Now I have a solution, without using string handler:
TabLib::String str;
TagLib::FileRef f(file);
if(!f.isNull() && f.tag()){
TagLib::Tag *tag = f.tag();
str=tag->title();
if(str.isLatin1()){
//the line below is python
//str=str.encode('iso-8859-1').decode('legacy encoding');
//actually I use another library to do this
}
}
Regards,
Buganini