JP2000090567A - Transmission device and method for digital signal and recording medium for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable transmitting a digital signal even to the current equipments and also to effectively protect a copyright by generating a digital signal whose quality is degraded while degrading the quality of an input digital signal and transmitting the digital signal having the degraded quality. SOLUTION: After the master disk 2 exposed by an optical disk recording device 1 is developed, a mother disk is formed by being electroformingly processed and a compact disk is formed. The master disk 2 to be exposingly processed is formed by coating photo-sensitive agent on a flat glass substrate. A bit operating part 10 receives 16-bit parallel audio data DA to be outputted from a prescribed server to operate 8 bits of a lower-order and the part 10 performs the degrading of sound quality to the effect that the degradation can be sensed as to the sound quality of the digital audio data and the degraded sound quality can be recovered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital signal transmission apparatus, a digital signal transmission method, and a digital signal recording medium, and can be applied to, for example, a compact disk and a compact disk recording / reproducing apparatus. The present invention manipulates and transmits digital signals so that the quality is degraded to a degree that can be perceived, and the quality that has been degraded by predetermined processing can be restored. An audio signal can be transmitted, and copyright can be effectively protected.

[0002]

2. Description of the Related Art Conventionally, in digital audio equipment such as a compact disk player, SCMS (Serial
rial Copy Management System).

That is, a compact disk player performs binary identification of a reproduction signal obtained by irradiating a laser beam onto a compact disk to obtain reproduction data, and performs EFM demodulation, error correction processing, deinterleaving processing, and digital reproduction. Play audio signals. The compact disk player converts this digital audio signal to digital-to-analog output for audio equipment with analog signal input, and outputs this digital audio signal in a predetermined format to digital audio equipment and the like. I do. In this format, the compact disc player sets a code indicating copy prohibition, one-time copy permission, and unrestricted copy permission, thereby protecting the copyright by reflecting the intention of the copyright holder. I have.

[0004]

By the way, even when such a code is added to output a digital audio signal, in a device which operates ignoring this kind of code, there is no limit against the intention of the copyright holder. May be copied to

As one method for solving this problem, for example, a method of scrambling a digital audio signal and transmitting the signal can be considered. In the case of this method, for example, it is considered that various works can be protected according to the intention of the copyright holder by giving and receiving key data necessary for the descrambling process.

However, this causes a problem that digital audio signals cannot be transmitted to conventional audio equipment.

The present invention has been made in view of the above points, and a digital signal transmission apparatus and a digital signal transmission apparatus capable of transmitting digital signals to conventional equipment and effectively protecting copyrights. A transmission method and a digital signal recording medium are proposed.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is applied to a digital signal transmission apparatus or a digital signal transmission method so that quality deterioration can be perceived and the deteriorated quality can be recognized. So that you can recover
The quality of the input digital signal is degraded to generate a degraded digital signal, and the degraded digital signal is transmitted.

In addition, the present invention is applied to a digital signal transmission apparatus or a digital signal transmission method, and inputs a digital signal whose quality has deteriorated so that the deterioration of quality can be perceived and the deteriorated quality can be recovered. The quality of this digital signal is restored.

[0010] Further, the present invention is applied to a digital signal recording medium so that the quality deterioration can be perceived and the quality deteriorated so that the deteriorated quality can be recovered. Record the signal.

[0011] The present invention is applied to a digital signal transmission apparatus or a digital signal transmission method, and the quality of an input digital signal is degraded by deteriorating the quality of an input digital signal so that the degradation of quality can be perceived and the degraded quality can be recovered. If a signal is generated and a digital signal of this quality deterioration is transmitted, it can be used also in a device that directly processes the transmitted digital signal. This makes it possible to transmit digital signals to conventional equipment. At this time, if the protection of the copyright is doubtful such that the digital signal is copied in its entirety, the digital signal is copied due to the deteriorated quality, thereby protecting the copyright. On the other hand, in a digital signal of this quality deterioration, since the quality is recoverably deteriorated, in a device capable of reliably protecting copyright, by recovering the quality and processing the digital signal, High quality digital signals can be provided.

Further, by applying the present invention to a digital signal transmission device or a digital signal transmission method, a digital signal of degraded quality is input and the quality of the digital signal is restored, whereby compatibility with conventional equipment is improved. While holding
In a device whose copyright is completely protected, a high-quality digital signal can be processed.

Further, when the present invention is applied to a digital signal recording medium, and a digital signal having a deteriorated quality is recorded so that the quality can be perceived as being deteriorated and the deteriorated quality can be recovered, the recording can be performed via the recording medium. When transmitting a digital signal, the digital signal can be transmitted to a conventional device, and the copyright can be effectively protected.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(1) First Embodiment FIG. 1 is a block diagram showing an optical disk recording apparatus used for manufacturing a compact disk. In the first embodiment, a mother disc is created by developing the master disc 2 exposed by the optical disc recording apparatus 1 and then performing an electroforming process. Further, a compact disc is created using the mother disc.

The master disc 2 to be exposed in this manner is formed by applying a photosensitive agent to, for example, a flat glass substrate. The spindle motor 3 rotationally drives the master disc 2 under the control of a spindle servo circuit 4.
At this time, the spindle motor 3 is driven by the FG provided at the bottom.
The signal generator outputs an FG signal FG whose signal level rises at each predetermined rotation angle. Spindle servo circuit 4
Drives the spindle motor 3 so that the FG signal FG has a predetermined frequency, thereby rotating the disk master 2 under the condition of a constant linear velocity.

The recording laser 5 is composed of a gas laser or the like, and emits a predetermined amount of laser beam. The optical modulator 6 is configured by an electroacoustic optical element or the like, and controls on / off of a laser beam L incident from the recording laser 5 according to a drive signal S3.

The mirror 8 bends the optical path of the laser beam L and emits it toward the master disc 2. The objective lens 9 focuses the light reflected by the mirror 8 on the recording surface of the master disc 2. The mirror 8 and the objective lens 9 are sequentially moved in the radial direction of the master disc 2 by a thread mechanism (not shown) in synchronization with the rotation of the master disc 2. Accordingly, the optical disc recording apparatus 1 sequentially displaces the condensing position of the laser beam L in the outer circumferential direction of the disc master 2, and forms a spiral track on the disc master 2. At this time, the modulation signal S
A pit row corresponding to No. 3 is formed.

The bit operation unit 10 is a 16-bit parallel audio data DA output from a predetermined server.
Then, the lower 8 bits of the audio data DA are operated. Here, the bit operation unit 10 operates these bits by dividing the lower 8 bits in units of 2 bits and converting a combination of each 2 bits according to a predetermined rule. That is, as shown by the combination of two bits in FIG. 2, the combination of logic “00” is changed to the combination of logic “11”, and the combination of logic “01” is changed to the combination of logic “10”. . For the combination of logic “10” and “11”, the logic “00” and “0”
Change the combination to “1”.

As a result, the bit operating section 10 degrades the sound quality, which is the quality of the digital audio signal, to such an extent that the deterioration can be perceived. Further, at this time, the sound quality is deteriorated so that the deteriorated sound quality can be recovered.

The data processing circuit 11 inputs the TOC data DI to be recorded in the lead-in area of the compact disc, and processes the TOC data DI according to a format prescribed for the compact disc. Thereby, the data processing circuit 11 generates and outputs channel data corresponding to the pit string. Similarly, the data processing circuit 11 processes the digital signal D2 output from the bit operation unit 10 according to a format prescribed for the compact disc, and generates and outputs channel data corresponding to a pit string.

The TOC data recorded in this manner includes a disc identification data ID indicating that the digital audio signal DA is bit-operated and recorded, and
Copy identification data IC indicating that the disc is an original compact disc created from a mother disc is assigned. Thus, in this embodiment, at the time of reproduction, the bit-operated digital audio signal DA can be reproduced based on the detection result of the disc identification data ID. It is also possible to determine whether the disc is an original compact disc or a copied compact disc based on the copy identification data IC.

