JP3303368B2 - Transmission apparatus and method, transmission system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plurality of recording / reproducing apparatuses, for example, digital VTRs, each connected via a transmission line, and reading digital data recorded on a recording medium via one recording / reproducing apparatus. And a transmission system for dubbing the digital data to a recording medium of another recording / reproducing apparatus, in particular, the number of dubbing times is recorded in dubbing regulation information recorded together with main data (in this case, video data) on a recording medium. The present invention relates to a transmission apparatus and method for managing data and a transmission system.

[0002]

2. Description of the Related Art At present, digital VTRs of the D1, D2, and D3 systems have already been commercialized as VTRs for broadcasting. On the other hand, digital VTRs for consumer use
Various formats have been proposed for practical use of.

FIG. 11 shows a digital cosine transform (hereinafter simply referred to as DCT) and a digital VT used for variable-length coding.
FIG. 3 is a block diagram showing a configuration of R.

In FIG. 1, an input analog component video signal (Y, RY, BY) is converted into a digital component video signal by an A / D converter 1 and a blocking circuit 2 uses a frame memory. 8 samples in the horizontal direction, 8 lines in the vertical direction (hereinafter, referred to as
(Referred to as 8 × 8 unit) as one block, and are shuffled and Y / C multiplexed.

The data in units of 8 × 8 are stored in the DCT circuit 3
, And the data in the time amplitude domain is converted into the data in the frequency domain. The DCT-processed data is requantized by the encoder 4, subjected to variable-length coding using a two-dimensional Huffman code or the like, and compressed. This variable length coding is performed by using a predetermined number of DCT blocks (for example, 30DT).
) Is controlled so as to have a fixed length for each buffering unit composed of blocks.

The variable-length encoded data is divided into blocks by an ECC (Error Correction Code) by a framing circuit 5, parity is added by a parity generation circuit 6, and serial data is added by a channel encoder 7. And recorded on a magnetic tape.

At the time of reproduction, data detection and serial / parallel conversion are performed by the channel decoder 8 in reverse.
Error correction is performed by the C circuit 9. The error-corrected data is decomposed into variable-length code words by a deframing circuit 10, decoded by a decoder 11,
The data is inversely quantized and inversely DCT-processed by the inverse DCT circuit 12 to obtain data of 8 × 8 units. The data is subjected to deshuffling, Y / C separation, data interpolation, and the like by the deblocking circuit 13, and is returned to a digital component video signal. The D / A converter 14 converts the data to an original analog component video signal and outputs the signal. Is done.

Next, the case of dubbing with the digital VTR will be described with reference to FIG.

In the figure, a dubbing method using a dubbing path indicated by A is an analog dubbing in which an analog output from a D / A converter 14 of a reproducing apparatus is input to an A / D converter 1 of a recording apparatus. In the dubbing method using a dubbing path indicated by B, the digital component output of the playback device is a digital interface (hereinafter simply referred to as I / F) 15 of a FIFO (first-in first-out) system.
Is digital dubbing that is input to the blocking circuit 2 of the recording device via the.

However, among the above dubbing methods, the dubbing method using the dubbing path indicated by A is analog dubbing, and therefore has a disadvantage that the image quality is deteriorated during dubbing. Further, the dubbing method using the dubbing path indicated by B processes an uncompressed video signal, so that the transmission rate becomes 216 Mbps. If it is implemented as a device, it will be disadvantageous in terms of price,
There is a problem that it is difficult to commercialize the product.

[0011]

According to the present invention, dubbing control information and main data which are recorded on a recording medium and to which a recording parity code is respectively added are read out together by one recording / reproducing apparatus. Transmitting the regulation information and the main data to another recording / reproducing device via a transmission path,
In the transmission apparatus, method, and transmission system for recording the dubbing restriction information and the main data on a recording medium in the another recording / reproduction apparatus only when the dubbing restriction information indicates that dubbing is possible, the one recording / reproduction apparatus In the above, when the dubbing control information means that dubbing is impossible, a start signal is generated, the main data is rearranged in response to the generated start signal, the recording parity code is removed during transmission, and the dubbing control is performed. An error correction code is simultaneously added to the main data together with information and supplied to the transmission path. Further, the present invention also reads out the dubbing control information and the main data, which are recorded on the recording medium and to which the recording parity codes are respectively added, by one recording / reproducing apparatus, and transmits the read dubbing control information and the main data. A transmission device that transmits the dubbing restriction information and the main data to a recording medium in the another recording / reproducing device only when the dubbing restriction information indicates that dubbing is possible, by transmitting the dubbing restriction information to the other recording / reproducing device via a channel. And the method and the transmission system, wherein the one recording / reproducing device stores the main data based on the supplied write address, and stores the main data in order of the write address when the dubbing restriction information indicates that dubbing is possible. The main data is read and supplied to the transmission path, and the dubbing control information indicates that dubbing is impossible. When taste, and it generates an activation signal, generated by receiving the activation signal in a different order than the write address,
The stored main data is read and supplied to the transmission path, the recording parity code is removed at the time of transmission, and an error correction code is simultaneously added to the main data together with the dubbing control information and supplied to the transmission path. Constitute.

According to this dubbing method, the transmission rate is 25 Mbp in order to process the compressed video signal.
s, which is advantageous in realizing a device as a transmission device and commercializing it.

