Audio data structure, recording medium thereof, and processing apparatus thereof Number:7,095,704 from the United States Patent and Trademark Office (PTO) owispatent

Title: Audio data structure, recording medium thereof, and processing apparatus thereof

Abstract: In audio contents which have cells for defining an audio title playback unit and whose actual playback sequence is determined by defining the playback sequence of the cells, cell information to specify the cells is provided with identification information to identify the types of the cells according to the difference in the contents of the data included in the cells. One type of the contents of the data in the cells is for obtaining the length of the silent period of time. The identification information corresponding to the cell indicates a silent cell.

Patent Number: 7,095,704 Issued on 08/22/2006 to Otomo,   et al.

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Inventors:	Otomo; Hitoshi (Yokohama, JP), Mimura; Hideki (Yokohama, JP)
Assignee:	Kabushiki Kaisha Toshiba (Kawasaki, JP)
Appl. No.:	10/386,459
Filed:	March 13, 2003

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Related U.S. Patent Documents

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	Application Number	Filing Date	Patent Number	Issue Date
	09381615		6567371
	PCT/JP99/00248	Jan., 1999

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Foreign Application Priority Data

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Jan 23, 1998 [JP]			10/11679

Current U.S. Class:	369/275.3 ; 369/30.04; 369/47.15; 386/125; 386/95; 386/98
Current International Class:	G11B 7/24 (20060101); H04N 5/91 (20060101)
Field of Search:	369/275.3,275.1,47.1,47.12,47.15,53.41,53.32,30.04,30.07 360/78.04 386/95,125,126,98,120,96,104,105,54

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References Cited [Referenced By]

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U.S. Patent Documents

	5530686		June 1996		Schylander et al.
	5625611		April 1997		Yokota et al.
	5636200		June 1997		Taira et al.
	5719837		February 1998		Aramaki
	5841793		November 1998		Fukuda
	6222806		April 2001		Mori et al.
	6385389		May 2002		Maruyama et al.
	6392984		May 2002		Mori et al.
	6453119		September 2002		Maruyama et al.
	6532335		March 2003		Otomo et al.
	6724979		April 2004		Otomo et al.
	6748160		June 2004		Otomo et al.

Foreign Patent Documents

	0 810 757		Dec., 1997		EP
	0 910 082		Apr., 1999		EP
	0 918 331		May., 1999		EP
	59-195307		Nov., 1984		JP
	60-119671		Jun., 1985		JP
	64-88964		Apr., 1989		JP
	8-336104		Dec., 1996		JP
	9-22577		Jan., 1997		JP
	9-259506		Oct., 1997		JP
	09-259539		Oct., 1997		JP
	11-16282		Jan., 1999		JP
	11-203794		Jul., 1999		JP
	WO 97/21310		Jun., 1997		WO

Other References

H Mimura, et al., Toshiba Review, vol. 51, No. 12, 9 pages, "Application Format DVD-Video," Dec. 1, 1996 (see partial English description on p. No. 12). cited by other . Pohlmann K C, "The Compact Disc System", XP-002163595, pp. 47-101, GB, 1992. cited by other.

Primary Examiner: Neyzari; Ali
Attorney, Agent or Firm: Oblon, Spivak, McClelland, Maier & Neustadt, P.C.

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Claims

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The invention claimed is:

1. An audio data recording medium, comprising: a video recording zone; and an audio recording zone, the audio recording zone including an audio manager area and an audio title set recording area configured to store an audio title set, the audio manager area being configured to store information used for accessing video information of the video recording zone, the audio title set recording area being configured to include an audio object area, a management table configured to describe an identifier of the audio set, a start address of the audio object, and an audio title set program chain information table configured to designate a reproduction order of the audio object, the audio object being configured to include a program that is configured to include a plurality of cells, each of the plurality of cells being configured to include a plurality of packs in which data is stored, each of the plurality of packs being configured to include an audio pack and a real time pack, the real time pack being configured to store additional data that is not video data, each of the plurality of cells being configured to include audio cells having data contents configured to be used for obtaining an audio output, and silent cells configured to include non-sound output data, the management table being configured to include an area in which a table of mixing coefficients is recorded, the table of mixing coefficients being configured to include mixing coefficients for signals for respective reproduction channels such that a plurality of reproduction channels used when the audio object is reproduced are changed to output channels that are smaller in number than a number of the plurality of reproduction channels, the audio title set program chain information table being configured to include audio title set program information, cell play back information configured to designate a reproduction order of the audio cells, and a table number of a mixing coefficient to be used, the cell playback information being configured to include cell type information that is configured to identify a type of the audio and the silent cells, a start and an end address of the audio and the silent cells, and cell index numbers of the audio and the silent cells, and the cell type information being configured to include information that is configured to identify an audio cell containing only audio data as "00b", to identify an audio cell containing both audio data and real-time information as "01b", and to identify a silent cell as "10b", the cell type information also being configured to include usage information that is configured to indicate that a corresponding cell constitutes a spotlight portion.

