CTL timecode

Control track longitudinal, or CTL, timecode, developed by JVC in the early 1990s, is a unique technique for embedding, or striping, reference SMPTE timecode onto a videotape.

Similar to the way VITC timecode is embedded in the vertical interval area of a video signal, CTL timecode embeds SMPTE timecode in the control track area of helical scan video recordings. The advantage of both VITC and CTL timecode is that a precious audio track does not have to be sacrificed for linear timecode.

Though a very effective technology, and still probably in limited use today, CTL timecode never really caught on. JVC is apparently the only manufacturer that included CTL timecode capability in their video products, and this was limited to select professional S-VHS equipment.

When it was introduced, there was a lot of undeserved negativity about CTL timecode, because people misunderstood how it worked. Many incorrectly assumed that CTL timecode was nothing more than a control track pulse signal. The only real problem with CTL timecode was that JVC chose to call it "CTL timecode".