movement from its last position this motion vector and the difference between the two areas are then encoded there are a number of chips commercially available encoder chips such as the go7007sb streaming media encoder chip available from wischip international ltd that can compress raw digital video into mpeg 4 or mpeg 2 formats the video compression is achieved by removing spatial and temporal redundancy in order to remove temporal redundancy a process called motion compensation is performed in this process each incoming image is partitioned into blocks of 16 u00d7 16 or 8 u00d7 8 a best match for each block is found from the previous frame temporal redundancy is reduced by using the best match block in the previous frame to represent the block in the current frame the process of motion compensation is to find the best match for each block in the current frame by searching through certain range of area in the previous frame the sum of absolute distortion between the block in the current frame and the blocks in the previous frame are computed the one with the minimum distortion is the best match in one embodiment of the present invention the motion vector that is stored in the standard mpeg bitstream by an mpeg compliant encoder chip is used to detect motion in the video frame in another embodiment an mpeg compliant encoder chip is modified such as in its firmware to provide either the motion vector or the sum of absolute values of distortion between the frames or both and store them in the meta data portion of the syntax fig1 illustrates one embodiment of the present invention a camera 10 is.