JP2009212588A - Descrambling apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make a specific (for instance, under viewing) program smaller than the delay of a specific (for instance, under viewing) program, and to obtain the descrambling keys of more programs by one CAS card. <P>SOLUTION: According to a first invention, a delay amount is made smaller than that of the program not under viewing and ES packets are not delayed for the specific (under viewing) program, scrambled ES packets are delayed for 400 ms at maximum for the program not under viewing, and decoding processing in the CAS card is executed fully utilizing the cycle of 2,000 ms at maximum. Also, according to a second invention, by delaying the scrambled ES packets for 400 ms, the decoding processing in the CAS card is executed fully utilizing the cycle of 2,000 ms. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a receiving device that receives a transport stream, and more particularly, to a descrambling device that descrambles a plurality of transport streams in which content is scrambled.

2. Description of the Related Art Conventionally, a descrambling apparatus that delays ES (Elementary Stream) and simultaneously descrambles a plurality of programs with one IC card is known (see, for example, Patent Document 1).
JP-A-2005-080142

  In a conventional descrambling apparatus, a specific (for example, viewing) program (for example, viewing) has a smaller amount of delay than other (not viewing) programs and does not delay the scrambled ES packet. There is a problem that the number of TSs that can be processed per CAS card cannot be increased while the delay in the program is smaller than that of other programs.

  In addition, the conventional descrambling apparatus has a problem that the number of TSs that can be processed per CAS card cannot be maximized by making full use of the delayable time.

  An object of the present invention is to provide a descrambling apparatus that can reduce the delay of a specific (for example, viewing) program to a delay of the specific (for example, viewing) program.

  Another object of the present invention is to provide a descrambling device that can obtain a descramble key for a plurality of programs with a single CAS card.

  In order to achieve the above object, in the present invention, an ES separation means for separating an ES (Elementary Stream) from a scrambled transport stream, and an ECM (Entitlement Control Message) from the scrambled transport stream. ECM separation means for separating, ECM holding means for holding ECM separated by the ECM separation means, and a plurality of receiving means including descrambler for descrambling the ES using an input key, First delay means for delaying the ECM of a program which is a specific transport stream among the scrambled transport streams by a delay amount of 0 or a predetermined time, and among the plurality of the specific transport streams ECMs other than programs that are A second delay means for delaying for a longer time, and an arbitration order for outputting the ECMs held by the plurality of ECM holding means in the plurality of receiving units, and an arbitration for outputting the ECMs in the arbitrated order And the ECM from the first or second delay means are input, and a key for outputting to the descrambler corresponding to the ECM a key for descrambling the ES corresponding to the ECM is output A descrambling apparatus comprising: a scrambler.

  In order to achieve the above object, in the present invention, an ES separation means for separating an ES (Elementary Stream) from a scrambled transport stream, and an ECM (Entitlement Control Message) from the scrambled transport stream. ECM separation means for separating, ECM holding means for holding ECM separated by the ECM separation means, and a plurality of receiving means including descrambler for descrambling the ES using an input key, First delay means for delaying a plurality of ECMs obtained by a plurality of ECM separation means by a time during which an ECM including key information for the next same scramble key usage period is always transmitted; and Arbitrate the output order of the ECMs held by multiple ECM holding means. An arbitration unit that outputs the ECM in the stopped order, and the ECM from the first or second delay means are input, and a key for releasing the scrambling of the ES corresponding to the ECM is used as the ECM. And a key generation unit that outputs the descrambler to the descrambler.

The present invention relating to the apparatus is also established as an invention relating to a method, and the present invention relating to a method is also established as an invention relating to an apparatus.
Further, the present invention relating to an apparatus or a method has a function for causing a computer to execute a procedure corresponding to the invention (or for causing a computer to function as a means corresponding to the invention, or for a computer to have a function corresponding to the invention. It can also be realized as a program (for realizing the program), and can also be realized as a computer-readable recording medium on which the program is recorded.

