HK1112101B - Information storage medium with data structure for multi-angle and apparatus therefor - Google Patents

Description

Information storage medium having data structure for multi-angle and apparatus therefor

This application is a divisional application of a patent application entitled "information storage medium having a data structure for multi-angle and apparatus therefor" filed on 10/13/2003 and having an application number of 200380101470.7.

Technical Field

The present invention relates to an information storage medium having a structure for multi-angle data and a recording and reproducing apparatus therefor.

Background

A Digital Versatile Disc (DVD) is a representative example of a conventional information storage medium on which multi-angle data can be recorded. Multi-angle data is recorded on a DVD by using an interleaving method in which data is divided into predetermined units and the units are alternately recorded.

Hereinafter, a video (including audio, as the case may be) data structure of a DVD, which is a conventional multimedia storage medium, will be described with reference to the accompanying drawings. Fig. 1 is a diagram of a conventional DVD data structure. Referring to fig. 1, a DVD is divided into a Video Manager (VMG) area and a plurality of Video Title Set (VTS) areas. Information on video titles (i.e., video title related data) and menu information for the video titles are stored in the VMG area, and the video title data is stored in a plurality of VTS areas. Generally, the VMG area includes two or three files, and each VTS area includes three to twelve files.

Fig. 2 is a data structure of a conventional VMG area. Referring to fig. 2, the VMG area includes: a video manager information (VMGI) area containing additional information on the VMG area, a video object set (VOBS) area containing video object information on the video title menu, and a VMGI backup area. Each of the VMGI area, VOBS area, and VMGI backup area exists as a file. However, it is optional to include the VOBS area in the VMG area, so that the VOBS area may not be formed in the VMG area in some cases.

Each VTS area contains title data, which is a unit of reproduction, and video object information VOBS. A plurality of titles may be recorded on the VTS area. Fig. 3 is a diagram of a data structure of a conventional VTS area. Referring to fig. 3, Video Title Set Information (VTSI), VOBS of a video title menu screen, VOBS of a video title set, and VTSI backup data are recorded in a VTS area. Recording of the video title menu screen VOBS is optional for displaying the title menu screen. Each video title set VOBS is divided into a plurality of video objects VOBS that are units of data records, and each VOB includes a cell (cell) that is the smallest unit of a VOB (i.e., a data unit) of a title. Therefore, the VOB or the data record unit includes a plurality of cells which are the most basic unit of the data record unit.

In the DVD, reproduction units are recorded in a hierarchical structure. The title (i.e., data record) is formed at the uppermost layer of the hierarchical structure. Typically, a title (i.e., a data record of the title) is linked to at least one program chain (PGC). The PGC that is first reproduced among the plurality of PGCs is referred to as an entry PGC. Fig. 4 is a diagram illustrating a title linked to a first PGC, i.e., an entry PGC, according to a conventional multi-angle data recording method. Fig. 5 is a diagram illustrating a title linked to a plurality of PGCs according to a conventional multi-angle data recording method. When one of the plurality of PGCs is selected and reproduced after one PGC is reproduced as shown in fig. 5, a command for determining the PGC to be selected and reproduced may be stored in the DVD. Controlling the order of reproduction is called navigation. The command for determining navigation is contained in program chain information (PGCI).

FIG. 6 is a diagram of a PGC when linked to a title data record according to a conventional multi-angle data recording and reproducing method. Referring to fig. 6, the PGC includes PGC information (PGCI) and a video title set VOBS including title data records. The PGCI contains a pre-command (pre-command) including a navigation command, a post-command (post-command), and a plurality of program information. The pre-command is executed before reproduction of the PGC, and the post-command is executed after the reproduction. Each PGCI program contains a plurality of cell information, each program cell being a reproduction unit. Cells included in a program (i.e., PGCI program cells) are linked to cells included in a VOB of a video title set VOBS, each VOB cell being a unit of a data record. Each program cell, i.e., reproduction unit, has a cell command (cc) provided after reproduction thereof. The PGCI is a part of a hierarchical description of the PGC as a reproduction unit, and the PGC has an information structure that links a PGCI program cell as a most basic reproduction unit to a VOB cell as a most basic data record unit. Specifically, the PGC is a link of a plurality of PGCI program cells as a reproduction unit. Here, the plurality of PGCI program cells may form an angle block.

Fig. 7 is a diagram of a data structure of a conventional angle block. Referring to fig. 7, the angle block is constructed in such a manner that a plurality of reproduction cells are arranged in parallel so that only one of the cells can be reproduced. The reproduction cells forming the angle block have the same reproduction time. Each of the reproduction cells corresponds to a specific angle. If cells, which are units of reproduction, form an angle block, data of a specific angle is divided into predetermined interleaved units (ILVUs) by using an interleaving method and recorded on VOBs including the cells, which are units of data recording.

