JP3998031B2 - Audio visual signal transmitting / receiving apparatus and transmitting / receiving method - Google Patents

Description

The present invention relates to an audiovisual signal transmission / reception apparatus and transmission / reception method for preventing unauthorized duplication of such information in order to protect the copyright of an audiovisual signal recorded on a recording medium, for example.

  Conventionally, for the purpose of protecting the copyright of video signals, for example, it is known to prevent duplication of video signals by adding a macrovision signal or a color stripe copy protection signal to a composite video signal. ing.

  However, even if a copy protect signal is added to a composite video signal, such as a macrovision signal or a color stripe copy protect signal, it cannot be applied to a baseband signal such as an RGB signal.

  Even if a copy protect signal is added, if a device is physically connected, a video signal is output regardless of the type and function of the device to which it is connected.

The present invention has been made in view of such circumstances, without degrading the audiovisual signals, transceiver and an audio visual signal which can prevent the replication of these audiovisual signals illegally An object is to provide a transmission / reception method .

The present invention is an audiovisual signal transmission / reception device that receives an audiovisual signal from a first external device and transmits the received audiovisual signal to a second external device, the audiovisual signal and the audio First receiving means for receiving copyright information indicating whether or not a visual signal can be copied or copyright generation management information for the audio visual signal from the first external device, the audio visual signal, and the copyright First transmission means for transmitting information to the second external device, second transmission means for transmitting authentication information for permission to transmit the audiovisual signal to the first external device, and the second Second receiving means for receiving authentication information of the second external device from the external device; When the audio visual signal and the copyright information are transmitted from the first transmitting means to the second external device, if it is determined that the copyright information can be copied, the transmission is permitted, and the copyright information If it is determined that there is a copy prohibition or a copy generation limitation by the above, if it is determined that transmission is permitted by the authentication information received by the second receiving means, transmission is permitted, and if it is determined that transmission is not possible And control means for controlling the first transmission means so as to prohibit transmission .

The present invention is an audiovisual signal transmission / reception method for receiving an audiovisual signal from a first external device and transmitting the received audiovisual signal to a second external device, wherein the audiovisual signal is transmitted from the second external device. Whether authentication information possessed by the second external device is received, authentication information for determining whether or not the audiovisual signal can be transmitted is transmitted to the first external device, and the audiovisual signal and the audiovisual signal can be duplicated. Or receiving copyright information indicating the copy generation management information for the audiovisual signal from the first external device, and transmitting the audiovisual signal and the copyright information to the second external device, Transmission of the audiovisual signal and copyright information to the second external device Therefore, if it is determined by the copyright information that copying is possible, transmission is permitted. If it is determined by the copyright information that copying is prohibited or copy generation is restricted, it is received from the second external device. If it is determined that transmission is permitted by the authentication information, transmission is permitted. If it is determined that transmission is not possible, transmission is prohibited .

According to the present invention, when receiving the audiovisual signal from the first external device and transmitting the received audiovisual signal to the second external device, the second external device transmits the audio visual signal to the second external device. Authentication information for transmitting or receiving the audio visual signal is transmitted to the first external device, and the audio visual signal and the audio visual signal can be duplicated or the audio visual signal is transmitted. Copyright information indicating copy generation management information for the signal is received from the first external device, the audiovisual signal and the copyright information are transmitted to the second external device, and the second external device is transmitted. When sending the audiovisual signal and copyright information to the If it is determined that transmission is permitted, transmission is permitted. If it is determined that there is a copy prohibition or copy generation restriction based on the copyright information, it is determined that transmission is permitted based on the authentication information received from the second external device. In this case , unauthorized copying can be prevented without degrading the video signal to be transmitted to the second external device by permitting transmission and prohibiting transmission when it is determined that transmission is impossible. .

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a communication system according to a first embodiment between an apparatus 10 and an apparatus 20 in which an audiovisual signal reproduced from the apparatus 10 (hereinafter simply referred to as an AV signal) cannot be illegally copied by the apparatus 20. Explain. The device 10 and the device 20 are connected via the composite cable 1.

