JP2003273747A - Method and device for receiving variable length coding data - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the constitution of a semi-disclosed content signal encoder which operates by securing a prescribed security level to the contents of an object to be encoded. <P>SOLUTION: By assigning a prescribed code word to each data value of the number of pieces of time-series data obtained by orthogonally converting supplied picture and sound signals, a variable length coding table 14 is obtained. Among the code word described in the variable length coding table, the number of the pieces of the time-series data is assigned as the same number and code words different to each other are exchanged to prepare an exchanged variable length coding table 15. A CPU 16 generates a coding selection signal for identifying which of the variable length coding table and the exchanged variable length coding table to use for performing variable length coding of a VLC device 121 and outputs it to a communication network with a compressed coding signal. Thus the constitution of the content signal encoder 10 is realized. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to compression coding of a digital image signal or digital audio signal and decoding of the compression coded signal, and in particular, decoding of digital data by a decoding device without deterioration. , Or a variable-length coded data receiving method and a variable-length coded data receiving apparatus for supplying decoded data of different qualities to each user so that digital data is slightly deteriorated at the decoding stage.

[0002]

2. Description of the Related Art When an analog video signal is transmitted or recorded and reproduced, the reproduced video signal is deteriorated according to the quality of the transmission path or the recording medium, and the original video signal and the user are There is a slight difference in image quality between the video signals reproduced on the side.

Similarly, when an analog acoustic signal is transmitted or recorded and reproduced, the reproduced acoustic signal is deteriorated depending on the quality of the transmission path or the recording medium.
A slight difference in sound quality occurs between the original sound signal and the sound signal reproduced by the user.

In this way, the copyright holder who owns the video signal and / or the audio signal (hereinafter, these signals may be referred to as the content signal) and the user who reproduces the content signal Due to the difference in quality that occurs between
The content business is normally operated in such a manner that the copyright of the content signal owned by the copyright holder is protected.

In recent years, digital signal processing technology has been developed, and content signals using the same can be broadcast, communicated, or supplied to users by a recording medium so that quality deterioration of the content signals can be reduced. As a result, the difference between the quality of the content owned by the copyright holder and the quality of the content played back by the user is reduced, and it is difficult to operate the business normally using the content owned by the copyright holder. Is becoming.

[0006] Therefore, an encryption technique and a conditional access technique for supplying the contents only to the users who have a specific contract have been developed, and the contents are supplied using them. The signal processed by encryption and conditional access in that case is used in a contractual relationship by selecting either normal reproduction or no reproduction at all. It is used in such a way that content is supplied only to specific users such as users.

[0007] Further, when the content of the copyright holder is transmitted or supplied to the user by a recording medium and the user secondarily uses the content, information for identifying the right holder of the content is provided. A method of embedding it in the content information using a digital watermark has also been developed. In that case, the quality of the content is less deteriorated when the content is secondarily used, and the protection of the content by the digital watermark is used only for identifying the content owner. .

[0008] In this way, the digital technology has been used to develop a content transmission and recording / reproducing technology in which quality deterioration hardly occurs. Then, there is a demand for the development of a signal technology for protecting the copyright holder in order to carry out a preferable content business, which incorporates a technology related to protection of a preferable copyright such as an analog signal has in the digital technology.

[0009] First of all, the MPEG (moving pic) technique for compressing and encoding the content signal will be described.
ture experts group) The present invention relates to a video and MPEG audio technology, and then relates to a method for disclosing content in order to realize suitable encoding for performing a content business on the encoded compression encoded signal. The encoding technology will be described.

First, the MPEG video technology will be described. The system using so-called MPEG video, which efficiently encodes a moving image signal such as a television signal, includes digital satellite broadcasting and DVD (Digital versatile D).
isc), digital tape recorders, and widely used as signals transmitted in communication networks, and is planned to be adopted in digital terrestrial broadcasting from 2003.

That is, the MPEG video standard is 198.
8 years ISO / IEC (International Organization for
Standardization / International Electrotechnical
Commission) JTC1 / SC2 (Joint Technical Co
mmittee 1 / Sub committee2; International standard established by the deliberation started by the organization that examines the moving picture coding standard established in the International Standardization Organization / International Electrotechnical Standardization Committee Technical Committee 1 / Specialized Committee 2). Is.

The deliberation body SC2 is currently SC2.
9 continues to establish standards for encoding moving images, audio signals, etc. The international standard established by MPEG people is also commonly called the MPEG standard.

The MPEG1 (MPEG phase 1) standard first established by MPEG is 1.5 Mbp.
An encoding standard for moving image signals accompanied by acoustic signals for storage media recorded at a transmission rate of about s.
JPEG (Joint Photogra) for encoding still images
phic Coding Experts Group) and ISDN (Integrate
H.264 for the purpose of video compression for low transfer rates of video conferencing and video telephony of d services digital network). 26
It is an encoding standard using the basic technology of 1 (CCITT SGXV, standardized by the current ITU-T SG15).

As such, MPEG 1
The disc, which was enacted as ISO / IEC 11172 in January and is recorded by being encoded by the MPEG1 standard, has been commercialized in many cases.

The MPEG2 (MP
EG Phase 2) aims to be a universal standard to support various applications such as communication and broadcasting.
Established in November 1994 as ISO / IEC13818 and "H.262".

And, these MPEG1 and MPEG
The coding method according to 2 is composed of a plurality of coding techniques, and these techniques divide a “frame” image forming a moving image into blocks of 16 × 16 pixels called “macroblocks” and perform coding. Perform processing.

The encoding process is performed by "motion vector" between a reference image and a coded image that are separated by a predetermined number of frames in the future in the future or in the past, for each macroblock unit.
"Motion Compensation Prediction" technology that calculates the amount of motion called, and encodes the encoded image from the reference image based on the amount of motion,
The DCT (Discrete Transform), which is one of the orthogonal transform techniques, is applied to the error signal of the motion compensation prediction or the encoded image itself.
te Cosine Transform (discrete cosine transform) is used to transform image information into frequency information, and compression coding is performed so that only visually significant information is obtained from the transformed frequency domain information. "Encoding" technology and two elemental technologies of image coding.

There are three prediction directions in motion-compensated prediction in the case of prediction from both the past, future, and past future, and these three modes are 16 pixels × 1.
It can be switched and used for each macro block composed of 6-pixel data.

The picture type given to the frame of the input image is I (Intra-coded) or P (Predi
ctive-coded), and B (Bidirectionally predictive-
There are three types of picture coded) defined.

The I picture is a picture that is coded without motion prediction, but the P picture has predictions from the past and two modes that are coded without prediction, and the B picture is also a B picture. Includes four predictions from the future, predictions from the past, predictions from both past and future directions, and four MCs (MotionCom) that perform intra-frame coding without prediction.
There is a (pensation) mode.

In the motion compensation performed by using the future or past images, the pattern matching is performed for each macroblock in the motion area and the half-pel (pixel-to-pixel distance of 1 is used).
/ 2) A motion vector is calculated with accuracy, and an input image is referenced by referring to a reference image formed by moving a future or past reference image position in the vector direction in correspondence with the calculated motion vector amount. Encode the signal.

There are a horizontal direction and a vertical direction in the direction of the motion vector thus obtained, and the vector information thereof is transmitted as additional information of the macroblock together with the MC mode.

Of the picture data thus obtained, three types of pictures of I, P, and B are arranged in a predetermined order with the I picture at the head and transmitted, and the I picture next to the I picture is transmitted. The set of pictures (frame images) up to the picture in front of the GOP (Gro
up of picture). In encoding that is performed on a normal storage medium, about 15 pictures make G
The OP is constructed.

The I picture and the P and B pictures coded as motion-compensated images are DCTs, that is, orthogonal transformations in which the integral transformation having a cosine function as an integral kernel is discretely transformed into a finite space.

In the orthogonal transformation, the macro block is composed of 8 pixels ×
Two-dimensional DCT is performed by dividing it into 8-pixel DCT blocks. Generally, since the frequency component of image data is large in the low frequency range and low in the high frequency range, the image data is subjected to DCT and the conversion coefficient in which energy is concentrated in the low frequency range Can be compressed and expressed.

Then, the DCT-processed image data (D
The CT coefficient is quantized by a quantizer. That is, the quantizer obtains the DCT coefficient by dividing it by a predetermined quantized value. The quantized value is obtained as a quantized value in which a two-dimensional frequency of 8 pixels × 8 pixels is weighted by visual characteristics. The quantized value used is one that is scalar-multiplied by a predetermined quantization scale.

Further, the quantized value is multiplied by the inverse quantized value obtained at the time of decoding the encoded image data so that the characteristic by the quantized value given at the time of encoding is canceled at the time of decoding. There is.

Next, the structure of an MPEG encoder which performs encoding and decoding by such a method will be described. Figure 4
The structure of the MPEG encoder is shown in FIG. 7, and its operation is outlined.

The MPEG encoder 50 has an input terminal 5
1, adder 52, DCT device 53, quantizer 54, VLC
(Variable length coding) device 55, buffer 56, code amount controller 57, inverse quantizer 61, inverse DCT device 62, adder 63, image memory 64, and motion compensation predictor 65.

First, the moving picture signal supplied to the input terminal 51 is supplied to the motion compensation predictor 65 and the adder 52. In the adder 52, the signals supplied from the motion compensation predictor 65 are inverted in polarity and added. , And the signal obtained by addition is supplied to the DCT unit 53.

In the DCT unit 53, the supplied image signal is subjected to the above-mentioned discrete cosine transform, and D obtained by the transform is obtained.
The CT transform coefficient is supplied to the quantizer 54, quantized based on the predetermined quantized value, and the quantized quantized data is supplied to the inverse quantizer 61 and the VLC unit 55.

In the VLC unit 55, the supplied quantized data is variable length coded, but the direct current (DC) component obtained by the DCT conversion of the quantized value is DP.
CM (differential pulse code modulation) modulation is performed.

The alternating current (AC) component is obtained by performing zigzag scan in the order of high frequency component data from low frequency component data, and the obtained data is zero run length and effective. Huffman coding is performed by using coefficient values as one event, and assigning codes with shorter code lengths in order from the one with the highest occurrence probability.

The Huffman-encoded data, which is the variable length encoding, is temporarily stored in the buffer 56, and the temporarily stored data is output as an encoded data output at a predetermined transfer rate.

The generated code amount for each macroblock of the output data is supplied to the code amount controller 57, compared with a preset target code amount, and the generated code amount obtained by the comparison. The code amount of the difference between and is supplied to the quantizer 54. Then, the quantizer 54 controls the code amount so as to obtain coded data at a predetermined transfer rate by changing the value of the quantization scale based on the code amount of the difference.

On the other hand, the image data quantized by the quantizer 54 is supplied to the inverse quantizer 61 and inversely quantized. The inversely quantized data is supplied to the inverse DCT unit 62, where the inverse DCT is performed, and the inverse DCT data is supplied to the adder 63.

In the adder 63, the reference image supplied from the motion compensation predictor 65 is added, and the signal obtained by the addition is supplied to the image memory 64 and temporarily stored therein. The temporarily stored image data is used as a reference decoded image for calculating a difference image in the motion compensation predictor 65, so that it is output from the MPEG encoder 50 as motion compensated encoded data. Has been done.

The encoded data thus output is supplied to the MPEG decoder and decoded. FIG. 48
The structure of the MPEG decoder is shown in FIG.

The MPEG decoder 70 shown in the figure includes an encoded data input terminal 71, a buffer 72, a VLD unit 73,
The inverse quantizer 74, the inverse DCT unit 75, the adder 76, the image memory 77, and the motion compensation predictor 78 are included.

First, the coded data supplied to the input terminal 71 is temporarily stored in the buffer 72, and the coded data temporarily stored therein is VLD (variable len) as needed.
gth decoding device 73.

In the VLD unit 73, the data encoded by the VLC unit 55 is subjected to variable length decoding, and the data relating to the direct current (DC) component and the alternating current (AC) component are obtained.

Among the obtained data, the AC component data is quantized in a matrix of 8 × 8 in the order of zigzag scanning from low frequency components to high frequency components, which is the same as that performed by the MPEG encoder 50. Obtained as data,
The quantized data obtained is supplied to the inverse quantizer 74.

In the inverse quantizer 74, inverse quantization is performed based on the above-mentioned quantization matrix arrangement, and the data obtained by the inverse quantization is supplied to the inverse DCT device 75.
An inverse DCT operation is performed there to obtain image data as decoded data.

Then, the obtained image data is temporarily stored in the image memory 77, and the temporarily stored image data is supplied to the motion compensation predictor 78. Then, the image data is used as a reference decoded image for calculating a difference image in motion compensation prediction.

In this way, the image data forming the moving picture is coded by the MPEG encoder 50 and transmitted or recorded, and the received or reproduced coded data is decoded by the MPEG decoder 70. It is designed to be obtained as video information. Although such a method is used in both MPEG1 and MPEG2, in both cases, noise in the transmission line,
It also enables transmission of video signals that are less affected by non-linearity.

Regarding the copyright protection of the image signal encoded in this way, the image data encoded using a plurality of types of encoding modes is converted into encoded data based on the input security data. There is a method of determining whether reproduction is permitted or not, and decoding the encoded image signal according to the determination result (see, for example, Patent Document 1).

The encoding and decoding of the image signal have been described above. Next, regarding the compression encoding of the acoustic signal, MP
EG-2 AAC (Advanced Audio Coding) will be described as an example. FIG. 49 shows the configuration of a coding apparatus based on the MPEG-2 AAC system for compressing and coding a digital audio signal, and its operation will be described.

Audio signal coding apparatus 40 shown in FIG.
0 is a psychoacoustic analyzer 401, MDCT (Modified Dis
crete cosine transform) 402, scale factor calculator 403, quantizer 404, codebook selector 4
05, variable length encoder 406, minimum code amount detector 40
7, a code amount decision unit 408, and a bit stream generator 409.

First, in the MPEG-2 AAC audio encoding device, an FFT (Fast Fourier Trans) is applied to the input digital audio signal by the psychoacoustic analyzer 401.
form) processing to obtain the frequency spectrum,
Based on this, the masking amount for the auditory sense is calculated, and the allowable quantization noise power for each preset frequency band is calculated.

On the other hand, the MDCT unit 402 obtains spectrum data by MDCTing the supplied audio signal. That data is called the MDCT coefficient. Then, a long or short conversion block length is selected based on the window selection information determined by the psychoacoustic analyzer 401. The MDCT operation is executed while overlapping the operation block lengths by 50%.

When the window selection is selected as the long window, 2048 sample audio signals are output for 1024
Converted to MDCT coefficient of book, and 2 for short window
Convert 56 samples to 128 MDCT coefficients.

Next, the scale factor calculator 403 calculates 1024 for each frequency band based on human auditory characteristics.
The audio signal is divided into a plurality of scale factor bands with the MDCT coefficient of the book as a unit. Then, the number of quantization steps (scale factors) of each scale factor band is set so that the quantization noise calculated in each scale factor band does not become larger than the allowable quantization noise power calculated in the psychoacoustic analyzer 401. It is calculated.

In the stippling in the figure, it is shown that processing is performed in units of scale factor bands. That is, the quantizer 404 performs quantization in units of scale factor bands. Then, in the scale factor calculator 403, the MDCT coefficient for the signal within the scale factor band is obtained from the scale factor thus calculated and the total number of quantization steps, and quantization is performed based on the obtained coefficient value. . In addition, the number of bits required for quantization is controlled to be within the number of usable bits so that the total number of quantization steps is controlled.
Quantization of the T coefficient is performed.

The next codebook selector 405 selects a usable Huffman codebook from the maximum absolute value of the quantized value. FIG. 50 shows a table of a Huffman codebook used in MPEG-2 AAC.

Then, in the variable length encoder 406, the Huffman codebook based on the maximum absolute value of the quantized value is selected and used, and the variable length encoding is performed there. For example, when the maximum absolute value of the quantized value is 5, Haman codebooks of 7 or more can be used. Then, the selected Huffman codebook is supplied to the variable length encoder 406.

In the variable length encoder 406, the quantized value of the MDCT coefficient output from the quantizer 404 is variable length encoded using the Huffman codebook selected by the codebook selector 405. Be seen. When a plurality of Huffman codebooks are selected, the Huffman codebooks are used to perform encoding, and the encoded results are supplied to the minimum code amount detector 407. Further, in the variable length encoder 406, the supplied scale factor is also variable length encoded, and the encoding result with reduced redundancy is supplied to the code amount determiner 408.

The minimum code amount detector 407 selects the Huffman codebook having the smallest code amount generated based on the respective coding results coded by using each Huffman codebook, and selects the Huffman codebook. The generated Huffman codebook and the coding result are supplied to the code amount determination unit 408.

The code amount determining unit 408 determines whether the code amount generated by encoding is within the usable code amount, and if it exceeds the usable code amount, the quantization is performed again. This is repeated until the generated code amount becomes less than or equal to the usable code amount.

Then, the coded data output with the number of usable bits being satisfied is the bit stream generator 409.
Is supplied to. There it is multiplexed with coding parameters such as sampling frequency, coding rate,
It is generated as a bit stream and output from the audio signal encoding device.

Next, the AAC coded in this way
An audio signal decoding device for decoding a bitstream will be described. FIG. 51 shows the MPEG-2 AAC.
MPEG-2 AA for decoding corresponding to the encoder
A conventional example of the C decoder will be shown and described below with reference to FIG.

The audio signal decoding device 42 shown in FIG.
0 is a bit stream analyzer 421, a variable length decoder 422, an inverse quantizer 423, and an IMDCT (Inverse).
Modified Discrete Cosine transform) device 424.

First, in the MPEG-2 AAC decoder, the AAC bit stream in which a plurality of signals are multiplexed and input is input to the bit stream analyzer 421.
Each of the encoding parameters such as the sampling frequency and the encoding rate, and the encoded data are separated.

Then, the variable length decoder 422 receives the coded data, the scale factor as the coding parameter, and the quantized value, and the variable length decoder performs the variable length decoding based on these data. That is, for the scale factor, the Huffman codebook for the scale factor is used,
The quantized value is decoded by selecting the Huffman codebook for the quantized value based on the Huffman codebook number obtained from the bitstream analyzer 421 for each scale factor band.

Next, the decoded quantized value and scale factor are supplied to the inverse quantizer 423. Where,
The quantization value is inversely quantized for each scale factor band unit by using the total number of quantization steps, which is one of the encoding parameters output from the bitstream analyzer 421, and the scale factor, and the MDCT coefficient is calculated. To be done.

The MDCT coefficient is input to the IMDCT device 424, where it is subjected to inverse MDCT conversion, converted into an audio signal, and output from there. The operation in which the digital audio signal is compression-encoded by the audio signal encoder and the encoded signal is decoded by the audio signal decoder to obtain the digital audio signal has been described above.

Then, security information such as digital watermark information is included in the encoded digital audio signal in the audio signal decoding device, and the optical disc is recorded with S.
An optical disk device which records by using the CMS (Serial Copy Management System) system and records only a part of the encoded digital audio signal on the recording medium when the permission by the security system cannot be obtained. There is (for example, refer to Patent Document 2).

[0067]

[Patent Document 1] Japanese Patent Laid-Open No. 2000-175162

[Patent Document 2] Japanese Patent Laid-Open No. 2001-312853

[0068]

By the way, MPEG
It is preferable for the user to transmit a content signal by using a high-quality compression coded signal such as a moving picture signal such as 1 and MPEG2, and an audio signal. However, it is not always preferable for the copyright holder to promote the content business.

