Microsoft Corporation
The New Era of Digital Broadcasting
Microsoft Products for Digital Broadcasting
Digital broadcasting—the transmission of digital media from one to many points over diverse digital networks—is the new common ground of broadcasting, television, and computers.
Digital broadcasting offers consumers an enriched experience through better pictures, enhanced programming, and new services.
Digital broadcasting brings new opportunities for content producers, broadcasters, and advertisers in the areas of new markets, new distribution channels, and new audiences. For businesses, this means a new and more cost-efficient means of communicating with customers and employees. For equipment makers, this means a new upgrade path for consumer electronics and computing devices.
The digital broadcasting infrastructure—multiuse, multinetwork, and multiresolution—is evolving quickly from existing platforms, technologies and tools. The new digital broadcasting infrastructure will be capable of carrying both traditional television video and dynamic, timely Web-based data.
Several trends underlie the emergence of this new digital broadcasting infrastructure, such as digital-video compression and transmission, the Broadcast Web (channels, media streaming, and multicasting), and the parallel evolution of TVs and PCs. The net meaning of these trends is clear: The digital broadcasting era is here and it offers the prospect of vast new possibilities for both the consumers and the industry.
Microsoft Corporation sees both television and personal computers improving and evolving to become receivers of the new digital broadcasts. Both will be capable of receiving the same types of enhanced content and programming, yet they will differ in that personal computers will continue to be "general purpose" devices that can be configured in many different ways, while televisions will be "special purpose" devices with far fewer configuration options.
Today, personal computers are capable of receiving digital broadcasts in the form of low-bandwidth, Web-based data and video. Over time, personal computers will add such features as broadband digital broadcast reception, distance-viewing user-interface options, and support for enhanced content. Similarly, televisions will improve over time, adding capabilities such as Web access, broadband digital broadcast reception, and support for enhanced content.
Microsoft is providing a host of key enabling technologies for this new digital-broadcasting era, including Microsoft® Internet Explorer 4.0, Microsoft NetShow™ server, and the Microsoft broadcast architecture for Microsoft Windows® and Windows CE operating systems. This article will explore these products in some detail, after first examining the impact of digital broadcasting on consumers, the industry, and the infrastructure.
Digital broadcasting provides first and foremost an opportunity to deliver more value to consumers. The new consumer experience can be thought about in terms of a richer display, enhanced programming, and new services.
Digital broadcasting will offer TV viewers and PC users a better viewing experience. This will be accomplished through the emergence of digital television formats that specify higher resolution digital-image display with a wide aspect ratio. This will allow the content-development community to give the viewer a richer experience by mixing text, graphics, and video under the user's control.
Digital broadcasting will offer consumers a combination of video, audio, and Web data. This will open up a wealth of new content experiences. Existing broadcast shows can incorporate additional information and entertainment. For example, graphics and text generated on the viewer's television set can provide background story information, games, and advertising that runs parallel with the broadcast show. News and information channels can dramatically increase their information content by combining the simultaneous broadcast of video and Web data. The mix of video, audio, and Web data is equally important in computer and Internet venues, as Web sites increasingly include video, audio, and streaming media.
Digital broadcasting will offer consumers a wealth of new services. The Web and the PC have proved that instant on-demand access to critical news and information resonates with consumers. Additionally, personalized information delivery such as the daily delivery of personalized financial news is already popular on the Web and will likely be enhanced and delivered on both TVs and PCs in the future.
The enhancement of the consumer experience and deployment of the new digital broadcasting infrastructure presents an enormous opportunity for the industry. The Web has created new opportunities in production, publishing, advertising, and commerce. The digital broadcasting era will create similar opportunities, including but not limited to the following:
A new multinetwork, digital-based broadcasting infrastructure is emerging. Unlike the old analog broadcasting networks, content, transmission format, and display are no longer hardwired together—digital content can travel over any digital network.
Figure 1. Digital broadcasting infrastructure
This decoupling of digital-content origination, transmission, and viewing formats defines the power of digital broadcasting. The following is the digital broadcasting infrastructure:
Digital broadcasting will require a host of products and technologies. Consider the spectrum of production, broadcasting, and viewing: Microsoft already provides some key enabling technologies and will provide more in the future. Today's products include the Windows NT® Workstation operating system for content creation, NetShow for Internet broadcasting, and Microsoft Internet Explorer and Windows for viewing. The actual process of delivering broadcast information clearly has many steps and stages, and in areas where Microsoft does not have products, it is working with other companies and is actively involved in industry standard-setting efforts such as those describing layered progressive scan formats.