The drive circuit 12 receives the channel data D3 output from the data processing circuit 11 in this way, and generates a drive signal S3 whose signal level changes in accordance with the logical level of the channel data D3.

Thus, in this embodiment, of the 16-bit data constituting the digital audio signal DA, 8 bits are recorded on the master disc 2 so that they can be reproduced and reproduced correctly by a normal compact disc player. With respect to the remaining lower 8 bits, audio data reproduced on a normal compact disc is further bit-operated in accordance with the conversion rule described above with reference to FIG.

Hereinafter, the compact disk manufactured by the optical disk recording apparatus 1 shown in FIG. 1 is referred to as an ECD disk when it is distinguished from a conventional compact disk.

FIG. 3 is a block diagram showing a compact disc player, which reproduces a conventional compact disc and ECD disc. That is, in the compact disk player 20, the compact disk 21 is a reproduction signal R obtained from the optical pickup 23.
It is rotationally driven by the spindle motor 22 under the condition of a constant linear velocity with reference to F.

The RF circuit 24 amplifies the reproduced signal RF obtained from the optical pickup 23 with a predetermined gain and outputs the amplified signal.
An FM (eight to fourteen) demodulation circuit 25 generates reproduction data by performing binary identification on the reproduction signal output from the RF circuit 24. Further, the EFM demodulation circuit 25 performs EFM demodulation on the reproduced data and outputs the data.

The CIRC decoder 26 descrambles the EFM demodulation circuit 25 and performs an error correction process using an error correction code added at the time of recording, thereby reproducing and outputting the digital audio signal D4. Thus, in the compact disc player 20, when the compact disc 21 is a conventional compact disc, the digital audio signal D4 is output with a 16-bit high sound quality, whereas when the compact disc 21 is an ECD disc, The lower 8 bits of the 16 bits are bit-operated, and the sound quality is degraded and output.

The bit operation unit 28 performs bit operations on the lower 8 bits of the digital audio signal D4 so as to reverse the conversion rule described above with reference to FIG. As a result, the bit operation unit 28 indicates that the compact disc 21
In the case of a disc, the degraded digital audio signal D
4 is restored and output.

The disk discriminating section 29 is constituted by a system controller. Here, when the compact disk 21 is loaded, the system controller seeks the optical pickup 23, obtains information such as the number of music pieces and performance time recorded on the compact disk 21 from the lead-in area of the compact disk 21, and Is displayed by the display means. At this time, the system controller also acquires the disk identification data ID of the compact disk 21, and according to the disk identification data ID, determines whether the compact disk 21 is a conventional compact disk or an EC.
Determine whether the disc is a D disk. The disc discrimination unit 29 controls switching of the contacts of the selection circuit 30 based on the result of the discrimination.

The disc discriminating section 29 judges whether or not the compact disc 21 is a copy compact disc based on the copy identification data IC similarly obtained. Here, such a compact disc by copying is created by, for example, dubbing the content recorded on an original compact disc to a CD-ROM by a computer. The disc discriminating section 29 switches the operation of the switch circuit 34 based on the result of the discrimination, so that when the compact disc 21 is copied, the output of the digital audio signal is stopped.

The selection circuit 30 includes the compact disk 21
Is a conventional compact disc, the digital audio signal D4 output from the CIRC decoder 26 is
Is selectively output to the digital-to-analog conversion circuit (D / A) 31. On the other hand, when the compact disk 21 is an ECD disk, the digital audio signal output from the bit operation section 28 and having a restored sound quality is selectively output.

The digital-to-analog conversion circuit 31 performs a digital-to-analog conversion process on the digital audio signal output from the selection circuit 30, and outputs an audio signal SA based on the analog signal. As a result, in the compact disk player 20, as shown in FIG. 4, in the reproduction sound quality by the analog signal, the high sound quality (corresponding to the CD sound quality) corresponding to 16 bits is obtained in both the conventional compact disk and the ECD disk. ). In FIG. 4, the compact disk 21 having the configuration shown in FIG. 3 is shown as an ECD player, and the conventional compact disk player is shown as a CD player. Further, a conventional compact disk is shown as a CD disk, and sound quality reduced by bit operation is shown as FM sound quality.

In the conventional compact disk player, the digital audio signal D4 output from the CIRC decoder 26 is output without passing through the bit operation unit 28, so that in the case of the conventional compact disk and ECD disk, Output is performed according to the CD sound quality and the FM sound quality, respectively.

An interface (I / F) 32 constitutes an input / output circuit for transmitting and receiving various data to and from external devices and the like, outputs a digital audio signal to a personal computer in SCMS format, and outputs a digital audio signal. Send and receive various data related to.

The external device discriminating unit 33 includes the disc discriminating unit 2
Similarly to 9, the system is configured by the system controller of the compact disk player 20 and executes a predetermined authentication process with an external device via the interface 32. In this authentication process, the external device determination unit 33
Predetermined data is transmitted to the external device, and a response from the external device to the data determines whether the computer connected to the interface 32 is a device for protecting copyright.

Here, the device for protecting the copyright as described above is a device having a function of prohibiting the creation of a copy from a copy (a so-called secondary copy), such as the compact disc player 20. Further, when the compact disc 21 is copied, it means a device capable of stopping the output of the digital audio signal and preventing the recording of the digital audio signal by an external device. Therefore, for example, when the external device is a personal computer, this compact disc player 20
When a compact disc of a copy is created from a digital audio signal output from a personal computer, this personal computer corresponds to a device for protecting copyright when the personal computer has a function of correctly setting a copy identification data IC. (In FIG. 4, a secondary copy prohibited PC is shown by comparison with a conventional personal computer (conventional PC).)

The selection circuit 35 includes an external device discriminating unit 33
In the case where the external device is a device for protecting copyright based on the result of the determination, the digital audio signal output from the selection circuit 30 is selected and output, while the external device is not a device for protecting copyright. , CIRC decoder 26
The selected digital audio signal S4 is output. Accordingly, the selection circuit 35 outputs a digital audio signal with high sound quality regardless of whether the external device is a device for protecting copyright, the compact disk 21 is a conventional compact disk, or an ECD disk. On the other hand, if the external device is not a device for protecting the copyright, the compact disc 21 outputs a digital audio signal with high sound quality when the compact disc 21 is a conventional compact disc.
Is an ECD disc, a digital audio signal is output according to the degraded sound quality.

The switch circuit 34 outputs the digital audio signal output from the selection circuit 35 directly or via an interface 32 to an external device. At this time, the switch circuit 34 determines whether the compact disc 21 is
Is a disc by copying, the output of these digital audio signals is stopped.

In the above configuration, in the manufacturing process of the compact disk (FIG. 1), the lower 8 bits of the digital audio signal DA of 16 bits are bit-operated by the bit operation unit 10 according to a certain rule (FIG. 2). This degrades the sound quality to the extent that it can be perceived. After that, the digital audio signal DA is recorded on the disk master 2 in the same manner as when a normal compact disk is created, and then a mother disk and a stamper are sequentially created from the disk master 2 and recorded on the compact disk from the stamper. Is done. On the other hand, in the conventional compact disc, the sound quality of the digital audio signal is recorded on the compact disc without any deterioration in sound quality.

When the master disc 2 is exposed in this manner, a lead-in area is formed by the TOC data output from the predetermined server, and the sound quality is degraded by the disc identification data ID assigned to the TOC data. The disc is set so that it can be identified whether the disc is a compact disc recorded and a conventional compact disc. Similarly, the copy identification data IC assigned to the TOC data determines whether the original compact disc is
It is set so that it can be identified whether it is a compact disc by copying.