2. A reproduction method for reproducing audio information from an information recording medium, the information recording medium comprising: a video recording zone; and an audio recording zone, the audio recording zone including an audio manager area and an audio title set recording area configured to store an audio title set, the audio manager area being configured to store information used for accessing video information of the video recording zone, the audio title set recording area being configured to include an audio object area, a management table configured to describe an identifier of the audio set, a start address of the audio object, and an audio title set program chain information table configured to designate a reproduction order of the audio object, the audio object being configured to include a program that is configured to include a plurality of cells, each of the plurality of cells being configured to include a plurality of packs in which data is stored, each of the plurality of packs being configured to include an audio pack and a real time pack, the real time pack being configured to store additional data that is not video data, each of the plurality of cells being configured to include audio cells having data contents configured to be used for obtaining an audio output, and silent cells configured to include non-sound output data, the management table being configured to include an area in which a table of mixing coefficients is recorded, the table of mixing coefficients being configured to include mixing coefficients for signals for respective reproduction channels such that a plurality of reproduction channels used when the audio object is reproduced are changed to output channels that are smaller in number than a number of the plurality of reproduction channels, the audio title set program chain information table being configured to include audio title set program information, cell play back information configured to designate a reproduction order of the audio cells, and a table number of a mixing coefficient to be used, the cell playback information being configured to include cell type information that is configured to identify a type of the audio and the silent cells, a start and an end address of the audio and the silent cells, and cell index numbers of the audio and the silent cells, and the cell type information being configured to include information that is configured to identify an audio cell containing only audio data as "00b", to identify an audio cell containing both audio data and real-time information as "01b", and to identify a silent cell as "10b", the cell type information also being configured to include usage information that is configured to indicate that a corresponding cell constitutes a spotlight portion, wherein the method comprises: reproducing information from the management table; and reproducing the audio object based on the information reproduced from the management table.

3. A reproduction apparatus for reproducing audio information from an information recording medium, the information recording medium comprising: a video recording zone; and an audio recording zone, the audio recording zone including an audio manager area and an audio title set recording area configured to store an audio title set, the audio manager area being configured to store information used for accessing video information of the video recording zone, the audio title set recording area being configured to include an audio object area, a management table configured to describe an identifier of the audio set, a start address of the audio object, and an audio title set program chain information table configured to designate a reproduction order of the audio object, the audio object being configured to include a program that is configured to include a plurality of cells, each of the plurality of cells being configured to include a plurality of packs in which data is stored, each of the plurality of packs being configured to include an audio pack and a real time pack, the real time pack being configured to store additional data that is not video data, each of the plurality of cells being configured to include audio cells having data contents configured to be used for obtaining an audio output, and silent cells configured to include non-sound output data, the management table being configured to include an area in which a table of mixing coefficients is recorded, the table of mixing coefficients being configured to include mixing coefficients for signals for respective reproduction channels such that a plurality of reproduction channels used when the audio object is reproduced are changed to output channels that are smaller in number than a number of the plurality of reproduction channels, the audio title set program chain information table being configured to include audio title set program information, cell play back information configured to designate a reproduction order of the audio cells, and a table number of a mixing coefficient to be used, the cell playback information being configured to include cell type information that is configured to identify a type of the audio and the silent cells, a start and an end address of the audio and the silent cells, and cell index numbers of the audio and the silent cells, and the cell type information being configured to include information that is configured to identify an audio cell containing only audio data as "00b", to identify an audio cell containing both audio data and real-time information as "01b", and to identify a silent cell as "10b", the cell type information also being configured to include usage information that is configured to indicate that a corresponding cell constitutes a spotlight portion, the reproduction apparatus comprising: means for reproducing information from the management table; and means for reproducing the audio object based on the information reproduced from the management table.

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Description

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TECHNICAL FIELD

This invention relates to an audio data structure which facilities the handling of high sound-quality audio data in processing (recording, reproducing, transmitting, and constructing) the data and fulfills the high sound-quality requirement, a recording medium for the audio data structure, and an apparatus for processing its signal.

BACKGROUND ART

DVD video disks are optical disk on which video (moving picture) information can be recorded very densely with high quality and further various types of information, including multiangle pictures, sub-pictures, multilingual voice, and multichannel audio, can be recorded. Such DVD video disks have been developed and on the market and are finding their way into wide application. (DVD is an abbreviation for Digital Versatile Disk.)

The specifications for DVD video disks cover not only compressed multichannel audio (including AC-3 and MPEG) but also uncompressed linear PCM (including 48 kHz sampling, 16-bit quantization, 96 kHz sampling, and 24-bit quantization). The DVD video linear PCM meets the high-frequency sampling, high-number bit, high sound quality specifications, which surpass those for conventional music CDs (with 44.1 kHz sampling and 16 bit quantization). Linear PCM with 96-kHz sampling and 20- to 24-bit quantization is sufficiently qualified for the next generation digital audio disks (what is called super CDs or super audio disks).

However, the DVD video specifications have been determined by video requirements rather than audio requirements. In terms of not only sampling frequency and the number of quantization bits but also the number of recordable channels and recordable time, audio-oriented specifications surpassing the DVD video sound specifications have been expected.

To meet the expectation, DVD audio specifications have been studied (it should be noted that the DVD audio specifications have not been in the prior art yet). The DVD audio specifications have been considered to be capable of supporting linear PCM with 48- to 96-kHz sampling and 24-bit quantization employed in the DVD video specifications up to linear PCM with 192-kHz sampling and 24-bit quantization. Moreover, future versions of the DVD audio specifications might introduce much higher sound quality.

The reason why the DVD audio provides upward compatibility is that it has a part shared with DVD video that can record a large volume of data covering high-definition television images. Moreover, the DVD audio is characterized by having technical, marketable, and economical advantages in the future when it can be used as a result of advance in the DVD video.

For example, when high-capacity DVD disks to be put in practical use in future DVD video are used in DVD audio, if the recording time is constant, there is a possibility that the sampling frequency in recording, the number of quantization bits, and the number of recording channels will be increased more and more. In addition, the technique for DVD video recorders using DVD-RAMs (or rewritable DVD-RW or write-once DVD-R) to be put in practical use in the near future can be used in DVD audio recorders to come in practice soon or later.

Furthermore, as the popularization of DVD video expands its market, DVD video and DVD audio share increasingly more of the recording mediums (including DVD-ROM disks, DVD-RAM/DVD-RW disks, and DVD-R disks), unit parts (including disk drives, optical pickups, and various types of ICs), and various control programs. This accelerates the cost reduction of DVD audio products featuring high sound quality and other advantages. When DVD audio is used widely, DVD video will enjoy the future technical, marketable, and economical advantages available as a result of advance in DVD audio.

