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Apparatus and method for segmentation and time synchronization of the transmission of a multiple program multimedia data 원문보기

IPC분류정보
국가/구분 United States(US) Patent 등록
국제특허분류(IPC7판)
  • H04N-007/62
출원번호 US-0687268 (1996-07-25)
발명자 / 주소
  • Davenport David William (Raleigh NC) Delp Gary Scott (Rochester MN) Lynch Jeffrey James (Apex NC) Plotz Kevin G. (Byron MN) Leichty Philip Lynn (Rochester MN)
출원인 / 주소
  • International Business Machines Corporation (Armonk NY 02)
인용정보 피인용 횟수 : 182  인용 특허 : 6

초록

Method and apparatus are provided for segmenting a multiple program multimedia digital data stream for transmission over a distribution communications network. Each program multimedia digital data stream includes sequential transport system (TS) packets with program clock references (PCRs) at a set

대표청구항

A system for communicating a stream of multiple program multimedia digital data comprising: a distribution communications network; multimedia server means for receiving and segmenting the multiple program multimedia digital data stream and transmitting said segmented multiple program multimedia digi

이 특허에 인용된 특허 (6)

  1. Deiss Michael S. (Zionsville IN), Clock recovery apparatus as for a compressed video signal.
  2. Wendorf James W. (Cortlandt Manor NY), Identification of a data stream transmitted as a sequence of packets.
  3. Auerbach Richard A. (Somers NY) Blades Jerry A. (Rochester MN) Byrn Jonathan W. (Rochester MN) Delp Gary S. (Rochester MN), Method and apparatus for batching the receipt of data packets.
  4. Radice Anthony M. (Riverside NJ), Method and apparatus for communicating a plurality of asynchronous signals over a digital communication path.
  5. Holden Brian D. (Half Moon Bay CA) Presuhn Randall M. (Campbell CA) Robertson William L. (San Jose CA), Microprocessor based packet isochronous clocking transmission system and method.
  6. Haskell Barin G. (Tinton Falls NJ) Reibman Amy R. (East Windsor NJ), Timing recovery for variable bit-rate video on asynchronous transfer mode (ATM) networks.

이 특허를 인용한 특허 (182)

  1. Bunri Osaki JP, AAL5 jitter reduction method and apparatus.
  2. Fukui, Takayuki; Nakatsuka, Monta, AV server.
  3. Laksono, Indra, Adaptive bandwidth footprint matching for multiple compressed video streams in a fixed bandwidth network.
  4. Delp, Gary Scott; Slane, Albert Alfonse, Apparatus and method for reassembling frame data into stream data.
  5. Won-Ho Kim KR; Jae-Young Ahn KR; Yong-Hoon Cho KR; Seong-Pal Lee KR, Apparatus and method of network synchronization in asymmetric two-way satellite communication system.
  6. Min,Kyung pa, Apparatus and methods for storing and comparing PIDs.
  7. Ramos, Aurelio Rafael, Audio output balancing.
  8. Ramos, Aurelio Rafael; Sheen, Timothy W., Audio output balancing.
  9. Crinon,Regis J., Buffer system for controlled and timely delivery of MPEG-2 data services.
  10. Crinon, Regis J., Buffer system for controlled and timely delivery of MPEG-2F data services.
  11. Blatter Harold ; Beyers ; Jr. William Wesley ; Deiss Michael Scott, Bus and interface system for consumer digital equipment.
  12. McBride,Chad B.; Byrn,Jonathan W.; Broberg, III,Robert N.; McClannahan,Gary P., Cache line cut through of limited life data in a data processing system.
  13. Millington, Nicholas A. J., Causing a device to join a synchrony group.
  14. Millington, Nicholas A. J, Ceasing playback among a plurality of playback devices.
  15. Gary Scott Delp ; Philip Lynn Leichty ; Kevin Gerard Plotz, Cell/frame scheduling method and communications cell/frame scheduler.
