JPH10312636A - Signal processing device, signal processing method and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an audio signal from being illegally copied. SOLUTION: A digital audio signal in a prescribed block unit supplied via a segmentation part 12 is fast-Fourier-transformed by an FFT(fast Fourier transform) part 13, and a resultingly obtained frequency spectrum is supplied to a spectrum operating part 14. When the frequency spectrum is received from the FFT part 13 by the spectrum operating part 14, copyright information is comprised in its one spectrum component or more, and is outputted to an IFFT(inverted fast Fourier transform) part 15. In this IFFT part 15, the frequency spectrum from the spectrum operating part 14 is inverted-fast-Fourier- transformed in the same block unit as in the case of the FFT, thus outputting the audio signal with the copyright information buried in one spectrum component or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal processing apparatus, a signal processing method, and a recording medium, and more particularly to, for example, preventing unauthorized copying of an audio signal recorded on a CD (Compact Disc) or the like. The present invention relates to a signal processing device, a signal processing method, and a recording medium that enable the processing.

[0002]

2. Description of the Related Art For example, a CD-ROM (Read Only), which is often used recently as an external peripheral device of a computer, is used.
In a memory drive or the like, an audio signal recorded on a CD or the like can be read out as a digital signal, and the digital audio signal thus read out is recorded (copied) on a hard disk or the like built in a computer. It is possible. If the computer has a digital audio board as an input interface for digital audio signals, for example, or if the computer is equipped with such a board, a CD player is used instead of a CD-ROM drive. And reproduce the digital audio signal output from its digital output terminal.
The data can be recorded on a hard disk built in the computer via the digital audio board.

On the other hand, recently, DAT (Digital Audio
Devices that can record digital audio signals as digital signals, such as tape (Tape) devices and CD-R (Recordable) drives, are becoming widespread.

[0004]

Therefore, for example, FIG.
As shown in 0, the correct CD1
01 (pirate board creator) can easily create a so-called pirate CD-R 105 having the same (almost the same) sound quality as the audio signal recorded therein.

That is, the CD 101 is reproduced by the CD-ROM drive 102, the digital audio signal obtained by the reproduction is stored in the hard disk built in the computer 103, and the CD-R drive 104 records it on the CD-R 105. By that, CD101
You can make a copy of

[0006] However, producing the CD-R 105 as a copy of the CD 101 without the permission of the copyright owner is undesirable because the interests of the copyright owner are harmed. Also, C
Since the recording of the audio signal in the D-R 105 is performed as a digital signal, there is basically no deterioration in sound quality.
Therefore, a pirate disc without sound quality deterioration can be produced based on the CD-R 105 in the same manner as in the case of FIG. 20, and the pirate disc is further produced from the pirate disc in this manner. The interests of the right holders are harmed, which is undesirable.

By the way, for example, a CD (Compact Disc)
, Sub-codes and the like are recorded in addition to digital audio signals. Subcodes include ISO 3901, JIS X
ISRC (International Stand
ard Recording Code) is recorded. The ISRC includes a country code representing a country, a company code representing a company, the date of recording, a recording number as a unique number relating to recording, and the like.

In order to prevent a pirated board from being produced, a method of including a flag in the ISRC as to whether or not copying is permitted and restricting copying by the flag is conceivable. However, in the CD-ROM drive, only the audio signal can be read from the CD, and therefore, the ISRC is not always read. Further, even if the ISRC is read, the falsification is relatively easy. Therefore, even if a flag indicating that copying is not permitted is recorded, the flag is falsified so that copying without deterioration in sound quality is performed. Is expected to be fraudulently produced.

In addition, a flag indicating whether or not to permit copying is set, for example, as an LSB (Least Significant Bibit) as a bit in the audio signal that does not significantly affect sound quality.
Although a method of arranging the audio signal in t) or the like is conceivable, it is easy to extract the LSB of the audio signal, and therefore, the alteration can be performed relatively easily.

[0010] The present invention has been made in view of such a situation, and it is an object of the present invention to prevent unauthorized copying of an audio signal.

[0011]

According to a first aspect of the present invention, there is provided a signal processing apparatus for performing a process of causing at least one of discrete spectrum components of an audio signal to include copyright information relating to the copyright of the audio signal. It is characterized by comprising means.

A signal processing method according to claim 18 is characterized in that one or more discrete spectral components of an audio signal include copyright information on the copyright of the audio signal.

A recording medium according to a nineteenth aspect is characterized in that one or more of the discrete spectral components of an audio signal include copyright information on the copyright of the audio signal.

According to a twentieth aspect of the present invention, there is provided the signal processing device further comprising a detecting unit for detecting copyright information on a copyright of the audio signal, which is included in one or more discrete spectral components of the audio signal. Features.

A signal processing method according to claim 27 is characterized in that copyright information relating to the copyright of the audio signal, which is included in one or more of the discrete spectral components of the audio signal, is detected.

In the signal processing device according to the first aspect, the processing means performs a process of including, in one or more of the discrete spectral components of the audio signal, copyright information on the copyright of the audio signal. It has been done.

In the signal processing method according to the present invention, copyright information on the copyright of the audio signal is included in one or more of the discrete spectral components of the audio signal.

In the recording medium according to the nineteenth aspect,
At least one of the discrete spectral components of the audio signal recorded therein contains copyright information on the copyright of the audio signal.

According to a twentieth aspect of the present invention, the detecting means detects copyright information on the copyright of the audio signal, which is included in one or more of the discrete spectral components of the audio signal. Has been made.

In the signal processing method according to the present invention, copyright information on the copyright of the audio signal, which is included in one or more of the discrete spectral components of the audio signal, is detected. .

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below, but before that, the correspondence between each means of the invention described in the claims and the following embodiments will be clarified. For this reason, the features of the present invention are described as follows by adding the corresponding embodiment (however, an example) in parentheses after each means.

That is, the signal processing device according to claim 1 is
A signal processing device for processing an audio signal, the processing unit performing a process of including, in one or more of the discrete spectral components of the audio signal, copyright information relating to the copyright of the audio signal (for example, as illustrated in FIG. 2). An FFT (Fast Fourier Transform) unit 13, a spectrum operation unit 14, an IFFT (Inverse Fast Fourier Transform unit) 15, and the like are provided.

According to a ninth aspect of the present invention, in the signal processing apparatus, the processing means analyzes the frequency of the audio signal and obtains a discrete spectrum component thereof (for example, an FFT unit 13 shown in FIG. 2). A change unit (for example, the spectrum operation unit 14 shown in FIG. 2) that changes one or more of the spectral components output by the frequency analysis unit to a value corresponding to the copyright information; , A conversion means for converting to a signal on the time axis (for example,
(Such as the IFFT unit 15 shown in FIG. 2).

