The DVD Specification
To develop a DVD application (software or hardware), one must first licence the particular book of DVD specifications from DVD Format/Logo Licensing Corporation, a Japanese corporation. The different DVD formats have different books; each book contains hundreds of pages and costs approximately $5000. After obtaining this licence, the developer must become a licensee — which requires an additional fee. Without becoming a licensee, the book can be used only for reference, not for actual creation of DVD applications.
The DVD specifications were written in Japanese and then translated to other languages such as English. This process has resulted in text that can be difficult to interpret, and to this day, many companies interpret various parts of the specifications in different ways. This is the reason DVD players from different manufacturers do not always conform to the same rules – each developer understands the specifications in a slightly different way.
Read more about this topic: DVD Authoring