  16. Millington, Nicholas A. J., Clock rate adjustment in a multi-zone system.
  17. Oz,Ran M.; Strassman,Nery; Basan eskenazi,Amir; Yruski,Andrey; Golan,Oded, Communication management system and method.
  18. Ikeda, Koji; Kurobe, Akio; Kuroda, Gou; Yoshizawa, Kensuke, Communication terminal device, method, program, recording medium, and integrated circuit for use in communication network system.
  19. Ikeda,Koji; Kurobe,Akio; Kuroda,Gou; Yoshizawa,Kensuke, Communication terminal device, method, program, recording medium, and integrated circuit for use in communication network system.
  20. Branstad, Mark William; Byrn, Jonathan William; Delp, Gary Scott; Leichty, Philip Lynn; Leonard, Todd Edwin; McClannahan, Gary Paul; Nordman, John Emery; Plotz, Kevin Gerard; Shaffer, John Handley; S, Communications adapter for implementing communications in a network and providing multiple modes of communications.
  21. Mark William Branstad ; Jonathan William Byrn ; Gary Scott Delp ; Philip Lynn Leichty ; Todd Edwin Leonard ; Gary Paul McClannahan ; John Emery Nordman ; Kevin Gerard Plotz ; John Handley Sha, Communications methods and gigabit ethernet communications adapter providing quality of service and receiver connection speed differentiation.
  22. Slik, David, Content distribution system for generating content streams to suit different users and facilitating E-commerce transactions using broadcast content metadata.
  23. Kondo, Satoshi; Maeda, Akiyoshi; Uenaka, Hiroyuki; Kitaura, Hiromu; Takeda, Hidetoshi; Mitui, Yoshitaka, Data transmitting device, data receiving device, and data recording device.
  24. Temple, Daniel Alexander; Waller, Arthur Simon; Hurley, Terrence Ralph, Demultiplexer.
  25. Laksono, Indra, Device and method for compression of a video stream.
  26. Millington, Nicholas A. J., Disengaging and engaging zone players.
  27. Nguyen, Julien Tan, Dynamic preloading of web pages.
  28. Nguyen, Julien Tan, Dynamic preloading of web pages.
  29. Richard E. Anderson ; Eric M. Foster ; Mark R. Hodges, Embedded clock recovery and difference filtering for an MPEG-2 compliant transport stream.
  30. Schmieder, Wilhelm R.; Ben-Shachar, Ido; Chik, Joy; Parsons, John E., Encoding for remoting graphics to decoder device.
  31. Millington, Nicholas A. J.; Hainsworth, Paul V., Establishing a secure wireless network with a minimum human intervention.
  32. Millington, Nicholas A. J.; Hainsworth, Paul V., Establishing a secure wireless network with minimum human intervention.
  33. Pereira, Michael; Wu, Fang, Fault tolerance and synchronous failover for broadcast video across the network.
  34. Hahn-Carlson, Dean W., Financial institution-based transaction processing system and approach.
  35. Hahn-Carlson, Dean W., Financial institution-based transaction processing system and approach.
  36. Fichou Aline,FRX ; Foriel Pierre-Andre,FRX ; Kermarec Francois,FRX ; Nicolas Laurent,FRX, Flow control for very bursty connections in high speed cell switching networks.
  37. Deshpande, Sachin Govind, Hypothetical reference decoder.
  38. Deshpande, Sachin Govind, Hypothetical reference decoder.
  39. Deshpande,Sachin Govind, Hypothetical reference decoder.
  40. Kallai, Christopher; Ericson, Michael Darrell Andrew; Lambourne, Robert A., Identification of playback device and stereo pair names.
  41. Millington, Nicholas A. J.; Hainsworth, Paul V., Indicator on a network device.
  42. Kallai, Christopher; Chamness, Mike; Ericson, Michael Darrell Andrew, Intelligently increasing the sound level of player.
  43. Kallai, Christopher; Chamness, Mike; Ericson, Michael Darrell Andrew, Intelligently modifying the gain parameter of a playback device.
