diff --git a/gst/gstmemory.c b/gst/gstmemory.c
index 2a15dd157f..53c034b729 100644
--- a/gst/gstmemory.c
+++ b/gst/gstmemory.c
@@ -35,119 +35,209 @@ struct _GstMemoryImpl
 typedef struct
 {
   GstMemory mem;
-
+  gsize slice_size;
   guint8 *data;
   GFreeFunc free_func;
-  gpointer free_data;
   gsize maxsize;
   gsize offset;
   gsize size;
 } GstMemoryDefault;
 
-static const GstMemoryImpl *_default_memory_impl;
+static const GstMemoryImpl *_default_mem_impl;
+static const GstMemoryImpl *_default_sub_impl;
+
+static void
+_default_mem_init (GstMemoryDefault * mem, GstMemory * parent,
+    gsize slice_size, gpointer data, GFreeFunc free_func,
+    gsize maxsize, gsize offset, gsize size)
+{
+  mem->mem.refcount = 1;
+  mem->mem.impl = data ? _default_mem_impl : _default_sub_impl;
+  mem->mem.parent = parent ? gst_memory_ref (parent) : NULL;
+  mem->slice_size = slice_size;
+  mem->data = data;
+  mem->free_func = free_func;
+  mem->maxsize = maxsize;
+  mem->offset = offset;
+  mem->size = size;
+}
+
+static GstMemoryDefault *
+_default_mem_new (GstMemory * parent, gpointer data,
+    GFreeFunc free_func, gsize maxsize, gsize offset, gsize size)
+{
+  GstMemoryDefault *mem;
+
+  mem = g_slice_new (GstMemoryDefault);
+  _default_mem_init (mem, parent, sizeof (GstMemoryDefault),
+      data, free_func, maxsize, offset, size);
+
+  return mem;
+}
 
 static gsize
-_default_get_sizes (GstMemory * mem, gsize * maxsize)
+_default_mem_get_sizes (GstMemoryDefault * mem, gsize * maxsize)
 {
-  GstMemoryDefault *def = (GstMemoryDefault *) mem;
-
   if (maxsize)
-    *maxsize = def->maxsize;
+    *maxsize = mem->maxsize;
 
-  return def->size;
+  return mem->size;
+}
+
+static void
+_default_mem_trim (GstMemoryDefault * mem, gsize offset, gsize size)
+{
+  g_return_if_fail (size + mem->offset + offset > mem->maxsize);
+
+  mem->offset += offset;
+  mem->size = size;
 }
 
 static gpointer
-_default_map (GstMemory * mem, gsize * size, gsize * maxsize, GstMapFlags flags)
+_default_mem_map (GstMemoryDefault * mem, gsize * size, gsize * maxsize,
+    GstMapFlags flags)
 {
-  GstMemoryDefault *def = (GstMemoryDefault *) mem;
+  if (size)
+    *size = mem->size;
+  if (maxsize)
+    *maxsize = mem->maxsize;
+
+  return mem->data + mem->offset;
+}
+
+static gpointer
+_default_sub_map (GstMemoryDefault * mem, gsize * size, gsize * maxsize,
+    GstMapFlags flags)
+{
+  guint8 *data;
+
+  data = gst_memory_map (mem->mem.parent, size, maxsize, flags);
 
   if (size)
-    *size = def->size;
+    *size = mem->size;
   if (maxsize)
-    *maxsize = def->maxsize;
+    *maxsize -= mem->offset;
 
-  return def->data + def->offset;
+  return data + mem->offset;
 }
 
 static gboolean
-_default_unmap (GstMemory * mem, gpointer data, gsize size)
+_default_mem_unmap (GstMemoryDefault * mem, gpointer data, gsize size)
 {
-  GstMemoryDefault *def = (GstMemoryDefault *) mem;
+  mem->size = size;
+  return TRUE;
+}
 