[0013] Recently, with respect to the digital dubbing, it is necessary to regulate the number of dubbing due to copyright issues. For this reason, conventionally, SCMS (Serial Copy Matrix) already implemented in R-DAT (Digital Audio Tape Recorder using a rotating head).
The number of dubbing times is restricted using a dubbing control code similar to the nagement system) code.

Here, the dubbing number control code is
It is recorded together with main data (video data and audio data) on a magnetic tape.
A bit for determining whether the image data is a target of copyright protection, data indicating the current number of dubbing times, and type data indicating whether the source of the target image data is a tape, a disk, or a broadcast are allocated.

At the time of dubbing, when the discrimination bit is transmitted from the reproducing apparatus to the recording apparatus via a transmission path, and the discrimination bit indicates a copyright protection target, and the number of dubbing exceeds a predetermined number, On the magnetic tape of the recorder,
No recording is made. On the other hand, if the discrimination bit means that the copyright is not protected, or if the number of dubbing is less than a predetermined number, at the stage of transmission to the recording machine,
The number of dubbing times is updated (+1) and recorded together with the main data on the magnetic tape in the recorder.

[0016]

By the way, in the conventional transmission device, as shown in FIG. 13, transmission data is added to main data (video data and audio data) 21 with the dubbing frequency control data 22 as shown in FIG. A SYNC code 23 for synchronizing the transmission is added for transmission.

Therefore, when dubbing is illegally performed, for example, a device for changing data is inserted into the transmission path, and the discrimination bit of the dubbing frequency control code 22 is invalidated in the transmitted data, that is, It can be easily done by modifying it to something that is not protected. Moreover, since the dubbing frequency code 22 can be easily detected based on the SYNC code 23, the dubbing frequency control code 22 can be easily changed.

As described above, in the conventional transmission device,
Even if the number of dubbing exceeds a predetermined number, dubbing can be easily performed, and there is a problem that copyright protection cannot be strengthened.

The present invention has been made in view of the above problems, and has as its object to prevent data modification on a transmission path, prevent illegal dubbing, and enhance copyright protection. And a transmission system capable of reliably achieving the above.

[0020]

According to the present invention, dubbing control information 61 and main data 43 (53) recorded on a recording medium and having a recording parity code 44 (54) added thereto, respectively.
Are read together by one recording / reproducing device, and the read dubbing control information 61 and the main data 42 (5) are read.
3) is transmitted to another recording / reproducing apparatus via the transmission path D, and only when the dubbing restriction information 61 indicates that dubbing is possible, the dubbing restriction information 61 and the above-described information are recorded on a recording medium of the another recording / reproducing apparatus. In a transmission apparatus, method and transmission system for recording the main data 43 (53), the recording parity code 44 (5
4) is removed, and an error correction code is simultaneously added to the main data 43 (53) together with the dubbing control information 61 and supplied to the transmission path.

As the above error correction code, for example,
It may be an error correction code added when recording on a recording medium, or may be a parity code for transmission.

[0022]

In the transmission apparatus, method and transmission system according to the present invention, the data transmitted from one recording / reproducing apparatus to the transmission path D includes not only the main data 43 (53) and the dubbing number restriction information 61 but also an error. Correction code is included.

Then, the data is transmitted through the transmission path with the error correction code recorded on the recording medium added. Another recording / reproducing apparatus can perform error correction on the main data 43 (53) and the dubbing frequency control information 61 transmitted on the transmission path D based on an error correction code.

Therefore, even if a device capable of changing data is inserted into the transmission path and the dubbing frequency control information 61 is altered, another dubbing control information based on the error correction code added by one recording / reproducing apparatus side. Since error correction is performed by the recording / reproducing device, the altered data is restored to the original data. Therefore, alteration of data on the transmission path D can be invalidated, and illegal dubbing can be prevented and copyright protection can be reliably enhanced.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a dubbing system between digital VTRs (hereinafter simply referred to as a dubbing system according to the embodiment) will be described below with reference to FIGS.

The recording format of one helical track of the magnetic tape used in the dubbing system according to this embodiment is, as shown in FIG. Marginal areas 31a and 31b are allocated, a video area 32 in which actual image data is recorded is allocated in the center of the helical track T, and a first area is provided between the one marginal area 31a and the video area 32, respectively.
ATF area 33a and audio area (in which audio data is recorded) 34 are allocated, and subcode area 35 and second ATF area 33b are allocated between the other marginal area 31b and video area 32, respectively. .

Also, between each area, for example, the first and second areas
An ABLE area 36 is allocated to each of the head portions of the ATF areas 33a and 33b, both sides of the audio area 33, both sides of the video area 32, and both sides of the subcode area 35. Note that an area 37 indicated by oblique lines is a block gap area.

The subcode area 35 records a subcode signal (time, address, etc.), and the first and second ATF areas 33a and 33b record ATF signals for tracking correction.

The code structures of the image data recorded in the video area 32 and the audio data recorded in the audio area 34 among the data recorded in each of these areas are as shown in FIGS. Having a structure. That is, as shown in FIG. 2, the image data has a frame structure in which, for example, blocks each having 91 bytes in the column direction are arranged in the row direction, and a code structure in which three frames are arranged is further provided. Have.