In the compact disc 21 created in this way, the compact disc player 2
At 0 (FIG. 3), after the reproduction signal detected by the optical pickup 23 is amplified by the RF circuit 24, it is demodulated by the EFM demodulation circuit 25 to generate reproduction data, and the reproduction data is descrambled and error-corrected. The processed digital audio signal is output.

In a conventional compact disc player, the digital audio signal D4 output from the CIRC decoder 26 after this error correction processing is output to an external device and converted into an analog signal and output. Thus, when a conventional compact disc is loaded into a conventional compact disc player, a 16-bit high-quality digital audio signal is directly or converted into an analog signal and output (FIG. 4). On the other hand, when an ECD disk is loaded into a conventional compact disk player, a digital audio signal is output in an amount corresponding to approximately 8 bits, which is a deterioration in sound quality.

As a result, this compact disc can be reproduced by a conventional compact disc player.

On the other hand, in the compact disc player 20 capable of reproducing this ECD disc, the C
The digital audio signal output from the IRC decoder 26 is input to the bit operation unit 28, where the lower 8 bits are bit-operated, contrary to the recording operation. Thus, when the compact disc 21 is an ECD disc, a digital audio signal obtained by restoring sound quality is output.

In the compact disc player 20, the TO-in from the lead-in area of the compact disc is
C data is reproduced in advance, and the compact disc 21 is a conventional compact disc or an ECD based on the disc identification data ID assigned to the TOC data.
It is determined that it is a disk. Thus, when the compact disc 21 is a conventional compact disc, the CIRC
The digital audio signal D4 output from the decoder 26 is supplied to the selection circuit 30, the selection circuit 35, and the switch circuit 3.
4. The data is output to an external device in the SCMS format via the interface 32. Further, the digital audio signal D4 is input to the digital / analog conversion circuit 31 via the selection circuit 30, where it is converted to an analog signal and output.

As a result, when a conventional compact disc is played back, the result of reproduction with high sound quality can be output to an external device and used in various ways, as in the case of playing back with a conventional compact disc player. Becomes In addition, SCMS can protect copyright. This allows the compact disc player 20 to use a conventional compact disc without restricting the rights of existing users.

On the other hand, the compact disc 21
In the case of a CD disk, a digital audio signal whose sound quality has been restored is generated by the bit operation unit 28, and this digital audio signal is output as an analog signal via the selection circuit 30 and the digital / analog conversion circuit 31. As a result, even on ECD discs, you can listen to audio signals with high sound quality, just like conventional compact discs, and only for analog signals, you can enjoy private copying with high sound quality as before. Becomes

On the other hand, the compact disc 21
In the case of outputting a digital audio signal to an external device in the case of a CD disk, an authentication process is performed between the external device and the external device via the interface 32, and the external device uses a code based on SCMS like a conventional personal computer. It is determined whether or not the device ignores. Accordingly, it is determined whether the external device is a device for protecting copyright. If the external device is for protecting copyright, the digital audio signal whose sound quality has been restored by the bit operation unit 28 is selected by the selection circuit 3.
0, output to an external device via the selection circuit 35, the switch circuit 34, and the interface 32.

As a result, a high-quality digital audio signal is output to an external device, and since the external device is a device for protecting copyright, illegal duplication such as making another copy from a copy is prohibited. .

On the other hand, if the external device is not a device for protecting copyright, in this case, copying may be executed by an unlimited digital signal. The digital audio signal D4 resulting from the degraded sound quality is supplied to the selection circuit 35 and the switch circuit 3
4. Output to an external device via the interface 32. As a result, when there is a possibility that copying with an unlimited digital signal may be permitted, a digital audio signal whose sound quality is deteriorated is output as in the case where copying is repeated with an analog signal, and the sound quality is obtained even if copying is repeated. The advantage of copying by a digital signal that is not deteriorated cannot be utilized.

On the other hand, in a copy made by outputting a digital audio signal of high sound quality in an external device for copyright protection, when a copy is made in this kind of compact disc player 20, the lead-in area is In the compact disc player 20, the output of the digital audio signal is stopped by the switch circuit 34, and the digital audio signal recorded on the ECD disc is converted into a high-quality digital signal. Even when outputting to an external device by an audio signal, unlimited copying is prevented.

According to the above arrangement, the sound quality of the digital audio signal is degraded so that the sound quality can be perceived and the sound quality that has been restored can be recovered, and the digital audio signal is recorded. A compact disc that can be reproduced by a compact disc player and that can effectively protect copyright, and an optical disc recording device that creates a compact disc can be obtained.

Also, by judging an external device and outputting the digital audio signal recorded in this way directly or by recovering the sound quality, the conventional compact disc can be reproduced and the copyright is effectively protected. You can get a compact disc player that can.

(2) Second Embodiment In this embodiment, the optical disk recording apparatus is provided with the first
As in the optical disc recording apparatus 1 according to the embodiment, the master disc 2 is exposed by a digital audio signal having deteriorated sound quality. At this time, the optical disc recording apparatus according to the present embodiment uses the time information based on the subcode to be recorded in addition to the digital audio signal as a reference.
The same bit operation processing as that of the first embodiment is executed in a certain period during a certain period. As a result, in this embodiment, the sound quality of the digital audio signal is deteriorated so that the deterioration can be perceived, and the deteriorated sound quality can be recovered.

On the other hand, in the compact disc player, a digital audio signal is reproduced from the compact disc in the same manner as the compact disc player 20 according to the first embodiment, and is output to an external device. At this time, the compact disc player according to this embodiment obtains a subcode from playback data obtained by playing the compact disc. Further, time information is obtained from the subcode, and the sound quality of the reproduced digital audio signal is recovered based on the time information.

According to the configuration according to the second embodiment, the same bit operation as that of the first embodiment is repeated at a constant cycle based on the time information assigned to the subcode, whereby the first The same effect as that of the embodiment can be obtained. In particular, the time information assigned to the subcode in this way has a characteristic that the subcode itself is difficult to copy because it is not added to the digital audio signal and output. Thus, illegal copying can be more effectively prevented as compared with the first embodiment.

(3) Third Embodiment In the third embodiment, the optical disc recording apparatus is similar to the optical disc recording apparatus 1 according to the first or second embodiment in that the sound quality of the digital audio signal is Is exposed, and the master disc 2 is exposed. At this time, the optical disk recording apparatus according to this embodiment uses the public key encryption, DES
(Data Encryption Standard) or the like, the lower 8 bits of the digital audio signal are subjected to encryption processing to deteriorate the sound quality of the digital audio signal and expose the master disk. As a result, in this embodiment, the sound quality of the digital audio signal is deteriorated so that the deterioration can be perceived, and the deteriorated sound quality can be recovered.

On the other hand, in the compact disc player, a digital audio signal is reproduced from the compact disc in the same manner as the compact disc player 20 according to the first or second embodiment, and is output to an external device. At this time, in the compact disk player according to this embodiment, the sound quality of the digital audio signal is restored by processing corresponding to the encryption processing in the optical disk recording device.

According to the third embodiment, the same effect as in the first embodiment can be obtained even if the lower bit of the digital audio signal is encrypted to deteriorate the sound quality. Further, the copyright can be further strongly protected by the encryption.

(4) Fourth Embodiment In this embodiment, the optical disk recording apparatus is provided with the first
As in the optical disc recording apparatus 1 according to the embodiment, the master disc 2 is exposed by a digital audio signal having deteriorated sound quality.

That is, the optical disk recording apparatus inputs an 18-bit digital audio signal from the server,
The bit operation unit generates a 16-bit digital audio signal having deteriorated sound quality from the 18-bit digital audio signal.

That is, as shown in FIG. 5, the bit operating section 50 decomposes the 18-bit digital audio signal into upper 8 bits and lower 10 bits. Further, the bit operation unit 50 performs data compression processing or non-linear quantization processing on the lower 10 bits by the data processing circuit 51,
An 8-bit digital audio signal is generated.

