Last Updated 2 days ago
Definition
Timecode is a system for identifying positions in picture and sound using a time-based address. It is commonly displayed as hours, minutes, seconds and frames: HH:MM:SS:FF. Production crews use it to align recordings, identify moments and communicate precise edit notes.
At 25 frames per second, 01:02:03:12 means hour 1, minute 2, second 3, frame 12. The frame field is a frame count within that second, not a decimal fraction of a second. At that rate its normal values run from 00 to 24.
Source Timecode and Timeline Timecode
Source timecode belongs to recorded media. Timeline timecode identifies positions in an edited sequence. A source clip beginning at 10:15:00:00 can appear at 01:00:20:00 in an edit; both addresses are valid in their own context.
When giving feedback, specify the cut version and whether the number refers to the review timeline or original media. Timecode alone is not a globally unique file identifier. Different days, cameras or reset generators can produce repeated addresses, so preserve filenames, dates and camera or sound-roll information too.
Recording and Sharing Timecode
In a common dual-system workflow, cameras record picture while a separate recorder records sound. Giving the devices a shared timecode reference lets editing software align overlapping recordings without manually locating every slate.
A device with a compatible timecode input can write the received address into file metadata. Another approach records linear timecode, or LTC, as an audio signal on an audio channel. That recorded signal must be decoded by compatible software; it is not useful dialogue and should not appear in the finished mix.
Use the cable, input and signal level specified for the equipment. A microphone input and a dedicated timecode input are different destinations, even when an adapter can physically connect them. Test the resulting files in the actual post-production software before the shoot.
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Free Run, Record Run and Jam Sync
Free run advances continuously whether or not a device is recording. Time-of-day code is a common free-run choice. Record run advances while recording, which can be useful for some workflows but is not automatically a shared clock for independently operated cameras.
Jam sync sets one timecode generator from another reference, after which it may run independently. Whether a camera retains accurate code after a battery change or power-down depends on the model and settings. Check rather than assuming the morning jam remains valid all day.
Keep the capture rate and timecode plan agreed with post. 23.976 and 24 fps are different rates, as are 29.97 and 30 fps. Special high-frame-rate or off-speed recording requires a deliberate workflow rather than copying settings blindly.
Drop-Frame and Non-Drop-Frame
Drop-frame timecode adjusts the numbering scheme so a fractional-rate format can track elapsed clock time more closely. It does not remove recorded pictures or audio samples.
At 29.97 fps, drop-frame numbering skips frame labels 00 and 01 at the start of each minute except every tenth minute. A typical transition is 00:00:59;29 to 00:01:00;02. The semicolon commonly indicates drop-frame display. Non-drop-frame keeps consecutive labels, so its displayed time gradually differs from elapsed wall-clock time at this rate.
Drop-frame is a numbering convention, not a method for fixing drift. Confirm the required mode with post and keep the devices consistent. Do not apply the 29.97 numbering rule to every frame rate.
Timecode Does Not Guarantee Clock Sync
Two recordings can share matching timecode yet drift during a long take because their recording clocks run at slightly different speeds. Matching addresses also does not necessarily align the exact instant each camera exposes a frame.
Genlock addresses video timing, while word clock can provide an audio sample-clock reference. Some cameras can derive sensor synchronization from timecode, but this is device-specific. Check the manuals and production requirements, especially for long multicamera recordings, virtual production or tightly synchronized visual effects.
A Shoot-Day Checklist
- Agree the frame rate, counting mode and reference source with camera, sound and post.
- Connect or jam each device using the correct inputs and settings, then confirm the displayed values.
- Record a slate test and import the files. Verify synchronization at the start and end of a representative take.
- Recheck after power changes, rate changes or equipment swaps. Keep a visible and audible slate where practical as a backup.
- Preserve original timecode during copying, proxy creation and post handoff. Tell the editor about resets, offsets and known faults.
Frequently Asked Questions
Do I still need a clapperboard? A slate supplies scene and take identification and a visible/audible sync reference if timecode fails. Matching code is useful, but a verified backup is valuable.
Does a timecode box record sound? Some products combine functions; many only generate timecode. Confirm what your model actually records and whether an audio channel is being occupied by LTC.
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Related Terms
- Jam Sync
- Clapper
- 23.976 fps (23.98 fps)
- 29.97 fps
- 48 kHz Sample Rate
- Assistant Editor (Post-Production)