JPH10304324A - Information receiver and information imbedding processing method applied to the receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent insertion of a mark from giving any adverse effect on a coding characteristic of an information stream by determining a proper mark insertion position for a compression coded information stream so as to execute a fingerprint(FP) processing before expansion decoding processing thereby realizing real time performance of the mark insertion processing. SOLUTION: An information receiver has an FP processing module 6 that executes an FP processing to an information stream of a bit stream configuration by the coding method such as the MPEG2. The FP processing module 6 is provided with a syntax analysis section 21 to acquire syntax information relating to a coding characteristic of the information stream and a data structure and with a mark insertion position determinant 24 that determines an insertion position when a reproducible mark is imbedded in concealment based on the syntax information. A mark insertion processing section 22 inserts a mark at the determined insertion position of the information stream.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to information reception for receiving multimedia information provided via, for example, a computer network or a digital broadcasting network, and outputting and reproducing the information to, for example, a personal computer or a television receiver. Related to the device.

[0002]

2. Description of the Related Art In recent years, multimedia provided through a computer network (Internet), a digital broadcasting network such as digital satellite broadcasting, or an information package (individual recording medium) such as a DVD (digital video disk). An information receiving device for receiving information and outputting the information to a personal computer or a television receiver has been proposed. Here, the multimedia information means information that combines video (moving image), audio, data, and the like.

[0003] An information receiving apparatus is a set top box or an IRD (integer).
It corresponds to a user home device (home server) called a “great receiver decoder”. Further, a specific device includes an information receiving function provided in a personal computer or the like.

[0004] By arranging such an information receiving apparatus in a user at each home or the like, an information service system (a broad concept including digital broadcasting and cable television broadcasting) that provides multimedia information usable by the user is provided. Can be built. As a specific example, there is a video-on-demand service using a computer network or a cable television network.

When constructing the above information service system, it is important to protect the copyright and other rights of the creator of multimedia information and the information provider (individual or trader). Since multimedia information is provided in the form of digital information, it can be easily copied or modified by a personal computer or the like, and rights infringement is likely to occur.

Therefore, as a technique for protecting the rights such as the copyright of multimedia information which is a digital work, a data embedding technique of concealingly embedding specific information in multimedia information has attracted attention. This data embedding technique includes digital finger printing, digital watermarking, and digital watermarking.
This is a kind of data processing technique called "termmarking", digital watermarking method, or data hiding. Hereinafter, "FP technology" or "FP"
Processing ".

The FP process is basically a process of concealingly embedding specific information (hereinafter referred to as a mark) in digital information such as a video to be protected. Here, the mark is, for example, information indicating a copyright, identification information for identifying a providing destination, and the like, and usually includes character data or graphic data. Further, even if the original digital information to be protected (for example, video information such as a movie) is normally reproduced, the mark cannot be confirmed in a hidden state, but can be reproduced by a specific restoration process. .

[0008]

As described above, FP
The technology makes it possible to protect the copyright and other rights of multimedia information, and facilitates the realization of an information providing service system. In general, multimedia information is multiplexed with video information and audio information in accordance with, for example, the MPEG2 system specifications, and is transmitted as an information stream that is a compression-encoded bit stream (data sequence).

Incidentally, it is desirable that the above-mentioned FP process be performed in an information receiving apparatus provided on the user side. That is, when information provided by the user is used, a mark is embedded in the content by FP processing. When performing FP processing on the user side,
Normally, a compression-encoded information stream is subjected to decompression decoding before inserting a mark. this is,
This is because it is difficult to determine the correct position for inserting a mark in a compression-encoded bit stream. That is, when a mark is inserted into the information stream by the FP process, the image quality of the content information is degraded depending on the insertion position. In addition, there are positions in the information stream where a mark cannot be inserted by FP processing according to the syntax.

