Timecode
A timecode (alternatively, time code) is a sequence of numeric codes generated at regular intervals by a timing system.
Video and film timecode
In video and film production, SMPTE timecode is used extensively for synchronization, and for logging and identifying material in recorded media. During a film or video shoot, the camera assistant will typically log the start and end timecodes of shots, and the data generated will be sent on to the editorial department for use in referencing those shots. This shot-logging process was traditionally done by hand using pen and paper, but is now typically done using shot-logging software running on a laptop computer that is connected to the time code generator or the camera itself.
The SMPTE family of timecodes are almost universally used in film, video and audio production, and can be encoded in many different formats, including:
- Linear timecode
- Vertical interval timecode
- AES-EBU embedded timecode
- Burnt-in timecode
- CTL timecode
- MIDI timecode
Keykode, while not a timecode, is used to identify specific film frames in film postproduction that uses physical film stock. Keykode data is normally used in conjunction with SMPTE time code.
Rewritable consumer timecode is a proprietary consumer video timecode system that is not frame-accurate, and is therefore not used in professional post-production.
Other time code formats
Time codes for purposes other than video and audio production include:
- IRIG time codes Used for military, government and commercial purposes.
See also
- Binary Coded Decimal
- Global Positioning System
- Jam sync
- Network time protocol
- Time code ambiguity
- Time signal
- Timestamp, denoting the date/time in data logging
- Trusted timestamping, part of a digital signature
- Vinyl emulation software
References
- Timecode: A user's guide, second edition by John Ratcliff, [Focal Press]
- A Technical Introduction to Digital Video by Charles Poynton