JP2008172819A - Signal processing apparatus, receiver and signal processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily and freely restrict program viewing. <P>SOLUTION: An MPEG2 TS packet S3 as digital broadcast data is obtained from an ECC decoder 43. An NIT detection circuit 44 detects NIT from the packet S3, transmission frequency information is modified, and information (service information) of a program to restrict viewing is deleted to obtain a table NITb. An NIT permutation circuit 48 detects the NIT from the packet S3 and permutes the NIT with the table NITb to obtain an MPEG2 TS packet S4 as digital broadcast data in CATV. By applying error-correction code addition processing, modulation processing and frequency conversion processing to the packet S4, a digital broadcast signal BS1 for CATV is obtained. In a receiver which receives a prescribed program on the basis of the program information of the NIT, a program relating to the program information deleted from the NIT is not received any more. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a signal processing apparatus and a receiving apparatus suitable for use when a digital broadcast program broadcast on an arbitrary network is distributed on another network. Specifically, the NIT (network information table) of the digital broadcast data in the first network is detected, and the program information to be restricted from viewing is deleted from the program information included in the NIT. A signal processing apparatus which can easily and freely limit viewing of a program by replacing the NIT of the digital broadcast data in NIT with the NIT from which the program information has been deleted to obtain digital broadcast data in the second network. It is related. Further, it is possible to prevent the viewer from being confused by not displaying the program guide information related to the program information that does not exist in the network information table among the program guide information detected from the digital broadcast data. This relates to the receiving apparatus.

  For example, a digital broadcasting program broadcast on an arbitrary network such as a satellite television multi-channel broadcast is distributed by a cable television operator or the like using a network in its own facility by a modulation conversion transmission device or the like. It is conceivable to provide a distribution service.

  In this case, since the digital broadcast data has an NIT having physical information related to the transmission path, the digital broadcast broadcast on the first network only by converting the modulation method with a modulation conversion transmission device or the like. The program cannot be distributed on the second network, and transmission frequency information included in the NIT of the digital broadcast data needs to be adapted to the second network.

  The NIT also includes program information. For example, a set top box (in-home reception device) connected to a cable television transmission path detects the NIT and determines a predetermined value based on the program information included in the NIT. It is configured to receive a program.

  By the way, for example, when a satellite television multi-channel broadcast is provided by a cable television operator or the like using a network in its own facility and using a modulation conversion transmission device or the like, even if it is a program existing on the cable television transmission path, You may want to restrict viewing.

  Therefore, an object of the present invention is to provide a signal processing apparatus and a signal processing method that can easily and freely limit viewing of a program.

  In recent years, it has been proposed to detect program guide information from digital broadcast data in a satellite broadcast receiver or the like, display the program guide information on a display, and provide it for convenience such as selection of a viewer's program. . The program information included in the NIT and the program guide information do not correspond one-to-one. In this case, if guide information of a program that does not correspond to the program information included in the NIT and cannot be received is displayed, the program is selected even though the program is selected based on the program guide information. It may not be received and may confuse the viewer.

  Accordingly, an object of the present invention is to provide a receiving apparatus that prevents the viewer from being confused.

  The signal processing apparatus according to the present invention provides a second digital signal transmitted through a second network different from the first network as a digital signal corresponding to the first digital content signal transmitted through the first network. A signal processing apparatus for outputting a digital content signal, comprising: table detection means for detecting table information including transmission frequency information and program information of the first digital content signal from the first digital content signal; and table detection means Among the program information of the table information detected by the first table changing means and table information detected by the table detecting means, the viewing frequency information is changed to the information corresponding to the transmission format in the second network. A second table changing means for deleting information of the program to be restricted; a second table; Output means for outputting the table information changed by the message changing means as the table information of the second digital content signal, and the first digital content signal includes data constituting the program corresponding to the program information. It is a waste.

  In the present invention, for example, the first digital broadcast signal on the first network has a predetermined transmission frequency. This first digital broadcast signal is frequency-converted into a digital modulation signal, and further demodulated. Thus, digital broadcast data in the first network can be obtained. The digital broadcast data in the first network has NIT including transmission frequency information and program information. The NIT is detected from the digital broadcast data in the first network, at least the transmission frequency information is changed so as to be compatible with the second network, and the information on the program for which viewing restriction is to be restricted is deleted from the NIT program information. The

  Then, the NIT of the digital broadcast data in the first network is replaced with the NIT in which the transmission frequency information and the like are changed so as to be compatible with the second network, and the information of the program for which viewing restriction is to be performed is deleted. Digital broadcast data in the two networks is formed. The digital broadcast data in the second network is modulated into a digital modulated signal, and further frequency-converted to obtain a second digital broadcast signal to be transmitted on the second network.

  A receiving apparatus that receives a predetermined program based on NIT program information does not receive a program that is not included in the NIT program information. Therefore, as described above, by deleting the information of the program that is desired to be viewed from the NIT program information, it is possible to restrict the viewing of the program even on the transmission path.