Each block is composed of 2-byte SYNC data 41 for synchronizing transmission, 3-byte ID data 42, 78-byte main data 43, and 8-byte first parity code 44a. It is configured.
Blocks having these configurations (referred to as image data blocks for convenience) are arranged up to 45 in the row direction.
The remaining blocks have a code structure in which a 78-byte second parity code 44b and an 8-byte first parity code 44a are arranged in the column direction. Four blocks having these configurations are arranged in the row direction.

Next, as shown in FIG.
For example, it has a frame structure in which 14 blocks each having 91 bytes in the column direction are arranged in the row direction.

Each block is composed of 2-byte SYNC data 51 for synchronizing transmission, 3-byte ID data 52, 78-byte main data 53, and 8-byte first parity code 54a. It is configured.
Blocks having these configurations (referred to as audio data blocks for convenience) are arranged in a total of 10 blocks, five from the first row and five from the last row. The remaining blocks are
Second parity code 54b having 78 bytes in the column direction
And a code structure in which first parity codes 54a having an 8-byte configuration are arranged. Four blocks having these configurations are arranged in the row direction.

In this embodiment, as shown in FIG. 4, one is added to the head of each of the main data 43 and 53 in the image data block VB and the audio data block AB.
A dubbing frequency control code 61 having a byte structure is inserted. This dubbing frequency control code 61 is, for example, as shown in FIG.
As shown in FIG. 7, the first bit is assigned a bit for determining whether or not the image data is subject to copyright protection, the next two bits are assigned data indicating the current dubbing frequency, and the next five bits are assigned to the target image data. Type data indicating whether the source is a tape, disk, or broadcast is allocated.

The dubbing frequency control code 61 is, for example, “10” for a magnetic tape whose target image data and audio data are subject to copyright protection and have already been dubbed once.
1XXXXXX "(in this case, the category code is represented by Don't care XXXXXX).

As shown in FIG. 6, the configuration of the dubbing system according to the first embodiment basically includes two digital VTRs and a transmission line D for electrically connecting these VTRs.
Consists of Then, one digital VTR is set as a reproducing side, and the other digital VTR is set as a recording side. Each digital VTR incorporates a reproducing system and a recording system. In the illustrated example, only the reproducing system is shown on the reproducing VTR, and only the recording system is shown on the recording VTR.

The recording system converts the input analog component video signals (Y, RY, BY) into the same as the recording system in a normal digital VTR (see FIG. 11).
A / D to convert to digital component video signal
The converter 1 and the digital data from the A / D converter 1 are combined into data in which 8 samples in the horizontal direction and 8 lines in the vertical direction (hereinafter referred to as 8 × 8 unit) are formed into one block by using a frame memory. , Shuffling and Y / C
Blocking circuit 2 for performing multiplexing, and blocking circuit 2
DCT is performed on the data in the time amplitude domain from
A DCT circuit 3 for converting data into frequency domain data;
Encoder 4 for re-quantizing the compressed data, performing variable-length encoding using a two-dimensional Huffman code or the like, and compressing the data.
Having. This variable-length coding is controlled so as to have a fixed length for each buffering unit composed of a predetermined number of DCT blocks (for example, 30 DT blocks).

Further, in this recording system, the variable-length coded data from the decoder 4 is converted into an ECC (Error
A framing circuit 5 for blocking into a product code configuration of a Correction Code, a parity generation circuit 6 for adding a parity to the blocked data, and converting the data from the parity generation circuit 6 to serial data. A channel encoder 7 for outputting as recording data for recording on a magnetic tape.

As in the reproduction system of a normal digital VTR (see FIG. 11), the reproduction system includes a channel decoder 8 for detecting reproduction data and performing serial / parallel conversion of the reproduction data. An ECC circuit 9 for performing error correction, a deframing circuit 10 for decomposing the error-corrected data into word units of a variable length code, a decoder 11 for decoding and dequantizing the data decomposed in word units, An inverse DCT circuit 12 for performing inverse DCT on the data from the decoder 11 to convert the data into data of 8 × 8 units;
Deshuffling, Y / C separation,
It has a deblocking circuit 13 for performing data interpolation and the like to return to a digital component video signal, and a D / A converter 14 for converting the digital component video signal into an analog component video signal and outputting the analog component video signal.

In the first embodiment, a digital interface (hereinafter simply referred to as I / O) of a FIFO (first-in first-out) system is provided between the reproduction system ECC circuit 9 and the transmission line D in the reproduction side VTR. F) 62
And a parity generating circuit 63 for adding a parity code for transmission having an 8-byte structure, for example, is inserted.
An ECC circuit 64 that performs error correction between the recording system parity generation circuit 6 and the transmission path D in the TR based on the parity code added by the reproduction side parity generation circuit 63.
, An I / F 65, a dubbing determination circuit 66, and a changeover switch 67.

Here, the changeover switch 67 is normally
The movable contact 67a on the parity generation circuit 6 side and the fixed contact 67b on the framing circuit 5 side are electrically connected via a switch 67s, but the switch 67s switches based on the start of dubbing, and the movable contact 67a The fixed contact 67c on the dubbing determination circuit 66 side is electrically connected.