  According to the first aspect of the present invention, the delay of a specific (for example, viewing) program can be made smaller than that of a specific (for example, viewing) program. Further, according to the second aspect of the present invention, it is possible to obtain descrambling keys for a plurality of programs with a single CAS card.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram for explaining the configuration of a digital broadcast receiving apparatus as an example of a descrambling apparatus according to the present invention. This digital broadcast receiving apparatus is configured to simultaneously receive a plurality (n) of transport streams (TS). Note that FIG. 1 is a functional block diagram, and each block does not necessarily have to have its own hardware. For example, a single descrambler processes the roles of a plurality of descramblers in a time-sharing manner. It may be configured as described above.

  In FIG. 1, a transport stream received by a tuner (not shown) or the like is input to a TS demultiplexing unit (hereinafter referred to as TS demultiplexer) 101a. The TS demultiplexer 101a separates an ES (Elementary Stream), a flag, and an ECM (Entitlement Control Message) from the input transport stream (TS). The TS demultiplexer 101a outputs the separated ES to the delay unit 102a, and outputs the flag and ECM to the latch 104a.

  Note that digital broadcast program arrangement information is standardized by ARIB (Radio Industry Association) STD-B10 (program arrangement information used for digital broadcasting), and ECM is ARIB STD-B25 (limited in digital broadcasting). (Receiving method).

The delay unit 102a delays the ES input from the TS demultiplexer 101a by a time to be described later, and then outputs it to the descrambler 103a.
The descrambler 103a descrambles video and audio using the descrambling key supplied from the key register 107, and outputs the descrambled signal to, for example, an MPEG2 decoder subsequent to the subsequent stage.

  The latch 104 a is supplied with the flag and the ECM from the TS demultiplexer 101 a, latches the ECM at a timing based on the flag, and outputs the latched value to the arbitration unit 105.

  Similar to the processing of the TS demultiplexer 101a, the delay unit 102a, the descrambler 103a, and the latch 104a, the processing for the remaining n-1 transport streams is performed by the TS demultiplexer 101b,..., 101n, the delay unit 102b,. 102n, descramblers 103b,..., 103n and latches 104b,..., 104n, and signal processing for a plurality (n) of transport streams is simultaneously processed in parallel.

  The arbitration unit 105 receives ECMs for n transport streams, supplies these ECMs to a CAS card 106 as a key generation unit, obtains a key for descrambling video and audio from the CAS card 106, and converts the ECMs. It is stored in the key register 107 in association with the port stream. A key obtained by unraveling the ECM supplied from the latch 104a is held as a key for the descrambler 103a, and a key released from the ECM supplied from the latch 104n is held as a key for the descrambler 103n.

Further, the arbitration unit 105 arbitrates the order in which the stream ECM is supplied to the CAS card 106. This arbitration method will be described in detail later.
The CAS card 106 solves the ECM input from the arbitration unit 105 and returns a key for descrambling the solved video and audio to the arbitration unit 105.
The key register 107 holds the key obtained by releasing the ECM supplied from the latch 104a as a key for the descrambler 103a, and the key obtained after releasing the ECM supplied from the latch 104n as the key for the descrambler 103n.

  The code data decoding unit 110 receives descrambled ES, decodes the encoded ES, and outputs the decoded video / audio signal to a display or a speaker (not shown). The code data decoding unit 110 is not always necessary when a program is recorded on a recording medium.

FIG. 2 is a diagram for explaining the configuration of one TS demultiplexer 101 in FIG. 1 in more detail.
The TS input to the TS demultiplexer 101 is not limited to broadcasting, but is TS from a recording medium such as a DVD (Digital Versatile Disk) or HDD (Hard Disk Drive), or a network such as an IP network or a LAN. Also good.

  The received broadcast TS is scrambled and needs to be descrambled using a descrambling key in order to correctly decode and display images and sounds.

  The TS input from the input terminal 251 is supplied to the PID filter 201, the flag detection unit 202, the PID filter 211, the PID filter 213, and the PID filter 215.

The PID filter 201 extracts an ES (Elementary Stream) of a desired program and outputs it to the delay unit 102 via the output terminal 252.
The flag detection unit 202 detects a change in the scramble flag in the TS header, and outputs the detected timing signal to the delay unit 203.
The delay unit 203 delays the flag input from the flag detection unit 202 by a predetermined time, and then outputs it to the latch 104 via the output terminal 253.
The PID filter 211 extracts a packet having the PID of the packet including the PAT information from the TS input from the input terminal 251, and outputs the payload portion of the packet including the extracted PAT information to the section filter 212.

