WO2012024921A1 - Procédé et dispositif de désembrouillage de blocs de données multimédias - Google Patents

Procédé et dispositif de désembrouillage de blocs de données multimédias Download PDF

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Publication number
WO2012024921A1
WO2012024921A1 PCT/CN2011/072116 CN2011072116W WO2012024921A1 WO 2012024921 A1 WO2012024921 A1 WO 2012024921A1 CN 2011072116 W CN2011072116 W CN 2011072116W WO 2012024921 A1 WO2012024921 A1 WO 2012024921A1
Authority
WO
WIPO (PCT)
Prior art keywords
media data
data block
control word
descrambling
module
Prior art date
Application number
PCT/CN2011/072116
Other languages
English (en)
Chinese (zh)
Inventor
郭世亮
肖龙安
Original Assignee
中兴通讯股份有限公司
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 中兴通讯股份有限公司 filed Critical 中兴通讯股份有限公司
Publication of WO2012024921A1 publication Critical patent/WO2012024921A1/fr

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Classifications

    • 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
    • H04N21/234—Processing of video elementary streams, e.g. splicing of video streams or manipulating encoded video stream scene graphs
    • H04N21/2347—Processing of video elementary streams, e.g. splicing of video streams or manipulating encoded video stream scene graphs involving video stream encryption
    • 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
    • H04N21/4405—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 stream decryption