The dubbing determination circuit 66 reads the dubbing frequency control code 61 included in the data supplied through the transmission path D, determines whether the target data is subject to copyright protection, and further determines whether the data is subject to copyright protection. When the number of dubbing times is greater than or equal to the predetermined number of times, the controller 68 compares the number of times of dubbing recorded in the dubbing number control code 61 with a predetermined number of times of dubbing. Is output, and data transmission to the recording system is prohibited.

If the number of recorded dubbing times is less than the predetermined number, a permission signal is output to the controller 68 to permit data transmission to the recording system. In this case, in the dubbing determination circuit 66, the dubbing frequency data of the dubbing frequency control code 61 is updated (+1) and sent to the parity generation circuit 6 via the changeover switch 67 together with the main data. When at least an error signal is supplied from the dubbing determination circuit 66, the controller 68 outputs and displays an error message on a monitor connected to the VTR to notify the user of the error message.

When dubbing is performed in the dubbing system according to the first embodiment, first, data (see FIG. 7A) reproduced by the channel decoder 8 is supplied to the ECC circuit 9 in the reproducing VTR.
Error correction is performed by the C circuit 9. At this time, the first and second parity codes 44a (54a) and 44b (54b) for recording are removed (see FIG. 7B). An image data block group including the video data (in a compressed state) 43 and the dubbing number control code 61 from which the parity codes 44a (and 44b) are removed, and the audio data from which the parity codes 54a (and 54b) are removed. The audio data block group including the data 53 and the dubbing frequency control code 61 is written to the I / F 62 at the subsequent stage. From the I / F 62, the image data block group and the audio data block group are read out by a transmission clock, and these data block groups are transmitted by a parity generation circuit 63 at the subsequent stage after each data block. A parity code 69 is added (see FIG. 7C), and further transmitted to the recording side VTR via the transmission path D.

In the recording side VTR, first, the transmission path D
The data transmitted through the ECC circuit 64
The error correction is performed based on the parity code 69 added to each data block. That is, even if an error occurs in the transmission path, the ECC circuit 64
The error correction is performed by the ECC circuit 9 of the reproduction side VTR.
Is restored to the data output from.

Therefore, even if a device capable of changing data is inserted into the transmission path D and, for example, the dubbing frequency control code 61, particularly the discrimination bit, is changed, the change is made by the ECC circuit in the recording VTR. At 64, it is treated as a transmission error and will be restored to its original content. That is, the modification of the data on the transmission path D becomes invalid. In other words, from the point of view of the error correction code, this data alteration is equivalent to the 1-byte dubbing frequency control code 6.
This is the same as the occurrence of a transmission error in No. 1, and this transmission error can be sufficiently corrected by the added parity code 69 for 8 bytes. Therefore, it is impossible to perform illegal dubbing only by illegally inserting a device into the transmission line D and replacing data. If the dubbing control code 61 is modified to perform illegal dubbing, the parity 69 for transmission must also be recalculated,
The circuit configuration for modification becomes very complicated.

The data from the ECC circuit 64 is
It is supplied to the dubbing determination circuit 66 via the I / F 65,
Prohibition / permission of dubbing is electrically determined based on the dubbing frequency restriction code 61 included in the data.
In the case of dubbing permission, the data from the I / F 65 is
The data is supplied to the parity generating circuit 6 via the changeover switch 67 and is further recorded on the magnetic tape through the channel encode 7. On the other hand, when dubbing is prohibited, the above I / F
The data from 65 is not supplied to the parity generation circuit 6 and is discarded as it is. In this case, for example, a message is displayed via the controller 68 to notify the monitor that dubbing is prohibited.

As described above, according to the dubbing system of the first embodiment, the parity generation circuit 63 for adding the parity code 69 is connected to the output stage of the transmission line D of the reproducing VTR, and the transmission of the recording VTR is performed. Since the ECC circuit 64 that performs error correction of transmission data is connected to the input stage of the path D based on the added parity code 69,
Modification of data on the transmission line D can be invalidated,
It is possible to reliably prevent illegal dubbing and strengthen copyright protection.

Next, a dubbing system according to a second embodiment will be described with reference to FIG. Components corresponding to those in FIG. 6 are denoted by the same reference numerals, and redundant description thereof will be omitted.

In the dubbing system according to the second embodiment, after the error correction at the time of reproduction is performed in the ECC circuit 9 of the reproduction side VTR, the first parity code 44a
The data is transmitted via the I / F 62 with (54a) added. Therefore, the reproducing VTR is connected to the ECC circuit 9.
Only the I / F 62 is connected between the transmission path D and the transmission line D, and the circuit configuration is simpler than that of the first embodiment.

The recording VTR includes a transmission line D and a reproduction system EC.
I / F 65 and first changeover switch 7 between C circuits (9)
0, and a dubbing determination circuit 66 and a second changeover switch 67 are inserted between the reproduction system ECC circuit (9) and the recording system parity generation circuit 6.
The circuit configuration is such that the ECC circuit 64 according to the embodiment is omitted.

First and second changeover switches 70 and 6
Normally, each of the movable contacts 70a and 67a and one of the fixed contacts 70b and 67b have a switch 70s.
And 67s electrically. Therefore, in the reproducing system, the reproduced data from the channel decoder (8) is supplied to the ECC circuit (9) via the first changeover switch 70, and in the recording system, the data from the framing circuit 5 is supplied to the second circuit. The data is supplied to the parity generation circuit 6 via the changeover switch 67.