  The section filter 212 extracts a PAT (Program Association Table) from the payload portion of the packet including the PAT information input from the PID filter 211, and sets the PID value of the PMT extracted from this PAT in the PID filter 213.

  The PID filter 213 extracts a packet having a PID of a packet having PMT information from the TS input from the input terminal 251, and outputs the payload portion of the packet having the extracted PMT information to the section filter 214.

  The section filter 214 extracts a PMT (Program Map Table) from the payload portion of the packet having the PMT information input from the PID filter 213, and sets the PID value of the ECM extracted from the PMT to the PID filter 215.

  The PID filter 215 extracts a packet having the PID of the ECM information from the TS input from the input terminal 251, and outputs the payload portion of the extracted ECM information packet to the section filter 216.

  The section filter 216 extracts an ECM (Entitlement Control Message) from the payload portion of the packet of the ECM information input from the PID filter 213, and outputs the extracted ECM to the latch 104 via the output terminal 253.

Prior to describing the processing of the present invention, the scramble unit of Japanese digital broadcasting to which the present invention relates will be described in detail with reference to FIGS.
8 to 12 are diagrams for explaining Japanese digital broadcasting standards.
Key data for descrambling is sent in the same TS as video and audio in the section format data called ECM. FIG. 8 and FIG. 9 are diagrams for explaining the ECM transmitted by the data in the section format. The ECM section includes an 8-byte ECM section header, an ECM body, and a section CEC.

  When the arbitration unit 105 of the digital broadcast receiving apparatus transmits the ECM together with the command to the CAS card 106, the CAS card 106 returns a key as a response. FIG. 10 is a diagram for explaining a command for transmitting the ECM together with the CAS card 106. A command needs to be added before ECM data for transmission.

FIG. 12 is a diagram illustrating timings of the same ECM transmission period and the same scramble key usage period.
As shown in FIG. 12, the length of the same ECM transmission period (ECM update cycle), that is, T1 + T2, is T1 + T2> 2000 [ms], and is close to 2000 [ms] (for example, 2001 [ms]). Scramble with the same key is performed for about 2 seconds.

  Also, as shown in FIG. 12, since it is standardized by the limitations of 1600 [ms] <T1 and 0 <T2, 1600 [ms] (T1 period after the changed key is transmitted) It shows that an ECM including key information for the next same scramble key usage period is always transmitted within 2000 [ms] -400 [ms]).

The TS scramble key change timing is indicated by a flag included in the TS header.
As described in FIG. 12 as 1600 [ms] <T1, in order to be able to continuously descramble normally, the time required to obtain the descrambling key after receiving the ECM is Within 1600 [ms].

FIG. 11 is a diagram showing a time chart that can be used for switching from the non-scrambled state to the scrambled state.
Next, the operation of the digital broadcast receiving apparatus as an example of the descrambling apparatus of the present invention will be described with reference to FIG.
As described with reference to FIG. 1, the digital broadcast receiving apparatus receives a plurality (n) of TSs simultaneously. When all the n TSs are scrambled, it is necessary to descramble the n TSs.

  That is, in accordance with the Japanese digital broadcast standard, the digital broadcast receiving apparatus needs to operate so that n keys can be obtained within 1600 [ms] after receiving the ECM.

Serial communication is used for communication of the CAS card 106 as a low-speed interface used in Japanese digital broadcasting.
Also, the extraction of the ECM from the TS and the command transmission to the CAS card 106 are often implemented by software control and require time Tk0. Further, it takes time to perform processing inside the CAS card 106.

Also, it takes time Tk1 to receive the key from the CAS card 106 and set it in the descrambler.
Now, let the total time of these Tk0 and Tk1 be Tk2 (Tk2 = Tk0 + Tk1).
No matter how fast the internal processing of the CAS card 106 is, it takes more than Tk2 to decode the ECM.
If the scramble key update timings of all n TSs are the same, it is desired to send n ECMs to the CAS card 106 at the same time, but since the CAS card 106 can process one command at a time, the arbitration unit It is necessary to send the ECMs to the CAS card 106 in order under the arbitration of 105. Since one key process takes Tk2 time, n key processes take Tk2 × n time. Therefore, in order to correctly descramble all n TSs, it is necessary to satisfy the condition of Tk2 × n <1600 [ms].