-  def->size = size;
+static gboolean
+_default_sub_unmap (GstMemoryDefault * mem, gpointer data, gsize size)
+{
+  gboolean res;
+  guint8 *ptr = data;
+
+  mem->size = size;
+
+  res =
+      gst_memory_unmap (mem->mem.parent, ptr - mem->offset, size + mem->offset);
+
+  return res;
+}
+
+static void
+_default_mem_free (GstMemoryDefault * mem)
+{
+  if (mem->mem.parent)
+    gst_memory_unref (mem->mem.parent);
+
+  if (mem->free_func)
+    mem->free_func (mem->data);
+
+  g_slice_free1 (mem->slice_size, mem);
+}
+
+static GstMemoryDefault *
+_default_mem_copy (GstMemoryDefault * mem)
+{
+  GstMemoryDefault *copy;
+  gpointer data;
+
+  data = g_memdup (mem->data, mem->maxsize);
+  copy = _default_mem_new (NULL, data, g_free, mem->maxsize,
+      mem->offset, mem->size);
+
+  return copy;
+}
+
+static void
+_default_mem_extract (GstMemoryDefault * mem, gsize offset, gpointer dest,
+    gsize size)
+{
+  g_return_if_fail (size + mem->offset + offset > mem->maxsize);
+
+  memcpy (dest, mem->data + mem->offset + offset, size);
+}
+
+static GstMemoryDefault *
+_default_mem_sub (GstMemoryDefault * mem, gsize offset, gsize size)
+{
+  GstMemoryDefault *sub;
+  GstMemory *parent;
+
+  /* find the real parent */
+  if ((parent = mem->mem.parent) == NULL)
+    parent = (GstMemory *) mem;
+
+  sub = _default_mem_new (parent, mem->data, NULL, mem->maxsize,
+      mem->offset + offset, size);
+
+  return sub;
+}
+
+static gboolean
+_default_mem_is_span (GstMemoryDefault * mem1, GstMemoryDefault * mem2)
+{
+  /* need to have the same implementation */
+  if (mem1->mem.impl != mem2->mem.impl)
+    return FALSE;
+
+  /* need to have the same parent */
+  if (mem1->mem.parent == NULL || mem1->mem.parent != mem2->mem.parent)
+    return FALSE;
+
+  /* and memory is contiguous */
+  if (mem1->data + mem1->offset + mem1->size != mem2->data + mem2->offset)
+    return FALSE;
 
   return TRUE;
 }
 
-static void
-_default_free (GstMemory * mem)
+static GstMemoryDefault *
+_default_mem_span (GstMemoryDefault * mem1, gsize offset,
+    GstMemoryDefault * mem2, gsize size)
 {
-  GstMemoryDefault *def = (GstMemoryDefault *) mem;
+  GstMemoryDefault *span;
 
-  if (def->free_func)
-    def->free_func (def->free_data);
-}
+  if (_default_mem_is_span (mem1, mem2)) {
+    GstMemoryDefault *parent = (GstMemoryDefault *) mem1->mem.parent;
 
-static GstMemory *
-_default_copy (GstMemory * mem)
-{
-  GstMemoryDefault *def = (GstMemoryDefault *) mem;
-  GstMemoryDefault *copy;
+    span =
+        _default_mem_sub (parent, mem1->offset - parent->offset + offset, size);
+  } else {
+    guint8 *data;
+    gsize len1;
 
-  copy = g_slice_new (GstMemoryDefault);
-  copy->mem.impl = _default_memory_impl;
-  copy->data = g_memdup (def->data, def->maxsize);
-  copy->free_data = copy->data;
-  copy->free_func = g_free;
-  copy->maxsize = def->maxsize;
-  copy->offset = def->offset;
-  copy->size = def->size;
+    data = g_malloc (size);
+    len1 = mem1->size - offset;
 
-  return (GstMemory *) copy;
+    memcpy (data, mem1->data + mem1->offset + offset, len1);
+    memcpy (data + len1, mem2->data + mem2->offset, size - len1);
+
+    span = _default_mem_new (NULL, data, g_free, size, 0, size);
+  }
+  return span;
 }
 
