JP2003242715A - Copy preventing method of coded information - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a copy preventing method of coded information which enables both of user's convenience and copyright protection in copying digital signals. <P>SOLUTION: The high quality digital signal which is A/D converted in 24 bits is D/A converted by a D/A converter 45, and the analog signal is outputted via an output-terminal 55. In addition, copyright data associated with the data is added to the high quality digital signal and is outputted via a digital output terminal 90. <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 analog information such as a voice signal with a certain number of quantization bits.
The present invention relates to a code information copy prevention method for preventing and managing copying of digital data when digital (A / D) conversion is performed and recorded on a recording medium or transmitted through a transmission medium.

[0002]

C as an optical disk for audio reproduction
It has been ten years since D (Compact Disc) was put on the market, and it has already been remarkably popular as a recording medium for audio information, surpassing conventional cassette tapes. The physical / logical format of a CD, which is a digital disc, is EF with a fixed data length symbol of 8 bits.
M modulation recording method, subcode, audio data, CR
It has been established as a data format system such as C,
CD players with various application functions have been developed.

A CD is also used as a CD-ROM for data by identifying it by the control bit (4 bits) of the Q channel in its subcode or by identifying it in the absence of TOC. It is expanding its applications in the field of electronic publishing by effectively utilizing the large capacity and high-speed accessibility of discs. By the way, in the above CD-ROM, the audio is ADP.
Since it is compressed by CM, the original sound quality cannot be reproduced by the compression, and recording with higher hi-fi property is desired. In other words, it is a normal CD even if compressed
It is expected that a disc capable of recording an audio signal having a frequency band twice that of the above-mentioned disc will appear.

However, if such a high-quality high-fidelity signal is copied in the state of digital information, it is convenient for the user because it is not deteriorated, but it is not desirable from the viewpoint of copyright protection. . In addition,
As a method for solving such a problem, there has been proposed a method of limiting the number of times of copying digital information, or a method of not providing a digital output terminal in a device at all.

[0005]

However, it is difficult to satisfy both the convenience of the user and the protection of the copyright by a method of limiting the number of times of copying digital information or not providing a digital output terminal in the device at all. There is a problem. By the way, although copying of high quality digital data A / D converted with a relatively large number of quantization bits is not permitted, copying of low quality digital data with a substantially small number of quantization bits is permitted. There is a good idea.

Further, there is an idea that copying may be permitted if the copyright holder can prove that the product is a duplicate by adding copyright data to the extent that the quality of high-quality digital data is not deteriorated. . Further, in the analog copy, since the copyright related information such as the copy number limit information included in the digital data is not included, there is a possibility that the data once analog copied may be subsequently copied without restriction. It is not preferable from the viewpoint of protection.

[0007] Therefore, an object of the present invention is to provide a code information copy prevention method which can achieve both user convenience and copyright protection.

[0008]