The signal processing apparatus according to the present invention further includes a determination unit (for example, a start position determination unit 11 shown in FIG. 2) for determining a start point at which the frequency analysis unit starts frequency analysis of the audio signal. The frequency analysis means starts frequency analysis of the audio signal from the starting point determined by the determination means.

A signal processing device according to a twentieth aspect is a signal processing device for processing an audio signal, and relates to a copyright of the audio signal, which is included in at least one of discrete spectral components of the audio signal. It is characterized by including detection means for detecting copyright information (for example, a copyright signal detection unit 55 shown in FIG. 16, a maximum value detection unit 61 and a nearby spectrum value comparison unit 62 shown in FIG. 17).

The signal processing device according to claim 21 further includes a judging unit (for example, a fraud check unit 64 shown in FIG. 17) for judging whether the copyright information detected by the detecting unit has been falsified. It is characterized by the following.

A signal processing apparatus according to a twenty-fifth aspect of the present invention provides a frequency analysis means (for example, an FF shown in FIG. 16) for analyzing the frequency of an audio signal and obtaining its discrete spectral components.
T section 53), wherein the detecting means detects copyright information included in one or more spectral components of the audio signal output by the frequency analyzing means.

The signal processing apparatus according to the twenty-sixth aspect further includes determining means (for example, a start position determining unit 51 shown in FIG. 16) for determining a starting point at which the frequency analyzing means starts frequency analysis of the audio signal. The frequency analysis means starts frequency analysis of the audio signal from the starting point determined by the determination means.

Of course, this description does not mean that each means is limited to those described above.

Next, an outline of the present invention will be described with reference to FIG.

The author of an authorized CD, for example, decides whether to permit copying of an audio signal together with the audio signal, the copyright holder of the audio signal, and the ISRC.
Thus, a CD 1 is produced in which information about the copyright of the audio signal, such as information indicating the source of the audio signal (hereinafter referred to as copyright information or copyright signal as appropriate) is recorded.

Here, if the audio signal and the copyright information are separately recorded, it is difficult to prohibit copying when only the audio signal is read out, as described above. Therefore, the copyright information is recorded at least in a form embedded in the audio signal.

Production of a CD is performed through editing and mastering of an audio signal. Embedding of copyright information in an audio signal is performed in the final step of mastering. This is because, for example, if the copyright information is embedded before the editing of the audio signal is completed, the copyright information is also edited by the subsequent editing of the audio signal (accordingly, the copyright information is destroyed). Be done)
Because.

The pirate creator who has obtained the CD 1 produced as described above has a CD-ROM drive 2
Then, the CD 1 is reproduced, and the digital audio signal obtained thereby is stored in the hard disk built in the computer 3. Then, the audio signal is transferred to CD-R drive 4 connected to computer 3 (however, CD-R drive 4 may be connected to a computer other than computer 3).
At this time, the CD-R drive 4 detects the copyright information embedded in the audio signal. Then, for example, when the copyright information prohibits copying of the audio signal, or when the copyright information is removed, the CD-R drive 4 converts the audio signal into, for example, a CD-R. Not recorded in R5.

Alternatively, the CD-ROM drive 2
At the time of reading the audio signal recorded on the CD1, the copyright information embedded in the audio signal is detected. For example, when the copyright information prohibits copying of the audio signal or when the copyright information is removed, the CD
-In the ROM drive 2, reading of the audio signal is stopped, for example.

Therefore, in this case, illegal production of CD-R5 as a copy of CD1 can be prevented.

By the way, if the copyright information prohibits the copying of the audio signal, the falsification is performed. For example, when the copyright information is changed to the one permitting the copying of the audio signal, the CD as a pirated board is changed. -The production of R5 cannot be prevented.

That is, for example, if the copyright information is detected in the CD-R drive 4 instead of the CD-ROM drive 2, the audio signal can be stored in the computer 3. On the computer,
Many softwares for editing images and sounds and for applying effects are sold. According to such software, the computer 3 can change the amplitude of an audio signal or a part thereof. It is possible to perform editing processing such as taking out an audio signal and effect processing such as applying an echo to an audio signal. In this case, since the copyright information is included in the audio signal, the fact that the audio signal can be edited and the like means that the copyright information can be edited and the like. The information can be falsified.

On the other hand, the copyright information must be easily detectable in the CD-ROM drive 2, the CD-R drive 4, and the like. Therefore,
The embedding of the audio signal in the copyright information needs to be performed so as to satisfy the two conditions that the copyright information can be easily detected and that the copyright information is difficult to falsify.

However, if the copyright information can be easily detected, the falsification can be easily performed.
It is difficult to satisfy the above two conditions.

By the way, in order to restrict the production of pirated boards, it is only necessary to be able to prohibit copying the audio signal recorded on CD1 as it is. Therefore,
When the copyright information is tampered with, the audio signal in which the copyright information is embedded is also deformed by the tampering. For example, the sound quality is degraded, thereby substantially preventing the copying of the audio signal. be able to. That is,
Pirates with such degraded audio signals are of low value and have no buyers (if at all,
It is expected that the production of pirated boards can be prevented.

Therefore, the creator of the CD1 embeds the copyright information in such a manner that it is included in one or more discrete spectral components of the audio signal.

FIG. 2 shows an example of the configuration of an embodiment of a signal processing device for generating an audio signal containing copyright information as described above.

The audio signal is supplied to the start position determining unit 1
1 and the segmentation unit 12. The start position determination unit 11 determines a start point at which the segmentation unit 12 starts cutting out the audio signal based on the audio signal supplied thereto, and supplies the start point to the segmentation unit 12. The segmentation unit 12 cuts out the audio signal supplied thereto for each predetermined time length, and supplies the audio signal for each predetermined time length (hereinafter, appropriately referred to as a block) to the FFT unit 13. ing. Note that the segmentation unit 12
In, the cutout of the audio signal is started from the start point specified by the output of the start position determination unit 11.

[0045] The FFT unit 13 includes the segmentation unit 1
The audio signal supplied from 2 is block-by-block
For example, frequency analysis is performed by performing FFT, and a discrete frequency spectrum (a signal (frequency component) on the frequency axis) obtained as a result is supplied to the spectrum operation unit 14. The spectrum operation unit 14 uses the FFT
An operation for including copyright information in one or more components of the frequency spectrum from the unit 13 is performed, and the operation is supplied to the IFFT unit 15. Note that, in the present embodiment, the predetermined threshold values pwr _th and pw
r _{th2 is} also supplied, and the operation of including the copyright information is performed only for blocks satisfying a predetermined condition using these thresholds pwr _th and pwr _th2 .

