Opportunities for improving accessibility with the new specification 2.0.1 of standard HbbTV

1. Juan Pedro López, Pablo Mateos, Álvaro Llorente, José Manuel Menéndez
Nem Summit - Madrid, 30th November 2017
1245
Universidad Politécnica de Madrid, Madrid, Spain
Opportunities for improving accessibility with
the new specification 2.0.1 of standard HbbTV

2. Index
• Introduction
• Objectives
• Implementation of the platform
• CS and Terminal Applications
• Tests and Validation
• Conclusions
• Ackowledgement
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3. Introduction
• Connected TV refers to broadcast applications that provide
access to internet-based services like traditional broadcast
television channels.
• Services available via TV sets and other connected screens
which create a multiplatform ecosystem, such as
smartphones, tablets, Smart TVs or videogame consoles
• Examples of powerful offered services: interactive
advertising, accessibility and personalisation tools, televoting,
games, social networking and other multimedia applications.
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4. Objectives
• The challenge for broadcasters is how to reinvent
value in the digital domain to create new business
models that take advantage of the content
interaction.
• Improving the access to digital content for people
with special necessities offering accessibility tools
and personalised content.
• Exploiting the advances of HbbTV 2.0.1
specification for connected TV based on interaction
and synchronization of devices.
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5. HbbTV opportunities
• HbbTV was adopted in 2011 as a platform to standardize the
access to interactive tools.
• HbbTV 2.0.1, try to add new functionalities to the applications
and services in order to offer a better user experience to
Connected TV, such as connection with 2nd
screen devices
and other tools: HTML5, the encoder HEVC or MPEG-DASH.
• Opportunity of improving the interaction services facilitating the
access to synchronized audiodescription, subtitles, clean-
audio or sign language video through 2nd
screen devices.
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6. Use Case: domestic environment
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Connected TV (HbbTV)
2nd Screen Device with
Accessibility tools:
•Audiodescription
•Subtitles
•Clean Audio
•Sign Language Videos

7. HbbTV 2.0.1 Especification
• WebSocket technology defined by the W3C and IETF and
DIAL (DIscovery And Launch) protocol to send information
thorough different devices in same network.
• Protocols for time synchronization included in the DVB
technical specification:
– CSS-WC (Wall Clock) for defining a common timer.
– CSS-CII (Content Identification and other Information) to exchange
data between devices
– CSS-TS (Time Synchronization) for timing audiovisual contents in
different devices.
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8. Implementation of the platform
• Proposed framework for integrating the functionalities
of the new specification HbbTV 2.0.1
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9. Terminal and CS Applications (I)
• Architecture based on two interactive applications
with HTML, JavaScript and Node.js:
– Terminal App (Television).
– CS App (Companion Screen , such as smartphones or
tablets) connected through WebSocket calls through a
DIAL server.
– The CS App presents accessibility tools: audiodescription
and subtitles, accurately synchronized with the contents
displayed on the Terminal App, broadcasted on television.
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10. Terminal and CS Applications (II)
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Terminal APP
CS APP interface
(complete)
CS APP
(fullscreen, only subtitles)
Time Synchronization
(DVB-CSS Protocols)

11. Tests and Validation
Tests from the CS/Terminal Apps:
– Search of the terminals (or TV screens)
– Establishing connection through
WebSockets.
– Exchange of information (timing and data).
– Presentation of subtitles/audiodescription.
– Time synchronization of multimedia
contents (video, audio, subtitles) between
terminal and 2nd
screen devices.
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12. Conclusions
• The starting point of usage for the HbbTV 2.0.1 specification suggests
that the new possibilities offers a future set of interactive services and
accessible contents.
• HbbTV 2.0.1 specification allows accurate time synchronization and
communication between devices.
• The results demonstrates that this technology offers good expectations
of the current state of the market, revealed by the prototypes developed
that are in process of integration in real environments.
• Broadcasters are expected to be able to offer new business models
based on the interactivity of users and the consumption of second screen
applications, allowing the expansion of new services.
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13. Acknowledgement
• Spanish Broadcaster RTVE for the cession of contents from
the TV series “Acacias 38” (videos, subtitles, and
audiodescriptions)
• Cellnex Telecom for the organization of the Interoperability
Workshop, held in May 2017, with tests running on Samsung
and Panasonic HbbTV 2.0.1 TV’s.
• Fraunhofer for their help with HbbTV development.
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14. Thanks for your attention!!
For more information, write:
jlv@gatv.ssr.upm.es
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