ancillary time code (ATC)

The Ancillary Time Code(ATC) is an auxiliary time code that is inserted in the vertical (VANC) and horizontal blanking intervals (HANC) of SDI signals. The ATC was standardized by the Society of Motion Picture and Television Engineers( SMPTE) in 1998 and is used in place of the Vertical Interval Time Code( VITC).

The ATC time code can include the VITC and Longitudinal Time Code( LTC) data and is usually inserted in lines 9 and 10.