The bit operation unit 50 allocates the lower 8 bits of the digital audio signal and the upper 8 bits of the digital audio signal generated as described above to the upper 8 bits and the lower 8 bits, respectively, and assigns them to the 16 bits. To generate a synthesized digital audio signal. Thereby, in this embodiment, the deterioration can be perceived,
An 18-bit digital audio signal is converted into a 16-bit synthesized digital audio signal to degrade the sound quality of the digital audio signal and to recover the degraded sound quality. The optical disk recording device creates a compact disk by exposing the disk master 2 using the synthesized digital audio signal.

On the other hand, in the compact disc player, a digital audio signal is reproduced from the compact disc in the same manner as the compact disc player 20 according to the first or second embodiment, and is output to an external device.

At this time, the compact disc player reproduces the synthesized digital audio signal from the reproduction data obtained from the compact disc, and the bit operation section restores the sound quality of the synthesized digital audio signal. That is, as shown in FIG. 6, the bit operation unit 52 restores the sound quality of the digital audio signal by data expansion processing or nonlinear inverse quantization processing corresponding to the processing in the optical disk recording device in the data processing circuit 53, Selectively output.

According to the fourth embodiment, even if the sound quality of a digital audio signal is degraded by data compression processing or non-linear quantization processing, the same effect as in the above-described embodiment can be obtained. In addition, the digital audio signal is degraded in sound quality by data compression processing or non-linear quantization processing, and the degraded sound quality is restored. A signal can be output.

(5) Fifth Embodiment In the fifth embodiment, the optical disc recording apparatus degrades the sound quality of the digital audio signal in the same manner as the optical disc recording apparatus 1 according to the above-described embodiment. The master disc 2 is exposed. At this time, in the optical disk recording device according to this embodiment, the bit operation unit 55
As shown in FIG. 7, the arithmetic circuit 56 generates a digital signal PN for sound quality deterioration of 8 bits which is repeated in units of a predetermined number of frames by sub-code, and converts the lower 8 bits of the digital audio signal of the digital signal into digital signals. Calculate. Note that the operation is performed by an addition process between corresponding bits, a subtraction process, an exclusive OR operation, or the like. As a result, in this embodiment, the sound quality of the digital audio signal is deteriorated so that the deterioration can be perceived, and the deteriorated sound quality can be recovered. The digital signal PN for sound quality deterioration is constituted by, for example, pseudo noise by a PN code.

In response to this, a compact disk player obtains reproduction data from a compact disk in the same manner as the compact disk player according to the above-described embodiment, reproduces a digital audio signal from this reproduction data, and transmits the reproduced digital audio signal to an external device. Output. At this time, in the compact disk player according to the present embodiment, the bit operation unit 57 generates the digital signal PN for sound quality deterioration corresponding to the processing in the optical disk recording device. Further, as shown in FIG.
The digital signal PN is subjected to arithmetic processing with the lower 8 bits of the reproduced digital audio signal, thereby recovering the sound quality of the digital audio signal.

According to the fifth embodiment, even if the sound quality of a digital audio signal is deteriorated by performing arithmetic processing on a digital signal for sound quality deterioration and a digital audio signal, the same effect as in the above-described embodiment can be obtained. The effect can be obtained.

(6) Sixth Embodiment In the sixth embodiment, the optical disc recording apparatus degrades the sound quality of the digital audio signal in the same manner as the optical disc recording apparatus 1 according to the above-described embodiment. The master disc 2 is exposed. At this time, in the optical disc recording apparatus according to this embodiment, as shown in FIG.
The disc master 2 is exposed so as to form a recording area AR3 for additional data between the lead-out area AR4 and the user area AR2, thereby producing a compact disc.

Further, in the optical disc recording apparatus, by setting the TOC to be recorded in the lead-in area AR1,
The conventional compact disc player is set so as not to access the recording area AR3 of the additional data. Also, a digital signal for sound quality deterioration (8-bit digital signal) that is periodically repeated in units of a predetermined frame (for example, 98 frames) of the digital audio signal is recorded in the recording area AR3 of the additional data.

Further, the additional data and the lower 8 bits of the digital audio signal are arithmetically processed with reference to the time code, so that the sound quality of the digital audio signal is deteriorated so that the deterioration can be perceived, and the deteriorated sound quality is recovered. It can be so. The optical disk recording device records the digital audio signal having the deteriorated sound quality in the user area AR2. The digital signal for sound quality deterioration is constituted by, for example, pseudo noise by a PN code.

Correspondingly, in the compact disk player, reproduction data is obtained from the compact disk in the same manner as the compact disk player according to the above-described embodiment, and a digital audio signal is reproduced from the reproduction data to be transmitted to an external device. Output. At this time, if the compact disc player determines that the compact disc is an ECD disc based on the TOC data, the compact disc player accesses the recording area AR3 of the additional data to acquire a digital signal for sound quality deterioration. Further, the digital audio signal reproduced based on the time code and the digital signal for sound quality deterioration are arithmetically processed, thereby recovering the sound quality of the digital audio signal.

According to the sixth embodiment, the same effect as in the above-described embodiment can be obtained even if a digital signal necessary for restoring sound quality is separately recorded on a compact disc and transmitted. Can be.

(7) Seventh Embodiment In this embodiment, the optical disc recording apparatus degrades the sound quality of the digital audio signal in the same manner as in the optical disc recording apparatus 1 according to the above-described embodiment, and the disc master 2 Is exposed. At this time, the optical disk recording device operates the lower 8 bits of the digital audio signal by various methods such as encryption, for example, so that the sound quality of the digital audio signal is degraded and recorded. Further, key data and the like necessary for recovering the sound quality of the deteriorated digital audio signal are recorded between the lead-out area and the user data. As a result, in this embodiment, the sound quality of the digital audio signal is deteriorated so that the deterioration can be perceived, and the deteriorated sound quality can be recovered.

In response to this, in a compact disk player, reproduction data is obtained from a compact disk in the same manner as the compact disk player according to the above-described embodiment, and a digital audio signal is reproduced from the reproduction data to be transmitted to an external device. Output. At this time, the compact disc player reproduces key data necessary for restoring the sound quality of the digital audio signal from the compact disc in advance, and restores the sound quality of the digital audio signal using the key data.

According to the seventh embodiment, the sound quality is degraded by encryption or the like, and various data necessary for restoring the sound quality are separately recorded. The same effect as in the embodiment can be obtained.

(8) Eighth Embodiment In this embodiment, the optical disc recording apparatus decomposes a digital audio signal into upper 8 bits and lower 8 bits, and then, for example, in units of digital audio signal frames. The lower 8 bits of the lever are replaced according to a predetermined rule, thereby deteriorating the sound quality of the digital audio signal. As a result, the optical disc recording apparatus degrades the sound quality of the digital audio signal so as to be perceptible and recoverable by operating in the time axis direction instead of the operation in the amplitude direction according to the above-described embodiment. The optical disk recording device exposes the master disk with the digital audio signal.

In response to this, in the compact disk player according to this embodiment, the digital audio signal obtained by reproducing the compact disk is decomposed into upper 8 bits and lower 8 bits, and the time in the optical disk recording apparatus is reduced. Lower side 8 corresponding to axial operation
The bits are swapped, thereby restoring the sound quality of the digital audio signal.

As in the eighth embodiment, the same effect as in the above-described embodiment can be obtained by operating the digital audio signal in the time axis direction to degrade the sound quality.

(9) Ninth Embodiment In this embodiment, the optical disc recording apparatus uses the digital audio signal whose sound quality has deteriorated in the same manner as the optical disc recording apparatus 1 according to the above-described embodiment, to obtain the master disc 2. Is exposed.

