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Captioning Solutions for Handheld Media and Mobile Devices

Millions of Americans of all ages use cell phones, PDAs or dedicated portable media players to access content related to almost every aspect of daily life. Video content on portable devices ranges from streamed television programs and "Webisodes" to elementary school science experiments, from university lectures to health and behavior management information for heart attack survivors. Companies increasingly use video podcasts as cost-effective methods for delivering product and training materials to their employees or customers. Emergency management agencies are developing alert and information systems that send content sent directly to portable devices.

However, the 22 million Americans who are deaf or hard-of-hearing cannot benefit from this content because mobile-video technologies do not address the technical requirements for packaging and delivering captions. Even video-enabled mobile devices that have the technical capability of downloading captioned content from the Web do not provide user interfaces to allow caption display.

NCAM is researching these barriers and develop captioning solutions that will serve as models for the mobile media and technology industries and for public-policy developers. The project team has identified the problems that currently exist in the creation and delivery of captions to mobile devices, and is testing required accessibility changes in production tools, formats, delivery methods and display technologies. Prototypes model technical solutions for compression, packaging, identification, retrieval, downloading and processing of captioned video to portable devices. Prototypes also model caption display options and explore customization capabilities; consumers who are deaf or hard-of-hearing are now evaluating the usability of project solutions.

Project activities include:

• creation of demonstration models that show multiple methods of creating, distributing, downloading and displaying captioned content on handheld devices;
• publication of usability research on accessible interface and caption-display options;
distributing information for content creators, service providers, and third-party tool developers to create and transcode captions;
• detailing the requirements necessary for non-proprietary as well as proprietary text and video formats to render captions.

Please note: On October 15, 2009, the Advanced Television Systems Committee (ATSC) approved the A/153 ATSC Mobile DTV Standard, which defines the technical specifications necessary for broadcasters to provide services to mobile and handheld devices using their DTV transmissions. ATSC Mobile DTV supports a variety of services including free (advertiser-supported) television, interactive services delivered in real-time, subscription-based TV and content download for playback at a later time. A/153 includes support for the transmission of CEA-708 closed-caption data. Download and read the ATSC Mobile DTV standard for complete details; see Part 7 for information regarding closed captions.