  The device 10 is a playback device that plays back an AV signal recorded on a recording medium. The device 10 includes a signal processing unit 11, a communication control unit 12 that communicates with the device 20 connected to the device 10, and a collective output terminal 13 that connects the device 20 and the composite cable 1.

  The signal processing unit 11 includes a reproduction circuit that reproduces the AV signal recorded on the recording medium, and a transmission circuit that transmits the AV signal to the outside. The reproduction circuit of the signal processing unit 11 reproduces the AV signal from a recording medium, for example, an optical disk, a magnetic disk, a magnetic tape, etc., and supplies it to the transmission circuit. The transmission circuit of the signal processing unit 11 transmits this AV signal to the device 20 via the composite cable 1.

  Here, the AV signal transmitted from the device 10 to the device 20 is an analog video signal such as an RGB signal, a Y color difference signal, a composite video signal + audio signal, a Y + C signal, and an audio signal.

  The signal processing unit 11 reproduces copyright information together with the AV signal from the recording medium, and supplies the copyright information to the communication control unit 12.

  The copyright information indicates whether or not the video and audio recorded on the recording medium can be duplicated, and is provided for the purpose of protecting the copyright of the video and audio. From this copyright information, it can be determined whether or not the video and audio recorded on the recording medium can be duplicated, or the management information of the duplicate generation.

  The communication control unit 12 includes a control circuit having a control function and a communication circuit having a bidirectional communication function. The communication control unit 12 controls the prohibition of transmission of the AV signal and the permission of transmission based on the copyright information supplied from the signal processing unit 11 and the authentication information transmitted from the communication control unit 22 of the device 20 described later. .

  The device 20 is a monitor device that receives the AV signal transmitted from the device 10 and displays the AV signal, or a recording device that records the AV signal on a magnetic tape, an optical disk, or the like. The device 20 includes a signal processing unit 21, a communication control unit 22 that communicates with the device 10 connected to the device 20, and a collective input terminal 23 that connects the device 10 and the composite cable 1.

  The signal processing unit 21 includes a receiving circuit that receives the transmitted AV signal and a signal processing circuit that performs signal processing on the received AV signal. The signal processing content of the signal processing unit 21 varies depending on the type of the device 20. For example, if the device 20 is a monitor device, the received AV signal is displayed on the screen. If the device 20 is a recording device, the AV signal is recorded on an optical disk, magnetic disk, magnetic tape, or the like.

  The communication control unit 22 includes a control circuit having a control function and a communication circuit having a bidirectional communication function. The communication control unit 22 manages authentication information unique to the device 20 and manages the operation state of the device 20, that is, the signal processing content of the signal processing unit 21.

  Here, the authentication information is information indicating the type and function of the device, address information for specifying the device, the operating state of the device, and the like. That is, if the device is a recording device, information indicating that the device is a recordable device, information indicating that the recording device is operating and recording data, and the like.

  The communication control unit 22 performs bidirectional communication with the communication control unit 12 of the device 10 and exchanges these pieces of authentication information.

  The composite cable 1 that connects the device 10 and the device 20 is a single cable in which signal lines for signal transmission or communication between devices are combined. That is, the composite cable 1 communicates with signal lines for AV signals, for example, signal lines for RGB signals, signal lines for composite video signals + audio signals, signal lines for analog video signals such as Y + C signals, and signal lines for audio signals. A communication line for performing bidirectional communication between the control unit 12 and the communication control unit 22 is incorporated.

  In addition, collective connectors 1a and 1b are provided at both ends of the composite cable 1, respectively. Furthermore, the device 10 and the device 20 are provided with a collective output terminal 13 and a collective output terminal 23 so as to correspond to the collective connectors 1a and 1b.

  These collective terminals 13 and 23 can transmit all signal lines with a single cable, such as an S (separate) video terminal provided in a commercially available AV device, for example, and may be removed or connected. There is no need to handle multiple cables. That is, a communication line for the communication control units 12 and 22 to perform bidirectional communication is connected simultaneously with connection of the AV signal line.

  Next, in the communication system, a case where the device 10 reproduces a recording medium will be described with reference to the flowchart shown in FIG.

