本标准定义了数字电视信号到SMPTE 354M定义的ATM公共层的映射。受支持的数字信号格式在ITU-R BT.656-4第1部分和第2部分（4:2:2、13.5 MHz、525线或625线，带定时参考信号）中定义。

This standard defines a mapping of digital television signals into the ATM common layer defined by SMPTE 354M. The digital signal formats supported are defined in ITU-R BT.656-4, Parts 1 and 2 (4:2:2, 13.5 MHz, 525-line or 625-line, with timing reference signals).