JP5011369B2 - Content recording method, content reproducing method, and content reproducing apparatus - Google Patents

Description

The present invention is a content distribution medium corresponding to a new copyright management system in which a reproduced video signal retaining the image quality at the time of recording is prohibited from copying, but a reproduced video signal whose image quality is sufficiently lowered with respect to the recorded image quality is permitted to be copied. This relates to the recording / reproducing method.

A typical content distribution medium is a DVD disk, and a mechanism for protecting the copyright of the DVD disk is described in the DVD ROM standard document of Non-Patent Document 1. As copyright management information, copyright management information CGMS (copy-prohibited, copy-once, copy-free, or copy-free copy conditions for recorded content)
Copy Generation Management System) is adopted.

Also, in this DVD disc and DVD player, a DVD copyright protection system CSS (Content Scramble System) that prevents unauthorized copying by general users.
An example of m) is described in Non-Patent Document 2.

With this DVD disc, almost all movie software DVDs are in accordance with the intention of the copyright holder,
A copy prohibition code is multiplexed in the CGMS specified area in the DVD disc, and CGMS-A or CGMS indicating copy prohibition is output in the analog or digital video signal output.
-D is added. For this reason, even if the copyright holder intends to permit copying if a certain reduction in image quality is applied, the copy-protected DVD video signal cannot be copied to a small HDD or flash memory under the current copyright management rules. The DVD movie software could not be enjoyed outdoors with a portable movie player (PMP) with a small screen.

DVD Specialties for Read-Only Disc Part 1 Physical Specifications Version 1.02: September 1999 (page 44) Attached Sheets for DVD Specialization National Technical Report Vol. 43 No. 3 Jun. 1997 (pages 339-341)

While copyright owners who own movie software want to reduce illegal copying as much as possible, they are eager to increase added value in the content business represented by DVD movies they sell, that is, to find new market needs. The fastest way to realize the market needs of “Ubiquitous Movie” is to enjoy movies anytime, anywhere. It is possible to enjoy DVD movie software with PMP. Specifically, image quality restrictions that can only be satisfied with a small PMP display. The introduction of a new copyright management system for video signals that have the same quality creates a new business model that allows the copyright owner, consumer, and manufacturer to co-exist and prosper.

  An object of the present invention is to contribute to the merits of copyright holders, consumers and manufacturers.

In order to achieve the object , for example, it may be configured as described in the claims. The conventional copyright management rules are copy prohibition, copy once, and copy free. “Video signals that are output with the same image quality as when recording are prohibited. However, copying is not possible for video signals that are sufficiently degraded in image quality compared to recording. New copyright management rules that allow "

  According to the present invention, it contributes to the merit of the copyright owner, the manufacturer, and the consumer.

The figure which shows the Example of the content distribution medium of this invention The block diagram which shows the Example of the reproducing | regenerating apparatus of the content distribution medium of this invention The table | surface which shows one Example of the conversion content of the pixel conversion circuit of this invention The block diagram which shows the Example of PMP of this invention

The present invention has developed a new copyright management system that allows copying of a reproduced video signal that retains the image quality at the time of recording, but permits copying of a reproduced video signal whose image quality is sufficiently lowered with respect to the recorded image quality. The present invention relates to a recording / playback system for a content distribution medium that is suitable for recording a reduced playback video signal of movie software on a PMP recording medium and playing it back on the PMP.

  Examples of the present invention will be described below.

FIG. 1 shows a configuration example of an embodiment of a content distribution medium. Reference numeral 1 denotes an optical disk medium, 2 an area in which information indicating that a new copyright management system is adopted is recorded, 3 a content including video and audio information, and copyright management information compatible with the new copyright management system This is the area to be recorded.

