JP2002051321A - Digital video transmitter, digital video receiver and digital video transmitter-receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a digital video receiver which gives viewers a chance to watch at least one commercial program, by inserting an ECM containing a work key for decoding a scramble into the part of the commercial program constituting a TS stream that transmits by scrambling. SOLUTION: This digital video receiver is provided with a program supplying server digital broadcasting programs, a CM-supplying server to supply commercial programs, a scrambler for scrambling a digital broadcasting program by using a prescribed work key, and a CASS controller for generating digital broadcasting data by inserting digital program data, commercial program data and an ECM that have a work key, into the commercial data and multiplexing them with a multiplexer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a digital video transmitter, a digital video receiver, and a digital video transceiver, and more particularly to a CASS (Condi).
Tional Access Sub-System;
ECM (Ent) which is an element of the conditional access device module
The present invention relates to a digital video transmitter, a digital video receiver, and a digital video transceiver that insert an element control message into a commercial portion of a broadcast program only.

[0002]

2. Description of the Related Art Digital Video Broadcast (Digital Video Broadcast);
A receiver (hereinafter referred to as DVB) is a conditional access device (Condi).
It is configured so that it can be connected to a Tional Access Sub-System (hereinafter referred to as CASS) module. The DVB receiver receives and demodulates a plurality of broadcast signals distributed from a plurality of broadcast stations. Data of a specific broadcast channel or broadcast data of a specific program in these channels is stored in a transport stream (Toransport Str) such as MPEG.
eam; hereinafter, referred to as TS) data is scrambled so that a non-subscriber cannot receive the data, and the packet of this TS is EC which is common information including program information and control information.
M (Entitlement Control Mes)
Sage) section and EMM (En)
Title Management Message
age) section inserted and sent. The CASS module controls reception of broadcast data, for example, by descrambling broadcast data. The CASS module having such a function also has service contract information managed by a service provider. The service provider provides key information for descrambling the scrambled data (hereinafter referred to as a work key and EC).
M) and service contract information (present in EMM). The service provider uses a work key to descramble the scrambled data and an encrypted message carrying the service management information.
Access the ASS module. As a result, it becomes possible to perform conditional access in which only those who have contracted with the service provider can enjoy the broadcast service.

[0003] As shown in FIG. 5, an ECM having program information contained in a TS packet forms an ECM section, and is composed of an ECM section header, an ECM body, and a section CRC.

[0004] The structure of the ECM section is shown in Figs.
As shown in ECM section header, ECM body,
And a section CRC. The ECM main body includes a fixed part, a variable part, and falsification detection. The fixed unit includes a protocol number, a paying entity identification, a work key identification, a scramble key (ODD), a scramble key (EVEN), a determination type, a date and time, and a recording control.

[0005]

However, in a digital video broadcast transmitted by scrambling / descrambling described in the prior art, an ECM having program information including a work key as a decryption key is inserted into a broadcast program portion. In such a case, there is a problem that even if the desired broadcast program can be viewed, the program provider does not see the commercial desired to be watched or misses the opportunity to watch the commercial.

[0006] Therefore, there is a problem that must be solved in order to watch a commercial at least once when watching a broadcast program.

[0007]

In order to solve the above problems, the configurations of a digital video transmitter, a digital video receiver and a digital video transceiver according to the present invention are as follows.

(1) A program supply server for supplying a digital broadcast program, a CM supply server for supplying commercials, a scrambler for scrambling the digital broadcast program using a predetermined work key, and a scrambled digital broadcast A digital video transmitter comprising at least a CASS controller for multiplexing program data and commercial data into which ECM having program information including a work key is inserted by a multiplexer to generate digital broadcast data. (2) The digital video transmitter according to (1), wherein the ECM is inserted into the commercial data at random timing. (3) The digital video transmitter according to (1), wherein the ECM is divided into portions of the commercial data and inserted at random timing.

(4) A tuner for receiving digital broadcast data, a work key is extracted from an ECM having program information included in commercial data of the received digital broadcast data, and digital broadcast data is decompressed based on the work key. A digital video receiver comprising at least a scrambling controller. (5) The digital video receiver according to (4), wherein the ECM is inserted into the commercial data at random timing. (6) The digital video receiver according to (4), wherein the ECM is divided into the commercial data portions and inserted at random timing.

