REPORT

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Hybridcast services, inaugurated in September 2013, have expanded beyond NHK to include 24 private broad-casters, and as of May 2017, over 5.8 million televisions supporting Hybridcast have been shipped. Hybridcast is a service for displaying HTML applications distributed by broadcasters on televisions, using a built-in HTML5* browser. HTML5 is widely used on the Web, so adopting it has made it easy to link the worlds of broadcasting and the Web. It also facilitates the provision of a wide range of services without being limited by the capabilities of the television, since complex processing can be done by serv-ers on the cloud. In August 2016, “Hybridcast (4K) Video” and “Hybridcast Connect” were added to Hybridcast. NHK STRL has contributed to the standardization for the realiza-tion of these two features, and is still working to improve their functionality.

Hybridcast (4K) Video is a functionality for implement-ing video distribution services in a television’s browser. It uses the MPEG Dynamic Adaptive Streaming over HTTP (MPEG-DASH) standard. MPEG-DASH can adjust the quality when communication conditions are poor, so that viewing can continue, and supports services such as switching between broadcast video (2K) and Net-distrib-

uted video (4K) and the substitution of advertising content (Fig. 1). NHK STRL has contributed to the implementation of Hybridcast (4K) Video by developing a library for the playback and control of MPEG-DASH video on television receivers with limited CPU and memory, called dashNX. This can be expected to help expand video distribution services that are responsive to the needs and environments of users and providers.

Hybridcast Connect was created to enable smartphones to interface with all Hybridcast televisions via a single application, regardless of manufacturer. It enables users to use the same application for terminal-linking features without needing to know the television manufacturer (Fig. 2). It is also easier for broadcasters to inform users of how to install and use the application. For developers, it also eliminates the need to develop and test software specific to each manufacturer, reducing development costs. We can expect Hybridcast Connect to invigorate the expansion of terminal-linked services.

* HTML5 (Hypertext Markup Language, Ver. 5): The latest ver-sion of the programming language for describing Web Pages

Masaya Ikeo

Hybridcast Development

Figure 1: Example of Hybridcast 4K video service

Broadcast Video

Switch

Switchable

Switch operation

Automaticreturn to broadcast

Broadcast Video 4K Distributed Video4K Distributed Video

Figure 2: Terminal-linking concept (left: conventional, right: Hybridcast Connect)

Companion Apps Hybridcast Connect

Up to now Going forward

Each company has it’ s own terminal-linking protocol

Standard terminal-linking protocol

A Inc.

B Inc.

C Inc.

A Inc.

B Inc.

C Inc.