Fig. 8 is a diagram of a conventional data structure of video title sets VOBs and cells in which multi-angle support is not applied. Referring to fig. 8, VOBs are sequentially stored and recorded in adjacent blocks of an information storage medium, the adjacent blocks being adjacent recording spaces. However, as shown in FIG. 9, when multi-angle support is applied, VOBs for each angle and their cells are recorded in ILVUs on an interleaved block by using an interleaving method. As a result, data of a specific angle is not recorded on the adjacent recording area. That is, in general, angle data is sequentially recorded on alternate VOBs by using the interleaving method.

More specifically, fig. 9 is a conventional data structure of two angle data sequentially and alternately recorded using an interleaving method. Referring to FIG. 9, the ILVUs each have the same reproduction time. The amount of data to be recorded may vary according to the type of compression method used. In the case of interleaved data, in order to reproduce data of one angle or reproduce data of a changed angle, it is necessary to jump to a desired ILVU. For example, in order to reproduce data at a first angle, data for the first angle in the ILVU must be detected. For such first angle data detection, the video object bitstream contains ILVU position data (i.e., NXT _ ILVU _ SA and NXT _ ILVU _ SZ as in the data structure shown in fig. 11). The ILVU position data indicates the position and size of the next ILVU data belonging to the bitstream. After reproduction of ILVU data, jumping to the next ILVU data using NXT _ ILVU _ SA and NXT _ ILVU _ SZ.

In order to change an angle during data reproduction, it is necessary to jump to a position of data for the changed angle. The extent of the jump is determined in the ILVU. FIG. 10 is a diagram illustrating jumping to ILVU data for a selected angle in view of cells according to conventional multi-angle data reproduction. Referring to FIG. 10, even if a user issues a command to change an angle at a certain time during reproduction of ILVU data, subsequent image data can be reproduced without pause for seamless change. This is achieved by the following method: the reproduction of the ILVU data is first completed, the link is followed by jumping to the ILVU data for the changed angle, and the ILVU data for the changed angle is reproduced. Information on the position of ILVU data is multiplexed and contained in a bitstream of video object data recorded using an interleaving method.

Fig. 12 is a diagram of a conventional data structure of ILVU angle position information SML _ AGL _ Cn _ DSTA contained in a video object bitstream specifying the position and size of ILVU data for nine angles (n is a natural number between 1 and 9). Typically, the maximum number of angles supported by a DVD is 9. The ILVU angle position data SML _ AGL _ Cn _ DSTA provides information about ILVU data for angle # n through a link in the current ILVU data. After reproduction of the current ILVU data, it is possible to change the current angle to a desired angle and reproduce data for the desired angle by using ILVU angle position data SML _ AGL _ Cn _ DSTA.

In a DVD editing process for multi-angle data support, images photographed at different angles are compressed to form several bit streams of data having the same reproduction length. Then, a bitstream is formed by using an interleaving method and information is inserted into each bitstream, which allows other angles to be referred to during data reproduction. Accordingly, video object data is recorded on the DVD so that angles can be changed during data reproduction.

However, if multi-angle data is divided into predetermined units and stored in a DVD by using an interleaving method, the multi-angle data is not continuously recorded in contiguous areas of the DVD. Therefore, in order to continuously reproduce data for an angle, in general, a reproducing apparatus needs to move an optical pickup position many times to read data. In particular, if a reproducing apparatus reproduces data from an optical disc or a hard disk, the apparatus takes a considerable time to change the optical pickup position. There is also a bit rate limit on the compressed bit stream to compensate for the time delay offset caused when the device changes the optical pickup position.

Disclosure of Invention

The present invention provides an information storage medium having a data structure in which random access can be performed regardless of the position of multi-angle data, and an apparatus therefor.

Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

The present invention provides an information storage medium on which video object data for multiple angles is recorded, the medium including: and at least one clip, which is a recording unit in which video object data for each angle is recorded, wherein the at least one clip for a certain angle is recorded in contiguous areas of the information storage medium.

According to an aspect of the present invention, the video object data for each angle includes: a plurality of jumping points, which are access points enabling video object data of different angles to be continuously reproduced; and additional information containing information on the jumping points.

According to an aspect of the invention, the video object data contains clip information as additional information on the clips, and the clip information contains information on the jumping points.

According to an aspect of the invention, the additional information regarding each jumping point includes information regarding a starting point to each jumping point of the clip, and is stored in the clip information in a table form.

According to an aspect of the invention, the clip information contains information regarding entry points that are randomly accessible, and the information regarding the jumping points is added to the entry point information and specifies whether each entry point can serve as a jumping point.

According to an aspect of the invention, the additional information regarding the jumping points is commonly and additionally recorded on clips of the video object data for the respective angles, and the information regarding the positions of the respective jumping points of the respective clips is sequentially contained in the common jumping point information.

According to an aspect of the invention, the positions of the jumping points and the distance between adjacent jumping points may be determined such that when a reproduction position is changed at a jumping point for an angle change during reproduction of a clip for a certain angle, the clip is continuously reproduced without pause.

According to an aspect of the invention, information regarding PlayItems and PlayLists is recorded as information regarding units of reproduction, and information regarding a plurality of PlayItems forming an angle block is recorded as information regarding PlayItems for a plurality of angles, the PlayItems corresponding to respective clips, and each PlayList having a plurality of PlayItems.

