ISO/IEC 23000-19:2018 信息技术 多媒体应用格式（MPEG-A） 第19部分：分割媒体用通用媒体应用程序格式（CMAF）
标准编号：ISO/IEC 23000-19:2018
中文名称：信息技术 多媒体应用格式（MPEG-A） 第19部分：分割媒体用通用媒体应用程序格式（CMAF）
英文名称：Information technology — Multimedia application format (MPEG-A) — Part 19: Common media application format (CMAF) for segmented media
发布日期：2018-01
标准范围
ISO/IEC 23000-19:20 18规定了CMAF多媒体格式，其包含针对自适应多媒体演示中的终端用户设备上的流式传送和解码而优化的分段媒体对象。CMAF指定从ISO基本媒体文件格式导出的轨道格式，然后从CMAF轨道导出可用于存储和传递的可寻址媒体对象。CMAF指定共享编码和打包约束的轨道集合，所述编码和打包约束使得能够选择多个轨道以形成多媒体呈现，并且允许以不同比特率、帧率、分辨率等无缝切换相同内容的替代编码。CMAF指定了一个假设的应用模型，该模型确定CMAF演示中的轨道如何被组合和同步以形成多媒体演示。该模型抽象了交付，以允许任何交付方法。假设的应用程序模型假设清单和播放器，但是CMAF没有指定清单、播放器或交付协议，其意图是可以使用任何支持假设的应用程序模型的协议。CMAF指定了约束CMAF轨道的媒体编码和打包的媒体配置文件和品牌，以实现轨道的无缝自适应切换，并允许设备通过其品牌识别兼容内容。CMAF指定演示简档，该演示简档有条件地要求符合指定媒体简档的CMAF轨道集合，并允许内容创建者和设备识别兼容的多媒体演示。CMAF通过指定如何指定和识别新的媒体配置文件和演示配置文件来实现可扩展性，并包括这些规范的指南。
ISO/IEC 23000-19:2018 specifies the CMAF multimedia format, which contains segmented media objects optimized for streaming delivery and decoding on end user devices in adaptive multimedia presentations.
CMAF specifies a track format derived from the ISO Base Media File Format, then derives addressable media objects from CMAF tracks that can be used for storage and delivery.
CMAF specifies sets of tracks that share encoding and packaging constraints that enable the selection of multiple tracks to form a multimedia presentation and allow seamless switching of alternative encodings of the same content at different bit rates, frame rates, resolution, etc.
CMAF specifies a hypothetical application model that determines how tracks in a CMAF presentation are intended to be combined and synchronized to form a multimedia presentation. The model abstracts delivery to allow any delivery method. The hypothetical application model assumes a manifest and player, but CMAF does not specify a manifest, player, or delivery protocol, with the intent that any that support the hypothetical application model can be used.
CMAF specifies media profiles and brands that constrain media encoding and packaging of CMAF tracks to enable seamless adaptive switching of tracks and allow devices to identify compatible content by its brand.
CMAF specifies presentation profiles that conditionally require sets of CMAF tracks conforming to specified media profiles and allow content creators and devices to identify compatible multimedia presentations.
CMAF enables extensibility by specifying how new media profiles and presentation profiles can be specified and identified and includes guidelines for those specifications.
标准预览图