As described above, the development of DVD audio has been expected, but, as seen from the aforementioned DVD video, DVD audio with various functions and performances will possibly be proposed and developed as a result of a high-density recording disk having been developed. Specifically, there is a possibility that DVD audio with a different data structure in terms of sampling frequency, the number of quantization bits, and the number of channels will be produced. Moreover, DVD audio with a different data structure in terms of functions, such as DVD audio with or without menu images, or DVD audio with or without background images, will possibly be produced.

Accordingly, an object of the present invention is to provide a data structure that enables audio attributes to be specified track by track. The data structure makes it possible to allow the reproduction side to deal with DVD audio easily even if various functions and performances are included in the DVD audio.

The reproduction side needs a preparation time for changing the hardware devices according to the change of the attributes. The preparation time causes a break in the sound output. Accordingly, another object of the present invention is to provide a data structure which positively recognizes a break in sound and allows the designer or producer to set a sound break period arbitrary. The data structure makes it possible to make silent periods between pieces of music constant when, for example, a DVD audio disk is played back, which provides the user with a stable playback condition.

DISCLOSURE OF THE INVENTION

To achieve the foregoing objects, identification information to identify the type of cells by the difference in the contents of the data included in the cells is provided in cell information to specify the cells in audio contents that have cells defining at least an audio title playback unit and determines the actual playback sequence by defining the playback sequence of the cells. This enables the data structure creator side to deliberately realize data processing management, timing management, and setting management on the reproducing apparatus side during playback according to the contents of the data on the basis of the identification information.

One type of the contents of the data in the cells is for determining the length of a silent period of time. The identification information corresponding to the cell is characterized by indicating a silent cell. Providing a silent cell for determining the time of the silent period enables a silent period to be set. Using the silent period, the reproducing apparatus side can change or set the attributes. In a case where tracks with a break on sound are mingled with tracks without a break in sound, effective use of silent cells at the head of a track without a break in sound makes it possible to edit the data in such a manner that a uniform pause period giving no unnatural feeling on the whole is taken.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view to help explain the configuration of an optical disk usable as a DVD audio recording medium;

FIG. 2 is a view to help explain the correlation between the data recording area on the optical disk of FIG. 1 and recording tracks of data recorded in the area;

FIG. 3 is a diagram to help explain the hierarchical structure of the information recorded in a DVD audio zone among the various types of information recorded on the optical disk of FIG. 2;

FIG. 4 is a diagram to help explain an example of the data structure of AOTT_AOBS among the pieces of information recorded in the DVD audio zone of FIG. 3;

FIG. 5 is a diagram to help explain the hierarchical structure of the information recorded in a DVD video zone among the various types of information recorded on the optical disk of FIG. 2;

FIG. 6 is a diagram to help explain an example of the data structure of VTSTT_VOBS in the information recorded in the DVD video zone of FIG. 5;

FIG. 7 is a diagram to help explain an example of video information (e.g., VTS_C #2) accessed by both program chain information (ATS_PGCI) in the DVD audio zone of FIG. 3 and program chain information (VTS_PGCI) in the DVD video zone of FIG. 5;

FIG. 8 is a diagram to help explain an example of the data structure that is about the recorded contents of user-accessible DVD audio and is recorded on one side of the optical disk shown in FIG. 1;

FIG. 9 is a diagram to help explain an example of the directory structure of the information (in data files of DVD audio and DVD video) recorded on the optical disk of FIG. 1;

FIG. 10 is a diagram to help explain another example of the directory structure of the information (in data files of DVD audio and DVD video) recorded on the optical disk of FIG. 1;

FIG. 11 is a diagram to help explain a case where the directory on the audio content side accesses a file in the directory on the video content side in the directory structure shown in FIG. 9;

FIG. 12 is a diagram to help explain a case where a file in the directory on the audio content side links with a file in the directory on the video content side in the directory structure shown in FIG. 9;

FIG. 13 is a diagram to help explain an example of how file accessing of FIG. 11 is effected in the volume spaces shown in FIG. 3 of 5;

FIG. 14 is a diagram to help explain another example of how file accessing of FIG. 11 is effected in the volume space shown in FIG. 3 of 5;

FIG. 15 is a diagram to help explain still another example of how file accessing of FIG. 11 is effected in the volume space shown in FIG. 3 or 5;

FIG. 16 is a diagram to help explain the recorded contents of audio manager information (AMGI) in the DVD audio zone shown in FIG. 3;

FIG. 17 shows the recorded contents of the audio manager information management table (AMGI_MAT) included in the audio manager information (AMGI) shown in FIG. 16;

FIG. 18 is a diagram to help explain the contents of the audio title search pointer table (ATT_SRPT) included in the audio manager information (AMGI) shown in FIG. 16;

FIG. 19 is a diagram to help explain the contents of the audio title search pointer (ATT_SRP) included in the audio title search pointer table (ATT_SRPT) shown in FIG. 18;

FIG. 20 is a diagram to help explain the contents of the audio-only title search pointer table (AOTT_SRPT) included in the audio manager information (AMGI) shown in FIG. 16;

FIG. 21 is a diagram to help explain the contents of the audio-only title search pointer (AOTT_SRP) included in the audio-only title search pointer table (AOTT_SRPT) shown in FIG. 20;

FIG. 22 is a table showing the relationship between a group of audio-only titles (AOTT_GR) accessed using the audio-only title search pointer (AOTT_SRP) in the audio manager information (AMGI) shown in FIG. 16 and a group of audio titles (ATT_GR) accessed using the audio title search pointer (ATT_SRP) in the audio manager information (AMGI);

FIG. 23 is a diagram to help explain the recorded contents of an audio title set (ATS) in the DVD audio zone shown in FIG. 3;

FIG. 24 shows the recorded contents of the audio title set information management table (ATSI_MAT) included in the audio title set information (ATSI) shown in FIG. 23;