  44. Hwang, Sung-Oh; Keum, Ji-Eun; Rhyu, Sung-Ryeul; Song, Jae-Yeon; Park, Kyung-Mo, Interface apparatus and method for transmitting and receiving media data.
  45. Hahn-Carlson, Dean W., Inventory-based payment processing system and approach.
  46. Taylor,James L., Maintaining a global time reference among a group of networked devices.
  47. Kallai, Christopher; Ericson, Michael Darrell Andrew; Lambourne, Robert A., Making and indicating a stereo pair.
  48. Laksono, Indra, Managed degradation of a video stream.
  49. Bates, Paul; Keyser-Allen, Lee; Roberts, Diane; Lang, Jonathan P., Media playback system with guest access.
  50. Millington, Nicholas A. J., Method and apparatus for adjusting volume in a synchrony group.
  51. Stahl, Thomas Anthony; Richardson, John William, Method and apparatus for changing received streaming content channels.
  52. Mandal Kallol ; Kleiman Steven, Method and apparatus for delivering simultaneous constant bit rate compressed video streams at arbitrary bit rates with.
  53. Rodgers, Stephane W.; Nguyen, Ut, Method and apparatus for demultiplexing, merging, and duplicating packetized elementary stream/program stream/elementary stream data.
  54. Aaker Kenneth Dale ; Delp Gary Scott ; Poulter David Richard ; Slane Albert Alfonse, Method and apparatus for detecting and controlling data stream splicing in ATM networks.
  55. Raisanen, Vilho; Rosti, Jari, Method and apparatus for determining VoIP QoS characteristics of a network using multiple streams of packets and synchronizing measurements of the streams.
  56. Ward, Christopher; Wine, Charles M., Method and apparatus for distributing a globally accurate knowledge of time and frequency to a plurality of a high definition television studios.
  57. Millington, Nicholas A. J., Method and apparatus for dynamic channelization device switching in a synchrony group.
  58. Millington, Nicholas A. J., Method and apparatus for dynamic master device switching in a synchrony group.
  59. Millington, Nicholas A. J., Method and apparatus for playback by a synchrony group.
  60. Aaker Kenneth Dale ; Delp Gary Scott ; Luning Stephen Gouze ; Lynch Jeffrey James, Method and apparatus for queuing and triggering data flow streams for ATM networks.
  61. Bunri Osaki JP, Method and apparatus for reducing jitter of a program clock reference in a transport stream of MPEG over ATM, and MPEG decoder.
  62. Bhatt Bhavesh ; Lowe Raymond, Method and apparatus for splicing compressed information signals.
  63. Millington, Nicholas A. J., Method and apparatus for switching between a directly connected and a networked audio source.
  64. Virdi,Gurpratap; Davis,Jeffrey A., Method and apparatus for synchronizing clocks.
  65. Monta, Peter; Krause, Edward A.; Tom, Adam, Method and apparatus for time-multiplexed processing of multiple digital video programs.
  66. Chan,Jason; Laksono,Indra, Method and system for bit-based data access.
  67. Rault,Patrick, Method and system for encoding and decoding data in a video stream.
  68. Zeng, Steve Zhihua, Method and system for noise reduction in an image.
  69. Ducharme,Paul; Eng,Steven, Method and system for protecting video data.
  70. De Bonet, Jeremy S.; Viola, Paul, Method and system for providing an audio element cache in a customized personal radio broadcast.
  71. Laksono, Indra; Zeng, Zhihua, Method and system for rate control during video transcoding.
  72. Laksono,Indra; Zeng,Zhihua, Method and system for rate control during video transcoding.
  73. Zeng,Steve Zhihua, Method and system for scaling images.
  74. Ducharme,Paul, Method and system for secure content distribution.
  75. Rault, Patrick, Method and system for transcoding video data.
  76. Rault,Patrick, Method and system for transcoding video data.
  77. Rault,Patrick, Method and system for transcoding video data.
  78. Doyle,James, Method and system for transmitting video content while preventing other transmissions in a contention-based network.
  79. Pereira, Michael; Wu, Fang, Method of fault tolerance and synchronous failover for broadcast video across the network.
