Add lot of documentation.

Original commit message from CVS:
Add lot of documentation.

1 files changed, 448 insertions, 173 deletions

diff --git a/ext/metadata/metadataxmp.c b/ext/metadata/metadataxmp.c
index cc8172ce..6712fbdb 100644
--- a/ext/metadata/metadataxmp.c
+++ b/ext/metadata/metadataxmp.c
@@ -41,40 +41,76 @@
  * Boston, MA 02111-1307, USA.
  */
 
+/*
+ * SECTION: metadataxmp
+ * @short_description: This module provides functions to extract tags from
+ * XMP metadata chunks and create XMP chunks from metadata tags.
+ * @see_also: #metadatatags.[c/h]
+ *
+ * If lib exempi isn't available at compilation time, only the whole chunk
+ * (#METADATA_TAG_MAP_WHOLECHUNK) tags is created. It means that individual
+ * tags aren't mapped.
+ *
+ * <refsect2>
+ * <para>
+ * #metadata_xmp_init must be called before any other function in this
+ * module and must be paired with a call to #metadata_xmp_dispose
+ * </para>
+ * </refsect2>
+ *
+ * Last reviewed on 2008-01-24 (0.10.15)
+ */
+
+/*
+ * includes
+ */
+
 #include "metadataxmp.h"
 #include "metadataparseutil.h"
 #include "metadatatags.h"
 
+/*
+ * defines
+ */
+
 GST_DEBUG_CATEGORY (gst_metadata_xmp_debug);
 #define GST_CAT_DEFAULT gst_metadata_xmp_debug
 
-#ifndef HAVE_XMP
-
-void
-metadataparse_xmp_tag_list_add (GstTagList * taglist, GstTagMergeMode mode,
-    GstAdapter * adapter, MetadataTagMapping mapping)
-{
+/*
+ * Implementation when lib exempi isn't available at compilation time
+ */
 
-  if (mapping & METADATA_TAG_MAP_WHOLECHUNK) {
-    GST_LOG ("XMP not defined, here I should send just one tag as whole chunk");
-    metadataparse_util_tag_list_add_chunk (taglist, mode, GST_TAG_XMP, adapter);
-  }
+#ifndef HAVE_XMP
 
-}
+/*
+ * extern functions implementations
+ */
 
 gboolean
-metadataparse_xmp_init (void)
+metadata_xmp_init (void)
 {
   return TRUE;
 }
 
 void
-metadataparse_xmp_dispose (void)
+metadata_xmp_dispose (void)
 {
   return;
 }
 
 void
+metadataparse_xmp_tag_list_add (GstTagList * taglist, GstTagMergeMode mode,
+    GstAdapter * adapter, MetadataTagMapping mapping)
+{
+
+  if (mapping & METADATA_TAG_MAP_WHOLECHUNK) {
+    GST_LOG ("XMP not defined, sending just one tag as whole chunk");
+    metadataparse_util_tag_list_add_chunk (taglist, mode, GST_TAG_XMP, adapter);
+  }
+
+}
+
+void
 metadatamux_xmp_create_chunk_from_tag_list (guint8 ** buf, guint32 * size,
     const GstTagList * taglist)
 {
@@ -83,10 +119,20 @@ metadatamux_xmp_create_chunk_from_tag_list (guint8 ** buf, guint32 * size,
 
 #else /* ifndef HAVE_XMP */
 
+/*
+ * Implementation when lib exempi isn't available at compilation time
+ */
+
+/*
+ * includes
+ */
+
 #include <xmp.h>
 #include <string.h>
 
-#define XMP_SCHEMA_NODE 0x80000000UL
+/*
+ * enum and types
+ */
 
 typedef struct _tag_SchemaTagMap
 {
@@ -102,6 +148,12 @@ typedef struct _tag_SchemaMap
   const SchemaTagMap *tags_map;
 } SchemaMap;
 