Definitions

  • the present invention relates to the field of communications, and in particular to a method and apparatus for media data block solution.
  • digital mobile multimedia broadcasting technologies especially mobile TV technologies
  • Various television standards provide mobile multimedia broadcast terminal users with rich and colorful content, such as news, sports programs, variety shows, TV dramas, and movies. You can choose the service program of mobile multimedia broadcasting in your own hobby.
  • Content operators often provide paid multimedia broadcast services in order to sustain the benefits of broadcast operations. This requires adding 4 special programs to the program stream. Only users who have been authorized to watch the program can watch the program. After the user is authorized, the program stream is received, and then the program stream is descrambled before being played.
  • a terminal supporting a mobile multimedia broadcast function includes at least a media broadcast module and a player module.
  • the media broadcast module is composed of a receiving and demodulating chip, a demultiplexing module, a descrambling module, and a Conditional Access System (CAS).
  • the player module generally refers to a player on a terminal such as a personal computer, a personal digital assistant (PDA), and a mobile phone.
  • the receiving and demodulating chip is responsible for receiving and demodulating the digital broadcast signal, and after obtaining the data frame, the demultiplexing module demultiplexes the media data block and the 4 authorized control information (Entitlement Control Message, referred to as ECM), then send the ECM to the CAS module, and send the scrambled media data block to the solution 4 module;
  • ECM Entitlement Control Message
  • ⁇ ⁇ Entitlement Management Message can be transmitted in the broadcast channel or through interaction Channel transmission (shown in Figure 1 is transmitted through the interactive channel) to the CAS, the CAS module calculates the control word (Control Word, referred to as CW) according to the EMM/ECM, and solves the media data block of the 4th module after obtaining the CW.
  • De-scrambling is performed, and the stream is cleared and transmitted to the player module, and the player module decodes and plays the clear stream.
  • Both the media data block and the ECM are delivered via the broadcast channel.
  • the key stream generally carries two keys at a time, that is, one ECM packet contains two CWs, one for solving the media data block of the current moment, and one for solving the solution.
  • the general policy of the terminal is: Save two keys at the same time, and update the local key in time as the key of the code stream is updated. After the descrambling module of the terminal obtains the CW, it first needs to synchronize the media data block and the CW to correctly solve the 4th.
  • FIG. 2 is a schematic diagram of synchronization of a key stream and a media stream according to the related art.
  • a key stream is represented by a Key stream
  • a media stream is represented by an A/V stream. Since the key synchronization mechanism of the terminal is synchronized with the code stream at any time, the Key stream is actually the key stream held by the terminal.
  • Kl and ⁇ 2 in the key stream respectively represent the first control word and the second control word, and are placed in a box to indicate that one ECM packet contains two CWs.
  • K1 in the media stream indicates that the media block must be descrambled with the first control word, and descrambling with other control words will fail.
  • FIG. 3 is a schematic diagram of a key stream in advance according to a related art, in which a media block is urgent represented by a shadow, and the remaining parameters are defined in the same manner as in FIG. 2. As shown in FIG. 3, in the case where the key stream is advanced compared to the media stream, if the media data block is descrambled, the appropriate CW will not be found, that is, the key is out of synchronization.
  • the main object of the present invention is to provide a media data block solution.
  • methods and devices are used to solve the above problems.
  • a media data block descrambling method is provided.
  • the media data block descrambling method includes: the descrambling module receives the control word from the conditional receiving system; the descrambling module saves the control word; the descrambling module receives the media data block from the demultiplexing module; the descrambling module The media data block is descrambled using the saved control word.
  • the descrambling module saves the control word including: The descrambling module saves the control word to the control word database in the descrambling module.
  • the descrambling module uses the saved control word to descramble the media data block.
  • the descrambling module searches the control word database for the presence of a control word corresponding to the media data block. If the search result is yes, the used control word is used.
  • the method further includes: the demultiplexing module receiving the data frame from the receiving and demodulating chip; and the demultiplexing module demultiplexing the data frame to obtain the authorization control information
  • the demultiplexing module transmits the authorization control information to the conditional receiving system; the conditional receiving system receives the authorization management information; and the conditional receiving system uses the authorization control information and the authorization management information to calculate the control word.
  • the method further includes: the demultiplexing module receives the data frame from the receiving and demodulating chip; and the demultiplexing module demultiplexes the data frame to obtain the media data.
  • the method further includes: the descrambling module sends the descrambled media data block to the player module; and the player module pairs the descrambled media data
  • the block is decoded and played.
  • a media data block descrambling apparatus includes: a first receiving unit configured to receive a control word from a conditional receiving system; a saving unit configured to save a control word; and a second receiving unit configured to receive from the demultiplexing module Media data block; descrambling unit, set to use the saved control word to descramble the media data block.
  • the media data block solution 4 device further includes a control word database, and the saving unit comprises: a saving subunit, configured to save the control word to the control word database.
  • the descrambling unit includes: a lookup subunit, configured to search in the control word database for whether there is a control word corresponding to the media data block; and a descrambling subunit, configured to use the searched control word when the search result is yes, Deblock the media data block.
  • the media data block descrambling device further includes: a sending unit, configured to send the descrambled media data block to the player module, so that the player module decodes and plays the descrambled media data block.
  • FIG. 1 is a schematic diagram of a mobile multimedia broadcast scheme (terminal) according to the related art
  • FIG. 2 is a schematic diagram of key stream synchronization with a media stream according to the related art
  • FIG. 3 is a key stream phase according to the related art.
  • FIG. 4 is a schematic diagram of a mobile multimedia broadcast scheme (terminal) according to an embodiment of the present invention
  • FIG. 5 is a flowchart of a media data block descrambling method according to an embodiment of the present invention
  • FIG. 7 is a flowchart of a key synchronization method according to a preferred embodiment of the present invention
  • FIG. 8 is a flowchart of a key synchronization method according to a preferred embodiment of the present invention
  • FIG. 4 is a schematic diagram of a mobile multimedia broadcast solution (terminal) according to an embodiment of the present invention. As shown in FIG. 4, it includes two parts: a media broadcast module and a player module.
  • the number of media broadcast modules The word broadcast signal receiving and demodulating chip, the demultiplexing sub-module, the descrambling sub-module, and the CAS sub-module are composed.
  • the improvement of the scheme is that a control word database for locally storing control words is added to the descrambling sub-module.
  • the present invention provides a media data block descrambling method, which can be implemented based on the mobile multimedia broadcast scheme (terminal) shown in FIG.
  • FIG. 5 is a flowchart of a method for descrambling a media block according to an embodiment of the present invention, including steps S502 to S508. Step S502, the descrambling module receives the control word from the conditional access system.