  The receiving apparatus according to the present invention is a receiving apparatus for receiving a second digital content signal transmitted on a second network different from the first network, and is transmitted on the first network. A process of detecting table information including transmission frequency information and program information from the first digital content signal, and changing the transmission frequency information in the table information to information corresponding to a transmission format in the second network; Of the table information of the second digital content signal, the table information that has been subjected to the process of deleting the information of the program whose viewing is restricted is used as the table information of the second digital content signal. A second digital content signal including data constituting the program corresponding to the program information before the information is deleted; Receiving means, table detecting means for detecting table information from the second digital content signal, information detecting means for detecting program guide information from the digital content signal, and program guide detected by the information detecting means Display means for displaying information, and the display means does not display program guide information relating to program information deleted so as not to be displayed.

  In the present invention, the program guide information relating to the program information not existing in the NIT detected by the table detecting means is not displayed on the display means. That is, the program guide information displayed on the display means is only guide information of receivable programs. Therefore, all programs selected by the viewer based on the program guide information are received. As a result, the program selected by the viewer based on the program guide information cannot be received, and the confusion of the viewer can be prevented.

  The signal processing apparatus according to the present invention detects the NIT of the digital broadcast data in the first network, deletes the information of the program whose viewing is to be restricted from the program information included in the NIT, and in the first network The digital broadcast data in the second network is obtained by replacing the NIT of the digital broadcast data with the NIT from which the program information has been deleted. In a receiving apparatus that receives a predetermined program based on NIT program information, a program without the program information is not received. Therefore, as described above, by deleting the information of the program that is to be restricted from viewing among the NIT program information, even if the program exists on the transmission path, the viewing of the program can be easily and freely restricted. Can do. In addition, since it is possible to restrict viewing of a program only by replacing NIT, it is possible to perform viewing restriction more easily than when digital broadcast data in the second network is obtained by deleting program data for which viewing is restricted. .

  The receiving apparatus according to the present invention prevents display of program guide information related to program information that does not exist in the NIT among the program guide information detected from the digital broadcast data. In this case, the program guide information displayed on the display means is only guide information of receivable programs. Therefore, the program selected by the viewer based on the program guide information cannot be received, and confusion of the viewer can be prevented.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a digital CATV (cable television) system 10 using satellite digital multi-channel broadcasting as an embodiment. This system 10 has an antenna 11 for receiving digital broadcast signals from a plurality of transponders (satellite repeaters) of a communication satellite 20 and changes the transmission frequency, modulation method, etc. of the received digital broadcast signals for CATV. And a modulation conversion sending device 12 for generating a digital broadcast signal and sending it to the transmission line 13. The transmission line 13 is connected to set-top boxes (in-home receivers) 14-1 to 14-m, which are receiving terminals, and selected by these set-top boxes 14-1 to 14-m. Channel number images are displayed on the monitors 15-1 to 15-m.

  Here, the digital broadcast signal transmitted from the communication satellite 20 will be described. In the present embodiment, the digital broadcasting signal corresponds to a DVB (Digital Video Broadcasting) system. FIG. 2B shows a frame structure of digital broadcast data in the DVB system, and one frame is composed of eight MPEG2 transport packets (see FIG. 2A). In this case, the synchronization byte (= 47H) in the packet is used, and the synchronization byte is inverted (= B8H) once in 8 packets to obtain frame synchronization. Note that an error correction code according to Reed-Solomon (204, 188) is added to each MPEG2 transport packet (MPEG2TS packet). The digital broadcast data shown in FIG. 2B is modulated by QPSK (Quadrature Phase Shift Keying), and then frequency-converted to the SHF band to become a digital broadcast signal transmitted from the communication satellite 20.

  FIG. 3 shows the packet structure of an MPEG2 transport packet, and the first 4 bytes of 188 bytes form a packet header. In the packet header, PID (Packet Identification) indicating the attribute of the individual stream (data string) of the packet is arranged. As is well known, a PES (Packetized Elementary Stream) packet whose packet structure is shown in FIG. 4 is subdivided and arranged in the payload (data portion) of the MPEG2 transport packet, and is further defined in the MPEG2 system. Tables such as PAT (Program Association Table), PMT (Program Map Table), and NIT (Network Information Table) as PSI (Program Specific Information) are also arranged in a section format.

  Here, PSI is information necessary for realizing a simple channel selection operation and program selection. PAT indicates the PID of the PMT that transmits the information of the packets constituting the program for each program number (16 bits), and FIG. 5 shows the table structure of the PAT. As the PID of the PAT itself, PID = “0” is fixedly assigned.

