JP2001283520A - Multimedia recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multimedia recording device which correctly duplicates data or inhibits the duplication even if it takes a long time to detect copy management information. SOLUTION: When digital watermark data representing 'copy inhibition' are detected through the judgement of a digital watermark detection insertion unit 19, a disk interface part 23 erases information having been already recorded on an optical disk and a CPU 33 erases index information of a program having been already recorded in a storage memory 37.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multimedia recording apparatus having a copy protection function.

[0002]

2. Description of the Related Art In recent years, digital media has rapidly spread due to the spread of the Internet and low-cost, large-capacity recording media. As a result, the user can easily obtain digital data, and can view high-quality image data and high-quality sound audio data.
However, digital data has a serious copyright problem because the original data can be copied as it is. For this reason, copy protection techniques for solving copyright problems are rapidly being developed.

As one method of this copy protection technique, there is an electronic watermark for inserting protection information into data itself. For example, Japanese Patent Application Laid-Open No. H10-191330 discloses a technique in which 8-bit copy information information is inserted by manipulating quantized value data after discrete cosine transform. Here, the copy information information includes “copy never (copy prohibited)” and “copy never”.
py allowed (copy permitted) "," one c
opp (one-generation copy permitted). Further, in order to manage the generation of the copy, "c
A technology has been developed that inserts generation management information called “opy mark” and controls whether the next duplication is permitted based on the copy information information and the generation management information. Specifically, the copy information information "one c
If "copy mark" is inserted in "copy", it is determined that the copy has already been performed once, and further copy is prohibited. Since this digital watermark is mixed in the data itself, the copy management information is not deleted even if it is converted into analog data.

[0004]

However, in order to prevent the digital watermark from interfering with the object to be inserted, it is necessary to lower the energy level of the digital watermark and insert the digital watermark in a manner that it is hidden as little as possible. It takes some time (several seconds to several tens of seconds) to detect data. When this digital watermarking technology is used in a digital recording device, during the detection of digital watermark data, it is not determined whether copying is permitted or prohibited, so the duplication recording operation is not performed. However, there was a problem that the data could not be recorded.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a multimedia recording apparatus for duplicating data or prohibiting duplication even if it takes time to detect copy management information.

[0006]

A multimedia recording apparatus according to the present invention is configured as follows.

A multimedia recording apparatus according to the present invention comprises a detecting means for detecting inserted digital watermark data, and means for detecting the prohibition information indicating copy prohibition by the detecting means until the prohibition information is detected. Erasing means for erasing the recorded digital information.

With this configuration, it is possible to erase the digital information recorded when the copy prohibition is detected while recording the digital information until the detection of the digital watermark data is completed.

Further, the multimedia recording apparatus of the present invention comprises a detecting means for detecting the inserted digital watermark data, a buffer means for temporarily holding digital information until the detecting means detects the digital watermark data, Recording means for recording digital information temporarily stored after the permission information indicating copy permission is detected by the detection means on the recording medium.

With this configuration, it is possible to reliably record digital information until the detection of digital watermark data is completed.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic block diagram showing a configuration of a multimedia recording apparatus according to an embodiment of the present invention.

The multimedia recording apparatus is provided with an analog input terminal 11, a digital input terminal 12, and an analog output terminal 13. The analog input terminal 11 is connected to an A / D converter 15, and the A / D converter 15 is connected to an MPEG2 encoder 17. The digital input terminal 12 and the MPEG2 encoder 17 are connected to a digital watermark detector / inserter 19. The digital watermark detector / inserter 19 is connected to a disk interface unit 23 that controls an optical disk 21 as a recording medium. The disk interface unit 23 is connected to a digital watermark detector 25, and this detector 25 is connected to an MPEG2 decoder 27. The decoder 27 is connected to a video encoder 29, which is connected to a D / A converter 31. The D / A converter 31 is connected to the analog output terminal 13. The CPU 33 includes an MPEG encoder 17, an electronic watermark detector / inserter 19, a disk interface unit 23, an electronic watermark detector 25, an MPE
It controls the G2 decoder 27 and is connected to a user interface unit 35 and a storage memory 37.

