JP4457167B2 - Content reproduction apparatus and content reproduction method - 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 Generation Management System) relating to copy-prohibited, copy-free (copy-once), or copy-free copy conditions is employed for recorded content. .

  Further, in this DVD disk and DVD player, Non-Patent Document 2 describes an example of a DVD copyright protection system CSS (Content Scramble System) that prevents unauthorized copying by general users.

  In this DVD disc, almost all movie software DVDs have a copy prohibition code multiplexed in the CGMS specified area in the DVD disc in accordance with the intention of the copyright holder, and CGMS indicating copy prohibition is output for the analog or digital video signal output. -A or CGMS-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 be satisfied only 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. An optical disk having the same diameter of 12 cm as that of a DVD is used as the optical disk medium 1, and in the area 3, the video information of the total number of pixels 337K having the number of horizontal pixels 704 and the number of vertical pixels 480 is MPEG2 compressed and the audio data is compressed by Dolby AC3 , Corresponding to the first conventional copyright management information and the new copyright management system that stipulate that the subtitle data and CGMS are copy-prohibited “Copy to the video signal output limited to 168K, which is less than half of the recording time. Second new copyright management information that means “permit” is recorded. As the second new copyright management information recording method, when using 2 bits of CGMS in the Copy Management Information Information (CPR_MAI) recording area of the conventional DVD Data Frame, “01” reserved can be used. The definition of copyright management information in this case is “coexistence of“ 01 ”in CSS and CGMS permits copying of a reproduction signal with a limited number of pixels”. In the lead-in area of area 2, third new copyright management information indicating that “the optical disk 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

  The second new copyright management information may be a method of adding data in the same format as the copyright management information that defines the CGMS adopted by the current DVD, or a digital watermark (Video Water Mark: WM) in the video information. ) Format may be used to embed the second new copyright management information.

  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 reproduce the DVD medium compatible with the new copyright management system as usual on the conventional DVD player and copy only the new DVD player compatible with the new copyright management system. It is to be able to output a video signal output in which the number of possible pixels is limited. Therefore, the above can be realized only by the second or third new copyright management information.

  The above is an example when the present invention is implemented in the current DVD format, but when the present invention is implemented in the Blu-ray Disc format or the HD DVD format, the following is performed.

  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 compressed by VC9, etc. 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, 11 is a CGMS signal control circuit, 12 is a pixel number conversion circuit, and 13 and 14, respectively. , 16 are second, third, and fourth signal processing circuits, 15 is a video data compression circuit, 17, 18, and 19 are first, second, and third video signal output terminals, respectively, and 20 is an external memory. is there.

  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 detects the conventional first copyright management information and the second copyright management information in the DVD format format that defines the CGMS recorded in the area 3, and this data is displayed on the screen. It is determined whether or not copying of the video signal output whose total number is limited is permitted.

  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.

  The CGMS signal control circuit 11 copies CGMS-A and CGMS-D added to the video signal output with no number of pixels if the conventional first copyright management information read by the reading circuit 9 determines that copying is prohibited. Set to prohibited.

  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. The control of CGMS is not limited to the above, but only when both the reading circuits 8 and 9 are permitted to copy or when both the reading circuits 8 and 10 are permitted to copy, “video signal output with a limited number of pixels” is performed. It is also possible to "allow copying of". 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 to 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 of 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. Representative examples of the number of pixels of video data that is an input signal of the circuit 12 can be broadly classified into three types: (A) horizontal 704, vertical 480, (B) horizontal 640, vertical 480, (C) horizontal 1920, vertical 1080.

  On the other hand, the number of pixels of the display mounted on the PMP can be roughly divided into three types: (a) horizontal 320 to 352, vertical 480, (b) horizontal 480, vertical 270, (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, but 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 a 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 holder, manufacturer and 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, in addition to the above-described purpose, the WM indicates an added value improvement of the device for the manufacturer “video signal output with limited number of pixels can be copied”, and “realization of a ubiquitous movie” for the end user.

  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.

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

DESCRIPTION OF SYMBOLS 1 ... Optical disk 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 ... second signal processing circuit, 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 size display

Claims (2)

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 from a plurality of outputs ,
The content reproduction apparatus according to claim 1, wherein the output means outputs the content without permitting copying from the first output, and permits and outputs the copy with the resolution reduced to half or less than the second output. In a content reproduction method for reproducing and outputting content accompanied by copyright management information from a recording medium,
Playing content from the recording medium,
A content reproduction method comprising: outputting the reproduced content without permitting copying from the first output; permitting copying with the resolution reduced to half or less than the second output; and outputting the content.

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