  • step S504 the solution 4 saves the control word.
  • step S506 the descrambling module receives the media data block from the demultiplexing module.
  • Step S508, the descrambling module uses the saved control word to descramble the media data block.
  • the key out of synchronization will cause the descrambling of the media data block to fail.
  • the control word used for decoding the media data block is saved, so that the media data block can be correctly decoded, thereby ensuring the play of the program stream.
  • 6 is a schematic diagram of a key stream not causing a key out of synchronization in advance of a media stream according to an embodiment of the present invention. As can be seen from comparison with FIG.
  • the descrambling module saves the control word comprising: the descrambling module saves the control word to a control word database in the descrambling module.
  • a control word database for locally storing the control word is added, and the control word for decoding the media data block is saved in the control word database, which can further ensure that the media data block is correctly decoded. , in order to ensure the playback of the program stream.
  • the control word database is used to save the control word, and the implementation is simple and reliable.
  • the solution 4 uses a saved control word
  • the solution 4 of the media data block includes: the descrambling module searches the control word database for whether there is a control word corresponding to the media data block; if the search result is yes, The media data block is descrambled using the lookup control word.
  • the preferred embodiment describes a process for solving a block of media data using control words stored in a control word database. By finding the control word corresponding to the media data block, it is ensured that the media data block is correctly decoded, thereby ensuring the playback of the program stream.
  • the demultiplexing module receives the data frame from the receiving and demodulating chip; the demultiplexing module demultiplexes the data frame to obtain the authorization control information; The module transmits the authorization control information to the conditional receiving system; the conditional receiving system receives the authorization management information; and the conditional receiving system uses the authorization control information and the authorization management information to calculate the control word.
  • the preferred embodiment describes a process for understanding a multiplexing module to calculate a control word, which is similar to the prior art, and can be used in various multimedia encryption protocols, various player applications without modification, and has good scalability. , debuggability and wide adaptability.
  • the demultiplexing module receives the data frame from the receiving and demodulating chip; the demultiplexing module demultiplexes the data frame to obtain the media data block.
  • the preferred embodiment describes a process for the multiplexing module to demultiplex a data frame to obtain a media data block.
  • the implementation manner is similar to that in the prior art, and can be used in various multimedia encryption protocols and various player applications without modification. It has good scalability, debugability and wide adaptability.
  • the descrambling module sends the descrambled media data block to the player module; and the player module performs the descrambled media data block.
  • Decode and play The preferred embodiment describes a process in which the player module decodes and plays the descrambled media data block, and the implementation manner is similar to that in the prior art, and can be used in various multimedia encryption protocols and various players without modification. In the application, it has good scalability, debugability and wide adaptability. The implementation process of the embodiment of the present invention will be described in detail below with reference to examples. FIG.
  • Step S702 receiving and demodulating the chip to receive the signal to obtain a data frame, and sending the data frame to the demultiplexing module.
  • Step S704 the demultiplexing module solves the ECM and sends the ECM to the CAS, and the decoded media data block is sent to the descrambling module.
  • Step S706 the CAS calculates the CW according to the EMM of the outband transmission and the ECM that has been received, and then transmits the CW to the descrambling module.
  • Step S708 the descrambling module first saves the CW to the CW DB, and then according to the media data block.
  • Step S710 the player module decodes and plays the clear stream.
  • the steps shown in the flowchart of the accompanying drawings may be performed in a computer system such as a set of computer executable instructions, and, although the logical order is shown in the flowchart, in some cases, The steps shown or described may be performed in an order different than that herein.
  • the embodiment of the present invention provides a media data block descrambling device, and the media data block descrambling device can be used to implement the foregoing media data block descrambling method.
  • FIG. 8 is a structural block diagram of a media block descrambling apparatus according to an embodiment of the present invention, including a first receiving unit 82, a saving unit 84, a second receiving unit 86, and a solution unit 88.
  • the structure is described in detail below.
  • a first receiving unit 82 configured to receive a control word from the conditional receiving system;
  • the control word used for decoding the media data block is saved, so that the media data block can be correctly decoded, thereby ensuring the play of the program stream.
  • the media data block solution device further includes a control word database
  • the saving unit 84 includes a saving subunit 842 connected to the first receiving unit 82, and configured to save the control word received by the first receiving unit 82 to the control word database.
  • a control word database for locally storing the control word is added, and the control word for decoding the media data block is saved in the control word database, which may be further Ensure that the media data block is correctly decoded to ensure the playback of the program stream.
  • the control word database is used to save the control word, and the implementation is simple and reliable.
  • the solution unit 88 includes: a lookup subunit 882 and a solution 4 subunit 884, the structure of which is described in detail below.
  • the lookup subunit 882 is connected to the saving unit 84 and the second receiving unit 86, and is arranged to look up in the control word database held by the saving subunit 842 included in the saving unit 84 whether there is a corresponding corresponding to the media data block received by the second receiving unit 86.
  • the control word; the solution 4 sub-unit 884, connected to the lookup sub-unit 882, is set to descramble the media data block using the searched control word if the lookup sub-unit 882 looks for a yes result.
  • the preferred embodiment describes a process for solving a block of media data using control words stored in a control word database. By finding the control word corresponding to the media data block, it is ensured that the media data block is correctly decoded, thereby ensuring the playback of the program stream.
  • the media data block solution 4 device further includes a sending unit 89 connected to the solution 4 unit 88, and configured to send the media data block descrambled by the descrambling unit 88 to the player module, so that the player module pairs the solution 4
  • the media data block of the unit 88 is decoded and played.
  • the preferred embodiment describes a process in which the player module decodes and plays the descrambled media data block, and the implementation manner is similar to that in the prior art, and can be used in various multimedia encryption protocols and various players without modification. In the application, it has good scalability, debugability and wide adaptability.
  • the media data block descrambling device described in the device embodiment corresponds to the foregoing method embodiment, and the specific implementation process has been described in detail in the method embodiment, and details are not described herein again.
  • the descrambling module saves the control word, and uses the saved control word to descramble the media data block, thereby solving the problem that the descrambling failure is caused by the key out of synchronization in the related art, thereby ensuring the playback of the program stream. It should be noted that the above methods are applicable to various terminal players and various descrambling algorithms.
  • ISMACryp Internet Streaming Media Alliance Encryption and Authentication
  • SRTP Secure Real-time Transport Protocol
  • IPsec IP Security