  80. Morelli, John Vernon, Method of transmitting streams of video data, in multi-length frames, at a single average bit rate.
  81. Rault,Patrick; Zeng,Zhihua, Method of video encoding using windows and system thereof.
  82. Raveendran, Vijayalakshmi R.; Silberger, Amnon; Collins, Bruce; Radhakrishnan, Dhinakar; Walker, Gordon Kent; Nagaraj, Thadi M.; Balraj, Sajith, Methods and apparatus for packetization of content for transmission over a network.
  83. Monteiro, Antonio M.; Butterworth, James F., Methods and systems for playing media.
  84. Monteiro, Antonio M; Butterworth, James F, Methods and systems for playing media.
  85. Handman, Etienne F.; Conrad, Thomas J.; Kennedy, Joseph J.; Westergren, Timothy B., Methods and systems for utilizing contextual feedback to generate and modify playlists.
  86. Nguyen, Julien T., Micro-client for internet appliance.
  87. Nguyen, Julien T, Micro-client for internet appliances.
  88. Ducharme,Paul, Monolithic semiconductor device for preventing external access to an encryption key.
  89. Kallai, Christopher; Ericson, Michael Darrell Andrew; Lambourne, Robert A.; Reimann, Robert; Triplett, Mark, Multi-channel pairing in a media system.
  90. Kallai, Christopher; Ericson, Michael Darrell Andrew; Lambourne, Robert A.; Reimann, Robert; Triplett, Mark, Multi-channel pairing in a media system.
  91. Evron,Roni; Rosner,Benjamin; Buzzerio,Jonas, Multi-media system and method for simultaneously delivering multi-media data to multiple destinations.
  92. Hahn-Carlson, Dean W., Multi-supplier transaction and payment programmed processing approach with at least one supplier.
  93. Satran, Julian; Zeidner, Efraim; Rochwerger, Benny, Multicast data transmission over a one-way broadband channel.
  94. Monteiro,Antonio M; Butterworth,James F, Multicasting method and apparatus.
  95. Monteiro,Antonio M; Butterworth,James F, Multicasting method and apparatus.
  96. Rasmussen Steffen, Multiple video screen display system.
  97. Reid Richard ; Sherer William Paul ; Connery Glenn, Network and adaptor with time-based and packet number based interrupt combinations.
  98. Millington, Nicholas A. J., Obtaining and transmitting audio.
  99. Millington, Nicholas A. J., Obtaining content based on control by multiple controllers.
  100. Millington, Nicholas A. J., Obtaining content based on control by multiple controllers.
  101. Millington, Nicholas A. J., Obtaining content from direct source and other source.
  102. Millington, Nicholas A. J., Obtaining content from direct source and remote source.
  103. Millington, Nicholas A. J., Obtaining content from local and remote sources for playback.
  104. Millington, Nicholas A. J., Obtaining content from local and remote sources for playback.
  105. Millington, Nicholas A. J., Obtaining content from multiple remote sources for playback.
  106. Millington, Nicholas A. J., Obtaining content from multiple remote sources for playback.
  107. Millington, Nicholas A.J., Obtaining content from remote source for playback.
  108. Millington, Nicholas A.J., Obtaining content from remote source for playback.
  109. Hahn-Carlson, Dean W.; Suits, David A.; Kanathur, Raghunandan N., Order-resource fulfillment and management system and approach.
  110. Kallai, Christopher; Ericson, Michael Darrell Andrew; Lambourne, Robert A., Pair volume control.
  111. De Bonet, Jeremy S.; Viola, Paul, Personal broadcast server system for providing a customized broadcast.
  112. De Bonet, Jeremy S.; Viola, Paul A., Personal broadcast server system for providing a customized broadcast.
  113. Millington, Nicholas A. J., Playback device.
  114. Millington, Nicholas A. J., Playback device.
  115. Millington, Nicholas A. J., Playback device.
  116. Millington, Nicholas A. J., Playback device.
  117. Millington, Nicholas A. J.; Hainsworth, Paul V., Playback device connection.
  118. Millington, Nicholas A. J., Playback device operating states.
  119. Kallai, Christopher; Ericson, Michael Darrell Andrew; Lambourne, Robert A.; Reimann, Robert; Triplett, Mark, Playback device pairing.
