MPEG-4 tapped for set-tops, home networks

MPEG-4 tapped for set-tops, home networks
By Junko Yoshida, EE Times
January 4, 2002 (6:54 p.m. EST)
URL: http://www.eetimes.com/story/OEG20011130S0093

ANAHEIM, Calif. — MPEG-4 compression technology is gathering steam, earning keen interest from set-top-box vendors and semiconductor companies hungry to add features to current designs, and from service providers eyeing it for home networking and for set-tops integrated with personal video recorders.

The bandwagon is led by satellite providers exploring ways to reduce the bit rates of their broadcast streams, and by cable operators looking to add object-based interactive features to their programming. Meanwhile, some service operators are also considering MPEG-4 as a way of saving hard-disk-drive space in set-tops equipped with personal video recorders (PVRs). Others see MPEG-4 as effective in squeezing the bandwidth required for real-time video streaming in home-networking applications.

None of the PVR-integrated cable set-tops demonstrated at the Western Show here this past week — such as those from Motorola or Scientific-Atlanta & #151; featured MPEG-4 yet. But Cirrus Logic, LSI Logic, Philips Semiconductors and Sigma Designs are among the chip companies showing MPEG-4 silicon road maps and set-top-system reference designs with MPEG-4 capabilities.

Mark Samuel, marketing director for set-top boxes at Philips Semiconductors, tabbed "bit-rate reductions, picture-in-picture applications and home networking" as the three primary factors motivating network service operators to consider MPEG-4.

Scientific-Atlanta Inc. is "actively looking at MPEG-4 solutions right now," said Jim Kiker, director of home gateways for the company's subscriber networks sector. The point, he emphasized, is not to replace MPEG-2 with MPEG-4, but to equip a set-top box to transcode MPEG-2 streams into MPEG-4.

Stream Machine, now part of Cirrus Logic Inc., unveiled at the Western Show a pair of reference designs that incorporate MPEG-4: Maestro 2, designed to provide next-generation PVR capabilities for home media centers, and Spigot, a thin-media cli ent that decodes networked digital audio that's video streamed off a home media server.

In addition to pause, instant replay and other time-shifting features for live broadcasts, the Maestro 2 reference design allows consumers to access stored media in such formats as MPEG-1, -2 and -4, said Brian Heuckroth, vice president of marketing for Stream Machine.

In contrast, the Spigot reference design is a small, low-cost set-top that decodes networked digital audio and video streams for playback on existing analog consumer electronics systems such as TVs and stereos. At Spigot's heart is a TriMedia 1300 decoder chip that handles audio/video playback of MPEG-1, MPEG-2 or MPEG-4 streams over a home network.

The server-and-client architecture based on Maestro 2 and Spigot lets viewers independently access stored or live media files, without requiring them to purchase an expensive PVR-based set-top for every TV in a household, Heuckroth said.

Interoperability demos

Meanwhile, iVast an d Sigma Designs, which recently partnered to develop a complete solution for digital set-top-box deployments, gave interoperability demonstrations of their technologies at the Western Show. The pair demonstrated the playback of iVast MPEG-4 audio and video encoded content on the Sigma MPEG-4 decoder chip, the EM8475.

Marty Levine, vice president of business development for consumer platforms at iVast, said that requests for proposals for MPEG-4 have already been put forward by service operators in Asia. U.S. cable operators, meanwhile, are still studying the issues involved in adding MPEG-4 capabilities, he said.

Philips Semiconductors' Samuel pointed to strong interest in MPEG-4 among satellite vendors, which have traditionally been very bandwidth conscious. Using the MPEG-4 Advanced Coding Efficiency profile, satellite broadcast streams — currently delivered at bit rates of 2.5 to 3 Mbits/second — can be trimmed to 1.6 Mbits/s while maintaining good-quality video, he claimed.

Samuel also said there is a real pull in the market for MPEG-4 in picture-in-picture applications. While a national NBA broadcast occupied the screen, he said, a local game compressed in MPEG-4 in CIF resolution could be layered atop it so that it appears as a picture within the picture.

Further, Internet-streaming content — compressed in MPEG-4, Windows Media or Real — could also be displayed on screen in a picture-in-picture format.

The flexible nature of the TriMedia core makes it "perfect" for such applications, Samuel said. "Imagine what a company like AOL Time Warner can do," he said, with a picture-in-picture feature that marries the main video broadcast content with AOL's Internet content.

Clearly, the versatility of the MPEG-4 standard is playing to its advantage as MPEG-4 finds its way into different set-top uses.

Philips Semiconductors has a Viper set-top platform that uses its own Nexperia PNX-8525 chip. The chip is integrated with TriMedia's 32-bit, 200-MHz TM32 processor c ore and a 150-MHz MIPS 3940 RISC core. It also packs a 2-D drawing engine and high-level MPEG-2 decoder.

Decoding Simple Profile MPEG-4 on its TriMedia core, for example, uses up less than 60 MHz of processing power, leaving the rest of the TriMedia core's processing power free, Samuel said.