指定编码的系统层。主要用于支持ISO/IEC 11172-2和ISO/IEC 11172-3中定义的视频和音频编码方法的组合。系统层支持以下基本功能:回放时多个压缩流的同步、多个压缩流交织成单个流、回放启动缓冲区的初始化、连续缓冲区管理和时间识别。

Specifies the system layer of the coding. Was developed principally to support the combination of the video and audio coding methods defined in ISO/IEC 11172-2 and ISO/IEC 11172-3. The system layer supports the following basic functions: the synchronization of multiple compressed streams on playback, the interleaving of multiple compressed streams into a single stream, the initializiation of buffering for playback start up, continuous buffer management, and time identification.