Information AboutMheg-5 |
| CATEGORIES ABOUT MHEG-5 | |
| iso standards | |
| interactive television | |
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CHARACTERISTICS MHEG-5 is an Object-based Declarative programming 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 , or starting a video clip playing. MHEG-5 specifies a hierarchy of classes that are available to the application author. Unlike in Object Oriented 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 . 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 Kiosks and Interactive Television services. PROFILES The MHEG-5 language itself is just that, a language. To be useful in any particular context, the language needs to be Profiled . In the UK and in New Zealand , MHEG-5 is used to provide Interactive services for digital television. The full specification of how MHEG-5 is used in the context of the UK Freeview platform is the UK Profile Of MHEG-5 . A similar specification is used in New Zealand. A broadcast profile of the language has also been standardized by ETSI forming ETSI standard ES 202 184. SEE ALSO
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