JP2008017207A - Image signal receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an integrated image signal receiver having a signal system receiving an RF and applicable both to an IP-retransmitted broadcasting program and to a program exclusive to an IP network. <P>SOLUTION: A part of information of the IP-retransmitted broadcasting program and the program exclusive to the IP network are received by one IP network interface 11 where a common protocol stack is set. The TS packet of the IP-retransmitted broadcasting program and the program exclusive to the IP network is input in decrypters 16 and 17 through buffers 12 and 14 and error correctors 13 and 15, and is decoded by a key from IC cards 18 and 19. A demultiplexer 20 isolates each elementary stream (ES) by a multiple isolation processing and takes it out. Decoders 21 and 22 decode each ES. Multimedia data are converted into a screen image signal by a browser 23, and are superposed on a video signal by an adder 24. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a video signal receiving apparatus, and more particularly to a video signal receiving apparatus that receives a broadcast program that has been retransmitted by IP and an IP network-dedicated program that is uniquely produced by a communication carrier.

  With the widespread use of IP networks, IPTV program distribution services that distribute TV programs over IP networks have come to be performed. In IPTV in Japan, in addition to video-on-demand (VOD), TV distribution services are provided by IP multicast, but there are also problems with the legal system, and now it is produced independently by IPTV operators such as telecom operators. Only IP network-only programs are allowed to be distributed over IP.

  For this reason, broadcast programs are still received by RF signals (RF reception), and the video signal receiving apparatus is not only an IP network interface that receives IP network dedicated programs, but also an RF interface for RF reception, that is, an RF tuner. It is necessary to have

  FIG. 4 is a block diagram showing an architecture of a video signal receiving apparatus including an IP network interface and an RF tuner. In the following, a video signal receiving apparatus is a set-top box (referred to as STB), and a configuration including an IP network interface and an RF tuner is referred to as a hybrid STB architecture.

The upper part of FIG. 4 is a receiving system for RF reception of broadcast programs. The RF tuner 41 receives an RF signal from the antenna, demodulates an MPGE-2 TS (transport stream) packet, and sends it to the decryptor 16. The decryptor 16 decrypts the TS packet using the scramble key K _S1 sent from the broadcast IC card 18 and sends the decrypted TS packet to the demultiplexer 20. That is, the TS packet of the MPEG-2 TV signal (RF signal) is demodulated by the RF tuner 41 and decoded by the decryptor 16. Note that the format of TS packets for transmitting broadcast programs is defined in the specifications of the MPEG-2 system standard (ISO / IEC 13813-1) and the Radio Industry Association (ARIB).

  The demultiplexer 20 demultiplexes the TS packet. From the demultiplexer 20, audio packets and video packets are extracted as elementary streams (ES), and further, multimedia (BML: broadcast markup language) data repeatedly transmitted by the data carousel is extracted. BML data includes graphic information such as characters and graphic information in data broadcasting.

  The audio packet output from the demultiplexer 20 is delivered to the audio decoder 21 and reproduced as an audio signal, and the video packet is delivered to the video decoder 22 and reproduced as a video signal. The multimedia data is passed to the browser 23 and converted into a screen image signal. This screen image signal is superimposed on the video signal from the video decoder 22 by the adder 24 and output.

ECM and EMM for controlling conditional access system (CAS) of broadcast programs are received via the RF tuner 41 and taken out from the demultiplexer 20. The ECM includes program attribute information for each program, and the EMM includes contract information for each viewer. If the scramble key K _S1 is not given, the decryptor 16 outputs the input as it is. The ECM and EMM taken out from the demultiplexer 20 are sent to the broadcast IC card 18.

Broadcast IC card 18, ECM output from the demultiplexer 20, generates a scramble key K _S1 using a unique master key for each EMM and IC card, and sends it to the decryptor 16.

  The lower part of FIG. 4 is a receiving system for receiving an IP network dedicated program. The IP network interface 42 receives the IP multicast packet of the IP network dedicated program, and sends the TS packet extracted therefrom to the decryptor 17 via the buffer 14 and the error correction unit 15.