In order to achieve the above object, the present invention comprises means described in 1) and 2) below. That is, 1) A / D conversion of an analog signal using a sampling frequency higher than that of CD and a quantization bit number larger than that of CD, and the A / D conversion. The sub-header in which the digital data generated by the step of arranging is placed in the user data area of the audio packet, and the copyright data managed by the copy number limit information and the ID number related to the analog signal are provided in the user data area of the audio packet. Generating a data signal according to a format arranged in, a format of the formatted data signal to extract the audio packet, and a step of extracting the digital data from a user data area of the audio packet. A step of extracting the copyright data from a subheader provided in a user data area of the audio packet, and a sampling frequency based on the extracted digital data when the copyright data is not accompanied by a copy count limitation. Outputting as a digital signal using the original number of quantized bits; and when the copyright data is accompanied by a copy number limitation, the extracted digital data is approximately equal to the number of quantized bits of the CD. Quantized bit number and the CD
Although it is allowed to output as a digital signal using a sampling frequency that is approximately equal to the sampling frequency of, the analog data is not D / A converted, or is output after D / A conversion. To control not to do,
A method of preventing code information from being copied. 2) A sampling frequency higher than the sampling frequency of the CD is used in the state where the copyright data of the analog signal and the ID number related to the analog signal are added to the analog signal, and the quantum is larger than the quantization bit number of the CD. A / D conversion using the digitized bit number, digital data generated by the A / D conversion step is arranged in a user data area of an audio packet, and copyright data managed by copy number restriction information and Generating a data signal in a format in which an ID number related to the analog signal is arranged in a sub-header provided in a user data area of the audio packet; and deformatting the formatted data signal to extract the audio packet Step and said Extracting said digital data from the user data area of over audio packet, and extracting the copyright data from a sub-header provided in the user data area of the audio packet,
If the copyright data does not have a copy count limit,
Outputting the extracted digital data as a digital signal using a base sampling frequency and a base quantization bit number; and when the copyright data is accompanied by a copy number limitation, regarding the extracted digital data, Although it is allowed to output as a digital signal using the number of quantized bits deteriorated to be substantially equal to the number of quantized bits of the CD and the sampling frequency that is substantially equal to the sampling frequency of the CD. , A step of controlling so that the digital data of the analog signal is not D / A converted, or is not output after D / A conversion.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 is a block diagram showing an encoder for realizing a first reference example of a code information copy protection method according to the present invention, FIG. 2 is a block diagram showing in detail a signal processing circuit 32 of FIG. 1, and FIG. FIG. 4 is an explanatory diagram showing a sampling period and a data string of the A / D converter, FIG. 4 is an explanatory diagram showing user data packed by the allocation circuit of FIG. 2, and FIG. 5 is a copy information copy prevention method applied to the present invention. 6 is a block diagram showing a decoder for realizing the first reference example, FIG. 6 is a block diagram showing in detail the signal processing circuit of FIG. 5, and FIG. 7 is an explanatory diagram showing a data string decoded by the decoder of FIG. 6 and a sampling period. is there.

An analog signal such as a voice signal is input to the input terminal IN shown in FIG. 1, and this input signal is A
The / D converter 31 samples at a sufficiently high sampling frequency (sampling period Δt shown in FIG. 3) enough to prohibit copying, for example, 192 kHz, and converts it into a 24-bit high-resolution PCM signal, which is shown in FIG. Thus, the data strings xb1, x1, xa1, x2, xb2, x3, xa2, ..., X corresponding to the curve α
It is converted into bi, x2i-1, xai, x2i, ....

This data string (xbi, x2i-1, xai, x2
i) is the signal processing circuit 32 and the memory 3 shown in detail in FIG.
3 and then the DVD encoding circuit 34
Packed by. This packing data is output to the output terminal OUT1 or is modulated by the modulation circuit 35 by the modulation method according to the medium and output to the output terminal OUT2.

The configuration of the signal processing circuit 32 will be described in detail with reference to FIG. First, by using a low-pass filter 36 that passes a ½ band, for example, an FIR filter,
The data string (xbi, x2i-1, xa corresponding to the curve α shown in
i, x2i), the data strings xc1, *, *, *, xc2, *, *, *, xc3, *, *, corresponding to the band-limited curve β
*, ..., Xci, *, *, *, ... are obtained, and then data “*” in this data string is thinned out by the thinning circuit 37, so that the data strings xc1, xc2, xc3 ,. ., Xci, ... Is generated. In addition, the data string (xbi, x2i-1, xai, x
2i), the data xi is thinned by the thinning circuit 38 to generate the data strings xb1, xa1, xb2, xa2, ..., Xbi, xai ,.

Then, these data strings xci, xbi, x
Based on ai, the difference calculator 39 configured by an adder calculates the difference xbi−xci = Δ1i xai−xci = Δ2i. Here, the difference data Δ1i and Δ2i are, for example, 2
It is 4 bits or less, and the number of bits may be fixed or variable. The allocation circuit 40 packs the data string xci and the difference data Δ1i and Δ2i as user data as shown in FIG. 4, and outputs the user data to record it on a recording medium such as a DVD (digital video disc). , Is transmitted to the transmission line. If the user data is 2034 bytes like a DVD, the data xci and the difference data Δ1i and Δ2i are both 22.
There are 5 subheaders, and the subheader has 9 bytes. Here, the data string xci is a data string in which the sampling frequency is reduced to 1/4 by limiting the band of the digital data A / D converted by the A / D converter 31.