Therefore, the above-mentioned MPEG of high coding quality is used.
In comparison with the compression encoding method using the image or sound, the digital content data in a semi-disclosed state slightly deteriorated like an analog system can be obtained when the data is decoded by a normal decoding device. There is a demand for a compression coding method for protecting the content business so that digital content data without deterioration can be obtained when decoded by a predetermined decoding device.

As an encoding method for protecting the content business, a function for preventing illegal copying of illegal contents and illegal reproduction performed by using an illegal reproducing device is provided. In addition, the contents that have undergone signal processing for the security protection of the contents to prevent illegal reproduction are supplied to the market.

On the other hand, a method of performing security protection by directly encrypting a bit stream which is encoded data obtained by compression-encoding the content to be security-protected by the MPEG method, for example. There is also.

However, in this method, the encrypted coded data is decrypted only by a specific authorized user to obtain content data without deterioration, but the encrypted decryption process is not performed. There is a problem that the person cannot obtain any image or audio signal information related to the content.

Therefore, in the present invention, when the content data is orthogonally transformed by, for example, MPEG, and the coefficient value data obtained by the orthogonal transformation is variable-length coded, the encoded content signal obtained is variable-length coded. VLC (variable length) using so-called Huffman code
The coding table is changed and used so that the quality of the reproduced image and the quality of the audio signal in the general decoder are different from those in the regular decoder.

In the case of an event whose occurrence probabilities are greatly different, the length of each code is generally different, and if the table is replaced, the code amount increases,
The coding efficiency may be poor. However, in the case of the present invention, particularly when the VLC code is read, the codes having the same length in the VLC code are read, so that the deterioration of the coding efficiency is prevented and an absurd error signal is generated. Also try to prevent.

Further, the VLC used by switching the above
The VLC codes in the table are, for example, MPEG video and MPEGAA commonly used in the market as an international standard.
A code in the VLC code system defined by the C audio standard or the like is used for the configuration, and the content compression encoding method is realized by a method having good compatibility with a method used in many markets in the market.

Furthermore, the commonly used MPEG
The coding selection signal for switching the event indicated by the VLC code using the syntax of is, for example, the data described in the user data recording area defined by MPEG, the digital watermark data mixed in the image or sound, and the image or The transmission is made possible by a plurality of methods such as additional data transmitted separately from voice data. Then, an object of the present invention is to provide a variable-length coded data receiving method and a variable-length coded data receiving device which are performed while securing a predetermined security level for a desired content to be encoded.

[0077]

The present invention comprises the following means 1) to 8) in order to solve the above problems. That is,

1) Time-series data obtained by performing data conversion, quantization, and arrangement by a predetermined method on a content signal including at least one of an image signal and an audio signal Variable-length coding and packetizing the packetized compression-coded signal output to the communication network, and variable-length decoding to obtain the time-series data, and decoding the obtained time-series data to obtain the time-series data. A variable length coded data receiving method for obtaining a content signal, wherein the packetized compression coded signal is described by assigning a predetermined codeword to a plurality of data values of the time series data. The number of the time-series data in the coded table and the codewords described in the variable-length coding table are the same and different from each other. A coding selection signal that specifies which of the two coding tables, the exchange variable-length coding table and the variable-length coding table that are described by exchanging codewords A compression-coded signal generated by performing variable-length coding of the time-series data is written in the information data description area for transmitting the content signal by using the coding table specified by A packetized compression coded signal in which the coding selection signal is described in a user data description area which is a user-defined area for transmitting data,
A variable length coded data receiving method for performing the decoding using the packetized compression coded signal, wherein the compression coding described in the information data description area is performed by receiving the packetized compression coded signal. The first step (222) of acquiring the signal and the encoding selection signal described in the user data description area, and the encoding table specified by the acquired encoding selection signal are used to obtain A second step (221) of variable-length decoding the compressed coded signal to obtain the time-series data, and a third step of decoding the time-series data obtained in the second step to obtain the content signal. And a step (22a) of step (22a). 2) Variable-length time-series data obtained by performing data conversion, quantization, and arrangement on a content signal including at least one of an image signal and an audio signal by a predetermined method. Variable that receives the packetized compressed coded signal that is encoded and packetized and is output to the communication network, and performs variable length decoding to obtain time series data, and decodes the obtained time series data to obtain a content signal. A method for receiving long coded data, wherein the packetized compressed coded signal is described by assigning a predetermined codeword to a plurality of data values of the time series data, and a variable length coding table thereof. Among the codewords described in the variable length coding table, the codewords having the same number of the time-series data and different from each other are set. One of two coding tables, an exchange variable-length coding table described by being exchanged, which is specified by a coding selection signal that specifies which coding table is used to perform the variable-length coding. A compression coded signal generated by performing variable length coding of the time-series data using the coding table of 1 is described in the information data description area for transmitting the content signal, and the coding selection is performed. A packetized compression coded signal in which a signal is described in a user data description area which is a user-defined area for transmitting data, and variable length coded data for performing the decoding using the packetized compression coded signal A receiving method, wherein the packetized compression coded signal is received, and the compression coded signal described in the information data description area and the user data description area are described. A first step of acquiring the coding selection signal and (222),
Variable length decoding is performed using the encoding table specified by the acquired encoding selection signal, or use of the exchange variable length encoding table is specified by the acquired encoding selection signal. In that case, the second step (23) of ignoring the use of the table and selecting whether to perform variable length decoding using the variable length coding table,
A third step (22) of performing variable-length decoding of the obtained compression-coded signal using a coding table corresponding to the selection result in the second step to obtain time-series data
1) and the fourth step (2) of decoding the time-series data obtained in the third step to obtain a content signal.
2) A variable-length coded data receiving method comprising: 3) Variable-length code is used for time-series data obtained by performing data conversion, quantization, and arrangement by a predetermined method on a content signal including at least one of an image signal and an audio signal. The packetized compressed coded signal generated by packetization is received and the packetized compressed coded signal output to the communication network is received, and variable length decoding is performed to obtain the time series data. A variable length coded data receiving method for decoding sequence data to obtain the content signal, wherein the compressed coded signal is predetermined for a plurality of data values of the time series data for a predetermined portion of the content signal. Of the variable-length coding table described by assigning codewords and the codeword described in the variable-length coding table, the time system The variable length is determined by using which of the two encoding tables, the exchange variable length encoding table in which the number of column data is the same and different codewords are exchanged and described. A first variable-length coded signal obtained by variable-length coding the time-series data for a predetermined portion of the content signal, using the coding table designated by the coding selection signal designating whether or not to perform coding. And digital watermark processing time-series data obtained by performing processing for embedding the coding selection signal by digital watermarking on a portion other than the predetermined portion of the content signal, using the variable length coding table. A variable-length code that is obtained by arranging a second variable-length coded signal that has been variable-length coded by performing the decoding using the compressed-coded signal. A compressed data reception method, the first step (27) of depacketizing the packetized compressed coded signal obtained by receiving to obtain the compressed coded signal, and the obtained compressed coding The signal is subjected to variable length decoding using the variable length encoding table to obtain the digital watermark processing time series data, and the code embedded by a digital watermark based on the obtained digital watermark processing time series data. A second step (26) of detecting an encoding selection signal and an encoding table designated by the encoding selection signal detected in the second step are used to obtain the obtained compressed encoding signal. A third step (221) of variable-length decoding to obtain the time series data, and a fourth step of decoding the time series data obtained in the third step to obtain the content signal.
And a variable length coded data receiving method including the step (22). 4) Variable-length code of time-series data obtained by performing data conversion, quantization, and arrangement by a predetermined method on a content signal including at least one of an image signal and an audio signal The packetized compressed coded signal generated by packetization is received and the packetized compressed coded signal output to the communication network is received, and variable length decoding is performed to obtain the time series data. A variable length coded data receiving method for decoding sequence data to obtain the content signal, wherein the compressed coded signal is predetermined for a plurality of data values of the time series data for a predetermined portion of the content signal. Of the variable-length coding table described by assigning codewords and the codeword described in the variable-length coding table, the time system The variable length is determined by using which of the two encoding tables, the exchange variable length encoding table in which the number of column data is the same and different codewords are exchanged and described. A first variable-length coded signal obtained by variable-length coding the time-series data for a predetermined portion of the content signal, using the coding table designated by the coding selection signal designating whether or not to perform coding. And digital watermark processing time-series data obtained by performing processing for embedding the coding selection signal by digital watermarking on a portion other than the predetermined portion of the content signal, using the variable length coding table. A variable-length code that is obtained by arranging a second variable-length coded signal that has been variable-length coded by performing the decoding using the compressed-coded signal. A compressed data reception method, the first step (27) of depacketizing the packetized compressed coded signal obtained by receiving to obtain the compressed coded signal, and the obtained compressed coding The signal is subjected to variable length decoding using the variable length encoding table to obtain the digital watermark processing time series data, and the code embedded by a digital watermark based on the obtained digital watermark processing time series data. Variable-length decoding is performed using a second step (26) of detecting an encoding selection signal and an encoding table designated by the encoding selection signal detected in the second step, or When the use of the exchange variable length coding table is designated by the detected coding selection signal, the use of the table is ignored, and the variable length coding table is used to change the variable length. A third step of performing one of selecting performs No. of (23)
And a fourth step (221) of performing time-series data by performing variable length decoding of the obtained compressed coded signal using the coding table according to the selection result in the third step. And a fifth step (22) of decoding the time series data obtained in the fourth step to obtain a content signal, the variable length coded data receiving method. 5) Variable-length time-series data obtained by performing data conversion, quantization, and arrangement according to a predetermined method on a content signal including at least one of an image signal and an audio signal. The packetized compression coded signal that is coded and packetized and output to the communication network is received, and the variable time length decoding is performed to obtain the time series data, and the obtained time series data is decoded to obtain the content signal. A variable length coded data receiving device to obtain
The packetized compression coded signal is described in a variable length coding table described by allocating a predetermined codeword to a plurality of data values of the time series data, and the variable length coding table. Of the codewords, the number of the time-series data is the same, and among the two coding tables, the exchange variable-length coding table in which different codewords are exchanged and described.
It is generated by performing variable-length coding of the time-series data using the coding table designated by the coding selection signal that specifies which coding table is used to perform the variable-length coding. A packet in which a compressed coded signal is written in an information data description area for transmitting the content signal, and the coded selection signal is written in a user data description area which is a user-defined area for transmitting data. A variable length coded data receiving device for performing the decoding using the packetized compression coded signal, wherein the packetized compression coded signal is received, and an information data description area is received. Packetized decoding means (22) for obtaining the compressed coded signal described in (1) and the coded selection signal described in the user data description area.
2) and a variable-length decoding means for variable-length decoding the acquired compressed coded signal to obtain the time-series data by using the coding table specified by the acquired coding selection signal ( 221) and content signal decoding means (22a) for decoding the time series data obtained by the variable length decoding means to obtain the content signal, and the variable length code. Data receiving device. 6) Variable-length time-series data obtained by performing data conversion, quantization, and arrangement by a predetermined method on a content signal including at least one of an image signal and an audio signal. Variable that receives the packetized compressed coded signal that is encoded and packetized and is output to the communication network, and performs variable length decoding to obtain time series data, and decodes the obtained time series data to obtain a content signal. A long coded data receiving device, wherein the packetized compression coded signal is described by assigning a predetermined codeword to a plurality of data values of the time series data, and a variable length coding table thereof. Among the codewords described in the variable length coding table, the codewords having the same number of the time-series data and different from each other are set. One of two coding tables, an exchange variable-length coding table described by being exchanged, which is specified by a coding selection signal that specifies which coding table is used to perform the variable-length coding. A compression coded signal generated by performing variable length coding of the time-series data using the coding table of 1 is described in the information data description area for transmitting the content signal, and the coding selection is performed. A packetized compression coded signal in which a signal is described in a user data description area which is a user-defined area for transmitting data, and variable length coded data for performing the decoding using the packetized compression coded signal A receiving device, which receives the packetized compression coded signal and describes the compression coded signal described in the information data description area and the user data description area Packet decoding means for acquiring the coding selection signal (222)
And variable-length decoding is performed using the encoding table specified by the obtained encoding selection signal, or the exchange variable-length encoding table is used according to the obtained encoding selection signal. A coding table selecting means (23) for ignoring use of the table when specified and selecting whether to perform variable length decoding using the variable length coding table, and the coding table selecting means. Variable length decoding means (221) for performing variable length decoding of the obtained compressed coded signal to obtain time-series data, using a coding table corresponding to the selection result of the variable length decoding means. And a content signal decoding means (22) for decoding the time-series data obtained by (1) to obtain a content signal. 7) Variable-length coding of time-series data obtained by performing data conversion, quantization, and arrangement by a predetermined method on a content signal that includes at least one of an image signal and an audio signal. The packetized compressed coded signal generated by packetization is received and the packetized compressed coded signal output to the communication network is received, and variable length decoding is performed to obtain the time series data. A variable length coded data receiving device for decoding sequence data to obtain the content signal, wherein the compressed coded signal has a predetermined value with respect to a plurality of data values of the time series data with respect to a predetermined portion of the content signal. Of the variable-length coding table described by assigning codewords and the codeword described in the variable-length coding table, the time system The variable length is determined by using which of the two encoding tables, the exchange variable length encoding table in which the number of column data is the same and different codewords are exchanged and described. A first variable-length coded signal obtained by variable-length coding the time-series data for a predetermined portion of the content signal, using the coding table designated by the coding selection signal designating whether or not to perform coding. And digital watermark processing time-series data obtained by performing processing for embedding the coding selection signal by digital watermarking on a portion other than the predetermined portion of the content signal, using the variable length coding table. A variable-length code that is obtained by arranging a second variable-length coded signal that has been variable-length coded by performing the decoding using the compressed-coded signal. A packetized decoding device (27) for depacketizing the packetized compressed coded signal obtained by receiving to obtain the compressed coded signal; and the obtained compressed coding. The signal is subjected to variable length decoding using the variable length encoding table to obtain the digital watermark processing time series data, and the code embedded by a digital watermark based on the obtained digital watermark processing time series data. Using the encoding selection signal detecting means (26) for detecting the encoding selection signal and the encoding table designated by the encoding selection signal detected by the encoding selection signal detecting means, the obtained compression is performed. Variable length decoding means (221) for variable length decoding the encoded signal to obtain the time series data, and decoding the time series data obtained by the variable length decoding means Variable-length coded data reception apparatus characterized by configured by including a content signal decoding means (22) to obtain the content signal. 8) Time-series data obtained by performing data conversion, quantization, and arrangement by a predetermined method on a content signal that includes at least one of an image signal and an audio signal is a variable-length code. The packetized compressed coded signal generated by packetization is received and the packetized compressed coded signal output to the communication network is received, and variable length decoding is performed to obtain the time series data. A variable length coded data receiving device for decoding sequence data to obtain the content signal, wherein the compressed coded signal has a predetermined value with respect to a plurality of data values of the time series data with respect to a predetermined portion of the content signal. Of the variable-length coding table described by assigning codewords and the codeword described in the variable-length coding table, the time system The variable length is determined by using which of the two encoding tables, the exchange variable length encoding table in which the number of column data is the same and different codewords are exchanged and described. A first variable-length coded signal obtained by variable-length coding the time-series data for a predetermined portion of the content signal, using the coding table designated by the coding selection signal designating whether or not to perform coding. And digital watermark processing time-series data obtained by performing processing for embedding the coding selection signal by digital watermarking on a portion other than the predetermined portion of the content signal, using the variable length coding table. A variable-length code that is obtained by arranging a second variable-length coded signal that has been variable-length coded by performing the decoding using the compressed-coded signal. A packetized decoding device (27) for depacketizing the packetized compressed coded signal obtained by receiving to obtain the compressed coded signal; and the obtained compressed coding. The signal is variable-length decoded using the variable-length coding table to obtain the digital watermark processing time-series data, and the code embedded by a digital watermark based on the obtained digital watermark processing time-series data. Variable length decoding is performed by using an encoding selection signal detecting means (26) for detecting an encoding selection signal and an encoding table designated by the encoding selection signal detected by the encoding selection signal detecting means. If the exchange variable length coding table is designated by the detected coding selection signal, the use of the exchange variable length coding table is ignored, and the variable length coding is performed. The compression table obtained by using a coding table selection means (23) for selecting whether to perform variable length decoding using a table and a coding table according to the selection result by the coding table selection means. Variable length decoding means (221) for performing variable length decoding of the encoded signal to obtain time series data
And variable-length coded data receiving means for decoding the time-series data obtained by the variable-length decoding means to obtain a content signal (22). apparatus.

[0079]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a variable length coded data receiving method and a variable length coded data receiving apparatus of the present invention will be described below with reference to preferred embodiments.

The signal to be coded here is a content signal including at least one of an image signal and / or an audio signal. First, an encoding method when the content signal is an image will be described based on its basic embodiment. <First Embodiment> FIG. 1 shows an image signal coding apparatus according to the first embodiment equipped with the image signal coding method (hereinafter,
It may be simply referred to as an encoding device. ), And will be described with reference to the drawings.

The image signal encoding apparatus 10 shown in the figure includes an image data converter 11, an MPEG encoder 12 and a VLC.
Table selector 13, standard VLC table 14, special V
It is composed of an LC table 15 and a CPU 16. The MPEG encoder 12 includes a VLC device 121.

Next, the operation of the image signal coding apparatus 10 will be described. First, the input image signal to be encoded by the MPEG encoder 12 is supplied to the image data converter 11, where an encoding selection signal, which is a VLC table switching signal described later, supplied from the CPU 16 is used as electronic watermark information. It is supplied and embedded in the image signal.

The encoding selection signal embedded in the image signal is output from the CPU 16, and the encoding selection signal output from the CPU 16 is also supplied to the VLC table 13. Then, the VLC table selector 13
Then, of the VLC tables supplied from the standard VLC table 14 and the special VLC table 15, the VLC table selected by the coding selection signal is the VLC unit 1.
21 and the MPEG encoder 12 performs compression encoding based on the VLC table temporarily stored in the VLC unit 121.

That is, the MPEG encoder 12 has
An image signal in which the encoding selection signal is embedded by a digital watermark is supplied. Then, the image signal is compressed and encoded using the VLC table designated by the embedded encoding selection signal.

In this way, when the coding selection signal supplied from the CPU 16 is, for example, "0", the standard VL
The C table is selected and coded, and when it is "1", the special VLC table is selected and coded. Then, the encoding selection signal is converted by the image data converter 11, for example, embedded in the image signal at the first position at a predetermined interval using a digital watermarking method, and compression encoded by MPEG. The encoded data is generated.

Next, the decoding of the generated encoded data will be described. FIG. 2 shows the configuration of an image signal decoding apparatus (hereinafter, also simply referred to as a decoding apparatus) according to the first embodiment equipped with the method for decoding encoded data, which will be described below with reference to the drawings. .

The image signal decoding apparatus 20 shown in FIG.
It comprises a PEG decoder 22, a VLC table selector 23, a standard VLC table 24, a special VLC table 25, and an image watermark detector 26. And MP
The EG decoder 22 includes a VLC decoder 221.

Next, the operation of the image signal decoding apparatus 20 will be described. First, the encoded data compressed and encoded by the image signal encoding device 10 is supplied to the MPEG decoder 22. The signal that is compression-encoded here is the VLC decoder 2
The value of the VLC table temporarily stored in 21 is used for decoding. The image signal obtained by the decoding is input to the image digital watermark detector 26.

