SMPTE ST 318 PDF

This standard specifies the use of a derivative of a color black signal as a reference for the synchronization of all forms of composite or component, digital or analog equipment using a system standard related to 60/1.001 (nominal 59.94) or 50 Hz. It also provides the option for the reference signal to carry VITC. This will allow the reference to distribute local or UTC time data.

In the case of the reference for 60/1.001 Hz related signals, the signal may carry optionally a ten-field sequence identification signal. This facilitates interworking with equipment operating at related rates (e.g. 24/1.001 (nominal 23.98) Hz or 48 kHz).

Note: SMPTE ST 12-1 Annex B gives guidance on conversion of 24/1.001 (23.98) frames-per-second video to 30/1.001 (29.97) frames-per-second video using the ten-field sequence.