CROSS-REFERENCE TO RELATED APPLICATIONSThis application is a continuation of U.S. patent application Ser. No. 10/793,955, filed Mar. 8, 2004, now pending, which claims the benefit of Korean Patent Application No. 2003-19683 and Korean Patent Application No. 2004-1088, filed on Mar. 28, 2003 and Jan. 8, 2004 respectively, in the Korean Intellectual Property Office, and of U.S. Provisional Application No. 60/458,431, filed Mar. 31, 2003; U.S. Provisional Application No. 60/452,558filed Mar. 7, 2003; and U.S. Provisional Application No. 60/452,551, filed Mar. 7, 2003, the disclosures of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION1. Field of the Invention
The present invention relates to multi-path data, and more particularly, to a recording/reproducing apparatus recording and reproducing data with a multi-path structure and an information storage medium on which the multi-path data is recorded.
2. Description of the Related Art
A multi-path denotes a plurality of paths including language credit data and multi-angle data, through which Audio-Video (AV) data is reproduced/recorded. A digital versatile disc (DVD) is a representative of conventional information storage media on which multi-path data is recorded using an interleaving method in which the data is divided into predetermined units and the units are alternately recorded. The interleaving method enables quick reproduction of data stored on a related path when a path change is instructed by a user. Generally, the multi-path recording is performed with regard to an information storage medium which has no recording position restrictions and a multi-path data structure in which data is recorded to have different reproduction times.
FIG. 1 illustrates a data structure of a DVD with a multi-path data configuration according to the interleaving method. Referring toFIG. 1, the DVD is divided into a video management group (VMG)area110 and a plurality of video title set (VTS)areas120athrough120n. Information regarding management of titles and title menus is stored in the VMGarea110 and information regarding titles is recorded in the plurality ofVTS areas120athrough120n. In general, the VMGarea110 comprises two or three files and each of theVTS120athrough120narea comprises three to twelve files.
FIG. 2 illustrates a detailed data structure of the VMGarea110 ofFIG. 1. Referring toFIG. 2, the VMGarea110 includes a video management group information (VMGI)area112 containing additional information regarding theVMG area110, a video object subtitle (VOBS)area114 containing video object information regarding the title menu, and a VMGIbackup area116. Each of the VMGIarea112, the VOBSarea114, and the VMGIbackup area116 exists as a file. However, the inclusion of theVOBS area114 in theVMG area110 is optional, so that in some cases, theVOBS area114 may not be formed in the VMG area.
FIG. 3 illustrates a detailed data structure of theVTS area120nofFIG. 1. Referring toFIG. 3, video title set information (VTSI)310,VOBS320 for a menu, which is presentation data for a menu screen, VOBS330 for a video title set, andVTSI backup data340 are recorded in theVTS area120n. Recording of the VOBS320 for menu is optional for displaying a menu screen. The VOBS330 for a video title set is divided into a plurality of video objects (VOBs) and a plurality of cells that are recording units. Each VOB comprises a plurality of cells. In this disclosure, the basic recording unit is a recording cell.
FIG. 4 illustrates a video title linked to a plurality of program chains (PGCs) for controlling reproduction of the video title video objects according to the interleaving method. As shown inFIG. 4, when one of the plurality of PGCs is selected and reproduced after reproduction of another PGC, a command for determining the PGC to be selected and reproduced may be stored on the DVD. Controlling the sequence of reproduction is referred to as navigation. A command for determining navigation is contained in program chain information (PGCI).
FIG. 5 illustrates a data structure of the PGC according to the interleaving method. Referring toFIG. 5, the PGC is stored in a PGCI510. The PGCI510 contains a pre-command512 that includes a navigation command, apost-command516, and a plurality ofprograms514athrough514n. The pre-command512 is carried out prior to reproduction of a particular program linked to the PGC and thepost-command516 is carried out after the reproduction of the particular program linked to the PGC. Each of theprograms514athrough514ncontains a plurality of reproduction cell information. Reproduction cells included in theprograms514athrough514nare linked to respective recording cells as recording units included in a VOB. Each reproduction cell, i.e., a reproduction unit, has a reproduction cell command (CC) that is carried out after reproduction thereof. Therefore, the PGCI is a hierarchical description of the PGC, which is a reproduction unit, and has an information structure that links a reproduction cell, which is the basic reproduction unit, to a recording cell that is the basic recording unit. In particular, the PGC is a link of a plurality of reproduction cells that are reproduction units. Here, the plurality of reproduction cells of a program514 may form a path block.
