Patent Publication Number: US-8989556-B2

Title: Recording medium, playback device, recording device, and recording method

Description:
This application is the National Stage of International Application No. PCT/JP2012/005293, filed Aug. 23, 2012, which claims the benefit of U.S. Provisional Application No. 61/526,816, filed Aug. 24, 2011. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a technology for recording and playback of stereoscopic video images, i.e., 3D video images, and especially to the structure of stream data on a recording medium. 
     BACKGROUND ART 
     In recent years, movies featuring 3D video images have gained popularity. This causes people to become familiar with household playback devices that can playback 3D video content from recording media such as optical discs. Household recording devices that can record 3D television programs on recording media and household video cameras that can record 3D video images have also been developed. It is preferable that, on recording media handled by such devices, 3D video content can be recorded in such a way to be also played back as monoscopic video images, i.e., as 2D video content. More specifically, it is preferable that the 3D video content recorded on the recording media allows 2D playback devices to play back 2D video images and 3D playback devices to play back 3D video images. Here, “2D playback devices” refer to conventional playback devices that can only play back 2D video images, whereas “3D playback devices” refer to playback devices that can play back 3D video images. It is assumed in this description that a 3D playback device can also play back conventional 2D video images. 
       FIG. 64  is a schematic diagram illustrating the technology for ensuring the compatibility of an optical disc storing 3D video content with 2D playback devices (see, for example, Patent Document 1). Two types of video streams are stored in an optical disc PDS: One is a 2D/left-view video stream, and the other is a right-view video stream. The “2D/left-view video stream” is used for 3D video playback to represent 2D video images to be shown to the left eye of a viewer, i.e., “left views,” and is used for 2D video playback to constitute 2D video images themselves. The “right-view video stream” is used for 3D video playback to represent 2D video images to be shown to the right eye of the viewer, i.e., “right views.” The left- and right-view video streams have the same frame rate but different presentation times shifted from each other by half a frame period. For example, when the frame rate of the 2D/left- and right-view video streams is 24 frames per second, the frames of the video streams are alternately displayed every 1/48 seconds. 
     As shown in  FIG. 64 , the left- and right-view video streams are divided into a plurality of extents EX 1 A-C and EX 2 A-C, respectively, on the optical disc PDS. An “extent” is the smallest unit of data that can be read from the optical disc drive (see “Supplement” for details). Each extent contains at least one group of pictures (GOP). Hereinafter, the extents belonging to the 2D/left-view video stream are referred to as “2D/left-view extents,” and the extents belonging to the right-view video stream are referred to as “right-view extents.” The 2D/left-view extents EX 1 A-C and the right-view extents EX 2 A-C are alternately arranged on a track TRC of the optical disc PDS. Such an arrangement of extents is referred to as an “interleaved arrangement.” A group of extents recorded in an interleaved arrangement on a recording medium is used both in 3D video playback and 2D video image playback, as described below. 
     From the optical disc PDS, a 2D playback device PL 2  causes an optical disc drive DD 2  to read only the 2D/left-view extents EX 1 A-C in order, skipping the reading of right-view extents EX 2 A-C. Furthermore, an image decoder VDC sequentially decodes the extents read by the optical disc drive DD 2  into video frames VFL. In this way, a display device DS 2  only displays left views, and viewers can watch normal 2D video images. 
     A 3D playback device PL 3  causes an optical disc drive DD 3  to alternately read 2D/left- and right-view extents from the optical disc PDS. When expressed as codes, the extents are read in the order of EX 1 A, EX 2 A, EX 1 B, EX 2 B, EX 1 C, and EX 2 C. Furthermore, from among the read extents, those belonging to the 2D/left- and right-view video streams are supplied to a left-video decoder VDL and a right-video decoder VDR, respectively. The video decoders VDL and VDR alternately decode the video streams into video frames VFL and VFR. As a result, left and right views are alternately displayed on a display device DS 3 . In synchronization with the switching of the views by the display device DS 3 , shutter glasses SHG cause its left and right lenses to become opaque alternately. Therefore, the left views are shown only to the viewer&#39;s left eye, and the right views are only to the viewer&#39;s right eye. At this point, the viewer perceives differences in shape between the left and right views as binocular parallax, and thus sees the pair of 2D video images displayed by the display device DS3 as one 3D video image. 
     The above-described interleaved arrangement of extents is used when 3D video content is stored on any recording medium, not only on an optical disc. This allows the recording medium to be used both for 2D and 3D video playbacks. 
     CITATION LIST 
     Patent Literature 
     [Patent Literature 1] 
     Japanese Patent No. 3935507 
     [Non-Patent Literature 1] 
     Blu-ray Disc Association, “White Paper Blu-ray Disc TM Format,” [online], October, 2010, http://www.blu-raydisc.com/en/Technical/TechnicalWhitepapers/General.aspx 
     SUMMARY OF INVENTION 
     Technical Problem 
     In recent years, the development of 4K2K, one of the next-generation display technologies, has been advanced. “4K2K” is the technology for displaying video images at a high resolution of 3940×2160 pixels, which is approximately four times the conventional resolution of 1920×1080 pixels. If the screen size is fixed, the representation of video images becomes finer as the resolution increases. Therefore, 4K2K is a promising technology for achieving a further increase in image quality. At the same time, during the development of 4K2K, importance is being placed on ensuring compatibility with schemes of displaying video images at conventional resolutions. In particular, when 4K2K video content is recorded on a recording medium, it is preferable that a conventional 2D playback device be able to play back the video content at a conventional resolution. Accordingly, one current suggestion is to divide 4K2K video content into first and second portions, and then record both the portions on a recording medium: the first portion represents the video content at a conventional resolution, and the second portion includes extended data necessary for converting the resolution of the first portion into the 4K2K resolution. A conventional playback device is allowed to read only the first portion from the recording medium, and then play back video images at a conventional resolution from the first portion. On the other hand, a 4K2K-compatible playback device is allowed to read both the first and second portions from the recording medium, and then play back video images at the 4K2K resolution from these portions. This approach enables the 4K2K video content to be used to play back video images both at the conventional resolution and at the 4K2K resolution. 
     As another technology striving for a further increase in image quality, increasing the number of bits in the color information of each pixel from the current value “8” to “12,” for example, has also been developed. This technology is referred to as “bit extension.” Since increase in the number of bits in the color information enables each pixel to express a richer variety of colors, the bit extension holds the promise of a further increase in image quality. In order to preserve compatibility with conventional technologies, the bit extension also adopts a suggestion to separate bit-extended content into a portion representing 8-bit color information and another portion of extended data necessary for converting the 8-bit color information into 12-bit one or the like, and then to record both the portions on a recording medium. 
     In addition to 4K2K and bit extension, various technologies for further improvement in the quality of video content or the diversity of its attributes represent video content as a combination of conventional video content and extended data in order to preserve compatibility with conventional technologies. On the other hand, the above-described technology for recording and playback of 3D video images allows 3D video content to be compatible with 2D playback devices by adding extended data, i.e., the right-view video stream, to 2D video content, i.e., the 2D/left-view video stream. Accordingly, it is expected that incorporating extended data for 4K2K, bit extension, or the like, into 3D video content enables recording of the 3D video content on recording media in a structure to be usable for all of these technologies. Such recording of the 3D video content, however, is not easy in practice for the following reasons. 
     As shown in  FIG. 64 , when 2D video images are played back from extents placed in an interleaved arrangement, the optical disc drive DD 2  skips reading of the right-view extents EX 2 A-C. This operation is referred to as a “jump.” During a jump period, data is not provided from the optical disc drive DD 2  to a buffer built in the image decoder VDC, and therefore the data stored in the buffer decreases because of being processed by the image decoder VDC. Accordingly, in order to allow the 2D playback device PL 2  to seamlessly play back 2D video images, each of the 2D/left-view extents EX 1 A-C has to be designed to have a lower limit of its data amount, i.e., a minimum extent size, so that buffer underflow does not occur during the jump period. 
     When 3D video images are played back from the same extents, the optical disc drive DD 2  does not read the right-view extents EX 2 A-C while being read the 2D/left-view extents EX 1 A-C. Therefore, during this period, the data of the right-view extents EX 2 A-C stored in a buffer built in the right-video decoder VDR decreases because of being processed by the right-video decoder VDR. Conversely, the optical disc drive DD 2  does not read the 2D/left-view extents EX 1 A-C while being read the right-view extents EX 2 A-C. Therefore, during this period, the data of the 2D/left-view extents EX 1 A-C stored in another buffer built in the left-video decoder VDL decreases because of being processed by the left-video decoder VDL. As a result, in order to allow the 3D playback device PL 3  to seamlessly play back 3D video images, each of the extents EX 1 A-C and EX 2 A-C has to be designed to have a minimum extent size so that buffer underflow does not occur during the period when the next extent is read. 
     Furthermore, since the read rate of an optical disc drive is higher than the processing rate of a video decoder, a buffer that stores the data of an extent has an increasing data amount while the optical disc drive is reading the extent. In order to prevent the buffer from overflow without providing an excessive capacity, each extent is required to have an upper limit of its data amount, i.e., a maximum extent size. 
     As described above, recording of 3D video content on a recording medium requires that the size of each extent satisfy a plurality of conditions. Accordingly, addition of extended data to the 3D video content further requires that an arrangement of the extended data do not violate any of these conditions. Such an arrangement is never obvious even to a person of ordinary skill in the art. 
     In an optical disc that includes multiple recording layers, such as a so-called two-layer disc, a series of video content is sometimes recorded across two layers. On a single layer disc as well, a series of video content may be recorded with other data included therebetween. While an optical disc drive is reading such a series of video content, the pickup of the optical disc drive has to perform a focus jump to switch between layers and a track jump to move in the radial direction of the optical disc. 
     These jumps typically have long seek times and are therefore referred to as “long jumps.” In order to cause a video decoder to play back video images seamlessly despite the occurrence of a long jump, the extent to be accessed immediately before the long jump needs to has a sufficiently large size, so that buffer underflow does not occur during the long jump. 
     In order to prevent buffer underflow from occurring during a long jump, the sizes of extents typically satisfy different conditions for playback of 2D video images and for playback of 3D video images. The extents in an interleaved arrangement as shown in  FIG. 64 , however, must satisfy both the conditions for playback of 2D video images and for playback of 3D video images. Accordingly, the size of each right-view extent typically far exceeds the value necessary for seamless playback of 3D video images. As a result, a 3D playback device has to ensure a buffer capacity within its right view decoder much larger than the value necessary for seamless playback of 3D video images. This is not preferable, since this situation prevents a further reduction in the buffer capacity within the 3D playback device and further improvement in the efficiency of memory usage. 
     The following technology, for example, has been proposed as one that prevents buffer underflow from occurring in playback devices during long jumps, and in addition, provides further reduced buffer capacity to 3D playback devices. This technology provides the data recording areas of a recording medium with a first area that is accessed only during playback of 2D video images and a second area that is accessed only during playback of 3D video images; the first and second areas are located immediately before or after a location where a long jump is required. Extents representing the same left view are duplicated in the first and second areas, and an extent representing the right view that is paired with the left view is recorded in the second area. As a result, the sizes of the extents recorded in the first area only have to satisfy the conditions for preventing buffer underflow from occurring during a long jump performed in 2D video playback. On the other hand, the size of the extents recorded in the second area only have to satisfy the conditions for preventing buffer underflow from occurring during a long jump performed in 3D video playback. This technology therefore enables seamless playback of both 2D and 3D video images and in addition, further reduction in buffer capacity of 3D playback devices. 
     As described above, the data recording areas of a recording medium include a more complicated arrangement of extents immediately before or after a location where a long jump is required. Accordingly, it is never obvious even to a person of ordinary skill in the art how extended data, when added to 3D video content, should be arranged immediately before and after a location where a long jump is required. 
     An object of the present invention is to solve the above-discussed problems, in particular, to provide a recording medium including a combination of 3D video content and extended data recorded thereon so as to enable a playback device to maintain good playback performance. 
     Solution to Problem 
     In one aspect of the present invention, a recording medium includes a main-view stream, a sub-view stream, and an extended stream recorded thereon. The main-view stream represents main views of stereoscopic video images. The sub-view stream represents sub-views of the stereoscopic video images. The extended stream is used in combination with the main-view stream. The main-view stream includes a plurality of main-view extents, the sub-view stream includes a plurality of sub-view extents, and the extended stream includes a plurality of extended extents. The recording medium comprises a shared section, a stereoscopic video specific section, a monoscopic video specific section, and an extended data specific section. The shared section includes a continuous, interleaved arrangement of extents having one each of the plurality of main-view extents, the plurality of sub-view extents, and the plurality of extended extents. The stereoscopic video specific section includes a continuous, interleaved arrangement of extents having one each of the plurality of main-view extents and the plurality of sub-view extents. The monoscopic video specific section is located adjacent to the stereoscopic video specific section and includes a continuous arrangement of a copy of the main-view extent arranged in the stereoscopic video specific section. The extended data specific section is located immediately before a continuous arrangement of the stereoscopic video specific section and the monoscopic video specific section and includes one of the plurality of extended extents that is to be used in combination with the copy of the main-view extent arranged in the monoscopic video specific section. The shared section is accessed when the stereoscopic video images are played back, when the main views are played back as monoscopic video images, and when the extended stream is used in combination with the main-view stream. The stereoscopic video specific section is accessed during playback of the stereoscopic video images, next to the shared section immediately before start of a long jump, or ahead of the shared section immediately after completion of a long jump. The monoscopic video specific section is accessed during playback of the monoscopic video images, next to the shared section immediately before start of a long jump, or ahead of the shared section immediately after completion of a long jump. The extended data specific section and the monoscopic video specific section are accessed when the extended stream is read along with the main-view stream, next to the shared section immediately before start of a long jump, or ahead of the shared section immediately after completion of a long jump. 
     In another aspect of the present invention, a playback device is for reading a main-view stream, a sub-view stream, and an extended stream from a recording medium, and for playing back stereoscopic video images, playing back main views as monoscopic video images, and using the extended stream in combination with the main-view stream. The playback device comprises a read unit, a switching unit, a first read buffer, a second read buffer, a third read buffer, and a decoding unit. The read unit is configured to read data from the recording medium. The switching unit is configured to extract the main-view stream, the sub-view stream, and the extended stream from the data read by the read unit. The first read buffer is for storing the main-view stream extracted by the switching unit. The second read buffer is for storing the sub-view stream extracted by the switching unit. The third read buffer is for storing the extended stream extracted by the switching unit. The decoding unit is configured to read and decode the main-view stream from the first read buffer, the sub-view stream from the second read buffer, and the extended stream from the third read buffer. The read unit accesses the shared section on the recording medium when the stereoscopic video images are played back, when the main views are played back as monoscopic video images, and when the extended stream is used in combination with the main-view stream. The read unit accesses the stereoscopic video specific section during playback of the stereoscopic video images, next to the shared section on the recording medium immediately before performing a long jump, or ahead of the shared section immediately after performing a long jump. The read unit accesses the monoscopic video specific section during playback of the monoscopic video images, next to the shared section on the recording medium immediately before performing a long jump, or ahead of the shared section immediately after performing a long jump. The read unit accesses the extended data specific section and the monoscopic video specific section when reading the extended stream along with the main-view stream, next to the shared section on the recording medium immediately before performing a long jump, or ahead of the shared section on the recording medium immediately after performing a long jump. 
     Advantageous Effects of Invention 
     In the above-described aspect of the present invention, the playback device, when reading data from the recording medium, accesses different sections on the recording medium immediately before or after performing a long jump during playback of stereoscopic video images, playback of monoscopic video images, and use of the extended stream in combination with the main-view stream. As a result, the sizes of extents arranged in the different sections may separately satisfy different conditions for preventing buffer underflow from occurring during the long jump. This enables the playback device to seamlessly play back both stereoscopic video images and monoscopic video images, and in addition, to ensure a further reduced buffer capacity. Furthermore, the same monoscopic video specific section is accessed both during playback of the monoscopic video images and during use of the extended stream in combination with the main-view stream. As a result, the data amount of the main-view extents to be redundantly recorded on a single recording medium is reduced to a minimum. Accordingly, playback of stereoscopic video images, playback of monoscopic video images, and use of the extended stream in combination with the main-view stream all can include only long jumps with distances falling within acceptable ranges. The above-defined recording medium thus includes a combination of 3D video content and extended data recorded thereon so as to enable the playback device to maintain good playback performance. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a schematic diagram showing a home theater system that uses a recording medium according to Embodiment 1 of the present invention; 
         FIG. 2  is a schematic diagram showing the data structure of a BD-ROM disc shown in  FIG. 1 ; 
         FIG. 3A  is a list of elementary streams multiplexed in a main TS on the BD-ROM disc shown in  FIG. 1 ,  FIG. 3B  is an example of a list of elementary streams multiplexed in a sub-TS on the BD-ROM disc,  FIG. 3C  is another example of a list of elementary streams multiplexed in the sub-TS on the BD-ROM disc, and  FIG. 3D  is a list of elementary streams multiplexed in an extended stream on the BD-ROM disc; 
         FIG. 4A  is a table showing the data structure of resolution extension information, and  FIG. 4B  is a schematic diagram showing the role of resolution extension information in the process to extend a full HD video frame to a 4K2K video frame; 
         FIG. 5  is a schematic diagram showing an arrangement of TS packets in multiplexed stream data; 
         FIG. 6A  is a schematic diagram showing a data structure of a TS header,  FIG. 6B  is a schematic diagram showing a format of a TS packet sequence comprising multiplexed stream data;  FIG. 6C  is a schematic diagram of a format of a source packet sequence composed of a TS packet sequence in multiplexed stream data, and  FIG. 6D  is a schematic diagram showing sectors located in a volume area of the BD-ROM disc, in which a sequence of source packets are continuously recorded; 
         FIG. 7  is a schematic diagram showing the pictures for a base-view video stream and a right-view video stream in order of presentation time; 
         FIG. 8  is a schematic diagram showing details on the data structure of a video stream; 
         FIG. 9  is a schematic diagram showing details on a method for storing a video stream into a PES packet sequence; 
         FIG. 10  is a schematic diagram showing correspondence between PTSs and DTSs assigned to each picture in a base-view video stream and a dependent-view video stream; 
         FIG. 11  is a schematic diagram showing a physical arrangement of a main TS, a sub-TS, and an extended stream on the BD-ROM disc; 
         FIG. 12  is a schematic diagram showing three types of playback paths for three continuous extended extent blocks T[m], D[m+i], B[m+i] (m=0, 1, 2, i=0, 1); 
         FIG. 13  is a schematic diagram showing the relationship between one extended extent T[m] (m=0, 1, 2, . . . ) and the extent blocks B[k], D[k] (k=m, m+1, . . . , m+n−1) arranged immediately thereafter; 
         FIG. 14  is a schematic diagram showing arrangement  1  of extents recorded before and after a layer boundary on the BD-ROM disc, as well as the playback paths in their respective modes designed for the extents; 
         FIG. 15  is a schematic diagram showing arrangement  2  of extents recorded before and after a layer boundary on the BD-ROM disc, as well as the playback paths in their respective modes designed for the extents; 
         FIG. 16  is a block diagram showing a playback processing system built in the playback device in 2D playback mode; 
         FIG. 17A  is a graph showing the change in the data amount stored in the read buffer during operation in 2D playback mode, and  FIG. 17B  is a schematic diagram showing a playback path in 2D playback mode for an extended extent block for playback; 
         FIG. 18  is an example of a correspondence table between jump distances S JUMP  and maximum jump times T JUMP-MAX  for a BD-ROM disc; 
         FIG. 19  is a block diagram showing a playback processing system built in the playback device in 3D playback mode; 
         FIGS. 20A and 20B  are graphs showing changes in data amounts DA 1  and DA 2 , respectively stored in the RB 1  and RB 2 , when 3D video images are played back seamlessly from a single extended extent block, and  FIG. 20C  is a schematic diagram showing a playback path in 3D playback mode for the corresponding extended extent block; 
         FIG. 21A  is a graph showing changes in data amounts DA 1  and DA 2 , stored in the RB 1  and RB 2 , respectively, and changes in their sum DA 1 +DA 2 , when 3D video images are played back seamlessly and continuously from two contiguous extended extent blocks, and  FIG. 21B  is a schematic diagram showing the (n+1) th  extended extent block, the (n+2) th  extended extent block, and the playback path in 3D playback mode for these extent blocks; 
         FIGS. 22A and 22B  are graphs showing changes over time in the first transfer rate R EXT1  and the second transfer rate R EXT2  when the total of the first transfer rate R EXT1  and the second transfer rate R EXT2  is restricted, and  FIG. 22C  is a graph showing changes over time in R EXT1  R EXT2 , i.e. the sum of the first transfer rate R EXT1  and the second transfer rate R EXT2  shown in  FIGS. 22A and 22B ; 
         FIG. 23  is a block diagram showing a playback processing system built in the playback device in extended playback mode; 
         FIGS. 24A and 24B  are graphs showing changes in data amounts DA 1  and DA 3 , respectively stored in the RB 1  and RB 2 , when 4K2K 2D video images are played back seamlessly from two contiguous extended extent blocks, and  FIG. 24C  is a schematic diagram showing a playback path in extended playback mode corresponding to the extended extent blocks; 
         FIG. 25  is a schematic diagram showing the arrangement of extents when two recording layers on the BD-ROM disc only include shared sections before and after a layer boundary, as well as the playback paths in their respective modes designed for the extents; 
         FIG. 26  is a schematic diagram showing an arrangement of extents when playback paths are completely separated in all modes immediately before a layer boundary on the BD-ROM disc, as well as the playback paths in their respective modes designed for the extents; 
         FIG. 27  is a schematic diagram showing the data structure of a 2D clip information file; 
         FIG. 28A  is a schematic diagram showing the data structure of an entry map, 
         FIG. 28B  is a schematic diagram showing source packets that are included in a source packet group belonging to a file  2 D, and are associated with EP IDs by the entry map, and  FIG. 28C  is a schematic diagram showing extents D[n], B[n] (n=0, 1, 2, 3, . . . ) on a BD-ROM disc corresponding to the source packet group; 
         FIG. 29A  is a schematic diagram showing the data structure of an extent start points included in a 2D clip information file,  FIG. 29B  is a schematic diagram showing the data structure of an extent start point included in a DEP clip information file,  FIG. 29C  is a schematic diagram representing the base-view extents B[ 0 ], B[ 1 ], B[ 2 ], . . . extracted from the file SS by the playback device in 3D playback mode,  FIG. 29D  is a schematic diagram representing correspondence between dependent-view extents EXT 2 [ 0 ], EXT 2 [ 1 ], . . . belonging to a file DEP and the SPNs shown by the extent start point, and  FIG. 29E  is a schematic diagram showing correspondence between an extent EXTSS[ 0 ] belonging to the file SS and extent blocks on the BD-ROM disc; 
         FIG. 30  is a schematic diagram showing the data structure of a 2D playlist file; 
         FIG. 31  is a schematic diagram showing the data structure of the N th  piece of playitem information; 
         FIG. 32  is a schematic diagram showing correspondence between PTSs indicated by a 2D playlist file and sections played back from a file  2 D; 
         FIG. 33  is a schematic diagram showing the data structure of a 3D playlist file; 
         FIG. 34  is a schematic diagram showing the data structure of an STN table SS; 
         FIG. 35  is a schematic diagram showing correspondence between PTSs indicated by a 3D playlist file and sections played back from a file SS; 
         FIG. 36  is a schematic diagram showing the data structure of an extended playlist file; 
         FIG. 37  is a schematic diagram showing the data structure of an STN table EX; 
         FIG. 38  is a schematic diagram showing correspondence between PTSs indicated by the extended playlist file and sections played back from the file  2 D and the extended stream file; 
         FIG. 39  is a schematic diagram showing a data structure of an index file; 
         FIG. 40  is a functional block diagram of the playback device shown in  FIG. 1 ; 
         FIG. 41  is a flowchart of 2D playlist playback by the playback control unit shown in  FIG. 40 ; 
         FIG. 42  is a flowchart of 3D playlist playback by the playback control unit shown in  FIG. 40 ; 
         FIG. 43  is a flowchart of extended playlist playback by the playback control unit shown in  FIG. 40 ; 
         FIG. 44  is a functional block diagram of a system target decoder in 2D playback mode; 
         FIG. 45  is a functional block diagram of a system target decoder in 3D playback mode; 
         FIG. 46  is a functional block diagram of a system target decoder in extended playback mode; 
         FIG. 47  is a flowchart of resolution conversion from full HD to 4K2K; 
         FIG. 48  is a schematic diagram showing an example of constructing a left view and a right view from the combination of a 2D video image and a depth map; 
         FIG. 49  is a block diagram of a system that generates a base-view video stream and an extended stream from a sequence of original pictures; 
         FIG. 50  is a schematic diagram showing a method of processing color coordinates in the system shown in  FIG. 49 ; 
         FIG. 51  is a block diagram showing an example of a processing system that is built in the system target decoder in extended playback mode to process the base-view video stream and the extended stream; 
         FIG. 52  is a schematic diagram showing a method of processing color coordinates by the bit extender shown in  FIG. 51 ; 
         FIG. 53  is a block diagram showing another example of a processing system that is built in the system target decoder in extended playback mode to process the base-view video stream and the extended stream; 
         FIG. 54  is a schematic diagram showing a method of processing color coordinates by the bit extender shown in  FIG. 53 ; 
         FIG. 55  is a functional block diagram of a recording device according to Embodiment 2 of the present invention; 
         FIG. 56  is a schematic diagram showing a method to align extent ATC times between consecutive extents; 
         FIG. 57  is a flowchart of a method for real-time recording of content onto a BD disc or the like using the recording device shown in  FIG. 55 ; 
         FIG. 58  is a functional block diagram of a recording device according to Embodiment 3 of the present invention; 
         FIG. 59  is a flowchart of a method for recording movie content on a BD-ROM disc using the recording device shown in  FIG. 58 ; 
         FIGS. 60A and 60B  are graphs showing changes in data amounts stored in the RB 1  and RB 3  when a playback device in extended playback mode plays back video images seamlessly from extents placed in arrangement  1  shown in  FIG. 14 , and  FIG. 60C  is a schematic diagram showing the playback path in extended playback mode corresponding to the extents; 
         FIGS. 61A and 61B  are graphs showing changes in data amounts stored in the RB 1  and RB 3  when a playback device in extended playback mode plays back video images seamlessly from extents placed in arrangement  2  shown in  FIG. 15 , and  FIG. 61C  is a schematic diagram showing the playback path in extended playback mode corresponding to the extents; 
         FIGS. 62A and 62B  are graphs showing changes in data amounts stored in the RB 1  and RB 3  when a playback device in extended playback mode plays back video images seamlessly from extents when an extended data specific section, a monoscopic video specific section, and a stereoscopic video specific section are located only immediately before a layer boundary, and  FIG. 62C  is a schematic diagram showing the playback path in extended playback mode corresponding to the extents; 
         FIGS. 63A and 63B  are graphs showing changes in data amounts stored in the RB 1  and RB 3  when a playback device in extended playback mode plays back video images seamlessly from extents when the locations of the monoscopic video specific section and the stereoscopic video specific section are reversed compared to those shown in  FIG. 62C , and  FIG. 63C  is a schematic diagram showing the playback path in extended playback mode corresponding to the extents; and 
         FIG. 64  is a schematic diagram showing technology for ensuring compatibility with 2D playback devices for an optical disc on which 3D video content is recorded. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     The following describes embodiments of the present invention with reference to the drawings. 
     Embodiment 1 
     1: System Structure 
       FIG. 1  is a schematic diagram showing a home theater system that uses a recording medium according to Embodiment 1 of the present invention. In addition to 2D video images and 3D video images at 1920×1080 pixels (hereinafter referred to as full HD (full High Definition)), this home theater system can display 2D video images in 4K2K. As shown in  FIG. 1 , this home theater system plays back a recording medium  101  and includes a playback device  102 , a display device  103 , shutter glasses  104 , and a remote control  105 . 
     The recording medium  101  is a read-only Blu-ray disc (BD, registered trademark), i.e. a BD-ROM disc, and in particular is a multi-layer disc that includes a plurality of recording layers. The BD-ROM disc  101  stores movie content. This content includes a video stream representing 2D video images in full HD, a video stream representing 3D video images, and a video stream representing 2D video images in 4K2K. These video streams are arranged on the BD-ROM disc  101  in units of extents and are accessed using a file structure described below. 
     A BD-ROM drive  121  is mounted on the playback device  102 . The BD-ROM drive  121  is an optical disc drive conforming to the BD-ROM format. The playback device  102  uses the BD-ROM drive  121  to read content from the BD-ROM disc  101 . The playback device  102  further decodes the content into video data/audio data. The playback device  102  can play the content back as 2D video images, as 3D video images, or as 2D video images in 4K2K. Hereinafter, the operational mode of the playback device  102  is referred to as “2D playback mode” when playing back full HD 2D video images, as “3D playback mode” when playing back 3D video images, and as “extended playback mode” when playing back 2D video images in 4K2K. 
     The playback device  102  is connected to the display device  103  via a High-Definition Multimedia Interface (HDMI) cable  122 . The playback device  102  converts the video data/audio data into a video signal/audio signal in the HDMI format and transmits the signals to the display device  103  via the HDMI cable  122 . Additionally, the playback device  102  exchanges CEC messages with the display device  103  via the HDMI cable  122 . The playback device  102  can thus ask the display device  103  whether it supports playback of 3D video images and of video images at 4K2K. 
     The display device  103  is a liquid crystal display. The display device  103  displays video on the screen  131  in response to a video signal, and causes the speakers to produce audio in response to an audio signal. The display device  103  supports playback of 3D video images and of video images at 4K2K. During playback of 2D video images, either the left view or the right view is displayed on the screen  131 . During playback of 3D video images, the left view and right view are alternately displayed on the screen  131 . 
     The display device  103  includes a left/right signal transmitting unit  132 . The left/right signal transmitting unit  132  transmits a left/right signal LR to the shutter glasses  104  via infrared rays or by radio transmission. The left/right signal LR indicates whether the image currently displayed on the screen  131  is a left-view or a right-view image. During playback of 3D video images, the display device  103  detects switching of frames by distinguishing between a left-view frame and a right-view frame based on a control signal that accompanies a video signal. Furthermore, the display device  103  causes the left/right signal transmitting unit  132  to switch the left/right signal LR synchronously with the detected switching of frames. 
     The shutter glasses  104  include two liquid crystal display panels  141 L and  141 R and a left/right signal receiving unit  142 . The liquid crystal display panels  141 L and  141 R respectively constitute the left and right lens parts. The left/right signal receiving unit  142  receives a left/right signal LR, and in accordance with changes therein, transmits the signal to the left and right liquid crystal display panels  141 L and  141 R. In response to the signal, each of the liquid crystal display panels  141 L and  141 R either lets light pass through the entire panel or shuts light out. For example, when the left/right signal LR indicates a left-view display, the liquid crystal display panel  141 L for the left eye lets light pass through, while the liquid crystal display panel  141 R for the right eye shuts light out. When the left/right signal LR indicates a right-view display, the display panels act oppositely. The two liquid crystal display panels  141 L and  141 R thus alternately let light pass through in sync with the switching of frames. As a result, when the viewer looks at the screen  131  while wearing the shutter glasses  104 , the left view is shown only to the viewer&#39;s left eye, and the right view is shown only to the right eye. The viewer is made to perceive the difference between the images seen by each eye as the binocular parallax for the same stereoscopic object, and thus the video image appears to be stereoscopic. 
     The remote control  105  includes an operation unit and a transmitting unit. The operation unit includes a plurality of buttons. The buttons correspond to each of the functions of the playback device  102  and the display device  103 , such as turning the power on or off, starting or stopping playback of the BD-ROM disc  101 , etc. The operation unit detects when the user presses a button and conveys identification information for the button to the transmitting unit as a signal. The transmitting unit converts this signal into a signal IR and outputs it via infrared rays or radio transmission to the playback device  102  or the display device  103 . On the other hand, the playback device  102  and display device  103  each receive this signal IR, determine the button indicated by this signal IR, and execute the function associated with the button. In this way, the user can remotely control the playback device  102  or the display device  103 . 
     2: Data Structure of the BD-ROM Disc 
       FIG. 2  is a schematic diagram showing the data structure of a BD-ROM disc  101 . As shown in  FIG. 2 , a Burst Cutting Area (BCA)  201  is provided at the innermost part of the data recording area on the BD-ROM disc  101 . Only the BD-ROM drive  121  is permitted to access the BCA, and access by application programs is prohibited. The BCA  201  can thus be used as technology for copyright protection. In the data recording area outside of the BCA  201 , tracks spiral from the inner to the outer circumference. In  FIG. 2 , a track  202  is schematically extended in a transverse direction. The left side represents the inner circumferential part of the disc  101 , and the right side represents the outer circumferential part. As shown in  FIG. 2 , track  202  contains a lead-in area  202 A, a volume area  202 B, and a lead-out area  202 C in order from the inner circumference. The lead-in area  202 A is provided immediately on the outside edge of the BCA  201 . The lead-in area  202 A includes information necessary for the BD-ROM drive  121  to access the volume area  202 B, such as the size, the physical address, etc. of the data recorded in the volume area  202 B. The lead-out area  202 C is provided on the outermost circumferential part of the data recording area and indicates the end of the volume area  202 B. The volume area  202 B includes application data such as video images, audio, etc. 
     The volume area  202 B is divided into small areas  202 D called “sectors.” The sectors have a common size, for example 2048 bytes. Each sector  202 D is consecutively assigned a serial number in order from the top of the volume area  202 B. These serial numbers are called logical block numbers (LBN) and are used in logical addresses on the BD-ROM disc  101 . During reading of data from the BD-ROM disc  101 , data to be read is specified through designation of the LBN for the destination sector. The volume area  202 B can thus be accessed in units of sectors. Furthermore, on the BD-ROM disc  101 , logical addresses are substantially the same as physical addresses. In particular, in an area where the LBNs are consecutive, the physical addresses are also substantially consecutive. Accordingly, the BD-ROM drive  121  can consecutively read data from sectors having consecutive LBNs without making the optical pickup perform a seek. 
     The data recorded in the volume area  202 B is managed under a predetermined file system. Universal Disc Format (UDF) is adopted as this file system. Alternatively, the file system may be ISO9660. The data recorded on the volume area  202 B is represented in a directory/file format in accordance with the file system (see “Supplement” for details). In other words, the data is accessible in units of directories or files. 
     As further shown in  FIG. 2 , an index file  211 , an AV (audio-visual) stream file  220 , a clip information file  230 , a playlist file  240 , and a BD program file  250  are recorded in the volume area  202 B. The AV stream file  220  includes a file  2 D  221 , a file dependent (file DEP)  222 , a stereoscopic interleaved file (SSIF; hereinafter referred to as a file SS)  223 , and an extended stream file  224 . The clip information file  230  includes a  2 D clip information file  231 , a dependent-view (DEP) clip information file  232 , and an extended clip information file  233 . The playlist file  240  includes a 2D playlist file  241 , a 3D playlist file  242 , and an extended playlist file  243 . The BD program file  250  includes a movie (MV) object file  251 , a BD-J (BD Java (registered trademark)) object file  252 , and a Java archive (JAR) file  253 . 
     The “index file”  211  contains information for managing as a whole the content recorded on the BD-ROM disc  101 . In particular, this information includes both information to make the playback device  102  recognize the content, as well as an index table. The index table is a correspondence table between titles and BD program files constituting the content. A “BD program file” is a file storing objects. An “object” is a program for controlling operations of the playback device  102 . Object types are a MV object and a BD-J (BD-J) object. 
     An “AV stream file”  220  refers to a file, from among an actual video content recorded on a BD-ROM disc  101 , that complies with the file format determined by the file system. Such an actual video content generally refers to stream data in which different types of stream data representing video, audio, subtitles, etc., i.e. elementary streams, have been multiplexed. This multiplexed stream data has three types: a main transport stream (TS), a sub-TS, and an extended stream. 
     A “main TS” is multiplexed stream data that includes a base-view video stream as a primary video stream. A “base-view video stream” is a video stream that can be played back independently and that represents full HD 2D video images. Note that a base-view is also called a “main-view.” 
     A “sub-TS” is multiplexed stream data that includes a dependent-view video stream as a primary video stream. A “dependent-view video stream” is a video stream that requires a base-view video stream for playback and represents 3D video images by being combined with the base-view video stream. Note that a dependent-view is also called a “sub-view.” The types of dependent-view video streams are a right-view video stream, left-view video stream, and depth map stream. When 2D video images represented by a base-view video stream are used by a playback device as the left view of 3D video images, the “right-view video stream” is used as the video stream representing the right view of the 3D video images. When 2D video images represented by a base-view video stream are used by a playback device as the right view of 3D video images, the “left-view video stream” is used as the video stream representing the left view of the 3D video images. When 2D video images represented by a base-view video stream are used by a playback device as a projection of 3D video images on a virtual 2D screen, the “depth map stream” is used as stream data representing the depth map of the 3D video images (for details, see 5: Modifications). When the playback device  102  is in 3D playback mode and uses the right-view video stream (or the left-view video stream) as the dependent-view video stream, the operation mode is referred to as “left/right (L/R) mode.” On the other hand, when the playback device  102  is in 3D playback mode and uses the depth map stream as the dependent-view video stream, the operation mode is referred to as depth mode. 
     The “extended stream” is multiplexed stream data storing information used in combination with the main TS, i.e. extended data. In Embodiment 1 of the present invention, the extended data includes information necessary for extending full HD 2D video images representing the base-view video stream to 2D video images at 4K2K. 
     The “file  2 D”  221  is an AV stream file used by the playback device  102  in 2D playback mode and includes a main TS. The “file DEP” is an AV stream file that includes a sub-TS. The “file SS”  223  is an AV stream file used by the playback device  102  in 3D playback mode and includes both a main TS and a sub-TS. The “extended stream file  224 ” is an AV stream file used by the playback device  102  in extended playback mode and includes an extended stream. 
     The file SS  223  shares its main TS with a file  2 D  221  and shares its sub-TS with a file DEP  222 . In other words, in the file system on the BD-ROM disc  101 , the main TS can be accessed as either the file SS  223  or the file  2 D  221 , and the sub-TS can be accessed as either the file SS  223  or the file DEP  222 . 
     The clip information file  230  is a file associated on a one-to-one basis with the file  2 D  221 , the file DEP  222 , and the extended stream file  224  and includes an entry map for each of the files  221 ,  222 , and  224 . The “entry map” is a correspondence table between the presentation time for each scene represented by the file  2 D  221 , the file DEP  222 , and the extended stream file  224  and the address within the respective one of the files  221 ,  222 , and  224  at which the scene is recorded. The “2D clip information file”  231  is associated with the file  2 D  221 , the “DEP clip information file”  232  is associated with the file DEP  222 , and the “extension clip information file”  233  is associated with the extended stream file  224 . 
     The “playlist file”  240  is a file that specifies the playback path of the AV stream file  220 . The “playback path” refers to the correspondence between the part of the AV stream file  220  for playback and the order of playback. The “2D playlist file”  241  specifies the playback path of the file  2 D  221 . The “3D playlist file”  242  specifies, for the playback device  102  in 2D playback mode, the playback path of the file  2 D  221 , and for the playback device  102  in 3D playback mode, the playback path of the file SS  223 . The “extended playlist file”  243  specifies, for the playback device  102  in 2D playback mode, the playback path of the file  2 D  221 , and for the playback device  102  in extended playback mode, the playback path of the file  2 D  221  and of the extended stream file  224 . 
     The MV object file  251  generally stores a plurality of MV objects. Each MV object includes a sequence of navigation commands. A navigation command is a control command causing the playback device  102  to execute a playback process similar to general DVD players. Types of navigation commands are, for example, a read-out command to read out a playlist file corresponding to a title, a playback command to play back stream data from an AV stream file indicated by a playlist file, and a transition command to make a transition to another title. Navigation commands are written in an interpreted language and are deciphered by an interpreter, i.e. a job control program, included in the playback device  102 , thus making the control unit execute the desired job. A navigation command is composed of an opcode and an operand. The opcode describes the type of operation that the playback device  102  is to execute, such as dividing, playing back, or calculating a title, etc. The operand indicates identification information targeted by the operation such as the title&#39;s number, etc. The control unit of the playback device  102  calls a MV object in response, for example, to a user operation and executes navigation commands included in the called MV object in the order of the sequence. In a manner similar to general DVD players, the playback device  102  first displays a menu on the display device  103  to allow the user to select a command The playback device  102  then executes playback start/stop of a title, switches to another title, etc. in response to the selected command, thereby dynamically changing the progress of video playback. 
     The BD-J object file  252  includes a single BD-J object. The BD-J object is a bytecode program to cause a Java virtual machine mounted on the playback device  102  to play back a title and render graphics images. The BD-J object is written in a compiler language such as Java or the like. The BD-J object includes an application management table and identification information for the playlist file to which is referred. The “application management table” is a list of the Java application programs to be executed by the Java virtual machine and their period of execution, i.e. lifecycle. The “identification information of the playlist file to which is referred” identifies a playlist file that corresponds to a title to be played back. The Java virtual machine calls a BD-J object in response to a user operation or an application program and executes the Java application program according to the application management table included in the BD-J object. Consequently, the playback device  102  dynamically changes the progress of the video for each title played back, or causes the display device  103  to display graphics images independently of the title video. 
     The JAR directory  253  generally includes a plurality of actual Java application programs to be executed in accordance with the application management table shown in the BD-J object. A “Java application program” is a bytecode program written in a compiler language such as Java or the like, as is the BD-J object. Types of Java application programs include programs causing the Java virtual machine to perform playback of a title and programs causing the Java virtual machine to render graphics images. The JAR file  261  is a Java archive file, and when it is read by the playback device  102 , it is loaded in internal memory. In this way, a Java application program is stored in memory. 
     2-1: Structure of Multiplexed Stream Data 
       FIG. 3A  is a list of elementary streams multiplexed in a main TS on a BD-ROM disc  101 . The main TS is a digital stream in MPEG-2 Transport Stream (TS) format and includes the file  2 D  221  shown in  FIG. 2 . As shown in  FIG. 3A , the main TS includes a primary video stream  301  and primary audio streams  302 A and  302 B. The main TS may additionally include presentation graphics (PG) streams  303 A and  303 B, an interactive graphics (IG) stream  304 , a secondary audio stream  305 , and a secondary video stream  306 . 
     The primary video stream  301  represents the primary video of a movie, and the secondary video stream  306  represents secondary video of the movie. The primary video is the main video pertaining to the content, such as the main feature of a movie, and is displayed on the entire screen, for example. On the other hand, the secondary video is displayed on the screen simultaneously with the primary video with the use, for example, of a picture-in-picture method, so that the secondary video images are displayed in a smaller window within the primary video images. The primary video stream  301  and the secondary video stream  306  are both a base-view video stream. Each of the video streams  301  and  306  is encoded by a video compression encoding method, such as MPEG-2, MPEG-4 AVC, or SMPTE VC-1. Each of the video frames included in the video streams  301  and  306  is thus compressed into one picture. Here, a “video frame” is a 2D array of pixel data, the size of the array being equal to the resolution of the frame. For example, a full HD video frame is a 1920×1080 2D array. A set of pixel data is formed by a combination of chromatic coordinate values and an a value (opacity). The chromatic coordinate value is expressed as 8-bit RGB values or YCrCb values. The α value is also an 8-bit value. 
     The primary audio streams  302 A and  302 B represent the primary audio of the movie. In this case, the two primary audio streams  302 A and  302 B are in different languages. The secondary audio stream  305  represents secondary audio to be mixed with the primary audio, such as sound effects accompanying operation of an interactive screen. Each of the audio streams  302 A,  302 B, and  305  is encoded by a method such as AC-3, Dolby Digital Plus (“Dolby Digital” is a registered trademark), Meridian Lossless Packing™ (MLP), Digital Theater System™ (DTS), DTS-HD, or linear Pulse Code Modulation (PCM). The audio frames included in the audio streams  302 A,  302 B, and  305  are thus individually compressed. 
     Each of the PG streams  303 A and  303 B represents graphics images, such as subtitles formed by graphics, to be displayed superimposed on the video images represented by the primary video stream  301 . The two PG streams  303 A and  303 B represent, for example, subtitles in a different language. The IG stream  304  represents Graphical User Interface (GUI) graphics elements, and the arrangement thereof, for constructing an interactive screen on the screen  131  in the display device  103 . 
     The elementary streams  301 - 306  are identified by packet identifiers (PIDs). PIDs are assigned, for example, as follows. Since one main TS includes only one primary video stream, the primary video stream  301  is assigned a hexadecimal value of 0x1011. When up to 32 other elementary streams can be multiplexed by type in one main TS, the primary audio streams  302 A and  302 B are each assigned any value from 0x1100 to 0x111F. The PG streams  303 A and  303 B are each assigned any value from 0x1200 to 0x121F. The IG stream  304  is assigned any value from 0x1400 to 0x141F. The secondary audio stream  305  is assigned any value from 0x1A00 to 0x1A1F. The secondary video stream  306  is assigned any value from 0x1B00 to 0x1B1F. 
       FIG. 3B  is an example of a list of elementary streams multiplexed in a sub-TS on a BD-ROM disc  101 . The sub-TS is multiplexed stream data in MPEG-2 TS format and is included in the file DEP  222  shown in  FIG. 2 . As shown in  FIG. 3B , the sub-TS includes a primary video stream  311 . The sub-TS may additionally include left-view PG streams  312 A and  312 B, right-view PG streams  313 A and  313 B, a left-view IG stream  314 , a right-view IG stream  315 , and a secondary video stream  316 . When the primary video stream  301  in the main TS represents the left view of 3D video images, the primary video stream  311 , which is a right-view video stream, represents the right view of the 3D video images. The pairs of left-view and right-view PG streams  312 A+ 313 A and  312 B+ 313 B represent the left view and right view of graphics images, such as subtitles, when these graphics images are displayed as 3D video images. The pair of left-view and right-view IG streams  314  and  315  represent the left view and right view of graphics images for an interactive screen when these graphics images are displayed as 3D video images. When the secondary video stream  306  in the main TS represents the left view of 3D video images, the secondary video stream  316 , which is a right-view video stream, represents the right view of the 3D video images. 
     PIDs are assigned to the elementary streams  311 - 316  as follows, for example. A PID of 0x1012 is assigned to the primary video stream  311 . When up to 32 other elementary streams can be multiplexed by type in one sub-TS, the left-view PG streams  312 A and  312 B are assigned any value from 0x1220 to 0x123F, and the right-view PG streams  313 A and  313 B are assigned any value from 0x1240 to 0x125F. The left-view IG stream  314  is assigned any value from 0x1420 to 0x143F, and the right-view IG stream  315  is assigned any value from 0x1440 to 0x145F. The secondary video stream  316  is assigned any value from 0x1B20 to 0x1B3F. 
       FIG. 3C  is another example of a list of elementary streams multiplexed in the sub-TS on the BD-ROM disc  101 . As shown in  FIG. 3C , the sub-TS includes a primary video stream  321 . The sub-TS may additionally include depth map PG streams  323 A and  323 B, a depth map IG stream  324 , and a secondary video stream  326 . The primary video stream  321  is a depth map stream and represents 3D video images in combination with the primary video stream  301  in the main TS. When the 2D video images represented by the PG streams  303 A and  303 B in the main TS are used to project 3D video images on a virtual 2D screen, the depth map PG streams  323 A and  323 B are used as the PG streams representing a depth map for the 3D video images. When the 2D video images represented by the IG stream  304  in the main TS are used to project 3D video images on a virtual 2D screen, the depth map IG stream  324  is used as the IG stream representing a depth map for the 3D video images. The secondary video stream  326  is a depth map stream and represents 3D video images in combination with the secondary video stream  306  in the main TS. 
     PIDs are assigned to the elementary streams  321 - 326  as follows, for example. A PID of 0x1013 is assigned to the primary video stream  321 . When up to 32 other elementary streams can be multiplexed by type in one sub-TS, the depth map PG streams  323 A and  323 B are assigned any value from 0x1260 to 0x127F. The depth map IG stream  324  is assigned any value from 0x1460 to 0x147F. The secondary video stream  326  is assigned any value from 0x1B40 to 0x1B5F. 
       FIG. 3D  is a list of elementary streams multiplexed in an extended stream on a BD-ROM disc  101 . As shown in  FIG. 3D , the extended stream includes resolution extension information  331  as extended data. The resolution extension information  331  is information necessary for extending each full HD video frame included in the primary video stream  301  in the main TS to a 4K2K video frame. A value of 0x1014 is allocated as the PID to the resolution extension information  331 . 
       FIG. 4A  shows the data structure of resolution extension information. As illustrated in  FIG. 4A , the resolution extension information includes an extended resolution  401 , interpolation method  402 , and pixel difference information  403  for each video frame. The extended resolution  401  indicates a 4K2K resolution. The interpolation method  402  indicates an interpolation method to be used to increase the number of pieces of pixel data included in a full HD video frame to the number of pieces of pixel data included in a 4K2K video frame. The interpolation methods include bicubic and bilinear methods. The pixel difference information  403  represents the difference between the pixel data obtained by interpolation from a full HD video frame and the pixel data included in the original 4K2K video frame. When pixel data is represented as YCrCb values, the pixel difference information  403  includes a difference Y_d in the luminance component Y, a difference Cr_d in the red-difference component Cr, a difference Cb_d in the blue-difference component Cb, and a difference α_d in the opacity α. 
       FIG. 4B  is a schematic diagram showing the role of resolution extension information in the process to extend a full HD video frame to a 4K2K video frame. This process requires the following two steps. In the first step  410 , interpolation is performed based on pixel data  411  included in a full HD video frame. New pixel data  412  is thus added to the video frame. As a result, the total number of pieces of pixel data is increased to the number of pieces of pixel data included in a 4K2K video frame. The extended resolution  401  specifies the increased number of pieces of pixel data as a resolution. The interpolation method  402  specifies the interpolation method to be used in the first step. In the second step, the pixel difference information  403  is added to the pieces of pixel data  411 ,  412  in the video frame obtained by the interpolation. As a result, pieces of pixel data  413  included in the original 4K2K video frame are reconstructed. 
       FIG. 5  is a schematic diagram showing the arrangement of TS packets in the multiplexed stream data  500 . The same packet structure is shared by the main TS, sub-TS, and the extended stream. In the multiplexed stream data  500 , the elementary streams  501 ,  502 ,  503 , and  504  are respectively converted into sequences of TS packets  521 ,  522 ,  523 , and  524 . For example, in the video stream  501 , each video frame  501 A is first converted into one Packetized Elementary Stream (PES) packet  511 . Next, each PES packet  511  is generally converted into a plurality of TS packets  521 . Similarly, the audio stream  502 , PG stream  503 , and IG stream  504  are respectively first converted into a sequence of PES packets  512 ,  513 , and  514 , after which they are converted into a sequence of TS packets  522 ,  523 , and  524 . Finally, the TS packets  521 ,  522 ,  523 , and  524  obtained from the elementary streams  501 ,  502 ,  503 , and  504  are time-multiplexed into one piece of stream data  500 . 
       FIG. 6B  is a schematic diagram showing a TS packet sequence constituting multiplexed stream data. Each TS packet  601  is 188 bytes long. As shown in  FIG. 6B , each TS packet  601  includes a TS header  601 H and either, or both, a TS payload  601 P and an adaptation field (hereinafter abbreviated as “AD field”)  601 A. The TS payload  601 P and AD field  601 A together constitute a 184 byte-long data area. The TS payload  601 P is used as a storage area for a PES packet. The PES packets  511 - 414  shown in  FIG. 5  are typically divided into a plurality of parts, and each part is stored in a different TS payload  601 P. The AD field  601 A is an area for storing stuffing bytes (i.e. dummy data) when the amount of data in the TS payload  601 P does not reach 184 bytes. Additionally, when the TS packet  601  is, for example, a PCR as described below, the AD field  601 A is used as a region for storing such information. The TS header  601 H is a four-byte long data area. 
       FIG. 6A  is a schematic diagram showing the data structure of a TS header  601 H. As shown in  FIG. 6A , the TS header  601 H includes a TS priority  611 , a PID  612 , and an AD field control  613 . The PID  612  indicates the PID for the elementary stream whose data is stored in the TS payload  601 P of the TS packet  601  containing the PID  512 . The TS priority  611  indicates the degree of priority of the TS packet  601  among the TS packets that share the value indicated by the PID  612 . The AD field control  613  indicates whether the TS packet  601  contains an AD field  601 A and/or a TS payload  601 P. 
       FIG. 6C  is a schematic diagram showing the formation of a source packet sequence composed of the TS packet sequence for multiplexed stream data. As shown in  FIG. 6C , each source packet  602  is 192 bytes long and includes one TS packet  601 , shown in  FIG. 6B , and a four-byte long header  602 H. When the TS packet  601  is recorded on the BD-ROM disc  101 , a source packet  602  is constituted by attaching a header  602 H to the TS packet  601 . The header  602 H includes an ATS (Arrival_Time_Stamp). The “ATS” is time information used by a system target decoder in the playback device  102  as follows. The “system target decoder” is a device that decodes multiplexed stream data one elementary stream at a time. When a source packet  602  is sent from the BD-ROM disc  101  to the system target decoder, the system target decoder extracts the TS packet  602 P from the source packet  602  and transfers the TS packet  602 P to a PID filter. The system target decoder transfers the TS packet  602 P at a point in time when the value of an internal clock, referred to as an arrival time clock (ATC), matches with the ATS in the header  602 H of the source packet  602 . Details regarding the system target decoder and its use of the ATS are provided below. 
       FIG. 6D  is a schematic diagram of sectors located in the volume area  202 B of the BD-ROM disc  101 , in which a sequence of source packets  602  are consecutively recorded. As shown in  FIG. 6D , each sequence of 32 source packets  602  is recorded on three consecutive sectors  621 ,  622 , and  623 . This is because the data amount for 32 source packets, i.e. 192 bytes×32=6144 bytes, is the same as the total size of three sectors, i.e. 2048 bytes×3=6144 bytes. 32 source packets  602  that are recorded in this way in three consecutive sectors  621 ,  622 , and  623  are referred to as an “aligned unit”  620 . The BD-ROM drive  121  in the playback device  102  reads source packets  602  from the BD-ROM disc  101  by each aligned unit  620 , i.e. 32 source packets at a time. The sectors  621 ,  622 ,  623 , . . . are divided into sections of 32 sectors in order from the top, each section forming one error correcting code (ECC) block  630 . The BD-ROM drive  121  performs error correction process for each ECC block  630 . 
     Data Structure of the PG Stream 
     The PG stream includes a plurality of data entries. The data entries represent the PG stream in display sets and are composed of data necessary for the playback device  102  to form one graphics plane. A “graphics plane” refers to plane data generated from graphics data representing a 2D graphics image. “Plane data” is a two-dimensional array of pixel data. The size of the array is the same as the resolution of the video frame. Types of graphics planes include a PG plane, IG plane, image plane, and On-Screen Display (OSD) plane. A PG plane is generated from a PG stream in the main TS. An IG plane is generated from an IG stream in the main TS. An image plane is generated in accordance with a BD-J object. An OSD plane is generated in accordance with firmware in the playback device  102 . 
     Each data entry includes a plurality of functional segments. In order from the top, these functional segments include a Presentation Control Segment (PCS), Window Define Segment (WDS), Palette Define Segment (PDS), and Object Define Segment (ODS). WDS defines a rectangular region inside the graphics plane, i.e. a window. PDS defines the correspondence between a predetermined type of color ID and a chromatic coordinate value (for example, luminance Y, red-difference Cr, blue-difference Cb, and opacity α). There are usually a plurality of ODSs, which represent one graphics object. A “graphics object” is data that expresses graphics rendering via correspondence between pixel codes and color IDs. After being compressed via run-length encoding, a graphics object is divided up and distributed among ODSs. A PCS indicates details on display sets belonging to the same data entry and in particular defines a screen layout that uses graphics objects. Types of screen layout include Cut-In/Out, Fade-In/Out, Color Change, Scroll, and Wipe-In/Out. A content provider refers to the parameters of the PCS to indicate the screen layout to the playback device  102 . Accordingly, it is possible to cause the playback device  102  to implement a visual effect whereby, for example, “a certain subtitle gradually disappears, and the next subtitle is displayed.” 
     2-2: Data Structure of the IG Stream 
     The IG stream includes an Interactive Composition Segment (ICS), PDS, and ODS. PDS and ODS are the same functional segments as included in the PG stream. In particular, a graphics object that includes an ODS represents a GUI graphics element, such as a button, pop-up menu, etc., that forms an interactive screen. An ICS defines interactive operations that use these graphics objects. Specifically, an ICS defines the states that each graphics object, such as a button, pop-up menu, etc. can take when changed in response to user operation, states such as normal, selected, and active. An ICS also includes button information. Button information includes a command that the playback device  102  is to perform when the user performs a certain operation on the button or the like. 
     2-3: Data Structure of the Video Stream 
       FIG. 7  is a schematic diagram showing the pictures for a base-view video stream  701  and a right-view video stream  702  in order of presentation time. As shown in  FIG. 7 , the base-view video stream  701  includes pictures  710 ,  711 ,  712 , . . . ,  719  (hereinafter “base-view pictures”), and the right-view video stream  702  includes pictures  720 ,  721 ,  722 , . . . ,  729  (hereinafter “right-view pictures”). Each of the pictures  710 - 719  and  720 - 729  represents one frame and is compressed by a video compression encoding method, such as MPEG-2, MPEG-4 AVC, etc. 
     This compression of each picture via the above encoding uses the picture&#39;s spatial or temporal redundancy. Here, picture encoding that only uses the picture&#39;s spatial redundancy is referred to as “intra-picture encoding.” On the other hand, picture encoding that uses temporal redundancy, i.e. the similarity between data for a plurality of pictures displayed sequentially, is referred to as “inter-picture predictive encoding.” In inter-picture predictive encoding, first, a picture earlier or later in presentation time is assigned to the picture to be encoded as a reference picture. Next, a motion vector is detected between the picture to be encoded and the reference picture, and then motion compensation is performed using the motion vector. Furthermore, the difference value between the picture after motion compensation and the picture to be encoded is sought, and spatial redundancy is removed using the difference value. In this way, the amount of data for each picture is compressed. 
     As shown in  FIG. 7 , the base-view pictures  710 - 719  are typically divided into a plurality of GOPs  731  and  732 . A “GOP” refers to a sequence of pictures having an I (Intra) picture at the top of the sequence. An “I picture” refers to a picture compressed by intra-picture encoding. In addition to an I picture, a GOP typically includes P (Predictive) and B (Bidirectionally Predictive) pictures. A “P picture” refers to a picture compressed by inter-picture predictive encoding, having used as a reference picture one picture, either an I picture or another P picture, that has an earlier presentation time. A “B picture” refers to a picture compressed by inter-picture predictive encoding, having used as a reference picture two pictures, either I pictures or other P pictures, that have an earlier or later presentation time. B pictures that are used as a reference picture for other pictures in inter-picture predictive encoding are particularly referred to as “Br (reference B) pictures.” 
     In the example shown in  FIG. 7 , the base-view pictures in the GOPs  731  and  732  are compressed in the following order. In the first GOP  731 , the top base-view picture is compressed as I 0  picture  710 . The subscripted number indicates the serial number allotted to each picture in order of presentation time. Next, the fourth base-view picture is compressed as P 3  picture  713  using I 0  picture  710  as a reference picture. The arrows shown in  FIG. 7  indicate that the picture at the head of the arrow is a reference picture for the picture at the tail of the arrow. Next, the second and third base-view pictures are respectively compressed as Br 1  picture  711  and Br 2  picture  712 , using both I 0  picture  710  and P 3  picture  713  as reference pictures. Furthermore, the seventh base-view picture is compressed as P 6  picture  716  using P 3  picture  713  as a reference picture. Next, the fourth and fifth base-view pictures are respectively compressed as Br 4  picture  714  and Br 5  picture  715 , using both P 3  picture  713  and P 6  picture  716  as reference pictures. Similarly, in the second GOP  732 , the top base-view picture is first compressed as I 7  picture  717 . Next, the third base-view picture is compressed as P 9  picture  719  using I 7  picture  717  as a reference picture. Subsequently, the second base-view picture is compressed as Br 8  picture  718  using both I 7  picture  717  and P 9  picture  719  as reference pictures. 
     In the base-view video stream  701 , each GOP  731  and  732  always contains an I picture at the top, and thus base-view pictures can be decoded GOP by GOP. For example, in the first GOP  731 , the I 0  picture  710  is first decoded independently. Next, the P 3  picture  713  is decoded using the decoded I 0  picture  710 . Then the Br 1  picture  711  and Br 2  picture  712  are decoded using both the decoded I 0  picture  710  and P 3  picture  713 . The subsequent pictures  714 ,  715 , . . . are similarly decoded. In this way, the base-view video stream  701  can be decoded independently and furthermore can be randomly accessed in units of GOPs. 
     As further shown in  FIG. 7 , the right-view pictures  720 - 729  are compressed by inter-picture predictive encoding. However, the encoding method differs from the encoding method for the base-view pictures  710 - 719 , since in addition to redundancy in the temporal redundancy of video images, redundancy between the left and right-video images is also used. Specifically, as shown by the arrows in  FIG. 7 , the reference picture for each of the right-view pictures  720 - 729  is not selected from the right-view video stream  702 , but rather from the base-view video stream  701 . In particular, the presentation time is substantially the same for each of the right-view pictures  720 - 729  and the corresponding base-view picture selected as a reference picture. These pictures represent a right view and a left view for the same scene of a 3D video image, i.e. a parallax video image. The right-view pictures  720 - 729  and the base-view pictures  710 - 719  are thus in one-to-one correspondence. In particular, the GOP structure is the same between these pictures. 
     In the example shown in  FIG. 7 , the top right-view picture in the first GOP  731  is compressed as P 0  picture  720  using I 0  picture  710  in the base-view video stream  701  as a reference picture. These pictures  710  and  720  represent the left view and right view of the top frame in the 3D video images. Next, the fourth right-view picture is compressed as P 3  picture  723  using P 3  picture  713  in the base-view video stream  701  and P o  picture  720  as reference pictures. Next, the second right-view picture is compressed as B 1  picture  721 , using Br 1  picture  711  in the base-view video stream  701  in addition to P 0  picture  720  and P 3  picture  723  as reference pictures. Similarly, the third right-view picture is compressed as B 2  picture  722 , using Br 2  picture  712  in the base-view video stream  701  in addition to P 0  picture  720  and P 3  picture  730  as reference pictures. For each of the remaining right-view pictures  724 - 729 , a base-view picture with a presentation time substantially the same as the right-view picture is similarly used as a reference picture. 
     The revised standards for MPEG-4 AVC/H.264, called Multiview Video Coding (MVC), are known as a video compression encoding method that makes use of correlation between left and right-video images as described above. MVC was created in July of 2008 by the Joint Video Team (JVT), a joint project between ISO/IEC MPEG and ITU-T VCEG, and is a standard for collectively encoding video that can be seen from a plurality of perspectives. With MVC, not only is temporal similarity in video images used for inter-video predictive encoding, but so is similarity between video images from differing perspectives. This type of predictive encoding has a higher video compression ratio than predictive encoding that individually compresses data of video images seen from each perspective. 
     As described above, a base-view picture is used as a reference picture for compression of each of the right-view pictures  720 - 729 . Therefore, unlike the base-view video stream  701 , the right-view video stream  702  cannot be decoded independently. On the other hand, however, the difference between parallax video images is generally very small; that is, the correlation between the left view and the right view is high. Accordingly, the right-view pictures generally have a significantly higher compression rate than the base-view pictures, meaning that the amount of data is significantly smaller. 
     While not shown in  FIG. 7 , a depth map stream includes a plurality of depth maps. The depth maps are in one-to-one correspondence with base-view pictures and each represent the depth map corresponding to a 2D video image in one field as indicated by a base-view picture. The depth maps are compressed by a video compression encoding method, such as MPEG-2, MPEG-4 AVC, etc., in the same way as the base-view pictures. In particular, inter-picture predictive encoding is used in this encoding method. In other words, each depth map is compressed using another depth map as a reference picture. Furthermore, the depth map stream is divided into units of GOPs in the same way as the base-view video stream, and each GOP always contains an I picture at the top. Accordingly, depth maps can be decoded GOP by GOP. However, since a depth map itself is only information representing the depth of each part of a 2D video image pixel by pixel, the depth map stream cannot be used independently for playback of video images. The encoding method used in compression of the depth map stream is the same as that used in compression of the right-view video stream. For example, if the right-view video stream is encoded in MVC format, the depth map stream is also encoded in MVC format. In this case, during playback of 3D video images, the playback device  102  can smoothly switch between L/R mode and depth mode, while maintaining a constant encoding method. 
       FIG. 8  is a schematic diagram showing details on the data structure of a video stream  800 . This data structure is substantially the same for the base-view video stream and the dependent-view video stream. As shown in  FIG. 8 , the video stream  800  is generally composed of a plurality of video sequences # 1 , # 2 , . . . . A “video sequence” is a combination of pictures  811 ,  812 ,  813 ,  814 , . . . that constitute a single GOP  810  and to which additional information, such as a header, has been individually attached. The combination of this additional information and a picture is referred to as a “video access unit (VAU).” That is, in the GOPs  810  and  820 , a single VAU # 1 , # 2 , . . . is formed for each picture. Each picture can be read from the video stream  800  in units of VAUs. 
       FIG. 8  further shows the structure of VAU # 1   831  located at the top of each video sequence in the base-view video stream. The VAU # 1   831  includes an access unit (AU) identification code  831 A, sequence header  831 B, picture header  831 C, supplementary data  831 D, and compressed picture data  831 E. Except for not including a sequence header  831 B, VAUs from the second VAU # 2  on have the same structure as VAU # 1   831 . The AU identification code  831 A is a predetermined code indicating the top of the VAU # 1   831 . The sequence header  831 B, also called a GOP header, includes an identification number for the video sequence # 1  which includes the VAU # 1   831 . The sequence header  831 B further includes information shared by the whole GOP  810 , e.g. resolution, frame rate, aspect ratio, and bit rate. The picture header  831 C indicates a unique identification number, the identification number for the video sequence # 1 , and information necessary for decoding the picture, such as the type of encoding method. The supplementary data  831 D includes additional information regarding matters other than the decoding of the picture, for example closed caption text information, information on the GOP structure, and time code information. The compressed picture data  831 E includes a base-view picture. 
     Additionally, the VAU # 1   831  may include any or all of padding data  831 F, a sequence end code  831 G, and a stream end code  831 H as necessary. The padding data  831 F is dummy data. By adjusting the size of the padding data  831 F to match with the size of the compressed picture data  831 E, the bit rate of the VAU # 1   831  can be maintained at a predetermined value. The sequence end code  831 G indicates that the VAU # 1   831  is located at the end of the video sequence # 1 . The stream end code  831 H indicates the end of the base-view video stream  800 . 
       FIG. 8  also shows the structure of a VAU # 1   832  located at the top of each video sequence in the dependent-view video stream. The VAU # 1   832  includes a sub-sequence header  832 B, picture header  832 C, supplementary data  832 D, and compressed picture data  832 E. Except for not including a sub-sequence header  832 B, VAUs from the second VAU # 2  on have the same structure as VAU # 1   832 . The sub-sequence header  832 B includes an identification number for the video sequence # 1  which includes the VAU # 1   832 . The sub-sequence header  832 B further includes information shared by the whole GOP  810 , e.g. resolution, frame rate, aspect ratio, and bit rate. These values are the same as the values set for the corresponding GOP in the base-view video stream, i.e. the values shown by the sequence header  831 B in the VAU # 1   831 . The picture header  832 C indicates a unique identification number, the identification number for the video sequence # 1 , and information necessary for decoding the picture, such as the type of encoding method. The supplementary data  832 D includes additional information regarding matters other than the decoding of the picture, for example closed caption text information, information on the GOP structure, and time code information. The compressed picture data  832 E includes a dependent-view picture. 
     Additionally, the VAU # 1   831  may include any or all of padding data  832 F, a sequence end code  832 G, and a stream end code  832 H as necessary. The padding data  832 F is dummy data. By adjusting the size of the padding data  832 F in conjunction with the size of the compressed picture data  831 E, the bit rate of the VAU # 1   832  can be maintained at a predetermined value. The sequence end code  832 G indicates that the VAU # 1   832  is located at the end of the video sequence # 1 . The stream end code  832 H indicates the end of the dependent-view video stream  800 . 
     The specific content of each component in a VAU differs according to the encoding method of the video stream  800 . For example, when the encoding method is MPEG-4 AVC, the components in the VAUs shown in  FIG. 8  are composed of a single Network Abstraction Layer (NAL) unit. Specifically, the AU identification code  831 A, sequence header  831 B, picture header  831 C, supplementary data  831 D, compressed picture data  831 E, padding data  831 F, sequence end code  831 G, and stream end code  831 H respectively correspond to an Access Unit (AU) delimiter, Sequence Parameter Set (SPS), Picture Parameter Set (PPS), Supplemental Enhancement Information (SEI), View Component, Filler Data, End of Sequence, and End of Stream. 
       FIG. 9  is a schematic diagram showing details on a method for storing a video stream  901  into a PES packet sequence  902 . This storage method is the same for the base-view video stream and the dependent-view video stream. As shown in  FIG. 9 , in the actual video stream  901 , pictures are multiplexed in the order of encoding, not in the order of presentation time. For example, in the VAUs in the base-view video stream, as shown in  FIG. 9 , I 0  picture  910 , P 3  picture  911 , B 1  picture  912 , B 2  picture  913 , . . . are stored in order from the top. The subscripted number indicates the serial number allotted to each picture in order of presentation time. I 0  picture  910  is used as a reference picture for encoding P 3  picture  911 , and both I 0  picture  910  and P 3  picture  911  are used as reference pictures for encoding B 1  picture  912  and B 2  picture  913 . Each of these VAUs is stored as a different PES packet  920 ,  921 ,  922 ,  923 , . . . . Each PES packet  920 , . . . includes a PES payload  920 P and a PES header  920 H. Each VAU is stored in a PES payload  920 P. Each PES header  920 H includes a presentation time, (Presentation Time-Stamp, or PTS), and a decoding time (Decoding Time-Stamp, or DTS), for the picture stored in the PES payload  920 P in the same PES packet  920 . The “PTS” indicates the timing at which data, such as a picture, decoded by a decoder in the playback device  102  is output by the decoder. The “DTS” indicates the timing at which to cause the decoder to begin decoding the data, such as a picture. 
     As with the video stream  901  shown in  FIG. 9 , the other elementary streams shown in  FIG. 3  are stored in PES payloads in a sequence of PES packets. Furthermore, the PES header in each PES packet includes the PTS for the data stored in the PES payload for the PES packet. 
       FIG. 10  is a schematic diagram showing correspondence between PTSs and DTSs assigned to each picture in a base-view video stream  1001  and a dependent-view video stream  1002 . As shown in  FIG. 10 , between the video streams  1001  and  1002 , the same PTSs and DTSs are assigned to a pair of pictures representing the same frame in a 3D video image. For example, the top frame in the 3D video image is rendered from a combination of I 1  picture  1011  in the base-view video stream  1001  and P 1  picture  1021  in the dependent-view video stream  1002 . Accordingly, the PTS and DTS for these two pictures  1011  and  1021  are the same. The subscripted numbers indicate the serial number allotted to each picture in the order of DTSs. Also, when the dependent-view video stream  1002  is a depth map stream, P 1  picture  1021  is replaced by an I picture representing a depth map for the I 1  picture  1011 . Similarly, the PTS and DTS for the pair of second pictures in the video streams  1001  and  1002 , i.e. P 2  pictures  1012  and  1022 , are the same. The PTS and DTS are both the same for the pair of third pictures in the video streams  1001  and  1002 , i.e. Br 3  picture  1013  and B 3  picture  1023 . The same is also true for the pair Br 4  picture  1014  and B 4  picture  1024 . 
     A pair of VAUs that include pictures for which the PTS and DTS are the same between the base-view video stream  1001  and the dependent-view video stream  1002  is called a “3D VAU.” Using the allocation of PTSs and DTSs shown in  FIG. 10 , it is easy to cause the decoder in the playback device  102  in 3D playback mode to process the base-view video stream  1001  and the dependent-view video stream  1002  in parallel in units of 3D VAUs. In this way, the decoder definitely processes a pair of pictures representing the same frame in a 3D video image in parallel. Furthermore, the sequence header in the 3D VAU at the top of each GOP includes the same resolution, the same frame rate, and the same aspect ratio. In particular, this frame rate is equal to the value when the base-view video stream  1001  is decoded independently in 2D playback mode. 
     2-4: Other TS Packets Included in the AV Stream File 
     In addition to the TS packets converted from the elementary stream as shown in  FIG. 3 , the types of TS packets included in an AV stream file include a Program Association Table (PAT), Program Map Table (PMT), and Program Clock Reference (PCR). The PCR, PMT, and PAT are specified by the European Digital Broadcasting Standard and regulate the AV stream in the same way as the partial transport stream constituting a single program. Specifically, the PAT shows the PID of a PMT included in the same AV stream file. The PID of the PAT itself is 0. The PMT includes the PID of each elementary stream included in the AV stream file and the corresponding attribute information. The attribute information includes identification information for the codec used for compressing the elementary stream as well as a frame rate and an aspect ratio of the elementary stream. The PMT also includes various descriptors relating to the AV stream file. The descriptors indicate attributes shared throughout the AV stream file and particularly include copy control information showing whether copying of the AV stream file is permitted or not. The PCR includes information indicating the value of a system time clock (STC) to be associated with the ATS assigned to the PCR itself. The STC referred to here is a clock used as a reference for the PTS and the DTS by a decoder in the playback device  102 . This decoder uses the PCR to synchronize the STC with the ATC. By using PCR, PMT, and PAT, the decoder in the playback device  102  can be made to process the AV stream file in the same way as the partial transport stream in the European Digital Broadcasting Standard. In this way, it is possible to ensure compatibility between a playback device for the BD-ROM disc  101  and a terminal device conforming to the European Digital Broadcasting Standard. 
     2-5: Interleaved Arrangement of Multiplexed Stream Data 
     In order to seamlessly play back any of full HD 2D video images, 3D video images, and 4K2K 2D video images from the BD-ROM disc  101 , it is important how to physically arrange the base-view video stream, the dependent-view video stream, and the extended stream on the BD-ROM disc  101 . “Seamless playback” refers to playing back images and sounds from multiplexed stream data without interruption. 
       FIG. 11  is a schematic diagram showing a physical arrangement of a main TS, a sub-TS, and an extended stream on the BD-ROM disc  101 . As shown in  FIG. 11 , the main TS, the sub-TS, and the extended stream are divided into a plurality of data blocks B[n], D[n], and T[n], respectively (n=0, 1, 2, 3, . . . ). The number “n” is a serial number allocated to the data blocks constituting a sequence of multiplexed stream data, starting from their top. The data blocks B[n], D[n], and T[n] are recorded in a plurality of sectors physically contiguous on the BD-ROM disc  101 . The (n+1) th  data block B[n] of the main TS can be accessed as the (n+1) th  extent EXT 2 D[n] of the file  2 D  221 . The (n+1) th  data block D[n] of the sub-TS can be accessed as the (n+1) th  extent EXT 2 [n] of the file DEP  222 . The (n+1) th  data block T[n] of the extended stream can be accessed as the (n+1) th  extent EXT  3 [n] of the extended stream file  224 . In other words, the size and the first LBN of the data blocks B[n], D[n], and T[n] can be known from the file entries of the file  2 D  221 , the file DEP  222 , and the extended stream file  224 , respectively (see “Supplement” for details). Since physical addresses on the BD-ROM disc  101  are substantially the same as logical addresses thereon, LBNs are also continuous within each of the data blocks B[n], D[n], and T[n]. Accordingly, the BD-ROM drive  121  can continuously read the data blocks B[n], D[n], and T[n] without causing the optical pickup to perform a seek. Hereinafter, the data blocks B[n] belonging to the main TS are referred to as “base-view extents,” the data blocks D[n] belonging to the sub-TS are referred to as “dependent-view extents,” and the data blocks T[n] belonging to the extended stream are referred to as “extended extents.” 
     As shown in  FIG. 11 , the extents B[n], D[n], and T[n] are recorded continuously along a track on the BD-ROM disc  101 . In particular, immediately after one extended extent T[n], at least two base-view extents B[n+1] and at least two dependent-view extents D[n+1] are arranged alternately (i=0, 1). This arrangement of the extents B[n+1], D[n+1] is referred to as an “interleaved arrangement,” and the sequence of extents B[n+1], D[n+1] recorded in an interleaved arrangement is referred to as an “extent block.” Each extent blocks can be accessed as one extent EXTSS[n] of the file SS  223 . In other words, the size and the first LBN of the extent block B[n+i], D[n+1] can be known from the file entry of the file SS  223 . The extents EXTSS[ 0 ], EXTSS[ 1 ], and EXTSS[ 2 ] of the file SS share the base-view extents B[n] with the file  2 D  221  and share the dependent-view extents D[n] with the file DEP  222 . Furthermore, the combination of one extended extent T[n] and the extent block B[n+i], D[n+i] arranged immediately thereafter is referred to as an “extended extent block.” 
     Playback Path for Continuous Extended Extent Blocks 
       FIG. 12  is a schematic diagram showing three types of playback paths,  1201 ,  1202 , and  1203 , for three continuous extended extent blocks T[m], D[m+i], B[m+i] (m=0, 1, 2, i=0, 1). The first playback path  1201  is a playback path for the file 2D  221 . The second playback path  1202  is a playback path for the file SS  223 . The third playback path  1203  is a playback path for the extended stream file  224 . As shown in  FIG. 12 , among the graphics representing the playback paths  1203 - 1203 , straight lines represent recording areas of extents read by the BD-ROM drive, whereas curved lines represent recording areas for which reading of data is skipped by a jump. 
     The playback device  102  in 2D playback mode plays back the file  2 D  221 . Accordingly, as shown by the first playback path  1201 , only the base-view extents B[m+1] are read in order from the three extended extent blocks shown in  FIG. 12  as extents EXT 2 D[m+i] of the file  2 D  221 . Specifically, the top base-view extent B[ 0 ] is first read, and then reading of the immediately subsequent dependent-view extent D[ 1 ] is skipped by a jump J 2D . Next, the second base-view extent B[ 1 ] is read, and then reading of the immediately subsequent extended extent T[ 1 ] and dependent-view extent D[ 2 ] is skipped by a jump J 2D . Reading of base-view extents and jumps are similarly repeated thereafter. 
     The playback device  102  in 3D playback mode plays back the file SS  223 . Accordingly, as shown by the second playback path  1202 , the three extent blocks D[m+i], B[m+i] are read in order from the three extended extent blocks shown in  FIG. 12  as extents EXTSS[ 0 ], EXTSS[ 1 ], and EXTSS[ 2 ] of the file SS  223 . Specifically, the top extent blocks D[ 0 ], B[ 0 ], D[ 1 ] and B[ 1 ] are first sequentially read, then reading of the immediately subsequent extended extent T[ 1 ] is skipped by a jump J 3D . Next, the second extent blocks D[ 2 ], B[ 2 ], D[ 2 ] and B[ 3 ] are sequentially read, then reading of the immediately subsequent extended extent T[ 2 ] is skipped by a jump J 3D . Subsequently, the third extent blocks D[ 4 ], B[ 4 ], D[ 5 ], B[ 5 ] are sequentially read. The playback device  102  then uses the clip information file to divide the extents EXTSS[ 0 ], EXTSS[ 1 ], . . . read from file SS  223  into dependent-view extents and base-view extents. 
     The playback device  102  in extended playback mode plays back the extended stream file  224  along with the file  2 D  221 . Accordingly, from the three extended extent blocks shown in  FIG. 12 , the extended extents T[m] are read as extents EXT 3 [ 0 ], EXT 3 [ 1 ], and EXT 3 [ 2 ] of the extended stream file  224 , and the base-view extents B[m+i] are read as extents EXT 2 D[ 0 ], EXT 2 D[ 1 ], and EXT 2 D[ 2 ] of the file  2 D  221 , as shown by the third playback path  1203 . Specifically, the top extended extent T[ 0 ] is first read, and then reading of the immediately subsequent dependent-view extent D[ 0 ] is skipped by a jump J EX . Next, the top base-view extent B[ 0 ] is read, and then reading of the immediately subsequent dependent-view extent D[ 1 ] is skipped by a jump J EX . Subsequently, the second base-view extent B[ 1 ] and the second extended extent T[ 1 ] are contiguously read, and then reading of the immediately subsequent dependent-view extent D[ 2 ] is skipped by a jump J Ex . Thereafter, reading of extended extents T[m] and base-view extents B[m+i] followed by jumps is similarly repeated. 
     When reading two adjacent extents continuously, the BD-ROM drive  121  actually performs a zero sector transition J 0  from the end of the first extent to the beginning of the next extent, as shown in  FIG. 12 . A “zero sector transition” is a movement of the optical pickup between two consecutive extents. During a period in which a zero sector transition is performed (hereinafter referred to as a “zero sector transition period”), the optical pickup temporarily suspends its read operation and waits. For this reason, a zero sector transition is considered “a jump whose jump distance equals zero sectors.” The length of the zero sector transition period, that is, the zero sector transition time period, may include, in addition to the time for shifting the position of the optical pickup via revolution of the BD-ROM disc  101 , overhead caused by error correction process. “Overhead caused by error correction process” refers to excess time caused by performing error correction process twice using an ECC block when the boundary between ECC blocks does not match with the boundary between two extents. A whole ECC block is necessary for error correction process. Accordingly, when two consecutive extents share a single ECC block, the whole ECC block is read and used for error correction process during reading of either extent. As a result, each time one of these extents is read, a maximum of 32 sectors of excess data is additionally read. The overhead caused by error correction process is estimated at the total time for reading the excess data, i.e. 32 sectors×2048 bytes×8 bits/byte×2 times/read rate. Note that extents may be structured in units of ECC blocks. In this case, the size of each extent equals an integer multiple of the size of an ECC block. The overhead caused by error correction process can thus be removed from the zero sector transition period. 
     Structure of Extent Blocks 
     Within one extent block, the (i+1) th  base-view extent B[m+i] and dependent-view extent D[m+i] have the same extent ATC time. Hereinafter, such a pair of extents B[m+i], D[m+i] is referred to as an “extent pair.” The “extent ATC time” indicates the range of ATSs assigned to source packets in one extent, i.e. the difference from the ATS of the top source packet in an extent to the ATS of the top source packet in the next extent. This difference equals the time, expressed as an ATC value, required for the playback device  102  to transfer all of the source packets in the extent from the read buffer to the system target decoder. The method of aligning the extent ATC times is described below. The “read buffer” is a buffer memory in the playback device  102  where extents read from the BD-ROM disc  101  are temporarily stored before being transmitted to the system target decoder. Details on the read buffer are provided later. 
     The VAUs located at the top of each extent pair D[m+1], B[m+1] belong to the same 3D VAU, and in particular include the top picture of the GOP representing the same 3D video image. For example, the top dependent-view extent D[m+i] includes a P picture in the right-view video stream, and the top base-view extent B[m+1] includes an I picture in the base-view video stream. The 2D video image represented by the P picture in the right-view video stream and the 2D video image represented by the I picture in the base-view video stream together represent one 3D video image. In particular, the P picture, as shown in  FIG. 7 , is compressed using the I picture as a reference picture. Accordingly, the playback device  102  in 3D playback mode can start playback of 3D video images from any extent pair D[m+1], B[m+1]. That is to say, the device can perform the process that requires random access of video streams, such as interrupt playback. 
     Relationship Between Extended Extents and Extent Blocks 
       FIG. 13  is a schematic diagram showing the relationship between one extended extent T[m] (m=0, 1, 2, . . . ) and the extent blocks B[k], D[k] (k=m, m+1, . . . , m+n−1) arranged immediately thereafter. As illustrated in  FIG. 13 , one extent block includes “n” base-view extents B[k] and “n” dependent-view extents D[k]. The number “n” is two or greater, and different extent blocks may have different numbers “n.” The reason why the number “n” is 2 or greater is described below. The extended extents T[m] include extended data T, to be used in combination with the following “n” base-view extents B[m+1] (i=0, 1, n−1). The (i+1) th  piece of extended data T, is resolution extension information for the pictures included in the (m+1+1) th  base-view extent B[m+1] and is used when extending these full HD pictures to 4K2K pictures. During random access, such as interrupt playback or the like, an extended extent to be first read includes extended data for a base-view picture located at the playback start position. The extent ATC time of the extended extent T[m] is equal to the extent ATC time of the entirety of the following “n” base-view extents B[m+1]. 
     As shown in  FIG. 13 , the (m+1) th  extended extent block has the extended extent T[m] located before the extent block D[m+i], B[m+i] (i=0, 1, . . . , n−1). The reason is, as described below, that the extended extent T[m] has a lower bit rate than either the dependent-view extent D[m+i] or the base-view extent B[m+i] constituting the extent block. Furthermore, each extent pair has the dependent-view extent D[k] located before the base-view extent B[k]. The reason is, as described below, that the dependent-view extent D[k] generally has a lower bit rate than the base-view extent B[k]. 
     When the (k+1) th  dependent-view extent D[k] includes a right-view picture, the picture is compressed by using the base-view picture included in the (k+1) th  base-view extent B[k] as a reference picture. On the other hand, when the dependent-view extent D[k] includes a depth map, the amount of data per pixel in the depth map, i.e., the number of bits of a depth value is generally smaller than the amount of data per pixel of the base-view picture, i.e., the sum of the number of bits of chromatic coordinate values and an a value. Furthermore, as shown in  FIGS. 3A through 3D , unlike the sub-TS, the main TS includes other elementary streams such as a primary audio stream, in addition to the primary video stream. Accordingly, the bit rate of the dependent-view extent D[k] is generally equal to or less than the bit rate of the base-view extent B[k]. Since both the extents D[k] and B[k] have the same extent ATC time, the size S EXT2 [k] of the dependent-view extent D[k] is generally equal to or less than the size S EXT1 [k] of the base-view extent B[k]: S EXT2 [k] ≦S EXT1 [k]. 
     The bit rate of the extended extent T[m] is determined by the amount of data per frame of the pixel difference information  403  shown in  FIG. 4 . The pixel difference information  403  is simply the difference between the pixel data obtained by interpolation from a full HD video frame and the pixel data included in the original 4K2K video frame. Accordingly, even for the entirety of “n” frames, the amount of data in the pixel difference information  403  is sufficiently smaller than the amount of data in one full HD frame. Therefore, the size S EXT3 [k] of the extended extent T[m] is generally no larger than the size S EXT2 [k] of any of the dependent-view extents D[k]: S EXT3 [k] ≦S EXT2 [k]. 
     Placing extents at the top of each extended extent block and in each extent pair in order from the extent with the smallest bit rate has the following advantage. The playback device  102  in 3D playback mode, when reading an extent from the top of each extent block, or when reading an extent from the playback start position, does not transfer the read extent to the system target decoder until finishing the reading of the entirety of the extent into the read buffer. After finishing the reading, the playback device  102  transfers the extent to the system target decoder in parallel with the next extent. This process is called “preloading.” The playback device  102  in extended playback mode similarly performs preloading during reading of each extended extent. 
     The technical significance of preloading is as follows. In L/R mode, decoded base-view pictures are necessary for decoding dependent-view pictures. Therefore, in order to maintain the minimum capacity of a buffer required for holding decoded pictures until output process, it is preferable to simultaneously provide one extent pair to the system target decoder to be simultaneously decoded. In depth mode, it is necessary to generate a pair of video frames that represents parallax images from a pair of a decoded base-view picture and a decoded depth map. Therefore, in order to maintain the minimum capacity of the buffer necessary for holding the decoded data until generation of the pair of video frames, it is preferable to simultaneously provide the extent pair to the system target decoder to be simultaneously decoded. In extended playback mode, it is necessary to use resolution extension information to extend a decoded base-view picture to a 4K2K video frame. Therefore, in order to maintain the minimum capacity of the buffer necessary for holding the decoded data until extension of its resolution, it is preferable to simultaneously provide an extended extent and a base-view extent to the system target decoder to be simultaneously decoded. Therefore, preloading is performed in both 3D playback mode and extended playback mode. The playback device  102  can thereby simultaneously provide an extent that is first read and its next extent from the read buffer to the system target decoder. 
     When preloading, the entirety of the extent that is read first is stored in the read buffer. Accordingly, the read buffer requires at least a capacity equal to the size of the extent. in order to maintain the capacity of the read buffer at a minimum, the size of the extent to be preloaded should be as small as possible. Therefore, as shown in  FIG. 13 , an extent with a small amount of data is placed first. This enables the minimum capacity to be maintained in the read buffer. 
     2-6: Arrangement of Extents Near Locations where a Long Jump is Necessary 
     Since the BD-ROM disc  101  is a multi-layer disc, a sequence of multiplexed stream data may be recorded continuously across a layer boundary. A “layer boundary” refers to the boundary between two portions of the logical address space of a multi-layer disc; one of the portions belonging to one recording layer and the other to another recording layer. Even when the BD-ROM disc  101  is a single layer disc, a sequence of multiplexed stream data may be recorded so as to sandwich a recording area for other data. When reading the multiplexed stream data, the BD-ROM drive performs a long jump in order to skip over the layer boundary or the recording area of the other data. A “long jump” is a collective term for a jump with a long seek time and specifically refers to (i) a jump performed to switch recording layers and (ii) a jump whose distance exceeds a predetermined threshold value. “Jump distance” refers to the length of the area on the BD-ROM disc  101  where reading is skipped during a jump period. The jump distance is expressed as the number of sectors included in the area, or as the amount of data that can be stored in the area. The threshold value in type (ii) is specified as 40,000 sectors=about 78.1 MB, for example, in the BD-ROM standard. This threshold value, however, depends on the type of BD-ROM disc and on the reading performance of BD-ROM drive. Long jumps particularly include focus jumps and track jumps. A “focus jump” is a jump caused by switching recording layers, and includes the process to change the focus distance of the optical pickup. A “track jump” includes the process to move the optical pickup in a radial direction along the BD-ROM disc  101 . 
     On the BD-ROM disc  101 , immediately before or immediately after the location where a long jump is necessary, such as a layer boundary, extents are arranged so that a playback path in 3D playback mode is separated from playback paths in 2D playback mode and in extended playback mode. These patterns for arrangement include, for example, arrangement  1  and arrangement  2  described below. For ease of explanation, arrangements  1  and  2  are assumed to be used for both an extent group recorded immediately before a layer boundary on the BD-ROM disc  101  and another extent group recorded immediately after the layer boundary. Note that the following explanation holds true when the recording area of extents is separated, not by a layer boundary, by a recording area of other data that exceeds a predetermined number of sectors (such as 40,000 sectors). 
     Arrangement  1   
       FIG. 14  is a schematic diagram showing arrangement  1  of extents recorded before and after a layer boundary LB on the BD-ROM disc  101 , as well as the playback paths in their respective modes designed for the extents. As illustrated in  FIG. 14 , a first recording layer L 0  located before the layer boundary LB includes a first shared section  1401 , and a second recording layer L 1  located after the layer boundary LB includes a second shared section  1402 . The “shared sections”  1401  and  1402  are sectors in which extended extent blocks are arranged continuously and are accessed by the playback device in every mode: 2D playback mode, 3D playback mode, and extended playback mode. In each extended extent block, two extent pairs D, B are provided in an interleaved arrangement immediately after one extended extent T. 
     As illustrated in  FIG. 14 , the first recording layer L 0  includes a first extended data specific section  1411 , a first monoscopic video specific section  1412 , and a first stereoscopic video specific section  1413  between the first shared section  1401  and the layer boundary LB. One extended extent T is located in the first extended data specific section  1411 , one base-view extent B 2D  is located in the first monoscopic video specific section  1412 , and two extent pairs D, B 3D  are located in the first stereoscopic video specific section  1413 . The base-view extent B 2D  in the first monoscopic video specific section  1412  is a copy of the entirety of the base-view extents B 3D  in the first stereoscopic video specific section  1413 , i.e., the extent B 2D  matches with the entirety of the extents B 3D  bit for bit. In other words, the same data is recorded in duplicate. The extended extent T in the first extended data specific section  1411  includes extended data to be used in combination with the base-view extent B 2D  in the first monoscopic video specific section  1412 . Accordingly, the extended extent T and the base-view extent B 2D  have the same extent ATC time. The extended extent T in the first extended data specific section  1411  can be accessed as one extent EXT 3 [ 1 ] of the extended stream file. The base-view extent B 2D  in the first monoscopic video specific section  1412  can be accessed as one extent EXT 2 D[ 2 ] of the file  2 D. The base-view extent B 3D  in the first stereoscopic video specific section  1413 , along with the dependent-view extent D therein, can be accessed as one extent EXTSS[ 1 ] of the file SS. 
     The second recording layer L 1  includes a second extended data specific section  1421 , a second monoscopic video specific section  1422 , and a second stereoscopic video specific section  1423  between the layer boundary LB and the second shared section  1402 . One extended extent T is located in the second extended data specific section  1421 , one base-view extent B 2D  is located in the second monoscopic video specific section  1422 , and one extent pair D, B 3D  is located in the second stereoscopic video specific section  1423 . The base-view extent B 2D  in the second monoscopic video specific section  1422  is a copy of the base-view extent B 3D  in the second stereoscopic video specific section  1423 , i.e., the former extent B 2D  matches with the latter extent B 3D  bit for bit. In other words, the same data is recorded in duplicate. The extended extent T in the second extended data specific section  1421  includes extended data to be used in combination with the base-view extent B 2D  in the second monoscopic video specific section  1422 . Accordingly, the extended extent T and the base-view extent B 2D  have the same extent ATC time. The extended extent T in the second extended data specific section  1421  can be accessed as one extent EXT 3 [ 2 ] of the extended stream file. The base-view extent B 2D  in the second monoscopic video specific section  1422  can be accessed as one extent EXT 2 D[ 3 ] of the file  2 D. The base-view extent B 3D  in the second stereoscopic video specific section  1423 , along with the dependent-view extent D therein, can be accessed as one extent EXTSS[ 2 ] of the file SS. 
     As shown in  FIG. 14 , arrangement  1  has the monoscopic video specific sections  1412  and  1422  immediately after the extended data specific sections  1411  and  1421 , respectively, and in addition the stereoscopic video specific sections  1413  and  1423  immediately after the monoscopic video specific sections  1412  and  1422 , respectively. 
     The playback device  102  in 2D playback mode plays back the file  2 D. Accordingly, from the extents shown in  FIG. 14 , the extents EXT 2 D[ 0 ]-EXT 2 D[ 5 ] of the file  2 D are read, as shown by the playback path  1431  in 2D playback mode. Specifically, in the first shared section  1401 , two base-view extents B are read as two extents EXT 2 D[ 0 ] and EXT 2 D[ 1 ] of the file  2 D, and reading of the dependent-view extent D located therebetween is skipped. Next, access to the first extended data specific section  1411  is skipped, and then the base-view extent B 2D  is read from the immediately subsequent first monoscopic video specific section  1412  as one extent EXT 2 D[ 2 ] of the file  2 D. Immediately thereafter, a long jump J LY  occurs to move the position of reading over the first stereoscopic video specific section  1413 , the layer boundary LB, and the second extended data specific section  1421 . The base-view extent B 2D  in the second monoscopic video specific section  1422  is then read as one extent EXT 2 D[ 3 ] of the file  2 D. A jump J 2D  occurs immediately thereafter to skip access to the second stereoscopic video specific section  1423 , as well as reading of the extended extent T and dependent-view extent D at the top of the second shared section  1402 . Furthermore, in the second shared section  1402 , two base-view extents B are read as two extents EXT 2 D[ 4 ] and EXT 2 D[ 5 ] of the file  2 D, and reading of the dependent-view extent D located therebetween is skipped. 
     The playback device  102  in 3D playback mode plays back the file SS. Accordingly, from the extents shown in  FIG. 14 , the extents EXTSS[ 0 ]-EXTSS[ 3 ] of the file SS are read, as shown by the playback path  1432  in 3D playback mode. Specifically, an extent block D, B, D, and B is read continuously from the first shared section  1401  as one extent EXTSS[ 0 ] of the file SS. Immediately thereafter, a jump J 3D  occurs to skip access to the first extended data specific section  1411  and the first monoscopic video specific section  1412 . Next, an extent block D, B 3D , D, and B 3D  is read continuously from the first stereoscopic video specific section  1413  as one extent EXTSS[ 1 ] of the file SS. Immediately thereafter, a long jump J LY  occurs to move the position of reading over the layer boundary LB, the second extended data specific section  1421 , and the second monoscopic video specific section  1422 . Subsequently, an extent pair D and B 3D  is read continuously from the second stereoscopic video specific section  1423  as one extent EXTSS[ 2 ] of the file SS. Furthermore, in the second shared section  1402 , reading of the extended extent T is skipped, and then the subsequent extent block D, B, D, and B is read continuously as one extent EXTSS[ 3 ] of the file SS. 
     The playback device  102  in extended playback mode plays back the extended stream file and the file  2 D. Accordingly, from the extents shown in  FIG. 14 , the extents EXT 3 [ 0 ]-EXT 3 [ 3 ] of the extended stream file and the extents EXT 2 D[ 0 ]-EXT 2 D[ 5 ] of the file  2 D are read, as shown by the playback path  1433  in extended playback mode. Specifically, in the first shared section  1401 , the extended extent T=EXT 3 [ 0 ] is first read, and then two base-view extents B are read as two extents EXT 2 D[ 0 ] and EXT 2 D[ 1 ] of the file  2 D, and further reading of two dependent-view extents D is skipped. Next, the extended extent T=EXT 3 [ 1 ] is read from the first extended data specific section  1411 , and then the base-view extent B 2D  is read from the first monoscopic video specific section  1412  as one extent EXT 2 D[ 2 ] of the file  2 D. Immediately thereafter, a long jump J LY  occurs to move the position of reading over the first stereoscopic video specific section  1413  and the layer boundary LB. Subsequently, the extended extent T=EXT 3 [ 2 ] is read from the second extended data specific section  1421 , and then the base-view extent B 2D  is read from the second monoscopic video specific section  1422  as one extent EXT 2 D[ 3 ] of the file  2 D. A jump J EX  occurs immediately thereafter to skip access to the second stereoscopic video specific section  1423 . Furthermore, in the second shared section  1402 , the extended extent T=EXT 3 [ 3 ] is first read, and then two base-view extents B are read as two extents EXT 2 D[ 4 ] and EXT 2 D[ 5 ] of the file  2 D, and in addition reading of two dependent-view extents D is skipped. 
     Arrangement  2   
       FIG. 15  is a schematic diagram showing arrangement  2  of extents recorded before and after a layer boundary LB on the BD-ROM disc  101 , as well as playback paths in their respective modes designed for the extents. As is clear when  FIG. 15  is compared with  FIG. 14 , arrangement  2  differs from arrangement  1  only in that monoscopic video specific sections  1512  and  1522  and stereoscopic video specific sections  1513  and  1523  are located at the reversed positions. In other words, arrangement  2  has the stereoscopic video specific sections  1513  and  1523  located immediately after the extended data specific sections  1411  and  1421 , respectively, and further the monoscopic video specific sections  1512  and  1522  located immediately after the stereoscopic video specific sections  1513  and  1523 , respectively. 
     As indicated by the playback path  1431  in 2D playback mode, the playback device  102  in 2D playback mode reads the extents EXT 2 D[ 0 ]-EXT 2 D[ 5 ] of the file 2D from the extents shown in  FIG. 15 . Specifically, in the first shared section  1401 , two base-view extents B are read as two extents EXT 2 D[ 0 ] and EXT 2 D[ 1 ] of the file  2 D, and reading of the dependent-view extent D located therebetween is skipped. Immediately thereafter, a jump J 2D  occurs to skip access to the first extended data specific section  1411  and the first stereoscopic video specific section  1513 . The base-view extent B 2D  is then read from the first monoscopic video specific section  1512  as one extent EXT 2 D[ 2 ] of the file  2 D. Immediately thereafter, a long jump J LY  occurs to move the position of reading over the layer boundary LB, the second extended data specific section  1421 , and the second stereoscopic video specific section  1523 . The base-view extent B 2D  in the second monoscopic video specific section  1522  is then read as one extent EXT 2 D[ 3 ] of the file  2 D. Next, in the second shared section  1402 , reading of an extended extent T and two dependent-view extents D is skipped, and two base-view extents B are read as two extents EXT 2 D[ 4 ] and EXT 2 D[ 5 ] of the file  2 D. 
     As indicated by the playback path  1532  in 3D playback mode, the playback device  102  in 3D playback mode reads the extents EXTSS[ 0 ]-EXTSS[ 3 ] of the file SS from the extents shown in  FIG. 15 . Specifically, an extent block D, B, D, and B is read continuously from the first shared section  1401  as one extent EXTSS[ 0 ] of the file SS. Next, access to the first extended data specific section  1411  is skipped, and then an extent block D, B 3D , D, and B 3D  is read continuously from the first stereoscopic video specific section  1513  as one extent EXTSS[ 1 ] of the file SS. Immediately thereafter, a long jump J LY  occurs to move the position of reading over the first monoscopic video specific section  1512 , the layer boundary LB, and the second extended data specific section  1421 . Subsequently, an extent pair D and B 3D  is read continuously from the second stereoscopic video specific section  1523  as one extent EXTSS[ 2 ] of the file SS. A jump J 3D  occurs immediately thereafter to skip access to the second monoscopic video specific section  1522 . Furthermore, in the second shared section  1402 , reading of the extended extent T is skipped, and then the subsequent extent block D, B, D, and B is read continuously as one extent EXTSS[ 3 ] of the file SS. 
     As shown by the playback path  1533  in extended playback mode, the playback device  102  in extended playback mode reads the extents EXT 3 [ 0 ]-EXT 3 [ 3 ] of the extended stream file and the extents EXT 2 D[ 0 ]-EXT 2 D[ 5 ] of the file  2 D from the extents shown in  FIG. 15 . Specifically, in the first shared section  1401 , the extended extent T=EXT 3 [ 0 ] is first read, and then two base-view extents B are read as two extents EXT 2 D[ 0 ] and EXT 2 D[ 1 ] of the file  2 D, and in addition reading of two dependent-view extents D is skipped. 
     Next, the extended extent T=EXT 3 [ 1 ] is read from the first extended data specific section  1411 . A jump J EX1  occurs immediately thereafter to skip access to the first stereoscopic video specific section  1513 . The base-view extent B 2D  in the first monoscopic video specific section  1512  is then read as one extent EXT 2 D[ 2 ] of the file  2 D. Immediately thereafter, a long jump J LY  occurs to move the position of reading over the layer boundary LB. Subsequently, the extended extent T=EXT 3 [ 2 ] is read from the second extended data specific section  1421 . A jump J EX2  occurs immediately thereafter to skip access to the second stereoscopic video specific section  1523 . Furthermore, the base-view extent B 2D  is then read from the second monoscopic video specific section  1522  as one extent EXT 2 D[ 3 ] of the file  2 D. In the second shared section  1402 , the extended extent T=EXT 3 [ 3 ] is first read, and then two base-view extents B are read as two extents EXT 2 D[ 4 ] and EXT 2 D[ 5 ] of the file  2 D, and reading of two dependent-view extents D is skipped. 
     As shown in  FIGS. 14 and 15 , in 2D playback mode, the monoscopic video specific sections are accessed, whereas access to the extended data specific sections and the stereoscopic video specific sections is skipped. In 3D playback mode, the stereoscopic video specific sections are accessed, whereas access to the extended data specific sections and the monoscopic video specific sections is skipped. In extended playback mode, the extended data specific sections and the monoscopic video specific sections are accessed, whereas access to the stereoscopic video specific sections is skipped. In this way, arrangements  1  and  2  separate playback paths in different modes immediately before and after the long jump J LY ; the playback paths in 2D playback mode and in extended playback mode run through the monoscopic video specific sections, whereas the playback path in 3D playback mode runs through the stereoscopic video specific sections. In other words, the playback path in 3D playback mode is separated from the playback paths in 2D playback mode and in extended playback mode. Since the entirety of the base-view extents B 3D  in the stereoscopic video specific sections matches with the entirety of the base-view extents B 2D  in the monoscopic video specific sections bit for bit, the same base-view video frames are played back in both the playback modes. 
     2-7: Conditions on Extent Size 
     The base-view extent B, the dependent-view extent D, and the extended extent T are each structured in aligned units. Accordingly, the size of each extent equals a multiple of the size of an aligned unit (=6,144 bytes, or approximately 6 KB). Accordingly, the BD-ROM drive can reliably read any extent continuously in its entirety, since the boundary between extents coincides with the boundary between sectors. 
     As illustrated in  FIG. 12 , in any of 2D playback mode, 3D playback mode, and extended playback mode, the playback device  102  performs a jump. Accordingly, in order to play back video images seamlessly in any playback mode, the lower limit of the size of each data block, i.e. the minimum extent size, should be designed so that underflow does not occur in the read buffer during the jump. 
     2-7-A: Conditions in 2D Playback Mode 
       FIG. 16  is a block diagram showing a playback processing system built in the playback device  102  in 2D playback mode. As shown in  FIG. 16 , this playback processing system includes a BD-ROM drive  1601 , read buffer  1602 , and system target decoder  1603 . The BD-ROM drive  1601  reads extents in the file  2 D from the BD-ROM disc  101  and transfers the extents to the read buffer  1602  at a read rate R UD2D . The read buffer  1602  is a buffer memory that is built in the playback device  102  and receives and stores extents from the BD-ROM drive  1601 . The system target decoder  1603  reads source packets from each extent stored in the read buffer  1602  at a mean transfer rate R EXT2D  and decodes the source packets into video data VD and audio data AD. 
     The mean transfer rate R EXT2D  equals 192/188 times the mean processing rate at which the system target decoder  1603  extracts TS packets from source packets stored in the read buffer  1602 . In this case, the coefficient 192/188 is the ratio of the byte numbers between a source packet and a TS packet. The mean transfer rate R EXT2D  is conventionally represented in bits/second and specifically equals the size of an extent, which is expressed in bits, divided by the extent ATC time. The “size of an extent expressed in bits” equals the number of source packets in the extent times the bit number per source packet (=192 bytes×8 bits/byte). The mean transfer rate R EXT2D  typically varies with extent. The maximum value R MAX2D  of the mean transfer rate R EXT2D  equals 192/188 times the bit rate of the file  2 D. The maximum value of the speed at which the system target decoder  1603  is requested to process TS packets, i.e., the “system rate” R TS , is set to be equal to the bit rate of the file  2 D. The system rate R TS  is normally expressed in bits per second (bps) and equals eight times the main TS recording rate expressed in bytes per second (Bps). 
     The read rate R UD2D  is normally expressed in bits/second and is set at a higher value, e.g., 54 Mbps, than the maximum value R MAX2D  of the mean transfer rate R EXT2D :R UD2D &gt;R MAX2D . This prevents decoding operation of the system target decoder  1603  from causing underflow of the read buffer  1602  while the BD-ROM drive  1601  is reading an extent from the BD-ROM disc  101 . 
       FIG. 17A  is a graph showing the change in the data amount DA stored in the read buffer  1602  during operation in 2D playback mode.  FIG. 17B  is a schematic diagram showing a playback path  1720  in 2D playback mode designed for an extended extent block  1710  to be played back. As shown in  FIG. 17B , in accordance with the playback path  1720 , the base-view extents B[m] (m=n, n+1, n+2, where the number “n” is an integer equal to or greater than zero) included in the extended extent block  1710  are read from the BD-ROM disc  101  into the read buffer  1602  as one extent EXT 2 D[m] of the file  2 D. As shown in  FIG. 17A , during the read period PR 2D [n] for each extent EXT 2 D[n], the stored data amount DA increases at a rate equal to R UD2D -R EXT2D [n], the difference between the read rate R UD2D  and the mean transfer rate R EXT2D [n]. A jump J 2D [n] occurs between two contiguous 2D extents EXT 2 D[n] and EXT 2 D[n+1]. Reading of data from the BD-ROM disc  101  is interrupted during this jump period PJ 2D [n], since the reading of the dependent-view extent D[n+1] is skipped. Accordingly, the stored data amount DA decreases at a mean transfer rate R EXT2D [n] during each jump period PJ 2D [n]. 
     Reading and transfer operations by the BD-ROM drive  1601  are not actually performed in a continuous manner, as suggested by the graph in  FIG. 17A , but rather in an intermittent manner. This prevents the stored data amount DA from exceeding the capacity of the read buffer  1602 , i.e., overflow in the read buffer  1602  during the read period PR 2D [n] for each extent. Accordingly, the graph in  FIG. 17A  represents actual step-wise changes as approximated linear changes. 
     For seamless playback of full HD 2D video images from the extent block  1710  shown in  FIG. 17B , the following two conditions should be satisfied: first, the size S EXT2D [n] of each extent EXT 2 D[n] of the file  2 D should satisfy expression (1) below. Second, the distance between extents of the file  2 D should not exceed a predetermined upper limit. 
     Minimum Extent Size of Extents of the File  2 D 
     During each jump period PJ 2D [n], data needs to be so continuously provided from the read buffer  1602  to the system target decoder  1603  that the system target decoder  1603  can ensure its continuous output. To do so, the size of each extent in the file  2 D should satisfy the following condition 1. 
     The size S EXT2D [n] of each extent EXT 2 D[n] is the same as the data amount transferred from the read buffer  1602  to the system target decoder  1603  from the read period PR 2D [n] through the next jump period PJ 2D [n]. In this case, as shown in  FIG. 17A , the stored data amount DA at the end of the jump period PJ 2D [n] does not fall below the value at the start of the read period PR 2D [n]. In other words, during each jump period PJ 2D [n], data is continuously provided from the read buffer  1602  to the system target decoder  1603 . In particular, underflow does not occur in the read buffer  1602 . Note that the length of the read period PR 2D [n] equals a value S EXT2D [n]/R UD2D , the size S EXT2D [n] of an extent EXT 2 D[n] divided by the read rate R UD2D . Accordingly, condition 1 indicates the following. The minimum extent size of each extent EXT 2 D[n] in the file  2 D is expressed in the right-hand side of expression (1): 
     