Then, based on the start of dubbing, the switches 70 s and 67 s are switched, and the movable contacts 7 are switched.
0a and 67a are electrically connected to the other fixed contacts 70c and 67c, respectively. Therefore, in this case, in the reproduction system, the transmission data from the I / F 65 is supplied to the ECC circuit (9) via the first changeover switch 70, and in the recording system, the transmission data from the dubbing determination circuit 66 is supplied. The data is supplied to the parity generation circuit 6 via the second changeover switch 67.

When dubbing is performed in the dubbing system according to the second embodiment, first, data reproduced by the channel decoder 8 in the reproducing VTR is supplied to the ECC circuit 9, and the ECC circuit 9 corrects the error. Is performed. In this case, the recording first parity code 44a (54a) remains added. Note that the second parity code 44b (54b) is removed.

An image data block group including a video data to which the first parity code 44a is added and a dubbing frequency control code, and an audio data block including an audio data to which the first parity code 54a is added and a dubbing frequency control code. The group is written to the subsequent I / F 62. From the I / F 62, the image data block group and the audio data block group are read by a transmission clock and transmitted to the recording VTR via the transmission path D.

In the recording side VTR, first, the transmission path D
The data transmitted through the I / F 65 and the first changeover switch 70 is supplied to the ECC circuit (9) of the reproduction system. The data supplied to this ECC circuit (9) is the added first parity code 44a.
Error correction is performed based on (54a). Therefore, even if an error occurs in the transmission path D, the error is corrected by the ECC circuit (9) in the reproduction system, and the data is restored to the data output from the ECC circuit 9 of the reproduction side VTR.

Therefore, even in this case, even if a device capable of changing data is inserted into the transmission line D and, for example, the dubbing frequency control code 61, particularly the discrimination bit is changed, the change is not made on the recording side. E in VTR playback system
Is processed as a transmission error in the CC circuit (9),
The original contents will be restored.

The data from the ECC circuit (9) is supplied to a reproducing-system deframing circuit (10) and a dubbing determination circuit 66, respectively. The data supplied to the deframing circuit (10) of the reproduction system is then subjected to reproduction processing and displayed on a monitor, for example, as a video. Also,
From the data supplied to the dubbing determination circuit 66, the dubbing number restriction code 61 included in the data is read out by the dubbing determination circuit 66, and based on the dubbing number restriction code 61, prohibition / permission of dubbing is performed. Is electrically determined.

When dubbing is permitted, the data from the ECC circuit (9) is supplied to the parity generation circuit 6 via the second changeover switch 67, and is further recorded on the magnetic tape through the channel encode 7. On the other hand, when dubbing is prohibited, the data from the ECC circuit (9) is not supplied to the parity generation circuit 6 and is discarded as it is. In this case, for example, the controller 68
Is displayed on the monitor to inform the monitor that dubbing is prohibited.

As described above, according to the dubbing system according to the second embodiment, similar to the case of the first embodiment,
Modification of data on the transmission line D can be invalidated,
It is possible to reliably prevent illegal dubbing and strengthen copyright protection.

In particular, the first parity code 44a for recording
(54a) is added to the transmission.
A circuit configuration in which only the I / F 62 is connected to the output stage of the transmission path D of the reproduction-side VTR can be employed. In addition, since the first parity code 44a (54a) for recording is added to the transmission data, it is possible to perform error correction in the ECC circuit (9) of the reproduction system on the recording side. There is no need to insert a new ECC circuit. As described above, according to the second embodiment, the circuit configuration of the dubbing system can be simplified, which is advantageous in terms of manufacturing cost.

In the second embodiment, only the first parity code 44a (54a) is added for transmission, but, of course, the first and second parity codes 44a (54a) are added.
(54a) and 44b (54b) may be added for transmission. In this case, the code configuration of the data transmitted to the transmission path is the same as the frame structure shown in FIGS.

Next, a dubbing system according to a third embodiment will be described with reference to FIG. Components corresponding to those in FIG. 6 are denoted by the same reference numerals, and redundant description thereof will be omitted.

In the dubbing system according to the third embodiment, the reproducing ECC circuit 9 in the reproducing VTR is used.
I / F 62 and a scramble circuit 71 between
And a parity generation circuit 63 are inserted. The recording system parity generation circuit 6 and the transmission path D
In between, an ECC circuit 64, a dubbing determination circuit 66, and I
/ F65 and a changeover switch 67 are inserted.

A dubbing data read circuit 72 for reading only the dubbing frequency control code 61 from the data from the ECC circuit 9 is connected to the reproducing VTR. The read circuit 72 has almost the same function as the dubbing determination circuit 66 of the recording-side VTR, and outputs a start signal to the scramble circuit 71 at the subsequent stage when the data to be transmitted is dubbing prohibited data.

The scramble circuit 71 rearranges (scrambles) only the data from the ECC circuit 9, particularly the video data 43 and the audio data 53, based on the supply of the start signal. Therefore, other SYNC
The data 41 (51), the ID data 42 (52) and the dubbing number control code 61 are not to be rearranged. The data scrambled by the scramble circuit 71 is supplied to a parity generation circuit 63 at the next stage.

On the other hand, when the data from the ECC circuit 9 is permitted to be dubbed, the data is not rearranged in the scramble circuit 71 and is supplied to the parity generation circuit 63 as it is.

