SMPTE RP 198:1998 (R2018)

This practice specifies digital test signals suitable for evaluating the low-frequency response of equipment handling high-definition serial digital video signals as defined in ANSI/SMPTE 292M. Although a range of signals will produce the desired low-frequency effects, two specific signals are defined to test cable equalization and phase locked loop (PLL) lock-in, respectively. In the past, these two signals have been colloquially called “pathological signals.”