Guest Editorial Beyond MPEG-2
MPEG-2 video and audio compression, the current standard for digital broadcasting, has been a strong point of stability in designing and building digital broadcasting systems. However, new algorithms are emerging that are poised to create a fundamental change in broadcast video compression.
MPEG-2 made digital satellite and multichannel broadcasting explode and as bit-rate requirements fell and more products were developed, it created and fulfilled new markets: digital SNG, distribution, high definition broadcasting, wireless cameras, and most recently, video over IP. MPEG-2 has been refined since its early installations such that channels once requiring 8Mbps now require only 2 or 3 for the same picture quality. The codec has delivered excellent performance, but MPEG-2’s coding efficiency is reaching its peak.
While advances in MPEG-2 over the years have delivered new efficiencies and improved the business and quality case for broadcasters everywhere, each increase in performance is getting smaller and more difficult to implement. This slowed performance upgrade has opened the doors for new standards within the professional broadcast codec market.
MPEG-4 and Windows Media 9 Series are at the top of this group. The common theme of both techniques is the ability to reduce the bit-rate required to carry video content by up to a factor of three over current MPEG-2 solutions. MPEG-4 has been a topic of conversation in recent years, but it has many different flavors and classifications. In broadcast television, the only classification that counts is MPEG-4 part 10. Earlier versions, such as “Simple Profile,” “Advanced Simple Profile,” and “part 2” never escaped the Internet and mobile telephony arenas. These have now been technically superseded by “part 10” for digital broadcasting.
Just as the launch of MPEG-2 in the mid-1990s created the digital broadcasting industry, the emergence of Windows Media 9 and MPEG-4 will take broadcast video and audio to new levels. Possibilities include broadcast-quality television at 1Mbps, high definition at 5Mbps and television broadcasting to PDAs and cell phones at rates as low as 100kbps. This massive shift in bit-rate requirements will alter business models and make possible many new video services that would have been impossible against the bit-rate constraints of MPEG-2 environments.
With two or more televisions in the home, MPEG-2 over ADSL struggles to provide telcos, for example, with a competitive solution to today’s digital cable offerings. With advanced codecs providing better bit-rate management or the ability to increase audience reach, ADSL providers can offer multiple channels of television to the home on a single twisted-pair connection, making MPEG-4 and Windows Media 9 powerful weapons in the telcos’ battle to provide “triple-play” (television and video on demand, telephony, and high-speed Internet access) to the home.
In the high definition realm, ATSC HD offers 19Mbps in the MPEG-2 environment. Reducing that bandwidth by a factor of four dramatically changes the economics of multichannel HD broadcasting. Along with the growth in multichannel HD on satellite and cable that the new codecs enable, another exciting proposition is the possibility of HD DVDs.
Outside of traditional means, broadcast television to new devices opens interesting avenues for revenue generation. MPEG-2 was never designed for very low bit rates and consequently does not perform well at bit rates of 2Mbps or lower. Delivering low-bit rate, realtime content, such as sports and news channels, over a cell phone network to PDAs or new-generation smart phones (hybrid PDA/cell phone devices) creates new revenue opportunities for broadcasters and content owners.
Manufacturers throughout the industry are working on products to enable these visions. Companies such as TANDBERG Television and Pace Micro Technologies are building Windows Media 9 Series broadcast headends and set-top boxes. MPEG-4 part 10 is not expected as a standard until summer 2003 but the eventual products based on it should be impressive.
Even with this headlong rush toward new codecs and business models, MPEG-2 has a healthy future. There are almost 80 million MPEG-2 set-top boxes installed today, and compression technology cannot be swapped overnight. Additionally, while 2003 will be a year of much visionary work on Windows Media 9 Series and MPEG-4 part 10, it will be light on deliveries. Because not all manufacturers have taken the opportunity to work on Windows Media 9 Series and MPEG-4 part 10, it will likely be some time before hardware product solutions reach the market. Even then, only a few will have something of real value to offer. A good compression product or algorithm does not make a business solution. These new techniques need new systems from experienced and skilled providers.
Still, 2003 is and will continue to be a year in which a large amount of interest will be shown toward powerful new codec technologies. This technological effort will drive growth in core TV markets and enable some exciting new opportunities for manufacturers and broadcasters. The broadcasters, operators, and owners first to grasp these opportunities will have much to gain. However, as with any new technology, broadcasters should be careful to evaluate and choose the right products as they strive to reduce costs and increase revenues derived from the increased bandwidth efficiency of MPEG-4 and Windows Media 9 Series codecs.
Charles Cartwright is the business development manager for advanced encoding for TANDBERG Television.
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