Next, the decoder will be described with reference to FIG. First, the input signal is the modulation circuit 35 on the encoder side.
Of the signal processing circuit 43 (and the memory 44) shown in detail in FIG. 6 after being demodulated by the demodulation circuit 41 and then decoded by the DVD decoding circuit 42 according to the modulation method of FIG. And switch 51
Applied to. In the signal processing circuit 43, as shown in FIG. 6, first, the addition section 46 calculates Δ1i + xci = xbi Δ2i + xci = xai to restore the data strings xbi and xai. Here, the data strings xbi and xai are the original 24 bits.

Next, in the interpolation processing circuit 47, the data string xa
A plurality of data of i and xbi are used to interpolate a data string xi between them as shown in FIG. The interpolation processing circuit 4
7, the interpolation data string xi can be obtained by filling 0 data in each and passing through a low-pass filter using, for example, an upsampling method. The interpolated data string xi may also be obtained by curve approximation or prediction approximation. In this case, the approximation degree can be increased by adding and transmitting the approximation auxiliary data.

The data interpolated in this way are xb1, x1, xa1, x2, xb2, x3, xa2 ,.
xbi, x2i-1, xai, x2i, ... Arranged as follows: D / A converter 45 and adder 56
Applied to. In the D / A converter 45, the input data is converted into an analog signal at a sampling frequency of 192 kHz and is output via the analog output terminal 55.

On the other hand, the data string (xbi, x2i-1, xai, x
Dither noise is generated from the dither generator 57 as random noise for substantially limiting the number of quantization bits (24 bits) of each data of 2i) to about 16 bits. In the adder 56, the dither noise and the data string (xb
i, x2i-1, xai, x2i) are added and output via the output terminal 53. Note that dither noise and data string (x
Instead of simply adding (bi, x2i-1, xai, x2i), dither noise is added after the lower 17 bits of the 24-bit data in the data string (xbi, x2i-1, xai, x2i) are truncated. May be. Further, instead of dither noise, white noise or pink noise may be added to deteriorate the S / N ratio of the data string (xbi, x2i-1, xai, x2i).

Therefore, a data string (xbi, x2i-1, xai, x) which is A / D converted with a quantization bit number of 24 bits, encoded, recorded on a recording medium, and decoded.
In 2i), since the S / N ratio is deteriorated and output as digital data, it is possible to prevent copying with a high-quality quantized bit number. Also, the DVD decoding circuit 4
The output data string xci, Δ1i, Δ2i of No. 2 is output to the digital output terminal 52 via the switch 51, and the terminal 49 for inputting the personal identification number and the personal identification number input via this terminal 49 are decoded. A decryption unit 50 is provided for turning on the switch 51 in the case of doing so. Therefore,
Only the specified person can copy the encrypted data string (xci, Δ1i, Δ2i), but the high quality data string (xbi, x2i)
-1, xai, x2i) cannot be copied.

FIG. 8 is a block diagram showing a signal processing circuit of a decoder which realizes a second reference example of the code information copy protection method applied to the present invention, and FIG. 9 is an S / N of the signal processing circuit of FIG. It is explanatory drawing which shows a ratio deterioration process. The encoder is the same as that of the first reference example, and the circuit shown in FIG. 8 is different only in the circuit that deteriorates the high-quality data string (xbi, x2i-1, xai, x2i), and the other configurations are the same. is there.

Here, the ID number of the DVD is recorded together with video and audio. Therefore, the ID number (AB ... Z in the drawing) and the character code "COPY" decoded by the DVD decoding circuit 42 are converted into, for example, an ASCII code by the pattern generator 58, and this is converted into noise and copy proof data as shown in FIG. As shown, the high-quality data string (xbi, x2i-1, xai, x2i) is replaced with the lower 8 bits and output as digital data.