In the image digital watermark detector 26, the coding selection signal embedded as digital watermark information by the image data converter described later is detected, and the coding selection signal obtained by the detection is the VLC table selector 23. Is supplied to.

In the VLC table selector 23, the VLC table to be stored in the standard VLC table 24 or the special VLC table 25 is determined based on the supplied coding selection signal, that is, the coding selection signal supplied from the CPU 16. It is selected and supplied to the VLC decoder 221. That V
The values in the LC table are temporarily stored in the VLC decoder 221.

Next, using the VLC table temporarily stored in the VLC table 221, the MPEG decoder 2
In 2, the supplied encoded data is decoded.
Then, the decoding is performed by the VLC of the MPEG encoder 12.
VL that is the same as the VLC table temporarily stored in the device 121
The C table is used for decoding. Therefore, a high quality image signal is decoded and obtained.

As described above, in the image signal encoding device 10 and the image signal decoding device 20 in the first embodiment, the one selected by the encoding selection signal embedded by the image digital watermark method. Since the VLC table is used for compression encoding and decoding of the compression encoded data, a high quality image signal is reproduced.

On the other hand, when the image signal decoding apparatus does not have the function of detecting the image digital watermark information, or when the image signal decoding apparatus does not have the information of the special VLC table, it is installed in a normal MPEG decoder. Since the standard VLC table is used for decoding, the image signal obtained by decoding is reproduced as an image signal containing a distortion component based on the difference between the VLC tables.

By using the above-described method, the copyright holder who owns the copyright of the content has image signals of different qualities with respect to a special decoder having a contract relationship with the held content and a general decoder having no contract relationship. Can be supplied. That is, a special decoder has an image watermark detector,
By installing the special VLC table and the special VLC table, the image signals of different qualities are supplied to the general person and the special person.

Even if an ordinary person has an image signal decoding apparatus equipped with a special VLC table, the digital watermark information to be embedded in the encoded data is given information related to the method of embedding the digital watermark information. Only the specified special person can decode the image signal so that only the contractor having a special relationship can obtain the image signal without quality deterioration.

The digital watermark signal in which the predetermined information is embedded is, for example, a method of embedding some information in an image so that it is hidden. Further, there are a plurality of methods for embedding the information, but the image signal encoding device side and the image signal decoding device side mutually use a predetermined digital watermarking method to encode the information. The transmission of the activation selection signal is performed.

As an example proposed as the digital watermark method, for example, NTT uses SCIS'97 (The 19
97 Symposium on Cryptography and Information Secur
cit; 1997, Symposium on Cryptography and Information Security) -31G, "Method of embedding copyright information in digital moving images using DCT" was announced.
The method is that the information to be embedded is MPEG (moving pic).
In ture experts group) coding, especially DCT (di
It is proposed as an information embedding method based on the change of a coefficient, a motion vector, and a quantization characteristic.

Also, SCIS '97 -26 at National Defense University
In B, "Watermark signature method for images by PN series" was announced.
It has been proposed as a method of synthesizing signature information with an image by diffusing an image signal with a (pseudo noise) sequence.

It is possible to transmit the coding selection signal by using any of the proposed digital watermarking methods, and other digital watermarks in which the coding selection signal is embedded by the encryption processing and then transmitted. It can also be realized by a method.

As described above, by transmitting the coded signal generated by the image signal coding apparatus based on the coded selection signal transmitted by the digital watermarking method to the image signal decoding apparatus, the quality different for each user can be obtained. The configurations and operations of the image signal encoding device and the decoding device capable of obtaining the image of are described.

An image transmitted by embedding the coding selection signal is, for example, a GOP (Gr (Gr)
The first image of the “up of picture” or the first image at predetermined intervals is encoded using the standard VLC table, and the second and subsequent images are described by the transmitted digital watermark method. Encoding is performed using the generated VLC table. Furthermore, there is also a method of recording VLC table information described by a digital watermark, for example, at a place where program software is started by encoding it using a standard VLC table for a predetermined time.

As another method, there is a method of transmitting the digital watermark information related to the VLC table by the location of transmitting the DC component of the image block obtained by DCT transforming the image signal. In normal encoding, the DC component has a fixed bit length (for example, 8 bits) regardless of the quantized value.
Since many cases are quantized by, the redundancy of that part is large. Therefore, for example, the digital watermark data can be transmitted by setting the value of the DC component of the entire one screen to "0" for "even" and "1" for "odd".

The coding selection signal is transmitted using the above method. Then, an image without deterioration is reproduced when the same decoded VLC table as that at the time of encoding is used, and a slightly deteriorated image is reproduced when a different VLC table is used. However, even when a different VLC table is used, an image that causes a reproduction image to be broken is not reproduced. that's all,
The configurations of the image signal coding apparatus and the image signal decoding apparatus according to the first embodiment for transmitting the coding selection signal by the digital watermark method and the operations of these apparatuses have been described. next,
A method for transmitting the encoded selection signal by describing it in a user data description area that can be defined and transmitted by the user will be described.

<Second Embodiment> FIG. 3 shows the structure of an image signal coding apparatus according to the second embodiment equipped with the image signal coding method, which will be described below with reference to the drawings. The image signal encoding device 10a shown in FIG.
a, VLC table selector 13, standard VLC table 1
4, a special VLC table 15 and a CPU 16a, and the MPEG encoder 12a has VLC.
A device 121 and a user data description device 122 are included. In the figure, blocks having the same functions as those in the first embodiment described above are designated by the same reference numerals.

Next, the operation of the image signal coding apparatus 10a having such a configuration, which is different from that of the first embodiment, will be described. That is, the image signal coding apparatus 10a uses the coding selection signal supplied from the CPU 16a as the user data description unit 122 of the MPEG encoder 12a.
, The coding selection signal is described in the user data area there.

Then, the VLC table selector 13 supplies the VLC table based on the coding selection signal supplied from the CPU 16a to the VLC unit 121. Then, the input image data is compression-encoded on the basis of the encoding selection signal supplied from the CPU 16a, and the encoding selection signal is described in the user data area of the compression-encoded signal. The data is output from the image signal encoding device 10a.

Next, the description of the coding selection signal in the user data description area will be described. FIG. 4 shows a description format of the sequence header in the encoded data,
explain.

In the figure, the description syntax of the sequence header is shown. 3 in the sequence header
Following the 2-bit sequence header code, a 12-bit horizontal image size and a 12-bit vertical image size are described in this order. And the next with a halftone dot
bits () == User_data after user_data_start_code
User data can be described at the location.

User data can also be described in the GOP layer. FIG. 5 shows a description format of the encoded data in the GOP layer. The user data description points in the figure are shown with halftone dots as in FIG. That is, nextbits () == user_data_sta
User data similar to the above can be described in User_data after rt_code.

Such user data can be similarly described in the picture layer. FIG. 6 shows a description format of the picture layer in the encoded data. Similarly, the user data can be described at the places shown with halftone dots.

As described above, the description of the user data in MPEG includes a sequence header, a GOP layer,
And each area of the picture layer is possible. Then, in the user_data description area, other user_contents with different contents
Since data may be described, when describing an encoding selection signal which is a VLC table switching signal,
For example, 3 such as "ffee2424" in hexadecimal display
Described after the 2-bit header signal.

That is, a 1-bit signal for selecting a VLC table such as "0" or "1" in binary notation is described after the header signal. Alternatively, the VLC table selection information is described by a byte-aligned 8-bit signal.

In this way, the coding selection signal is described in the user data area. Then, the encoding device generates encoded data which has been compression-encoded using the VLC table selected by the encoding selection signal. Next, the decoding of the coded data thus generated will be described.

FIG. 7 shows the structure of an image signal decoding apparatus according to the second embodiment equipped with the coded data decoding method, which will be described below with reference to the drawings. The image signal decoding device 20a shown in the figure comprises an MPEG decoder 22a, a VLC table selector 23, a standard VLC table 24, and a special VLC table 25. And MPEG
The decoder 22a includes a VLC decoder 221 and a user data decoder 222. In the figure, blocks having the same functions as those of the first embodiment described above are designated by the same reference numerals. Also in the drawings shown after this figure, the parts having the same numbers indicate the blocks having the same functions unless otherwise specified.

Next, the operation of the image signal decoding apparatus 20a having such a configuration will be described. First, the encoded data compressed and encoded by the image signal encoding device 10a is M
It is supplied to the PEG decoder 22a. Here, MPE
The signal compressed and encoded by the G method is used by the VLC decoder 2
The value of the VLC table temporarily stored in 21 is used for decoding.

The decoding is carried out by decoding the user data described by the user data description device 122 shown in FIG. 3 by the user data decoder 222 to obtain a coding selection signal, and the coding selection signal. Is used to perform the decoding operation of the encoded data.

That is, the coding selection signal obtained by the user data decoder 222 is supplied to the VLC table selector 23. In the VLC table selector 23, the CPU 16
a standard VL based on the encoding selection signal supplied from a.
The value of one of the VLC tables stored in the C table 24 and the special VLC table 25 is selected.
Then, the selected VLC table is stored in the VLC decoder 22.
1 and is temporarily stored therein.

Using the VLC table temporarily stored in the VLC table 221, the MPEG decoder 22
At a, the supplied encoded data is decoded. In this way, the image signal obtained by decoding is M
Since the same VLC table as the VLC table temporarily stored in the VLC unit 121 of the PEG encoder 12a is used for decoding, a decoded image signal without quality deterioration is obtained.

As described above, the image signal coding device 10a and the image signal decoding device 20 in the second embodiment are arranged.
The a is because the VLC table selected based on the encoding selection signal described in the user data description area defined in the MPEG standard is used for compression encoding and compression encoding. , A high quality image signal is encoded and decoded.

The configurations of the image signal coding apparatus and the image signal decoding apparatus according to the second embodiment, which describe and transmit the coding selection signal in the user data description area, and the operations of these apparatuses have been described above. Next, a third embodiment will be described in which the encoding selection signal is transmitted by using the digital watermark data embedded by using the quantized value defined by the MPEG standard, for example.

<Third Embodiment> FIG. 8 shows the arrangement of an image signal coding apparatus according to the third embodiment equipped with the image signal coding method, and will be described with reference to the drawing. The image signal encoding device 10b shown in FIG.
b, VLC table selector 13, standard VLC table 1
4, a special VLC table 15, and a CPU 16b. The MPEG encoder 12b has a VL
A C unit 121 and a quantized value digital watermark information description unit 123 are included.

Next, with regard to the operation of the image signal encoding device 10b, the operation different from that of the first embodiment will be mainly described. First, the encoding selection signal supplied from the CPU 16b is supplied to the quantized value digital watermark information descriptor 123 of the MPEG encoder 12b. There, it is described as the quantized value of the input image obtained by DCT transforming the information related to the encoding selection signal as digital watermark information.

Then, the VLC table selector 13 selects the VLC table based on the coding selection signal supplied from the CPU 16b, and the selected VLC table is supplied to the VLC unit 121. Then, the input image data in which the coding selection signal is described and embedded by the quantized value electronic watermark information description device 123 is subjected to variable length coding using the VLC table stored in the VLC device 121. The coded data thus compressed and coded is output from the image signal coding device 10b.

Next, the operation of the digital watermark described as being embedded by the quantized value digital watermark information description device 123 will be described. FIG. 9 shows an example in which digital watermark information is described in a quantized value obtained by DCT transformation.

In the figure, the whole image is shown by a large rectangle. The small squares shown therein indicate macroblocks each having 16 pixels in the vertical and horizontal directions. The numbers shown therein are examples of quantized values used when quantizing macroblock data.

Here, it is said that the information of "1" when the value of the quantization scale, which is set for each macroblock defined by the MPEG standard, is odd, for example, is "0" when it is even. In this way, the digital watermark information is embedded. That is, the data of "0" and "1" can be embedded as the data of the number of macroblocks by the odd number and the even number of the quantization value of the macroblock.

The quantized value of the macroblock is 1 to 31.
It is defined by the MPEG standard that it is represented by a value of (5 bits). Then, even if compression coding is performed by using a predetermined quantized value that is an odd number or an even number by using a value that is different from the value at the time of optimum encoding, the encoded data It has been confirmed by experiments that the decoded image obtained by decoding is a visually comparable image deterioration.

In this way, by using the information embedded by the quantized value digital watermark information description device 123, the coding selection signal that can be transmitted by 1 bit is only one macroblock that is transmitted first. You may make it transmit using it. Furthermore, the same data may be transmitted by using one macroblock of a specific address or by repeating a plurality of macroblocks.

As described above, the configuration and operation of the image signal coding apparatus of the third embodiment in which the quantized value digital watermark information description device 123 performs the coding by embedding the coding selection signal has been described. Next, the decoding of the coded data thus generated will be described.

FIG. 10 shows a configuration example of the image signal decoding apparatus of the third embodiment for decoding the encoded data encoded by the image signal encoding apparatus of the third embodiment. It will be described with reference to FIG. Image signal decoding apparatus 20 shown in FIG.
b is composed of an MPEG decoder 22b, a VLC table selector 23, a standard VLC table 24, and a special VLC table 25. Then, the MPEG decoder 22
b includes a VLC decoder 221 and a quantized value digital watermark information detector 223.

Next, the operation of the image signal decoding apparatus 20b having such a configuration will be mainly described, which is different from that of the decoding apparatus 20 of the first embodiment. First, the encoded data compressed and encoded by the image signal encoding device 10b is supplied to the MPEG decoder 22b. Therefore,
The signal compressed and encoded by the MPEG system is VL
The value of the VLC table temporarily stored in the C decoder 221 is used for decoding.

Then, a part of the quantized value information obtained by decoding there is inversely quantized and inversely DCT-transformed to obtain image data. The other part is supplied to the quantized value digital watermark information detector 223. There, the coding selection signal is obtained by detecting the information described by the quantized value digital watermark information description device 123.

The obtained coding selection signal is supplied to the VLC table selector 23. Then, in the VLC table selector 23, the VLC table stored in the standard VLC table 24 or the special VLC table 25 based on the supplied coding selection signal, that is, the coding selection signal output from the CPU 16b. The value of is selected. The selected VLC table value is the VLC decoder 2
21 and the VLC table value is temporarily stored in the VLC decoder 221.

As described above, the image signal coding apparatus according to the third embodiment for describing and transmitting the coding selection signal by setting the quantized value for each macroblock to an odd number and an even number, and transmitted by the apparatus. The configuration of the image signal decoding device for decoding the encoded data and the operation of these devices have been described.

<Fourth Embodiment> Next, the coding selection signal is set to M.
A fourth embodiment will be described in which a coding selection signal is embedded as digital watermark data in a vector value of a motion vector defined by the PEG standard and transmitted.

FIG. 11 shows the configuration of an image signal encoding apparatus according to the fourth embodiment which incorporates the image signal encoding method, which will be described below with reference to the drawings. The image signal encoding device 10c shown in the figure includes an MPEG encoder 12c, a VLC table selector 13, a standard VLC table 14, and a special VL.
It is composed of a C table 15 and a CPU 16c. The MPEG encoder 12c includes a VLC unit 121 and a motion vector digital watermark information description unit 124.

Next, the operation of the image signal coding apparatus 10c having such a configuration will be described mainly with respect to the operation different from that according to the first embodiment. That is, the image signal encoding device 1
At 0c, the encoding selection signal supplied from the CPU 16c is supplied to the motion vector digital watermark information descriptor 124 of the MPEG encoder 12c. Then, the information related to the coding selection signal is described as a digital vector information as a motion vector value in motion prediction coding.

Then, in the VLC table selector 13, C
V based on the encoding selection signal supplied from the PU 16c
LC table is selected and its VLC table is VLC
Supplied to the vessel 121. Further, the motion vector digital watermark information description device 124 generates a motion vector signal in which the coding selection signal is described and embedded. And DCT
The quantized value of the converted input recorded image data is the VLC unit 12
Variable length coding is performed by the VLC table stored in No. 1, and coded data is generated. The motion vector signal and the encoded data generated in this way are output from the image signal encoding device 10c.

Next, the operation of the digital watermark described as being embedded by the motion vector digital watermark information description device 124 will be described. FIG. 12 shows an example in which digital watermark information is described in a motion vector obtained by motion prediction detection.

In the figure, the whole image is shown by a large rectangle. The small squares shown therein are macroblocks, each of which has 16 pixels in the vertical and horizontal directions,
The numbers shown therein are the motion vector values of the horizontal direction of the macroblock data in pixel units.

Here, it is said that when one set motion vector value defined by the MPEG standard for one macroblock is, for example, an odd number, the embedded information is "1", and when it is an even number, it is "0". Like this, 0
And the information of 1 is embedded. That is, the digital watermark information is described by embedding the data “0” and “1” as the data for the number of macroblocks by the odd and even motion vector values of the macroblock.

The motion vector value of this macroblock is 0.
It is specified by, for example, the MPEG standard that it is basically expressed with a value of ± 16 (VLC) with an accuracy of 5 pixels. In such a case where a vector value is intentionally set by an odd number or an even number, that is, 1 for a predetermined motion vector value.
It has been confirmed by experiments that the decoded image obtained by decoding the encoded data based on the vector value can be obtained with a visually comparable image quality even when compression encoding is performed using different values. ing.

In this way, by using the information embedded by the motion vector digital watermark information descriptor 124, only one macroblock transmitted first is used as the encoding selection signal which can be transmitted by 1 bit. You may make it transmit it. Further, the same data may be transmitted by using one macroblock of a specific address or by repeating a plurality of macroblocks.

The configuration and operation of the image signal coding apparatus of the fourth embodiment in which the coding selection signal is embedded and coded by the motion vector digital watermark information descriptor have been described above. Next, the decoding of the coded data thus generated will be described.

FIG. 13 shows the decoding of coded data coded by the image signal coding apparatus of the fourth embodiment.
A configuration example of the image signal decoding apparatus according to the fourth embodiment is shown and will be described below with reference to the drawings. Image signal decoding device 2 shown in FIG.
0c includes an MPEG decoder 22c, a VLC table selector 23, a standard VLC table 24, and a special VLC table 25. And the MPEG decoder 2
2c includes a VLC decoder 221 and a motion vector digital watermark information detector 224.

Next, the operation of the image signal decoding apparatus will be described. First, the coded data including the motion vector information compressed and coded by the image signal coding apparatus 10c is M
It is supplied to the PEG decoder 22c.

Then, the motion vector information is supplied to the motion vector electronic watermark information detector 224, and the coding selection signal embedded in the motion vector is detected. The detected encoded selection signal is supplied to the VLC table selector 23, and the transmitted motion vector information is used to decode the signal compressed and encoded by the MPEG method to obtain an image signal, The obtained output image is output from the image signal decoding device 20c.

As described above with reference to the first to fourth embodiments, the coding selection signal is embedded in the image signal data as digital watermark information, the method is described in a predetermined user data description area, and the quantum signal is Transmission is possible by a method of embedding as digitized value digital watermark information or a method of embedding as motion vector digital watermark information.

Among the above-mentioned four methods, there are a method of transmitting by one method and a method of simultaneously transmitting by using a plurality of methods. Further, for example, the information in which the encoding selection signal information is transmitted by the user data may be described and transmitted, and the value of the encoding selection signal may be transmitted by the digital watermark information.

In this way, the coding selection signal can be transmitted from the image signal coding device to the image signal decoding device. Next, V which is switched by the encoding selection signal
The LC table will be described.

