JPH09330560A - Preventing method for copying of code information, encoding device therefor, decoding device therefor, and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make convenience of a user and protection of copyright compatible in the case when digital signals are copied. SOLUTION: Digital signals of low quality subjected to A/D conversion on the basis of a sampling frequency of 48kHz are outputted as they are through a digital output terminal 23, while they are subjected to D/A conversion by a D/A converter 15 and outputted through an analog output terminal 17. Digital signals of high quality subjected to A/D conversion on the basis of a sampling frequency of 96kHz are subjected to D/A conversion by a D/A converter 16 and outputted through an analog output terminal 18, and they are not outputted as the digital signals. In the case when a bit stream is allowed to be copied, it is copied only with copyright data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a case where analog information such as an audio signal is analog-digital (A / D) converted at a certain sampling frequency and recorded on a recording medium or transmitted via a transmission medium. In particular, the present invention relates to a code information copy prevention method, an encoding device, a decoding device, and a recording medium that prevent copying of digital data.

[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, there is an idea that copying of high quality digital data is not permitted, but copying of low quality digital data having a narrow band may be permitted.

There is also an idea that digital copying may be permitted if the copyright holder can confirm that the copy has been made.

Therefore, an object of the present invention is to provide a code information copy prevention method, an encoding apparatus, a decoding apparatus, and a recording medium that are compatible with user convenience and copyright protection.

[0008]

In order to achieve the above object, the present invention permits copying of digital data obtained by A / D converting an analog signal at a relatively low first sampling frequency and comparing the analog signals. Copying is prohibited for digital data A / D-converted at a second sampling frequency that is higher than usual. According to the present invention, digital data obtained by A / D converting an analog signal at a relatively high first sampling frequency is band-limited to a relatively low second sampling frequency to allow copying. For example, when the analog signal is a voice signal, the combination of the first and second sampling frequencies is 24 kHz, 48 kHz, 96 kHz, 19
Two such as 2 kHz can be used. The present invention also allows for copying of the bitstream only with the copyright data.

That is, according to the present invention, the analog signal is A / D converted at a relatively low first sampling frequency to generate a first digital data string, and the analog signal is converted from the first sampling frequency. A / D converting at a high second sampling frequency to generate a second digital data string, and calculating each difference data string of the first and second data strings at the same sampling point, Transmitting the first data sequence and the differential data sequence via a medium; restoring the second data sequence based on the first data sequence and the differential data sequence; Of the second data string is converted into an analog signal and is output, and the second data string is converted to an analog signal only. And outputting by conversion, copy protection method of code information with is provided.

Further, according to the present invention, a first A / D conversion means for A / D converting an analog signal at a relatively low first sampling frequency to generate a first digital data string, and an analog signal. Second A / D conversion means for A / D converting the signal at a second sampling frequency higher than the first sampling frequency to generate a second digital data string,
It has a difference calculating means for calculating each difference data string of the first and second data strings at the same sampling point, and an output means for packing the first data string and the difference data string and outputting the packed data. An encoding device for encoded information is provided.

Further, according to the present invention, the analog signal is A / D converted at a relatively low first sampling frequency to generate a first digital data string, and the analog signal is higher than the first sampling frequency. The A / D conversion is performed at a second sampling frequency to generate a second digital data string, and the difference data string between the first and second data strings at the same sampling point is calculated to generate the second data string. A decoding device of code information for decoding a first data string and the differential data string, wherein the restoring means restores the second data string based on the first data string and the difference data string, A digital output terminal for outputting the first data string in the state of digital data, a first D / A conversion means for D / A converting the first data string, and the first D A first analog signal output terminal for outputting an analog signal which is D / A converted by the A converting means, the second data stream restored by the restoration means D
Second D / A conversion means for performing A / A conversion, and the second D / A conversion means
A second analog signal output terminal for outputting an analog signal D / A converted by the A conversion means is provided, and the second data string restored by the restoration means is not output in a digital data state. An apparatus for decoding code information is provided.

Further, according to the present invention, the analog signal is A / D converted at a relatively low first sampling frequency to generate a first digital data string, and the analog signal is higher than the first sampling frequency. The A / D conversion is performed at a second sampling frequency to generate a second digital data string, and the difference data string between the first and second data strings at the same sampling point is calculated to generate the second data string. A recording medium on which a first data string and the difference data string are recorded is provided.

Further, according to the present invention, a step of A / D converting the analog signal at a relatively high first sampling frequency to generate a first digital data string, and the first digital data string are provided.
Generating a second digital data string having a sampling frequency lower than the first sampling frequency by band limiting the digital data string of, and each differential data string of the first and second data strings at the same sampling point And transmitting the second data string and the difference data string through a medium, and restoring the first data string based on the second data string and the difference data string. A method for preventing copy of code information, the method including: converting the first data string into an analog signal and outputting the analog signal; and outputting the first data string only in a band-limited digital data state. Will be provided.