Therefore, when the user copies this data and performs D / A conversion, the quality of the audio signal deteriorates, so that it is possible to prevent copying with a high-quality quantized bit number, and the copyright holder. By reproducing the recording medium and identifying the ASCII code, the side can detect whether or not the recording medium is a copy. Also, I
Instead of the D number, the current time data of the clock 59 (data output time) may be converted into, for example, an ASCII code, which may be used to deteriorate the quality of the audio signal and to be used for copy determination.

In the above reference example, the data string xci is A
The digital data A / D converted by the / D converter 31 is a data string in which the sampling frequency is low-banded to 1/4 by limiting the band, and the differential data is calculated based on the data string xci. The data string xci is a data string in which the sampling frequency is reduced to 1/2 by limiting the band of the digital data A / D converted by the A / D converter 31, and the difference data is calculated based on this data string xci. May be. In the above embodiment, the data string xci reduces the sampling frequency of the digital data A / D converted by the A / D converter 31 to ¼, but the data string xci is A / D converted by the A / D converter 31. D
The interpolation data may not be calculated as a data string having the same sampling frequency as the converted digital data.

Next, a third reference example will be described with reference to FIGS. 10 is a block diagram showing an encoder that implements a code information copy protection method according to the reference example, FIG. 11 is a block diagram showing in detail the signal processing circuit of FIG. 10, and FIG. 12 is sampling of the A / D converter of FIG. FIG. 13 is an explanatory view showing a cycle and a data string, FIG. 13 is a block diagram showing a decoder for realizing the first embodiment of the code information copy protection method according to the present invention, and FIG. 14 is a block showing the signal processing circuit of FIG. 13 in detail. It is a figure. In addition, FIG.
The user data packed by the allocation circuit is similar to that shown in FIG. 4, and the data string decoded by the decoder shown in FIG. 13 and the sampling period are similar to those shown in FIG.

In the encoder shown in FIG. 10, a copyright identification signal supply section 100 is added to the configuration shown in FIG. 1, and the signal processing circuit 32 performs the processing shown in FIGS. 11 and 12. First, as in the first and second reference examples, the analog signal input via the input terminal IN is A
Sufficiently high sampling frequency (sampling period Δ
t), for example, sampled at 192 kHz and converted into a 24-bit high resolution PCM signal, for example, as shown in FIG.
As shown in, the data sequence (xbi, x2i-
1, xai, x2i).

This data string (xbi, x2i-1, xai, x2
i) is encoded by the signal processing circuit 32 and the memory 33 shown in detail in FIG. 11, and this data is then processed by the DVD encoding circuit 34 together with the copyright data as the copyright identification signal from the copyright identification signal supply unit 100. Will be packed. This packing data is output terminal OUT
1 or is modulated by the modulation circuit 35 by the modulation method according to the medium and output to the output terminal OUT2,
Information for identifying the copyright is output terminal OUT3.
Is output to. The output terminal OUT3 is also used as an input terminal when searching from an external device.

In the signal processing circuit 32, as shown in detail in FIGS. 11 and 12, as in the first and second reference examples, the data string (xbi, x2i-1, xai, x2i) is first divided into 1/4. Is divided into a low band by the low-pass filter 36 which divides into a band of 1, and down-sampled into a band of 1/4. The low band signal (xci) in this is extracted by the thinning circuit 37 and applied to the allocation circuit 40. Further, the thinning circuit 38 extracts the data string (xbi, xai),
The difference Δ1i xbi-xci = Δ1i is calculated by the subtractor 39 and applied to the allocation circuit 40.

In the third reference example, the predicted value xdi 'of the curve β at the time of the sample (xai) of the curve α is calculated by the predictor 101 using, for example, the quadratic prediction method, and then the subtractor 102 is used. Then, the difference Δ2i xai−xdi ′ = Δ2i between the predicted value xdi ′ and the actual sample value xai is calculated and applied to the allocation circuit 40. As shown in FIG. 4, the allocation circuit 40 packs these low-frequency components xci, two types of prediction differences Δ2i and Δ1i, and a copyright identification signal in different channels in a predetermined arrangement, and the DVD encoding circuit 34 Supply to.

