JP3406312B2 - Digital signal recording device, digital signal reproducing device, and digital signal recording / reproducing device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a digital signal recording / reproducing apparatus, in particular, image data is subjected to block coding at the time of recording and block decoding at the time of reproducing. TECHNICAL FIELD The present invention relates to a digital signal recording device for reproducing data, a digital signal reproducing device, and a digital signal recording / reproducing device.

[Conventional technology]

Conventionally, a digital VTR that compresses image data to reduce the amount of data and records the image has an advantage over the analog VTR in that image quality does not deteriorate during dubbing.

[Problems to be Solved by the Invention]

By the way, although there is no problem when the user dubbs the software shot by the user himself, some measures are desired for dubbing of sources (hereinafter referred to as video software) that are not dubbable.

Therefore, an object of the present invention is to provide a digital signal recording apparatus and a digital signal reproducing apparatus, and a digital signal recording / reproducing apparatus, which can easily and surely prevent dubbing of video software.

[Means for Solving the Problems]

The present invention relates to a digital signal recording apparatus for block-coding an input digital signal and for shuffling a block-coded signal in a predetermined unit in order to prevent a burst error at the time of reproduction and recording it on a recording medium. Identification code extracting means for extracting an identification code in the input digital signal, encoding means for block encoding the input digital signal, and digital for which the input digital signal is block encoded by the block encoding means. Extraction: storage means for storing signals; a plurality of shuffling tables that define read addresses in predetermined units from the storage means so that digital signals are shuffled in predetermined units to prevent burst errors during reproduction; Switching means for switching a plurality of shuffling tables based on the identified identification code; Code discrimination change means for discriminating the discrimination code and selectively outputting a new discrimination code based on the discrimination result, the discrimination code output from the code discrimination change means, and the shuffling table switched by the switching means. A recording unit that records the block-encoded digital signal, which is address-controlled based on a predetermined unit and is read from the storage unit on a recording medium, on a recording medium.

In addition, the present invention shuffles a block-encoded signal in a predetermined unit to prevent a burst error at the time of reproduction, reproduces a digital signal recorded on a recording medium from the recording medium, and reproduces the block-encoded signal. An identification code extracting means for extracting an identification code in an input digital signal in a digital signal reproducing device for block-decoding the digital signal and deshuffling and outputting the block-decoded digital signal. A storage means for storing the input digital signal, and a read address in a predetermined unit from the storage means, so that the digital signal is shuffled in a predetermined unit to prevent a burst error during recording so that the digital signal is deshuffled. Based on the multiple deshuffling tables defined in and the extracted identification code, Switching means for switching the number of deshuffling tables, and decoding means for block-decoding the digital signals read out from the storage means in predetermined units under the address control based on the deshuffling tables switched by the switching means. In the configuration, when the identification code has a predetermined value, the digital signal to be block-decoded by the decoding means is read from the storage means without applying the deshuffling table.

Further, according to the present invention, an input digital signal is block-encoded, and a block-encoded signal is shuffled in a predetermined unit and recorded on a recording medium in order to prevent a burst error during reproduction. As a countermeasure, the block-coded signal is shuffled in a predetermined unit to reproduce the digital signal recorded on the recording medium from the recording medium, and the reproduced block-encoded digital signal is block-decoded and block-decoded. In a digital signal recording / reproducing apparatus adapted to deshuffle and output a digitized digital signal, first identification code extracting means for extracting an identification code in the input digital signal, and the input digital signal Block coding means for block coding, and the input digital signal is block coded by the block coding means. A first storage means for storing the reproduced digital signal and a read address in a predetermined unit from the first storage means are defined so that the digital signal is shuffled in a predetermined unit as a countermeasure against a burst error during reproduction. A plurality of shuffling tables and a shuffling table switching means for switching a plurality of shuffling tables based on the identification code extracted by the first identification code extraction means, and a first identification code extraction means at the time of recording. The extracted identification code is discriminated, and a code discrimination changing means for selectively outputting a new identification code based on the discrimination result, an identification code output from the code discrimination changing means, and a shuffling table switching means are used for switching. The address is controlled based on the shuffling table, and the predetermined unit is stored in the first storage means. Recording means for recording the projected block-encoded digital signal on a recording medium; reproducing means for reproducing the digital signal from the recording medium; and extracting an identification code in the digital signal reproduced by the reproducing means. The second identification code extracting means, the second storage means for storing the reproduced digital signal, and the read address in a predetermined unit from the second storage means are digitalized to prevent a burst error at the time of reproduction by the reproducing means. A plurality of deshuffling tables that regulate the signals to be shuffled in a predetermined unit so that the recorded digital signal is deshuffled, and a plurality of deshuffling tables based on the identification code extracted by the second identification code extracting means. Deshuff ring table switching means for switching the ring table and switching by the deshuffling table switching means. And a decoding means for block-decoding the digital signal read out from the second storage means in a predetermined unit under the address control based on the deshuffling table, and at the time of reproduction, by the second identification code extraction means. When the extracted identification code has a predetermined value, the deshuffling table is not applied to the digital signal block-decoded by the decoding means, and the digital signal is read from the second storage means.