Further, according to the present invention, A / D conversion means for A / D converting an analog signal at a relatively high first sampling frequency to generate a first digital data string, and the first digital signal Band limiting means for band limiting the data string to generate a second digital data string having a sampling frequency lower than the first sampling frequency, and differential data of the first and second data strings at the same sampling point. There is provided an encoding device for code information, which has difference calculation means for calculating a sequence and output means for packing the second data sequence and the difference data sequence and outputting them.

Further, according to the present invention, an analog signal is A / D converted at a relatively high first sampling frequency to generate a first digital data string, and the first digital data string is band-limited. To generate a second digital data string having a sampling frequency lower than the first sampling frequency, and to calculate each differential data string of the first and second data strings at the same sampling point. A decoding device of code information for decoding a second data string and the difference data string, wherein the restoring means restores the first data string based on the second data string and the difference data string, and the restoring device. Means for D / A converting the first data string restored by the means, and an output for outputting an analog signal D / A converted by the D / A converting means. A log signal output terminal, a band limiting means for band limiting the first data string restored by the restoring means, and a digital signal output terminal for outputting the output of the band limiting means in a digital data state. ,
There is provided a code information decoding device configured such that the output of the restoring means is not output as it is as digital data.

Further, according to the present invention, an analog signal is A / D converted at a relatively high first sampling frequency to generate a first digital data string, and the first digital data string is band-limited. To generate a second digital data string having a sampling frequency lower than the first sampling frequency, and to calculate each differential data string of the first and second data strings at the same sampling point. A recording medium on which the second data string and the difference data string are recorded is provided.

Further, according to the present invention, the analog signal is
D / D converting to generate a digital data string,
Code information having a step of transmitting the digital data string and copyright data regarding the analog signal via a medium, and a step of outputting the digital data string transmitted via the medium only together with the copyright data. A copy protection method is provided.

According to the present invention, the analog signal is
Encoding of code information having digital data generating means for performing D / D conversion to generate a digital data string, and packing means for packing the digital data string generated by the digital data generating means and the copyright data relating to the analog signal. A device is provided.

Further, according to the present invention, the analog signal is
There is provided a recording medium in which digital data strings generated by D / D conversion and copyright data regarding the analog signal are recorded.

Further, according to the present invention, the analog signal is
A decoding device for code information, which decodes digital data string generated by D / D conversion and copyright data related to the analog signal, and has digital data output means for outputting the digital data string together with the copyright data. There is provided a code information decoding device configured so that the digital data string is not output without being accompanied by the copyright data.

Further, according to the present invention, the analog signal is A / D converted at a relatively low first sampling frequency to generate a first digital data string, and the analog signal is converted from the first sampling frequency. A / D converting at a high second sampling frequency to generate a second digital data string, and calculating each difference data string of the first and second data strings at the same sampling point, Transmitting the first data sequence, the differential data sequence and copyright data relating to the analog signal through a medium, and the second data sequence based on the first data sequence and the differential data sequence. And a step of restoring the first data string into an analog signal and outputting the analog signal, and outputting the first data string in the state of digital data. A data string is converted into an analog signal and output, and a step of outputting only the first data string and the difference data string together with the copyright data is provided. Provided.

Further, according to the present invention, a first A / D conversion means for A / D converting an analog signal at a relatively low first sampling frequency to generate a first digital data string, and an analog signal. Second A / D conversion means for A / D converting the signal at a second sampling frequency higher than the first sampling frequency to generate a second digital data string,
A difference calculating means for calculating each difference data string of the first and second data strings at the same sampling point, the first data string, the difference data string, and the copyright data regarding the analog signal are packed. And an output unit that outputs the encoded information.

Further, according to the present invention, the analog signal is A / D converted at a relatively low first sampling frequency to generate a first digital data string, and the analog signal is higher than the first sampling frequency. The A / D conversion is performed at a second sampling frequency to generate a second digital data string, and the difference data string between the first and second data strings at the same sampling point is calculated to generate the second data string. A decoding device of code information for decoding copyright data relating to a first data string, the differential data string and the analog signal, wherein the second data is based on the first data string and the differential data string. Restoring means for restoring a column, a digital output terminal for outputting the first data sequence in a digital data state, and D / A conversion of the first data sequence A first D / A converting means, a first analog signal output terminal for outputting an analog signal D / A converted by the first D / A converting means, and a second analog signal restored by the restoring means. Second D / A conversion means for D / A converting the data string of, and a second analog signal output terminal for outputting an analog signal D / A converted by the second D / A conversion means, A digital output terminal for outputting the first data string and the differential data string together with the copyright data, and configured not to output the first data string and the differential data string without accompanying the copyright data There is provided a decoding device for the coded information.

Further, according to the present invention, the analog signal is A / D converted at a relatively low first sampling frequency to generate a first digital data string, and the analog signal is higher than the first sampling frequency. The A / D conversion is performed at a second sampling frequency to generate a second digital data string, and the difference data string between the first and second data strings at the same sampling point is calculated to generate the second data string. A recording medium on which a first data string, the differential data string, and copyright data regarding the analog signal are recorded is provided.

