JP3177355B2 - Digital recording and playback device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital recording / reproducing apparatus for recording / reproducing a digital signal on a magnetic tape or an optical disk using magnetism or light.

[0002]

2. Description of the Related Art For example, video tape recorders (hereinafter referred to as "VTRs") have become widely used in ordinary households, and as a result, the emergence of next-generation VTRs having higher functions is desired. The reason why the VTR has developed so far is that recording from a television receiver or a video camera can be freely performed. However, apart from recording from a television receiver, in the case of recording from a video camera with many private recordings, there is a demand that a function that only a specific person can see when reproducing is required. Is strong. That is, there is a demand for a so-called scramble function in which a user-specific password is input in advance during recording and a reproduced image cannot be viewed unless the same password is input during reproduction.

In a conventional analog VTR, it has been considered to add a scrambling function, but a very complicated dedicated circuit is provided. In addition, no conventional digital VTR has a scramble function. Also, there has been no optical disk recording / reproducing apparatus, which is an example of a digital recording / reproducing apparatus other than a VTR, which has a scramble function having a simple configuration.

[0004]

As described above, the conventional digital recording / reproducing apparatus has a problem that it does not have a scramble function having a simple structure. In addition, the scrambling function in the analog VTR requires a very complicated dedicated circuit, and has a problem that the manufacturing cost is high.

The present invention has been made in view of such circumstances, and has as its object to provide an inexpensive and reliable digital recording / reproducing apparatus having a scramble function.

According to the first aspect of the present invention, the recording system is provided with zero users.
Password is a number selected from multiple numbers including
Setting means for performing the setting, a shuffling means for performing a shuffling process on the digital signal to be recorded on the recording medium, and a password value set in the setting means .
Address that indicates the location of the digital signal
Double, the and a shuffling control means for setting the shuffling addresses in the shuffling process by the shuffling means, the reproduction system, the user including 0
Input means for inputting a numerical value of one selected from numerical values as a password, deshuffling means for performing a deshuffling process on the reproduced digital signal, and a digital signal corresponding to the value of the password input to the input means.
And a deshuffling control means for setting a deshuffling address in the deshuffling process by the deshuffling means by shifting the address indicating the arrangement position of the deshuffling means.

[0007] The second aspect of the present invention is, in the recording system, the user 0
Password is a number selected from multiple numbers including
Setting means for performing the setting, a shuffling means for performing a shuffling process on the digital signal to be recorded on the recording medium, and a password value set in the setting means .
Address that indicates the location of the digital signal
By this, shuffling control means for setting a shuffling address in the shuffling process by the shuffling means, and a password recording means for recording the password set in the setting means in a predetermined area of the recording medium, The reproduction system has a plurality of numbers including 0 by the user.
An input unit for inputting a numerical value of 1 selected from the values as a password, a deshuffling unit for performing a deshuffling process on the reproduced digital signal, and comparing the reproduced password with the input password so that they match. comparison means for determining whether, when it is determined that both passwords match by the comparison means, only the value of the password inputted to the input means, unmatched when
When it is determined, the password of 0
Only the value indicates the address indicating the location of the digital signal.
And a deshuffling control means for setting a deshuffling address in the deshuffling processing by the deshuffling means.

[0008] The invention of claim 3 is the invention of claim 1 or 2 above.
In the invention, a digital signal is a fixed number of blocks.
Shows a sequence of frames consisting of
Deshuffling is performed by arranging blocks for each frame.
Is the process of changing the shuffling address.
And the setting of the deshuffling address
The password indicates the address indicating the location of the block
It is characterized in that it is a process of shifting by only one value.

[0009] In the first aspect of the present invention, the setting means is used.
Pass the number 1 selected by the user from multiple numbers including 0
Set as a word. The shuffling means performs a shuffling process on the digital signal to be recorded. The shuffling control unit is configured to set the password value set in the setting unit.
Only shift the address indicating the location of the digital signal
Thus, the shuffling address in the shuffling process by the shuffling means is set. Input means
Is a numerical value of 1 selected from multiple numerical values including 0 by the user
As a password. The deshuffling means is
A deshuffling process is performed on the reproduced digital signal. The deshuffling control means includes an address indicating the arrangement position of the digital signal by the value of the password input to the input means.
By shifting the dress, a deshuffling address in the deshuffling processing by the deshuffling means is set.