According to an aspect of the invention, information regarding playltems and playlists is recorded as information regarding units of reproduction, and the information regarding the respective playlists are recorded to correspond to the respective angles, the respective playltems corresponding to the respective clips and each PlayList having a plurality of playltems.

According to an aspect of the invention, additional information regarding a certain angle is added to each PlayList, the respective playlists being information for different angles and being recorded to correspond to the respective angles.

According to an aspect of the invention, the clip information contains information regarding entry points that are randomly accessible, and the jumping point information is the entry point information since all the entry points are jumping points.

According to an aspect of the present invention, a portion of a clip for which jumping to an entry point is not allowed immediately after clip reproduction or jumping to an entry point is determined, and a length of the portion for which jumping is not allowed is determined, within a range that underflow of a buffer is not caused.

According to an aspect of the invention, the clip information contains information about the portion where jumping is not allowed immediately after data reproduction or jumping.

The present invention can also be achieved by a reproducing apparatus that reproduces data recorded on an information storage medium in which a plurality of video object data are recorded in units of clips that are recording units, the clips being separately recorded in contiguous areas, when the video object data are multi-angle video object data, each clip containing information on the video object data corresponding to each angle being recorded, the apparatus comprising: and a detector detecting the related clip and reading and reproducing the detected related clip in contiguous areas of the information storage medium when reproducing the multi-angle video object data.

According to an aspect of the invention, the video object data for the respective angles has a plurality of jumping points for enabling video object data for different angles to be continuously reproduced, additional information regarding the jumping points is recorded on the information storage medium, the jumping points indicating positions of clips divided by the same reproduction time, the apparatus reads and reproduces a clip for an angle in contiguous areas of the information storage medium by reproducing the clip to a certain jumping point, and reproduces another clip for a changed angle from a jumping point corresponding to the certain jumping point when an angle change is required during the clip reproduction to reproduce the multi-angle video object data.

According to an aspect of the invention, each video object data further includes clip information providing additional information on clips that are recording units, the clip information being additional information on the jumping points, the apparatus detecting the additional information on the jumping points from the clip information on the associated clips.

According to an aspect of the invention, the additional information regarding the jumping points includes information for a starting point of each jumping point in the clip and is stored in the clip information in a table form, the apparatus estimates that the jumping points of the clips for the multi-angle data are connected to each other when changing angles during reproduction of the clips, the additional jumping point information of the clips being recorded at a predetermined position in the table, detects the connected jumping points of the clips being reproduced and the clips for the changed angles, and reproduces the clips at the detected jumping points, respectively.

According to an aspect of the invention, the clip information contains information regarding entry points that are randomly accessible, and the information regarding the jumping points is added to the entry point information to specify whether the associated entry point serves as a jumping point, the apparatus estimates that the jumping points of clips for the multi-angle data are connected to each other when angles are changed, the jumping point information is recorded at the same position as the entry point information, detects the connected jumping points, and reproduces clips at the detected jumping points.

According to an aspect of the invention, the additional information regarding the jumping points is commonly contained in the video object data in units of a plurality of clips for a plurality of angles, and the information regarding the positions of the jumping points of each clip is sequentially contained in a table format in the common jumping point information, the apparatus reads the common jumping point information regarding clips for multi-angle data reproduction when angles are changed, detects connected jumping points based on the common jumping point information, and reproduces clips at the detected jumping points.

According to an aspect of the invention, the positions of the respective jumping points and the distance between adjacent jumping points are determined such that when an angle is changed during reproduction of a clip for an angle, the clip is continuously reproduced without pause, the apparatus reproduces even when an angle change signal is input by a user by completing reproduction of the clip to a jumping point closest to the reproduction position, and reproduces the clip for the changed angle from a jumping point corresponding to a previous jumping point.

According to an aspect of the invention, information regarding PlayItems and PlayLists is recorded as information regarding units of reproduction, information regarding a plurality of PlayItems forming an angle block is recorded as information regarding PlayItems for a plurality of angles, each PlayItem indicating a clip or a portion thereof, the respective PlayItems corresponding to the respective clips and each PlayList having a plurality of PlayItems, the apparatus reproduces one of the plurality of PlayItems forming the angle block to reproduce the plurality of PlayItems of the angle block, and reproduces another PlayItem from the angle block when an angle change is required.

According to an aspect of the invention, information regarding PlayItems and PlayLists are recorded as information regarding units of reproduction, each PlayItem indicating a clip or a portion thereof, the respective PlayLists being recorded to correspond to respective angles, the respective PlayItems corresponding to the respective clips and the respective PlayLists having a plurality of PlayItems, the apparatus reproducing a PlayList corresponding to a desired angle.

According to an aspect of the invention, each PlayList further contains information regarding a corresponding angle, and the apparatus reproduces the playlists corresponding to the corresponding angles.

The present invention can also be achieved by a recording apparatus for recording multi-angle video object data on an information storage medium in which random access can be performed, the apparatus comprising: and a recorder which records the respective video object data for the respective angles in units of clips in contiguous areas of the information storage medium by dividing the video object data in units of clips, and records the clips in the information storage medium without using an interleaving method.

