DualSup is a unique blu-ray subtitle tool which not only can convert a single subtitle from SRT, ASS, SSA, SST, BDN to SUP or BDN, but also can transfer two arbitrary subtitles with different time line to a single subtitle. For example, you can display two language subtitles like English and Chinese at the same time. Also you can show dialogue and director review subtitle simultaneously. All features in SupConverter are supported. With BDN output, you can import the output in the third-party authoring tools like Scenarist.