Java TV API Overview

The Java TV application programming interface (API) is an extension of the Java platform developed through an open process by Sun Microsystems and leaders in the digital television industry. Major consumer electronics manufacturers have announced their public support for the adoption of this API as a digital television standard worldwide.

The Java TV API is being designed to provide access to functionality unique to digital television receivers, including:

• Audio/video streaming
• Conditional access
• Access to in-band and out-of-band data channels
• Access to service information
• Tuner control for channel changing
• On-screen graphics control

In addition, the Java TV API is being designed to provide additional functionality in the form of media synchronization and control of the application life-cycle. Media synchronization will allow interactive television content to be synchronized with the underlying video and background audio of a television program. Application life-cycle control will enable content to coexist gracefully with television programming content such as commercials.

Overall, the Java TV API and the underlying Java platform will enable content developers to create truly compelling, differentiated interactive television content for the viewer.

Figure 1 depicts the hardware and software environment for the Java TV API when implemented on a digital television receiver.

Figure 1: Typical Software Stack on a Digital TV Receiver

Software Environment

The software environment consists of the Java platform and the Java TV API, typically running on top of a real-time operating system (RTOS).

At the highest level of the software environment, an application developed for a television receiver can use the Java TV API and the class libraries in the underlying Java platform. These libraries enable television content developers to offer consumers interactive television content such as enhanced television, video-on-demand (VOD), electronic programming guides (EPGs), and viewer selection of multiple camera angles, in broadcasts of sporting events for example.

At the lowest level, the RTOS and related device-specific libraries control the hardware through a collection of device drivers. The RTOS provides the system-level support needed to implement the Java virtual machine and class libraries that compose the Java platform. The Java TV API encapsulates the functionality exposed by the system libraries that control the hardware, so that developers can focus on their applications rather than on device-specific details.

Hardware Environment

The Java TV API operates within the hardware context of a television receiver. The defining feature of a television receiver, digital or analog, is the existence of a broadcast medium and a data pipeline. This pipeline typically has certain commonly understood features, or subsystems, such as a tuner and a demultiplexor. The Java TV API provides a layer of abstraction that allows the application programmer to take advantage of the underlying television hardware while ignoring device-specific details.

The Java TV API is intended to address the needs of manufacturers, system operators, and content providers as they seek standards to deliver interactive content securely to consumers via cable set-top boxes, satellite receivers, and digital televisions:

• Manufacturers will benefit by delivering Java technology-enabled televisions and set-top boxes to the marketplace that support the most compelling interactive television content for their consumers. Java TV's aim is to enable manufacturers to introduce new products into the market that can evolve to support new forms of interactive content as they become available.

• System operators will benefit from the ability to deliver their value-added services to a diverse array of Java technology-enabled devices in their networks, regardless of the underlying processors or operating systems on those devices. Platform-independence enables television service providers to reduce time-to-market and costs by avoiding the need to port their services and applications to new platforms. It will also allow them the freedom to deploy competitive set-top box solutions within their networks. Finally, they will benefit from compatibility with existing interactive television content that may already be deployed in their systems.

• Content creators will benefit from the adoption of a universal standard that broadens the market opportunities for interactive television, and allows them to develop content once and deploy it securely to a wide range of digital television receivers. In addition, content developers will benefit from the ability to employ a true object-oriented language, allowing them to reuse existing software components to deliver their interactive services to market rapidly and cost-effectively. Finally, developers will be able to create more compelling, differentiated content for their audiences.