According to an aspect of the invention, the apparatus creates a plurality of jumping points and information regarding the plurality of jumping points, in addition to the video object data for the respective angles, on the information storage medium, the jumping points enabling the video object data for different angles to be continuously reproduced.

According to an aspect of the invention, the apparatus creates clip information for clips other than the video object data, the clips being units of data records and the clip information containing information regarding the jumping points.

According to an aspect of the invention, the jumping point information includes information regarding starting points for each jumping point of each clip, and the jumping point information is contained in the clip information in a table form.

According to an aspect of the invention, the apparatus records the clip information to contain entry point information regarding points that are randomly accessible and adds the jumping point information to the entry point information to indicate whether the respective entry points serve as jumping points.

According to an aspect of the invention, the apparatus commonly records clips for multi-angle data to contain jumping point information, the common jumping point information sequentially containing information regarding positions of jumping points of each clip in a table format.

According to an aspect of the invention, the apparatus determines and records the positions of the jumping points and the distance between adjacent jumping points such that clips are continuously reproduced when the position of reproduction is changed at a jumping point for angle change during reproduction of a clip for a certain angle.

According to an aspect of the invention, the apparatus records information regarding PlayItems and PlayLists as information regarding units of reproduction, records information regarding a plurality of PlayItems, which form an angle block, as information regarding a plurality of angles, the respective PlayItems corresponding to the respective clips, and each PlayList having a plurality of PlayItems.

According to an aspect of the invention, the apparatus records information regarding PlayItems and PlayLists as information regarding units of reproduction, and records the respective PlayItems to correspond to the respective clips, the respective PlayItems corresponding to the respective clips and the respective PlayLists having a plurality of PlayItems.

According to an aspect of the invention, the apparatus adds additional information regarding a certain angle to respective playlists that are recorded to correspond to the respective angles.

Drawings

The above and/or other aspects and advantages of the present invention will become more apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 illustrates a data structure of a conventional DVD;

FIG. 2 shows a data structure of a conventional VMG area;

fig. 3 illustrates a data structure of a conventional VTS area;

FIG. 4 illustrates an example of titles linked to one PGC as an entry PGC according to a conventional multi-angle data record;

FIG. 5 illustrates an example of a title including a plurality of linked PGCs according to a conventional multi-angle data recording;

FIG. 6 illustrates a conventional data structure of a PGC according to a conventional multi-angle data recording and reproducing;

fig. 7 illustrates a conventional data structure of an angle block;

FIG. 8 illustrates a conventional data structure of VOBs and cells as a unit of record when multi-angle viewing is applied;

fig. 9 illustrates angle data alternately recorded using a conventional interleaving method;

FIG. 10 illustrates data jumping to an angle for selection in view of cells according to a conventional multi-angle data reproduction;

fig. 11 illustrates a conventional data structure of information contained in a video object bitstream having interleaved unit (ILVU) data for angle # 1;

fig. 12 illustrates a conventional data structure of information contained in a video object bitstream for a plurality of angles;

fig. 13 is a diagram of a relationship between a PlayList, a PlayItem, clip (clip) information, and a clip according to an embodiment of the present invention;

FIG. 14 is a diagram of a relationship between jumping units and jumping points in an audio/video (AV) stream clip, according to an embodiment of the present invention;

FIG. 15 is a diagram illustrating a plurality of linked angle data clips for multi-angle data reproduction of the clips, according to an embodiment of the present invention;

FIG. 16 is a diagram of a relationship between angle data clip jumping and a buffer enabling multi-angle video object data to be reproduced without pause, according to an embodiment of the present invention;

FIG. 17 is a diagram of a data structure of a PlayList having a multi-angle structure, according to an embodiment of the present invention;

fig. 18 is a diagram of a data structure of jumping points, according to a first embodiment of the present invention;

fig. 19 is a diagram of a data structure of jumping points, according to a second embodiment of the present invention;

fig. 20 is a diagram of a data structure of jumping points, according to a third embodiment of the present invention;

FIG. 21 is a diagram of an example PlayList having PlayItems that form an angle block, according to an embodiment of the present invention;

FIG. 22 is a diagram of an example PlayLists for different angles, according to an embodiment of the present invention;

FIG. 23 is a diagram of an example PlayList having PlayItems that do not form an angle block, according to an embodiment of the present invention;

FIGS. 24 to 26 are diagrams illustrating a structure of an information storage medium storing multi-angle data and reproduction from the information storage medium, according to another embodiment of the present invention; and

fig. 27 to 31 are diagrams of jumping points and a jumping manner according to an exemplary embodiment of the present invention.

Detailed Description

Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.

According to the embodiments of the present invention, multi-angle support is enabled such that angle data is recorded on an information storage medium by using a separate recording method instead of an interleaving method. In other words, multi-angle support is achieved by recording bitstreams for respective angle data in contiguous recording areas of the information storage medium. During data reproduction, angle change is achieved by: data for each angle is divided into jumping units (JPUs), a start address of the JPU is designated as a jumping point, and information regarding the jumping points of the respective angle data is recorded as additional jumping point information. According to an aspect of the invention, if the entry points are the jumping points, the jumping points may be detected based on information regarding the entry points.