Further, according to the present invention, a step of A / D converting the analog signal at a relatively high first sampling frequency to generate a first digital data string, and the first digital data string are provided.
Generating a second digital data string having a sampling frequency lower than the first sampling frequency by band limiting the digital data string of, and each differential data string of the first and second data strings at the same sampling point And transmitting the second data string and the differential data string together with copyright data relating to the analog signal via a medium, and based on the second data string and the differential data string, Restoring the first data string, converting the first data string into an analog signal and outputting the analog signal, and outputting the first data string only in the state of band-limited digital data; And outputting the second data string and the difference data string only together with the copyright data. Copy protection method is provided.

Further, according to the present invention, A / D conversion means for A / D converting an analog signal at a relatively high first sampling frequency to generate a first digital data string, and the first digital signal. Band limiting means for band limiting the data string to generate a second digital data string having a sampling frequency lower than the first sampling frequency, and differential data of the first and second data strings at the same sampling point. A difference calculating means for calculating a row, the second data row, and an output means for packing and outputting the difference data row and copyright data relating to the analog signal.
An encoding device for code information having the same is provided.

Further, according to the present invention, an analog signal is A / D converted at a relatively high first sampling frequency to generate a first digital data string, and the first digital data string is band-limited. To generate a second digital data string having a sampling frequency lower than the first sampling frequency, and to calculate each differential data string of the first and second data strings at the same sampling point. A decoding device of code information for decoding the second data string, the differential data string, and copyright data relating to the analog signal, wherein the first data string is based on the second data string and the differential data string. A D / A conversion unit for D / A converting the first data string restored by the restoration unit;
An analog signal output terminal for outputting an analog signal D / A converted by the A conversion means, a band limiting means for band limiting the first data string restored by the restoring means, and an output of the band limiting means. A digital signal output terminal for outputting the digital data, a digital signal output terminal for outputting the second data string and the difference data string together with the copyright data, and the second data string and the difference There is provided a code information decoding device configured so that a data string is not output without being accompanied by the copyright data.

Further, according to the present invention, an analog signal is A / D converted at a relatively high first sampling frequency to generate a first digital data string, and the first digital data string is band-limited. To generate a second digital data string having a sampling frequency lower than the first sampling frequency, and to calculate each differential data string of the first and second data strings at the same sampling point. There is provided a recording medium on which two data strings, the differential data string, and copyright data regarding the analog signal are recorded.

[0029]

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 that implements a first embodiment of a code information copy protection method according to the present invention, and FIG. 2 is an explanatory diagram showing sampling periods and data strings of the two A / D converters of FIG. ,
FIG. 3 is an explanatory diagram showing user data packed by the packing encoder of FIG. 1, FIG. 4 is a block diagram showing a decoder for implementing the first embodiment of the code information copy protection method according to the present invention, and FIG. FIG. 5 is an explanatory diagram showing a data string decoded by the decoder of FIG. 4 and a sampling period.

An analog signal such as a voice signal is input to the input terminal 1 shown in FIG. 1, and this input signal is A /
It is applied to the D converters 2 and 3. The A / D converters 2 and 3 have a sampling clock f of a relatively low sampling frequency, for example 48 kHz, and a relatively high sampling frequency of 96, for example, from the clock generator 5.
A sampling clock 2f of kHz is applied.

As shown in FIG. 2, the A / D converter 2 has 4
The input signal is sampled at the cycle of the sampling clock f of 8 kHz, and xa1, xa2, xa3, ..., Xai ,.
.. is converted to a relatively low quality digital data string xai. Further, the A / D converter 3 samples the input signal at a cycle of a sampling clock 2f of 96 kHz as shown in FIG. 2, and outputs (xb1, xc1), (xb2, xc
2), (xb3, xc3), ..., (xbi, xci), ...
A relatively high-quality digital data string (xbi, x
ci).

Here, of the data string (xbi, xci), the sampling position of the data string xbi is the same as that of the data string xai at 48 kHz, and among the data string (xbi, xci),
The sampling position of the data string xci is an intermediate position of the data string xai at 48 kHz. The sampling data is converted with a resolution of 24 bits, for example.

The data string (xbi, xci) A / D converted by the A / D converter 3 is applied to the switch 4, and only the data string xbi is selected based on the sampling clock 2f of 96 kHz from the clock generator 5. , The data string xci is thinned out. In the difference calculator 6, sampling data xai which is A / D converted by the A / D converter 2
And the sampling data x selected by the switch 4
Based on bi, xbi−xai = Δi is calculated. Here, the difference data Δi is 24 bits or less.

The subsequent packing encoder 7 uses the data string xai A / D converted by the A / D converter 2 and the difference data string Δi calculated by the difference calculator 6 as the user data having the arrangement shown in FIG. By packing and outputting the user data via the output terminal 8, it is recorded on a recording medium, for example, a DVD (digital video disc or digital versatile disc) or transmitted to a transmission medium.