       
         
           
             
               
                 
                   
                     
                       
                         S 
                         
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                           ⁢ 
                           
                               
                           
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                                   ⁢ 
                                   
                                       
                                   
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                                 ⁢ 
                                 
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                           ⁢ 
                           
                               
                           
                           ⁢ 
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                         ⁡ 
                         
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                                     ⁢ 
                                     
                                         
                                     
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                                   ⁢ 
                                   
                                       
                                   
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                                   JUMP 
                                   ⁢ 
                                   
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                       . 
                     
                   
                 
               
               
                 
                   ( 
                   1 
                   ) 
                 
               
             
           
         
       
     
     In expression (1), the jump time T JUMP-2D [n] represents the length of the jump period PJ 2D [n] in seconds. The read rate R UD2D  and the mean transfer rate R EXT2D  are both expressed in bits per second. Accordingly, in expression (1), the mean transfer rate R EXT2D  is divided by 8 to convert the size S EXT2D [n] of the extent from bits to bytes. That is, the size S EXT2D [n] of the extent is expressed in bytes. The function CEIL( ) is an operation to round up fractional numbers after the decimal point of the value in parentheses. 
     As is clear from the playback path  1201  in 2D playback mode shown in  FIG. 12 , jumps occur frequently in 2D playback mode. Accordingly, to further ensure seamless playback during the jumps, it is preferable to add a margin to the minimum extent size expressed in the right-hand side of expression (1). The following lists three methods for adding a margin. 
     The first method is to replace the mean transfer rate R EXT2D  included in the denominator of the right-hand side of expression (1) with the maximum value thereof, R MAX2D . In other words, the size S EXT2D  of the extent in the file  2 D satisfies expression (1A) instead of expression (1): 
     
       
         
           
             
               
                 
                   
                     
                       S 
                       
                         EXT 
                         ⁢ 
                         
                             
                         
                         ⁢ 
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                       ⁡ 
                       
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     The second method is to extend the extent ATC time of an extent in the file 2D by ΔT seconds. In other words, the size S EXT2D  of the extent satisfies expression (1B) or (1C) instead of expression (1): 
     
       
         
           
             
               
                 
                   
                     
                       
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                                       ⁢ 
                                       
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                                     n 
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                               + 
                               ΔT 
                             
                             ) 
                           
                         
                         } 
                       
                       . 
                     
                   
                 
               
               
                 
                   ( 
                   
                     1 
                     ⁢ 
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                   ) 
                 
               
             
           
         
       
     
     The extension time ΔT may be determined by the length of a GOP, or by the upper limit of the number of extents that can be played back during a predetermined time. For example, if the length of a GOP is one second, the extension time ΔT is set to one second. On the other hand, if the number of extents that can be played back during a predetermined time [sec] has the upper limit of k, then the extension time ΔT is set to the predetermined time/k [sec]. 
     The third method is to replace all of the mean transfer rates R EXT2D  included in the right-hand side of expression (1) with the maximum value thereof, R MAX2D . In other words, the size S EXT2D  of the extent in the file  2 D satisfies expression (1D) instead of expression (1): 
     
       
         
           
             
               
                 
                   
                     
                       S 
                       
                         EXT 
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         2 
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         D 
                       
                     
                     ⁡ 
                     
                       [ 
                       n 
                       ] 
                     
                   
                   ≥ 
                   
                     
                       CEIL 
                       ⁡ 
                       
                         ( 
                         
                           
                             
                               R 
                               
                                 MAX 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 2 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 D 
                               
                             
                             8 
                           
                           × 
                           
                             
                               R 
                               
                                 UD 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 2 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
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                                   UD 
                                   ⁢ 
                                   
                                       
                                   
                                   ⁢ 
                                   2 
                                   ⁢ 
                                   
                                       
                                   
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                               - 
                               
                                 R 
                                 
                                   MAX 
                                   ⁢ 
                                   
                                       
                                   
                                   ⁢ 
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                                   ⁢ 
                                   
                                       
                                   
                                   ⁢ 
                                   D 
                                 
                               
                             
                           
                           × 
                           
                             
                               T 
                               
                                 JUMP 
                                 ⁢ 
                                 
                                   - 
                                 
                                 ⁢ 
                                 2 
                                 ⁢ 
                                 D 
                               
                             
                             ⁡ 
                             
                               [ 
                               n 
                               ] 
                             
                           
                         
                         ) 
                       
                     
                     . 
                   
                 
               
               
                 
                   ( 
                   
                     1 
                     ⁢ 
                     D 
                   
                   ) 
                 
               
             
           
         
       
     
     The third method can add a larger margin to the minimum extent size than the first method. On the other hand, even when the bit rate of the file  2 D is low, a sufficiently large capacity has to be guaranteed in the read buffer since the size of the extent is large. Accordingly, it is necessary to weigh the size of the margin against the use efficiency of the read buffer. 
     Interval Between Extents of the File  2 D 
     Since the capacity of the read buffer  1602  is limited, the maximum value of the jump time T JUMP-2D [n] is restricted. In other words, even if the stored data amount DA fills the capacity of the read buffer  1602  immediately before a jump period PJ 2D [n], the jump time T JUMP-2D [n] being too long would cause the stored data amount DA to reach zero during the jump period PJ 2D [n], and thus there would be a risk of underflow occurring in the read buffer  1602 . Hereinafter, the time for the stored data amount DA to decrease from the capacity of the read buffer  1602  to zero while data supply from the BD-ROM disc  101  to the read buffer  1602  has stopped, that is, the maximum value of the jump time T JUMP-2D  that guarantees seamless playback, is referred to as the “maximum jump time T JUMP-MAX .” 
     Standards of optical discs determine correspondence between jump distances and maximum jump times from the access speed of an optical disc drive and other factors.  FIG. 18  is an example of a correspondence table between jump distances S JUMP  and maximum jump times T JUMP-MAX  for a BD-ROM disc. As shown in  FIG. 18 , jump distances S JUMP  are represented in units of sectors, and maximum jump times T JUMP-MAX  are represented in milliseconds. One sector equals 2048 bytes. When a jump distance S JUMP  is within a range of 1-10000 sectors, 10001-20000 sectors, 20001-40000 sectors, 40001 sectors- 1/10 of a stroke (=640000 sectors), and 1/10 of a stroke or greater, the corresponding maximum jump time T JUMP-MAX  is 200 ms, 300 ms, 350 ms, 700 ms, and 1400 ms, respectively. Furthermore, when the jump distance S JUMP  is zero sectors, the maximum jump time T JUMP-MAX  is equal to the zero sector transition time T JUMP0 =0 ms. 
     Based on the above considerations, the jump time T JUMP-2D [n] to be substituted into expression (1) is the maximum jump time T JUMP-MAX  specified for each jump distance by BD-ROM disc standards. Specifically, in the table in  FIG. 18 , the maximum jump time T JUMP-MAX  corresponding to the jump distance S JUMP  between two contiguous extents EXT 2 D[n] and EXT 2 D[n+1] in the file  2 D is substituted into expression (1) as the jump time T JUMP-2D [n]. The jump distance S JUMP  equals the number of sectors within the range from the end of the (n+1) th  extent EXT 2 D[n] to the top of the (n+2) th  extent EXT 2 D[n+1]. 
     In order to reduce the capacity of the read buffer that is to be stored in the playback device in 2D playback mode, it is preferable to set the minimum extent size for the file  2 D to be as small as possible. Accordingly, the jump time T JUMP-2D [n] to be substituted into expression (1) is set to be 200 ms, the next smallest value after 0 ms among the maximum jump times T JUMP-MAX  specified in the table in  FIG. 18 . As a result, the jump distance S JUMP  between the extents EXT 2 D[n] and EXT 2 D[n+1] in the file  2 D, i.e. the interval between these extents EXT 2 D[n] and EXT 2 D[n+1], is restricted to be a maximum of 10000 sectors. Like this maximum for the jump distance S JUMP , a jump distance S JUMP  corresponding to a jump time T JUMP  equal to its maximum jump time T JUMP-MAX  is referred to as a “maximum jump distance S JUMP-MAX .” 
     In each extent block, the interval between extents in the file  2 D is restricted to at most the maximum jump distance S JUMP-MAX =10000. In this context, this interval equals the size of a dependent-view extent. Accordingly, the size of the dependent-view extents is restricted to at most the amount of data that can be stored in the area for the maximum jump distance S JUMP-MAX =10000 sectors, approximately 19.5 MB (1 MB=1024×1024 bytes). 
     As shown in  FIG. 12 , an extended extent is arranged between two adjacent extent blocks. Accordingly, during the jump from the base-view extent located at the end of one extent block until the base-view extent located at the beginning of the next extent block, reading of not only the dependent-view extent but also of the extended extent needs to be skipped. A margin is therefore added to the extents in the file  2 D so as to satisfy any of expressions (1A)-(1D) instead of expression (1). In this case, the maximum jump distance S JUMP-MAX  between extent blocks is expanded to 20000 sectors. In other words, it suffices for the sum of the size of the extended extent and of the dependent-view extent to be at most 20000 sectors. 
     2-7-B: Conditions in 3D Playback Mode 
       FIG. 19  is a block diagram showing a playback processing system built in the playback device  102  in 3D playback mode. As shown in  FIG. 19 , this playback processing system includes a BD-ROM drive  1901 , a switch  1902 , a pair of read buffers  1911  and  1912 , and a system target decoder  1903 . The BD-ROM drive  1901  reads extents in the file  3 D from the BD-ROM disc  101  and transfers the extents to the switch  1902  at a read rate R UD3D . The switch  1902  separates the extents in the file SS into base-view extents and dependent-view extents. Details on separation process are provided below. The first read buffer  1911  and the second read buffer  1912  (hereinafter abbreviated as RB 1  and RB 2 ) are buffer memories internal to the playback device  102  and store extents separated by the switch  1902 . The RB 1   1911  stores base-view extents, and the RB 2   1912  stores dependent-view extents. The system target decoder  1903  reads source packets from the base-view extents in the RB 1   1911  at a first transfer rate R EXT1  and reads source packets from the dependent-view extents in the RB 2   1912  at a second transfer rate R EXT2 . The system target decoder  1903  also decodes pairs of read base-view extents and dependent-view extents into video data VD and audio data AD. 
     The first transfer rate R EXT1  equals 192/188 times the mean processing rate at which the system target decoder  1903  extracts TS packets from source packets stored in the RB 1   1911 . The maximum value R MAX1  of the first transfer rate R EXT1  equals 192/188 times the system rate R TS1  for the file  2 D: R MAX1 =R TS1 ×192/188. This system rate R TS1  is normally expressed in bits per second (bps) and equals eight times the main TS recording rate expressed in bytes per second (Bps). The second transfer rate R EXT2  equals 192/188 times the mean processing rate at which the system target decoder  1903  extracts TS packets from source packets stored in the RB 2   1912 . The maximum value R MAX2  of the second transfer rate R EXT2  equals 192/188 times the system rate R TS2  for the file DEP: R MAX2 =R Ts 2×192/188. This system rate R TS2  is normally expressed in bits per second (bps) and equals eight times the sub-TS recording rate expressed in bytes per second (Bps). The transfer rates R EXT1  and R EXT2  are typically represented in bits/second and specifically equal to the size of each extent, which is expressed in bits, divided by the extent ATC time thereof. The extent ATC time equals the time required to transfer all of the source packets in the extent from the RB 1   1911  and RB 2   1912  to the system target decoder  1903 . 
     The read rate R UD3D  is typically expressed in bits/second and is set at a higher value, e.g. 72 Mbps, than either of the maximum values R MAX1 , R MAX2  of the transfer rates R EXT1 , R EXT2 : R UD3D &gt;R MAX1 , R UD3D &gt;R MAX2 . This prevents decoding process of the system target decoder  1903  from causing underflow of the RB 1   1911  and RB 2   1912  due to while the BD-ROM drive  1901  is reading an extent of the file SS from the BD-ROM disc  101 . 
     Seamless Playback from One Extended Extent Block 
       FIGS. 20A and 20B  are graphs showing changes in data amounts DA 1  and DA 2 , respectively stored in the RB 1   1911  and RB 2   1912 , when 3D video images are played back seamlessly from a single extended extent block.  FIG. 20C  is a schematic diagram showing a playback path  2020  in 3D playback mode for the corresponding extended extent block  2010 . As shown in  FIG. 20C , in accordance with the playback path  2020 , a portion of the extended extent block  2010  other than the top extended extent T is read all at once as one extent in the file SS. Subsequently, the switch  1902  separates the extent into dependent-view extents D[k] and base-view extents B[k] (k= . . . n, n+1, n+2, . . . ). 
     Reading and transfer operations by the BD-ROM drive  1901  are not actually performed in a continuous manner, as suggested by the graphs in  FIGS. 20A and 20B , but rather in an intermittent manner During the read periods PR D [k] and PR B [k] of the extents D[k] and B[k], this prevents overflow in the RB 1   1911  and RB 2   1912 . Accordingly, the graphs in  FIGS. 20A and 20B  represent actual step-wise changes as approximated linear changes. 
     As shown in  FIGS. 20A and 20B , during the read period PR D [n] for the (n+1) th  dependent-view extent D[n], the data amount DA 2  stored in the RB 2   1912  increases at a rate equal to R UD3D  R EXT2 [n], the difference between the read rate R UD3D  and the second transfer rate R EXT2 [n], whereas the data amount DA 1  stored in the RB 1   1911  decreases at the first transfer rate R EXT [n−1]. As shown in  FIG. 20C , a zero sector transition J 0 [n] occurs from the (n+1) th  dependent-view extent D[n] to the (n+1) th  base-view extent B[n]. As shown in  FIGS. 20A and 20B , during the zero sector transition period PJ 0 [n], the data amount DA 1  stored in the RB 1   1911  continues to decrease at the first transfer rate R EXT1 [n−1], whereas the data amount DA 2  stored in the RB 2   1912  decreases at the second transfer rate R EXT2 [n]. 
     As further shown in  FIGS. 20A and 20B , during the read period PR B [n] for the (n+1) th  base-view extent B[n], the stored data amount DA 1  in the RB 1   1911  increases at a rate equal to R UD3D  R EXT1 [n], the difference between the read rate R UD3D  and the first transfer rate R EXT1 [n]. On the other hand, the data amount DA 2  stored in the RB 2   1912  continues to decrease at the second transfer rate R EXT2 [n]. As further shown in  FIG. 20C , a zero sector transition J 0 [n+1] occurs from the base-view extent B[n] to the next dependent-view extent D[n+1]. As shown in  FIGS. 20A and 20B , during the zero sector transition period PJ 0 [n+1], the data amount DA 1  stored in the RB 1   1911  decreases at the first transfer rate R EXT1 [n], whereas the data amount DA 2  stored in the RB 2   1912  continues to decrease at the second transfer rate R EXT2 [n]. 
     In order to seamlessly play back 3D video images from the first extended extent block  2010 , the size of each of the extents B[n] and D[n] in the extended extent block should satisfy conditions 2 and 3 described below. 
     The size S EXT1 [n] of the (n+1) th  base-view extent B[n] is at least equal to the data amount transferred from the RB 1   1911  to the system target decoder  1903  during the period from the start of the corresponding read period PR B [n] until immediately before the read period PR B [n+1] of the next base-view extent B[n+1]. In this case, as shown in  FIG. 20A , immediately before the read period PR B [n+1] of the next base-view extent B[n+1], the stored data amount DA 1  in the RB 1   1911  does not fall below the amount immediately before the read period PR B [n] of the (n+1) th  base-view extent B[n]. Here, the length of the read period PR B [n] of the (n+1) th  base-view extent B[n] equals a value S EXT1 [n]/R UD3D , the size S EXT1 [n] of this base-view extent B[n] divided by the read rate R UD3D . On the other hand, the length of the read period PR D [n+1] of the (n+2) th  dependent-view extent D[n+1] equals a value S EXT1 [n+1]/R UD3D , the size S EXT2 [n+1] of this dependent-view extent D[n+1] divided by the read rate R UD3D . Accordingly, condition 2 indicates the following. The minimum extent size of the (n+1) th  base-view extent B[n] is expressed in the right-hand side of expression (2): 
     
       
         
           
             
               
                 
                   
                     
                       
                         S 
                         
                           EXT 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           1 
                         
                       
                       ⁡ 
                       
                         [ 
                         n 
                         ] 
                       
                     
                     ≥ 
                     
                       
                         ( 
                         
                           
                             
                               
                                 S 
                                 
                                   EXT 
                                   ⁢ 
                                   
                                       
                                   
                                   ⁢ 
                                   1 
                                 
                               
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                                 ⁢ 
                                 
                                     
                                 
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                                 ⁢ 
                                 
                                     
                                 
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                                   JUMP 
                                   ⁢ 
                                   
                                       
                                   
                                   ⁢ 
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                               ⁡ 
                               
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                                   n 
                                   + 
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                                 ] 
                               
                             
                             ⁢ 
                             
                               
                                 
                                   S 
                                   
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                                     ⁢ 
                                     
                                         
                                     
                                     ⁢ 
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                                   ⁢ 
                                   
                                       
                                   
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                                   ⁢ 
                                   
                                       
                                   
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                                 ⁢ 
                                 
                                     
                                 
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                             ⁢ 
                             
                                 
                             
                             ⁢ 
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                         ⁡ 
                         
                           [ 
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                           EXT 
                           ⁢ 
                           
                               
                           
                           ⁢ 
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                       ⁡ 
                       
                         [ 
                         n 
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                         CEIL 
                         ( 
                         
                           
                             
                               
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                                   ⁢ 
                                   
                                       
                                   
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                             8 
                           
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                                 ⁢ 
                                 
                                     
                                 
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                                 ⁢ 
                                 
                                     
                                 
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                                   ⁢ 
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                                     ⁢ 
                                     
                                         
                                     
                                     ⁢ 
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                                 ⁡ 
                                 
                                   [ 
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                           × 
                           
                             ( 
                             
                               
                                 
                                   T 
                                   
                                     JUMP 
                                     ⁢ 
                                     
                                         
                                     
                                     ⁢ 
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                                 ⁡ 
                                 
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                                     + 
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                                 8 
                                 × 
                                 
                                   
                                     
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                                         ⁢ 
                                         
                                             
                                         
                                         ⁢ 
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                                         + 
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                                       ] 
                                     
                                   
                                   
                                     R 
                                     
                                       UD 
                                       ⁢ 
                                       
                                           
                                       
                                       ⁢ 
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                                       ⁢ 
                                       
                                           
                                       
                                       ⁢ 
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                               + 
                               
                                 
                                   T 
                                   
                                     JUMP 
                                     ⁢ 
                                     
                                         
                                     
                                     ⁢ 
                                     0 
                                   
                                 
                                 ⁡ 
                                 
                                   [ 
                                   
                                     n 
                                     + 
                                     2 
                                   
                                   ] 
                                 
                               
                             
                             ) 
                           
                         
                         } 
                       
                       . 
                     
                   
                 
               
               
                 
                   ( 
                   2 
                   ) 
                 
               
             
           
         
       
     
     The size S EXT2 [n] of the (n+1) th  dependent-view extent D[n] is at least equal to the data amount transferred from the RB 2   1912  to the system target decoder  1903  during the period from the start of the corresponding read period PR D [n] until immediately before the read period PR D [n+1] of the next dependent-view extent D[n+1]. In this case, as shown in  FIG. 20B , the data amount DA 2  stored in the RB 2   1912  immediately before the read period PR D [n+1] of the next dependent-view extent D[n+1] does not fall below the amount immediately before the read period PR D [n] of the (n+1) th  dependent-view extent D[n]. Here, the length of the read period PR D [n] of the (n+1) th  dependent-view extent D[n] equals a value S EXT2 [n]/R UD3D , the size S EXT2 [n] of this dependent-view extent D[n] divided by the read rate R UD3D . Accordingly, condition 3 indicates the following. The minimum extent size of the (n+1)th dependent-view extent D[n] is expressed in the right-hand side of expression (3): 
                         S     EXT   ⁢           ⁢   2       ⁡     [   n   ]       ≥       (           S     EXT   ⁢           ⁢   2       ⁡     [   n   ]         R     UD   ⁢           ⁢   3   ⁢           ⁢   D         +         T     JUMP   ⁢           ⁢   0       ⁡     [   n   ]       ⁢         S     EXT   ⁢           ⁢   1       ⁡     [   n   ]         R     UD   ⁢           ⁢   3   ⁢           ⁢   D           +       T     JUMP   ⁢           ⁢   0       ⁡     [     n   +   1     ]         )     ×       R     EXT   ⁢           ⁢   2       ⁡     [   n   ]           ∴         S     EXT   ⁢           ⁢   2       ⁡     [   n   ]       ≥       CEIL   (           R     EXT   ⁢           ⁢   2       ⁡     [   n   ]       8     ×       R     UD   ⁢           ⁢   3   ⁢           ⁢   D           R     UD   ⁢           ⁢   3   ⁢           ⁢   D       -       R     EXT   ⁢           ⁢   2       ⁡     [   n   ]           ×     (         T     JUMP   ⁢           ⁢   0       ⁡     [   n   ]       +     8   ×         S     EXT   ⁢           ⁢   1       ⁡     [   n   ]         R     UD   ⁢           ⁢   3   ⁢           ⁢   D           +       T     JUMP   ⁢           ⁢   0       ⁡     [     n   +   1     ]         )       }     .               (   3   )               
Seamless Playback from Continuous Extended Extent Blocks
 
       FIG. 21B  is a schematic diagram showing the (n+1) th  extended extent block  2101 , the (n+2) th  extended extent block  2102 , and the playback path  2110  in 3D playback mode for these extent blocks. As shown in  FIG. 21B , two contiguous extents EXTSS[n] and EXTSS[n+1] in the file SS are separated by an extended extent T 1 . In accordance with the playback path  2110 , the (n+1) th  extent EXTSS[n] is first read. A jump J 3D  occurs immediately thereafter, and then the (n+2) th  extent EXTSS[n+1] is read all at once. 
       FIG. 21A  is a graph showing changes in data amounts DA 1  and DA 2 , stored in the RB 1   1911  and RB 2   1912 , respectively, and changes in their sum DA 1 +DA 2 , when 3D video images are played back seamlessly and continuously from two contiguous extended extent blocks  2101  and  2102 . In  FIG. 21A , the alternating long and short dashed line indicates changes in the data amount DA 1  stored in the RB 1   1911 , the dashed line indicates changes in the data amount DA 2  stored in the RB 2   1912 , and the solid line indicates changes in the sum DA 1 +DA 2  of the two data amounts. In this graph, the solid line is an approximation that averages small changes each time an extent is read. Furthermore, the zero sector transition time T JUMP0  is assumed to be zero ms. 
     As shown in  FIG. 21A , during the period PR BLK [n] while the extent block EXTSS[n] is being read from the (n+1) th  extended extent  2101  to the RB 1   1911  and the RB 2   1912 , the data amounts DA 1  and DA 2  stored therein increase. Specifically, during the read period PR BLK [n], the sum of the stored data amounts DA 1 +DA 2  increases at a rate equal to R UD3D  R EXTSS [n], the difference between the read rate R UD3D  and the mean transfer rate R EXTSS [n]. The mean transfer rate R EXTSS [n] is estimated at the size S EXTSS [n] of the entirety of the extent block EXTSS[n] divided by the extent ATC time T EXTSS . 
     In  FIG. 21A , when the base-view extent B 1  at the end of the (n+1) th  extent block EXTSS[n] is read into the RB 1   1911 , the sum DA 1 +DA 2  of the stored data amount reaches the maximum value. During the immediately subsequent jump period PJ, the sum DA 1 +DA 2  of the stored data amount decreases at the mean transfer rate R EXTSS [n]. Accordingly, by adjusting the maximum value of sum DA 1 +DA 2  of the stored data amount to be sufficiently large, underflow of both RB 1   1911  and RB 2   1912  can be prevented from occurring during the jump J 3D  over the recording area of the extended extent T 1 . As a result, 3D video images can be played back seamlessly from two contiguous extended extent blocks  2101  and  2102 . 
     The maximum value of the sum DA 1 +DA 2  of the stored data amount in  FIG. 21A  depends on the size of the (n+1) th  extent block EXTSS[n]. Accordingly, during the jump J 3D  between the extended extent blocks  2101  and  2102 , the size of the (n+1) th  extent block EXTSS[n] should satisfy the following four conditions in order to prevent underflow in either the RB 1   1911  or the RB 1   1912 . 
     Preloading is performed during the read period PR D   0  of the dependent-view extent D 0  located at the top of the (n+1) th  extent block EXTSS[n]. During the preload period PR D   0 , data in the n th  extent block continues to be transferred from the RB 2   1912  to the system target decoder  1903  as during the immediately prior jump period. Data supply to the system target decoder  1903  is thus maintained. Similarly, preloading is performed during the read period PR D   1  of the dependent-view extent D 2  located at the top of the (n+2) th  extent block EXTSS[n+1]. Accordingly, during the preload period PR D   1 , data in the (n+1) th  extent block EXTSS[n] continues to be transferred from the RB 2   1912  to the system target decoder  1903  as during the immediately prior jump period PJ. Data supply to the system target decoder  1903  is thus maintained. Therefore, in order to prevent underflow in the RB 1   1911  and the RB 2   1912  during the jump J 3D , the extent ATC time T EXTSS  of the (n+1) th  extent block EXTSS[n] needs to be at least equal to the length of the period from the end point t 0  of the first preload period PR D   0  until the end point t 1  of the next preload period PR D   1 . In other words, the size S EXTSS [n] of the (n+1) th  extent block EXTSS[n] needs to be at least equal to the sum of the amount of data transferred from the RB 1   1911  and the RB 2   1912  to the system target decoder  1903  during the period t 0 -t 1 . 
     As is clear from  FIG. 21A , the length of the period t 0 -t 1  is equal to the sum of the length of the read period PR BLK [n] of the (n+1) th  extent block EXTSS[n], the length T JUMP [n] of the jump period PJ, and the difference T DIFF [n] between the lengths of the preload periods PR D   0  and PR D   1  between the two extent blocks EXTSS[n] and EXTSS[n+1]. Furthermore, the length of the read period PR BLK [n] of the (n+1) th  extent block EXTSS[n] is equal to S EXTSS [n]/R UD3D , i.e. the size S EXTSS [n] of the extent block EXTSS[n] divided by the corresponding read rate R UD3D . Accordingly, condition 4 indicates the following. The minimum extent size of the (n+1) th  extent EXTSS[n] in the file SS is expressed in the right-hand side of expression (4): 
     
       
         
           
             
               
                 
                   
                     
                       
                         S 
                         EXTSS 
                       
                       ⁡ 
                       
                         [ 
                         n 
                         ] 
                       
                     
                     ≥ 
                     
                       
                         ( 
                         
                           
                             
                               
                                 S 
                                 EXTSS 
                               
                               ⁡ 
                               
                                 [ 
                                 n 
                                 ] 
                               
                             
                             
                               R 
                               
                                 UD 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 3 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 D 
                               
                             
                           
                           + 
                           
                             
                               T 
                               JUMP 
                             
                             ⁡ 
                             
                               [ 
                               n 
                               ] 
                             
                           
                           + 
                           
                             
                               T 
                               DIFF 
                             
                             ⁡ 
                             
                               [ 
                               n 
                               ] 
                             
                           
                         
                         ) 
                       
                       × 
                       
                         
                           R 
                           EXTSS 
                         
                         ⁡ 
                         
                           [ 
                           n 
                           ] 
                         
                       
                     
                   
                   ∴ 
                   
                     
                       
                         S 
                         EXTSS 
                       
                       ⁡ 
                       
                         [ 
                         n 
                         ] 
                       
                     
                     ≥ 
                     
                       
                         
                           
                             R 
                             
                               UD 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               3 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               D 
                             
                           
                           × 
                           
                             
                               R 
                               EXTSS 
                             
                             ⁡ 
                             
                               [ 
                               n 
                               ] 
                             
                           
                         
                         
                           
                             R 
                             
                               UD 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               3 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               D 
                             
                           
                           - 
                           
                             
                               R 
                               EXTSS 
                             
                             ⁡ 
                             
                               [ 
                               n 
                               ] 
                             
                           
                         
                       
                       × 
                       
                         
                           ( 
                           
                             
                               
                                 T 
                                 JUMP 
                               
                               ⁡ 
                               
                                 [ 
                                 n 
                                 ] 
                               
                             
                             + 
                             
                               
                                 T 
                                 DIFF 
                               
                               ⁡ 
                               
                                 [ 
                                 n 
                                 ] 
                               
                             
                           
                           ) 
                         
                         . 
                       