[0010] In the invention according to claim 2, the setting means is used.
Pass the number 1 selected by the user from multiple numbers including 0
Set as a word. The shuffling means performs a shuffling process on the digital signal to be recorded on the recording medium. The shuffling control means includes an address indicating the digital signal arrangement position by the value of the password set in the setting means.
By shifting the address, a shuffling address in the shuffling process by the shuffling means is set. The password recording means records the password set by the setting means in a predetermined area of the recording medium. Input means
Is a numerical value of 1 selected from multiple numerical values including 0 by the user
As a password. The deshuffling means is
A deshuffling process is performed on the reproduced digital signal. The comparing means compares the reproduced password with the input password to determine whether the two match. The deshuffling control unit determines that when the comparison unit determines that the two passwords match, only the value of the password input to the input unit is determined not to match.
When the password is 0, the password
By shifting the address indicating the location of the digital signal,
The deshuffling address is set in the deshuffling process by the deshuffling means.

According to the third aspect of the present invention, the shuffling means and the deshuffling means comprise a block for each frame.
The shuffling control and the deshufflin
The controller controls the block arrangement position in the frame.
The indicated address is shifted by the value indicated by the password.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram of a recording system of a digital VTR as an example of a digital recording / reproducing apparatus according to an embodiment of the present invention.
, An A / D conversion unit 2, a DCT unit 3, an encoding unit 4,
Macroblocking unit 5, shuffling unit 6, adding unit 7, final processing unit 8, password input unit 9, shuffling control unit 10, password processing unit 11, adder 12, magnetic head 13 is provided. The A / D converter 2 converts an analog input video signal passed through the pre-filter 1 into a digital video signal. The DCT unit 3
The digital video signal converted by the A / D converter 2 is divided into compressed block units and subjected to discrete cosine transform (hereinafter referred to as “DCT”). The encoding unit 4 performs weighting, quantization, and zigzag cancellation on the compressed block from the DCT unit 3 and encodes the compressed block. The macroblock forming unit 5 collects a predetermined number of compressed blocks from the coding unit 4 and forms a macroblock. The shuffling unit 6 includes a shuffling control unit 10.
, A shuffling process is performed on the macroblock from the macroblock forming unit 5. Additional part 7
Adds a redundant bit such as an error correction code to the macroblock from the shuffling unit 6. The final processing unit 8 converts the macroblock from the adding unit 7 into multiple channels and multiple segments. The password input unit 9 inputs a password specified by a user using a remote controller or operation keys. The shuffling control unit 10 controls the shuffling unit 6 according to the password from the password input unit 9. The password processing unit 11 performs a predetermined process to record the password from the password input unit 9 in an area where a user can freely record a control code, such as a sub-code area of a magnetic tape. Adder 1
2 adds the macroblock from the final processing unit 8 and the password from the password processing unit 11. The magnetic head 13 records the digital signal from the adder 12 on a magnetic tape.

FIG. 2 is a block diagram of a reproducing system of a digital VTR as an example of a digital recording / reproducing apparatus according to an embodiment of the present invention.
, A waveform equalizing unit 22, a clock PLL unit 23, a data processing unit 24, an error correcting unit 25, a deshuffling unit 26, a subcode analyzing unit 27, and a password comparing unit 2.
8, a switch 29, a deshuffling control unit 30,
Conversion unit 31, decompression unit 32, D / A converter 33
, A post filter 34, and a password input unit 35. The magnetic head 21 reproduces a digital signal recorded on a magnetic tape. Waveform equalizer 22
Performs a waveform equalization process on the digital signal reproduced by the magnetic head 21. The data processing unit 24 receives the clock P
The digital signal passed through the LL section 23 is subjected to data processing from multiple channels and multiple segments. Error correction unit 25
Corrects an error in the digital signal from the data processing unit 24. The deshuffling unit 26 is controlled by the deshuffling control unit 30, and performs a deshuffling process on the digital signal from the error correction unit 25. The subcode analysis unit 27 analyzes a password or the like recorded in the subcode. The password comparison unit 28 includes a password from the subcode analysis unit 27 and a password input unit 35.
Then, the switch 29 is controlled by comparing the password with the password and determining whether or not the passwords match each other. Switch 29
Is controlled by the password comparison unit 28, if the passwords match, the password from the password input unit 35 is passed to the deshuffling control unit 30. If the passwords do not match, the signal “0” from the password comparison unit 28 is used as the password. It is passed to the deshuffling control unit 30. The deshuffling control unit 30 controls the deshuffling unit 26 according to the password input through the switch 29. The conversion unit 31 converts the macroblock from the deshuffling unit 26 into a compressed block. The expansion unit 32 expands the compressed block from the conversion unit 31. The D / A converter 33 converts the digital signal from the expansion unit 32 into an analog signal. The password input unit 35 inputs a password specified by the user using a remote controller or operation keys.