[Action]

When reproducing and recording a digital signal, an identification code is added and recorded according to the switching state of block coding.

In the case of a source that cannot be dubbed, that is, in the case of video software, the above identification code is converted into a specific identification code and recorded.

During playback, if a non-dubbing identification code is played,
Switching of the characteristics of the block encoding according to the above-mentioned identification code, for example, switching of the shuffling table is performed. Specifically, when the non-dubbing identification code is played back, a different shuffling table is designated during recording and playback, or a shuffling table that does not exist during playback is designated.

This can prevent dubbing of video software.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. In this embodiment, the digital signal recording / reproducing apparatus according to the present invention is applied to a cassette digital recorder. As a premise of this embodiment, an ID code representing a shuffling pattern is provided at the same position as the identification code of the buffering table in the video software.
It is assumed that CD (= (“1”)) is recorded, and whether or not dubbing is possible is determined by this ID code CD.

Before going into the description of one embodiment, the basic idea of the present invention will be described.

Shuffling is one of the characteristics of block coding, and this shuffling is an effective technique as a countermeasure against burst errors. When the shuffling pattern is different on the recording side and the reproducing side, a normal image cannot be reproduced at the time of reproduction, and only an image having a simple geometric pattern with a disordered block pattern can be reproduced.

Therefore, by managing this shuffling pattern with the ID code CD, it becomes possible to prevent dubbing of video software.

First, the recording system 2 of the cassette digital recorder 1 will be described.

The configuration of the main part of this cassette digital recorder 1 is the first
It is shown by a solid line A in the figure.

As shown in FIG. 1, the cassette digital recorder 1 is provided with a digital input terminal 3 and an analog input terminal 4 on the input side.

For example, a digital output supplied from another cassette digital recorder 5 can be connected to the digital input terminal 3, and the analog input terminal 4 can be connected to, for example,
The analog output supplied from another cassette digital recorder 5, video camera 6, tuner 7, etc. can be connected. Reference numeral 8 is a switch circuit for selecting analog output.

The digital input terminal 3 described above is connected to the terminal 9a of the switch circuit 9 in the cassette digital recorder 1, and
The analog input terminal 4 is connected to the terminal 9b of the switch circuit 9 via the A / D converter 10. Incidentally, 9c is a terminal of the switch circuit 9.

The digital video signal DV supplied from the outside and passed through the switch circuit 9 is supplied to the block encoding circuit 11 and the ID separation circuit 12.

In the block encoding circuit 11, the above digital video signal DV is subjected to block encoding processing such as ADRC and DCT to form recording data. The block-coded recording data is sequentially written in the shuffling memory 13.

Meanwhile, the digital video signal supplied to the ID separation circuit 12
The ID code CD is separated from the DV, and the ID discrimination / change circuit 14
Is supplied to.

