International Business Machines Corporation

Other

Nstreams Technologies, Inc.

Pong-sheng Wang

James J Myers

Ching-San Hsu

Ahmad Zandi

William H Tetzlaff

Robert Baird

Mark Anthony Sovik

Gerald P Bozman

George Eisenberger

Ashok Raj Saxena

Alexander S Lett

Brian J Smith

Nancy Y Young

John J McAssey

Albert Kamerman

A video server system and method has a modular and expandable system design to deliver a plurality of video streams on user demand and under user control. The video server system and method has a central control module adapted to receive control commands such as SELECT, PLAY, REWIND, PAUSE etc. to select and playback a video from a plurality of videos stored in a storage module. The central control module is a computer motherboard having a first small computer serial interface (SCSI) coupled to the storage device. The central control module also has memory for buffering data blocks of video retrieved from the storage device or devices prior to delivery to the delivery module also included in the system. The delivery module is also a computer motherboard having memory and also having a plurality of video processors for processing the video data prior to coupling the data to a client location. The delivery module additionally has a SCSI interface configured to operate in a target mode so that the central control module transfers video data to the delivery module in the same manner that it would use if it were writing to a conventional SCSI disk drive.

System and process for delivering digital data on demand

A media streamer (10) includes at least one control node (18); a user interface (64, 65, 66) having an output coupled to the at least one control node; at least one storage node (16, 17) for storing a digital representation of at least one video presentation; and a plurality of communication nodes (14) each having an input port for receiving a digital representation of at least one video presentation therefrom. The video presentation requires a time T to present in its entirety, and is stored as a plurality of N data blocks. Each data block stores data corresponding to a T/N period of the video presentation. Each communication nodes further has a plurality of output ports for outputting a digital representation. A circuit switch (12) is connected between the at least one storage node and the input ports of communication nodes for coupling one or more input ports to the at least one storage node. The user interface includes a capability for specifying commands for execution, and the at least one control node is responsive to individual ones of the commands for controlling at least one of the at least one storage node and at least one of the plurality of communication nodes, in cooperation with the circuit switch, so as to execute a function associated with individual ones of the commands. The commands may include video cassette recorder-like commands that include commands selected from a group that includes a Load command, an Eject command, a Play command, a Slow command, a Fast Forward command, a Pause command, a Stop command, a Rewind command, and a Mute command. The commands may also include commands selected from a group that includes a Play List command, a Play Length command, and a Batch command. A synchronous application program interface (API) is provided for coupling, via the user interface, a user application program to the at least one control node. The API includes Remote Procedure Call (RPC) procedures.

Video optimized media streamer user interface employing non-blocking

A computer system constructs a compression dictionary for compressing a character string by interrogating an initial substring portion to determine input string characteristics that are used to select one or more dictionary segments from a library of predetermined dictionary segments individually adapted for compressing strings with particular characteristics. The initial substring portion is dynamically determined during the interrogation. A first set of dictionary segments that meet predetermined automatic selection criteria are selected and a second set of candidate dictionary segments that meet second-level selection criteria are identified for a sampling phase. During the sampling phase, the candidate dictionary segments are alternately used to compress the initial substring portion and determine compression performance statistics. The performance of the dictionary segments in the sampling phase determines which candidate dictionary segments will be added to the first selected dictionary segments, within dictionary total size limits. The first selected dictionary segments and the identified segments constitute a system-built compression dictionary that is used to compress the remainder of the input string. In this way, predetermined compression dictionaries are selected for maximum efficiency in accordance with the data actually being compressed and compression can be carried out quickly and efficiently as input data is received.

Access method data compression with system-built generic dictionaries

A computer implemented method for robustly copying pages to system managed storage in order to maintain data in a consistent state and in order to provide continuous access availability of the pages to executing applications. The method achieves data consistency by atomically shadow copying application referenced pages and amending directories in a failure independent medium on (1) an access path interrupt as well as on (2) a page update basis. Availability is enhanced by duplexing the pages and directories as part of the atomic shadow copying step.

Highly available fault tolerant relocation of storage with atomicity

A CPU implemented method for managing the backup copying of data sets residing in non-volatile storage and for the recovery thereof in the event of CPU failure. The first step is to invoke a modified incremental backup copy policy using a small backup window and less data than that heretofore used in full, incremental or mixed policies. That is, a backup copy is made to a first designated part of non-volatile storage of only those data sets in a storage group satisfying a pair of adjustable parameters relating the last backup date, the last update, and the current date. The second step occurs during a recovery cycle in the event of CPU failure wherein the backed up datasets are copied from said first designated part into a second designated part of non-volatile storage.

CPU implemented method for backing up modified data sets in non-volatile

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San Jose, CA, United States of America

Pong-sheng Wang