Editing Linear timecode (section)

{{Short description|Timecode encoded as an audio signal}}
'''Linear (or Longitudinal) Timecode''' ('''LTC''') is an [[encoding]] of [[SMPTE timecode]] data in an [[audio signal]], as defined in SMPTE 12M specification. The [[Sound reproduction|audio]] signal is commonly recorded on a [[VTR]] track or other storage media.  The bits are encoded using the [[biphase mark code]] (also known as ''FM''):  a 0 bit has a single transition at the start of the bit period.  A 1 bit has two transitions, at the beginning and middle of the period.  This encoding is [[self-clocking]]. Each frame is terminated by a '[[sync word]]' which has a special predefined [[synchronization|sync]] relationship with any [[video]] or [[telecine|film]] content.

A special bit in the linear timecode frame, the ''biphase mark correction'' bit, ensures that there are an even number of AC transitions in each timecode frame.

The sound of linear timecode is a jarring and distinctive noise and has been used as a sound-effects shorthand to imply ''telemetry'' or ''computers''.