Next, the content distribution medium of the embodiment shown in FIG. 1 will be described. Optical disk medium 1
As a DVD, an optical disk having a diameter of 12 cm is used, and in area 3, the number of horizontal pixels is 704,
Video data obtained by compressing MPEG2 compressed video data of 337K of vertical pixels of 480 pixels and D
olby AC3 compressed audio data, subtitle data and CGMS are defined as copy-prohibited first conventional copyright management information corresponding to the new copyright management system “the number of pixels is limited to 168K which is less than half of the recording time. Second new copyright management information that means “copying is permitted for the output of the video signal” is recorded. As a second new copyright management information recording method, conventional DVD Data Frame Copy Management Info
"01" when using 2 bits of CGMS in the rmation (CPR_MAI) recording area
"Reserved" can also be used. The definition of copyright management information in this case is "C
The coexistence of “01” in SS and CGMS is “allows copy of reproduction signal with limited number of pixels”. In the lead-in area of area 2, third new copyright management information indicating that “the optical disc adopts a new copyright management system” is recorded. As the third new copyright management information, in addition to the above, information on the number of pixels of the recorded video, information on the number of pixels permitted to be copied, or information specifying whether the copy permission when the number of pixels is limited is copy free or copy once is recorded. You can also

As the second new copyright management information, a method of adding data in the same format as the copyright management information that defines CGMS adopted by the current DVD may be added, or a digital watermark (Vid) may be included in the video information.
The second new copyright management information may be embedded in the eo Water Mark (WM) format.

In the case of the WM method, a Veil that is a 1-bit WM is adopted, and if the Veil exists, it means “copy permitted if the number of pixels is limited”, and if the Veil does not exist, the “number of pixels is limited. Copy prohibition "can be specified.

When a WM of 2 bits or more is adopted, new copyright management information of a copy permission code with a limited number of pixels can be provided in addition to the conventional copy prohibition code.

The purpose of adding the second and third new copyright management information is to DV for new copyright management system.
D media is played back as usual on a conventional DVD player, and the new D is compatible with the new copyright management system.
Only a VD player can output a video signal output with a limited number of pixels that can be copied. Therefore, the above can be realized only by the second or third new copyright management information.

The above is an example in which the present invention is implemented in the current DVD format.
When the present invention is applied to the y Disc format or the HD DVD format, it is as follows.

The HD video information recorded in area 3 has a horizontal pixel count of 1920 and a vertical pixel count of 1080, and the total pixel count is 2073K. H.264 AVC,
Video data and the like compressed by VC9 are recorded. The copyright management rules in this case are as follows.

For reproduction video signal output equivalent to 2073K, which has the same number of pixels as at the time of recording, encryption and a copy prohibition code are required, and for reproduction video signal output without encryption, the total number of pixels is limited to 540K or less and copying. A CGMS code indicating that copying is permitted is allowed only for the reproduction video signal output in which the prohibition code CGMS code is required to be added and the total number of pixels is limited to 168K or less.

  FIG. 2 shows an example of the configuration of a playback apparatus for the content distribution medium 1 of the present invention.

2, 4 is a DVD player apparatus compatible with the new copyright management system, 5 is a DVD drive circuit, 6 is a first signal processing circuit, 7 is MPEG2, H.264, and so on. H.264 AVC, VC9, and other video data decompression circuits, 8, 9, and 10 are first, second, and third copyright management information reading circuits,
1 is a CGMS signal control circuit, 12 is a pixel number conversion circuit, 13, 14 and 16 are second and third, respectively.
, A fourth signal processing circuit, 15 is a video data compression circuit, 17, 18 and 19 are first and second, respectively.
The third video signal output terminal 20 is an external memory.

In FIG. 2, digital data recorded on the optical disk medium 1 of the present invention is read out by the DVD drive circuit 5, demodulated by the first signal processing circuit 6, and various data corrected for errors are taken out. The first copyright management information reading circuit 8 detects the third new copyright management information read from the area 2 in the various data, and whether or not the medium 1 adopts the new copyright management system. Is determined.

The second copyright management data reading circuit 9 defines the CGMS recorded in the area 3
The conventional first copyright management information and second copyright management information in the VD format are detected, and it is determined whether or not this data permits copying of the video signal output with the total number of images limited.

The video data in the various types of error-corrected data is returned to the original uncompressed video data by the video data decompression circuit 7.

The third copyright management data reading circuit 10 detects the second new copyright management information in the digital watermark format recorded in the area 3 from the uncompressed video data, and the second new copyright management information. Determines whether or not copying of the video signal output with the limited number of pixels is permitted.

