Vertical interval time code (abbreviated VITC and sometimes pronounced VIHT-see) is a timing signal that is part of a video recording. It is recorded in the vertical blanking interval s between successive picture frames, hence the "vertical interval."
longitudinal time code (LTC)
Longitidinal time code (LTC) is a timing signal...(WhatIs.com)
VITC is one of two timing schemes adopted by the Society of Motion Picture and Television Engineers ( SMPTE ) in the 1960s. The other, known as longitudinal time code ( LTC ), is used with audio recordings.
VITC assigns a specific time in hours, minutes, and seconds to each vertical blanking interval in a video recording, along with a frame number. The time code can be used to start a recording at a certain chronological time (such as 5:00:00 p.m.), or it can be used to keep a playback machine synchronized with a master time source. The former application might be used by a home television viewer, while the latter application would more likely be used by a broadcaster.