At this time, the optical disk recording apparatus processes the digital audio signal by the bit operation unit 61 shown in FIG. 10, and operates the digital audio signal so that the conventional compact disk player can reproduce almost monaurally. I do. Thus, the optical disk recording apparatus can degrade the sound quality of the digital audio signal so that it can be perceived, and can recover the deterioration of the sound quality.

That is, in the bit operating section 61, the digital audio signals R and L of the right channel and the left channel of each 16 bits are input to the arithmetic circuit 62, where predetermined arithmetic processing is performed between corresponding data. Thus, a 16-bit, 2-channel digital audio signal represented by (R + L) / 2 and (RL) / 2 is generated.

The bit operation section 61 is an addition signal (R) of the two-channel digital audio signal.
The digital audio signal LM of (+ L) / 2 is assigned as the main digital audio signal to the left channel of the conventional compact disc and output.

The comparison circuit 63 outputs (R)
-L) / 2, comparing the upper 8 bits of the digital audio signal with predetermined reference data REF,
Since the digital audio signal represented by (RL) / 2 generated in this manner has a small data amount, the digital audio signal represented by (RL) / 2 is converted to the lower 8 bits. It is determined whether or not expression is possible.

The selection circuit 64 selectively outputs the synthesized digital audio signal DM and the digital audio signal R of the right channel based on the comparison result SEL of the comparison circuit 63. Here, the synthesized digital audio signal DM
Are the lower 8 bits of the digital audio signal represented by (RL) / 2 and the upper 8 bits of the digital audio signal LM of (R + L) / 2, respectively. Is generated.

That is, the selection circuit 64 calculates the (RL)
/ 2 can be expressed by the lower 8 bits, that is, (RL) /
If the digital audio signal represented by 2 does not overflow by more than 8 bits, this synthesized digital audio signal DM is selectively output.

On the other hand, when the digital audio signal represented by (RL) / 2 is difficult to represent by the lower 8 bits, that is, when the digital audio signal represented by (RL) / 2 is 8 bits. When overflow occurs from the bit, the digital audio signal R of the right channel is selectively output.

The bit operation unit 61 allocates the digital audio signal LS output from the selection circuit 64 to the right channel of a conventional compact disc as a sub-digital audio signal and outputs it.

In this optical disk recording apparatus, the master disk is exposed by the two-channel digital audio signals LM and LS output from the bit operation section 61. Thus, in this embodiment, the digital audio signal is operated between channels to degrade the sound quality of the digital audio signal.

In response, the compact disk player obtains reproduction data from the compact disk in the same manner as the compact disk player according to the above-described embodiment, reproduces a digital audio signal from the reproduction data, and outputs it to an external device. I do. At this time, the compact disc player recovers the sound quality of the digital audio signal by the bit operation unit 65 shown in FIG.

That is, in the bit operation section 65, the two-channel digital audio signals LM and LS reproduced from the compact disk are input to the comparison circuit 66, where these digital audio signals LM and L
It is determined whether the upper 8 bits of S match.

The arithmetic circuit 67 receives the two-channel digital audio signals LM and LS, multiplies the amplitude of the main digital audio signal LM by two, and then subtracts it from the sub-digital audio signal LS. As a result, the arithmetic circuit 67 operates when the digital audio signal represented by (RL) / 2 overflows from 8 bits and the right digital audio signal R is assigned to the sub digital audio signal LS. , A digital audio signal representing the left channel L is reproduced. The arithmetic circuit 67 outputs the digital audio signal generated in this way together with the sub digital audio signal LS.

The arithmetic circuit 68 receives the two channels of digital audio signals LM and LS, and adds and subtracts these two digital audio signals LM and LS. Thereby, the arithmetic circuit 67 represents the left channel L and the right channel R when the digital audio signal represented by (RL) / 2 is assigned to the lower 8 bits of the sub digital audio signal LS. Play digital audio signals.

The selection circuit 64 selects these two operation circuits 67 and 68 based on the comparison result SEL of the comparison circuit 66.
2 channels of digital audio signals output from the digital audio signal are selectively output. That is, when the upper 8 bits of the digital audio signals LM and LS match, in this case, the digital audio signal represented by (RL) / 2 is allocated to the lower 8 bits of the sub digital audio signal LS. Thus, the digital audio signal output from the selection circuit 68 is selectively output. On the other hand, the digital audio signals LM and L
If the upper 8 bits of S do not match, the digital audio signal output from the selection circuit 67 is selectively output because the right digital audio signal is assigned to the sub digital audio signal LS in this case.

This compact disc player outputs a digital audio signal whose quality has been restored in the same manner as in the first embodiment.

As in the ninth embodiment, even if the digital audio signal is manipulated between channels to deteriorate the sound quality, the same effect as in the above-described embodiment can be obtained.

(10) Tenth Embodiment In this embodiment, the optical disc recording apparatus uses the digital audio signal whose sound quality has deteriorated in the same manner as the optical disc recording apparatus 1 according to the above-described embodiment, and uses the digital audio signal as the master disc 2. Is exposed. Further, bits are manipulated between channels to degrade the sound quality of the digital audio signal.

At this time, in the present embodiment, the ninth
A digital audio signal represented by (R + L) / 2 and (RL) / 2 is generated in the same manner as in the embodiment. Further, of these two-channel digital audio signals, the digital audio signal represented by (R + L) / 2 is allocated to the conventional right and left channels and recorded. On the other hand, in the digital audio signal represented by (RL) / 2, since the data amount is small, the data is compressed, allocated to subcodes, and recorded on the master disk.

Thus, the optical disk recording apparatus operates the digital audio signal between the channels to degrade the quality of the digital audio signal, and further allows the quality to be perceived and to recover the degraded quality. .

In response, the compact disk player obtains reproduction data from the compact disk in the same manner as the compact disk player according to the above-described embodiment, reproduces a digital audio signal from the reproduction data, and outputs the digital audio signal to an external device. I do. At this time, the compact disc player is obtained from the subcode (R-
L) / 2 and data represented by (R + L) / 2 reproduced as a digital audio signal are sequentially processed, thereby reproducing and outputting a two-channel digital audio signal.

As in the tenth embodiment, the same effect as in the above-described embodiment can be obtained by operating a digital audio signal between channels and transmitting data necessary for sound quality recovery by subcode. Can be obtained.

(11) Eleventh Embodiment In this embodiment, as described above with reference to FIG. 9, the lead-out area AR4 and the user area AR2
To form an additional data recording area AR3. Further, instead of the subcode described in the tenth embodiment, (R-
L) / 2 to record a digital audio signal.

In response to this, in the compact disk player, the user area AR2 and the recording area AR3 of the additional data are accessed simultaneously and in parallel by two optical pickups. Alternatively, one optical pickup is repeatedly sought to alternately access the user area AR2 and the additional data recording area AR3,
The reproduction data obtained from each of the areas AR2 and AR3 is buffered and output. Thereby, the compact disc player reproduces the compact disc so that the data represented by (RL) / 2 and the data represented by (R + L) / 2 can be processed simultaneously and in parallel. Further, the reproduced data represented by (RL) / 2 and the data represented by (R + L) / 2 are sequentially processed, whereby a 2-channel digital audio signal is reproduced and output.

As in the eleventh embodiment, the same effect as in the above-described embodiment can be obtained by operating the digital audio signal between channels and transmitting the operated channels individually. Can be.

(12) Other Embodiments In the above-described first embodiment, a case has been described in which bit manipulation is performed according to a fixed rule in units of two bits, but the present invention is not limited to this. For example, when the bit operation is performed by the bit inversion, the bit operation can be widely applied to the case where the lower 8 bits are changed according to a predetermined rule and the bit operation is performed.

In the third embodiment described above,
The case where the sound quality of the digital audio signal is degraded by the key data as the additional data and the additional data is recorded on the outer peripheral side of the compact disc has been described. However, the present invention is not limited to this. Data or the like transmitting significant information may be recorded, and the sound quality of the digital audio signal may be degraded by a logical operation between the data and the digital audio signal. In this case, as data for transmitting this kind of meaningful information, text data indicating a copyright owner, text data of lyrics, image data of a jacket,
HTML data or the like for guiding related works can be applied.

