tag: xmp: Write the same tag to all schemas

Instead of writing only the xmp tag for the first found entry
that matches the gstreamer tag, look for all mappings to write
the tag to different schemas.

The rationale here is that some reader application might only
be interested on a particular schema tags, so we should try
to write as many tags for all schemas.

diff --git a/gst-libs/gst/tag/gstxmptag.c b/gst-libs/gst/tag/gstxmptag.c
index ca05895..cc6c766 100644 (file)
--- a/gst-libs/gst/tag/gstxmptag.c
+++ b/gst-libs/gst/tag/gstxmptag.c
@@ -182,6 +182,21 @@ gst_xmp_schema_new ()
  */
 static GHashTable *__xmp_schemas;
 
+static GstXmpSchema *
+_gst_xmp_get_schema (const gchar * name)
+{
+  GQuark key;
+  GstXmpSchema *schema;
+
+  key = g_quark_from_string (name);
+
+  schema = g_hash_table_lookup (__xmp_schemas, GUINT_TO_POINTER (key));
+  if (!schema) {
+    GST_WARNING ("Schema %s doesn't exist", name);
+  }
+  return schema;
+}
+
 static void
 _gst_xmp_add_schema (const gchar * name, GstXmpSchema * schema)
 {
@@ -240,6 +255,7 @@ _gst_xmp_schema_add_simple_mapping (GstXmpSchema * schema,
  * appended, and the API is not public, so we shouldn't
  * have our lists modified during usage
  */
+#if 0
 static GPtrArray *
 _xmp_tag_get_mapping (const gchar * gst_tag, XmpSerializationData * serdata)
 {
@@ -260,6 +276,7 @@ _xmp_tag_get_mapping (const gchar * gst_tag, XmpSerializationData * serdata)
   }
   return ret;
 }
+#endif
 
 /* finds the gst tag that maps to this xmp tag in this schema */
 static const gchar *
@@ -1520,22 +1537,14 @@ gst_value_serialize_xmp (const GValue * value)
 }
 
 static void
-write_one_tag (const GstTagList * list, const gchar * tag, gpointer user_data)
+write_one_tag (const GstTagList * list, const gchar * tag,
+    GPtrArray * xmp_tag_array, gpointer user_data)
 {
   guint i = 0, ct = gst_tag_list_get_tag_size (list, tag), tag_index;
   XmpSerializationData *serialization_data = user_data;
   GString *data = serialization_data->data;
-  GPtrArray *xmp_tag_array = NULL;
   char *s;
 
-  /* map gst-tag to xmp tag */
-  xmp_tag_array = _xmp_tag_get_mapping (tag, serialization_data);
-
-  if (!xmp_tag_array) {
-    GST_WARNING ("no mapping for %s to xmp", tag);
-    return;
-  }
-
   for (tag_index = 0; tag_index < xmp_tag_array->len; tag_index++) {
     XmpTag *xmp_tag;
 
@@ -1635,8 +1644,31 @@ gst_tag_list_to_xmp_buffer_full (const GstTagList * list, gboolean read_only,
   g_string_append (data, ">\n");
   g_string_append (data, "<rdf:Description rdf:about=\"\">\n");
 
-  /* iterate the taglist */
-  gst_tag_list_foreach (list, write_one_tag, &serialization_data);
+  /* iterate the schemas */
+  if (schemas == NULL) {
+    /* use all schemas */
+    schemas = gst_tag_xmp_list_schemas ();
+  }
+  i = 0;
+  for (i = 0; schemas[i] != NULL; i++) {
+    GstXmpSchema *schema = _gst_xmp_get_schema (schemas[i]);
+    GHashTableIter iter;
+    gpointer key, value;
+
+    if (schema == NULL)
+      continue;
+
+    /* Iterate over the hashtable */
+    g_hash_table_iter_init (&iter, schema);
+    while (g_hash_table_iter_next (&iter, &key, &value)) {
+      const gchar *tag = g_quark_to_string (GPOINTER_TO_UINT (key));
+
+      if (gst_tag_list_get_value_index (list, tag, 0) != NULL) {
+        write_one_tag (list, tag, value, (gpointer) & serialization_data);
+      }
+
+    }
+  }
 
   /* xmp footer */
   g_string_append (data, "</rdf:Description>\n");