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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a recording medium, such as an optical disk, for recording compressed moving picture data, audio data and the like or different kinds of data, an apparatus and method of recording data on this recording medium,
and an apparatus and method of reproducing data from the same.
2. Description of the Related Art
Recently, optical disk players, which can handle moving pictures and play optical disks on which picture and audio data are digitally recorded, have been developed, and are widely used as players for movie software, karaoke and so forth.
Further, MPEG (Moving Picture Image Coding Expert Group) standards have recently become international standards for a data compression system for moving pictures. This MPEG system performs variable length compression of picture data.
The MPEG2 system is now also being internationally standardized, so that the system format which matches with the MPEG compression system is defined as an MPEG2 system layer. This MPEG2 system layer defines the setting of a transfer start time
and a playback start time, expressed by using a reference time, in moving picture data, audio data and other data, so that those data can be transferred and reproduced synchronously. Playback is normally executed using this information.
With the increasing availability of optical disks designed for multiple uses, it is not sufficient to consider only the synchronism among individual pieces of data.
For educational purposes, such as learning languages, for example, main picture data used as video data may present questions to users, while sub-picture data superimposed on the picture may give answers to the users. In this case, it is
significant to show answers after, and not before or during the time questions are given.
SUMMARY OF THE INVENTION
Accordingly, it is a primary object of the present invention to provide a recording medium on which various types of data, such as main picture data, audio data and sub-picture data, constructed in a reproducible manner, are recorded in such a
way that the sub-picture data can be reproduced after a predetermined time delay with respect to the main picture data.
It is a secondary object of the present invention to provide a method and apparatus of reproducing data from a recording medium on which various types of data, such as main picture data, audio data and sub-picture data, constructed in a
reproducible manner, are recorded in such a way that the sub-picture data can be reproduced with a predetermined time delay after respect to the main picture data.
It is a third object of the present invention to provide a method and apparatus of recording various types of data, such as main picture data, audio data and sub-picture data, constructed in a reproducible manner, in such a way that the
sub-picture data can be reproduced with a predetermined time delay after respect to the main picture data.
It is a fourth object of the present invention to provide a method and apparatus of reproducing various types of data, such as main picture data, audio data and sub-picture data, constructed in a synchronously reproducible manner, in such a way
that the sub-picture data can be reproduced after a predetermined time delay, preset in a machine, with respect to the main picture data.
It is a fifth object of the present invention to provide a method and apparatus of reproducing various types of data, such as main picture data, audio data and sub-picture data, constructed in a synchronously reproducible manner, in such a way
that the sub-picture data is reproduced after a delay time, arbitrarily set using a menu screen, with respect to the main picture data.
It is a sixth object of the present invention to provide a method and apparatus of reproducing various types of data, such as main picture data, audio data and sub-picture data, constructed in a synchronously reproducible manner, in such a way
that the sub-picture data is reproduced after a delay time, computed from the difference between the display start time given in sub-picture data for one still picture and the display end time, with respect to the main picture data.
It is a seventh object of the present invention to provide a method and apparatus of displaying pictures in such a way that at the time of reproducing superimposition data or the like as sub-picture data after an arbitrary time delay, with
respect to main picture data belonging to various types of data, such as main picture data, audio data and sub-picture data, constructed in a reproducible manner, the superimposition data or the like appears as if hidden by a mosaic or a black filler
during the delay period.
To achieve the above object, the present invention includes a recording medium comprising a plurality of data units recorded thereon, which become objects to be reproduced in a time sequential manner, each object being reproduced within a given
time period; each of the data units being constituted of a stream of a plurality of data packs and playback time information, the data packs containing packets of reproduction data including at least one of audio data, video data and sub-picture data;
the time information of that data unit which includes a sub-picture being later by a predetermined time than time information of that data unit which includes audio data or video data; reproduction data of the data unit including the sub-picture being
reproduced after reproduction of reproduction data of the data unit including the audio data or video data.
The present invention also includes a recording apparatus for recording reproduction data on a recording medium, comprising: means for generating a plurality of data packs and playback time information, the data packs containing packets of
reproduction data including at least one of audio data, video data and sub-picture data; means for preparing a plurality of data units including playback time information and having a stream of data packs to be reproduced within a given time period as a
unit; and means for recording the data units on the recording medium in a time-sequentially reproducible manner, time information of that data unit which includes a sub-picture to be reproduced within the given time period being later by a predetermined
time than time information of that data unit which includes audio data or video data to be reproduced within the given time period.
