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AU2001246261A1 - Distributed cooperative memory for interactive and scalable video-on-demand system - Google Patents

Distributed cooperative memory for interactive and scalable video-on-demand system

Info

Publication number
AU2001246261A1
AU2001246261A1 AU2001246261A AU4626101A AU2001246261A1 AU 2001246261 A1 AU2001246261 A1 AU 2001246261A1 AU 2001246261 A AU2001246261 A AU 2001246261A AU 4626101 A AU4626101 A AU 4626101A AU 2001246261 A1 AU2001246261 A1 AU 2001246261A1
Authority
AU
Australia
Prior art keywords
interactive
scalable video
demand system
distributed cooperative
cooperative memory
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
AU2001246261A
Inventor
Claudio Luis Amorim
Edson Ishikawa
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Coordenacao dos Programas de Pos Graduacao de Engenharia da UFRJ
Original Assignee
Coordenacao dos Programas de Pos Graduacao de Engenharia da UFRJ
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Coordenacao dos Programas de Pos Graduacao de Engenharia da UFRJ filed Critical Coordenacao dos Programas de Pos Graduacao de Engenharia da UFRJ
Publication of AU2001246261A1 publication Critical patent/AU2001246261A1/en
Abandoned legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N7/00—Television systems
    • H04N7/16—Analogue secrecy systems; Analogue subscription systems
    • H04N7/173—Analogue secrecy systems; Analogue subscription systems with two-way working, e.g. subscriber sending a programme selection signal
    • H04N7/17345—Control of the passage of the selected programme
    • H04N7/17354—Control of the passage of the selected programme in an intermediate station common to a plurality of user terminals
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
    • H04N21/20—Servers specifically adapted for the distribution of content, e.g. VOD servers; Operations thereof
    • H04N21/23—Processing of content or additional data; Elementary server operations; Server middleware
    • H04N21/231—Content storage operation, e.g. caching movies for short term storage, replicating data over plural servers, prioritizing data for deletion
    • H04N21/23106—Content storage operation, e.g. caching movies for short term storage, replicating data over plural servers, prioritizing data for deletion involving caching operations
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
    • H04N21/40—Client devices specifically adapted for the reception of or interaction with content, e.g. set-top-box [STB]; Operations thereof
    • H04N21/43—Processing of content or additional data, e.g. demultiplexing additional data from a digital video stream; Elementary client operations, e.g. monitoring of home network or synchronising decoder's clock; Client middleware
    • H04N21/433—Content storage operation, e.g. storage operation in response to a pause request, caching operations
    • H04N21/4331—Caching operations, e.g. of an advertisement for later insertion during playback
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
    • H04N21/40—Client devices specifically adapted for the reception of or interaction with content, e.g. set-top-box [STB]; Operations thereof
    • H04N21/43—Processing of content or additional data, e.g. demultiplexing additional data from a digital video stream; Elementary client operations, e.g. monitoring of home network or synchronising decoder's clock; Client middleware
    • H04N21/44—Processing of video elementary streams, e.g. splicing a video clip retrieved from local storage with an incoming video stream or rendering scenes according to encoded video stream scene graphs
    • H04N21/44004—Processing of video elementary streams, e.g. splicing a video clip retrieved from local storage with an incoming video stream or rendering scenes according to encoded video stream scene graphs involving video buffer management, e.g. video decoder buffer or video display buffer
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
    • H04N21/40—Client devices specifically adapted for the reception of or interaction with content, e.g. set-top-box [STB]; Operations thereof
    • H04N21/47—End-user applications
    • H04N21/472—End-user interface for requesting content, additional data or services; End-user interface for interacting with content, e.g. for content reservation or setting reminders, for requesting event notification, for manipulating displayed content
    • H04N21/47202—End-user interface for requesting content, additional data or services; End-user interface for interacting with content, e.g. for content reservation or setting reminders, for requesting event notification, for manipulating displayed content for requesting content on demand, e.g. video on demand
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
    • H04N21/40—Client devices specifically adapted for the reception of or interaction with content, e.g. set-top-box [STB]; Operations thereof
    • H04N21/47—End-user applications
    • H04N21/478—Supplemental services, e.g. displaying phone caller identification, shopping application
    • H04N21/4788—Supplemental services, e.g. displaying phone caller identification, shopping application communicating with other users, e.g. chatting
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
    • H04N21/60—Network structure or processes for video distribution between server and client or between remote clients; Control signalling between clients, server and network components; Transmission of management data between server and client, e.g. sending from server to client commands for recording incoming content stream; Communication details between server and client 
    • H04N21/61—Network physical structure; Signal processing
    • H04N21/6106—Network physical structure; Signal processing specially adapted to the downstream path of the transmission network
    • H04N21/6125—Network physical structure; Signal processing specially adapted to the downstream path of the transmission network involving transmission via Internet
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
    • H04N21/60—Network structure or processes for video distribution between server and client or between remote clients; Control signalling between clients, server and network components; Transmission of management data between server and client, e.g. sending from server to client commands for recording incoming content stream; Communication details between server and client 
    • H04N21/63—Control signaling related to video distribution between client, server and network components; Network processes for video distribution between server and clients or between remote clients, e.g. transmitting basic layer and enhancement layers over different transmission paths, setting up a peer-to-peer communication via Internet between remote STB's; Communication protocols; Addressing
    • H04N21/632—Control signaling related to video distribution between client, server and network components; Network processes for video distribution between server and clients or between remote clients, e.g. transmitting basic layer and enhancement layers over different transmission paths, setting up a peer-to-peer communication via Internet between remote STB's; Communication protocols; Addressing using a connection between clients on a wide area network, e.g. setting up a peer-to-peer communication via Internet for retrieving video segments from the hard-disk of other client devices
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
    • H04N21/60—Network structure or processes for video distribution between server and client or between remote clients; Control signalling between clients, server and network components; Transmission of management data between server and client, e.g. sending from server to client commands for recording incoming content stream; Communication details between server and client 
    • H04N21/63—Control signaling related to video distribution between client, server and network components; Network processes for video distribution between server and clients or between remote clients, e.g. transmitting basic layer and enhancement layers over different transmission paths, setting up a peer-to-peer communication via Internet between remote STB's; Communication protocols; Addressing
    • H04N21/643—Communication protocols
    • H04N21/64322—IP
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N7/00—Television systems
    • H04N7/16—Analogue secrecy systems; Analogue subscription systems
    • H04N7/173—Analogue secrecy systems; Analogue subscription systems with two-way working, e.g. subscriber sending a programme selection signal
    • H04N7/17309—Transmission or handling of upstream communications
    • H04N7/17318—Direct or substantially direct transmission and handling of requests
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N7/00—Television systems
    • H04N7/16—Analogue secrecy systems; Analogue subscription systems
    • H04N7/173—Analogue secrecy systems; Analogue subscription systems with two-way working, e.g. subscriber sending a programme selection signal
    • H04N7/17309—Transmission or handling of upstream communications
    • H04N7/17336—Handling of requests in head-ends