  In the device 10, the signal processing unit 11 reproduces the AV signal recorded on the recording medium, and transmits the analog AV signal from the collective output terminal 13. At this time, the signal processing unit 11 also reproduces the copyright information of the AV signal and supplies the copyright information to the communication control unit 12.

  When the reproduction is started and the copyright information is supplied, the communication control unit 12 confirms the copyright information. That is, the communication control unit 12 determines whether the AV signal reproduced from the recording medium can be freely copied from the copyright information, is prohibited from being copied, or is copied only for one generation. It is determined whether it is possible (step S1).

  If the communication control unit 12 determines that copying of the AV signal reproduced from the copyright information is possible, the AV signal is permitted to be output and the AV signal is transmitted from the signal processing unit 11 (step S2). .

  Further, when the communication control unit 12 determines that copying of the AV signal to be reproduced from the copyright information is prohibited and when it is determined that only one generation can be copied, it is connected from the authentication information from the device 20. It is determined whether the device to be installed is correct (step S3). If it is determined that the device is correct, the output of the AV signal is permitted (step S2). If it is determined that the device is not correct, output of the AV signal is stopped (step S4), and a message for stopping output of the AV signal is output (step S5).

  Specifically, when the reproduction of the AV signal to be reproduced is prohibited, it is determined from the authentication information whether the device 20 that is the destination of the AV signal is a non-recording device, for example, a monitor device. Judge whether. If the device 20 is a non-recording device, output of the AV signal is permitted and the AV signal is transmitted from the signal processing unit 11. Further, even if the device 20 is a recording device, for example, a recording device, the output of the AV signal is permitted when the recording device is not in a recording state. This is because, for example, when a playback device and a monitor device are connected, there is a case where a so-called cascade connection is established between the playback device and the monitor device via a recording device. If the recording device is not in the recording state, output of the AV signal is permitted. Note that the case where such a cascade connection is made will be described in detail later.

  When the AV signal to be reproduced can be copied for only one generation, output of the AV signal is permitted. At this time, the communication control unit 12 transmits the copyright information of the AV signal that only one generation can be copied to the communication control unit 22 of the device 20. When the device 20 is a recording device and is in a recording state, the communication control unit 22 records the copy-prohibited copyright information together with the AV signal on the recording medium. As a result, when a recording medium on which an AV signal that can be copied for only one generation is recorded is copied to another recording medium, the copied recording medium is further copied to the next recording medium. I can't.

  The processing from step S1 to step S5 as described above is performed at regular intervals after the devices 10 and 20 are connected and the power is turned on. For this reason, for example, if the device 20 enters the recording state from where it is not in the recording state, the state can be detected and transmission can be prohibited. If a part of the AV signal recorded on the recording medium to be reproduced is copy-prohibited, transmission can be prohibited only when the part is reproduced. At this time, a message indicating that the output has been stopped due to copyright protection is output because there is no equipment failure.

  As described above, in the communication system according to the first embodiment, when the device 10 transmits an AV signal to the device 20, a signal is transmitted only when it is determined that the device 20 is a correct connection partner based on the authentication information. However, if the connection partner is not correct, transmission from the device 10 is prohibited. Therefore, unauthorized duplication of these signals can be prevented without deteriorating the audio signal and the video signal. Further, it is possible to prevent unauthorized duplication without disturbing the connected device.

  Further, by using the composite cable 1 having a single signal line for connection between the device 10 and the device 20, the above-described authentication information can be exchanged between the devices and compatible with other connectors. The risk of being duplicated by connecting to other models can be avoided by not having the characteristics.

  The communication control unit 12 described in the above embodiment can communicate additional information in addition to authentication information and copyright information. In this case, the additional information is device information such as device type, serial number, device-specific address, device setting information, communication information, and the like. The device has a predetermined serial number and address. It is also possible to perform control such that recording can be performed only by the device.