The details of the variable-length or fixed-length coding, the audio system, and the like are not directly related to the gist of the present invention, and the description thereof will be omitted. Next, the operation will be described. In the recording system,
The input analog video signal passes through a pre-filter unit 1 and is converted into a digital signal by an A / D converter 2. This digital signal is divided by the DCT unit 3 into compressed block units and subjected to DCT.

That is, one frame is 72 frames in the horizontal direction.
Since there are 0 pixels and 480 pixels in the vertical direction, if a Y signal of 8 × 8 pixels is defined as one compression block, one frame corresponds to FIG.
, It can be divided into 90 × 60 compressed blocks. Actually, there is a color difference signal in addition to the Y signal.
Since R: CB = 4: 1: 1 is often set, in this case, one color signal compression block may be created for each of the four Y signal compression blocks.

The DCT is applied, for example, in NTS
For C, 100 Mbps for simple calculation, for studio standard, 216 Mbps with a margin, 1 Gbps for HDTV
This is because the above-mentioned amount of information is required, and it is necessary to perform compression such as concentrating the energy distribution in order to record this huge amount of information. DCT unit 3 sets D
The compression block to which the CT has been applied is encoded by the encoding unit 4.
Weighting, quantization, and zigzag scanning are performed and encoded. Then, a plurality of compressed blocks are collected and macroblocked by the macroblock generator 5.

That is, the four Y signal compression blocks and the two color signal compression blocks are combined into one macro block, and as shown in FIG.
350 macroblocks are created. Here, the compressed blocks of four Y signals included in one macroblock often take adjacent blocks so as to be advantageous for the subsequent control, that is, encoding. This is because adjacent blocks have similar pixels, so that correlation can be easily obtained.

On the other hand, the password input to the password input unit 9 by the user using a remote controller or operation keys is input to the shuffling control unit 10,
The shuffling control unit 10 controls the shuffling unit 6 according to the password. The macroblocks that have been macroblocked by the macroblocking unit 5 are subjected to shuffling processing by the shuffling unit 6 based on control from the shuffling control unit 10.

That is, there are 1350 macroblocks per frame.
0 to MB1349. The purpose of the shuffling process is to dispose them separately as shown in FIG. The reason for such a disjointed arrangement is to reduce the influence on various errors occurring in the electromagnetic conversion system, especially on burst errors. Note that this shuffling process is generally performed based on a predetermined rule. Here, the number of the macro block is MB _n (n: 0 to 134)
9), and assuming that the password is m (m: 1 to 999), the shuffling control unit 10 changes the macroblock number as in the following equation 1. And shuffling part 6
Performs shuffling by giving a shuffling address according to a predetermined rule using the number of the macroblock changed by the shuffling control unit 10. As a result, the shuffling address is changed according to the password, and when the password is 0, it matches the shuffling address obtained by the normal shuffling process.

[0020]

(Equation 1)

The macroblock shuffled by the shuffling unit 6 is added with a redundant bit such as an error correction code by the adding unit 7, and is multi-channeled and multi-segmented by the final processing unit 8. Passed to. On the other hand, the password from the password input unit 9 is
By the password processing unit 11, the subcode area, etc.
The adder 1 is processed to write a password in the area of the magnetic tape where the user can freely record the control code.
Passed to 2.

The macroblock from the final processing unit 8 and the password from the password processing unit 11 are added by the adder 12 and written on the magnetic tape by the magnetic head 13. In the reproducing system, the macroblock reproduced by the magnetic head 21 is waveform-equalized by the waveform equalizing unit 22, passed through the clock PLL unit 23, and subjected to data processing from multiple channels and multiple segments by the data processing unit 24. Then, the data error is corrected by the error correction unit 25 and is passed to the deshuffling unit 26.

On the other hand, the sub-code reproduced by the magnetic head 21 is analyzed by the sub-code analyzing section 27, a password is taken out, and passed to the password comparing section 28. Further, the password input to the password input unit 35 by the user using the remote controller or the operation keys is transferred to the password comparing unit 28. The password comparison unit 28 compares the password from the subcode analysis unit 27 with the password from the password input unit 35, and if they match, controls the switch 29 to deshuffle the password from the password input unit 35. If the two do not match, the switch 29 is controlled to pass "0" to the deshuffling control unit 30. Thereby, the deshuffling control unit 30 controls the deshuffling unit 26 so that the deshuffling process is performed based on the password from the password input unit 35 or the password comparison unit 28, and the deshuffling unit 2
6 performs a deshuffling process on the macroblock from the error correction unit 25 based on the control by the deshuffling control unit 30.

