Recording media, and recording/reproducing apparatus

In order to search for an image recorded on an optical disk 10, a registration trigger is generated automatically or in response to an instruction of the user from a microcomputer block 30, a pointer indicating the recording position of a main image which is used as an index image in a preset area of the optical disk 10 via a data processor 36 and disk drive 32, index image data which becomes the index image is created in an encoder section 50 and data is recorded from an index image buffer memory 59 into a user menu file on the optical disk 10 via a formatter 56, data processor 36 and disk drive 32.

TECHNICAL FIELD
 This invention relates to a recording medium, playback apparatus and
 recording/playback apparatus thereof and more particularly to a
 recordable/playable recording medium such as a DVD-RAM and a
 recording/playback apparatus which can be applied to a recording/playback
 DVD player for recording or playing back an image and voice by use of the
 recording medium.
 BACKGROUND ART
 A playback-only optical disk having an image and voice recorded thereon is
 already put into practice as a music CD, laser disk, video CD or the like.
 MPEG2 (Moving Picture Experts Group Phase 2) which is the international
 standard specification for compression of moving pictures and a DVD
 specification using the AC3 audio compression system are defined and it is
 put into practice as a DVD video. The DVD specification is initially
 designed by taking a playback-only disk or a ROM disk which cannot be
 recorded by the user into consideration, but recently, a DVD-RAM
 specification which can be played back and recorded by the user was made.
 At present, the DVD-RAM specification is realized in a data
 recording/playback apparatus for a computer, but as a matter of course,
 application to a DVD recording/playback apparatus for recording/playback a
 moving picture and voice is studied. When application of the DVD-RAM
 specification to the DVD recording/playback apparatus is considered, it is
 desirable to effect the searching operation in the same manner as in the
 specification for DVD audio and DVD video based on the DVD specification
 for playback only.
 In the DVD video specification, VMG.cndot.VTS menus are provided for disk
 title creating companies. The menus are created by use of an exclusive
 authoring instrument. Then, the recording content of the disk is displayed
 in the form of menu in addition to normal video data at the time of
 playback and buttons are displayed by use of a sub-video image so as to
 permit the user to select them, thereby making it possible to search for a
 desired portion.
 On the other hand, when a moving picture is recorded by use of the DVD-RAM,
 the user creates a title, and if VMG.cndot.VTS menu data used in the DVD
 video specification is used, the user also creates them. However, it is
 extremely difficult for the ordinary user to create the VMG.cndot.VTS menu
 data when considering the large amount of data and devices which must be
 prepared to create the menu data and it is not practical. Further, in the
 case of recordable/playable DVD, the operation for re-recording main
 record data (video, voice data) is frequently effected, but if the
 VMG.cndot.VTS menu data is used, the VMG.cndot.VTS menu data must be
 rewritten each time the main record data is rewritten and the amount of
 operations for this purpose becomes extremely large.
 As described above, when a moving picture and voice are recorded by use of
 the DVD-RAM, use of VMG.cndot.VTS menu data used in the DVD video
 specification in which the main record data is not assumed to be rewritten
 imposes an extremely heavy load on the user and it is not practical.
 SUMMARY OF THE INVENTION
 This invention has been made to solve the above problem and an object of
 this invention is to provided a recordable/playable recording medium and
 recording/playback apparatus capable of easily effecting the searching and
 editing operations without making it necessary to create troublesome menu
 data.
 A recording/playback apparatus according to this invention is a
 recording/playback apparatus for recording or playing back main record
 data containing information of at least one of an image and voice and
 comprises trigger supplying means for supplying a trigger for registering
 an index image; position information acquiring means for acquiring
 recording position information on the recording medium of an image which
 is now being recorded in response to a trigger supplied by the trigger
 supplying means; and position recording means for recording the recording
 position information acquired by the position information acquiring means
 on the recording medium at the time of termination of the image recording.
 As the recording position information, a sector number and cell number of
 an image which is now being recorded are contained.
 Further, a recording/playback apparatus according to this invention
 comprises creating means for creating index image data in response to a
 trigger supplied from the trigger supplying means; and index image
 recording means for recording the recording position information acquired
 by the position information acquiring means and the index image data
 created by the creating means on the recording medium at the time of
 termination of the image recording.
 Further, a recording/playback apparatus according to this invention
 comprises time information acquiring means for acquiring display time
 information of an image which is now being recorded in response to a
 trigger supplied from the trigger supplying means; and time information
 recording means for recording the display time information acquired by the
 time information acquiring means on the recording medium at the time of
 termination of the image recording. The recorded image is processed in the
 unit of program and the time information is the number of fields counted
 from the starting time of the program which is now to be defined.
 Further, a recordable/playable recording medium according to this invention
 comprises an area for recording record position information of an image
 selected in the main record data; and an index image recording area for
 recording image data of the selected image in the main record data as an
 index image.
 According to this invention, recording position information of an image
 selected in the main record data is recorded on the recording medium and
 image data of the image selected in the main record data is alternatively
 or additionally recorded as an index image. By using information of an
 image and voice recorded in a recording position indicated by the position
 information or the index image (compressed or reduced image data) as a
 menu at the time of playback, the user can immediately detect the
 recording information on the recording medium.
 Therefore, it becomes possible for the user to quickly search for a desired
 portion based on the menu or efficiently effect the editing operation such
 as erase or replacement of information of a desired area on the recording
 medium.

BEST MODE OF CARRYING OUT THE INVENTION
 There will now be described an embodiment of this invention with reference
 to the accompanying drawings.
 As a typical embodiment of a recording/playback apparatus according to this
 invention, there is provided an apparatus, for example, a DVD digital
 video recorder for recording/playing back a moving picture encoded based
 on MPEG2 at a variable bit rate.
 FIG. 1 is a perspective view for illustrating the structure of a recordable
 optical disk 10 used for the DVD digital video recorder. As shown in FIG.
 1, the optical disk 10 has a structure obtained by laminating together one
 pair of transparent base plates 14 each having a recording layer 17 by use
 of an adhesive layer 20. Each base plate 14 can be formed of polycarbonate
 with a thickness of 0.6 mm and the adhesion layer 20 can be formed of
 extremely thin ultraviolet curing resin (for example, 40 .mu.m thick). By
 laminating the pair of 0.6 mm base plates together with the recording
 layers 17 disposed on the respective surfaces of the adhesive layer 20,
 the optical disk 10 of large capacity with a 1.2 mm thickness can be
 obtained.
 A central hole 22 is formed in the optical disk 10 and a clamp area 24 for
 clamping the optical disk 10 at the rotational driving time is provided
 around the central hole 22 on each surface of the disk. The spindle of a
 disk motor is inserted into the central hole 22 when the optical disk 10
 is loaded on a disk drive device (not shown). The optical disk 10 is
 clamped in the clamp area 24 during the rotation by means of a disk
 clamper (not shown).
 The optical disk 10 has an information area 25 in which video data, audio
 data and other information can be recorded around the clamp area 24. A
 lead-out area 26 is provided on the outer peripheral side of the
 information area 25 and a lead-in area 27 is provided on the inner
 peripheral side thereof in contact with the clamp area 24. A data
 recording area 28 is defined between the lead-out area 26 and the lead-in
 area 27.
 A recording track is continuously formed in a spiral form, for example, on
 the recording layer 17 of the information area 25. The continuous
 recording track is divided into a plurality of physical sectors and
 consecutive numbers are attached to the sectors. The sector is used as a
 recording unit to record various data on the optical disk 10.
 The data recording area 28 is an actual data recording area and, for
 example, video data (main video data) of a movie or the like, sub-video
 data such as caption, menu or the like, and audio data such as speeches
 and sound effects are recorded in the form of phase change marks as
 recording/playback information.
 The optical disk 10 is a recording/playback RAM disk and the recording
 layer 17 is formed of a three-layered structure having a phase change
 recording material layer formed of a Ge.sub.2 Sb.sub.2 Te.sub.5 layer held
 between two layers of zinc sulfide/silicon oxide mixture (ZnS/SiO.sub.2),
 for example. A continuous groove is formed in the base plate 14 having the
 recording/playback recording layer 17 and the phase change recording layer
 is formed on the groove. Generally, the phase change recording layer on
 the land portion other than the groove is also used for information
 recording.
 A DVD digital video recorder which will be described later is constructed
 to effect the repetitive recording operation, repetitive playback
 operation (read/write operation) for a DVD-RAM disk (or DVD-RW disk) and
 the repetitive playback operation for a DVD-ROM disk.
