In a precursory move to next week's National Association of Broadcasters 2002 show, the MPEG-4 Industry Forum (M4IF) Thursday said 29 MPEG-4 vendors have completed three rounds of interoperability tests for various MPEG-4-based products.

While "tests" may not sound like such an exciting prospect, they really are, in this case. MPEG-4 -- a schema of streaming for the Web considered crucial for the delivery of quality video and audio over wireless devices -- is currently undergoing tests by disparate and competing companies intent on creating non-proprietary multimedia software.

The collective thinking of these firms, is that everyone will benefit from having a choice of whose playback applications they use, as opposed to proprietary offerings from a Microsoft Corp., or a RealNetworks Inc..

The tests began in early 2001, and include raw video bitstreams, raw audio bitstreams, MP4 files with video and audio, and MPEG-4 Systems bitstreams. The profiles -- a subset of the standard that provides interoperability between products from different vendors -- include Simple, Simple Scalable and Advanced Simple Visual Profiles, and High Quality Audio.

This means, said test leader Jae-Seob Shin, that vendors do not have to use the whole tool set on an appliance, such as a personal digital assistant.

"Profiles allow MPEG-4 implementations to be exactly as complex as they need to be for a certain application," said Shin, who works for Samsung. "They are the key to an interoperable MPEG-4 ecosystem with products from many different vendors. MPEG-2 has shown the concept to work well."

Participants in the interoperability program include: Amphion, Apple Computer, Avipix, Cirrus Logic, Comverse, Diamondback Vision, DivX Networks, Emblaze System, Ecole Nationale Superieure des Telecommunications, Envivio, Fraunhofer IIS-A, Hantro, IBM, iVast, Luxxon, MTREC, NeoMagic, OnTimetek, Philips, PacketVideo, Reakosys, Samsung, Serome Technology, Sorenson Media, Thomson Multimedia, VideoSpheres, WebCast Technologies.

MPEG applications demonstrating interoperability will be shown at NAB 2002 in Las Vegas from April 6 to April 11. M4IF is also working on a self-certification program, which will allow companies to test the compliance of their products.