  The main contents will be described. The table ID indicates the type of the table and is “0 × 00” (hexadecimal notation) in the PAT. TS (transport stream) ID identifies a stream (multiplexed encoded data), and corresponds to a transponder in the case of a satellite. The version number is added every time the contents of the table are updated. The current next indicator is used for identification when the old and new versions are transmitted simultaneously. The program number identifies each channel. The network PID indicates the PID of the NIT when the program number is “0 × 0000”. The program map PID indicates the PID of the PMT.

  The PMT indicates, for each program number, the PID of a packet in which a stream of video, audio, additional data, etc. constituting the program is transmitted. The PID of the PMT itself is specified by the PAT as described above. FIG. 6 shows a table structure of the PMT. The main contents not overlapping with PAT will be described. The table ID indicates the type of table and is “0 × 02” in the PMT. The PCR PID indicates the PID of a packet including a clock (PCR) that serves as a reference for decoding. The stream type indicates the type of signal transmitted in the stream, such as video, audio, and additional data.

  The NIT indicates physical information on the transmission path, that is, in the satellite, the orbit of the satellite, the polarization, the frequency for each transponder, and the like. The PID of the NIT itself is specified by the PAT as described above. FIG. 7 shows the NIT table structure. Main contents not overlapping with PAT and PMT will be described. The table ID indicates the type of the table. The network is “0 × 40” and the other networks are “0 × 41”. The network ID identifies the network. In the case of a satellite, it corresponds to an individual satellite.

  Furthermore, two descriptors that play an important role as part of the NIT will be described. First, the satellite delivery system descriptor will be described. This descriptor is used as the first descriptor repeated according to the TS (Transport Stream) descriptor length, and is paired with a TS (Transport Stream) ID.

  FIG. 8 shows the structure of the satellite delivery system descriptor. The descriptor tag is defined by DVB and indicates the type of descriptor. In this descriptor, it is “0 × 43”. The frequency indicates a transmission frequency for each stream (here, transponder). The orbit / west longitude / east longitude flag / polarization indicates the orbit and polarization of the satellite. The modulation / symbol rate / inner error correction coding rate indicates a specification related to the transmission method.

  Next, the service list descriptor will be described. This descriptor is used as the second and subsequent descriptors repeated according to the TS (transport stream) descriptor length, and indicates the ID of the service (channel) multiplexed in the stream (here, transponder). is there. That is, a plurality of service list descriptors are attached to one TS (Transport Stream) ID.

  FIG. 9 shows the structure of the service list descriptor. The descriptor tag is defined by DVB and indicates the type of descriptor. In this descriptor, it is “0 × 41”. The service ID identifies a service. Usually, the service matches the channel that the viewer selects. The service type indicates the contents of the service such as video, audio, and data.

  In addition, information of EPG (Electronic Program Guide) is also arranged in the payload part (data part) of the MPEG2 transport packet. EPG is one of services unique to digital multi-channel broadcasting. By receiving information about the program and displaying it on the monitor screen as program guide information, the viewer can easily find the desired program. The EPG is used to display a program that is currently being broadcast and select a channel, or to reserve a program several days ahead. The EPG information is described in section format tables called SI (Service Information), and the receiver extracts necessary information from the table and displays it on the screen. Typical tables include an SDT (Service Description Table) representing channel information and an EIT (Event Information Table) representing event (program) information.

  The SDT describes a channel number, a channel name, channel contents, etc., and the PID is fixedly “0 × 0011”. FIG. 10 shows the SDT table structure. The main contents will be described. The table ID indicates the type of the table. The network is “0 × 42” and the other networks are “0 × 46”. In SDT, the presence or absence of scrambling for each service multiplexed in the transport stream having the TSID in the table, and the service name, service content, service type, etc. of the service in the descriptor included in SDT is described.

  The EIT describes a program name, a program start time, a synopsis, a genre, etc., and the PID is fixedly “0 × 0012”. FIG. 11 shows an EIT table structure. The main contents will be described. The table ID is “0 × 4E” for the network and “0 × 4F” for the other networks. In the EIT, for a plurality of normal events (= programs) constituting one service (= program = channel), in addition to the start time, duration, progress status, presence / absence of scramble, the descriptors included in the EIT include Information related to the program name, program genre, pay-per-view program fee, synopsis, and the like is described.

  FIG. 12 shows the configuration of the modulation conversion sending device 12 in the digital CATV system 10 of FIG. This sending device 12 changes the transmission frequency, modulation method, etc. of the digital broadcast signal sent from the first to Nth transponders (satellite repeaters) of the communication satellite 20 to generate a CATV digital broadcast signal. Are sent to the transmission line 13. Note that a plurality of channels of programs are multiplexed in each digital broadcast signal.