If the conventional first copyright management information read by the reading circuit 9 determines that copying is prohibited, the CGMS signal control circuit 11 adds CGMS-A,
Set CGMS-D to copy prohibition.

If any of the reading circuits 8, 9, and 10 determines that "copying is permitted for video signal output with limited number of pixels", the CGMS signal control circuit 11 adds CGMS-A to the video signal output with limited number of pixels. , CGMS-D is set to copy free or copy once. The role of the reading circuits 8, 9, and 10 is that “copying is not permitted for a conventional DVD player that does not perform copyright management according to the new copyright management information, but only for a new DVD player that complies with the new copyright management information. Since the CGMS control is not limited to the above, the reading circuits 8 and 9
"Copying of video signal output with a limited number of pixels" can be made only when both are permitted to copy or when both reading circuits 8 and 10 are permitted to copy. Further, when it is desired to strictly manage the copy permission, it is only necessary to set “permit copying of the video signal output with the number of pixels limited” only when all of the reading circuits 8, 9, and 10 are permitted to copy.

The uncompressed video data output from the video data decompression circuit 7 is added with CGMS-A or CGMS-D controlled by the CGMS signal control circuit 11 by the second signal processing circuit 13 and then the first video signal output. Leaded to the terminal.

Another output of the video data decompression circuit 7 is guided to the pixel number conversion circuit 12, and when the total number of uncompressed video data images is 704 × 480, the pixel number conversion circuit 12 reduces the horizontal pixel number 704 to 352. The number of pixels is thinned out and converted into the number of pixels 352 × 480. After the copy-free or copy-on CGMS-A or CGMS-D is added by the third signal processing circuit 14, it is led to the second video signal output terminal 18.

Another output of the pixel number conversion circuit 12 is H.264. The third video signal output terminal 19 is converted into compressed video data by the video data compression circuit 15 such as H.264 AVC or VC9, and copyright management information representing copy-free or copy-once is added by the fourth signal processing circuit 16. And recorded in an external memory 20 such as an SD card or a small HDD. The DVD player device 4 in FIG. 2 has the video data decompression circuit 7 and the video data compression circuit 15 built in the same device, so that the decompression circuit 7 detects the compression performance in the compression circuit 15. Information such as a motion vector can be transmitted to the compression circuit 15, and the compression circuit 15 can be a so-called 2-pass compression circuit.

FIG. 3 is a table showing an example of conversion contents of the pixel number conversion circuit 12 of the present invention. Circuit 1
Representative examples of the number of pixels of the video data that is the input signal of 2 are (A) horizontal 704, vertical 480, (B
) Horizontal 640, vertical 480, and (C) horizontal 1920, vertical 1080.

On the other hand, the number of pixels of the display mounted on the PMP is (a) horizontal 320 to 352, vertical 4
80, (b) horizontal 480, vertical 270, and (c) horizontal 320, vertical 240.

Therefore, in response to the number of pixels of the input signal and the number of pixels of the PMP display, the user selects the pixel number conversion table shown as an example in FIG. You can select the total number of images for the eyes, and if the external memory does not have enough room, you can select a smaller number of pixels at the expense of image quality.

In addition, the content (selection result) of the pixel number conversion table selected by the user is recorded in the external memory 20 together with the compressed video data, and is used for video data expansion processing so that the reproduced image is optimized when the video data is played back by PMP. You can also

2 and 3, only video information is mentioned. However, if it is desirable to convert audio data suitable for a PMP small memory or a headphone-based viewing environment, Dolby AC3 or MPEG1 audio data recorded on the content distribution medium Can be recorded in an external memory together with the above-mentioned high-compressed video data with a limited number of pixels after conversion into high-compression audio data such as MP3 and AAC. FIG. 4 shows a configuration example of a PMP equipped with the external memory of the present invention. In FIG. 4, 20 is a recorded external memory, 40 is a PMP with a small display, 41 is a signal processing circuit for reproducing recorded video data, 42 is a compression method of recorded video data, the number of selected pixels, etc. A pixel conversion information reading circuit, 43 is a video data expansion circuit, and 44 is a small display.