An analog signal input from an analog input terminal 11 is converted into a digital signal by an A / D converter 15, and then converted to an MPEG2 signal by an MPEG2 encoder 17.
Video and audio encoding processing based on the standard is performed. M
After encoding, the PEG2 encoder 17 converts a plurality of video and audio signals defined as the MPEG2 system into one bit stream and inputs the bit stream to the digital watermark detection / inserter 19. In the case of a DVD system, a program stream (hereinafter, referred to as PS) is used. On the other hand, the digital signal input from the digital input terminal 12 is already
It is G2 encoded and directly input to the digital watermark detection / inserter 19.

The digital watermark detecting / inserting unit 19 converts the signal encoded in MPEG2 into MPEG2.
Partially decode the PS video. Specifically, variable-length coding (Huffman code) is decoded, and digital watermark data is extracted from an 8 * 8 discrete cosine transform (hereinafter, referred to as DCT) block. The extracted data is copy management information of the input video / audio signal, and at least “n”.
ever copy (copy prohibition) "," one copy
py (one-generation copy permitted) "," copy allow
ed (copy permitted) ". The digital watermark detection / inserter 19 determines any one of these three states.

Furthermore, copy generation management information is inserted in another area or method other than the three states, and the digital watermark detection / inserter 19 detects this copy generation management information. When the copy management information is “one copy (one-generation copy permitted)” and the copy generation management information is added, the digital watermark
Judgment that copying has been performed once and prohibits recording. The digital watermark detection / inserter 19 sets the copy management information to "one c
If "copy (permits one-generation copy)" and there is no copy generation management information, it is determined that this is the first copy and recording is permitted. In this case, the digital watermark detecting / inserting unit 19 inserts copy generation management information indicating that copying has been performed once so that the second copying is not performed.

The signal output from the digital watermark detector / inserter 19 is sent to the disk interface unit 23.
The interface unit 23 is an optical disk 21 as a recording medium.
Are sequentially written to the address specified by the CPU 33. When reproducing the already recorded signal, the interface unit 23 reads the signal from the optical disc 21 and inputs the signal to the digital watermark detector 25. The digital watermark detector 25 has the same configuration as the detection portion of the digital watermark detection / inserter 19, and detects digital watermark data hidden in a signal.
The digital watermark detector 25 detects whether the recording medium is an unauthorized recording medium. Here, the unauthorized recording medium is a recordable medium whose digital watermark data is “never copy”.
The copy generation management information is inserted regardless of whether it is “y” or “one copy”. In this case, the reproduction operation is prohibited.

The signal output from the digital watermark detector 25 is decoded by the MPEG2 decoder 27 and converted by the video encoder 29 into a format that can be output to a television. The format-converted signal is converted to an analog signal by the D / A converter 31 and output from the analog output terminal 13 as an analog signal.

The CPU 33 controls the entire apparatus. The storage memory 37 records information on programs recorded via the CPU 33. The user interface unit 35 notifies the CPU 33 under the control of the user. For example,
The code is received from the remote controller, converted into a key number of the remote controller, and notified to the CPU 33.

Next, the operation of the present apparatus will be described with reference to FIGS. FIG. 2 is a flowchart for explaining the operation of the present embodiment.

When the user interface unit 35 receives a recording start instruction from the user by pressing a recording start button or the like (step S201), the CPU 33 gives a recording instruction to the disk interface unit 23. The disk interface unit 23 includes an A / D converter 15, an MPEG2 encoder 17,
Data input from the analog input terminal 11 via the digital watermark detection / insertion unit 19 or data input from the digital input terminal 12 via the digital watermark detection / insertion unit 19 can be written on the optical disk independently of the digital watermark data. 2
1 is started (step S202). Further, the disk interface unit 23 records identification information (hereinafter, referred to as index information) on the program in the storage memory 37 via the CPU 33. At the start of recording, the CPU 33
Displays "WM detected" on the television screen indicating that digital watermark information is being detected. FIG. 3 is a diagram showing an example of displaying a comment on a television screen at the start of recording.