 FIG. 2 is a diagram for illustrating the correspondence relation between
 the data recording area 28 of the optical disk (DVD-RAM) 10 of FIG. 1 and
 the recording track of data recorded thereon. If the disk 10 is a DVD-RAM,
 the main body of the disk 10 is inserted into a cartridge 11 to protect
 the delicate disk surface. When the DVD-RAM disk 10 is inserted together
 with the cartridge 11 into the disk drive of the DVD video recorder which
 will be described later, the disk 10 is extracted from the cartridge 11,
 clamped on the turn table of a spindle motor (not shown) and rotated and
 driven while it is set to face an optical head (not shown).
 The data recording track is continuously formed in a spiral form on the
 recording layer 17 of the information area 25 shown in FIG. 1. As shown in
 FIG. 2, the continuous track is divided into a plurality of logical
 sectors (minimum recording unit) of constant recording capacity and data
 is recorded by using the logical sector as a reference. The recording
 capacity of one logical sector is set to 2048 bytes (or 2 kbytes) which is
 the same as one pack data length as will be described later.
 The data recording area 28 is an actual data recording area and management
 data, main video data, sub-video data and voice (audio) data are similarly
 recorded.
 FIG. 3 shows the hierarchical structure of data recorded on the optical
 disk 10 used as an information recording medium on which video information
 and music information shown in FIGS. 1 and 2 can be recorded and played
 back. The data recording area 28 formed on the optical disk 10 has a data
 hierarchical structure as shown in FIG. 3. For example, the logical format
 of the structure is defined in conformity to the universal disk format
 (UDF) bridge and ISO9660 which is a standard specification.
 As shown in FIG. 3, the lead-in area 27 is formed on the inner peripheral
 side of the optical disk 10, the lead-out area 26 is formed on the outer
 peripheral side thereof, the data recording area 28 between the lead-in
 area 27 and the lead-out area 26 is assigned as a volume space 28, and the
 volume space 28 includes a space (volume/file management area 70) for
 information of the volume and file structure and a space (DVD data area
 72) for application of the DVD specification.
 The lead-in area 27 includes a read-only emboss zone having an optical
 reflection surface formed in an irregular form, a mirror zone having a
 flat mirror surface and a rewritable data zone in which information can be
 rewritten. The lead-out area 26 includes a rewritable data zone in which
 information can be rewritten.
 Information associated with the entire portion of the information recording
 medium such as a physical sector number indicating the recording
 start/recording end position, recording density, disk size, disk type of
 the DVD-ROM (read-only DVD disk), DVD-RAM (DVD disk for
 recording/playback) and DVD-R (additionally recording type DVD disk) is
 recorded on the emboss data zone of the leak-in area 27, for example, and
 information associated with the recording/playback/erase characteristics
 such as the recording power and recording pulse width required for
 recording data on the recording layer 17, erase power required for erasing
 data recorded on the recording layer 17, playback power required for
 playing back data recorded on the recording layer 17, and linear velocity
 at the time of recording/erase is also recorded. Further, information
 associated with the manufacturing of each information recording medium
 such as a manufacturer's serial number is recorded on the emboss data zone
 of the leak-in area 27. In the rewritable data zone of the lead-in area 27
 and the rewritable data zone of the lead-out area 26, a recording area for
 recording an inherent disk name of each information recording medium, a
 trial recording area for determining whether or not the recording and
 erase operations can be effected in the recording/erase condition, and a
 management information recording area for determining whether or not a
 defective area is present in the data area 72 and recording an address of
 the area are provided and a preparation process for permitting data to be
 recorded on the data area 72 is effected in the above area and information
 necessary for data recording/erase/playback after this is recorded in the
 area.
 The volume space 28 is physically divided into a large number of sectors
 and consecutive numbers are attached to the physical sectors. The logical
 address of data recorded in the volume space (data recording area) 28
 indicates a logical sector number as defined by the ISO9660 and UDF
 bridge. Like the effective data size of the physical sector, the logical
 sector size is set to 2048 bytes (2 kbytes) and consecutive numbers are
 attached according to the ascending order of the physical sector numbers
 as the logical sector numbers.
 The volume space 28 has a hierarchical structure and includes a volume/file
 management area 70 and a data area 72 formed of at least one video object.
 The areas 70, 72 are divided on the boundary between the logical sectors.
 One logical sector is defined to have 2048 bytes and one logical block is
 also defined to have 2048 bytes. Therefore, one logical sector is defined
 to be the same as one logical block.
 The volume/file management area 70 is a rewritable data zone in which data
 can be rewritten by the user and corresponds to a management area defined
 by the ISO9660 and UDF bridge and information associated with the whole
 volume or a file of audio/video data is stored in a system memory (not
 shown) in the DVD video recorder as will be described later based on the
 description of the area 70. Generally, the volume/file management area 70
 is constructed by one file.
 As shown in FIG. 3, in the data area 72, an area in which computer data and
 audio/video data can be recorded together is defined. The recording order
 of the computer data and audio/video data and the recording information
 size can be arbitrarily set, areas in which the computer data is recorded
 are referred to as computer data areas 74-1, 74-2, and an area in which
 audio/video data is recorded is referred to as an audio/video data area
 76.
 The computer data areas 74-1, 74-2 are not particularly necessarily
 provided from the viewpoint of its property if only audio/video data is
 recorded in the recording area 72 and the audio/video data area 76 is not
 particularly necessarily provided from the viewpoint of its property if
 only computer data is recorded in the recording area 72. The computer data
 areas 74-1, 74-2 and the audio/video data area 76 can be formed of one
 file or a plurality of files.
 As shown in FIG. 3, in the audio/video data area 76, control information 78
 necessary when the processes such as image recording (sound recording),
 playback, edition and searching operations are effected and a video object
 set 80 formed of one or a plurality of objects 82, 84, 86 as the
 reproduction object or the contents thereof are recorded. In the video
 object set 80, the video object 82 whose contents are video data, the
 picture object 84 whose contents are a still picture such as a still/slide
 picture or picture data such as a searching or editing index image or a
 location of a desired portion of video data, and the audio object 86 whose
 contents are audio data are provided. As is clearly understood, the video
 object set 80 is not required to have all of the objects 82, 84, 86 and
 may be constructed by at least one of the objects 82, 84, 86. Likewise,
 the objects 82, 84, 86 are each constructed by one or a plurality of
 files.
 As shown in FIG. 4, in the video object set 80 constructed by one or a
 plurality of objects 82, 84, 86, video data (video pack 88 which will be
 described later) compressed according to the MPEG2 specification, audio
 data (audio pack 90 which will be described later) compressed according to
 the preset specification or non-compressed and sub-video data (sub-video
 pack 92 including bit map data in which one pixel is constructed by a
 plurality of bits as will be described later) compressed according to the
 run-length are stored.
 If the video object set 80 is constructed only by the video object 82, it
 has a data structure as shown in FIG. 4, if the video object set 80 is
 constructed only by the picture object 84, it has a data structure
 constructed only by the sub-video pack 92 and/or the video pack 88 which
 does not include the audio pack 90, and if the video object set 80 is
 constructed only by the video object 86, it has a data structure
 constructed only by the audio pack 90 which does not include the sub-video
 pack 92 and video pack 88.
 As shown in FIG. 4, logically, the video object set 80, that is, the video,
 picture and audio objects 82, 84, 86 are constructed by a plurality of
 cells 94 and each cell 94 is constructed by at least one video object unit
 (VOBU) 96.
 In the cell 94, the video object unit (VOBU) 96 is decoded and played back
 in the arrangement order in the cell 94 as a rule. The video object unit
 96 is a set (pack string) of the video pack (V pack) 88, audio pack (A
 pack) 90 and sub-video pack (SP pack) 92 and defined as data played back
 in a preset period, for example, in a period of 0.5 to 1.2 seconds. Each
 pack is a minimum unit used for effecting the data transfer process and
 the cell is logically the minimum unit used for effecting the data
 process.
 Identification numbers (IDN#k; k=0 to k) are attached to the video object
 units (VOBU) 96 and the video object unit 96 can be specified by the
 identification number. The playback period of the video object unit (VOBU)
 96 normally corresponds to a playback period of video data constructed by
 at least one video group (group of pictures; GOP) contained in the video
 object unit 96. Generally, the length of one GOP is approx. 0.5 second in
 terms of the MPEG2 specification and image data compressed to play back
 the frame images of approx. 15 sheets during the above period is stored.