FIG. 25 is a diagram to help explain the contents of the audio title set program chain information table (ATS_PGCIT) included in the audio title set information (ATSI) shown in FIG. 23;

FIG. 26 is a table showing the contents of the audio title set program information (ATS_PGI) shown in FIG. 25;

FIG. 27 is a table showing the contents of the audio title set cell playback information (ATS_C_PBI) shown in FIG. 25;

FIG. 28 is a diagram to help explain the contents of the audio title set audio still video playback information table (ATS_ASV_PBIT) shown in FIG. 25;

FIG. 29 is a table showing the contents of the audio title set program audio still video playback information search pointer (ATS_PG_ASV_PBI_SRP) shown in FIG. 28;

FIG. 30 is a block diagram of an apparatus for reproducing the recorded information in the DVD audio zone of FIG. 3 or the recorded information in the DVD video zone of FIG. 5 from the optical disk of FIG. 1;

FIG. 31 is a front view of an example of the front panel of the reproducing apparatus of FIG. 30;

FIG. 32 describes the types of audio data cells forming the important part of the present invention;

FIGS. 33A and 33B are diagrams to help explain the types of audio title set program and the data allocation structure;

FIG. 34 is a diagram to help explain an example of audio-only data pack trains in the audio-only title;

FIG. 35 is a diagram to help explain pack trains when audio-only title audio and real-time data are present;

FIG. 36 is a diagram to help explain pack trains when audio-only title audio cells and a silent cell are present;

FIGS. 37A to 37C are diagrams to help explain a pack train where programs in front of and behind a program have the same attributes and are composed of only audio cells, and the change of the presentation time stamp and the change of the playback time caused by the playback sequence;

FIGS. 38A to 38C are diagrams to help explain a pack train where programs in front of and behind a program have different attributes and are composed of audio cells including silent cells, and the change of the presentation time stamp and the change of the playback time caused by the playback sequence;

FIG. 39 is a block diagram of another example of the disk reproducing apparatus according to the present invention; and

FIG. 40 is a block diagram of still another example of the disk reproducing apparatus according to the present invention.

DESCRIPTION OF THE INVENTION

Hereinafter, referring to the accompanying drawings, an embodiment of the present invention will be explained. This invention relates to an audio data structure which facilitates the handling of high sound quality audio data and assures the high sound quality in processing (recording, reproducing, transferring, and constructing) the high sound quality audio data, a recording medium thereof, a processing apparatus thereof, and a processing method thereof.

In the embodiment, explanation will be given as to a case where the present invention is applied to a system where the objects of contents (including various video contents and various audio contents) are shared. In addition, explanation will be given as to a case where the invention is applied to an information recording medium with management data used to share the objects of contents, an apparatus for reproducing the recorded information from the medium, a method of recording information including the management data on the medium, and a method of reproducing the information from the medium on the basis of the management data.

FIG. 1 is a perspective view showing the configuration of an optical disk 10 that can be used as a DVD audio recording medium. As shown in FIG. 1, the optical disk 10 is such that two transparent substrates 14 on each of which a recording layer 17 is provided are laminated together with an adhesion layer 20. Each substrate 14 is made of 0.6-mm-thick polycarbonate. The adhesion layer 20 is made of very thin (for example, 40-.mu.m-thick) ultraviolet-curing resin. The two 0.6-mm-thick substrates 14 are laminated together in such a manner that the recording layer 17 of each substrate is in contact with one surface of the adhesion layer 20, which produces a 1.2-mm-thick large-capacity optical disk 10.

In the optical disk 10, a central hole 22 is made. Around the central hole 22 on both sides of the optical disk 10, clamp areas 24 for clamping the optical disk 10 during rotation are provided. When the optical disk 10 is loaded into a disk drive unit (not shown), the spindle of a disk motor is inserted in the central hole 22. While the optical disk 10 is rotating, the disk is clamped by disk dampers (not shown) in the clamp areas 24.

The optical disk 10 has an information area 25 around the clamp areas 24 in which video data, audio data, and other pieces of information can be recorded.

In the information area 25, a lead-out area 26 is provided at the outer edge and a lead-in area 27 is provided at the inner edge adjacent to the clamp area 24. A data recording area 28 is defined between the lead-out area 26 and lead-in area 27.

In the recording layer (light reflecting layer) 17 of the information area 25, recording tracks are formed continuously, for example, in a spiral. The continuous tracks are divided into physical sectors. Serial numbers are allocated to the sectors. Using the sectors as recording units, various types of data are recorded on the optical disk 10.

The data recording area 28 is an actual data recording area including a DVD audio data recording area and a DVD video data recording area (the DVD video data recording area might not be used in a pure audio disk).

In the DVD audio data recording area, audio data is chiefly written as recording and playback information in the form of pit trains (or in a physical shape or phase that optically changes the laser reflected light). Depending on the situation, still picture data may be recorded in the DVD audio data recording area. The audio data recorded in the DVD audio data recording area can include completely silent data (not a silent portion in music but intentionally silent data).

On the other hand, in the DVD video data recording area, video data (main picture data) for movies, sub-picture data for subtitles and menus, and audio data for words and sound effects are recorded as recording and playback information in the form of pit trains.

When the optical disk 10 is a single-sided single layer, double-sided recording DVD-RAM disk (or a rewritable disk; DVD-RW disk), each recording layer 17 is composed of a triple layer formed by sandwiching a phase change recording material (e.g., Ge.sub.2Sb.sub.2Te.sub.5) between two zinc sulfidesilicon oxide mixtures (ZnS.SiO.sub.2).

When the optical disk 10 is a single-sided single layer, single-sided recording RAM disk, the recording layer 17 on the reading face 19 side is composed of a triple layer including the phase change recording material layer. In this case, the layer 17 located on the opposite side when viewed from the reading face 19 side need not be an information recording layer. It may be a simple dummy layer.