+/*
+ * defines and static global vars
+ */
+
+#define XMP_SCHEMA_NODE 0x80000000UL
+
 static const SchemaTagMap schema_map_dublin_tags_map[] = {
   {"description", GST_TAG_DESCRIPTION},
   {"title", GST_TAG_TITLE},
@@ -109,7 +161,8 @@ static const SchemaTagMap schema_map_dublin_tags_map[] = {
   {NULL, NULL}
 };
 
-static const SchemaMap schema_map_dublin = { "http://purl.org/dc/elements/1.1/",
+static const SchemaMap schema_map_dublin = {
+  "http://purl.org/dc/elements/1.1/",
   "dc:",
   3,
   schema_map_dublin_tags_map
@@ -120,10 +173,22 @@ static const SchemaMap *schemas_map[] = {
   NULL
 };
 
+/*
+ * static helper functions declaration
+ */
+
+static const SchemaTagMap *metadataparse_xmp_get_tagsmap_from_path (const
+    SchemaMap * schema_map, const gchar * path, uint32_t opt);
+
+static const SchemaTagMap *metadatamux_xmp_get_tagsmap_from_gsttag (const
+    SchemaMap * schema_map, const gchar * tag);
+
 static void
-metadataparse_xmp_iter_add_to_tag_list (GstTagList * taglist,
-    GstTagMergeMode mode, const char *path, const char *value,
-    const SchemaMap * schema_map, const uint32_t opt);
+metadataparse_xmp_iter (GstTagList * taglist, GstTagMergeMode mode, XmpPtr xmp);
+
+static void
+metadataparse_xmp_iter_node_schema (GstTagList * taglist, GstTagMergeMode mode,
+    XmpPtr xmp, const char *schema, const char *path);
 
 static void
 metadataparse_xmp_iter_array (GstTagList * taglist, GstTagMergeMode mode,
@@ -131,34 +196,75 @@ metadataparse_xmp_iter_array (GstTagList * taglist, GstTagMergeMode mode,
     const SchemaMap * schema_map);
 
 static void
-metadataparse_xmp_iter_node_schema (GstTagList * taglist, GstTagMergeMode mode,
-    XmpPtr xmp, const char *schema, const char *path);
+metadataparse_xmp_iter_simple_qual (GstTagList * taglist, GstTagMergeMode mode,
+    const char *path, const char *value, const SchemaMap * schema_map);
 
 static void
 metadataparse_xmp_iter_simple (GstTagList * taglist, GstTagMergeMode mode,
-    const char *schema, const char *path, const char *value,
-    const SchemaMap * schema_map);
+    const char *path, const char *value, const SchemaMap * schema_map);
 
 static void
-metadataparse_xmp_iter_simple_qual (GstTagList * taglist, GstTagMergeMode mode,
-    const char *schema, const char *path, const char *value,
-    const SchemaMap * schema_map);
+metadataparse_xmp_iter_add_to_tag_list (GstTagList * taglist,
+    GstTagMergeMode mode, const char *path, const char *value,
+    const SchemaMap * schema_map, const uint32_t opt);
 
 static void
-metadataparse_xmp_iter (GstTagList * taglist, GstTagMergeMode mode, XmpPtr xmp);
+metadatamux_xmp_for_each_tag_in_list (const GstTagList * list,
+    const gchar * tag, gpointer user_data);
+
+/*
+ * extern functions implementations
+ */
+
+/*
+ * metadata_xmp_init:
+ *
+ * Init lib exempi (if present in compilation time)
+ * This function must be called before any other function from this module.
+ * This function must not be called twice without call
+ * to #metadata_xmp_dispose beteween them.
+ * @see_also: #metadata_xmp_dispose
+ *
+ * Returns: nothing
+ */
 
 gboolean
-metadataparse_xmp_init (void)
+metadata_xmp_init (void)
 {
   return xmp_init ();
 }
 