  As described with reference to FIG. 12, the update cycle of the descrambling key is defined as 2000 [ms] at the shortest. Therefore, the upper limit of Tk2 × n is set to 1600 [ms] by delaying the timing of the scrambled packet. ] To 2000 [ms] is theoretically possible.

In the example of FIG. 1, the delay unit 102 delays the timing of the scrambled packet.
If Tk2 is constant, n can be increased, and an effect that the number of TSs that can be processed per CAS card 106 can be increased can be obtained. As a result, it is possible to avoid the need to use a plurality of CAS cards 106 as a receiver capable of simultaneously receiving multiple programs. As a result, it can be expected that the cost of the receiver will be reduced and the trouble of issuing and receiving cards will be saved.

Next, the operation when the timing of the scrambled packet is delayed will be described in detail with reference to FIG.
FIG. 3 shows the delay processing.
FIG. 3A shows a PMT.
FIG. 3B is a diagram showing an ECM obtained from the PMT of FIG. In FIG. 3 (b), it is an indefinite period whether an ECM can be obtained for the part indicated by "X", and the blank white part is a period for obtaining an ECM. The ECM sent during the period 302 in FIG. 3B is used for the ES during the next period 303.

  3C is a diagram showing a scrambled ES packet (TS header is taken) obtained from the PID filter 201 of FIG. 2 from the original TS from which FIG. 3A is extracted. Is a diagram showing a signal when no delay processing is performed (delay time = 0).

FIG. 3C 'is a diagram showing signal timings when descrambling is performed by delaying the ES packet of FIG. 3C by 100 [ms].
FIG. 3C ″ is a diagram illustrating signal timing when the descrambling process is performed by delaying the ES packet of FIG. 3C by 400 [ms].
The lower limit of Tk2 is obtained from the communication speed of the CAS card 106, the ECM, and the key data length. Now, the lower limit of Tk2 is assumed to be 100 [ms]. Then, as shown in FIG. 3 (c ′), there should be no problem even if the scrambled packet is delayed by 100 [ms] and the descrambling process is performed. For this reason, for example, as shown in FIG. 3C ′, it is examined whether there is a problem with the processing when the descramble processing is performed by delaying the scrambled packet with respect to the ECM processing by D1 = 100 [ms]. I will do it.

  Even if the ECM is updated immediately after the key update, in order to obtain a new key, 100 [ms], which is the lower limit of Tk2, is necessary. Therefore, a new key may come out from a scrambled packet. Absent. Conversely, if the ECM is sent 1600 [ms] before the next scramble key, the scrambled packet is delayed by 100 [ms], so the time Tk2 required to obtain a new key is obtained. Can be increased up to 1600 [ms] +100 [ms] = 1700 [ms].

Therefore, even if the descramble process is performed by delaying the scrambled packet by 100 [ms], a problem such as failure does not occur in the timing of the process.
Further, as shown in FIG. 3C ″, the ECM processing unit is configured to start the ECM processing after D2 = 400 [ms] from the key update timing, and the scrambled packet is delayed by 400 [ms]. By performing the descrambling process, the upper limit of Tk2 can be increased to 2000 [ms]. Further, even if the descramble process is performed by delaying the scrambled packet by 400 [ms], problems such as failure do not occur in the timing of the process.

  The value of D2 = 400 [ms] to be delayed in FIG. 3 (c ″) is always determined from the conditions of T1 + T2 = 2000 [ms] and T1 <1600 [ms] defined in the operation rule of FIG. It is a value of a period until the ECM of the next period is transmitted, and is a value obtained as 2000 [ms] -1600 [ms] = 400 [ms].

Although the processing timing when one TS (program) is delayed has been described with reference to FIG. 3, in practice, operation with a plurality of TSs is possible as shown in FIG.
1 may be an independent TS, or the same TS including a plurality of programs may be supplied to a plurality of 101. In this case, a part of each 101 can share a circuit with each other.