For a better understanding of the invention, the main elements of the invention are listed below:

(a) compressed and encoded audio/video (AV) streams with respect to respective angles;

(b) a clip information file containing information on an encoded audio/video (AV) stream, such as attribute information;

(c) a PlayItem as reproduction information indicating a reproduction time for a reproduction portion between times IN _ time and OUT _ time of a clip including the above elements (a) and (b);

(d) a PlayList as reproduction information including at least one PlayItem; and

(e) a jumping point map in which the positions of jumping points are recorded in a table form.

In the present invention, multi-angle data is referred to as multi-angle object (e.g., AV, video, audio, other data) data including a plurality of reproduction units corresponding to a certain reproduction time. That is, the multi-angle data includes data (e.g., data photographed by a camera in case of video) obtained at different angles by several receiving/data collecting apparatuses. In general, audio data is created as the same angle data at different angles, but may be created differently at different angles. In summary, in general, multi-video object data that can be reproduced in the same time zone is referred to as multi-angle data, and multi-content (e.g., audio, other data) that can be reproduced in the same time zone is referred to as multi-angle content, but all types of multi-data that can be reproduced in the same time zone are referred to as multi-angle data herein for convenience.

In describing the present invention, using multi-angle AV data as an example of multi-angle data, generally, the size of video object data is large and thus is stored or transmitted as a compressed bitstream. The present invention uses a clip as a recording unit (i.e., a data unit) and a PlayList and a PlayItem as a reproduction unit. The clip corresponds to a video title set VOB cell as a recording unit in a conventional DVD as shown in fig. 3 and 6, and the PlayList and PlayItem correspond to a PGCI program and a PGCI cell as a reproduction unit in a DVD as shown in fig. 6, respectively.

More specifically, according to the present invention, AV streams are recorded in units of clips in contiguous areas of an information storage medium. Usually, the AV stream is also compressed and recorded to reduce the size of the AV stream. When reproducing the recorded clips, the characteristics of the clips recorded in each clip are used to interpret the compressed video object data. The clip characteristics or clip information contains the audio and video properties of each clip and an entry point map with information about the location of the randomly accessible entry points. In the case of Moving Picture Experts Group (MPEG) video compression techniques, the entry point is located in an intra-coded I-picture. The entry point map is mainly used during a time search for detecting the position of data at a predetermined time after the reproduction of the data.

Fig. 13 shows the relationship between a PlayList, playitems, clip information, and clips according to an embodiment of the present invention. Referring to fig. 13, a PlayList is a basic reproduction unit. In an information storage medium according to the present invention, a plurality of playlists are stored. A PlayList includes one or more playitems. The PlayItem is linked to a portion of the clip, and more particularly, indicates start and end times of reproduction in the clip. Thus, the clip information is used to easily detect a desired part of the clip. Hereinafter, a data structure and recording positions of multi-angle data will be described with reference to the accompanying drawings.

FIG. 14 is a diagram of a relationship between jumping units and jumping points in a clip AV stream, according to an embodiment of the present invention. Referring to FIG. 14, if a clip represents video object data and a portion of multi-angle data at a specific angle, the clip is divided into a plurality of jumping units and a starting point of each jumping unit is referred to as a jumping point. Each jumping point denotes a point in a certain clip for another angle, which is a starting point or a destination point, respectively, when jumping in or out from a clip for a different angle to a clip for a different angle during reproduction of the certain clip. Thus, a clip jumping point links the clip to another angle data. According to an aspect of the invention, the jumping points are entry points. However, for seamless data reproduction, not all entry points are always set as jumping points, because the entry points are formed at intervals of about 0.5 seconds.

FIG. 15 is a diagram illustrating a plurality of linked angle data clips for multi-angle data reproduction of the clips, according to an embodiment of the present invention. As shown in fig. 15, assuming that a plurality of clips having the same number of jumping points are linked to each other, the respective clips are recorded in different areas and linked to each other through jumping points at the same reproduction time. In order to reproduce different clips (different angle data clips) during reproduction of the clips, the different clips are reproduced from the respective jumping units after completing reproduction of the clips to a predetermined jumping point and detecting a jumping unit of the different clips corresponding to the predetermined jumping unit, thereby enabling seamless, continuous reproduction of the clips. In fig. 15, for example, arrows indicate a procedure in which a clip for a third angle is first partially reproduced, a first angle is selected during reproduction of the clip for the third angle, a clip for the first angle is reproduced, an mth angle is selected during reproduction of the clip for the first angle, and a clip for the mth angle is reproduced. When the user inputs a command to change the angle, the change is performed in units of jumping units.