Therefore, conventionally, when a mark is inserted into an information stream by FP processing, a mark is inserted into the expanded and decoded information stream, and a mark is inserted into the information stream into which the mark is inserted. The compression encoding process is performed again. However, such F
In the mark insertion by the P processing, realization of the real-time property is difficult. For this reason, when multimedia information is provided in real time, such as in a movie, it is difficult to provide multimedia information in real time as a result of the influence of mark insertion processing on the information stream.

An object of the present invention is to make it possible to determine an appropriate position for inserting a mark in a compression-encoded information stream so that FP processing can be executed before decompression decoding processing, It is an object of the present invention to realize real-time insertion processing and to prevent the adverse effects of mark insertion from affecting the encoding and decoding characteristics of an information stream.

[0012]

SUMMARY OF THE INVENTION The present invention is an apparatus for receiving multimedia information provided over a digital broadcast network, such as a computer network or digital satellite broadcast, and more particularly, a set top box. Alternatively, it is an information receiving device applied to a user home device such as an IRD. The apparatus receives information transmitted from the outside as an information stream having a bit stream configuration encoded according to a predetermined encoding scheme, executes syntax analysis processing on the information stream, and encodes the information stream. It has a parsing means for acquiring syntax information on characteristics and data structures. Further, the present apparatus sets the insertion position when concealably embedding a reproducible mark in the information stream based on the syntax information obtained by the syntax analysis means and predetermined parameter information prepared in advance. There is a deciding means for deciding, and an embedding processing means for executing a data embedding process for inserting a mark at the insertion position of the information stream decided by the deciding means.

[0013] With this configuration, the user's information receiving apparatus side can appropriately determine the information stream provided from the information provider side based on the syntax information on the compression encoding characteristics and the data structure. An FP that inserts a mark at a location to protect rights such as copyright
Processing can be realized. Therefore, it is possible to perform the FP processing in real time without pre-expanding and decoding the compressed and encoded information stream. In other words, decompression decoding and compression decoding for FP processing of mark insertion can be omitted. Further, since it is not necessary to perform the compression encoding process on the information stream after the mark insertion, it is possible to prevent a situation in which the compression rate is reduced and the data amount is expanded.

Here, the information stream has a different syntax according to the encoding / decoding (CODEC) system employed. Therefore, when a mark is inserted by the FP process, the influence on the content information (user information which is the multimedia information body used by the user) differs depending on the insertion position. Specifically, the degree of deterioration of the image quality when reproduced is different. In addition, there are positions where marks cannot be inserted due to syntax. According to the present invention, an appropriate mark insertion position is determined by acquiring syntax information on an encoding characteristic and a data structure by syntactic analysis of a compression-encoded information stream.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram illustrating a main part of an information receiving apparatus related to the present embodiment, FIG. 2 is a block diagram illustrating a configuration of an FP processing module related to the present embodiment, and FIG. It is a flowchart for explaining operation. (Configuration of Information Receiving Apparatus) In this embodiment, as shown in FIG. 1, for example, an information transmitting system 2 and information receiving apparatus 1 are connected via a communication medium 3 of a computer network or a digital broadcasting network. Assume a service system. The information transmission system 2 is an information provider having an information transmission device for transmitting multimedia information in which video, audio, data, and the like are multiplexed in response to a request from a user or contract contents (hereinafter, information provision). May be expressed as a concept that includes people). On the other hand, the information receiving device 1 assumes a user premises device (corresponding to a set top box or an IRD) arranged on the user side, and executes a process described below on the received multimedia information, This is a device for reproducing and outputting content information included in multimedia information (hereinafter, may be expressed as a concept including a user).

As shown in FIG. 1, the information receiving apparatus 1 has a receiving interface 4, a descrambler 5, an FP processing module 6, a decoding unit 7, and an output unit 8. The receiving interface 4 receives an information stream having a bit stream configuration transmitted via the communication medium 3. The descrambler 5 executes a descrambling process (a type of decryption process) for restoring information that has been subjected to a predetermined scramble (a type of encryption) to an original state. Here, the descrambler 5 does not need to be provided when receiving unscrambled information or when performing descrambling processing by another device.

