What is Drop Frame?
Drop-frame timecode periodically omits timecode numbers, not video frames, to compensate for fractional frame rates. It keeps 29.97 or 59.94 fps footage closely aligned with elapsed clock time.
How Drop Frame works
Fractional television rates run slightly slower than their neighboring integer labels, so naïvely numbered timecode gradually disagrees with wall-clock duration. Drop-frame notation corrects the label count by skipping selected frame numbers at scheduled minute boundaries while every captured picture remains present. It changes addressing, not cadence, encoding, or playback speed. Editors and broadcast automation use it when program clocks, logs, and schedules must refer to the same elapsed time.
Key facts
- 1At 29.97 fps, labels 00 and 01 are omitted at each minute boundary except every tenth minute; no picture is removed, and the next existing frame receives the later label.
- 2At 59.94 fps, the analogous convention skips four labels at affected minute boundaries, reflecting the doubled nominal timecode count while retaining the same clock correction.
- 3A semicolon commonly distinguishes drop-frame notation from non-drop-frame notation, but software should also retain an explicit mode flag because punctuation can be lost in interchange.
When Drop Frame matters
Use drop-frame timecode when broadcast schedules or program durations must track real time accurately. Mixing it with non-drop-frame notation creates duration and edit-point discrepancies despite identical footage.