System Software Extensions

The operating-system software that forms part of Broadcast Architecture is intentionally based on industry standards, as described in Sticking to Standard Technologies. These standards guarantee developers, manufacturers, and viewers a stable, well-supported platform that will gracefully evolve to support new technologies as they appear.

In some areas, extensions to these standard technologies have been required. These extensions include:

• Extensions to accommodate the very large bandwidth required by high-quality digital audio and video streams, and to provide for flexible control over these streams. These extensions are special filters based on the Microsoft® DirectShow™ application programming interface (API). For more information on DirectShow, see the Microsoft Platform SDK.
• Extensions to support interactions with users. Broadcast clients use specialized software to control, process, and display high-bandwidth broadcast streams. Some of this software, such as the Guide database system, also handles user interactions. The Guide database provides a single secure repository for program data. At the same time, any service provider can deliver application data to the database by writing a loader program.

Microsoft also provides other types of system software extensions, such as a transport layer specifically designed for broadcast needs. Because such components all function as part of the Microsoft® Windows® 98 operating system, third-party programmers can easily write programs that take advantage of them.

Microsoft makes interfaces that support operating-system extensions available through the Microsoft Platform Software Development Kit (SDK) and the Windows 98 Driver Development Kit (DDK). The Broadcast Architecture Programmer's Reference and the Broadcast Architecture DDK documentation cover these interfaces.