Keyframes

The word keyframe has at least 3 contextual meanings in the NLE environment. First, the oldest meaning, is the I-Frame definition used in codecs algorithms. These are key frames that begin a new sequence of pictures (GOP= Group Of Pictures), and are anchor points for repositioning (seeks) . Next are the automation parameter data points. These are usually input to primitive math forms, like translation and zoom. And last are blobs of data that are chunks of parameters to plugins that can do almost anything. The data can be a simple value, like a fader value, or more complex like a group of points and colors in a sketcher plugin keyframe. The word keyframe has changed a lot in meaning. In the context of CINELERRA-GG, keyframes are data values that have been associated to media on the timeline which affect the media presentation. So a keyframe no longer refers to a frame, but to a position on the timeline (timecode).

In CINELERRA-GG, there are two general types of keyframe data, automation keyframes (autos) which are drawn as colored lines and box icons overlayed at a point on a media track, and plugin keyframes which are drawn as gold key symbols on a plugin bar of a track. Auto ← Keyframe → Plugin

It is important to understand the fundamental difference between CINELERRA-GG Autos (zoom, pan, etc.) is that Autos are interpolable in any way (linear, bezier, etc.) while Plugin keyframes may be interpolable in various ways or not be interpolable at all.