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  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Two-Way Televisions, Distribution Of Moving Picture Or The Like (AREA)

Abstract

L'invention porte sur un procédé et un dispositif de désembrouillage de blocs de données multimédias, le procédé comprenant les étapes suivantes : des mots de commande provenant d'un système d'accès conditionnel sont reçus par un module de désembrouillage ; les mots de commande sont sauvegardés par le module de désembrouillage ; des blocs de données multimédias provenant d'un module de démultiplexage sont reçus par le module de désembrouillage ; et les blocs de données multimédias sont désembrouillés par le module de désembrouillage à l'aide des mots de commande sauvegardés. La lecture d'un flux de programme est assurée par la présente invention.
PCT/CN2011/072116 2010-08-23 2011-03-24 Procédé et dispositif de désembrouillage de blocs de données multimédias WO2012024921A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN2010102670921A CN101917589A (zh) 2010-08-23 2010-08-23 媒体数据块解扰方法及装置
CN201010267092.1 2010-08-23

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101917589A (zh) * 2010-08-23 2010-12-15 中兴通讯股份有限公司 媒体数据块解扰方法及装置
CN102164320B (zh) 2011-04-11 2016-06-22 北京数字太和科技有限责任公司 一种改进的基于条件接收技术的终端

Citations (6)

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US20020080971A1 (en) * 2000-12-15 2002-06-27 Yukiyasu Fukami Broardcast apparatus and reception apparatus for providing a storage service by which scrambled content is stored and descrambled using scrambling key list
CN1585478A (zh) * 2003-08-20 2005-02-23 王耀 一种无需寻址授权的条件接收组合控制方法
CN1868206A (zh) * 2003-08-13 2006-11-22 汤姆森许可公司 为了减少频道改变时间而对解扰数据进行预处理
CN1960552A (zh) * 2006-09-20 2007-05-09 中兴通讯股份有限公司 一种机卡分离的移动多媒体业务接收终端
CN101272474A (zh) * 2007-03-23 2008-09-24 北京东方广视科技有限责任公司 快速切换频道的方法
CN101917589A (zh) * 2010-08-23 2010-12-15 中兴通讯股份有限公司 媒体数据块解扰方法及装置

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020080971A1 (en) * 2000-12-15 2002-06-27 Yukiyasu Fukami Broardcast apparatus and reception apparatus for providing a storage service by which scrambled content is stored and descrambled using scrambling key list
CN1868206A (zh) * 2003-08-13 2006-11-22 汤姆森许可公司 为了减少频道改变时间而对解扰数据进行预处理
CN1585478A (zh) * 2003-08-20 2005-02-23 王耀 一种无需寻址授权的条件接收组合控制方法
CN1960552A (zh) * 2006-09-20 2007-05-09 中兴通讯股份有限公司 一种机卡分离的移动多媒体业务接收终端
CN101272474A (zh) * 2007-03-23 2008-09-24 北京东方广视科技有限责任公司 快速切换频道的方法
CN101917589A (zh) * 2010-08-23 2010-12-15 中兴通讯股份有限公司 媒体数据块解扰方法及装置

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