View Source Timecode: A History
But first: what is timecode?
If you're already familiar with timecode, it's history, and it's flavors, feel free to skip this section.
how-we-got-here
How we got here
Back in the days of film, a running strip of numbers ran along the edge of the film stock to uniquely identify each frame, called keycode
Keycode was essential to the film editing process. The raw negative of a film is irreplaceable: you loose quality each time you make a copy. Editing film is necessarily a destructive process, and often required multiple iterations. It would be just a tad nerve-wracking to take a pair of scissors and some glue to the one-of-a-kind film reels straight out of the camera on set, then running it over and over through a flatbed.
To avoid potential disaster, editors made their cut of the film using copies of the raw negative, called a work print, allowing the editor to work without fear of sinking a project from slicing, dicing, and wearing at the film.
When the edit was complete, it was necessary to know exactly where the edits had been made, so it could be recreated with the raw negative for finishing. A cut list would be written out, with the exact reels and keycodes for every cut, and would be used to make an exact duplicate of the editor's work print with the mint condition raw negative.
In video and digital filmmaking, the same approach is used. Massive RAW files from a RED, ARRI, Sony, or other cinema camera are rendered down to more manageable files an Editor's machine won't choke on. Once the edit is complete, the raw files are re-assembled using a digital cutlist on a powerful machine for finishing out the film.
In film, we referenced keycode to know exactly what frame was being displayed on screen at any given time. In digital video, we reference the timecode of a given frame, as defined by the SMPTE Timecode standard.
further-reading
Further Reading
For a technical deep-dive into the many flavors of timecode, check out Frame.io's excellent blog post on the subject.