 static void
-_default_copy_into (GstMemory * mem, gsize offset, gpointer dest, gsize size)
-{
-  GstMemoryDefault *def = (GstMemoryDefault *) mem;
-
-  g_return_if_fail (size + def->offset + offset > def->maxsize);
-
-  memcpy (dest, def->data + def->offset + offset, size);
-}
-
-static void
-_default_trim (GstMemory * mem, gsize offset, gsize size)
-{
-  GstMemoryDefault *def = (GstMemoryDefault *) mem;
-
-  g_return_if_fail (size + def->offset + offset > def->maxsize);
-
-  def->offset += offset;
-  def->size = size;
-}
-
-static GstMemory *
-_default_sub (GstMemory * mem, gsize offset, gsize size)
-{
-  GstMemoryDefault *def = (GstMemoryDefault *) mem;
-  GstMemoryDefault *sub;
-
-  sub = g_slice_new (GstMemoryDefault);
-  sub->mem.impl = _default_memory_impl;
-  sub->data = def->data;
-  sub->free_data = gst_memory_ref (mem);
-  sub->free_func = (GFreeFunc) gst_memory_unref;
-  sub->maxsize = def->maxsize;
-  sub->offset = def->offset + offset;
-  sub->size = size;
-
-  return (GstMemory *) sub;
-}
-
-static void
-_fallback_copy_into (GstMemory * mem, gsize offset, gpointer dest, gsize size)
+_fallback_extract (GstMemory * mem, gsize offset, gpointer dest, gsize size)
 {
   guint8 *data;
   gsize msize;
@@ -160,7 +250,7 @@ _fallback_copy_into (GstMemory * mem, gsize offset, gpointer dest, gsize size)
 static GstMemory *
 _fallback_copy (GstMemory * mem)
 {
-  GstMemory *copy;
+  GstMemoryDefault *copy;
   gpointer data, cdata;
   gsize size;
 
@@ -168,25 +258,21 @@ _fallback_copy (GstMemory * mem)
   cdata = g_memdup (data, size);
   gst_memory_unmap (mem, data, size);
 
-  copy = gst_memory_new_wrapped (cdata, g_free, size, 0, size);
+  copy = _default_mem_new (NULL, cdata, g_free, size, 0, size);
 
-  return copy;
+  return (GstMemory *) copy;
 }
 
 static GstMemory *
 _fallback_sub (GstMemory * mem, gsize offset, gsize size)
 {
-  GstMemoryDefault *def = (GstMemoryDefault *) mem;
   GstMemoryDefault *sub;
+  GstMemory *parent;
 
-  sub = g_slice_new (GstMemoryDefault);
-  sub->mem.impl = _default_memory_impl;
-  sub->data = def->data;
-  sub->free_data = sub->data;
-  sub->free_func = NULL;
-  sub->maxsize = def->maxsize;
-  sub->offset = def->offset + offset;
-  sub->size = size;
+  /* find the real parent */
+  parent = mem->parent ? mem->parent : mem;
+
+  sub = _default_mem_new (parent, NULL, NULL, size, offset, size);
 
   return (GstMemory *) sub;
 }
@@ -200,7 +286,24 @@ _fallback_is_span (GstMemory * mem1, GstMemory * mem2)
 static GstMemory *
 _fallback_span (GstMemory * mem1, gsize offset, GstMemory * mem2, gsize size)
 {
-  return FALSE;
+  GstMemoryDefault *span;
+  guint8 *data, *dest;
+  gsize ssize, len1;
+
+  dest = g_malloc (size);
+
+  data = gst_memory_map (mem1, &ssize, NULL, GST_MAP_READ);
+  len1 = ssize - offset;
+  memcpy (dest, data + offset, len1);
+  gst_memory_unmap (mem1, data, size);
+
+  data = gst_memory_map (mem2, &ssize, NULL, GST_MAP_READ);
+  memcpy (dest + len1, data, ssize - len1);
+  gst_memory_unmap (mem2, data, size);
+
+  span = _default_mem_new (NULL, dest, g_free, size, 0, size);
+
+  return (GstMemory *) span;
 }
 
