Keyframes
In animation and video editing the term Keyframe is used in 3 contexts ...
Animation inbetweening
Optimising and compressing
Video editing
Animation inbetweening
In animation an artist will draw keyframes in the action (perhaps 1 every half second) and inbetweening artists will draw all the frames in between. Computer animation programs now do the inbetweening for the artist. Flash and Director are examples of programs which can automate inbetweening.
Animation keyframes in Director
Optimising & compressing
When compressing video files, keyframes are used to determine how often the video frame is analysed before the following frames are compressed.
Setting video compression keyframe frequency in QuickTime Pro
Click here for full information on the compression process including an in-depth overview of keyframe frequency.
Video editing
In video editing, keyframes are used to determine points on a timeline where filter or effect settings will change. Processes that can be specified with keyframes include ...
Motion paths
Opacity changes
Filter setting changes
Fades in and out
etc
Motion keyframes in Final Cut Pro
Opacity keyframes in Final Cut Pro