DN - Defence Notes

Cooling-off period for closed captions?

27th February 2009 - 11:59 GMT | by The Shephard News Team

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Three years after it was first proposed, a US Department of Transportation (DoT) requirement that captions – subtitles - be added to all IFE content is still on the table. But there are signs that the DoT may be looking to slow the process even further at a time when the airlines are desperately seeking to avoid any addition to their costs.

In 2006 the DoT issued a notice of proposed rulemaking (NPRM) to compel equipment manufacturers, content providers and airlines to make IFE and onboard information fully accessible to the hard of hearing. The NPRM is still active and any ruling that may emerge will apply to all airlines operating within or into the USA.

Industry observers currently anticipate no final decision for several months yet. Meantime, there are signs that the DoT is trying to promote a rapprochement between the IFE industry and bodies like the US National Association of the Deaf, one of the prime movers behind the original initiative. If such a dialogue does take place, the IFE community can be expected to cite its financial difficulties as good grounds for watering down the proposed measures or at least delaying their introduction.   

While it hopes for the best, the industry has for some time been planning for the worst, with the World Airline Entertainment Association and its Technical Committee taking the lead.    

Until recently the only way to add captions to digital video was to “burn” them in, making them a permanent part of the video file. Known as “open captions,” this text is always present on the screen whether the viewer wants it or not. The emerging alternative is “closed” captioning, which the viewer can switch off and on at will.

There are at present two different  ways of providing closed captions, depending on whether the aircraft’s IFE system runs video encoded to the MPEG-1 and MPEG-2 standards, or to MPEG-4 and VC-1/Windows Media. At this week’s meeting of the WAEA Technical Committee in Los Angeles the focus was on the pros and cons of the two methods.

Manufacturer Panasonic has developed an MPEG-1/2 solution that has already been adopted by IFE trendsetter Emirates. It is based on the use of bitmap graphic images to render the captions. At the same time, Californian handheld IFE specialist The IMS Company has worked with the US National Centre for Accessible Media to develop a VC-1/Windows Media solution based on the use of a technology called “timed text”.

Michael Childers is IMS’ managing director for content and media development. He is also co-chair of the Technical Committee’s Digital Content Management Working Group (DCMWG), which in recent years has been responsible for developing WAEA 0403, the standard governing many aspects of how digital IFE content is generated and delivered to the screen.
 
“The biggest difference between bitmap solutions and those using timed text is that the former require the management of 1,500-2,000 graphic image overlays per movie,” he explains. “Timed text doesn’t depend on overlays because VC-1/Windows Media allows the standardised text to be synched to the frame in playback and to reside on the hard drive as an external rather than an embedded file. Benefits include fewer changes to system firmware and reduced processor loading.”

Childers also points to the flexibility of timed-text solutions. “Timed text can be used by virtually any player or processor, and supports the transformation of captions from one format to another,” he explains. “Timed-text captions could be easily converted into bitmap images to run on Panasonic IFE hardware, whereas bitmaps do not lend themselves to the creation of text. Standardising on timed text for the delivery of closed captions would therefore seem to be the best outcome for everyone.”

Panasonic has proposed to DCMWG that its bitmap solution be added to WAEA 0403 as an “informative reference”. IMS plans to do the same with its timed-text method at a future Technical Committee meeting.   

When the caption question first arose three years ago the airlines saw it as a new but probably bearable source of cost. Now that they are nose-diving more steeply than at any time in living memory, it’s one of the many straws that could break the camel’s back. The next few months will show whether the IFE industry, fronted by the WAEA, can negotiate a sensible compromise with the DoT and the US hard-of-hearing community.

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