The ID discriminating / changing circuit 14 uses the separated ID code CD to identify the ID code CD if necessary to prevent dubbing.
Make changes. That is, when dubbing video software, when recording, the ID code CD is the ID code of the shuffling pattern not provided in the playback system described later.
It is to be rewritten to a CD.

When the reproduced and separated ID code CD is (“0”), that is, in the case of a dubbable source, the ID code CD =
It is supplied to the switch circuit 15 and the ID addition circuit 16 as (“0”).

Similarly, when the reproduced and separated ID code CD is (“1”), that is, in the case of video software, the ID code CD =
(“1”) is changed to the ID code CD = (“2”) and supplied to the switch circuit 15 and the ID adding circuit 16.

When the reproduced and separated ID code CD is ("2"), the ID code CD = ("2") is the same as the switch circuit.
15 and the ID adding circuit 16 are supplied.

In the switch circuit 15, switch switching control is performed based on the above-mentioned ID code CD. For example, ID code CD =
If it is (“0”), switch circuit 15 terminal 15
The a and 15c are connected and the shuffling table 17 is selected.

In addition, ID code CD = ("1") or ID code CD =
If it is (“2”), switch circuit 15 terminal 15
b and 15c are connected, and the shuffling table 18 is selected.

Shuffling table 17 or shuffling table
Under the control of a controller (not shown), each address data of the block-coded recording data is read out in a shuffled state, and is supplied to the address generator 19 via the switch circuit 15.

The address generator 19 forms address data in pixel units based on the above-mentioned address data, and the address data in pixel units is supplied to the shuffling memory 13.

Under the control of a controller (not shown), the shuffling memory 13 reads out recording data in pixel units based on address data in pixel units and supplies the read data to the ID adding circuit 16.

The ID adding circuit 16 adds the ID code CD (= (“0”), to the recording data read from the shuffling memory 13
After ((1)) or (“2”) is added, it is supplied to the recording processing circuit 20. This ID code CD has the same position as the identification code of the buffering table described above,
For example, it may be added during the vertical blanking period. If there is no ID code CD, ID code CD
It is recorded as (= (“0”)).

In the recording processing circuit 20, after the block coded recording data with the ID code CD is subjected to predetermined signal processing such as framing, it is recorded on a magnetic tape (not shown) by the magnetic head 21. .

Next, the reproducing system 31 of the cassette digital recorder 1 will be described.

The RF signal reproduced from the magnetic table (not shown) by the magnetic head 32 is subjected to predetermined signal processing in the reproduction processing circuit 33 to be reproduced data, and then supplied to the deshuffling memory 34 and the ID separation circuit 35. It

The reproduced data which has been subjected to the block coding process is sequentially written in the deshuffling memory 34.

On the other hand, the ID code CD is separated from the block-encoded reproduction data supplied to the ID separation circuit 35 and supplied to the ID discrimination circuit 36.

The ID discrimination circuit 36 controls the switch circuit 37 based on the separated ID code CD, and at the same time outputs the ID code CD.
It is supplied to the ID adding circuit 38.

If the ID code CD = (“0”), the source is dubbable, so the ID code CD is not changed and the ID code
CD = (“0”) is supplied to the switch circuit 37 and the ID adding circuit 38.

If the ID code CD = ("1"),
Since the video software allows only normal reproduction, the ID code CD = (“1”) is supplied to the switch circuit 37 and the ID adding circuit 38.

Furthermore, in the case of a source with ID code CD = ("2"), normal playback is not possible as well as dubbing, so the ID code
CD = (“2”) is supplied to the switch circuit 37 and the ID adding circuit 38.

In the switch circuit 37, switch switching control is performed based on the above-mentioned ID code CD. For example, ID code CD =
If (“0”) is supplied, the switch circuit 37 terminal
37a and 37c are connected, and the deshuffling table 39 is selected.

When the ID code CD = (“1”) is supplied,
The terminals 37b and 37c of the switch circuit 37 are connected and the deshuffling table 40 is selected.

When the ID code CD = (“2”) is supplied, the terminals 37d and 37c of the switch circuit 37 are connected. In this case, since there is no target deshuffling table, normal image reproduction cannot be performed.

