Video server streaming synchronization

• US 6,240,105 B1
• Filed: 03/30/1998
• Issued: 05/29/2001
• Est. Priority Date: 03/30/1998
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Zetts, John Mark
• Primary Examiner(s): Olms, Douglas
• Assistant Examiner(s): HOM, SHICK C
• Application Number:
  US09/050,168
• Time in Patent Office: 1,156 Days
• Field of Search: 370/252, 370/332, 370/395, 370/485, 370/503, 370/507, 370/216, 370/217, 370/218, 370/219, 370/220, 348/6, 348/7, 348/10, 348/17, 380/3, 380/4, 380/5
• US Class Current: 370/503
• CPC Class Codes: H04N 21/23116 involving data replication, e.g. over plural servers synchronization of replicated data G06F11/1658; error detection or correction by means of data replication G06F11/2053; replication in distributed file systems G06F16/10; replication in distributed file systems G06F16/27; replication or mirroring of data in data networks H04L67/1095
• CPC Class Codes: H04N 21/23805 Controlling the feeding rate to the network, e.g. by controlling the video pump
• CPC Class Codes: H04N 21/2383 Channel coding or modulation of digital bit-stream, e.g. QPSK modulation arrangements for detecting or preventing errors in the information received by adapting the channel coding H04L1/0009; analogue front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 21/242 Synchronization processes, e.g. processing of PCR [Program Clock References] arrangements for synchronising broadcast or distribution via plural systems in broadcast distribution systems H04H20/18
• CPC Class Codes: H04N 21/4382 Demodulation or channel decoding, e.g. QPSK demodulation analog front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002

Abstract

Primary and secondary servers are coupled together for furnishing a backed-up video streaming function for outputting a series of video content presentations to a user group. The primary server functions as the primary provider of the video files and the secondary server is arranged to operate as a “hot stand-by” to back-up the primary server. In the event the primary server is disabled, the secondary server takes over for the primary server in furnishing video content in accordance with a common playlist. When the secondary server goes down for any reason, the illustrated methodology effectively re-synchronizes the video content and the video stream of the secondary server with that of the primary server such that the secondary server is enabled to resume the back-up function without interruption of the video file streaming process being carried on by the primary server. Various program routines and sample screen displays are illustrated in an exemplary embodiment of the back-up dual server video streaming system and methodology.

Claims

1. A synchronization method for a transferring process wherein a first video file is transferred from a first video server at a transfer rate to a second video server during a first time period, said first video server being selectively operable during substantially said first time period, for outputting said first video file at a play rate from said first video server to a video station output device, said synchronization method comprising:

determining a value of said transfer rate;

determining a value of said play rate;

initiating said transferring process when said transfer rate is determined to have a first predetermined relationship with said play rate, wherein said first predetermined relationship includes said play rate being less than said transfer rate by a predetermined differential amount, and wherein said initiating is further conditioned upon a determination that a predetermined portion of said first video file has been output from said first video server to said video station output device.

2. The method as set forth in claim 1 wherein said transferring process is initiated when said transfer rate is determined to have said first predetermined relationship with said play rate, and a predetermined offset portion of said first video file has been output from said first video server to said video station output device.

3. A synchronization method for a transferring process wherein a first video file is transferred from a first video server at a transfer rate to a second video server during a first time period, said first video server being selectively operable during substantially said first time period, for outputting said first video file at a play rate from said first video server to a video station output device, said synchronization method comprising:

presenting at least one selection screen on a display device associated with said video station, said selection screen being arranged to solicit a selection from an operator for enabling an automatic completion of said synchronization method;

determining a value of said transfer rate;

determining a value of said play rate; and

initiating said transferring process when said transfer rate is determined to have a first predetermined relationship with said play rate.

4. A synchronization method for a transferring process wherein a first video file is transferred from a first video server at a transfer rate to a second video server during a first time period, said first video server being selectively operable during substantially said first time period, for outputting said first video file at a play rate from said first video server to a video station output device, said synchronization method comprising:

presenting at least one selection screen on a display device associated with said video station, said selection screen being arranged to solicit a selection from an operator for enabling a manual completion of said synchronization method;

determining a value of said transfer rate;

determining a value of said play rate; and

initiating said transferring process when said transfer rate is determined to have a first predetermined relationship with said play rate.