The present invention further includes a method of recording reproduction data on a recording medium, comprising the steps of: generating a plurality of data packs containing packets of reproduction data including at least one of audio data,
video data and sub-picture data; preparing a plurality of data units including playback time information and having a stream of data packs to be reproduced within a given time period as a unit; and recording the data units on the recording medium in a
time-sequentially reproducible manner, time information of that data unit which includes a sub-picture to be reproduced within the given time period being later by a predetermined time than time information of that data unit which includes audio data or
video data to be reproduced within the given time period.
The present invention also includes a reproducing apparatus for reproducing reproduction data from a recording medium, comprising: means for acquiring, from the recording medium, a plurality of data units recorded thereon, which become objects to
be reproduced in a time sequential manner, each object being reproduced within a given time period, each of the data units being constituted of a stream of a plurality of data packs and playback time information, the data packs containing packets of
reproduction data including at least one of audio data, video data and sub-picture data, time information of that data unit which includes a sub-picture to be reproduced within a given time period being later by a predetermined time than time information
of that data unit which includes audio data or video data to be reproduced within the given time period; and means for converting the data unit of the acquired reproduction data to a reproduction signal in accordance with the time information included in
the data unit and reproducing the reproduction signal, whereby after reproduction data of that data unit which includes audio data or video data to be reproduced within a given time period is reproduced, the reproducing means reproduces reproduction data
of the data unit including the sub-picture to be reproduced within the given period.
The present invention also includes a reproducing apparatus for reproducing reproduction data from a recording medium, comprising: means for acquiring, from the recording medium, a plurality of data units recorded thereon, which become objects to
be reproduced in a time sequential manner, each object being reproduced within a given time period, each of the data units being constituted of a stream of a plurality of data packs and playback time information, the data packs containing packets of
reproduction data including at least one of audio data, video data and sub-picture data; and means for converting the data unit of the acquired reproduction data to a reproduction signal in accordance with the time information included in the data unit
and reproducing the reproduction signal, whereby after reproduction data of that data unit which includes audio data or video data to be reproduced within a given time period is reproduced, the reproducing means reproduces reproduction data of the data
unit including the sub-picture to be reproduced within the given period when a predetermined time previously set elapses.
The present invention also includes a reproducing apparatus for reproducing reproduction data from a recording medium, comprising: means for acquiring, from the recording medium, a plurality of data units recorded thereon, which become objects to
be reproduced in a time sequential manner, each object being reproduced within a given time period, each of the data units being constituted of a stream of a plurality of data packs and playback time information, the data packs containing packets of
reproduction data including at least one of audio data, video data and sub-picture data; means for setting a delay time at which reproduction data of that data unit which includes a sub-picture to be reproduced within a given time period after
reproduction data of that data unit which includes audio data or video data to be reproduced within the given time period is reproduced; and means for converting the data unit of the acquired reproduction data to a reproduction signal in accordance with
the time information included in the data unit and reproducing the reproduction signal, whereby after reproduction data of that data unit which includes at least one of audio data and video data to be reproduced within a given time period is reproduced,
the reproducing means reproduces reproduction data of the data unit including the sub-picture to be reproduced within the given period when the set delay time elapses.
The present invention also includes apparatus for reproducing reproduction data from a recording medium, comprising: means for acquiring, from the recording medium, a plurality of data units recorded thereon, which become objects to be reproduced
in a time sequential manner, each object being reproduced within a given time period, each of the data units being constituted of a stream of a plurality of data packs and playback time information, the data packs containing packets of reproduction data
including at least one of audio data, video data and sub-picture data, the time information of that data unit which includes a sub-picture consisting of a playback start time and playback stop time; means for computing a delay time of the data unit
including the sub-picture from the playback start time and playback stop time recorded in the data unit including the sub-picture of the acquired reproduction data; and means for converting the data unit of the acquired reproduction data to a
reproduction signal in accordance with the time information included in the data unit and reproducing the reproduction signal, whereby after reproduction data of that data unit which includes at least one of audio data and video data to be reproduced
within a given time period is reproduced, the reproducing means reproduces reproduction data of the data unit including the sub-picture to be reproduced within the given period when the computed delay time elapses.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention
may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the invention and, together with the general description given above and the detailed description of
the preferred embodiments given below, serve to explain the principles of the invention.