+/*
+ * metadata_xmp_dispose:
+ *
+ * Call this function to free any resource allocated by #metadata_xmp_init
+ * @see_also: #metadata_xmp_init
+ *
+ * Returns: nothing
+ */
+
 void
-metadataparse_xmp_dispose (void)
+metadata_xmp_dispose (void)
 {
   xmp_terminate ();
 }
 
+/*
+ * metadataparse_xmp_tag_list_add:
+ * @taglist: tag list in which extracted tags will be added
+ * @mode: tag list merge mode
+ * @adapter: contains the XMP metadata chunk
+ * @mapping: if is to extract individual tags and/or the whole chunk.
+ * 
+ * This function gets a XMP chunk (@adapter) and extract tags from it
+ * and then to add to @taglist.
+ * Note: The XMP chunk (@adapetr) must NOT be wrapped by any bytes specific
+ * to any file format
+ * @see_also: #metadataparse_xmp_iter
+ *
+ * Returns: nothing
+ */
+
 void
 metadataparse_xmp_tag_list_add (GstTagList * taglist, GstTagMergeMode mode,
     GstAdapter * adapter, MetadataTagMapping mapping)
@@ -172,8 +278,9 @@ metadataparse_xmp_tag_list_add (GstTagList * taglist, GstTagMergeMode mode,
   }
 
   /* add chunk tag */
-  if (mapping & METADATA_TAG_MAP_WHOLECHUNK)
+  if (mapping & METADATA_TAG_MAP_WHOLECHUNK) {
     metadataparse_util_tag_list_add_chunk (taglist, mode, GST_TAG_XMP, adapter);
+  }
 
   if (!(mapping & METADATA_TAG_MAP_INDIVIDUALS))
     goto done;
@@ -196,32 +303,96 @@ done:
 
 }
 
-static const SchemaTagMap *
-metadataparse_get_tagsmap_from_gsttag (const SchemaMap * schema_map,
-    const gchar * tag)
+/*
+ * metadatamux_xmp_create_chunk_from_tag_list:
+ * @buf: buffer that will have the created XMP chunk
+ * @size: size of the buffer that will be created
+ * @taglist: list of tags to be added to XMP chunk
+ *
+ * Get tags from @taglist, create a XMP chunk based on it and save to @buf.
+ * Note: The XMP chunk is NOT wrapped by any bytes specific to any file format
+ *
+ * Returns: nothing
+ */
+
+void
+metadatamux_xmp_create_chunk_from_tag_list (guint8 ** buf, guint32 * size,
+    const GstTagList * taglist)
 {
-  SchemaTagMap *tags_map = NULL;
-  int i;
+  GstBuffer *xmp_chunk = NULL;
+  const GValue *val = NULL;
+  XmpPtr xmp = NULL;
+  XmpStringPtr xmp_str_buf = xmp_string_new ();
 
-  if (NULL == schema_map)
+  if (!(buf && size))
     goto done;
+  if (*buf) {
+    g_free (*buf);
+    *buf = NULL;
+  }
+  *size = 0;
 
+  val = gst_tag_list_get_value_index (taglist, GST_TAG_XMP, 0);
+  if (val) {
+    xmp_chunk = gst_value_get_buffer (val);
+    if (xmp_chunk)
+      xmp = xmp_new (GST_BUFFER_DATA (xmp_chunk), GST_BUFFER_SIZE (xmp_chunk));
+  }
 
-  for (i = 0; schema_map->tags_map[i].gst_tag; i++) {
-    if (0 == strcmp (schema_map->tags_map[i].gst_tag, tag)) {
-      tags_map = (SchemaTagMap *) & schema_map->tags_map[i];
-      break;
-    }
+  if (NULL == xmp)
+    xmp = xmp_new_empty ();
+
+  gst_tag_list_foreach (taglist, metadatamux_xmp_for_each_tag_in_list, xmp);
+
+  if (!xmp_serialize (xmp, xmp_str_buf, 0, 2)) {
+    GST_ERROR ("failed to serialize xmp into chunk\n");
+  } else if (xmp_str_buf) {
+    unsigned int len = strlen (xmp_string_cstr (xmp_str_buf));
+
+    *size = len + 1;
+    *buf = malloc (*size);
+    memcpy (*buf, xmp_string_cstr (xmp_str_buf), *size);
+  } else {
+    GST_ERROR ("failed to serialize xmp into chunk\n");
   }
 
 done:
 