  The procedure for receiving an IP network-dedicated program is basically the same as the procedure for receiving a broadcast program except that an RF signal for transmitting a TS packet is replaced with an IP packet. However, there is a difference in the BML data and EMM communication forms between the broadcast program and the IP network dedicated program, and this difference causes a difference in the reception processing of both. BML data and EMM are retrieved from the IP network interface 41 according to the request, and sent to the browser 23 and the IPTV IC card 19, respectively.

  FIG. 5 shows a protocol stack used in the hybrid STB. As described above, there is a difference in BML data and EMM communication mode between broadcast programs and IP network dedicated programs, so the hybrid STB has a protocol stack that is suitable for receiving broadcast programs and receiving IP network dedicated programs. Are set individually. As a result, programs dedicated to IP networks that are transmitted only on the IP network can be streamlined by taking full advantage of the benefits of using the IP network, such as eliminating the need for repeated transmission using a data carousel.

  As described above, in the hybrid STB architecture, a protocol stack for receiving broadcast program distribution (hereinafter referred to as a broadcast portion) and a protocol stack for receiving IP network dedicated program distribution (hereinafter referred to as an IP portion). Coexist separately.

  Various studies have been conducted on institutional and technical aspects of IP retransmission, where broadcast programs distributed as radio waves are received once, converted into IP packets by a server, and distributed over the IP network. The service is likely to start.

  At that time, it is normal to think that it is desirable to use the IP portion in the hybrid STB as a framework for receiving a broadcast program by IP retransmission. However, the IP portion in the hybrid STB is a specification that does not consider receiving broadcast programs distributed over radio waves, but only receiving IP network-only programs transmitted only over the IP network. There is a problem that it is difficult to apply to receiving broadcast programs by IP retransmission.

  The broadcast program is a specification that can handle both the case where the broadcast program of the RF signal is directly received by the TV receiver without using the STB and the case where the broadcast program by IP retransmission is received via the IP network, that is, It is required that IP retransmission is performed while maintaining a signal format capable of RF reception. This means that, in the case of IP retransmission, there is no case in the case of an RF signal, and the advantage that exists only in the case of communication on the IP network cannot be used effectively.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an integrated video signal receiving apparatus capable of supporting both broadcast programs and IP network-dedicated programs that are retransmitted by IP while maintaining a signal format capable of RF reception.

  In order to solve the above-described problems, the present invention is based on an IP network interface that receives a broadcast program and an IP network-dedicated program that have been retransmitted by IP while maintaining a signal format capable of RF reception, and IP retransmission from the IP network interface. A plurality of error correction units that perform error correction processing on each of TS packets of broadcast programs and IP network dedicated programs, and encryption of TS packets connected to each of the plurality of error correction units and input from each error correction unit A plurality of encryption / decryption processing units that perform decryption processing and a plurality of encryption / decryption processing units are provided corresponding to each of the plurality of encryption / decryption processing units, obtain a key for the encryption / decryption processing, and give the key to the corresponding encryption / decryption processing unit One TS packet multiplex / demultiplexer that performs TS packet multiplex / demultiplex processing by inputting TS packets encrypted and decrypted by the plurality of key supply units and the plurality of encryption / decryption processing units. A decoding unit that decodes each elementary stream separated by the TS packet demultiplexing unit, and a multimedia data conversion unit that converts the multimedia data separated by the TS packet demultiplexing unit into a screen image signal The IP network interface is constructed on the same IP, and the broadcast program and IP network program by IP retransmission are in accordance with a protocol stack that is standardized for a part of broadcast program and IP network program information by IP retransmission. There is a first feature in receiving.

  In addition, the present invention has a second feature in that the protocol stack is shared for information excluding multimedia data and contract information for each viewer for limited reception.

  Further, the present invention provides several types of error correction schemes and parameters thereof, or encryption schemes differ depending on a plurality of reception systems each including the plurality of error correction units and the plurality of encryption / decryption processing units. A third feature is that it can handle reception of packets.

  Furthermore, the present invention has a fourth feature in that the decoding unit can cope with reception of several types of packets having different encoding methods.

  According to the present invention, in a video distribution service using a broadband network, an integrated video signal receiving apparatus capable of supporting both a broadcast program retransmitted by IP and a program dedicated to IP network while maintaining a signal format capable of receiving RF. Can be realized.