                     
                   
                 
               
               
                 
                   ( 
                   4 
                   ) 
                 
               
             
           
         
       
     
     The lengths of the preload periods PR D   0  and PR D   1  are respectively equal to S EXT2   0 /R UD3D  and S EXT2   1 /R UD3D , which are the sizes S EXT2   0  and S EXT2   1  of the dependent-view extents D 0  and D 1  located at the respective tops of the extent blocks EXTSS[n] and EXTSS[n+1] divided by the read rate R UD3D . Accordingly, the difference T DIFF  between the lengths of the preload periods PR D   0  and PR D   1  equals the difference between these values: T DIFF =S EXT2   1 /R UD3D −S EXT2   0 /R UD3D . Like the right-hand side of expressions (1)-(3), the right-hand side of expression (4) may be expressed as an integer value in units of bytes. 
     When decoding of multiplexed stream data is modified in the following manner, the difference T DIFF  in expression (4) may be considered to be zero. First, the maximum value of the difference T DIFF  throughout the multiplexed stream data, i.e. the worst value of the difference T DIFF , is sought. Next, when the multiplexed stream data is played back, the start of decoding is delayed after the start of reading by a time equal to the worst value of T DIFF . 
     2-7-C: Maximum Extent Size 
     By condition 1-4, the minimum extent size of the extents in the file  2 D, the file DEP, and the file SS is limited. On the other hand, as the size of the extents grows larger, the capacity required for the read buffers generally increases. For details, see “Supplement”). Accordingly, in order to reduce the capacities of the read buffers as much as possible, it is preferable to restrict the upper limits on the sizes of extents as much as possible. The upper limits are referred to as “maximum extent sizes.” 
     The extent ATC time is equal for a base-view extent EXT 1 [k] and a dependent-view extent EXT 2 [k] constituting one extent pair (the letter k represents an integer equal to or greater than zero). Accordingly, if the extent ATC time is shortened by a restriction on the maximum extent size of the base-view extent EXT 1 [k], the maximum extent size of the dependent-view extent EXT 2 [k] is also restricted. Therefore, in order to maintain the lower limits of the capacities of RB 11911  and RB 2   1912  within permissible ranges, the size of each base-view extent EXT 1 [k] should satisfy condition 5 below. 
     In the shared sections, the base-view extent B[k] is shared between the file 2D and the file SS. Accordingly, the sizes S EXT1 [k] of the base-view extent B[k] should satisfy expression (1). In order to reduce the size S EXT1 [k] of the base-view extent B[k] as much as possible while satisfying expression (1), the maximum extent size should be as close as possible to upper limit of the right-hand side of expression (1), i.e. the upper limit of the minimum extent size of the base-view extent B[k]. 
     Accordingly, condition 5 indicates the following. The maximum extent size of the base-view extent B[k] is expressed in the right-hand side of expression (5): 
     
       
         
           
             
               
                 
                   
                     
                       S 
                       
                         EXT 
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         1 
                       
                     
                     ⁡ 
                     
                       [ 
                       k 
                       ] 
                     
                   
                   ≤ 
                   
                     
                       CEIL 
                       ⁡ 
                       
                         ( 
                         
                           
                             
                               
                                 R 
                                 
                                   EXT 
                                   ⁢ 
                                   
                                       
                                   
                                   ⁢ 
                                   1 
                                 
                               
                               ⁡ 
                               
                                 [ 
                                 k 
                                 ] 
                               
                             
                             8 
                           
                           × 
                           
                             
                               R 
                               
                                 UD 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 2 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 D 
                               
                             
                             
                               
                                 R 
                                 
                                   UD 
                                   ⁢ 
                                   
                                       
                                   
                                   ⁢ 
                                   2 
                                   ⁢ 
                                   
                                       
                                   
                                   ⁢ 
                                   D 
                                 
                               
                               - 
                               
                                 R 
                                 
                                   MAX 
                                   ⁢ 
                                   
                                       
                                   
                                   ⁢ 
                                   2 
                                   ⁢ 
                                   
                                       
                                   
                                   ⁢ 
                                   D 
                                 
                               
                             
                           
                           × 
                           
                             T 
                             
                               JUMP 
                               ⁢ 
                               
                                 - 
                               
                               ⁢ 
                               2 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               D_MIN 
                             
                           
                         
                         ) 
                       
                     
                     . 
                   
                 
               
               
                 
                   ( 
                   5 
                   ) 
                 
               
             
           
         
       
     
     The right-hand side of expression (5) differs from the right-hand side of expression (1) in the following ways. First, the mean transfer rate R EXT2D  included in the denominator is replaced by the maximum value thereof, R MAX2D . Accordingly, the second fraction in the right-hand side of expression (5) equals the maximum value of the same fraction in expression (1). Next, the jump time T JUMP-2D-MIN  in expression (5) is equal to the minimum value among the maximum jump times defined by the standards. For example, among the maximum jump times T JUMP-MAX  specified in the table in  FIG. 18 , the next largest value after 0 ms, namely 200 ms, is adopted as the jump time T JUMP-2D-MIN  in expression (5). In this case, the interval between the extents EXT 2 D[k] and EXT 2 D[k+1] in the shared sections of the file 2D is restricted to being at most the corresponding maximum jump distance S JUMP-MAX =10000 sectors. 
     By adopting expression (1A) instead of expression (1), the size of the base-view extents satisfies the expression (5A) below instead of expression (5) when a margin is added to the base-view extents: 
     
       
         
           
             
               
                 
                   
                     
                       S 
                       
                         EXT 
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         1 
                       
                     
                     ⁡ 
                     
                       [ 
                       n 
                       ] 
                     
                   
                   ≤ 
                   
                     CEIL 
                     ⁢ 
                     
                       
                         { 
                         
                           
                             
                               
                                 R 
                                 
                                   EXT 
                                   ⁢ 
                                   
                                       
                                   
                                   ⁢ 
                                   2 
                                   ⁢ 
                                   
                                       
                                   
                                   ⁢ 
                                   D 
                                 
                               
                               ⁡ 
                               
                                 [ 
                                 n 
                                 ] 
                               
                             
                             8 
                           
                           × 
                           
                             ( 
                             
                               
                                 
                                   
                                     R 
                                     
                                       UD 
                                       ⁢ 
                                       
                                           
                                       
                                       ⁢ 
                                       2 
                                       ⁢ 
                                       
                                           
                                       
                                       ⁢ 
                                       D 
                                     
                                   
                                   
                                     
                                       R 
                                       
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                                         ⁢ 
                                         
                                             
                                         
                                         ⁢ 
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                                         ⁢ 
                                         
                                             
                                         
                                         ⁢ 
                                         D 
                                       
                                     
                                     - 
                                     
                                       R 
                                       
                                         MAX 
                                         ⁢ 
                                         
                                             
                                         
                                         ⁢ 
                                         2 
                                         ⁢ 
                                         
                                             
                                         
                                         ⁢ 
                                         D 
                                       
                                     
                                   
                                 
                                 × 
                                 
                                   T 
                                   
                                     JUMP 
                                     ⁢ 
                                     
                                       - 
                                     
                                     ⁢ 
                                     2 
                                     ⁢ 
                                     D_MIN 
                                   
                                 
                               
                               + 
                               ΔT 
                             
                             ) 
                           
                         
                         } 
                       
                       . 
                     
                   
                 
               
               
                 
                   ( 
                   
                     5 
                     ⁢ 
                     A 
                   
                   ) 
                 
               
             
           
         
       
     
     The maximum extent size expressed in the right-hand side of expression (5A) is larger than the minimum extent size expressed in the right-hand side of expression (5) by a data amount that is read from the read buffer to the system target decoder during an extension time AT. This data amount is guaranteed as a margin. 
     Transfer Rate of Stream Data 
     As shown in  FIG. 7 , dependent-view pictures are compressed with reference to base-view pictures. Accordingly, on average, the bit rate for a dependent-view video stream is lower than for a base-view video stream. As a result, it suffices to set the system rate R TS2  for the file DEP lower than the system rate R TS1  for the file  2 D. For example, if the system rate R TS1  for the file  2 D is set to 48 Mbps or less, it suffices to set the system rate R TS2  for the file DEP to 32 Mbps or less: R TS1 ≦48 Mbps, R TS2 ≦32 Mbps. 
     Here, it is assumed that the sum of the system rates R TS1  and R TS2  is restricted to a constant threshold value or less. This threshold value is set to be equal to or less than a transfer bandwidth allocated to the system target decoder  1903  and equals, for example, 64 Mbps: R TS1 +R TS2 ≦64 Mbps. In this case, if the system rate R TS1  for the file  2 D is set to 48 Mbps, the system rate R TS2  for the file DEP is set to 16 Mbps or less: R TS1 =48 Mbps, R TS2 ≦16 Mbps. As long as the bit rate of each video stream is maintained at a normal value, this sort of restriction on the sum of the system rates R TS1  and R TS2  is useful for efficient use of the transfer bandwidth. In practice, however, the bit rate of a dependent-view video stream may temporarily exceed the bit rate of the base-view video stream. Such a reversal of bit rates may occur, for example, during playback of 3D video images representing a natural landscape, if the base view (for example, the left view) suddenly goes out of focus and only the dependent view (for example, the right view) is in focus. In this case, even though the first transfer rate R EXT1  is much lower than the system rate R TS1 =48 Mbps for the file  2 D, the second transfer rate R EXT2  cannot not exceed the system rate R TS2 ≦16 Mbps for the file DEP (to be precise, 16 Mbps multiplied by 192/188, which is approximately 1.02. Hereinafter, this coefficient is considered to be one unless precision is required). When the sum of the system rates R TS1  and R TS2  is thus restricted, the second transfer rate R EXT2  cannot be adapted to a temporary rise in the bit rate of the dependent-view video stream. 
     In order to enable such adaptation, instead of restricting the sum of the system rates R TS1  and R TS2 , the sum of the first transfer rate R EXT1  [n] and the second transfer rate R EXT2 [n] in units of extents should be restricted: R EXT [n] R EXT2 [n]≦64 Mbps. Here, among the (n+1) th  extent pair, the average value when transferring source packets that include the base-view extent EXT 1 [n] is the first transfer rate R EXT1 [n], and the average value when transferring source packets that include the dependent-view extent EXT 2 [n] is the second transfer rate R EXT2 [n]. 
       FIGS. 22A and 22B  are graphs showing changes over time in the first transfer rate R EXT1  and the second transfer rate R EXT2  when the total of the first transfer rate R EXT1  and the second transfer rate R EXT2  is restricted. As shown in  FIG. 22A , the first transfer rate R EXT1  suddenly falls from a maximum value R MAX1  approximately equal to 48 Mbps at a first time T 0 , and during a period T str  from the first time T 0  until a second time T 1  remains at a low level of 16 Mbps. On the other hand, as shown by the solid curve GR 1  in  FIG. 22B , the change in the second transfer rate R EXT2  is complementary to the change in the first transfer rate R EXT1 . In particular, during the period T str , the peak P 0  reaches a maximum value R MAX2  of approximately 32 Mbps. When the sum of the first transfer rate R EXT1  and the second transfer rate R EXT2  is thus restricted in units of extents, the second transfer rate R EXT2  can adapt to a temporary rise in the bit rate of the dependent-view video stream. 
     To further effectively use the transfer bandwidth allocated to the system target decoder  1903  for transfer of stream data, it is preferable for the system rate R TS2  for a file DEP to be set even higher.  FIG. 22C  is a graph showing changes over time in R EXT1  R EXT2 , i.e. the sum of the first transfer rate R EXT1  and the second transfer rate R EXT2  shown in  FIGS. 22A and 22B . As indicated by the depression CV in the solid curve GR 3  in  FIG. 22C , R EXT1  R EXT2 , i.e. the sum of the first transfer rate R EXT1  and the second transfer rate R EXT2 , falls below the threshold value of 64 Mbps during the period T str  from the first time T 0  to the second time T 1 . As shown by the solid curve GR 1  in the graph in  FIG. 22B , this is because the second transfer rate R EXT2  is restricted to the system rate R TS2  for the file DEP, i.e. to 32 Mbps or less. As shown in  FIG. 22A , the first transfer rate R EXT1  falls to 16 Mbps during the period T str , and thus there remains a margin of at least 48 Mbps in the transfer bandwidth; the value 48 Mbps is the difference between the threshold value of 64 Mbps and the above value of 16 Mbps. Accordingly, the system rate R TS2  for the file DEP is set within a higher range than 32 Mbps, or preferably, the same range as the system rate R TS1  for the file  2 D, such as 48 Mbps or less: R TS1 ≦48 Mbps, R TS2 ≦48 
     Mbps. In  FIGS. 22B and 22C , the changes over time in the second transfer rate R EXT2 , as well as the changes over time in the sum R EXT1  R EXT2  of the first transfer rate R EXT1  and the second transfer rate R EXT2 , are respectively indicated by dashed curves GR 2  and GR 4 . As shown by the dashed curve GR 2  in  FIG. 22B , the peak P 1  of the second transfer rate R EXT2  cannot exceed 32 Mbps. As a result, as the dashed curve GR 4  in  FIG. 22C  indicates, the sum R EXT1  R EXT2  of the first transfer rate R EXT1  and the second transfer rate R EXT2  is maintained near the threshold value of 64 Mbps during the period T str . Efficient use of the transfer bandwidth can thus be further improved. 
     When the system rate R TS2  for the file DEP is set as high as the system rate R TS1  for the file  2 D, it is assumed that the second transfer rate R EXT2  can also rise to the same level. When the transfer rate R EXT2 [n] for the (n+1) th  dependent-view extent in the (n+1) th  extent pair rises in this way, then based on the limit on the sum of the transfer rates, the transfer rate R EXT1 [n] for the base-view extent falls conspicuously below the maximum value R MAX1 . On the other hand, the mean transfer rate R EXT2D  included in the denominator in the definition of the maximum extent size in expression (5) is estimated at the maximum value thereof, R MAX2D . Furthermore, the upper limit on the extent ATC time of the base-view extent is the value yielded by dividing the maximum extent size by the first transfer rate R EXT1 [n]. Accordingly, the upper limit is conspicuously longer than the actual extent ATC time. Since the extent ATC time is shared in the (n+1) th  extent pair, the maximum size of the dependent-view extent reaches the product of the second transfer rate R EXT2 [n] and the above upper limit on the extent ATC time. This product is conspicuously larger than the actual value necessary for seamless playback. As a result, further reduction of the capacity of the RB 2   1912  is prevented. 
     In order to permit further reduction of the capacity of the RB 2   1912  even when the system rate R TS2  for the file DEP is set approximately as high as the system rate R TS1  for the file  2 D, condition 5 for the maximum extent size, i.e. expression (5), is changed to expression (5B): 
     
       
         
           
             
               
                 
                   
                     
                       S 
                       
                         EXT 
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         1 
                       
                     
                     ⁡ 
                     
                       [ 
                       n 
                       ] 
                     
                   
                   ≤ 
                   
                     
                       CEIL 
                       ⁡ 
                       
                         ( 
                         
                           
                             
                               
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                                   ⁢ 
                                   
                                       
                                   
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                                             ⁢ 
                                             
                                                 
                                             
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     In the right-hand side of expression (5B), the lower of (i) the maximum value R MAX2D  of the mean transfer rate for the extent in the file  2 D and (ii) the difference between the sum R MAX1 +R MAX2  of the maximum values of the transfer rates and the second transfer rate R EXT2 [n] is used as the transfer rate included in the denominator. In this context, the sum R MAX1 +R MAX2  of the maximum values of the transfer rates equals 192/188 times the sum R TS1 +R TS2  of the system rates. 
     Accordingly, when the second transfer rate R EXT2 [n] rises to the same level as the system rate R TS2 , the maximum extent size is estimated at the above difference. As a result, the upper limit on the extent ATC time of the base-view extent is maintained at a value near the actual extent ATC time. Therefore, the size of the dependent-view extent is maintained at a level actually necessary for seamless playback. The capacity of the RB 2   1912  is thus kept sufficiently low. 
     When expression (5B) is complicated to estimate the maximum extent size, the maximum extent size may be preliminarily determined depending on a range for the second transfer rate R EXT2 [n]. For example, the size S EXT1 [n] of the base-view extent and the size S EXT2 [n] of the dependent-view extent are set so as to satisfy the following expression (5C): 
     When the second transfer rate R EXT2 [n] is equal to or less than 32 Mbps×192/188,
 
 S   EXT1   [n]≦ 20×106 bytes=approximately 19 MB,
 
 S   EXT2   [n]≦ 6.5×106 bytes=approximately 6.2 MB,
 
     when the second transfer rate R EXT2 [n] exceeds 32 Mbps×192/188,
 
 S   EXT1   [n]≦ 20×106 bytes=approximately 19 MB, and
 
 S   EXT2   [n]≦ 8.1×106 bytes=approximately 7.7 MB.  (5C)
 
2-7-D: Conditions in Extended Playback Mode
 
       FIG. 23  is a block diagram showing a playback processing system built in the playback device  102  in extended playback mode. As shown in  FIG. 23 , this playback processing system includes a BD-ROM drive  2301 , a switch  2302 , a pair of read buffers  2311  and  2312 , and a system target decoder  2303 . The BD-ROM drive  2301  reads extended extents and base-view extents from the BD-ROM disc  101  and transfers the extents to the switch  2302  at a read rate R UDEX . The switch  2302  separates extended extents from base-view extents. A first read buffer  2311  and a third read buffer  2313  (hereinafter abbreviated as RB 1  and RB 3 ) are buffer memories internal to the playback device  102  and store extents separated by the switch  2302 . The RB 1   2311  stores base-view extents, and the RB 3   2312  stores extended extents. The system target decoder  2303  reads source packets from the base-view extents in the RB 1   2311  at a first transfer rate R EXT1  and reads source packets from the extended extents in the RB 3   2312  at a third transfer rate R EXT3 . The system target decoder  2303  also decodes pairs of read base-view extents and extended extents into video data VD and audio data AD. 
     The first transfer rate R EXT1  is equal to the first transfer rate in 3D playback mode. The third transfer rate R EXT3  equals 192/188 times the mean processing rate at which the system target decoder  2303  extracts TS packets from source packets stored in the RB 3   2312 . The maximum value R MAX3  of the third transfer rate R EXT3  equals 192/188 times the system rate R TS3  for the extended stream file: R MAX3 =R TS3 ×192/188. The system rate R TS3  is normally expressed in bits/second (bps) and equals eight times the recording rate of the extended stream expressed in bytes/second (Bps). The transfer rates R EXT1  and R EXT3  are typically represented in bits/second and specifically equal to the size of each extent, which is expressed in bits, divided by the extent ATC time thereof. 
     The read rate R UDEX  is typically expressed in bits/second and is set at a higher value, e.g., 72 Mbps, than either of the maximum values R MAX1 , R MAX3  of the transfer rates R EXT1 , R EXT3 : R UDEX &gt;R MAX1 , R UDEX &gt;R MAX2 . This prevents decoding process of the system target decoder  2303  from causing underflow of the RB 1   2311  and the RB 3   2312  while the BD-ROM drive  2301  is reading an extent of the file  2 D or reading an extent of the extended stream file from the BD-ROM disc  101 . 
     Extent ATC Time of Extended Extents 
       FIGS. 24A and 24B  are graphs showing changes in data amounts DA 1  and DA 3 , respectively, that are stored in the RB 1   2311  and RB 2   2312 , respectively, when 4K2K 2D video images are played back seamlessly from two contiguous extended extent blocks  2410  and  2411 .  FIG. 24C  is a schematic diagram showing a playback path  2420  in extended playback mode corresponding to the extended extent blocks  2410  and  2411 . As shown in  FIG. 24C , in accordance with a playback path  2420 , the top extended extent T is first read from the extended extent blocks  2410  and  2411 . Subsequently, a jump J SJ  over the recording area of the dependent-view extent D and reading of the base-view extent B are repeated multiple times. 
     Reading and transfer operations by the BD-ROM drive  2301  are not actually performed in a continuous manner, as suggested by the graphs in  FIGS. 24A and 24B , but rather in an intermittent manner. Thus, overflow in the RB 1   2311  and RB 2   2312  is prevented during the read periods of the extents T and B. Accordingly, the graphs in  FIGS. 24A and 24B  represent actual step-wise changes as approximated linear changes. Furthermore, the zero sector transition time T JUMP0  is assumed to be zero milliseconds. 
     As shown by  FIGS. 24A and 24B , during the read period PR T   0  for the first extended extent T 0 , the data amount DA 3  stored in the RB 3   2312  increases at a rate equal to R UDEX −R EXT3 , the difference between the read rate R UDEX  and the third transfer rate R EXT3 , whereas the data amount DA 1  stored in the RB 1   2311  decreases at the first transfer rate R EXT1 . As shown in  FIG. 24C , a jump J SJ  occurs at the end of the read period PR T   0  of the first extended extent T 0 , and reading of the first dependent-view extent D is skipped. As shown in  FIGS. 24A and 24B , during the jump period PSJ, the data amount DA 1  stored in the RB 1   2311  continues to decrease at the first transfer rate R EXT1 , whereas the data amount DA 2  stored in the RB 3   2312  decreases at the third transfer rate R EXT3 . Thereafter, during the read period PR B  of the first base-view extent B, the data amount DA 1  stored in the RB 1   2311  increases at a rate equal to R UDEX −R EXT1 , the difference between the read rate R UDEX  and the first transfer rate R EXT1 . Subsequently, the data amount DA 1  stored in the RB 1   2311  decreases during the jump J SJ  over the recording area of the dependent-view extent D and increases during the read period of the base-view extent B. Overall, however, the data amount DA 1  stored in the RB 1   2311  increases until the end of the first extended extent block  2410  is read. On the other hand, the data amount DA 3  stored in the RB 3   2312  continues to decrease at the third transfer rate R EXT3 . 
     Once all of the first extended extent blocks  2410  have been read, reading of the second extended extent T 1  begins. During the read period PR T   1 , the data amount DA 3  stored in the RB 3   2312  increases at a rate equal to R UDEX −R EXT3 , the difference between the read rate R UDEX  and the third transfer rate R EXT3 , whereas the data amount DA 1  stored in the RB 1   2311  decreases at the first transfer rate R EXT1 . Furthermore, a jump J SJ  occurs at the end of the read period PR T   1  of the second extended extent T 1 , and reading of the dependent-view extent D is skipped. During the jump period PSJ, the data amount DA 1  stored in the RB 1   2312  continues to decrease at the first transfer rate R EXT1 , whereas the data amount DA 2  stored in the RB 3   2312  decreases at the third transfer rate R EXT3 . 
     For seamless playback of 4K2K 2D video images from the extent blocks  2410  and  2411  shown in  FIG. 24C , the size of the extended extent T should fulfill condition 6 below. 
     The first extended extent T 0  should be transferred from the RB 3   2312  to the system target decoder  2303  during the period from the first read start time tA until the second read start time tB; at the first read start time tA, the base-view extent B located immediately after the first extended extent T 0  starts to be read, and at the second read start time tB, the base-view extent B located immediately after the next extended extent T 1  starts to be read. As shown in  FIG. 24B , the data amount DA 3  stored in the RB 3   2312  does not fall below the level at which the data amount was kept immediately before the read period PR T   0  of the first extended extent T 0 . Here, the read period PR B  of one base-view extent B has a length equal to the value S B /R UDEX , i.e., the size S B  of the base-view extent B divided by the read rate R UDEX . On the other hand, the read period PR T   1  of the second extended extent T 1  has a length equal to the value S T /R UDEX , i.e., the size S T  of the extended extent T 1  divided by the read rate R UDEX . Accordingly, condition 6 indicates that the extent ATC time ATC(T 0 ) of the first extended extent T 0  satisfies the following expression (6): 
     
       
         
           
             
               
                 
                   
                     ATC 
                     ⁡ 
                     
                       ( 
                       
                         T 
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         0 
                       
                       ) 
                     
                   
                   ≥ 
                   
                     
                       Σ 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       
                         T 
                         JUMP 
                       
                     
                     + 
                     
                       Σ 
                       ⁢ 
                       
                         
                           S 
                           B 
                         
                         
                           R 
                           UDEX 
                         
                       
                     
                     + 
                     
                       
                         
                           S 
                           T 
                         
                         
                           R 
                           UDEX 
                         
                       
                       . 
                     
                   
                 
               
               
                 
                   ( 
                   6 
                   ) 
                 
               
             
           
         
       
     
     Here, the summation symbols represent the sum of the jump times T jump  included in a period and the sum of the lengths S B /R UDEX  of the read periods of the base-view extents included in the same period; the period is from the first read start point tA until the second read start point tB; at the first read start point tA, the base-view extent B located immediately after the first extended extent T 0  starts to be read, and at the second read start point tB, the base-view extent B located immediately after the next extended extent T 1  starts to be read. 
     The extent ATC time ATC(T 0 ) of the extended extent T 0  equals the sum of the extent ATC times ATC(B) of the base-view extents B included in the extent block located immediately after the extended extent T 0 : ATC(T 0 )=ΣATC(B). 
     2-8: Number of Extent Pairs that Extended Extent Block Should Include 
     As shown in  FIGS. 21A and 21B , by reading the extent block EXTSS[n] located immediately after the first extended extent T, the playback device  102  in 3D playback mode stores, in the RB 1   1911  and the RB 2   1912 , the data amount to be transmitted to the system target decoder  1903  during the jump over the recording area of the next extended extent T 1 . In this case, the lower limit on the extent ATC time of the extent block EXTSS[n] is determined by condition 4. On the other hand, the maximum extent sizes of the base-view extent and the dependent-view extent are determined by condition 5. Accordingly, supposing that the extent block EXTSS[n] only included one extent pair, the extent ATC time of the extent block EXTSS[n] would run the risk of not reaching its lower limit even if the size of each extent in the pair is expanded to the maximum extent size. Therefore, as shown in  FIG. 13 , at least two extent pairs D[k] and B[k] are provided immediately after one extended extent T[m]. This allows for the extent ATC time of the extent block constituted by these extent pairs to be designed so as to be at least the lower limit. 
     Preferably, the number of extent pairs D[k] and B[k] provided immediately after one extended extent T[m] is fixed at two. This reduces the extent ATC time of the extended extent T[m] to a minimum, thus reducing the necessary capacity of the RB 3   2312  to a minimum. Furthermore, when the playback device in extended playback mode performs interrupt playback or trickplay such as fast forward or reverse, the range for searching for the base-view picture and the extended data located at the playback start position is reduced to a minimum. Accordingly, the playback device can easily search for the base-view picture and the extended data located at the playback start position. 
     2-9: Separation of Playback Paths at Locations where a Long Jump is Necessary 
     The Case when Only Shared Sections are Provided Before and after a Layer Boundary 
       FIG. 25  is a schematic diagram showing the arrangement of extents when two recording layers on the BD-ROM disc  101  only include shared sections before and after a layer boundary LB, as well as the playback paths in their respective modes designed for the extents. As illustrated in  FIG. 25 , the playback path  2501  in 2D playback mode, the playback path  2502  in 3D playback mode, and the playback path  2503  in extended playback mode all pass through the fourth base-view extent B[ 3 ] to be read immediately before a long jump J LY  to jump over the layer boundary LB. Accordingly, the size of this base-view extent B[ 3 ] must fulfill all of conditions 1, 4, and 6. The value to be substituted for the jump time T JUMP  in the right-hand side of expressions (1), (4), and (6) is the maximum jump time of the long jump J LY . This time includes “layer switching time” in addition to the maximum jump time T JUMP-MAX  corresponding to the maximum jump distance S JUMP-MAX  of the long jump J LY  in the table shown in  FIG. 18 ; the layer switching time is necessary for an operation to switch recording layers. The maximum jump distance S JUMP-MAX  of the long jump J LY  is, for example, 40,000 sectors, and the corresponding maximum jump time T JUMP-MAX  is 350 msec. On the other hand, the layer switching time is, for example, 350 msec. In this case, the value substituted for the jump time T jump  in the right-hand side of expressions (1), (4), and (6) is 350 msec+350 msec=700 msec. 
     The data amount of the main TS to be processed by the system target decoder during the long jump J LY  is guaranteed by the size of the fourth base-view extent B[ 3 ] in accordance with condition 1 in 2D playback mode and is guaranteed by the size of the third base-view extent B[ 2 ] and the fourth base-view extents B[ 3 ] in accordance with condition 4 in 3D playback mode. Therefore, the minimum extent size required by condition 1 for the fourth base-view extent B[ 3 ] is generally larger than the minimum extent size required by condition 2. The dependent-view extent D[ 3 ] located immediately before the base-view extent B[ 3 ] has the same extent ATC time as the base-view extent B[ 3 ]. Hence, the size of the dependent-view extent D[ 3 ] is generally larger than the minimum extent size required by condition 2. Therefore, the capacity of the RB 2  is generally larger than the minimum necessary value for seamless playback in 3D playback mode. With the arrangement shown in  FIG. 25 , it is less difficult to reduce the capacity of the RB 2  to the minimum necessary value. 
     In order to further reduce the capacity of the RB 2  while maintaining the capability of seamless playback of video images during the long jump J LY , it suffices to separate the playback path in 3D playback mode from the playback path in 2D playback mode immediately before or immediately after the long jump J LY . Specifically, the same portion of the main TS is recorded at least twice into different areas located either immediately before or immediately after the layer boundary LB. Next, when the playback device in 2D playback mode and the playback device in 3D playback mode are caused to play back that portion, the playback devices access the different areas separately. When the portion of the main TS is duplicated into the different areas located immediately before the layer boundary LB, the base-view extent located in one of the areas accessed by the playback device in 3D playback mode need not to have a size satisfying condition 1. On the other hand, when the portion of the main TS is duplicated into the different areas located immediately after the layer boundary LB, the long jump in 2D playback mode can have a jump distance shorter than the jump distance of the long jump in 3D playback mode. As a result of these facts, the playback device in 3D playback mode is allowed to maintain the capacity of the RB 2  at the minimum necessary value. 
     The Case when the Playback Paths are Completely Separated in all Modes 
       FIG. 26  is a schematic diagram showing an arrangement of extents when playback paths are completely separated in all modes immediately before a layer boundary LB on the BD-ROM disc  101 , as well as the playback paths in their respective modes designed for the extents. As illustrated in  FIG. 26 , a first recording layer L 0  located before the layer boundary LB includes a first shared section  2601 , and a second recording layer L 1  located after the layer boundary LB includes a second shared section  2602 . In addition to a monoscopic video specific section  2611  and a stereoscopic video specific section  2612 , the first recording layer L 0  includes an extended data specific section  2613  between the first shared section  2601  and the layer boundary LB. A portion B 2D  of the main TS is provided in the monoscopic video specific section  2611 , two extent pairs D and B 3D  are provided in the stereoscopic video specific section  2612 , and a pair of an extended extent T and a base-view extent B EX  is provided in the extended data specific section  2613 . The portion B 2D  of the main TS provided in the monoscopic video specific section  2611  (hereinafter referred to as a 2D-playback-only block) and the base-view extent B EX  provided in the extended data specific section  2613  (hereinafter referred to as an extended-playback-only block) are each a copy of the entirety of the base-view extents B 3D  provided in the stereoscopic video specific section  2612  (hereinafter referred to as 3D-playback-only blocks), i.e., the 2D- and extended-playback-only blocks each match with the entirety of the 3D-playback-only blocks bit for bit. In other words, the same data is recorded in triplicate. The 2D-playback-only block B 2D  can be accessed along with the immediately previous base-view extent B[ 1 ] as one extent EXT 2 D[ 1 ] of the file  2 D. The 3D-playback-only blocks B 3D  can be accessed along with the dependent-view extents D as one extent EXTSS[ 1 ] of the file SS. The extended extents T[ 0 ]-T[ 2 ], the base-view extents B[ 0 ], B[1], B[ 4 ], and B[ 5 ] in the shared sections  2601  and  2602 , and the extended-playback-only block B EX  can each be accessed as one extent EXT 3 [ 0 ]-EXT 3 [ 7 ] of the extended stream file. 
     The playback device  102  in 2D playback mode plays back the file  2 D. Accordingly, from the extents shown in  FIG. 26 , the extents EXT 2 D[ 0 ]-EXT 2 D[ 3 ] of the file  2 D are read, as shown by the playback path  2621  in 2D playback mode. Specifically, the top base-view extent B[ 0 ] in the first shared section  2601  is read as one extent EXT 2 D[ 0 ] of the file  2 D, and reading of the dependent-view extent D[ 1 ] located immediately thereafter is skipped. Next, the base-view extent B[ 1 ] located at the end of the first shared section  2601  and the 2D-playback-only block B 2D  are read as one extent EXT 2 D[ 1 ] of the file  2 D. Immediately thereafter, a long jump J LY  occurs, and thus the position of reading moves over the stereoscopic video specific section  2612 , the extended data specific section  2613 , and the layer boundary LB. In the second shared section  2602 , the reading of the top extended extent T[ 2 ] and the two dependent-view extents D[ 4 ] and D[ 5 ] is skipped, whereas the two base-view extents B[ 4 ] and B[ 5 ] are read as two extents EXT 2 D[ 2 ] and EXT 2 D[ 3 ] of the file  2 D. 
     The playback device  102  in 3D playback mode plays back the file SS. Accordingly, from the extents shown in  FIG. 26 , the extents EXTSS[ 0 ]-EXTSS[ 3 ] of the file SS are read, as shown by the playback path  2622  in 3D playback mode. Specifically, the extent block D[ 0 ], B[ 0 ], D[ 1 ], and B[ 1 ] is read continuously from the first shared section  2601  as one extent EXTSS[ 0 ] of the file SS. A jump J 3D  occurs immediately thereafter, and access to the monoscopic video specific section  2611  is skipped. Next, the extent block D[ 2 ], B 3D , D[ 3 ], and B 3D  is read continuously from the stereoscopic video specific section  2612  as one extent EXTSS[ 1 ] of the file SS. Immediately thereafter, a long jump J LY  occurs, and thus the position of reading moves over the extended data specific section  2613  and the layer boundary LB. In the second shared section  2602 , the reading of the extended extent T[ 2 ] is skipped, and the subsequent extent block D[ 4 ], B[ 4 ], D[ 5 ], and B[ 5 ] is read continuously as one extent EXTSS[ 2 ] of the file SS. 
     The playback device  102  in extended playback mode plays back the extended stream file. Accordingly, from the extents shown in  FIG. 26 , the extents EXT 3 [ 0 ]-EXT 3 [ 7 ] of the extended stream file are read, as shown by the playback path  2623  in extended playback mode. Specifically, in the first shared section  2601 , the top extended extent T[ 0 ]=EXT 3 [ 0 ] is first read, then two base-view extents B[ 0 ] and B[ 1 ] are read as two extents EXT 3 [ 1 ] and EXT 3 [ 2 ] of the extended stream file, and the reading of two dependent-view extents D[ 0 ] and D[ 1 ] is skipped. Next, access to the monoscopic video specific section  2611  and the stereoscopic video specific section  2612  is skipped by a jump J EX . The extended extent T[ 1 ] and the extended-playback-only block B EX  are then read from the extended data specific section  2613  as two extents EXT 3 [ 3 ] and EXT 3 [ 4 ] of the extended stream file. Immediately thereafter, a long jump J LY  occurs, and thus the position of reading moves over the layer boundary LB. In the second shared section  2602 , the extended extent T[ 2 ] and the two base-view extents B[ 4 ] and B[ 5 ] are read as three extents EXT 3 [ 5 ], EXT 3 [ 6 ], and EXT 3 [ 7 ] of the extended stream file, and the reading of the two dependent-view extents D[ 4 ] and D[ 5 ] is skipped. 
     As described above, the arrangement shown in  FIG. 26  separates the playback path  2621  in 2D playback mode, the playback path  2622  in 3D playback mode, and the playback path  2623  in extended playback mode from each other immediately before the long jump J LY . Note that the entirety of the 3D-playback-only blocks B 3D  match bit for bit with each of the 2D-playback-only block B 2D  and the extended-playback-only block B EX , and therefore the same base-view video frames are played back in every playback mode. 
     For seamless playback in 2D playback mode, the 2D-playback-only block B 2D  should be transferred from the read buffer  1602  to the system target decoder  1603  during the period from the start time of reading from the BD-ROM disc  101  until the end time of the long jump J LY . Accordingly, the size S DUP     —     FOR     —     SSIF  of the 2D-playback-only block B 2D  and the extent ATC time T DUP     —     FOR     —     SSIF  are set to satisfy expression (7) below: 
     
       
         
           
             
               
                 
                   
                     
                       T 
                       
                         DUP_FOR 
                         ⁢ 
                         _SSIF 
                       
                     
                     ≥ 
                     
                       
                         
                           S 
                           
                             DUP_FOR 
                             ⁢ 
                             _SSIF 
                           
                         
                         
                           R 
                           
                             UD 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             2 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             D 
                           
                         
                       
                       + 
                       
                         T 
                         JUMP 
                       
                     
                   
                   , 
                   
                     
                       S 
                       
                         DUP_FOR 
                         ⁢ 
                         _SSIF 
                       
                     
                     = 
                     
                       
                         
                           T 
                           
                             DUP_FOR 
                             ⁢ 
                             _SSIF 
                           
                         
                         × 
                         
                           R 
                           
                             MAX 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             2 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             D 
                           
                         
                       
                       ∴ 
                       
                         
                           T 
                           
                             DUP_FOR 
                             ⁢ 
                             _SSIF 
                           
                         
                         ≥ 
                         
                           
                             
                               R 
                               
                                 UD 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 2 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 D 
                               
                             
                             
                               
                                 R 
                                 
                                   UD 
                                   ⁢ 
                                   
                                       
                                   
                                   ⁢ 
                                   2 
                                   ⁢ 
                                   
                                       
                                   
                                   ⁢ 
                                   D 
                                 
                               
                               - 
                               
                                 R 
                                 
                                   MAX 
                                   ⁢ 
                                   
                                       
                                   
                                   ⁢ 
                                   2 
                                   ⁢ 
                                   
                                       
                                   
                                   ⁢ 
                                   D 
                                 
                               
                             
                           
                           × 
                           
                             
                               T 
                               JUMP 
                             
                             . 
                           
                         
                       
                     
                   
                 
               
               
                 
                   ( 
                   7 
                   ) 
                 
               
             
           
         
       
     
     For example, when the jump time of the long jump J LY  is 700 msec, the system rate R TS =R MAX2D /192×188 for the file  2 D is 48 Mbps, and the read rate R UD2D  of the BD-ROM drive is 54 Mbps, the extent ATC time T DUP     —     FOR     —     SSIF  of the 2D-playback-only block may be approximately 7.6 sec or more. 
     The 2D-playback-only block B 2D , the entirety of the 3D-playback-only blocks B 3D , and the extended-playback-only block B EX  are all the same data, and thus have the same size. This size equals the size S DUP     —     FOR     —     SSIF  of the 2D-playback-only block B 2D , i.e., the product of the extent ATC time T DUP     —     FOR     —     SSIF  provided in expression (7) and 192/188 times the system rate R TS  for the file  2 D: S DUP     —     FOR     —     SSIF =T DUP     —     FOR     —     SSIF ×R TS ×192/188. For example, when the system rate R TS  for the file  2 D equals its maximum value of 48 Mbps and the extent ATC time T DUP     —     FOR     —     SSIF  is approximately 7.6 sec, then the size S DUP     —     FOR     —     SSIF  of each of the blocks B 2D , B 3D , and B Ex  is approximately 44 MB. 
     In the arrangement of extents shown in  FIG. 26 , the same portion of the main TS B 2D , B 3D , and B EX  is recorded in triplicate in the vicinity of the location where a long jump J LY  is necessary. For example, when the system rate R TS  for the file  2 D equals its maximum value of 48 Mbps, data of at least 44 MB×2=88 MB is duplicated. Accordingly, it is difficult to further effectively utilize the volume area  202 B on the BD-ROM disc  101 . The playback path  2621  in 2D playback mode shown in  FIG. 26  has to use a long jump J LY  to skip the entirety of the 3D-playback-only blocks B 3D  and the extended-playback-only block B EX . Accordingly, when the system rate R TS  for the file  2 D equals its maximum value of 48 Mbps, the jump distance of the long jump J LY  exceeds approximately 88 MB=approximately 45,000 sectors. This value is larger than the maximum jump distance for a long jump=40,000 sectors=approximately 78.1 MB. Therefore, at least in the vicinity of the location where the long jump J LY  is necessary, the system rate R TS  for the file  2 D needs to be restricted to be lower than the actual bit rate for the file  2 D=48 Mbps. This would result in undesirable deterioration of the image quality in 2D playback mode. 
     To merely prevent degradation of the quality of video images to be played back in 2D playback mode, it would suffice to replace the monoscopic video specific section  2611  and the extended data specific section  2613  with each other within the arrangement shown in  FIG. 26 , and to reduce the jump distance of the long jump J LY  in 2D playback mode to 40,000 sectors. In this case, however, a long jump in extended playback mode has to be used to skip the reading of the entirety of the 3D-playback-only blocks B 3D  and the 2D-playback-only block B 2D . The jump distance of the long jump would thus exceed 40,000 sectors. In order to have a playback device in extended playback mode maintain its good playback performance, it becomes necessary to improve the jump performance of the playback device. This would result in undesirable increase in manufacturing cost of the playback device. 
     Advantages Shared by Arrangements  1  and  2  of Extents 
     Unlike the arrangement shown in  FIG. 26 , arrangement  1  shown in  FIG. 14  and arrangement  2  shown in  FIG. 15  allow the monoscopic video specific sections  1412 ,  1422 ,  1512 , and  1522  to be accessed by both the playback devices in 2D playback mode and extended playback mode. Thus, only the 2D-playback-only block B 2D  has to exist on the BD-ROM disc  101  as a copy of the entirety of the 3D-playback-only blocks. As a result, the volume area  202 B on the BD-ROM disc  101  can be utilized more effectively. 
     Furthermore, it suffices for the playback device in any mode to use a long jump J LY  to skip the reading of either the 2D-playback-only block B 2D  or the entirety of the 3D-playback-only blocks B 3D . Accordingly, even if the system rates for the file  2 D and the file SS are set to the maximum values of 48 Mbps and 64 Mbps, respectively, the jump distance of the long jump J LY  in either mode does not exceed the maximum jump distance of 40,000 sectors. As a result, the playback device in any mode can maintain high image quality regardless of the need for a long jump. 
     In practice, for arrangement  1  shown in  FIG. 14 , the jump distance of the long jump J LY  in each mode is calculated as follows. Here, the following case is assumed for this calculation: the long jump J LY  has the maximum jump time of 700 msec, and the playback path  1431  in 2D playback mode includes the jump J 2D  occurring immediately after the second monoscopic video specific section  1422  and having the maximum jump time of 350 msec. In this case, the maximum jump distance for any jump is restricted to 40,000 sectors. The file  2 D, the file DEP, and the extended stream file have system rates R TS1 , R TS2 , and R TS3  of 48 Mbps, 16 Mbps, and 16 Mbps, respectively. These values are determined by the transfer bandwidths of 48 Mbps, 64 Mbps, and 64 Mbps allocated to the system target decoders in 2D playback mode, 3D playback mode, and extended playback mode, respectively. The BD-ROM drives in 2D playback mode, 3D playback mode, and extended playback mode have read rates R UD2D , R UD3D , and R UDEX  of 54 Mbps, 72 Mbps, and 72 Mbps, respectively. 
     First, in order to guarantee the maximum jump time of 700 msec for the long jump J LY  in 2D playback mode, the base-view extent B 2D  located in the first monoscopic video specific section  1412  should have the size S DUP     —     FOR     —     SSIF  of at least approximately 44 MB, and the extent ATC time T DUP     —     FOR     —     SSIF  of approximately 7.6 sec at the shortest. 
     Next, for seamless playback in 3D playback mode, the extent block D, B 3D , D, and B 3D  located in the first stereoscopic video specific section  1413  should be transferred from the RB 1   1911  and the RB 2   1912  to the system target decoder  1903  during the period from the start time of reading from the BD-ROM disc  101  until the end time of the long jump J LY . Accordingly, the size S EXTSS  and extent ATC time T EXTSS  of the extent block D, B 3D , D, and B 3D  are set so as to satisfy expression (8) described below: 
     
       
         
           
             
               
                 
                   
                     
                       T 
                       EXTSS 
                     
                     ≥ 
                     
                       
                         
                           S 
                           EXTSS 
                         
                         
                           R 
                           
                             UD 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             3 
                             ⁢ 
                             
                                 
                             
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                       + 
                       
                         T 
                         JUMP 
                       
                     
                   
                   , 
                   
                     
                       S 
                       EXTSS 
                     
                     = 
                     
                       
                         
                           T 
                           EXTSS 
                         
                         × 
                         
                           ( 
                           
                             
                               R 
                               
                                 MAX 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 1 
                               
                             
                             + 
                             
                               R 
                               
                                 MAX 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 2 
                               
                             
                           
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                       ∴ 
                       
                         
                           T 
                           EXTSS 
                         
                         ≥ 
                         
                           
                             
                               R 
                               
                                 UD 
                                 ⁢ 
                                 
                                     
                                 
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                                 ⁢ 
                                 
                                     
                                 
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                                   ⁢ 
                                   
                                       
                                   
                                   ⁢ 
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                                   ⁢ 
                                   
                                       
                                   
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                               - 
                               
                                 ( 
                                 
                                   
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                                       MAX 
                                       ⁢ 
                                       
                                           
                                       
                                       ⁢ 
                                       1 
                                     
                                   
                                   + 
                                   
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                                       ⁢ 
                                       
                                           
                                       
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                               JUMP 
                             
                             . 
                           
