标准摘要
[中文适用范围]： 1.1 概述 ISO/IEC 21000 的这一部分规定了可用于协助数字项目改编的工具的语法和语义，即数字项目声明和声明所引用的资源。 这些工具可用于满足传输、存储和消耗限制，以及各个用户的服务质量管理。 需要强调的是，适配引擎本身是 ISO/IEC 21000 本部分的非标准化工具。1.2 文件的组织 本节描述了 ISO/IEC 21000 本部分规定的各种数字项目适配工具。 作为 ISO/IEC 21000 的一部分，每个工具由以下子条款描述： ——语法：使用 XML 模式的工具语法的规范规范。 - 语义：工具及其组件的语义的规范规范。 - 信息示例：可选地，说明该工具的使用的信息示例。1.3 数字化项目适应概述 1.4 数字化项目适应工具概述 1.5 数字化项目适应与 ISO/IEC 21000 其他部分之间的关系 1.6 数字化项目适应与 ISO/IEC 15938 之间的关系 [外文原描述]： ISO/IEC 21000-7:2007 specifies the syntax and semantics of tools that may be used to assist the adaptation of Digital Items, i.e. the Digital Item Declaration and resources referenced by the declaration. Users can use the tools to satisfy transmission, storage and consumption constraints, as well as Quality of Service management. ISO/IEC 21000-7:2007 specifies tools to describe: user characteristics, terminal capabilities, network characteristics and natural environment characteristics; the high-level syntax of a binary media resource, media resource and XML streaming instructions, and properties style sheet; the relationship between Quality of Service constraints, feasible adaptation operations satisfying these constraints and associated media resource qualities that result from adaptation: limitation and optimization constraints on adaptations; means for linking adaptation decisions with actual media resource adaptation engines; metadata adaptation hint information; configuration-state information of a Digital Item; information required for the configuration of an adaptation engine; and permitted changes and change constraints. ISO/IEC 21000-7:2007 does not specify the adaptation engines themselves.
英文名称Information technology - Multimedia framework (MPEG-21) - Part 7: Digital Item Adaptation