JPH05258463A - Device for recording and reproducing digital signal - Google Patents

Abstract

PURPOSE:To restrict the copying of digital signals transmitted in a packet mode. CONSTITUTION:In the recording and reproducing part 13 of a first digital VTR 1, a video tape is set, in which information for protection against copying indicating kinds of protection against copying such as the limitation of the number of times for copying and parameters such as the availability of the number of times for copying is recorded, in a predetermined position. By the first digital VTR 1, reproduced digital video signals and digital audio signals are converted into the packet mode, added with a protection bit group, and transmitted to a second digital VTR 2. By the second digital VTR 2, the protection bit group is detected, and if the availability for copying is indicated, the copying of digital video signals, etc., is performed.

Description

Detailed Description of the Invention

[0001]

This invention relates to digital video signals,
The present invention relates to a copy protection technique for transmitting a digital signal such as a digital audio signal in the form of a packet.

[0002]

2. Description of the Related Art Conventionally, as a copy protection technology for limiting dubbing of digital signals, for example, DAT's SCMS (Serial Copy Management System) is known. In this system, CD and DAT
Even if the music tape, digital audio of satellite broadcasting, etc. were provided with a copy prohibition flag, the digital audio signal could be copied only for one generation.

[0003]

However, in the above-mentioned conventional SCMS, the copy prohibition flag is added to permit copying of the digital audio signal for only one generation, or the copy prohibition flag is not added to allow unlimited copying of the digital audio signal. Since you can only select whether to allow it, the degree of freedom in setting the type of copy protection was low.

A digital VTR (hereinafter referred to as a DVTR)
In the communication system (multimedia communication system) of digital video signal, digital audio signal, character code signal, etc. using a digital communication network, the copy protection technology is necessary but not realized. The present invention solves the above problems and provides a copy protection technique which has a high degree of freedom in setting the type of copy protection and can be applied to general recording / reproducing apparatuses for digital signals such as digital video signals and digital audio signals. The purpose is.

[0005]

In order to solve the above-mentioned problems, the present invention relates to a copy protection provided to a packet in a device for inputting, recording and reproducing a digital signal transmitted in the form of a packet. A means for controlling the recording and reproduction of a digital signal to a recording medium and recording of the type and parameter of copy protection on the recording medium by detecting a protection bit group consisting of the type and the parameter, and recording the digital signal on the recording medium based on the output of the means , Means for recording the types of reproduction and copy protection and parameters.

[0006]

According to the present invention, since the digital signal recording / reproducing apparatus is configured as described above, when the digital signal reproduced from the video software is transmitted in the form of packets,
When a protection bit group consisting of copy protection type and parameter is added to the packet, the recording / reproducing apparatus takes in the copy protection type and parameter, and based on the contents, recording of the digital signal, reproduction operation and copy protection type and parameter recording. Control movements. Therefore, various kinds of copy protection such as copy number restriction, timed copy prohibition, copy image quality restriction, etc. can be performed by setting the type and parameter of copy protection, and thus unlimited digital dubbing can be prevented.

[0007]

Embodiments of the present invention will now be described in detail with reference to the drawings. (First Embodiment) In this embodiment, a digital video signal and an audio signal reproduced by the first DVTR are converted into data in a packet form, and the second DVTR is transmitted via an AV bus.
It is supplied to and dubbed there.

In order to facilitate understanding of this embodiment, first,
The AV bus and packet type data in this embodiment will be described. FIG. 4 shows A in the first embodiment of the present invention.
In the explanatory diagram of the V bus, the monitor device 31, the VTR 32, the tuner 33, the LDP 34, and the camcorder 35 are the AV bus 36.
a, 36b, 37a, 37b, 38a, 38b, 39
They are connected by a and 39b to form a ring-shaped network. That is, for example, the data output from the monitor device 31 passes through the AV bus 36a and the VTR 32.
To the tuner 33 through the AV bus 37a,
It reaches LDP34 through AV bus 38a, AV bus 3
The camcorder 35 is reached through 9a. Then, it reaches the LDP 34 through the AV bus 39b, the tuner 33 through the AV bus 38b, and the VT through the AV bus 37b.
R32, monitor device 31 through AV bus 36b
Return to.

The AV buses 36a and 36b are housed in one cable, and are buses made of, for example, optical fibers and having a speed of 100 Mbit / sec. AV buses 37a, 37b, 38a, 38b, 39
The same applies to a and 39b. FIG. 5 is a format diagram showing a main part configuration of packet-type data in the first embodiment of the present invention.

The packet in this embodiment is a control bit group and data (audio, video, command, etc.).
have. The control bit group has a source address indicating the AV equipment or the like that has transmitted the data, a destination address indicating the AV equipment or the like to which the data is to be transmitted, and a protect bit group or the like indicating the copy protection information of the digital AV equipment such as DVTR or DAT.