FIG. 1 is a schematic block diagram of an optical disk apparatus according to the first embodiment of the present invention;
FIG. 2 is a detailed block diagram of the mechanical section of the disk drive unit of FIG. 1;
FIG. 3 is a schematic perspective view of the structure of an optical disk loaded in the disk drive unit of FIG. 1;
FIG. 4 shows the structure of the logic format of the optical disk of FIG. 3;
FIG. 5 shows the structure of the video manager of FIG. 4;
FIG. 6 shows an example of the structure of the video object set (VOBS) shown in FIG. 5;
FIG. 7 is a diagram to help explain the structure of the video object unit of FIG. 6;
FIG. 8 shows the parameters and contents of the volume manger information management table (VMGI.sub.-- MAT) in the video manager (VMGI) of FIG. 5;
FIG. 9 shows the structure of the title search pointer table (TSPT) in the video manager (VMGI) of FIG. 5;
FIG. 10 shows the parameters and contents of the title search pointer table information (TSPTI) in the title search pointer table (TSPT) of FIG. 9;
FIG. 11 shows the parameters and contents of the title search pointer (TT.sub.-- SRP) corresponding to the input number in the title search pointer table (TSPT) of FIG. 9;
FIG. 12 illustrates the structure of the video title set of FIG. 4;
FIG. 13 shows the parameters and contents of the video title set information management table (VTSI.sub.-- MAT) of the video title set information (VTSI) of FIG. 12;
FIG. 14 illustrates the structure of the video title set program chain information table (VTS.sub.-- PGCIT) of the video title set information (VTSI) of FIG. 12;
FIG. 15 shows the parameters and contents of the information (VTS.sub.-- PGCITI) in the video title set program chain information table (VTS.sub.-- PGCIT) of FIG. 14;
FIG. 16 shows the parameters and contents of the search pointer (VTS.sub.-- PGCIT.sub.-- SRP) corresponding to the program chain in the video title set program chain information table (VTS.sub.-- PGCIT) of FIG. 14;
FIG. 17 illustrates the structure of the program chain information (VTS.sub.-- PGCI) in the video set corresponding to the program chain in the video title set program chain information table (VTS.sub.-- PGCIT) of FIG. 14;
FIG. 18 shows the parameters and contents of the program chain general information (PGC.sub.-- GI) in the program chain information (VTS.sub.-- PGCI) of FIG. 17;
FIG. 19 illustrates the structure of a program chain map (PGC.sub.-- PGMAP) of the program chain information (VTS.sub.-- PGCI) of FIG. 17;
FIG. 20 shows the parameters and contents of the entry cell numbers (ECELLN) corresponding to the programs written in the program chain map (PGC.sub.-- PGMAP) of FIG. 19;
FIG. 21 illustrate the structure of the cell playback information table (C.sub.-- PBIT) of the program chain information (VTS.sub.-- PGCI) of FIG. 17;
FIG. 22 shows the parameters and contents of the cell playback information table (C.sub.-- PBIT) of FIG. 21;
FIG. 23 illustrates the structure of the cell position information (C.sub.-- POSI) in the program chain information (VTS.sub.-- PGCI) of FIG. 18;
FIG. 24 shows the parameters and contents of the cell position information (C.sub.-- POSI) of FIG. 23;
FIG. 25 illustrates the structure of the navigation pack of FIG. 23;
FIG. 26 illustrates the structure of the video, audio, sub-picture, or VBI pack of FIG. 6;
FIG. 27 shows the parameters and contents of the presentation control information (PCI) in the navigation pack of FIG. 26;
FIG. 28 shows the parameters and contents of the general information (PCI.sub.-- GI) in the presentation control information (PCI) of FIG. 27;
FIG. 29 shows the parameters and contents of the disk search information (DSI) in the navigation pack of FIG. 26;
FIG. 30 shows the parameters and contents of the DSI general information (DSI.sub.-- GI) in the disk search information of FIG. 29;
FIG. 31 shows the parameters and contents of the synchronizing playback information (SYNCI) on the video object (VOB) of FIG. 29;
FIG. 32 shows the structure of a sub-picture unit;
FIG. 33 shows parameters and contents of a sub-picture unit header (SPUH) of the sub-picture unit shown in FIG. 32;
FIG. 34 shows the parameters and contents of a display control sequence table (DCSQT) of the sub-picture unit shown in FIG. 32;
FIG. 35 shows the parameters and contents of a display control sequence (DCSQ) shown in FIG. 34;
FIGS. 36A through 36L present a timing chart for explaining the relationship among an input clock, output clock, PTS and DTS for use in the reproduction of video data, audio data and sub-picture data;