FIG. 14 shows a standard VLC table defined by the MPEG standard. In the figure, the relationship between the run length and the level for the VLC code is shown. That is, this table is a variable length coding table for coding and transmitting a data string represented by a 6-bit number from "-31" to "+31". Then, particularly when the data string includes many "0" values, the number of consecutive "0" s is defined as the run length, and the value transmitted following the consecutive "0" s is defined as the level. A VLC code is assigned according to the number of consecutive "0" s and the level value transmitted subsequently.

The table to which the VLC code is assigned in this way is stored in a normal MPEG decoder, and the table is used for decoding a bit stream encoded by a normal MPEG system.

By the way, the image signal coding apparatus according to the present embodiment allows the copyright holder to reproduce the image as a slightly deteriorated reproduced image with respect to the normal image signal decoding apparatus, and has a contract relationship. For example, a special VLC table is used for compression encoding so that a high-quality image without deterioration is reproduced for a special image signal decoding device.

Next, the special VLC table will be described. 15 and 16 show examples of the special VLC table used in this embodiment. VLC in these figures
The table is shown by dividing one special VLC table into two.

That is, this table shows, for a defined VLC code, a run length indicating a continuous length of data "0" and a level which is a value of data arranged after the continuous "0". It has been prescribed. Then, the replacement address is shown in the right column.

The replacement addresses A1 to
A38, B1-B5, and C1-C2 are listed. Then, when the values in the table shown therein are used as they are, the encoding is performed using the standard VLC table. Also, the special VLC table can be created by exchanging the addresses where the exchange address values are the same.

Next, the operation of exchanging the addresses will be described. The groups A, B, and C shown in the replacement address column of the table indicate the VLC categories. Then, the categories are grouped based on the run length value.

That is, A has a run length of 0, B has a run length of 1,
C indicates the classification when the run length is 2. Although only a part of the VLC table is displayed here, run lengths that are not displayed are grouped in the same manner.

VL in the special VLC table
The replacement of the address values designating the C code is performed between VLC codes having the same category, that is, the same run length value.

VLC codes having the same run length are replaced with each other by performing variable length coding on coefficient value data obtained by, for example, zigzag scanning of coefficient values obtained by orthogonal transformation as in MPEG. In such a compression encoding method, it is important as a change performed while keeping the number and arrangement of data constant.

That is, DC in the MPEG DCT block
The total run length of T-factors must not exceed 63 for intra-pictures and 64 for inter-pictures. Therefore, even if VLC follows the Huffman code system, 63 or 64 can be read by replacing
If the number exceeds, the absurd error occurs at the time of decoding the coded signal, the decoding cannot be performed, and the decoded image fails.

Therefore, the VLCs to be read need to be read in the same category, and in the example shown here, A, B, and A, which are shown as the same category, that "run lengths are the same", The same symbols in C are replaced with each other. For example, A2
And A3 can be read, but A2 and B2 cannot be read.

As described above, the replacement address is A1.
It is possible to create a special VLC table based on the standard VLC table by rereading each of the groups A38, B1 to B5, and C1 to C2.

Then, in the case of replacing VLC codes having a large difference in level value among the VLC codes by the combination of the run length and the level value which often occur when encoding a normal image, the semi-disclosure deteriorated to a predetermined degree. The image is decoded and obtained. That is, the semi-disclosure image referred to here indicates an image that is displayed in a deteriorated state that is reproduced with distortion when the image signal is analog-recorded.

For example, when each of A1 and A4 and A2 and A3 is replaced, a semi-disclosed image having a moderate deterioration is obtained. The same applies to the reading of B1 and B5, B2 and B4, and C1 and C2. Furthermore, such combinations relating to replacement are created as 32 to 64 kinds of replacement rules, and the identification signal is used as the replacement rule so that the combination can be decoded with a desired semi-disclosure image quality. Is also possible.

The method for exchanging VLC codes based on the exchange address has been described above. The VLC code events having the same run lengths are defined by the MPEG standard.
Therefore, the special decoder equipped with the special VLC code operates in a manner that ensures compatibility with the conventional standard decoder.

Since the VLC code is replaced with a code having a different level value for the same run length, the coded data encoded using the special VLC table is mounted only on the standard VLC table. When the image is decoded by the standard decoder, an image whose resolution is changed due to the reduction or improvement of the high frequency signal level of the image signal or the reduction or improvement of the low frequency signal level is reproduced.

Next, such a change in image resolution will be described. FIG. 17 shows the quality of an image signal obtained by decoding the encoded data compressed and encoded by the encoder by the decoder, the conventional apparatus using the conventional standard VLC table, the special VLC table and the standard VLC table. The relationship between encoding and decoding with a special device equipped with both of

In the same figure, the quality of the reproduced image by each of the four combinations is shown, and the mark ◯ indicates that a high quality image is reproduced, and the mark Δ indicates that the image is reproduced as a somewhat deteriorated image. There is.

That is, an image signal whose image quality is deteriorated is output only when it is coded by the special device and decoded by the conventional device, and when it is coded by the special device and decoded by the special device, it has a high quality. It is shown that the image is reproduced and compatibility with other conventional encoders is ensured.

In this way, since it is possible to give a difference in image quality to be reproduced within the range in which compatibility is ensured, the conventional type of decoding can be performed at the will of the person who holds the copyright of the image signal. It is possible to provide image data with different image quality to the decoder and the special type decoder. Then, the generation of the coding selection signal in the image signal coding device for that, the embedding in the coding data of the coding control signal, the acquisition of the coding selection signal in the image signal decoding device, and the decoding of the coding data, These operations are performed by the arithmetic processing of signals by the computer and by the control of the circuit section by the computer.

Next, a method of performing those signal processings by causing a computer to execute the program will be described. FIG. 18 is a flow chart showing the flow of a computer program executed for image signal coding.

In the figure, in step S11, whether or not the special processing of the image signal for reproducing the image data with different image quality is performed with respect to the conventional type decoder and the special type decoder. If it is checked and special processing is performed, an encoding control signal is generated from the computer in S12.

The generated coding control signal is supplied to the VLC table selector, and the VLC table selector acquires the special VLC table in S14. And S
The special VLC table acquired in 15 is loaded into the VLC unit of the MPEG encoder, and in S16, a transmission encoding control signal for transmitting the encoding control signal to the image signal decoding apparatus is generated.

The transmission encoded control signal is embedded in the image signal data as digital watermark information, described in a predetermined user data description area, embedded as quantized value digital watermark information, or motion vector digital watermark information. Is generated by the method of embedding as.

The generated encoded control signal for transmission is transmitted together with the encoded image data. Further, the MPEG encoder in which the VLC table for encoding the image data is a special VLC table, the image signal supplied in S17 is DCT-converted to obtain the quantized number data. Next, the obtained quantized number data is subjected to variable length coding using a special VLC table and is generated as coded data.

The generation of such a coded signal for transmission and the coding of the image data are repeatedly executed by the operations of S16 and S17 until the supply of the image data related to the coding is completed.

The coded data obtained by coding in this way is decoded by the image signal decoding device. Next, a computer program for operating the image signal decoding apparatus will be described.

FIG. 19 is a flow chart showing the flow of a computer program executed for image signal decoding. In the figure, it is checked whether or not the information of the encoding control signal is transmitted to the encoded data supplied in S21, and if the information is transmitted with the encoding control signal, it is embedded in the encoded data in S22. The encoded control signal transmitted by being transmitted is read so as to be decoded.

The read control signal is supplied to the VLC table selector to acquire the special VLC table in S23, and the acquired special VLC table is S2.
4 is loaded into the VLC decoder of the MPEG decoder.

Then, in the MPEG decoder, variable length decoding or the like is performed based on the loaded VLC table, and image data obtained by decoding the supplied encoded data is obtained. Further, the obtained image data is supplied as an output signal from the image signal decoding apparatus.
The operation of 6 is executed until the supply of the supplied encoded signal is completed.

As described above in detail, on the encoding side of the image signal, the decoding device having the standard VLC table and the decoding device having the special VLC table try to supply the reproduced video with different image quality. When is that special VL
Information related to the use of the C table is embedded in the image signal data as digital watermark information, described in a predetermined user data description area, and embedded as quantized value digital watermark information.
Alternatively, it can be performed by a method such as embedding as motion vector electronic watermark information.

The configurations and operations of the image signal coding device and the image signal decoding device according to the first to fourth embodiments have been described above. Next, an example in which the image signal encoding device and the image signal decoding device are applied to the transmission device and the reception device will be described.

<Fifth Embodiment> FIG. 20 shows the arrangement of an image signal coding transmission (transmission) apparatus according to the fifth embodiment, which will be described below with reference to the drawings.

The image signal encoding / transmitting device 10d shown in FIG.
In comparison with the configuration of the image signal encoding apparatus according to the first embodiment shown in FIG. 1, the transmission line packet encoder 17 and the transmission line interface 18 are arranged after the output of the MPEG encoder 12. It's different. And
The blocks having the same function are denoted by the same reference numerals.

Next, the operation of the image signal coding and transmitting apparatus 10d having such a configuration, different from the first embodiment, will be described. That is, the compression coded signal obtained by embedding the coded selection signal, which is a VLC table switching signal, as digital watermark information and compression-coded by the MPEG encoder 12 is the transmission path packet encoder 1.
7 is supplied.

In this case, a multiplexing process for packetizing the compression-coded signal into a bit stream as defined by the MPEG system for each information such as audio and video and supplying it to the transmission path is performed. The encoded packet data subjected to the multiplexing processing is transmitted via the transmission line interface 18 to the image signal encoding and transmitting device 10.
It is output from d to the communication network. Then, the transmitted multiplexed signal is received by the image signal decoding receiver.

FIG. 21 shows the arrangement of an image signal decoding / receiving apparatus according to the fifth embodiment, which will be described below with reference to the drawing. The image signal decoding receiving apparatus 20d shown in FIG.
The difference from the image signal decoding apparatus according to the first embodiment shown in FIG. 3 is that a transmission path packet decoder 27 is arranged between the input terminal and the MPEG decoder 22.
The blocks having the same function are denoted by the same reference numerals.

Next, the operation of the image signal decoding / receiving device 20d having such a configuration, different from the first embodiment, will be described. That is, the packetized compressed coded signal (coded packet data) received from the communication network via the transmission line interface 28 is supplied to the transmission line packet decoder 27.

There, the transmission path packet encoder 17 packetizes and performs a complementary process to the transmitted packetization to obtain a compression encoded signal.
The compression coded signal is supplied to the MPEG decoder 22 and is decoded in the same manner as described above. Then, the image signal obtained by the decoding is output as an output image.

The configurations and operations of the image signal encoding and transmitting device and the image signal decoding and receiving device according to the fifth embodiment have been described above. Then, those operations may be controlled and executed by a computer program.

FIG. 22 is a flow chart showing the flow of a computer program executed for image signal coding transmission according to the fifth embodiment. In the figure, parts that perform the same operations as those in the flowchart shown in FIG. 18 are given the same reference numerals. Next, an operation part different from that described in the fourth embodiment will be described.

That is, the next operation of the encoding of the image data in S17 is the processing operation relating to the packetization of the encoded data in S31, and then the operation of checking whether or not the packetization processing is completed in S32. The difference is that they are made.

Then, the packetization of the encoded data in S31 is an operation of generating, for example, an audio video multiplexed bit stream, which is performed by the transmission path packet encoder 17 in FIG. Then, the generated bit stream is supplied to the communication network and transmitted. In addition, packetization processing peculiar to the transmission path is performed for transmission on the transmission path as required, in accordance with the transmission conditions specified in the transmission path.

The generation of the generated transmission encoded signal and the encoding of the image data are performed in S16 and S1 until the packetization of the encoded image data in S32 is completed.
The operations of 7 and S31 are repeatedly executed.

The coded packet data obtained by the coding and packetization in this way is sent from the image signal coding transmitter 10d to the communication network.
Then, the data is received and decoded by the image signal decoding receiving device 20d. Next, the operation of receiving and decoding the image signal shown as the fifth embodiment will be described.

FIG. 23 is a flow chart showing the operation of the computer program executed for the image signal decoding reception according to the fifth embodiment. In the same figure, parts that perform the same operations as those in the flow chart shown in FIG. 19 are given the same reference numerals. Next, the different operation will be described.

That is, the next operation of loading the VLC unit in S24 is the packet decoding operation of the decoded data in S41, and the data obtained by the decoding is S25.
The difference is that it is passed to the decoding of the encoded data of.

That is, the packet decoding of the decoded data in S41 is an operation performed by the transmission path packet decoder 27 in FIG. 21 described above, in which the bit stream transmitted in a multiplexed manner is described above. The signal processing operation complementary to that of the transmission line packet encoder 17 in FIG.

In this way, the packet-decoded signal is passed to the decoding of the encoded data in S25, and the next processing is performed. Then, the signal processing is performed until the determination of Yes is made depending on whether the image decoding in S27 is completed or not.
The operations of 41, S25, S26, and S27 are repeatedly executed. The operations executed by being controlled by the computer programs of the image signal encoding and transmitting device and the image signal decoding and receiving device according to the fifth embodiment have been described above.

As described in detail above, the decoding of the image signal encoded by using the special VLC table on the encoding transmitter side is performed by the decoding receiver having only the standard VLC table, the standard VLC table and the special VLC table. A decoding receiving device that has a table and is switched and used can be realized as a decoding receiving device that can reproduce with different desired image quality.

Information relating to the use of the special VLC table is embedded in the image signal data as digital watermark information, described in a predetermined user data description area, embedded as quantized value digital watermark information, or motion vector digital watermark information. It is transmitted by a method such as embedding as.

Decoding of the compressed coded signal thus transmitted detects the transmitted VLC table control signal from the syntax defined by MPEG which is a standard for transmitting the coded signal. , Its detected V
VLC used for encoding based on LC table control signal
Detect the table. Then, decoding is performed using the detected table so that an image signal having a desired degree of deterioration can be obtained.

Also, the VLC code of the VLC table used by switching is constructed by using a code existing in the VLC code system defined by the MPEG standard which is an international standard and is generally used, and the special VLC code is used.
The exchangeability of the signal between the signal encoded using the LC table and the signal encoded using the standard VLC table is kept within a predetermined range. As a result, it is possible to ensure the configuration of signal exchange with a device compliant with the MPEG standard which is widely used in a wide market.

Furthermore, information regarding the use of the special VLC code is, for example, user data defined by MPEG, digital watermark data mixed in an image, digital watermark data mixed by using a quantized value, and a motion vector. Since at least any one of the digital watermark data embedded by using a value or the like is transmitted by using a plurality of pieces as necessary, a plurality of pieces of content can be encoded for a desired content to be encoded. An image signal encoding method that is performed by setting a security level has been realized.

The MPEG2 video compression coding method in which the moving picture signal is coded by using the special VLC table instead of the standard VLC table has been described above as an example of the coding method. Then a similar standard VLC table and special VLC
The compression encoding of the acoustic signal performed using the LC table and the decoding of the encoded data that is encoded and supplied will be described.

First, MPEG-2 AAC (Advanced Audio Codin), which is a typical audio signal compression encoding system, is used.
This section describes the encoding and decoding of audio signals in the g) method.

<Sixth Embodiment> FIG. 24 shows the arrangement of an audio signal encoding apparatus according to the sixth embodiment (hereinafter, also simply referred to as an encoding apparatus), which will be described below with reference to the drawings.

The audio signal encoding device 43 shown in FIG.
0 comprises an MPEG-2 AAC encoder 431, a Huffman codebook selector 432, a scale factor standard Huffman codebook 433, a scale factor special Huffman codebook 434, and a CPU 435. And the MPEG-2 AAC encoder 4
31 includes a variable length encoder 436 that performs variable length encoding using the Huffman codebook.

The MPEG-2 AAC encoder 431 has the same structure as the conventional one, but the variable length encoder 4
36 differs from the standard VLC table conventionally used in that a control signal for performing variable length coding using a special VLC table is input. The Huffman code coding is a coding method included in VLC coding, and the Huffman codebook is a coding table used for that purpose. Therefore, the concept of Huffman codebook is included in the VLC table in a broad sense.

Next, the operation of the audio signal coding apparatus 430 having such a configuration will be described. First, the audio signal to be encoded is input to the MPEG-2 AAC encoder 431, and the external switching signal is sent to the CPU 4
35 is input. The CPU 435 generates an encoding selection signal for switching the Huffman codebook based on the supplied external switching signal.

The encoding selection signal is generated as a cipher in which the external switching signal supplied from the CPU 435 is used as an initial value, and the external switching signal is subjected to some cryptographic processing by using, for example, a pseudo random number. Then, by decoding the generated external switching signal, a coding selection signal which is a Huffman codebook switching signal is output.

Then, an encoding selection signal which is a Huffman codebook switching signal is supplied from the CPU 435 to the Huffman codebook selector 432. Its CPU4
The encoding selection signal supplied from 35, for example, selects the standard Huffman codebook for scale factors when it is "0", and selects the special Huffman codebook for scale factors when it is "1". It is set to be encoded.

That is, the Huffman codebook selector 432
Then the standard Huffman codebook for scale factors 43
3 and the Huffman codebook selected from the special Huffman codebook for scale factor 434 by the coding selection signal is supplied to the variable length encoder 436.

Then, in the MPEG-2 AAC encoder 431, the supplied audio signal is subjected to variable length encoding based on the Huffman codebook temporarily stored in the variable length encoder 436. Next, a Huffman codebook for scale factors will be described.

FIG. 25 shows the scale factor band (Sf
An example of obtaining the scale factor in b) will be shown. In the figure, on the upper side, N from 0 to (N-1)
The scale factor in each scale factor band is shown. The lower side shows the index values for those scale factor bands.

That is, the supplied audio signal is FF
Results of psychoacoustic analysis by T and MDCT (Modifi
ed Discrete Cosine Transform) The scale factor is calculated based on the coefficient value data obtained by the conversion. Then, the difference value of the scale factor is obtained. That is, the (k-1) th Sfb is subtracted from the kth Sfb to obtain the difference value. Next, using the value obtained by adding 60 to the offset value, variable length coding is performed so that the value (hereinafter referred to as the index) corresponding to the Huffman codebook for the scale factor is read.

The Huffman codebook for scale factors shows that the difference value of the scale factor is 0 when the index is 60, and the occurrence frequency decreases as the absolute value of the difference value increases. Has been created.

FIG. 26 is a table showing a part of the Huffman codebook for scale factors used in the MPEG-2 AAC coding system. Then, the scale factor Huffman codebook shown in this table is used as the scale factor standard Huffman codebook 433. Further, the scale factor special Huffman code book 434 is created by replacing the indexes of the scale factor standard Huffman code book 433.

FIG. 27 exemplifies a method of exchanging indexes. In the figure, the table on the left side shows a part of the standard Huffman codebook and its replacement method. And
The table on the right is part of the special Huffman codebook created by swapping.

That is, the replacement is performed in the table having the same codeword length in the index larger than the index 60 and the index smaller than the index 60 in the table. For example, a special Huffman codebook is created by replacing the indexes 56 and 55 and the indexes 64 and 65 each having a codeword length of 6 with each other.

FIG. 28 shows an example of variable length coding of a scale factor using the above Huffman codebook. In the figure, the scale factors of sfb0 to sfb4 are set to 10, 15, 19, 14, and 10, respectively. Then, when the total quantization step is set to 30, the difference value between the adjacent sfb when performing the variable length coding is −2.
0, 5, 4, -5, -4 are obtained.