 If the video object unit (VOBU) 96 includes video data, GOPs (in conformity
 to the MPEG specification) including the video pack 88, sub-video pack 90
 and audio pack 92 are arranged to construct a video data stream. If
 playback data is formed of only the audio and/or sub-video data, the
 playback data is constructed with the video object unit (VOBU) 96 used as
 one unit. For example, the audio pack 90 to be played back in a playback
 period of the video object unit (VOBU) 96 to which target audio data
 belongs is stored in the video object unit (VOBU) 96.
 Identification numbers (IDN#i; i=0 to i) are attached to the video objects
 82, 84, 86 constructing the video object set 80 and the video objects 82,
 84, 86 can be specified according to the identification number. Further,
 identification numbers (C_IDN#j) are attached to the cells 94 like the
 case of the video objects 82, 84, 86.
 FIG. 5 shows the general structure of the video pack 88, sub-video pack 92
 and audio pack 90. Like the logical sector of FIG. 2, the packs are each
 constructed by data of 2048 byte unit. As shown in FIG. 5, the video,
 audio and sub-video packs 88, 90, 92 are each constructed by a pack header
 98 and a packet 100. The packet 100 includes a packet header in which a
 decode time stamp (DTS) and presentation time stamp (PTS) are recorded.
 The control information 78 shown in FIG. 3 includes playback control
 information 102 indicating control information necessary at the time of
 playback, recording control information 104 indicating control information
 necessary at the time of recording (image recording or sound recording),
 edition control information 106 indicating control information necessary
 at the time of edition and index image control information 108 indicating
 management information associated with a searching or editing index image
 of a desired position of video data.
 As shown in FIG. 6, the playback control information 102 shown in FIG. 3
 includes a management information table (PLY_MAT) 112, program chain (PGC)
 information table (PGCIT) 110 and time map table 111. Information as shown
 in FIG. 7 is described in the management information table (PLY_MAT) 112
 and the program chain (PGC) information table 110 has a data structure as
 shown in FIG. 8.
 In the program chain (PGC) information table 110, information associated
 with the playback order of cells and the program chain (PGC) is mainly
 described and data of the cell 94 recorded in the video object 82 (that
 is, movie data used as real data constructed by the video object unit 96)
 is played back according to the description of the program chain (PGC)
 information table 110. As shown in FIG. 8, the program chain (PGC)
 information table 110 is constructed by index scene information 120, PGC
 information management information 122, search pointers #1 to #n 124 for
 searching each PGC information and PGC information #1 to #n 126. In the
 index scene information 120, cell numbers of scenes (index scenes) used as
 index images are described.
 If the PGC number is determined, PGC information corresponding to the PGC
 number is obtained by referring to the search pointer 124. The playback
 order of cells is derived from the PGC information, data of the cells 94
 as real data is acquired from the video object 82 according to the
 playback order of cells and video data is played back. In this case, the
 video object 82 is explained, but cell data is derived as real data and
 played back according to the description of the program chain (PGC)
 information table 110 in the same manner as in the case of the picture
 object 84 and audio object 86.
 In this case, the PGC corresponds to the chapter of the movie story and
 indicates a unit in which a series of playback operations for specifying
 the playback order of cells is effected. In other words, if one PGC
 corresponds to one drama, it is possible to consider that a plurality of
 cells 94 constructing the PGC correspond to various scenes in the drama.
 The contents of the PGC (or the contents of the cells) may be determined
 by a software provider making the contents recorded on the disk 10, for
 example. More specifically, if a video data stream as shown in FIG. 10A is
 present, the contents thereof are divided into video object units 96 which
 are played back in a preset period of time and a set of video object units
 96 which are continuous in principle are defined in the cell 94.
 Since the video object unit 96 is continuous in principle, the cell 94 is
 defined by the first video object unit 96 and the last video object unit
 96 constructing the cell 94 in the PGC information table 110 as will be
 described later, more specifically, in the cell playback information 130
 shown in FIG. 8. That is, information in a playback segment specified by a
 start address 134 and end address 136 of playback data constructing the
 cell as shown in FIG. 9 is described in the cell playback information 130.
 If the cell 94 is thus defined, the PGC is constructed by determining the
 playback order of the cell. For example, as shown in FIG. 10B, the PGC #1
 is defined by arranging the three cells 94 in the cell playback
 information table so as to play back the cells in the order of cell-A,
 cell-B, cell-C. Likewise, the PGC #2 is defined by arranging the three
 cells 94 in the cell playback information table so as to play back the
 cells in the order of cell-D, cell-E, cell-F. Further, the PGC #3 is
 defined by arranging the five cells 94 in the cell playback information
 table so as to play back the cells in the order of cell-Q, cell-R, cell-S,
 cell-T, cell-U.
 The PGC #2 corresponding to a chapter which continues from the PGC #1
 corresponding to a previous chapter is played back by linking the PGC #1
 and PGC #2 together. In other words, the cells are successively played
 back in the order of cell-A to cell-F. In the PGC, the cells 94 are played
 back in the arrangement order thereof, but the construction of the PGC and
 the playback order of the PGC are arbitrarily set. Therefore, for example,
 a PGC can be defined by use of the cells constructing another PGC.
 Further, since the way of linking or link information can be arbitrarily
 determined, various stories can be formed or edited. For example, it is
 possible to link the PGC #3 following the PGC #1 or add the same cell, for
 example, the cell G, to the PGC #1 and PGC #2 to make different chapters.
 That is, a desired story can be realized by linking the PGC #3 to the PGC
 #1 or PGC #2 according to the selection by the user.
 In the playback management table 112 shown in FIG. 7, an identifier ID
 indicating playback control information is described, a start address
 (VOBS_SA) and end address (VOBS_EA) of the video object set 80 are
 described and an end address (CTLI_EA) of control information (CTLI) 78
 and an end address (PLYI_EA) of playback control information (PLYI) 102
 are described. Further, in the playback management table 112, attribute
 (CAT) indicating that the management information attributes to the format
 of the recording/playback DVD is described to indicate attribute of video
 data in the video object set recorded in the audio/video data area 76, for
 example, the attribute of NTSC system or wide-television system. Further,
 in the playback management table 112, the number (AST_Ns) of audio streams
 in the video object set and a table (AST_ATR) in which the attribute
 thereof, for example, the compression system or the like is described are
 described and the number (SPST_Ns) of sub-video streams in the video
 object set and a table (SPST_ATR) in which the attribute thereof is
 described are described. If the user records searching index image data
 and menu image data as an independent user menu file in the audio video
 data area 76, a flag (01) indicating that the user menu is present or a
 flag (00) indicating no user menu if the menu is not present is described.
 If the index image is recorded in the audio video data area 76, the number
 of a PGC which is used as the basis of a typical index image is described.
 Further, a flag (0: not yet played back, 1: already played back)
 indicating whether the playback operation by the user for the video object
 set controlled by the control information 78 is terminated or not is
 described.
 As shown in FIG. 11, in PGC information management information (PGC_MAI)
 122 shown in FIG. 8, information indicating the total number of PGCs is
 contained and information pointing the head portion of each PGC
 information is contained as described before in the search pointer 124 of
 PGC information to make it easy to search for the PGC. PGC information 126
 is constructed by PGC general information 128 shown in FIG. 8 and at least
 one cell playback information 130 shown in FIG. 8.
 As shown in FIG. 11, in the PGC information management information
 (PGC_MAI) 122, the end address (PGC_TABLE_EA) of the PGC information table
 110, the end address (PGC_MAI_EA) of the PGC information management
 information (PGC_MAI) 122, the start address (PGC_SRP_SA) and end address
 (PGC_SRP_EA) of the PGC information search pointer (PGC_SRP) 124, the
 start address (PGCI_SA) and end address (PGCI_EA) of all of the PGC
 information items (PGCI) 126 and the number (PGC_NS) of all of the PGCs
 are described.
 As shown in FIG. 12, in the PGC general information (PGC_GI) 128,
 information indicating the number of cells and the playback time of the
 PGC is described. That is, in the PGC general information (PGC_GI) 128,
 the contents (PGC_CNT) of the PGC in which the number of cells and the
 number of PGCs are described, the playback time (PGC_PB_TM) of the PGC, a
 table (PGC_AST_CTL) in which information for controlling the audio stream
 contained in the PGC is described, and a table (PGC_SPST_CTL) in which
 information for controlling the sub-video stream contained in the PGC is
 described are described.