In the IFFT unit 15, the spectrum operation unit 1
4 is converted into a signal on the time axis by, for example, inverse FFT, and the signal, that is, an audio signal in which copyright information is embedded in one or more spectral components is output. I have.

Next, the operation will be described.

For example, a digital audio signal sampled at 44.1 kHz is supplied to a start position determining unit 11 and a segmentation unit 12.
In the start position determining unit 11, based on the audio signal supplied thereto, a start point at which the segmentation unit 12 starts to cut out the audio signal (the cut-out audio signal is subjected to FFT by the FFT unit 13; Is also the point at which the FFT is started) and is supplied to the segmentation unit 12. The segmentation unit 12 receives the start point from the start position determination unit 11, and starts cutting out the audio signal in block units from the start point. The audio signal cut out in block units is supplied to the FFT unit 13. In the FFT unit 13, the segmentation unit 1
2. The block-based audio signal from 2 is FFT,
The resulting frequency spectrum is supplied to the spectrum operation unit 14.

Here, the result of the FFT as the frequency analysis in the FFT unit 13 differs depending on which range of the audio signal is subjected to the FFT. That is,
For example, when the audio signal shown in FIG. 3A is subjected to FFT in a range indicated by b or c in FIG.
A spectrum as shown in FIG. In FIG. 3, the sampling frequency of the audio signal is 44.1 kHz, and the range (block) of the FFT is 1024 samples (1010 in terms of time).
24 × 1 / (44.1 × 10 ³ ) seconds). FIG.
(B) and FIG. 3 (C) show the FFT results in which the other conditions are the same except that the section of the audio signal to be subjected to the FFT is shifted by 88 samples (about 2 milliseconds). The two are clearly different.

As described above, since the copyright information is embedded in one or more components of the frequency spectrum, in order to accurately detect the copyright information, the point at which the FFT of the audio signal is started, that is, the audio information in block units, The starting point for starting signal extraction needs to be strictly determined.
Therefore, the start position determination unit 11 determines a sample point of an audio signal that satisfies a predetermined condition as a start point.

That is, in the start position determining unit 11, for example, after the input of the audio signal is started, the absolute value of the amplitude is set to a sample point where the absolute value is a value other than 0 or a positive value equal to or more than a predetermined threshold. A sample point or the like is determined as a starting point. When the sample point at which the absolute value of the amplitude is equal to or more than the predetermined positive threshold value is set as the start point, the position of the start point does not easily change even if the copyright information is falsified.

Since the FFT performed in the subsequent FFT section 13 generally targets sample points of the number of powers of two, the length of the audio signal cutout unit (block length) in the segmentation section 12 is assumed. ) Is preferably a power of two.

Further, here, the FFT unit 13 performs the FFT, which is a fast algorithm of the Fourier transform, so as to perform the frequency analysis of the audio signal. (Discrete cosine transform) It can be performed by other orthogonal transform. However, at least it is necessary that the audio signal can be inversely converted into the original audio signal.

Normally, when frequency analysis such as FFT is performed, portions of both ends of an audio signal cut out for each block are reduced in order to reduce the influence of sudden changes at both ends. A window function such as a Hamming window or Hanning window to be attenuated is multiplied.
After the copyright information is embedded in the frequency spectrum in the spectrum operation unit 14, the IFFT unit 15
The frequency spectrum of the original audio signal (however,
(Because copyright information is embedded in the frequency spectrum, it is not strictly the original audio signal.)
Analysis using frequency analysis results (for example, parameter extraction for speech recognition or speaker recognition)
It doesn't mean that. Therefore, it does not matter that the above-mentioned effects appear in the frequency spectrum, and there is no need to perform multiplication by a Hanning window or the like.

It is also possible to perform FFT after multiplying a block by a window function such as a Hanning window. In this case, when the IFFT unit 15 converts the frequency spectrum into an audio signal, The effect of the window function remains in the signal, and in order to reduce the effect, it is necessary to cut out the audio signal in the segmentation unit 12 while shifting it by half the block length. That is, when the window function is not applied,
It is sufficient to cut out the audio signal while shifting it by the block length, but when applying a window function, it is necessary to cut out the audio signal by shifting it by half the block length in order to reduce the effect. . Therefore, when a window function is applied, the number of blocks output by the segmentation unit 12 is twice as large as when no window function is applied, and the number of times of the FFT processing in the FFT unit 13 is also doubled. Therefore, it is desirable not to apply a window function since the processing amount increases.

Here, when the audio signal shown in FIG. 4 is subjected to FFT without applying a window function, that is, an audio signal obtained by applying a rectangular window, which corresponds to clipping in block units, while shifting by a block length. To F
If the FT is performed, the FFT is performed on the audio signal clipped while shifting the Hanning window by the block length, or the FFT is performed on the clipped audio signal while shifting the Hanning window by half the block length. The resulting waveform is shown in FIG. 5, FIG. 6, or FIG.

That is, the FFT of the audio signal cut out by applying only a rectangular window as shown in FIG.
When the result is subjected to IFFT, an audio signal shown in FIG. In this case, almost the original audio signal is restored.

The FFT result of the audio signal cut out by applying a rectangular window as shown in FIG. 5A and further applying a Hanning window as shown in FIG.
When FT is performed, an audio signal shown in FIG. In this case, a signal in which the original audio signal changes according to the shape of the Hanning window is restored.

A rectangular window as shown in FIG. 5A is shifted while being shifted by half its length, and similarly, as shown in FIG. 7A, a Hanning window is also shifted by half its length. When the FFT result of the audio signal cut out by applying the IFFT is IFFT, FIG.
An audio signal as shown in FIG. In this case, as in the case of FIG. 5, almost the original audio signal is restored.

Referring back to FIG. 2, the spectrum operation unit 14
When the frequency spectrum is received from the FT unit 13, the copyright information is included in one or more of the spectrum components.

Here, when the frequency spectrum is changed,
The phase may change, resulting in a deterioration in sound quality.
Therefore, it is desirable to change the frequency spectrum within the minimum necessary range so that deterioration of sound quality can be minimized. Therefore, here, the copyright information is embedded by setting a certain spectral component to 0.

FIG. 8 shows an example of the configuration of the spectrum operation unit 14.

The frequency spectrum from the FFT unit 13 is
The power is supplied to the power calculation unit 21 and the spectrum change unit 23. The power calculator 21 calculates a power spectrum from the frequency spectrum. That is, the frequency spectrum sp (i) (i
Is a complex number that represents a sample point of the FFT result, and the real part or the imaginary part is represented by Re (sp (i)) or Im (s), respectively.
p (i)), the power spectrum pwr (i)
Is obtained by calculating the following equation.