Following is an overview of current Microsoft products of interest to the broadcast industry.
In the area of production, Windows NT Workstation, in combination with a growing suite of tools products, provides a cost-effective, high-performance platform for such tasks as video capture, video editing, 3-D animation and Hypertext Markup Language (HTML) integration. Designers and producers appreciate the ease of use of the Windows user interface combined with high-performance features such as seamless symmetric multiprocessor support and high-speed hard disk access.
Many of the most popular products for media creation and production are now available for Windows NT, including products from Microsoft, Softimage Inc., Adobe Systems Inc., Avid Technologies Inc., Kinetix (a division of Autodesk Inc.), Macromedia Inc., and others.
In the area of Internet-broadcast viewing, Microsoft Internet Explorer 4.0 will add a number of features that enable one-to-many personalized information delivery. A new, channel-based paradigm in the user interface will make Web-based digital broadcasting an immediate reality to thousands of Web publishers and millions of Internet users.
At the heart of the implementation of channels in Microsoft Internet Explorer 4.0 is the Channels Definition Format (CDF), an open standard that Microsoft has developed and submitted to the World Wide Web Consortium (W3C). More than 30 key Internet vendors have rallied behind the CDF specification, including AirMedia Inc., America Online Inc., AudioNet Inc., BackWeb Technologies, CompuServe Inc., Excite Inc., FirstFloor Software, Hotwired Inc., Infoseek Corp., Lycos Inc., Starwave Corp., and Ziff-Davis Publishing Co.
CDF offers several compelling benefits as an open-industry standard, including:
In the area of Internet broadcasting and viewing, NetShow 2.0 provides the foundation for a new generation of Web-based applications using powerful, rich media streaming. With leading-edge multicast and on-demand media-streaming technology, NetShow 2.0 allows users to experience live and recorded video, audio, and multimedia broadcasts in real time over low- to high-bandwidth networks.
NetShow provides a complete platform for Internet and intranet streaming video, audio and multimedia in applications such as entertainment, news and information services, corporate communications, advertising, and online training and sales support.
Because NetShow uses open, industry standards, provides an extensible platform, exposes client and server application programming interfaces (APIs) and includes the Active Streaming Format (ASF), it represents a significant opportunity for third-party, value-added products including tools. Independent software developers and tool vendors can augment their own products with NetShow functionality or provide compatible add-ons.
The NetShow 2.0 client is an integral part of Microsoft Internet Explorer 4.0, extending the strength of the Microsoft browser in the area of one-to-many communication. NetShow 2.0 is tightly integrated with Windows NT Server and Microsoft Internet Information Server to provide an efficient, reliable, and scalable platform for streaming media.
Production deployments of audio and video broadcast on the Web need a server that can scale up to thousands of streams to enable full-scale, one-to-many communication. NetShow server takes full advantage of the high scalability of Windows NT Server to provide a powerful and robust system that can take full advantage of microprocessors such as Pentium, Pentium Pro, and Digital Alpha.
NetShow takes advantage of and integrates with all key Microsoft BackOffice® applications and Windows NT Server manageability features, including the graphical administration console, performance monitoring, and an integrated directory and security model. An integrated-server solution offers easier management, better connectivity and lower support costs.
NetShow 2.0 administration is provided through an intuitive Web-based interface, which enables both local and remote administration. This lets administrators manage server installations and make configuration changes, without having to physically accessing each server.
For viewing broadcast video and integration with Web-based data, the Microsoft Windows products will enable PCs as client systems for digital and analog broadcast networks. These broadcast networks include the following one-way and two-way broadcast networks:
The Microsoft Windows family uses a modular design approach to achieve the following design goals:
This approach uses existing content and technologies, and suggests new avenues for the distribution of home entertainment, news, information, education, software, and general retail merchandise.