When the optical disk 10 is a single-sided reading dual-layer RAM/ROM disk, two recording layers 17 are composed of a single phase change recording layer (the rear side viewed from the reading face 19; for reading) and a single translucent metal reflecting layer (the front side viewed from the reading face 19; for playback).

When the optical disk 10 is a write-once DVD-R, polycarbonate is used for a substrate. Gold may be used for a reflecting film (not shown) and an ultraviolet-curing resin may be used as a protective film (not shown). In this case, organic pigment is used for the recording layer 17. Cyanine, squarilium, chroconic, triphenylmethane dyes, xanthene, quinone dyes (e.g., naphthoquine or anthraquinone), and metal complex dyes (e.g., phthalocyanine, porphyrin, dithiol Complex, and the like) may be used as the organic pigment.

Data can be written onto such a DVD-R disk using, for example, a semiconductor laser with an output of about 6 to 12 mW at a wavelength of 650 nm.

When the optical disk 10 is a single-sided reading, dual-layer ROM disk, two recording layers 17 are composed of a single metal reflecting layer (at the back viewed from the reading face 19) and a translucent metal reflecting layer (at the front viewed from the reading face 19).

In a read-only DVD-ROM disk (for DVD audio and/or DVD video), pit trains are formed by a stamper on a substrate 14 in advance. On the surface of the substrate 14 on which the pit trains have been formed, a reflecting layer of metal or the like is formed. The reflecting layer is used as the recording layer 17. In such a DVD-ROM disk, groups serving as recording tracks are normally not provided. Instead, the pit trains formed at the surface of the substrate 14 function as tracks.

In the various types of optical disk 10, the playback-only ROM information is recorded as an emboss signal in the recording layer 17. In contrast, an emboss signal is not recorded on the substrate 14 having the read/write (or write-once) recording layer 17. Instead, a continues groove is inscribed. The groove is provided with phase change recording layers and others. In the case of a read/write DVD-RAM disk, phase change recording layers in the land portions as well as the groove are used for information recording.

When the optical disk 10 is of the single-sided reading type (with either one or two recording layers), the substrate 14 on the reverse side viewed from the reading face 19 is not necessarily transparent to a read/write laser beam. In this case, a label may be printed on the whole surface of the reverse-side substrate 14.

FIG. 2 is a diagram to help explain a correlation between the data recording area 28 on the optical disk 10 of FIG. 1 and recording tracks of data items recorded there. When the optical disk 10 is a DVD-RAM (or DVD-RW), the body of the optical disk 10 is housed in a cartridge (not shown) to protect the delicate disk surfaces. When the DVD-RAM disk together with the cartridge is inserted in the disk drive of a DVD player explained later, the optical disk 10 is drawn out of the cartridge and clamped to the turn table of a spindle motor (not shown). Then, the disk is rotated in such a manner that it faces an optical head (not shown).

On the other hand, when the disk 10 is a DVD-R or a DVD-ROM, the body of the optical disk 10 is not housed in a cartridge. The naked optical disk 10 is set directly in the disk tray of the disk drive.

On the recording layer 17 in the information area 25 of FIG. 1, data tracks are formed continuously in a spiral. As shown in FIG. 2, the continues tracks are divided into logical sectors (the minimum recording unit), each sector having a specific storage capacity. Data is recorded in logical sectors. The storage capacity of one logical sector is set at 2048 bytes (or 2 kilobytes) equal to the data length of one pack.

The data recording area 28 is an actual data recording area, in which management data and sound data have been recorded for DVD audio and similarly management data, main picture (video) data, sub-picture data, and sound data have been recorded.

Although not shown, when the optical disk 10 of FIG. 2 is a DVD-RAM disk, the data recording area 28 may be divided into ring-like (annual-ring-like) recording areas (recording zones). In this case, the angular speed of the disk rotation differs from one recording zone to another. In each zone, however, the linear speed or angular speed can be made constant. When the optical disk 10 of FIG. 2 is a DVD-ROM disk, various data items are recorded on all of the data recording area 28 at a constant linear speed.

FIG. 3 is a diagram to help explain the hierarchical structure of those recorded in the DVD audio zone among the various pieces of information recorded on the optical disk 10 of FIG. 2. In FIG. 3, the data recording area 28 formed on the optical disk 10 has a structure shown in the figure. A logical format in the structure is determined so as to comply with, for example, ISO 9660, one of the standards, and the universal disk format (UDF) bridge.

The data recording area 28 between the lead-in area 27 and the lead-out area 26 is allocated as a volume space 28. The volume space 28 can include a space (volume/file structure area 70) for information on volume and file structure, a space (DVD audio zone 71 and DVD video zone 72) for applications complying with the DVD standard, and a space (other recording areas 73) for applications other than those complying with the DVD standard.

The volume space 28 is physically divided into a large number of sectors. Serial numbers are allocated to the physical sectors. The logical addresses for the data items recorded in the volume space 28 mean logical sector numbers as determined in ISO 9660 and the UDF bridge. Like the effective data size of a physical sector, the size of a logical sector is set at 2048 bytes (2 kilobytes). The logical sector numbers are serial in such a manner that they correspond to ascending order of physical sector number.

Unlike a logical sector, a physical sector is given redundant information, such as error correction information. To be precise, the physical sector size therefore does not correspond to the logical sector size.

As shown in FIG. 3, the volume space 28 includes a volume/file structure area 70, a DVD audio zone 71, a DVD video zone 72, and other recording areas 73. These areas 70 to 73 are separated at the boundaries of logical sectors shown in FIG. 2. Here, one logical sector is defined as containing 2048 bytes. One logical block is defined as containing 2048 bytes. Consequently, one logical sector is defined in the same manner as one logical block.