Here, when one user data (packet) is 2034 bytes like a DVD, 334 low-frequency data xci of 3 bytes and difference data Δ2i and Δ1i are 167 of 1.5 bytes each on average. They are packed individually, and 33 bytes are allocated to the subheader. Data from the copyright identification signal supply unit 100 is recorded in the sub-header, and as an example, the disc serial number (16 bytes) is information for managing the copy state to identify the copyright. Code (4 bytes) -Recording date (3 bytes) -Number of recordings (3 bytes) -Number of copies (4 bytes) and-Number of copies possible (3 bytes) for managing copyright status are recorded. In addition to the sub-header for DVD,
Information for identifying these copyrights is recorded in more detail in a copyright management information area (CMI area) provided on the inner circumference of the disc so as to correspond to the TOC area defined in a CDR disc or the like.

Next, the decoder will be described with reference to FIGS. 13 and 14. In the decoder shown in FIG. 13, the decoder shown in FIG.
Instead of the adder 56, the dither generator 57, and the digital output terminal 53 shown in (4), a high-quality data string (xbi, x2i-
A digital output terminal 90 is provided to add copyright information to LSB of PCM data of 1, xai, x2i) and output the PCM data.

The signal processing circuit 43 will be described with reference to FIG. 14. In the circuit shown in the upper stage, x is added by the adder 46.
bi = Δ1i + xci is calculated, xai = Δ2i + xdi 'is calculated by the predictor 111 and the adder 112, and then xi is calculated by the interpolation processing circuit 47 based on the xai and xbi.
By calculating the high-quality data string (xbi, x2i-
1, xai, x2i) is restored. This data string (xbi, x2
i-1, xai, x2i) is output as an analog signal via the D / A converter 45 and the analog output terminal 55, and a high-quality data string (xbi, x2i) is output in the circuit shown in the lower stage.
Digital data obtained by adding (adder 118) the copyright data to the multi-valued data (-1, xai, x2i) is output through the digital output terminal 90.

More specifically, the copyright data reproduced from the sub-header is, for example, 5 kHz from the oscillator 113.
The modulated signal is modulated by the FM modulator 114 at the frequency of z, and then the modulated signal is spread by the spreading modulator 116 using the spreading code 115 to be spread to a low level. Further, the Δ modulator 117
Bits (192 kHz) are converted and applied to the adder 118, and the adder 118 outputs a high-quality data string (xbi,
(x2i-1, xai, x2i) is added to the LSB of the data and then output as digital data.

Therefore, when outputting in the state of digital data, since the data includes the copyright data, the copy state can be managed even if copied, and as a result, unlimited copying is prevented. can do. Further, in this example, since the copyright data is transmitted through the medium, even when only the specific person copies the encrypted data string (xci, Δ1i, Δ2i), the decryption unit 50 decrypts the personal identification number. Since the copyright data is included, the copy status can be managed.

Next, an embodiment applied to the present invention will be described with reference to FIGS. FIG. 15 is a block diagram showing in detail a signal processing circuit of an encoder for realizing the first embodiment of the code information copy protection method applied to the present invention, and FIG. 16 is the code information copy protection method applied to the present invention. 3 is a block diagram showing in detail a signal processing circuit of a decoder that realizes the first embodiment of FIG. The first embodiment is a modification of the third reference example, and FIGS. 15 and 16 correspond to FIGS. 11 and 14, respectively.

As shown in FIGS. 15 and 16, the copyright identification signal is modulated to form a data string (xbi, x2i-1, xai, x2).
oscillator 113 for adding to i), FM modulator 11
4, spread modulator 116, Δ modulator 117 and adder 11
8 is provided not on the decoder side but on the encoder side. That is, as shown in FIG. 15, data obtained by adding copyright data to the LSB of multi-valued data of a high-quality data string (xbi, x2i-1, xai, x2i) on the encoder side is low-pass of the signal processing circuit 32. It is input to the filter 36, compressed, and transmitted.