  The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the architecture of an embodiment of a video signal receiving apparatus according to the present invention, and this video signal receiving apparatus is also configured as an STB. In addition, the same code | symbol is attached | subjected to the same or equivalent part as FIG.

  The video signal receiving apparatus according to the present invention includes an IP network interface and has an architecture capable of supporting both a broadcast program retransmitted by IP and a program dedicated to IP network while maintaining a signal format capable of RF reception. This configuration of the video signal receiving apparatus can be called an all-IP monolithic STB architecture.

  In FIG. 1, an IP network interface 11 receives an IP packet of a broadcast program and an IP network-dedicated program that have been retransmitted while maintaining a signal format that can be received by RF, extracts a TS packet, and extracts a broadcast program by IP retransmission. The TS packet is sent to the decryptor 16 via the buffer 12 and the error correction unit 13, and the TS packet of the IP network dedicated program is sent to the decryptor 17 via the buffer 14 and the error correction unit 15. The TS packet here is encrypted.

  The reason why the error correction units 13 and 14 are provided separately is that the quality required for the service differs between the broadcast program based on the IP retransmission and the IP network dedicated program. Depending on the required quality conditions, the required values for the resistance to packet loss and the delay amount are different. Thus, by providing the error correction unit separately, it is possible to use an error correction method or an error correction parameter according to each request condition. In general, the quality required for a broadcast program by IP retransmission is higher than that for an IP network dedicated program.

The decryptor 16 decrypts the TS packet using the scramble key K _S1 sent from the broadcast IC card 18, and the decryptor 17 decrypts the TS packet using the scramble key K _S2 sent from the IPTV IC card 19. To do.

  The demultiplexer 20 receives the TS packet decoded by the decryptors 16 and 17 and performs demultiplexing processing. Audio packets and video packets are extracted from the demultiplexer 20 as elementary streams (ES). In a broadcast program based on IP retransmission, multimedia (BML) data repeatedly transmitted by a data carousel is further extracted from the demultiplexer 20, whereas in an IP network dedicated program, it is extracted from the IP network interface 11 according to a request.

  The audio packet output from the demultiplexer 20 is delivered to the audio decoder 21 and reproduced as an audio signal, and the video packet is delivered to the video decoder 22 and reproduced as a video signal. The multimedia data is passed to the browser 23 and converted into a screen image. This screen image signal is superimposed on the video signal from the video decoder 22 by the adder 24 and output.

ECM and EMM for controlling limited reception (CAS) of broadcast programs by IP retransmission are received via the IP network interface 11 and taken out from the demultiplexer 20. If the scramble key K _S1 is not given, the decryptor 16 transfers the input as it is to the output side. The ECM and EMM taken out from the demultiplexer 20 are sent to the broadcast IC card 18.

Broadcast IC card 18, ECM output from the demultiplexer 20, generates a scramble key K _S1 using a unique master key for each EMM and IC card, giving the decryptor 16.

  On the other hand, the ECM for controlling conditional reception (CAS) of broadcast programs by IP retransmission is taken out from the demultiplexer 20 and sent to the IPTV IC card 19, while the EMM is taken out from the IP network interface 11. It is sent to the IC card 19 for IPTV.

IPTV for IC card 19 generates a scramble key K _S2 using a unique master key ECM output from the demultiplexer 20, each EMM and IC card is outputted from the IP network interface 11, and sends the decryptor 14 .

FIG. 2 is a block diagram showing processing in encryption and decryption for controlling conditional access (CAS). On the transmission side, the first encryption unit 31 encrypts the program signal (TS packet) with the scramble key K _S to generate an encrypted program signal. Further, the scramble key K _S and program attribute information in the second encryption unit 32 encrypts the work key K _W, to generate an ECM. The program attribute information is information for each program, and includes information indicating charge / free of charge of the program, viewing fee for the program, and the like.

Further, the third encryption unit 33 encrypts the work key K _W and the contract information for each viewer with the master key K _m unique to each IC card, and generates an EMM. The contract information for each viewer includes a contract channel and a contract expiration date. The encrypted program signals, ECM and EMM generated as described above are multiplexed and transmitted as IP packets from the transmission side to the reception side through the IP network.