The FP processing module 6 is a constituent element of the present invention (see FIG. 2). As will be described later, the FP processing module 6 inputs an information stream compressed and encoded according to, for example, the MPEG2 system specification, and a mark for protecting rights such as copyright (for example, information for identifying a user). FP processing for embedding (inserting) based on a predetermined algorithm. This algorithm, as described above, uses digital watermarking.
rmarking, a digital watermarking method, or a data embedding process such as data hiding. The FP processing module 6 has a specific configuration including a memory holding an FP processing program including the above algorithm, and a microprocessor (CPU) for executing the FP processing program.

The FP processing module 6 executes an embedding process of inserting a mark at a predetermined position (a mark insertion position described later) of the compression-encoded information stream,
The information stream is output to the decoding unit 7. Decoding section 7
Is a component for decompressing and decoding an information stream compressed and encoded according to, for example, the MPEG2 system specification. The output unit 8 is a signal conversion processing unit for converting the decompressed and decoded information stream into a signal conforming to the specifications of the information reproducing device 9.

The information reproducing device 9 specifically means, for example, a personal computer or a television receiver (TV) having a display device. The output unit 8 includes a D / A conversion circuit for converting digital information into an analog signal or a CVS conversion circuit for converting the digital information into a composite video signal (CVS) for a television receiver. In addition to the display device, the information reproducing device 9 includes an output device such as a DVD (Digital Video Disk) drive. The DVD drive receives the digital information output from the output unit 9 and records the digital information on a DVD serving as a recording medium. (Configuration of FP Processing Module) As shown in FIG.
, A syntax (syntax rule) analysis unit 21, a mark insertion processing unit 22, an output buffer 23, a mark insertion position determination unit 24, a mark insertion control unit 25, a parameter storage unit 26, and a mark insertion history storage. And a portion 27.

The input buffer 20 temporarily holds the information stream having a bit stream structure after descrambling by the descrambler 5 and outputs the information stream to the syntax analysis unit 21. The syntax analysis unit 21 analyzes a syntax (syntax: rule of a coded data sequence) related to a coding characteristic and a data structure from the information stream, and outputs the syntax information CD. The encoding characteristic refers to VLC (variab) used for compression encoding.
le length code (variable length code) or FLC
(Fixed length code: fixed length code) and characteristic information such as a data position that is not skipped. The data structure is, for example, the encoding /
A sequence layer, which is a hierarchical structure of image data in a decoding method, a GOP (Group of Picture)
s) layer, picture layer, slice layer, macroblock layer,
This means specific information such as a block layer, and data elements (data items) set for each of the layers. That is, the syntax is a rule expressing the order and position of data elements (blocks of a meaningful bit string) before or after encoding. Therefore,
The syntax analysis unit 21 determines the position, type, and value of a data element constituting the information stream, and outputs it as syntax information CD. The syntax analysis unit 21 is configured by software executed by a CPU or dedicated hardware (such as a logic circuit).

The mark insertion position determination unit 24 includes a syntax information CD, marking / parameter information stored in a parameter storage unit 26, and a mark insertion history storage unit 27.
A mark insertion position and a mark for inserting a mark in the information stream are determined based on the mark insertion history information stored in the information stream. The determined information is used as insertion position information PD.

The marking / parameter information in the parameter storage unit 26 includes, for example, user identification information for identifying a user, usage terminal identification information for identifying a usage terminal (information receiving apparatus 1) used by the user, and usage service. Service use information for specifying the content of the service, use area specifying information for specifying the use area, use time information when the user uses the provided information, predetermined shared secret information, random information, marking parameters, Parity information, marking parameter integrity information, and the like.
Further, the mark insertion history storage unit 27 records information indicating the mark insertion position actually inserted into the information stream by the mark insertion control unit 25.