 Further, in the PGC general information (PGC_GI) 128, PGC navigation
 control (PGC_NV_CTL) in which link information associated with the PGC to
 be linked with the PGC, for example, a preceding PGC, next PGC or a
 skipped (GOup) PGC is described, a sub-video pallet table (PGC_SP_PLT) in
 which reproduction information associated with color of sub-video pallet
 is described and the start address (PGC_PGMAP_SA) of a program table (not
 shown) in which a list of programs constructing the PGC is described are
 described. Further, in the table (PGC_GI), the start address
 (CELL_PLY_I_SA) of cell playback information (CELL_PLY_I) 120, a flag (01:
 menu data is present, 00: menu data is not present) indicating whether
 menu data associated with the PGC and formed by the user is present or
 not, reservation, a flag (0: not yet played back, 0: already played back)
 indicating whether the playback operation for the PGC by the user is
 completed or not and a flag (ARCHIVE Flag) indicating whether or not it is
 desired to hold the PGC after this, that is, a flag (0: free [erasable],
 1: permanent storage) indicating whether or not it is desired to
 permanently store the PGC are described.
 In the index scene information 120 shown in FIG. 8, the cell number N of a
 scene registered as an index image in the pointer recording mode which
 will be described later is described.
 As shown in FIG. 9, the cell playback information (CELL_PLY_I) 130 shown in
 FIG. 8 is roughly divided into cell general information 132 and index
 scene pointer information 134.
 As shown in FIG. 13, in the cell general information 132, the category
 (C_CAT) of a cell, for example, information indicating whether or not the
 cell belongs to a block and whether or not the block is an angle block if
 it belongs to the block is described. In this case, the angle block
 indicates a block whose angle can be switched. The angle switching
 indicates that an angle (camera angle) at which an object image is viewed
 is changed. More specifically, in a musical performance scene (in the same
 event) of the same music in a rock concert video, for example, it
 indicates that various scenes such as a scene obtained by viewing the
 vocalist as a main object, a scene obtained by viewing the guitarist as a
 main object and a scene obtained by viewing the drummer as a main object
 can be observed at different angles. As the case wherein the angle
 switching (or angle changing) is made, a case wherein the angle can be
 selected according to the preference of the audience or a case wherein the
 same scene is automatically repeated in the development of the story while
 changing the angle (a case wherein the software creator/provider makes the
 story to attain the above effect or a case wherein the user of the DVD
 video recorder edits the story to attain the above effect) is provided.
 Further, as shown in FIG. 13, in the cell general information 132, cell
 playback time (absolute time) in the PGC is described and a flag (0: not
 yet played back, 1: already played back) indicating whether or not the
 playback operation of the cell by the user is terminated and a flag
 (ARCHIVE Flag) indicating whether or not it is desired to hold the cell
 after this, that is, a flag (0: free [erasable], 1: permanent storage)
 indicating whether or not it is desired to permanently store the cell are
 described.
 Further, as shown in FIG. 13, in the cell general information 132, a cell
 start address (CELL_SA) and end address (CELL_EA) are described. The cell
 start address and end address are described by use of relative addresses
 of the first and last video object units (VOBU) of the cell from the head
 of the video object set 80. Further, in the cell general information 132,
 the end address (CELL_PLY_I_EA) of the cell playback information
 (CELL_PLY_I) 130 is also described. The end address of the cell playback
 information is provided since the length of the index scene pointer
 information 134 is not constant although the length of the cell general
 information is constant.
 As shown in FIG. 13, in the index scene pointer information 134, a physical
 sector number (which is referred to as an index scene pointer address
 (INDEX_PT)) of PGC information containing the cell number of an index
 scene (which is a scene used as an index image) recorded in the index
 scene information 120 is described. In FIG. 13, M index scene pointer
 addresses are provided and M is a variable number.
 Therefore, at the time of searching for an image recorded on the optical
 disk 10, an index image can be searched for by reading the cell number of
 a cell containing the index scene from the index scene information 120 in
 the PGC information table 110 shown in FIG. 8 and searching the PGC
 information 126 containing the cell number to read the index scene pointer
 information 134 on the cell playback information 130 in the PGC general
 information 128 of the PGC information 126.
 The procedure for registering the cell number into the index scene
 information 120 and registering the index scene pointer information 134 is
 described later in detail.
 The recording control information 104 shown in FIGS. 3 and 6 contains a
 recording management table 114 shown in FIG. 14 and the end address
 (RECI_EA) of the recording control information 104 and the end address
 (REC_MAT_EA) of the recording management table 114 are described in the
 recording management table 114 and a free area (FREE_SE) for writing
 information associated with the recording management is provided. Further,
 in the recording management table 114, a flag (ARCHIVE Flag) indicating
 whether or not it is desired to hold the VOBU or a flag (0: free
 [erasable], 1 permanent storage) indicating whether or not it is desired
 to permanently hold the VOBU is described.
 The reduced drawing control information 108 shown in FIG. 3 includes a
 first anchor pointer 108-A, picture address table 108-B and a second
 anchor pointer 108-C, and the picture address table 108-B includes menu
 index information INFO1, index picture information INFO2, information
 picture information INFO3, defective area information INFO4 and wall paper
 picture information INFO5.
 FIG. 15 shows the construction of a device (DVD video recorder) used for
 recording/playing back digital moving image information at a variable
 recording rate with respect to the disk of FIG. 1 by use of information
 with the construction explained with reference to FIGS. 3 to 14.
 The device main body of the DVD video recorder rotates and drives the
 optical disk 10 which is a DVD-RAM or DVD-R disk, for example, and is
 constructed by a disk drive section (disk drive 32, temporary storage
 section 34, data processor 36, system time counter 38 and the like) for
 reading/writing information with respect to the optical disk 10, an
 encoder section 50 constructing the recording section, a decoder section
 60 constructing the playback section, and a microcomputer block 30 for
 controlling the operation of the device main body.
 The encoder section 50 includes an ADC (analog-digital converter) 52, video
 encoder (V encoder) 53, audio encoder (A encoder) 54, sub-video encoder
 (SP encoder) 55, formatter 56, buffer 57, index image creating section 58
 and index image buffer memory 59.
 The ADC 52 is supplied with an external analog video signal and external
 analog audio signal from the AV input section 42, or an analog TV signal
 and analog voice signal from the TV tuner 44. The ADC 52 converts an input
 analog video signal into a digital form with a sampling frequency 13.5 MHz
 and quantization bit number of 8 bits, for example. That is, a luminance
 component Y, color difference component Cr (or Y-R) and color difference
 component Cb (or Y-B) are quantized by use of 8 bits. Further, the ADC 52
 converts an input analog audio signal into a digital form with a sampling
 frequency 48 kHz and quantization bit number of 16 bits, for example.
 When an analog video signal and digital audio signal are input to the ADC
 52, the ADC 52 passes the digital audio signal therethrough as it is. At
 this time, a process for reducing the jitter attached to the digital
 signal or a process for changing the sampling rate or quantization bit
 number may be effected without changing the contents of the digital audio
 signal. Further, when a digital video signal and digital audio signal are
 input to the ADC 52, the ADC 52 passes the digital video signal and
 digital audio signal therethrough as they are. The jitter reducing process
 or sampling rate changing process may be effected without changing the
 contents of the digital signals.
 The digital video signal component from the ADC 52 is supplied to the
 formatter 56 via the video encoder (V encoder) 53. The digital audio
 signal component from the ADC 52 is supplied to the formatter 56 via the
 audio encoder (A encoder) 54.
 The V encoder 53 has a function of converting the input digital video
 signal into a compressed digital signal at a variable bit rate based on
 the MPEG2 or MPEG1 specification.
 The A encoder 54 has a function of converting the input digital audio
 signal into a digital signal (or digital signal of linear PCM) compressed
 at a fixed bit rate based on the MPEG audio or AC-3 specification.
 When a DVD video signal with data construction shown in FIGS. 4 and 5 or a
 signal from the DVD video player with independent output terminal for the
 sub-video signal is input from the AV input section 42 or when the DVD
 video signal with the above data construction is broadcasted and received
 by the TV tuner 44, the sub-video signal component (sub-video pack) in the
 DVD video signal is input to the sub-video encoder (SP encoder) 55. The
 sub-video data input to the SP encoder 55 is converted into a preset
 signal configuration and then supplied to the formatter 56.
 The formatter 56 performs the preset signal processing for the input video
 signal, audio signal, sub-video signal and the like while using the buffer
 memory 57 as a work area and outputs record data which coincides with the
 above format (file structure) to the data processor 36.