Next, the offset value 60 is added,
Each sfb is calculated as an index value of 40, 65, 64, 55, 56. Here, since there is no previous sfb for the first sfb0, the difference calculation for the entire quantization step value 30 is performed.

Then, when a codeword is obtained using the standard Huffman codebook shown in FIG.
9, 3b, 39, 3a, 38 are obtained. However, since the Huffman codebook used here is a special Huffman codebook in which codewords are exchanged, the codewords ff9, 3a, 38, 3b, and 39 shown in are obtained. Then, a bit stream is generated using the obtained data.

Then, the generated and transmitted bit stream is decoded. And in a normal decoder, M
If you have only the standard Huffman codebook of PEG-2 AAC encoding system, you can use variable length decoding
The index of each sfb is 40, 55, 56, 65, 6
Obtained as 4.

Next, the offset value 60 is subtracted from the data, and the scale factors are 10, 5, 1, and
It is calculated as 6, 10. This value is different from the original scale factor.

In this way, different audio signals are reproduced when decoding a coded bit stream using a scale factor different from that used for coding. Therefore, the scrambling process for generating the semi-disclosed audio signal can be performed by using this method.

Next, the decoding of the bit stream thus encoded and generated will be described. FIG. 29
The configuration of an audio signal decoding apparatus according to the sixth embodiment (hereinafter, also simply referred to as a decoding apparatus) is shown in FIG.

Audio signal decoding device 44 shown in FIG.
0 is composed of an MPEG-2 AAC decoder 441, a Huffman codebook selector 442, a scale factor standard Huffman codebook 443, a scale factor special Huffman codebook 444, and a CPU 445. Then, the MPEG-2 AAC decoder 441
Includes a variable length decoder 446 that performs variable length decoding using the Huffman codebook.

The MPEG-2 AAC decoder 441 is configured in the same manner as the conventional one, but the variable length decoder 446 uses the special Huffman codebook in addition to the conventional standard Huffman codebook to perform variable length decoding. The difference is that they are made.

Next, the operation of the audio signal decoding apparatus 440 having such a configuration will be described. First, the external switching signal output from the audio signal encoding device 430 is supplied to the CPU 445.

There, the audio signal encoding device 43
Processing equivalent to that of the CPU 435 in 0 is performed. That is, a coding selection signal which is a Huffman codebook switching signal is generated, and the signal is supplied to the Huffman codebook selector 442.

Next, the bit stream compressed and encoded by the audio signal encoding device 430 is MPEG-2.
It is supplied to the AAC decoder 441. Here, MP
The signal compression-coded by the EG-2 AAC system is decoded using the Huffman codebook value temporarily stored in the variable length decoder 446.

In the Huffman codebook selector 442,
Based on the supplied coding selection signal, that is, the coding selection signal supplied from the CPU 445, the one of the Huffman codebooks stored in the standard Huffman codebook for scale factor 443 or the special Huffman codebook for scale factor 444 is selected. The value is selected and provided to the variable length decoder 446. Then, the value of the Huffman codebook is temporarily stored in the variable length decoder 446.

In the MPEG-2 AAC decoder 441, the Huffman codebook thus temporarily stored is used to decode the supplied bit stream. And the decoding is MPEG-2 AAC.
Since the same Huffman codebook as the Huffman codebook temporarily stored in the variable length encoder 436 of the encoder 431 is used for decoding, a decoded audio signal with high fidelity can be obtained.

However, when the audio signal decoding apparatus does not have the special Huffman codebook for scale factor, the standard Huffman codebook for scale factor installed in the ordinary MPEG-2 AAC decoder is used to generate the bitstream. Is decrypted,
The decoded audio signal will be decoded as an audio signal containing a distortion component based on the difference between the Huffman codebooks.

As described above, the configuration and operation of the audio signal coding apparatus and the audio signal decoding apparatus according to the sixth embodiment for performing variable-length coding of the scale factor using the standard Huffman codebook and the special Huffman codebook. Said.

<Seventh Embodiment> Next, a configuration of an audio signal coding apparatus and an audio signal decoding apparatus according to a seventh embodiment in which the standard Huffman codebook and the special Huffman codebook are used for variable length coding of spectrum signals. And the operation is described. FIG. 30 shows the configuration of an audio signal encoding apparatus according to the seventh embodiment, which will be described below with reference to the drawings.

The audio signal encoding device 45 shown in FIG.
0 is composed of an MPEG-2 AAC encoder 451, a Huffman codebook selector 452, a spectrum standard Huffman codebook 453, a spectrum special Huffman codebook 454, and a CPU 455. The MPEG-2 AAC encoder 451 includes a variable length encoder 456 that performs variable length encoding using the Huffman codebook.

The audio signal coding apparatus 450 having such a structure has a standard Huffman codebook for scale factors as compared with the audio signal coding apparatus according to the sixth embodiment shown in FIG. However, a standard Huffman codebook for spectrum and a special Huffman codebook for spectrum are used for variable length coding of an audio signal obtained by MDCT.

Next, the operation of the audio signal coding apparatus 450 having such a configuration will be described. First, MPE
The audio signal to be encoded is supplied to the G-2 AAC encoder 451 and at the same time, the external switching signal is input to the CPU 455. On the other hand, the external switching signal is supplied to an audio signal decoding device 460 (described later) that performs a decoding operation complementarily to the audio signal coding device 450.

An external switching signal is supplied to the CPU 455, and an encoding selection signal which is a Huffman codebook switching signal is generated based on the external switching signal. For example, CPU
When the external switching signal 455 generates a pseudo-random number with the external switching signal as an initial value, or when the external switching signal is supplied as a code subjected to some cryptographic processing, the external switching signal is decrypted so that the Huffman codebook switching signal can be obtained. An encoding selection signal is obtained.

In this way, the CPU 455 supplies the Huffman codebook selector 452 with the coding selection signal which is a Huffman codebook switching signal. The coding selection signal supplied from the CPU 455 is, for example, selected by the standard Huffman code book for spectrum when it is "0", and selected by the special Huffman code book for spectrum when it is "1". Is set to do.

Next, the Huffman codebook selector 452
Then, of the standard Huffman codebook for spectrum 453 and the special Huffman codebook for spectrum 454, the Huffman codebook selected by the coding selection signal is supplied to the variable-length encoder 456. It

In the MPEG-2 AAC encoder 451, variable length encoding is performed on the spectrum signal of the MDCT audio input signal based on the Huffman codebook temporarily stored in the variable length encoder 456.
We now describe the Huffman codebook for that spectrum.

When variable-length coding the quantized value of the spectrum, the index is converted into a Huffman codebook for the spectrum on the basis of the quantized value of the spectrum calculated for each two or four in sfb. Read the corresponding codeword. There are 11 types of Huffman codebooks for spectra, and a combination that is coded and generated and has the minimum code amount in the entire code is selected from among them.

FIG. 31 is a table showing a part of the standard Huffman codebook for spectra. The standard Huffman codebook for spectra shown in FIG.
It is a part of a codebook used for the AAC coding method, and this codebook is used here as a standard Huffman codebook 453 for spectrum. As the special Huffman codebook 454, the index of the standard Huffman codebook for spectrum 453 is replaced.

FIG. 32 shows an example of exchanging codewords of the standard Huffman codebook to create a special Huffman codebook. The Huffman codebook for spectra shown here is part of the second one defined in the AAC standard.

There are a plurality of codebooks having the same codeword length across the index 40. Thus, for example, indexes 36 to 39
And a new Huffman codebook created by replacing each of the indexes 44 to 41 and used as a special Huffman codebook.

FIG. 33 shows an example of variable length coding of spectral quantized values using the above Huffman codebook. Each of the four quantized values in the figure is 0, 0, -1,
It is 1. Next, the conversion to the index in that case will be described.

That is, when the Huffman codebook No. 2 is used, the following expression (1) is used as a conversion expression to the index (IDX) for the four spectrums Q0 to Q3. IDX = 27 × Q0 + 9 × Q1 + 3 × Q2 + Q3 + 40 (1) For each of Q0 to Q3, the above 0, 0, -1, 1
Is substituted.

The index value of the spectrum shown as (a) in the figure is IDX = 27 × 0 + 9 × 0 + 3 × (−1) + 1 + 40 =
38, and the codeword corresponding to the Huffman codebook No. 2 replaced based on the value is read out.

That is, the value in the special Huffman codebook whose index value is 38 is 1d, and that value is read. Then, a bitstream in which the audio signal is encoded is generated based on the read value, and is output from the audio signal encoding device 450.

Next, the bit stream is input to the audio signal decoding device and decoded. In FIG. 34,
A configuration of an audio signal decoding apparatus according to a seventh embodiment is shown and will be described below with reference to the drawings.

Audio signal decoding apparatus 46 shown in FIG.
0 is composed of an MPEG-2 AAC decoder 461, a Huffman codebook selector 462, a spectrum standard Huffman codebook 463, a spectrum special Huffman codebook 464, and a CPU 465. The MPEG-2 AAC decoder 461 includes a variable length decoder 466 for performing variable length decoding using the Huffman codebook.

The audio signal decoding apparatus 460 having such a configuration has a standard Huffman codebook for scale factors as compared with the audio signal decoding apparatus according to the sixth embodiment shown in FIG. However, a standard Huffman codebook and a special Huffman codebook are used for variable length decoding for the spectrum.

Next, the operation of the audio signal decoding apparatus 460 having such a configuration will be described. First, the bit stream compressed and encoded by the audio signal encoding device 450 is supplied to the MPEG-2 AAC decoder 461.

Then, the audio signal encoding device 450
The external switching signal transmitted from the CPU is supplied to the CPU 465. The CPU 465 processes the signal supplied in the same manner as the CPU 455 in the audio signal encoding device 450. Next, a coding selection signal which is a Huffman codebook switching signal is generated, and the signal is supplied to the Huffman codebook selector 462.

In the Huffman codebook selector 462, based on the supplied coding selection signal, that is, the coding selection signal supplied from the CPU 465, the spectrum standard Huffman codebook 463 and the spectrum special Huffman codebook 464. The Huffman codebook value stored in one of the two is selected and supplied to the variable length decoder 466. The Huffman codebook value is temporarily stored in the variable length decoder 466.

The Huffman codebook temporarily stored in the variable length decoder 466 in this way is used to
The EG-2 AAC decoder 461 decodes the supplied bitstream.

Decoding performed in this way is MPEG-
2 Since the same Huffman codebook as the Huffman codebook temporarily stored in the variable length encoder 456 of the AAC encoder 451 is used for decoding, a high quality decoded audio signal is obtained. ing.

However, when the audio signal decoding apparatus does not have the special Huffman codebook information for spectrum, the standard Huffman codebook installed in the ordinary MPEG-2 AAC decoder is used to decode the bitstream. Therefore, the decoded audio signal is decoded as an audio signal containing a distortion component according to the difference between the Huffman codebooks.

For example, the index value for each of the four quantized values 0, 0, -1, 1 was calculated as 38. An index value 42 is obtained by subjecting it to variable length coding using a special Huffman codebook and performing variable length decoding using a standard Huffman codebook.

The above decoding is shown in FIG. 33 (b). Here, the index value 42 is Q
Calculated as 0 = 0, Q1 = 0, Q2 = 1, and Q3 = -1. That is, the four quantized values are 0, 0,
Since it is obtained as 1, -1, a value different from the original quantization of the spectrum is obtained.

Then, the quantized value thus obtained is subjected to inverse quantization and IMDCT (Inverse Modified Discr).
When the audio signal is decoded by ete cosine transform), the original signal cannot be reproduced. That is, the audio signal thus reproduced is reproduced as a signal that is pseudo-audio scrambled.

As described above, the standard Huffman codebook and the special Huffman codebook are used to perform the variable length coding of the spectrum of the audio signal obtained by MDCT, and the audio signal coding apparatus and the audio signal decoding apparatus according to the seventh embodiment. Described the configuration and operation of.

In this embodiment, the case where the Huffman codebook No. 2 for spectrum is used has been described as an example. Furthermore, the Huffman codebook for spectra is 1
Since there is one type, when special Huffman codebooks are created for variable length coding, or only some of them are coded using special Huffman codebooks. May be done by any of them.

Also, the Huffman codebook 1 to 10
Up to the number 1, 1 and 2, 3 and 4, 5 and 6, 7 and 8, and 9 and 10 are created in pairs with each other, and have the same number of codewords between the pairs. . Therefore, by using the conversion formulas for the same index to each other, the special Huffman codebook No. 1 is used as the standard Huffman codebook No. 2 and the special Huffman codebook is used as the special Huffman codebook. It can be encoded in this way, and may be realized by such a method.

The configuration of the apparatus for switching between the standard and special Huffman codebooks by the external switching signal for coding and the operation thereof have been described above. Then, it is also necessary to scramble the external switching signal transmitted from the audio signal encoding device of the present embodiment to the audio signal decoding device so that the user cannot freely operate the scrambled audio signal. . That is, in order to reliably perform scrambling, it is necessary to encrypt the external switching signal generated by the audio signal encoding device.

Then, the encrypted signal generated by the audio signal encoding device is decrypted by the CPU in the audio signal decoding device so as to be obtained, and variable length decoding is performed using the obtained external switching signal. To do so.

Also, in the audio signal encoding device, MP
An external switching signal is embedded as electronic watermark information in the EG-2 AAC bitstream, the electronic watermark information is extracted from the MPEG-2 AAC bitstream supplied to the audio signal decoding device, and the Huffman code is extracted based on the information. There is also a method of generating a book switching signal.

Furthermore, as a method of not transmitting an external switching signal separately from the bit stream, the digital watermarking method used in the above-mentioned image signal encoding and decoding apparatus is used, for example, the scale factor or spectrum value is set to an even value. A method of embedding watermark data by rounding, rounding to an odd value, or the like may be used.

The method is, for example, using a digital watermarking method, by embedding a coding selection signal as a signal conforming to the external switching signal in the audio signal at the first position at a predetermined interval, and by using the MPEG2 AAC encoder. Is a method for generating an MPEG-2 AAC bitstream compression-encoded by.

In decoding the signal encoded by the method, an encoding selection signal embedded as digital watermark information is detected, and an appropriate Huffman codebook is selected from the detected encoding selection signal. A Huffman codebook switching signal may be obtained.

The method of transmitting the encoded selection signal encrypted by using the digital watermark method has been described above. As a method that does not rely on a digital watermark, for example, MPE
Data_ specified by the G-2 AAC encoding method
There is also a method in which the data based on the external switching signal is described and transmitted in the stream_element by being encrypted.

[0276] Then, a method of decoding data_stream_element on the audio signal decoding device side to obtain decoded information, and generating a Huffman codebook switching signal based on the obtained information.

Further, in the case of that method, data
The data related to the external switching signal described in _stream_element only needs to be consistent between the encoding side and the decoding side, and an appropriate encryption method is set on the encoding side and the decoding side. It suffices to perform transmission and reception.

As described above, by using the standard variable length table and the special variable length table when the coefficient value signal obtained by performing the orthogonal transform on each of the image signal and the audio signal is variable length encoded and transmitted. The variable length data encoding method and the decoding method thereof, which can be reproduced as an image signal and an audio signal with some distortion, have been described. Then, the addition of the distortion can be individually set for either the image signal or the audio signal or for both by using the standard or special variable length table.

Next, by using such a variable-length data encoding method and its decoding method, an image is encoded for a preferred embodiment of a business model usable in broadcasting, communication, or an information recording medium. The case of conversion will be mainly described.

<Eighth Embodiment> FIG. 35 is a block diagram showing a variable length coded data transmission apparatus according to an eighth embodiment equipped with a semi-disclosed variable length data coding method used for broadcasting or communication (hereinafter, referred to as It may be simply referred to as a transmitting device), and will be described with reference to the drawings.

Variable length coded data transmission device 5 shown in FIG.
10 is an image data converter 511, an encryption device 512, an encryption method setting device 513, an encryption key setting device 514, and a CPU.
515, MPEG encoder 516, VLC table selector 517, standard VLC table 518, special VLC table 519, transmission line packet encoder 521, and encrypted information transmitter 522. And MPE
The G encoder 516 includes a VLC unit 531.

Next, the operation of the variable length coded data transmission device 510 having such a configuration will be described. First, the input image signal is supplied to the image data converter 511, where the identification signal is embedded as digital watermark information in the image signal by the method described above.

The image signal in which the digital watermark information is embedded is supplied to the MPEG encoder 516, where the VLC table temporarily stored in the VLC unit 531 is used to perform variable length coding and the like to perform compression coding. A signal is generated.

Next, the compression coded signal is multiplexed with an audio signal (not shown) and other auxiliary signals according to the MPEG system standard by the transmission line packet encoder 521. In this way, the packetized signal is output from the variable length coded data transmission device 510 as a transmission signal.

At this time, the CPU 515 uses the encoding selection signal supplied to the VLC table selector 517 to identify whether the VLC table selector 517 selects the standard VLC table or the special VLC table. An identification signal, an encryption method related to the identification signal, and encryption information about an encryption key for decrypting the encryption are generated.

Then, in the VLC table selector 517,
Based on the encoding selection signal supplied from the CPU 515,
Either the standard VLC table or the special VLC table is selected, and the selected VLC table is supplied to the VLC unit 531 of the MPEG encoder 516.

In the encryptor 512, the identification information concerning the VLC table selected by the VLC table selector 517 supplied via the CPU 515 and the encryption method set by the encryption method setting device 513 are set. And the information related to the encryption key set by the encryption key setting unit 514 are encrypted, and the encrypted information is supplied to the image data converter 511.

Further, in the CPU 515, information indicating that encryption has been performed as encryption information, information regarding the encryption method set by the encryption method setting device, and information regarding the encryption key set by the encryption key setting device. And are supplied to the encrypted information transmitter 522, from which they are output as an encrypted information signal.

In this way, the MPEG encoder 51
The encrypted identification signal is supplied to 6 as an image signal embedded with a digital watermark. Then, the image signal is compression-encoded using the VLC table designated by the encoding selection signal corresponding to the embedded identification signal.

For example, when the coding selection signal supplied from the CPU 515 to the VLC table selector 517 is "0", the standard VLC table is selected and obtained by the VLC table selector 517, and the standard VLC table is M.
It is supplied to the VLC unit 531 of the PEG encoder 516,
It is temporarily stored there.

At this time, the CPU 515 sends the standard VLC
A 64-bit bit string "0" indicating that the table is selected
101 ... 0101 ”is used as the identification information in the encryption device 51.
2 is supplied. Then, in the encryption device 512, the DES (Data Encryption) set by the encryption method setting device 513 is set.
Standard: International de facto standard data encryption standard) encryption and the DES encryption encryption key 64 bits (8 bits of which are parity bits) set by the encryption key setting device 514 are used to encrypt the identification information. .

Next, the encrypted identification information is embedded in the input image signal as digital watermark information and supplied to the MPEG encoder 516. There, a standard VLC table temporarily stored in the VLC unit 531 is used for compression of the supplied signal.

When the coding selection signal is "1", a special VLC table is obtained from the VLC table selector 517, and the table is the MPEG encoder 516.
Is supplied to the VLC device 531 and is temporarily stored therein.
At this time, in the CPU 515, a 64-bit bit string “1010 ...
“1010” is supplied to the encryptor 512 as identification information.

Then, the encryption device 512 uses the DES encryption set by the encryption method setting device 513 and the 64-bit DES encryption key set by the encryption key setting device 514 to determine the identification information. Encrypted. Also, the identification information obtained by the encryption is embedded in the input image as digital watermark information and is stored in the VLC unit 531 as a special VLC.
Encoding is performed using a table.