-  return tags_map;
+  if (xmp_str_buf)
+    xmp_string_free (xmp_str_buf);
+
+  if (xmp)
+    xmp_free (xmp);
 
+  return;
 }
 
+/*
+ * static helper functions implementation
+ */
+
+/*
+ * metadataparse_xmp_get_tagsmap_from_path:
+ * @schema_map: Structure containg a map beteween GST tags and tags into a XMP
+ * schema
+ * @path: string describing a XMP tag
+ * @opt: indicates if the string (@path) has extras caracters like '[' and ']'
+ *
+ * This returns a structure that contains the GStreamer tag mapped to an XMP
+ * tag.
+ *
+ * Returns:
+ * <itemizedlist>
+ * <listitem><para>Structure containing the GST tag mapped
+ * to the XMP tag (@path)
+ * </para></listitem>
+ * <listitem><para>%NULL if there is no mapped GST tag for XMP tag (@path)
+ * </para></listitem>
+ * </itemizedlist>
+ */
+
 static const SchemaTagMap *
-metadataparse_get_tagsmap_from_path (const SchemaMap * schema_map,
+metadataparse_xmp_get_tagsmap_from_path (const SchemaMap * schema_map,
     const gchar * path, uint32_t opt)
 {
 
@@ -238,7 +409,7 @@ metadataparse_get_tagsmap_from_path (const SchemaMap * schema_map,
 
     string = g_string_new (path);
 
-    /* remove the language qualifier */
+    /* remove the language qualifier "[xxx]" */
     ch = string->str + string->len - 3;
     while (ch != string->str + schema_map->prefix_len) {
       if (*ch == '[') {
@@ -266,75 +437,154 @@ done:
 
 }
 
-static void
-metadataparse_xmp_iter_add_to_tag_list (GstTagList * taglist,
-    GstTagMergeMode mode, const char *path, const char *value,
-    const SchemaMap * schema_map, const uint32_t opt)
-{
-
-  const SchemaTagMap *smaptag =
-      metadataparse_get_tagsmap_from_path (schema_map, path, opt);
+/*
+ * metadatamux_xmp_get_tagsmap_from_gsttag:
+ * @schema_map: Structure containg a map beteween GST tags and tags into a XMP
+ * schema
+ * @tag: GStreaner tag to look for
+ *
+ * This returns a structure that contains the XMP tag mapped to a GStreamer
+ * tag.
+ *
+ * Returns:
+ * <itemizedlist>
+ * <listitem><para>Structure containing the XMP tag mapped
+ * to the GST tag (@path)
+ * </para></listitem>
+ * <listitem><para>%NULL if there is no mapped XMP tag for GST @tag
+ * </para></listitem>
+ * </itemizedlist>
+ */
 
-  if (NULL == smaptag)
-    goto done;
+static const SchemaTagMap *
+metadatamux_xmp_get_tagsmap_from_gsttag (const SchemaMap * schema_map,
+    const gchar * tag)
+{
+  SchemaTagMap *tags_map = NULL;
+  int i;
 
-  if (NULL == smaptag->gst_tag)
+  if (NULL == schema_map)
     goto done;
 
-  GType type = gst_tag_get_type (smaptag->gst_tag);
 
-  switch (type) {
-    case G_TYPE_STRING:
-      gst_tag_list_add (taglist, mode, smaptag->gst_tag, value, NULL);
-      break;
-    default:
+  for (i = 0; schema_map->tags_map[i].gst_tag; i++) {
+    if (0 == strcmp (schema_map->tags_map[i].gst_tag, tag)) {
+      tags_map = (SchemaTagMap *) & schema_map->tags_map[i];
       break;
+    }
   }
 
 done:
 