The CPU 33 has a disk interface unit 2
At the same time as the recording start instruction to the digital watermark detector 3, the digital watermark detector / inserter 19 is given a detection start instruction. In response to this instruction, the digital watermark detection / inserter 19 starts detecting digital watermark data (step S203). Digital watermark detection / inserter 1
Step 9 is performed over several seconds in order to suppress the false detection rate of the digital watermark data determination. When the detection is completed, the digital watermark detection / inserter 19 notifies the CPU 33 of the detection result.
The CPU 33 determines whether the digital watermark data is "copy prohibited" based on the notification of the detection result (step S204). When it is determined that the digital watermark data is “copy permitted”, the CPU 33 continues the data recording on the optical disc 21 (step S205).

When it is determined that the digital watermark data is "copy prohibited", the CPU 33 instructs the disk interface unit 23 to stop recording data on the optical disk 21 and to delete already recorded data. Also,
The CPU 33 also deletes the index information recorded in the storage memory 37 (Step S206). Furthermore, CPU
A display 33 indicates on the television screen that the detection of digital watermark information has been completed and that copying has been prohibited. FIG. 4 is a diagram showing an example of displaying a comment on a television screen when digital watermark information for which copying is prohibited is detected.

Here, the digital watermark data judgment processing of the digital watermark detection / inserter 19, the disk interface unit 2
The disk recording / erasing process 3 and the temporal change in the contents of the storage memory 37 will be described with reference to FIG. FIG. 5 is a diagram for explaining a temporal state change from the digital watermark data determination to the copy prohibition operation.

When the recording start instruction is received, the determination processing by the digital watermark detection / insertion unit 19 is in the state of determining the digital watermark data. The input image being determined is information A of the program P3. During the determination of the digital watermark data, the disk processing of the disk interface unit 23 is in a recording operation state of the input image information A. Assuming that the program P1 and the program P2 are already recorded on the optical disc 21, the disc interface unit 23 records the input image information A from the end position of the program P2. Immediately after the recording start instruction, the CPU 33 records the index information of the program P3 in the storage memory 37 in the area next to the area where the index information of the programs P1 and P2 is recorded.

When the digital watermark detection / insertion unit 19 completes the determination of the digital watermark data and detects "copy prohibited", the disk processing of the disk interface unit 23 enters a recording stop / erase / idle state. The information A recorded on the optical disk is deleted, and the index information of the program recorded in the storage memory 37 is also deleted by the CPU 33.

As an example of the index information of a program, as shown in FIG. 6, the program name / recorder name /
Recording information includes recording date / time / data amount / program category / performer name.

Next, a second embodiment of the present invention will be described.

FIG. 7 is a schematic block diagram showing a configuration of a multimedia recording apparatus according to a second embodiment of the present invention. In FIG. 7, the same parts as those in FIG.

The second embodiment differs from the first embodiment in that the recording operation is started after the digital watermark detection / inserter 19 detects the digital watermark data. Therefore, while detecting the digital watermark data, the apparatus shown in FIG.
A buffer unit 71 for temporarily holding input data is provided. The buffer unit 71 is a FIFO type buffer memory, and data is output first from data input first. The input data is temporarily held in the buffer unit 71 until the detection / determination of the digital watermark data is completed, and is output to the disk interface unit 23 after the determination is completed.

Next, the operation of the second embodiment will be described with reference to FIGS. FIG. 8 is a flowchart for explaining the operation of the second embodiment of the present invention. After the recording start instruction (S801) by the user, the digital watermark detection /
Digital watermark detection is performed by the inserter 19 (step S802). The data input until the end of the determination is temporarily stored in the buffer unit 71. Digital watermark detection / inserter 19
Is notified of the determination result of "copy permitted" to the CPU 33, the CPU 33 instructs the disk interface unit 23 to record the data temporarily stored in the buffer unit 71 on the optical disk 21. Further, the CPU 33 records the index information of the program in the storage memory 37.