In response to this, the compact disc player can display information on the compact disc by the data transmitting the significant information, and can restore the sound quality by using the data. Further, in these cases, the significant data recorded on the outer peripheral side may be separately encrypted and recorded.

In the fourth embodiment described above,
Although the lower 8 bits of the 18-bit digital audio signal are data-compressed and synthesized with the upper 10 bits, the sound quality of the 18-bit digital audio signal is degraded and recorded. The present invention is not limited to this. For example, a 20-bit digital audio signal is decomposed into a 16-bit high-order digital signal and a 4-bit low-order digital audio signal, and the low-order 4 bit digital audio signal is recorded on the outer peripheral side of the compact disk. The sound quality of the digital audio signal may be degraded by a logical operation of the lower 4 bits of the 16-bit digital audio signal and the 4-bit digital audio signal recorded on the outer peripheral side. In this way, in a dedicated device for reproducing the compact disc, a digital audio signal can be output with a higher sound quality by executing a process corresponding to the process of deteriorating the sound quality.

In many of the above embodiments, a case has been described where the lower 8 bits of the digital audio signal are bit-operated to degrade and restore the sound quality of the digital audio signal. Not limited to this, the number of bits to be manipulated as necessary is
Various settings such as 6 bits, 4 bits, and 2 bits can be set, and the same effect can be obtained by performing bit operations on only predetermined bits of the digital audio signal.

In the above-described embodiment, the case where the present invention is applied to a compact disc to degrade and restore the sound quality of a digital audio signal obtained by simply quantizing a sampling value has been described. However, the present invention is not limited to this. For example, even if the present invention is applied to a mini disc to deteriorate the sound quality of a data-compressed digital audio signal and restore the deteriorated sound quality, the same effects as in the above-described embodiment can be obtained. Can be. In this case, the digital audio signal obtained by data compression is composed of coefficient data indicating the frequency spectrum and data indicating the gain, so that the sound quality is easily degraded by manipulating the digital audio signal in the frequency axis direction. In addition, deteriorated sound quality can be recovered.

In the above-described embodiment, a case has been described where sound quality is degraded by operating a predetermined bit which is a fixed ratio to all bits of the digital audio signal, and the degraded sound quality is restored. However, the present invention is not limited to this, and the number of bits to be operated may be changed according to, for example, the amplitude of the digital audio signal, and thereby the degree of deterioration and the degree of recovery may be changed according to the digital audio signal. Alternatively, the number of bits to be operated may be changed by a time code or the like, thereby varying the degree of deterioration and the degree of recovery.

Further, in these cases, by changing the number of bits to be operated according to the peak value, dynamic range, distribution of the frequency spectrum, etc. of the digital audio signal, the digital audio signal is restored to the extent of deterioration according to the digital audio signal. The degree may be variable. In this way, it is possible to perform various operations on the audible sound quality deterioration that changes depending on the source.

In these cases, the same effect can be obtained even if the number of bits to be operated is changed according to the genre of the source. That is, for example, the piano solo of a classical music has a large dynamic range and the signal level is extremely reduced in a part with a small volume,
Even if the number of bits for bit manipulation is reduced, sound quality degradation can be perceived reliably. On the other hand, pops and the like are characterized by a relatively small dynamic range and a relatively small decrease in signal level even in a portion with a small volume. With this, in pops, etc., the number of bits to be bit-operated is increased compared to piano solos, etc.
Sound quality deterioration can be perceived to the same degree as in the case of a piano solo or the like.

In the above-described embodiment, when the copyright can be reliably protected, the digital audio signal is output with the sound quality completely restored. Otherwise, the sound quality is not restored at all. Although the description has been given of the case where the output is performed without any error, the present invention is not limited to this, and the degree of sound quality deterioration may be changed according to the external device. That is, in this case, in the above-described first embodiment, for example, the conventional SCMS
For example, when a digital audio signal is output to an external device according to (1), 12 bits out of 16 bits are output with a correct digital value.

In these cases, as shown in FIG. 12, for example, a device ID is obtained from an external device 70 connected by IEEE 1394 or the like, and a bit operation based on the device ID is performed to perform digital audio processing in accordance with the external device. The sound quality of the signal may be degraded. In this case, in the bit operation unit 72 of the compact disc player 71, for example, the bit operation is performed by encryption so that the sound quality of the digital audio signal DM is degraded.

On the other hand, in the external system 70, the recording system is configured so that the input digital audio signal can be recorded without any bit manipulation.
A bit operation unit for restoring the quality of the digital audio signal based on the device ID of the external device is arranged in the reproduction system.

In this way, it is possible to set so that a digital audio signal can be reproduced with high sound quality only when reproduced by the external device 70, and only a private copy can be enjoyed with high sound quality. Thereby, the external device 70
And illegal distribution of the copied recording medium can be prevented.

Conversely, the device ID obtained from the device to which the digital audio signal is transmitted is determined, and the digital audio signal is output to a device such as a mini disk device integrated with a compact disk player. Only when this is done, the sound quality of the digital audio signal is restored and output.

At this time, in the integrated device, the digital audio signal input with high sound quality is recorded with its sound quality degraded based on its own device ID, and the sound quality of the reproduced digital audio signal is changed. Recovery is performed based on the own device ID. Even in this case, only private copies can be enjoyed with high sound quality, and illegal distribution of the copied recording medium can be prevented.

Further, in the above-described embodiment, a case has been described in which the sound quality of a digital audio signal recorded on a compact disc is degraded. However, the present invention is not limited to this. The present invention can be widely applied to optical disk devices, digital audio tape recorders, and the like. In this case, the sound quality is deteriorated and restored not only when the digital audio signal is input / output to / from an external device but also when the digital audio signal is recorded / reproduced on / from a recording medium. By performing the deterioration and recovery of each device on the basis of the device ID, the serial number, and the like of each device, duplication for purposes other than personal purposes can be significantly restricted.

Further, in the above-described embodiment, a case has been described in which the sound quality of a digital audio signal recorded on a compact disc is degraded. However, the present invention is not limited to this. The present invention can be widely applied to a case where an audio signal is transmitted.

In the above embodiment, the case where digital audio signals are transmitted has been described.
The present invention is not limited to this, and can be widely applied to transmission of various digital signals such as digital video signals.

[0125]

As described above, according to the present invention, a digital signal is manipulated and transmitted so that the quality is degraded to a degree that can be perceived and the quality degraded by predetermined processing can be recovered. By doing so, digital signals can be transmitted to conventional devices, and copyright can be effectively protected.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an optical disc recording device according to a first embodiment of the present invention.

FIG. 2 is a chart provided for describing an operation of the optical disc recording apparatus of FIG. 1;

FIG. 3 is a block diagram showing a compact disc player according to the first embodiment of the present invention.

FIG. 4 is a table provided for explaining the operation of the compact disc player of FIG. 3;

FIG. 5 is a block diagram showing a bit operation unit applied to an optical disc recording device according to a fourth embodiment.

FIG. 6 is a block diagram showing a bit operation unit applied to a compact disc player according to a fourth embodiment.

FIG. 7 is a block diagram showing a bit operation unit applied to an optical disc recording device according to a fifth embodiment.

FIG. 8 is a block diagram showing a bit operation unit applied to a compact disc player according to a fifth embodiment.

FIG. 9 is a perspective view showing a compact disc according to a sixth embodiment.

FIG. 10 is a block diagram showing a bit operation unit applied to an optical disk recording device according to a ninth embodiment.

FIG. 11 is a block diagram showing a bit operation unit applied to a compact disc player according to a ninth embodiment.

FIG. 12 is a block diagram showing an audio system according to another embodiment.