On the receiving side, the encrypted program signal is sent to the first decryption unit 34, and the ECM and EMM are sent to the second decryption unit 35 and the third decryption unit 36, respectively. The third decryption unit 36 decrypts the EMM using the master key K _m, which is held in advance in an IC card, and generates the contract information for each work key K _W and viewers. In addition, when the viewer is not contracted, an EMM message such as a message prompting the contract can be generated.

Work key K _W decoded by the third decoder 36 is sent to the second decoding unit 35, contract information of each viewer is sent to the viewing determination section 37. The EMM message is sent to the output side of the first decoding unit 34.

Second decryption unit 35 decrypts the ECM using the work key K _W, generates a scramble key K _S and program attribute information. The decrypted scramble key K _S is sent to the first decryption unit 34, and the contract information for each viewer is sent to the viewing permission / inhibition determining unit 37.

  The viewing permission / non-permission determining unit 37 determines whether or not the program can be viewed based on the contract information and program attribute information for each viewer, and a switch disposed between the first and second decoding units 34 and 35 according to the determination result. The unit 38 is controlled. That is, if the program is a free program, the switch unit 38 is turned on regardless of the contract information for each viewer, but if the program is a paid program, the switch is made when the viewer IC card has a valid contract for the program. Part 38 is turned on.

The first decoding unit 24, the scramble key K _S is given decodes the program signal sent from the transmitting side, and sends a program signal decoded.

  FIG. 3 shows a protocol stack that can be used in the architecture of FIG. In the protocol stack shown in FIG. 3, a part handling an IP network dedicated program (IP portion) and a part handling a broadcast program by IP retransmission (broadcasting part) are constructed on the same IP.

  Here, the IP portion is exactly the same as the IP portion in FIG. On the other hand, the broadcast potion is shared with the IP potion for some information constituting the program. In FIG. 3, information other than BML data and EMM is shared, which is the maximum sharing. Stream media such as video and audio need only be received and played back at the moment of transmission, but BML data must be reliably acquired regardless of the reception start timing. Also, regarding EMM, since it is necessary to reliably acquire individual information in the receiving device, it is difficult to share the broadcasting portion and the IP portion. The BML data and EMM have the following differences (1) and (2) in the communication form between the broadcast program and the IP network dedicated program.

  (1) In a broadcast program, BML data is not always received from the beginning of a data set by RF reception, so it is repeatedly distributed by the MPEG-2 TS data carousel, and one cycle until one data set can be constructed During this period, reception continues. In this method, the delivery is continued repeatedly within a certain time, independently of the presence or absence of the recipient. On the other hand, for IP network-only programs, BML data is distributed by TCP unicast in terms of efficiency, and can be controlled on the transmission side so that it is always transmitted from the beginning of the data set when reception starts on the reception side. . For this reason, it is possible to efficiently transmit only the necessary information at the timing required on the receiving side.

  (2) In broadcast programs, EMM is distributed by sectioned MPEG-2 TS, and contract information other than that for the receiver itself is also distributed, so filtering on the receiving side is necessary. On the other hand, in the IP network dedicated program, EMM is transmitted by TCP unicast from the viewpoint of efficiency, and information is individually transmitted to each receiving apparatus, so that filtering on the receiving side is unnecessary.

  Considering the difference between (1) and (2) above, the protocol stack for BML data and EMM is different between the broadcast portion and the IP portion. In other words, BML data and EMM are communicated over TCP / IP using the secure (encrypted) communication procedure (TLS / SSL) using HTTP in the IP portion. (section) and MPEG-2 TS packet to be distributed on RTP / UDP / IP. Even if it is a broadcast portion, BML data that does not need to be repeatedly transmitted by carousel is made PES and MPEG-2 TS packets and distributed over RTP / UDP / IP. The IP portion SDP / RTSP is a command for communicating a video on demand (VOD) request, and is distributed over TCP / IP by TLS / SSL.