  The sending device 12 includes a microcomputer, and performs digital broadcasting in the SHF (Super High Frequency) band sent from the control unit 31 that controls the operation of the entire device and the first to Nth transponders of the communication satellite 20. The first to Nth signal processing units 32-1 to 32-N that process the signals and generate digital broadcast signals BS1 to BSN for CATV in the VHF (Very High Frequency) band or the UHF (Ultra High Frequency) band. And an adder 33 that adds these digital broadcast signals BS1 to BSN and sends them to the transmission line 13. The control unit 31 displays the operation unit 34 for setting the reception frequency in the tuners of the signal processing units 32-1 to 32-N, the status of the sending device 12, and the like, and a liquid crystal display or the like. The display part 35 comprised by these is connected.

  The signal processing unit 32-1 selects a digital broadcast signal transmitted from the first transponder of the communication satellite 20 from a plurality of SHF band digital broadcast signals received by the antenna 11, and outputs the digital broadcast signal to the digital broadcast signal. A tuner 41 that performs frequency conversion processing to obtain a QPSK modulated signal S1, a demodulator 42 that demodulates the QPSK modulated signal S1 to obtain a signal S2 having a DVB frame structure, and a DVB output from the demodulator 42 An ECC (Error Correction Code) decoder 43 that performs error correction on the frame-structured signal S2 and sequentially obtains MPEG2 transport packets S3 as digital broadcast data is provided.

  The signal processing unit 32-1 detects the NIT (network information table) from the MPEG2 transport packet S3 sequentially output from the ECC decoder 43, and the NIT detection circuit 44 detects the NIT detection circuit 44. The memory 45 stores the table NITa, and the memory 46 stores the table NIb obtained by changing the table NITa stored in the memory 45 by the control unit 31. The NIT detection circuit 44 detects NIT based on a fixed PID. As described above, since the NIT table structure in the digital broadcast data related to the communication satellite 20 is as shown in FIG. 7, the table structure of the table NITa detected by the NIT detection circuit 44 is the same.

  In obtaining the table NITb, the control unit 31 changes the satellite delivery system descriptor (see FIG. 8) having transmission frequency information and the like in the table NITa to a CATV delivery system descriptor whose structure is shown in FIG. Is done. Since the total length of the CATV delivery system descriptor is the same as that of the satellite delivery system descriptor, it can be simply replaced.

  The main contents will be explained. The descriptor tag is defined by DVB and indicates the type of descriptor. In this descriptor, it is “0 × 44”. The frequency indicates a transmission frequency for each stream (multiplexed encoded data) in CATV. FEC (outer code) indicates an error correction code as an outer code, and is “0010” in this descriptor. Modulation / symbol rate / FEC (inner code) indicates a specification related to a transmission method.

  Further, in obtaining the table NITb, the control unit 31 deletes information on services (programs) that should be restricted for viewing corresponding to the operation of the operation unit 34. In this case, the contents of the table NITa detected by the NIT detection circuit 44 (services multiplexed in the transport stream for each TSID) can be displayed on the display unit 35. In this state, when a service that should be restricted from viewing is designated by the operation unit 34, information on the service is deleted from the table NITa.

  For example, when all the services multiplexed on a certain TSID are designated as services that should be restricted from viewing, all the information related to that TSID (information from TSID to descriptor in FIG. 7) is deleted. Also, for example, when a part of a service multiplexed on a certain TSID is designated as a service that should be restricted from viewing, the service information (in FIG. 9, service ID, Service type) is deleted.

  In some cases, the number of digital broadcast signals in CATV is smaller than the number of digital broadcast signals in satellite digital broadcast. That is, when the communication satellite 20 includes L transponders and the number of digital broadcast signals in the satellite digital broadcast is L, CATV uses N (N <L) digital broadcasts among the L digital broadcast signals. The signal may be used selectively. In this case, in obtaining the table NITb, the control unit 31 deletes information related to the TSID (information from transport stream ID to descriptor in FIG. 7) corresponding to the digital broadcast signal not used in CATV in the table NITa. The

  Writing to and reading from the memories 45 and 46 are controlled by the control unit 31 via the interface 47. The reception frequency of the tuner 41 described above is also controlled by the control unit 31 via the interface 47.

  Further, the signal processing unit 32-1 has an NIT replacement circuit 48 that detects NIT from the MPEG2 transport packet S3 sequentially output from the ECC decoder 43 and replaces the NIT with a table NITb stored in the memory 46. ing. The NIT replacement circuit 48 also detects NIT based on a fixed PID. Further, when the control unit 31 obtains the table NITb, when information on a service (program) to be restricted from viewing is deleted, a dummy bit is inserted into a portion related to the deleted information, not described above. As a result, the total length of the NIT becomes the same as before deletion, and replacement is easy. The NIT replacement circuit 48 only replaces the NIT, and the EPG information included in the packet S3 and the packet S4 is common for the EPG information.

  Further, the signal processing unit 32-1 adds a Reed-Solomon (204, 188) error correction code to the MPEG2 transport packet S4 in which the NIT is replaced by the NIT replacement circuit 48, etc. ECC encoder 49 that obtains a signal S5 (see FIG. 2B), a modulator 50 that performs modulation processing of 64QAM (Quadrature Amplitude Modulation) on the signal S5 having the DVB frame configuration, and 64QAM modulation output from the modulator 50 A frequency converter 51 for converting the frequency of the signal to obtain a digital broadcast signal BS1 for CATV in the VHF band or the UHF band.