The protect bit group is made up of one or more sets of information, with the type of protect and its parameters as one set. As the types of protection, copy number limit (07 in the figure, parameter 01 = 1 copy is possible), playback number limit (08 in the figure, parameter 0)
5 = 5 times reproducible), timed copy prohibited (copying can not be done from 〇 ×× day, or can be copied from 〇 ×× day, not shown), timed program erase (programmed on 〇 ×× day) Disappears (not shown), copy image quality restrictions, etc. Of the above, the playback count limitation and the timed program erasure are suitable for a large-capacity hard disk device rather than a DVTR, DAT, or the like.

The data is, for example, measured by the monitor device 31 by the VT.
A command for instructing the R32 to transmit a reproduction program, a command for instructing the tuner 33 to transmit a reception program of a predetermined channel, the VTR 32 and the tuner 33.
It is composed of an audio signal, a video signal, etc. sent from the etc. to the monitor device 31, and has a length according to the content of the data.

FIG. 1 is a block diagram showing the structure of a dubbing system using a digital signal recording / reproducing apparatus according to the first embodiment of the present invention. Here, transmission lines for only digital video signals and digital audio signals are indicated by thick lines. The first DVTR 1 includes an operation unit 11 for setting an operation mode, a control unit 12 including a microcomputer, a recording / reproducing unit 13 for recording and reproducing digital video signals and digital audio signals, and the like.
The interface 14 between the control unit 12, the recording / reproducing unit 13 and the AV bus, the electro-optical converter 15 for converting the packet output from the interface 14 into an optical signal and transmitting the optical signal to the AV bus 27a, and the input from the AV bus 27b. The optical / electrical converter 16 for converting the optical signal into an electric signal is provided.
The operation unit 11 may be a remote control device configured separately from the main body of the DVTR 1. It should be noted that the tuner, the servo system and the like are omitted because they are not necessary for the description of this embodiment.

Similarly, the second DVTR 2 has an operating section 21.
The control unit 22, the recording / reproducing unit 23, the interface 24, the optical / electrical converter 25, and the electric / optical converter 26 are provided. 2 and 3 are flow charts showing the copy protect operation of the second DVTR in the first embodiment of the present invention. Hereinafter, referring to FIGS. 1 to 3 and 5,
The copy protection operation of this embodiment will be described. In the recording / reproducing unit 13 of the first DVTR 1, a videotape on which copy protection information indicating the type of copy protection and its parameters is recorded at a predetermined position is set, and the recording of the second DVTR 2 is performed. Playback part 2
It is assumed that a video tape for recording is set in 3.

The user operates the operation unit 21 of the second DVTR 2 to set the recording mode, and the first DVT
The operation unit 11 of R1 is operated to set the reproduction mode. It is also possible to exchange commands and responses between the first DVTR1 and the second DVTR2, and automatically set the second DVTR2 to the recording mode in synchronization with the reproduction mode setting of the first DVTR1. .

The control unit 12 and the interface 14 of the first DVTR 1 provide the digital video signal, the digital audio signal and the copy protect information reproduced by the recording / reproducing unit 13 at a predetermined length as shown in FIG. Data is converted into a packet in which a control bit group including a protect bit group, a source address, a destination address and the like is added, and the data is converted from the electric / optical converter 15 to the AV bus 2
7a. Here, the source address is the first DV
Although TR1 and the destination address are the second DVTR2, the address may be omitted in the case of one-to-one communication as in the present embodiment.

The control unit 22 of the second DVTR 2 confirms the destination address of the packet input from the AV bus 27a and fetches the protect bit group (step S in FIG. 2).
1). Then, it is determined whether the type of protection is the copy count limit (step S2). If YES, it is determined whether the copy limit count n indicated by the parameter is 0 (step S3).

If the parameter n is 0, copying is prohibited, so the recording operation by the recording / reproducing unit 23 is stopped,
The fact is displayed on the operation unit 21. Also, the first DVTR
Data indicating that copying of the video software is prohibited is sent to 1 (step S4). When the first DVTR 1 receives the data indicating that copying is prohibited, the reproducing operation by the recording / reproducing unit 13 is stopped and the fact is displayed on the operation unit 11.

On the other hand, if n is not 0, copying is permitted n times, so recording is performed by the recording / reproducing unit 23 (step S5). At this time, the information indicating the copy number limit and its parameter are updated to n-1 and recorded at a predetermined position on the copied video tape (step S).
6). Therefore, if the parameter n recorded on the video tape set in the first DVTR1 is 1, the parameter n = 0 is recorded on the copied video tape, and the copied video tape is copied again. You can't do that.