In the example shown in FIG. 3, one user data is composed of a sub-header, n sampling data xa1 to xan and n difference data Δ1 to Δn, and the user data is 2034 bytes like a DVD. In this case, the data xa1 to xan and the difference data Δ1 to Δn are both 338.
(= N), and the subheader is 6 bytes. In DVD, user data is called a packet, and subheader is called a packet header.

Next, the decoder will be described with reference to FIG. User data input through the input terminal 9 is applied to the unpacking decoder 10 and the switch 21. In the unpacking decoder 10, the data string xai and the difference data string Δi are separated, and the data string xai is added by the addition unit 1.
1, the D / A converter 15 and the output terminal 23, and the difference data sequence Δi is applied to the adder 11. In the adder 11, Δi + xai = xbi is calculated, and this data string xbi is applied to the interpolation processing circuit 12 and the switch 13. The number of bits of each data of this data string xbi is 24 bits.

The interpolation processing circuit 12 uses a plurality of data of the data string xbi to interpolate the data string xci between them.
For example, using an upsampling method,
By interpolating the data and passing it through the low-pass filter, the interpolated data string xci can be obtained. In the subsequent switch 13, the data strings xbi, xci are generated based on the sampling clock 2f of 96 kHz from the clock generator 14.
Are alternately selected, and therefore, the sampling frequency of 96 kHz in the encoder shown in FIG.
It is restored to the converted data string (xbi, xci) (Fig. 5
reference).

This data string (xbi, xci) is sampled by the D / A converter 16 at a sampling frequency 2f of 96 kHz.
Is D / A converted based on the above, and is output via the analog output terminal 18. The data xai separated by the unpacking decoder 10 is output as it is through the digital output terminal 23, and also D / A converted by the D / A converter 15 based on the sampling frequency f of 48 kHz, and the analog output terminal is output. It is output via 17.

Therefore, the relatively low-quality digital data xai which is A / D converted at 48 kHz and compressed and recorded on the recording medium is directly output to the digital output terminal 23.
It can be copied because it is output via
Relatively high-quality digital data (xbi, xc) that has been A / D converted by Hz, recorded on a recording medium, and decoded.
Since i) is not output as it is, copying can be prevented.

Further, in this embodiment, the input terminal 9 is connected to the digital output terminal 22 via the switch 21,
Further, there are provided a terminal 19 for inputting a personal identification number, and a decryption unit 20 for turning on the switch 21 when the personal identification number input via the terminal 19 is decrypted. Therefore, only the specified person can obtain the encrypted data string (xai, Δ
i) can be copied. Also in this case, the decoded relatively high quality digital data (xbi, xci)
Cannot be copied.

Next, a second embodiment will be described with reference to FIGS. 6 is a block diagram showing an encoder that implements a second embodiment of the code information copy protection method according to the present invention, FIG. 7 is a block diagram showing the signal processing circuit of FIG. 6 in detail, and FIG. 8 is A of FIG. FIG. 9 is an explanatory diagram showing a sampling period and a data string of the / D converter, FIG. 9 is a block diagram showing a decoder for realizing the second embodiment of the code information copy protection method according to the present invention, and FIG. 10 is the signal processing of FIG. FIG. 11 is a block diagram showing the circuit in detail, and FIG. 11 is an explanatory diagram showing a data string decoded by the decoder of FIG. 9 and a sampling period.

An analog signal such as a voice signal is input to the input terminal IN shown in FIG. 6, and this input signal is A
Sufficiently high sampling frequency (FIG. 8) to prohibit unlimited digital copying by the / D converter 31.
Sampling frequency Δt) shown in, for example, a 192 kHz high-resolution PC sampled at 192 kHz
As shown in FIG. 8, the data sequences xb1, x1, xa1, x2, xb2, x3, xa2, ...
.., xbi, 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, for example, an FIR filter, which passes a ½ band, as shown in FIG.
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 the 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, x2i), the data xi is thinned out by the thinning circuit 3
By thinning out by 8, the data strings xb1, xa1, xb2,
, xbi, xai, ... Are generated.

Then, these data strings xci, xbi, x
Based on ai, a difference xbi−xci = Δ1i xai−xci = Δ2i is calculated by an adder 39 which functions as a difference calculator. 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 has a data string x
The ci and the difference data Δ1i and Δ2i are packed as user data as shown in FIG.
Recording medium such as DVD by outputting data
It is recorded on (digital video disc) or transmitted to a transmission path. That is, in the former case, the DVD encoding circuit 34 adds a pack header consisting of pack start, SCR, Mux rate, and stuffing shown in the DVD format shown in FIG. 20 to the user data and encodes it in units of 2,048 bytes. The modulation circuit 35
And the recording medium DVD is manufactured. 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.
Signal is demodulated by the demodulation circuit 41 according to the modulation method of No. 1 and then decoded by the DVD decoding circuit 42, and the decoded data (data string xci and difference data Δ1i, Δ2i) is shown in detail in FIG. Applied to. In the signal processing circuit 43, as shown in FIG.
The adder 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 xb
A plurality of data of i and xai are used to interpolate a data string xi between them as shown in FIG. Note that the interpolation processing circuit 47 can obtain the interpolation data string xi 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 is xb
1, x1, xa1, x2, xb2, x3, xa2, ..., xb
i, x2i-1, xai, x2i, ...
It is applied to the / A converter 45 and the low pass filter 56. In the D / A converter 45, the input data is 192kH
It is converted into an analog signal at the sampling frequency of z and output through the output terminal 55. On the other hand, in the low-pass filter 56, the input data is, for example, 1/4 band (48 kHz).
z) and is output as digital data via the output terminal 53.