                         
                       
                     
                   
                 
               
               
                 
                   ( 
                   8 
                   ) 
                 
               
             
           
         
       
     
     The maximum value R MAX1  of the first transfer rate R EXT1  equals 192/188 times the system rate R TS1  for the file  2 D, and the maximum value R MAX2  of the second transfer rate R EXT2  equals 192/188 times the system rate R TS2  for the file DEP: R MAX1 =R TS1 ×192/188, R MAX2 =R TS2 ×192/188. Accordingly, in order to guarantee the maximum jump time of the long jump J LY  of 700 msec during 3D playback mode, it suffices for the extent block D, B 3D , D, and B 3D  located in the first stereoscopic video specific section  1413  to have the size S EXTSS  of at least approximately 59 MB and the extent ATC time T EXTSS  of approximately 7.6 sec at the shortest. 
     As is understood from expression (1), in order to guarantee the maximum jump time of 350 msec for the jump J 2D  included in the playback path  1431  in 2D playback mode, occurring immediately after the second monoscopic video specific section  1422 , it suffices for the base-view extent B 2D  located in the second monoscopic video specific section  1422  to have the size S EXT2D  of at least approximately 33 MB, and the extent ATC time T EXT2D =S EXT2D /R MAX2D  of 5.7 sec at the shortest. Since the extended extent T located in the second extended data specific section  1421  has the same extent ATC time as the base-view extent B 2D  located in the second monoscopic video specific section  1422 , the size of the extended extent T is at least approximately 11 MB. 
     As shown in  FIG. 14 , the playback path  1431  in 2D playback mode includes the long jump J LY  with the jump distance that equals the total number of sectors included in the first stereoscopic video specific section  1413  and the second extended data specific section  1421 . Here, the extent block D, B 3D , D, and B 3D  located in the first stereoscopic video specific section  1413  has the size S EXTSS  of at least approximately 59 MB, and the extended extent T located in the second extended data specific section  1421  has the size of at least approximately 11 MB. Accordingly, the long jump J LY  in 2D playback mode has the jump distance of at least 59 MB+11 MB=70 MB. 
     Next, the playback path  1432  in 3D playback mode includes the long jump J LY  with the jump distance that equals the total number of sectors included in the second extended data specific section  1421  and the second monoscopic video specific section  1422 . Here, the extended extent T located in the second extended data specific section  1421  has the size of at least approximately 11 MB, and the base-view extent B 2D  located in the second monoscopic video specific section  1422  has the size S EXT2D  of at least approximately 33 MB. Accordingly, the long jump J LY  in 3D playback mode has the jump distance of at least 11 MB+33 MB=44 MB. 
     Furthermore, the playback path  1433  in extended playback mode includes the long jump J LY  with the jump distance that equals the number of sectors included in the first stereoscopic video specific section  1413 . Accordingly, the long jump J LY  in extended playback mode has the jump distance of at least 59 MB. 
     The jump distance of the long jump J LY  in any mode is calculated as described above. As indicated by the calculated results, the jump distance in any mode can be reduced below the maximum jump distance of the long jump J LY =40,000 sectors=approximately 78.1 MB. The same is true for arrangement  2  shown in  FIG. 15 . 
     Advantages Unique to Arrangement  2  of Extents 
     Arrangement  1  shown in  FIG. 14  allows the playback path  1432  in 3D playback mode to include a jump J 3D  to occur immediately after completion of data read from the first shared section  1401  to skip access to the first extended data specific section  1411  and the first monoscopic video specific section  1412 . Here, the conditions for guaranteeing the maximum jump time of 700 msec for the long jump J LY  in 2D playback mode requires that the base-view extent B 2D  located in the first monoscopic video specific section  1412  have the size S DUP     —     FOR     —     SSIF  of at least approximately 44 MB and the extent ATC time T DUP     —     FOR     —     SSIF  of at least approximately 7.6 sec. In this case, since the extended extent T located in the first extended data specific section  1411  has the extent ATC time of at least approximately 7.6 sec, the extended stream file which requires the system rate of 16 Mbps, has the extended extent T with the size of 16 Mbps/8×192/188×7.6 sec=at least approximately 15 MB. Accordingly, the above-mentioned jump J 3D  needs to have the jump distance S JUMP  of at least 15 MB+44 MB=59 MB=approximately 30,000 sectors. From the table shown in  FIG. 18 , the maximum jump time T JUMP-MAX  of the jump J 3D  needs to be at least 350 msec. 
     Condition  4  requires that the data amount to be processed by the system target decoder  1903  in 3D playback mode during the above-mentioned jump J 3D  is guaranteed by the size of the last extent block D, B, D, and B in the first shared section  1401 . Here, it is assumed that each of extents constituting this extent block has the maximum extent size determined by expression (5C), and that the second transfer rate R EXT2  for the extent block is 48 Mbps×192/188. In this case, the dependent-view extent D belonging to the extent block has the size of at most 8.1×10 6  bytes, and therefore the extent ATC time T EXT2  of approximately 1.32 sec at the longest: T EXT2 =8.1×10 6  bytes×8/R EXT2 =approximately 1.32 sec. Accordingly, when the extent block includes “n” extent pairs, the entirety of the extent block has the extent ATC time T EXTSS  of approximately 1.32×n sec at the longest. On the other hand, as is clear from expression (4), the jump time T AMP  for the above-mentioned jump J 3D  satisfies expression (9) described below: 
     
       
         
           
             
               
                 
                   
                     T 
                     EXTSS 
                   
                   = 
                   
                     
                       
                         
                           S 
                           EXTSS 
                         
                         
                           R 
                           EXTSS 
                         
                       
                       ≥ 
                       
                         
                           
                             R 
                             
                               ED 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               3 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               D 
                             
                           
                           
                             
                               R 
                               
                                 UD 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 3 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 D 
                               
                             
                             - 
                             
                               R 
                               EXTSS 
                             
                           
                         
                         × 
                         
                           T 
                           JUMP 
                         
                       
                     
                     ∴ 
                     
                       
                         T 
                         JUMP 
                       
                       ≤ 
                       
                         
                           ( 
                           
                             1 
                             - 
                             
                               
                                 R 
                                 EXTSS 
                               
                               
                                 R 
                                 
                                   UD 
                                   ⁢ 
                                   
                                       
                                   
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                                   ⁢ 
                                   
                                       
                                   
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                         × 
                         
                           
                             T 
                             EXTSS 
                           
                           . 
                         
                       
                     
                   
                 
               
               
                 
                   ( 
                   9 
                   ) 
                 
               
             
           
         
       
     