 Now, the standard encode processing contents for creating the above record
 data is simply explained. If the encode process is started in the encoder
 section 50 of FIG. 15, parameters necessary for encoding video (main
 video) data and audio data are set. Next, the main video data is
 pre-encoded by use of the set parameters and a distribution code amount
 suitable for the set average transfer rate (recording rate) is derived.
 The main video data is encoded based on the distribution code amount
 obtained by the pre-encoding operation. At this time, the encoding
 operation for the audio data is simultaneously effected.
 In a case where the data compression amount is insufficient, for example,
 in a case where a desired program cannot be stored into the DVD-RAM disk
 or DVD-R disk to be used for recording as the result of pre-encoding, the
 partial encoding operation for the main video data is effected again and
 the main video data which is encoded again is substituted for a main video
 data portion previously pre-encoded if a chance for pre-encoding the main
 video data again can be obtained, that is, if the recording source is a
 repetitive playable source such as a video tape or video disk, for
 example. The main video data and audio data are encoded by a sequence of
 processes and the value of an average bit rate necessary for recording is
 significantly reduced. Likewise, a parameter necessary for encoding the
 sub-video data is set and the encoded sub-video data is formed.
 The main video data, audio data and sub-video data thus encoded are
 combined and converted into a structure of video object.
 That is, a cell used as a minimum unit of the main video data (video data)
 is set and playback information (C_PLY_I) as shown in FIG. 13 is created.
 Next, the construction of the cell constructing the program chain (PGC)
 and the main video, sub-video and audio attributes are set (as part of the
 attributes, information obtained when corresponding data is encoded is
 used) and the playback control information 102 including various
 information items explained with reference to FIGS. 3 and 6 is created.
 The encoded main video data, audio data and sub-video data are finely
 divided into packs with a preset size (2048 bits) as shown in FIG. 5. In
 the packs, time stamps such as a PTS (presentation time stamp) and DTS
 (decode time stamp) are adequately described. As the PTS of the sub-video,
 time delayed by a given amount with respect to the PTS of the main video
 data or audio data of the same playback time range can be described.
 The packs are set into the VOBU 96 as data played back in a preset period
 of time so as to be played back in the time stamp order of the packs and
 each data cell is defined while arranging the VOBUs 96 and a VOB 82
 constructed by a plurality of cells is formed. The VOBS 80 obtained by
 combining at least one VOB is formatted into a structure shown in FIG. 4.
 The disk drive section for effecting the information reading/writing (image
 recording and/or playback) with respect to the DVD disk 10 includes a disk
 changer section (not shown), disk drive 32, temporary storage section 34,
 data processor 36, and system time counter (or system time clock; STC) 38.
 The temporary storage section 34 buffers a preset amount of data among data
 (data output from the encoder section 50) written into the disk 10 via the
 disk drive 32 or buffers a preset amount of data among data (data input to
 the decoder section 60) played back from the disk 10 via the disk drive
 32.
 For example, if the temporary storage section 34 is constructed by a
 4-Mbyte semiconductor memory (DRAM), the buffering of playback data or
 record data of approx. 8 seconds at the average recording rate of 4 Mbps
 can be attained. Further, if the temporary storage section 34 is
 constructed by a 16-Mbyte EEPROM (flash memory), the buffering of playback
 data or record data of approx. 30 seconds at the average recording rate of
 4 Mbps can be attained. Also, if the temporary storage section 34 is
 constructed by a 100-Mbyte micro HDD (hard disk), the buffering of
 playback data or record data of more than 3 minutes at the average
 recording rate of 4 Mbps can be attained.
 The temporary storage section 34 can be used to temporarily store recording
 information until the disk 10 is replaced by a new disk when the disk 10
 is used up in the course of recording. Further, when a high-speed drive
 (higher than twice the original speed) is used as the disk drive 32, the
 temporary storage section 34 can be used to temporarily store data which
 is excessively read out in comparison with the case of normal drive in a
 preset period of time. If readout data at the time of playback is buffered
 in the temporary storage section 34, a playback image can be prevented
 from being interrupted by substituting playback data buffered in the
 temporary storage section 34 even when an optical pickup (not shown)
 causes a readout error due to vibration shock or the like.
 The data processor 36 of FIG. 15 supplies DVD record data from the encoder
 section 50 to the disk drive 32, extracts a DVD playback signal played
 back from the disk 10 from the drive 32, rewrites management information
 recorded on the disk 10, or deletes data (file or VTS) recorded on the
 disk 10 according to the control of the microcomputer block 30.
 The microcomputer block 30 includes an MPU (or CPU), a ROM in which control
 programs are stored and a RAM which provides a work area necessary for
 execution of the program.
 The contents to be notified to the user of the DVD video recorder among the
 results of execution by the MPU 30 are displayed on the display section 48
 of the DVD video recorder or displayed on a monitor display in an
 on-screen display (OSD) manner.
 The timings at which the MPU 30 controls the disk changer section, disk
 drive 32, data processor 36, encoder section 50 and/or decoder section 60
 can be set based on time data from the STC 38. The recording/playback
 operation is normally effected in synchronism with the time clock from the
 STC 38 and the other process may be effected at a timing independent from
 the STC 38.
 The data section 60 includes a separator 62 for separating and extracting
 each pack from the DVD playback data having the pack construction as shown
 in FIG. 5, a memory 63 used at the time of pack separation or execution of
 the other signal processing, a video decoder (V decoder) 64 for decoding
 main video data separated by the separator 62, a sub-video decoder (SP
 decoder) 65 for decoding sub-video data (sub-video pack 90) separated by
 the separator 62, an audio decoder (A decoder) 68 for decoding audio data
 (audio pack 91 of FIG. 9) separated by the separator 62, a video processor
 66 for adequately combining the sub-video data from the SP decoder 65 with
 the video data from the V decoder 64, superposing the menu, highlight
 button, caption and other sub-video image on the main video image and
 outputting the result of superposition, a video digital/analog converter
 (V.cndot.DAC) 67 for converting a digital video output from the video
 processor 66 to an analog video signal, and an audio digital/analog
 converter (A.cndot.DAC) 67 for converting a digital audio output from the
 audio processor 68 to an analog audio signal.
 The analog video signal from the V.cndot.DAC 67 and the analog audio signal
 from the A.cndot.DAC 67 are supplied to external components (not shown)
 (2-channel to 6-channel multi-channel stereo device+monitor TV or
 projector) via an AV output section 46.
 Next, the basic data processing operations, that is, the recording process
 and playback process of the DVD video recorder according to this
 embodiment are explained.
 At the time of data processing for recording, if the user first effects the
 key-in operation and the MPU of the microcomputer block 30 receives a
 recording instruction, necessary management data is read out from the DVD
 disk 10 via the disk drive 32 to determine an area in which video data is
 recorded. Then, the thus determined area is set in the management area and
 the recording start address of video data is set on the disk drive 32.
 In this case, the management area specifies the file management section 70
 (specifies the directory decode in ISO9660) for managing the files and
 control information 78 and parameters necessary for the file management
 section are sequentially recorded.
 Next, the microcomputer block 30 resets time of the STC section 38. In this
 example, the STC 38 is a timer of the system and the recording/playback
 operation is effected with the time thereof used as a reference. After
 this, the microcomputer block 30 sets the contents of other sections.
 The flow of a video signal is as follows. That is, an AV signal input from
 the TV tuner section 44 or external input section is A/D converted by the
 ADC 52 and the video signal and audio signal are respectively supplied to
 the video encoder 53 and audio encoder 54, and the closed caption signal
 from the TV tuner 44 or the text signal of text broadcasting is supplied
 to the SP encoder 55.
 The encoders 53, 54, 55 compress the respective input signals to make
 packets (in this case, each packet is made such that each pack has 2048
 bytes when each packet is formed into packs) and the packets are input to
 the formatter section 56. In this case, the encoders 53, 54, 55 determine
 and record PTS, DTS of each packet according to the value of the STC 38 as
 required.
 The formatter 56 temporarily holds packet data to the buffer memory 57, and
 then sets each input packet data into packs, mixes the packs for each GOP
 and supplies the result of mixing to the data processor 36.
 The data processor 36 deals with every 16 packs as an ECC (error correction
 code) block and supplies the same to the disk drive 32 after attaching the
 ECC thereto. However, if the disk drive 32 does not make ready for
 recording on the disk 10, data is transferred to the temporary storage
 section 34, the standby state is kept until the preparation for recording
 data is set up, and data recording is started when the preparation is set
 up. In this case, it is assumed that the temporary storage section 34 is
 formed of a large-capacity memory since it holds record data of several
 minutes or more by high-speed access.
