Ginga extensions to support depth-based 3D media

This paper presents an end-to-end interactive 3DTV chain based on ISDB-T standard. After discussing some problems we have faced when extending ISDB-T to support depth-based 3D media, the paper focuses on proposing extensions to Ginga middleware and its declarative specification language (NCL), allowing authors to be aware of and manipulate depth information for each individual graphical component of an interactive digital TV application. Ginga and NCL are part of the ISDB-T standard adopted in almost all Latin America countries and also compose the ITU-T Recommendation for IPTV services. By using a depth-based media approach (not only for the main broadcasted video, but also for additional and interactive content), we provide a solution, backward-compatible with 2DTV sets, that supports both stereoscopic and glasses-free multiview auto-stereoscopic displays. In principle, the extensions proposed to Ginga and NCL can also be applied to other terrestrial digital TV and IPTV systems and declarative multimedia languages.