信息技术.异构环境中的高效编码和媒体传送.第1部分:MPEG媒体传输（MMT）

[中文适用范围]： 本文件规定了 MPEG 媒体传输 (MMT) 技术，包括单一封装格式、交付协议和信令消息，用于通过异构分组交换网络传输和交付多媒体数据，以实现多媒体服务。本文件支持的分组交换网络类型包括双向网络（如互联网协议 (IP) 网络）和单向网络（如数字广播网络（可能使用或不使用 IP））。本文件规定的技术属于 MMT 的三个功能领域之一：媒体处理单元 (MPU) 格式、信令消息和交付协议。MPU 格式规定了“mpuf”品牌的基于 ISO 的媒体文件格式 (ISOBMFF)，该格式封装了定时和非定时媒体内容。MPU 格式是一种独立的 ISOBMFF 结构，支持独立使用媒体数据，从而隐藏了交付功能中特定于编解码器的细节。信令功能领域规定了信令消息的格式，这些信令消息携带用于管理媒体内容交付和使用的信息，例如特定的媒体位置和媒体内容的交付配置。交付功能区指定独立于媒体和编解码器类型的有效载荷格式，允许对本文档所指定封装的内容进行分段和聚合，以便使用面向分组交换的传输协议进行交付。交付功能区还提供了应用层传输协议，允许对媒体内容进行高级交付。 [外文原描述]： This document specifies MPEG media transport (MMT) technologies, which include a single encapsulation format, delivery protocols and signalling messages for transport and delivery of multimedia data over heterogeneous packet-switched networks for multimedia services. Types of packet-switched networks supported by this document include bidirectional networks such as Internet Protocol (IP) networks and unidirectional networks such as digital broadcast networks (which may or may not use the IP). The technologies specified by this document belong to one of three functional areas of MMT: media processing unit (MPU) format, signalling messages and delivery protocol. The MPU format specifies the “mpuf” branded ISO-based media file format (ISOBMFF) encapsulating both timed and non-timed media contents. The MPU format is a self-contained ISOBMFF structure enabling independent consumption of media data, which hides codec-specific details from the delivery function. The signalling functional area specifies the formats of signalling messages carrying information for managing media content delivery and consumption, e.g. specific media locations and delivery configuration of media contents. The delivery functional area specifies the payload formats that are independent of media and codec types, which allow fragmentation and aggregation of contents encapsulated as specified by this document for delivery using packet-switched oriented transport protocols. The delivery functional area also provides an application layer transport protocol that allows for advanced delivery of media contents.