     When the mean transfer rate R EXTSS  for the extent block is at the maximum value of 64 Mbps×192/188, then expression (9) shows that the above-mentioned jump J 3D  has the jump time T AMP  of at most 122 msec×n. For seamless playback of 3D video images during the jump J 3D  in 3D playback mode to skip access to the first extended data specific section  1411  and the first monoscopic video specific section  1412 , the jump time T AMP =approximately 122 msec×n must be at least 350 msec. 
     Accordingly, arrangement  1  illustrated in  FIG. 14  requires that the number n of extent pairs included in the last extent block in the first shared section  1401  must be at least three. Furthermore, raising the system rate R TS3  for the extended stream file higher than the value of 16 Mbps assumed in the above-described calculation needs a corresponding increase in the data amount of the first extended data specific section  1411 , and thus requires a further increase in the above-mentioned number “n” of extent pairs. Here, an increase in the number “n” of extent pairs prolongs the extent ATC time of the extended extent T that is arranged immediately before the extent pairs, thereby increasing the capacity required for the RB 3   2312 . Accordingly, it is not preferable to increase the number “n” of extent pairs to three or more. 
     On the other hand, arrangement  2  illustrated in  FIG. 15 , unlike arrangement 1, does not need the above-described limitation on the number “n” of extent pairs per extent block. In practice, arrangement  2  allows the playback path  1532  in 3D playback mode to include a jump occurring immediately after completion of data reading from the first shared section  1401  in order to skip only access to the first extended data specific section  1511 . Here, the conditions for guaranteeing the maximum jump time of 700 msec for the long jump J LY  to move across the layer boundary LB during 2D playback mode require that the base-view extent B 2D  located in the first monoscopic video specific section  1512  has the extent ATC time T DUP     —     FOR     —     SSIF  of at least approximately 7.6 sec. In this case, the extended extent T located in the first extended data specific section  1511  has the extent ATC time of at least approximately 7.6 sec, and thus, when the system rate for the extended stream file is 16 Mbps, the extended extents T have the size of at least approximately 15 MB. Accordingly, the above-mentioned jump included in the playback path  1532  in 3D playback mode must have the jump distance of at least the lower limit of the data amount in the first extended data specific section  1511 ; the lower limit equals approximately 15 MB or approximately 7,680 sectors. From the table shown in  FIG. 18 , this jump needs to have the maximum jump time T JUMP-MAX  of at least 200 msec. Under this condition, when the mean transfer rate R EXTSS  for the last extent block in the first shared section  1401  has the maximum value of 64 Mbps×192/188, the jump time T AMP  of the jump is limited up to approximately 122 msec×n. For this upper limit, approximately 122 msec×n, to exceed 200 msec, the number “n” of extent pairs included in the extent block should be at least two. In other words, the restriction on the number “n” is no different from the original restriction on the extended extent block. 
     In addition, arrangement  2 , unlike arrangement  1 , allows the system rate R TS3  for the extended stream file to be set higher than 16 Mbps even with the number “n” of extent pairs included in the last extent block in the first shared section  1401  being two. In practice, when the mean transfer rate R EXTSS  for the extent block is the maximum value of 64 Mbps×192/188, the jump included in the playback path  1532  in 3D playback mode immediately after reading of the extent block may have possible jump time of up to approximately 122 msec×2=approximately 243 msec. Accordingly, the first extended data specific section  1511  should have at most 10,000 sectors, i.e., the extended extent T located in this section should have the size S EXT3  of at most approximately 19.5 MB. On the other hand, the conditions on the long jump J LY  for moving across the layer boundary LB allows the extent ATC time T EXT3  of this extended extent T to be approximately 7.6 sec at the shortest. Therefore, without increasing the capacity necessary in the RB 3   2312 , the system rate R TS3  for the extended stream file can be raised up to approximately 21 Mbps: R TS3 =S EXT3 /T EXT3 ≦19.5 MB×8/7.6 sec/192×188=approximately 21 Mbps. 
     2-10: Clip Information File 
       FIG. 27  is a schematic diagram showing the data structure of a 2D clip information file  231 . As shown in  FIG. 27 , the 2D clip information file  231  includes clip information  2710 , stream attribute information  2720 , an entry map  2727 , and 3D meta data  2740 . The 3D meta data  2740  includes an extent start point  2742 . The DEP clip information file and the extended clip information file  233  also have the same data structure. 
     As shown in  FIG. 27 , the clip information  2710  includes a system rate  2711 , a playback start time  2712 , and a playback end time  2713 . The system rate  2711  specifies a system rate R TS  for the file  2 D  221 . In this context, as shown in  FIG. 16 , the playback device  102  in 2D playback mode transfers “TS packets” belonging to the file  2 D  221  from the read buffer  1602  to the system target decoder  1603 . 
     Accordingly, the interval between the ATSs of the source packets in the file  2 D  221  is set so that the transfer rate of the TS packets is limited to the system rate R TS  or lower. The playback start time  2712  indicates the PTS allocated to the VAU located at the top of the file  2 D  221 , e.g. the PTS of the top video frame. The playback end time  2713  indicates the value of the STC delayed a predetermined time from the PTS allocated to the VAU located at the end of the file  2 D  221 , e.g. the sum of the PTS of the last video frame and the playback time of one frame. 
     As shown in  FIG. 27 , the stream attribute information  2720  is a correspondence table between the PID  2721  for each elementary stream included in the file  2 D  221  and pieces of attribute information  2722 . Each piece of attribute information  2722  is different for a video stream, audio stream, PG stream, and IG stream. For example, the attribute information corresponding to the PID 0x1011 for the primary video stream includes a codec type used for the compression of the video stream, as well as a resolution, aspect ratio, and frame rate for each picture constituting the video stream. On the other hand, the attribute information corresponding to the PID 0x1100 for the primary audio stream includes a codec type used for compressing the audio stream, a number of channels included in the audio stream, language, and sampling frequency. The playback device  102  uses this attribute information  2722  to initialize the decoder. 
     Entry Map 
       FIG. 28A  is a schematic diagram showing the data structure of an entry map  2730 . As shown in  FIG. 28A , the entry map  2730  includes tables  2800 . There is the same number of tables  2800  as there are video streams multiplexed in the main TS, and tables are assigned one-by-one to each video stream. In  FIG. 28A , each table  2800  is distinguished by the PID of the video stream to which it is assigned. Each table  2800  includes an entry map header  2801  and an entry point  2802 . The entry map header  2801  includes the PID corresponding to the table  2800  and the total number of entry points  2802  included in the table  2800 . An entry point  2802  associates each pair of a PTS  2803  and source packet number (SPN)  2804  with one of individually differing entry point IDs (EP_ID)  2805 . The PTS  2803  is equivalent to the PTS for one of the I pictures included in the video stream for the PID indicated by the entry map header  2801 . The SPN  2804  is equivalent to the first SPN of the source packets containing the corresponding I picture. An “SPN” refers to the serial number assigned to source packets belonging to a single AV stream file, beginning from their top. The SPN is used as the address for each source packet in the AV stream file. In the entry map  2730  in the 2D clip information file  231 , the SPN refers to the number assigned to the source packets belonging to the file  2 D  221 , i.e. the source packets containing the main TS. Accordingly, the entry point  2802  expresses the correspondence between the PTS and the address, i.e. the SPN, of each I picture included in the file  2 D  221 . 
     An entry point  2802  does not need to be set for all of the I pictures in the file  2 D  221 . However, when an I picture is located at the top of a GOP, and the TS packet that includes the top of that I picture is located at the top of an extent, an entry point  2802  has to be set for that I picture. 
       FIG. 28B  is a schematic diagram showing source packets that are included in a source packet group  2810  belonging to a file  2 D  221 , and are associated with EP IDs  2805  by the entry map  2730 .  FIG. 28C  is a schematic diagram showing extents D[n], B[n] (n=0, 1, 2, 3, . . . ) on a BD-ROM disc  101  corresponding to the source packet group  2810 . When the playback device  102  plays back 2D video images from the file  2 D  221 , it refers to the entry map  2730  to specify the SPN for the source packet that includes a frame representing an arbitrary scene from the PTS for that frame. Specifically, when for example a PTS=360000 is indicated as the PTS for a specific entry point for the playback start position, the playback device  102  first retrieves the SPN=3200 allocated to this PTS in the entry map  2730 . Next, the playback device  102  seeks the quotient SPN×192/2048, i.e. the value of the SPN multiplied by 192 bytes, the data amount per source packet, and then divided by 2048 bytes, the data amount per sector. As can be understood from  FIGS. 6C and 6D , this quotient is the same as the total number of sectors recorded in the main TS prior to the source packet to which the SPN is assigned. In the example shown in  FIG. 28B , this quotient is 3200×192/2048=300, and is equal to the total number of sectors on which are recorded source packets  2811  to which SPNs  0  through  3199  are allocated. Next, the playback device  102  refers to the file entry in the file  2 D  221  and specifies the LBN of the (total number+1) th  sector, counting from the top of the sectors in which extents of the file  2 D  221  are recorded. In the example shown in  FIG. 28C , the LBN of a sector is specified; the sector is located at the 301 st  counting from the top of the sectors in which the base-view extents B[ 0 ], B[ 1 ], B[ 2 ], . . . accessible as extents EXT 2 D[ 0 ], EXT 2 D[ 1 ], EXT 2 D[ 2 ], . . . are recorded. The playback device  102  indicates the LBN to the BD-ROM drive. In this way, base-view extents are read in aligned units, beginning from the sector at the LBN. Furthermore, from the aligned unit that is first read, the playback device  102  selects the source packet indicated by the entry point for the playback start position, and then extracts and decodes an I picture from the source packet. From then on, subsequent pictures are decoded in order referring to already decoded pictures. In this way, the playback device  102  can play back 2D video images from the file  2 D  221  from a specified PTS onwards. 
     Furthermore, the entry map  2730  is useful for efficiently perform trickplay such as fast forward, reverse, etc. For example, the playback device  102  in 2D playback mode first refers to the entry map  2730  to read SPNs starting at the playback start position, e.g. to read SPN=3200, 4800, . . . in order from the entry points EP_ID=2, 3, . . . that include PTSs starting at PTS=360000. Next, the playback device  102  refers to the file entry in the file  2 D  221  to specify the LBN of the sectors corresponding to each SPN. The playback device  102  then indicates each LBN to the BD-ROM drive. Aligned units are thus read from the sector for each LBN. Furthermore, from each aligned unit, the playback device  102  selects the source packet indicated by each entry point and then extracts and decodes an I picture. The playback device  102  can thus selectively play back I pictures from the file  2 D  221  without analyzing the extents EXT 2 D[n] themselves. 
     Extent Start Point 
       FIG. 29A  is a schematic diagram showing the data structure of an extent start point  2742 . As shown in  FIG. 29A , an “extent start point”  2742  includes base-view extent IDs (EXT 1 _ID)  2911  and SPNs  2912 . The EXT 1 _IDs  2911  are serial numbers assigned consecutively from the top to the base-view extents belonging to the file SS  223 . One SPN  2912  is assigned to each EXT 1 _ID  2911  and is the same as the SPN of the source packet located at the top of the base-view extent identified by the EXT 1 _ID  2911 . This SPN is a serial number assigned to source packets in order from the top; the source packets are included in the base-view extents belonging to the file SS  223 . 
     As shown in  FIG. 11 , the base-view extents B[ 0 ], B[ 1 ], B[ 2 ], . . . included in the extended extent blocks are shared between the file  2 D  221  and the file SS  223 . On the other hand, as shown in  FIGS. 14 and 15 , the extents arranged near the location where a long jump is necessary, such as a layer boundary, includes base-view extents belonging only to either the file  2 D  221  or the file SS  223 . Accordingly, the SPN  2912  indicated by the extent start point  2742  generally differs from the SPN for the source packet located at the top of the base-view extent belonging to the file  2 D  221 . 
       FIG. 29B  is a schematic diagram showing the data structure of the extent start point  2920  included in the DEP clip information file  232 . As shown in  FIG. 29B , the extent start point  2920  includes dependent-view extent IDs (EXT 2 _ID)  2921  and SPNs  2922 . The EXT 2 _IDs  2921  are serial numbers assigned consecutively from the top to the dependent-view extents belonging to the file SS  223 . One SPN  2922  is assigned to each EXT 2 _ID  2921  and is the same as the SPN for the source packet located at the top of the dependent-view extent identified by the EXT 2 _ID  2921 . This SPN is a serial number assigned to source packets in order from the top; the source packets are included in the dependent-view extents belonging to the file SS  223 . 
       FIG. 29D  is a schematic diagram representing correspondence between dependent-view extents EXT 2 [ 0 ], EXT 2 [ 1 ], . . . belonging to the file DEP  222  and the SPNs  2922  shown by the extent start point  2920 . As shown in  FIG. 11 , the file DEP  222  and the file SS  243  share dependent-view extents in common. Accordingly, as shown in  FIG. 29D , each SPN  2922  shown by the extent start point  2920  is the same as the SPN for the source packet located at the top of each dependent-view extent EXT 2 [ 0 ], EXT 2 [ 1 ], . . . . 
     As described below, the extent start point  2742  in the 2D clip information file  231  and the extent start point  2920  in the clip information file  232  are used for detecting the boundary between base-view extents and dependent-view extents included in each extent in the file SS  223  when playing back 3D video images from the file SS  223 . 
       FIG. 29E  is a schematic diagram showing correspondence between an extent EXTSS[ 0 ] belonging to the file SS  223  and extent blocks on the BD-ROM disc  101 . As shown in  FIG. 29E , the extent block includes extents D[n] and B[n] (n=0, 1, 2, . . . ) in an interleaved arrangement. The extent block can be accessed as the extent EXTSS[ 0 ] in the file SS  223 . Furthermore, in the extent EXTSS[ 0 ], the number of source packets included in the (n+1) th  base-view extent B[n] is, at the extent start point  2742 , the same as the difference A(n+1)−An between SPNs respectively corresponding to EXT 1 _ID=n+1 and n. In this case, A 0 =0. On the other hand, the number of source packets included in the dependent-view extent D[n+1] is, at the extent start point  2920 , the same as the difference B(n+1)−Bn between SPNs respectively corresponding to EXT 2 _ID=n+1 and n. In this case, B 0 =0. 
     When the playback device  102  in 3D playback mode plays back 3D video images from the file SS  223 , the playback device  102  refers to the entry maps and the extent start points  2742  and  2920  respectively found in the clip information files  231  and  232 . By doing this, the playback device  102  specifies, from the PTS for a frame representing the right view of an arbitrary scene, the LBN for the sector on which a dependent-view extent that is required for composing the frame is recorded. Specifically, the playback device  102  for example first retrieves the SPN associated with the PTS from the entry map in the DEP clip information file  232 . It is assumed that the source packet indicated by the SPN is included in the third dependent-view extent EXT 2 [ 2 ]=D[ 2 ] in the file DEP  222 . Next, the playback device  102  retrieves “B 2 ,” the largest SPN smaller than the target SPN, from among the SPNs  2922  shown by the extent start point  2920  in the DEP clip information file  232 . The playback device  102  also retrieves the corresponding EXT 2 _ID “2.” Then the playback device  102  retrieves the value “A 2 ” for the SPN  2912  corresponding to the EXT 1 _ID, which is the same as the EXT 2 _ID “2,” from the extent start point  2742  in the 2D clip information file  231 . The playback device  102  further seeks the sum B 2 +A 2  of the retrieved SPNs. As can be seen from  FIG. 29E , this sum B 2 +A 2  is the same as the total number of source packets located before the third dependent-view extent D[ 2 ] within the extent EXTSS[ 0 ] in the file SS  223 . Accordingly, this sum B 2 +A 2  multiplied by 192 bytes, the data amount per source packet, and divided by 2048 bytes, the data amount per sector, i.e. (B 2 +A 2 )×192/2048, is the same as the number of sectors from the top of the extent EXTSS[ 0 ] in the file SS  223  until immediately before the third dependent-view extent D[ 2 ]. Using this quotient, the LBN for the sector on which the top of the dependent-view extent D[ 2 ] is recorded can be specified by referencing the file entry for the file SS  223 . 
     After specifying the LBN via the above-described procedure, the playback device  102  indicates the LBN to the BD-ROM drive  121 . In this way, the portion of the extent EXTSS[ 0 ] of the file SS  223  is read in aligned units; the portion is recorded in the sectors located at and after the LBN, i.e., the third dependent-view extent D[ 2 ] and the following extents B[ 2 ], D[ 3 ], B[3], . . . . 
     The playback device  102  further refers to the extent start points  2742  and  2920  to extract dependent-view extents and base-view extents alternately from the extents read from the file SS  223 . For example, assume that extents D[n], B[n] (n=0, 1, 2, . . . ) are read in order from an extent EXTSS[ 0 ] of the file SS  223  shown in  FIG. 29E . The playback device  102  first extracts B 1  source packets from the top of the extent EXTSS[ 0 ] as the dependent-view extent D[ 0 ]. Next, the playback device  102  extracts the (B 1 +1) th  source packet and the subsequent (A 1 −1) source packets, a total of A 1  source packets, as the first base-view extent B[ 0 ]. The playback device  102  then extracts the (B 1 +A 1 +1) th  source packet and the subsequent (B 2 −B 1 −1) source packets, a total of (B 2 −B 1 ) source packets, as the second dependent-view extent D[ 1 ]. The playback device  102  further extracts the (A 1 +B 2 +1) th  source packet and the subsequent (A 2 −A 1 −1) source packets, a total of (A 2 −A 1 ) source packets, as the second base-view extent B[ 1 ]. Thereafter, the playback device  102  thus continues to detect the boundary between dependent-view and base-view extents in the extents of the file SS  223  based on the number of read source packets, thereby alternately extracting dependent-view and base-view data extents. The extracted base-view and dependent-view extents are transmitted to the system target decoder to be decoded in parallel. In this way, the playback device  102  in 3D playback mode can play back 3D video images from the file SS  223  starting at a specific PTS. 
     2-11: File Base 
       FIG. 29C  is a schematic diagram representing the base-view extents B[ 0 ], B[ 1 ], B[ 2 ], . . . extracted from the file SS  223  by the playback device  102  in 3D playback mode. As shown in  FIG. 29C , when SPNs are allocated to source packets included in base-view extents B[n] (n=0, 1, 2, . . . ), beginning from their top, the source packet located at the top of each base-view extent B[n] has a SPN equal to one of the SPNs  2912  indicated by the extent start point  2742 . Base-view extents extracted from a single file SS by referring to extent start points, like the base-view extents B[n], are referred to as a “file base.” As shown in  FIG. 29E , each base-view extent EXT 1 [ 0 ], EXT 1 [ 1 ] . . . is referred to by an extent start point  2742  or  2920  in a clip information file. 
     An extent EXT 1 [n] in the file base shares the same base-view extent B[n] with an extent EXT 2 D[n] in the file  2 D. Accordingly, the file base includes the same main TS as the file  2 D. Unlike the file  2 D, however, the file base does not include a file entry. Furthermore, an extent start point is necessary to refer to a base-view extent. In this sense, the file base is a “virtual file.” In particular, the file base is not recognized by the file system and does not appear in the file structure shown in  FIG. 2 . 
     2-12: 2D Playlist File 
       FIG. 30  is a schematic diagram showing the data structure of a 2D playlist file. As shown in  FIG. 30 , the 2D playlist file  241  includes a main path  3001  and two sub-paths  3002  and  3003 . 
     The main path  3001  is a sequence of playitem information pieces (hereinafter abbreviated as PI) that defines the main playback path for the file  2 D  221 , i.e. the section for playback and the section&#39;s playback order. Each PI is identified with a unique playitem ID=#N (N=1, 2, 3, . . . ). Each PI #N defines a different playback section along the main playback path with a pair of PTSs. One of the PTSs in the pair represents the start time (In-Time) of the playback section, and the other represents the end time (Out-Time). Furthermore, the order of the PIs in the main path  3001  represents the order of corresponding playback sections in the playback path. 
     Each of the sub-paths  3002  and  3003  is a sequence of sub-playitem information pieces (hereinafter abbreviated as SUB_PI) that defines a playback path that can be associated in parallel with the main playback path for the file  2 D  221 . Such a playback path is a different section of the file  2 D  221  than is represented by the main path  3001 , or is a section of stream data multiplexed in another file  2 D, along with the corresponding playback order. The stream data indicated by the playback path represents other 2D video images to be played back simultaneously with 2D video images played back from the file  2 D  221  in accordance with the main path  3001 . These other 2D video images include, for example, sub-video in a picture-in-picture format, a browser window, a pop-up menu, or subtitles. Serial numbers “0” and “1” are assigned to the sub-paths  3002  and  3003  in the order of registration in the 2D playlist file  241 . These serial numbers are used as sub-path IDs to identify the sub-paths  3002  and  3003 . In the sub-paths  3002  and  3003 , each SUB_PI is identified by a unique sub-playitem ID=#M (M=1, 2, 3, . . . ). Each SUB_PI #M defines a different playback section along the playback path with a pair of PTSs. One of the PTSs in the pair represents the playback start time of the playback section, and the other represents the playback end time. Furthermore, the order of the SUB PIs in the sub-paths  3002  and  3003  represents the order of corresponding playback sections in the playback path. 
       FIG. 31  is a schematic diagram showing the data structure of PI #N. As shown in  FIG. 31 , a PI #N includes a piece of reference clip information  3101 , playback start time (In-Time)  3102 , playback end time (Out-Time)  3103 , and a stream selection table (hereinafter referred to as “STN table” (stream number table))  3105 . The reference clip information  3101  is information for identifying the 2D clip information file  231 . The playback start time  3102  and playback end time  3103  respectively indicate PTSs for the beginning and the end of the section for playback of the file  2 D  221 . The STN table  3105  is a list of elementary streams that can be selected from the file  2 D  221  by the decoder in the playback device  102  from the playback start time  3102  until the playback end time  3103 . 
     The data structure of a SUB_PI is the same as the data structure of the PI shown in  FIG. 31  insofar as it includes reference clip information, a playback start time, and a playback end time. In particular, the playback start time and playback end time of a SUB_PI are expressed as values along the same time axis as a PI. 
     STN Table 
     Referring again to  FIG. 31 , the STN table  3105  is an array of stream registration information. “Stream registration information” is information individually listing the elementary streams that can be selected for playback from the main TS between the playback start time  3102  and playback end time  3103 . The stream number (STN)  3106  is a serial number allocated individually to stream registration information and is used by the playback device  102  to identify each elementary stream. The STN  3106  further indicates priority for selection among elementary streams of the same type. The stream registration information includes a stream entry  3109  and stream attribute information  3110 . The stream entry  3109  includes stream path information  3107  and stream identification information  3108 . The stream path information  3107  is information indicating the file  2 D to which the selected elementary stream belongs. For example, if the stream path information  3107  indicates “main path,” the file  2 D corresponds to the 2D clip information file indicated by reference clip information  3101 . On the other hand, if the stream path information  3107  indicates “sub-path ID=1,” the file  2 D to which the selected elementary stream belongs corresponds to the 2D clip information file indicated by the reference clip information of the SUB_PI included in the sub-path with a sub-path ID=1. The playback start time and playback end time specified by this SUB_PI are both included in the interval from the playback start time  3102  until the playback end time  3103  specified by the PI included in the STN table  3105 . The stream identification information  3108  indicates the PID for the elementary stream multiplexed in the file  2 D specified by the stream path information  3107 . The elementary stream indicated by this PID can be selected from the playback start time  3102  until the playback end time  3103 . The stream attribute information  3110  indicates attribute information for each elementary stream. For example, the attribute information for each of an audio stream, PG stream, and IG stream indicates a language type of the stream. 
     Playback of 2D Video Images in Accordance with a 2D Playlist File 
       FIG. 32  is a schematic diagram showing correspondence between PTSs indicated by the 2D playlist file  241  and sections played back from the file  2 D  221 . As shown in  FIG. 32 , in the main path  3001  in the 2D playlist file  241 , the PI # 1  specifies a PTS # 1 , which indicates a playback start time IN 1 , and a PTS # 2 , which indicates a playback end time OUT 1 . The reference clip information for PI # 1  indicates the 2D clip information file  231 . When playing back 2D video images in accordance with the 2D playlist file  241 , the playback device  102  first reads the PTS # 1  and PTS # 2  from the PI # 1 . Next, the playback device  102  refers to the entry map in the 2D clip information file  231  to retrieve from the file  2 D  221  the SPN # 1  and SPN # 2  that correspond to the PTS # 1  and PTS # 2 . The playback device  102  then calculates the corresponding numbers of sectors from the SPN # 1  and SPN # 2 . Furthermore, the playback device  102  refers to these numbers of sectors and the file entry of the file  2 D  221  to specify LBN # 1  and LBN # 2  assigned to the top and end, respectively, of the sector group P 1  on which extents EXT 2 D[ 0 ], . . . , EXT 2 D[n] to be played back are recorded. Calculation of the numbers of sectors and specification of the LBNs are as per the description about  FIGS. 28A ,  28 B, and  28 C. Finally, the playback device  102  indicates the range from LBN # 1  to LBN # 2  to the BD-ROM drive  121 . In response, the BD-ROM drive  121  uses the file entry of the file  2 D  221  to read source packets belonging to the extents EXT 2 D[ 0 ], . . . , EXT 2 D[n] from the sector group P 1  located in the range. Similarly, the pair PTS # 3  and PTS # 4  indicated by the PI # 2  are first converted into a pair of SPN # 3  and SPN # 4  by referring to the entry map in the 2D clip information file  231 . Then, referring to the file entry for the file  2 D  221 , the pair of SPN # 3  and SPN # 4  are converted into a pair of LBN # 3  and LBN # 4 . Furthermore, source packets belonging to extents of the file  2 D  221  are read from the sector group P 2  located in a range from LBN # 3  to LBN # 4 . Conversion of a pair of PTS # 5  and PTS # 6  indicated by PI # 3  to a pair of SPN # 5  and SPN # 6 , conversion of the pair of SPN # 5  and SPN # 6  to a pair of LBN # 5  and LBN # 6 , and reading of source packets from the sector group P 3  located in a range from LBN # 5  to LBN # 6  are similarly performed. The playback device  102  thus plays back 2D video images from the file  2 D  221  in accordance with the main path  3001  in the 2D playlist file  241 . 
     The 2D playlist file  241  may include an entry mark  3201 . The entry mark  3201  indicates a time point in the main path  3001  at which playback is actually to start. For example, as shown in  FIG. 32 , a plurality of entry marks  3201  can be set for the PI # 1 . The entry mark  3201  is particularly used for searching for a playback start position during interrupt playback. For example, when the 2D playlist file  241  specifies a playback path for a movie title, the entry marks  3201  are assigned to the top of each chapter. Consequently, the playback device  102  can play back the movie title by chapters. 
     2-13: 3D Playlist File 
       FIG. 33  is a schematic diagram showing the data structure of a 3D playlist file  242 . As shown in  FIG. 33 , the 3D playlist file  242  includes a main path  3301 , sub-path  3302 , and extended data  3303 . 
     The main path  3301  specifies the playback path for the main TS. Accordingly, the main path  3301  is substantially the same as the main path  3001  for the 2D playlist file  241 . In other words, the playback device  102  in 2D playback mode can play back 2D video images from the file  2 D  221  in accordance with the main path  3301  in the 3D playlist file  242 . 
     The sub-path  3302  specifies the playback path for the sub-TS, i.e. the playback path for the file DEP  222 . The data structure of the sub-path  3302  is the same as the data structure of the sub-paths  3002  and  3003  in the 2D playlist file  241 . Accordingly, details on this similar data structure can be found in the description about  FIG. 30 , in particular details on the data structure of the SUB_PI. 
     The SUB_PI #N (N=1, 2, 3, . . . ) in the sub-path  3302  are in one-to-one correspondence with the PI #N in the main path  3301 . Furthermore, the playback start time and playback end time specified by each SUB_PI #N is the same as the playback start time and playback end time specified by the corresponding PI #N. The sub-path  3302  additionally includes a sub-path type  3310 . The “sub-path type” generally indicates whether playback according to the main path should be synchronized with playback according to the sub-path or not. In the 3D playlist file  242 , the sub-path type  3310  in particular indicates the type of the 3D playback mode, i.e. the type of the dependent-view video stream to be played back in accordance with the sub-path  3302 . In  FIG. 33 , the value of the sub-path type  3310  is “3D L/R,” thus indicating that the 3D playback mode is L/R mode, i.e. that the right-view video stream is to be played back. On the other hand, a value of “3D depth” for the sub-path type  3310  indicates that the 3D playback mode is depth mode, i.e. that the depth map stream is to be played back. When the playback device  102  in 3D playback mode detects that the value of the sub-path type  3310  is “3D L/R” or “3D depth,” the playback device  102  synchronizes playback according to the main path  3301  with playback according to the sub-path  3302 . 
     Extended data  3303  is interpreted only by the playback device  102  in 3D playback mode, and is ignored by the playback device  102  in 2D playback mode. In particular, the extended data  3303  includes an extended stream selection table  3330 . The extended stream selection table (hereinafter abbreviated as STN table SS) is an array of stream registration information to be added to the STN tables indicated by the PIs in the main path  3301  in 3D playback mode. This stream registration information indicates elementary streams that can be selected for playback from the sub TS. 
     STN Table SS 
       FIG. 34  is a schematic diagram showing the data structure of the STN table SS  3330 . As shown in  FIG. 34 , an STN table SS  3330  includes stream registration information sequences  3401 ,  3402 ,  3403 , . . . . The stream registration information sequences  3401 ,  3402 ,  3403 , . . . individually correspond to the PI # 1 , PI # 2 , PI # 3 , . . . in the main path  3301 . The playback device  102  in 3D playback mode uses these stream registration information sequences  3401 ,  3402 , and  3403  in combination with the stream registration information sequences included in the STN tables in the corresponding PIs. The stream registration information sequences  3401 - 3403  for the PIs include a stream registration information sequence  3412  for the dependent-view video streams, a stream registration information sequence  3413  for the PG streams, and a stream registration information sequence  3414  for the IG streams. 
     The stream registration information sequence  3412  for the dependent-view video streams, stream registration information sequence  3413  for the PG streams, and stream registration information sequence  3414  for the IG streams respectively include stream registration information indicating the dependent-view video streams, PG streams, and IG streams that can be selected for playback from the sub-TS. These stream registration information sequences  3412 ,  3413 , and  3414  are used in combination with the stream registration information sequences, included in the STN table of the corresponding PI, that indicate base-view video streams, PG streams, and IG streams. When reading a stream registration information sequence from an STN table, the playback device  102  in 3D playback mode automatically also reads the stream registration information sequence, located in the STN table SS, that has been combined with that stream registration information sequence. When simply switching from 2D playback mode to 3D playback mode, the playback device  102  can thus maintain already recognized STNs and stream attributes such as language. 
     The stream registration information sequence  3412  for the dependent-view video streams generally includes a plurality of pieces of stream registration information (SS_dependent_view_block)  3420 . These are the same in number as the pieces of stream registration information in the corresponding PI that indicate the base-view video stream. Each piece of stream registration information  3420  includes an STN  3421 , stream entry  3422 , and stream attribute information  3423 . The STN  3421  is a serial number assigned individually to pieces of stream registration information  3420  and is the same as the STN of the piece of stream registration information, located in the corresponding PI, with which the piece of stream registration information  4120  is combined. The stream entry  3422  includes sub-path ID reference information (ref_to_Subpath_id)  3431 , stream file reference information (ref_to_subClip_entry_id)  3432 , and a PID (ref_to_stream_PID_subclip)  3433 . The sub-path ID reference information  3431  indicates the sub-path ID of the sub-path that specifies the playback path of the dependent-view video stream. The stream file reference information  3432  is information to identify the file DEP storing this dependent-view video stream. The PIDs  3433  are the PIDs for the dependent-view video streams. The stream attribute information  3423  includes attributes the dependent-view video stream, such as frame rate, resolution, and video format. In particular, these attributes are the same as those for the base-view video stream shown by the piece of stream registration information, located in the corresponding PI, with which each piece of stream registration information is combined. 
     The stream registration information sequence  3413  of the PG stream generally includes a plurality of pieces of stream registration information  3440 . These are the same in number as the pieces of stream registration information in the corresponding PI that indicate the PG stream. Each piece of stream registration information  3440  includes an STN  3434 , base-view stream entry (stream_entry_for_base_view)  3443 , dependent-view stream entry (stream_entry_for_dependent_view)  3444 , and stream attribute information  3445 . The STN  3434  is a serial number assigned individually to pieces of stream registration information  3440  and is the same as the STN of the piece of stream registration information, located in the corresponding PI, with which the piece of stream registration information  4120  is combined. Both the base-view stream entry  3443  and the dependent-view stream entry  3444  include sub-path ID reference information  3451 , stream file reference information  3452 , and PIDs  3453 . The sub-path ID reference information  3451  indicates the sub-path IDs of the sub-paths that specify the playback paths of the base-view and dependent-view PG streams. The stream file reference information  3452  is information to identify the file DEP storing the PG streams. The PIDs  3453  are the PIDs for the PG streams. The stream attribute information  3445  includes attributes for the PG streams, such as language type. The stream registration information sequence  3414  of the IG stream has the same data structure. 
     Playback of 3D Video Images in Accordance with a 3D Playlist File 
       FIG. 35  is a schematic diagram showing correspondence between PTSs indicated by the 3D playlist file  242  and sections played back from the file SS  223 . As shown in  FIG. 35 , in the main path  3301  in the 3D playlist file  242 , the PI # 1  specifies a PTS # 1 , which indicates a playback start time IN 1 , and a PTS # 2 , which indicates a playback end time OUT 1 . The reference clip information for PI # 1  indicates the 2D clip information file  231 . In the sub-path  3302 , the SUB_PI # 1  specifies the same PTS # 1  and PTS # 2  as the PI # 1 . The reference clip information for SUB_PI # 1  indicates the DEP clip information file  232 . 
     When playing back 3D video images in accordance with the 3D playlist file  242 , the playback device  102  first reads PTS # 1  and PTS # 2  from the PI # 1  and SUB_PI # 1 . Next, the playback device  102  refers to the entry map in the 2D clip information file  231  to retrieve from the file  2 D  221  the SPN # 1  and SPN # 2  that correspond to the PTS # 1  and PTS # 2 . In parallel, the playback device  102  refers to the entry map in the DEP clip information file  232  to retrieve from the file DEP  222  the SPN # 11  and SPN # 12  that correspond to the PTS # 1  and PTS # 2 . As described with reference to  FIG. 29E , the playback device  102  then uses the extent start points  2742  and  2920  in the clip information files  231  and  232  to calculate, from SPN # 1  and SPN # 11 , the number of source packets SPN # 21  from the top of the file SS  223  to the playback start position. Similarly, the playback device  102  calculates, from SPN # 2  and SPN # 12 , the number of source packets SPN # 22  from the top of the file SS  223  to the playback end position. The playback device  102  further calculates the numbers of sectors corresponding to the SPN # 21  and SPN # 22 . Next, the playback device  102  refers to these numbers of sectors and the file entry of the file SS  243  to specify LBN # 1  and LBN # 2  at the start and end, respectively, of the sector group P 11  on which extents EXTSS[ 0 ], . . . , EXTSS[n] to be played back are recorded. Calculation of the numbers of sectors and specification of the LBNs are as per the description about  FIG. 29E . Finally, the playback device  102  indicates the range from LBN # 1  to LBN # 2  to the BD-ROM drive  121 . In response, the BD-ROM drive  121  uses the file entry of the file SS  223  to read the source packets belonging to the extents EXTSS[ 0 ], . . . , EXTSS[n] from the sector group P 11  located in this range. Similarly, the pair PTS # 3  and PTS # 4  indicated by PI # 2  and SUB_PI # 2  are first converted into a pair of SPN # 3  and SPN # 4  and a pair of SPN # 13  and SPN # 14  by referring to the entry maps in the clip information files  231  and  232 . Then, the number of source packets SPN # 23  counted from the top of the file SS  223  to the playback start position is calculated from SPN # 3  and SPN # 13 , and the number of source packets SPN # 24  counted from the top of the file SS  223  to the playback end position is calculated from SPN # 4  and SPN # 14 . Next, the file entry of the file SS  223  is referred to convert the pair of SPN # 23  and SPN # 24  into a pair of LBN # 3  and LBN # 4 . Furthermore, source packets belonging to extents of the file SS  223  are read from the sector group P 12  located in the range from LBN # 3  to LBN # 4 . 
     In parallel with the above-described read process, as described with reference to  FIG. 32E , the playback device  102  refers to the extent start points  2742  and  2920  in the clip information files  231  and  232  to extract base-view extents and dependent-view extents from each extent in the file SS  223  and decode the extents in parallel. The playback device  102  thus plays back 3D video images from the file SS  223  in accordance with the 3D playlist file  242 . 
     2-14: Extended Playlist File 
       FIG. 36  is a schematic diagram showing the data structure of the extended playlist file  243 . As shown in  FIG. 36 , the extended playlist file  243  includes a main path  3601 , sub-path  3602 , and extended data  3603 . 
     The main path  3601  specifies the playback path for the main TS. 
     Accordingly, the main path  3601  is substantially the same as the main path  3001  of the 2D playlist file  241 . In other words, the playback device  102  in 2D playback mode can play back full-HD 2D video images from the file  2 D  221  in accordance with the main path  3601  of the extended playlist file  243 . 
     The sub-path  3602  specifies the playback path for the extended stream file  224 . The data structure of the sub-path  3602  is the same as the data structure of the sub-paths  3002  and  3003  of the 2D playlist file  241 . Accordingly, details on this similar data structure, in particular, details on the data structure of SUB_PI, can be found in the description about  FIG. 30 . 
     The SUB_PI #N (N=1, 2, 3, . . . ) of the sub-path  3602  are in one-to-one correspondence with the PI #N of the main path  3601 . Furthermore, the playback start time and playback end time specified by each SUB_PI #N are the same as the playback start time and playback end time specified by the corresponding PI #N, respectively. The sub-path  3602  additionally includes a sub-path type  3610 . In particular, the extended playlist file  243  has the sub-path type  3610  of “4K2K” that indicates the playback device  102  being in extended playback mode. When the playback device  102  in extended playback mode detects that the sub-path type  3610  indicates extended playback mode, the playback device  102  synchronizes playback according to the main path  3601  with playback according to the sub-path  3602 . 
     Extended data  3603  is interpreted only by the playback device  102  in extended playback mode, and is ignored by the playback device  102  in 2D playback mode and in 3D playback mode. In particular, the extended data  3603  includes an extended stream selection table  3630 . The extended stream selection table (hereinafter abbreviated as STN table EX) is an array of stream registration information to be added to the STN tables indicated by the PIs in the main path  3601  for extended playback mode. This stream registration information indicates elementary streams that can be selected for playback from the extended stream. 
     STN Table EX 
       FIG. 37  is a schematic diagram showing the data structure of the STN table EX  3630 . As shown in  FIG. 37 , the STN table EX  3630  includes stream registration information sequences  3701 ,  3702 ,  3703 , . . . . The stream registration information sequences  3701 ,  3702 ,  3703 , . . . individually correspond to the PI # 1 , PI # 2 , PI # 3 , . . . in the main path  3301 . The playback device  102  in extended playback mode uses these stream registration information sequences  3701 ,  3702 , and  3703  in combination with the stream registration information sequences included in the STN tables of the corresponding PIs. The stream registration information sequence  3701  for each PI includes a stream registration information sequence  3710  of the extended stream. 
     This stream registration information sequence  3710  of the extended stream is used in combination with another stream registration information sequence that is included in the STN table of the corresponding PI and indicates the base-view video stream. When reading a first stream registration information sequence from an STN table, the playback device  102  in extended playback mode automatically reads a second stream registration information sequence that is located in the STN table EX and to be combined with the first stream registration information sequence read from the STN table. When simply switching from 2D playback mode to extended playback mode, the playback device  102  can thus maintain already recognized STNs and stream attributes such as language without any changes. 
     The stream registration information sequence  3710  of the extended stream generally includes a plurality of pieces of stream registration information  3720 . These pieces are the same in number as the pieces of stream registration information of the corresponding PI that indicate the base-view video stream. Each piece of stream registration information  3720  includes an STN  3721 , stream entry  3722 , and stream attribute information  3723 . The STN  3721  is a serial number assigned individually to the piece of stream registration information  3720  and is the same as the STN of another piece of stream registration information that is located in the corresponding PI and to be combined with the piece of stream registration information  3720 . The stream entry  3722  includes sub-path ID reference information  3731 , stream file reference information  3732 , and a PID  3733 . The sub-path ID reference information  3731  indicates the sub-path ID of the sub-path that specifies the playback path of the extended stream. The stream file reference information  3732  is information to identify the extended stream file containing the extended stream. The PID  3733  is the PID of the elementary stream to be selected from among the extended stream, in particular, the PID of the resolution extension information. The stream attribute information  3723  includes attributes of the extended stream. 
     Playback of 4K2K Video Images in Accordance with Extended Playlist File 
       FIG. 38  is a schematic diagram showing correspondence between PTSs indicated by the extended playlist file  243  and sections played back from the file  2 D  221  and the extended stream file  224 . As shown in  FIG. 38 , PI # 1  in the main path  3601  of the extended playlist file  243  specifies PTS # 1  that indicates the playback start time IN 1  and PTS # 2  that indicates the playback end time OUT 1 . The reference clip information of PI # 1  indicates the 2D clip information file  231 . In the sub-path  3602 , SUB_PI # 1  specifies the same PTS # 1  and PTS # 2  as PI # 1 . The reference clip information of SUB_PI # 1  indicates the extended clip information file  233 . 
     When playing back 4K2K 2D video images in accordance with the extended playlist file  243 , the playback device  102  first reads PTS # 1  and PTS # 2  from PI # 1  and SUB_PI # 1 . Next, the playback device  102  refers to the entry map in the 2D clip information file  231  to retrieve from the file  2 D  221  SPN # 1  and SPN # 2  that correspond to PTS # 1  and PTS # 2 , respectively. In parallel, the playback device  102  refers to the entry map in the extended clip information file  233  to retrieve from the extended stream file  224  SPN # 11  and SPN # 12  that correspond to PTS # 1  and PTS # 2 , respectively. The playback device  102  then calculates the corresponding numbers of sectors from SPN # 1  and SPN # 2 . Furthermore, the playback device  102  refers to these numbers of sectors and the file entry of the file  2 D  221  to specify LBN # 1  and LBN # 2  at the start and end, respectively, of the sector group P 1  on which extents EXT 2 D[ 0 ], . . . , EXT 2 D[n] to be played back are recorded. 
     Calculation of the numbers of sectors and specification of LBNs are as per the description about  FIGS. 28A ,  28 B, and  28 C. Finally, the playback device  102  indicates the range from LBN # 1  to LBN # 2  to the BD-ROM drive  121 . Similarly, the playback device  102  calculates the corresponding numbers of sectors from SPN # 11  and SPN # 12 , and then uses these numbers of sectors and the file entry of the extended stream file  224  to specify LBN # 11  and LBN # 12  at the start and end, respectively, of the sector group P 3  on which extended extents EXT 3 [ 0 ], . . . , EXT 3 [i] to be played back are recorded. Furthermore, the playback device  102  indicates the range from LBN # 11  to LBN # 12  to the BD-ROM drive  121 . In response to the indication from the playback device  102 , the BD-ROM drive  121  uses the file entry of the file  2 D  221  to read extents EXT 2 D[ 0 ], . . . , EXT 2 D[n] of the file  2 D  221  from the sector group P 1  in the range from LBN # 1  to LBN # 2 . In parallel, the BD-ROM drive  121  uses the file entry of the extended stream file  224  to read extended extents EXT 3 [ 0 ], . . . , EXT 3 [i] from the sector group P 3  in the range from LBN # 11  to LBN # 12 . As can be understood from  FIG. 11 , the range from LBN # 1  to LBN # 2  and the range from LBN # 11  to LBN # 12  overlap with each other. Therefore, the extents EXT 2 D[ 0 ], . . . , EXT 2 D[n] of the file  2 D  221  and the extended extents EXT 3 [ 0 ], . . . , EXT 3 [i] are read, beginning from one whose top is located at the smallest LBN. In this way, the playback device  102  can play back 4K2K 2D video images from the file  2 D  221  and the extended stream file  224  in accordance with the main path  3601  and the sub-path  3602  of the extended playlist file  243 . 
     2-15: Index File 
       FIG. 39  is a schematic diagram showing the data structure of the index file  211  shown in  FIG. 2 . As shown in  FIG. 39 , the index file  211  includes an index table  3910 . The index table  3910  stores the items “first play”  3901 , “top menu”  3902 , and “title k”  3903  (k=1, 2, . . . , n, where n is an integer greater than or equal to 1). Each item is associated either with a MV object MVO- 2 D, MVO- 3 D, or MVO-EX, or with a BD-J object BDJO- 2 D, BDJO- 3 D, or BDJO-EX. Each time a title or a menu is called in response to a user operation or an application program, a control unit in the playback device  102  refers to a corresponding item in the index table  3910 . Furthermore, the control unit calls an object associated with the item from the BD-ROM disc  101  and accordingly executes a variety of processes. Specifically, the item “first play”  3901  specifies an object to be called when the BD-ROM disc  101  is loaded into the BD-ROM drive  121 . The item “top menu”  3902  specifies an object for displaying a menu on the display device  103  when, for example, a command “go back to menu” is input by user operation. In the items “title k”  3903 , the titles that constitute the content on the BD-ROM disc  101  are individually allocated. For example, when a title for playback is specified by user operation, in the item “title k” in which the title is allocated, the object for playing back video images from the AV stream file corresponding to the title is specified. 
     In the example shown in  FIG. 39 , the items “title  1 ” and “title  2 ” are allocated to titles of full HD 2D video images. The MV object associated with the item “title  1 ,” MVO- 2 D, includes commands related to playback processes for full HD 2D video images by using the 2D playlist file  241 . When the playback device  102  refers to the item “title  1 ,” then in accordance with the MV object MVO- 2 D, the 2D playlist file  241  is read from the BD-ROM disc  101 , and playback processes for full HD 2D video images are executed in accordance with the playback path specified therein. The BD-J object associated with the item “title  2 ,” BDJO- 2 D, includes an application management table related to playback processes for full HD 2D video images using the 2D playlist file  241 . When the playback device  102  refers to the item “title  2 ,” then in accordance with the application management table in the BD-J object BDJO- 2 D, a Java application program is called from the JAR file  253  and executed. In this way, the 2D playlist file  241  is read from the BD-ROM disc  101 , and playback processes for full HD 2D video images are executed in accordance with the playback path specified therein. 
     Furthermore, the item “title  3 ” and the item “title  4 ” are allocated to titles of 3D video images. The MV object associated with the item “title  3 ,” MVO- 3 D, includes commands related to playback processes for full HD 2D video images by using the 2D playlist file  241 , as well as commands related to playback processes for 3D video images by using the 3D playlist file  242 . When the playback device  102  refers to the item “title  3 ,” then, in accordance with the MV object MVO- 3 D, the 3D playlist file  242  is read from the BD-ROM disc  101 , and playback processes for 3D video images are executed in accordance with the playback path specified therein. In the BD-J object associated with the item “title  4 ,” BDJO- 3 D, the application management table specifies, in addition to a Java application program related to playback processes for 2D video images using the 2D playlist file  221 , a Java application program related to playback processes for 3D video images using the 3D playlist file  242 . When the playback device  102  refers to the item “title  4 ,” then in accordance with the application management table in the BD-J object BDJO- 3 D, a Java application program is called from the JAR file  253  and executed. In this way, the 3D playlist file  242  is read from the BD-ROM disc  101 , and playback processes for 3D video images are executed in accordance with the playback path specified therein. 
     Additionally, the item “title  5 ” and the item “title  6 ” are allocated to titles of 4K2K 2D video images. The MV object associated with the item “title  5 ,” MVO-EX, includes commands related to playback processes for full HD 2D video images by using the 2D playlist file  241 , as well as commands related to playback processes for 4K2K 2D video images by using the extended playlist file  243 . When the playback device  102  refers to the item “title  5 ,” then in accordance with the MV object MVO-EX, the extended playlist file  243  is read from the BD-ROM disc  101 , and playback processes for 4K2K 2D video images are executed in accordance with the playback path specified therein. The BD-J object associated with the item “title  6 ,” BDJO-EX, includes an application management table related to playback processes for full HD 2D video images using the 2D playlist file  241 , as well as a Java application program related to playback processes for 4K2K 2D video images using the extended playlist file  243 . When the playback device  102  refers to the item “title 6,” then in accordance with the application management table in the BD-J object BDJO-EX, a Java application program is called from the JAR file  253  and executed. 
     In this way, the extended playlist file  243  is read from the BD-ROM disc  101 , and playback processes for 4K2K 2D video images are executed in accordance with the playback path specified therein. 
     3: Structure of 3D Playback Device 
       FIG. 40  is a functional block diagram of the playback device  102  shown in  FIG. 1 . As shown in  FIG. 40 , the playback device  102  includes a BD-ROM drive  4001 , playback unit  4002 , and control unit  4003 . The playback unit  4002  includes a switch  4020 , first read buffer (RB 1 )  4021 , second read buffer (RB 2 )  4022 , third read buffer (RB 3 )  4023 , system target decoder  4024 , and plane adder  4025 . The control unit  4003  includes a dynamic scenario memory  4031 , static scenario memory  4032 , user event processing unit  4033 , program execution unit  4034 , playback control unit  4035 , and player variable storage unit  4036 . The playback unit  4002  and the control unit  4003  are each implemented on a different integrated circuit. In particular, the program execution unit  4034  and the playback control unit  4035  are implemented by functions of the CPU in the playback device  102 . Alternatively, the playback unit  4002  and the control unit  4003  may be integrated on a single integrated circuit. 
     When the BD-ROM disc  101  is loaded into the BD-ROM drive  4001 , the BD-ROM drive  3701  radiates laser light to the disc  101  and detects change in the reflected light. Furthermore, using the change in the amount of reflected light, the BD-ROM drive  3701  reads data recorded on the disc  101 . Specifically, the BD-ROM drive  4001  has an optical pickup, i.e. an optical head. The optical head has a semiconductor laser, collimate lens, beam splitter, objective lens, collecting lens, and optical detector. A beam of light radiated from the semiconductor laser sequentially passes through the collimate lens, beam splitter, and objective lens to be collected on a recording layer of the disc  101 . The collected beam is reflected and diffracted by the recording layer. The reflected and diffracted light passes through the objective lens, the beam splitter, and the collecting lens, and is collected onto the optical detector. The optical detector generates a playback signal at a level in accordance with the amount of collected light. Furthermore, data is decoded from the playback signal. 
     Upon receiving an indication from the playback control unit  4035  of a range of LBNs as a file read request, the BD-ROM drive  4001  uses the file entry of the file to read extents in the file included in the range on the BD-ROM disc  101 . When a plurality of files are to be read, and the ranges of LBNs indicated for the files overlap, the BD-ROM drive  4001  reads extents in order from the smallest top LBN in the overlapping sections, regardless of the file to which the extents belong. Among the files that are read in this way, the AV stream file is transferred to the switch  4020 , dynamic scenario information is transferred to the dynamic scenario memory  4031 , and static scenario information is transferred to the static scenario memory  4032 . The “dynamic scenario information” includes an index file and a BD program file. The “static scenario information” includes a playlist file and a clip information file. 
     The switch  4020  transfers the AV stream file in units of extents from the BD-ROM drive  4001  to one of the read buffers  4021 - 4023 . In the playback device  102  in 2D playback mode, the switch  4020  transfers extents from the file  2 D to the RB 1   4021 . In the playback device  102  in 3D playback mode, the switch  4020  receives boundary information related to the extents in the file SS in advance from the playback control unit  4035 . The boundary information indicates the boundary between the base-view extents and the dependent-view extents included in each extent in the file SS. Specifically, the boundary information indicates the number of source packets from the top of each extent included in the file SS to each boundary between a base-view extent and a dependent-view extent included in the extent. The switch  4020  then refers to the boundary information to extract base-view extents and dependent-view extents from each extent SS, transmit the base-view extents to the RB 1   4021 , and transmit the dependent-view extents to the RB 2   4022 . In the playback device  102  in extended playback mode, the switch  4020  transmits the extents in the file  2 D to the RB 1   4021  and transmits the extents in the extended stream file to the RB 3   4023 . Information on whether each extent transmitted from the BD-ROM drive  4001  to switch  4020  belongs to the file  2 D or the extended stream file is transmitted from the BD-ROM drive  4001  to the switch  4020 . 
     The RB 1   4021 , the RB 2   4022 , and the RB 3   4023  are buffer memories that use a memory element in the playback unit  4002 . In particular, different areas in a single memory element are used as the RB 1   4021 , the RB 2   4022 , and the RB 3   4023 . 
     Alternatively, different memory elements may be used as the read buffers  4021 - 4023 . The RB 1   4021  receives base-view extents from the switch  4020  and stores these extents. The RB 2   4022  receives dependent-view extents from the switch  4020  and stores these extents. The RB 3   4023  receives extended extents from the switch  4020  and stores these extents. 
     The system target decoder  4024  reads extents from the read buffers  4021 - 4023  in units of source packets and demultiplexes the extents. The system target decoder  4024  then decodes each of the elementary streams obtained by the demultiplexing. At this point, the PIDs of the elementary streams to be decoded, as well as information necessary for decoding each elementary stream, such as the type of codec and attributes of the stream, are transferred in advance from the playback control unit  4035  to the system target decoder  4024 . Furthermore, the system target decoder  4024  transmits the video frames decoded from the primary video stream (hereinafter referred to as the primary video plane), the video frames decoded from the secondary video stream (hereinafter referred to as the secondary video plane), the PG plane decoded from the PG stream, and the IG plane decoded from the IG stream to the plane adder  4025 . These pieces of plane data represent the following: full HD 2D video images in 2D playback mode, a pair of left-view and right-view 2D video images in 3D playback mode, and 4K2K 2D video images in extended playback mode. On the other hand, the system target decoder  4024  mixes the decoded primary audio stream and secondary audio stream and transmits the resultant data to an audio output device, such as an internal speaker  103 A of the display device  103 . In addition, the system target decoder  4024  receives graphics data from the program execution unit  4034 . The graphics data is used for rendering graphics on the screen for a GUI menu or the like and is in a raster data format such as JPEG or PNG. The system target decoder  4024  processes the graphics data for conversion to an image plane and outputs the image plane to the plane adder  4025 . Details on the system target decoder  4024  are provided below. 