According to an aspect of the present invention, even when data is recorded in non-continuous different areas of an information storage medium in which random access can be performed, the data can be continuously reproduced from the information storage medium when a position of a reproducing apparatus is changed within a predetermined time. In the present invention, the change of the position of the reproducing apparatus is described as jumping. In general, no additional time is required for jumping in a volatile electronic information storage medium such as a memory. However, in the case of a nonvolatile information storage medium such as an optical disc in which data is read by moving an optical pickup, additional time is required for jumping. Further, when the speed of reading video object data from the information storage medium and the speed of reproducing the read video object data are different, the information storage medium requires an apparatus that can compensate for the difference between the reading and reproducing speeds even if data is recorded in adjacent areas for reading and reproducing. According to the present invention, a video object buffer is used as an apparatus that allows multi-angle data to be continuously reproduced from an information storage medium when the position of a reproducing apparatus is changed within a predetermined time even when the multi-angle data is recorded in non-continuous different areas of the information storage medium in which random access can be performed, and provides compensation for a difference between reading and reproducing speeds. Data read from an information storage medium at a predetermined speed is stored in a video object buffer, and then the data is reproduced from the buffer. During data reading, it is important to control the speed of data reading to prevent overflow or underflow of the video object buffer. The use of the video object buffer enables seamless reproduction of data even if the video object data is recorded at a Variable Bit Rate (VBR).

FIG. 16 is a diagram of a relationship between angle data clip jumping and a buffer enabling multi-angle video reproduction without pause, according to an embodiment of the present invention. As shown in fig. 16, the size of each jumping unit (JPU) is determined within a range that allows video object data stored in a video object buffer to be seamlessly reproduced when jumping to a clip of video object data for a different angle, and reproduction of the next jumping unit for the different angle starts before buffer underflow occurs. As shown in fig. 14, a JPU is obtained by dividing an angle data clip. In the case of a reproducing apparatus that requires additional time to JUMP to a jumping point for a different angle, the size of a jumping unit is determined by assuming that the longest jumping time is T _ JUMP, the speed of reading data is V _ R, and the speed of reproducing video object data is V _ O:

jumping unit size > V _ R V _ O T _ JUMP/(V _ R-V _ O). (1)

Furthermore, in general, the size of the video object buffer satisfies the following:

buffer size (B) > V _ O T _ JUMP. (2)

Fig. 17 is a diagram of a data structure of a PlayList having a multi-angle structure, according to an embodiment of the present invention. The PlayList of fig. 17 includes a plurality of playitems having a sequential structure and an angle block PlayItem having a multi-angle structure. The angle block PlayItem includes a plurality of playitems corresponding to a plurality of respective angle data clips. In the case of angle block PlayItems, only one PlayItem is reproduced when reproducing a PlayList. Further, during reproduction of the angle block PlayItem, angle change may be performed by selecting a PlayItem of a changed angle from the angle block PlayItem and reproducing the selected PlayItem. In general, PlayItems constituting an angle block have reproduction times of the same length. More specifically, in fig. 17, clips 2 to 4 specified by respective playitems of the angle block PlayItem are not interleaved but recorded in contiguous areas. In other words, clips 2 to 4 are recorded in the recording area in the same manner as clips (i.e., clips 1 and 5) specified by playitems that do not belong to the angle block PlayItem, respectively. However, clips 2 through 4 include jumping point information.

Hereinafter, three types of jumping point data structures in clip information will be described with reference to the accompanying drawings. Fig. 18 is a diagram of a data structure of jumping points in a clip for an angle, according to a first embodiment of the present invention. Referring to fig. 18, the clip information includes a jumping point map in addition to general information of the PGC or MPEG standard and an entry point map. The jumping point information contained in the jumping point map is closely related to the video object data. Accordingly, the jumping point information is included in the clip information data and provides additional information regarding the clip.

In fig. 18, general information of clip information contains the following information:

-version _ number: the version of the clip information file.

-EPMap _ start _ address: the start address of the entry point map indicated by a byte number starting from the first byte of the clip information file.

-JPMap _ start _ address: the start address of the jumping point map indicated by a byte number starting from the first byte of the clip information file. If the value of JPMap _ start _ address is 0, this means that the clip associated with the clip information file is not for angle data and the clip does not contain information regarding the jumping point map.

-ClipInfo: attributes of AV stream files related to clip information files.

In fig. 18, the entry point map of clip information contains information on the time and location of entry points that can be randomly accessed. The jumping point map of the clip information contains information of jumping points through which the angle data clip can be actually connected to clips of different angles. According to an aspect of the invention, the jumping manager information included in the jumping point map indicates the number of jumping points and the number of jumping point information entries following the jumping manager information. The jumping point information is used to detect the position of each jumping point and the start position in the associated angle data clip. According to an aspect of the present invention, the jumping point information is expressed in bytes or some sectors. Also, if the video object data is encoded as an MPEG transport stream, according to an aspect of the present invention, each jumping point information is represented in some MPEG-TS packets.

Fig. 19 is a diagram of a data structure of jumping points in a clip for an angle, according to a second embodiment of the present invention. The data structure of jumping points of FIG. 19 represents an entry point map containing jumping point information. Therefore, the data structure of fig. 19 is advantageous in that it does not require any additional space to store the jumping point information. As described above, when video object data is encoded by using temporal-spatial compression such as MPEG, a jumping point should be set as an entry point that is a random access entry point. By incorporating information as to whether an entry point serves as a jumping point into the entry point map, jumping information is easily recorded.