When dubbing is performed in the dubbing system according to the third embodiment, first, the reproduction side V
In the TR, the data reproduced by the channel decoder 8 is supplied to the ECC circuit 9, and the ECC circuit 9 performs error correction. In this case, the first
And second parity codes 44a (54a) and 44b
(54b) is removed. Parity codes 44a and 4
An image data block group including the video data 43 and the dubbing number control code 61 excluding the video data 4b, and the audio data 5 excluding the parity codes 54a and 54b.
The audio data block group including the number 3 and the dubbing frequency control code 61 is supplied to the scramble circuit 71 via the I / F 62 at the next stage.

The scramble circuit 71 includes a read circuit 7
When the start signal is supplied from 2, the video data 43 and the audio data 53 of the data block group are scrambled and supplied to the parity generation circuit 63. On the other hand, when the activation signal is not supplied, the activation signal is supplied to the parity generation circuit 63 without scrambling.

A scrambled data block group or an unscrambled data block group is
A parity code 69 for transmission is added to the end of each data block by the parity generation circuit 63, and further transmitted to the recording side VTR via the transmission path D.

In the recording side VTR, first, the transmission path D
The data transmitted through the ECC circuit 64
The error correction is performed based on the parity code 69 added to each data block. That is, even if an error occurs in the transmission path D, the ECC circuit 6
The error is corrected in step 4, and the data is restored to the data output from the scramble circuit 71 of the reproducing VTR.

The data from the ECC circuit 64 is supplied to a dubbing determination circuit 66, and the prohibition / permission of dubbing is electrically determined based on the dubbing frequency control code 61 included in the data. For dubbing permission, ECC
The data from the circuit 64 is supplied to the parity generation circuit 6 via the I / F 65 and the changeover switch 67, and is further recorded on the magnetic tape through the channel encode 7. On the other hand, when dubbing is prohibited, the data from the ECC circuit 64 is not supplied to the parity generation circuit 6 and is discarded as it is. In this case, for example, a message is displayed via the controller 68 to notify the monitor that dubbing is prohibited.

As described above, according to the dubbing system according to the third embodiment, the scrambling circuit 71 for scrambling the output stage of the transmission path D of the reproducing VTR only when dubbing is prohibited, the parity code for transmission An ECC circuit 64 for connecting a parity generating circuit 63 for adding an error code 69 to the input stage of the transmission path D of the recording side VTR based on the added parity code 69.
Is connected, so that alteration of data on the transmission path D can be invalidated. In addition, since data for which dubbing is prohibited is scrambled, it must be descrambled to change the data into data that can be dubbed on the transmission path D. This makes it extremely difficult to change the data. Enhanced protection can be realized more reliably.

Next, a dubbing system according to a fourth embodiment will be described with reference to FIG. Components corresponding to those in FIG. 9 are denoted by the same reference numerals, and redundant description is omitted.

The dubbing system according to the fourth embodiment has substantially the same configuration as the dubbing system according to the third embodiment, except that the scramble circuit 71 and the I / O
The difference is that the RAM 73 is used instead of the F62. The RAM 73 temporarily stores the data from the ECC circuit 9 based on the write address from the write address generation circuit 74 and reads the data according to the read address from the read address generation circuit 75. Normally, the read address generation circuit 75 updates the read address sequentially to the write address. However, based on the start signal (indicating dubbing inhibition) from the read circuit 72, the read address generation circuit 75 changes the read address to the write address sequence. Update in a different order. For example, the read address is updated so that data is read in reverse order in sync block units.

When dubbing is performed in the dubbing system according to the fourth embodiment, first, the reproduction side V
In the TR, the data reproduced by the channel decoder 8 is supplied to the ECC circuit 9, and the ECC circuit 9 performs error correction. Also in this case, the recording first and second parity codes 44a (54a) and 44b
(54b) is removed. Parity codes 44a and 4
An image data block group including the video data 43 and the dubbing number control code 61 excluding the video data 4b, and the audio data 5 excluding the parity codes 54a and 54b.
The audio data block group including the number 3 and the dubbing number control code 61 are stored in the RAM 73 in order from the write address from the write address generation circuit 74.

When the start signal is supplied from the read circuit 72, the update of the read address from the read address generation circuit 75 is performed in a reverse order, and the data blocks stored in the RAM 73 are rearranged in the reverse order. The data is read out and supplied to the parity generation circuit 63 at the subsequent stage. On the other hand, when the start signal is not supplied to the read address generation circuit 75, the data blocks in the RAM 73 are sequentially read out at normal read addresses and supplied to the subsequent parity generation circuit 63.

The rearranged data blocks or the non-rearranged data blocks are added with a parity code 69 for transmission after each data block by a parity generation circuit 63, and further transmitted through a transmission path D. And transmitted to the recording VTR.

In the recording side VTR, the data transmitted through the transmission path D is transmitted to the ECC circuit 64 by the ECC circuit 64.
Error correction is performed based on the parity code 69 added to each data block. Thus, the data is restored to the data output from the RAM 73 of the reproducing VTR.

