MPEG, in addition to being an international standard, is currently the most popular coding scheme for stored video. For several applications that require stored video, such as video-on-demand, it is advantageous to group MPEG frames into segments. Retrieving segments instead of individual frames can result in a more efficient use of disk retrieval resources and consequently, in the support of a larger number of users and in a more cost-effective system. Depending on the value of parameters such as desired user quality of service, size and cost of required buffers, number of disks to stripe a segment across, etc., a certain segment length (defined as the number of frames per segment) may be preferred over others. In this paper, we propose a generalized grouping scheme that may be used to achieve any desired segment length. Properties of such a grouping scheme and formulae that may be used to achieve such a grouping have been provided. Since a segment is an atomic unit of video retrieval...