 At the time of termination of the recording operation, information
 necessary for the volume & file management area 70 and the playback
 control information 102 of the control information are recorded and the
 recording operation is terminated. In this case, the microcomputer block
 30 can effect the read/write operation with respect to the data processor
 36 via a microcomputer bus to read/write the volume & file management area
 70 of the file.
 In the data processing at the time of playback operation, the user first
 effects the key-in operation and the microcomputer block 30 receives a
 playback instruction and the volume & file management area 70 is read out
 via the data processor 36 by use of the disk drive 32 to determine the
 address to be played back. In this case, the volume & file management area
 70 indicates the volume descriptor and file management section. That is,
 whether the optical disk 10 is a DVD disk or not is determined by use of
 the volume descriptor and the control information 78 is read out by use of
 address information of the file management section to determine the
 playback start address in the video object 82, 84 or 86 corresponding to
 the title played back by the control information 78.
 Next, the microcomputer block 30 supplies a read instruction and address of
 previously determined data to be played back to the disk drive 32. The
 disk drive 32 reads out sector data from the disk 10 according to the
 supplied instruction, corrects the error in the data processor 36, and
 outputs the data in a pack data form to the decoder section 60.
 In the decoder section 60, the separator 62 receives the readout pack data,
 forms the data into a packet form, transfers the video packet data (MPEG
 video data) to the video decoder 64, transfers the audio packet data to
 the audio decoder 68, and transfers the sub-video packet data to the SP
 decoder 65.
 After this, the decoders 64, 65, 68 effect the playback processes in
 synchronism with the values of the PTS (presentation time stamp) of the
 respective packet data items (output packet data decoded at the timing at
 which the values of the PTS and STC 38 coincide with each other) and can
 supply a moving picture with voice caption to the TV.
 Next, the feature of this invention of the registration procedure of index
 scene to the optical disk 10 is explained by taking a case wherein an
 index image is most frequently used as the index scene as an example.
 The index image is an image used for searching or editing the recording
 contents of the optical disk 10. As the method for registering the index
 image in this embodiment, two methods are provided which include a method
 (which is called a pointer recording mode) for recording position
 information (pointer) indicating the recording position of the index image
 in the main record data (video data) on the optical disk 10 and a method
 (which is called an index image recording mode) for recording index image
 data created from the input video data by the index image creating section
 58 on the optical disk 10.
 According to the pointer recording mode, the index image can be expressed
 by use of a pointer to the main image without particularly and actually
 creating an index image. Therefore, since the index image is not actually
 provided, an advantage that the disk capacity used is reduced accordingly
 can be attained. However, since the index image is displayed while it is
 created on the decoder side at the time of menu display, the disk
 searching operation is frequently effected and it takes a bit long time to
 display the user menu in comparison with the index image recording mode.
 For registration of the index image, the above two modes may be selectively
 used by the specification of the user or both of the recording modes may
 be combined. in this embodiment, a case wherein both recording modes are
 combined is explained.
 For registration of the index image, the device automatically detects the
 recording start/termination, for example, as shown in FIG. 16, images 1, 2
 of a cell-1 can be registered at the recording start time of the cell-1 or
 an image 5 of the last frame of a cell-3 can be registered at the
 recording termination time. Further, the user can register the image by
 manually effecting the key-in operation or the like while the user
 monitors the image which is now being recorded on the display screen. In
 this case, as shown by images 3, 4 in FIG. 16, a plurality of desired
 images in the cell-2 generated during the recording operation can be
 registered.
 First, the index image registration procedure in the pointer recording mode
 is explained by use of the flowchart shown in FIG. 17.
 If the user issues a registration instruction of the index image via a
 key-in section 49, the MPU in the microcomputer block 30 determines that
 the registration trigger is present as shown in the step S101, issues a
 registration trigger to the encoder section 50, receives a GOP creation
 start signal from the video encoder 53, and detects the start of the I
 picture creation operation which will be described later (step S102). The
 I picture is used as an index image and the I picture recording position
 becomes a registration point.
 The registration trigger from the MPU may be generated, for example, once
 each time the user inputs a registration instruction or the MPU may
 automatically generate the registration trigger at the time of recording
 start/termination with respect to the optical disk 10 or at the time of
 change of scenes of video or audio. It is preferable that the user can
 specify the above selection via the key-in section 49.
 Next, the MPU in the microcomputer block 30 detects the physical sector
 number M (head sector address of the I picture) which is now being
 recorded on the optical disk 10 via the disk drive 32 and data processor
 36 and stores the same in the RAM (step S103), further detects the cell
 number N of a cell which is to be defined (that is, which includes the I
 picture as the index image) and stores the same in the RAM (step S104).
 Then, the MPU in the microcomputer block 30 determines whether the
 recording operation is terminated or not according to the instruction from
 the key-in section 49 or via the disk drive 32 and data processor 36 (step
 S105). If the recording operation is not terminated, the process is
 returned and the step S101 is effected again after the elapse of preset
 time. If it is detected in the step S105 that the recording operation is
 terminated, the cell number N stored in the step S104 is registered in the
 index scene information 120 of the PGC information table 110 shown in FIG.
 8 on the optical disk 10 (step S106).
 Next, the MPU in the microcomputer block 30 searches the PGC information
 table 110 shown in FIG. 8 and determines the number (PGC information #X)
 of PGC information containing the cell number N described in the index
 scene information 120 (step S107).
 Then, the MPU in the microcomputer block 30 records the physical sector
 number M stored in the RAM in the step S103 on the optical disk 10 (step
 S108). For example, if the PGC information searched for in the step S107
 is #1, the physical sector number M is recorded in the column of the index
 scene pointer address of the index scene pointer information 134 (FIG. 13)
 of the cell playback information 130 in which the PGC information is #I.
 Basically, video data which is now being recorded on the optical disk 10 is
 continuous on the time base if the recording thereof is not interrupted
 and the continuous portion can be grouped into the same type from the
 viewpoint of the contents thereof. The grouping is effected in the unit of
 cells as described before. If the actual recording operation is
 considered, one cell is generated by the recording start and recording
 termination operations. Therefore, as the position information of the
 index image, one physical sector number M of the typical I picture of a
 desired cell may be registered.
 In the DVD specification, MPEG2 is used for video encoding. In the MPEG2
 (also, in the MPEG1), the encoding operation is effected in a cycle called
 GOP as shown in FIG. 18. An intra-coding image screen (I picture) and an
 inter-coding image screen (P picture, B picture) are contained in each
 GOP, but since the former is an image screen in which the coding is
 effected only in the image screen thereof and the latter is an image
 screen obtained by predicting the other image screen as a reference image
 screen, the latter cannot be used as an index image. Therefore, in the
 pointer recording mode of FIG. 17, the I picture is used as the index
 image and the position information thereof is set as the registration
 point as shown in FIG. 18.
 Next, the index image registration procedure by the index image recording
 mode is explained by use of the flowchart shown in FIG. 19.
 Like the case of the pointer recording mode, if the user first supplies a
 registration instruction of index image via the key-in section 49, the MPU
 in the microcomputer block 30 determines that the registration trigger is
 present as shown in the step S201 and issues a registration trigger to the
 encoder section 50. The registration trigger from the MPU may be
 generated, for example, once each time the user inputs a registration
 instruction or the MPU may automatically generate the registration trigger
 at the time of recording start/termination with respect to the optical
 disk 10 or at the time of change of scenes of video or audio. It is
 preferable that the user can specify the above selection via the key-in
 section 49.
 Next, if it is determined in the step S201 that the registration trigger is
 present, the MPU in the microcomputer block 30 detects the physical sector
 number M (head sector address of the I picture) which is now being
 recorded on the optical disk 10 via the disk drive 32 and data processor
 36 and stores the same in the RAM (step S202) and starts the index image
 creating section 58 to create an I picture to be registered as the index
 image (step S203). Then, the index image data thus created is formed into
 a packet form together with the present PGC number and stored into the
 index image buffer memory 59.
 Next, the MPU in the microcomputer block 30 determines whether the
 recording operation is terminated or not according to the instruction from
 the key-in section 49 or via the disk drive 32 and data processor 36 (step
 S205). If the recording operation is not terminated, the process is
 returned to the step S201.
 If it is detected in the step S205 that the recording operation is
 terminated, a logical address of the picture address table shown in FIG.