[Explanation of symbols]

1 ... optical disk recording device, 2 ... disk master, 1
0, 28, 50, 52, 55, 57, 61, 65... Bit operating section, 20, 71... Compact disk player, 29... Disk discriminating section, 33.

Claims (93)

[Claims] 1. A quality deterioration means for deteriorating the quality of an input digital signal and generating a quality-degraded digital signal so that the quality deterioration can be perceived and the degraded quality can be recovered. A transmission device for digital signals, comprising: transmission means for transmitting digital signals. 2. The digital signal transmission device according to claim 1, wherein said quality deterioration means operates said input digital signal in an amplitude direction to generate said quality-degraded digital signal. 3. The digital signal transmission apparatus according to claim 2, wherein said quality deterioration means operates a predetermined bit of said input digital signal to operate said input digital signal in an amplitude direction. 4. The apparatus according to claim 2, wherein said quality degrading means operates predetermined bits of said input digital signal with a digital signal deteriorating quality to operate said digital signal in an amplitude direction. Digital signal transmission equipment. 5. The digital signal processing system according to claim 2, wherein said quality deterioration means operates predetermined bits of said input digital signal by data deteriorating quality to operate said digital signal in an amplitude direction. Signal transmission equipment. 6. The digital signal transmission device according to claim 5, wherein the data is data for transmitting significant information related to the digital signal. 7. The digital signal transmission apparatus according to claim 1, wherein said quality deterioration means operates said input digital signal in a time axis direction to generate said quality-degraded digital signal. 8. The apparatus according to claim 7, wherein said quality deterioration means operates the input digital signal in the time axis direction by replacing at least a part of the bits of the input digital signal in the time axis direction. Digital signal transmission equipment. 9. The digital signal transmission apparatus according to claim 1, wherein said quality deterioration means operates said input digital signal in a frequency axis direction to generate said quality-degraded digital signal. 10. The digital signal according to claim 9, wherein said input digital signal is a data-compressed digital signal.
A digital signal transmission device according to claim 1. 11. The input digital signal is a digital signal of a plurality of channels, and the quality deterioration means operates the input digital signal between channels to generate the digital signal of the quality deterioration. The digital signal transmission device according to claim 1. 12. The digital signal transmission apparatus according to claim 1, wherein said quality deterioration means deteriorates the quality of said input digital signal at a predetermined cycle. 13. The digital signal transmission apparatus according to claim 1, wherein said quality deterioration means changes a degree of quality deterioration in accordance with said input digital signal. 14. The digital signal transmission apparatus according to claim 1, wherein said quality deterioration means varies a degree of quality deterioration according to a transmission target of said transmission means. 15. The digital signal transmission apparatus according to claim 1, wherein said transmission means separately transmits data necessary for restoring the quality of the quality-degraded digital signal. 16. The digital signal transmission apparatus according to claim 15, wherein said data is data for transmitting significant information related to said digital signal. 17. The digital signal transmission apparatus according to claim 1, wherein said transmission means transmits said input digital signal in place of said quality-degraded digital signal according to a transmission target. 18. The digital signal transmission apparatus according to claim 1, wherein said transmission means records the quality-degraded digital signal on an optical disk and transmits the quality-degraded digital signal. 19. The transmission means records the quality-degraded digital signal on an optical disk, transmits the quality-degraded digital signal, and stores data necessary for restoring the quality of the quality-degraded digital signal. 2. The digital signal transmission apparatus according to claim 1, wherein the digital signal is transmitted after being recorded on an optical disk. 20. An apparatus according to claim 19, wherein said data is data for transmitting significant information related to said digital signal. 21. Deteriorating the quality of an input digital signal to generate a degraded digital signal so that the degraded quality can be perceived and the degraded quality can be recovered, and transmitting the degraded digital signal. A method of transmitting a digital signal. 22. The digital signal transmission method according to claim 21, wherein said quality-deteriorated digital signal is generated by manipulating said input digital signal in an amplitude direction. 23. The digital signal transmission method according to claim 22, wherein a predetermined bit of the input digital signal is operated to operate the input digital signal in an amplitude direction. 24. The digital signal transmission method according to claim 22, wherein a predetermined bit of the input digital signal is manipulated by a digital signal deteriorating quality to manipulate the digital signal in an amplitude direction. 25. The digital signal according to claim 2, wherein predetermined bits of said input digital signal are manipulated by data deteriorating quality to manipulate said digital signal in an amplitude direction.
3. The digital signal transmission method according to 2. 26. The method according to claim 25, wherein said data is data for transmitting significant information related to said digital signal. 27. The digital signal transmission method according to claim 21, wherein the digital signal having the quality deterioration is generated by operating the input digital signal in a time axis direction. 28. The digital signal transmission method according to claim 27, wherein at least a part of bits of said input digital signal is replaced in a time axis direction and said input digital signal is operated in a time axis direction. 29. The digital signal transmission method according to claim 21, wherein the input digital signal is operated in a frequency axis direction to generate the quality-degraded digital signal. 30. The input digital signal according to claim 2, wherein the input digital signal is a data-compressed digital signal.
10. The method for transmitting a digital signal according to item 9. 31. The input digital signal is a digital signal of a plurality of channels, and the method of transmitting the digital signal comprises operating the input digital signal between channels to generate the quality-degraded digital signal. 22. The digital signal transmission method according to claim 21, wherein: 32. The digital signal transmission method according to claim 21, wherein the quality of the input digital signal is degraded at a predetermined cycle. 33. An apparatus according to claim 2, wherein a degree of deteriorating quality is varied according to the input digital signal.
2. The digital signal transmission method according to 1. 34. The apparatus according to claim 2, wherein the degree of quality deterioration is varied according to the transmission target of said transmission means.
2. The digital signal transmission method according to 1. 35. The digital signal transmission method according to claim 21, wherein data necessary for restoring the quality of the quality-degraded digital signal is separately transmitted. 36. The digital signal transmission method according to claim 35, wherein said data is data for transmitting significant information related to said digital signal. 37. The digital signal transmission method according to claim 21, wherein the input digital signal is transmitted instead of the quality-degraded digital signal according to a transmission target. 38. The digital signal transmission method according to claim 21, wherein the quality-deteriorated digital signal is recorded on an optical disc and the quality-deteriorated digital signal is transmitted. 39. Recording the quality-deteriorated digital signal on an optical disc and transmitting the quality-degraded digital signal, and recording data necessary for restoring the quality of the quality-degraded digital signal on the optical disc. 22. The digital signal transmission method according to claim 21, wherein the digital signal is transmitted. 40. The digital signal transmission method according to claim 39, wherein said data is data for transmitting significant information related to said digital signal. 41. A transmission means for inputting a quality-degraded digital signal whose quality has been degraded so that quality deterioration can be perceived and can be recovered from the degraded quality from a predetermined transmission path; And a quality recovery unit for recovering the quality of the digital signal. 42. The transmission of a digital signal according to claim 41, wherein said quality recovery means recovers the quality of the quality-degraded digital signal by operating the quality-degraded digital signal in an amplitude direction. apparatus. 43. The digital signal according to claim 42, wherein said quality recovery means operates a predetermined bit of said quality-degraded digital signal to operate said quality-degraded digital signal in an amplitude direction. Transmission equipment. 44. The quality restoring means, wherein a predetermined bit of the quality-degraded digital signal is manipulated by a digital signal whose quality is to be restored, and the quality-degraded digital signal is manipulated in an amplitude direction. Item 43. The digital signal transmission device according to Item 42. 45. The quality restoring means, wherein a predetermined bit of the quality-degraded digital signal is manipulated by data for quality restoration, and the quality-degraded digital signal is manipulated in an amplitude direction. 43. The digital signal transmission device according to 42. 46. The digital signal transmission apparatus according to claim 45, wherein said data is data for transmitting significant information related to said digital signal. 47. The digital signal according to claim 41, wherein said quality recovery means recovers the quality of the quality-degraded digital signal by operating the quality-degraded digital signal in a time axis direction. Transmission equipment. 48. The quality recovery means, wherein at least a part of bits of the quality-deteriorated digital signal are replaced in the time axis direction, and the quality-deteriorated digital signal is manipulated in the time axis direction. 4
