When taglib get empty or null title from file/album, use file name or folder name as the tag_title field. It could be confuse to user, but at leaset it is better than tracks/albums can't be search in ID3 mode API.
When taglib get empty or null title from file/album, use file name or folder name as the tag_title field. It could be confuse to user, but at leaset it is better than tracks/albums can't be search in ID3 mode API.