信息技术.视听对象编码.第27部分:3D制图法一致性

[中文适用范围]： 本部分规定了如何设计测试，以验证压缩数据（即比特流）和解码器是否符合ISO/IEC 14496-11:2005、ISO/IEC 14496-16:2006、ISO/IEC 14496-21:2006和ISO/IEC 14496-25:2009中规定的合成3D图形工具的要求。本部分不专门针对编码器。就合成3D图形而言，如果编码器生成的压缩数据符合ISO/IEC 14496-11、ISO/IEC 14496-16、ISO/IEC 14496-21和ISO/IEC 14496-25中规定的语法和语义比特流负载要求，则该编码器可被称为ISO/IEC 14496编码器。ISO/IEC 14496-11、ISO/IEC 14496-16、ISO/IEC 14496-21和ISO/IEC 14496-25定义了编码比特流和解码器的特性。比特流的特性定义了比特流中利用的标准子集。例如，应用的比特率值或范围。解码器特性定义了所应用解码过程的属性和能力。例如，应用的算术精度。解码器的能力指定了解码器可以解码和重构哪些编码比特流，通过定义可解码比特流中可利用的标准子集。如果编码比特流的特性在参考标准的子集内，则解码器可以解码该比特流。本部分描述了测试压缩数据和解码器是否符合ISO/IEC 14496-11、ISO/IEC 14496-16、ISO/IEC 14496-21和ISO/IEC 14496-25中定义的要求的程序；给定所声称的特性集，必须满足的要求由这些部分完全确定。本部分总结了要求，将其交叉引用到特性，并定义了如何测试是否符合要求。给出了构建测试以验证解码器符合性的指南。 [外文原描述]： ISO/IEC 14496-27:2009 specifies how tests can be designed to verify whether compressed data (i.e. bitstreams) and decoders meet the requirements for the synthetic 3D graphics tools specified in ISO/IEC 14496‑11:2005, ISO/IEC 14496‑16:2006, ISO/IEC 14496‑21:2006, and ISO/IEC 14496‑25:2009. ISO/IEC 14496-27:2009 does not specifically address encoders. As far as synthetic 3D graphics are concerned, an encoder can be said to be an ISO/IEC 14496 encoder if it generates compressed data compliant with the syntactic and semantic bitstream payload requirements specified in ISO/IEC 14496‑11, ISO/IEC 14496‑16, ISO/IEC 14496‑21, and ISO/IEC 14496‑25. Characteristics of coded bitstreams and decoders are defined for ISO/IEC 14496‑11, ISO/IEC 14496‑16, ISO/IEC 14496‑21, and ISO/IEC 14496‑25. The characteristics of a bitstream define the subset of the standard that is exploited in the bitstream. Examples are the applied values or range of the bitrate. Decoder characteristics define the properties and capabilities of the applied decoding process. An example of a property is the applied arithmetic accuracy. The capabilities of a decoder specify which coded bitstreams the decoder can decode and reconstruct, by defining the subset of the standard that may be exploited in decodable bitstreams. A bitstream can be decoded by a decoder if the characteristics of the coded bitstream are within the subset of the normative references. ISO/IEC 14496-27:2009 describes procedures for testing conformance of compressed data and decoders to the requirements defined in ISO/IEC 14496‑11, ISO/IEC 14496‑16, ISO/IEC 14496‑21, and ISO/IEC 14496‑25; given the set of characteristics claimed, the requirements that shall be met are fully determined by these parts. ISO/IEC 14496-27:2009 summarizes the requirements, cross references them to characteristics, and defines how conformance with them can be tested. Guidelines are given on constructing tests to verify decoder conformance.