Method for accessing one or more streams in a video storage system using

Abstract

A method is disclosed for interfacing a video storage system, such as a disk array, and a video stream application executing on a computer network or stand-alone system. The interface provides a method for storing video stream data by allocating storage space in units of stripes and for accessing the data in units of fixed length segments, wherein each stripe includes one fixed length segment from each disk of the array. The interface also queues submitted I/O transaction requests so that I/O transactions requested on a current I/O cycle i are not performed until the next I/O cycle i+1. The I/O transactions thus queued are performed in an order which permits a maximum number of I/O transactions to be performed each I/O cycle, regardless of the order in which they were submitted. In addition, the interface also queues the submitted I/O transaction requests so that the completion of an I/O transaction on a current I/O cycle i is not returned until the next I/O cycle i+1. The completions of the I/O transactions thus queued are returned in the order they were submitted regardless of the order in which they were performed. Furthermore, the interface provides a state machine which controls the amount of data accessed each I/O cycle for a corresponding stream. The state machine permits no more than a particular allotted amount of data to be accessed each I/O cycle, wherein the allotted amount of data is selected according to the bandwidth requirement of the corresponding stream.