FIG. 6 illustrates a structure of a path block600 shown inFIG. 5. Referring toFIG. 6, the path block600 is constructed such that a plurality of reproduction cells are arranged in parallel so that only one of these reproduction cells can be reproduced. The reproduction cells forming the path block600 may have the same reproduction time or different reproduction times, and each of the reproduction cells corresponds to a specific path block in the path block600. If reproduction cells, which are reproduction units, form a path block600, corresponding linked VOBs and recording cells, which are recording units, of a path of the path block600 are not continuously and sequentially recorded per path, but recorded according to the interleaving method.
FIG. 7 illustrates an example of a reproduction path of presentation data. A presentation engine reproduces presentation data in response to a presentation command given from a navigation manager. A series of presentation data are recorded in consecutive logical sectors according to a sequence of reading the series of presentation data during multi-path presentation data recording. The presentation data contains multiple recording cells and the navigation manager gives the presentation command with respect to at least one recording cell. Thus, the reproduction path of the presentation data is determined by the sequence of recording cells prescribed by a PGC.
FIG. 7 illustrates multi-path reproduction of presentation data for a movie, where a recording cell from among a plurality of recording cells of the movie is reproduced according to navigation (reproduction command) data. InFIG. 7, “language credit” indicates reproduction of the movie according to a type of language. For instance, in the last scene of the movie, the type of language describing subtitle information regarding characters or producing staff is determined by the “language credit.” Otherwise, when the movie includes a scene where a character reads a newspaper, the newspaper may be determined to be a Korean newspaper or an English newspaper according to the “language credit”. Also, “director's cut” denotes a particular sequence of video objects of the movie, selected by a movie manufacturer, and “multi-angle” denotes that the movie was shot at multiple camera angles. The presentation data shown inFIG. 7 can be reproduced following multiple paths without pause. Such reproduction of data is called seamless play. Regarding angle data, typically, during reproduction of a movie, a user can change reproduction of one of angle data to another angle data. However, typically, change of a language determined by the language credit is not allowed, that is, reproduction paths according to the language credit might not be changeable.
FIG. 8 illustrates a layout of presentation data with a multi-path structure for seamless play according to the interleaving method. Referring toFIG. 8, the presentation data is recorded using the interleaving method. A presentation engine sequentially reads data from an interleaved block and reproduces the presentation data following a designated path of reproduction while skipping reproduction of undesired data. If data is reproduced following afirst path810, interleaved data, i.e., a first interleaving unit (ILVU)811, a second ILVU812, and a third ILVU813, for thefirst path810 is reproduced while skipping reproduction of a first ILVU821, asecond ILVU822, and athird ILVU823 for asecond path820. For jumping to a desired track, the presentation engine requires a track buffer that enables the presentation data to be supplied to a decoder without intermission.
Therefore, when multi-path data is divided into predetermined units and recorded using the interleaving method for multi-path reproduction, data stored on the same reproduction path is not continuously recorded in the same area. Accordingly, reproduction positions are unavoidably repeatedly changed, i.e., unnecessary jumps between cells occur, during data reading. In particular, when reproducing data from an optical storage medium or a hard disc that requires a lot of time to change reproduction positions, bit rates of compressed bit streams would be limited to compensate for the reproduction position changes on the optical or hard disc storage medium that requires additional position jumping time, so that the AV data can be reproduced without intermission).
SUMMARY OF THE INVENTIONThe present invention provides a recording apparatus effectively recording multi-path data by separately recording presentation streams on respective paths, a reproducing apparatus for reproducing the multi-path data, and an information storage medium on which the multi-path data is recorded. A benefit of the present invention is to record and reproduce without using an interleaving recording and reproducing method, thereby allowing compression of bit streams (AV data) recorded on optical storage media according to unlimited bit rates with respect to a maximum reproducing rate from the optical storage media.
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.
According to an aspect of the present invention, there is provided an information storage medium on which multi-path presentation data is recorded, the information storage medium comprising a plurality of PlayLists storing information regarding reproduction paths forming the multi-path; and at least one clip that is a recording unit recording the presentation data, wherein each PlayList contains at least one PlayItem linked to the at least one clip that is recorded continuously.
According to another aspect of the present invention, there is provided an information storage medium on which multi-path presentation data is recorded, the information storage medium comprising at least one clip that is a recording unit recording the presentation data with respect to respective paths; and additional information regarding a path block (i.e., path block information) including a set of information specifying reproduction paths of the respective paths (specifying reproduction path links to continuously recorded clips). Therefore, according to the present invention, data for a predetermined path is seamlessly reproduced without changing paths when reproducing the presentation data for the respective paths, and the path block additional information is recorded separately from the presentation data.