Then, as shown in FIG. 16, on the decoder side, the data obtained by adding the copyright data to the LSB of the multi-valued data of the high quality data string (xbi, x2i-1, xai, x2i) is output in a digital state. Enable and allow digital copying. That is, the copyright data is copied at the time of digital copying and not at the time of analog copying in the third reference example, whereas it is copied at both digital copying and analog copying in the first embodiment. When the decryption unit 50 decrypts the personal identification number and only the specific person copies the encrypted data string (xci, Δ1i, Δ2i),
The copyright data recorded in the subheader of the recording medium can be copied in a perfect state without being damaged, restricted, or disturbed.

Next, a second embodiment will be described with reference to FIG. This embodiment is a modification of the decoder of the first reference example shown in FIG. 5, and is provided with a control unit 126 that responds to the copy number limit information output from the decryption unit 50, and the copy number limit information exists. When a digital signal is output from the digital signal output terminal 53,
The A / A converter 45 is disabled so that the analog signal is controlled not to be output from the analog signal output terminal 55. This prevents unlimited copying of analog data that does not include copyright data.

FIG. 18 is a block diagram showing a third embodiment, which is a modification of the decoder shown in FIG. As in the fifth embodiment, the control unit 126 that responds to the copy number limit information output from the decryption unit 50 to the copyright data disables the D / A converter 45 when the copy number limit information exists. The analog signal is controlled so as not to be output from the analog signal output terminal 55.
Instead, the output signal of the signal processing circuit 43 is output through the digital signal output terminal 90, and the digital signal to which the copyright data is added is output. This prevents unlimited copying of analog data that does not include copyright data. In the third embodiment and the fourth embodiment, the operation of the D / A converter 45 is stopped when the copy number limit information exists, but the operation is not limited to this, and the D / A converter is not limited to this. Switches may be provided before and after 45 to prevent an analog signal from being output from the analog signal output terminal.

[0038]

As described above, according to the present invention, in particular, copying is permitted in the state of digital data in which high-quality digital data is added with data indicating a copyright, so that the user's copy is permitted. Both convenience and copyright protection can be achieved. In addition, if the number of copies for digital signals is limited, output is allowed only as digital signals and analog signals are not output, making unlimited copying as analog signals effective. Can be prevented.

[Brief description of drawings]

FIG. 1 is a first copy protection method for code information according to the present invention.
3 is a block diagram showing an encoder that realizes the reference example of FIG.

2 is a block diagram showing the signal processing circuit of FIG. 1 in detail.

FIG. 3 is an explanatory diagram showing a sampling cycle and a data string of the A / D converter in FIG.

4 is an explanatory diagram showing user data packed by the allocation circuit of FIG. 1. FIG.

FIG. 5 is a first copy information copy protection method according to the present invention.
3 is a block diagram showing a decoder that realizes the reference example of FIG.

FIG. 6 is a block diagram showing the signal processing circuit of FIG. 5 in detail.

FIG. 7 is an explanatory diagram showing a data string decoded by the decoder of FIG. 6 and a sampling cycle.

FIG. 8 is a second copy protection method for code information according to the present invention.
3 is a block diagram showing a signal processing circuit of a decoder that realizes the reference example of FIG.

9 is an explanatory diagram showing S / N ratio deterioration processing of the signal processing circuit of FIG. 8;

FIG. 10 is a block diagram showing an encoder that implements a first embodiment of a code information copy protection method according to the present invention.

11 is a block diagram showing in detail the signal processing circuit of FIG.

12 is an explanatory diagram showing a sampling cycle and a data string of the A / D converter in FIG.

FIG. 13 is a block diagram showing a decoder that realizes the first embodiment of the code information copy protection method according to the present invention.

FIG. 14 is a block diagram showing the signal processing circuit of FIG. 13 in detail.

FIG. 15 is a block diagram showing in detail a signal processing circuit of an encoder which realizes a second embodiment of the code information copy protection method according to the present invention.

FIG. 16 is a block diagram showing in detail a signal processing circuit of a decoder which realizes a second embodiment of the code information copy protection method according to the present invention.

FIG. 17 is a block diagram showing a decoder that implements a third embodiment of the code information copy protection method according to the present invention.