Next, the operation when a plurality of TSs are processed will be described in detail with reference to FIG.
FIG. 4 shows the delay processing.
FIG. 4A shows a PMT.
FIG. 4 (b1) is a diagram showing an ECM obtained from the PMT of FIG. 4 (a).
FIG. 4 (c1) is a diagram showing the scrambled ES obtained from the PID filter 201 of FIG. 2 from the original TS from which FIG. 4 (a) was extracted. It is a figure which shows the timing of the signal in the case of performing a scramble process. Here, the reason for delaying 400 [ms] is that T1 + T2 = 2000 [ms] and T1 <1600 defined in the operation rule of FIG. 12, as described above with reference to FIG. It is the value of the period until the ECM of the next period is transmitted from the condition of [ms], and is a value obtained as 2000 [ms] -1600 [ms] = 400 [ms].

The data shown in FIG. 4 (b1) and FIG.
FIG. 4B2 is a diagram illustrating an ECM obtained from a TS different from the TS from which FIG. 4A is extracted.
FIG. 4 (c2) is a diagram showing the scrambled ES obtained from the PID filter 201 of FIG. 2 from the other TS, and a signal when the descrambling process is performed with the packet delayed by 400 [ms]. It is a figure which shows the timing of.

The data shown in FIGS. 4B2 and 4C2 is referred to as program 2.
Here, in order to simplify the description, the following description will be continued on the assumption that there are data for n-1 programs from program 2 to program n (FIG. 4 (bn) and FIG. 4 (cn)).
Next, the arbitration operation by the arbitration unit 105 will be described in detail with reference to FIG.
FIG. 5 is a flowchart showing the priority order of arbitration by the arbitration unit 105.
Step S501: First, the arbitration unit 105 proceeds to the process of Step S502 if the ECM of the program 1 has been obtained, and proceeds to the process of Step S503 if not obtained.
Step S502: The arbitration unit 105 uses the CAS card 106 to solve the ECM of program 1, and then proceeds to step S503.
Step S503: The arbitration unit 105 proceeds to the process of step S504 if the ECM of the program 2 has been obtained, and proceeds to the process of step S505 if not obtained.
Step S504: The arbitration unit 105 uses the CAS card 106 to solve the ECM of program 2, and then proceeds to step S505.
Step S505: The arbitration unit 105 proceeds to the process of step S506 if the ECM of the program n is obtained, and proceeds to the process of step S507 if it is not obtained.
Step S506: The arbitration unit 105 uses the CAS card 106 to solve the ECM of program n, and then proceeds to step S501.
By repeating steps S501 to S506 described above, the ECM of each program is sequentially sent to the CAS card 106, and the ECM is descrambled.
Next, an example of the arbitration operation of the arbitration unit 105 in ECM descrambling will be described with reference to FIGS. 4 and 5.
In the example shown in FIG. 4, since the ECM of program 1 is first obtained at the timing of reference numeral 305 (Yes in step S501), the ECM of program 1 is solved by the CAS card 106 at the timing of reference numeral 305 (step S502). .

  Next, a plurality of ECMs of programs 2,. As shown in FIG. 4, the arbitration unit 105 sends ECMs to the CAS card 106 in the order of ECMs of programs 2,.

  As described above, according to the present invention, the process until the descramble key is obtained from the ECM by delaying the timing of the scrambled packet by delaying the scrambled ES packet by 400 [ms] may be applied. Since the upper limit of time has been raised from 1600 [ms] to 2000 [ms], it is possible to execute the decryption process with the CAS card by making full use of the period of 2000 [ms]. If Tk2 is constant, n can be increased, and the effect that the number of TSs that can be processed per CAS card 106 can be increased can be obtained.

  As a result, it is possible to avoid the need to use a plurality of CAS cards 106 as a receiver capable of simultaneously receiving multiple programs. As a result, it can be expected that the cost of the receiver will be reduced and the trouble of issuing and receiving cards will be saved.

  In the above description, the merits of using one CAS card have been described. However, the present invention may be applied when a plurality of CAS cards are used, and more TSs may be processed. Even if it does in this way, the same effect as a previous example can be acquired.

(Second Embodiment)
The second embodiment of the present invention will be described below with reference to the drawings.
Since the second embodiment is different in that FIG. 4 is changed to FIG. 6 and FIG. 5 is changed to FIG. 7, only the changed portion will be described.
When the scrambled packet is delayed, the viewing time is delayed. This is because the packet delay time is set assuming that the key processing takes the longest time. Even a receiver that receives a plurality of programs may have only one program to watch and then only record.