To take advantage of these new broadcast capabilities, PCs must be equipped with future versions of Microsoft Windows software and enabling hardware in the form of an Entertainment PC. The Entertainment PC specification is a part of the overall PC 97 specification as determined by the personal computer hardware industry. It includes a television tuner and, as an option, a tuner to decode satellite signals. An Entertainment PC can use a normal 15- to 17-inch monitor, a large-screen monitor (31-37 inches) or a television as its display surface. If used in the living room as an entertainment device, the PC would typically use a wireless control and/or keyboard as its input device. The Entertainment PC is a versatile computer that blends television with exciting new forms of information and entertainment. The following are examples of five new capabilities possible with an Entertainment PC:
These capabilities are achieved through a combination of hardware and software components that allows personal computers to serve as clients of broadband digital and analog broadcast networks. In the home, they serve as data and video tuners that receive and process broadcast streams provided by powerful servers that are transmitters of all sorts. The client systems receive data and video via the vertical blanking interval (VBI) as a part of the television broadcast network accessed from an over-the-air broadcast, a cable subscription, or a satellite transponder. The consumer will have the option of purchasing an Entertainment PC with a television tuner only for a VBI transmission of data and video, or a television and satellite tuner for high-speed satellite transmission of data and video.
Microsoft believes Entertainment PCs are the most flexible and cost-effective path to television of the future. Not only do they have a lot to offer immediately, they also support low-cost, incremental steps to higher resolutions, increasing back-channel bandwidth, and increasing interactivity while offering new forms of enhanced television. For viewers and content producers alike, these PCs provide painless interim solutions at every stage. Rather than becoming obsolete as technology evolves, they are designed to incorporate technological advances smoothly.
Almost all of the technology and infrastructure needed to create broadcast-enabled computers is currently in place. In particular, Entertainment PCs rely on current broadcast networks and phone-line back channels that are inexpensive and available in virtually every home today.
Software for these computers has been designed so that simple, impressive combinations of television and information content can be delivered in the form of World Wide Web pages simultaneously with the broadcast. Broadcasters can take advantage of standard Web design tools, scripts built using Microsoft Visual Basic®, and skills they already have to create enhanced television rapidly and easily. In cases where Web functionality is insufficient, programmers can readily take advantage of the power of the software tools available to write special-purpose applications.
For viewing video and enhanced content on non-PC devices, Microsoft initiatives fall into the categories of enhancement and extension of the Windows CE product line. Windows CE is an entirely new compact and portable operating system built from the ground up to be appropriate for a broad range of business and consumer devices.
Figure 2.The Windows CE family
Windows CE is the cornerstone of a complete, standards-based operating environment designed to significantly lower the barriers for original equipment manufacturers (OEMs), hardware manufacturers, and software developers to create Windows-based communications, entertainment, and mobile-computing devices. The complete Windows CE environment includes built-in hardware, multimedia, and communications support, which means that a broad range of Windows CE-based mobile companion, information access, and entertainment devices can be created that communicate with each other, integrate with Windows-based personal computers, and access the Internet.
The first products based on Windows CE fall into a new category of mobile-companion devices for Windows-based PCs called Handheld PCs. Handheld PCs are designed to provide an affordable, easy-to-use PC companion for millions of mobile professionals who use Windows-based personal computers that contains their most important information.
Suitable categories of devices for Windows CE include other small form-factor mobile-computing devices, such as wallet PCs; wireless communications devices, such as digital information pagers and cellular smart phones; and next-generation Internet and multimedia devices, including smart TVs, set-top boxes, digital video disc (DVD) players, telephones, and other Internet appliances.
Windows CE brings the functionality of the PC to mass-market consumer devices: TVs, cable boxes, satellite boxes, telephones, cellular phones, organizers and more. Windows CE–based television devices will bring the full promise of digital broadcast networks to much wider audiences.
Supporting many Microsoft products for digital broadcasting is a new unified and comprehensive multimedia API solution that includes media integration and local streaming services.
This expanded set of APIs, representing a major enhancement to the highly successful DirectX® technology, is organized into two layers: a high-level DirectX media and a low-level DirectX foundation.
DirectX media provides an open, extensible component architecture to enable developers to easily incorporate animation, local streaming and interactivity into their applications, regardless of programming language or platform, while taking advantage of the device-independent hardware acceleration provided by DirectX foundation.
DirectX media services include the following:
The DirectX foundation hardware acceleration layer is based on Microsoft's highly successful DirectX game APIs and provides extremely efficient access to advanced features of high-performance hardware. DirectX foundation includes the following:
By providing a standardized media API solution, DirectX foundation and DirectX media lower the barriers to developer innovation and thus create major new business opportunities for multimedia and game developers, tool vendors, and hardware makers.
Conversion to higher-resolution displays will not happen overnight. An incremental path will reduce upgrade-cost barriers for consumers, lower infrastructure investments, and bring about a resurgence in consumer electronic purchases.