  FIG. 3 illustrates a communication system according to the second embodiment in which the device 20 and the device 30 are connected in cascade to the device 10. In describing the communication system according to the second embodiment, components having the same functions as those of the first embodiment described above are denoted by the same reference numerals in the drawings, and detailed description thereof is omitted. . The same applies to the following third embodiment. The device 10 and the device 20 are connected via the composite cable 1. In addition, the device 20 and the device 30 are connected via the composite cable 1.

  The device 30 is a monitor device that receives the AV signal transmitted from the device 10 and displays the AV signal, a recording device that records the AV signal on a magnetic tape, an optical disk, or the like. The device 30 includes a signal processing unit 31, a communication control unit 32 that communicates with the device 10 and the device 20 connected to the device 30, a collective input terminal 33 that connects the device 10 and the composite cable 1, and a device 20 And a collective input terminal 34 for connecting the composite cable 1. The device 30 differs from the device 10 and the device 20 in having both input / output terminals, and the signal processing unit 31 includes a signal processing circuit that performs signal processing of an AV signal, and an AV signal receiving circuit. And having a transmission circuit is different. That is, the device 30 is, for example, a monitor device having an input / output terminal or a recording device that records an AV signal on a magnetic tape, an optical disk, or the like.

  The communication control unit 32 of the device 30 includes a control circuit having a control function and a communication circuit having a bidirectional communication function with both the device 10 and the device 20. Based on the copyright information supplied from the communication control unit 12 and the authentication information transmitted from the communication control unit 22 of the device 20, the transmission of AV signals transmitted from the device 30 to the device 20 is prohibited and the transmission permission is controlled. Do. In addition, the communication control unit 32 manages authentication information unique to the device 30, and manages the operation state of the device 30 and the contents of signal processing of the signal processing unit 31. The communication control unit 32 performs bidirectional communication with the communication control unit 12 of the device 10 and exchanges authentication information. That is, the communication control unit 32 supplies authentication information to the communication control unit 12 of the device 10 based on the processing content of the signal processing unit 31 and the like.

  Specifically, when the device 20 is a recording device and the device 30 is a monitor device, an AV signal is always transmitted from the device 10 to the device 30. However, transmission of the AV signal from the device 30 to the device 20 is prohibited depending on the operating state of the device 20 and the content of the copyright information. When the device 20 is a monitor device and the device 30 is a recording device, an AV signal is transmitted from the device 10 to the device 20 via the device 30 when the device 30 is not in a recording state. However, when the device 30 is in a recording state, transmission of AV signals from the device 10 to the device 30 is prohibited depending on the content of the copyright information.

  That is, the communication control unit 32 of the device 30 has both the functions of the communication control unit 12 of the device 10 and the communication control unit 22 of the device 20 described above.

  Note that the communication control unit 32 of the device 30 may supply not only the authentication information of the device 30 to the communication control unit 12 of the device 10 but also the authentication information of the device 20. In this case, transmission of AV signals from the device 10 can be prohibited even when the device 30 is a monitor device.

  In such a communication system according to the second embodiment, reliable copy control can be performed even between a plurality of cascade-connected devices.

  In the second embodiment described above, the case where three models are connected in a column is shown, but the number of models in the column may be larger than this.

  FIG. 4 illustrates a communication system according to the third embodiment when a plurality of devices 20 are connected in parallel to the device 10a. The device 10 a and each device 20 are connected via the composite cable 1. The device 20 is the same as that in the first embodiment described above.

  The device 10a includes a signal processing unit 11, a communication control unit 12a that communicates with each device 20 connected to the device 10a, and collective input terminals 13a and 13b that connect the device 20 and the composite cable 1. The device 10a is different from the device 10 of the first embodiment described above in that it has a plurality of collective output terminals. For example, when the device 10a is connected to a plurality of external devices from one device having a plurality of output terminals, the device 10a can be connected to a monitor device and a recording device from an optical disk reproducing device, for example.

  The communication control unit 12a exchanges authentication information and the like with the communication control unit 22 of each device 20. This communication control unit 12a is different from the communication control unit 12 of the first embodiment described above in that it can communicate with each communication control unit 22 individually.

  In the communication system according to the third embodiment, for example, transmission can be prohibited when a connection is made to copy a large amount of AV signals recorded on a recording medium. In the third embodiment, transmission can be prohibited for each output terminal by providing transmission means for each aggregate output terminal individually.