Therefore, a data string (xbi, x2i-1, x) is A / D converted at a sampling frequency of 192 kHz, encoded, recorded on a recording medium, and decoded.
ai, x2i) is limited to the band of 48 kHz and is output as digital data, so that it can be prevented from being copied in the high quality band. Also in this embodiment, similarly, the output data string (xci, Δ1i, Δ2i) of the DVD decoding circuit 42 is output to the digital output terminal 52 via the switch 51. The decoder is also provided with a terminal 49 for inputting a personal identification number, and a decryption unit 50 for turning on the switch 51 when the personal identification number input via the terminal 49 is decrypted. 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.

Next, a third embodiment will be described with reference to FIGS. This third embodiment corresponds to the first embodiment, FIG. 12 corresponds to the encoder shown in FIG. 1, FIG. 13 corresponds to the user data shown in FIG. 3, and FIG. Corresponds to the decoder shown. FIG.
As shown in FIG. 2, in this embodiment, the copyright data supply unit 100 is added, and the copyright data supplied from the copyright data supply unit 100 is the bitstream data string (xa
It is packed together with i, Δi) by the packing encoder 7.

The copyright data is recorded in the sub-header as shown in FIG. 13, and as an example, the serial number (16 bytes) of the disc, which is the information for managing the copy state to identify the copyright, the ISRC ( International Standard Recording Code: Inte
national Standard Recordi
ng Code) -Player identifier code (2 to 4 bytes) -Recording date (3 bytes) -Recorded number (3 bytes) -Number of duplicates (4 bytes) -Number of duplications for managing copyright status ( (1 to 3 bytes) are dispersed and recorded in the subheader. In addition to the subheader, the DVD further stores the copyright data 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. It will be recorded in detail.

When the data recorded on the recording medium is copied by the decoder, the bit stream data string (xai, Δi) and the copyright data are both output via the digital output terminal 22, as shown in FIG. Therefore, when this output signal is copied to another medium, the copyright holder side can confirm the copy state of the bitstream data string (xai, Δi) by reproducing the medium. Further, as indicated by a broken line in FIG. 14, even when the relatively low quality digital data xai is directly output through the digital output terminal 23, the relatively low quality digital data xai is output by outputting it together with the copyright data. You can check the copy status of. In this case, FIG.
The copyright data can be added to the subcodes such as the U bit attached to the PCM digital signals D0 to D23 defined in the digital audio interface format IEC958 as shown in FIG.

By this sub-code, a set of data such as the above ISRC is periodically sent. In FIG. 19, in the digital audio interface format, one sample has two words, and each word is assigned to the L channel and the R channel (data L, data R). Looking at one word,
4-bit preamble indicating the beginning of the word and 1
6-bit or 24-bit digital audio data,
Further, one word is composed of a total of 32 bits of 1-bit validity flag V, user-definable data U, channel status data C, and parity bit P. The validity flag V is a flag indicating whether or not the audio data has been subjected to interpolation and data pre-hold processing, and "H" indicates that those processings have been performed. The user definable data U is now supposed to carry a subcode. The channel status data C carries data such as channel information indicating 2 channels or 4 channels, copy inhibit information indicating whether copying is possible, and emphasis information indicating presence or absence of pre-emphasis. Parity bit P
It is a bit provided so that the number of "H" s in 1-word data is an even number. These data are bi-phase modulated.

Next, a fourth embodiment will be described with reference to FIGS. The fourth embodiment corresponds to the second embodiment, FIG. 15 corresponds to the encoder shown in FIG. 6, FIG. 16 corresponds to the signal processing circuit shown in FIG. 7, and FIG. Corresponds to the decoder shown. FIG.
5, as shown in FIG. 16, the copyright data supply unit 100 is also added in this embodiment, and the copyright data supplied from the copyright data supply unit 100 is the bit stream data string (xci, Δ1i, Δ2i). ) With the allocation circuit 40. Then, in the decoder, as shown in FIG. 17, the bit stream data string (xci, Δ1i, Δ2i) is output to the digital output terminal 52 together with the copyright data. Also, as shown by the broken line, LP
The digital data whose band is limited by F56 may be output to the digital output terminal 55 together with the copyright data.

