MHEG-5, or ISO/

IEC The International Electrotechnical Commission (IEC; in French: ''Commission électrotechnique internationale'') is an international standards organization that prepares and publishes international standards for all electrical, electronic and r ...

13522-5, is part of a set of international standards relating to the presentation of multimedia information, standardised by the

Multimedia Multimedia is a form of communication that uses a combination of different content forms such as text, audio, images, animations, or video into a single interactive presentation, in contrast to tradit ...

and

Hypermedia Hypermedia, an extension of the term hypertext, is a nonlinear medium of information that includes graphics, audio, video, plain text and hyperlinks. This designation contrasts with the broader term ''multimedia'', which may include non-interacti ...

Experts Group (MHEG). It is most commonly used as a language to describe

interactive television Interactive television is a form of media convergence, adding data services to traditional television technology. It has included on-demand delivery of content, online shopping, and viewer polls. Interactive TV is an example of how new informatio ...

services.

Characteristics

MHEG-5 is a licence-free and public standard for interactive TV middleware that is used both to send and receive interactive TV signals. It allows a wide range of TV-centric interactive services to be deployed. It is used by

Freeview Freeview may refer to: *Freeview (Australia), the marketing name for the digital terrestrial television platform in Australia *Freeview (New Zealand), a digital satellite and digital terrestrial television platform in New Zealand *Freeview (UK), a ...

and

Freesat Freesat is a British free-to-air satellite television service, first formed as a joint venture between the BBC and ITV plc and now owned by Digital UK. The service was formed as a memorandum in 2007 and has been marketed since 6 May 2008. Free ...

in the UK,

in New Zealand, TVB in Hong Kong,

in Australia, Saorview in Ireland and has been specified in South Africa. Recent work by the DTG in the UK has led to the development of the MHEG-5 Interaction Channel (MHEG-IC), which enables an extension of broadcast interactive services to be delivered via an IP connection. The principles behind the MHEG-IC are to provide a seamless viewer experience of broadcast delivered content augmented with content delivered over IP as an extension of the channel or network. Broadcasters have full editorial control of the user experience. The MHEG-IC gives access to streamed on-demand video content in addition to traditional text and graphics as well as the ability to support secure transactions. MHEG-5 is an

object-based The term object-based language may be used in a technical sense to describe ''any'' programming language that uses the idea of encapsulating state and operations inside ''objects''. Object-based languages need not support inheritance or subtyping, b ...

declarative programming In computer science, declarative programming is a programming paradigm—a style of building the structure and elements of computer programs—that expresses the logic of a computation without describing its control flow. Many languages that a ...

language which can be used to describe a presentation of text, images and video. An MHEG-5 application consists of a number of ''Scenes'' which the user of the application can move between. Each ''Scene'' lists the items of text and graphics to be presented and can contain blocks of procedural code which are executed in response to one of a predefined set of events such as keys being pressed, timers firing or content being successfully loaded into memory. These blocks of code consist of ''elementary actions'' which can perform operations such as changing the text displayed by a text

object Object may refer to: General meanings * Object (philosophy), a thing, being, or concept ** Object (abstract), an object which does not exist at any particular time or place ** Physical object, an identifiable collection of matter * Goal, an ...

, or starting a video clip playing. MHEG-5 specifies a hierarchy of classes that are available to the application author. Unlike in

object oriented Object-oriented programming (OOP) is a programming paradigm based on the concept of "objects", which can contain data and code. The data is in the form of fields (often known as attributes or ''properties''), and the code is in the form o ...

languages, it is not possible for new classes to be defined. The standard defines two representations of MHEG applications, one of which is textual and the other is represented in

ASN.1 Abstract Syntax Notation One (ASN.1) is a standard interface description language for defining data structures that can be serialized and deserialized in a cross-platform way. It is broadly used in telecommunications and computer networking, and ...

. Applications are normally written in the textual notation and then encoded into ASN.1 for interpretation by the MHEG ''engine''. MHEG-5 is suited to programming

interactive kiosk An interactive kiosk is a computer terminal featuring specialized hardware and software that provides access to information and applications for communication, commerce, entertainment, or education. By 2010, the largest bill pay kiosk networ ...

s and

services.

Use in other standards

MHEG-5 has been selected as the mandatory interactivity engine for CI+ compliant TVs (and other CI+ devices).

Profiles and commercial roll-out

The MHEG-5 language itself is just that, a language. To be useful in any particular context, the language needs to be profiled. A broadcast profile of the language has been standardized by

ETSI The European Telecommunications Standards Institute (ETSI) is an independent, not-for-profit, standardization organization in the field of information and communications. ETSI supports the development and testing of global technical standard ...

, forming ETSI standard ES 202 184.

United Kingdom

In the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and ...

, MHEG-5 is used to provide

interactive Across the many fields concerned with interactivity, including information science, computer science, human-computer interaction, communication, and industrial design, there is little agreement over the meaning of the term "interactivity", but mo ...

services for digital television such as the BBC's red button

Ceefax Ceefax (, punning on "seeing facts") was the world's first teletext information service and a forerunner to the current BBC Red Button service. Ceefax was started by the BBC in 1974 and ended, after 38 years of broadcasting, at 23:32:19 BST ...

replacement service. The full specification of how MHEG-5 is used in the context of the UK

platform is the

UK Profile of MHEG-5 The UK Profile of MHEG-5 is a technical specification describing how the MHEG-5 language is used to provide interactive television services. It was developed to provide interactive services for the UK digital terrestrial television platform by ...

. MHEG is also used on

for its programming guide in addition to the DVB EIT, as opposed to the OpenTV platform used on Sky.

New Zealand and Australia

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island coun ...

, the same profile as in UK is used, with minor additions for the Maori language and its use of the ''guide'' key on ''certified'' Freeview receivers. The ''guide'' receiver key is used to activate the MHEG-5 programming guide; this however disables use of the more compatible and faster loading DVB EIT guide feature. In Australia, this guide practice was adopted for the phase 2 Freeview and

VAST Vast or VAST may refer to: * ''Vast'' (novel), a 1998 science fiction novel by Linda Nagata * ''Vast'' (2011 film), a Dutch film, winner of the 2011 Golden Calf for Best Television Drama * Vast Broadband, an American cable and internet compan ...

receivers referenced by the label ''Freeview EPG''.

Hong Kong

In Hong Kong, TVB has also selected MHEG-5 for interactive services available on its digital-only channels.

Ireland

Ireland has selected MHEG-5 (v1.06) middleware for interactive services as a recommended feature of its Minimum Receiver Requirements for DTT in Ireland.Minimum Receiver Requirements for DTT in Ireland v1.0
. The name for Ireland's free digital service is Saorview.

Class hierarchy

Note: You can download the PDF version of above image from http://mheg5.net/down/class.pdf.

References

External links

* {{DEFAULTSORT:Mheg-5 Interactive television IEC standards ISO standards Hypermedia Multimedia