According to yet another aspect of the present invention, there is provided a reproducing apparatus that reproduces multi-path presentation data, comprising a reading unit that reads the presentation data; and a reproducing unit that reproduces clips that are recording units of the presentation data, based on a PlayList that records a reproduction path of the read presentation data, wherein the clips of the reproduction path are continuously recorded in a same area of an information storage medium.
According to yet another aspect of the present invention, there is provided a recording apparatus that records multi-path presentation data, comprising a processor that processes AV data and generates multi-path presentation data; and a recording unit that records each presentation data of each path in clip units in a same area of an information storage medium and records PlayList information recording reproduction paths of the multi-path presentation data.
BRIEF DESCRIPTION OF THE DRAWINGSThe above and/or other aspects and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:
FIG. 1 illustrates a data structure of a digital versatile disc (DVD) with a multi-path data structure according to an interleaving method;
FIG. 2 illustrates a data structure of a video manager (VMG) area ofFIG. 1;
FIG. 3 illustrates a data structure of a video title set (VTS) area ofFIG. 1;
FIG. 4 illustrates a structure of a title linked to a plurality of program chains (PGCs) according to the interleaving method;
FIG. 5 illustrates a data structure of a PGC according to the interleaving method;
FIG. 6 illustrates a path block;
FIG. 7 illustrates a reproduction path of presentation data;
FIG. 8 illustrates a layout of presentation data with a multi-path structure, which is reproduced using seamless play according to the interleaving method;
FIG. 9 illustrates the relation among a PlayList, a PlayItem, clip information, and a clip, according to an embodiment of the present invention;
FIG. 10 illustrates a PlayList with a multi-path structure, according to an embodiment of the present invention;
FIG. 11 illustrates a data structure of a PlayList that includes PlayItems that form a path block, and a data structure of a PlayItem included in the path block, according to an embodiment of the present invention;
FIG. 12 illustrates PlayLists that are reproduction units, the PlayLists being constructed for respective paths, according to another embodiment of the present invention;
FIG. 13 illustrates a data structure of a PlayList constructed for a path as shown inFIG. 12, according to an embodiment of the present invention;
FIG. 14 illustrates the relation among a PlayList, a PlayItem, clip information, and a clip, according to another embodiment of the present invention;
FIG. 15 is a block diagram of a reproducing apparatus, according to an embodiment of the present invention; and
FIG. 16 is a block diagram of a recording apparatus, according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTSReference 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 to explain the present invention by referring to the figures.
Since the presentation data is bulky, it is compressed and stored (or transmitted) as compressed bit streams. The present invention discloses use of a clip as a recording unit of the presentation data and a PlayList and a PlayItem as reproduction units. With respect to the DVD, the clip conceptually corresponds to a recording cell that is a recording unit and the PlayList and the PlayItem correspond to a program and a reproducing cell that are reproduction units. In other words, an AV stream is recorded in clip units on an information storage medium according to the present invention. In general, clips (i.e., clips of each path) are recorded in contiguous areas of the information storage medium. An AV stream is also compressed and recorded to reduce the size thereof. When reproducing a recorded clip, clip information recorded in clips is required to interpret the characteristics of compressed presentation data. The clip information specifies AV attributes of each clip and includes an entry point map that describes the positions of entry points enabling random access at predetermined intervals. In the case of the motion picture experts group (MPEG) video compression technique, an entry point is a group of pictures (GOP) header or an I picture that is used as a random access point. The entry point map is mainly used for detecting the position of data in a predetermine time zone after starting of data reproduction.
FIG. 9 illustrates the relation among a PlayList, a PlayItem, clip information, and a clip, according to an embodiment of the present invention. Referring toFIG. 9, aPlayList910 is a basic reproduction unit. An information storage medium according to the present invention contains a plurality of PlayLists. ThePlayList910 is linked to a plurality ofPlayItems920. A PlayItem is a portion of a clip, and more particularly, indicates starting and finishing times of reproduction in a clip. Thus, clip information is used to easily detect a desired portion of a clip.