If NO in step S2, it is determined whether the type of protection is copy image quality restriction (step S2).
7) If YES, the recording / reproducing unit 23 performs an image quality limiting process such as reducing the number of bits of the digital signal and displays the fact on the operating unit 21 (step S8).
In the case of NO in step S7, it is judged whether or not the timed copying is prohibited (step S9 in FIG. 3), and if YES, DVT.
The clock (not shown) in R2 is checked to determine whether it is the date and time specified in the parameter (step S10), and YES
If so, the recording operation by the recording / reproducing unit 23 is stopped as in step S4, and the fact is displayed on the operation unit 21. In addition, data indicating that the video software is time-limited copy prohibited is transmitted to the first DVTR 1 (step S1).
1). On the other hand, if NO in step S10, the recording / reproducing unit 23 performs recording (step S12). At this time, the information indicating the limited number of times of copying and its parameter (date and time) are directly copied to a predetermined position of the copied video tape.

The control unit 12 of the first DVTR 1 is
When the copy prohibition is detected by looking at the copy protect information recorded on the video tape, the reproducing operation of the recording / reproducing unit 13 may be stopped. The operation when the type of protection is limited to the number of times of playback, timed program erasure, and the like is the same, and therefore the description is omitted. However, the operation in this case is not the recording operation as in the above embodiment, but the reproducing operation. Further, as described above, it is suitable for a large-capacity hard disk device or the like.

(Second Embodiment) FIG. 6 is an explanatory diagram of a digital signal recording / reproducing apparatus according to a second embodiment of the present invention.
In this embodiment, a general household 41 is provided with a high-definition monitor device (hereinafter referred to as an HD monitor device) 42 and a home storage 43 as a digital signal recording / reproducing device, and a B-ISDN is provided via a home AV bus 44. Is connected to a high speed, large capacity digital communication network 45.

The home storage 43 is a digital signal recording / reproducing device having a storage capacity of several G bits, which is composed of a hard disk device, a magneto-optical disk device, etc., and distributes movie software through a high speed and large capacity digital communication network 45. The movie software output from the movie software storage 47 of the company 46, newspaper articles input from a newspaper article database of a newspaper company (not shown), and the like are recorded and reproduced.

Also in this embodiment, as in the first embodiment, the movie software storage 47 reproduces a hard disk, a magneto-optical disk, a video tape, etc., and sets a protect bit group for each predetermined length of a video signal, an audio signal, etc. A packet to which a control bit group including a source address, a destination address, etc. is added is sent via the high-speed large-capacity digital communication network 45 to the home storage 4 in the general home 41.
Send to 3. The home storage 43 is the D of the first embodiment.
The control unit (not shown) has the same configuration as the VTR, takes in the protect bit group added to the packet, and executes the copy protect process based on it. Therefore, movie software distributor 46 with unlimited dubbing
Can prevent the loss of.

The present invention is not limited to the above embodiments, and various modifications can be made based on the spirit of the present invention, and these modifications are not excluded from the scope of the present invention. For example, the present invention is not limited to the video software in the above embodiment, but audio software such as DAT, CD, CD, etc.
-It can be applied to multimedia software such as I and DVI, computer software, and the like. Also magnetic tape,
It can be applied not only to a recording medium such as a magnetic disk, but also to a recording medium such as an EEPROM.

[0026]

As described above in detail, according to the present invention, in a device for inputting, recording and reproducing a digital signal transmitted in the form of a packet, the type of copy protection given to the packet and By detecting the protection bit group consisting of parameters and controlling the recording and reproduction of digital signals to the recording medium and the recording of the type and parameters of copy protection, copy number restriction, timed copy prohibition, copy image quality restriction, timed program erase, play It is possible to perform various copy protections such as limiting the number of times of backing.

Further, since the present invention can be applied to the receiving / recording apparatus of the multimedia communication system, the multimedia communication system can be smoothly introduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a dubbing system using a digital signal recording / reproducing apparatus according to a first embodiment of the present invention.

FIG. 2 is a part of a flow chart showing a copy protect operation of the second DVTR in the first embodiment of the present invention.

FIG. 3 is a part of a flow chart showing a copy protect operation of the second DVTR in the first embodiment of the present invention.

FIG. 4 is an explanatory diagram of an AV bus according to the first embodiment of the present invention.

FIG. 5 is a format diagram showing a main configuration of packet-type data in the first embodiment of the present invention.

FIG. 6 is an explanatory diagram of a digital signal recording / reproducing apparatus according to a second embodiment of the present invention.

[Explanation of symbols]

 1 1st DVTR 2 2nd DVTR 43 Home storage 47 Movie software storage

Claims (1)

[Claims] 1. An apparatus for inputting, recording and reproducing a digital signal transmitted in the form of a packet, (a) detecting and recording a protection bit group consisting of a type and a parameter of copy protection given to the packet. Means for controlling the recording and reproduction of the digital signal on the medium and the recording of the type and parameter of copy protection;
(B) An apparatus for recording / reproducing a digital signal, comprising means for recording / reproducing the digital signal on / from the recording medium and recording the type and parameter of copy protection on the basis of the output of the means.