In the third and fourth embodiments, the case where the copyright data is recorded in the sub-header or CMI area of the recording medium has been described, but it may be recorded in other areas such as the user channel. Good. That is, the copyright data is contained in a so-called navigation NV (in the case of DVD video) which is a packet (user channel) independent of these data strings and is arranged about every 0.4 to 1 second. In DVD audio, navigation NV is also called audio navigation ANV. That is, in the DVD video, as shown in FIG. 21A, the related data group video object VOBU
As shown in FIG. 21B, is composed of a plurality of sets of navigation NV, audio A, video V, V, V, V, and sub-picture SP user channels. Copyright data is stored in this NV packet. Also, DV
The D audio has an audio navigation ANV shown in FIG. 21C while maintaining compatibility with these, and stores copyright data therein. If necessary, a pack of P (picture) can be placed in addition to A (audio).

[0056]

As described above, according to the present invention, copying of digital data obtained by A / D converting an analog signal at a relatively low first sampling frequency is allowed, and copying of an analog signal at a relatively high second sampling frequency is performed. A / in frequency
Since the D-converted digital data is prohibited from being copied, both convenience for the user and protection of the copyright can be achieved.

Further, according to the present invention, digital data obtained by A / D converting an analog signal at a relatively high first sampling frequency is band-limited to a relatively low second sampling frequency to permit copying. Therefore, the convenience of the user and the protection of the copyright can be compatible.

Further, according to the present invention, when the bit stream copy is permitted, the copy is made only with the copyright data, so that the convenience for the user and the copyright protection can be made compatible.

[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 embodiment of FIG.

FIG. 2 is an explanatory diagram showing sampling periods and data strings of the two A / D converters in FIG.

FIG. 3 is an explanatory diagram showing user data packed by the packing encoder of FIG.

FIG. 4 is a first copy information copy protection method according to the present invention.
3 is a block diagram showing a decoder that realizes the embodiment of FIG.

5 is an explanatory diagram showing a data string decoded by the decoder of FIG. 4 and a sampling period.

FIG. 6 is the second copy protection method for coded information according to the present invention.
3 is a block diagram showing an encoder that realizes the embodiment of FIG.

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

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

FIG. 9 is the second copy protection method for code information according to the present invention.
3 is a block diagram showing a decoder that realizes the embodiment of FIG.

10 is a block diagram showing the signal processing circuit of FIG. 9 in detail.

FIG. 11 is an explanatory diagram showing a data string decoded by the decoder of FIG. 9 and a sampling period.

FIG. 12 is a block diagram showing an encoder of a third embodiment.

FIG. 13 is an explanatory diagram showing user data according to the third embodiment.

FIG. 14 is a block diagram showing a decoder of the third embodiment.

FIG. 15 is a block diagram showing an encoder of a fourth embodiment.

16 is a block diagram showing the signal processing circuit of FIG. 15 in detail.

FIG. 17 is a block diagram showing a decoder of the fourth exemplary embodiment.

FIG. 18 is a diagram schematically showing an example of packing user data.

FIG. 19: Digital audio interface
It is a figure which shows a format typically.

FIG. 20 is a diagram schematically showing a DVD format.

FIG. 21 is a schematic diagram showing a storage place of copyright data in a DVD video and a DVD audio.

[Explanation of symbols]

2 A / D converter (first A / D conversion means) 3 A / D converter (second A / D conversion means) 6 difference calculator (difference calculation means) 7 packing encoder (output means / packing means) 10 Unpacking decoder 11 Adder (constituting restoration means together with interpolation processing circuit 12, switch 13 and clock generator 14) 12 Interpolation processing circuit 13 Switch 14 Clock generator 15 D / A converter (first D / A conversion means) ) 16 D / A converter (second D / A conversion means) 17 analog output terminal (first analog signal output terminal) 18 analog output terminal (second analog signal output terminal) 20, 50 cryptanalysis section 21, 51 switch 22 digital output terminal (digital data output means) 23, 52, 53 digital output terminal 31 A / D converter Data (A / D conversion means) 32 Signal processing circuit 33 Memory 34 DVD encoding circuit 35 Modulation circuit 36, 56 Low pass filter (band limiting means) 37, 38 Thinning circuit 39 Adder (Differential calculation together with thinning circuits 37, 38 Means 40) allocation circuit (output means / packing means) 45 D / A converter (D / A conversion means) 46 adder (constitutes restoration means together with interpolation processing section 47) 47 interpolation processing circuit 55 analog signal output Terminal 100 Copyright data supply section (2-6), (31-33) Digital data generation means

Claims (28)