  For a specific TS (for example, the TS of a program being viewed), the descrambling process is performed with a delay time shorter (or without delay) than other TS (for example, a TS for recording a program). Furthermore, the ECM of a specific TS (for example, the TS of the program being viewed) is preferentially processed, such as being transmitted to the CAS card preferentially over the ECM of another TS (for example, the TS that records the program). is there.

Next, the arbitration operation by the arbitration unit 105 will be described in detail with reference to FIG.
FIG. 7 is a flowchart showing the priority order of arbitration by the arbitration unit 105.
Step S701: First, the arbitration unit 105 proceeds to the process of Step S702 if the ECM of the program 1 which is a specific TS (for example, the TS of the program being viewed) is obtained, and in the case where it is not obtained, the process proceeds to Step S703. Move on to processing.

  Step S702: The arbitration unit 105 uses the CAS card 106 to solve the ECM of program 1 that is a specific TS (for example, the TS of the program being viewed), and then proceeds to step S703.

  Step S703: The arbitration unit 105 proceeds to the process of step S704 if it has obtained the ECM of the program 2, which is another TS (for example, the TS that records the program), and proceeds to the process of step S705 if it has not been obtained.

Step S704: The arbitrating unit 105 uses the CAS card 106 to solve the ECM of the program 2, which is another TS (for example, a TS for recording the program), and then proceeds to step S705.
Step S705: The arbitration unit 105 proceeds to the process of step S706 if the ECM of the program 1 which is a specific TS (for example, the TS of the program being viewed) is obtained, and proceeds to the process of step S707 if not obtained. .

  Step S706: The arbitration unit 105 uses the CAS card 106 to solve the ECM of program 1 that is a specific TS (for example, the TS of the program being viewed), and then proceeds to step S707.

  Step S707: The arbitration unit 105 proceeds to the process of step S708 if it has obtained the ECM of the program 3, which is another TS (for example, the TS to record the program), and proceeds to the process of step S709 if it has not been obtained.

Step S708: The arbitration unit 105 uses the CAS card 106 to solve the ECM of the program 3, which is another TS (for example, a TS for recording a program), and then proceeds to step S709.
Step S709: The arbitration unit 105 proceeds to the process of step S710 if the ECM of the program 1 which is a specific TS (for example, the TS of the program being viewed) is obtained, and proceeds to the process of step S711 if it is not obtained. .

  Step S710: The arbitration unit 105 uses the CAS card 106 to solve the ECM of program 1 that is a specific TS (for example, the TS of the program being viewed), and then proceeds to step S711.

This is repeated up to n-1 programs.
Step S711: The arbitration unit 105 proceeds to the process of step S706 if the ECM of the program n has been obtained, and proceeds to the process of step S707 if not obtained.
Step S712: The arbitration unit 105 uses the CAS card 106 to solve the ECM of program n, and then proceeds to step S701.
In this way, when the ECM of each program is sequentially sent to the CAS card 106 and the ECM is descrambled, the ECM of the program 1 that is a specific TS (for example, the TS of the program being viewed) is preferentially processed.

This makes it possible to process more programs with one CAS card while reducing the delay time of the program to be viewed.
In the above example, priority is given to processing the ECM of program 1 which is a specific TS (for example, the TS of the program being viewed) once every two times, but the present invention is not limited to this. Priority may be given to processing once every three times, or priority may be given to processing twice consecutively.

  As described above, according to the present invention, a specific (currently viewed) program is scrambled for a program that is not viewed without delaying a scrambled ES packet with a smaller delay than a program that is not viewed. The delayed ES packet is delayed by a maximum of 400 [ms], and the decoding process by the CAS card is executed using the full cycle of a maximum of 2000 [ms]. In addition, the effect that the number of TSs that can be processed per one CAS card 106 can be increased can be obtained.

  As a result, it is possible to avoid the need to use a plurality of CAS cards 106 as a receiver capable of simultaneously receiving multiple programs. As a result, it can be expected that the cost of the receiver will be reduced and the trouble of card issuance and reception procedures will be saved.