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • General Engineering & Computer Science (AREA)
  • Databases & Information Systems (AREA)
  • Human Computer Interaction (AREA)
  • Two-Way Televisions, Distribution Of Moving Picture Or The Like (AREA)
  • Computer And Data Communications (AREA)
  • Television Signal Processing For Recording (AREA)
AU2001246261A 2000-03-28 2001-03-26 Distributed cooperative memory for interactive and scalable video-on-demand system Abandoned AU2001246261A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
BR00018104 2000-03-28
BRPI0001810-4A BRPI0001810B1 (en) 2000-03-28 2000-03-28 Distributed cooperative memory for scalable interactive vod system
PCT/BR2001/000029 WO2001074076A1 (en) 2000-03-28 2001-03-26 Distributed cooperative memory for interactive and scalable video-on-demand system

Publications (1)

Publication Number Publication Date
AU2001246261A1 true AU2001246261A1 (en) 2001-10-08

Family

ID=3944175

Family Applications (1)

Application Number Title Priority Date Filing Date
AU2001246261A Abandoned AU2001246261A1 (en) 2000-03-28 2001-03-26 Distributed cooperative memory for interactive and scalable video-on-demand system

Country Status (4)

Country Link
US (1) US7913282B2 (en)
AU (1) AU2001246261A1 (en)
BR (1) BRPI0001810B1 (en)
WO (1) WO2001074076A1 (en)

