This Recommendation specifies methods for digitally coding video signals. It includes a 13.5 MHz sampling rate for both 4:3 and 16:9 aspect ratios with performance adequate for present transmission systems. An alternative 18 MHz sampling rate for those 16:9 systems which require proportionately higher horizontal resolution is also specified. Specifications applicable to any member of this family of standards are presented first. Then follows in Part A the specific characteristics for 13.5 MHz sampling and in Part B the specific characteristics for 18 MHz sampling.……