That is, since the shuffling address is changed according to the password at the time of recording, correct deshuffling is performed by changing the address used for deshuffling at the time of reproduction according to the same password as at the time of recording. Since the images are rearranged in the correct order before the shuffling, the images can be reproduced. If the password input to the password input unit 35 is different from that at the time of recording, “0” is output as the password from the password comparison unit 28, so that the deshuffling based on the normal rules is performed, and the correct deshuffling is performed. And the original video cannot be reproduced. If you did not enter a password at the time of recording,
Even if a password is erroneously input to the password input unit 35 at the time of reproduction, "0" is output as the password from the password comparison unit 28, so that the reproduction can be performed correctly.

The macroblock deshuffled by the deshuffling unit 26 is converted into a compressed block by the conversion unit 31, expanded by the expansion unit 32, converted into an analog video signal by the D / A converter 33, and passed through the post filter 34. Output. in this way,
Since the shuffling address is changed according to the password during recording, and the deshuffling address is changed according to the password during playback, a normal playback image can be obtained only when the same password as during recording is input during playback. A simple scramble function can be realized. Also, since shuffling and deshuffling processes are usually always performed in a digital recording / reproducing apparatus, there is no need to provide a complicated dedicated circuit for the scrambling function, and the scrambling function can be realized at low cost.

In the above embodiment, the password at the time of recording is recorded on the magnetic tape, and the password reproduced at the time of reproduction is compared with the password from the password input unit 35 by the password comparison unit 28. The password at the time may not be recorded on the magnetic tape, and the password from the password input unit 35 may be directly input to the deshuffling control unit 30. In this way, if the password at the time of recording is forgotten, reproduction becomes extremely difficult even by using an emergency means.
And the switch 29 can be omitted. If you do this,
Shuffling and deshuffling are performed according to the password, so that the scramble function is not impaired.

In the above embodiment, the number of the macro block is changed by simply adding the password at the time of shuffling, but a more complicated conversion may be performed. For example, the numbers of macroblocks are 0 to 500,
Divided into three sets of 501-1000, 1001-1349,
The number in each set may be changed in a complicated manner according to the password.

In the above embodiment, the shuffling address is changed in accordance with the password at the time of recording. However, at the time of recording, the password is only recorded on the magnetic tape, and the password input at the time of reproduction is compared with the reproduced password. Then, if they match, deshuffling may be performed based on a normal rule, and if they do not match, deshuffling may be performed based on, for example, an input password. In this way, if it is played back on a device of another company, it will be played back normally, so it can not be said that it is a perfect scramble function, but this is not enough as a scramble function in a narrow range such as at home It is thought that there are many cases.

In the above-described embodiment, an example has been described in which shuffling at the time of compression for changing the arrangement of macroblocks is controlled in accordance with a password. However, error correction processing in a tape system is performed in order to randomize burst errors. In many cases, a Reed-Solomon product code is used, and at this time, it is clear that the mapping is as shown in FIG. 5. Therefore, shuffling at that time may be controlled according to the password.

In the above embodiment, a digital VTR was described as an example of a digital recording / reproducing apparatus. However, the present invention can be applied to other digital recording / reproducing apparatuses such as an optical disk recording / reproducing apparatus. Of course.

As described above, according to the present invention, the number of 1s selected by the user from a plurality of numerical values including 0 is stored in the recording system.
Setting means for setting a value as a password, shuffling means for performing a shuffling process on a digital signal to be recorded, and a password value set in the setting means .
Address that indicates the location of the digital signal
And shuffling control means for setting a shuffling address in the shuffling process by the shuffling means .
Input means for inputting a numerical value of one selected from numerical values as a password, deshuffling means for performing a deshuffling process on the reproduced digital signal, and arrangement of the digital signal by the value of the password input to the input means
And a deshuffling control means for setting a deshuffling address in the deshuffling process by the deshuffling means by shifting the address indicating the location, so that the shuffling address is set according to the contents of the password during recording, and the password is Since the deshuffling address is set in accordance with the contents of the above, the reproduction is normally performed only when the same password as that at the time of recording is input at the time of reproduction, and an accurate scramble function can be realized. Also, since shuffling and deshuffling processes are usually always performed in a digital recording / reproducing apparatus, there is no need to provide a complicated dedicated circuit for the scrambling function, and the scrambling function can be realized at low cost.