FIG. 10 illustrates a PlayList with a multi-path structure according to an exemplary embodiment of the present invention. As shown inFIG. 10, in general, a plurality of PlayItems corresponding to respective PlayLists have a sequential structure. However, when a plurality of PlayItems are recorded to support multi-path as shown inFIG. 10, the plurality of PlayItems form a PlayItem path block1010 (referred to as path block hereinafter). Thepath block1010 includes PlayItems for multi paths. When reproducing the path block, only one PlayItem thereof is reproduced following a predetermined path. In the exemplary embodiments of the present invention, during the reproduction of the PlayItem, path change is not allowed in the path block PlayItems. In other words, during reproduction of the PlayItem, path change is not allowed in the path block in response to a user input. The path block PlayItems may be constructed to have either the same reproduction time or different reproduction times. Here, clips representing presentation data are divided into predetermined units and recorded in consecutive areas of an information storage medium without using interleaving. Therefore, in contrast to the interleaving units (e.g., ILVU1-3 of first path) of the interleaved block, which are not stored continuously and sequentially as shown inFIG. 8, according to the present invention, each path block PlayItem clip (e.g.,clip2 of a path) is recorded in consecutive areas as shown inFIG. 10.
FIG. 11 illustrates a data structure of a PlayList that includes PlayItems that form a path block, and a data structure of a PlayItem included in the path block. Referring toFIG. 11, each of the PlayItems included in the path block contains the present invention's PlayItem general information and path block information. In general, path block information basically specifies whether some PlayItems included in a PlayList form a path block. Clips referred to by PlayItems forming a path block can be sequentially recorded as shown inFIG. 10. When reproducing presentation data, only one PlayItem is selected from the plurality of path block PlayItems, which constitute the PlayList, to be reproduced. As mentioned above, changes of PlayItems belonging to the same path block are not allowed.
FIG. 12 illustrates an example of PlayLists, i.e., reproduction units, which are constructed for respective paths, according to another embodiment of the present invention. Referring toFIG. 12, a PlayItem belonging to each of the PlayLists does not form a path block, that is, each PlayItem corresponds to a path, and as described in more detail below, the PlayLists include path information.
FIG. 13 illustrates a data structure of a PlayList constructed for a path as shown inFIG. 12, according to an embodiment of the present invention. According to the present invention, as shown inFIG. 13, each PlayList corresponding to different paths further contains path information that specifies its path. When reproducing presentation data, one of the PlayLists for multiple paths is selected and reproduced. As mentioned above, change of PlayLists at the same multiple paths is not allowed. As described above, according to the present invention, multi-path presentation data is divided into predetermined recording units (clip or clips) and recorded in consecutive areas of an information storage medium per path. Also, reproduction units (PlayLists) are provided to be linked to related recording units, which further include multi-path information.
Accordingly, a method of reproducing a multi-path presentation data using a reproducing apparatus according to the present invention will now be described. First, additional information regarding selection of a desired path (i.e., a PlayList with path information, which can be path block information as the case may be) is recorded on an information storage medium, separately from the presentation data. The reproducing apparatus reads the additional information (reads the PlayList with path information) from the information storage medium prior to reproduction of the presentation data and stores the read information in a memory. Next, the reproducing apparatus detects data having the selected path and reproduces the detected data according to the PlayList with the path information. Each clip, which is a recording unit, contains path-block linkage information (a PlayList with path information) regarding the clip presentation data for a corresponding path. Thus, when a path is selected via a PlayList with path information, the linked clips of the PlayList for a related path is continuously reproduced.
The multi-path presentation data can be read from consecutive areas of the information storage medium and reproduced, since clips for respective paths are not interleaved but are recorded in the consecutive areas. For this reason, the multi-path presentation data can be encoded as in general presentation data. Accordingly, for seamless reproduction of data for a path, the multi-path presentation data is not required to be divided into predetermined units and recorded using interleaving.
A recording apparatus according to the present invention records the above clips, additional information for selection of a path (i.e., path information) and reproduction-unit information (i.e., a PlayList with the path information) on an information storage medium, so that PlayLists are made to correspond to paths (FIG. 12). According to an aspect of the present invention, information regarding reproduction units having multiple paths (i.e., a PlayList with path block information) is created and recorded, in which a plurality of PlayItems corresponding to respective clips are formed as the path block, and the PlayList is constructed to be linked to the plurality of PlayItems as the path block (FIG. 10).
FIG. 14 illustrates the relation among a PlayList, a PlayItem, and a clip, according to another embodiment of the present invention. Each PlayList includes at least one PlayItem and a PlayItem is linked to a clip. Depending, for example, on a value of language credit as navigation data, one of afirst PlayList1410 and asecond PlayList1420 may be reproduced. Parts ofPlayItems1412,1414, and1416 belonging to thefirst PlayList1410 andPlayItems1422,1424, and1426 belonging to the second PlayList420 may be linked to the same clips. Since only parts of PlayItems are differently reproduced according to the value of the language credit, they can be linked to additional clips.