Pwr (i) = ((Re (sp (i))) ² + (Im (sp (i))) ² ) ^1/2

The power spectrum obtained by the power calculation unit 21
The vector pwr (i) is supplied to the maximum value detection unit 22.
You. The maximum value detection unit 22 has a power spec for one block.
When receiving the torque pwr (i), in the block,
Sample point i with maximum power_{ma x}Is detected. And
The maximum value detection unit 22 calculates the sampling point i_maxAlong with
Sample point i_max, The power of one block
Maximum value pwr in power spectrum_maxThe spect
To the file change unit 23.

The spectrum changing unit 23 includes a frequency spectrum, a sample point i _max and a maximum value p of the power.
In addition to wr _max , thresholds pwr _th and pwr _th2 are also supplied. Then, the spectrum changing unit 23
Then, one of the frequency spectra satisfying a predetermined condition
The copyright information is embedded by setting the above spectral components to, for example, 0.

Here, in the spectrum changing section 23, in order to reduce deterioration of sound quality due to embedding of copyright information, for example, a spectrum component masked by a masking effect is set to 0.

That is, for example, the spectrum changing unit 23
The maximum value of the power (hereinafter referred to as maximum power as appropriate) pw
It is determined whether or not r _max is equal to or greater than a predetermined threshold value pwr _th . The maximum power pwr _max is, when a predetermined threshold pwr _th or more, the spectrum changing unit 23, the power at the sample point i _max +1 frequency spectrum, maximum power pwr _max from the predetermined threshold pwr _th2 (<
pwr _th ) is determined to be less than or equal to the subtracted value,
The power at the sample point i _max +1 is the maximum power p
When it is equal to or less than a value obtained by subtracting a predetermined threshold value pwr _th2 from wr _max , that is, the maximum power pwr _max and the sample point i _max
When the power difference from +1 is equal to or greater than a predetermined threshold value pwr _th2 , the frequency spectrum at the sample point i _max +1 is set to 0.

Here, FIG. 9 shows the waveform of the audio signal before performing the above-mentioned spectrum operation (FIG. 9A).
And its power spectrum (FIG. 2B). FIG. 10 shows the audio signal of FIG.
The waveform after performing the above-described spectrum operation (FIG. 10)
(A)) and its power spectrum (FIG. 10 (B)). Further, FIG. 11 shows a subtraction result obtained by subtracting the power spectrum after the spectrum operation (FIG. 10B) from the power spectrum before the spectrum operation (FIG. 9B).

In the above case, the operation of setting the frequency spectrum at the sample point i _max +1 to 0 is performed when the maximum power pwr _max is equal to or greater than the predetermined threshold value pwr _th and the maximum power pwr _max and the sample point i _max
Difference in power between +1, but to perform when the predetermined threshold pwr _th2 or more, the addition, the maximum power pwr _max
Is only equal to or greater than the predetermined threshold value pwr _th, or the difference between the power between the maximum power pwr _max and the sample point i _max +1 is only equal to or greater than the predetermined threshold value pwr _th2. Also, the operation of setting the frequency spectrum at the sample point i _max +1 to 0 can be performed.

Further, in the above case, FIG.
As shown in (A), the frequency spectrum at the sample point i _max +1 (the sample point with the higher frequency) on the right of the sample point i _max with the maximum power pwr _max was changed to copyright information. In addition, for example, FIG.
(B), the it is possible to target the frequency spectrum at the sample point i _max to the left of the sample points i _max -1 (sample points lower frequency). Further, as shown respectively in FIG. (C) or (D), maximum power pwr _max sample points i _max of the right or left side of the predetermined range w (eg, i _{ma x} +1 through i _max +10 or i _max, It is also possible to cover any one or more frequency spectra at sample points in the range (eg, −10 to i _max −1). Furthermore, it is also possible to target a frequency spectrum having the minimum or maximum power at a sample point in such a range w.

That is, any frequency component that can provide a sufficient masking effect in order to reduce the deterioration of sound quality may be changed to copyright information.

Here, paying attention to the frequency, a sound having a frequency closer to the frequency of the masking sound (here, the sound having the frequency corresponding to the sample point i _max ) is more likely to be masked. Further, a sound having a higher frequency than the frequency of the masking sound is more easily masked than a sound having a lower frequency. Further, a masking sound of a certain frequency is involved in a masking effect of a sound of a predetermined frequency band centered on the frequency, and has little effect on a masking of a sound of a frequency other than the frequency band.

Looking further at the power, the greater the power of the masking sound is relative to the power of the sound to be masked, the greater the masking effect.

As the frequency component to be changed to the copyright information, it is desirable to select a frequency component which is sufficiently masked in order to reduce the deterioration of the sound quality in consideration of the above-described nature of the masking effect. . Further, it is desirable to set the above-mentioned thresholds pwr _th and pwr _th2 from such a viewpoint.

However, if the deterioration of the sound quality is not a problem, any frequency component can be changed to the copyright information. That is, for example, a frequency component that is separated from the sample point i _max by a predetermined number of samples, a frequency component that is equal to or more than a predetermined value, and a frequency component whose difference from the maximum power is equal to or less than a predetermined value can be changed to copyright information. It is.

The frequency spectrum in which the copyright information is embedded by setting the predetermined frequency component to 0 is supplied from the spectrum operation unit 14 to the IFFT unit 15. IF
In the FT unit 15, the frequency spectrum from the spectrum operation unit 14 is inversely FFTed in the same block unit as in the case of the FFT performed by the FFT unit 13, whereby the audio information in which the copyright information is embedded in one or more of the spectral components is obtained. A signal is output. The audio signal thus obtained is recorded on the CD 1 of FIG.

According to the above processing, the number of blocks having a frequency spectrum of 0 depends on the audio signal to be processed, but is generally expected to be about several thousand.

That is, in the above case, the operation of setting the frequency spectrum at the sample point i _max +1 to 0 is performed by setting the maximum power pwr _{max to} be equal to or greater than the predetermined threshold value pwr _th and the maximum power pwr _max and the sample point i _max
Difference in power between +1, since to carry out when more than a predetermined threshold value pwr _th2, the number of blocks in which the frequency spectrum at the sample point i _max +1 is 0 is basically the subject of processing audio It depends on the signal.

On the other hand, the number of blocks whose frequency spectrum at sample point i _max +1 is 0 may be desired to be a predetermined number N regardless of the audio signal.