At this time, the encryption information is "0" when the identification information is not encrypted and "1" when the identification information is encrypted. When the encryption method can be selected from, for example, four methods, the DES encryption is set to "00", and the other three encryptions are set to "01", "10", and "11", respectively.
And Furthermore, as for the encryption key, the encryption keys each having 64 bits such as Key A, Key B, Key C, and Key D, which are preset keys, are determined and used.

Key A is "00" and Key B is "0".
1 ”, Key C is“ 10 ”, and Key D is“ 11 ”. As a result, when the identification information is encrypted with DES and KeyC is used, the encrypted information is "10
It is represented by a 5-bit bit string "0 10".

The configuration and operation of the variable length coded data transmitting apparatus according to the eighth embodiment have been described above. Here, as the encryption information, information about the encryption mode,
Encryption including information about the key length of the encryption key,
It may be transmitted.

Next, a variable length coded data receiving device (hereinafter, also simply referred to as a receiving device) for receiving and decoding the coded data thus generated and transmitted will be described. FIG. 36 shows the configuration of the variable-length coded data receiving device according to the eighth embodiment, which will be described with reference to FIG.

[0299] The variable length coded data receiving device 5 shown in the figure.
50 is a transmission path packet decryptor 551, encrypted information receiver 552, MPEG decoder 561, VLC table selector 562, standard VLC table 563, special VLC.
Table 564, CPU 565, digital watermark detector 56
6, a decryption unit 567, a decryption method selection unit 568, and a decryption key selection unit 569. And MPEG
The decoder 561 includes a VLC decoder 571.

Next, the operation of the variable length coded data receiving device 550 configured as described above will be described. First, the packet-encoded data configured by multiplexing is packet-decoded by the transmission-line packet decoder 551 by a complementary operation to the transmission-line packetization encoder 521, and a compression code obtained by decoding is obtained. The converted image data is MPE
It is supplied to the G decoder 561.

In this case, the signal compression-coded by the MPEG system is V stored in the VLC decoder 571 temporarily.
The values in the LC table are used to make the MPEG encoder 51
Decoded by a method complementary to that done by 6.
Then, the image signal obtained by decoding is supplied to the digital watermark detector 566.

In the digital watermark detector 566, the identification signal encrypted and embedded as digital watermark information by the image data converter 511 shown in FIG. 35 is detected by the digital watermark detector 566, and is then sent to the decoder 567. Supplied.

If the CPU 565 determines that the detected digital watermark information is encrypted based on the encrypted information received by the encrypted information receiver 552,
Information about the encryption method is sent to the decryption method selector 568.
Information about the encryption key is supplied to the decryption key selector 569.

The decryption method selector 568 selects the decryption method based on the information on the encryption method, and the decryption key selector 569 selects the encryption key on the basis of the information on the encryption key. It The selected decryption method and decryption key information are used to decrypt the encrypted identification information in the decryptor 567, and the decrypted signal is supplied to the CPU 565. The CPU 565 generates a coding selection signal corresponding to the decoded identification information, and the signal is supplied to the VLC table selector 562.

The VLC table selector 562 selects one of the standard VLC table and the special VLC table on the basis of the supplied coding selection signal and supplies the selected VLC table to the VLC decoder 571. The table is temporarily stored in the VLC decoder 571.

For example, when the encrypted information is obtained as a 5-bit bit string of "100 10", in the variable-length coded data receiving device 550, the digital watermark detector 566 first causes the 64-bit bit string "b ₆₃ ". b ₆₂ b ₆₁
.. b ₁ b ₀ "is detected, and the signal of the detected bit string is supplied to the decoder 567.

[0307] Next, in the CPU 565, the 5-bit encrypted information "10 obtained by the encrypted information receiver 552 is obtained.
It is determined that the identification information is encrypted by the most significant bit "1" of "0 10". Then, from the lower 4 bits “00 10” of the encryption information, the decryption method selector selects D
ES encryption, and Key C in the decryption key selector 569
Each is selected and supplied to the decoder 567.

Further, in the decryptor 567, the key Key C is used in the DES encryption and the 64-bit bit string “b ₆₃ b ₆₂
b ₆₁ ··· b ₁ b ₀ "is decoded," 0101 ... 0
The data of "101" or "1010 ... 1010" is obtained.

In the CPU 565, the decryption result "0101.
... "0101" is "1010 ... 1" for "0101"
“1” is generated as an encoding selection signal for “010”, and the generated signal is supplied to the VLC table selector 562. From the VLC table selector, when the coding selection signal is "0", the standard VLC table is displayed, when it is "1", the special VLC table is displayed, and the special VLC table is displayed.
It is supplied to the decoder 571.

In this way, the VLC table temporarily stored in the VLC decoder 571 is used, and the MPEG decoder 561 decodes the encoded data supplied. Then, the decoding is performed by the above-mentioned M in FIG.
Since the same VLC table as the VLC table temporarily stored in the VLC unit 531 of the PEG encoder 516 is used for decoding, an image signal without deterioration is decoded.

As described above, the variable-length coded data transmitting apparatus 510 and the variable-length coded data receiving apparatus 550 according to the eighth embodiment embed the encrypted identification signal in the image data as a digital watermark and transmit it. The method of receiving the transmitted signal is described.

Heretofore, the method for embedding the encrypted identification signal in the image signal has been described above. The identification signal is not limited to being embedded in the image signal, but may be embedded in the audio signal as digital watermark data using the method described above. Furthermore, there is also a method of embedding image data and audio data as independent identification data and transmitting them.

Next, a variable-length coded data receiving apparatus for billing the signal transmitted by the variable-length coded data transmitting apparatus 510 according to the eighth embodiment and receiving the signal will be described.

<Ninth Embodiment> FIG. 37 shows the arrangement of a variable length coded data receiving device according to the ninth embodiment, which will be described with reference to FIG. The variable length coded data receiving device 550a shown in FIG.
Compared with 50, it is different in that a large number of IC card readers / writers 572 are arranged.

The parts having the same functions as those in FIG. 36 are designated by the same reference numerals. The IC card reader / writer 572 is connected to the CPU 565, and the IC card 601 is inserted therein.

Next, the operation of the variable-length coded data receiving device 550a having such a configuration, which is different from that of the above-described variable-length coded data receiving device 550, will be described. First, the encrypted identification signal embedded as digital watermark information by the image data converter 511 of the variable length coded data transmission device 510 is the digital watermark detector 566.
And is supplied to the decoder 567.

When the CPU 565 determines that the detected digital watermark information is encrypted based on the encryption information received by the encryption information receiver 552, the information about the encryption method is decrypted. Conversion method selector 56
8, the information about the encryption key is the decryption key selector 569.
, Respectively.

At this time, the CPU 565 determines whether or not to perform the decryption based on the amount information recorded on the IC card via the IC card reader / writer 572 and the charging information at the time of reproduction. Then, based on the result, the coding selection signal corresponding to the identification information obtained from the decoder 567 is supplied to the VLC table selector 562, or the coding selection signal not corresponding to the identification information is supplied to the VLC table selector 562. Is supplied to.

For example, it is assumed that the IC card is of a prepaid type and the amount information of 6000 yen is recorded in advance. When it is assumed that the transmitted information is decrypted at a rate of, for example, 1 yen / minute, the CPU 565 causes the decryption unit 567 to perform the decryption processing of the encrypted information for 1 minute.
The amount of money in the C card is reduced by 1 yen.

Then, the amount information of the IC card 601 is 0.
When it becomes a circle, the CPU 565 causes the decoder 567 to operate.
The VLC table selector 562 is supplied with "1" when the coding selection signal corresponding to the identification information obtained by decrypting the code is "0", and when the coding selection signal is "1".

The VLC table selector 562 selects the standard VLC table or the special VLC table based on the supplied coding selection signal, and supplies the selected one to the VLC decoder 571.
In this way, when the amount information in the IC card becomes 0 yen, a VLC table different from that at the time of encoding is supplied to the VLC decoder 571 thereafter, and a high quality image cannot be reproduced.

As the information recorded in the IC card 601, information for identifying the user is recorded in addition to the amount information, and the CPU 565 causes the correct encoding selection signal only for a certain user. Are supplied to the VLC table selector.

Furthermore, by recording information on various reproduction conditions preferred by the user in the IC card 601,
The correct encoding selection signal may be supplied from the CPU 565 to the VLC table selector only when the reproduction condition from the IC card 601 is satisfied.

Alternatively, by recording the information (seed) which is the basis of the decryption key necessary for decrypting the encrypted identification information in the IC card 601, and the information regarding the encryption algorithm, the IC card 601 is recorded. Only when 601 is used, the identification information may be correctly decoded and the correct encoding selection signal may be supplied from the CPU 565.

Furthermore, in addition to the IC card 601, the variable length coding is performed via the Internet using a modem, or by the user's own operation input using the operation remote control button of the variable length coding data receiving device 550a. The amount information, the user information, or the reproduction condition information may be acquired from the outside of the data receiving device 550a, and the correct encoding selection signal may be supplied to the VLC table selector 562 based on these conditions. .

As described above, according to the variable length coded data receiving device 550a in the ninth embodiment, the VLC decoder 5 in the MPEG decoder 561 can be used only when a predetermined condition is satisfied.
In 71, the same VLC table as at the time of encoding is supplied, and the encoded image data is decoded, so that a high quality image signal can be obtained from the receiving device.

If the receiving apparatus does not have the function of detecting the image digital watermark information, the function of decoding the watermark information, or the special VLC table is not provided, the standard VLC table is used. Is used to decode the encoded data. Therefore, the decoded image signal at that time is decoded as an image signal including a distortion component based on the difference between the VLC tables.

Even when the electronic watermark information is read out, decoded by an appropriate method, and the coded data is decoded by a predetermined VLC table, billing or the like is set. If the conditions are not met,
By supplying a VLC table different from that at the time of encoding, the decoded image signal includes a distortion component based on the difference between the VLC tables.

In this way, the copyright holder who owns the copyright of the content has a special receiving apparatus which has a contractual relationship with the held content, a general receiving apparatus which does not have a contractual relationship with a receiving apparatus satisfying a specific condition, or When an image signal of different quality is to be supplied to a receiver that does not satisfy a specific condition, the special receiver is equipped with an image watermark detector, an identification information decoder, and a special VLC table. By having a control device capable of supplying a VLC table suitable for decoding to the decoder, it is possible to supply image signals of different qualities to ordinary persons and special persons.

The configuration and operation of the variable length coded data receiving apparatus according to the ninth embodiment have been described above. <Tenth Embodiment> Next, a variable length coded data transmitter and a variable length coded data receiver according to a tenth embodiment will be described.

FIG. 38 shows the configuration of a variable length coded data transmission apparatus according to the tenth embodiment, which will be described with reference to the figure. Variable length coded data transmission device 510b shown in FIG.
In comparison with the variable length coded data transmission device 510 according to the eighth embodiment shown in FIG. 35 described above, a VLC table selector 517, a standard VLC table 518, and a special VLC.
The difference is that a VLC table generator 523 is arranged instead of the table 519.

The components having the same function are designated by the same reference numerals. Next, the operation of the variable length coded data transmission device 510b configured as described above will be described.

First, the input image signal is the image data converter 5
11, the encrypted identification signal is embedded as digital watermark information and is supplied to the MPEG encoder 516. Then, the VL temporarily stored in the VLC unit 531
The compression coding is performed based on the C table, and the transmission path packet encoder 521 packetizes the transmission path and outputs the packet.

Then, the VLC table generator 523 generates the VLC table supplied to the VLC unit 531 of the MPEG encoder 516. The generated V
The LC table is encrypted by the encryption device 512 using the encryption method set by the encryption method setting device 514 and the encryption key set by the encryption key setting device 513. The encrypted code table is supplied to the image data converter 511.

[0335] Further, the CPU 515 outputs information indicating that encryption has been performed as encryption information, information regarding the encryption method set by the encryption method setting unit 513, and the encryption set by the encryption key setting unit 514. Information about the activation key,
It is supplied to the encrypted information transmitter 522. Then, it is output as an encrypted information signal from there.

At this time, for example, as the encrypted information, VL
When the C table is not encrypted, it is set to "0", and when it is encrypted, it is set to "1". If four encryption methods can be selected, the DES encryption is "00" and the other three encryptions are "01", "10", and "11", respectively.
64-bit encryption key Key A, Key for those ciphers
Preset B, Key C, and Key D.

Key A is "00" and Key B is "0".
1 ", Key C is" 10 ", and Key D is" 11 ", the VLC table information is DES encryption, and the encryption information when encrypted using Key C is" 1 00 10 ", which is 5
It is represented by a bit string of bits.

In this way, the MPEG encoder 51
Information on the encrypted VLC table is supplied to 6 as an image signal embedded by a digital watermark method. Then, the image signal is compressed and encoded using the embedded VLC table.

Next, a variable length coded data receiving apparatus for receiving and decoding the coded data thus generated and transmitted will be described. FIG. 39 shows the configuration of the variable length coded data receiving device 550b in the tenth embodiment, which will be described with reference to the drawing.

Variable length coded data receiving device 5 shown in FIG.
50b is different from the variable length coded data receiving device 550 according to the eighth embodiment shown in FIG. 36, in that the VLC table selector 562, the standard VLC table 563, and the special VLC table 564 are not arranged. It's different.

Also, instead of the VLC decoder 571, VLC
A generator / decoder 571a is arranged. The same functional blocks are designated by the same reference numerals. next,
Regarding the operation of the variable length coded data receiving device 550b,
The operation different from that of the eighth embodiment will be mainly described.

First, the digital watermark information detected by the digital watermark detector 566 is supplied to the decoder 567. When the CPU 565 determines that the detected digital watermark information is encrypted based on the encryption information received by the encryption information receiver 552, the information about the encryption method is the decryption method selector. At 568, the information about the encryption key is supplied to the decryption key selector 569, respectively.

The decryption method selector 568 selects a predetermined decryption method from the information about the encryption method, and the decryption key selector 569 selects a predetermined encryption key from the information about the encryption key. The selected decryption method and decryption key information are supplied to the VLC generator / decoder 571a via the CPU 565.

Then, the VLC generation decoder 571a generates the same VLC table as that generated by the VLC table generator 523 based on the supplied information. Then, in the MPEG decoder 561, the VLC generation decoder 57
The VLC table generated in 1a is used to decode the encoded data.

As described above, in the variable length coded data transmission device 510b and the variable length coded data reception device 550b according to the tenth embodiment, the information related to the encrypted VLC table is digitally watermarked in the image data. Is embedded and transmitted and received.

Next, another variable length coded data receiving device for receiving the signal transmitted by the variable length coded data transmitting device 510b according to the tenth embodiment will be described. <Eleventh Embodiment> FIG. 40 shows the arrangement of a variable length coded data receiving device according to the eleventh embodiment, and the operation thereof will be described with reference to the drawings.

Variable length coded data receiving device 5 shown in FIG.
Compared to the variable length coded data receiving device 550 shown in FIG. 36, the VLC table selector 562 and the special VLC table 564 are not provided in the unit 50c.

Then, instead of the VLC decoder 571, the VL
A C generation decoder 571a is arranged. Another difference is that an IC card reader / writer 572 is arranged and an IC card 601 is inserted therein.
The same reference numerals are given to the parts having the same functions as those in FIG.

Next, the operation of the variable length coded data receiving device 550c having such a configuration, which is different from that of the eighth embodiment, will be mainly described. First, the digital watermark detector 56
At 6, the embedded digital watermark information is detected and supplied to the decoder 567. In the CPU 565, when the detected digital watermark information is encrypted, the information about the encryption method is supplied to the decryption method selector 568, and the information about the encryption key is supplied to the decryption key selector 569. To be done.

At this time, the CPU 565 obtains the information about the amount of money of the IC card and the information about the reproduction condition via the IC card reader / writer 572, and based on the obtained information, it is determined whether or not the decryption is performed. When performing the decryption, the VLC table obtained by decrypting the cipher is supplied to the VLC decoder 571.

The reproducing operation including the IC prepaid card at that time is performed in the same manner as in the ninth embodiment. Since the standard VLC table 563 is connected to the CPU 565, the table stored in the standard VLC table 563 during normal reproduction is the VLC generation decoder 571.
The image data supplied to a and compressed and encoded is decoded.

When the decoding performed using the special VLC table is permitted, the VLC generation decoder 571a.
Then, a special VLC table is created based on the input VLC table information, and thereby an image without quality deterioration is decoded.

The configuration and operation of the variable length coded data transmitter and variable length coded data receiver in the eleventh embodiment have been described above. Next, the configuration and operation of the variable-length coded data reproducing device for recording the signal generated by the variable-length coded data recording device on the recording medium and reproducing it will be described.

<Twelfth Embodiment> FIG. 41 shows the arrangement of a variable-length coded data recording apparatus according to the twelfth embodiment of the present invention, which will be described with reference to the drawings.

Variable length coded data recording device 5 shown in FIG.
10d is a modulator 581 instead of the transmission path packet encoder 521 and the encrypted information transmitter 522, and a recording device, as compared with the variable length coded data transmitter according to the eighth embodiment shown in FIG. The difference is that the container 582 is arranged and configured. In addition, the variable length coded data recording device 51
A recording medium 610 is inserted in 0d.

The same functional parts are designated by the same reference numerals. Next, the operation of the variable-length coded data recording device (hereinafter, also simply referred to as a recording device) configured as described above will be described mainly regarding the difference from the eighth embodiment.

First, the input image signal is the image data converter 5
The identification signal that has been input to 11 and is encrypted is embedded as electronic watermark information. Next, the image signal in which the electronic watermark information is embedded is supplied to the MPEG encoder 516, and compression encoding based on the VLC table temporarily stored in the VLC unit 531 is performed. The encoded image data and the encrypted information output from the CPU 515 are input to the modulator 581.

There, digital modulation for recording the image data and the encrypted information on the recording medium 610 is performed. Moreover, an error correction signal for error signal correction is added as necessary. Then, the digitally modulated signal is supplied to the recorder 582, where a signal for recording on the recording medium 610 is generated by modulating the light intensity of the laser beam, and the signal is generated, for example, the recording medium 610 such as a DVD. And is recorded.

In this way, the recording medium 610 has V
Standard VLC table 518 with LC table selector 517
Alternatively, an encryption method in which an identification signal for identifying which of the special VLC tables 519 is selected is encrypted, encryption information about an encryption key, and compression-encoded image data are recorded. .

The encrypted information at this time may be time-division multiplexed and recorded together with the encoded data of the modulated image signal, or the signals may be recorded in different areas on the recording medium. Alternatively, each may be recorded on a plurality of different recording media.

Next, a variable length coded data reproducing apparatus for reproducing and decoding the recording medium thus recorded will be described. FIG. 42 shows the configuration of a variable length coded data reproducing device according to the twelfth embodiment, which will be described with reference to the drawings.

Variable length coded data reproducing device 5 shown in FIG.
Compared with the variable-length coded data receiving apparatus according to the eighth embodiment shown in FIG. 36, 50d is a regenerator 591 and a demodulator instead of the transmission path packet decoder 551 and the encrypted information receiver 552. The difference is that 592 is arranged. In addition, the variable length coded data reproducing device 55
A recording medium 610 is inserted in 0d.

The same functional parts are designated by the same reference numerals. Next, the operation of the variable-length coded data reproducing device (hereinafter, also simply referred to as a reproducing device) configured in this way will be described mainly regarding the differences from the eighth embodiment.

