X-Git-Url: http://review.tizen.org/git/?a=blobdiff_plain;f=gst%2Fgstmeta.c;h=4bcaa7aa512ba83d06b20936c5fa5cd846ac6542;hb=ce43de86902c4e9c8ed4e9682602664cb9bce2ee;hp=ef6f53326c93fcf0e55fbfa4ee4b85f8f8a95563;hpb=10f7e52698ad2ad051c9ca2c261a7433bab5d791;p=platform%2Fupstream%2Fgstreamer.git

diff --git a/gst/gstmeta.c b/gst/gstmeta.c
index ef6f533..4bcaa7a 100644
--- a/gst/gstmeta.c
+++ b/gst/gstmeta.c
@@ -1,5 +1,7 @@
-/* Gnome-Streamer
- * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
+/* GStreamer
+ * Copyright (C) 2011 Wim Taymans <wim.taymans@gmail.com>
+ *
+ * gstmeta.c: metadata operations
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ -13,45 +15,263 @@
  *
  * 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.
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
  */
 
+/**
+ * SECTION:gstmeta
+ * @title: GstMeta
+ * @short_description: Buffer metadata
+ *
+ * The #GstMeta structure should be included as the first member of a #GstBuffer
+ * metadata structure. The structure defines the API of the metadata and should
+ * be accessible to all elements using the metadata.
+ *
+ * A metadata API is registered with gst_meta_api_type_register() which takes a
+ * name for the metadata API and some tags associated with the metadata.
+ * With gst_meta_api_type_has_tag() one can check if a certain metadata API
+ * contains a given tag.
+ *
+ * Multiple implementations of a metadata API can be registered.
+ * To implement a metadata API, gst_meta_register() should be used. This
+ * function takes all parameters needed to create, free and transform metadata
+ * along with the size of the metadata. The function returns a #GstMetaInfo
+ * structure that contains the information for the implementation of the API.
+ *
+ * A specific implementation can be retrieved by name with gst_meta_get_info().
+ *
+ * See #GstBuffer for how the metadata can be added, retrieved and removed from
+ * buffers.
+ */
+#include "gst_private.h"
 
-#include <gst/gstmeta.h>
-#include <gst/gsttrace.h>
+#include "gstbuffer.h"
+#include "gstmeta.h"
+#include "gstinfo.h"
+#include "gstutils.h"
 
+static GHashTable *metainfo = NULL;
+static GRWLock lock;
 
-GstMeta *gst_meta_new_size(gint size) {
-  GstMeta *meta;
+GQuark _gst_meta_transform_copy;
+GQuark _gst_meta_tag_memory;
 
-  meta = g_malloc(size);
-  gst_meta_ref(meta);
+void
+_priv_gst_meta_initialize (void)
+{
+  g_rw_lock_init (&lock);
+  metainfo = g_hash_table_new (g_str_hash, g_str_equal);
 
-  return meta;
+  _gst_meta_transform_copy = g_quark_from_static_string ("gst-copy");
+  _gst_meta_tag_memory = g_quark_from_static_string ("memory");
 }
 
-void gst_meta_ref(GstMeta *meta) {
-  g_return_if_fail(meta != NULL);
+/**
+ * gst_meta_api_type_register:
+ * @api: an API to register
+ * @tags: (array zero-terminated=1): tags for @api
+ *
+ * Register and return a GType for the @api and associate it with
+ * @tags.
+ *
+ * Returns: a unique GType for @api.
+ */
+GType
+gst_meta_api_type_register (const gchar * api, const gchar ** tags)
+{
+  GType type;
 
-  gst_trace_add_entry(NULL,0,meta,"ref meta");
-  meta->refcount++;
-}
+  g_return_val_if_fail (api != NULL, 0);
+  g_return_val_if_fail (tags != NULL, 0);
 
-void gst_meta_unref(GstMeta *meta) {
-  g_return_if_fail(meta != NULL);
+  GST_CAT_DEBUG (GST_CAT_META, "register API \"%s\"", api);
+  type = g_pointer_type_register_static (api);
 
-  gst_trace_add_entry(NULL,0,meta,"unref meta");
-  meta->refcount--;
+  if (type != 0) {
+    gint i;
 
-  if (meta->refcount == 0) {
-//    gst_trace_add_entry(NULL,0,meta,"destroy meta");
-    g_free(meta);
-//    g_print("freeing metadata\n");
+    for (i = 0; tags[i]; i++) {
+      GST_CAT_DEBUG (GST_CAT_META, "  adding tag \"%s\"", tags[i]);
+      g_type_set_qdata (type, g_quark_from_string (tags[i]),
+          GINT_TO_POINTER (TRUE));
+    }
   }
+
+  g_type_set_qdata (type, g_quark_from_string ("tags"),
+      g_strdupv ((gchar **) tags));
+
+  return type;
 }
 