 20 is acquired from the volume & file management area 70 which is
 previously read out on the optical disk 10 (step S206). Then, the contents
 of the picture address, more specifically, the PGC number N, the head
 sector address of the index image actually recorded, the head sector
 address of the I picture and the like are added and updated (step S207).
 Then, the MPU in the microcomputer block 30 reads out the index image data
 which is created by the index image creation section 58 in the step S203
 and stored into the index image buffer memory 59 in the packet form and
 forms the readout index image data into a pack form. Then, the MPU records
 the index image data set into the pack form in an area (area in the
 picture object 84) on the optical disk 10 which is defined by the contents
 of the picture address table in the steps S206, S207 via the data
 processor 36 and disk drive 32 (step S208).
 Then, whether or not all of the index image data stored in the index image
 buffer memory 59 is read out is determined (S209). If index image data is
 left behind in the index image buffer 59, the PGC number N of the next
 index image is specified and the process of the steps S207, S208 is
 repeatedly effected. If all of the index image data is read out, an image
 having the playback control information 102 and volume & file management
 area 70 recorded therein as shown in FIG. 3 is sequentially updated (steps
 S211, S212) and the process is terminated.
 Next, the format of the user menu file on the optical disk 10 associated
 with the index image is explained. The user menu file is a file name of
 the reduced drawing control information 108 (the reduced drawing control
 information is hereinafter referred to as a user menu file) shown in FIG.
 3. The format of the user menu file can conceptually take a construction
 as shown in 20 and is specifically constructed as shown in FIGS. 21 and
 22.
 First, as indicated from the top to the bottom in FIG. 20, data in the user
 menu file 108 is described in the order of a first anchor pointer, picture
 address table, index image data group, backup of the picture address table
 and second anchor pointer.
 A pointer address called the first anchor pointer (a, p, b, q) is first set
 in the user menu file, and "a" and "p" are a start address and end address
 of the picture address table and "b" and "q" are a start address and end
 address of backup data of the picture address table.
 Next to the first anchor pointer, the picture address table is recorded.
 Menu index information (INFO1) is recorded in the first position of the
 picture address table. The menu index information contains the number of
 index pictures, the number of information pictures, the number of
 defective areas and the number of wall paper picture registering sheets.
 Among them, the number of information pictures indicates the number of
 registered sheets of index images recorded in the pointer recording mode
 (the image is called an information picture). The number of index pictures
 is equal to the total sum of the number of index images recorded in the
 index image recording mode and the number of information pictures.
 The "correlation table between PGC and index image recording position" set
 after the menu index information is actual data relating to each index
 image constructing the user menu file and the PGC number (PGCN) of the
 index image, PTS (the playback timing of the I picture as the index
 image), the head address (c) of the index image, the number of use sectors
 of the index image including the dummy area, the size only of the index
 image, the head address (pointer) of the I picture as the index image,
 text data used for searching and entitling, the head address and data
 length of a defective area if the defective area is present in the file,
 the number of wall paper picture registering sheets of the user menu and
 the head address (s) thereof and the like are recorded in this portion.
 The total data amount of the picture address table is aligned with 32
 kbytes (32k.times.N bytes) as will be described later.
 After the picture address table, an actual index image data group created
 in the index image data creation section 58 shown in FIG. 15 is recorded.
 Further, after the correlation table, the backup of the picture address
 table is recorded. The backup is recorded for insurance against breakage
 of the picture address table. The index image data and backup are formed
 in a pack form and are actually recorded in the picture object 84 shown in
 FIG. 3. The index image and backup are also aligned with 32 kbytes as will
 be described later.
 In the last position of the user menu file, a second anchor pointer (a, p,
 b, q) which is the same as the first anchor in the head position of the
 user menu file is described. The reason for this arrangement is that the
 file is normally destroyed from the head management area to which access
 is frequently made. By setting the anchor pointer in the last position of
 the file, the safety is further enhanced.
 The user menu file of FIG. 20 has the following features.
 (1) At least one menu selection index image data (that is, index image
 data) which expresses a still image of at least part of video data is
 recorded in the same user menu file.
 (2) All of the index image data items recorded on the optical disk 10
 (DVD-RAM disk, DVD-RW disk or DVD-R disk) are collectively managed (a
 video signal corresponding to the recording position is specified) by use
 of the picture address table.
 More specifically, information shown in FIGS. 21, 22, for example, is
 written into the user menu file of FIG. 20. That is, as shown in FIGS. 21,
 22, as the first anchor pointer for the picture address table, the start
 position of the picture address table, the end position of the picture
 address table, the start position of a spare picture address table and the
 end position of the spare picture address table are described. AS the
 picture address table (corresponding to 108B of FIG. 3), menu index
 information (INFO1), a plurality of index picture information items
 (INFO2), defective area information (INFO4), wall paper picture
 information (INFO5) and padding data are described. As the second anchor
 pointer for the picture address table, the start position of the picture
 address table, the end position of the picture address table, the start
 position of the backup of the picture address table and the end position
 of the backup of the picture address table are described. In the picture
 address table shown in FIGS. 21, 22, the information picture information
 INFO3 shown in FIG. 3 may be adequately described.
 Menu index information of FIG. 21 contains the number of index pictures,
 the number of information pictures, the number of defective areas and the
 number of wall paper pictures. Index picture information contains the
 contents characteristic, ID of the index picture program chain, the time
 code of the index picture, the start position of the index picture, the
 number of sectors used for recording the index picture, the picture size,
 and the address and searching text data of the index picture (I picture).
 As the time code of the index picture, PTS of the head sector of the I
 picture is described. However, it is possible to describe the number of
 fields and the number of pictures (the number of fields.times.2) as the
 time code. Further, a picture which can be specified as the index picture
 is not limited to the I picture, but it is possible to specify the P
 picture or B picture (that is, specify the field number) to derive the I
 picture as will be described in another embodiment.
 In the contents characteristic contained in the index picture information,
 "1" is described if the index image used in the user menu is already
 recorded and "0" is described if only the recording position (address) of
 the index image is recorded.
 The index picture information in a case where a user menu image is
 specified only by use of an address contains the contents characteristic
 in which "0" is described as shown in FIG. 22, ID of the information
 picture program chain PGC, the time code in the PGC corresponding to the
 information picture, and an address of the PGC corresponding to the
 information picture.
 The wall paper picture information of FIG. 22 contains the number of wall
 paper pictures which can be used as the wall paper picture of the user
 menu (the number of a registered wall paper picture), the start position
 of the wall paper picture, and the number of sectors used in an area in
 which the wall paper picture is recorded and the padding data of FIG. 22
 contains the contents of the index picture, the contents of the defective
 area and the contents of the wall paper picture.
 Next, the "32-kbyte aligning process" is explained.
 The internal portion of the user menu file shown in FIGS. 20 to 22 is
 divided for every 32 kbytes corresponding to a unit of error correction
 code (ECC block) irrespective of the already recorded area and
 non-recorded area and the position of the "ECC boundary" which is the
 boundary portion thereof is previously determined.
 When the index image data, anchor pointer, picture address table and backup
 of the picture address table are recorded, the recording start position
 and the recording end position of all of the data items are recorded to
 coincide with the "ECC boundary" positions.
 If the data amount is slightly smaller than an integral number of 32
 kbytes, a "dummy area" is added as shown in FIG. 20 so as to make the
 recording end position coincident with the "ECC boundary" position. The
 "dummy area" indicates the "padding" area in FIG. 21.
 At the time of recording/erasing of index image data, the recording/erasing
 operation of information is effected for each "ECC boundary". In this
 case, since it is not necessary to change part of information in the ECC
 block, reduced data can be directly overwritten in alignment with the ECC
 boundary at the recording time.
 If the "32-kbyte aligning process" described above is effected, the
 operation speed of the recording/erasing operation in the unit of ECC
 block can be enhanced since it becomes unnecessary to correct error
 correction information which is added to record/erase the index image data
 in the unit of ECC block.
 The user menu file of FIG. 20 is designed by considering the transportation
 to another type of recording medium by use of a personal computer or the
 like. Therefore, the storage addresses of the index image, wall paper
 picture and picture address table of the user menu are expressed by
 difference addresses (relative addresses) from the head position of the
 user menu file.
 In the "correlation table between PGC and index image recording position"
 in the picture address table of FIG. 20, two lines from the PGC number to
 the searching text data size express one set of correspondence tables. In
 this case, the relation between the recorded index image data and the
 video signal can be understood based on the correspondence relation
 between the time code (PTS) of the video signal and the head address.
