OBJECT_CAST (mem), GST_TYPE_MEMORY,
-      slice_size);
+  gst_mini_object_init (GST_MINI_OBJECT_CAST (mem), GST_TYPE_MEMORY);
 
   mem->mem.mini_object.copy = (GstMiniObjectCopyFunction) _gst_memory_copy;
   mem->mem.mini_object.dispose = NULL;
@@ -152,6 +154,7 @@ _default_mem_init (GstMemoryDefault * mem, GstMemoryFlags flags,
   mem->mem.align = align;
   mem->mem.offset = offset;
   mem->mem.size = size;
+  mem->slice_size = slice_size;
   mem->data = data;
   mem->user_data = user_data;
   mem->notify = notify;
@@ -254,7 +257,7 @@ _default_mem_free (GstMemoryDefault * mem)
   if (mem->notify)
     mem->notify (mem->user_data);
 
-  g_slice_free1 (GST_MINI_OBJECT_SIZE (mem), mem);
+  g_slice_free1 (mem->slice_size, mem);
 }
 
 static GstMemoryDefault *
@@ -764,7 +767,7 @@ _gst_allocator_free (GstAllocator * allocator)
   if (allocator->notify)
     allocator->notify (allocator->user_data);
 
-  g_slice_free1 (GST_MINI_OBJECT_SIZE (allocator), allocator);
+  g_slice_free1 (allocator->slice_size, allocator);
 }
 
 static GstAllocator *
@@ -804,12 +807,12 @@ gst_allocator_new (const GstMemoryInfo * info, gpointer user_data,
 
   allocator = g_slice_new0 (GstAllocator);
 
-  gst_mini_object_init (GST_MINI_OBJECT_CAST (allocator),
-      GST_TYPE_ALLOCATOR, sizeof (GstAllocator));
+  gst_mini_object_init (GST_MINI_OBJECT_CAST (allocator), GST_TYPE_ALLOCATOR);
 
   allocator->mini_object.copy = (GstMiniObjectCopyFunction) _gst_allocator_copy;
   allocator->mini_object.free = (GstMiniObjectFreeFunction) _gst_allocator_free;
 
+  allocator->slice_size = sizeof (GstAllocator);
   allocator->info = *info;
   allocator->user_data = user_data;
   allocator->notify = notify;
diff --git a/gst/gstmessage.c b/gst/gstmessage.c
index ae03f99c41..948449da7a 100644
--- a/gst/gstmessage.c
+++ b/gst/gstmessage.c
@@ -64,10 +64,13 @@ typedef struct
 {
   GstMessage message;
 
+  gsize slice_size;
+
   GstStructure *structure;
 } GstMessageImpl;
 
-#define GST_MESSAGE_STRUCTURE(m) (((GstMessageImpl *)(m))->structure)
+#define GST_MESSAGE_SLICE_SIZE(m) (((GstMessageImpl *)(m))->slice_size)
+#define GST_MESSAGE_STRUCTURE(m)  (((GstMessageImpl *)(m))->structure)
 
 typedef struct
 {
@@ -198,7 +201,7 @@ _gst_message_free (GstMessage * message)
     gst_structure_free (structure);
   }
 
-  g_slice_free1 (GST_MINI_OBJECT_SIZE (message), message);
+  g_slice_free1 (GST_MESSAGE_SLICE_SIZE (message), message);
 }
 
 static void
@@ -239,14 +242,15 @@ static void
 gst_message_init (GstMessageImpl * message, gsize size, GstMessageType type,
     GstObject * src)
 {
-  gst_mini_object_init (GST_MINI_OBJECT_CAST (message), _gst_message_type,
-      size);
+  gst_mini_object_init (GST_MINI_OBJECT_CAST (message), _gst_message_type);
 
   message->message.mini_object.copy =
       (GstMiniObjectCopyFunction) _gst_message_copy;
   message->message.mini_object.free =
       (GstMiniObjectFreeFunction) _gst_message_free;
 