-  return;
+  return tags_map;
 
 }
 
+/*
+ * metadataparse_xmp_iter:
+ * @taglist: tag list in which extracted tags will be added
+ * @mode: tag list merge mode
+ * @xmp: handle to XMP data from lib exempi
+ *
+ * This function looks all the shemas in a XMP data (@xmp) and then calls
+ * #metadataparse_xmp_iter_node_schema for each schema. In the end, the idea is
+ * to add all XMP mapped tags to @taglist by unsing a specified merge @mode
+ * @see_also: #metadataparse_xmp_tag_list_add
+ * #metadataparse_xmp_iter_node_schema
+ *
+ * Returns: nothing
+ */
+
 void
-metadataparse_xmp_iter_simple_qual (GstTagList * taglist, GstTagMergeMode mode,
-    const char *schema, const char *path, const char *value,
-    const SchemaMap * schema_map)
+metadataparse_xmp_iter (GstTagList * taglist, GstTagMergeMode mode, XmpPtr xmp)
 {
-  GString *string = g_string_new (path);
-  gchar *ch;
+  XmpStringPtr xstr_schema = xmp_string_new ();
+  XmpStringPtr xstr_path = xmp_string_new ();
+  XmpStringPtr xstr_prop = xmp_string_new ();
+  uint32_t opt = 0;
+  XmpIteratorPtr xmp_iter = NULL;
 
-  /* remove the language qualifier */
-  ch = string->str + string->len - 3;
-  while (ch != string->str + schema_map->prefix_len) {
-    if (*ch == '[') {
-      *ch = '\0';
+  xmp_iter = xmp_iterator_new (xmp, NULL, NULL, XMP_ITER_JUSTCHILDREN);
+
+  if (NULL == xmp_iter)
+    goto done;
+
+  while (xmp_iterator_next (xmp_iter, xstr_schema, xstr_path, xstr_prop, &opt)) {
+    const char *schema = xmp_string_cstr (xstr_schema);
+    const char *path = xmp_string_cstr (xstr_path);
+
+    if (XMP_IS_NODE_SCHEMA (opt)) {
+      GST_LOG ("%s", schema);
+      metadataparse_xmp_iter_node_schema (taglist, mode, xmp, schema, path);
+    } else {
+      GST_LOG ("Unexpected iteraction");
     }
-    --ch;
   }
 
-  GST_LOG ("  %s = %s", string->str, value);
+done:
 
-  metadataparse_xmp_iter_add_to_tag_list (taglist, mode, path, value,
-      schema_map, XMP_PROP_HAS_QUALIFIERS);
+  if (xmp_iter)
+    xmp_iterator_free (xmp_iter);
 
-  g_string_free (string, TRUE);
+  if (xstr_prop)
+    xmp_string_free (xstr_prop);
+
+  if (xstr_path)
+    xmp_string_free (xstr_path);
+
+  if (xstr_schema)
+    xmp_string_free (xstr_schema);
 }
 
+/*
+ * metadataparse_xmp_iter_node_schema:
+ * @taglist: tag list in which extracted tags will be added
+ * @mode: tag list merge mode
+ * @xmp: handle to XMP data from lib exempi
+ * @schema: schema name string
+ * @path: schema path
+ *
+ * This function gets a @schema, finds the #SchemaMap (structure 
+ * containing @schema description and map with GST tags) to it. And then call
+ * #metadataparse_xmp_iter_array. In the end, the idea is
+ * to add all XMP Schema mapped tags to @taglist by unsing a specified
+ * merge @mode
+ * @see_also: #metadataparse_xmp_iter
+ * #metadataparse_xmp_iter_array
+ *
+ * Returns: nothing
+ */
 
 void
-metadataparse_xmp_iter_simple (GstTagList * taglist, GstTagMergeMode mode,
-    const char *schema, const char *path, const char *value,
-    const SchemaMap * schema_map)
+metadataparse_xmp_iter_node_schema (GstTagList * taglist, GstTagMergeMode mode,
+    XmpPtr xmp, const char *schema, const char *path)
 {
-  GST_LOG ("  %s = %s", path, value);
+  SchemaMap *schema_map = NULL;
 