FIG. 18 is a block diagram showing a decoder for implementing a fourth embodiment of the code information copy protection method according to the present invention.

[Explanation of symbols]

31 A / D converter (A / D conversion means) 32, 43 Signal processing circuit 33, 44 Memory 34 DVD encoding circuit 35 Modulation circuit 36 Low-pass filter 37, 38 Decimation circuit 39 Adder (difference calculation unit) 40 Allocation circuit ( Output means) 41 Demodulation circuit 42 DVD decoding circuit 45 D / A converter (D / A conversion means) 46 Adder (constructs restoration means together with interpolation processing circuit 47) 47 Interpolation processing circuit 49 Terminal 50 Decryption section 51 Switch 52 , 53, 90 Digital output terminals 55, 132 Analog output terminal 56 Adder (dither generator 57, pattern generator 5
8, and constitutes the S / N ratio deterioration means together with the clock 59) 57 dither generator 58 pattern generator 59 clock 100 copyright identification signal supply unit 101, 111 predictor 102, 112 adder 113 oscillator (FM modulator 114) , Spreading code 115,
A modulation means is configured with the spread modulator 116 and the Δ modulator 117) 114 FM modulator 115 Spread code 116 Spread modulator 117 Δ modulator 118 Adder (adding means) 126 Control unit (control means)

Continued front page    (72) Inventor Tokuhiko Fuchigami             3-12 Moriya-cho, Kanagawa-ku, Yokohama-shi, Kanagawa             Local Victor Company of Japan, Ltd. F-term (reference) 5D044 AB05 BC02 CC06 DE50 EF01                       EF05 FG14 FG18 GK08 GK14                       GK17 HL08

Claims (2)

[Claims] 1. A / D conversion of an analog signal using a sampling frequency higher than a CD sampling frequency and a quantization bit number larger than a CD quantization bit number; The digital data generated by the converting step is arranged in the user data area of the audio packet, and the copyright data managed by the copy number restriction information and the ID number related to the analog signal are provided in the user data area of the audio packet. Generating a data signal in a format arranged in a sub-header; deformatting the formatted data signal to extract the audio packet; extracting the digital data from a user data area of the audio packet When Extracting the copyright data from a sub-header provided in the user data area of the audio packet when said copyright data is not accompanied by a copy count limit,
Outputting the extracted digital data as a digital signal using a base sampling frequency and a base quantization bit number; and when the copyright data is accompanied by a copy number limitation, regarding the extracted digital data, Although it is allowed to output as a digital signal using the number of quantized bits deteriorated to be substantially equal to the number of quantized bits of the CD and the sampling frequency that is substantially equal to the sampling frequency of the CD. ,
A method for preventing copy of code information, which comprises a step of controlling so that the digital data of an analog signal is not D / A converted or is not output after D / A conversion. 2. An analog signal is used with a sampling frequency higher than the sampling frequency of the CD in the state where the copyright data of the analog signal and the ID number relating to the analog signal are modulated and added, and compared with the number of quantization bits of the CD. A / D conversion using a large number of quantized bits, and digital data generated by the A / D conversion step is placed in the user data area of the audio packet and managed by copy number restriction information. Generating a data signal according to a format in which the right data and the ID number related to the analog signal are arranged in a sub-header provided in the user data area of the audio packet; and de-formatting the formatted data signal to convert the audio signal. Steps to retrieve packets A step of extracting the digital data from the user data area of the audio packet; a step of extracting the copyright data from a subheader provided in the user data area of the audio packet; When not accompanied by,
Outputting the extracted digital data as a digital signal using a base sampling frequency and a base quantization bit number; and when the copyright data is accompanied by a copy number limitation, regarding the extracted digital data, Although it is allowed to output as a digital signal using the number of quantized bits deteriorated to be substantially equal to the number of quantized bits of the CD and the sampling frequency that is substantially equal to the sampling frequency of the CD. ,
A method for preventing copy of code information, which comprises a step of controlling so that the digital data of an analog signal is not D / A converted or is not output after D / A conversion.