  The signal processing units 32-2 to 32-N are respectively the tuner 41, the demodulator 42, the ECC decoder 43, the interface 47, the NIT replacement circuit 48, the ECC encoder 49, and the modulator 50 in the signal processing unit 32-1. The frequency converter 51 is provided. Then, in the NIT replacement circuit 48 of the signal processing units 32-2 to 32-N, the NIT replacement is performed by using the table NITb stored in the memory 46 of the signal processing unit 32-1, respectively. In the tuners of the signal processing units 32-2 to 32-N, digital broadcast signals transmitted from the second to Nth transponders of the communication satellite 20 are selected from a plurality of digital broadcast signals received by the antenna 11, respectively. Then, frequency conversion processing is performed on the digital broadcast signal to obtain a QPSK modulated signal S1. The reception frequencies of the tuners of the signal processing units 32-2 to 32-N are controlled by the control unit 31 via the interface 47. Further, the frequency converter 51 of the signal processing units 32-2 to 32-N performs frequency conversion so that the transmission frequencies of the digital broadcast signals BS1 to BSN are different from each other.

  Next, the operation of the modulation conversion sending device 12 shown in FIG. 12 will be described. A plurality of digital broadcast signals in the SHF band received by the antenna 11 are supplied to the tuner 41 of the signal processing unit 32-1. In the tuner 41, a digital broadcast signal transmitted from the first transponder of the communication satellite 20 is selected, and further, a frequency conversion process is performed on the digital broadcast signal to obtain a QPSK modulated signal S1. The QPSK modulation signal S1 is supplied to a demodulator 42, which demodulates the QPSK modulation signal S1 to obtain a DVB frame-structured signal S2 (see FIG. 2B). Then, the DVB frame configuration signal S2 is supplied to the ECC decoder 43. The ECC decoder 43 performs an error correction process on the DVB frame configuration signal S2 and performs MPEG2 transport packet S3 as digital broadcast data. Are obtained sequentially (see FIG. 2A).

  The MPEG2 transport packet S3 sequentially output from the ECC decoder 43 is supplied to the NIT detection circuit 44, and the NIT detection circuit 44 detects NIT from the MPEG2 transport packet S3. The detected table NITa is supplied to the memory 45 and stored therein. Although not described above, the NIT detection operation in the NIT detection circuit 44 is performed only once a day, for example. The control unit 31 reads the table NITa from the memory 45, changes the satellite delivery system descriptor (see FIG. 8) in the table NITa to the CATV delivery system descriptor (see FIG. 13), and also changes the table NITa in the table NITa. The table NITb is obtained by deleting the information of the service (program) designated to restrict viewing and deleting the information related to the TSID corresponding to the digital broadcast signal not used in CATV in the table NITa. Is stored in the memory 46.

  The MPEG2 transport packet S3 sequentially output from the ECC decoder 43 is supplied to the NIT replacement circuit 48. The NIT replacement circuit 48 detects the NIT, and the NIT portion is stored in the table NITb stored in the memory 46. Replaced. In this case, when the control unit 31 obtains the table NITb, when information on a service (program) to be restricted from viewing is deleted, a dummy bit is inserted into a portion related to the deleted information.

  Further, the MPEG2 transport packet S4 in which the NIT is replaced by the NIT replacement circuit 48 is supplied to the ECC encoder 49. The ECC encoder 49 adds the error correction code of Reed-Solomon (204, 188), etc. to the DVB. The signal S5 having the frame configuration is formed. The DVB frame-structured signal S5 is supplied to the modulator 50, which performs 64QAM modulation processing on the DVB frame-structured signal S5 to obtain a 64QAM modulated signal S6. The 64QAM modulated signal S6 is supplied to the frequency converter 51. The frequency converter 51 performs a frequency conversion process on the 64QAM modulated signal, and a CATV digital broadcast signal having a predetermined transmission frequency in the VHF band or the UHF band. BS1 is obtained.

  A plurality of SHF band digital broadcast signals received by the antenna 11 are supplied to the signal processing units 32-2 to 32-N, and are sent from the second to Nth transponders of the communication satellite 20 in each tuner. An incoming digital broadcast signal is selected, and frequency conversion processing is performed on the digital broadcast signal to obtain a QPSK modulated signal S1. In each of the signal processing units 32-2 to 32-N, the NIT replacement circuit 48 uses the table NITb stored in the memory 46 of the signal processing unit 32-1 to perform NIT replacement. Processing similar to that of the unit 32-1 is performed to obtain CATV digital broadcast signals BS2 to BSN having a predetermined transmission frequency in the VHF band or the UHF band. These digital broadcast signals BS1 to BSN are supplied to the adder 33 and added, and the added signal is sent to the CATV transmission line 13.