+  GST_MESSAGE_SLICE_SIZE (message) = size;
+
   GST_MESSAGE_TYPE (message) = type;
   if (src)
     gst_object_ref (src);
@@ -298,7 +302,7 @@ gst_message_new_custom (GstMessageType type, GstObject * src,
   /* ERRORS */
 had_parent:
   {
-    g_slice_free1 (GST_MINI_OBJECT_SIZE (message), message);
+    g_slice_free1 (GST_MESSAGE_SLICE_SIZE (message), message);
     g_warning ("structure is already owned by another object");
     return NULL;
   }
diff --git a/gst/gstminiobject.c b/gst/gstminiobject.c
index 55d846bb3f..705152a25f 100644
--- a/gst/gstminiobject.c
+++ b/gst/gstminiobject.c
@@ -80,12 +80,11 @@ _priv_gst_mini_object_initialize (void)
  * Returns: (transfer full): the new mini-object.
  */
 void
-gst_mini_object_init (GstMiniObject * mini_object, GType type, gsize size)
+gst_mini_object_init (GstMiniObject * mini_object, GType type)
 {
   mini_object->type = type;
   mini_object->refcount = 1;
   mini_object->flags = 0;
-  mini_object->size = size;
   mini_object->n_weak_refs = 0;
   mini_object->weak_refs = NULL;
 
diff --git a/gst/gstminiobject.h b/gst/gstminiobject.h
index 69843086bf..76cc193d3b 100644
--- a/gst/gstminiobject.h
+++ b/gst/gstminiobject.h
@@ -149,14 +149,6 @@ typedef enum
  */
 #define GST_MINI_OBJECT_REFCOUNT_VALUE(obj)     (g_atomic_int_get (&(GST_MINI_OBJECT_CAST(obj))->refcount))
 
-/**
- * GST_MINI_OBJECT_SIZE:
- * @obj: a #GstMiniObject
- *
- * Get the allocated size of @obj.
- */
-#define GST_MINI_OBJECT_SIZE(obj)              ((GST_MINI_OBJECT_CAST(obj))->size)
-
 /**
  * GstMiniObject:
  * @type: the GType of the object
@@ -179,7 +171,6 @@ struct _GstMiniObject {
   /*< public >*/ /* with COW */
   gint    refcount;
   guint   flags;
-  gsize   size;
 
   GstMiniObjectCopyFunction copy;
   GstMiniObjectDisposeFunction dispose;
@@ -195,8 +186,7 @@ struct _GstMiniObject {
   } *weak_refs;
 };
 
-void            gst_mini_object_init            (GstMiniObject *mini_object,
-                                                 GType type, gsize size);
+void            gst_mini_object_init            (GstMiniObject *mini_object, GType type);
 
 GstMiniObject * gst_mini_object_copy		(const GstMiniObject *mini_object) G_GNUC_MALLOC;
 gboolean        gst_mini_object_is_writable	(const GstMiniObject *mini_object);
diff --git a/gst/gstquery.c b/gst/gstquery.c
index 5fadc9deb7..694113c9c8 100644
--- a/gst/gstquery.c
+++ b/gst/gstquery.c
@@ -77,10 +77,12 @@ static GType _gst_query_type = 0;
 typedef struct
 {
   GstQuery query;
+  gsize slice_size;
 
   GstStructure *structure;
 } GstQueryImpl;
 
+#define GST_QUERY_SLICE_SIZE(q) (((GstQueryImpl *)(q))->slice_size)
 #define GST_QUERY_STRUCTURE(q)  (((GstQueryImpl *)(q))->structure)
 
 
@@ -202,7 +204,7 @@ _gst_query_free (GstQuery * query)
     gst_structure_free (s);
   }
 
-  g_slice_free1 (GST_MINI_OBJECT_SIZE (query), query);
+  g_slice_free1 (GST_QUERY_SLICE_SIZE (query), query);
 }
 
 static GstQuery *
@@ -223,11 +225,12 @@ _gst_query_copy (GstQuery * query)
 static void
 gst_query_init (GstQueryImpl * query, gsize size, GstQueryType type)
 {
-  gst_mini_object_init (GST_MINI_OBJECT_CAST (query), _gst_query_type, size);
+  gst_mini_object_init (GST_MINI_OBJECT_CAST (query), _gst_query_type);
 
   query->query.mini_object.copy = (GstMiniObjectCopyFunction) _gst_query_copy;
   query->query.mini_object.free = (GstMiniObjectFreeFunction) _gst_query_free;
 