The data from the ECC circuit 64 is supplied to a dubbing determination circuit 66, and the prohibition / permission of dubbing is electrically determined based on the dubbing frequency control code 61 included in the data. In the case of dubbing permission, E
The data from the CC circuit 64 is supplied to the parity generation circuit 6 via the I / F 65 and the changeover switch 67, and is further recorded on the magnetic tape through the channel encode 7. On the other hand, when dubbing is prohibited, the ECC circuit 64
Is not supplied to the parity generation circuit 6,
It will be thrown away. In this case, for example, a message is displayed via the controller 68 to notify the monitor that dubbing is prohibited.

As described above, according to the dubbing system according to the fourth embodiment, the output stage of the transmission line D of the reproduction side VTR has the RAM 73 in which the read address update order changes only when dubbing is prohibited, An ECC circuit 6 is connected to a parity generation circuit 63 for adding a parity code 69 and performs error correction of transmission data based on the added parity code 69 at the input stage of the transmission path D of the recording-side VTR.
4, the modification of the data on the transmission path D can be invalidated.

When dubbing is prohibited, the RAM 73
In this case, the update order of the read addresses is different from the normal update order, which is equivalent to pseudo scrambling. Therefore, in order to change the data into data that can be dubbed on the transmission path D, the data must be descrambled, and the change becomes extremely difficult. As in the third embodiment, the prevention of illegal dubbing and the protection of copyright are prohibited. Reinforcement can be realized more reliably.

In the third and fourth embodiments, the parity generation circuit 63 is provided at the output stage of the transmission line D of the reproducing VTR, and the ECC circuit 64 is provided at the input stage of the transmission line D of the recording VTR. Although the example of providing was shown, of course, the second
It is also possible to adopt a configuration according to the configuration of the dubbing system according to the embodiment.

In each of the above embodiments, two digital VTs
Although an example in which the present invention is applied to a dubbing system between Rs has been described, the present invention can also be applied to a dubbing system between digital VTRs having one reproducing side and a plurality of recording sides. Of course, the present invention can be applied to a DAT (Digital Audio Recorder).

[0084]

As described above, according to the present invention, dubbing control information and main data which are recorded on a recording medium and to which a recording parity code is respectively added are read out together by one recording / reproducing apparatus. Transmitting the dubbing regulation information and the main data to another recording / reproducing apparatus via a transmission path,
In the transmission apparatus, method, and transmission system for recording the dubbing restriction information and the main data on a recording medium in the another recording / reproduction apparatus only when the dubbing restriction information indicates that dubbing is possible, the one recording / reproduction apparatus In the above, when the dubbing control information means that dubbing is impossible, a start signal is generated, the main data is rearranged in response to the generated start signal, the recording parity code is removed during transmission, and the dubbing control is performed. An error correction code is simultaneously added to the main data together with the information and supplied to the transmission path. Accordingly, the transmission apparatus, the method, and the transmission system according to the present invention can invalidate data modification on the transmission path, and when the dubbing control information indicates that dubbing is impossible, (simulated) Since the scrambled data must be further descrambled, it is very difficult to modify the data for which dubbing is prohibited, so that illegal dubbing can be prevented and copyright protection can be more reliably realized.

[Brief description of the drawings]

FIG. 1 is a concept showing a recording format of one helical track of a magnetic tape used in an embodiment in which a transmission apparatus according to the present invention is applied to a dubbing system between digital VTRs (hereinafter simply referred to as a dubbing system according to the embodiment). FIG.

FIG. 2 is a conceptual diagram showing a code structure of image data recorded in a video area in a recording format of one helical track of a magnetic tape used in the dubbing system according to the embodiment.

FIG. 3 is a conceptual diagram showing a code structure of audio data recorded in an audio area in a recording format of one helical track of a magnetic tape used in the dubbing system according to the embodiment.

FIG. 4 is a conceptual diagram showing a recording position of a dubbing number control code recorded in image data and audio data.

FIG. 5 is a conceptual diagram showing a bit configuration of a dubbing frequency control code.

FIG. 6 is a block diagram showing a circuit configuration of the dubbing system according to the first embodiment.

FIG. 7 is an explanatory diagram showing a data transmission process in the dubbing system according to the first embodiment.

FIG. 8 is a block diagram illustrating a circuit configuration of a dubbing system according to a second embodiment.

FIG. 9 is a block diagram illustrating a circuit configuration of a dubbing system according to a third embodiment.

FIG. 10 is a block diagram showing a circuit configuration of a dubbing system according to a fourth embodiment.

FIG. 11 is a block diagram showing a circuit configuration of a general digital VTR.

FIG. 12 is a block diagram showing various dubbing methods according to a conventional example.

FIG. 13 is a conceptual diagram showing the contents of transmission data in dubbing according to a conventional example.

