motioncompensated

Motion compensated is a technique used in digital video processing to improve the efficiency and quality of video compression. It exploits the fact that consecutive frames in a video often share many similarities, with only certain areas undergoing motion. Instead of encoding each frame independently, motion compensation identifies and encodes the motion of objects between frames. This allows the encoder to transmit only the differences (residuals) and the motion vectors, which describe how pixels or blocks of pixels have moved from one frame to another.

The process typically involves dividing frames into blocks. For each block in a current frame, the encoder searches for a matching block in a reference frame (either a previous or future frame). Once a match is found, the encoder records the displacement of the block (the motion vector) and the difference between the current block and the matched block in the reference frame. The decoder then uses the motion vectors and the residual information to reconstruct the current frame.

This approach significantly reduces the amount of data needed to represent a video, leading to higher compression ratios. It is a fundamental component of modern video codecs such as H.264 (AVC) and H.265 (HEVC), enabling efficient streaming and storage of video content. Without motion compensation, video compression would be far less effective, resulting in much larger file sizes for the same visual quality. The accuracy of motion estimation and compensation directly impacts the overall compression performance and the visual quality of the decoded video.