Ginga-NCL: the declarative environment of the Brazilian digital TV system

Abstract

As in all main terrestrial DTV Systems, the Brazilian middleware, named Ginga, supports both declarative applications (through its presentation, or declarative, environment Ginga-NCL) and procedural applications (through its execution, or procedural, environment Ginga-J). Since hybrid applications are common, either type of Ginga application may make use of facilities of both presentation and execution application environments. This paper focuses on the presentation environment Ginga-NCL. The main Brazilian inovations are then presented, regarding the Ginga architecture, the declarative NCL language specification, the editing commands for live application production, and the transport data structure.

Bringing All Users to the Television: A Platform Based on Java for Building Interactive Television Applications

“…In the context of SBTVD-T, the middleware supports the development of interactive applications through its two environments: the first one, an imperative, called Ginga-J (Filho, 2007); the second, named Ginga-NCL (Soares, 2007), is declarative. This work focuses on the environment Ginga-J, especially in regard to the specification JavaDTV (JavaDTV, 2010), having the following basic assumptions: a) your TV as access terminal (screen) to the basic interactive applications, b) the remote control as main device (remote device) to the viewer/user interaction, c) the automatic identification of the characteristics of the access terminal (memory, disk and network interfaces) available for operating of the back channel (interactivity channel) (Meloni, 2007).…”

“…Interactive services may require different levels of communication between the viewer/user and service provider (Soares, 2007). The, it is possible to classify a system according to the way they interact with the viewer/user.…”

“…The, it is possible to classify a system according to the way they interact with the viewer/user. This interaction can be a local way, in which the back channel in the access terminal is not required in this case (pseudo-interactivity) (Soares, 2007). In this form of interaction, the viewer/user can interact with applications, but there is no back of information to a provider/server accessible over the communication infrastructure.…”

Using the iDTV as the Center of an Ubiquitous Environment

“…Ginga is the middleware of the International Standard for Digital Television (ISDTV), the Brazilian Digital TV System. The specification is compliant with ITU J.200, J.201 and J.202 recommendations by providing an environment that supports declarative and procedural content, using an execution machine for Java-based applications (xlets) and a presentation machine for the treatment of declarative content based mainly on NCL (Nested Context Language) (Soares et al, 2007). In the Ginga software stack, a core structure (Ginga Common Core) is responsible for providing services that integrate the two environments.…”

“…Other types of content supported by Ginga-NCL are the ECMA Script, CSS and XHTML. Ginga-NCL also offers support for treatment of procedural content, through the implementation of the Lua API (Soares et al, 2007), allowing developers to construct audiovisual programs and to insert some sort of dynamic programming. The support for content (such as scripts, Lua, JPEG, PNG, and MPEG) is guaranteed by the Adapter, a component located on Ginga Common Core.…”