[Claims] 1. An analog signal is A / D converted at a relatively low first sampling frequency to generate a first digital data string, and an analog signal is second sampling frequency higher than the first sampling frequency. At A /
A step of D-converting to generate a second digital data string; a step of calculating each differential data string of the first and second data strings at the same sampling point; and a difference between the first data string and the difference Transmitting a data string through a medium; restoring the second data string based on the first data string and the difference data string; converting the first data string into an analog signal And outputting in the form of digital data, and the second data string is converted into an analog signal and then output. 2. A first A / D conversion means for A / D converting an analog signal at a relatively low first sampling frequency to generate a first digital data string; and an analog signal for the first sampling. Second A / D conversion means for A / D converting at a second sampling frequency higher than the frequency to generate a second digital data string, and each of the first and second data strings at the same sampling point An encoding device for code information, comprising: a difference calculating means for calculating a difference data string; and an output means for packing and outputting the first data string and the difference data string. 3. An analog signal is A / D converted at a relatively low first sampling frequency to generate a first digital data string, and the analog signal is converted at a second sampling frequency higher than the first sampling frequency. A / D
The first data string and the difference data generated by converting to generate a second digital data string and calculating each difference data string of the first and second data strings at the same sampling point. A decoding device of code information for decoding a column, comprising: a restoring unit that restores the second data sequence based on the first data sequence and the difference data sequence; A digital output terminal for outputting in a state, a first D / A conversion unit for D / A converting the first data string, and an analog signal D / A converted by the first D / A conversion unit. The first analog signal output terminal for outputting and the second data string restored by the restoring means are D / A
A second D / A conversion unit for converting and a second analog signal output terminal for outputting an analog signal D / A converted by the second D / A conversion unit are provided, and restored by the restoration unit. A decoding device for code information configured so as not to output the second data string in a digital data state. 4. The decoding device for code information according to claim 3, wherein when the copy permission condition is presented, the first data string and the difference data can be output in the state of digital data. . 5. An analog signal is A / D converted at a relatively low first sampling frequency to generate a first digital data string, and the analog signal is converted at a second sampling frequency higher than the first sampling frequency. A / D
The first data string and the difference data generated by converting to generate a second digital data string and calculating each difference data string of the first and second data strings at the same sampling point. A recording medium on which a row is recorded. 6. A step of subjecting an analog signal to A / D conversion at a relatively high first sampling frequency to generate a first digital data string; A second lower than the first sampling frequency
A step of generating a digital data sequence of the above, a step of calculating each differential data sequence of the first and second data sequences at the same sampling point, and a step of transmitting the second data sequence and the differential data sequence via a medium. Transmitting, restoring the first data sequence based on the second data sequence and the difference data sequence, converting the first data sequence into an analog signal and outputting the analog signal, and For the data string of No. 1, outputting only in the state of band-limited digital data, a code information copy protection method. 7. A / D conversion means for A / D converting an analog signal at a relatively high first sampling frequency to generate a first digital data string, and band limiting the first digital data string. A second sampling frequency lower than the first sampling frequency
Band limiting means for generating the digital data string of the above, difference calculating means for calculating each difference data string of the first and second data strings at the same sampling point, the second data string and the difference data string And an output unit for packing and outputting the code information. 8. An analog signal is A / D converted at a relatively high first sampling frequency to generate a first digital data string, and the first digital data string is band-limited to have a sampling frequency of the first sampling frequency. A second digital data string lower than a sampling frequency of 1 and calculating the respective difference data strings of the first and second data strings at the same sampling point; A decoding device of code information for decoding a differential data string, comprising: a restoring unit that restores the first data string based on the second data string and the differential data string; and the restoring unit restored by the restoring unit. The first data string is D
D / A conversion means for A / A conversion, an analog signal output terminal for outputting an analog signal D / A converted by the D / A conversion means, and a band for the first data string restored by the restoration means. Code information having a band limiting unit for limiting and a digital signal output terminal for outputting the output of the band limiting unit in the state of digital data, and the output of the restoring unit is not output as it is in the state of digital data. Decoding device. 9. The decoding device for code information according to claim 8, wherein the second data string and the difference data can be output in the state of digital data when a copy permission condition is presented. 10. An analog signal is A / D converted at a relatively high first sampling frequency to generate a first digital data string, and the first digital data string is band-limited so that the sampling frequency is the first frequency. A second digital data string lower than a sampling frequency of 1 and calculating the respective difference data strings of the first and second data strings at the same sampling point; A recording medium on which a differential data string is recorded. 11. A step of A / D converting an analog signal to generate a digital data sequence, a step of transmitting copyright data relating to the digital data sequence and the analog signal via a medium, and via the medium. Outputting the transmitted digital data string only together with the copyright data. 12. Digital data generating means for A / D converting an analog signal to generate a digital data string, and packing for packing the digital data string generated by the digital data generating means and the copyright data relating to the analog signal. Means for encoding code information. 13. A recording medium in which a digital data string generated by A / D converting an analog signal and copyright data regarding the analog signal are recorded. 14. A decoding device for code information, which decodes a digital data string generated by A / D converting an analog signal and copyright data relating to the analog signal, wherein the digital data string together with the copyright data. A decoding device for code information, comprising a digital data output means for outputting, and configured so that the digital data string is not output without being accompanied by the copyright data. 15. An analog signal is A / D converted at a relatively low first sampling frequency to generate a first digital data string, and the analog signal is converted to a second sampling frequency higher than the first sampling frequency. And then A