FIG. 37 illustrates the structure of the video buffer section shown in FIG. 1;
FIG. 38 illustrates the structure of the video decoder section shown in FIG. 1;
FIG. 39 illustrates the structure of the audio decoder section shown in FIG. 1;
FIG. 40 illustrates the structure of the sub-picture decoder section shown in FIG. 1;
FIG. 41 is a flowchart illustrating the procedures of reproducing video data, audio data and sub-picture data;
FIG. 42 is a flowchart illustrating the detailed reproduction procedures;
FIGS. 43A through 43C show the output states of video data, audio data and sub-picture data in the reproduction process illustrated in FIG. 41;
FIG. 44 is a block diagram schematically showing an optical disk apparatus according to the second embodiment of this invention;
FIGS. 45A through 45M present a timing chart for explaining the relationship among an input clock, output clock, PTS and DTS for use in the reproduction of video data, audio data and sub-picture data according to this second embodiment;
FIG. 46 is a flowchart illustrating the procedures of reproducing video data, audio data and sub-picture data by the optical disk apparatus shown in FIG. 44;
FIGS. 47A and 47B show display examples of a menu on a key/display section according to the third embodiment of this invention;
FIG. 48 is a flowchart illustrating the procedures of reproducing video data, audio data and sub-picture data according to the third embodiment;
FIGS. 49A through 49M present a timing chart for explaining the relationship among an input clock, output clock, PTS and DTS for use in the reproduction of video data, audio data and sub-picture data according to this fourth embodiment;
FIG. 50 is a flowchart illustrating the procedures of reproducing video data, audio data and sub-picture data by the optical disk apparatus shown in FIG. 48;
FIGS. 51A through 51C show the output states of video data, audio data and sub-picture data at the time superimposition is displayed after a phrase;
FIGS. 52A through 52C show the output states of video data, audio data and sub-picture data at the time of displaying superimposition before freezing the video and audio;
FIGS. 53A through 53C show the output states of video data, audio data and sub-picture data at the time sounds for only a phrase portion are reproduced with some delay and the video image and sub-picture are frozen;
FIGS. 54A through 54C show the output states of video data, audio data and sub-picture data at the time the second sound is reproduced with some delay and the video image, sub-picture and first sound are frozen;
FIGS. 55A through 55C show the output states of video data, audio data and sub-picture data at the time the first sound and sub-picture are reproduced with some delay and the video image and second sound are frozen;
FIGS. 56A through 56C show the output states of video data, audio data and sub-picture data at the time the second sub-picture is reproduced with some delay and the video image, sounds and the first sub-picture are frozen;
FIG. 57 is a block diagram schematically showing an optical disk apparatus according to another embodiment;
FIGS. 58A and 58B show the output states of video data, audio data and sub-picture data at the time of presenting the mosaic display of sub-pictures for a delay time;
FIG. 59 is a block diagram of an encoder system that encodes the video data and generates a video file;
FIG. 60 is a flowchart for an encoding process of FIG. 59;
FIG. 61 is a flowchart for combining the main video data, audio data, and sup-picture data all encoded according to the flow of FIG. 60 to create a video data file;
FIG. 62 is a block diagram of a disk formatter system that records the formatted video files on an optical disk;
FIG. 63 is a flowchart for creating logic data to be recorded on a disk in the disk formatter of FIG. 62;
FIG. 64 is a flowchart for creating from the logic data the physical data to be recorded on a disk; and
FIG. 65 is a schematic diagram of a system that transfers the video title set of FIG. 4 via a communication route.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, referring to FIGS. 1 through 43C, an optical disk reproducing apparatus according to the first embodiment of the present invention will be explained.
FIG. 1 is a block diagram of an optical disk reproducing apparatus that reproduces the data from an optical disk associated with an embodiment of the present invention. FIG. 2 is a block diagram of the disk drive section that drives the optical
disk shown in FIG. 1. FIG. 3 shows the structure of the optical disk shown in FIGS. 1 and 2.