-  metadataparse_xmp_iter_add_to_tag_list (taglist, mode, path, value,
-      schema_map, 0);
+  if (0 == strcmp (schema, "http://purl.org/dc/elements/1.1/")) {
+    schema_map = (SchemaMap *) & schema_map_dublin;
+  }
 
+  metadataparse_xmp_iter_array (taglist, mode, xmp, schema, path, schema_map);
 }
 
+/*
+ * metadataparse_xmp_iter_array:
+ * @taglist: tag list in which extracted tags will be added
+ * @mode: tag list merge mode
+ * @xmp: handle to XMP data from lib exempi
+ * @schema: schema name string
+ * @path: schema path
+ * @schema_map: structure containing @schema description and map with GST tags
+ *
+ * This function looks all the tags into a @schema and call other functions in
+ * order to add the mapped ones to @taglist by using a specified merge @mode
+ * @see_also: #metadataparse_xmp_iter_node_schema
+ * #metadataparse_xmp_iter_simple_qual metadataparse_xmp_iter_simple
+ *
+ * Returns: nothing
+ */
+
 void
 metadataparse_xmp_iter_array (GstTagList * taglist, GstTagMergeMode mode,
     XmpPtr xmp, const char *schema, const char *path,
@@ -362,10 +612,10 @@ metadataparse_xmp_iter_array (GstTagList * taglist, GstTagMergeMode mode,
       if (strcmp (path, "") != 0) {
         if (XMP_HAS_PROP_QUALIFIERS (opt)) {
           /* ignore language qualifier, just get the first */
-          metadataparse_xmp_iter_simple_qual (taglist, mode, schema, path,
-              value, schema_map);
+          metadataparse_xmp_iter_simple_qual (taglist, mode, path, value,
+              schema_map);
         } else {
-          metadataparse_xmp_iter_simple (taglist, mode, schema, path, value,
+          metadataparse_xmp_iter_simple (taglist, mode, path, value,
               schema_map);
         }
       }
@@ -408,64 +658,141 @@ done:
 
 }
 
+/*
+ * metadataparse_xmp_iter_simple_qual:
+ * @taglist: tag list in which extracted tags will be added
+ * @mode: tag list merge mode
+ * @path: schema path
+ * @value: value of the (@path) tag
+ * @schema_map: structure containing @schema description and map with GST tags
+ *
+ * This function gets a XMP tag (@path) with quilifiers and try to add it
+ * to @taglist by calling  #metadataparse_xmp_iter_add_to_tag_list
+ * @see_also: #metadataparse_xmp_iter_array
+ * #metadataparse_xmp_iter_simple #metadataparse_xmp_iter_add_to_tag_list
+ *
+ * Returns: nothing
+ */
+
 void
-metadataparse_xmp_iter_node_schema (GstTagList * taglist, GstTagMergeMode mode,
-    XmpPtr xmp, const char *schema, const char *path)
+metadataparse_xmp_iter_simple_qual (GstTagList * taglist, GstTagMergeMode mode,
+    const char *path, const char *value, const SchemaMap * schema_map)
 {
-  SchemaMap *schema_map = NULL;
+  GString *string = g_string_new (path);
 
-  if (0 == strcmp (schema, "http://purl.org/dc/elements/1.1/")) {
-    schema_map = (SchemaMap *) & schema_map_dublin;
+#ifndef GST_DISABLE_GST_DEBUG
+  gchar *ch;
+
+  /* remove the language qualifier */
+  ch = string->str + string->len - 3;
+  while (ch != string->str + schema_map->prefix_len) {
+    if (*ch == '[') {
+      *ch = '\0';
+    }
+    --ch;
   }
+  GST_LOG ("  %s = %s", string->str, value);
+#endif /* #ifndef GST_DISABLE_GST_DEBUG */
 