In FIG. 4, the video data recorded in the external memory 20 is read, the data is demodulated by the signal processing circuit 41, and the error-corrected data is guided to the video data decompression circuit 43.
The image conversion information reading circuit 42 reads the compression method of the video data and the number of selected pixels, inputs them to the video data decompression circuit 43, performs processing such as selection of the decompression method of the video data decompression circuit 43 and control of the number of pixels. Uncompressed video data with a limited number is output to the small display 44.

The present invention develops a new copyright management rule that permits copy-free or copy-once for video signals that have been recorded with the recorded image quality, but copy-prohibited as before, but with image quality restrictions that are not inconvenient to enjoy with PMP. Thus, the movie software whose image quality is limited can be recorded on a recording medium for PMP, and the “ubiquitous movie” business is realized at an early stage.
According to the above embodiments, in movie software such as a DVD, video signals that maintain the recording image quality are kept copy-prohibited as before, and new copyright management information that permits copying is added to video signals that have been image-quality restricted. Thus, it is possible to record on a PMP recording medium, and it is possible to easily enjoy movie software on a small PMP display. As a result, copyright holders can realize higher added value than conventional DVD media for content distribution media compatible with the new copyright management system, and manufacturers can expand the business of DVD players and PMPs compatible with the new copyright management system. Can enjoy ubiquitous movies early and inexpensively. Therefore, it is possible to achieve the object of the present invention which contributes to the merits of the copyright owner, the manufacturer and the consumer.

When WM (Water Mark) is used for the second new copyright management information in the present invention, a new business model for spreading WM can be provided. In other words, since the conventional WM has only the purpose of protecting the copyright, there is no merit only for the copyright owner, and there is no merit for the device manufacturer equipped with the WM reading function and the end user. For this reason, the spread of WM has not been realized. In the present invention, the WM has the above purpose,
For manufacturers that “copying video signal output with limited number of pixels is possible”, this indicates an improvement in the added value of the device, and for end users, “realization of a ubiquitous movie”.

Even if the first copyright protection information is copy prohibited, in the case of a move, the output video data may be permitted to be copied.

Note that, even if the second copyright protection information is copy permission, copying may be permitted only in the case of a move. That is, the video data may be erased from the original medium, and the video data with the number of pixels limited may be output and recorded in a memory or the like.

The present invention is a playback device for enjoying video information such as movies outdoors on a small display, etc.
This is effective for a PMP system in which an external memory such as a small HDD or flash memory in which low-resolution video information with limited resolution is copied can be played back by a playback device.

DESCRIPTION OF SYMBOLS 1 ... Optical disc medium, 2 ... Recording area of 3rd copyright management information, 3 ... Recording area of content and 2nd copyright management information, 5 ... DVD drive circuit, 6 ... First signal processing circuit, 7... Video data decompression circuit, 8... First copyright management information reading circuit, 9... Second copyright management information reading circuit, 10. 3 copyright management information reading circuit, 11... CGMS signal control circuit, 12... Pixel number conversion circuit, 13.
, 14... Third signal processing circuit, 15... Video data compression circuit, 16.
... 4th signal processing circuit, 20 ... external memory, 42 ... image conversion information reading circuit, 43 ... video data decompression circuit, 44 ... small display

Claims (3)

In a content recording method for recording content and copyright management information of the content on a recording medium,
Recording the content, the first copyright management information of the content, and the second copyright management information of the content on the recording medium;
The first copyright management information and the second copyright management information are output without allowing the first copyright management information to copy the content when the content is reproduced and output. The content recording method is characterized by having a state indicating that copying is permitted and output when the resolution of the content is reduced to half or less according to the second copyright management information. In a content reproduction method for reproducing and outputting content recorded with copyright management information from a recording medium,
According to the copyright management information recorded on the recording medium,
When the content is reproduced and output, a first output state in which the content is not permitted to be copied and a second output state in which the content resolution is reduced to half or less and the content is permitted to be copied . content playback method characterized by and an output state. In a content playback apparatus that plays back and outputs content accompanied by copyright management information from a recording medium,
Playback means for playing back content from the recording medium;
Output means for outputting the content reproduced by the reproduction means,
Before Kide force means includes a first output state of outputting not allow copies than the first output the content reproduced, less than half the resolution of the reproduced the said content from a second output content And a second output state in which copying is permitted and output.

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