A step of performing D / D conversion to generate a second digital data string; a step of calculating each differential data string of the first and second data strings at the same sampling point; and the first data string, Transmitting the differential data sequence and copyright data related to the analog signal via a medium; restoring the second data sequence based on the first data sequence and the differential data sequence; The first data string is converted into an analog signal and output, and is output in a digital data state, and the second data string is converted into an analog signal only and output. And outputting the differential data string only together with the copyright data. 16. A first A / D conversion means for A / D converting an analog signal at a relatively low first sampling frequency to generate a first digital data string; and an analog signal for the first sampling. Second A / D conversion means for A / D converting at a second sampling frequency higher than the frequency to generate a second digital data string, and each of the first and second data strings at the same sampling point An encoding device for code information, comprising: a difference calculating means for calculating a difference data sequence; the first data sequence; and an output means for packing and outputting the difference data sequence and copyright data concerning the analog signal. 17. An analog signal is A / D converted at a relatively low first sampling frequency to generate a first digital data string, and the analog signal is converted at a second sampling frequency higher than the first sampling frequency. A /
The first data string generated by D-converting to generate a second digital data string, and calculating each differential data string of the first and second data strings at the same sampling point; A decoding device of code information for decoding copyright data relating to a differential data sequence and the analog signal, wherein the restoring means restores the second data sequence based on the first data sequence and the differential data sequence, A digital output terminal for outputting the first data string in the state of digital data; a first D / A conversion unit for D / A converting the first data string; and a first D / A conversion unit. A first analog signal output terminal for outputting an analog signal D / A converted by the D / A converter and a second data string restored by the restoring means.
Second D / A converting means for converting; a second analog signal output terminal for outputting an analog signal D / A converted by the second D / A converting means; the first data string; A code information decoding device, comprising: a digital output terminal that outputs a differential data string together with the copyright data, and is configured not to output the first data string and the differential data string without the copyright data. 18. When a copy permission condition is presented,
18. The code information decoding apparatus according to claim 17, wherein the first data string and the difference data can be output together with the copyright data in a digital data state. 19. An analog signal is A / D converted at a relatively low first sampling frequency to generate a first digital data string, and the analog signal is converted at a second sampling frequency higher than the first sampling frequency. A /
The first data string generated by D-converting to generate a second digital data string, and calculating each differential data string of the first and second data strings at the same sampling point; A recording medium on which a differential data string and copyright data regarding the analog signal are recorded. 20. A / D converting an analog signal at a relatively high first sampling frequency to generate a first digital data string, and limiting the band of the first digital data string to a sampling frequency. A second lower than the first sampling frequency
The step of generating a digital data sequence of, the step of calculating each differential data sequence of the first and second data sequences at the same sampling point, and the second data sequence and the differential data sequence related to the analog signal. Transmitting through a medium together with copyright data, restoring the first data string based on the second data string and the difference data string, converting the first data string into an analog signal And outputting the first data string only in the state of band-limited digital data, and further outputting the second data string and the difference data string only together with the copyright data. And a copy protection method of code information. 21. A / D conversion means for A / D converting an analog signal at a relatively high first sampling frequency to generate a first digital data string, and band limiting the first digital data string. A second sampling frequency lower than the first sampling frequency
Band limiting means for generating a digital data string of, a difference calculating means for calculating each difference data string of the first and second data strings at the same sampling point, the second data string, and the difference data An encoding device for code information, comprising a column and an output means for packing and outputting copyright data relating to the analog signal. 22. An analog signal is A / D converted at a relatively high first sampling frequency to generate a first digital data string, and the first digital data string is band-limited to have a sampling frequency of the first sampling frequency. A second digital data string lower than a sampling frequency of 1 and calculating the respective differential data strings of the first and second data strings at the same sampling point; A decoding device for code information, which decodes copyright data relating to the differential data sequence and the analog signal, and restoring means for restoring the first data sequence based on the second data sequence and the differential data sequence. , D is the first data string restored by the restoring means
D / A conversion means for A / A conversion, an analog signal output terminal for outputting an analog signal D / A converted by the D / A conversion means, and a band for the first data string restored by the restoration means. Band limiting means for limiting, a digital signal output terminal for outputting the output of the band limiting means in a digital data state, and a digital signal output terminal for outputting the second data string and the difference data string together with the copyright data. And a decoding device for code information configured such that the second data string and the difference data string are not output without being accompanied by the copyright data. 23. When a copy permission condition is presented,
23. The decoding device for code information according to claim 22, wherein the second data string and the difference data can be output together with the copyright data in a digital data state. 24. An analog signal is A / D converted at a relatively high first sampling frequency to generate a first digital data string, and the first digital data string is band-limited so that the sampling frequency is the first sampling frequency. A second digital data string lower than a sampling frequency of 1 and calculating the respective differential data strings of the first and second data strings at the same sampling point; A recording medium on which the differential data string and copyright data regarding the analog signal are recorded. 25. The copyright data is recorded in a user channel or a subheader.
A method of preventing code information copy according to 1, 15, or 20. 26. The copyright data is recorded in a user channel or a subheader.
An encoding device for code information according to 2, 16 or 21. 27. The copyright data is recorded in a user channel or a subheader.
The recording medium according to 3, 19 or 24. 28. The copyright data is output to a subcode.
Alternatively, the decoding device of the code information described in 23.