FIG. 13 shows a configuration example of a second embodiment of a signal processing device for generating an audio signal containing copyright information. In the figure, portions corresponding to those in FIG. 2 are denoted by the same reference numerals, and a description thereof will be omitted as appropriate below. That is, this signal processing device is basically configured in the same manner as in FIG. 2 except that switches 31 and 32, a power calculation unit 33, and a sorting unit 34 are newly provided.

In this signal processing device, the FFT of the audio signal is performed twice, and the switch 31 is turned on when the first FFT is performed, and turned on when the second FFT is performed. It has been made to be off. The switch 32 selects the terminal “a” when the first FFT is performed, and thereby the FFT unit 1
3 is supplied to the power calculator 33. Also, the switch 32 selects the terminal b when the second FFT is performed, and thereby the FFT unit 13
Is supplied to the spectrum operation unit 14. The power calculation unit 33 obtains a power spectrum from the block-unit frequency spectrum supplied from the FFT unit 32 via the switch 32 in the same manner as in the power calculation unit 21 in FIG.
_max is supplied to the sorting unit 34.
The sorting unit 34 calculates the maximum value of the power for all the blocks of the audio signal to be processed by the power calculating unit 33.
, The N-th largest value pwr from the
_N is selected and supplied to the spectrum operation unit 14 as the threshold value pwr _th described above.

Next, the operation will be described with reference to the flowchart of FIG.

The signal processing apparatus shown in FIG. 13 is roughly divided into steps S1 and S1 as first-pass processing for detecting the Nth largest signal from the maximum frequency component (maximum power) of an audio signal in block units. To S5 and the second pass processing for setting the frequency spectrum of the sample point i _max +1 from the block having the largest maximum frequency component to the block having the N-th largest frequency component to be 0. Step S6 as
The processing from S9 to S9 is performed.

That is, first, the switch 31 is turned on and the switch 32 is switched to the terminal a. Thereby, the audio signal to be processed is supplied to the start position determination unit 11 and the segmentation unit 12. Upon receiving the audio signal, the start position determining unit 11 determines a start point (start position) as described above in step S1, and outputs the start point (start position) to the segmentation unit 12. Segmentation unit 1
2, in step S2, the start position determining unit 1
The audio signal from the start point supplied from 1 is cut out in block units, and the process proceeds to step S3.
In step S3, the FFT unit 13 performs FFT on the audio signal in block units from the segmentation unit 12, and obtains a frequency spectrum. In this case,
Since the switch 32 selects the terminal a, the FFT unit 1
The frequency spectrum in block units output by 3 is supplied to the power calculation unit 33 via the switch 32.

In step S4, the power calculator 33 calculates a power spectrum from the frequency spectrum of each block, and detects the maximum frequency component in each block. This detection result is supplied to the sorting unit 34. In step S5, the sorting unit 34 sorts the largest frequency component in each block from the power calculation unit 33, for example, in ascending order. further,
The sorting unit 34 detects the N-th of the sorting result, that is, the N-th largest pwr _N among the largest frequency components in each block, and supplies it to the spectrum operation unit 14 as a threshold value pwr _th. You.

After that, the switch 31 is turned off and the switch 32 is switched so as to select the terminal b, and the supply of the audio signal is started again. In this case, since the switch 31 is off,
The audio signal is not supplied to the start position determination unit 11, but is supplied only to the segmentation unit 12. The segmentation unit 12 is determined in step S1,
The start point supplied from the start position determination unit 11 is stored. In step S6, the audio signal from the start point is cut out in units of blocks, as in step S2. Output.

The FFT unit 13 determines in step S7
As in the case of step S3, the audio signal of the block unit from the
And outputs it as a frequency spectrum. In this case, since the switch 32 selects the terminal b, the FFT unit 13
Are output to the spectrum operation unit 14 via the switch 32.

In step S8, as described above, the spectrum operation unit 14 sends the switch 3
2. Manipulate the block-wise frequency spectrum supplied via block 2. However, in this case, the spectrum operation unit 14
Is an operation of the frequency spectrum to zero at the sample point i _max +1, maximum power pwr _max is, sorting section 3
This is performed for all blocks that are equal to or larger than the threshold value pwr _th supplied from No. 4. As described above, the sorting unit 34
Largest of frequency components, because it is the power of the larger to the N-th spectrum of the operation in the spectrum operation unit 14, the largest maximum frequency component in but threshold pwr _th outputs, each block cut out from the audio signal To the block having the N-th largest frequency component.

The block processed by the spectrum operation unit 14 is supplied to the IFFT unit 15 and the IFFT unit 1
In step S9, an inverse FFT is performed on the block in step S9, whereby an audio signal including N blocks in which the copyright information is embedded in the spectral component is output. finish.

As described above, according to the signal processing device of FIG. 13, the number of blocks in which copyright information is embedded can be a predetermined number N irrespective of an audio signal.

In this case, since the audio signal is cut out and the FFT is performed twice, the processing becomes somewhat complicated and it is difficult to perform the processing in real time. If the FFT result in the first pass processing is stored, the audio signal is cut out and FFT is performed only once, but in this case, a storage medium (or recording medium) such as a memory having a considerable capacity is used. Is required.

Here, the operation of the spectrum for embedding the copyright information can be performed in addition to the above, for example, for all blocks of the audio signal or blocks at predetermined intervals.

Next, FIG. 15 shows a CD 1 on which an audio signal in which copyright information is embedded as described above is recorded.
Playback device (for example, a CD player or a CD-R)
1 shows a configuration example of an embodiment (such as an OM drive).

The pickup 41 irradiates the CD 1 with light and receives the reflected light. Furthermore, pickup 41
Is converted into a reproduced signal as an electric signal by photoelectrically converting the received reflected light from the CD 1 to a reproducing unit 42.
Output to The reproducing unit 42 performs demodulation, error correction, and other necessary processing on the reproduced signal from the pickup 41. Then, the resulting audio signal is supplied to the signal processing unit 43 and the output unit 44. In the signal processing unit 43, copyright information is detected from the audio signal from the reproduction unit 42, and the output unit 44 is controlled based on the detection result.

That is, the output section 44 controls the output of the audio signal from the reproduction section 42 to the outside according to the control of the signal processing section 43. Then, when the copyright information can be normally detected from the audio signal, the signal processing unit 43 controls the output unit 44, for example, to permit the output to the outside. Therefore, in this case, the audio signal is output from the output unit 44 to the outside. Further, when the copyright information cannot be normally detected from the audio signal, the signal processing unit 43 may, for example, prohibit the output to the outside.
The output unit 44 is controlled. Therefore, in this case, the audio signal is not output to the outside.

Next, FIG. 16 shows the signal processing section 43 of FIG.
Is shown.