  FIG. 14 shows the configuration of the set top box 14 (14-1 to 14-m) in the digital CATV system 10 of FIG.

  The set top box 14 includes a terminal 101 connected to the CATV transmission line 13, a microcomputer 102 configured to control the overall operation, and a terminal from the CATV transmission line 13. And a tuner 105 that selects a broadcast signal of a predetermined RF channel from the digital broadcast signal CDBS supplied to 101 and outputs digital modulation data corresponding to the broadcast signal of the predetermined RF channel.

  Connected to the controller 102 are a key input unit 103 for accepting operations such as channel selection by the viewer, and a display unit 104 composed of a liquid crystal display element for displaying the operation state of the apparatus and the like. . The tuning operation in the tuner 105 is controlled by the controller 102 based on the operation of the viewer's key input unit 103.

  Further, the set top box 14 demodulates the digital modulation data output from the tuner 105, and performs error correction processing on the output data of the demodulator 106, and performs the above-described predetermined processing. ECC decoder 107 that obtains an MPEG2 transport stream TS corresponding to a broadcast signal of an RF channel of the computer, and a desk that performs descrambling processing on the scrambled video data and audio data packets of the transport stream TS A rambla 108.

  Further, the set top box 14 separates the video data and audio data packets of the channel designated by the user's operation of the key input unit 103 from the transport stream TS output from the descrambler 108, and separates them. A demultiplexer 109 that outputs a video data stream VDS and an audio data stream ADS composed of a plurality of packets, separates additional data packets of the channel, and outputs an additional data stream SDS composed of the packets. ing.

  The demultiplexer 109 also acquires NIT, PAT, and PMT as the above-described program specification information (PSI) and SDT and EIT in which the above-described EPG information is described based on the control of the controller 102. Is called. The acquired information is supplied to the controller 102.

  Further, the set top box 14 includes a video processing unit 110 that obtains a video signal SV by performing a data expansion process on the video data stream VDS, a video output terminal 111 that outputs the video signal SV, a video A synthesizer 112 that is inserted between the processing unit 110 and the video output terminal 111 and synthesizes a character display signal SCH such as program guide information, which will be described later, and an audio data stream ADS that performs data expansion processing and the like. An audio processing unit 113 that obtains the signal SA and an audio output terminal 114 that outputs the audio signal SA are provided.

  The set top box 14 has an IC card interface unit 116 to which the IC card 115 is connected. The IC card interface unit 116 is connected to the controller 102. The IC card 115 stores scramble key information and determines whether or not viewing is possible based on the limited reception information sent from the controller 102 via the IC card interface unit 116. It has a function of sending scramble key information to the controller 102 via the IC card interface unit 116.

  The set top box 14 has an OSD (On Screen Display) circuit 117 for generating a character display signal SCH for displaying characters on the screen. The OSD circuit 117 is connected to the controller 102, and the character display signal generation operation is controlled by the controller 102.

  Next, the reception operation of the set top box 14 shown in FIG. 14 will be briefly described with reference to the flowchart of FIG.

  Note that the program number in PAT and PMT, and the service ID in NIT correspond to the channel number selected by each viewer. Furthermore, the NIT contains information for the entire network, ie all transponders, and the same table is transmitted in parallel by all transponders, whereas the PAT and PMT are only from the program information in the transponder to which each is transmitted. Therefore, the contents are different for each transponder.

  It is assumed that the viewer selects the “M” channel by operating the key input unit 103 (step ST1). In this case, the controller 102 controls the demultiplexer 109 so that the NIT is acquired by a fixed PID, and searches for “M” for the service ID in the service list descriptor attached to each TSID of the NIT ( Step ST2).

  When the service ID “M” is present (step ST3), the controller 102 selects the “M” channel from the CATV delivery system descriptor combined with the service list descriptor including the service ID “M”. The frequency of the transmitting transponder is recognized, and the reception frequency of the tuner 105 is controlled (step ST4). As a result, the tuner 105 selects a digital broadcast signal from a predetermined signal processing unit of the modulation conversion transmission device 12 transmitting the “M” channel.

  Then, the controller 102 controls the demultiplexer 109 to acquire the PAT with the fixed PID, searches for “M” for the program number in the PAT, recognizes the program number “M” in the PAT, A program map PID associated with the program number “M” is obtained (step ST5). Then, the controller 102 controls the demultiplexer 109 to acquire the PMT by the program map PID, and the elementary for each stream type (video, audio, etc.) corresponding to the program number “M” in the PMT. A PID is recognized (step ST6).

  Then, the controller 102 controls the demultiplexer 109 to separate the transport stream packet having the PID that matches the elementary PID (step ST7). In this case, the demultiplexer 109 separates the video data and audio data packets of the “M” channel and also separates the additional data packets of the “M” channel.

