Key Frame - Everything You Need To Know

Keyframes, also known as I-frames or Intra-coded frames, are independent frames in video streaming that contain a full picture of the scene. They serve as starting points for new viewers and enable random access within the video for operations like seeking and fast-forwarding. Keyframes play a crucial role in video compression and efficient streaming by reducing dependency on preceding frames. The concept of keyframes first emerged in traditional hand-drawn animation, where they were used to set critical positions of characters or objects at significant points of motion or change. In digital animation software, keyframes became points in time where the animator sets values for certain properties like position, rotation, and scale. With the development of video compression techniques, keyframes gained a new dimension as frames that are encoded without reference to other frames. Key framing is vital in efficiently encoding and delivering video content by reducing redundancy in video data through selecting certain frames to be fully encoded as complete images (keyframes or I-frames) and using other types of frames like P-frames and B-frames to store only the changes from preceding or following frames. The optimal keyframe interval for streaming depends on the content and application, with a general guideline being between 2 to 5 seconds.