Time code
Encyclopedia
A timecode is a sequence of numeric codes generated at regular intervals by a timing
system.
and filmmaking
, SMPTE timecode is used extensively for synchronization
, and for logging and identifying material in recorded media. During filmmaking
or video production
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:
Keykode
, while not a timecode, is used to identify specific film frame
s in film post-production
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.
Timing
Timing is the time when something happens or the spacing of events in time. Some typical uses are:* The act of measuring the elapsed time of something or someone, often at athletic events such as swimming or running, where participants are timed with a device such as a stopwatch...
system.
Video and film timecode
In video productionVideo production
Video production is videography, the process of capturing moving images on electronic media even streaming media. The term includes methods of production and post-production...
and filmmaking
Filmmaking
Filmmaking is the process of making a film, from an initial story, idea, or commission, through scriptwriting, casting, shooting, directing, editing, and screening the finished product before an audience that may result in a theatrical release or television program...
, SMPTE timecode is used extensively for synchronization
Synchronization
Synchronization is timekeeping which requires the coordination of events to operate a system in unison. The familiar conductor of an orchestra serves to keep the orchestra in time....
, and for logging and identifying material in recorded media. During filmmaking
Filmmaking
Filmmaking is the process of making a film, from an initial story, idea, or commission, through scriptwriting, casting, shooting, directing, editing, and screening the finished product before an audience that may result in a theatrical release or television program...
or video production
Video production
Video production is videography, the process of capturing moving images on electronic media even streaming media. The term includes methods of production and post-production...
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 timecodeLinear timecodeLinear Timecode is an encoding of SMPTE timecode data in an audio signal, as defined in SMPTE 12M specification. The 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 zero bit has a single transition...
(LTC) - Vertical interval timecodeVertical interval timecodeVertical Interval TimeCode is a form of SMPTE timecode embedded as a pair of black-and-white bars in a video signal. These lines are typically inserted into the vertical blanking interval of the video signal...
(VITC) - AES-EBU embedded timecode used with digital audioDigital audioDigital audio is sound reproduction using pulse-code modulation and digital signals. Digital audio systems include analog-to-digital conversion , digital-to-analog conversion , digital storage, processing and transmission components...
- Burnt-in timecodeBurnt-in timecodeBurnt-in timecode is a human-readable on-screen version of the timecode information for a piece of material superimposed on a video image...
- CTL timecodeCTL timecodeCTL timecode, developed by JVC in the early 1990s, is a unique technique for embedding, or striping, reference SMPTE timecode onto a videotape....
(Control track) - MIDI timecodeMIDI timecodeMIDI time code , or MIDI time division, embeds the same timing information as standard SMPTE timecode as a series of small 'quarter-frame' MIDI messages. There is no provision for the user bits in the standard MIDI time code messages, and SysEx messages are used to carry this information instead...
Keykode
Keykode
KeyKode is an Eastman Kodak Company advancement on edge numbers, which are letters, numbers and symbols placed at regular intervals along the edge of 35 mm and 16 mm film to allow for frame-by-frame specific identification...
, while not a timecode, is used to identify specific film frame
Film frame
In filmmaking, video production, animation, and related fields, a film frame or video frame is one of the many still images which compose the complete moving picture...
s in film post-production
Post-production
Post-production is part of filmmaking and the video production process. It occurs in the making of motion pictures, television programs, radio programs, advertising, audio recordings, photography, and digital art...
that uses physical film stock
Film stock
Film stock is photographic film on which filmmaking of motion pictures are shot and reproduced. The equivalent in television production is video tape.-1889–1899:...
. Keykode data is normally used in conjunction with SMPTE time code.
Rewritable consumer timecode
Rewritable consumer timecode
The Rewriteable Consumer Timecode is a nearly frame accurate timecode method developed by Sony for 8mm and Hi8 analog tape formats. The RC timecode is written by the video camera directly to analog tape tracks and records the hour, minute, second and frame for each frame of video recorded to tape...
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:- Inter-range instrumentation group time codesInter-range instrumentation group time codesInter-range instrumentation group time codes, commonly known as IRIG timecodes, were created by the TeleCommunications Working Group of the Inter-Range Instrumentation Group, the standards body of the Range Commanders Council...
(IRIG) is used for military, government and commercial purposes.
See also
- Binary Coded Decimal
- Global Positioning SystemGlobal Positioning SystemThe Global Positioning System is a space-based global navigation satellite system that provides location and time information in all weather, anywhere on or near the Earth, where there is an unobstructed line of sight to four or more GPS satellites...
- Jam syncJam syncJam sync refers to the practice of applying a phase hit to a system to bring it in synchronization with another. The term originates from the use of this technique to replace defective time code on a video tape recording by replacing it with a new time code sequence, which may be an extension of a...
- Network time protocolNetwork Time ProtocolThe Network Time Protocol is a protocol and software implementation for synchronizing the clocks of computer systems over packet-switched, variable-latency data networks. Originally designed by David L...
- Time code ambiguityTime code ambiguityIn telecommunication, time code ambiguity is the shortest interval between successive repetitions of the same time code value.For example, in a time code in which year-of-century is the most slowly changing field, the time code ambiguity would be 100 years; it is ambiguous whether this value...
- Time signalTime signalA time signal is a visible, audible, mechanical, or electronic signal used as a reference to determine the time of day.-Audible and visible time signals:...
- TimestampTimestampA timestamp is a sequence of characters, denoting the date or time at which a certain event occurred. A timestamp is the time at which an event is recorded by a computer, not the time of the event itself...
, denoting the date/time in data logging - Trusted timestampingTrusted timestampingTrusted timestamping is the process of securelykeeping track of the creation and modification time of a document. Securityhere means that no one — not even the owner of the document — should be able to change it once it has been recorded provided that the timestamper's integrity is never...
, part of a digital signature - Vinyl emulation softwareVinyl Emulation SoftwareVinyl emulation software allows the user to physically manipulate the playback of digital audio files on a computer using the turntables as an interface, thus preserving the hands-on feel of deejaying with vinyl while allowing playback of audio recordings not available in phonograph form...