  Multiple control information PSI (Program Specific Information) such as audio packet and video packet (Audio / Video), ECM for conditional access (CAS) and information indicating the correspondence between packet ID number and media (Audio / Video / Multimedia) / For SI (Service Information) indicating an electronic program guide, the broadcast portion is shared with the IP portion. That is, for both broadcast programs and IP dedicated programs by IP retransmission, Audio / Video is converted to PES and MPEG-2 TS packets and distributed over RTP / UDP / IP. ECM and PSI / SI are sectioned and MPEG-2 TS packets are distributed over RTP / UDP / IP.

  According to the above, it is possible to receive a broadcast program and an IP network-dedicated program retransmitted by IP without changing the signal format that can be received by RF, using only one IP network interface.

  As mentioned above, although embodiment was described, this invention is not limited to the said embodiment. For example, in the above-described embodiment, there are two reception systems including a buffer, an error correction unit, and a decryptor. However, depending on the program, there are cases where packets of several formats having different error correction methods and encryption methods are transmitted. Such a case can be dealt with by individually providing a receiving system for processing them, or by selectively switching the decryption process in the decryptor. In addition, it is possible to cope with packets having different encoding methods by providing a plurality of decoders or switching processing in the decoders.

  As another embodiment, an error correction function can be provided in the IP protocol stack, and after performing error correction at the IP packet level, TS packets can be output.

  In all-IP monolithic STBs, it is desirable to use a downloadable CAS based on a security processor because it is necessary to handle multiple CAS systems simultaneously.

It is a block diagram which shows the architecture of one Embodiment of the video receiver which concerns on this invention. It is a block diagram which shows the process by the encryption and decoding for controlling conditional access (CAS). It is explanatory drawing which shows the protocol stack which can be used with the architecture of FIG. It is a block diagram which shows the architecture of the video signal receiver provided with the IP network interface and RF tuner. It is explanatory drawing which shows the protocol stack used by the architecture of FIG.

Explanation of symbols

11, 42 ... IP network interface, 12, 14 ... buffer, 13, 15 ... error correction unit, 16, 17 ... decryptor, 18 ... IC card for broadcasting, 19 ... IPTV IC card, 20 ... demultiplexer, 21 ... audio decoder, 22 ... video decoder, 23 ... browser, 24 ... adder, 31,32,33 ... encryptor, 34, 35, 36 ... Decoding unit, 37 ... Viewing availability determination unit, 38 ... Switch unit, 41 ... RF tuner

Claims (4)

One IP network interface for receiving a broadcast program and an IP network-dedicated program which are retransmitted IP while maintaining a signal format capable of RF reception;
A plurality of error correction units for performing error correction processing on each of the TS packets of the broadcast program and IP network dedicated program by IP retransmission from the IP network interface;
A plurality of encryption / decryption processing units connected to each of the plurality of error correction units and performing encryption / decryption processing of a TS packet input from each error correction unit;
A plurality of key supply units provided corresponding to each of the plurality of encryption / decryption processing units, obtaining a key for encryption / decryption processing, and giving the key to the corresponding encryption / decryption processing unit;
One TS packet demultiplexing unit that receives TS packets decrypted by the plurality of decryption processing units and performs TS packet demultiplexing processing;
A decoding unit for decoding each elementary stream separated by the TS packet demultiplexing unit;
A multimedia data conversion unit that converts the multimedia data separated by the TS packet demultiplexing unit into a screen image signal;
The IP network interface is constructed on the same IP, and receives a broadcast program and an IP network-dedicated program by IP retransmission according to a common protocol stack for a part of broadcast program and IP network-dedicated program by IP retransmission. A video signal receiving device. 2. The video signal receiving apparatus according to claim 1, wherein the protocol stack is shared for information excluding multimedia data and contract information for each viewer for limited reception. Multiple reception systems consisting of each of the plurality of error correction units and the plurality of encryption / decryption processing units can support reception of packets of several types with different error correction methods and parameters, or different encryption methods. The video signal receiving apparatus according to claim 1, wherein the video signal receiving apparatus is a video signal receiving apparatus. 4. The video signal receiving apparatus according to claim 1, wherein the decoding unit is capable of receiving a plurality of types of packets having different encoding methods.

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