Fig. 20 is a diagram of a data structure of jumping points in a clip for an angle, according to a third embodiment of the present invention. In fig. 20, jumping point information of clips (see fig. 17) forming an angle block is included. The jumping point map information structure is a data structure separate from the clip information structure. The jumping point mapping information includes: jumping manager information indicating the number of clips forming an angle block and the number of jumping points present in the clips; and jumping point information of each clip, sequentially following the jumping manager information. The jumping point mapping information structure enables easy detection of the location of a desired angle.

FIG. 21 is a diagram of an example PlayList having PlayItems that form an angle block, according to an embodiment of the present invention. Referring to fig. 21, each PlayItem information contains general PlayItem information and angle block information. The angle block information mainly specifies whether PlayItems form angle block PlayItems. In general, PlayItems forming an angle block are sequentially recorded. During reproduction of the PlayList, at least one PlayItem selected from the playitems forming the angle block is reproduced. During reproduction of one PlayItem of the angle block playitems, another PlayItem forming the angle block may be reproduced.

Fig. 22 is a diagram of an example PlayList as a unit of reproduction for different angles. Referring to fig. 22, respective playlists include a single PlayItem not forming an angle block or a plurality of playitems for a single angle. That is, each PlayList corresponds to an angle. Fig. 23 is a diagram of an example PlayList having playitems that do not form an angle block (i.e., the PlayList includes a single PlayItem), according to an embodiment of the invention. As shown in fig. 23, each PlayList contains angle block information regarding angles, which indicates that the PlayItem information does not form an angle block in this case. When the user selects an angle or changes an angle, the related/corresponding angle PlayList is reproduced.

According to the present invention, data recording units constituting multi-angle data are recorded in contiguous areas of an information storage medium. The jumping points inserted in the recording units interface with recording units of different angles, and information regarding the jumping points is stored as additional information (i.e., clip characteristics or clip information). Then, information regarding units of reproduction corresponding to the units of recording is stored as multi-angle information (i.e., playlists and playitems).

The reproducing apparatus according to the present invention reproduces multi-angle data and has the following advantages:

first, when angle data is being reproduced and if an angle is changed, multi-angle data may be read from adjacent areas of an information storage medium and the read data may be continuously reproduced. That is, multi-angle data is encoded by using the same method for encoding non-multi-angle data. Therefore, in contrast to the interleaving method, additional data and an encoding operation are not required to continuously reproduce data for an angle.

Second, a clip as a recording unit contains jumping point information enabling connection to video object data for another angle. In order to change an angle when reproducing video object data for a current angle, the reproducing apparatus reproduces the video object data for the current angle to a next jumping point and then reproduces the video object data for the changed angle from a jumping point corresponding to the next jumping point.

Third, when multi-angle information is recorded in a plurality of PlayItems, which are units of reproduction, forming an angle block and belonging to a PlayList (see FIGS. 17 and 21), in order to change angles during reproduction of one PlayItem of the angle block, the reproducing apparatus reproduces PlayItem to a jumping point closest to a current reproduction position of a clip and then reproduces the clip for the changed angle from the jumping point. If a single PlayList is recorded for each angle as shown in fig. 22, when a user wants to change angles during reproduction of the playlists, the playlists for the changed angles are detected and reproduced.

A recording apparatus according to the present invention records multi-angle data as clips, including clip information regarding jumping points, on an information storage medium, and records reproduction unit records linked to the data records. The recording apparatus according to an embodiment of the present invention determines the size of a jumping unit that is a part of a divided clip based on the reading speed V _ R, the jumping time T _ JUMP, and the highest bit rate V _ O of video object data of the reproducing apparatus (see equations (1) and (2)).

Then, the determined jumping unit size is converted into a reproduction time. Then, the video object data is encoded so that a random access (entry) point is set to be greater than or the same as the reproduction time. Here, in general, the interface to the video object data is a jumping point. In general, a random access point is a starting point of a group of pictures (GOP) in temporal-spatial compression coding such as MPEG, and in the case of MPEG, a jumping point is set as an entry point. Thus, with MPEG, each jumping unit includes multiple GOPs. Further, in general, jumping points are formed in the same reproduction time zone of each video object data.

For each angle, the encoded video object data is recorded in contiguous areas of the information storage medium. Information on the positions of the jumping points is recorded as the additional information. According to an embodiment of the present invention, information regarding jumping points of each clip may be recorded as clip information, thereby providing clip characteristics.

Then, information on a reproduction unit forming multi-angle data is created and recorded. For example, a PlayList including playltems corresponding to respective clips of a multi-angle is formed by linking the playltems to each other (i.e., angle block playltems). On the other hand, a single PlayList may correspond to a single angle.

FIGS. 24 through 26 are diagrams illustrating a structure of an information storage medium storing multi-angle data and reproduction from the information storage medium, according to another embodiment of the present invention. According to an aspect of the present invention, an information storage medium has a data structure in which video object data for a multi-angle is recorded in units of clips and all entry points formed in the clips are set as jumping points.