(7) An ECM including a work key is inserted into a commercial data portion attached to a digital broadcast program, a transport stream composed of scrambled digital broadcast data is transmitted, and the transport stream is received. A digital video transceiver for extracting an ECM including a work key inserted in a data portion, and scrambling the disk with the work key to obtain a desired digital broadcast program. A digital video transceiver based on a request from a broadcast program receiver. (8) The digital video transceiver according to (7), wherein the received digital broadcast program can be stored in a predetermined recording medium. (9) The ECM including a work key to be inserted into the commercial data portion is inserted into the commercial data portion at random timing. (7)
A digital video transceiver according to claim 1. (10) The digital video transceiver according to (7), wherein the ECM including a work key to be inserted into the commercial data portion is divided into the commercial data portion and inserted at random timing.

As described above, by inserting the ECM having the program information including the work key for decrypting the scramble into the commercial part, the broadcast program receiver is given an opportunity to watch the commercial at least once. Will be able to do it.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of a digital video transmitter, a digital video receiver and a digital video transceiver according to the present invention will be described with reference to the drawings.

In the digital video transceiver according to the present invention, the CASS module includes a broadcast program status, that is, an ECM describing program information and an EM describing recipient rights.
Using M, a work key for descrambling is extracted based on a match between the information described in both. In a broadcast program, the transmission frequency of the ECM is generally very high. For example, the ECM is transmitted once every 100 ms, and descrambling can be immediately canceled after the receiver starts receiving.

In the present invention, the transmission of the ECM is inserted into the commercial part in front of the broadcast program main body and transmitted, and the receiver cannot cancel the scramble of the broadcast program main body without receiving the commercial. . Also, if this ECM is transmitted at random timing during the commercial transmission, it becomes difficult for the receiver to receive the broadcast program main body after shifting from the commercial to another broadcast program, and receiving at least one commercial If not, descrambling of the desired broadcast program becomes impossible, which is more suitable. It is more expedient to divide the contents of the ECM into several packets and send them at several times during the commercial period. If the present invention is applied to general broadcasting, there is a problem because descrambling cannot be canceled until a commercial is sent. However, in the case of a Broadband system, that is, a server is provided on the sending side and reception is started by a request from the receiving side. However, there is no problem in applying this method. Also, there is no problem in the case where the receiving side has a recording medium and the broadcast program is once recorded and held here.

Thus, the ECM is added to the commercial part.
As shown in FIG. 1, a digital video transmitter that inserts and transmits a digital broadcast program includes a program supply server 110 that supplies a digital broadcast program, and a CM supply server 12 that supplies commercials.
0, a scrambler 130 for scrambling a digital broadcast program using a predetermined work key, and scrambled digital broadcast program data, commercial data,
And a CASS controller 150 that inserts ECM having program information including a work key into commercial data, multiplexes the commercial data with a multiplexer 140, and generates digital broadcast data. E having program information including a work key to be inserted into the commercial data
The CM may be inserted into the commercial data at a random timing, or may be an ECM having program information including a work key to be inserted into the commercial data portion.
May be divided and randomly inserted into the commercial data portion. A method of dispersing and inserting the ECM will be described later.

Here, a method for the CASS controller 150 to insert an ECM into a commercial part will be described first. A method for linking the ECM with time information in a broadcast program will be described. MPEG (standard; IEC / ISO1)
3818-6; DSM-CC), assuming accumulation,
The link to the time in the broadcast program is changed to NPT (NormalP
(Layback Time). This NPT is "NPT Referenc
e Descriptor ”is inserted at any time, so that“ Clock Reference (ST)
C), information on the time axis of the broadcast program is given. In FIG. 3, at the start of the broadcast number, NPT is set to 0, monotonically increased while synchronizing with the STC, the NPT is frozen at the start of the commercial (NPT = T1), and is increased again at the end of the commercial.

A desired function can be obtained by describing the effective range to the NPT in the ECM. In FIG. 3 described above, the effective range of the ECM in the commercial CM1 is NPT =
If NPT = T2 is described from T1, viewing is possible during that time. In addition, the “Contro
If "1 Word (Work Key; work key)" is stored in the memory together with the NPT range, an arbitrary portion can be freely reproduced after a commercial (CM) is viewed once.