As shown in FIG. 1, the optical disk reproducing apparatus comprises a key/display section 4, a monitor section 6, and a speaker section 8. When the user operates the key/display section 4, this causes the recorded data to be reproduced from an
optical disk 10. The recorded data contains video data, sub-picture data, and audio data, which are converted into video signals and audio signals. The monitor section 6 displays images according to the audio signals and the speaker section 8 generates
sound according to the audio signals.
It is known that the optical disk 10 is available with various structures. For instance, one type of the optical disk 10 is a read-only disk on which data is recorded with a high density as shown in FIG. 3. The optical disk 10, as shown in FIG.
3, is made up of a pair of composite layers 18 and an adhesive layer 20 sandwiched between the composite disk layers 18. Each of the composite disk layers 18 is composed of a transparent substrate 14 and a recording layer or a light-reflecting layer 16. The disk layer 18 is arranged so that the light-reflecting layer 16 may be in contact with the surface of the adhesive layer 20. A center hole 22 is made in the optical disk 10. On the periphery of the center hole 22 on both sides, clamping areas 24
are provided which are used to clamp the optical disk 10 during its rotation. When the disk 10 is loaded in the optical disk apparatus, the spindle of a spindle motor 12 shown in FIG. 2 is inserted into the center hole 22. As long as the disk is being
rotated, it continues to be clamped at the clamping areas 24.
As shown in FIG. 3, the optical disk 10 has an information zone 25 around the clamping zone 24 on each side, the information zones allowing the information to be recorded on the optical disk 10. In each information area 25, its outer
circumference area is determined to be a lead-out area 26 in which no information is normally recorded, its inner circumference area adjoining the clamping area 24 is determined to be a lead-in area 27 in which no information is normally recorded, and
the area between the lead-out area 26 and the lead-in area 27 is determined to be a data recording area 28.
At the recording layer 16 in the information area 25, a continuous spiral track is normally formed as an area in which data is to be recorded. The continuous track is divided into a plurality of physical sectors, which are assigned serial
numbers. On the basis of the sectors, data is recorded. The data recording area 28 in the information recording area 25 is an actual data recording area, in which management data, main video data, sub-picture data, and audio data are recorded in the
form of pits (that is, in the form of changes in the physical state) as explained later. With the read-only optical disk 10, a train of pits is previously formed in the transparent substrate 14 by a stamper, a reflecting layer is formed by evaporation
on the surface of the transparent substrate 14 in which the pit train is formed, and the reflecting layer serves as the recording layer 16. In the read-only optical disk 10, a groove is normally not provided as a track and the pit train in the surface
of the transparent substrate 14 serves as a track.
The optical disk apparatus 12, as shown in FIG. 1, further comprises a disk drive section 30, a system CPU section 50, a system ROM/RAM section 52, a system processor section 54, a data RAM section 56, a buffer control STC control section 57, a
video decoder 58, a video buffer section 59, an audio decoder section 60, an audio buffer section 61, a sub-picture decoder section 62, a sub-picture buffer section 63, a mixing section 64, a video D/A section 66 and an audio D/A section 68.
As shown in FIG. 2, the disk drive section 30 contains a motor driving circuit 11, a spindle motor 12, an optical head 32 (i.e., an optical pickup), a feed motor 33, a focus circuit 36, a feed motor driving circuit 37, a tracking circuit 38, a
head amplifier 40, and a servo processing circuit 44. The optical disk 10 is placed on the spindle motor 12, driven by the motor driving circuit 11 and is rotated by the spindle motor 12. The optical head 32 that projects a laser beam on the optical
disk 10 is located under the optical disk 10. The optical head 32 is placed on a guide mechanism (not shown). The feed motor driving circuit 37 is provided to supply a driving signal to the feed motor 33. The motor 33 is driven by the driving signal
and moves in and out the optical head 32 across the radius of the optical disk 10. The optical head 32 is provided with an object lens 34 positioned to face the optical disk 10. The object lens 34 is moved according to the driving signal supplied from
the focus circuit 36 to move along its optical axis.
