Grass Valley LGK-3901 - Manual (Page 24)

GUIDE TO INSTALLATION AND OPERATION
18 | LGK-3901/DSK-3901
To buffer half a line of 1080i / 59.94, increase the above reference timing to: 0 line +4.3µs (+15µs) = 0 line +19.3µs.
Note: If the path delay of the SDI input sources is such that they are all offset from reference by several lines then
adjust the reference by the same number of lines to align the output to the unusual input timing. Then add 10 to 20
microseconds to give some buffering in the line FIFOs.