  120. Millington, Nicholas A. J., Playback device synchrony group states.
  121. Ducharme, Paul, Processing feature revocation and reinvocation.
  122. Chaney John W. ; Beyers ; Jr. Bill W. ; Johnson Michael W. ; Hailey James E. ; Bridgewater Kevin E. ; Deiss Michael S. ; Horton Raymond S., Program guide in a digital video system.
  123. Chaney John William ; Beyers ; Jr. Billy Wesley ; Johnson Michael Wayne ; Hailey James Edwin ; Bridgewater Kevin Elliott ; Deiss Michael Scott ; Horton Raymond Scott, Program guide in a digital video system.
  124. Mendenhall Todd ; Neuman Darren ; Gozu Manabu, Programmable byte wise MPEG systems layer parser.
  125. Yao Hiroshi,JPX ; Kanai Tatsunori,JPX ; Kizu Toshiki,JPX ; Maeda Seiji,JPX, Real time stream server for handling a plurality of real time stream data with different data rates.
  126. Akamatsu, Chiyo; Shinagawa, Tetsuo; Kudo, Yoshimichi, Receiver set, information apparatus and receiving system.
  127. Akamatsu, Chiyo; Shinagawa, Tetsuo; Kudo, Yoshimichi, Receiver set, information apparatus and receiving system.
  128. Akamatsu, Chiyo; Shinagawa, Tetsuo; Kudo, Yoshimichi, Receiver set, information apparatus and receiving system.
  129. Akamatsu,Chiyo; Shinagawa,Tetsuo; Kudo,Yoshimichi, Receiver set, information apparatus and receiving system.
  130. Kitazato, Naohisa, Receiver, reception method, transmitter, transmission method, program and broadcasting system.
  131. Hahn-Carlson, Dean W.; Armstrong, Kevin M., Recurring transaction processing system and approach.
  132. Wang, Ye-Kui; Curcio, Igor; Aksu, Emre; Hannuksela, Miska, Refined quality feedback in streaming services.
  133. Wang, Ye-Kui; Curcio, Igor; Aksu, Emre; Hannuksela, Miska, Refined quality feedback in streaming services.
  134. Wang, Ye-Kui; Curcio, Igor; Aksu, Emre; Hannuksela, Miska, Refined quality feedback in streaming services.
  135. Leichtling, Ivan; Zhong, Chenyin; Chik, Joy; Khouzam, Gilles; David, Paul; Ungureanu, Oreste Dorin, Remote client graphics rendering.
  136. Brugiolo, Ivan, Remoting redirection layer for graphics device interface.
  137. Millington, Nicholas A. J., Resuming synchronous playback of content.
  138. Millington, Nicholas A. J., Resuming synchronous playback of content.
  139. Millington, Nicholas A. J., Resuming synchronous playback of content.
  140. Millington, Nicholas A. J, Resynchronization of playback devices.
  141. Nguyen, Julien T., Secure graphical objects in web documents.
  142. Yao Hiroshi,JPX ; Kanai Tatsunori,JPX, Stream scheduling system for real time stream server.
  143. Millington, Nicholas A. J., Switching between a directly connected and a networked audio source.
  144. Teng Peter Y. ; Thompson Bruce Albert ; Tobagi Fouad A., Synchronization of audio and video signals in a live multicast in a LAN.
  145. Millington, Nicholas A. J.; Ericson, Michael, Synchronizing operations among a plurality of independently clocked digital data processing devices.
  146. Astrachan,Paul M., System and method for adaptive DC offset compensation in wireless transmissions.
  147. Laksono, Indra, System and method for dynamic transrating based on content.
  148. Ryan Robert T., System and method for interfacing a transport decoder to a bitrate-constrained audio recorder.
  149. Ducharme,Paul; Girardeau, Jr.,James; Chiu,Adeline; Doyle,James, System and method for multimedia delivery in a wireless environment.