To reproduce the data from the above optical disk, the optical head 32 projects a laser beam on the optical disk 10 via the object lens 34. The object lens 34 is moved little by little across the radius of the optical disk 10 according to the
driving signal supplied from the tracking circuit 38. Furthermore, the object lens 34 is moved along its optical axis according to the driving signal supplied from the focusing circuit 36 so that its focal point may be positioned on the recording layer
16 of the optical disk 10. This causes the laser beam to form the smallest beam spot on the spiral track (i.e., the pit train), enabling the beam spot to trace the track. The laser beam is reflected from the recording layer 16 and returned to the
optical head 32. The optical head 32 converts the beam reflected from the optical disk 10 into an electric signal, which is supplied from the optical head 32 to the servo processing circuit 44 via the head amplifier 40. From the electric signal, the
servo processing circuit 44 produces a focus signal, a tracking signal, and a motor control signal and supplies these signals to the focus circuit 36, tracking circuit 38, and motor driving circuit 11, respectively.
Therefore, the object lens 34 is moved along its optical axis and across the radius of the optical disk 10, its focal point is positioned on the recording layer 16 of the optical disk 10, and the laser beam forms the smallest beam spot on the
spiral track. Furthermore, the spindle motor 12 is rotated by the motor driving circuit 11 at a specific rotating speed. This allows the beam to track at, for example, a constant linear speed.
The system CPU section 50 of FIG. 1 supplies to the servo processing circuit 44 a control signal serving as an access signal. In response to the control signal, the servo processing circuit 44 supplies a head-moving signal to the feed motor
driving circuit 37, which supplies a driving signal to the feed motor 33. Then, the feed motor 33 is driven, causing the optical head 32 to move across the radius of the optical disk 10. Then, the optical head 32 accesses a specific sector formed at
the recording layer 16 of the optical disk 10. The data is reproduced from the specific sector by the optical head 32, which then supplies it to the head amplifier 40. The head amplifier 40 amplifies the reproduced data, which is outputted at the disk
drive section 30.
The reproduced data is transferred and stored in a data RAM section 56 by the system processor section 54 which is controlled by the system CPU section 50 which is operated in accordance with the programs stored in the system ROM/RAM section 52.
The stored reproduced data is processed at the system processor section 54, which sorts the data into video data, audio data, and sub-picture data. The video data is sent via the video buffer section 59 to the video decoder section 58 to be decoded, the
audio data is sent via the audio buffer section 61 to the audio decoder section 66 to be decoded, and the sub-picture data is sent via the sub-picture buffer section 63 to the sub-picture decoder section 62 to be decoded. The decoded video data and
sub-picture data are mixed by the mixing section 64, and the resultant data is converted to an analog video signal by the video D/A section 66. This analog video signal is then supplied to the monitor section 6. The audio data is converted by the audio
D/A section 68 to an audio signal which is supplied to the speaker section 8. Then, on the basis of the video signal, an image is displayed on the monitor section 6 and according to the audio signal, sound is simultaneously reproduced from the speaker
section 8.
The detailed operation of the optical disk apparatus of FIG. 1 will be described later with reference to the logic format of the optical disk explained below.
The data recording area 28 between the lead-in area 27 and the lead-out area 26 on the optical disk of FIG. 1 has a volume and file structure as shown in FIG. 4. The structure has been determined to conform to specific logic format standards,
such as Micro UDF or ISO 9660. The data recording area 28 is physically divided into a plurality of sectors as described earlier. These physical sectors are assigned serial numbers. In the following explanation, the term "logical address" refers to a
logical sector number (LSN) as determined in Micro UDF or ISO 9660. Like a physical sector, a logical sector contains 2048 bytes. The numbers (LSN) of logical sectors are assigned consecutively in ascending order as the physical sector number
increments upward.
As shown in FIG. 4, the volume and file structure is a hierarchial structure and contains a volume and file structure area 70, a video manager 71, at least one video title set #i 72, and another recorded area 73. These areas 70, 71, 72, 73 are
aligned with the boundaries between logical sectors. As with a conventional CD, a logical sector is defined as a set of 2048 bytes. Accordingly, one logical sector corresponds to one logical block.
The volume and file structure area 70 corresponds to a management area determined in Micro UDF or ISO 9660. According to the description in the management area, the video manager 71 is stored in the system ROM/RAM section 52. As explained with
reference to FIG. 5, the information used to manage video title sets 72 is written in the video manager 71, which is composed of a plurality of files, starting with file #0. In each video title set 72, compressed video data, compressed audio data,
compressed sub-picture data, and the reproducing information about these data items are stored as explained later. Each video title set is composed of a plurality of files 74. The number of video title sets 72 is limited to a maximum of 99.