The start position determining unit 51, the segmentation unit 52, or the FFT unit 53 has the same configuration as the start position determining unit 11, the segmentation unit 12, or the FFT unit 13 in FIG. The power calculator 54 is configured similarly to the power calculator 21 of FIG. The copyright signal detection unit 55 includes the power calculation unit 5
By searching for the maximum value of the power spectrum for each block supplied from 4, a frequency component having a value of 0 as a copyright signal is detected, and based on the detection result, an output is performed. The unit 44 is controlled.

In the signal processing unit 43 configured as described above, the start point is determined by the start position determination unit 51 in the same manner as in the start position determination unit 11 of FIG. 2 and supplied to the segmentation unit 52. You. The segmentation unit 52 receives the start point from the start position determination unit 51 and starts clipping the audio signal in block units from the start point, as in the case of the segmentation unit 12 in FIG. The audio signal cut out in block units is supplied to the FFT unit 53. In the FFT unit 53, the audio signal in block units from the segmentation unit 52 is subjected to FFT, and the resulting frequency spectrum is supplied to a power calculation unit 54.

The power calculator 54 obtains a power spectrum for each block in the same manner as in the case of the power calculator 21 in FIG. 8, and supplies the power spectrum to the copyright signal detector 55. In the copyright signal detection unit 55, the power calculation unit 54
The copyright information is detected from the power spectrum from, and a control signal for controlling the output unit 44 is output based on the detection result.

That is, FIG. 17 shows an example of the configuration of the copyright signal detection unit 54.

The power spectrum from the power calculator 54 is supplied to a maximum value detector 61 and a nearby spectrum value comparator 6.
2 is supplied. The maximum value detection unit 61 detects the maximum frequency component pwr _max from the power spectrum of the block unit from the power calculation unit 54 and supplies it to the neighboring spectrum value comparison unit 62. Near spectrum value comparison unit 6
In 2, the frequency component near the frequency component (maximum power) pwr _max from the maximum value detection unit 61 is detected as the minimum frequency component (hereinafter, appropriately referred to as “neighboring minimum power”) and compared with the maximum power pwr _max. You.

Then, the neighboring spectrum value comparing section 62
As a result of the comparison between the maximum power pwr _max and the minimum neighboring power, if the difference is a value, for example, 80 dB or more, such that the minimum neighboring power can be regarded as 0, the control signal is transmitted to the copyright signal counting unit. 63. That is, the frequency component whose value is set to 0 as the copyright information is
Originally, it should be 0 like that,
For example, the value may be a value other than 0 due to a calculation error in the inverse FFT by the IFFT 15 in FIG. 2 or other necessary signal processing. Therefore, the neighboring spectrum value comparing unit 6
2 is the maximum power pw even if the neighborhood minimum power is not zero.
The difference between _rmax and the minimum neighboring power is
If the value is such a value that the copyright information can be regarded as being, it outputs a control signal indicating that the copyright information is embedded in the audio signal in a normal state without being falsified.

When the difference between the maximum power pwr _max and the minimum neighboring power is not a value that allows the minimum neighboring power to be regarded as 0, the neighboring spectrum value comparing section 62 performs tampering. No control signal is output.

Here, in the case described above, the nearby spectrum value comparing section 62 is caused to detect the minimum one of the frequency components near the maximum power pwr _max as the nearby minimum power, and to detect this as the maximum power pwr _max. However, in the signal processing device of FIGS. 2 and 13,
A frequency component having a value of 0 is defined as, for example, a maximum power pw
The frequency component may be determined based on the positional relationship with r _max, and the nearby spectrum value comparing section 62 may detect such a frequency component as the nearby minimum power. That is,
For example, when the frequency component at the sample point i _max +1 on the right of the sample point i _max of the maximum power pwr _max is set to 0 in the spectrum operation unit 14 of FIG. 2 or FIG. The unit 62 includes the frequency component at such a sample point i _max +1
It can be detected as the nearby minimum power.

The copyright signal counting section 63 counts the number of control signals output by the neighboring spectrum value comparing section 62. When the counting of control signals for a certain audio signal is completed, the count value c is changed to an illegal value. Output to the check unit 64. The count value c is supplied from the copyright signal counting unit 63 to the fraud check unit 64, and the number of frequency components whose value is set to 0 (or the expected C) is supplied, and by comparing them, it is determined whether or not the copyright information has been falsified.

That is, when the count value c from the copyright signal counting section 63 is sufficiently smaller than the number C of frequency components whose value is 0, the fraud check section 64 determines that the copyright information has been tampered with. In this case, a control signal for prohibiting the output of the audio signal is supplied to the output unit 44. When the count value c from the copyright signal counting unit 63 is not sufficiently smaller than the number C of frequency components whose value is 0, the fraud check unit 64 determines that the copyright information has not been tampered with. In this case, a control signal for permitting the output of the audio signal is supplied to the output unit 44.

A pirate creator who does not know how to embed the copyright information is expected to deform the waveform by editing the audio signal to destroy the copyright information embedded in the audio signal. However, when such an audio signal transformation is performed, the frequency component whose value is set to 0 has a certain value, and the count value c from the copyright signal counting unit 63 becomes: This is sufficiently smaller than the number C of frequency components whose value is set to 0. Accordingly, in this case, since no audio signal is output, it is possible to prevent a pirated board from being produced for the edited audio signal.

In the above case, when the count value c from the copyright signal counting section 63 is sufficiently smaller than the number C of the frequency components whose value is 0, the output of the audio signal is prohibited. Otherwise, the output of the audio signal is permitted, so that it is possible to copy an unedited audio signal.

On the contrary, when the count value c from the copyright signal counting section 63 is sufficiently smaller than the number C of the frequency components whose value is set to 0, the output of the audio signal is permitted. Otherwise, the output of the audio signal can be prohibited. In this case, the audio signal that has not been edited cannot be copied. That is, in this case, copying of the audio signal is prohibited. On the other hand, the edited audio signal can be copied, but in this case, the frequency component whose value is set to 0 has a certain value, that is, the audio signal originally has As a result, the sound quality deteriorates basically as a result. As a result, the value of the copy is reduced, and as a result, the copy of the audio signal can be substantially prevented.

Next, as described above, the production of the pirated board can be restricted by controlling the output of the audio signal to the outside by the reproducing apparatus for reproducing the CD1, but the recording apparatus for performing the recording is controlled. Can also be performed by controlling the recording operation in.

That is, FIG. 18 shows a recording apparatus (for example, CD) for recording an audio signal obtained by reproducing CD1 on which an audio signal in which copyright information is embedded is recorded.
-R drive, etc.).

