SMPTE timecode is based on a bit rate of 2400 bits per second, which provides a data format of 80 bits per frame (in a 30-frame per second system). This way it can be read on variable speed from one-fifth up to 20 times normal speed.
Longitudinal Timecode (called LTC) is recorded on an audio track. Vertical Interval Timecode (called VITC) is recorded into the vertical synch period of the video frame signal. This way it can be read even with the video tape player in Pause.