Furthermore, the number of files 74 (from file #j to file #j+9) constituting each video title set 72 is determined to be a maximum of 10. These files 74 are also aligned with the boundaries between logical sectors.
In the other recorded area 73, the information capable of utilizing the aforementioned video title sets 72 is recorded. The other recorded areas 73 are not necessarily provided.
As shown in FIG. 5, the video manager 71 contains at least three items, each corresponding to individual files 74. Specifically, the video manager 71 is made up of volume manager information (VMGI) 75, a video object set for video manager menu
(VMGM.sub.-- VOBS) 76, and backup of video manager information (VMGI.sub.-- BUP) 77. Here, the volume manager information (VMGI) 75 and the backup of video manager information (VMGI.sub.-- BUP) 77 are determined to be indispensable items, and the video
object set for video manager menu (VMGM.sub.-- VOBS) 76 is determined to be an optional item. In the video object set 76 for VMGM, the video data, audio data, and sup-picture data about a menu of the volumes of the optical disk managed by the video
manager 71 are stored.
By the video object set 76 for VMGM (VMGM.sub.-- VOBS), the volume name of the optical disk 10, the sound accompanying the volume name representation, and the description of the sub-picture are displayed. At the same time, selectable items are
provided in the form of sub-pictures as in video reproduction explained later. For example, the video object set 76 for VMGM (VMGM.sub.-- VOBS) indicates that the optical disk 10 contains the video data representing English conversation for learning
English. Specifically, lessons on English conversation, together with a volume name, such as the contents of English conversation, is reproduced in the form of video data, and at the same time, a theme song is reproduced in sound, and the level of the
teaching material is displayed in a sub-picture. Furthermore, the user is asked which one of lessens 1 to N to select. Thus, for example, the VMGM video object set 76 (VMGM.sub.-- VOBS) provides the user with preparations to watch an English
conversation program for learning English.
Here, the structure of a video object set (VOBS) 82 will be described with reference to FIG. 6. FIG. 6 shows an example of a video object set (VOBS) 82. The video object set (VOBS) 82 comes in three types for two menus and a title.
Specifically, the video object set (VOBS) 82 contains the video title set for video manager menu (VMGM.sub.-- VOBS) 76, a video object set (VTSM.sub.-- VOBS) 95 for a menu in the video title sets 72 and a video object set (VTSTT.sub.-- VOBS) 82 for the
titles of at least one video title set 72 in a video title set (VTS) 72 as explained later. Each video object set 82 has the same structure except that their uses differ.
As shown in FIG. 6, a video object set (VOBS) 82 is defined as a set of one or more video objects (VOB) 83. The video objects 83 in a video object set (VOBS) 82 is used for the same application. A video object set (VOBS) 82 for menus is usually
made up of one video object (VOB) 83 and stores the data used to display a plurality of menu screens. In contrast, a video object set (VTSTT.sub.-- VOBS) 82 for title sets is usually composed of a plurality of video objects (VOB) 83.
When the aforementioned video of an English conversation program for learning English is taken as example, a video object (VOB) 83 corresponds to the video data of each lesson. Specifying a particular video object (VOB) 83 enables, for example,
lesson 1 to be reproduced on a video. The video object set (VTSM.sub.-- VOBS) 95 for a menu of the video title sets 72 contains the menu data for the English conversation. According to the presentation of the menu, a particular lesson, for example,
lesson 1, can be specified. In the case of a usual single story movie, one video object (VOB) 83 corresponds to one video object set (VOBS) 82. One video stream is completed with one video object set (VOBS) 82. In the case of a collection of animated
cartoons or an omnibus movie, a plurality of video streams, each corresponding to individual stories, are provided in a single video object set (VOBS) 82. Each video stream is stored in the corresponding video object 83. Accordingly, the audio stream
and sub-picture stream related to the video stream are also completed with each video object (VOB) 83.
An identification number (IDN#j) is assigned to a video object (VOB) 83. By the identification number (ID#j), the video object (VOB) 83 can be identified. A video object (VOB) 83 further comprises one or more such cells 84. Although a usual
video stream is made up of a plurality of cells 84, a menu video stream, or a video object (VOB) 83 may be composed of one cell 84. A cell 84 is likewise assigned an identification number (C.sub.-- IDN#j). By the identifi | | |