The mark insertion control unit 25 controls the mark insertion processing unit 22, and sets the mark insertion position in the information stream and the contents of the mark to be inserted, based on the insertion position information PD output from the mark insertion position determination unit 24. I do. The mark insertion processing unit 22 executes an embedding process (FP process) for inserting the set mark at the insertion position on the information stream sent via the syntax analysis unit 21. The output buffer 23 temporarily holds the information stream after the mark is inserted by the mark insertion processing unit 22 and outputs the information stream to the decoding unit 7. (Effects of this embodiment) In addition to FIGS. 1 and 2, FIG.
The operation and effect of this embodiment will be described with reference to the flowchart of FIG.

This embodiment assumes an information providing service system in which multimedia information such as a movie is provided to a user 1 contracted from an information provider 2 via, for example, a digital broadcasting network. The information transmission system 2 transmits an information stream having a bit stream configuration including content information (combined information of video and audio) such as a movie and compression-encoded by the syntax of the MPEG2 system specification (step S1).

The information receiving apparatus 1 receives the information stream transmitted by the receiving interface 4 and performs descrambling by the descrambler 5 (steps S2 and S3). Next, in the present embodiment, as described above, the FP processing module 6 sets a mark, which is specific information for protecting a right such as a copyright of the multimedia information,
A mark insertion process (FP process) to be inserted at the determined position in the information stream is executed (steps S4 to S6). That is, in the FP processing module 6 of the present embodiment, as shown in FIG. 2, the syntax analysis unit 21 analyzes the syntax relating to the encoding characteristics and the data structure from the compression-coded information stream, and The information is output (step S4).

Further, the mark insertion position determining section 24 determines the mark information based on the syntax information CD, the marking / parameter information stored in the parameter storage section 26, and the mark insertion history information stored in the mark insertion history storage section 27.
The mark insertion position and the mark for inserting the mark in the information stream are determined (step S5). Here, the determination of the mark insertion position is specifically, for example, MP
This is designation of a block in the data structure of EG2, and is to select a block that is less likely to be lost due to skipping. Here, the information stream is the MP to be adopted.
The syntax differs depending on the encoding / decoding method such as EG2. Therefore, when a mark is inserted by the FP process, the influence on the content information (user information which is the multimedia information body used by the user) differs depending on the insertion position. Specifically, the degree of deterioration of the image quality when reproduced is different. In addition, there are positions where marks cannot be inserted due to syntax. The mark insertion position determining unit 24 determines an appropriate mark insertion position based on syntax information on encoding characteristics and a data structure obtained by parsing the compression-encoded information stream.

The mark insertion processing section 22 has an insertion position information PD
Under the control of the mark insertion control unit 25 based on the above, an embedding process of inserting a mark at the determined insertion position in the information stream is executed (step S6). Decoding section 7
Executes the decompression decoding process on the FP-processed information stream and outputs it to the output unit 8 (step S8).
The output unit 8 performs a signal conversion process for converting a signal according to the specification of the information reproducing device 9 connected to the information receiving device 1.

As described above, according to the present embodiment, in the information stream provided by the FP processing module 6 of the information receiving apparatus 1 on the user side, the right such as the copyright of the information provider is protected. FP processing for inserting a mark that is specific information for performing the FP processing can be performed. In this case, in the present embodiment, for example, syntax analysis processing is performed on an information stream that has been compression-encoded according to the MPEG2 system specification, and syntax information on encoding characteristics and a data structure is acquired. An appropriate mark insertion position for inserting a mark is determined. Thereby, the FP processing module 6
The mark insertion position required for the FP process can be determined and the mark insertion process can be executed without performing the expansion decoding on the compression-encoded information stream. A mark can be inserted at an appropriate position in the information stream without performing the decompression decoding process and the re-compression coding process on the information stream. Therefore, as a result, the mark insertion processing can be executed in real time.

Further, not only the normal user specifying information but also the use time information, the use terminal specifying information,
By preparing the use area specifying information in the parameter storage unit 26 in advance and using it as the mark information, there is also an effect of increasing the evidentiality supporting the so-called rights infringement. In addition, by including parity or hash information in the mark itself or in the parameter information, it is possible to easily realize the falsification of the mark.