-  metadataparse_xmp_iter_array (taglist, mode, xmp, schema, path, schema_map);
+  metadataparse_xmp_iter_add_to_tag_list (taglist, mode, path, value,
+      schema_map, XMP_PROP_HAS_QUALIFIERS);
+
+  g_string_free (string, TRUE);
 }
 
+/*
+ * metadataparse_xmp_iter_simple:
+ * @taglist: tag list in which extracted tags will be added
+ * @mode: tag list merge mode
+ * @path: schema path
+ * @value: value of the (@path) tag
+ * @schema_map: structure containing @schema description and map with GST tags
+ *
+ * This function gets a simple XMP tag (@path) and try to add it to @taglist by
+ * calling # metadataparse_xmp_iter_add_to_tag_list
+ * @see_also: #metadataparse_xmp_iter_array
+ * #metadataparse_xmp_iter_simple_qual #metadataparse_xmp_iter_add_to_tag_list
+ *
+ * Returns: nothing
+ */
+
 void
-metadataparse_xmp_iter (GstTagList * taglist, GstTagMergeMode mode, XmpPtr xmp)
+metadataparse_xmp_iter_simple (GstTagList * taglist, GstTagMergeMode mode,
+    const char *path, const char *value, const SchemaMap * schema_map)
 {
-  XmpStringPtr xstr_schema = xmp_string_new ();
-  XmpStringPtr xstr_path = xmp_string_new ();
-  XmpStringPtr xstr_prop = xmp_string_new ();
-  uint32_t opt = 0;
-  XmpIteratorPtr xmp_iter = NULL;
+  GST_LOG ("  %s = %s", path, value);
 
-  xmp_iter = xmp_iterator_new (xmp, NULL, NULL, XMP_ITER_JUSTCHILDREN);
+  metadataparse_xmp_iter_add_to_tag_list (taglist, mode, path, value,
+      schema_map, 0);
 
-  if (NULL == xmp_iter)
+}
+
+/*
+ * metadataparse_xmp_iter_add_to_tag_list:
+ * @taglist: tag list in which extracted tags will be added
+ * @mode: tag list merge mode
+ * @path: schema path
+ * @value: value of the (@path) tag
+ * @schema_map: structure containing @schema description and map with GST tags
+ * @opt: indicates if the string (@path) has extras caracters like '[' and ']'
+ *
+ * This function gets a XMP tag (@path) and see if it is mapped to a GST tag by
+ * calling #metadataparse_xmp_get_tagsmap_from_path, if so, add it to @taglist
+ * by using a specified merge @mode
+ * @see_also: #metadataparse_xmp_iter_simple_qual
+ * #metadataparse_xmp_iter_simple #metadataparse_xmp_get_tagsmap_from_path
+ *
+ * Returns: nothing
+ */
+
+static void
+metadataparse_xmp_iter_add_to_tag_list (GstTagList * taglist,
+    GstTagMergeMode mode, const char *path, const char *value,
+    const SchemaMap * schema_map, const uint32_t opt)
+{
+
+  const SchemaTagMap *smaptag =
+      metadataparse_xmp_get_tagsmap_from_path (schema_map, path, opt);
+
+  if (NULL == smaptag)
     goto done;
 
-  while (xmp_iterator_next (xmp_iter, xstr_schema, xstr_path, xstr_prop, &opt)) {
-    const char *schema = xmp_string_cstr (xstr_schema);
-    const char *path = xmp_string_cstr (xstr_path);
+  if (NULL == smaptag->gst_tag)
+    goto done;
 
-    if (XMP_IS_NODE_SCHEMA (opt)) {
-      GST_LOG ("%s", schema);
-      metadataparse_xmp_iter_node_schema (taglist, mode, xmp, schema, path);
-    } else {
-      GST_LOG ("Unexpected iteraction");
-    }
+  GType type = gst_tag_get_type (smaptag->gst_tag);
+
+  switch (type) {
+    case G_TYPE_STRING:
+      gst_tag_list_add (taglist, mode, smaptag->gst_tag, value, NULL);
+      break;
+    default:
+      break;
   }
 
 done:
 