In the recording system, a plurality of users including 0
Setting means for setting a numerical value of 1 selected from numerical values as a password; shuffling means for performing a shuffling process on a digital signal to be recorded on a recording medium; and a digital signal corresponding to the password value set in the setting means.
A shuffling control means for setting a shuffling address in the shuffling process by the shuffling means by shifting the address indicating the arrangement position of the shuffling means, and a password for recording the password set in the setting means in a predetermined area of the recording medium. Recording means for passing a numerical value of 1 selected from a plurality of numerical values including 0 by the user to the reproducing system.
Input means for inputting as a word, deshuffling means for performing a deshuffling process on the reproduced digital signal, and comparing means for comparing the reproduced password with the inputted password to determine whether or not the two match. And the value of the password input to the input means when the comparing means determines that the two passwords match .
If it is determined that they do not match, 0 is set as the password
The position of the digital signal by the password value.
A deshuffling control means for setting a deshuffling address in the deshuffling process by the deshuffling means by shifting the indicated address , if the shuffling address is set in accordance with the content of the password during recording, and Since the deshuffling address is set according to, the reproduction is normally performed only when the same password as that at the time of recording is input during reproduction, the reproduction is performed normally, and an accurate scramble function can be realized. Also, since shuffling and deshuffling processes are usually always performed in a digital recording / reproducing apparatus, there is no need to provide a complicated dedicated circuit for the scrambling function, and the scrambling function can be realized at low cost. Furthermore, since the password at the time of recording is recorded on the recording medium, if the password is forgotten, the password can be reproduced by reading the password recorded on the recording medium as an emergency measure.

A digital signal is a fixed number of blocks.
Shows the arrangement of frames consisting of
And the deshuffling process
This is the process of changing the array, and the shuffling address
Settings and deshuffling address settings are
Password indicating the array position of blocks in the password
The password is shifted by the value indicated by
Different shuffling depending on the value of
A digital recording / reproducing apparatus can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram of a recording system of a digital VTR as an example of a digital recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram of a reproduction system of a digital VTR as an example of a digital recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram of a compression block.

FIG. 4 is an explanatory diagram of a macro block.

FIG. 5 is an explanatory diagram of shuffling.

[Explanation of symbols]

 6 shuffling unit 9 password input unit 10 shuffling control unit 11 password processing unit 26 deshuffling unit 28 password comparison unit 30 deshuffling control unit 35 password input unit

Claims (3)

(57) [Claims] 1. A recording system in which a user selects a numerical value of 1 selected from a plurality of numerical values including 0.
And setting means for setting a password, a shuffling means for performing shuffling the digital signal to be recorded on a recording medium, only the value of the password set in the setting means Digitally
By shifting the address indicating the location of the
And a shuffling control means for setting a shuffling address in the shuffling processing by the shuffling means. A value selected by the user from a plurality of values including 0 is transmitted to the reproducing system.
Input means for inputting a password, a deshuffling means for performing the deshuffling process the reproduced digital signal, only the value of the password inputted to the input means Digitally
By shifting the address indicating the location of the
And a deshuffling control means for setting a deshuffling address in a deshuffling process by the deshuffling means. 2. A recording system in which a user selects a numerical value of 1 selected from a plurality of numerical values including 0.
And setting means for setting a password, a shuffling means for performing shuffling the digital signal to be recorded on a recording medium, only the value of the password set in the setting means Digitally
By shifting the address indicating the location of the
A shuffling control unit for setting a shuffling address in a shuffling process by the shuffling unit; and a password recording unit for recording a password set in the setting unit in a predetermined area of the recording medium. In the system, the user selects a value of 1 selected from multiple values including 0.
Input means for inputting a password, regenerated and deshuffling means for performing a deshuffling process on the digital signal, comparison means both by comparing the password entered and played password determines whether match And the value of the password input to the input means when the comparison means determines that the two passwords match .
If it is determined that they do not match, 0 is set as the password
The position of the digital signal by the password value.
And a deshuffling control means for setting a deshuffling address in the deshuffling process by the deshuffling means by shifting the indicated address . 3. The digital signal according to claim 1, wherein said digital signal is a fixed number of blocks.
Shows a sequence of frames made up of blocks , the shuffling process and the deshuffling process,
This is the process of changing the arrangement of blocks for each frame.
Ri, setting of the shuffling address and the Deshafurin
The address setting is based on the arrangement of blocks in the frame
The address indicating the position is shifted by the value indicated by the password.
3. The processing according to claim 1 or 2,
Digital recording and playback device.