The volume/file structure area 70 corresponds to the management area determined in ISO 9660 and the UDF bridge. On the basis of the description in the area 70, the contents of the audio manager (AMG) 711 are stored in the system memory in the DVD player explained later.

The DVD audio zone 71 is composed of a simple audio manager (SAMG) 710, an audio manager (AMG) 711, an audio still video set (ASVS) 712, and one or more audio title sets (ATS #m) 713 (the maximum number of audio title sets m is 99).

The SAMG 710 is a single file containing 128 kilobytes, into which a simple audio play pointer table (SAPPT) with the same contents has been written eight times.

The AMG 711 is composed of an audio manager information (AMGI) file 7110, an audio manager menu video object set (AMGM_VOBS) file 7111, and an audio manager information backup (AMGI_BUP) file 7112. The AMGM_VOBS file 7111 is an optional file and may be absent.

The ASVS 712 is composed of an audio still video set information (ASVSI) file 7210, an audio still video object set (ASVOBS) file 7121, and an audio still video set information backup (ASVSI_BUP) file 7122.

Each ATS 713 is composed of an audio title set information (ATSI) file 7130, an audio-only title audio object set (AOTT_AOBS) file 7131, and an audio title set information backup (ATSI_BUP) file 7132. Here, the AOTT_AOBS file 7131 is made up of one to nine files. It is an optional file and may be absent.

Referring to FIG. 4, AOTT_AOBS 7131 will be explained. As explained later, AOTT_AOBS 7131 defines a set of one or more audio objects (AOB). Each AOB defines a set of one or more audio title set cells (ATS_C #). A set of one or more cells constitutes an audio title set program. A set of one or more programs constitutes an audio title set program chain (PGC).

In FIG. 3, the structure of AOTT_AOBS 7131 is represented directly by a set of ATS_C #. Each PGC is expressed by the program chain information in the ATS.

When one PGC is compared to an opera, cells constituting the PGC correspond to various music scenes or singing senses in the opera. The contents of the PGC (or the contents of the cells) are determined by a software provider that creates the contents recorded on an optical disk 10. Specifically, the provider can reproduce the cells constituting AOTT_AOBS 7131 as it has planned, using cell playback information ATS_C_PBI written in program chain information ATS_PGCI in the ATS. Explanation of ATS_PGCI and ATS_C_PBI will be given later.

In the other recording areas 73, usable pieces of information in the DVD video zone 72 or other pieces of information unrelated to the DVD video zone 72 can be written. The recording area 73 is not indispensable and may be eliminated, if unnecessary.

FIG. 5 is a diagram to help explain the hierarchical structure of those recorded in the DVD video zone 72 among the various pieces of information recorded on the optical disk 10 of FIG. 2. Hereinafter, what has been explained in FIG. 3 will be omitted and only the part related to the DVD video zone 72 will be explained.

On the basis of the description in the volume/file structure area 70, the contents of the video manager (VMG) 721 are stored in the system memory in the DVD player explained later.

The DVD video zone 72 is composed of a video manager (VMG) 721 and one or more video title sets (VTS #n) 722 (the maximum number "n" of video title sets is 99).

The VMG 721 is composed of a video manager information (VMGI) file 7210, a video manager menu video object set (VMGM_VOBS) file 7211, and a video manger information backup (VMGI_BUP) file 7212. Here, the VMGM_VOBS file 7211 is an optional file and may be absent.

Each VTS 722 is composed of a video title set information (VTSI) file 7220, a video title set menu video object set (VTSM_VOBS) file 7221, a video title set title video object set (VTSTT_VOBS) file 7222, and a video title set information backup (VTSI_BUP) file 7223. Here, the VTSM_VOBS file 7221 is an optional file and may be absent.

Stored in each video title set (VTS) 722 are not only the video data (or video packs explained later) compressed according to the MPEG standard, the audio data (audio packs explained later) compressed or uncompressed according to a specific standard, and run-length-compressed sub-picture data (sub-picture packs used to reproduce these data items (navigation packs explained later, including presentation control information and data search information).

Referring to FIG. 6, VTSTT_VOBS 7222 will be explained. As explained later, VTSTT_VOBS 7222 defines a set of one or more video objects (VOB). Each VOB defines a set of one or more video title set cells (VTS_C #n). VTS_C #n is composed of one or more video object units (VOBU). A VOBU may include navigation packs, audio packs, and sub-picture packs. A set of one or more video title set cells (VTS_C #n) constitutes a video title set (VTS) program. A set of one or more programs constitutes a video title set (VTS) program chain (PGC).

FIG. 5 shows the relationship between a program chain (PGC) and video title set cells (VTS_C #n).

When one PGC is compared to a drama, cells constituting the PGC can be considered to correspond to various scenes in the drama. The contents of the PGC (or the contents of the cells) are determined by a software provider that creates the contents recorded on an optical disk 10. Specifically, as with the ATS_PGCI explained in FIG. 3, the provider can reproduce the cells constituting VTSTT_VOBS 7222 as it has planned, using the cell playback information (not shown) written in program chain information (VTS_PGCI) in the VTS.

FIG. 7 is a diagram to help explain a case where specific pieces of video information (VTS_C #2, VTS_C #3, VTS_C #5) are accessed (in different methods) by both the program chain information (ATS_PGCI) in the DVD audio zone 71 of FIG. 3 and the program chain information (VTS_PGCI) in the DVD video zone 72 of FIG. 5. In other words, FIG. 7 shows a case where the same video objects (VOB) are referred to in different methods by the audio reproducing unit and video reproducing unit.

Specifically, when video playback is carried out from the video title set (VTS) side, cells VTS_C #1 to VTS_C #6 in the VOB are reproduced in sequence on the basis of the cell playback information (not shown) in the VTS_PGCI.

On the other hand, when video playback (or still playback) is carried out from the audio title set (ATS) side, cells VTS_C #2, VTS_C #3, and VTS_C #5 in the VOB are selectively reproduced on the basis of the cell playback information (ATS_C_PBI) in the ATS_PGCI.