+  GST_QUERY_SLICE_SIZE (query) = size;
   GST_QUERY_TYPE (query) = type;
 }
 
@@ -711,7 +714,7 @@ gst_query_new_custom (GstQueryType type, GstStructure * structure)
   /* ERRORS */
 had_parent:
   {
-    g_slice_free1 (GST_MINI_OBJECT_SIZE (query), query);
+    g_slice_free1 (GST_QUERY_SLICE_SIZE (query), query);
     g_warning ("structure is already owned by another object");
     return NULL;
   }
diff --git a/gst/gstsample.c b/gst/gstsample.c
index 4a7551b744..44342ccf9c 100644
--- a/gst/gstsample.c
+++ b/gst/gstsample.c
@@ -37,6 +37,8 @@ struct _GstSample
 {
   GstMiniObject mini_object;
 
+  gsize slice_size;
+
   GstBuffer *buffer;
   GstCaps *caps;
   GstSegment segment;
@@ -74,7 +76,7 @@ _gst_sample_free (GstSample * sample)
   if (sample->caps)
     gst_caps_unref (sample->caps);
 
-  g_slice_free1 (GST_MINI_OBJECT_SIZE (sample), sample);
+  g_slice_free1 (sample->slice_size, sample);
 }
 
 /**
@@ -103,12 +105,12 @@ gst_sample_new (GstBuffer * buffer, GstCaps * caps, const GstSegment * segment,
 
   GST_LOG ("new %p", sample);
 
-  gst_mini_object_init (GST_MINI_OBJECT_CAST (sample), _gst_sample_type,
-      sizeof (GstSample));
+  gst_mini_object_init (GST_MINI_OBJECT_CAST (sample), _gst_sample_type);
 
   sample->mini_object.copy = (GstMiniObjectCopyFunction) _gst_sample_copy;
   sample->mini_object.free = (GstMiniObjectFreeFunction) _gst_sample_free;
 
+  sample->slice_size = sizeof (GstSample);
   sample->buffer = buffer ? gst_buffer_ref (buffer) : NULL;
   sample->caps = caps ? gst_caps_ref (caps) : NULL;
 
diff --git a/gst/gsttaglist.c b/gst/gsttaglist.c
index 5658fe7f46..b0e9fde545 100644
--- a/gst/gsttaglist.c
+++ b/gst/gsttaglist.c
@@ -58,10 +58,13 @@ typedef struct _GstTagListImpl
 {
   GstTagList taglist;
 
+  gsize slice_size;
+
   GstStructure *structure;
 } GstTagListImpl;
 
-#define GST_TAG_LIST_STRUCTURE(taglist) ((GstTagListImpl*)(taglist))->structure
+#define GST_TAG_LIST_SLICE_SIZE(taglist) ((GstTagListImpl*)(taglist))->slice_size
+#define GST_TAG_LIST_STRUCTURE(taglist)  ((GstTagListImpl*)(taglist))->structure
 
 
 /* FIXME 0.11: use GParamSpecs or something similar for tag registrations,
@@ -666,11 +669,13 @@ static void
 gst_tag_list_init (GstTagList * taglist, gsize size)
 {
   gst_mini_object_init (GST_MINI_OBJECT_CAST (taglist),
-      gst_tag_list_get_type (), size);
+      gst_tag_list_get_type ());
 
   taglist->mini_object.copy = (GstMiniObjectCopyFunction) __gst_tag_list_copy;
   taglist->mini_object.dispose = NULL;
   taglist->mini_object.free = (GstMiniObjectFreeFunction) __gst_tag_list_free;
+
+  GST_TAG_LIST_SLICE_SIZE (taglist) = size;
 }
 
 /* takes ownership of the structure */
@@ -706,7 +711,7 @@ __gst_tag_list_free (GstTagList * list)
   gst_structure_free (GST_TAG_LIST_STRUCTURE (list));
 
   /* why not just pass sizeof (GstTagListImpl) here? */
-  g_slice_free1 (GST_MINI_OBJECT_SIZE (list), list);
+  g_slice_free1 (GST_TAG_LIST_SLICE_SIZE (list), list);
 }
 
 static GstTagList *