本标准定义了4字节有效载荷标识符的规范，该标识符可添加到数字接口中，以识别视频有效载荷。有效载荷标识符旨在应用于现有和未来的数字接口。该标准定义了根据SMPTE 291M如何将有效负载标识符放入辅助数据包中。它指定了不同数字接口的辅助数据包的采样位置、行号和重复率。

This standard defines the specification of a 4-byte payload identifier which may be added to digital interfaces for the purpose of identifying the video payload. The payload identifier is intended for application to existing and future digital interfaces. The standard defines how the payload identifier is placed into an ancillary data packet according to SMPTE 291M. It specifies the sample position, line number(s), and repetition rate of the ancillary data packet for different digital interfaces.