First, the recording medium 610 recorded by the recording device 510d is loaded into the loading portion (not shown) of the playback device 560d. The recording medium 610 is irradiated with laser light, for example, by the reproducing device 591 and the above-mentioned recorded signal is read out.

The signal obtained by the reading is the demodulator 59.
2, the signal processing is performed complementarily to the modulator 581, and the compression-coded image data and the encrypted information are demodulated and obtained.

Next, the encrypted information is supplied to the CPU 565, and the compression-encoded image data is supplied to the MPEG decoder 561. Hereinafter, the same operation as that of the variable length coded data receiving device according to the ninth embodiment shown in FIG. 37 is performed.

The configurations of the recording apparatus and the reproducing apparatus according to the twelfth embodiment and their operations have been described above. Next, another embodiment of the reproducing apparatus will be described. <Thirteenth Embodiment> FIG. 43 shows the structure of a reproducing apparatus according to the thirteenth embodiment used in combination with the recording apparatus according to the twelfth embodiment.

Variable-length coded data receiving device 5 shown in FIG.
50e is different from the receiving apparatus 550b according to the tenth embodiment shown in FIG. 42 in that an IC card reader / writer 572 and an IC card 601 inserted therein are arranged. The same functional blocks are designated by the same reference numerals.

Next, the reproducing apparatus 550 having such a structure.
Regarding the operation of e, the part different from the operation of the reproducing device 550d will be mainly described. That is, the reproducing device 550e includes the IC card reader / writer 572 described in the eleventh embodiment shown in FIG. 40 and the IC card 601 inserted therein.
The function realized by is added.

Therefore, when the predetermined chargeable amount is stored in the IC card 601 and the predetermined reproduction condition is satisfied, the VLC decoder 571 in the MPEG decoder 561 causes the MPEG encoder 5 of the recording device 510d.
The same VLC table as when encoding by 16 is supplied. Since the coded image data that is input is decoded using this, a high quality image signal is obtained at that time.

Then, the copyright holder who owns the copyright of the content such as image data has a special reproducing apparatus which has a contract relationship with the held content or a reproducing apparatus which meets a specific condition, and a general reproducing apparatus which does not have a contract relationship. It is possible to supply image signals of different qualities to a reproducing device that does not satisfy a specific condition such as lack of billing information.

Further, the special reproducing apparatus is equipped with an image digital watermark detector, an identification information decoder, and a special VLC table, and a control device capable of supplying a VLC table suitable for decoding to the decoder is provided. As a result, it is possible to supply a recording medium that reproduces image signals of different qualities to the ordinary person and the special person, although the recording medium is the same.

The configuration and operation of the variable length coded data receiving device 550e according to the thirteenth embodiment have been described above.
Next, a recording device and a reproducing device for switching the VLC tables of the MPEG encoder and the MPEG decoder using the VLC table information will be described.

<Fourteenth Embodiment> FIG. 44 shows the arrangement of a variable length coded data recording apparatus according to the fourteenth embodiment, which will be described with reference to the drawings. The variable length coded data recording device 510f shown in the figure is different from the transmission device 510b according to the tenth embodiment shown in FIG. 38, instead of the transmission line packet encoder 521 and the encrypted information transmitter 522. Modulator 58
1 and the recorder 582 are arranged and configured differently. A recording medium 610 is inserted in the variable length coded data recording device 510f.

The same functional parts are designated by the same reference numerals. Next, the operation of the variable-length coded data recording device 510f configured as described above will be described mainly regarding the differences from the tenth embodiment.

First, the input image signal is the image data converter 5
The identification signal that has been input to 11 and is encrypted is embedded as electronic watermark information. Then, the image signal in which the electronic watermark information is embedded is supplied to the MPEG encoder 516, and compression encoding is performed based on the VLC table temporarily stored in the VLC unit 531. Further, the encoded image data and the encrypted information output from the CPU 515 are input to the modulator 581.

The image data and the encryption information input to the modulator 581 are recorded on the recording medium 610 in the same manner as in the twelfth embodiment shown in FIG. 41 described above, and the same operation as described above is performed. Done.

Next, a variable length coded data reproducing apparatus for reproducing and decoding the recording medium thus recorded will be described. FIG. 45 shows the configuration of a variable length coded data reproducing device according to the fourteenth embodiment, which will be described with reference to the drawings.

Variable length coded data reproducing device 5 shown in FIG.
Compared to the variable-length coded data receiving device 550b according to the tenth embodiment shown in FIG. 39, 50f is a reproducing unit 591 and demodulating unit instead of the transmission line packet decoding unit 551 and the encrypted information receiving unit 552. The difference is that the container 592 is arranged. A recording medium 610 is inserted in the variable length coded data reproducing device 550f.

The same functional parts are designated by the same reference numerals. Next, the operation of the variable-length coded data reproducing apparatus having such a configuration will be described mainly regarding the points different from the tenth embodiment.

First, the recording medium 610 recorded by the recording device 510f is loaded into the loading section (not shown) of the playback device 550f. The recording medium 610 is reproduced by the reproducing device 591 and the demodulating device 592, and the compression-coded image data and encrypted information are obtained.

Next, the encrypted information is supplied to the CPU 565, and the compression-encoded image data is supplied to the MPEG decoder 561. Hereinafter, the variable length coded data receiving device 55 according to the tenth embodiment shown in FIG.
The same operation as 0b is performed.

The configurations of the recording apparatus and the reproducing apparatus according to the fourteenth embodiment and their operations have been described above. Next, another embodiment of the reproducing apparatus will be described. <Fifteenth Embodiment> FIG. 46 shows the structure of a reproducing apparatus according to the fifteenth embodiment used in combination with the recording apparatus according to the fourteenth embodiment.

[0384] The variable length coded data reproducing device 5 shown in FIG.
Compared with the receiver 550f according to the fourteenth embodiment shown in FIG. 45, the IC card reader / writer 50g has a weight 50g.
72 and an IC card 601 to be inserted therein, and a VLC reproduction decoder 571a instead of the VLC decoder 571 is different. The same functional blocks are designated by the same reference numerals.

[0385] Next, the reproducing apparatus 550 configured as above.
Regarding the operation of g, the part different from the operation of the reproducing device 550f will be mainly described. That is, the reproducing device 550g includes the IC card reader / writer 572 described in the thirteenth embodiment shown in FIG. 43 and the IC card 60 inserted therein.
The function realized by 1 is added.

Therefore, when the predetermined chargeable amount is recorded in the IC card 601 and the predetermined reproduction condition is satisfied, the CPU 565 supplies the VLC table information to the VLC reproduction decoder 571a.

Then, when the decoding performed using the special VLC table is permitted, the VLC generation decoder 571a.
Then, a special VLC table is created, and the MPEG decoder 561 decodes an image without quality deterioration.

The configuration and operation of the receiving apparatus according to the fifteenth embodiment have been described above. In this way, it is possible to supply image signals of different qualities to the reproducing apparatus having a contract relationship and the reproducing apparatus having no contract relationship by the copyright holder who has the copyright of the content.

The copyright holder only needs to supply the contents recorded on the same recording medium, and the contents can be reproduced as a recording medium which can be reproduced as image signals of different qualities by ordinary persons and special persons. Can be supplied.

As described above, according to the first to fifteenth embodiments, MP
Decoding for reproducing content information with high quality in an encoding method, which is performed by EG, in which an image signal and an audio signal are orthogonally transformed to obtain a coefficient value signal, and the obtained coefficient value signal is run-length encoded. The configurations and operations of the apparatus and the decoding apparatus that reproduces the semi-disclosed content that is reproduced with distortion have been described.

In order to reproduce such contents having different qualities, it is possible to apply the same coding method as the above-mentioned run length coding to the coefficient value signal obtained by the orthogonal transform.

That is, the content signal is converted so that the energy of the information is concentrated on the predetermined information, and the information of the portion where the energy of the numerical information obtained by the conversion is not concentrated is run-length encoded and compressed. Any run length encoding method other than “0” may be used as long as the encoding method is used.

Further, as a rule for exchanging codes of the same code category in the code table of the variable length code, in the case of an image, the run length and level of the AC component, and in the case of voice, the information including the scale factor and spectrum is explained. However, as long as the parameters and the syntax change the quality of the image or the sound, the run length table generated by exchanging the code information may handle any kind of information at the time of encoding.

That is, even if the run length and level of the AC component in the case of an image and the fixed length coding of the information including the scale factor and the spectrum in the case of voice are encoded, the copyright holder who owns the copyright of the content , A different playback device that has a contractual relationship with the owned content or a playback device that meets specific conditions, and a general playback device that does not have a contractual relationship or a playback device that does not meet the specific conditions, with different quality image signals. Can be supplied.

Further, the method of having two or more code tables and selecting one of them to perform variable length coding has been described. Then, in addition to selecting and using a code table, only one code table is provided, and a part of the description content of the table can be replaced to perform the above operation.

The coding selection signal for identifying the replacement of the code table can be implemented by simply transmitting the number information such as the algorithm number for specifying the replacement rule. Therefore, the method realized by switching the table is one of a plurality of realizing means for realizing the above operation.

Further, in the above-described run-length encoding, when describing an event with few occurrence occurrences such as Huffman code according to the occurrence establishment of numerical information by a method of reducing redundancy, the number of pieces of numerical information is set. As long as encoding is performed by accurately counting and selecting the correct value and the approximate value as the numerical value described after the number information,
Any encoding method may be used.

Furthermore, in the present embodiment, an example of application to variable length coding has been mainly described, but the present invention can be similarly applied to coding using fixed length coding instead of variable length coding. That is, in the case of fixed-length coding, although the coding efficiency does not improve much, the above-mentioned method can be applied as a method for providing contents of different qualities.

Then, at that time, the reproducing apparatus designated as special by the copyright holder includes an image digital watermark detector, an identification information decoder, and parameters fixed-length coded by a special rule. It will be equipped with a function that has an algorithm for converting syntax.

By providing a control function for supplying information related to parameters and syntax for decoding a specially encoded signal to the special decoder, the general person and the special person can be provided with the same function. It is possible to provide services for images and audio signals in which image signals and audio signals having different qualities, though being encoded data, are reproduced.

As described above, the content disclosure and the content semi-disclosure are performed for both the fixed length coding application and the variable length coding application.
That is, for example, even in a decoder for an image signal and an audio signal that conforms to the MPEG standard, an abnormal error due to a VLC error or the like does not cause decoding failure, and a general regenerator does not convert the image signal and the audio signal. It enables semi-disclosure display and encrypted transmission with pronunciation effect.

[0402] Then, the content owned by the copyright holder who owns the copyright of the content including at least the image or the sound is not generally contracted with a special reproduction apparatus having a contract relationship or a reproduction apparatus satisfying a specific condition. Content with different qualities can be supplied to a playback device or a playback device that does not meet a specific condition.

Further, the special reproduction apparatus is equipped with the image digital watermark detector, the identification information decoder, and the special VLC table, and the control apparatus capable of supplying the VLC table suitable for decoding to the decoder is provided. As a result, it is possible to realize the content providing service for reproducing the content of the same encoded data but different quality for the general person and the special person.

That is, by using these devices, methods, and computer control programs, the contents are distributed and transmitted in a semi-disclosed state, and at the same time the user is encouraged to make an advertising effect that improves the willingness to purchase, and when the user makes a purchase, Special VL
It provides a C table identifiable playback method, where a business model capable of playing high quality content can be realized.

As the recording medium capable of semi-disclosure reproduction of such contents, a DVD recording medium has been mainly described. As long as the recording medium is a medium capable of recording content information, a DVD-ROM, a DVD-RAM,
The present invention can be applied not only to DVD-RW and DVD-R but also to digital recording media such as magneto-optical discs, magnetic discs, and magnetic tapes.

[0406] The content signal encoding method is such that the transformed data obtained by orthogonally transforming the content signal is quantized to obtain coefficient value data, and the obtained coefficient value data is arranged in a predetermined order to make a time series. The case of obtaining data was described. Then, the encoding method is, for example, a case where the content is orthogonally transformed to obtain coefficient value data like the MPEG method, and the transformation method including a technique other than the orthogonal transformation is also used like the fractal coding method. The same function as described in can be realized.

That is, when the content signal is encoded without dividing one image into small blocks as in the case of wavelet transform, for example, D is divided into blocks.
Compared with the method using orthogonal transformation for CT transformation, there is an advantage that the block division does not occur as block distortion.

The wavelet transform is performed by sub-band coding in which the image signal is frequency-divided, and the divided frequency band portions are sampled and coded at different sampling frequencies, and the above-mentioned orthogonal transform. This is an encoding method that combines and.

As another encoding method, there is a vector quantization method in which an image is divided into small blocks and each divided block is encoded by a vector value.

In the case where the image data is converted by any of the above methods to obtain time series data, and the time series data can be generated as a compression coded signal in which the information amount is compressed by performing variable length coding. The image data may be converted into time-series data by any method.

That is, when the information contained in a content content signal such as an image signal and an audio signal is converted by a predetermined method, and the energy (entropy) of the converted content is concentrated in a predetermined area, the energy is concentrated. It is possible to perform variable-length coding in which the time-series data represented by is described by the number of numerical values of the data and the level of the numerical value that follows.

Whichever encoding method is used, as a semi-disclosed content signal that can be obtained by recording / reproducing the content with an analog consumer device using the plurality of variable length encoding tables described above. It is possible to realize a method of encoding and decoding content that is expressed or expressed with high fidelity.

[0413]

According to the present invention, a coding selection signal designating whether the coding table used at the time of compression coding is the variable length coding table or the exchange variable length coding table is obtained, and the coding selection signal is used to obtain the coding selection signal. According to each variable-length coded data receiving method and each variable-length coded data receiving apparatus of the present invention that receives a compressed coded signal using a designated coding table, compression with a security level ensured It is possible to reliably receive a high-quality content signal with respect to the encoded signal.

[0414] An encoding selection signal designating whether the encoding table used at the time of compression encoding is the variable length encoding table or the exchange variable length encoding table is obtained, and the encoding selection signal is the exchange variable length. Each variable-length coded data receiving method of the present invention in which when a coding table is designated, a coding table used for decoding is selected from a variable-length coding table or an exchange variable-length coding table, and Each variable length coded data receiving device has the following effects. 1) When variable length decoding is performed using the exchange variable length encoding table designated by the encoding selection signal, there is an effect of reproducing high quality contents. 2) When variable-length decoding is performed using the variable-length coding table without using the exchange variable-length coding table specified by the coding selection signal, it is necessary to forcibly reproduce the content whose reproduction quality is lowered. It has an effect of performing (the effect of reproducing the content including the distortion component). Therefore, according to each of the variable length coded data receiving methods and each of the variable length coded data receiving devices, it is possible to reliably receive the content with the security level secured.

An encoding selection signal designating whether the encoding table used at the time of compression encoding is the variable length encoding table or the exchange variable length encoding table is embedded in the digital watermark and output to the communication network. The compressed coded signal is received, the coding select signal embedded in the compressed coded signal is detected, and the compressed coded signal is received using the coding table specified by the code select signal. According to each variable-length coded data receiving method and each variable-length coded data receiving apparatus of the present invention, it is possible to reproduce a high-quality content signal with respect to a compression-coded signal with a higher security level. .

Further, in each variable length coded data receiving method and each variable length coded data receiving device of the present invention, the reproduction of the content in which a predetermined security level is secured for the desired content to be encoded is reproduced. Variable length coding using the above exchange variable length coding table for
While the coding efficiency is prevented from deteriorating and the error signal is prevented from being generated due to an absurd operation at the time of reproduction, the variable length coding table is a standard coding table, so that it is available in the market. The present invention also has the effect of providing each variable-length coded data receiving method and the configuration of each variable-length coded data receiving device with good consistency.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an image signal encoding device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of an image signal decoding apparatus according to the first embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of an image signal encoding device according to a second embodiment of the present invention.

FIG. 4 is a diagram showing the syntax of a sequence header according to the second embodiment of the present invention.

FIG. 5 shows a syntax of a GOP layer according to a second embodiment of the present invention.

FIG. 6 shows a syntax of a picture layer according to a second embodiment of the present invention.

FIG. 7 is a block diagram showing a configuration of an image signal decoding device according to a second embodiment of the present invention.

FIG. 8 is a block diagram showing a configuration of an image signal coding device according to a third embodiment of the present invention.

FIG. 9 is a diagram showing a digital watermark to a macroblock quantized value according to the third exemplary embodiment of the present invention.

FIG. 10 is a block diagram showing a configuration of an image signal decoding device according to a third embodiment of the present invention.

FIG. 11 is a block diagram showing a configuration of an image signal encoding device according to a fourth embodiment of the present invention.

FIG. 12 is a diagram showing a digital watermark to a macroblock motion vector value according to the fourth embodiment of the present invention.

FIG. 13 is a block diagram showing a configuration of an image signal decoding device according to a fourth embodiment of the present invention.

FIG. 14 shows a variable length coding table used in the MPEG coding system.

FIG. 15 is a diagram showing a first half part of a variable length coding table used for coding according to a fourth embodiment of the present invention.

FIG. 16 shows the latter half of the variable length coding table used for coding according to the fourth embodiment of the present invention.

FIG. 17 is a diagram showing the relationship between the image quality according to the fourth embodiment of the present invention and the image quality according to the combination of the encoder and the decoder of the present invention.

FIG. 18 is a flowchart showing the operation of image encoding according to the fourth embodiment of the present invention.

FIG. 19 is a flowchart showing the operation of image decoding according to the fourth embodiment of the present invention.

FIG. 20 is a block diagram showing a configuration of an image signal encoding device according to a fifth embodiment of the present invention.

FIG. 21 is a block diagram showing a configuration of an image signal decoding device according to a fifth embodiment of the present invention.

FIG. 22 is a flowchart showing the operation of image encoding according to the fifth embodiment of the present invention.

FIG. 23 is a flowchart showing the operation of image decoding according to the fifth embodiment of the present invention.

FIG. 24 is a block diagram showing the structure of an audio signal encoding device according to a sixth embodiment of the present invention.

FIG. 25 is a diagram showing a relationship between scale factor bands and scale factors according to the sixth embodiment of the present invention.

FIG. 26 shows a part of a Huffman codebook used in the MPEG AAC encoding system.

FIG. 27 is a diagram showing a method of replacing indexes of a Huffman codebook according to the sixth embodiment of the present invention.

FIG. 28 is a diagram showing an example of variable-length coding and decoding of scale factors according to the sixth embodiment of the present invention.

FIG. 29 is a block diagram showing the structure of an audio signal decoding device according to a sixth embodiment of the present invention.

FIG. 30 is a block diagram showing the configuration of an audio signal encoding device according to a seventh embodiment of the present invention.

FIG. 31 shows a part of a Huffman codebook for spectra used in the MPEG AAC encoding system.

FIG. 32 is a diagram showing replacement of codewords in the Huffman codebook for spectra according to the seventh embodiment of the present invention.

FIG. 33 is a diagram for explaining exchange of codewords according to the seventh embodiment of the present invention.

FIG. 34 is a block diagram showing the structure of an audio signal decoding device according to a seventh embodiment of the present invention.

FIG. 35 is a block diagram showing the structure of an image signal coding device according to an eighth embodiment of the present invention.

FIG. 36 is a block diagram showing the configuration of an image signal decoding device according to the eighth embodiment of the present invention.

FIG. 37 is a block diagram showing the configuration of an image signal decoding device according to a ninth embodiment of the present invention.

