January 20, 2006 - THE future of IFE content is MPEG-4, 16x9 screen aspect ratio and data delivery at 1.0Mbit/sec – all defined by metadata, protected by digital rights management and supported by a range of interoperable technologies that are still evolving.

That was the conclusion of WAEA’s Digital Content Management Working Group (DCMWG), reporting on Wednesday at a meeting of the association`s Technology Committee in Los Angeles.

All-digital delivery of IFE content moved another step towards reality nearer with the working group’s submission of a formal draft of WAEA Specification 0403 - Standard Methodology for the Delivery of Digital Content for Airline In-Flight Entertainment.

At the same time the group - chaired by Michael Childers of IMDC, Julian Levin of Fox In-Flight and Pierre Schuberth of Rockwell Collins Airshow - announced that it planned to go on to standardise digital content delivery via wired and wireless systems to personal entertainment platforms owned by both airlines and passengers.

Capping more than five years of work by the DCMWG, the WAEA 0403 draft does not name a single codec, specifying instead that the MPEG-4-based codecs - including ISO/IEC 14496 MPEG-4 Part 2 Visual, MPEG-4 Part 10 AVC, and VC1 – are likely to meet the requirements. VC1, incidentally, is a Microsoft development based on MPEG-4 that underpins Windows Media Video and has been submitted for the approval of the Society of Motion Picture and Television Engineers (SMPTE).

Childers explained the decision to recommend a range of codecs and leave the choice to the marketplace, citing decreasing encoding costs, the ease of transcoding, and the ability to decode across multiple encodes with chips like the 8630.

DCMWG is now urging the industry to start moving away from MPEG-1 and 2, the codecs named in today’s WAEA Specification 0395, which 0403 will supplant. These are frame-based and so will not support interactive multimedia and new content applications that require object-based codecs.

The group called for a baseline data delivery bit rate of 1.0Mbit/sec and standard resolution of 720x480. They named two screen aspect ratios - 16x9 and 4x3 - but see 4x3 being phased out as more and more content is made available in 16x9. Currently some content providers consistently support 16x9 while some do not. But 16x9 is increasingly strongly associated with new types of content of the future, both films and television, and there will inevitably be a time when new content is no longer available in 4x3.

The recommendations in favour of 720x480 resolution and 1.0 Mbit/sec are intended to offer airlines that use more than one IFE system a single standard that can be used across all platforms.

However, it is possible that an airline deploying smaller screens, used in seatback systems and portables, might operate at lower throughput and data resolution values without being non-compliant with the standard. Some portables today feature 533x300 data resolution while some embedded systems operate at 480x320, neither of which will be considered non-compliant under 0403.

Similarly, an airline requiring high-definition (HD) display will not be constrained, since DCMWG plans to address HD in a subsequent phase of work.

A key part of the group’s work has been the identification of a security system acceptable to content providers supplying early-window content. DCMWG sees MPEG-21 - the digital rights management (DRM) multimedia standard - as likely to play a large role. “MPEG-4 as a toolset and multimedia codec, MPEG-7 as a metadata standard and MPEG-21 as a multimedia DRM standard together comprise a family of technologies designed to work together to create a secure digital supply chain,” says Childers.

“MPEG-7 is a metadata standard that supports some degree of interpretation of the information that can be accessed by a device or computer code,” he says. “It defines the content of the file for the computer. Importantly, the syntax for the associated description definition language (DDL) is XML, defined by DCMWG as the data interchange language for the IFE supply chain.”

IFE has to deal with two kinds of metadata in IFE: content attribute metadata, used to provide content descriptions for programme guides, and business rules metadata, reflecting the terms of the licence. “For security purposes it is important that we begin capturing the business rules of content licences and have the ability to use them electronically as a decision-support system (DSS) to enforce licence agreements,” Childers emphasises.

A key objective of DCMWG’s security standard is to enable the delivery of fully encrypted content from post-production to the aircraft server without its being decrypted at any time in transport or during the content integration process. One way that this will be accomplished will be by allowing only metadata and header information to remain in the clear.

Under 0403, the RSA algorithm Modulus 2048 will be used to secure decryption keys when they are being distributed, and the AES-128 cipher, in CBC mode, will be used to protect the content files.

The automation and integration of the IFE supply chain – that is, moving from physical to network delivery - is the third main objective of WAEA 0403. DCMWG has identified a number of technologies that will be utilized in this migration, including Web Services and the emerging Business Rules Management discipline. “These two technologies share many goals,” observes Childers.

DCMWG is seeking to identify and recommend technologies that ensure interoperability in the supply chain. “As long as the solutions are interoperable, decisions can be left to the marketplace,” says Childers. “More than one solution can be implemented without penalty because they are capable of working together.”

The so-called “last mile” from the airport landside to the aircraft represents could be bridged by a number of technologies, with most of the present focus being on wireless solutions. DCMWG plans to hand responsibility for the last mile to a separate working group to be formed by the WAEA Technology Committee.