In this case, because neither the ATS nor the VTS needs to have the same cell data items (VTS_C #2, VTS_C #3, and VTS_C #5) separately on the same optical disk 10, it is possible to use the limited storage capacity of the optical disk 10 effectively.

FIG. 4 shows an example of the data structure of the recorded contents (AOTT_AOBS) in the DVD audio zone 71 of FIG. 3. The AOTT_AOBS 7131 explained in FIG. 3 defines a set of one or more audio objects (AOTT_AOB #) as shown in FIG. 4. Each AOTT_AOB defines a set of one or more audio title set cells (ATS_C #). A set of one or more cells (ATS_C #) constitutes a program. A set of one or more programs constitutes a program chain (PGC). This PGC constitutes a logical unit indicating the whole of or part of an audio title.

In the example of FIG. 4, each audio title set cell (ATS_C #) is composed of a set of 2048-byte audio packs (A_PCK). These packs are the smallest units in performing a data transfer process. The smallest unit in logical processing is a cell. Logical processing is done in cells.

FIG. 6 shows an example of the data structure of the recorded contents (VTSTT_VOBS) in the DVD video zone 72 of FIG. 5.

As shown in FIG. 6, the VTSTT_VOBS 7222 explained in FIG. 5 defines a set of one or more video objects (AOB #). Each VOB defines a set of one or more video title set cells (VTS_C #). Each VTS_C defines a set of one or more video object units (VOBU). A set of one or more video title set cells constitutes a program. A set of one or more programs constitutes a program chain (PGC). The PGC constitutes a logical unit indicating the whole of or part of a video title or visual menu.

As shown in FIG. 6, each VOBU is a collection (a pack train) of a navigation pack, video packs (MPEG-compressed moving picture data), sub-picture packs (run-length-compressed bit map data), and audio packs (uncompressed linear PCM audio data or compressed multichannel audio data), with the navigation pack at the head. Specifically, the video object unit (VOBU) is defined as a collection of all the packs starting from a navigation pack to the one just before the next navigation pack. The navigation pack is incorporated in each VOBU to realize angle change (seamless angle change playback or nonseamless angle change playback).

Those packs are used as the smallest units in transferring data as in FIG. 4. The smallest unit in logical processing is a cell. Logical processing is done in cells.

The playback time of the VOBU corresponds to the playback time of the video data made up of one or more video groups (Groups of Pictures, abbreviated as GOPs) contained in the VOBU. The playback time is set in the range from 0.4 second to 1.2 seconds. In the MPEG standard, the playback time of one GOP is normally about 0.5 second. One GOP contains screen data compressed so that about 15 pictures may be reproduced in about 0.5 second.

When the VOBU includes video data, GOPs (complying with the MPEG standard) composed of video packs, sub-picture packs, and audio packs are arranged to produce a video data stream. The VOBU is determined on the basis of the playback time of the GOPs, regardless of the number of GOPs. At the head of the VOBU, a navigation pack is always placed.

In DVD video playback, even when the playback data contains only audio and/or sub-picture data, it is constructed using a VOBU as one unit. For example, when a VOBU is made up of only audio packs, with a navigation pack at the head, the audio packs to be reproduced within the playback time (0.4 second to 1.2 seconds) of the VOBU to which the audio data belongs are stored in the VOBU, as in the video data VOBU.

As shown in FIG. 6, the VTSTT_VOBS is defined as a set of one or more VOBs. The VOBs in the VOBS are used for the same application. A menu VOBS is usually composed of one VOB, in which menu screen display data items are stored. In contrast, a video title set VOBS is usually composed of more than one VOB.

When a concert video for a certain rock band is taken as an example, VOBs constituting a video object set (VTSTT_VOBS) for title sets can be considered to correspond to the video data for the performance of the band. In this case, by specifying particular VOBs, for example, the third piece on the band's concert program can be reproduced.

In the VOBs constituting a video object set (VTSM_VOBS) for menus, the menu data for all the pieces of the band's concert program is stored. According to the menu on the screen, a specific piece of music, for example, an encore, can be reproduced.

In an ordinary video program, one VOBS can be composed of one VOB. In this case, one video stream is completed with a single VOB.

On the other hand, for example, in the case of a collection of animations with multiple stories or omnibus movies, plural video streams [plural program chains (PGCs)] can be provided for each story in one VOBS. In this case, each video stream is stored in the corresponding VOB. At that time, the audio stream and sub-picture stream related to each video stream are also completed in each VOB.

Each video object (VOB) is assigned an identification number (#i; i=0 to i). By the identification number, the VOB can be identified. A VOB is composed of one or more cells. An ordinary video stream is made up of plural cells. A video stream for menus may be composed of one cell. Like the VOB, each cell is assigned an identification number (#j; j=1 to j).

FIG. 8 shows the recorded contents in the user-accessible DVD audio zone 71 to help explain an example of the data structure recorded on one side (of one or two layers) of the optical disk 10 shown in FIG. 1.

In DVD audio, a hierarchical structure composed of albums, groups, tracks, and indexes is prepared as a management structure for recorded contents viewed from the software producer side.

An album corresponds to one side of a DVD audio disk. For example, "The first volume of works by Beethoven" can be allocated to the album. In this case, the album may be composed of group #1 of Symphony No. 1 to group #9 of Symphony No. 9.

Each group (e.g., group #1) is composed of the first to fourth movements of the corresponding symphony (Symphony No. 1). Each track is composed of indexes #1 to #i, which are obtained by dividing a track (e.g., track #1) into i pieces.

When the user plays back a DVD audio disk with such a hierarchical structure as is shown in FIG. 8, the user sets the optical disk 10 in the DVD audio player, operates the remote controller (not shown), and selects group #1 and track #1.