An audio signal in which copyright information is embedded as a recording target is, for example, a CD-ROM (not shown).
The data is reproduced by a drive or the like and supplied to the signal processing unit 71 and the output unit 72. The output unit 72 controls the output of the audio signal supplied thereto to the recording unit 73 under the control of the signal processing unit 71. The recording unit 73
The audio signal from the output unit 72 is subjected to processing required for addition of error correction code, modulation, and other recording,
It is supplied to the pickup 74 as a recording signal. The pickup 74 irradiates the CD-R 75 with light in accordance with a recording signal from the recording unit 73, and thereby records an audio signal on the CD-R 75.

On the other hand, the signal processing section 71 detects copyright information from an external audio signal, and controls the output section 72 based on the detection result.

That is, for example, the signal processing unit 71
When the copyright information can be normally detected from the audio signal as in the case of the signal processing unit 43 of FIG.
The output unit 72 is controlled so as to permit output to the output unit 3.
Therefore, in this case, the audio signal is output from the output unit 72 to the recording unit 73 and recorded on the CD-R 75. The signal processing unit 71 controls the output unit 72 to prohibit the output to the recording unit 73 when the copyright information cannot be normally detected from the audio signal. Therefore, in this case, the audio signal is stored in the recording unit 73.
And is not recorded.

The signal processing unit 71 controls the supply of the audio signal to the recording unit 73 based on the result of the detection of the copyright information, and also controls the operation of the recording unit 73 (for example, (Operating or not operating), and even if an audio signal is recorded on the CD-R 75, processing can be performed such that the audio signal cannot be reproduced. Or,
For example, SCMS (Serial Copy Management System)
For example, it is also possible to perform processing such as restricting the generation of a copy (restricting the creation of a copy and further making a copy). In other words, based on the copyright information detection result,
There is no particular limitation.

Next, recently, the Internet, which is a worldwide computer network, has become widespread, and a system for providing video signals, audio signals, and the like on the Internet (a system is a logical collection of a plurality of devices) It does not matter whether the devices of each configuration are in the same housing or not), but they are being proposed and put to practical use, but in such a system, audio signals are provided without permission from the copyright holder. Is not preferred.

FIG. 19 shows an example of the configuration of an embodiment of an information providing system capable of restricting illegal provision of an audio signal.

For example, a recording medium 8 such as a hard disk
As described above, the audio signal 1 in which the copyright information is embedded is recorded (stored) in the server 1.
For example, when there is a request for the audio signal from the terminal 84 via the Internet 83, the terminal 2 reads the audio signal from the recording medium 81 and detects the copyright information. Then, on the basis of the detection result, the server 82 transmits, for example, an audio signal to the Internet 83.
Is determined to be transmitted to the terminal 84 via the.

In the above case, the server 82
In the above, the copyright information is detected, and based on the detection result, it is determined whether or not to transmit the audio signal to the terminal 84. In addition, for example, the audio signal is unconditionally transmitted from the server 82. It is also possible to make the terminal 84 detect the copyright information from the audio signal transmitted from the server 82 at the terminal 84 and determine whether or not to take in the audio signal based on the detection result. is there. Further, the present invention is also applicable to a case where a computer network other than the Internet is used.

As described above, while copyright information is included in one or more of the spectral components of the audio signal, the copyright information is detected, and the reproduction or recording of the audio signal is performed based on the detection result. Since transmission and reception are controlled, it is possible to prevent a copy of an audio signal from being illegally created or from being illegally distributed.

Further, when the copyright information is included in the frequency component masked by the masking effect, the deterioration of the sound quality due to the copyright information can be minimized.

In this embodiment, 0 as copyright information is included in a predetermined frequency component. In addition, as copyright information, for example, ISRC
It is possible to employ such information as can identify the source of the CD. In this case, when the CD is sold, for example, by associating the purchaser with the ISRC, the person who illegally made a copy of the audio signal or provided the copy (or provided the copy was not provided). Server) can be easily specified.

In the case where the copying of an audio signal is prohibited based on the copyright information, the reproduction or recording of the entire audio signal can be prohibited during the reproduction or recording, and the audio signal in a certain track can be prohibited. It is also possible to prohibit reproduction or recording of the data. Prohibiting the reproduction or recording of an audio signal in a specific track means that, for example, when the audio signal contains copyright information, the track for which the reproduction or recording of the audio signal is prohibited is set to the TOC (TaC).
ble Of Contents) or the like.

Further, in the present embodiment, a CD or CD-
Although the present invention is applied to a disk-shaped recording medium such as R, the present invention is applicable to, for example, a tape-shaped recording medium such as DAT other than the disk-shaped recording medium.

[0126]

According to the signal processing apparatus according to the first aspect and the signal processing method according to the eighteenth aspect, at least one of the discrete spectral components of the audio signal has the copyright related to the copyright of the audio signal. Information is included. Therefore, it is possible to prevent the audio signal from being illegally copied or distributed.

According to the recording medium of the nineteenth aspect, one or more of the discrete spectral components of the audio signal recorded thereon include copyright information on the copyright of the audio signal. Therefore, it is possible to prevent the audio signal from being illegally copied or distributed.

According to the signal processing device of the twentieth aspect and the signal processing method of the twenty-seventh aspect, the audio signal includes at least one of discrete spectral components.
Copyright information on the copyright of the audio signal is detected. Therefore, it is possible to prevent the audio signal from being illegally copied or distributed based on the copyright information.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining an outline of the present invention.

FIG. 2 is a block diagram illustrating a configuration example of a first embodiment of a signal processing device to which the present invention has been applied.

FIG. 3 is an FFT of an audio signal having different cut-out ranges.
It is a figure showing a result.

FIG. 4 is a waveform diagram showing an audio signal.

FIG. 5 is a waveform diagram showing a square window and a signal obtained by performing an inverse FFT on an FFT result of an audio signal cut out by the window.

FIG. 6 is a waveform diagram showing a Hanning window and a signal obtained by performing an inverse FFT on an FFT result of an audio signal cut out by the window.

FIG. 7 is a waveform diagram showing a Hanning window and a signal obtained by performing an inverse FFT on an FFT result of an audio signal cut out by the window.

8 is a block diagram illustrating a configuration example of a spectrum operation unit 14 in FIG.

FIG. 9 is a diagram showing an audio signal before a spectrum operation is performed in a spectrum operation unit and a power spectrum thereof.

FIG. 10 is a diagram showing an audio signal after a spectrum operation has been performed in the spectrum operation unit 14 and its power spectrum.

FIG. 11 is a diagram illustrating a subtraction result obtained by subtracting a power spectrum after the spectrum operation is performed from a power spectrum before the spectrum operation is performed.

FIG. 12 is a diagram for explaining a spectrum operation in the spectrum operation unit 14;

FIG. 13 is a block diagram illustrating a configuration example of a second embodiment of a signal processing device to which the present invention has been applied.