  150. Laksono, Indra; Chow, Hugh, System and method for multiple channel video transcoding.
  151. Laksono,Indra, System and method for multiple channel video transcoding.
  152. Cross, Joseph K., System and method for probabilistic quality of communication service determination.
  153. Rodgers, Stephane W., System and method for providing data commonality in a programmable transport demultiplexer engine.
  154. Laksono, Indra, System and method for storage device emulation in a multimedia processing system.
  155. Hong,Jiang; Kozintsev,Igor V.; Wirasinghe,Marco Y., System and method for streaming multimedia over packet networks.
  156. May, Michael R.; Cave, Michael D., System for allocating data in a communications system and method thereof.
  157. Settle Timothy Forrest ; Horlander Thomas Edward ; Bridgewater Kevin Elliott ; Lu Ligang, System for digital data format conversion and bit stream generation.
  158. Kelton,James Robert; Cave,Michael David; Girardeau, Jr.,James Ward; May,Michael R.; Astrachan,Paul Morris; Pilla,Anselmo; Doyle,James; Saleem,Shawn; Rybicki,Mathew A., System for providing data to multiple devices and method thereof.
  159. May,Michael R., System for signal mixing and method thereof.
  160. Zeng, Steve Zhihua, System of intra-picture complexity preprocessing.
  161. Goetz Tom ; Sridhar Manickam R. ; Prasad Mukesh, System, device, and method for streaming a multimedia file.
  162. Millington, Nicholas A. J., Systems and methods for synchronizing operations among a plurality of independently clocked digital data processing devices that independently source digital data.
  163. Bates, Paul; Keyser-Allen, Lee; Lang, Jonathan P.; Roberts, Diane; Millington, Nicholas A. J., Systems, methods, apparatus, and articles of manufacture to provide guest access.
  164. Hahn-Carlson, Dean W.; Beck, Elizabeth A.; Suits, David A., Transaction accounting auditing approach and system therefor.
  165. Hahn-Carlson, Dean W., Transaction finance processing system and approach.
  166. Hahn-Carlson, Dean W., Transaction processing with core and distributor processor implementations.
  167. Hahn-Carlson, Dean W., Transaction processing with core and distributor processor implementations.
  168. Yanagihara Naofumi,JPX ; Horiguchi Mari,JPX ; Sato Makoto,JPX ; Hamada Ichiro,JPX ; Nakano Takehiko,JPX, Transmitting apparatus and method, receiving apparatus and method.
  169. Aiello, Roberto; Gehring, Stephan; Lynch, William; Rahardja, Krisnawan K.; Rogerson, Gerald; Sparell, Carlton J., Ultra wide band communication network.
  170. Aiello,Roberto; Sparrell,Carlton; Rogerson,Gerald, Ultra wide band communication systems and methods.
  171. Lambourne, Robert A., Updating zone configuration in a multi-zone media system.
  172. Quigley, Thomas J.; Karaoguz, Jeyhan; Chen, Sherman (Xuemin); Dove, Michael; Rosmann, David; Gordon, Stephen E., Using program clock references to assist in transport of video stream to wireless device.
  173. Hahn-Carlson, Dean W., Validation approach for auditing a vendor-based transaction.
  174. Wolf Christopher K., Video output phase control in a decoder.
  175. Rao, R. Padmanabha; Siccardo, Paolo L.; Levesque, Gilbert, Video pedestal network.
  176. Rao,R. Padmanabha, Video pedestal network.
  177. Harris, Scott C., Videoconferencing systems with recognition ability.
  178. Harris, Scott C., Videoconferencing systems with recognition ability.
  179. Harris, Scott C., Videoconferencing systems with recognition ability.
  180. Harris, Scott C., Videoconferencing systems with recognition ability.
  181. Lambourne, Robert A., Zone configuration based on playback selections.
  182. Lambourne, Robert A., Zone configurations maintained by playback device.
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