  Here, the controller 102 supplies the limited reception information extracted from the additional data stream SDS to the IC card 113 via the IC card interface unit 116. The IC card 113 determines whether viewing is possible or not based on the limited reception information. Then, if it is possible, scramble key information is sent from the IC card 115 to the controller 102 via the IC card interface unit 116. This key information is set in the descrambler 108 by the controller 102. As a result, the descrambler 108 unscrambles the scrambled video data and audio data packets, and thus the video data stream VDS and audio data stream ADS obtained from the demultiplexer 109 are unscrambled. It will be related to the data.

  Then, video data and audio data output from the demultiplexer 109 are decoded, and an “M” channel video signal SV and audio signal SA are obtained (step ST8). That is, the video processing unit 110 performs processing such as data decompression on the video data stream VDS output from the demultiplexer 109 to generate a video signal SV, and this video signal SV is output via the synthesizer 112. Derived to the terminal 111. Further, the audio processing unit 113 performs processing such as data expansion on the audio data stream ADS output from the demultiplexer 109 to generate an audio signal SA, and this audio signal SA is derived to the output terminal 114. . By supplying the video signal SV obtained at the output terminal 111 to a monitor (not shown), an image of the “M” channel can be displayed, and the audio signal SA obtained at the output terminal 114 is displayed on a speaker (not shown). By supplying, the sound of the “M” channel can be output.

  Further, as a result of searching for “M” for the service ID in the service list descriptor attached to each TSID of the NIT, if the service ID “M” is not found (step ST3), the controller 102 cannot receive on the display unit 104. A message to that effect is displayed (step ST9), and the receiving operation is terminated. Therefore, as described above, in the modulation conversion transmission device 12 (see FIG. 12), the information related to the TSID and the service list descriptor service information are deleted from the NIT as information on services (programs) to be restricted. In this case, the set top box 14 cannot receive the service (program).

  In the flowchart of FIG. 15, the NIT is acquired at step ST2 every time there is a channel selection of the “M” channel at step ST1, and the search for “M” is performed using the NIT. Whenever there is a change, the NIT may be acquired as needed and stored in the built-in memory of the controller 102, and a search for “M” may be performed using the NIT. Incidentally, the change in the contents of the NIT is recognized by the version number.

  Next, an operation in the case where a program guide information display instruction is given by the operation of the viewer's key input unit 103 will be described.

  In this case, the controller 102 controls the demultiplexer 109 so that SDT and EIT as EPG information are acquired by a fixed PID, controls the OSD circuit 117 based on the SDT and EIT, and the OSD circuit 117 A character display signal SCH for displaying program guide information on the screen is output. This character display signal SCH is combined with the video signal SV by the combiner 112 and is output to the output terminal 111. Therefore, for example, the program guide information is displayed on the screen of the monitor on which the image by the video signal SV is displayed so as to overlap the image.

  Here, the controller 102 controls the demultiplexer 109 so that the NIT is further acquired, and the service ID described in the service list descriptor of the NIT (or NIT stored in the built-in memory) is set. Only such program guide information is displayed. Accordingly, the service ID is described in the NIT service list descriptor, and only the program guide information related to the service (program) that can be received by the set top box 14 is displayed.

  As described above, in the present embodiment, when a service (program) whose viewing is to be restricted is specified in the modulation conversion transmission device 12 (see FIG. 12), the service ID related to the service is deleted from the NIT. The The service (program) related to the service ID deleted from the NIT in this way cannot be received by the set top box 14 even if it is a service (program) existing on the transmission path 13. Therefore, in the modulation conversion device 12, there is an effect that viewing of programs can be easily and freely restricted.

  In the present embodiment, in the set top box 14, when there is an instruction to display program guide information, the character display signal SCH for displaying the program guide information from the OSD circuit 117 based on the information of the EPG is generated. The program guide information is displayed on the monitor screen. In this case, the service ID is described in the service list descriptor of the NIT, and only program guide information related to services (programs) that can be received by the set top box 14 is displayed. Therefore, program guide information relating to services (programs) that cannot be received by the set top box 14 is not displayed, and viewer confusion can be prevented.

It is a block diagram which shows the structure of the digital CATV system as embodiment. It is a figure which shows the frame structure of an MPEG2 transport packet and a DVB system. It is a figure which shows the packet structure of an MPEG2 transport packet. It is a figure which shows the packet structure of a PES packet. It is a figure which shows the table structure of a program association table (PAT). It is a figure which shows the table structure of a program map table (PMT). It is a figure which shows the table structure of a network information table (NIT). It is a figure which shows the structure of the satellite delivery system descriptor in NIT. It is a figure which shows the structure of the service list descriptor in NIT. It is a figure which shows the table structure of a service description table (SDT). It is a figure which shows the table structure of an event information table (EIT). It is a block diagram which shows the structure of the modulation conversion transmission apparatus which comprises a digital CATV system. It is a figure which shows the structure of a CATV delivery system descriptor. It is a block diagram which shows the structure of the set top box (STB) which comprises a digital CATV system. It is a flowchart for demonstrating reception operation | movement of a set top box (STB).

