Key/Delta Frames

Key/Delta Frames

Frames inside an animation can be stand alone frames, these frames do not need another frame to decompress correctly. These frames are called key frames .

Delta frames need other frames (mostly the previous frames) to decompress. This is done to reduce the size of the frames inside an animation, as only the differences from the previous to the next frame have to be processed.

First generation animation formats (like FLI, FLC, IFF-Anim) mostly have a key frame as the first frame and all other frames are delta frames. Second generation animation formats, like AVI and Quicktime mostly have key frames every few seconds. This enables the playback software to quickly find a specific position inside the stream and to skip frames when playback gets too slow.

Inside MainActor VE, gray frame icons in the frame list indicate key frames, transparent icons indicate delta frames.