Families Citing this family (71)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5986650A (en) 1996-07-03 1999-11-16 News America Publications, Inc. Electronic television program guide schedule system and method with scan feature
US8589975B2 (en) * 1998-08-21 2013-11-19 United Video Properties, Inc. Electronic program guide with advance notification
US7631080B2 (en) * 2000-06-20 2009-12-08 Nds Limited Unicast/multicast architecture
US6766376B2 (en) 2000-09-12 2004-07-20 Sn Acquisition, L.L.C Streaming media buffering system
US20020194601A1 (en) * 2000-12-01 2002-12-19 Perkes Ronald M. System, method and computer program product for cross technology monitoring, profiling and predictive caching in a peer to peer broadcasting and viewing framework
DE10146347A1 (en) 2001-09-20 2003-04-30 1 Mal 1 Software Gmbh Method for transmitting a data stream from one producer to a plurality of viewers
US20090282444A1 (en) * 2001-12-04 2009-11-12 Vixs Systems, Inc. System and method for managing the presentation of video
JP4223403B2 (en) * 2001-12-12 2009-02-12 コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ Method and apparatus for controlling interactive television applications
US8181215B2 (en) 2002-02-12 2012-05-15 Comcast Cable Holdings, Llc System and method for providing video program information or video program content to a user
BR0201115A (en) * 2002-04-02 2005-02-22 Coppe Ufrj Collapsed distributed cooperative memory for scalable interactive media-on-demand systems
US7725919B1 (en) * 2002-05-23 2010-05-25 Microsoft Corporation Manage content in a short-term content buffer with content identifiers
GB0214444D0 (en) 2002-06-21 2002-07-31 Thirdspace Living Ltd User interface system
US7739715B2 (en) * 2003-06-24 2010-06-15 Microsoft Corporation Variable play speed control for media streams
US7444419B2 (en) * 2003-10-10 2008-10-28 Microsoft Corporation Media stream scheduling for hiccup-free fast-channel-change in the presence of network chokepoints
US7011529B2 (en) * 2004-03-01 2006-03-14 Anritsu Company Hermetic glass bead assembly having high frequency compensation
US7530089B1 (en) * 2004-03-29 2009-05-05 Nortel Networks Limited System and method for improving video quality using a constant bit rate data stream
JP2006126894A (en) * 2004-10-26 2006-05-18 Sony Corp Content distribution method, program, and information processing apparatus
US7477653B2 (en) 2004-12-10 2009-01-13 Microsoft Corporation Accelerated channel change in rate-limited environments
US20060143612A1 (en) * 2004-12-28 2006-06-29 International Business Machines Corporation Deskside device-based suspend/resume process
US7954128B2 (en) * 2005-02-11 2011-05-31 Time Warner Cable Inc. Methods and apparatus for variable delay compensation in networks
US7788393B2 (en) * 2005-02-23 2010-08-31 Cisco Technology, Inc. Switching a client from unicasting to multicasting by increasing the unicast stream rate to the client
US8140699B2 (en) * 2005-02-23 2012-03-20 Cisco Technology, Inc. Switching a client from unicasting to multicasting by simultaneously providing unicast and multicast streams to the client
US8640166B1 (en) 2005-05-06 2014-01-28 Rovi Guides, Inc. Systems and methods for content surfing
US8095951B1 (en) 2005-05-06 2012-01-10 Rovi Guides, Inc. Systems and methods for providing a scan
WO2007015047A2 (en) * 2005-08-04 2007-02-08 Nds Limited Advanced digital tv system
JP2007122502A (en) * 2005-10-28 2007-05-17 Fujitsu Ltd Frame buffer management program, program storage medium, and management method
US20070157267A1 (en) * 2005-12-30 2007-07-05 Intel Corporation Techniques to improve time seek operations
US8713195B2 (en) 2006-02-10 2014-04-29 Cisco Technology, Inc. Method and system for streaming digital video content to a client in a digital video network
US20080022330A1 (en) * 2006-06-30 2008-01-24 Microsoft Corporation Multi-DVR Content Management
US20080022331A1 (en) * 2006-06-30 2008-01-24 Microsoft Corporation Multi-DVR Media Stream Transition
WO2008016617A2 (en) * 2006-07-31 2008-02-07 United Video Properties, Inc. Systems and methods for providing enhanced sports watching media guidance
US8219134B2 (en) 2006-12-13 2012-07-10 Quickplay Media Inc. Seamlessly switching among unicast, multicast, and broadcast mobile media content
US9571902B2 (en) 2006-12-13 2017-02-14 Quickplay Media Inc. Time synchronizing of distinct video and data feeds that are delivered in a single mobile IP data network compatible stream
US8892761B1 (en) 2008-04-04 2014-11-18 Quickplay Media Inc. Progressive download playback
JP5147278B2 (en) * 2007-04-09 2013-02-20 株式会社日立製作所 Video distribution apparatus and key frame distribution method
US8407737B1 (en) 2007-07-11 2013-03-26 Rovi Guides, Inc. Systems and methods for providing a scan transport bar