FIG. 38 is a block diagram showing the structure of an image signal coding device according to the tenth embodiment of the present invention.

FIG. 39 is a block diagram showing the structure of an image signal decoding device according to the tenth embodiment of the present invention.

FIG. 40 is a block diagram showing the structure of an image signal decoding device according to an eleventh embodiment of the present invention.

FIG. 41 is a block diagram showing a configuration of an image signal recording device according to a twelfth embodiment of the present invention.

FIG. 42 is a block diagram showing a configuration of an image signal reproducing device according to a twelfth embodiment of the present invention.

FIG. 43 is a block diagram showing a configuration of an image signal reproducing device according to a thirteenth embodiment of the present invention.

FIG. 44 is a block diagram showing a configuration of an image signal recording device according to a fourteenth embodiment of the present invention.

FIG. 45 is a block diagram showing a configuration of an image signal reproducing device according to a fourteenth embodiment of the present invention.

FIG. 46 is a block diagram showing the structure of an image signal reproducing device according to a fifteenth embodiment of the present invention.

FIG. 47 is a block diagram showing a configuration of a conventional MPEG encoder.

FIG. 48 is a block diagram showing a configuration of a conventional MPEG decoder.

FIG. 49 is a block diagram showing a configuration of a conventional MPEG AAC system encoder.

FIG. 50 shows a table of a Huffman codebook used in the conventional MPEG AAC system.

FIG. 51 is a block diagram showing a configuration of a conventional MPEG AAC system decoder.

[Explanation of symbols]

10, 10a, 10b, 10c Image signal encoder 10d Image signal encoder / transmitter 11 Image data converter 12, 12a, 12b, 12c MPEG encoder 13 VLC table selector 14 Standard VLC table 15 Special VLC table 16, 16a, 16b, 16c CPU 17 Transmission line packet encoder 18 Transmission line interface 20, 20a, 20b, 20c Image signal decoding device 20d Image signal decoding receiving device 22, 22a, 22b, 22c MPEG decoder 23 VLC table selector 24 Standard VLC table 25 Special VLC table 26 Digital watermark detector 27 Transmission line packet decoder 28 Transmission line interface 50 MPEG encoder 51 Input terminal 52 Adder 53 DCT unit 54 Quantizer 55 VLC unit 56 Buffer 57 Change Replacement code amount controller 61 Inverse quantizer 62 Inverse DCT device 63 Adder 64 Image memory 65 Motion compensation predictor 70 MPEG decoder 71 Coded data input terminal 72 Buffer 73 VLD device 74 Inverse quantizer 75 Inverse DCT device 76 adder 77 image memory 78 motion compensation predictor 121 VLC device 122 user data description device 123 quantized value electronic watermark information description device 124 motion vector electronic watermark information description device 221 VLC decoder 222 user data decoder 223 quantized value electron Watermark information detector 224 Motion vector electronic watermark information detector 400 Audio signal encoding device 401 Auditory psychological analyzer 402 MDCT device 403 Scale factor calculator 404 Quantizer 405 Codebook selector 406 Variable length encoder 407 Minimum code amount Detector 408 Code amount determiner 409 Bit Stream generator 420 Audio signal decoder 421 Bit stream analyzer 422 Variable length decoder 423 Inverse quantizer 424 IMDCT 430 Audio signal encoder 431 MPEG-2 AAC encoder 432 Huffman codebook selector 433 Standard Huffman code Book 434 Special Huffman Codebook 435 CPU 436 Variable Length Encoder 440 Audio Signal Decoding Device 441 MPEG-2 AAC Decoder 442 Huffman Codebook Selector 443 Standard Huffman Codebook 444 for Scale Factor Special Huffman Codebook 445 CPU for Scale Factor 446 Variable length decoder 450, 460 Audio signal decoding device 451, 461 MPEG-2 AAC decoder 452, 462 Huffman code book Selectors 453, 463 Spectrum standard Huffman codebooks 454, 464 Spectrum special Huffman codebooks 455, 465 CPU 456 Variable length decoders 510, 510b Variable length coded data transmitters 510d, 510f Variable length coded data recording Device 511 Image data converter 512 Encryption device 513 Encryption method setting device 514 Encryption key setting device 515 CPU 516 MPEG encoder 517 VLC table selector 518 Standard VLC table 519 Special VLC table 521 Transmission line packet encoder 522 Encryption Information transmitter 523 VLC table generator 531 VLC device 550, 550a, 550b, 550c Variable length coded data receiving device 550d, 550e, 550f, 550g Variable length coded data reproducing device 551 Transmission line Packet decoder 552 encrypted information receiver 561 MPEG decoder 562 VLC table selector 563 standard VLC table 564 special VLC table 565 CPU 566 digital watermark detector 567 decryptor 568 decryption method selector 569 decryption key selector 571 VLC decoder 571a VLC generation decoder 572 IC card reader / writer 581 Modulator 582 Recorder 591 Reproducer 592 Demodulator 601 IC card 610 Recording medium

Front page continuation (51) Int.Cl. ⁷ identification code FI theme code (reference) H04N 7/081 G10L 9/18 M 5J064 7/16 H04N 7/08 Z 7/24 (72) Inventor Wataru Inaba Kanagawa 3-12 Moriya-cho, Kanagawa-ku, Yokohama-shi, Japan F-term inside Victor Company of Japan (reference) 5C059 KK43 MA00 MA23 MC11 ME01 ME03 ME05 RB02 RC32 RC35 UA02 UA05 5C063 AB03 AB05 AC01 AC10 CA23 CA36 DA07 DA13 5C064 BA01 BB05 BC10 BC16 BC20 BC21 BD07 BD09 5C076 AA14 BA06 BA09 5D045 DA20 5J064 AA02 BA09 BA16 BC01 BC16 BD02 BD03

Claims (8)

[Claims] 1. Time-series data obtained by performing data conversion, quantization, and arrangement by a predetermined method on a content signal including at least one of an image signal and an audio signal. Variable-length coding and packetizing the packetized compression-coded signal output to the communication network, and variable-length decoding to obtain the time-series data, and decoding the obtained time-series data to obtain the time-series data. A variable length coded data receiving method for obtaining a content signal, wherein the packetized compression coded signal is described by assigning a predetermined codeword to a plurality of data values of the time series data. Of the code words described in the variable table and the variable length coding table, the number of the time-series data is the same and different from each other. Of the two coding tables, the exchange variable length coding table and the exchange variable description
It is generated by performing variable-length coding of the time-series data using the coding table designated by the coding selection signal that specifies which coding table is used to perform the variable-length coding. A packet in which a compressed coded signal is written in an information data description area for transmitting the content signal, and the coded selection signal is written in a user data description area which is a user-defined area for transmitting data. A variable length coded data reception method for performing the decoding using the packetized compression coded signal, wherein the packetized compression coded signal is received, and an information data description area is received. A first step of acquiring the compressed coded signal described in 1. and the coding selection signal described in a user data description area; and the acquired coding A second step of variable-length decoding the acquired compressed coded signal to obtain the time-series data using the coding table designated by the alternative signal; and the time obtained in the second step. A third step of decoding sequence data to obtain the content signal, and a variable length coded data reception method. 2. Time-series data obtained by performing data conversion, quantization, and arraying on a content signal including at least one of an image signal and an audio signal by a predetermined method. , Variable length coding and packetizing, receiving a packetized compression coded signal output to a communication network, and variable length decoding to obtain time series data, and decoding the obtained time series data to obtain a content signal A variable length coding data receiving method for obtaining a packetized compression coded signal, wherein a variable length coding table is described in which a predetermined codeword is assigned to a plurality of data values of the time series data. Of the codewords described in the variable length coding table, the codewords having the same number of the time-series data and different from each other. Of the two encoding tables, the exchange variable length encoding table and the exchange variable length encoding table,
It is generated by performing variable-length coding of the time-series data using the coding table designated by the coding selection signal that specifies which coding table is used to perform the variable-length coding. A packet in which a compressed coded signal is written in an information data description area for transmitting the content signal, and the coded selection signal is written in a user data description area which is a user-defined area for transmitting data. A variable length coded data reception method for performing the decoding using the packetized compression coded signal, wherein the packetized compression coded signal is received, and an information data description area is received. A first step of acquiring the compressed coded signal described in 1. and the coding selection signal described in a user data description area; and the acquired coding Variable-length decoding is performed using the encoding table designated by the selection signal, or if the use of the exchange variable-length coding table is designated by the obtained encoding selection signal Using the second step of ignoring the use and selecting whether to perform the variable length decoding using the variable length encoding table, and the encoding table according to the selection result in the second step, A third step of performing variable length decoding of the obtained compression-coded signal to obtain time-series data, and a fourth step of decoding the time-series data obtained in the third step to obtain a content signal A variable length coded data receiving method, comprising: 3. Time-series data obtained by performing data conversion, quantization, and arraying on a content signal including at least one of an image signal and an audio signal by a predetermined method. The compression-coded signal generated by variable-length coding is packetized, the packetized compression-coded signal output to the communication network is received, and variable-length decoding is performed to obtain the time-series data. Is a variable length coded data receiving method for decoding the obtained time series data to obtain the content signal, wherein the compressed coded signal is a plurality of data values of the time series data for a predetermined portion of the content signal. Of the variable-length coding table that is described by allocating a predetermined codeword and the codeword that is described in the variable-length coding table Which one of the two coding tables, the exchange variable length coding table in which the number of the time-series data is the same and different codewords from each other are exchanged to be described, is used. A first variable-length code obtained by variable-length coding the time-series data for a predetermined portion of the content signal using the coding table designated by the coding selection signal that designates whether to perform variable-length coding. Signal and a portion other than the predetermined portion of the content signal,
Digital watermark processing time-series data obtained by performing a process for embedding the encoding selection signal with a digital watermark,
And a second variable-length coded signal that is variable-length coded using the variable-length coding table, and a compressed coded signal obtained by arranging the variable-length coded table. A method for receiving coded data, comprising: a first step of depacketizing the packetized compression coded signal obtained by reception to obtain the compression coded signal; , Variable length decoding is performed using the variable length encoding table to obtain the digital watermark processing time series data, and the encoding selection embedded by a digital watermark based on the obtained digital watermark processing time series data Using the second step of detecting a signal and the encoding table specified by the encoding selection signal detected in the second step, the obtained compressed encoded signal is A third step of performing the variable-length decoding to obtain the time-series data, and a fourth step of decoding the time-series data obtained in the third step to obtain the content signal. Variable length coded data receiving method. 4. Time-series data obtained by performing data conversion, quantization, and arraying on a content signal including at least one of an image signal and an audio signal by a predetermined method. The compression-coded signal generated by variable-length coding is packetized, the packetized compression-coded signal output to the communication network is received, and variable-length decoding is performed to obtain the time-series data. Is a variable length coded data receiving method for decoding the obtained time series data to obtain the content signal, wherein the compressed coded signal is a plurality of data values of the time series data for a predetermined portion of the content signal. Of the variable-length coding table that is described by allocating a predetermined codeword and the codeword that is described in the variable-length coding table Which one of the two coding tables, the exchange variable length coding table in which the number of the time-series data is the same and different codewords from each other are exchanged to be described, is used. A first variable-length code obtained by variable-length coding the time-series data for a predetermined portion of the content signal using the coding table designated by the coding selection signal that designates whether to perform variable-length coding. Signal and a portion other than the predetermined portion of the content signal,
Digital watermark processing time-series data obtained by performing a process for embedding the encoding selection signal with a digital watermark,
A variable-length code that is obtained by arranging a second variable-length coded signal that has been variable-length coded using the variable-length coding table, and that performs the decoding using the compressed-coded signal. A compressed data reception method, the first step of depacketizing the packetized compressed coded signal obtained by receiving to obtain the compressed coded signal; Variable length decoding is performed using the variable length coding table to obtain the digital watermark processing time-series data, and the coding selection signal embedded by digital watermark based on the obtained digital watermark processing time-series data. Variable length decoding is performed by using the second step of detecting the variable length and the encoding table specified by the encoding selection signal detected in the second step. When the use of the exchange variable length coding table is designated by the coding selection signal, the use of the exchange variable length coding table is ignored, and the variable length coding table is used to select whether to perform variable length decoding. A fourth step of performing variable length decoding of the obtained compressed coded signal by using the third step and the coding table according to the selection result in the third step, and obtaining the time series data. And a fifth step of decoding the time-series data obtained in the fourth step to obtain a content signal, the variable-length coded data receiving method. 5. Time-series data obtained by subjecting a content signal including at least one of an image signal and an acoustic signal to data conversion, quantization, and arrangement by a predetermined method. Variable-length coding and packetizing the packetized compression-coded signal output to the communication network, and variable-length decoding to obtain the time-series data, and decoding the obtained time-series data to obtain the time-series data. A variable-length coded data receiving device for obtaining a content signal, wherein the packetized compression-coded signal is described by assigning a predetermined codeword to a plurality of data values of the time-series data. Of the code words described in the variable table and the variable length coding table, the number of the time-series data is the same and different from each other. Of the two coding tables, the exchange variable length coding table and the exchange variable description
It is generated by performing variable-length coding of the time-series data using the coding table designated by the coding selection signal that specifies which coding table is used to perform the variable-length coding. A packet in which a compressed coded signal is written in an information data description area for transmitting the content signal, and the coded selection signal is written in a user data description area which is a user-defined area for transmitting data. A variable length coded data receiving device for performing the decoding using the packetized compression coded signal, wherein the packetized compression coded signal is received, and an information data description area is provided. Packetized decoding means for acquiring the compressed coded signal described in 1. and the coded selection signal described in the user data description area, and the acquired code Variable-length decoding means for variable-length decoding the acquired compression-coded signal to obtain the time-series data using the coding table designated by the coding selection signal, and the variable-length decoding means A variable length coded data receiving device, comprising: a content signal decoding means for decoding the obtained time series data to obtain the content signal. 6. Time-series data obtained by subjecting a content signal including at least one of an image signal and an acoustic signal to data conversion, quantization, and arrangement by a predetermined method. , Variable length coding and packetizing, receiving a packetized compression coded signal output to a communication network, and variable length decoding to obtain time series data, and decoding the obtained time series data to obtain a content signal A variable length coded data receiving device for obtaining the packetized compression coded signal, wherein the packetized compression coded signal is described by assigning a predetermined code word to a plurality of data values of the time series data. Of the codewords described in the variable length coding table, the codewords having the same number of the time-series data and different from each other. Of the two encoding tables, the exchange variable length encoding table and the exchange variable length encoding table,
It is generated by performing variable-length coding of the time-series data using the coding table designated by the coding selection signal that specifies which coding table is used to perform the variable-length coding. A packet in which a compressed coded signal is written in an information data description area for transmitting the content signal, and the coded selection signal is written in a user data description area which is a user-defined area for transmitting data. A variable length coded data receiving device for performing the decoding using the packetized compression coded signal, wherein the packetized compression coded signal is received, and an information data description area is received. Packetized decoding means for acquiring the compressed coded signal described in 1. and the coded selection signal described in the user data description area, and the acquired code Variable-length decoding is performed using the encoding table specified by the encoding selection signal, or the use of the exchange variable-length encoding table is specified by the obtained encoding selection signal. The encoding table selection means for deciding whether to perform variable length decoding using the variable length encoding table and the encoding table according to the selection result by the encoding table selection means are ignored. A variable length decoding means for performing variable length decoding of the obtained compressed coded signal using the variable length decoding means, and time series data obtained by the variable length decoding means to decode the content signal A variable length coded data receiving device, comprising: a content signal decoding means for obtaining the above. 7. Time-series data obtained by performing data conversion, quantization, and arraying on a content signal including at least one of an image signal and an audio signal by a predetermined method. The compression-coded signal generated by variable-length coding is packetized, the packetized compression-coded signal output to the communication network is received, and variable-length decoding is performed to obtain the time-series data. A variable length coded data receiving device for decoding the time series data obtained to obtain the content signal, wherein the compression coded signal is a plurality of data values of the time series data for a predetermined portion of the content signal. Of the variable-length coding table that is described by allocating a predetermined codeword and the codeword that is described in the variable-length coding table Which one of the two coding tables, the exchange variable length coding table in which the number of the time-series data is the same and different codewords from each other are exchanged to be described, is used. A first variable-length code obtained by variable-length coding the time-series data for a predetermined portion of the content signal using the coding table designated by the coding selection signal that designates whether to perform variable-length coding. Signal and a portion other than the predetermined portion of the content signal,
Digital watermark processing time-series data obtained by performing a process for embedding the encoding selection signal with a digital watermark,
A variable-length code that is obtained by arranging a second variable-length coded signal that has been variable-length coded using the variable-length coding table, and that performs the decoding using the compressed-coded signal. A packetized decoding means for decompressing the packetized compressed coded signal obtained by receiving to obtain the compressed coded signal; and the acquired compressed coded signal, Variable length decoding is performed using the variable length encoding table to obtain the digital watermark processing time-series data, and the encoding selection signal embedded by digital watermark based on the obtained digital watermark processing time-series data. Is obtained by using an encoding selection signal detecting means for detecting the signal and an encoding table designated by the encoding selection signal detected by the encoding selection signal detecting means. Variable length decoding means for variable length decoding the compressed coded signal to obtain the time series data, and content signal decoding for decoding the time series data obtained by the variable length decoding means to obtain the content signal A variable-length coded data receiving device, characterized by comprising: 8. Time-series data obtained by performing data conversion, quantization, and arrangement by a predetermined method on a content signal including at least one of an image signal and an audio signal. The compression-coded signal generated by variable-length coding is packetized, the packetized compression-coded signal output to the communication network is received, and variable-length decoding is performed to obtain the time-series data. A variable length coded data receiving device for decoding the time series data obtained to obtain the content signal, wherein the compression coded signal is a plurality of data values of the time series data for a predetermined portion of the content signal. Of the variable-length coding table that is described by allocating a predetermined codeword and the codeword that is described in the variable-length coding table Which one of the two coding tables, the exchange variable length coding table in which the number of the time-series data is the same and different codewords from each other are exchanged to be described, is used. A first variable-length code obtained by variable-length coding the time-series data for a predetermined portion of the content signal using the coding table designated by the coding selection signal that designates whether to perform variable-length coding. Signal and a portion other than the predetermined portion of the content signal,
Digital watermark processing time-series data obtained by performing a process for embedding the encoding selection signal with a digital watermark,
A variable-length code that is obtained by arranging a second variable-length coded signal that has been variable-length coded using the variable-length coding table, and that performs the decoding using the compressed-coded signal. A packetized decoding means for decompressing the packetized compressed coded signal obtained by receiving to obtain the compressed coded signal; and the acquired compressed coded signal, Variable length decoding is performed using the variable length coding table to obtain the digital watermark processing time-series data, and the coding selection signal embedded by digital watermark based on the obtained digital watermark processing time-series data. By using a coding selection signal detecting means for detecting the variable length and a coding table designated by the coding selection signal detected by the coding selection signal detecting means. Or the use of the exchange variable length coding table is designated by the detected coding selection signal, the use of the table is ignored and variable length decoding is performed using the variable length coding table. Variable-length decoding of the obtained compressed coded signal is performed by using an encoding table selection unit that selects whether to perform encoding and an encoding table that corresponds to the selection result of the encoding table selection unit. A variable length decoding means for obtaining time series data, and a content signal decoding means for decoding the time series data obtained by the variable length decoding means to obtain a content signal. A variable length coded data receiving device.