     The plane adder  4025  reads the primary video plane, the secondary video plane, the PG plane, the IG plane, and the image plane from the system target decoder  4024  and superimposes these planes one on another to yield one video frame. In particular, in L/R mode, each of the planes is composed of a data pair representing a left view and a right view. The plane adder  4025  superimposes data of the planes representing left views on the primary video plane representing a left view and superimposes data of the planes representing right views on the primary video plane representing a right view. On the other hand, in depth mode, each of the planes is composed of a data pair representing 2D video images and a depth map. Accordingly, the plane adder  4025  first generates a pair of left-view and right-view plane data from each of the planes. Subsequent combination process in depth mode is the same as in L/R mode. The combined video data is converted into a video signal in HDMI format and transmitted to the display device  103 . The plane adder  4025  in 2D playback mode transmits video frames for full HD 2D video images. The plane adder  4025  in 3D playback mode alternately transmits a left-view video frame and a right-view video frame. The plane adder  4025  in extended playback mode transmits video frames for 4K2K 2D video images. 
     The dynamic scenario memory  4031  and static scenario memory  4032  are each a buffer memory. Different memory elements in the control unit  4003  are used as the dynamic scenario memory  4031  and the static scenario memory  4032 . Alternatively, different areas in a single memory element may be used as the dynamic scenario memory  4031  and the static scenario memory  4032 . The dynamic scenario memory  4031  stores dynamic scenario information, and the static scenario memory  4032  stores static scenario information. 
     The user event processing unit  4033  detects a user operation via the remote control  105  or the front panel of the playback device  102 . Depending on the type of operation, the user event processing unit  4533  requests the program execution unit  4034  or the playback control unit  4035  to perform data processing. For example, when a user instructs to display a pop-up menu by pushing a button on the remote control  105 , the user event processing unit  4033  detects the push and identifies the button. The user event processing unit  4033  further requests the program execution unit  4034  to execute a command corresponding to the button, i.e. a command to display the pop-up menu. On the other hand, when a user pushes a fast-forward or a rewind button on the remote control  105 , the user event processing unit  4033  detects the push and identifies the button. The user event processing unit  4033  then requests the playback control unit  4035  to fast-forward or rewind the playlist currently being played back. 
     The program execution unit  4034  reads programs from MV object files and BD-J object files stored in the dynamic scenario memory  4031  and executes these programs. Furthermore, the program execution unit  4034  performs the following operations in accordance with the programs: (1) The program execution unit  4034  orders the playback control unit  4035  to perform playlist playback. (2) The program execution unit  4034  generates graphics data for a menu or game as PNG or JPEG raster data, transfers the generated data to the system target decoder  4024 , and causes the generated data to be combined with other plane data. Via program design, specific details on these processes can be designed relatively flexibly. In other words, during the authoring process of the BD-ROM disc  101 , the nature of these processes is determined while programming the MV object files and BD-J object files. 
     The playback control unit  4035  controls transfer of different types of files from the BD-ROM disc  101  to the read buffers  4021 - 4023 , the dynamic scenario memory  4031 , and the static scenario memory  4032 . The file system of the BD-ROM disc  101  is used for this control. Specifically, when a certain file is to be transferred, the playback control unit  4035  first refers to the name of the file to retrieve the file entry of the file within the directory/file structure on the BD-ROM disc  101 . Next, the playback control unit  4035  refers to the file entry to specify sectors of the BD-ROM disc  101  in which extents of the file to be transferred are recorded. Subsequently, the playback control unit  4035  instructs the BD-ROM drive  4001  to read data from the sectors. In response to this instruction, the BD-ROM drive  4001  transfers, in units of extents, the file to be transferred from the BD-ROM disc  101  to the buffer memories  4021 - 4023 ,  4031 , and  4032 . 
     The playback control unit  4035  decodes video data and audio data from the AV stream file by controlling the BD-ROM drive  4001  and the system target decoder  4024 . Specifically, the playback control unit  4035  first reads a playlist file from the static scenario memory  4032 , in response to an instruction from the program execution unit  4034  or a request from the user event processing unit  4033 , and interprets the content of the file. In accordance with the interpreted content, particularly with the playback path, the playback control unit  4035  then specifies an AV stream file to be played back and instructs the BD-ROM drive  4001  and the system target decoder  4024  to read and decode the specified file. Such playback according to a playlist file is called “playlist playback.” 
     In the playback device  102  in 2D playback mode, when the playback control unit  4035  is instructed by the program execution unit  4034  or another unit to perform playlist playback, the playback control unit  4035  reads PIs in order from the 2D playlist file stored in the static scenario memory  4032 , setting the read PI as the current PI. Each time the playback control unit  4035  sets the current PI, it first sets operation conditions on the system target decoder  4024  in accordance with the STN table. In particular, the playback control unit  4035  selects the PID of the elementary stream for decoding and transmits the PID, together with the attribute information necessary for decoding the elementary stream, to the system target decoder  4024 . Next, in accordance with the current PI, the playback control unit  4035  indicates a range of LBNs to the BD-ROM drive  4001  via the procedures indicated in the description about  FIG. 32 ; in the sectors located within the range of the LBNs, extents of the file  2 D to be read are recorded. 
     In the playback device  102  in 3D playback mode, when the playback control unit  4035  is instructed by the program execution unit  4034  or another unit to perform playlist playback, the playback control unit  4035  reads PIs in order from the 3D playlist file stored in the static scenario memory  4032 , setting the read PI as the current PI. Each time the playback control unit  4035  sets the current PI, it sets operation conditions on the system target decoder  4024  and the plane adder  4025  in accordance with the STN table of the PI and the STN table SS in the 3D playlist file. In particular, the playback control unit  4035  selects the PID of the elementary stream for decoding and transmits the PID, together with the attribute information necessary for decoding the elementary stream, to the system target decoder  4024 . Next, in accordance with the current PI, the playback control unit  4035  indicates a range of LBNs to the BD-ROM drive  4001  via the procedures indicated in the description about  FIG. 35 ; in sectors located within the range of LBNs, extents of the file SS to be read are recorded. Meanwhile, the playback control unit  4035  refers to the extent start points in the clip information file stored in the static scenario memory  4032  to generate information on the boundaries of extents of the file SS, and then transmitting the boundary information to the switch  4020 . 
     In the playback device  102  in extended playback mode, when the playback control unit  4035  is instructed by the program execution unit  4034  or another unit to perform playlist playback, the playback control unit  4035  reads PIs in order from the extended playlist file stored in the static scenario memory  4032 , setting the read PI as the current PI. Each time the playback control unit  4035  sets the current PI, it first sets operation conditions on the system target decoder  4024  in accordance with the STN table of the PI and the STN table EX in the extended playlist file. In particular, the playback control unit  4035  selects the PID of the elementary stream for decoding and transmits the PID, together with the attribute information necessary for decoding the elementary stream, to the system target decoder  4024 . Next, in accordance with the current PI, the playback control unit  4035  indicates a range of LBNs to the BD-ROM drive  4001  via the procedures indicated in the description about  FIG. 38 ; in sectors located within the range of LBNs, extents of the file  2 D and extended stream file to be read are recorded. 
     In addition, the playback control unit  4035  sets various types of player variables in the player variable storage unit  4036  using the static scenario information. With reference to the player variables, the playback control unit  4035  further specifies to the system target decoder  4024  the PIDs of the elementary streams to be decoded and provides the information necessary for decoding the elementary streams. 
     The player variable storage unit  4036  is composed of a group of registers for storing player variables. Types of player variables include system parameters (SPRM) and general parameters (GPRM). An SPRM indicates the status of the playback device  102 . There may, for example, be 64 SPRMs that have the meanings listed below. 
     SPRM( 0 ): Language code 
     SPRM( 1 ): Primary audio stream number 
     SPRM( 2 ): Subtitle stream number 
     SPRM( 3 ): Angle number 
     SPRM( 4 ): Title number 
     SPRM( 5 ): Chapter number 
     SPRM( 6 ): Program number 
     SPRM( 7 ): Cell number 
     SPRM( 8 ): Key name 
     SPRM( 9 ): Navigation timer 
     SPRM( 10 ): Current playback time 
     SPRM( 11 ): Player audio mixing mode for karaoke 
     SPRM( 12 ): Country code for parental management 
     SPRM( 13 ): Parental level 
     SPRM( 14 ): Player configuration for video 
     SPRM( 15 ): Player configuration for audio 
     SPRM( 16 ): Language code for audio stream 
     SPRM( 17 ): Language code extension for audio stream 
     SPRM( 18 ): Language code for subtitle stream 
     SPRM( 19 ): Language code extension for subtitle stream 
     SPRM( 20 ): Player region code 
     SPRM( 21 ): Secondary video stream number 
     SPRM( 22 ): Secondary audio stream number 
     SPRM( 23 ): Player status 
     SPRM( 24 )-SPRM( 63 ): Reserved 
     The SPRM( 10 ) indicates the PTS of the picture currently being decoded and is updated every time a picture is decoded. Accordingly, the current playback point can be known by referring to the SPRM( 10 ). 
     The language code for audio stream in SPRM( 16 ) and the language code for subtitle stream in SPRM( 18 ) show default language codes of the playback device  102 . These codes may be changed by a user with use of the OSD or the like of the playback device  102 , or the codes may be changed by an application program via the program execution unit  4034 . For example, if the SPRM( 16 ) shows “English,” then during playlist playback, the playback control unit  4035  first searches the STN table in the PI showing the current playback section, i.e. the current PI, for a stream entry having the language code for “English.” The playback control unit  4035  then extracts the PID from the stream identification information of the stream entry and transmits the extracted PID to the system target decoder  4024 . As a result, an audio stream having the PID is selected and decoded by the system target decoder  4024 . These processes can be executed by the playback control unit  4035  with use of the MV object file or the BD-J object file. 
     During playback, the playback control unit  4035  updates the player variables in accordance with the status of playback. The playback control unit  3735  updates the SPRM( 1 ), SPRM( 2 ), SPRM( 21 ), and SPRM( 22 ) in particular. These SPRM respectively show, in the stated order, the STN of the audio stream, subtitle stream, secondary video stream, and secondary audio stream that are currently being processed. For example, suppose that the SPRM( 1 ) has been changed by the program execution unit  4034 . In this case, the playback control unit  4035  first refers to the STN shown by the new SPRM( 1 ) and retrieves the stream entry that includes this STN from the STN table in the current PI. The playback control unit  4035  then extracts the PID from the stream identification information in the stream entry and transmits the extracted PID to the system target decoder  4024 . As a result, an audio stream having the PID is selected and decoded by the system target decoder  4024 . This is how the audio stream to be played back is switched. The subtitle stream and the secondary video stream to be played back can be similarly switched. 
     3-1: 2D Playlist Playback 
       FIG. 41  is a flowchart of 2D playlist playback by a playback control unit  4035 . 2D playlist playback is performed according to a 2D playlist file and is started when the playback control unit  4035  reads a 2D playlist file from the static scenario memory  4032 . 
     In step S 4101 , the playback control unit  4035  first reads a single PI from the main path in the 2D playlist file and then sets the PI as the current PI. Next, from the STN table of the current PI, the playback control unit  4035  selects PIDs of elementary streams to be played back and specifies attribute information necessary for decoding the elementary streams. The selected PIDs and attribute information are indicated to the system target decoder  4024 . The playback control unit  4035  further specifies a SUB_PI associated with the current PI from the sub-paths in the 2D playlist file. Thereafter, the process proceeds to step S 4102 . 
     In step S 4102 , the playback control unit  4035  reads reference clip information, a PTS # 1  indicating a playback start time IN 1 , and a PTS # 2  indicating a playback end time OUT 1  from the current PI. From this reference clip information, a 2D clip information file corresponding to the file  2 D to be played back is specified. Furthermore, when a SUB_PI exists that is associated with the current PI, similar information is also read from the SUB_PI. Thereafter, the process proceeds to step S 4103 . 
     In step S 4103 , the playback control unit  4035  refers to the entry map in the 2D clip information file to retrieve from the file  2 D the SPN # 1  and SPN # 2  that correspond to the PTS # 1  and PTS # 2 . The pair of PTSs indicated by the SUB_PI is also converted to a pair of SPNs. Thereafter, the process proceeds to step S 4104 . 
     In step S 4104 , from the SPN # 1  and the SPN # 2 , the playback control unit  4035  calculates the number of sectors corresponding to the SPN # 1  and the SPN # 2 . Specifically, the playback control unit  4035  first obtains the product of each of the SPN # 1  and the SPN # 2  multiplied by the data amount per source packet, i.e. 192 bytes. Next, the playback control unit  4035  obtains a quotient by dividing each product by the data amount per sector, i.e. 2048 bytes: N 1 =SPN # 1 × 192 / 2048 , N 2 =SPN # 2 × 192 / 2048 . The quotients N 1  and N 2  are the same as the total number of sectors, in the main TS, recorded in portions previous to the source packets to which SPN # 1  and SPN # 2  are allocated, respectively. The pair of SPNs converted from the pair of PTSs indicated by the SUB_PI is similarly converted to a pair of numbers of sectors. Thereafter, the process proceeds to step S 4105 . 
     In step S 4105 , the playback control unit  4035  specifies LBNs from the numbers of sectors N 1  and N 2  obtained in step S 4104 ; at the LBNs, the top and end of extents to be played back are located. Specifically, with reference to the file entry of the file  2 D to be played back, the playback control unit  4035  counts from the top of sectors in which the extents are recorded, in order to specify the LBN of the (N 1 +1) th  sector=LBN # 1  and the LBN of the (N 2 +1) th  sector=LBN # 2 . The playback control unit  4035  further specifies a range from LBN # 1  to LBN # 2  to the BD-ROM drive  4001 . The pair of numbers of sectors converted from the pair of PTSs indicated by the SUB_PI is similarly converted to a pair of LBNs and specified to the BD-ROM drive  4001 . As a result, from the sectors located within the specified range, source packets belonging to extents are read in aligned units. Thereafter, the process proceeds to step S 4106 . 
     In step S 4106 , the playback control unit  4035  checks whether an unprocessed PI remains in the main path. When an unprocessed PI remains, the process is repeated from step S 4101 . When no unprocessed PI remains, the process is ended. 
     3-2: 3D Playlist Playback 
       FIG. 42  is a flowchart of 3D playlist playback by a playback control unit  4035 . 3D playlist playback is performed according to a 3D playlist file and is started when the playback control unit  4035  reads a 3D playlist file from the static scenario memory  4032 . 
     In step S 4201 , the playback control unit  4035  first reads a single PI from the main path in the 3D playlist file and then sets the PI as the current PI. Next, from the STN table of the current PI, the playback control unit  4035  selects PIDs of elementary streams to be played back and specifies attribute information necessary for decoding the elementary streams. The playback control unit  4035  further selects, from among the elementary streams corresponding to the current PI in the STN table SS  3330  in the 3D playlist file, PIDs of additional elementary streams for playback, and the playback control unit  4035  specifies attribute information necessary for decoding these elementary streams. The selected PIDs and attribute information are indicated to the system target decoder  4024 . The playback control unit  4035  additionally specifies, from among sub-paths in the 3D playlist file, a SUB_PI to be referenced at the same time as the current PI, specifying this SUB_PI as the current SUB_PI. Thereafter, the process proceeds to step S 4202 . 
     In step S 4202 , the playback control unit  4035  reads reference clip information, a PTS # 1  indicating a playback start time IN 1 , and a PTS # 2  indicating a playback end time OUT 1  from the current PI and the SUB_PI. From this reference clip information, clip information files corresponding to the file  2 D and the file DEP to be played back are specified. Thereafter, the process proceeds to step S 4203 . 
     In step S 4203 , with reference to the entry map in each of the clip information files specified in step S 4202 , the playback control unit  4035  retrieves the SPN # 1  and SPN # 2  in the file  2 D, and the SPN # 11  and SPN # 12  in the file DEP, corresponding to the PTS # 1  and the PTS # 2 . Referring to extent start points of each clip information file, the playback control unit  4035  further calculates, from the SPN # 1  and the SPN # 11 , the number of source packets SPN # 21  from the top of the file SS to the playback start position. The playback control unit  5035  also calculates, from the SPN # 2  and the SPN # 12 , the number of source packets SPN # 22  from the top of the file SS to the playback end position. Specifically, the playback control unit  4035  first retrieves, from among SPNs shown by extent start points of the 2D clip information file, a value “Am” that is the largest value less than or equal to SPN # 1 , and retrieves, from among the SPNs shown by extent start points of the DEP clip information file, a value “Bm” that is the largest value less than or equal to the SPN # 11 . The playback control unit  4035  then obtains the sum of the retrieved SPNs Am+Bm and sets the sum as SPN # 21 . Next, the playback control unit  4035  retrieves, from among SPNs shown by extent start points of the 2D clip information file, a value “An” that is the smallest value that is larger than the SPN # 2 , and retrieves, from among the SPNs shown by extent start points of the DEP clip information files, a value “Bn” that is the smallest value that is larger than the SPN # 12 . The playback control unit  4035  then obtains the sum of the retrieved SPNs An+Bn and sets the sum as SPN # 22 . Thereafter, the process proceeds to step S 4204 . 
     In step S 4204 , the playback control unit  4035  converts the SPN # 21  and the SPN # 22 , determined in step S 4203 , into a pair of numbers of sectors N 1  and N 2 . 
     Specifically, the playback control unit  4035  first obtains the product of SPN # 21  and the data amount per source packet, i.e. 192 bytes. Next, the playback control unit  4035  divides this product by the data amount per sector, i.e. 2048 bytes: SPN # 21 × 192 / 2048 . The resulting quotient is the same as the number of sectors N 1  from the top of the file SS to immediately before the playback start position. Similarly, from the SPN # 22 , the playback control unit  4035  calculates SPN # 22 × 192 / 2048 . The resulting quotient is the same as the number of sectors N 2  from the top of the file SS to immediately before the playback end position. Thereafter, the process proceeds to step S 4205 . 
     In step S 4205 , the playback control unit  4035  specifies LBNs from the numbers of sectors N 1  and N 2  obtained in step S 4204 ; at the LBNs, the start and end of the extents to be played back are located. Specifically, with reference to the file entry of the file SS to be played back, the playback control unit  4035  counts from the top of the sectors in which the extents are recorded, in order to specify the LBN of the (N 1 +1) th  sector=LBN # 1  and the LBN of the (N 2 +1) th  sector=LBN # 2 . The playback control unit  4035  further specifies the range from LBN # 1  to LBN # 2  to the BD-ROM drive  4001 . As a result, from the sectors located within the specified range, source packets belonging to extents are read in aligned units. Thereafter, the process proceeds to step S 4206 . 
     In step S 4206 , the playback control unit  4035  again refers to the extent start points of the clip information file used in step S 4203  to generate boundary information for extents of the file SS, then transmitting the boundary information to the switch  4020 . As a specific example, assume that SPN # 21  indicating the playback start position is the same as the sum of SPNs indicating the extent start points, An+Bn, and that SPN # 22  indicating the playback end position is the same as the sum of SPNs indicating the extent start points, Am+Bm. In this case, the playback control unit  4035  obtains a sequence of differences between SPNs from the respective extent start points, A(n+1)−An, B(n+1)−Bn, A(n+2)−A(n+1), B(n+2)−B(n+1), . . . , Am−A(m−1), and Bm−B(m−1), and transmits the sequence to the switch  4020  as the boundary information. As shown in  FIG. 29E , this sequence indicates the number of source packets in each of the base-view extents and dependent-view extents included in the extents in the file SS. The switch  4020  counts, from zero, the number of source packets of the extents in the file SS received from the BD-ROM drive  4001 . Each time the count is the same as the difference between SPNs indicated by the boundary information, the switch  4020  switches the destination of output of the source packets between the RB 1   4021  and RB 2   4022  and resets the count to zero. As a result, {B(n+1)−Bn} source packets from the top of each extent SS in the file SS, i.e. the first dependent-view extent, are output to the RB 2   4022 , and the following {A(n+1)−An}source packets, i.e. the first base-view extent, are transmitted to the RB 1   4021 . Thereafter, dependent-view extents and base-view extents are extracted from the extents in the file SS alternately in the same way, alternating each time the number of source packets received by the switch  4020  is the same as the difference between SPNs indicated by the boundary information. Thereafter, the process proceeds to step S 4207 . 
     In step S 4207 , the playback control unit  4035  checks whether an unprocessed PI remains in the main path. When an unprocessed PI remains, the process is repeated from step S 4201 . When no unprocessed PI remains, the processing is ended. 
     3-3: Extended Playlist Playback 
       FIG. 43  is a flowchart of extended playlist playback by the playback control unit  4035 . Extended playlist playback is performed according to an extended playlist file and is started when the playback control unit  4035  reads the extended playlist file from the static scenario memory  4032 . 
     In step S 4301 , the playback control unit  4035  first reads one PI from the main path in the extended playlist file and then sets the PI as the current PI. Next, from the STN table of the current PI, the playback control unit  4035  selects PIDs of elementary streams to be played back and specifies attribute information necessary for decoding the elementary streams. In addition, from the entry that is included in the STN table EX  3630  of the extended playlist file and corresponds to the current PI, the playback control unit  4035  selects the PID of resolution extension information and specifies the attribute information necessary for decoding the resolution extension information. The selected PID and attribute information are indicated to the system target decoder  4024 . The playback control unit  4035  further specifies a SUB_PI to be referenced at the same time as the current PI from the sub-path of the extended playlist file, and sets this SUB_PI as the current SUB_PI. 
     Thereafter, the process proceeds to step S 4302 . 
     In step S 4302 , the playback control unit  4035  reads reference clip information, PTS # 1  indicating a playback start time IN 1 , and PTS # 2  indicating a playback end time OUT 1  from each of the current PI and SUB_PI. From the reference clip information, clip information files individually corresponding to the file  2 D and the extended stream file to be played back are specified. Thereafter, the process proceeds to step S 4303 . 
     In step S 4303 , the playback control unit  4035  refers to the entry map in each of the clip information files specified in step S 4302 , and then retrieves the pair of SPN # 1  and SPN # 2  in the file  2 D and the pair of SPN # 11  and SPN # 12  in the extended stream file, the pairs correspond to the pair of PTS # 1  and PTS # 2 . Thereafter, the process proceeds to step S 4304 . 
     In step S 4304 , the playback control unit  4035  calculates the corresponding numbers of sectors from SPN # 1 , # 2 , # 11 , and # 12 . Specifically, the playback control unit  4035  first multiplies each of SPN # 1 , # 2 , # 11 , and # 12  by the data amount per source packet, i.e., 192 bytes. Next, the playback control unit  4035  divides 192 bytes times each of the SPNs by the data amount per sector, i.e., 2048 bytes: N 1 =SPN # 1 × 192 / 2048 , N 2 =SPN # 2 × 192 / 2048 , N 11 =SPN # 11 × 192 / 2048 , and N 12 =SPN # 12 × 192 / 2048 . The quotients N 1  and N 2  are equal to the total numbers of sectors in which first and second portions of the main TS are recorded, respectively; the first and second portions are located before the source packets to which SPN # 1  and SPN # 2  are allocated, respectively. The quotients N 11  and N 12  are equal to the total numbers of sectors in which first and second portions of the extended stream are recorded, respectively; the first and second portions are located before the source packets to which SPN # 11  and SPN # 12  are allocated, respectively. Thereafter, the process proceeds to step S 4305 . 
     In step S 4305 , the playback control unit  4035  determines LBNs that should be assigned to the start and end of extents of the file  2 D to be played back from the numbers of sectors N 1  and N 2  obtained in step S 4304 ; and determines LBNs that should be assigned to the start and end of extents of the extended stream file to be played back from the numbers of sectors N 11  and N 12  obtained in step S 4304 . Specifically, the playback control unit  4035  refers to the file entry of the file  2 D to be played back to specify the LBN of the (N 1 +1) th  sector=LBN # 1  and the LBN of the (N 2 +1) th  sector=LBN # 2  counting from the top of the sectors in which the extents of the file  2 D are recorded. Furthermore, the playback control unit  4035  refers to the file entry of the extended stream file to be played back to specify the LBN of the (N 11 +1) th  sector=LBN # 11  and the LBN of the (N 12 +1) th  sector=LBN # 12  counting from the top of the sectors in which the extents of the extended stream file are recorded. The playback control unit  4035  then indicates the range from LBN # 1  to LBN # 2  and the range from LBN # 11  to LBN # 12  to the BD-ROM drive  4001 . As a result, the extents of the file  2 D and extended stream file are read from the sectors located within the indicated ranges, beginning from the extent with its top located at the smallest LBN. Thereafter, the process proceeds to step S 4306 . 
     In step S 4306 , the playback control unit  4035  checks whether an unprocessed PI remains in the main path. When an unprocessed PI remains, the process is repeated from step S 4301 . When no unprocessed PI remains, the process is ended. 
     3-4: System Target Decoder 
     Structure in 2D Playback Mode 
       FIG. 44  is a functional block diagram of the system target decoder  4024  in 2D playback mode. As shown in  FIG. 44 , the system target decoder  4024  includes a source depacketizer  4410 , ATC counter  4420 , first 27 MHz clock  4430 , PID filter  4440 , STC counter (STC1)  4450 , second 27 MHz clock  4460 , primary video decoder  4470 , secondary video decoder  4471 , PG decoder  4472 , IG decoder  4473 , primary audio decoder  4474 , secondary audio decoder  4475 , image processor  4480 , primary video plane memory  4490 , secondary video plane memory  4491 , PG plane memory  4492 , IG plane memory  4493 , image plane memory  4494 , and audio mixer  4495 . 
     The source depacketizer  4410  reads source packets from the RB 1   4021 , extracts the TS packets from the read source packets, and transfers the TS packets to the PID filter  4440 . Furthermore, the source depacketizer  4410  synchronizes the time of the transfer with the time shown by the ATS of each source packet. Specifically, the source depacketizer  4410  first monitors the value of the ATC generated by the ATC counter  4420 . In this case, the value of the ATC is incremented by the ATC counter  4420  in accordance with a pulse of a clock signal from the first 27 MHz clock  4430 . Subsequently, at the instant the value of the ATC matches with the ATS of a source packet, the source depacketizer  4410  transfers the TS packets extracted from the source packet to the PID filter  4440 . By adjusting the time of transfer in this way, the mean transfer rate of TS packets from the source depacketizer  4410  to the PID filter  4440  does not surpass the value R TS  specified by the system rate  2711  in the 2D clip information file  231  shown in  FIG. 27 . 
     The PID filter  4440  first monitors a PID that includes each TS packet outputted by the source depacketizer  4410 . When the PID matches with a PID pre-specified by the playback control unit  4035 , the PID filter  4440  selects the TS packet and transfers it to the decoder  4470 - 4475  appropriate for decoding of the elementary stream indicated by the PID. For example, if a PID is 0x1011, the TS packets are transferred to the primary video decoder  4470 . TS packets with PIDs ranging from 0x1B00-0x1B1F, 0x1100-0x111F, 0x1A00-0x1A1F, 0x1200-0x121F, and 0x1400-0-141F are transferred to the secondary video decoder  4471 , primary audio decoder  4474 , secondary audio decoder  4475 , PG decoder  4472 , and IG decoder  4473 , respectively. 
     The PID filter  4440  further detects a PCR from TS packets using the PIDs of the TS packets. At each detection, the PID filter  4440  sets the value of the STC counter  4450  to a predetermined value. Then, the value of the STC counter  4450  is incremented in accordance with a pulse of the clock signal of the second 27 MHz clock  4460 . In addition, the value to which the STC counter  4450  is set is indicated to the PID filter  4440  from the playback control unit  4035  in advance. The decoders  4470 - 4475  each use the value of the STC counter  4450  as the STC. Specifically, the decoders  4470 - 4475  first reconstruct the TS packets received from the PID filter  4440  into PES packets. Next, the decoders  4470 - 4475  adjust the timing of the decoding of data included in the PES payloads in accordance with the times indicated by the PTSs or the DTSs included in the PES headers. 
     The primary video decoder  4470 , as shown in  FIG. 44 , includes a transport stream buffer (TB)  4401 , multiplexing buffer (MB)  4402 , elementary stream buffer (EB)  4403 , compressed video decoder (DEC)  4804 , and decoded picture buffer (DPB)  4405 . 
     The TB  4401 , MB  4402 , and EB  4403  are each a buffer memory and use an area of a memory element internally provided in the primary video decoder  4470 . Alternatively, some or all of the buffer memories may be separated between different memory elements. The TB  4401  stores the TS packets received from the PID filter  4440  as they are. The MB  4402  stores PES packets reconstructed from the TS packets stored in the TB  4401 . Note that when the TS packets are transferred from the TB  4401  to the MB  4402 , the TS header is removed from each TS packet. The EB  4403  extracts encoded VAUs from the PES packets and stores the VAUs therein. A VAU includes a compressed picture, i.e., an I picture, B picture, or P picture. Note that when data is transferred from the MB  4402  to the EB  4403 , the PES header is removed from each PES packet. 
     The DEC  4404  is a hardware decoder designed specifically for decoding of compressed pictures and is composed of an LSI that includes, in particular, a function to accelerate the decoding. The DEC  4404  decodes a picture from each VAU in the EB  4403  at the time shown by the DTS included in the original PES packet. During decoding, the DEC  4404  first analyzes the VAU header to specify the compressed picture, compression encoding method, and stream attribute stored in the VAU, selecting a decoding method in accordance with this information. Compression encoding methods include, for example, MPEG-2, MPEG-4 AVC, and VC1. Furthermore, the DEC  4404  transmits the decoded, uncompressed picture to the DPB  4405 . 
     Like the TB  4401 , MB  4402 , and EB  4403 , the DPB  4405  is a buffer memory that uses an area of a built-in memory element in the primary video decoder  4470 . Alternatively, the DPB  4405  may be located in a memory element separate from the other buffer memories  4401 ,  4402 , and  4403 . The DPB  4405  temporarily stores the decoded pictures. When a P picture or B picture is to be decoded by the DEC  4404 , the DPB  4405  retrieves reference pictures, in response to an instruction from the DEC  4404 , from among stored, decoded pictures. The DPB  4005  then provides the reference pictures to the DEC  4404 . Furthermore, the DPB  4405  writes the stored pictures into the primary video plane memory  4490  at the time shown by the PTSs included in the original PES packets. 
     The secondary video decoder  4471  includes the same structure as the primary video decoder  4470 . The secondary video decoder  4471  first decodes the TS packets of the secondary video stream received from the PID filter  4440  into uncompressed pictures. Subsequently, the secondary video decoder  4471  writes the uncompressed pictures into the secondary video plane memory  4491  at the time shown by the PTSs included in the PES packets decoded from the TS packets. 
     The PG decoder  4472  decodes the TS packets received from the PID filter  4440  into an uncompressed graphics object. The PG decoder  4472  then writes the uncompressed graphics object to the PG plane memory  4492  at the time shown by the PTSs included in the PES packets decoded from the TS packets. 
     The IG decoder  4473  decodes the TS packets received from the PID filter  4440  into an uncompressed graphics object. The IG decoder  4473  then writes the uncompressed graphics object to the IG plane memory  4493  at the time shown by the PTSs included in the PES packets decoded from the TS packets. 
     The primary audio decoder  4474  first stores the TS packets received from the PID filter  4440  in a buffer provided therein. Subsequently, the primary audio decoder  4474  removes the TS header and the PES header from each TS packet in the buffer, and decodes the remaining data into uncompressed LPCM audio data. Furthermore, the primary audio decoder  4474  transmits the resultant audio data to the audio mixer  4495  at the time shown by the PTS included in the original PES packet. The primary audio decoder  4474  selects the decoding method for compressed audio data in accordance with the compression encoding method and stream attributes for the primary audio stream included in the TS packets. Compression encoding methods include, for example, AC- 3  and DTS. 
     The secondary audio decoder  4475  has the same structure as the primary audio decoder  4474 . The secondary audio decoder  4475  first reconstructs PES packets from the TS packets of the secondary audio stream received from the PID filter  4440  and then decodes the data included in the PES payloads into uncompressed LPCM audio data. Subsequently, the secondary audio decoder  4475  transmits the uncompressed LPCM audio data to the audio mixer  4495  at the times shown by the PTSs included in the PES headers. The secondary audio decoder  4475  selects the decoding method for compressed audio data in accordance with the compression encoding method and stream attributes for the secondary audio stream included in the TS packets. Compression encoding methods include, for example, Dolby Digital Plus and DTS-HD LBR. 
     The audio mixer  4495  receives uncompressed audio data from both the primary audio decoder  4474  and the secondary audio decoder  4475  and then mixes the received data. The audio mixer  4495  also transmits the synthesized sound yielded by mixing audio data to, for example, an internal speaker  103 A of the display device  103 . 
     The image processor  4480  receives graphics data, i.e., PNG or JPEG raster data, from the program execution unit  4034 . Upon receiving the graphics data, the image processor  4480  renders the graphics data and writes the graphics data to the image plane memory  4494 . 
     The primary video plane memory  4490 , secondary video plane memory  4491 , PG plane memory  4492 , IG plane memory  4493 , and image plane memory  4494  are reserved as different areas in a memory element internal to the system target decoder  4024 . Alternatively, the plane memories  4490 - 4494  may be separated between different memory elements. The plane memories  4490 - 4494  can store the corresponding plane data and are equal in size to at least one video frame. 
     Structure in 3D Playback Mode 
       FIG. 45  is a functional block diagram of the system target decoder  4024  in 3D playback mode. The components shown in  FIG. 45  differ from those shown in  FIG. 44  in the following three points. (1) The input system from the read buffer to each of the decoders is doubled. (2) The primary video decoder, the secondary video decoder, the PG decoder, and the IG decoder can all decode the main TS and the sub-TS alternately. (3) Each plane memory can store plane data representing the left view and the right view. On the other hand, the primary audio decoder, secondary audio decoder, audio mixer, and image processor are the same as those shown in  FIG. 44 . Accordingly, among the components shown in  FIG. 45 , those differing from the components shown in  FIG. 44  are described below. Details on similar elements can be found in the description about  FIG. 44 . Furthermore, since the decoders each have a similar structure, only the structure of the primary video decoder  4515  is described below. This description is also valid for the structure of the other decoders. 
     The first source depacketizer  4511  reads source packets from the RB 1   4021 , furthermore extracting TS packets included therein and transmitting the TS packets to the first PID filter  4513 . The second source depacketizer  4512  reads source packets from the RB 2   4022 , furthermore extracting TS packets included therein and transmitting the TS packets to the second PID filter  4514 . Each of the source depacketizers  4511  and  4512  further synchronizes the time of transfer the TS packets with the time shown by the ATS of each source packet. This synchronization method is the same method as the source depacketizer  4410  shown in  FIG. 44 . Accordingly, details thereof can be found in the description provided for  FIG. 44 . With this sort of adjustment of transfer time, the mean transfer rate R TS1  of TS packets from the first source depacketizer  4511  to the first PID filter  4513  does not exceed the system rate indicated by the 2D clip information file. Similarly, the mean transfer rate R TS2  of TS packets from the second source depacketizer  4512  to the second PID filter  4514  does not exceed the system rate indicated by the DEP clip information file. 
     The first PID filter  4513  compares the PID of each TS packet received from the first source depacketizer  4511  with the selected PID. The playback control unit  4035  designates the selected PID beforehand in accordance with the STN table in the 3D playlist file. When the two PIDs match with each other, the first PID filter  4513  transfers the TS packets to the decoder assigned to the PID. For example, if a PID is 0x1011, the TS packets are transferred to TB 1   4501  in the primary video decoder  4515 . On the other hand, TS packets with PIDs ranging from 0x1B00-0x1B1F, 0x1100-0x111F, 0x1A00-0x1A1F, 0x1200-0x121F, and 0x1400-0x141F are transferred to the secondary video decoder, primary audio decoder, secondary audio decoder, PG decoder, and IG decoder respectively. 
     The second PID filter  4514  compares the PID of each TS packet received from the second source depacketizer  4512  with the selected PID. The playback control unit  4035  designates the selected PID beforehand in accordance with the STN table SS in the 3D playlist file. When the two PIDs match with each other, the second PID filter  4514  transfers the TS packets to the decoder assigned to the PID. For example, if a PID is 0x1012 or 0x1013, the TS packets are transferred to TB2  4508  in the primary video decoder  4515 . On the other hand, TS packets with PIDs ranging from 0x1B20-0x1B3F, 0x1220-0x127F, and 0x1420-0-147F are transferred to the secondary video decoder, PG decoder, or IG decoder respectively. 
     The primary video decoder  4515  includes a TB 1   4501 , MB 1   4502 , EB1  4503 , TB 2   4508 , MB 2   4509 , EB 2   4510 , buffer switch  4506 , DEC  4504 , DPB  4505 , and picture switch  4507 . The TB 1   4501 , MB 1   4502 , EB 1   4503 , TB 2   4508 , MB 2   4509 , EB 2   4510  and DPB  4505  are all buffer memories. Each of these buffer memories uses an area of a memory element included in the primary video decoder  4515 . Alternatively, some or all of these buffer memories may be separated between different memory elements. 
     The TB 1   4501  receives TS packets that include a base-view video stream from the first PID filter  4513  and stores the TS packets as they are. The MB 1   4502  decodes PES packets from the TS packets stored in the TB 1   4501  and stores the PES packets. The TS headers of the TS packets are removed at this point. The EB 1   4503  extracts encoded VAUs from the PES packets stored in the MB 1   4502  and stores the VAUs. The PES headers of the PES packets are removed at this point. 
     The TB 2   4508  receives TS packets that include a dependent-view video stream from the second PID filter  4514  and stores the TS packets as they are. The MB 2   4509  decodes PES packets from the TS packets stored in the TB 2   4508  and stores the PES packets. The TS headers of the TS packets are removed at this point. The EB 2   4510  extracts encoded VAUs from the PES packets stored in the MB 2   4509  and stores the VAUs. The PES headers of the PES packets are removed at this point. 
     The buffer switch  4506  transfers the headers of the VAUs stored in the EB 1 l  4503  and the EB 2   4510  in response to a request from the DEC  4504 . Furthermore, the buffer switch  4506  transfers the compressed picture data for the VAUs to the DEC  4504  at the times indicated by the DTSs included in the original PES packets. In this case, the DTSs are equal for a pair of pictures belonging to the same 3D VAU between the base-view video stream and dependent-view video stream. Accordingly, for a pair of VAUs that have the same DTS, the buffer switch  4506  first transmits the VAU stored in the EB 1   4503  to the DEC  4504 . 
     Like the DEC  4404  shown in  FIG. 44 , the DEC  4504  is a hardware decoder designed specifically for decoding of compressed pictures and is composed of an LSI that includes, in particular, a function to accelerate the decoding. The DEC  4504  decodes the compressed picture data transferred from the buffer switch  4506  in order. During decoding, the DEC  4504  first analyzes each VAU header to specify the compressed picture, compression encoding method, and stream attribute stored in the VAU, selecting a decoding method in accordance with this information. Compression encoding methods include, for example, MPEG-2, MPEG-4 AVC, MVC, and VC1. Furthermore, the DEC  4504  transmits the decoded, uncompressed picture to the DPB  4505 . 
     The DPB  4505  temporarily stores the decoded, uncompressed pictures. When the DEC  4504  decodes a P picture or a B picture, the DPB  4505  retrieves reference pictures from among the stored, uncompressed pictures in response to a request from the DEC  4504  and supplies the retrieved reference pictures to the DEC  4504 . 
     The picture switch  4507  writes the uncompressed pictures from the DPB  4505  to either the left-video plane memory  4520  or the right-video plane memory  4521  at the time indicated by the PTS included in the original PES packet. In this case, the PTSs are equal between a base-view picture and a dependent-view picture belonging to the same 3D VAU. Accordingly, for a pair of pictures that have the same PTS and that are stored by the DPB  4505 , the picture switch  4507  first writes the base-view picture in the left-video plane memory  4520  and then writes the dependent-view picture in the right-video plane memory  4521 . 
     Structure in Extended Playback Mode 
       FIG. 46  is a functional block diagram of the system target decoder  4024  in extended playback mode. The components shown in  FIG. 46  differ from those shown in  FIG. 45  in the following two points. (1) The primary video decoder, the secondary video decoder, the PG decoder, and the IG decoder can all decode the main TS and the extended stream alternately. (2) Each plane memory can store 4K2K plane data. On the other hand, the primary audio decoder, secondary audio decoder, audio mixer, and image processor are the same as those shown in  FIG. 45 . Accordingly, among the components shown in  FIG. 46 , those differing from the components shown in  FIG. 45  are described below. Details on similar elements can be found in the description about  FIG. 45 . Furthermore, since the decoders each have a similar structure, only the structure of the primary video decoder  4615  is described below. This description is also valid for the structure of the other decoders. 
     The second source depacketizer  4512  reads source packets from the RB 3   4023 , furthermore extracting and transmitting TS packets from the source packets to the second PID filter  4514 . The mean transfer rate R TS3  for the TS packets to be transferred from the second source depacketizer  4512  to the second PID filter  4514  does not exceed the system rate indicated by the extended clip information file. 
     Every time the second PID filter  4514  receives a TS packet from the second source depacketizer  4512 , the second PID filter compares the PID of the TS packet with PIDs to be selected. The PIDs to be selected have been preliminarily specified by the playback control unit  4035  in accordance with the STN table EX of the extended playlist file. When the PID of the TS packet matches with one of the PIDs to be selected, the second PID filter  4514  transfers the TS packet to the decoder assigned to its PID. For example, if the PID is 0x1014, the TS packet is transferred to TB 2   4608  in the primary video decoder  4615 . 
     The primary video decoder  4615  includes TB 1   4601 , MB 1   4602 , EB 1   4603 , TB 2   4608 , MB 2   4609 , EB 2   4610 , resolution extension control unit  4606 , DEC  4604 , DPB  4605 , and adder  4607 . TB 1   4601 , MB 1   4602 , EB 1   4603 , TB 2   4608 , MB 2   4609 , EB 2   4610 , and DPB  4605  are all buffer memories. Each of these buffer memories uses an area of a memory element included in the primary video decoder  4615 . Alternatively, some or all of these buffer memories may be separated into different memory elements. 
     TB 1   4601  receives TS packets that include a base-view video stream from the first PID filter  4513  and stores the TS packets as they are. MB 1   4602  decodes PES packets from the TS packets stored in TB 1   4601  and stores the PES packets. TS headers are removed from the TS packets at this point. EB 1   4603  extracts encoded VAUs from the PES packets stored in MB 1   4602  and stores the VAUs. PES headers are removed from the PES packets at this point. 
     TB 2   4608  receives TS packets that include resolution extension information from the second PID filter  4514  and stores the TS packets as they are. MB 2   4609  decodes PES packets from the TS packets stored in TB 2   4608  and stores the PES packets. TS headers are removed from the TS packets at this point. EB 2   4610  extracts encoded VAUs from the PES packets stored in MB 2   4609  and stores the VAUs. PES headers are removed from the PES packets at this point. 
     The resolution extension control unit  4606  reads an extended resolution and an interpolation method from the resolution extension information stored in EB 2   4610 , and indicates the read information to the DEC  4604 . Furthermore, the resolution extension control unit  4606  reads pixel difference information from the resolution extension information, and transmits the pixel difference information to the adder  4607  at the time indicated by the DTS included in the original PES packet. Here, a picture of the base-view video stream and resolution extension information of the extended stream, which are necessary for constituting a 4K2K video frame, have the same DTS. 
     Like the DEC  4404  shown in  FIG. 44 , the DEC  4604  is a hardware decoder designed specifically for decoding of compressed pictures and is composed of an LSI that includes, in particular, a function to accelerate the decoding. The DEC  4604  decodes the compressed picture data transferred from EB 1   4603  in order. During decoding, the DEC  4604  first analyzes each VAU header to specify the compression encoding method and stream attributes of the compressed picture stored in the VAU, then selecting a decoding method in accordance with this information. Options of the compression encoding method include, for example, MPEG-2, MPEG-4 AVC, and VC1. 
     Furthermore, the DEC  4604  uses the interpolation method indicated by the resolution extension control unit  4606  to increase the resolution of the decoded, uncompressed pictures from full HD to the resolution indicated by the resolution extension control unit  4606 , i.e., to 4K2K. Here, any of the well-known methods available to increase resolution of video images, such as the bilinear and bicubic methods, is used as the interpolation method. The DEC  4604  transmits the 4K2K pictures to the DPB  4605 . 
     The DPB  4605  temporarily holds the decoded, uncompressed pictures. When the DEC  4604  decodes a P picture or a B picture, the DPB  4605  responds to a request from the DEC  4604  to retrieve one or more reference pictures from among the uncompressed pictures that the DPB  4605  holds, and then supply the reference pictures to the DEC  4604 . 
     The adder  4607  reads a 4K2K picture from the DPB  4605 , and in parallel, receives pixel difference information from the resolution extension control unit  4606 . Then, the adder  4607  adds the difference in corresponding pixel data contained in the pixel difference information to pixel data contained in the picture. In this way, the video images represented by the 4K2K picture are converted to the original fine-resolution images. The 4K2K picture after converted is written to the primary video plane memory  4620  at the time indicated by the PTS included in the original PES packet. 
     Conversion of Resolution from Full HD to 4K2K 
       FIG. 47  is a flowchart of resolution conversion from full HD to 4K2K. This process is started when resolution extension information begins to be transferred from EB 2   4610  to the resolution extension control unit  4606 . 
     In step S 4701 , the resolution extension control unit  4606  reads an extended resolution and an interpolation method from the resolution extension information. The resolution extension control unit  4606  then indicates the extended resolution and the interpolation method to the DEC  4604 . Thereafter, the process proceeds to step S 4702 . 
     In step S 4702 , DEC  4604  reads the compressed picture data from EB 1   4603  and decodes a base-view picture from the compressed picture data. Furthermore, DEC  4604  uses the interpolation method indicated by the resolution extension control unit  4606  to increase the resolution of the base-view picture from full HD to the resolution indicated by the resolution extension control unit  4606 , i.e., to 4K2K. DEC  4603  then writes the 4K2K picture to DPB  4605 . Thereafter, the process proceeds to step S 4703 . 
     In step S 4703 , the adder  4607  reads the 4K2K base-view picture from DPB  4605  and receives pixel difference information from the resolution extension control unit  4606 . At this point, the adder  4607  adds the difference in pixel data contained in the pixel difference information to the corresponding pixel data contained in the base-view picture. The 4K2K picture is written into the primary video plane memory  4620 . Thereafter, the process proceeds to step S 4704 . 
     In step S 4704 , DEC  4604  confirms whether data of the next compressed picture exists in EB 1   4603 . If exists, the process is repeated from step S 4701 . If not, the process is ended. 
     4: Effects of Embodiment 1 
     As shown in  FIGS. 14 and 15 , the BD-ROM disc  101  according to Embodiment 1 of the present invention includes a combination of an extended data specific section, a monoscopic video specific section, and a stereoscopic video specific section immediately before and after the location where a long jump J LY  is required, such as a layer boundary LB. The same portion of the main TS is duplicated in the monoscopic video specific section and the stereoscopic video specific section. The playback devices in 2D playback mode and extended playback mode read this portion from the monoscopic video specific section, whereas the playback device in 3D playback mode reads this portion from the stereoscopic video specific section. As a result, conditions that the sizes of base-view extents should satisfy in order to prevent buffer underflow from occurring during a long jump J LY  can be set separately for the monoscopic video specific section and the stereoscopic video specific section. This technology therefore enables both seamless playback of video images during the long jump J LY  in every mode and a further reduction in the buffer capacity built in the playback device. 
     Furthermore, the monoscopic video specific section is accessed by both the playback devices in 2D playback mode and extended playback mode. Therefore, from the BD-ROM disc  101 , data that matches with the entirety of base-view extents B 3D  located in the stereoscopic video specific section can be eliminated except for the base-view extent B 2D  located in the monoscopic video specific section. As a result, the volume area  202 B on the BD-ROM disc  101  can be utilized more effectively. 
     Moreover, the playback device in any mode skips access to either the monoscopic video specific section or the stereoscopic video specific section via a long jump J LY . Accordingly, even if the system rates for the file  2 D and the file SS are set to the maximum values of 48 Mbps and 64 Mbps, respectively, the jump distance of the long jump J LY  in either mode does not exceed the maximum jump distance of 40,000 sectors. As a result, in any mode, a high image quality can be maintained regardless of the need for a long jump. 
     5: Modifications 
     (A) The display device  103  according to Embodiment 1 of the present invention is a liquid crystal display. Alternatively, the display device according to the present invention may be another type of flat panel display, such as a plasma display, an organic EL display, etc., or a projector. Furthermore, the display device  103  shown in  FIG. 1  is separate from the playback device  102 . Alternatively, the display device may be formed integrally with the playback device. 
     (B) The recording medium  101  according to Embodiment 1 of the present invention is a BD-ROM disc. Alternatively, the recording medium according to the present invention may be a different portable recording medium, for example, an optical disc with a different format such as DVD or the like, a removable hard disk drive (HDD), or a semiconductor memory device such as an SD memory card. 
     (C) The 3D glasses  102  according to Embodiment 1 of the present invention are shutter glasses. Alternatively, the 3D glasses according to the present invention may be those including left and right lenses covered by polarization films with different polarization directions, or those including left and right lenses with different transmission spectra. When the former glasses are used, the display device uses different polarized lights to display left-view and right-view video images. When the latter glasses are used, the display device uses lights with different spectra to display left-view and right-view video images. Left lenses of both the glasses only allow left-view video images to pass through, and right lenses thereof only allow right-view video images to pass through. 
     (D) A picture contained in a PES packet  511  shown in  FIG. 5  is the entirety of one encoded video frame. Alternatively, the picture may be one encoded field. 
     (E) The playback device  102  in L/R mode according to Embodiment 1 of the present invention plays back video frames representing left and right views from the base-view and dependent-view video streams, respectively. Conversely, the base-view and dependent-view video streams may represent right and left views, respectively. 
     (F) The arrangement of extents shown in  FIG. 11  includes dependent-view extents placed before base-view extents. Contrary to the assumption under which the arrangement has been determined, when the system rate R TS2  for the file DEP is set as high as the system rate R TS1  for the file  2 D, the second transfer rate R EXT2  may exceed the first transfer rate R EXT1  for the extent pair located at the top of an extent block. In this case, the base-view extent may be placed before the dependent-view extent. In other words, a smaller one of the extent pair is placed before the other larger one. This enables the read buffer to maintain a smaller capacity. 
     (G) Both arrangement  1  shown in  FIG. 14  and arrangement  2  shown in  FIG. 15  include the combinations of an extended data specific section, a monoscopic video specific section, and a stereoscopic video specific section located both immediately before and after the layer boundary LB. Alternatively, these sections may be only located either immediately before or immediately after the layer boundary LB. When these sections are located immediately before the layer boundary LB, the sizes of the base-view extents arranged in the stereoscopic video specific section need not satisfy condition 1. When the sections are located immediately after the layer boundary LB, the monoscopic video specific section can be located closer to the layer boundary LB than the stereoscopic video specific section, and thus the long jump in 2D playback mode can have a shorter jump distance than the long jump in 3D playback mode. In either case, the base-view extent to be read immediately before the long jump in 3D playback mode can have a reduced size, and thus the playback device in 3D playback mode allows the RB 2  to maintain its capacity at the minimum necessary value. 
     (H) According to Embodiment 1 of the present invention, the extended data included in the extended stream is resolution extension information, or information necessary for extending full HD 2D video images, which are represented by the base-view video stream, to 4K2K 2D video images. Other embodiments may use the following types of extended data. 
     Depth Map Stream 
     Extended data may be a depth map stream. In this case, extended playback mode of the playback device  102  is equivalent to depth mode. In other words, the playback device  102  plays back 3D video images from extents read in accordance with the third playback path  1203  shown in  FIG. 12 . 
     Depth maps are used for playback of 3D video images as follows. 2D video images represented by the base-view video stream are the 3D video images projected onto a virtual 2D screen. The depth maps represent, pixel by pixel, the depths of portions of the 3D video images with respect to the 2D screen. In particular, the depth of an image to be displayed by a pixel is expressed by the luminance of the pixel. In the playback device  102  in depth mode, the plane adder  4025  constructs left- and right-view video frames from the combination of the base-view video stream and the depth maps. 
       FIG. 48  is a schematic diagram showing an example of constructing a left view LVW and a right view RVW from the combination of 2D video images MVW and a depth map DPH. As shown in  FIG. 48 , the 2D video images MVW include a circular plate DSC shown in its background BGV. The depth map DPH expresses the depths for portions of the 2D video images MVW by the luminances of pixels. According to the depth map DPH, the area DA1 where the circular plate DSC is displayed in the 2D video images MVW is to be seen by viewers closer than the screen, while the area DA 2  where the background BGV is displayed is to be farer than the screen. In the plane adder  4025  of the playback device  102 , a parallax image generation unit PDG first calculates binocular parallax of each portion of the 2D video images MVW by using the depths of the portion indicated by the depth map DPH. Next, the parallax image generation unit PDG shifts the position of the portion to the left and right in the 2D video images MVW in accordance with the calculated binocular parallax to construct the left view LVW and the right view RVW. In the example shown in  FIG. 48 , the parallax image generation unit PDG shifts the circular plate DSC from its original position in the 2D video images MVW as follows: the circular plate DSL displayed in the left view LVW is located on the right side of the original position and at a distance S1 of half of the circular plate&#39;s binocular parallax from the original position, while the circular plate DSR displayed in the right view RVW is located on the left side of the original position and at the distance S1 therefrom. In this way, the circular plate DSC is seen by the viewers as being closer than the screen. Conversely, the parallax image generation unit PDG shifts the background BGV from its original position in the 2D video images MVW as follows: the background BGL displayed in the left view LVW is located on the left side of the original position and at a distance S2 of half of the background&#39;s binocular parallax from the original position, while the background BGR displayed in the right view RVW is located on the right side of the original position and at the distance S2 therefrom. In this way, the background BGV is seen by the viewers as being farer than the screen. 
     Pixel data included in the depth map only expresses the luminances of a single color, and therefore the bit rate of the depth map is generally lower than both the bit rates of the base-view and right-view video streams. Accordingly, the interleaved arrangement of extents shown in  FIG. 13  is effective. 
     Audio Stream Conforming to DTS Extended Standard 