[Explanation of symbols]

1 A / D converter 2 Blocking circuit 3 DCT (discrete cosine transform) circuit 4 Encoder 5 Framing circuit 6 Parity generation circuit 7 Channel encoder 8 Channel decoder 9 ECC circuit 10 Deframing circuit 11 Decoder 12 Inverse DCT circuit 13 Deblocking circuit 14 ..D / A converter 41 (51) SYNC data 42 (52) ID data 43 (53) Main data (video data, audio data) 44a (54a) First parity code 44b (54b) Second parity code 61 Dubbing frequency control code 62, 65 I / F 63 Parity generation circuit 64 E CC circuit 66 ... Dubbing determination circuit 67 ... Changeover switch (second changeover switch) 68 ... Controller 69 ... Parity code for transmission 70 ... First changeover switch 71 ... Scramble circuit 72 readout circuit 73 RAM 74 write address generation circuit 75 read address generation circuit

Continuation of the front page (72) Inventor Kazuyuki Ogawa 6-35-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (56) References JP-A-2-108280 (JP, A) JP-A-4-82055 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G11B 20/18, 20/10

Claims (6)

(57) [Claims] 1. A single recording / reproducing apparatus reads out dubbing control information and main data recorded on a recording medium and to which a recording parity code is respectively added, and transmits the read dubbing control information and the main data. Transmitted to another recording / reproducing apparatus via a path, and only when the dubbing restriction information means that dubbing is possible, the dubbing restriction information and the main data are recorded on a recording medium in the another recording / reproducing apparatus. The one recording / reproducing apparatus, when the dubbing restriction information indicates that dubbing is impossible, a start signal generating means for generating a start signal, and receiving the start signal from the start signal generating means. A scrambling means for rearranging the main data, removing the recording parity code during transmission, Transmission apparatus and supplying to the transmission line by adding an error correction code at the same time the main data together with the regulation information. 2. A single recording / reproducing apparatus reads out dubbing control information and main data recorded on a recording medium and to which a recording parity code is respectively added, and transmits the read dubbing control information and the main data. Transmitted to another recording / reproducing apparatus via a path, and only when the dubbing restriction information means that dubbing is possible, the dubbing restriction information and the main data are recorded on a recording medium in the another recording / reproducing apparatus. In the transmission apparatus, the one recording / reproducing apparatus stores a start signal generating unit that generates a start signal when the dubbing restriction information indicates that dubbing is impossible, and stores the main data based on a supplied write address. The main data stored in the storage means is read out in sequence from the storage means and the write address, and is supplied to the transmission path. Receiving the start signal from the start signal generating means, reading the main data in an order different from the write address, and changing the recording parity code during transmission. A transmission apparatus for removing the dubbing control information and simultaneously adding an error correction code to the main data and supplying the same to a transmission path. 3. A single recording / reproducing apparatus reads out the dubbing control information and main data recorded on a recording medium and to which a recording parity code is respectively added, and transmits the read dubbing control information and the main data. A transmission method for transmitting the dubbing restriction information and the main data to a recording medium in the another recording / reproducing apparatus only when the dubbing restriction information indicates that dubbing is possible by transmitting to the other recording / reproducing apparatus via a path. In the one recording / reproducing apparatus, when the dubbing control information indicates that dubbing is not possible, a start signal is generated, and the main data is rearranged in response to the generated start signal, The parity code is removed, an error correction code is added to the main data together with the dubbing control information, and the data is supplied to the transmission path. Transmission method characterized by. 4. A single recording / reproducing device reads out the dubbing control information and the main data, each of which is recorded on a recording medium and to which a recording parity code is added, and transmits the read dubbing control information and the main data. A transmission method for transmitting the dubbing restriction information and the main data to a recording medium in the another recording / reproducing apparatus only when the dubbing restriction information indicates that dubbing is possible by transmitting to the other recording / reproducing apparatus via a path. In the one recording / reproducing apparatus, the main data is stored based on a supplied write address, and when the dubbing restriction information indicates that dubbing is possible, the stored main data is read out in sequence with the write address. If the dubbing control information indicates that dubbing is impossible, the start signal is supplied to the transmission path. In response to the generated start signal, the stored main data is read out and supplied to the transmission line in a different order from the write address, and during recording, the recording parity code is removed, and the dubbing control is performed. A transmission method characterized in that an error correction code is simultaneously added to the main data together with information and supplied to a transmission path. 5. A dubbing control information and main data which are recorded on a recording medium and each of which has a recording parity code added thereto are read out, and when the dubbing control information indicates that dubbing is impossible, a start signal is generated and generated. One recording / reproducing apparatus that rearranges the main data in response to the start signal; a transmission apparatus that transmits the dubbing control information read by the one recording / reproducing apparatus and the main data via a transmission path; A transmission system including a recording / reproducing apparatus for recording the dubbing control information and the main data on a recording medium only when the control information and the main data are transmitted and the dubbing control information indicates that dubbing is possible. The transmission device removes the recording parity code during transmission and transmits the main data together with the dubbing control information. A transmission system wherein error correction codes are simultaneously added to data and supplied to a transmission path. 6. The dubbing control information and main data which are recorded on a recording medium and are respectively added with a recording parity code are read out, the main data is stored based on a supplied write address, and the dubbing control information can be dubbed. In the case of the above, in order of the write address, the stored main data is read out, and when the dubbing control information indicates that dubbing is impossible, a start signal is generated, and the generated start signal is received in response to the generated start signal. One recording / reproducing apparatus for reading out the stored main data in an order different from the write address; and a transmission apparatus for transmitting the dubbing control information and the main data supplied from the one recording / reproducing apparatus via a transmission path. The dubbing restriction information and the main data are transmitted, and the dubbing restriction information means that dubbing is possible. Only in the case, a transmission system comprising a dubbing control information and another recording / reproducing device that records the main data on a recording medium, wherein the transmission device removes the recording parity code during transmission, A transmission system, wherein an error correction code is simultaneously added to the main data together with the dubbing control information and supplied to a transmission path.