When a user wants to change angles during reproduction of a clip for an angle, a reproducing apparatus according to the present invention reproduces the clip to an entry point of the clip closest to a current reproduction position, jumps to an entry point of the clip for the changed angle corresponding to an entry point of the reproduced clip, and reproduces the clip for the changed angle after the entry point of the clip for the changed angle. Here, typically, all entry points for all angles are formed in clips in the same time zone. In other words, as shown in fig. 24, the respective video angle object data physically recorded in adjacent and different areas are logically linked to each other through the respective entry points.

In general, as shown in fig. 25, an entry point EP is a recording unit having a reproduction time between 0.5 seconds and 1 second and is also formed at a position where random access can be performed. When the multi-angle video object data is compressed using MPEG, the video object data includes a plurality of GOPs. In order to use entry points of video object data including a plurality of GOPs as jumping points during angle change, it is required that all pictures in a GOP are formed of a closed GOP (closed GOP) encoded using only pictures in the relevant GOP.

In the recording medium data structure in which all the entry points are jumping points, additional information regarding the jumping points is not required. However, in such a data structure, underflow of a reproduction buffer may be caused when a reproducing apparatus jumps to an entry point to change an angle. Therefore, according to an aspect of the present invention, in order to prevent a reproducing apparatus from jumping to an entry point of a certain portion of an information storage medium during jumping or immediately after jumping, as shown in fig. 25, a non-jumping portion is provided. The part where jumping is not allowed is called a no-jump block (NJB).

Referring to fig. 26, when the amount of data contained in the buffer immediately after data reproduction or jumping by the reproducing apparatus is less than the amount of data B, angle change is not allowed. Here, the data amount B is the lowest limit of the data amount that allows seamless reproduction of images of the JUMP time JUMP _ T. When the image reproduction continues beyond the length of the NJB, the amount of data in the buffer is always greater than the amount of data B and jumping is allowed at all entry points.

The length of the NJB can be calculated using the same method of calculating the length of the JPU. More specifically, assuming that the longest JUMP time is T _ JUMP, the speed of reading data is V _ R, and the speed of reproducing video object data is V _ O, the length of the NJB is calculated as follows:

NJB length > V _ R V _ O T _ JUMP/(V _ R-V _ O). (3)

Further, in general, the size of the buffer is determined to satisfy the following:

buffer size (B) > V _ O T _ JUMP. (4)

Industrial applicability

As described above, according to the present invention, video object data for multi-angle data is divided into predetermined units (i.e., clips and jumping units thereof) and recorded in contiguous areas of an information storage medium without using an interleaving method. More specifically, if the 'clips' of the present invention correspond to the related art VOB as a data record unit, in the present invention, the 'clips' are recorded in contiguous areas on the storage medium in the case of multi-angle data. In contrast to the present invention, in the prior art, in the case of multi-angle data, cells of VOBs are recorded according to an interleaving method or, for example, in the case of two angles as shown in FIG. 9, on alternate areas of a storage medium. Accordingly, in the present invention, the planning of a data area is easily controlled and managed by an optical recording and reproducing apparatus, and random access is easily performed, thereby efficiently recording/reading multi-angle data (i.e., less optical pickup position movement than conventional multi-angle data recording/reading) and expanding the conventional bit rate limit on a compressed bitstream.

The above-described multi-angle data recording and reproducing process of the present invention, which is included in the multi-angle data recorder/reproduction, is implemented by using software and/or computing hardware. For example, the process of the present invention may be embodied in a detector and reproducer of a multi angle data reproducer and a processor programmed to record received/input multi angle data from any source type on an information storage medium according to the multi angle data structure of the present invention. More specifically, the information storage medium controls a multi-angle data reproducing apparatus by having a data structure including at least one clip object for each angle, each clip being a data recording unit of multi-angle data for an angle. Each angle clip is divided into predetermined jumping units at predetermined jumping points, and each is recorded in contiguous areas of the information storage medium. Using the clip jumping points as links between adjacently recorded angle clips provides efficient random access for reading multi-angle data for angle change. Accordingly, the present invention provides an information storage medium recording apparatus comprising: a programmed computer processor dividing the multi-angle data into predetermined angle units (each angle unit including at least two or more data cells) designated at jumping points used to link the predetermined angle units of the multi-angle data, and recording each of the predetermined angle units including the jumping points in contiguous areas of the information storage medium.

Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.

Claims (2)

1. A method of reproducing data of a moving picture of different angles corresponding to the moving picture from an information storage medium, the method comprising:

reading clip AV streams corresponding to moving picture data of different angles from an information storage medium, the clip AV streams being interleaved with each other;

reproducing an AV stream corresponding to the clip information, wherein each clip information includes an entry point map including information regarding entry points of a corresponding one of the clip AV streams that are randomly accessed and information regarding whether each of the entry points is an angle change point, wherein the angle change point is a point at which a moving picture is reproduced from one angle to another angle.

2. The method of claim 1, wherein the information on the entry point comprises location information of the entry point in the AV stream.