 Further, by searching the whole correlation table, the non-recorded area
 in the user menu file or the free area obtained by erasing index image
 data can be detected and new index image data can be recorded in the area.
 In the user menu file of FIG. 20, a defective area is managed. A specific
 processing method effected in a case where the picture address table is
 damaged by dust or scratches attached to the surface of the disk
 (recording medium) 10 is explained.
 First, the damage of the picture address table due to the dust or scratch
 on the surface of the disk (recording medium) is detected (whether it is
 damaged or not can be determined according to whether the error correction
 of the ECC block fails or not).
 When the damage is detected, anchor pointer information is read out, the
 backup data address of the picture address table is checked and the backup
 data of the picture address table is read out.
 Next, the non-recorded area in the user menu file is searched for by use of
 the correlation table between the index image recording positions of FIG.
 20. Then, index image management data is recorded in the non-recorded area
 in the user menu file and the address information of the anchor pointer is
 updated.
 Then, the location in which the picture address table is damaged by the
 dust or scratch on the surface of the disk (recording medium) is
 registered as a defective area in the correlation table between the index
 image recording positions of FIG. 20.
 If the user menu file format of FIGS. 20 to 22 is used, the following
 effect can be expected.
 (a) The index image data can be added/searched and the access speed can be
 enhanced by effecting the "32-kbyte aligning process".
 (b) When a plurality of index images are simultaneously displayed on the
 display section of a monitor display (not shown), it becomes necessary to
 access a corresponding index image data position on the recording medium
 for each reduced image screen. If index position data items are randomly
 arranged (scattered) on the recording medium, it takes a long time to
 access and time required for displaying the plurality of index images
 becomes long. However, as shown in FIG. 20, if the plurality of index
 manage data items are collectively arranged in the same user menu file,
 the plurality of index images can be displayed at high speed simply by
 playing back the user menu file.
 (c) By collectively managing the whole index image data by use of the
 picture address table, the management of the process for deleting or
 adding the index image data becomes easier. That is, the searching
 operation for the non-recorded area (or the index image data deleting
 area) in the user menu file becomes easier and additional registration of
 new index image data can be effected at high speed.
 (d) In the DVD video recorder shown in FIG. 15, data is collected for every
 16 packs (=32 kbytes) to make an ECC block in the data processor 36 and
 the ECC block is recorded on the optical disk (DVD-RAM, DVD-RW or DVD-R)
 10 after error correction information is attached thereto. Therefore, if
 part of information in the ECC block is changed, it is necessary to
 correct the attached error correction information, the process becomes
 troublesome and it takes a long time to effect the information changing
 process. However, by effecting the "32-kbyte aligning process", correction
 of the error correction information attached when the index image data is
 erased in the unit of ECC block is made unnecessary and the user menu data
 can be erased at high speed.
 (e) The high reliability of the anchor pointer, picture address table and
 backup data of the picture address table can be securely attained by the
 following method.
 * Secure attainment of the reliability of the picture address table
 A backup area of the picture address table is provided to make ready for a
 case wherein the picture address table becomes defective and if the defect
 occurs, the recording location can be moved.
 * Secure attainment of the reliability of the anchor pointer information
 indicating the recording location of the picture address table
 The anchor pointer information is independently constructed in an ECC block
 to suppress the data changing times and the same information is recorded
 in two locations (first and second anchor pointers in FIG. 20).
 * Defect management process
 In a case where information playback from the picture address table or
 anchor pointer becomes impossible due to the dust or scratch on the
 surface of the optical disk (recording medium), data is read out from the
 backup section and recorded in another recording position again. As a
 result, it is prevented that the defective area is registered and the
 defective area is erroneously used again.
 A closed caption or multiplexed character is superposed on the original
 image in the index image data used for the user menu in some cases. In
 such a case, the index image may be constructed after the character is
 multiplexed. Further, it is considered that the index image may be
 constructed only by use of character data.
 FIG. 23 shows a concrete display example of the menu screen obtained by use
 of the index image registered on the optical disk 10 in this embodiment.
 In this example, an image of a map of the entire area of Africa as an
 image 1, images of maps of discrete countries as images 2, 3 are displayed
 in the form of a list. The menu screen is displayed by depressing a menu
 key in the key-in section 49. The user selects an image of a desired
 number in the screen so as to search for the position on the optical disk
 10 on which the selected image is recorded and edit the same. Further, by
 displaying the time code from the head point together with the images 1,
 2, . . . as shown in FIG. 23, a period of time from the playback start
 time in which the image is displayed can be derived from the recorded
 image.
 Next, another embodiment of this invention is explained. In this
 embodiment, as shown in FIG. 24, a plurality of cells 94 are collected to
 construct groups of programs (PG) 201 and the playback image is controlled
 in the unit of program. The position of the index image is specified by
 the cell number in the program and the display time (the number of fields)
 of the index image to be registered.
 In this embodiment, as shown in FIG. 25, program playback information 202
 is inserted between PGC general information 128 and cell playback
 information 130 in the format shown in FIG. 8. The contents of the program
 playback information 202 include program type information 204, the number
 206 of cells contained in the program, text information 208 and index
 image position information 210 and the position of the index image is
 specified by the cell number and the display time thereof (the number of
 fields) as shown in FIG. 26.
 FIG. 27 is a flowchart showing the procedure for registering the display
 time on the optical disk. First, the MPU in the microcomputer block 30
 determines whether or not the registration trigger is present as shown in
 the step S301. If the registration trigger is present, the MPU detects and
 holds the display time of the picture which is now being recorded on the
 optical disk 10, that is, the number F of fields in the program (PG) which
 is now being recorded (step S302). Then, the MPU detects and holds the
 cell number which is now to be defined (step S303).
 Whether or not the recording operation is terminated is determined in the
 step S304 and if it is not terminated, the step S302 is effected again. If
 it is determined in the step S304 that the recording operation is
 terminated, the MPU in the microcomputer block 30 registers the cell
 number N and field number F held in the steps S303 and 302 into the cell
 number 212 and index image display time of the program playback
 information 202 of FIG. 25.
 If other pointers (cell number and field number) are further held (step
 306), the step S305 is effected again and all of the pointers held are
 registered into the index image position information 210 of the optical
 disk.
 In the former embodiment, the index image is used to specify the head
 address of the I picture, but this embodiment is not limited to this case
 and it is possible to specify the B picture or P picture.
 FIG. 28 shows the relation between VOBU and the field in MPEG. An area from
 an I picture to a next I picture is collected as VOBU. The number of
 pictures in one second is determined to be 30 in the NTSC system. Since
 one picture corresponds to two fields, 60 fields are displayed in one
 second. In this example, an area from an I picture to a next I picture is
 defined as one GOP. However, one VOBU is not limited to one GOP and may
 include a plurality of GOPs in some cases.
 A time map table 111 as shown in FIG. 29 is recorded in the playback
 control information 102 of FIG. 6 to indicate the relation between the
 display time of each picture and the recording address on the optical disk
 for each VOBU. If the playback time (field) of each picture is specified,
 the position address on the optical disk on which it is recorded can be
 calculated.
 FIG. 30 is a flowchart showing the calculation procedure. First, the MPU in
 the microcomputer block 30 reads out the specified field number from the
 index image display time of the program playback information 202 of FIG.
 25 (step S401). Then, the number of the field is sequentially added
 starting from the first VOBU of the time map table 111 of FIG. 29 to
 derive the VOBU number which contains the specified field number (step
 S402).
 Next, the head address of VOBU which contains the specified field number is
 calculated from the time map table 111. As shown in FIG. 28, since data of
 the I picture is recorded in the head address of VOBU, the MPU in the
 microcomputer block 30 accesses the head address of VOBU and displays the
 I picture as the index image (step S404).
 In the above embodiments, registration of the index image is explained, but
 this invention can also be similarly applied to a case wherein specified
 audio data is registered.
 Further, this invention is not limited to the recording/playback apparatus,
 but can be applied to a playback apparatus, that is, playback-only
 apparatus having no recording function.
 As described above, according to this invention, the user can instantly
 detect the recording information on the recording medium by recording
 position information (pointer) indicating the recording position of an
 image selected from the main record data on the recording medium or
 recording an image selected from the main record data as the index image,
 and utilizing information of an image and voice recorded in the recording
 position indicated by the position information or the index image as a
 menu at the time of playback. Therefore, the user can rapidly search for a
 desired position based on the menu and efficiently effect the editing
 operation such as the operation for erasing and replacing information in a
 desired area on the recording medium.