Referring toFIG. 14, thefirst PlayItem1412 belonging to thefirst PlayList1410 is linked to a first clip linked to thefirst PlayItem1422 belonging to thesecond PlayList1420. Thethird PlayItem1416 belonging to thefirst PlayList1410 is linked to a fourth clip linked to thethird PlayItem1426 belonging to thesecond PlayList1420. Thesecond PlayItem1414 belonging to thefirst PlayList1410 is linked to a second clip and thesecond PlayItem1424 belonging to thesecond PlayList1420 is linked to a third clip. For instance, a scene where a character of a movie reads a Korean newspaper is the second clip and a scene where the character reads an English newspaper is the third clip. The first and fourth clips may be shared by the first andsecond PlayLists1410 and1420.
Selection of a PlayList to be reproduced has been described in a system parameter of a movie object. For instance, information regarding the language credit is stored in the system parameter. If a value of the language credit corresponds to Korean language, thefirst PlayList1410 is reproduced. If the value of the language credit corresponds to English language, thesecond PlayList1420 is reproduced.
FIG. 15 is a block diagram of a reproducing apparatus according to an embodiment of the present invention. Referring toFIG. 15, the reproducing apparatus includes areading unit1510 and a reproducingunit1520. Thereading unit1510 reads presentation data, and the reproducingunit1520 reproduces a clip, which is a recording unit of the presentation data, based on PlayList information regarding a reproduction path of the read representation data. Clips are continuously recorded in the same area of an information storage medium per path.
The reproducingunit1520 reproduces at least one clip that can be a recording unit of presentation data for a plurality of paths. In an information area of the clip, entry point information regarding points that can be randomly accessed is recorded. The entry point information enables sequential reproduction of data from a path. The reproducingunit1520 reproduces reproduction units (PlayLists) including PlayItems corresponding to respective clips. A PlayItem is linked to an entire clip or a portion thereof. Also, the reproducingunit1520 reproduces a path block comprising a plurality of multi path PlayItems. When the reproducing apparatus reproduces a plurality of PlayItems forming a path block, only one PlayItem is reproduced.
FIG. 16 is a block diagram of a recording apparatus according to an embodiment of the present invention. Referring toFIG. 16, the recording apparatus includes arecording unit1610 and aprocessor1620. Therecording unit1620 continuously records presentation data in clip units in the same area of an information storage medium. Therecording unit1610 records presentation data continuously for respective paths in at least one clip, records PlayItems corresponding to respective clips and a PlayList comprising the plurality of PlayItems as reproduction units to correspond to respective paths, and records information regarding multi-paths as a path block including the plurality of PlayItems (as the case may be).
As described above, according to the present invention, multi-path presentation data and additional path information for selection of a path are recorded in different areas of an information storage medium. The presentation data is divided into predetermined units and recorded in consecutive areas using a separate recording method different from the interleaving method. Accordingly, it is possible to more effectively use a recording space and reduce the frequency of jumping various path recording units of presentation data, thereby effectively reading the multi-path presentation data from the information storage medium. Therefore, the present invention provides a method of providing multi-path presentation data on an information storage medium without the interleaving, comprising recording continuously a plurality of clips containing presentation data of respective paths; recording separately from the clips a plurality of PlayLists specifying reproduction paths forming the multi-path; containing in each PlayList a plurality of PlayItems linked to clips for the respective paths; sharing some of the clips among differing PlayLists for the respective paths (i.e., path PlayLists or PlayLists per path) by linking PlayItems from the different PlayLists to same clips for one path; and seamlessly reproducing the at least one clip of a path without changing paths, when reproducing the presentation data for the respective paths via the PlayLists.
The present invention can be embodied as a computer readable code in a computer readable medium. Here, the computer readable medium may be any recording apparatus capable of storing data that is read by a computer system, e.g., read-only memory (ROM), random access memory (RAM), a compact disc (CD)-ROM, a magnetic tape, a floppy disk, an optical data storage device, and so on. Also, the computer readable medium may be a carrier wave that transmits data via the Internet, for example. The computer readable recording medium can be distributed among computer systems that are interconnected through a network, and the present invention may be stored and implemented as a computer readable code in the distributed system.
While this invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents.