JP2007318194A - Digital image recording and reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital image recording and reproducing device for preventing video data from being restored easily in encryption when storing the backup of video data, or the like on an external HDD, or the like. <P>SOLUTION: The digital image recording and reproducing device records contents, such as the video data, on a recording medium 17, and reads the recorded content from the recording medium 17 for reproduction. The digital image recording and reproducing device comprises: a means 13 for generating information for performing distinction for each equipment; a means 12 for performing the encryption based on the information for performing distinction for each equipment, when recording content; a means for recording encrypted content on the recording medium 17; a means 18 for holding an arrangement change pattern; a means for backing up the content from one of a plurality of recording media to another; and an arrangement control means 19 for performing recording at a separated position on the recording medium discontinuously according to the arrangement change pattern when performing backup for recording. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a content backup in an apparatus for recording / reproducing contents such as digital video, audio, and electronic information on a recording medium through digital broadcasting, and a management method thereof.

In recent years, digital broadcasting has been started, and there is a conventional example as described below (see Patent Document 1) regarding an apparatus that performs recording and reproduction for storing content such as digital broadcasting.
Devices that record digital broadcast signals as bit streams have been commercialized. This will be described with reference to FIG. In general, an MPEG transport stream (hereinafter abbreviated as MPEG-TS) is adopted for digital broadcasting. In digital broadcasting, in order to enable conditional access (limited reception), MPEG-TS is encrypted and a modulated signal is sent.
On the receiver side, the tuner 04 demodulates the signal received by the antenna 01, and a signal of a necessary channel is extracted. The extracted signal is subjected to authentication means for realizing conditional access, for example, authentication using a B-CAS card in digital broadcasting in Japan, and key information for decryption is extracted. Based on this key information, descrambling is performed by descrambler 05 to generate MPEG-TS.
In this MPEG-TS, a plurality of program streams are multiplexed, and in order to extract a stream required by the user, division is performed in TS-DEMUX09, and only a necessary part is extracted (partial). TS) is taken out.
For display, the partial TS is divided into section information indicating program information and electronic data such as a VIDEO stream, an AUDIO stream, and data broadcasting.
Thereafter, the VIDEO stream is subjected to video decoding processing by the VIDEO decoder 07 and output to the display device 08 for viewing together with information such as data broadcasting. The AUDIO stream is audio-decoded by the AUDIO decoder 10 and output to the speaker 11.
Examples of storage media include magnetic tape, HDD (Hard Disk Drive), DVD (Digital Versatile Disc), and memory.

  When recording a digital stream, since there is no deterioration due to recording unlike conventional analog recording, copyright management for protecting the copyright becomes important. For copyright management of digital broadcasting, specify copy conditions as copy control information (CCI: Copy Control Information) for each content, and specify one of “copy prohibited”, “copy once”, or “copy allowed”. To restrict replication.

  In addition to the copy management, it is necessary to prevent the content recorded on the recording medium from being illegally copied by other means. In a device that uses an HDD as a recording medium, the same HDD as that used in a PC (personal computer) is used in terms of performance and cost.

  The stream sent by digital broadcasting is authenticated by the B-CAS card and decrypted by the descrambler 05. The decrypted stream is subjected to local encryption by the encryption circuit 12 using a device-specific key before recording in the HDD, and recorded in a unique format. This prevents the HDD from being taken out and illegally copied or altered by another PC or the like.

  FIG. 6 illustrates the relationship between video contents recorded in the HDD. In the HDD, information is stored in sectors divided into a fixed block size on a plurality of tracks along the circumference of a disk-shaped disk. Numbers LBN (Logical Block Number) are continuously added to the sectors. An image in which the sectors on the circumference are replaced with a band from LBN = 0 to the maximum LBN = Max is shown. The video content Stream1 is recorded using a plurality of sectors. In the example of FIG. 6, Stream 1 is arranged in a distant sector that is not continuous at one place in the middle. In the HDD, when recording is performed in a distant sector, a seek accompanied by the movement of the head occurs, and a period during which access cannot be performed occurs.

  FIG. 7 shows how it is read from the HDD. The horizontal axis indicates time, the vertical axis indicates the transfer amount of the data that has run out, and the dotted line represents the transmission rate required for the decoder. In the figure, a seek occurs to access a distant sector, but the required transmission rate is satisfied.