  In the above description, the merits of using one CAS card have been described. However, the present invention may be applied when a plurality of CAS cards are used, and more TSs may be processed. Even if it does in this way, the same effect as a previous example can be acquired.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

The figure for demonstrating the structure of a digital broadcast receiver as an example of the descrambling apparatus in this invention. The figure for demonstrating in more detail the structure of one TS demultiplexer 101. FIG. The figure which shows the time chart of the signal for demonstrating operation | movement of the digital broadcast receiver as an example of the descrambling apparatus of this invention. The figure which shows the time chart of the signal for demonstrating operation | movement of the digital broadcast receiver as an example of the descrambling apparatus of this invention. The flowchart for demonstrating the arbitration operation | movement by an arbitration part. The figure which shows the time chart of the signal for demonstrating operation | movement of the digital broadcast receiver as an example of the descrambling apparatus of this invention. The flowchart for demonstrating the arbitration operation | movement by an arbitration part. ARIB STD-B25 “Access Control Method in Digital Broadcasting” Version 5.0 3.2.3.2 ECM Section Structure Table 3-1 shows the ECM section structure. ARIB STD-B25 “Access Control Method in Digital Broadcasting” 5.0 Version 3.2.3.1 Basic Configuration of ECM Figure 3-4 shows the configuration of the ECM section. ARIB STD-B25 “Access Control Method in Digital Broadcasting” 5.0 Version 4.3.3.3 Details of Command / Response Table in Table 4-11 ECM Receive Command. The figure which shows the start of ARIB TR-B14 "terrestrial digital television broadcast operation specification" 3.3 version 4.1.10.1 scramble. The figure which shows the update of ARIB TR-B14 "terrestrial digital television broadcast operation specification" 3.3 version 4.1.5.3 ECM and the change of a scramble key.

Explanation of symbols

101a to 101n ... TS demultiplexer (TS demultiplexer),
102a to 102n ... delay unit,
103a to 103n ... descrambler,
104a-104n ... Latch,
105 ... mediation department,
106 ... CAS card,
107: Key register,
110: Code data decoding unit.

Claims (5)

ES separation means for separating ES (Elementary Stream) from the scrambled transport stream;
ECM separation means for separating ECM (Entitlement Control Message) from the scrambled transport stream;
ECM holding means for holding the ECM separated by the ECM separation means;
A plurality of receiving means including a descrambler that descrambles the ES using an input key;
First delay means for delaying an ECM of a program which is a specific transport stream among the scrambled transport streams by a delay amount of 0 or a predetermined time;
Second delay means for delaying ECM other than the program that is the specific transport stream among the plurality of times longer than the predetermined time;
An arbitration unit that arbitrates the order of outputting the ECMs held by the plurality of ECM holding units in the plurality of reception units, and outputs the ECMs in the arbitrated order;
A key generation unit that receives the ECM from the first or second delay unit and outputs a key for descrambling the ES corresponding to the ECM to the descrambler corresponding to the ECM; A descrambling device comprising the scrambler.   The descrambling apparatus according to claim 1, wherein the arbitration unit outputs the ECM of the program that is the specific transport stream to the key generation unit in preference to other ECMs.   3. The descrambling apparatus according to claim 1, wherein the program that is the specific transport stream is a program that is being viewed.   4. The descrambling apparatus according to claim 1, further comprising decoding means for decoding the code data of the ES and display means for displaying a signal decoded by the decoding means. . ES separation means for separating ES (Elementary Stream) from the scrambled transport stream;
ECM separation means for separating ECM (Entitlement Control Message) from the scrambled transport stream;
ECM holding means for holding the ECM separated by the ECM separation means;
A plurality of receiving means including a descrambler that descrambles the ES using an input key;
First delay means for delaying a plurality of ECMs obtained by the plurality of ECM separation means by a time during which an ECM including key information for the next same scramble key usage period is necessarily transmitted;
An arbitration unit that arbitrates the order of outputting the ECMs held by the plurality of ECM holding units in the plurality of reception units, and outputs the ECMs in the arbitrated order;
A key generation unit that receives the ECM from the first or second delay unit and outputs a key for descrambling the ES corresponding to the ECM to the descrambler corresponding to the ECM; A descrambling device comprising:

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