     Extended data is not limited to a video stream, but may also be an audio stream. In particular, extended data may be an audio stream conforming to the DTS extended standard. The DTS extended standard includes DTS-ES (Extended Surround), DTS-HD master audio, and DTS-HD high-resolution sound. In all of these standards, the extended stream contains a data portion as extended data; the data portion is to be combined with the primary audio stream included in the main TS. Combining this data portion with the primary audio stream improves audio quality and increases the number of channels for surround sound. In the playback device  102  in extended playback mode, the primary audio decoder  4474  decodes the primary audio stream from the main TS, and in parallel decodes the extended data from the extended stream, and then constructs a target audio stream from the decoded data. 
     In an audio stream conforming to the DTS extended standard, portion extended from the primary audio stream included in the main TS has a data amount much smaller than both the data amounts of the base-view and dependent-view video streams. Accordingly, the interleaved arrangement of extents shown in  FIG. 13  is effective. 
     Video Stream for Super Picture-in-Picture 
     Extended data may be secondary video streams to be combined with the primary video stream of the main TS. The playback device  102  in extended playback mode can simultaneously display three or more types of video images on one screen by using the combination of the extended data and the primary video stream in addition to the secondary video streams of the main TS. 
     In picture-in-picture, the secondary video stream typically has a resolution lower than that of the primary video stream. Accordingly, the video stream included in the extended stream generally has a bit rate lower than both the bit rates of the base-view and dependent-view video streams. Accordingly, the interleaved arrangement of extents shown in  FIG. 13  is effective. 
     Additional Pictures in Temporal Scalable Coding 
     Extended data may be information necessary for increasing the frame rate of the base-view video stream. For example, when the base-view video stream has a frame rate of 60 fps, additional pictures necessary for raising this value to 120 fps is contained in the extended stream as extended data. In particular, the additional pictures are compressed with reference to base-view pictures. In the playback device  102  in extended playback mode, the primary video decoder  4470  decodes the base-view pictures from the main TS and in parallel decodes the additional pictures from the extended stream by using the base-view pictures. Furthermore, the primary video decoder  4470  inserts the additional pictures between the base-view pictures to increase the frame rate of the base-view video stream. This enables video images to change even finer over time. 
     Since the additional pictures are for changing video images even finer between base-view pictures, the similarity between the additional pictures and the base-view pictures are generally high. Accordingly, by compressing the additional pictures with reference to the base-view pictures, the extended stream can have a bit rate much lower than both the bit rates of the base-view and dependent-view video streams. Therefore, the interleaved arrangement of extents shown in  FIG. 13  is effective. 
     Difference in Video Images Before and after Camera&#39;s Angle of View is Enlarged 
     Extended data may be differences in video images before and after a camera&#39;s angle of view is enlarged. In this case, the base-view video stream represents video images captured by a camera with the original angle of view. In the playback device  102  in extended playback mode, the primary video decoder  4470  decodes one video frame from the base-view video stream and in parallel decodes pixel data from the extended stream; the pixel data represents video images to be displayed in a region outside video images represented by a video frame. The primary video decoder  4470  then reconstructs one video frame from the data. As a result, video images to be displayed within a wider angular range than the original video images can be played back. 
     The pixel data representing video images to be displayed in a region outside video images represented by the original video frame contained in the base-view video stream generally has a total data amount much smaller than those of the original video frame. Accordingly, the extended stream has a bit rate much lower than both the bit rates of the base-view and dependent-view video streams. Therefore, the interleaved arrangement of extents shown in  FIG. 13  is effective. 
     Dependent-View Video Stream 
     Extended data may be a dependent-view video stream to be combined with the base-view video stream of the main TS to represent 3D video images, or alternatively may be information representing parallax between left and right views that are generated from combination between the base-view and dependent-view video streams. In this case, the playback device  102  in extended playback mode plays back 3D video images, like the playback device  102  in 3D playback mode. The dependent-view video stream of the extended stream differs from that of the sub-TS in the degree of parallax between left and right views generated from combination with the common base-view video stream. 
     The parallax between left and right views has a maximum value normally equal to or shorter than an average viewer&#39;s interpupillary distance (in the case of children, 5 cm or less). As long as this condition is satisfied, the parallax will not exceed the viewer&#39;s interpupillary distance. This can reduce the viewer&#39;s risk of visually induced motion sickness and eye strain. Left and right views with larger parallax are displayed on a larger screen of the display device  103 . For example, when the dependent-view video stream of the sub-TS can be combined with the base-view video stream to generate left and right views having parallax suitable for a screen size of 50 inches or less, the dependent-view video stream of the extended stream is designed to be combined with the base-view video stream to generate left and right views having parallax suitable for a screen size of 100 inches or less. 
     When playing back 3D video images from the BD-ROM disc  101 , the playback control unit  4035  in the playback device  102  selects 3D playback mode or extended playback mode, whichever is suitable for the screen size of the display device  103 . Specifically, the playback control unit  4035  first acquires the screen size from the display device  103  via the HDMI cable  122 . Next, the playback control unit  4035  selects 3D playback mode if the screen size of the display device  103  is equal to or less than 50 inches, and selects extended playback mode if the screen size is larger than 50 inches but does not exceed 100 inches. Therefore, the parallax between left and right views is set to a value appropriate for the screen size. 
     The playback device  102  in extended playback mode reads all of base-view, dependent-view, and extended extents in order, in contrast to reading extents according to the third playback path  1203  shown in  FIG. 12 . The playback device  102  then uses the file entries of the file SS and the extended stream file as well as the extent start points contained in the 3D clip information file to distribute the read extents among the RB 1   4021 , the RB 2   4022 , and the RB 3   4023 . The system target decoder  4024  provides the primary video decoder with source packets containing the base-view video stream, the dependent-view video stream, and the extended data from the RB 1   4021 , the RB 2   4022 , and the RB 3   4023 , respectively. When the extended data includes dependent-view pictures, the dependent-view pictures are highly similar to dependent-view pictures of the sub-TS, and therefore are compressed with reference to dependent-view pictures of the sub-TS. In this case, the primary video decoder uses dependent-view pictures of the sub-TS to decode dependent-view pictures from the extended data. On the other hand, when the extended data includes parallax information, the primary video decoder uses the parallax information to shift pixel data to the left or right in a dependent-view picture of the sub-TS. By combining a resulting dependent-view picture with a base-view picture, the primary video decoder constructs a pair of video frames representing left and right views. 
     The extended data is either pictures compressed with reference to the dependent-view pictures of the sub-TS or parallax information. Accordingly, the extended stream has a bit rate much lower than both the bit rates of the base-view video stream and the dependent-view video stream of the sub-TS. Therefore, the interleaved arrangement of extents shown in  FIG. 13  is effective. 
     Resolution Extension Information for 3D Video Images 
     Extended data may include not only resolution extension information for the base-view video stream but also resolution extension information for the dependent-view video stream. In this case, the playback device  102  in extended playback mode plays back 4K2K 3D video images as follows. 
     The playback device  102  in extended playback mode reads all of base-view, dependent-view, and extended extents in order, in contrast to reading extents according to the third playback path  1203  shown in  FIG. 12 . The playback device  102  then uses the file entries of the file SS and the extended stream file as well as the extent start points contained in the 3D clip information file to distribute the read extents among the RB 1   4021 , the RB 2   4022 , and the RB 3   4023 . The system target decoder  4024  provides the primary video decoder with source packets containing the base-view video stream, the dependent-view video stream, and the extended data from the RB 1   4021 , the RB 2   4022 , and the RB 3   4023 , respectively. The primary video decoder first decodes full HD base-view and dependent-view pictures. The primary video decoder then increases the resolution of each picture to 4K2K through the interpolation method indicated by the resolution extension information. Next, the primary video decoder adds pixel difference information to each picture with increased resolution. thus generating a pair of video frames representing 4K2K left and right views. 
     The resolution extension information has a data amount much smaller than both base-view and dependent-view pictures. Accordingly, the extended stream has a bit rate much lower than both the bit rates of the base-view video stream and the dependent-view video stream of the sub-TS. Therefore, the interleaved arrangement of extents shown in  FIG. 13  is effective. 
     Physiological Information 
     Application of 3D video image technology to medical care is also in progress. For example, when a surgeon operates a surgical robot during endoscopic surgery, 3D video images of the operative field are presented to the surgeon. Alternatively, 3D video images of surgery scene are used for monitoring the progress of surgery, conferences, presentations at academic meetings, and education of medical students. In these cases, extended data may be video images to be displayed on a physiological information monitor, or may be physiological information itself. Physiological information is information about patient&#39;s physical conditions, in particular, patient&#39;s vital signs such as an electrocardiogram, pulse rate, respiratory rate, blood pressure, body temperature, and brain waves. The playback device  102  in extended playback mode generates graphics images representing physiological information from the extended data, and then combines the graphics images with 2D video images represented by the main TS. Thus, the playback device  102  enables the display of patient&#39;s physiological information to overlap 2D video images of operative fields. 
     Video images displayed on a physiological information monitor are relatively simple graphics images. Furthermore, physiological information itself is simply numerical data. Accordingly, the extended stream has a bit rate much lower than both the bit rates of the main TS and the sub-TS. Therefore, the interleaved arrangement of extents shown in  FIG. 13  is effective. 
     Additional Color Information for Bit Extension 
     Extended data may be information necessary for increasing the number of bits of color information included in pixel data of the base-view pictures. For example, when the pixel data of the base-view pictures expresses each of RGB or YCrCb color coordinates with eight bits, information necessary for converting the color coordinates to 12-bit representation is contained in the extended stream as extended data. 
       FIG. 49  is a block diagram of a system that generates a base-view video stream and an extended stream from a sequence of original pictures. As shown in  FIG. 49 , the system includes shift circuit 1  4901 , video encoder 1  4902 , a video decoder  4903 , shift circuit 2  4904 , a subtractor  4905 , an adder  4906 , video encoder 2  4907 , and a shift amount determiner  4908 . 
     Shift circuit 1  4901  extracts a bit sequence representing each color coordinate from pixel data of the original pictures OPC, and then shifts the bit sequence to the right by (N−8) bits. As a result, the number of bits representing each color coordinate is reduced from N to 8. Here, the number N is an integer larger than 8. When the original pictures OPC represent video images of a movie or the like, the number N is often 10 or 12. 
     Video encoder 1  4902  encodes and converts the original pictures OPC processed by shift circuit 1  4901  into the base-view video stream. The original pictures OPC are thus compressed and multiplexed into the base-view video stream. A compression encoding method to be used is MPEG-2, MPEG-4 AVC, MVC, or SMPTE VC-1. In particular, when MPEG-4 MVC is used, the pictures OPC are encoded as “Base view.” 
     The video decoder  4903  decodes pictures from the base-view video stream generated by video encoder 1  4902 . Here, the encoding by video encoder 1  4902  is irreversible. Accordingly, decoded pictures differ from pictures before processed by video encoder 1  4902  in a few lower-order bits among eight bits representing each color coordinate. 
     Shift circuit 2  4904  extracts a bit sequence representing each color coordinate from pixel data of pictures decoded by the video decoder  4903 , and then shifts the bit sequence to the left by (N−8) bits. As a result, (N−8) zeros are added to the right of the bit sequence, thereby increasing the number of bits representing each color coordinate from 8 to N. 
     The subtractor  4905  compares pictures processed by the series of shift circuit 1  4901 , video encoder 1  4902 , the video decoder  4903 , and shift circuit 2  4904  with the original pictures OPC, thus calculating a difference in N bits representing each color coordinate between pixels corresponding to each other. When the number of bits representing the difference exceeds eight, the subtractor  4905  rounds its lower-order bits up or down, so that the number of bits is limited up to eight. The difference in color coordinate and the output of the subtractor  4905  can therefore be treated as a new color coordinate and a picture, respectively. Hereinafter, this picture is referred to as an “extended picture.” 
     The adder  4906  adds a correction value to the difference calculated by the subtractor  4905 . The difference, even if negative, is thus converted into a positive number. Here, when video encoder 2  4907  can process pixel data that includes negative numbers, the adder  4906  may be omitted. 
     Video encoder 2  4907  encodes and converts extended pictures processed by the adder  4906  into the extended stream. The extended pictures are thus compressed and multiplexed into the extended stream. A compression encoding method to be used is MPEG-2, MPEG-4 AVC, MVC, or SMPTE VC-1. In particular, when MPEG-4 MVC is used, the extended pictures are encoded as “Non baseview.” In other words, the extended stream has the same data structure as the dependent-view video stream. 
     The shift amount determiner  4908  first compares a picture processed by shift circuit 1  4901  with another picture decoded by the video decoder  4903  to check how many consecutive bits starting from the most significant bit of eight bits representing each color coordinate, pixels corresponding to each other have in common. Next, the shift amount determiner  4908  determines the smallest number of bits among the checked ones for each picture as being a shift amount for the picture. When the smallest number exceeds N−8, the shift amount is fixed at N−8. The shift amount determiner  4908  then incorporates the shift amount for each picture into the base-view video stream or the extended stream. In this case, the shift amount is incorporated into the supplementary data  831 D,  832 D, etc., of each VAU shown in  FIG. 8 . Alternatively, the shift amounts for all pictures included in each video sequence may be incorporated collectively into the supplementary data of VAU # 1 , i.e., the VAU located at the top of the video sequence. 
       FIG. 50  is a schematic diagram showing a method of processing color coordinates by the system shown in  FIG. 49 . As shown in  FIG. 50 , shift circuit 1  4901  first shifts N bits  5001  to the right by (N−8) bits; for example, the N bits  5001  represent a red color coordinate in data of one pixel included in the original pictures OPC. The eight higher-order bits  5002  are thus extracted from the N bits  5001  and incorporated into the base-view video stream by video encoder 1  4902 . From the base-view video stream, eight bits  5003  representing the red color coordinate in the above-mentioned data of one pixel are decoded by the video decoder  4903 . Shift circuit 2  4904  shifts these eight bits  5003  to the left by (N−8) bits. (N−8) zeros are thus added to the right of the eight bits  5003 , then yielding new N bits  5004 . The subtractor  4905  calculates the difference  5005  between the new N bits  5004  and the original N bits  5001 . Furthermore, the subtractor  4905  extracts the eight higher-order bits  5006  from the difference  5005 , and the video encoder 2  4907  incorporates the higher-order bits  5006  into the extended stream. Similar processing is performed for other color coordinates as well. 
     As indicated by the hatched areas in  FIG. 50 , the decoded eight bits  5003  differs from the original eight bits  5002  in the (b+1) th  and subsequent bits from the most significant bit. Here, the number b is an integer at least zero and not more than eight. In this case, the difference  5005  is (N−b) bits. As indicated by the dotted areas in  FIG. 50 , the difference  5005  differs from (N−b) lower-order bits of the original N bits  5004  in (8−b) higher-order bits. The shift amount determiner  4908  calculates the value b for each color coordinate, and then determines the smallest value among the values b calculated for all color coordinates included in each picture as being the shift amount b for the picture. When the smallest value exceeds N−8, the shift amount b is fixed at N−8. 
       FIG. 51  is a block diagram showing an example of a processing system that is built in the system target decoder in extended playback mode to process the base-view video stream and the extended stream. As shown in  FIG. 51 , this processing system includes a first PID filter  4513 , a second PID filter  4514 , a primary video decoder  4515 , a bit extender  5110 , and a primary video plane memory  5120 . The two PID filters  4513 ,  4514 , and the primary video decider  4515  are similar to those shown in  FIG. 45 . Accordingly, differences from the elements shown in  FIG. 45  are described below. Details on elements similar to those shown in  FIG. 45  can be found in the description thereof. 
     Via the buffer switch  4506 , the compressed video decoder (DEC)  4504  receives base-view and extended pictures from the first PID filter  4513  and the second PID filter  4514 , respectively. The DEC  4504  then decodes the pictures in the order in which they were received. The DEC  4504  also reads the shift amounts b from the supplementary data or the like of the VAUs containing the pictures and then transmits the shift amounts b to the bit extender  5110 . 
     The bit extender  5110  combines an extended picture and a base-view picture to which the same PTS has been assigned to increase the number of bits, which represent each color coordinate in pixel data, from eight to N. The bit extender  5110  includes shift circuit  1   5101 , a subtractor  5102 , an adder  5103 , and shift circuit  2   5104 . 
     Shift circuit  1   5101  first receives a decoded base-view picture and a shift amount b from the picture switch  4507  and the DEC  4504 , respectively. Shift circuit  1   5101  next extracts a bit sequence representing each color coordinate from pixel data of the base-view picture, and then shifts the bit sequence to the left by b bits. As a result, b zeros are added to the right of the bit sequence, thereby increasing the number of bits representing the color coordinate from 8 to 8+b. 
     The subtractor  5102  receives a decoded extended picture from the picture switch  4507 , and then removes a correction value from a bit sequence representing each color coordinate in pixel data of the extended picture. The correction value equals the correction value used by the adder  4906  shown in  FIG. 49 . Here, when the adder  4906  is omitted from the system shown in  FIG. 49 , the subtractor  5102  is omitted from the bit extender  5110 . 
     The adder  5103  first receives (8+b) bits and 8 bits from shift circuit  1   5101  and the subtractor  5102 , respectively; the (8+b) bits represent each color coordinate in pixel data of a base-view picture, and the 8 bits represent a difference in color coordinate included in pixel data of the corresponding extended picture. The adder  5103  next calculates the sum of these received bits. 
     Shift circuit  2   5104  first receives (8+b) bits representing a color coordinate from the adder  5103 , and receives a shift amount b from the DEC  4504 . Shift circuit  2   5104  next shifts the (8+b) bits to the left by (N−8−b) bits. As a result, (N−8−b) zeros are added to the right of the (8+b) bits, so that the number of bits representing the color coordinate increases from 8+b to N. Shift circuit  2   5104  then writes the N bits representing the color coordinate into the primary video plane memory  5120 . 
     The primary video plane memory  5120  is a region that is reserved in a memory element built in the system target decoder  4024 . A full HD primary video plane that is composed of pixel data representing each color coordinate with N bits can be stored in the primary video plane memory  5120 . 
       FIG. 52  is a schematic diagram showing a method by which the bit extender  5110  processes color coordinates. As shown in  FIG. 52 , shift circuit  1   5101  first shifts eight bits  5201  to the left by b bits; for example, the eight bits  5201  represent a red color coordinate in data of one pixel included in a decoded base-view picture. As a result, b zeros are added to the right of the eight bits  5201 , and thus the eight bits  5201  are converted into (8+b) bits  5202 . Next, the adder  5103  adds eight bits  5203  to the (8+b) bits  5202 ; the eight bits  5203  represent a difference in red color coordinate in data of the corresponding pixel included in a decoded extended picture. Shift circuit  2   5104  then shifts the resultant (8+b) bits  5204  to the left by (N−8−b) bits. (N−8−b) zeros are thus added to the right of the (8+b) bits  5204 , thus yielding new N bits  5205 . As is clear from  FIG. 50 , (8+b) higher-order bits of the new N bits  5205  nearly match with (8+b) higher-order bits of the original N bits  5001  representing a red color coordinate in data of the corresponding pixel included in the original pictures OPC. The error in the higher-order bits are an error arising from encoding of the extended picture, i.e., a difference between the difference  5006  before the encoding and the difference  5203  after the decoding, which are shown in  FIGS. 50 and 52 , respectively. Accordingly, the difference between the new N bits  5205  and the original N bits  5001  is much smaller than the difference between the N bits  5004  after the decoding, which are shown by the hatched areas in  FIG. 50 , and the original N bits  5001 . Similar processing is performed for other color coordinates as well. In this way, the bit extender  5110  can restore the original pictures OPC at a high level of accuracy from the combination of the base-view pictures and the extended pictures. 
       FIG. 53  is a block diagram showing another example of a processing system that is built in the system target decoder in extended playback mode to process the base-view video stream and the extended stream. As shown in  FIG. 53 , this processing system is similar to the one shown in  FIG. 51 , except for the bit extender  5310 . Accordingly, the differences from the elements shown in  FIG. 51  are described below. Details on the similar elements can be found in the description about the elements shown in  FIG. 51 . 
     The bit extender  5310  combines an extended picture and a base-view picture to which the same PTS has been assigned, and thus increases the number of bits representing a color coordinate in pixel data from eight to N. The bit extender  5310  includes shift circuit  1   5301 , the subtractor  5102 , shift circuit  2   5303 , and an adder  5304 . 
     Shift circuit  1   5301  first receives a decoded base-view picture from the picture switch  4507 , next extracts bit sequences representing color coordinates from data of each pixel in the base-view picture, and then shifts each of the bit sequences to the left by (N−8) bits. As a result, (N−8) zeros are added to the right of each of the bit sequences, thereby increasing the number of bits representing each color coordinate from eight to N−8. 
     Shift circuit  2   5303  first receives eight bits representing the difference in color coordinate from the subtractor  5102 , and a shift amount b from the DEC  4504 . Shift circuit  2   5303  next shifts the eight bits to the left by (N−8−b) bits. As a result, (N−8−b) zeros are added to the right of the eight bits, thereby increasing the number of bits representing the difference in color coordinate from eight to N−b. 
     The adder  5304  first receives N bits and (N−b) bits from shift circuit  1   5301  and shift circuit  2   5303 , respectively; the N bits represent a color coordinate in data of each pixel included in the base-view picture, and the (N−b) bits represent the difference in color coordinate in data of the corresponding pixel included in the extended picture. The adder  5304  next calculates the sum of the N and (N−b) bits, and then writes N bits representing the sum into the primary video plane memory  5120 . 
       FIG. 54  is a schematic diagram showing a method by which the bit extender  5310  processes color coordinates. As shown in  FIG. 54 , shift circuit  1   5301  first shifts eight bits  5401  to the left by (N−8) bits; for example, the eight bits  5401  represent a red color coordinate in data of one pixel included in the decoded base-view picture. (N−8) zeros are thus added to the right of the eight bits  5401 , thus yielding N bits  5402 . On the other hand, shift circuit  2   5303  shifts other eight bits  5403  to the left by (N−8−b) bits; the eight bits  5403  represent the difference in red color coordinate in data of the corresponding pixel included in the decoded extended picture. As a result, (N−8−b) zeros are added to the right of the eight bits  5403 , and thus the eight bits  5403  are converted into (N−b) bits  5404 . Subsequently, the adder  5304  adds the (N−b) bits  5404  representing the difference to the yielded N bits  5402 , thus yielding new N bits  5405 . As is clear from  FIG. 50 , (8+b) higher-order bits of the new N bits  5405  nearly match with (8+b) higher-order bits of the original N bits  5001  representing the red color coordinate in data of the corresponding pixel included in the original pictures OPC. The error in the higher-order bits are the error arising from encoding of the extended picture, i.e., the difference between the difference  5006  before the encoding and the difference  5403  after the decoding, which are shown in  FIGS. 50 and 54 , respectively. Accordingly, the difference between the new N bits  5405  and the original N bits  5001  is much smaller than the difference between the N bits  5004  after the decoding, which are shown by the hatched areas in  FIG. 50 , and the original N bits  5001 . 
     Similar processing is performed for other color coordinates as well. In this way, the bit extender  5310  can restore the original pictures OPC at a high level of accuracy from the combination of the base-view pictures and the extended pictures. 
     The data amount of the differences between color coordinates included in pixel data of the extended pictures is generally smaller than the data amount of color coordinates included in pixel data of the base-view pictures. Accordingly, the extended stream has generally a bit rate lower than both the bit rates of the base-view video stream and the dependent-view video stream. Therefore, the interleaved arrangement of extents shown in  FIG. 13  is effective. 
     Embodiment 2 
     A recording device according to Embodiment 2 of the present invention records, in real-time, an AV stream file using the arrangement of extents according to Embodiment 1 of the present invention onto a writable recording medium, such as a BD-RE (Rewritable), BD-R (Recordable), hard disk, semiconductor memory card, or the like (hereinafter referred to as a BD disc or the like) that is mounted in an optical disc recorder or a video camera. The recording device converts a moving video content filmed by the video camera, or a content playback from another recording medium such as a BD-ROM disc, into an AV stream file using a predetermined compression encoding method and records the AV stream file on the recording medium. The content is expressed as both 2D video images at 4K2K and as full HD 3D video images. Next, the recording device generates a scenario. A “scenario” is information defining how each title included in the content is to be played back. Specifically, a scenario includes dynamic scenario information and static scenario information. The recording device then records the scenario on the recording medium. 
     Structure of Recording Device 
       FIG. 55  is a functional block diagram of a recording device according to Embodiment 2. As shown in  FIG. 55 , the recording device  5500  includes a storage unit  5501 , a video encoder  5502 , an audio encoder  5503 , a control unit  5504 , a multiplexer  5505 , a source packetizer  5506 , and a write unit  5507 . 
     The storage unit  5501  is a storage device embedded in the recording device  5500  and is in particular an HDD. Alternatively, the storage unit  5501  may be an external HDD connected to the recording device  5500 , or a semiconductor memory device internal or external to the recording device  5500 . 
     The video encoder  5502  is dedicated hardware for encoding of video data. Alternatively, the video encoder  5502  may be an element that functions by the CPU internal to the recording device  5500  executing specific software. The video encoder  5502  compresses an analog or digital input video signal VIN using a compression encoding method such as MPEG-4 AVC, MVC, or MPEG-2. The video data is thus converted into a combination of a base-view video stream, a dependent-view video stream, and an extended stream. The converted video streams  5511  and the extended stream  5512  are stored in the storage unit  5501 . 
     The video encoder  5502  uses a multiview coding method such as MVC to encode the 3D video image data. The 3D video image data is thus converted into a pair of a base-view video stream and a dependent-view video stream as shown in  FIG. 7 . In other words, the video frame sequence representing the left view is converted into a base-view video stream via inter-picture predictive encoding on the pictures in these video frames. On the other hand, the video frame sequence representing the right view is converted into a dependent-view video stream via predictive encoding on not only the pictures in these video frames, but also the base-view pictures. Note that the video frames representing the right view may be converted into a base-view video stream, and the video frames representing the left view may be converted into a dependent-view video stream. 
     When encoding the 3D video image data, the video encoder  5502  compares the left-view picture and the right-view picture before compression by macroblock during the inter-picture predictive encoding process, each macroblock being 8×8 or 16×16 pixels, in order to detect movement vectors in the video images between the pictures. The video encoder  5502  uses the detected movement vectors to compress each picture. The video encoder  5502  may instead use the movement vectors to calculate the binocular parallax of the video images, detecting depth information for each video image from the binocular parallax thereof. The video encoder  5502  may then use this depth information to generate a depth map for the left view or right view. In this case, the video encoder  5502  uses inter-picture predictive encoding on the pictures in the left-view or right-view stream data and the depth map stream to convert these into a base-view video stream and a depth map stream. 
     When encoding 2D video image data at 4K2K, the video encoder  5502  first extracts a full HD video frame from the base-view video stream obtained by encoding the 3D video image data and converts the video frame to a 4K2K video frame using a bicubic or a bilinear interpolation method. Next, the video encoder  5502  compares the converted 4K2K video frame with the original 4K2K video frame to generate pixel difference information. The video encoder  5502  then generates resolution extension information from the generated pixel difference information and converts the resolution extension information into the extended stream. 
     The audio encoder  5503  is dedicated hardware for encoding of audio data. Alternatively, the audio encoder  5503  may be an element that functions by the CPU internal to the recording device  5500  executing specific software. The audio encoder  5503  generates an audio stream  5513  from an audio input signal AIN, storing the audio signal  5513  in the storage unit  5501 . The audio input signal AIN is, for example, LPCM audio data and is encoded using a compression encoding method such as AC- 3 . 
     The control unit  5504  is an element that functions by the CPU internal to the recording device  5500  executing specific software. The control unit  5504  generates scenario data  5514  and stores the scenario data  5514  in the storage unit  5501 . The scenario data  5514  includes an index file, an MV object file, a clip information file, and a playlist file and specifies the playback method of the elementary streams  5511 - 5513  stored in the storage unit  5501 . 
     In particular, the control unit  5504  generates the entry map of the clip information file in real-time as follows. Each time the video encoder  5502  encodes one GOP, the video encoder  5502  transmits a PTS and two SPNs to the control unit  5504 ; the PTS is included in the I or P picture located at the top of the GOP; the first SPN is assigned to the top of source packets in which the I or P picture is to be stored; and the second SPN is assigned to the top of source packets in which resolution extension information on the I or P picture is to be stored. The control unit  5504  adds the PTS and the first SPN transmitted by the video encoder  5502  to the entry map as one entry point. 
     The control unit  5504  also generates the extent start points  2742  and  2920  shown in  FIGS. 29A and 29B  by referring to the respective entry maps of the 2D clip information file and the DEP clip information file. At this point, extent ATC times are aligned between extent pairs. Furthermore, the control unit  5504  designs the arrangement of extents so that the size of each base-view extent, dependent-view extent, and extended extent satisfies conditions 1-6. In particular, immediately before or immediately after locations where a long jump is necessary, an extended data specific section, a monoscopic video specific section, and a stereoscopic video specific section are provided, as in arrangement  1  shown in  FIG. 14  or arrangement 2 shown in  FIG. 15 . 
     The control unit  5504  also extracts the stream attribute information  2720  shown in  FIG. 27  from the elementary stream in which the main TS, the sub-TS, and the extended stream are to be multiplexed and associates a combination of an entry map  2730 , 3D meta data  2740 , and stream attribute information  2720  with a piece of clip information  2710 , as shown in  FIG. 27 . The 2D clip information file, the DEP clip information file, and the extended clip information file are thus generated. Subsequently, the control unit  5504  generates the 2D playlist file, the 3D playlist file, and the extended playlist file by referring to each clip information file. 
     The multiplexer  5505  multiplexes the elementary streams  5511 - 5513  stored in the storage unit  5501  into stream data in MPEG2-TS format. Specifically, as shown in  FIG. 5 , each of the elementary streams  5511 - 5512  is first converted into a series of TS packets. The series of TS packets are then multiplexed into one sequence of multiplexed stream data. The main TS, the sub-TS, and the extended stream are thus generated. These pieces of multiplexed stream data are output to the source packetizer  5506 . 
     The source packetizer  5506  converts each TS packet in the main TS, the sub-TS, and the extended stream into one source packet. The main TS, the sub-TS, and the extended stream are thus each converted into a series of source packet sequences and output to the write unit  5507 . 
     The write unit  5507  first writes the source packet sequences generated by the source packetizer  5506  on a BDR, such as a BD disc, in accordance with the arrangement of extents designed by the control unit  5504 . In parallel, the write unit  5507  generates the file entries for the file  2 D, the file DEP, the file SS, and the extended stream file within internal memory. Upon completion of writing all the source packet sequences to the BDR, such as a BD disc, the write unit  5507  writes the file entry for each AV stream file to the BDR, such as a BD disc. Each source packet sequence is thus recorded on the BDR, such as a BD disc, as an AV stream file. Subsequently, the write unit  5507  records the scenario data  5514  stored in the storage unit  5501  on the BDR, such as a BD disc. 
     When generating the file entry of the AV stream file, the write unit  5507  refers to the entry map and the 3D metadata included in the clip information file. Each SPN for entry points and extent start points is thereby used in creating allocation descriptors. In particular, the value of the LBN and the extent size to be represented by each allocation descriptor are determined in accordance with the arrangement of extents designed by the control unit  5504  so as to express an interleaved arrangement like the one shown in  FIG. 11 . 
     Method to Align Extent ATC Times 
       FIG. 56  is a schematic diagram showing a method to align extent ATC times between consecutive extents. For the sake of convenience, the following description applies to 3D playback mode. Extended playback mode is similar. First, ATSs along the same ATC time axis are assigned to source packets stored in a base-view extent (hereinafter, SP 1 ) and source packets stored in a dependent-view extent (hereinafter, SP 2 ). As shown in  FIG. 56 , the rectangles  5610  and  5620  respectively represent SP 1  #p (p=0, 1, . . . , k, k+1, . . . , i, i+1) and SP 2 #q (q=0, 1, . . . , m, m+1, . . . , j, j+1). Here, the numbers i and j are integers at least one, the number k is an integer at least zero and at most i, and the number m is an integer at least zero and at most j. These rectangles  5610  and  5620  are arranged in order along the time axis by the ATS of each source packet. The positions A 1 (p) and A 2 (q) respectively of the top of each rectangle  5610  and  5620  represent the value of the ATS of the source packet. The length AT 1  and AT 2  respectively of each rectangle  5610  and  5620  represent the amount of time needed for the playback device in 3D playback mode to transfer one source packet from the read buffer to the system target decoder. 
     From the ATS A 1 (0) of SP 1  # 0  until an extent ATC time T EXT [n] has passed, SP 1 , i.e. SP 1  # 0 ,  1 ,  2 , . . . , k, is transferred from the read buffer to the system target decoder and stored in the (n+1) th  base-view extent EXT 1 [n] (the number n being an integer at least zero). Similarly, from the ATS A 1 (k+1) of SP 1  #(k+1) until an extent ATC time T EXT [n+1] has passed, SP 1 , i.e. SP 1  #(k+1), . . . , i, is transferred from the read buffer to the system target decoder and stored in the (n+2) th  base-view extent EXT 1 [n+1]. 
     On the other hand, SP 2 , which is to be stored in the (n+1) th  dependent-view extent EXT 2 [n], is selected as follows. First, the sum of the ATS A1(0) of SP 1  # 0  and the extent ATC time T EXT [n] is sought as ATS A 1 (k+1) of SP 1  #(k+1): ATS A 1 (k+1)=A 1 (0)+T EXT [n]. Next, SP 2 , i.e. SP 2  # 0 ,  1 , . . . , m, is selected. Transfer of SP 2  from the read buffer to the system target decoder begins during the period from ATS A 1 (0) of SP 1  # 0  until ATS A 1 (k+1) of SP 1  #(k+1). Accordingly, the top SP 2 , i.e. ATS A 2 (0) of SP 2  # 0 , is always equal to or greater than the top SP 1 , i.e. ATS A 1 (0) of SP 1  # 0 : A 2 (0)≧A 1 (0). Furthermore, the last SP 2 , i.e. ATS A 2 (m) of SP 2  #m, is equal to or less than ATS A 1 (k+1) of SP 1  #(k+1): A 2 (m)≦A 1 (k+1). In this context, completion of transfer of SP 2  #m may be at or after ATS A 1 (k+1) of SP 1  #(k+1). 
     Similarly, SP 2 , which is to be stored in the (n+2) th  dependent-view extent EXT 2 [n+1], is selected as follows. First, ATS A 1 (i+1) of SP 1  #(i+1), which is located at the top of the (n+3) th  base-view extent EXT 1 [n+2], is calculated: ATS A 1 (i+1)=A 1 (k+1)+T EXT [n+1]. Next, SP 2 , i.e. SP 2  #(m+1), . . . , j, is selected. Transfer of SP 2  from the read buffer to the system target decoder begins during the period from ATS A 1 (k+1) of SP 1  #(k+1) until ATS A 1 (i+1) of SP 1  #(i+1). Accordingly, the top SP 2 , i.e. ATS A 2 (m+1) of SP 2  #(m+1), is equal to or greater than the top SP 1 , i.e. ATS A 1 (k+1) of SP 1  #(k+1): A 2 (m+1)≧A 1 (k+1). Furthermore, ATS A 2 (j) of the last SP 2  #j is equal to or less than ATS A 1 (i+1) of the SP 1  #(i+1) located at the top of the next base-view extent EXT 1 [n+2]: A 2 (j)≦A 1 (i+1). 
     Real-time Recording of Content 
       FIG. 57  is a flowchart of a method for real-time recording of content onto a BDR, such as a BD disc, using the recording device  5500  shown in  FIG. 55 . This method begins, for example, when power to the recording device  5500  is turned on. 
     In step S 5701 , the video encoder  5502  encodes a video input signal VIN to generate a picture and encodes an audio input signal AIN to generate an audio frame. In particular, the video frame representing the left view of a 3D video image is encoded as a base-view picture, and the video frame representing the right view is encoded as a dependent-view picture. Furthermore, a 4K2K video frame is converted into resolution extension information with reference to the base-view picture. The generated pictures, audio frame, and resolution extension information are stored in the storage unit  5501 . Thereafter, processing proceeds to step S 5702 . 
     In step S 5702 , the multiplexer  5505  multiplexes the pictures, audio frame, and resolution extension information stored in the storage unit  5501  into one TS. Furthermore, the source packetizer  5506  converts the TS into a source packet sequence and transfers the source packet sequence to the write unit  5507 . Thereafter, processing proceeds to step S 5703 . 
     In step S 5703 , the write unit  5507  accumulates the source packet sequence generated by the source packetizer  5506 . Based on the accumulated source packet sequence, the control unit  5504  designs the arrangement of extents to be recorded on the BDR, such as a BD disc. The write unit  5507  writes the source packet sequences on the BDR, such as a BD disc, in accordance with the arrangement of extents designed by the control unit  5504 . In parallel, the write unit  5507  generates the file entries for the AV stream files within internal memory. Thereafter, processing proceeds to step S 5704 . 
     In step S 5704 , the video encoder  5502  checks whether the picture generated in step S 5701  is at the top of a GOP. If the picture is at the top of a GOP, processing proceeds to step S 5705 . If the picture is not at the top of a GOP, processing proceeds to step S 5706 . 
     In step S 5705 , the picture generated in step S 5701  is at the top of a GOP. Accordingly, the video encoder  5502  transmits the PTS of the picture and two SPNs to the control unit  5504 ; the first SPN is assigned to the top of source packets in which the picture is to be stored; and the second SPN is assigned to the top of source packets in which resolution extension information for the picture is to be stored. The control unit  5504  adds the PTS and the first SPN transmitted by the video encoder  5502  to the entry map as one entry point. Thereafter, processing proceeds to step S 5706 . 
     In step S 5706 , the video encoder  5502  checks whether a video input signal YIN to be decoded exists. If the video input signal YIN exists, processing is repeated from step S 5701 . If the video input signal VIN does not exist, processing proceeds to step S 5707 . 
     In step S 5707 , all of the video input signals VIN to be decoded are converted into multiplexed stream data and recorded on the BDR, such as a BD disc. Accordingly, the write unit  5507  transmits the file entry for each AV stream from internal memory to the BDR, such as a BD disc. On the other hand, the control unit  5504  extracts the stream attribute information from the elementary streams to be multiplexed into the main TS, the sub-TS, and the extended stream and associates the stream attribute information with clip information along with the entry map and the 3D metadata. The 2D clip information file, the DEP clip information file, and the extended clip information file are thus generated. The write unit  5507  thus records these clip information files on the BDR, such as a BD disc. Thereafter, processing proceeds to step S 5708 . 
     In step S 5708 , the control unit  5504  uses the 2D clip information file, the DEP clip information file, and the extended clip information file to generate the 2D playlist file, the 3D playlist file, and the extended playlist file. The write unit  5507  records these playlist files on the BDR, such as a BD disc. Processing then terminates. 
     Embodiment 3 
     The recording device described in Embodiment 3 of the present invention is called an authoring device and records a content on a BD-ROM disc using the arrangement of extents according to Embodiment 1 of the present invention. The authoring device is generally located at a creation studio and used by authoring staff to create content to be distributed. First, in response to operations by the authoring staff, the recording device converts content into AV stream files using a predetermined compression encoding method. The content is expressed as both 2D video images at 4K2K and as full HD 3D video images. Next, the recording device generates a scenario. Then, the recording device generates a volume image for a BD-ROM disc from the AV stream files and scenario. Finally, the recording device records the value image on a BD-ROM disc. 
     Structure of Recording Device 
       FIG. 58  is a functional block diagram of a recording device according to Embodiment 3 of the present invention. As shown in  FIG. 58 , the recording device  5800  includes a database unit  5801 , video encoder  5802 , material creation unit  5803 , scenario generation unit  5804 , BD program creation unit  5805 , multiplex processing unit  5806 , and format processing unit  5807 . 
     The database unit  5801  is a nonvolatile storage device embedded in the recording device  5800  and is in particular an HDD. Alternatively, the database unit  5801  may be an external HDD connected to the recording device  5800 , or a nonvolatile semiconductor memory device internal or external to the recording device  5800 . 
     The video encoder  5802  is dedicated hardware for encoding of video data. Alternatively, the video encoder  5802  may be an element that functions by the CPU internal to the recording device  5800  executing specific software. The video encoder  5802  receives video data, such as uncompressed bit map data, from the authoring staff and compresses the received video data in accordance with a compression encoding method such as MPEG-4 AVC or MPEG-2. The video data is thus converted into a combination of a base-view video stream, a dependent-view video stream, and an extended stream. The converted video streams  5811  and the extended stream  5812  are stored in the database unit  5801 . 
     Like the video encoder  5502  shown in  FIG. 55 , the video encoder  5802  converts the 3D video image data into a pair of a base-view video stream and a dependent-view video stream. In particular, the video encoder  5802  calculates depth information of each 3D video image based on motion vectors between the left view and the right view and generates the depth map stream with reference to the depth information. The video encoder  5802  also refers to the base-view video stream obtained by encoding the 3D video image data to generate the extended stream that includes resolution extension information from the 2D video image data at 4K2K. 
     The material creation unit  5803  creates elementary streams other than the video stream  5811  and the extended stream  5812 , such as an audio stream  5813 , PG stream  5814 , and IG stream  5815  and stores the created streams in the database unit  5801 . For example, the material creation unit  5803  receives uncompressed LPCM audio data from the authoring staff, encodes the uncompressed LPCM audio data in accordance with a compression encoding method such as AC-3, and converts the encoded LPCM audio data into the audio stream  5813 . When a DTS-HD extended audio stream is generated as the audio stream, each audio frame is separated into a DTS-HD core audio frame and an extended portion. The former is stored in the audio stream, and the latter is stored in the extended stream. The material creation unit  5803  additionally receives a subtitle information file from the authoring staff and generates the PG stream  5814  in accordance with the subtitle information file. The subtitle information file defines image data or text data for showing subtitles, display timings of the subtitles, and visual effects to be added to the subtitles, such as fade-in/out. Furthermore, the material creation unit  5803  receives bit map data and a menu file from the authoring staff and generates the IG stream  5815  in accordance with the bit map data and the menu file. The bit map data shows images that are to be displayed on a menu. The menu file defines how each button on the menu is to be transitioned from one status to another and defines visual effects to be added to each button. 
     The scenario generation unit  5804  generates scenario data  5816  in response to an instruction received from the authoring staff via a GUI and then stores the created scenario data  5816  in the database unit  5801 . The scenario data  5816  includes an index file, an MV object file, and a playlist file and specifies the playback method of the elementary streams  5811 - 5815  stored in the database unit  5801 . The scenario generation unit  5804  further generates a parameter file PRF and transfers the generated parameter file PRF to the multiplex processing unit  5806 . The parameter file PRF defines, from among the elementary streams  5811 - 5815  stored in the database unit  5801 , the elementary streams to be respectively multiplexed into the main TS, the sub-TS, and the extended stream. 
     The BD program creation unit  5805  provides the authoring staff with a programming environment for programming BD-J objects and Java application programs. The BD program creation unit  5805  receives a request from a user via a GUI and generates each program&#39;s source code according to the request. The BD program creation unit  5805  further generates BD-J object files from the BD-J objects and compresses the Java application programs in JAR files. The program files BDP are transferred to the format processing unit  5807 . 
     The multiplex processing unit  5806  multiplexes the elementary streams  5811 - 5815  stored in the database unit  5801  as stream data in MPEG2-TS format in accordance with a parameter file PRF. Specifically, as shown in  FIG. 5 , each of the elementary streams  5811 - 5815  is first converted into a series of source packets. Next, the series of source packet are multiplex into a single series of multiplexed stream data. The main TS, the sub-TS, and the extended stream are thus generated. These pieces of multiplexed stream data MSD are output to the format processing unit  5807 . 
     The multiplex processing unit  5806  then generates a 2D clip information file, a DEP clip information file, and an extended clip information file by the following four steps (I)-(IV). (I) An entry map is generated for each of the file  2 D, the file DEP, and the extended clip information file. (II) Extent start points are generated by referring to the entry map of each clip information file. At this point, extent ATC times are aligned between extent pairs. Furthermore, the multiplex processing unit  5806  designs the arrangement of extents so that the size of each base-view extent, dependent-view extent, and extended extent satisfies conditions 1-6. In particular, immediately before or immediately after locations where a long jump is necessary, an extended data specific section, a monoscopic video specific section, and a stereoscopic video specific section are provided, as in arrangement  1  shown in  FIG. 14  or arrangement  2  shown in  FIG. 15 . (III) The multiplex processing unit  5806  extracts the stream attribute information from elementary streams to be multiplexed into the main TS, the sub-TS, and the extended stream. (IV) A combination of the entry map, 3D metadata, and stream attribute information is associated with the clip information. Each clip information file CLI is thus generated and transmitted to the format processing unit  5807 . 
     The format processing unit  5807  creates a BD-ROM disc image  5820  from (i) the scenario data  5816  stored in the database unit  5801 , (ii) program files BDP such as BD-J object files created by the BD program creation unit  5805 , and (iii) multiplexed stream data MSD and clip information files CLI generated by the multiplex processing unit  5806 . 
     The format processing unit  5807  stores the multiplexed stream data MSD in the file  2 D, the file DEP, the file SS, and the extended stream file. When generating the file entries of these AV stream files, the format processing unit  5807  refers to the entry map and the 3D metadata included in the clip information file. Each SPN for entry points and extent start points is thereby used in creating allocation descriptors. In particular, the value of the LBN and the extent size to be represented by each allocation descriptor are determined in accordance with the arrangement of extents designed by the multiplex processing unit  5806  so as to express an interleaved arrangement like the one shown in  FIG. 11 . 
     Authoring of BD-ROM Disc 
       FIG. 59  is a flowchart of a method for recording content on a BD-ROM disc using the recording device  5800  shown in  FIG. 58 . This method begins, for example, when power to the recording device  5800  is turned on. 
     In step S 5801 , the elementary streams, programs, and scenario data to be recorded on a BD-ROM disc are generated. In other words, the video encoder  5802  generates a video stream  5811  and an extended stream  5812 . The material creation unit  5803  generates an audio stream  5813 , PG stream  5814 , and IG stream  5815 . The scenario generation unit  5804  generates scenario data  5816 . These created pieces of data  5811 - 5816  are stored in the database unit  5801 . The scenario generation unit  5804  also generates a parameter file PRF and transfers the generated parameter file PRF to the multiplex processing unit  5806 . The BD program creation unit  5805  generates program files BDP, which include BD-J object files and JAR files, and transfers the program files BDP to the format processing unit  5807 . 
     Thereafter, processing proceeds to step S 5802 . 
     In step S 5802 , the multiplex processing unit  5806  reads the elementary streams  5811 - 5815  from the database unit  5801  in accordance with a parameter file PRF and multiplexes the elementary streams into stream data in MPEG2-TS format. Thereafter, processing proceeds to step S 5803 . 
     In step S 5803 , the multiplex processing unit  5806  then generates a 2D clip information file, a DEP clip information file, and an extended clip information file. Furthermore, the multiplex processing unit  5806  sets the size of each base-view extent, dependent-view extent, and extended extent so as to satisfy conditions 1-6. Thereafter, processing proceeds to step S 5804 . 
     In step S 5804 , the format processing unit  5807  creates a BD-ROM disc image  5820  from the scenario data  5816 , program files BDP, multiplexed stream data MDS, and clip information file CLI. In particular, when the multiplexed stream data MDS is stored in an AV stream file, the value of the LBN and the extent size to be represented by each allocation descriptor in the file entry are determined in accordance with the arrangement of extents designed by the multiplex processing unit  5806  so as to express an interleaved arrangement like the one shown in  FIG. 11 . Thereafter, processing proceeds to step S 5805 . 
     In step S 5805 , the BD-ROM disc image  5820  is converted into data for BD-ROM pressing. This data is recorded on a master BD-ROM disc by a mastering device. Thereafter, processing proceeds to step S 5806 . 
     In step S 5806 , BD-ROM discs  101  are mass produced by pressing the master obtained in step S 5805 . Processing thus concludes. 
     Supplement 
     File System on Recording Medium 
     When UDF is used as the file system for the recording medium, a data recording area such as the volume area  202 B of the BD-ROM disc  101  shown in  FIG. 2  generally includes areas in which a plurality of directories, a file set descriptor, and a terminating descriptor are respectively recorded. Each “directory” is a data group composing the directory. A “file set descriptor” indicates the LBN of the sector in which a file entry for the root directory is stored. The “terminating descriptor” indicates the end of the recording area for the file set descriptor. 
     Each directory shares a common data structure. In particular, each directory includes a file entry, directory file, and subordinate files. 
     The “file entry” includes a descriptor tag, Information Control Block (ICB) tag, and allocation descriptor. The “descriptor tag” indicates that the type of the data that includes the descriptor tag is a file entry. For example, when the value of the descriptor tag is “261,” the type of that data is a file entry. The “ICB tag” indicates attribute information for the file entry itself. The “allocation descriptor” indicates the LBN of the sector on which the directory file belonging to the same directory is recorded. 
     The “directory file” typically includes a plurality of each of a file identifier descriptor for a subordinate directory and a file identifier descriptor for a subordinate file. The “file identifier descriptor for a subordinate directory” is information for accessing the subordinate directory located directly below that directory. This file identifier descriptor includes identification information for the subordinate directory, directory name length, file entry address, and actual directory name. In particular, the file entry address indicates the LBN of the sector on which the file entry of the subordinate directory is recorded. The “file identifier descriptor for a subordinate file” is information for accessing the subordinate file located directly below that directory. This file identifier descriptor includes identification information for the subordinate file, file name length, file entry address, and actual file name. In particular, the file entry address indicates the LBN of the sector on which the file entry of the subordinate file is recorded. The “file entry of the subordinate file,” as described below, includes address information for the data constituting the actual subordinate file. 
     By tracing the file set descriptors and the file identifier descriptors of subordinate directories/files in order, the file entry of an arbitrary directory/file recorded on the recording medium can be accessed. Specifically, the file entry of the root directory is first specified from the file set descriptor, and the directory file for the root directory is specified from the allocation descriptor in this file entry. Next, the file identifier descriptor for the directory immediately below the root directory is detected from the directory file, and the file entry for that directory is specified from the file entry address therein. Furthermore, the directory file for that directory is specified from the allocation descriptor in the file entry. Subsequently, from within the directory file, the file entry for the subordinate directory or subordinate file is specified from the file entry address in the file identifier descriptor for that subordinate directory or subordinate file. 
     “Subordinate files” include extents and file entries. The “extents” are generally multiple in number and are data sequences whose logical addresses, i.e. LBNs, are consecutive on the disc. The entirety of the extents comprises the actual subordinate file. The “file entry” includes a descriptor tag, ICB tag, and allocation descriptors. The “descriptor tag” indicates that the type of the data that includes the descriptor tag is a file entry. The “ICB tag” indicates attribute information for the file entry itself. The “allocation descriptors” are provided in a one-to-one correspondence with each extent and indicate the arrangement of each extent in the data recording area, specifically the size of each extent and the LBN for the top of the extent. Accordingly, by referring to each allocation descriptor, each extent can be accessed. Also, the two most significant bits of each allocation descriptor indicate whether an extent is actually recorded on the sector for the LBN indicated by the allocation descriptor. Specifically, when the two most significant bits are “0,” an extent has been assigned to the sector and has been actually recorded thereat. When the two most significant bits are “1,” an extent has been assigned to the sector but has not been yet recorded thereat. 
     Like the above-described file system employing a UDF, when each file recorded on the recording medium is divided into a plurality of extents, the file system for the recording medium also generally stores the information showing the locations of the extents, as with the above-mentioned allocation descriptors, in the recording medium. By referring to the information, the location of each extent, particularly the logical address thereof, can be found. 
     Relationship Between Size of Extents and Capacity of Read Buffers 
     Arrangement  1   
       FIGS. 60A and 60B  are graphs showing changes in data amounts stored in the RB 1  and RB 3  when a playback device in extended playback mode plays back video images seamlessly from extents placed in arrangement  1  shown in  FIG. 14 .  FIG. 60C  is a schematic diagram showing the playback path in extended playback mode corresponding to the extents. The playback path is the same as the playback  1433  shown in  FIG. 14 . 
     As shown in  FIGS. 60A and 60C , during the preload period PR T   1  for the extended extent T 1  in the first extended data specific section  1411 , the stored data amount DA 1  in the RB 1  decreases at the first transfer rate R EXT1 . Accordingly, to prevent the stored data amount DA 1  in the RB 1  from reaching zero by the end of the period PR T   1 , the lower limit RB 1   1  on the stored data amount DA 1  in the RB 1  at the end of the read period PR BLK  of data from the first shared section  1401  is expressed in equation (10), using the maximum value of the first transfer rate R EXT1 , i.e. R MAX1 =R TS 1×192/188, and the size S T1  of the extended extent T 1 : 
     