  When video content is recorded, it is recorded in continuous sectors as much as possible in order to satisfy the transmission rate required for recording and reproducing the video content.

Recently, in order to protect video content in the built-in HDD, there has been a demand for recording a backup using the external HDD. As a connection method, there is a connection using the USB I / F 15 or the like. In this case, the recording format is readable by a PC, but the content to be recorded is subjected to local encryption using the encryption circuit 12 so that it can be reproduced only by the recording device. For external connection, it is possible to connect to other devices, move content, copy, etc., but copyright protection is performed by limiting the devices that can be played back.
JP 2003-37590 A

  However, as in the above-described apparatus, in backup to an external HDD by a conventional HDD recording / reproducing apparatus, recording is performed after encryption by an encryption circuit so that it cannot be reproduced by other devices. However, with encryption alone, there is a problem that if encryption key information is known, it is restored.

  The present invention has been made in view of such a situation, and provides a digital image recording / reproducing apparatus capable of improving security when creating a backup of content.

The present invention provides means for solving these problems, and the invention of each section constitutes the following technical means.
The digital image recording / reproducing apparatus according to the first aspect of the present invention is a recording / reproducing apparatus that records content such as video data on a recording medium, reads out the recorded content from the recording medium, and reproduces the content, and makes a distinction for each device. A means for generating the information, a means for encrypting based on information that is distinguished for each device when recording content, a means for recording the encrypted content on a recording medium, and a plurality of Means for holding a recording medium and backing up content from one recording medium to the other; and arrangement control means for performing discontinuous recording on distant positions on the recording medium in accordance with an arrangement change pattern when performing backup and recording. It is characterized by having.

  The digital image recording / reproducing apparatus according to Item 2 of the present invention is the same as the digital image recording / reproducing apparatus according to Item 1, wherein a plurality of patterns for changing the arrangement are prepared in advance and stored, and a certain rule is determined from the plurality of arrangement changing patterns. And selecting means according to the above.

  The digital image recording / reproducing apparatus according to item 3 of the present invention is the digital image recording / reproducing apparatus according to item 1, wherein means for generating a pattern for changing the arrangement each time and means for storing the generated arrangement change pattern in association with the video content. It was characterized by comprising.

  A digital image recording / reproducing apparatus according to item 4 of the present invention is characterized in that, in the digital image recording / reproducing apparatus according to item 1, a non-volatile memory is used as means for holding the arrangement change pattern.

The following effects are brought about by the present invention described above.
Since the digital image recording / playback apparatus according to the first aspect of the present invention is configured as described above, it is possible to change the arrangement freely so that it is difficult to restore after encrypting the video content when backing up. It is effective against the unauthorized removal of encryption by those who try to do.

  Since the digital image recording / reproducing apparatus according to item 2 of the present invention has the above-described configuration, the arrangement change pattern can be selected from a plurality, so that it is difficult to be guessed from unauthorized access.

  Since the digital image recording / reproducing apparatus according to item 3 of the present invention has the above-described configuration, the arrangement can be changed more complicatedly because there is no restriction on the type of arrangement change pattern.

  Since the digital image recording / reproducing apparatus according to item 4 of the present invention has the above-described configuration, the arrangement table is not lost even when power is not supplied, so that restoration can be guaranteed.

The best mode for carrying out the present invention will be described.
An example of an embodiment of the digital image recording / reproducing apparatus of the present invention will be described below with reference to FIGS. FIG. 1 is a functional block diagram of a digital image recording / reproducing apparatus according to a first embodiment of the present invention. The digital image recording / reproducing apparatus includes a control unit 02, a memory 03, a tuner 04, a descrambler 05, and a buffer control unit. 06, VIDEO decoder unit 07, TS-DEMUX09, AUDIO decoder unit 10, encryption unit (LOCAL system) 12, KEY generation unit 13, HDD I / F unit 14, USB I / F unit 15, built-in HDD 16, arrangement storage unit 18 , A placement control unit 19, the antenna 01 via the tuner 04, the display device 08 via the VIDEO decoder unit 07, the speaker 11 via the AUDIO decoder unit 10, and the external HDD and USB Each is connected via the I / F unit 15. Compared to the conventional configuration, an arrangement storage unit 18 and an arrangement control unit 19 are added.