In the mark insertion position determination processing of this embodiment, when the information stream is image data,
A method of superimposing on the characteristic pattern of the image (such as the peak of the DCT coefficient) in consideration of the visual influence of the image is considered. Here, DCT stands for Discrete Cosine
e Abbreviation of Transform (Discrete Cosine Transform). In this case, a method of selecting the most prominent peak can be considered. Also, the peak in the image is set to 1
The method of determining one or several has an effect of making it difficult to identify the mark and preventing tampering of the mark.
Furthermore, in selecting a mark insertion position from a plurality of candidates, a method of introducing randomness and making it difficult to specify a mark position is also effective.

Further, for the purpose of removing or rendering the inserted mark insignificant, the frame structure is shifted or thinned out and recompressed after decompression and decoding of the information stream with the mark inserted, so that the stream structure ( Falsify the mark by modifying the data structure (for example,
Frame is assumed to be a new I frame). Even if the previous P frame is not a frame in which a mark is directly inserted,
If the mark was inserted in the immediately preceding I frame,
The effect of the mark is left by the result of the predictive coding.
Therefore, even after recompression, the influence of the mark remains, and by detecting it, FP can be reproduced as a result. It is also desirable to embed the mark spatially in one I-frame or temporally over multiple I-frames. Further, it is desirable to embed the mark in the first and last macroblocks of the slice layer in the image data of MPEG2, for example, or in any of the macroblocks. (Modification of this embodiment) FIG. 4 is a block diagram showing the configuration of an FP processing module related to a modification of this embodiment. The FP processing module 6 of the present modification includes a conversion table generation unit 28 and a conversion table storage unit 29. Conversion table generator 2
8 is a bit stream (partial stream of a bit stream in which the influence of the mark insertion on each of the above VLC and FLC data is considered based on the coding characteristics of the information stream of the compression coding obtained by the syntax analysis unit 21. )
Conversion table (table showing conversion bit strings)
Generate The conversion table storage unit 29 stores the conversion table information.

The mark insertion control section 25 refers to the conversion table information in the conversion table storage section 29 to replace the bit string corresponding to the mark insertion position determined by the mark insertion position determination section 24 with a mark and inserts the bit string. The processing is performed by the mark insertion processing unit 22. That is, the mark insertion control unit 25 can obtain the current position information before the mark insertion based on the encoding characteristics based on the conversion table information.

The conversion table generator 28 does not always need to generate the conversion table, and may output conversion table information prepared in advance by default. In the present modification, other components are the same as those in the present embodiment.

[0034]

As described above in detail, according to the present invention, on the information receiving apparatus side of the user, the information stream provided from the information provider side is provided with the syntax information on the compression coding characteristics and the data structure. FP processing for inserting a mark for protecting a right such as a copyright at an appropriate position determined based on the FP process can be realized. Therefore,
FP processing can be performed in real time without previously performing expansion decoding on the information stream that has been compression-encoded. In other words, decompression decoding and compression decoding for FP processing of mark insertion can be omitted. Further, since it is not necessary to perform the compression encoding process on the information stream after the mark insertion, it is possible to prevent a situation in which the compression rate is reduced and the data amount is expanded. As a result, it is possible to realize an information providing service system that can efficiently and surely protect rights such as copyrights.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a main part of an information receiving apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of an FP processing module related to the embodiment;

FIG. 3 is a flowchart for explaining the operation of the embodiment.