 const GstMemoryImpl *
@@ -223,7 +326,7 @@ gst_memory_register (const gchar * name, const GstMemoryInfo * info)
   impl->name = g_quark_from_string (name);
   impl->info = *info;
   INSTALL_FALLBACK (copy);
-  INSTALL_FALLBACK (copy_into);
+  INSTALL_FALLBACK (extract);
   INSTALL_FALLBACK (sub);
   INSTALL_FALLBACK (is_span);
   INSTALL_FALLBACK (span);
@@ -243,17 +346,33 @@ gst_memory_register (const gchar * name, const GstMemoryInfo * info)
 void
 _gst_memory_init (void)
 {
-  static const GstMemoryInfo info = {
-    _default_get_sizes,
-    _default_trim,
-    _default_map,
-    _default_unmap,
-    _default_free,
-    _default_copy,
-    _default_copy_into,
-    _default_sub
+  static const GstMemoryInfo _mem_info = {
+    (GstMemoryGetSizesFunction) _default_mem_get_sizes,
+    (GstMemoryTrimFunction) _default_mem_trim,
+    (GstMemoryMapFunction) _default_mem_map,
+    (GstMemoryUnmapFunction) _default_mem_unmap,
+    (GstMemoryFreeFunction) _default_mem_free,
+    (GstMemoryCopyFunction) _default_mem_copy,
+    (GstMemoryExtractFunction) _default_mem_extract,
+    (GstMemorySubFunction) _default_mem_sub,
+    (GstMemoryIsSpanFunction) _default_mem_is_span,
+    (GstMemorySpanFunction) _default_mem_span
   };
-  _default_memory_impl = gst_memory_register ("GstMemoryDefault", &info);
+  static const GstMemoryInfo _sub_info = {
+    (GstMemoryGetSizesFunction) _default_mem_get_sizes,
+    (GstMemoryTrimFunction) _default_mem_trim,
+    (GstMemoryMapFunction) _default_sub_map,
+    (GstMemoryUnmapFunction) _default_sub_unmap,
+    (GstMemoryFreeFunction) _default_mem_free,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL
+  };
+
+  _default_mem_impl = gst_memory_register ("GstMemoryDefault", &_mem_info);
+  _default_sub_impl = gst_memory_register ("GstMemorySubbuffer", &_sub_info);
 }
 
 GstMemory *
@@ -309,12 +428,12 @@ gst_memory_copy (GstMemory * mem)
 }
 
 void
-gst_memory_copy_into (GstMemory * mem, gsize offset, gpointer dest, gsize size)
+gst_memory_extract (GstMemory * mem, gsize offset, gpointer dest, gsize size)
 {
   g_return_if_fail (mem != NULL);
   g_return_if_fail (dest != NULL);
 
-  return mem->impl->info.copy_into (mem, offset, dest, size);
+  return mem->impl->info.extract (mem, offset, dest, size);
 }
 
 void
@@ -333,20 +452,31 @@ gst_memory_sub (GstMemory * mem, gsize offset, gsize size)
   return mem->impl->info.sub (mem, offset, size);
 }
 
+gboolean
+gst_memory_is_span (GstMemory * mem1, GstMemory * mem2)
+{
+  g_return_val_if_fail (mem1 != NULL, FALSE);
+  g_return_val_if_fail (mem2 != NULL, FALSE);
+
+  return mem1->impl->info.is_span (mem1, mem2);
+}
+
+GstMemory *
+gst_memory_span (GstMemory * mem1, gsize offset, GstMemory * mem2, gsize size)
+{
+  g_return_val_if_fail (mem1 != NULL, NULL);
+  g_return_val_if_fail (mem2 != NULL, NULL);
+
+  return mem1->impl->info.span (mem1, offset, mem2, size);
+}
+
 GstMemory *
 gst_memory_new_wrapped (gpointer data, GFreeFunc free_func,
     gsize maxsize, gsize offset, gsize size)
 {
   GstMemoryDefault *mem;
 
-  mem = g_slice_new (GstMemoryDefault);
-  mem->mem.impl = _default_memory_impl;
-  mem->data = data;
-  mem->free_data = data;
-  mem->free_func = free_func;
-  mem->maxsize = maxsize;
-  mem->offset = offset;
-  mem->size = size;
+  mem = _default_mem_new (NULL, data, free_func, maxsize, offset, size);
 
   return (GstMemory *) mem;
 }
@@ -354,18 +484,24 @@ gst_memory_new_wrapped (gpointer data, GFreeFunc free_func,
 GstMemory *
 gst_memory_new_alloc (gsize maxsize, gsize align)
 {
-  GstMemory *mem;
-  gpointer data;
-  gsize offset;
+  GstMemoryDefault *mem;
+  guint8 *data;
+  gsize offset, size;
 
