- Nested Context Language
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Nested Context Language (NCL) is a declarative authoring language for hypermedia documents.
NCL is an XML application language, which provides several facilities for authoring a complete hypermedia document with synchronization relationships among its components. Among its main facilities, it treats hypermedia relations as first-class entities through the definition of hypermedia connectors, and it can specify arbitrary semantics for a hypermedia composition using the concept of composite templates.
Following others XML standards, NCL is specified by a modular approach. NCL modules can be added to standard web languages, such as XLink and SMIL.
NCL was initially designed for the Web environment, but currently it is included as the declarative language of the Japanese-Brazilian ISDB-Tb (International Standard for Digital Broadcasting) terrestrial DTV (digital TV) middleware (named Ginga). It is also the first standardized technology of the ITU-T multimedia application framework series of specifications for IPTV services.
Contents
NCL Historical Evolution
NCL 3.0 Profiles
Full Profile
NCL 3.0 Full Profile includes all NCL Modules.
Enhanced Digital TV profile (EDTV)
NCL 3.0 Enhanced DTV profile includes the Structure, Layout, Media, Context, MediaContentAnchor, CompositeNodeInterface, PropertyAnchor, SwitchInterface, Descriptor, Linking, CausalConnectorFunctionality, ConnectorBase, TestRule, TestRuleUse, ContentControl, DescriptorControl, Timing, Import, EntityReuse, ExtendedEntityReuse, KeyNavigation, Animation, TransitionBase, Transition and Metainformation modules of NCL 3.0.
NCL Basic Digital TV profile (BDTV)
Includes almost all Enhanced Digital TV profiles but it doesn't include Animation, TransitionBase and Transition modules.
NCL 3.0 Modules
NCL is partitioned in functional areas. Each functional area groups a set of related modules. NCL 3.0 functional areas and modules are:
- Structure
- Structure Module
- Layout
- Layout Module
- Components
- Media Module
- Context Module
- Interfaces
- MediaContentAnchor Module
- CompositeNodeInterface Module
- PropertyAnchor Module
- SwitchInterface Module
- Presentation Specification
- Descriptor Module
- Linking
- Linking Module
- Connectors
- ConnectorCommonPart Module
- ConnectorAssessmentExpression Module
- ConnectorCausalExpression Module
- ConnectorTransitionAssessment Module
- CausalConnector Module
- CausalConnectorFunctionality Module
- ConnectorBase Module
- Presentation Control
- TestRule Module
- TestRuleUse Module
- ContentControl Module
- DescriptorControl Module
- Timing
- Timing Module
- Reuse
- Import Module
- EntityReuse Module
- ExtendedEntityReuse Module
- Navigational Key
- KeyNavigation Module
- Animation
- Animation Module
- SMIL Transition Effects
- TransitionBase Module
Note: The TransitionBase Module is defined by NCL 3.0. SMIL 2.0 doesn't define this module. - BasicTransition Module
- TransitionModifers Module
- TransitionBase Module
- SMIL Meta-Information
- Metainformation Module
Authoring Tools
See also
External links
NCL Players
- GINGA-NCL Reference Implementation, available under GPLv2 (in Portuguese).
- GHTV GINGA-NCL player for Windows and Linux under Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License (in Portuguese).
Authoring tools
- NCL Eclipse official website (in Portuguese)
Categories:- Markup languages
- XML-based standards
- Technical communication
- Computer file formats
- Structure
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