From the deshuffling table 39 or 40, the address data of the block-encoded reproduction data is read in a deshuffling state by the control of a controller (not shown), and is supplied to the address generator 41 via the switch circuit 37. It

The address generator 41 forms address data in pixel units based on the above-mentioned address data, and the address data in pixel units is used as the deshuffling memory 34.
Is supplied to.

In the deshuffling memory 34, under the control of a controller (not shown), reproduction data is read in pixel units based on address data in pixel units and supplied to the block decoding circuit 42. The reproduction data is read from the deshuffling memory 34 based on the address data from the deshuffling table 39 when the ID code CD = (“0”), and the ID code CD = (“1 In the case of "), it is performed based on the address data from the deshuffling table 40. Then, when the ID code CD = (“2”), there is no corresponding deshuffling table, and thus the reproduction data is read from the deshuffling memory 34 in the shuffled state.

The block decoding circuit 42 decodes the block-encoded reproduction data into a pixel-unit digital video signal DV, and the reproduced digital video signal DV is reproduced.
It is supplied to the ID adding circuit 38.

The ID adding circuit 38 adds an ID to the digital video signal DV described above.
Code CD is added. This ID code CD has the same position as the identification code of the buffering table described above,
For example, it may be added during the vertical blanking period.

Then, the digital video signal with the ID code CD added
DV is taken out as a digital output from the terminal 43, or after being converted into an analog video signal by the D / A converter 44, taken out as an analog output from the terminal 45.

According to this embodiment, the terminal 43 of the reproduction system 31 or the terminal
If the 45 is connected to a monitor not shown, ID code CD =
If it is (“0”), the deshuffling table 39 is selected for the shuffling table 17, and the ID code CD =
If it is (“1”), the deshuffling table 40 is selected with respect to the shuffling table 18, so that the shuffling patterns of the recording system 2 and the reproducing system 31 match.
A normal image can be displayed.

However, when trying to dubb the video software, the ID code CD = (“2”) is recorded / reproduced, so that the reproduced data is read from the deshuffling memory 34 in the shuffled state, for example. As a result, as a result, only a geometrical pattern with a disordered block pattern can be seen, and a normal image cannot be seen.

In this way, when dubbing video software,
By recording a shuffling pattern that does not exist in the video signal as the ID code CD, it is possible to prevent dubbing without the trouble of passing the encryption key.

In this embodiment, an example in which the shuffling pattern ID code CD is used for management is described as one example of switching the characteristics of block coding, but the invention is not limited to this. For example, the threshold bit allocation in the ADRC buffering table may be all 0 bit allocation according to a specific ID code, or the block size may be changed.

〔The invention's effect〕

In the digital signal recording / reproducing apparatus according to the present invention, when reproducing and recording a digital signal, an identification code is added according to whether or not dubbing is possible, and in the case of a non-dubbing source, that is, video software, the above identification code is added. Is converted into a specific identification code and recorded, and at the time of reproduction, the characteristics of block coding are switched according to the identification code, for example, the shuffling table is switched, so that there is an effect that dubbing of video software can be prevented. is there.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention. Description of main symbols in the drawings 1, 5: Cassette digital recorder, 2: Recording system, 11: block coding circuit, 12, 35: ID separation circuit, 13: memory for shuffling, 14: ID discrimination / change circuit, 15, 37: switch circuit, 16, 38: ID addition circuit, 17, 18: shuffling table, 20: recording processing circuit, 21, 32: magnetic head, DV: Digital video signal, 31: Playback system, 34: Memory for deshuffling, 36: ID discrimination circuit, 39, 40: Deshuffling table, 42: Block decoding circuit.

