信息技术 — MPEG 系统技术 — 第 7 部分：ISO 基础媒体文件格式文件中的通用加密

[中文适用范围]： 本文档指定了适用于基于 ISO/IEC 14496-12 的任何文件格式的通用加密格式。文件、项目、轨道和轨道片段元数据被指定为使多个数字版权和密钥管理系统（DRM）能够访问相同的公共加密文件或流。本文档没有定义 DRM 系统。 AES-128 对称分组密码用于加密媒体样本中包含的基本流数据。 AES 计数器模式 (CTR) 和密码块链接 (CBC) 均在单独的保护方案中指定。使用加密和明文块模式的部分加密也在单独的保护方案中指定。每个方案都指定了加密密钥的识别、初始化向量存储和处理。子样本加密是为 NAL 结构视频（例如 AVC 和 HEVC）指定的，以便在解密之前启用视频基本流的正常处理和编辑。为重要的公共加密信息指定了 XML 表示形式，以便它可以作为标准元素和属性包含在 XML 文件中，以便在媒体文件下载之前实现可互操作的许可证和密钥管理。 [外文原描述]： This document specifies common encryption formats for use in any file format based on ISO/IEC 14496-12. File, item, track, and track fragment metadata is specified to enable multiple digital rights and key management systems (DRMs) to access the same common encrypted file or stream. This document does not define a DRM system. The AES-128 symmetric block cipher is used to encrypt elementary stream data contained in media samples. Both AES counter mode (CTR) and Cipher Block Chaining (CBC) are specified in separate protection schemes. Partial encryption using a pattern of encrypted and clear blocks is also specified in separate protection schemes. The identification of encryption keys, initialization vector storage and processing is specified for each scheme. Subsample encryption is specified for NAL structured video, such as AVC and HEVC, to enable normal processing and editing of video elementary streams prior to decryption. An XML representation is specified for important common encryption information so that it can be included in XML files as standard elements and attributes to enable interoperable license and key management prior to media file download.