Timecode Standards
Timecode has several standards. The subject of the various timecode formats can be very confusing due to the use and misuse of the shorthand names for specific timecode standards and frame rates. The timecode format can be divided into 2 variables: frame count and frame rate.
Frame count (frames per second)
The frame count of timecode defines the standard with which it is labeled. There are 4 timecode standards:
- 24 fps Film (F)
This frame count is the traditional count for film. It is also used for HD video formats and commonly referred to as 24 p. However, with HD video, the actual frame rate or speed of the video sync reference is slower, 23.976 frames per second, so timecode does not reflect the actual real time on the clock for 24 p HD video.
- 25 fps PAL (P)
This is the broadcast video standard frame count for European (and other PAL countries) television broadcast.
- 30 fps non-drop SMPTE (N)
This is the frame count of NTSC broadcast video. However, the actual frame rate or speed of the video format runs at 29.97 fps. This timecode clock does not run in real time. It is slightly slower by 0.1 %.
- 30 fps drop-frame SMPTE (D)
The 30 fps drop-frame count is an adaptation that allows a timecode display running at 29.97 fps to actually show the clock-on-the-wall-time of the timeline by dropping or skipping specific frame numbers in order to catch the clock up to real time.
Remember to keep the timecode standard (or frame count) and frame rate (or speed) separate.
Frame rate (speed)
Regardless of the frame counting system, the actual speed at which frames of video go by in real time is the true frame rate.
Cubase supports the following frame rates:
- 24 fps
This is the true speed of standard film cameras.
- 25 fps
This is the frame rate of PAL video.
- 29.97 fps/29.97 dfps
This is the frame rate of NTSC video. The count can be either non-drop or drop-frame.
- 30 fps/30 dfps
This frame rate is not a video standard anymore but has been commonly used in music recording. Many years ago, it was the black and white NTSC broadcast standard. It is equal to NTSC video being pulled up to film speed after a 2-3 telecine transfer. The count can be either non-drop or drop-frame.
Video formats with a variable frame rate (VFR) are not supported.
Frame count vs. frame rate
Part of the confusion in timecode stems from the use of frames per second in both the timecode standard and the actual frame rate. When used to describe a timecode standard, frames per second defines how many frames of timecode are counted before one second on the counter increments. When describing frame rates, frames per second define how many frames are played back during the span of one second of real time. In other words: Regardless of how many frames of video there are per second of timecode (frame count), those frames can be moving at different rates depending on the speed (frame rate) of the video format. For example, NTSC timecode (SMPTE) has a frame count of 30 fps. However, NTSC video runs at a rate of 29.97 fps. So the NTSC timecode standard known as SMPTE is a 30 fps standard that runs at 29.97 fps real time.