A layered-progressive-scan transmission architecture will enable broadcasters to deliver digital TV content soon, reduce the cost of display devices that handle text and graphics, and improve the quality of images sent depending on content (for example, movies) or equipment availability.
Microsoft supports a staged approach to introducing high-definition television (HDTV) that is matched to available and affordable decoding and display technologies. This proposal consists of a number of "layers" derived from Advanced Television Systems Committee (ATSC) formats that specify increased display resolutions. The base layer is called High Definition Zero (HD0); subsequent formats (HD1, HD2) add information, encoding higher resolutions to this signal in such a way that HD0 receivers can display HD1 signals at partial resolution. Thus, an HD0 set will not "go black" when tuned to HD1 signals. The approach uses emerging Internet standards for IP multicasting; signals are carried in an MPEG transport stream.
The base layer (HD0) has two modes: 480 pixels (p) 60 frames per second (fps), ideal for live action, and 720 p 24 fps, suited to high-resolution film material. Advanced Television Testing Center visual testing has shown that 720 p is comparable to 1080 interlace (i) content. This layer uses MPEG encode and decode at 2x Main Profile at Main Level.
The first enhancement layer (HD1) raises each mode of the base layer by one level of resolution. It offers live video at 720 p 60 fps and film material at 1080 p 24 fps.
HD2 requires further algorithm improvements and will offer 1080 p, 60 fps.
The rollout schedule for these layers depends on a multitude of factors, but the following schedule is expected:
HD0 uses about 9.5 Mbps of the available 19.2 Mbps of terrestrial broadcast bandwidth, leaving about 10 Mbps for data enhancements. HD1 essentially fills a 19.2 Mbps channel. Broadcasters with wider channels can use any additional capacity for data services. There is strong reason to believe that compression algorithms can be developed that will fit HD2 in a 19.2 Mbps channel.
The stated goal of the HDTV process is to reach 1080 p broadcasts. This is not economically feasible today, so the layered progressive scan provides an incremental approach.
As discussed, the broadcast process involves many steps that fall into three main categories: production, broadcasting, and viewing. We'll now examine these three steps from a digital-television perspective.
Content-creation techniques will continue to rely increasingly on digital tools and concepts. The dual-mode approach allows producers to choose the resolution most appropriate to the task at hand. For example, a local broadcaster might use currently available 480 p cameras for studio and live action, while a high-end studio might choose 720 p 60 fps, which is of archival quality. Film material can be readily telecined (converted from film to video) to 720 p 24 fps for broadcast.
While the layered-transmission proposal doesn't specify the production format, Microsoft expects that enhancement-layer encodings will be more effective on progressive-scan source material. It should also be noted that present and future progressive scan formats would coexist in the studio better than the mixture of interlace and progressive. If 1080 i production is preferred, one can filter down efficiently to 480 p 60 fps and reasonably well to 720 p 60 fps. Microsoft recommends that producers archive in the highest quality progressive format: 720 p 60 fps soon, and 1080 p 60 fps when it becomes available.
The layered compression and transmission proposal was discussed previously.
The goal of the layered-progressive-scan proposal is that both TVs and PCs are available as receivers from the beginning. The PC industry offers a significant opportunity to increase the number of digital TV receivers rapidly. Microsoft is working to ensure that base-layer digital TV decoders will be a standard part of entertainment PCs shipped in 1998. Further, PC 98 (the specification recommended by Microsoft at WinHEC for the configurations of PCs manufactured in 1998) will decode only the layered architecture signals described here, not other formats in the ATSC standard. Microsoft forecasts that consumer PC sales in 1998 will be approximately 15 million units. Thus, there will be a significant number of PC receivers ready to decode HD0 digital TV signals in 1998. Interlace broadcasts will not be received by this rapidly growing audience without additional equipment.
Progressive scan displays are significantly better than interlace for viewing the set-generated text and graphics that are an increasingly important part of television. The layered approach uses progressive scan formats in part to minimize the cost of receivers. Microsoft believes that it is more economical to de-interlace signals (if necessary) once at the point of broadcast, rather than in every display device.
The display technology used is the choice of the manufacturer. Microsoft foresees a multitude of possible displays ranging from legacy interlaced displays to very high-quality data monitors running at even higher resolution and frame rates than broadcast signals.
This White Paper is for informational purposes only. MICROSOFT MAKES NO WARRANTIES, EXPRESS OR IMPLIED, IN THIS DOCUMENT.
The information contained in this document represents the current view of Microsoft Corp. on the issues discussed as of the date of publication. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information presented after the date of publication.