JP5211569B2 (en) 2007-07-26 2013-06-12 ソニー株式会社 Content reproduction apparatus, content reproduction method, and program
US20090199250A1 (en) * 2007-08-08 2009-08-06 Harmonic Inc. Methods and System for Data Transfer Over Hybrid Fiber Cable Infrastructure
JP5282383B2 (en) * 2007-09-06 2013-09-04 ソニー株式会社 Content reproduction apparatus, content reproduction method, program, and content reproduction system
US7895629B1 (en) 2007-11-07 2011-02-22 At&T Mobility Ii Llc Video service buffer management in a mobile rate control enabled network
WO2009088481A1 (en) * 2008-01-04 2009-07-16 United Video Properties, Inc. Systems and methods for selecting media assets for display in a screen of an interactive media guidance application
US8612620B2 (en) * 2008-04-11 2013-12-17 Mobitv, Inc. Client capability adjustment
US7996875B2 (en) 2008-05-20 2011-08-09 Microsoft Corporation Adaptive timeshift service
US8601526B2 (en) 2008-06-13 2013-12-03 United Video Properties, Inc. Systems and methods for displaying media content and media guidance information
US20100306708A1 (en) * 2009-05-29 2010-12-02 Rovi Techonologies Corporation Systems and methods for handling profiles in a community
US20110016492A1 (en) * 2009-07-16 2011-01-20 Gemstar Development Corporation Systems and methods for forwarding media asset events
FR2948790A1 (en) * 2009-07-29 2011-02-04 Sagem Comm Method for downloading and reading content on e.g. multimedia device, involves downloading content from content server onto buffer memory, and managing downloading and reading of content on buffer memory in circular manner by reader
US20110070819A1 (en) * 2009-09-23 2011-03-24 Rovi Technologies Corporation Systems and methods for providing reminders associated with detected users
US9014546B2 (en) 2009-09-23 2015-04-21 Rovi Guides, Inc. Systems and methods for automatically detecting users within detection regions of media devices
US20110078731A1 (en) * 2009-09-25 2011-03-31 Rovi Technologies Corporation Systems and methods for multiple media guidance application navigation
US8539535B2 (en) * 2009-11-30 2013-09-17 Time Warner Cable Enterprises Llc Methods and apparatus for supporting VOD requests in a system with hierarchical content stores
US9201627B2 (en) * 2010-01-05 2015-12-01 Rovi Guides, Inc. Systems and methods for transferring content between user equipment and a wireless communications device
US9167196B2 (en) 2010-05-19 2015-10-20 Rovi Guides, Inc. Systems and methods for trimming recorded content using a media guidance application
EP2628305B1 (en) * 2010-10-15 2015-03-18 Cinemo GmbH Distributed playback architecture for media data using beacon packets for synchronisation
US9854318B2 (en) 2011-06-06 2017-12-26 Rovi Guides, Inc. Systems and methods for sharing interactive media guidance information
US8577988B2 (en) * 2011-08-24 2013-11-05 Lg Electronics Inc. Content device and control method thereof
US9218122B2 (en) 2011-12-29 2015-12-22 Rovi Guides, Inc. Systems and methods for transferring settings across devices based on user gestures
US20140129680A1 (en) * 2012-11-08 2014-05-08 BitGravity, Inc. Socket communication apparatus and method
US9538232B2 (en) * 2013-03-14 2017-01-03 Verizon Patent And Licensing Inc. Chapterized streaming of video content
GB2516316A (en) * 2013-07-19 2015-01-21 Sony Corp Video network
US9148702B1 (en) * 2013-09-19 2015-09-29 Google Inc. Extending playing time of a video playing session by adding an increment of time to the video playing session after initiation of the video playing session
US9674563B2 (en) 2013-11-04 2017-06-06 Rovi Guides, Inc. Systems and methods for recommending content
US9197717B2 (en) * 2013-11-27 2015-11-24 At&T Intellectual Property I, Lp Server-side scheduling for media transmissions according to client device states
US9432478B2 (en) * 2013-11-27 2016-08-30 At&T Intellectual Property I, L.P. Client-side location aware network selection
CN103702139B (en) * 2013-12-13 2017-02-01 华中科技大学 Video-on-demand system based on scalable coding under mobile environment
CN103731684B (en) * 2014-01-26 2017-06-16 飞狐信息技术（天津）有限公司 A kind of point is multicast to live video switching method, equipment and system
CN104410917A (en) * 2014-09-16 2015-03-11 东方有线网络有限公司 Realization method for cable interactive television cross-domain video service connection system
WO2017144506A1 (en) * 2016-02-25 2017-08-31 Telefonaktiebolaget Lm Ericsson (Publ) Predicting multimedia session mos
US10701447B2 (en) * 2016-11-18 2020-06-30 Rovi Guides, Inc. Systems and methods for slowing down fast-access playback operations
US10965986B2 (en) 2019-05-20 2021-03-30 Rovi Guides, Inc. Systems and methods for switching content providers to maintain streaming experience
US11706469B2 (en) * 2021-09-30 2023-07-18 Rovi Guides, Inc. Systems and methods for streaming media content during unavailability of content server