  FIG. 5 illustrates a communication system according to a third embodiment in which authentication information and the like are encrypted for communication. The device 10b and the device 20b are different from each other in that they include the device 10 and the device 20 and the encryption / decryption devices 14 and 24 of the first embodiment described above. The device 10b and the device 20 are connected via the composite cable 1.

  The communication control unit 12 of the device 10b and the communication control unit 22 of the device 20b communicate via the encryption / decryption devices 14 and 24, respectively. As a result, it is possible to improve the safety of communication data when communicating authentication information and copyright information.

  Note that this encryption / decryption can be performed by software by a microcomputer.

  FIG. 6 illustrates a communication system according to a fourth embodiment in which authentication information and the like are communicated via an AV signal line. The device 10c and the device 20c are different from each other in that they include the device 10, the device 20, and the modems 15 and 25 according to the first embodiment described above. The device 10c and the device 20c are connected via the composite cable 1.

  The communication control unit 12 of the device 10c and the communication control unit 22 of the device 20c communicate via the modems 15 and 25, respectively. The modems 15 and 25 perform communication by superimposing them on one of AV signal lines, for example, an R signal line or an audio signal line. The modems 15 and 25 need to perform modulation / demodulation in a frequency band that does not interfere with an AV signal or the like on which signals are superimposed. For example, when superimposed on an audio signal, it can be modulated at 455 kHz, which is an intermediate frequency of AM radio. In this way, if the above-described aggregate cable 1 is used by superimposing authentication information or the like on the AV signal, for example, if the communication control units 12 and 22 cannot establish communication, it is determined that the device is an unauthorized device and the AV signal is output. Is prohibited, so that reliable protection against unauthorized use can be provided.

  FIG. 7 illustrates a communication system according to a fifth embodiment in the case where a YUV signal that is an AV signal reproduced from a recording medium is converted into a composite video signal and output. The device 30a superimposes a signal processing unit 31 that converts a YUV signal transmitted from the device 10 into a composite video signal, a communication control unit 32a that communicates copyright information and authentication information with the device 10, and a composite video signal. A macrovision encoder 35 for generating a macrovision signal to be generated. The device 10 is the same as that in the first embodiment described above. The device 10 and the device 30a are connected via the composite cable 1.

  The composite video output output from the device 30a is transmitted to the connected device via a general connector terminal. Therefore, when the copyright information of the AV signal reproduced by the device 10 indicates that copying is prohibited or only one generation can be copied, the communication control unit 32a controls the macrovision encoder 35 to control composite video. The macrovision signal is superimposed on the signal. It should be noted that by incorporating the CGMS encoder in parallel with the macrovision encoder 36, it is possible to realize generation restrictions on the analog input of the digital device.

  In the communication system of the fifth embodiment as described above, conversion with a conventional composite video signal is possible.

  FIG. 8 illustrates a communication system according to a sixth embodiment in the case where an input composite video signal is converted into an AV signal output from a collective connector. The device 30b includes a signal processing unit 31 that converts an input composite video signal into an AV signal, a communication control unit 32b that communicates copyright information and authentication information with the device 20, and a macrovision superimposed on the composite video signal. A macrovision / CGMS detector 36 for detecting signals and CGMS signals. The device 20 is the same as that in the first embodiment described above. Further, the device 20 and the device 30b are connected via the composite cable 1.

  The composite video signal input to the device 30b is received via a general connector terminal. The macrovision / CGMS detection unit 36 detects a macrovision signal and a CGMS signal superimposed on the composite video signal, and supplies this detection information to the communication control unit 32b. Therefore, when a macrovision signal is superimposed on this composite video signal, the communication control unit 32b treats it as prohibiting recording as copyright information of the AV signal, and if the device 20 is in a recording state or the like, transmission is performed. Ban. If the CGMS signal is superimposed on the composite video signal, the generation information of the AV signal is supplied to the device 20 based on the information of the CGMS signal. In such a communication system according to the sixth embodiment, conversion with a conventional composite video signal is possible.

