Decoding MPEG 4 - Comment

Electronic News, May 6, 2002 by Barry Keepence

IMAGINE WATCHING GLADIator--not in the movie theater but over an Internet protocol (IP) network on a Web-enabled device. Very possibly you conjure up an image of herky-jerky video, but consider that in 2002 the MPEG-4 standard for digital video, with its promise of crystal clear Internet video, is finally receiving widespread attention.

While numerous digital formats have already been adopted by content providers, network operators and consumer electronics manufacturers, not even the sophisticated compression standard MPEG-2 is suitable for the needs of the emerging IP-connected digital video marketplace.

To meet to the challenges unique to video transmission over IP networks, content providers and network operators are adopting MPEG-4 to provide high-quality video over a network with limited, variable bandwidth. With organizations such as the Internet Streaming Media Alliance (ISMA) and companies such as Seattle's RealNetworks supporting the standard, it is important to take a closer look at MPEG-4's capabilities for video compression, implications for video applications and devices and the many permutations of MPEG-4 solutions on the market.

Even with competition from proprietary video compression formats from RealNetworks and Microsoft Corp., the clear advantages of MPEG-4 in regards to quality and scalability will ensure its eventual dominance in the consumer electronics and streaming industries.

MPEG-4 includes state-of-the-art compression techniques, which allow it to provide greater compression and higher quality than MPEG-2 and earlier standards. In the case of MPEG-4, scalability refers to MPEG-4's specific provision to allow it to work well over a range of bandwidths and screen sizes.

These scalability and quality advantages unique to MPEG-4 are driving the standard's acceptance within the streaming, electronics and even security/surveillance markets. The ISMA, for example, is promoting the use of MPEG-4 as the encoding standard for video delivered over the Internet.

Manufacturers of set-top boxes and DVD players are also increasingly providing support for MPEG-4. This will allow home users to access the wealth of video available on the Internet and will enable distribution of high-quality, low-cost video content on CD-ROM as well has the more expensive DVD disks. Camcorder manufacturers view the scalability and quality of MPEG-4 as integral to new applications, such as sending video clips by email. The 3G mobile phone industry consortia have also adopted MPEG-4, and phones with MPEG-4 capability are now coming onto the market in Japan.

A quiet revolution is also occurring in the security and surveillance (CCTV) world, where surveillance and monitoring systems are moving from analog video to IP network video using MPEG-4. MPEG-4 is replacing the blotchy security video seen on TV crime shows with crisp, high-quality images that can be viewed and searched around the world.

With all the activity in MPEG-4, technology providers have developed a range of solutions for encoding and decoding MPEG-4 video. At one end of the spectrum lie the PC software encode and decode programs. These are flexible but require a modem PC. However, while they can decode high-resolution video in real-time, encoding cannot be accomplished in real-time (it may take 5 minutes to encode 1 minute of video).

Other embedded solutions use a low-power RISC processor with special assist hardware to encode and decode small-screen video in real-time but at reduced frame rate. These solutions are focused at mobile phones and do a reasonable job for this market. They cannot, however, scale up for larger screen applications.

At the other end of the spectrum are hardware solutions. A hardware solution provides the optimal combination of performance and cost, providing high-resolution at high-frame rate, occupying little silicon area and consuming little power. They are difficult to design and lack flexibility, but for markets with well-defined requirements such as mobile phone and IP surveillance they are the best solution.

The future for MPEG-4 looks bright, though its adoption is not without challenges. Microsoft is a notable holdout against the adoption of MPEG-4, preferring to promote its own, proprietary Windows Media technology. Content providers are extremely wary of getting locked into proprietary protocols. The momentum behind MPEG-4 is growing every day and will soon achieve critical mass, providing consumers with a high-quality video experience and content providers with new revenue-generating opportunities.

Barry Keep ence is the CTO at Indigo Vision, an Edinburgh-based live networked video company. He can be reached at b. keepence@indigovision.com.