How to use it
- Choose whether you know the interval in seconds or the GOP in frames.
- Enter the frame rate, for example 30, 60, 25 or 29.97.
- Enter the interval or the GOP size, and the length of the video in minutes.
How it works
GOP (frames) = frame rate × interval (s); interval = GOP ÷ frame rate. Keyframes per minute = 60 ÷ interval. The number of keyframes in a video is its length divided by the interval, rounded up, because the first frame is always a keyframe.
Worked example
30 fps with a 2-second interval: GOP = 30 × 2 = 60 frames, 30 keyframes per minute, and a 10-minute video has 600 ÷ 2 = 300 keyframes. The other way, 60 fps with a GOP of 250 gives 250 ÷ 60 = 4.167 s between keyframes and 14.4 per minute.
Tips
- Set a fixed interval rather than “auto” when a platform asks for one; otherwise the encoder may place keyframes irregularly.
- For video files meant for editing, a shorter GOP makes scrubbing smoother.
- The bitrate calculator helps choose the bitrate that goes with these settings.