8. The digital signal transmission device according to 7. 49. The digital signal according to claim 41, wherein said quality recovery means recovers the quality of said quality-degraded digital signal by operating said quality-degraded digital signal in a frequency axis direction. Transmission equipment. 50. The digital signal transmission apparatus according to claim 49, wherein said quality-degraded digital signal is a data-compressed digital signal. 51. The quality-degraded digital signal is a digital signal of a plurality of channels, and the quality recovery means recovers the quality of the quality-degraded digital signal by operating the quality-degraded digital signal between channels. 42. The digital signal transmission device according to claim 41, wherein: 52. The digital signal transmission apparatus according to claim 41, wherein said quality recovery means recovers the quality of said quality-degraded digital signal at a predetermined cycle. 53. The digital signal transmission apparatus according to claim 41, wherein said quality recovery means recovers the quality of said quality-degraded digital signal in accordance with said quality-degraded digital signal. 54. The digital signal transmission as claimed in claim 41, wherein the digital signal whose quality has been restored and the digital signal whose quality has deteriorated are selectively output to the external device in accordance with the external device. apparatus. 55. The digital signal according to claim 41, wherein the quality-recovered digital signal is transmitted to an external device, and wherein the quality recovery unit changes a degree of quality to be recovered according to the external device. Digital signal transmission equipment. 56. The transmission means according to claim 41, wherein data necessary for restoring the quality of the quality-degraded digital signal is separately input.
A digital signal transmission device according to claim 1. 57. The digital signal transmission device according to claim 56, wherein said data is data for transmitting significant information related to said digital signal. 58. The digital signal transmission apparatus according to claim 41, wherein said transmission means is a reproduction system for reproducing the quality-degraded digital signal from an optical disk. 59. A transmission system according to claim 4, wherein said transmission means is a reproduction system for reproducing the quality-degraded digital signal and data necessary for restoring the quality of the quality-degraded digital signal from an optical disk.
2. The digital signal transmission device according to 1. 60. A quality-degraded digital signal whose quality has been degraded is input from a predetermined transmission path so that quality degradation can be perceived and the degraded quality can be recovered. A method for transmitting a digital signal, the method comprising restoring signal quality. 61. The digital signal transmission method according to claim 60, wherein the quality of the quality-degraded digital signal is restored by manipulating the quality-degraded digital signal in an amplitude direction. 62. The digital signal transmission method according to claim 61, wherein a predetermined bit of the quality-degraded digital signal is manipulated to manipulate the quality-degraded digital signal in an amplitude direction. 63. The digital signal according to claim 61, wherein a predetermined bit of the quality-degraded digital signal is manipulated by a digital signal for restoring quality, and the quality-degraded digital signal is manipulated in an amplitude direction. Signal transmission method. 64. The digital signal according to claim 61, wherein predetermined bits of the quality-degraded digital signal are manipulated by data for restoring quality, and the quality-degraded digital signal is manipulated in an amplitude direction. Transmission method. 65. A digital signal transmission method according to claim 64, wherein said data is data for transmitting significant information related to said digital signal. 66. A digital signal transmission method according to claim 60, wherein the quality of the quality-degraded digital signal is recovered by manipulating the quality-degraded digital signal in a time axis direction. 67. The digital signal according to claim 66, wherein at least a part of the bits of the quality-degraded digital signal are replaced in the time axis direction, and the quality-degraded digital signal is manipulated in the time axis direction. Transmission method. 68. The digital signal transmission method according to claim 60, wherein the quality of the quality-degraded digital signal is restored by manipulating the quality-degraded digital signal in a frequency axis direction. 69. The digital signal transmission method according to claim 68, wherein said quality-degraded digital signal is a data-compressed digital signal. 70. The quality-degraded digital signal is a digital signal of a plurality of channels, and the method of transmitting the digital signal includes: operating the quality-degraded digital signal between channels to control the quality of the quality-degraded digital signal. 61. The digital signal transmission method according to claim 60, wherein the digital signal is recovered. 71. The digital signal transmission method according to claim 60, wherein the quality of the quality-degraded digital signal is recovered at a predetermined cycle. 72. The digital signal transmission method according to claim 60, wherein the quality of the quality-degraded digital signal is restored in accordance with the quality-degraded digital signal. 73. The digital signal transmission according to claim 60, wherein the digital signal whose quality has been restored and the digital signal whose quality has deteriorated are selectively output to the external device according to the external device. Method. 74. A digital signal transmission method according to claim 60, wherein a digital signal whose quality has been restored is transmitted to an external device, and a degree of the quality to be recovered is varied according to said external device. . 75. The digital signal transmission method according to claim 60, wherein data necessary for restoring the quality of the quality-degraded digital signal is separately input. 76. The digital signal transmission method according to claim 75, wherein said data is data for transmitting significant information related to said digital signal. 77. The transmission path has an optical disk, and the digital signal transmission method is characterized in that the quality-degraded digital signal is reproduced from the optical disk and the quality-degraded digital signal is input. The method for transmitting a digital signal according to claim 60. 78. The transmission path has an optical disk, and the method of transmitting the digital signal includes the steps of: transmitting the quality-degraded digital signal and the data necessary to recover the quality of the quality-degraded digital signal from the optical disk 61. The digital signal transmission method according to claim 60, wherein the digital signal having the quality deterioration and the data are input after being reproduced. 79. The digital signal transmission method according to claim 78, wherein said data is data for transmitting significant information related to said digital signal. 80. A digital signal recording medium characterized by recording a quality-degraded digital signal obtained by deteriorating quality so that quality deterioration can be perceived and the degraded quality can be recovered. 81. The digital signal recording medium according to claim 80, wherein said quality-degraded digital signal is generated by manipulating a predetermined digital signal in an amplitude direction. 82. A digital signal recording medium according to claim 80, wherein said digital signal of deteriorated quality is generated by manipulating predetermined bits of a predetermined digital signal. 83. The recording of a digital signal according to claim 80, wherein said quality-degraded digital signal is generated by manipulating predetermined bits of a predetermined digital signal with the digital signal deteriorating quality. Medium. 84. The digital signal recording medium according to claim 80, wherein said quality-degraded digital signal is generated by manipulating predetermined bits of a predetermined digital signal with data degrading quality. . 85. The digital signal recording medium according to claim 84, wherein said data is data for transmitting significant information related to said digital signal. 86. The digital signal recording medium according to claim 80, wherein said quality-degraded digital signal is generated by manipulating a predetermined digital signal in a time axis direction. 87. The digital signal of deteriorated quality is generated by replacing at least a part of bits of a predetermined digital signal in a time axis direction.
0. A recording medium for digital signals according to item 0. 88. The digital signal recording medium according to claim 80, wherein said quality-degraded digital signal is generated by operating a predetermined digital signal in a frequency axis direction. 89. The digital signal recording medium according to claim 88, wherein said quality-degraded digital signal is a data-compressed digital signal. 90. The digital signal recording medium according to claim 80, wherein said quality-degraded digital signal is generated by operating a digital signal of a plurality of channels between channels. 91. The digital signal recording medium according to claim 80, wherein said quality-degraded digital signal is generated by deteriorating the quality of a predetermined digital signal at a predetermined cycle. 92. A digital signal recording medium according to claim 80, wherein data necessary for restoring the quality of said quality-degraded digital signal is recorded. 93. The digital signal recording medium according to claim 92, wherein said data is data for transmitting significant information related to said digital signal.