The MPEG-4 multimedia coding standard is gaining momentum as the number of companies testing products using the format grows, the M4IF (MPEG-4 Industry Forum) said today.

A total of 29 vendors, including Philips, Samsung, Apple and IBM, successfully concluded a third round of interoperability testing, said the M4IF. Content encoded on a product from one vendor was played using a decoder from another vendor.

"This is the first time that M4IF has gone public since the testing started. We have reached a benchmark," said an M4IF spokesman. "We have seen tremendous growth in the list of companies testing interoperability. Four vendors decided to get on board in the last two days and the number of people applying to be on the list is growing."

The next step in testing will be live streaming of content, the spokesman said. Additionally, the M4IF is working on a self-certification scheme so vendors can test compliance of their products, he said.

Interoperability is important as the multi-vendor model is what distinguishes MPEG-4 from competing coding technologies offered by RealNetworks and Microsoft, said Sebastian Moeritz, chief executive of Berlin-based Dicas Digital Image Coding, maker of video coding technology and a member of the M4IF.

"MPEG-4 offers something that RealNetworks and Microsoft don't — choice. If you want video coding technology from Microsoft, then Microsoft is your vendor. With MPEG-4 there is a choice of multiple vendors," he said.

MPEG-4, the successor to MPEG-2, promises a much better picture at lower bit rates than is common today. It is expected to be used in many devices, including TV set-top boxes and mobile phones. Moeritz expects to see MPEG-4 in use later this year, or early next year.