Front page continuation (51) Int.Cl. ⁷ identification code FI H04N 9/804 H04N 9/80 B 9/808 (58) Fields investigated (Int.Cl. ⁷ , DB name) G11B 20/10 G11B 20 / 12

Claims (3)

(57) [Claims] 1. A digital signal recording apparatus for block-coding an input digital signal and shuffling the block-coded signal in a predetermined unit in order to prevent a burst error at the time of reproduction and recording the shuffled signal on a recording medium. Identification code extracting means for extracting an identification code in the input digital signal, encoding means for encoding the input digital signal in the block, and the input digital signal in the block encoding means. Storage means for storing the block-encoded digital signal, and a read address in a predetermined unit from the storage means,
A plurality of shuffling tables that regulates the digital signal so that the digital signal is shuffled in the predetermined unit to prevent a burst error during reproduction, and a switch that switches the plurality of shuffling tables based on the extracted identification code. Means, a discrimination means for discriminating the extracted discrimination code, and selectively outputting a new discrimination code based on the discrimination result, the discrimination code output from the discrimination code changing means, and the switching. Recording means for recording on the recording medium the block-encoded digital signal which is read out from the storage means in the predetermined unit under the address control based on the shuffling table switched by the means. Signal recorder. 2. A digital signal recorded on a recording medium is reproduced from the recording medium by shuffling a block-coded signal in a predetermined unit to prevent a burst error at the time of reproduction.
An identification code extracting means for extracting an identification code in the input digital signal in a digital signal reproducing apparatus for deshuffling the reproduced block-encoded digital signal to block-decode and output it. A storage means for storing the input digital signal, and a read address in a predetermined unit from the storage means,
Based on the extracted identification code, a plurality of deshuffling tables that prescribe that the digital signal is shuffled in the predetermined unit for deshuffling in order to prevent a burst error during recording. Switching means for switching the deshuffling table, and the block-decoding of the digital signal read from the storage means in the predetermined unit under the address control based on the deshuffling table switched by the switching means. Decoding means, and when the identification code has a predetermined value, the digital signal stored in the storage means is read from the storage means without applying the deshuffling table, and the digital signal is read by the decoding means. Of digital signals characterized by block decoding Raw devices. 3. An input digital signal is block-encoded, and a block-encoded signal is shuffled in a predetermined unit and recorded on a recording medium in order to prevent a burst error at the time of reproduction. Therefore, the block-coded signal is shuffled in a predetermined unit to reproduce the digital signal recorded on the recording medium from the recording medium, and the reproduced block-encoded digital signal is deshuffled and block-decoded. In a digital signal recording / reproducing apparatus for outputting, a first identification code extracting means for extracting an identification code in the input digital signal, and a code for block-encoding the input digital signal Encoding means and a digital signal obtained by subjecting the input digital signal to the block encoding by the block encoding means. A first storage means for storing a digital signal and a read address in a predetermined unit from the first storage means so that the digital signal is shuffled in the predetermined unit as a countermeasure against a burst error during reproduction. A plurality of prescribed shuffling tables, a shuffling table switching means for switching the plurality of shuffling tables based on the identification code extracted by the first identification code extraction means, and the first shuffling table during recording. A code discrimination changing means for discriminating the discrimination code extracted by the discrimination code extracting means and selectively outputting a new discrimination code based on the discrimination result; and the discrimination code output from the code discrimination changing means, Address based on the shuffling table switched by the shuffling table switching means Recording means for recording the block-encoded digital signal read from the first storage means in the predetermined unit on the recording medium, and reproducing means for reproducing the digital signal from the recording medium. Second identification code extracting means for extracting the identification code in the digital signal reproduced by the reproducing means, second storage means for storing the reproduced digital signal, and the second storage A plurality of read addresses from the means are defined so that the digital signal is shuffled in the predetermined unit and the recorded digital signal is deshuffled in order to prevent a burst error during reproduction by the reproducing means. Based on the deshuffling table and the identification code extracted by the second identification code extracting means, Deshuffling table switching means for switching the deshuffling table, and address control based on the deshuffling table switched by the deshuffling table switching means and read from the second storage means in the predetermined unit. And a decoding means for block-decoding the digital signal, and when the identification code extracted by the second identification code extracting means has a predetermined value at the time of reproduction, the second storage means stores it. A digital signal recording / reproducing apparatus, wherein the stored digital signal is read from the second storage means without applying the deshuffling table, and the block decoding is performed by the decoding means.