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5357276A (en) * 1992-12-01 1994-10-18 Scientific-Atlanta, Inc. Method of providing video on demand with VCR like functions
CA2127347A1 (en) * 1993-07-07 1995-01-08 Donald F. Hooper Segmented video on-demand system
US5610841A (en) * 1993-09-30 1997-03-11 Matsushita Electric Industrial Co., Ltd. Video server
US5629732A (en) * 1994-03-29 1997-05-13 The Trustees Of Columbia University In The City Of New York Viewer controllable on-demand multimedia service
US6181867B1 (en) * 1995-06-07 2001-01-30 Intervu, Inc. Video storage and retrieval system
US6049823A (en) * 1995-10-04 2000-04-11 Hwang; Ivan Chung-Shung Multi server, interactive, video-on-demand television system utilizing a direct-access-on-demand workgroup
US5631694A (en) * 1996-02-01 1997-05-20 Ibm Corporation Maximum factor selection policy for batching VOD requests
US5920700A (en) * 1996-09-06 1999-07-06 Time Warner Cable System for managing the addition/deletion of media assets within a network based on usage and media asset metadata
US6543053B1 (en) * 1996-11-27 2003-04-01 University Of Hong Kong Interactive video-on-demand system
JPH10285510A (en) * 1997-04-04 1998-10-23 Sony Corp Video transmission method
EP0993163A1 (en) * 1998-10-05 2000-04-12 Backweb Technologies Ltd. Distributed client-based data caching system and method

Also Published As

Publication number Publication date
US7913282B2 (en) 2011-03-22
US20030093803A1 (en) 2003-05-15
WO2001074076A1 (en) 2001-10-04
BR0001810A (en) 2001-11-13
BRPI0001810B1 (en) 2015-06-23

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