add custom tags to flac file.

[Jacobo Luis Mejías Albertos]

I try to registry some custom tags with 'gst_tag_register()' for using 
it with flacenc, but when I do the merge the final output file only show 
the predefined tags.

This is and excerpt of the code related with the problem:

GstElement* encoder = gst_element_factory_make("flacenc", "encoder");
...
for (auto& tag : mytags) // mytags are a std::multimap<const char*, 
constchar*>
    gst_tag_register(tag.first, GST_TAG_FLAG_META, G_TYPE_STRING, 
tag.first, tag.second, gst_tag_merge_strings_with_comma);
...
GstTagSetter* tagger = GST_TAG_SETTER(encoder);
if (tagger) {
   gst_tag_setter_set_tag_merge_mode(tagger, GST_TAG_MERGE_APPEND);
   GstTagList* list = gst_tag_list_new_empty();
   for (auto& tag : meta)
      gst_tag_list_add_values(list, GST_TAG_MERGE_APPEND, tag.first, 
tag.second);
   gst_tag_setter_merge_tags(tagger, list, GST_TAG_MERGE_APPEND);
   gst_tag_list_unref(list);
}

gst_element_set_state(pipeline, GST_STATE_PLAYING);
...

I do something bad or flacenc don't support custom tags ?

-- 
Jacobo Luis Mejías Albertos