FIG. 4 is a block diagram showing a configuration of an FP processing module according to a modification of the embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Information receiving apparatus (user) 2 ... Information transmission system (information provider) 3 ... Communication medium (computer network, digital broadcasting network) 4 ... Receiving interface 5 ... Descrambler 6 ... FP processing module (data embedding processing means) 7 ... Decoding unit 8 ... Output unit 9 ... Information reproducing device 20 ... Input buffer 21 ... Syntax analysis unit 22 ... Mark insertion processing unit 23 ... Output buffer 24 ... Mark insertion position determination unit 25 ... Mark insertion control unit 26 ... Parameter storage Unit 27: Mark insertion history storage unit 28: Conversion table generation unit 29: Conversion table storage unit

Claims (8)

[Claims] An information receiving apparatus for receiving information transmitted from an external device as an information stream having a bit stream configuration encoded by a predetermined encoding method, and performing an output process in accordance with a reproduction output specification. Receiving means for receiving the information stream transmitted from the outside, and performing syntax analysis processing on the information stream received by the receiving means, to obtain a syntax relating to the encoding characteristics and data structure of the information stream. Syntactic analysis means for acquiring information, based on the syntax information acquired by the syntax analysis means and predetermined parameter information prepared in advance, concealing specific information reproducible for the information stream. Determining means for determining an insertion position at the time of performing an embedding process in the information processing apparatus, and the information stream determined by the determining means. Embedding processing means for executing data embedding processing for inserting the specific information into the insertion position of the stream; predetermined output processing according to the reproduction output specification for the information stream output from the embedding processing means And an output unit for performing the following. 2. The information receiving apparatus according to claim 1, wherein said output means includes a decoding means for performing a predetermined decoding process on the information stream output from said embedding processing means. . 3. The parameter information includes user identification information for identifying a user, user terminal identification information for identifying a user terminal device used by the user, usage time information, and usage area identification information. Information for setting, the determining means, when the specific information set by the parameter information is inserted, the reproduction output characteristics when reproducing and outputting the content information included in the information stream and the specific information 3. The information receiving apparatus according to claim 1, wherein an insertion position of the information stream that can suppress an adverse effect on reproducibility of the information stream is determined. 4. A memory means for storing information on the insertion position determined by said determination means as insertion position history information, wherein said determination means determines the insertion position of specific information for a new information stream. 4. The information receiving apparatus according to claim 1, wherein the information receiving apparatus uses the inserted position history information stored in the memory means to determine the inserted position. 5. The embedding processing means for executing data hiding processing, watermarking processing, or finger print processing for concealing embedding of reproducible and identifiable specific information prepared in advance. 5. The program according to claim 1, wherein the specific information is embedded at an insertion position of the information stream determined by the determination unit. The information receiving device according to the above. 6. The information transmitted from the outside includes content information usable by image output and audio output and encoded by a predetermined multimedia encoding method,
An information stream according to a predetermined synchronization and multiplexing specification transmitted through a computer network, a digital communication line, or a digital broadcasting network, wherein the output means transmits the content information output from the data embedding processing means to the multi-stream. 2. The apparatus according to claim 1, further comprising means for executing a decoding process based on a media encoding system and executing signal processing required for image output or audio output on the decoded content information. The information receiving device according to any one of claims 2, 3, 4, and 5. 7. A conversion table generating means for generating conversion table information for referring to a conversion result with the specific information in a partial stream configuration corresponding to the insertion position of the information stream determined by the determining means, and A conversion table storage unit for storing the conversion table information; the embedding processing unit based on the insertion position of the information stream determined by the determination unit and the conversion table information referred to from the conversion table storage unit 7. The information receiving apparatus according to claim 1, wherein a data embedding process for inserting the specific information is performed. . 8. An externally received information transmitted as an information stream having a bit stream configuration encoded according to a predetermined encoding scheme, output-processed in accordance with a reproduction output specification, and reproduced in the information stream. An information embedding method applied to an information receiving apparatus having a function of concealing and embedding specific information that is identifiable and capable of performing parsing on a received information stream, Acquisition processing for acquiring syntax information related to encoding characteristics and data structure, based on the syntax information acquired by the acquisition processing and predetermined parameter information prepared in advance, can be reproduced for the information stream. A determination process of determining an insertion position when the specific information is concealed and embedded, and An embedding process for performing a data embedding process for inserting the specific information into the determined insertion position of the information stream; and a reproduction output specification for the information stream into which the specific information has been inserted by the embedding process. Performing a predetermined output process in accordance with the information embedding process.