信息技术.移动画面和有关音频信息的通用编码.第1部分:系统

[中文适用范围]： 此建议|国际标准规定了系统层的编码。 它的开发主要是为了支持 ISO/IEC 13818 第 2 部分和第 3 部分中定义的视频和音频编码方法的组合。 系统层支持六种基本功能： 1) 解码时多个压缩流的同步； 2) 将多个压缩流交织成单个流； 3)解码启动缓冲的初始化； 4）连续的缓冲区管理； 5）时间识别； 6) 系统流中各个组件的复用和信令。 ITU-T 建议书。 H.222.0 | ISO/IEC 13818-1 复用比特流是传输流或节目流。 两个流均由 PES 数据包和包含其他必要信息的数据包构成。 两种流类型都支持对来自一个具有公共时基的节目的视频和音频压缩流进行复用。 传输流还支持来自具有独立时基的多个节目的视频和音频压缩流的复用。 对于几乎无错误的环境，节目流通常更合适，支持节目信息的软件处理。 传输流更适合在可能出现错误的环境中使用。 ITU-T 建议书。 H.222.0 | ISO/IEC 13818-1 复用比特流，无论是传输流还是节目流，都是由两层构成：最外层是系统层，最内层是压缩层。 系统层提供在系统中使用一个或多个压缩数据流所需的功能。 本规范的视频和音频部分定义了音频和视频数据的压缩编码层。 本规范未定义其他类型数据的编码，但系统层支持其他类型数据的编码，前提是其他类型数据遵守 2.7 中定义的约束。 [外文原描述]： ISO/IEC 13818-1:2007 specifies the system layer of the coding. It was developed principally to support the combination of the video and audio coding methods defined in ISO/IEC 13818-2 and ISO/IEC 13818-3. The system layer supports six basic functions: the synchronization of multiple compressed streams on decoding; the interleaving of multiple compressed streams into a single stream; the initialization of buffering for decoding start up; continuous buffer management; time identification; multiplexing and signalling of various components in a system stream. An ISO/IEC 13818-1:2007 multiplexed bit stream is either a Transport Stream or a Program Stream. Both streams are constructed from PES packets and packets containing other necessary information. Both stream types support multiplexing of video and audio compressed streams from one program with a common time base. The Transport Stream additionally supports the multiplexing of video and audio compressed streams from multiple programs with independent time bases. For almost error-free environments the Program Stream is generally more appropriate, supporting software processing of program information. The Transport Stream is more suitable for use in environments where errors are likely. An ISO/IEC 13818-1:2007 multiplexed bit stream, whether a Transport Stream or a Program Stream, is constructed in two layers: the outermost layer is the system layer, and the innermost is the compression layer. The system layer provides the functions necessary for using one or more compressed data streams in a system. The video and audio parts of ISO/IEC 13818-1:2007 define the compression coding layer for audio and video data. Coding of other types of data is not defined by ISO/IEC 13818-1:2007, but is supported by the system layer provided that the other types of data adhere to the constraints defined in 2.7.