Next, a method for distributing ECMs in commercials will be described. As described with reference to FIGS. 5 to 7 described in the related art, one ECM section includes one ECM section in one TS packet.
It is transmitted as “Section Data” called “M section”. This “Section Data” is described in “Standard; 2.4.4.10 of ISO / IEC 13818-1”.
yntax is defined. This syntax is, as shown in FIG. 4, "Private section".
Is defined in "section_sy
If “tax_indicator” is set to “1”, “Section Data” is set to “section_n”.
The packet can be divided into a plurality of packets using "number." Therefore, it is possible to divide the ECM into a desired number by using this syntax and insert the ECM in a commercial (CM) in a distributed manner on the time axis using the above-described NPT.

Next, a digital video receiver for receiving digital broadcast data in which an ECM having program information including a work key is inserted in a commercial part as described above will be described.

As shown in FIG. 2, the digital video receiver includes a tuner 210 for receiving digital broadcast data,
A demultiplexer 220 for separating the received digital broadcast data, and an ECM included in the commercial data.
, And a controller 230 for descrambling digital broadcast data based on the work key, and a controller 230 for controlling the controller 230, that is, a descrambler 240 for descrambling with the work key.
And a decoder 250 for demodulating the descrambled data, and a memory 26 for storing data including the ECM.
0. This ECM is inserted into the commercial data at random timing.
This ECM is randomly inserted into a commercial data portion in a divided state. Since the division of the ECM into the commercial part has been described with reference to FIG. 3, the description thereof is omitted.

As described above, in the digital video transceiver, since the ECM having the work key for descrambling is inserted into the commercial part, the descramble cannot be performed unless the commercial is decrypted. After giving the broadcast program recipient at least one opportunity to watch commercials, descrambling of a desired broadcast program becomes possible.

[0022]

As described above, the digital video transmitter, digital video receiver, and digital video transceiver according to the present invention have a configuration in which an ECM having a work key for descrambling is inserted in a commercial part. By doing so, there is an effect that the broadcast program receiver can always be given an opportunity to watch a commercial at least once.

[Brief description of the drawings]

FIG. 1 is a block diagram of a digital video transmitter according to the present invention.

FIG. 2 is a block diagram of the digital video receiver.

FIG. 3 is an explanatory diagram illustrating a method of inserting an ECM into a commercial part.

FIG. 4 is a list display of syntax of a private section.

FIG. 5 shows a configuration of a TS (Transport Stream) packet.

FIG. 6 shows a configuration of an ECM section of a TS packet.

FIG. 7 shows a structure of an ECM section of a TS packet.

[Explanation of symbols]

110; program supply server, 120; CM supply server, 1
30; scrambler, 140; multiplexer, 21
0; tuner, 220; demultiplexer, 230; controller, 240; descrambler, 250; decoder, 260;

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Claims (10)

[Claims] 1. A program supply server for supplying a digital broadcast program, a CM supply server for supplying commercials, a scrambler for scrambling the digital broadcast program using a predetermined work key, and a scrambled digital broadcast program C which multiplexes data and commercial data into which ECM having program information including a work key is inserted by a multiplexer to generate digital broadcast data.
A digital video transmitter comprising at least an ASS controller. 2. The digital video transmitter according to claim 1, wherein the ECM is inserted into the commercial data at random timing. 3. The digital video transmitter according to claim 1, wherein the ECM is divided into parts of the commercial data and inserted at random timing. 4. A tuner for receiving digital broadcast data, extracting a work key from an ECM having program information included in commercial data of the received digital broadcast data, and descrambling the digital broadcast data based on the work key. A digital video receiver, at least comprising: 5. The commercial data is inserted into the commercial data at random timing.
A digital video receiver according to claim 1. 6. The digital video receiver according to claim 4, wherein said ECM is divided into said commercial data portions and inserted at random timing. 7. A transport stream composed of scrambled digital broadcast data by inserting an ECM including a work key into a commercial data portion attached to a digital broadcast program, receiving the transport stream, and receiving the commercial data A digital video transceiver for extracting an ECM including a work key inserted in a part thereof and scrambling the disk with the work key to obtain a desired digital broadcast program. A digital video transceiver based on a request from a program receiver. 8. The digital video transceiver according to claim 7, wherein the received digital broadcast program can be stored in a predetermined recording medium. 9. The digital video transceiver according to claim 7, wherein the ECM including a work key to be inserted into the commercial data part is inserted into the commercial data part at random timing. 10. The digital video transceiver according to claim 7, wherein the ECM including a work key to be inserted into the commercial data portion is divided into the commercial data portion and inserted at random timing.