June 30, 2005 - IN a surprise turn-around, the World Airline Entertainment Association’s Digital Content Management Working Group (DCMWG) yesterday decided against producing a standard for video codecs, preferring to leave the choice to the market. A codec is the software algorithm used to code and decode digital video as a safeguard against piracy.

At its last meeting earlier this year the group appeared to favour a draft specification that would have made it impossible for handheld IFE systems to be compliant. Yesterday’s U-turn, allowing this emerging sector to stay in the mainstream, is therefore of great significance to the achievement of the vision of all-digital network delivery of IFE content from originator to airline.

Chaired by Michael Childers (IMDC), Julian Levin (20th Century Fox) and Pierre Schuberth (Rockwell Collins Airshow), the DCMWG reported its decision to the WAEA Technology Committee, meeting yesterday in Long Beach, California.

There were three primary reasons for the decision, according to Childers. “First, the MPEG-4-based codecs - MPEG-4 Part 2, Visual; MPEG-4 Part 10, AVC (also known as H.264); VC1; and DivX - are still evolving. Microsoft’s VC1 has been submitted for approval as an open standard, for example, and the tool-sets surrounding all of these codecs are still maturing.”

Second, says Childers, “it is now possible to transcode from one codec to another at relatively low cost. And third, new chips able to decode across multiple encodes are now becoming available. Taken together, these two factors make it much less necessary to fix on a single codec standard.”

Childers also points out that handheld IFE developers in particular need to have discretion over the choice of codec as they work to optimise the performance of their systems. “The ability to control the encoding selection is important to a system designer or content manager who is seeking optimum display and system performance, particularly when power consumption limitations are part of the requirements,” he says.

Instead of naming a specific existing codec and standardising on it, DCMWG will now express broad requirements - specifying that it be object-based, for instance – and draw up performance measures (normalised bit rate, peak signal-to-reconstructed image rating, maximum power consumption in different applications). Any codec meeting these requirements will be treated as compliant.

Significant though it is, the codec is only a part of the content delivery network that DCMWG is studying, says Childers. “Of even more importance is the metadata standard, currently emerging in MPEG-7, and the digital rights management (DRM) standard being captured in MPEG-21.”

Next milestone for the group is completion of its overall requirements document, which is due for delivery by the time of the WAEA show in Hamburg this September.