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... CATV system, 11 ... Antenna, 12 ... Modulation conversion transmission apparatus, 13 ... CATV transmission line, 14, 14-1-14-m ... Set top box, 15 -1 to 15-m ... monitor, 20 ... communication satellite, 31 ... control unit, 32-1 to 32-N ... signal processing unit, 33 ... adder, 34 ... Operation unit, 35 ... display unit, 41 ... tuner, 42 ... demodulator, 43 ... ECC decoder, 44 ... NIT detection circuit, 45, 46 ... memory, 47 ... Interface, 48 ... NIT replacement circuit, 49 ... ECC encoder, 50 ... Modulator, 51 ... Frequency converter, 102 ... Controller, 103 ... Key input unit, 104 ... Display unit, 105 ... tuner, 106 ... demodulator, 107 ... E C decoder 108, descrambler 109 109 demultiplexer 110 video processor 111 video output terminal 112 synthesizer 113 audio processor 114 ..Audio output terminal 115 ... IC card 116 ... IC card interface unit 117 ... OSD circuit

Claims (9)

Signal processing for outputting a second digital content signal transmitted on a second network different from the first network as a digital signal corresponding to the first digital content signal transmitted on the first network A device,
Table detecting means for detecting table information including transmission frequency information and program information of the first digital content signal from the first digital content signal;
First table changing means for changing transmission frequency information in the table information detected by the table detecting means to information corresponding to a transmission format in the second network;
Second table changing means for deleting information on a program whose viewing is restricted among the program information of the table information detected by the table detecting means;
Output means for outputting the table information changed by the second table changing means as table information of the second digital content signal;
The signal output apparatus according to claim 1, wherein the first digital content signal includes data constituting a program corresponding to the program information. 2. The signal output apparatus according to claim 1, wherein the second digital content signal includes data constituting the deleted program which is not included in the changed table information. 3. The signal output apparatus according to claim 2, wherein the data constituting the deleted program includes at least one of video data, audio data, and additional data. 2. The signal output apparatus according to claim 1, wherein the output means outputs the second digital content signal by inserting a dummy bit into a portion related to the deleted program information. A receiving device for receiving a second digital content signal transmitted in a second network different from the first network,
Table information including transmission frequency information and program information is detected from the first digital content signal transmitted on the first network, and the transmission frequency information in the table information corresponds to the transmission format in the second network. The second digital content signal table information is used as the table information of the second digital content signal, and the second digital content signal table processing is performed. Receiving means for receiving the second digital content signal including data constituting the program corresponding to the program information before deletion of the table information of the content signal and the information of the program whose viewing is restricted;
Table detecting means for detecting the table information from the second digital content signal;
Information detecting means for detecting program guide information from the digital content signal;
Display means for displaying the program guide information detected by the information detection means,
The receiving apparatus according to claim 1, wherein the display means does not display program guide information related to program information deleted so as not to be displayed. 6. The receiving apparatus according to claim 5, wherein the data constituting the deleted program includes at least one of video data, audio data, and additional data of the deleted program. 6. The receiving apparatus according to claim 5, wherein in the second digital content signal, a dummy bit is inserted in a portion related to the deleted program information. Signal processing for outputting a second digital content signal transmitted on a second network different from the first network as a digital signal corresponding to the first digital content signal transmitted on the first network In the signal processing method of the apparatus,
A table detection step of detecting table information including transmission frequency information and program information of the first digital content signal from the first digital content signal;
A first table changing step for changing transmission frequency information in the table information detected in the table detecting step to information corresponding to a transmission format in the second network;
A second table changing step of deleting information of a program whose viewing is restricted among the program information of the table information detected in the table detecting step;
An output step of outputting the table information changed in the second table changing step as table information of the second digital content signal;
The signal processing method, wherein the first digital content signal includes data constituting a program corresponding to the program information. A signal processing method of a receiving apparatus for receiving a second digital content signal transmitted in a second network different from the first network,
Table information including transmission frequency information and program information is detected from the first digital content signal transmitted on the first network, and the transmission frequency information in the table information corresponds to the transmission format in the second network. The second digital content signal table information is used as the table information of the second digital content signal, and the second digital content signal table processing is performed. A receiving step of receiving the second digital content signal including data constituting table information of the content signal and the program information corresponding to the program information before deletion of the information of the program whose viewing is restricted;
A table detection step of detecting the table information from the second digital content signal;
An information detection step of detecting program guide information from the digital content signal;
A display step for displaying the program guide information detected in the information detection step,
The signal processing method according to claim 1, wherein the display step does not display program guide information related to program information deleted so as not to be displayed.

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