  2 and 3 are diagrams for explaining the first embodiment, and are diagrams for explaining the case where the block configuration of FIG. 1 of the present embodiment is used. A case where video content recorded in the internal HDD 16 is backed up to the external HDD 17 will be described. The video content read from the internal HDD 16 is sent to the encryption unit 12 via the HDD I / F 14. The encryption unit 12 performs re-encryption when encryption for backup is necessary, and records it in the external HDD 17 via the USB I / F 15. When considering only the backup, it is not necessary to consider the input rate from the tuner 04 at the time of recording, the output rate to the VIDEO decode 07 and the AUDIO decode 10 at the time of reproduction, and it must be recorded in consecutive sectors of the HDD. There are no restrictions.

  As shown in FIG. 2, recording is performed in non-consecutive sectors during recording of Stream 1 and a lot of seeks occur as shown in FIG. 3, so that there is no problem even if the data transfer amount is reduced.

  In the present embodiment, instead of recording continuously when passing through the USB I / F 15, the address conversion unit 19 performs address conversion so that the disposition is separated. As a method for changing the arrangement, a method of performing address conversion according to a predetermined arrangement change pattern can be adopted. Further, it is possible to adopt a method of having a plurality of address conversion patterns and performing layout conversion by selectively applying the conversion patterns according to the features such as the content name for each video content to be recorded. In addition, after a change pattern is generated at random each time and a layout conversion is performed, a comparison table of the layout conversion pattern is stored in the layout storage unit 18 for each video content, and is referred to when restoring. Can be adopted. The arrangement change pattern can be held in a nonvolatile memory.

  FIG. 4 shows an example of a data table in the arrangement storage unit 18. By holding the arrangement patterns of the plurality of video contents Stream1 and Stream2 in the data table, the data table is referred to when restoration from the external HDD 17 to the built-in HDD 16 becomes necessary.

1 is a functional block diagram showing an embodiment of a digital image recording / reproducing apparatus of the present invention. It is a figure explaining the disk arrangement | positioning of one Example of the digital image recording / reproducing apparatus of this invention. It is a figure explaining the disk access of one Example of the digital image recording / reproducing apparatus of this invention. It is a figure explaining the arrangement | positioning pattern memory | storage part in one embodiment of the digital image recording / reproducing apparatus of this invention. It is a functional block diagram which shows the conventional digital image recording / reproducing apparatus. It is a figure explaining the disk arrangement | positioning of the conventional digital image recording / reproducing apparatus. It is a figure explaining the disk access of the conventional digital image recording / reproducing apparatus.

Explanation of symbols

01 antenna 02 control unit 03 memory 04 tuner 05 descrambler 06 buffer control unit 07 VIDEO decoder unit 08 display device 09 TS-DEMUX
10 AUDIO decoder unit 11 Speaker 12 Encryption unit (LOCAL system)
13 KEY generation unit 14 HDD I / F unit 15 USB I / F unit 16 Built-in HDD
17 External HDD
18 Arrangement storage unit 19 Arrangement control unit

Claims (4)

A digital image recording / reproducing apparatus that records content such as video data on a recording medium, reads the recorded content from the recording medium, and reproduces the content,
Means for generating information for making a distinction for each device, means for performing encryption based on the information for making a distinction for each device, and recording the encrypted content on a recording medium when recording the content Means for holding an arrangement change pattern, means for backing up content from one recording medium of the plurality of recording media to another recording medium, and according to the arrangement change pattern when performing backup and recording A digital image recording / reproducing apparatus comprising: an arrangement control means for controlling discontinuous recording at distant positions on the recording medium. The digital image recording / reproducing apparatus according to claim 1.
A digital image recording / reproducing apparatus comprising: means for storing a plurality of the arrangement change patterns; and means for selecting from the plurality of stored arrangement change patterns according to a certain rule. The digital image recording / reproducing apparatus according to claim 1.
A digital image recording / reproducing apparatus comprising: means for generating the arrangement change pattern each time; and means for storing the generated arrangement change pattern in association with video content. The digital image recording / reproducing apparatus according to claim 1.
A digital image recording / reproducing apparatus characterized in that the means for holding the arrangement change pattern is a non-volatile memory.