After the selection, when the user presses the playback button on the remote controller, the DVD audio player starts to reproduce Beethoven's symphony No. 1, starting at the first movement. When the user specifies a specific index from the remote controller, the specified index portion is searched for and playback is started at that portion. The first index part of the first track in the first group in the album can be reproduced in default, or even when the user specifies nothing.

In playing back a DVD disk, the user can recognize the title (such as, the title of a specific movie), whereas in playing back a DVD audio disk, the user cannot see the title. What the user can see are only the album, groups, tracks, and indexes shown in FIG. 8.

FIG. 9 shows the directory structure of the information (DVD audio and DVD video data files) recorded on the optical disk 10 shown in FIG. 1. The structure is an example of a file directory structure defined in the DVD file standard.

As in a hierarchical file structure used by a general-purpose computer operating system, a subdirectory of video title set (VTS), a subdirectory of audio title set (ATS), and a user-defined directory are connected to a root directory.

Specifically, in the subdirectory of video title set (VTS), various video files (including VMGI, VMGM, VTSI, VTSM, and VTS files) as shown in FIG. 5 are so arranged that the individual files can be managed in order.

Moreover, in the subdirectory of audio title set (ATS), various audio files (including AMGI, ATSI, and ATS files) as shown in FIG. 3 are so arranged that the individual files can be managed in order.

The user can access a specific file (for example, a specific VTS or a specific ATS) by specifying a path from the root directory to the file.

When a DVD video player produced according to the DVD video standard plays back a DVD video disk produced according to the DVD video standard, it first reads the management information (VMG) in the video title set (VTS) directory under the root directory and reproduces the video contents on the basis of the information. However, what can be reproduced according to the VMG is limited to the video contents (VTS) recorded in the VTS directory.

On the other hand, when a DVD audio player (or a DVD video-DVD audio compatible player) produced according to the DVD audio standard plays back a DVD audio disk produced according to the DVD audio standard, it first reads the management information (AMG) in the audio title set (ATS) directory under the root directory and reproduces the audio contents on the basis of the information.

In this case, what can be reproduced according to the AMG is not limited to the audio contents (ATS) recorded in the ATS directory. The video contents (VTS) in the VTS directory can also be reproduced (the reproducing method will be explained later).

FIG. 10 shows another example of the directory structure of the information (DVD audio and DVD video data files) recorded on the optical disk 10 shown in FIG. 1. In the example of FIG. 9, the VTS directory and the ATS directory are placed in the same level of hierarchy under the root directory. On the other hand, in the example of FIG. 10, the ATS directory (child directory) is placed in a level of hierarchy under the root directory (parent directory). The VTS directory (grandchild directory) is placed in a level of hierarchy under the ATS directory.

FIG. 11 is a diagram to help explain the way the directory on the audio content side accesses a file in the directory on the video content side in the directory structure shown in FIG. 9.

Specifically, in the hierarchical management structure for managing the data files recorded on the optical disk 10, the video title set directory (a child directory) and the audio title set directory (a child directory) are placed under the root directory (a parent directory).

The video title set directory (VTS directory) is a directory for dealing with the video content files recorded on the optical disk 10 and includes a video manger (VMG) file and one or more video title set (VTS) files (video content logical units) (see FIG. 5).

The audio title set directory (ATS directory) is a directory for dealing with the audio content files recorded on the optical disk 10 and includes an audio manger (AMG) file and one or more audio title set (ATS) files (audio content logical units) as well as the aforementioned SAMG and ASVS (not shown in FIG. 11) (see FIG. 3).

The VMG in the VTS directory manages only the VTS and is designed to access only the VTS in the VTS directory.

On the other hand, the AMG in the ATS directory manages mainly the ATS and is designed to access not only the ATS in the ATS directory but also the VTS in the VTS directory.

The AMG includes audio manger information (AMGI). The AMGI includes an audio title search pointer table (ATT_SRPT). The ATT_SRPT includes an audio-only title (AOTT) search pointer (ATT_SRP) and an audio video (AVTT) search pointer (ATT_SRP). The contents of these will be explained in detail later.

Specifically, the AMG in the ATS directory can access the audio title sets (ATS #1, ATS #2, . . . ) in the ATS directory using the AOTT search pointer ATT_SRPT. It can also access the video title sets (VTS #1, VTS #2, . . . ) in the VTS directory using the AVTT search pointer (ATT_SRPT). This enables a certain object (such as, VTS #1) to be shared by both the video contents and the audio contents. This is one of the important characteristics of "an object sharing system" according to the present invention.

FIG. 12 is a diagram to help explain a case where a file in the directory on the audio content side links with a file in the directory on the video content side. FIG. 12 can be considered to be a modification of FIG. 11.

Specifically, in the example of FIG. 11, the audio manager (AMG) is designed to be able to access both an audio title set (ATS) and a video title set (VTS). This enables a VTS to be shared by the video contents and audio contents.

On the other hand, in the example of FIG. 12, information (e.g., a pointer indicating an address for a specific part of VTS #1) to link with a video title set (here, VTS #1) is written in an audio title set (here, ATS #1). This enables, for example, the audio data in VTS #1 to be shared by the video contents and audio contents.

FIG. 13 shows a data structure to help explain an example of how file access in FIG. 11 is carried out in the volume space 28 shown in FIG. 3 or 5. The data structure of FIG. 13 corresponds to the directory structure of FIG. 11.

In FIG. 13, the shaded portions indicate examples of the contents shared by the video contents (or video volume) and the audio contents (or audio volume).

The basic idea of the data structure of FIG. 13 is to record a recording area (VMG+VTS) for video contents and a recording area (AMG+ATS) for audio contents in the volume space 28 independently and enable video contents shared by both video and audio uses to be managed by the AMG.

Specifically, in FIG. 13, the video title set (VTS #1) managed by the VMG can access p