-  if (xmp_iter)
-    xmp_iterator_free (xmp_iter);
-
-  if (xstr_prop)
-    xmp_string_free (xstr_prop);
-
-  if (xstr_path)
-    xmp_string_free (xstr_path);
+  return;
 
-  if (xstr_schema)
-    xmp_string_free (xstr_schema);
 }
 
+/*
+ * metadatamux_xmp_for_each_tag_in_list:
+ * @list: GStreamer tag list from which @tag belongs to
+ * @tag: GStreamer tag to be added to the XMP chunk
+ * @user_data: pointer to #XmpPtr in which the tag will be added
+ *
+ * This function designed to be called for each tag in GST tag list. This
+ * function adds get the tag value from tag @list and then add it to the XMP
+ * chunk by using #XmpPtr and related functions from lib exempi
+ * @see_also: #metadatamux_xmp_create_chunk_from_tag_list
+ *
+ * Returns: nothing
+ */
 
 static void
-metadataxmp_for_each_tag_in_list (const GstTagList * list, const gchar * tag,
-    gpointer user_data)
+metadatamux_xmp_for_each_tag_in_list (const GstTagList * list,
+    const gchar * tag, gpointer user_data)
 {
   XmpPtr xmp = (XmpPtr) user_data;
   int i;
@@ -474,7 +801,7 @@ metadataxmp_for_each_tag_in_list (const GstTagList * list, const gchar * tag,
 
     const SchemaMap *smap = schemas_map[i];
     const SchemaTagMap *stagmap =
-        metadataparse_get_tagsmap_from_gsttag (smap, tag);
+        metadatamux_xmp_get_tagsmap_from_gsttag (smap, tag);
 
     if (stagmap) {
 
@@ -501,56 +828,4 @@ metadataxmp_for_each_tag_in_list (const GstTagList * list, const gchar * tag,
 
 }
 
-void
-metadatamux_xmp_create_chunk_from_tag_list (guint8 ** buf, guint32 * size,
-    const GstTagList * taglist)
-{
-  GstBuffer *xmp_chunk = NULL;
-  const GValue *val = NULL;
-  XmpPtr xmp = NULL;
-  XmpStringPtr xmp_str_buf = xmp_string_new ();
-
-  if (!(buf && size))
-    goto done;
-  if (*buf) {
-    g_free (*buf);
-    *buf = NULL;
-  }
-  *size = 0;
-
-  val = gst_tag_list_get_value_index (taglist, GST_TAG_XMP, 0);
-  if (val) {
-    xmp_chunk = gst_value_get_buffer (val);
-    if (xmp_chunk)
-      xmp = xmp_new (GST_BUFFER_DATA (xmp_chunk), GST_BUFFER_SIZE (xmp_chunk));
-  }
-
-  if (NULL == xmp)
-    xmp = xmp_new_empty ();
-
-  gst_tag_list_foreach (taglist, metadataxmp_for_each_tag_in_list, xmp);
-
-  if (!xmp_serialize (xmp, xmp_str_buf, 0, 2)) {
-    GST_ERROR ("failed to serialize xmp into chunk\n");
-  } else if (xmp_str_buf) {
-    unsigned int len = strlen (xmp_string_cstr (xmp_str_buf));
-
-    *size = len + 1;
-    *buf = malloc (*size);
-    memcpy (*buf, xmp_string_cstr (xmp_str_buf), *size);
-  } else {
-    GST_ERROR ("failed to serialize xmp into chunk\n");
-  }
-
-done:
-
-  if (xmp_str_buf)
-    xmp_string_free (xmp_str_buf);
-
-  if (xmp)
-    xmp_free (xmp);
-
-  return;
-}
-
 #endif /* else (ifndef HAVE_XMP) */