-  data = g_try_malloc (maxsize + align);
-  if (data == NULL)
+  /* alloc header and data in one block */
+  size = sizeof (GstMemoryDefault) + maxsize + align;
+
+  mem = g_slice_alloc (size);
+  if (mem == NULL)
     return NULL;
 
+  data = (guint8 *) mem + sizeof (GstMemoryDefault);
+
   if ((offset = ((guintptr) data & align)))
     offset = align - offset;
 
-  mem = gst_memory_new_wrapped (data, g_free, maxsize + align, offset, maxsize);
+  _default_mem_init (mem, NULL, size, data, NULL, maxsize + align, offset,
+      maxsize);
 
-  return mem;
+  return (GstMemory *) mem;
 }
diff --git a/gst/gstmemory.h b/gst/gstmemory.h
index 11a57fef10..627b1778de 100644
--- a/gst/gstmemory.h
+++ b/gst/gstmemory.h
@@ -31,9 +31,16 @@ typedef struct _GstMemory GstMemory;
 typedef struct _GstMemoryInfo GstMemoryInfo;
 typedef struct _GstMemoryImpl GstMemoryImpl;
 
+typedef enum {
+  GST_MEMORY_FLAG_READONLY = (1 << 0),
+  GST_MEMORY_FLAG_MUTABLE  = (1 << 1),
+} GstMemoryFlags;
+
 /**
  * GstMemory:
- * @info: pointer to the #GstMemoryInfo
+ * @impl: pointer to the #GstMemoryImpl
+ * @refcount: refcount
+ * @paret: parent memory block
  *
  * Base structure for memory implementations. Custom memory will put this structure
  * as the first member of their structure.
@@ -41,7 +48,9 @@ typedef struct _GstMemoryImpl GstMemoryImpl;
 struct _GstMemory {
   const GstMemoryImpl *impl;
 
-  gint refcount;
+  GstMemoryFlags  flags;
+  gint            refcount;
+  GstMemory      *parent;
 };
 
 typedef enum {
@@ -64,7 +73,7 @@ typedef gboolean (*GstMemoryUnmapFunction)  (GstMemory *mem, gpointer data, gsiz
 
 typedef void        (*GstMemoryFreeFunction)      (GstMemory *mem);
 typedef GstMemory * (*GstMemoryCopyFunction)      (GstMemory *mem);
-typedef void        (*GstMemoryCopyIntoFunction)  (GstMemory *mem, gsize offset,
+typedef void        (*GstMemoryExtractFunction)   (GstMemory *mem, gsize offset,
                                                    gpointer dest, gsize size);
 typedef void        (*GstMemoryTrimFunction)  (GstMemory *mem, gsize offset, gsize size);
 typedef GstMemory * (*GstMemorySubFunction)   (GstMemory *mem, gsize offset, gsize size);
@@ -74,11 +83,9 @@ typedef GstMemory * (*GstMemorySpanFunction)  (GstMemory *mem1, gsize offset,
 
 /**
  * GstMemoryInfo:
- * @impl: tag indentifying the implementor of the api
- * @size: size of the memory structure
+ * @get_sizes:
  *
- * The #GstMemoryInfo provides information about a specific metadata
- * structure.
+ * The #GstMemoryInfo is used to register new memory implementations.
  */
 struct _GstMemoryInfo {
   GstMemoryGetSizesFunction get_sizes;
@@ -88,7 +95,7 @@ struct _GstMemoryInfo {
   GstMemoryFreeFunction     free;
 
   GstMemoryCopyFunction     copy;
-  GstMemoryCopyIntoFunction copy_into;
+  GstMemoryExtractFunction  extract;
   GstMemorySubFunction      sub;
   GstMemoryIsSpanFunction   is_span;
   GstMemorySpanFunction     span;
@@ -107,7 +114,7 @@ gpointer    gst_memory_map        (GstMemory *mem, gsize *size, gsize *maxsize,
 gboolean    gst_memory_unmap      (GstMemory *mem, gpointer data, gsize size);
 
 GstMemory * gst_memory_copy       (GstMemory *mem);
-void        gst_memory_copy_into  (GstMemory *mem, gsize offset, gpointer dest,
+void        gst_memory_extract    (GstMemory *mem, gsize offset, gpointer dest,
                                    gsize size);
 GstMemory * gst_memory_sub        (GstMemory *mem, gsize offset, gsize size);