+/**
+ * gst_meta_api_type_has_tag:
+ * @api: an API
+ * @tag: the tag to check
+ *
+ * Check if @api was registered with @tag.
+ *
+ * Returns: %TRUE if @api was registered with @tag.
+ */
+gboolean
+gst_meta_api_type_has_tag (GType api, GQuark tag)
+{
+  g_return_val_if_fail (api != 0, FALSE);
+  g_return_val_if_fail (tag != 0, FALSE);
+
+  return g_type_get_qdata (api, tag) != NULL;
+}
+
+/**
+ * gst_meta_api_type_get_tags:
+ * @api: an API
+ *
+ * Returns: (transfer none) (array zero-terminated=1) (element-type utf8): an array of tags as strings.
+ *
+ * Since: 1.2
+ */
+const gchar *const *
+gst_meta_api_type_get_tags (GType api)
+{
+  const gchar **tags;
+  g_return_val_if_fail (api != 0, FALSE);
+
+  tags = g_type_get_qdata (api, g_quark_from_string ("tags"));
+
+  if (!tags[0])
+    return NULL;
+
+  return (const gchar * const *) tags;
+}
+
+/**
+ * gst_meta_register:
+ * @api: the type of the #GstMeta API
+ * @impl: the name of the #GstMeta implementation
+ * @size: the size of the #GstMeta structure
+ * @init_func: (scope async): a #GstMetaInitFunction
+ * @free_func: (scope async): a #GstMetaFreeFunction
+ * @transform_func: (scope async): a #GstMetaTransformFunction
+ *
+ * Register a new #GstMeta implementation.
+ *
+ * The same @info can be retrieved later with gst_meta_get_info() by using
+ * @impl as the key.
+ *
+ * Returns: (transfer none) (nullable): a #GstMetaInfo that can be used to
+ * access metadata.
+ */
+
+const GstMetaInfo *
+gst_meta_register (GType api, const gchar * impl, gsize size,
+    GstMetaInitFunction init_func, GstMetaFreeFunction free_func,
+    GstMetaTransformFunction transform_func)
+{
+  GstMetaInfo *info;
+  GType type;
+
+  g_return_val_if_fail (api != 0, NULL);
+  g_return_val_if_fail (impl != NULL, NULL);
+  g_return_val_if_fail (size != 0, NULL);
+
+  if (init_func == NULL)
+    g_critical ("Registering meta implementation '%s' without init function",
+        impl);
+
+  /* first try to register the implementation name. It's possible
+   * that this fails because it was already registered. Don't warn,
+   * glib did this for us already. */
+  type = g_pointer_type_register_static (impl);
+  if (type == 0)
+    return NULL;
+
+  info = g_slice_new (GstMetaInfo);
+  info->api = api;
+  info->type = type;
+  info->size = size;
+  info->init_func = init_func;
+  info->free_func = free_func;
+  info->transform_func = transform_func;
+
+  GST_CAT_DEBUG (GST_CAT_META,
+      "register \"%s\" implementing \"%s\" of size %" G_GSIZE_FORMAT, impl,
+      g_type_name (api), size);
+
+  g_rw_lock_writer_lock (&lock);
+  g_hash_table_insert (metainfo, (gpointer) impl, (gpointer) info);
+  g_rw_lock_writer_unlock (&lock);
+
+  return info;
+}
+
+/**
+ * gst_meta_get_info:
+ * @impl: the name
+ *
+ * Lookup a previously registered meta info structure by its implementation name
+ * @impl.
+ *
+ * Returns: (transfer none) (nullable): a #GstMetaInfo with @impl, or
+ * %NULL when no such metainfo exists.
+ */
+const GstMetaInfo *
+gst_meta_get_info (const gchar * impl)
+{
+  GstMetaInfo *info;
+
+  g_return_val_if_fail (impl != NULL, NULL);
+
+  g_rw_lock_reader_lock (&lock);
+  info = g_hash_table_lookup (metainfo, impl);
+  g_rw_lock_reader_unlock (&lock);
+
+  return info;
+}
+
+/**
+ * gst_meta_get_seqnum:
+ * @meta: a #GstMeta
+ *
+ * Gets seqnum for this meta.
+ *
+ * Since: 1.16
+ */
+guint64
+gst_meta_get_seqnum (const GstMeta * meta)
+{
+  GstMetaItem *meta_item;
+  guint8 *p;
+
+  g_return_val_if_fail (meta != NULL, 0);
+
+  p = (guint8 *) meta;
+  p -= G_STRUCT_OFFSET (GstMetaItem, meta);
+  meta_item = (GstMetaItem *) p;
+  return meta_item->seq_num;
+}
+
+/**
+ * gst_meta_compare_seqnum:
+ * @meta1: a #GstMeta
+ * @meta2: a #GstMeta
+ *
+ * Meta sequence number compare function. Can be used as #GCompareFunc
+ * or a #GCompareDataFunc.
+ *
+ * Returns: a negative number if @meta1 comes before @meta2, 0 if both metas
+ *   have an equal sequence number, or a positive integer if @meta1 comes
+ *   after @meta2.
+ *
+ * Since: 1.16
+ */
+gint
+gst_meta_compare_seqnum (const GstMeta * meta1, const GstMeta * meta2)
+{
+  guint64 seqnum1 = gst_meta_get_seqnum (meta1);
+  guint64 seqnum2 = gst_meta_get_seqnum (meta2);
+
+  if (seqnum1 == seqnum2)
+    return 0;
 
-GstMeta *gst_meta_cow(GstMeta *meta) {
-  g_return_if_fail(meta != NULL);
+  return (seqnum1 < seqnum2) ? -1 : 1;
 }