5. A synchronization method for a transferring process wherein a first video file is transferred from a first video server at a transfer rate to a second video server during a first time period, said first video server being selectively operable during substantially said first time period, for outputting said first video file at a play rate from said first video server to a video station output device;

determining a value of said transfer rate;

determining a value of said play rate;

initiating said transferring process when said transfer rate is determined to have a first predetermined relationship with said play rate, wherein said transferring process further includes;

determining a current offset portion of said first video file, said current offset portion being representative of a portion of said first video file which has been output from said first video server to said video station output device;

determining a local time;

determining a transmission delay time for data being transferred from said first video server to said second video server; and

beginning a data transfer of said first video file when a second predetermined relationship is established among said current offset portion, said local time and said transmission delay time.

6. The method as set forth in claim 5 and further including:

queuing said first video file to begin to transfer said first video file from said first video server to said second video server at a start point in said first video file following a calculated delay from a current time.

7. The method as set forth in claim 6 and further including:

causing said second video server to begin to play when said first video file begins to transfer from said first video server whereby said first and second video servers output said first video file in synchronism.

8. The method as set forth in claim 6 wherein said calculated delay includes delay factors to account for elapsed time in accomplishing said initiating.

9. The method as set forth in claim 8 wherein said calculated delay further includes a wait delay factor, said wait delay factor comprising a predetermined time delay following an ascertainment of said elapsed time and said transmission delay time, said wait delay factor being further related to said start point for said first video file.

10. An information processing system for use in a video station, said information processing system comprising:

a first video server arranged to selectively output a first data stream comprised of a first video file;

a second video server coupled to said first video server, said second video server being arranged to selectively output a second data stream comprised of said first video file;

a video station output device coupled to said first and second video servers, said video station output device being selectively operable for outputting said first video file from a selected one of said first and second servers; and

a control device coupled to said first and second video servers, said control device being selectively operable for synchronizing said outputs from said first and second video servers such that said first and second data streams are substantially in synchronism, said control device further including;

control means selectively operable for effecting a synchronization of said first and second data streams whereby said first video file is transferred from said first video server at a transfer rate to said second video server during a first time period, said first video server being selectively operable during substantially said first time period, for outputting said first video file at a play rate from said first video server to said video station output device;

means for determining a value of said transfer rate;

means for determining a value of said play rate; and

means for initiating a transferring process when said transfer rate is determined to have a first predetermined relationship with said play rate, wherein said first predetermined relationship includes said play rate being less than said transfer rate by a predetermined differential amount, and wherein said initiating is further conditioned upon a determination that a predetermined portion of said first video file has been output from said first video server to said video station output device.

11. The information processing system as set forth in claim 10 wherein said video station is a broadcast station, said video station being selectively operable for broadcasting a selected one of said first and second data streams to air.

12. The information processing system as set forth in claim 10 wherein said video station is a network server station in a network, said network server station being selectively operable for providing a selected one of said first and second data streams to said network.

13. A storage medium including machine readable indicia, said storage medium being selectively coupled to a reading device, said reading device being selectively coupled to processing circuitry within a processing system, said reading device being selectively operable to read said machine readable indicia and provide program signals representative thereof, said program signals being effective for implementing a synchronization method for a transferring process wherein a first video file is transferred from a first video server at a transfer rate to a second video server during a first time period, said first video server being selectively operable during substantially said first time period, for outputting said first video file at a play rate from said first video server to a video station output device, said synchronization method comprising:

determining a value of said transfer rate;

determining a value of said play rate;

initiating said transferring process when said transfer rate is determined to have a first predetermined relationship with said play rate, wherein said first predetermined relationship includes said play rate being less than said transfer rate by a predetermined differential amount, and wherein said initiating is further conditioned upon a determination that a predetermined portion of said first video file has been output from said first video server to said video station output device.