ISO/IEC 21000-7:2007/Cor 1:2008 PDF

Overview

ISO/IEC 21000-7:2007/Cor 1:2008 is a technical corrigendum to Part 7 of the MPEG-21 Multimedia Framework - Digital Item Adaptation (DIA). It provides corrections and clarifications to the XML schema and normative text that define how adaptation descriptions (AdaptationQoS) and their interfaces (IOPin) are modeled. The corrigendum was prepared by ISO/IEC JTC 1/SC 29 and published in December 2008.

Key topics and requirements

• XML schema corrections to the AdaptationQoSType:
  • The corrigendum modifies the particle to allow maxOccurs="unbounded", enabling multiple interface/module/constraints entries in an AdaptationQoS description.
• IOPin element scoping and uniqueness:
  • The scope of the id attribute of an IOPin is explicitly limited to the containing AdaptationQoS description.
  • The id attribute must be unique within a single AdaptationQoS description.
• Attribute type changes (ID/IDREF → NMTOKEN/NMTOKENS):
  • id attributes for IOPin and related types are changed from type ID to NMTOKEN.
  • Reference attributes such as iOPinRef are changed from IDREF to NMTOKEN, and list references such as switchIOPinRefs from IDREFS to NMTOKENS.
  • Text clarifies that the content of an iOPinRef must match the id of an IOPin element within the same AdaptationQoS description.
• Specific schema updates:
  • Corrections are applied in the included schema document (AQoS-2nd.xsd), updating types for IOPin id and all iOPinRef occurrences.

Practical applications

• Ensures interoperability among implementations of MPEG-21 DIA by correcting schema semantics for identifiers and references.
• Helps developers of multimedia adaptation engines, content providers, and tool vendors to:
  • Properly author and validate AdaptationQoS descriptions.
  • Implement stable referencing and scoping rules for module interfaces (IOPin).
  • Avoid XML validation and integration issues caused by incorrect ID/IDREF usage.
• Useful for standards engineers, XML schema authors, and QA teams verifying compliance with MPEG-21 Digital Item Adaptation.

Who should use this corrigendum

• MPEG-21 implementers and integrators working with DIA (Part 7).
• XML/schema validators and tool creators targeting MPEG-21.
• Content adaptation platform vendors that need correct interface scoping and reliable reference resolution.

Related standards

• ISO/IEC 21000 family (MPEG-21) - see Part 7: Digital Item Adaptation for the base specification; this document is a corrigendum to that part.