SMPTE timecode

A high-frequency timing reference signal developed by by the Society of Motion Picture and Television Engineers and used for synchronizing film and videotape to audio tape and software-based playback systems. SMPTE is a tempo-independent code which comprises a continuous stream of absolute positional data, so if a short section of code gets lost or corrupted, the system knows exactly where it’s supposed to be the next time a piece of valid code is read. Usually generated at the picture source, i.e., the SMPTE master clock generator that drives the film or television camera system, the signal is recorded onto the videotape or along the edge of the motion picture film, and sent simultaneously to the audio recorder. The signal contains encoded numerical information, allowing the same point in film or tape time to be located on the separate strips of film/videotape and audio tape, for proper alignment or ADR. The playback operator can select a SMPTE timecode number that instructs videotape and audiotape machines to locate a certain point and begin playing in sync from that absolute location. TimecodeTime code data are in the form of a timecodetime code address (TCA), which make up the HH:MM:SS:FF part of the timecodetime code word, where HH is a two-byte number for absolute time hour, MM is minutes, SS is seconds, and FF denotes the absolute frame number. See framejam syncLTCMTCBITCVITC., and bi-phase modulation. Also called longitudinal timecodetime code. As opposed to speed-only sync codes such as pilot toneFSK, and DIN sync.