FIG. 14 is a flowchart illustrating the operation of the signal processing device of FIG. 13;

FIG. 15 is a block diagram illustrating a configuration example of an embodiment of a playback device to which the present invention has been applied.

16 is a block diagram illustrating a configuration example of a signal processing unit 43 in FIG.

17 is a block diagram illustrating a configuration example of a copyright signal detection unit 55 in FIG.

FIG. 18 is a block diagram illustrating a configuration example of an embodiment of a recording apparatus to which the present invention has been applied.

FIG. 19 is a block diagram illustrating a configuration example of an information providing system according to an embodiment of the present invention;

FIG. 20 is a diagram for describing a procedure for copying an audio signal.

[Explanation of symbols]

1 CD, 2 CD-ROM drive, 3 computer, 4 CD-R drive, 5 CD-R,
11 start position determination unit, 12 segmentation unit, 13 FFT unit, 14 spectrum operation unit,
15 IFFT unit, 21 Power calculation unit, 22
Maximum value detector, 23 Spectrum changer, 31, 3
2 switch, 33 power calculator, 34 sorter, 41 pickup, 42 reproducing unit, 43
Signal processing unit, 44 output unit, 51 start position determination unit, 52 segmentation unit, 53 FFT
Unit, 54 power calculation unit, 55 copyright signal detection unit, 61 maximum value detection unit, 62 nearby spectrum value comparison unit, 63 copyright signal count unit, 64 fraud check unit, 71 signal processing unit, 72 output unit, 7
3 recording unit, 74 pickup, 75 CD-R,
81 recording medium, 82 server, 83 Internet, 84 terminal

Claims (27)

[Claims] 1. A signal processing apparatus for processing an audio signal, comprising: processing means for performing a process of including, in one or more of discrete spectral components of the audio signal, copyright information on a copyright of the audio signal. A signal processing device comprising: 2. The signal processing apparatus according to claim 1, wherein the processing unit causes the copyright information to be included in a spectral component masked by a masking effect. 3. The signal processing apparatus according to claim 1, wherein the processing unit performs a process of setting one or more of spectral components of the audio signal to 0 as a process of including the copyright information. . 4. The signal processing apparatus according to claim 1, wherein the copyright information is included in one of the spectral components of the audio signal near a maximum value thereof. 5. The signal processing apparatus according to claim 1, wherein the copyright information is included in a spectral component of the audio signal adjacent to the left or right of the maximum value. 6. The signal processing apparatus according to claim 1, wherein the copyright information is included in a plurality of spectral components near the maximum value among the spectral components of the audio signal. 7. The copyright information is included in a maximum value or a minimum value of a plurality of spectral components near the maximum value among the spectral components of the audio signal. Signal processing device. 8. The signal processing apparatus according to claim 1, wherein the copyright information is included in a spectral component of the audio signal at a position separated by a predetermined number from a maximum value thereof. . 9. The processing means: frequency analysis means for frequency-analyzing the audio signal to obtain discrete spectrum components thereof; and at least one of the spectrum components output by the frequency analysis means, The signal processing device according to claim 1, further comprising: a changing unit configured to change the value to a value corresponding to the information; and a converting unit configured to convert a spectrum component output from the changing unit into a signal on a time axis. 10. The apparatus according to claim 1, further comprising: a determination unit that determines a start point at which the frequency analysis unit starts frequency analysis of the audio signal, wherein the frequency analysis unit determines the audio signal from the start point determined by the determination unit. The signal processing apparatus according to claim 9, wherein frequency analysis of the signal is started. 11. The signal processing apparatus according to claim 10, wherein said determining means determines a time point when an absolute value of an amplitude of said audio signal exceeds a predetermined threshold value as said start point. 12. The signal processing device according to claim 11, wherein the predetermined threshold is zero. 13. The processing means may include, over all of the audio signal, one or more of its spectral components:
The signal processing device according to claim 1, wherein the copyright information is included. 14. The signal processing apparatus according to claim 1, wherein the processing unit causes the copyright information to be included in at least one of spectral components at predetermined time intervals of the audio signal. 15. When the audio signal satisfies a predetermined condition, the processing means selects one of its spectral components.
The signal processing device according to claim 1, wherein the copyright information is included. 16. The method according to claim 15, wherein the predetermined condition is that the spectrum component for which the copyright information is to be included is equal to or higher than a predetermined threshold or equal to or lower than a predetermined threshold. A signal processing device according to claim 1. 17. The method according to claim 17, wherein a difference between a maximum value of the spectral components of the audio signal and a component that is to include the copyright information is equal to or greater than a predetermined threshold or equal to or less than a predetermined threshold. The signal processing device according to claim 15, wherein: 18. A signal processing method for processing an audio signal, wherein at least one of the discrete spectral components of the audio signal includes copyright information on the copyright of the audio signal. Processing method. 19. A recording medium on which an audio signal is recorded, wherein at least one of discrete spectral components of the audio signal includes copyright information on a copyright of the audio signal. Recording medium. 20. A signal processing apparatus for processing an audio signal, comprising: detecting means for detecting copyright information on a copyright of the audio signal, the copyright information being included in one or more discrete spectral components of the audio signal. A signal processing device comprising: 21. The signal processing apparatus according to claim 20, further comprising a determination unit configured to determine whether the copyright information detected by the detection unit has been falsified. 22. The apparatus according to claim 21, wherein the determination unit determines whether the copyright information has been tampered based on the number of the copyright information normally detected by the detection unit. Signal processing device. 23. The signal processing apparatus according to claim 21, wherein reproduction, recording, transmission, or reception of the audio signal is controlled based on a result of the determination by the determination unit. 24. The signal processing apparatus according to claim 20, wherein reproduction, recording, transmission, or reception of said audio signal is controlled based on a result of detection of said copyright information by said detection means. 25. A frequency analysis of the audio signal,
The audio signal further includes frequency analysis means for obtaining the discrete spectrum components, and the detection means detects the copyright information included in one or more of the spectral components of the audio signal output by the frequency analysis means. Claim 20.
The signal processing device according to claim 1. 26. The apparatus according to claim 26, further comprising a determination unit that determines a start point at which the frequency analysis unit starts frequency analysis of the audio signal, wherein the frequency analysis unit determines the audio signal from the start point determined by the determination unit. The signal processing apparatus according to claim 25, wherein frequency analysis of the signal is started. 27. A signal processing method for processing an audio signal, the method comprising detecting copyright information on a copyright of the audio signal, the copyright information being included in one or more discrete spectral components of the audio signal. Characteristic signal processing method.