It is a block block diagram of the communication system to which this invention is applied. It is a flowchart explaining the content of the communication process in the communication system to which this invention is applied. It is a block block diagram of the communication system to which this invention is applied. It is a block block diagram of the communication system to which this invention is applied. It is a block block diagram of the communication system to which this invention is applied. It is a block block diagram of the communication system to which this invention is applied. It is a block block diagram of the communication system to which this invention is applied. It is a block block diagram of the communication system to which this invention is applied.

Explanation of symbols

  1 composite cable 10, 10a, 10b, 10c, 20, 20b, 30, 30a, 30b equipment, 11, 21, 31 signal processing unit, 12, 22, 32 communication control unit, 13, 24 collective output terminal, 23, 33 collective input terminal, 14, 24 encryption / decryption device, 15, 25 modem

Claims (8)

An audiovisual signal transmission / reception device that receives an audiovisual signal from a first external device and transmits the received audiovisual signal to a second external device,
First receiving means for receiving, from the first external device, copyright information indicating whether or not the audiovisual signal and the audiovisual signal can be copied, or copy generation management information for the audiovisual signal;
First transmission means for transmitting the audiovisual signal and the copyright information to the second external device;
Second transmitting means for transmitting authentication information for determining whether or not the audiovisual signal can be transmitted to the first external device;
Second receiving means for receiving authentication information of the second external device from the second external device;
Regarding the transmission of the audiovisual signal and copyright information from the first transmission means to the second external device, if it is determined that copying is possible according to the copyright information, the transmission is permitted, and the copyright information If it is determined that there is a copy prohibition or a copy generation limitation by the above, if it is determined that transmission is permitted by the authentication information received by the second receiving means, transmission is permitted, and if it is determined that transmission is not possible And an audiovisual signal transmitting / receiving apparatus comprising: control means for controlling the first transmission means so as to prohibit transmission. The control means determines the recording function of the second external device based on the authentication information, and when the second external device has a recording function, the control device sends the second external device to the second external device. 2. The audio visual signal transmission / reception apparatus according to claim 1 , wherein transmission of a video signal to the network is prohibited . The control means determines the operation state of the second external device based on the authentication information, and when the second external device is in the recording operation state, the control means sends the second transmission device to the second transmission device. transceiver audiovisual signals according to claim 1, wherein the prohibiting transmission of the video signal to the external device. Above the said authentication information from the second transmission means for transmitting to said first external device, transceiver audiovisual signals according to claim 1, characterized in that it comprises the authentication information of the second external device.   An audiovisual signal transmitting / receiving method of receiving an audiovisual signal from a first external device and transmitting the received audiovisual signal to a second external device,
  Receiving authentication information of the second external device from the second external device;
  Transmitting authentication information for determining whether or not to transmit the audiovisual signal to the first external device;
  Receiving from the first external device copyright information indicating whether or not the audiovisual signal and the audiovisual signal can be replicated or the replication generation management information for the audiovisual signal;
  Sending the audiovisual signal and the copyright information to the second external device;
  When the audio visual signal and the copyright information are transmitted to the second external device, if the copyright information determines that copying is possible, the transmission is permitted, and the copyright information prohibits copying or copying generation restrictions. When it is determined that there is a transmission, the transmission is permitted when it is determined that the transmission is permitted by the authentication information received from the second external device, and the transmission is prohibited when it is determined that the transmission is impossible. Audio visual signal transmission and reception method. When the recording function of the second external device is determined based on the authentication information received from the second external device, and the second external device has the recording function, the audio visual to the second external device is displayed. 6. The audio visual signal transmission / reception method according to claim 5, wherein transmission of the signal is prohibited. Based on the authentication information received from the second external device, the operation state of the second external device is determined, and when the second external device is in the recording operation state, the second external device is transferred to the second external device. 6. The audio visual signal transmission / reception method according to claim 5, wherein transmission of the audio visual signal is prohibited. 6. The audio visual signal transmitting / receiving method according to claim 5, wherein the authentication information transmitted to the first external device includes authentication information of the second external device.

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