FIG. 9 is a view for explaining a temporal state change from the determination of digital watermark data to the copy prohibition operation in the second embodiment. When the digital watermark detection / inserter 19 is in the determination state, the disk interface unit 2
The disk process of No. 3 is in an idle state, and the information A is not recorded on the disk. Also, the index information of the program P3 is not recorded in the storage memory 37. When the determination by the digital watermark detector / inserter 19 is completed and “copy permitted” is detected, the disk processing of the disk interface unit 23 enters a recording state, information A is recorded on the disk, and the program is stored in the storage memory 37. The index information of P3 is recorded.

When there is a recording start instruction from the user, the CPU
33 displays "WM detected" on the television screen, indicating that digital watermark information is being detected, as in FIG. When "copy permitted" is detected, the CPU 33 displays on the television screen a message indicating that detection has been completed and that copying is in progress. FIG. 10 is an example of displaying a comment on the television screen when the detection of digital watermark data is completed and during data copy.

In the above embodiment, an optical disk is used as a recording medium. However, the present invention can be applied to a tape or the like. In the above embodiments, the status is displayed on the television screen. However, the present invention is also applicable to a status notification or the like using sound. Further, the program index information may include a recording disk number, source information of recording data, and the like.

[0035]

According to the present invention, even if it takes time to detect the copy management information, the data can be correctly copied or the copying can be prohibited.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram showing a configuration of a multimedia recording apparatus according to an embodiment.

FIG. 2 is a flowchart for explaining the operation of the embodiment.

FIG. 3 is an example of displaying a comment on a television screen at the start of recording.

FIG. 4 is an example of displaying a comment on a television screen when digital watermark information for which copying is prohibited is detected.

FIG. 5 is a view for explaining a temporal state change from the start of digital watermark data determination to a copy prohibition operation.

FIG. 6 is a diagram showing an example of index information of a program.

FIG. 7 is a schematic block diagram illustrating a configuration of a multimedia recording device according to a second embodiment.

FIG. 8 is a flowchart for explaining the operation of the second embodiment.

FIG. 9 is a diagram for explaining a temporal state change from the start of digital watermark data determination to a copy prohibition operation in the second embodiment.

FIG. 10 is an example of a comment display on a television screen when digital watermark data detection is completed and data is copied.

[Explanation of symbols]

 Reference Signs List 11 analog input terminal 12 digital input terminal 13 analog output terminal 15 A / D converter 15 17 MPEG2 encoder 19 digital watermark detector / inserter 21 optical disk 23 disk interface unit 25 digital watermark detector 27 MPEG2 decoder 29 video encoder 31 D / A Converter 33 CPU 35 User interface unit 37 Storage memory 71 Buffer unit

Claims (5)

[Claims] 1. A multimedia recording apparatus for recording digital information into which digital watermark data is inserted, a detecting means for detecting the inserted digital watermark data, and prohibition information indicating copy prohibition by the detecting means. A multimedia recording apparatus, comprising: an erasing means for erasing digital information recorded until the prohibition information is detected, when detected. 2. A multimedia recording apparatus for recording digital information with digital watermark data inserted therein, comprising: identification information storage means for storing identification information of the digital information; and detecting the inserted digital watermark data. Detecting means, and erasing means for erasing the identification information recorded in the identification information storage means before detecting the prohibition information when prohibition information indicating copy prohibition is detected by the detection means. A multimedia recording device, characterized in that: 3. A multimedia recording apparatus for recording digital information with digital watermark data inserted therein, comprising: identification information storage means for storing identification information of the digital information; and detecting the inserted digital watermark data. A multimedia recording apparatus comprising: a detection unit; and a recording unit that records identification information of the digital information in the identification information storage unit after permission information indicating copy permission is detected by the detection unit. . 4. A multimedia recording apparatus for recording digital information in which digital watermark data is inserted on a recording medium, wherein: a detecting means for detecting the inserted digital watermark data; Buffer means for temporarily holding the digital information until it is detected; and recording means for recording the temporarily held digital information on the recording medium after the detecting means detects permission information indicating copy permission. A multimedia recording device comprising: 5. The multimedia recording apparatus according to claim 1, wherein said detection means inserts copy generation management information into data to be recorded during detection of digital watermark data.