       
         
           
             
               
                 
                   
                     RB 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     
                       1 
                       1 
                     
                   
                   = 
                   
                     
                       
                         
                           S 
                           
                             T 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             1 
                           
                         
                         
                           R 
                           UDEX 
                         
                       
                       × 
                       
                         R 
                         
                           MAX 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           1 
                         
                       
                     
                     = 
                     
                       
                         
                           S 
                           
                             T 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             1 
                           
                         
                         
                           R 
                           UDEX 
                         
                       
                       × 
                       
                         R 
                         
                           TS 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           1 
                         
                       
                       × 
                       
                         
                           192 
                           188 
                         
                         . 
                       
                     
                   
                 
               
               
                 
                   ( 
                   10 
                   ) 
                 
               
             
           
         
       
     
     As further shown in  FIGS. 60A and 60C , during the period PLJ of the long jump J LJ  over the first stereoscopic video specific section  1413  and the layer boundary LB, and during the preload period PR T   2  for the extended extent T 2  in the second extended data specific section  1421 , the stored data amount DA 1  in the RB 1  decreases at the first transfer rate R EXT1 . Accordingly, to prevent the stored data amount DA 1  in the RB 1  from reaching zero by the end of the periods PLJ and PR T   2 , the lower limit RB 1   2  on the stored data amount DA 1  in the RB 1  at the start of the long jump J LJ  is expressed in equation (11), using the maximum value of the first transfer rate R EXT1 , i.e. R MAX1 =R TS1 ×192/188, the maximum jump time T u  of the long jump J LJ , and the size S T2  of the extended extent T 2 . 
     
       
         
           
             
               
                 
                   
                     RB 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     
                       1 
                       2 
                     
                   
                   = 
                   
                     
                       
                         ( 
                         
                           
                             T 
                             LJ 
                           
                           + 
                           
                             
                               S 
                               
                                 T 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 2 
                               
                             
                             
                               R 
                               UDEX 
                             
                           
                         
                         ) 
                       
                       × 
                       
                         R 
                         
                           MAX 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           1 
                         
                       
                     
                     = 
                     
                       
                         ( 
                         
                           
                             T 
                             LJ 
                           
                           + 
                           
                             
                               S 
                               
                                 T 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 2 
                               
                             
                             
                               R 
                               UDEX 
                             
                           
                         
                         ) 
                       
                       × 
                       
                         R 
                         
                           TS 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           1 
                         
                       
                       × 
                       
                         
                           192 
                           188 
                         
                         . 
                       
                     
                   
                 
               
               
                 
                   ( 
                   11 
                   ) 
                 
               
             
           
         
       
     
     As further shown in  FIGS. 60A and 60C , during the period PEX of the jump J EX  over the second stereoscopic video specific section  1423 , during the preload period PR T   3  for the extended extent T 3  in the second shared section  1402 , and during the period PSJ of the jump J SJ  to skip reading of the immediately subsequent dependent-view extent D, the stored data amount DA 1  in the RB 1  decreases at the first transfer rate R EXT1 . Therefore, to prevent the stored data amount DA 1  in the RB 1  from reaching zero by the end of the periods PEX, PR T   3 , and PSJ, the lower limit RB 1   3  on the stored data amount DA 1  in the RB 1  at the start of the jump J EX  is expressed in equation (12), using the maximum value of the first transfer rate R EXT1 , i.e. R MAX1 =R TS 1×192/188, the maximum jump time T EX  and T SJ  of the jumps J EX  and J SJ , and the size S T3  of the extended extent T 3 : 
     
       
         
           
             
               
                 
                   
                     RB 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     
                       1 
                       3 
                     
                   
                   = 
                   
                     
                       
                         ( 
                         
                           
                             T 
                             EX 
                           
                           + 
                           
                             
                               S 
                               
                                 T 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 3 
                               
                             
                             
                               R 
                               UDEX 
                             
                           
                           + 
                           
                             T 
                             SJ 
                           
                         
                         ) 
                       
                       × 
                       
                         R 
                         
                           MAX 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           1 
                         
                       
                     
                     = 
                     
                       
                         ( 
                         
                           
                             T 
                             EX 
                           
                           + 
                           
                             
                               S 
                               
                                 T 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 3 
                               
                             
                             
                               R 
                               UDEX 
                             
                           
                           + 
                           
                             T 
                             SJ 
                           
                         
                         ) 
                       
                       × 
                       
                         R 
                         
                           TS 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           1 
                         
                       
                       × 
                       
                         
                           192 
                           188 
                         
                         . 
                       
                     
                   
                 
               
               
                 
                   ( 
                   12 
                   ) 
                 
               
             
           
         
       
     
     As a result, the capacity RB 1  of the RB 1  should be at least the maximum value among the lower limits RB 1   1 , RB 1   2 , and RB 1   3  expressed in equations (10)-(12):
 
 RB 1≧max( RB 1 1   , RB 1 2   , RB 1 3 ).
 
     As shown in  FIGS. 60B and 60C , during the read period PR BLK  of data from the extent block located last in the first shared section  1401 , the stored data amount DA 3  in the RB 3  decreases at the third transfer rate R EXT3 . During the preload period PR T   1  of the extended extent T 1  in the first extended data specific section  1411 , the extended extent T 1  is not read from the RB 3 . Accordingly, in order to maintain the provision of data from the RB 3  to the system target decoder until the periods PLJ and PR T   1  have elapsed, the lower limit RB 3   1  on the stored data amount DA 3  in the RB 3  at the start of the read period PR BLK  of data from the extent block is expressed in equation (13), using the number n of extent pairs D, B included in the extent block, the size S B  of the base-view extents, the maximum jump time T SJ  of the jump J SJ  to skip reading of the dependent-view extents, the size S T1  of the extended extent T 1 , and the maximum value of the third transfer rate R EXT3 , i.e. R MAX3 =R TS3 ×192/188: 
     
       
         
           
             
               
                 
                   
                     RB 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     
                       3 
                       1 
                     
                   
                   = 
                   
                     
                       
                         { 
                         
                           
                             
                               ( 
                               
                                 
                                   T 
                                   SJ 
                                 
                                 + 
                                 
                                   
                                     S 
                                     B 
                                   
                                   
                                     R 
                                     UDEX 
                                   
                                 
                               
                               ) 
                             
                             × 
                             n 
                           
                           + 
                           
                             
                               S 
                               
                                 T 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 1 
                               
                             
                             
                               R 
                               UDEX 
                             
                           
                         
                         } 
                       
                       × 
                       
                         R 
                         
                           MAX 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           3 
                         
                       
                     
                     = 
                     
                       
                         { 
                         
                           
                             
                               ( 
                               
                                 
                                   T 
                                   SJ 
                                 
                                 + 
                                 
                                   
                                     S 
                                     B 
                                   
                                   
                                     R 
                                     UDEX 
                                   
                                 
                               
                               ) 
                             
                             × 
                             n 
                           
                           + 
                           
                             
                               S 
                               
                                 T 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 1 
                               
                             
                             
                               R 
                               UDEX 
                             
                           
                         
                         } 
                       
                       × 
                       
                         R 
                         
                           TS 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           3 
                         
                       
                       × 
                       
                         
                           192 
                           188 
                         
                         . 
                       
                     
                   
                 
               
               
                 
                   ( 
                   13 
                   ) 
                 
               
             
           
         
       
     
     As further shown in  FIGS. 60B and 60C , during the read period PR B   1  of data from the first monoscopic video specific section  1412  and during the period PLJ of the long jump J LJ  over the first stereoscopic video specific section  1413  and the layer boundary LB, the stored data amount DA 3  in the RB 3  decreases at the third transfer rate R EXT3 . During the preload period PR T   2  of the extended extent T 2  in the second extended data specific section  1421 , the extended extent T 2  is not read from the RB 3 . Accordingly, in order to maintain provision of data from the RB 3  to the system target decoder until the periods PR B   1 , PLJ, and PR T   2  have elapsed, the lower limit RB 3   2  on the stored data amount DA 3  in the RB 3  at the start of the long jump J LJ  is expressed in equation (14), using the size S B1  of the base-view extent in the first monoscopic video specific section  1412 , the maximum jump time T LJ  of the long jump J LJ , the size S T2  of the extended extent T 2 , and the maximum value of the third transfer rate R EXT3 , i.e. R MAX3 =R TS 3×192/188: 
     
       
         
           
             
               
                 
                   
                     RB 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     
                       3 
                       2 
                     
                   
                   = 
                   
                     
                       
                         ( 
                         
                           
                             
                               S 
                               
                                 B 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 1 
                               
                             
                             
                               R 
                               UDEX 
                             
                           
                           + 
                           
                             T 
                             LJ 
                           
                           + 
                           
                             
                               S 
                               
                                 T 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 2 
                               
                             
                             
                               R 
                               UDEX 
                             
                           
                         
                         ) 
                       
                       × 
                       
                         R 
                         
                           MAX 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           3 
                         
                       
                     
                     = 
                     
                       
                         ( 
                         
                           
                             
                               S 
                               
                                 B 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 1 
                               
                             
                             
                               R 
                               UDEX 
                             
                           
                           + 
                           
                             T 
                             LJ 
                           
                           + 
                           
                             
                               S 
                               
                                 T 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 2 
                               
                             
                             
                               R 
                               UDEX 
                             
                           
                         
                         ) 
                       
                       × 
                       
                         R 
                         
                           TS 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           3 
                         
                       
                       × 
                       
                         
                           192 
                           188 
                         
                         . 
                       
                     
                   
                 
               
               
                 
                   ( 
                   14 
                   ) 
                 
               
             
           
         
       
     
     As further shown in  FIGS. 60B and 60C , during the read period PR B   2  of data from the second monoscopic video specific section  1422  and during the period PEX of the jump J EX  over the second stereoscopic video specific section  1423 , the stored data amount DA 3  in the RB 3  decreases at the third transfer rate R EXT3 . Furthermore, during the preload period PR T   3  of the extended extent T 3  in the second shared section  1402  and during the period PSJ of the jump J SJ  to skip reading of the immediately subsequent dependent-view extent D, the extended extent T 3  is not read from the RB 3 . Accordingly, in order to maintain provision of data from the RB 3  to the system target decoder until the periods PR B   2 , PEX, PR T   3 , and PSJ have elapsed, the lower limit RB 3   3  on the stored data amount DA 3  in the RB 3  at the start of the read period PR B   2  of data from the second monoscopic video specific section  1422  is expressed in equation (15), using the size S B2  of the base-view extent in the second monoscopic video specific section  1422 , the maximum jump times T EX  and T SJ  of the jumps J EX  and J SJ , the size S T3  of the extended extent T 3 , and the maximum value of the third transfer rate R EXT3 , i.e. R MAX3 =R TS 3×192/188: 
     
       
         
           
             
               
                 
                   
                     RB 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     
                       3 
                       3 
                     
                   
                   = 
                   
                     
                       
                         ( 
                         
                           
                             
                               S 
                               
                                 B 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 2 
                               
                             
                             
                               R 
                               UDEX 
                             
                           
                           + 
                           
                             T 
                             EX 
                           
                           + 
                           
                             
                               S 
                               
                                 T 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 3 
                               
                             
                             
                               R 
                               UDEX 
                             
                           
                           + 
                           
                             T 
                             
                               S 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               J 
                             
                           
                         
                         ) 
                       
                       × 
                       
                         R 
                         
                           MAX 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           3 
                         
                       
                     
                     = 
                     
                       
                         ( 
                         
                           
                             
                               S 
                               
                                 B 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 2 
                               
                             
                             
                               R 
                               UDEX 
                             
                           
                           + 
                           
                             T 
                             EX 
                           
                           + 
                           
                             
                               S 
                               
                                 T 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 3 
                               
                             
                             
                               R 
                               UDEX 
                             
                           
                           + 
                           
                             T 
                             SJ 
                           
                         
                         ) 
                       
                       × 
                       
                         R 
                         
                           TS 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           3 
                         
                       
                       × 
                       
                         
                           192 
                           188 
                         
                         . 
                       
                     
                   
                 
               
               
                 
                   ( 
                   15 
                   ) 
                 
               
             
           
         
       
     
     The extended extents T 1  and T 2  read from the extended data specific sections  1411  and  1421  into the RB 3  are not transmitted from the RB 3  until reading of the extended extents T 1  and T 2  is complete. Accordingly, the lower limits RB 3   2  and RB 3   3  on the stored data amount DA 3  in the RB 3  at the end of preloading of the extended extents T 1  and T 2  should be at least the maximum extent sizes maxS T1  and maxS T2  of the extended extents T 1  and T 2 :
 
 RB 3 2 ≧max S   T1   , RB 3 3 ≧max  S   T2 .  (16)
 
     The extended extent T 3  read from the second shared section  1402  is not transferred from the RB 3  until the jump period PSJ immediately subsequent to reading has elapsed. Accordingly, the lower limit RB 3   4  of the stored data amount DA 3  in the RB 3  at the start of the jump period PSJ is expressed as the sum of the maximum extent size maxS T3  of the extended extent T 3  and the data amount T SJ  X R MAX3  provided from the RB 3  to the system target decoder during the jump period PSJ: 
     
       
         
           
             
               
                 
                   
                     RB 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     
                       3 
                       4 
                     
                   
                   = 
                   
                     
                       
                         max 
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         
                           S 
                           
                             T 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             3 
                           
                         
                       
                       + 
                       
                         
                           T 
                           
                             S 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             1 
                           
                         
                         × 
                         
                           R 
                           
                             MAX 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             3 
                           
                         
                       
                     
                     = 
                     
                       
                         max 
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         
                           S 
                           
                             T 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             3 
                           
                         
                       
                       + 
                       
                         
                           T 
                           
                             S 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             1 
                           
                         
                         × 
                         
                           R 
                           
                             TS 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             3 
                           
                         
                         × 
                         
                           
                             192 
                             188 
                           
                           . 
                         
                       
                     
                   
                 
               
               
                 
                   ( 
                   17 
                   ) 
                 
               
             
           
         
       
     
     As a result, the capacity RB 3  of the RB 3  should be at least the maximum value among the lower limits RB 3   1 , RB 3   2 , RB 3   3 , and RB 3   4  expressed in equations (13)-(17): 
               RB   ⁢           ⁢   3     ≥       max   ⁡     (       RB   ⁢           ⁢     3   1       ,     RB   ⁢           ⁢     3   2       ,     RB   ⁢           ⁢     3   3       ,     max   ⁢           ⁢     S     T   ⁢           ⁢   1         ,     max   ⁢           ⁢     S     T   ⁢           ⁢   2         ,       max   ⁢           ⁢     S     T   ⁢           ⁢   3         +       T   SJ     ×     R     TS   ⁢           ⁢   3       ×     192   188           )       .           
Arrangement  2 
 
       FIGS. 61A and 61B  are graphs showing changes in data amounts stored in the RB 2  and RB 3  when a playback device in extended playback mode plays back video images seamlessly from extents placed in arrangement  2  shown in  FIG. 15 .  FIG. 61C  is a schematic diagram showing the playback path in extended playback mode corresponding to the extents. The playback path is the same as the playback  1533  shown in  FIG. 15 . 
     As shown in  FIGS. 61A and 61C , during the preload period PR T   1  for the extended extent T 1  in the first extended data specific section  1411 , and during the period P EX1  of the jump J EX1  over the first stereoscopic video specific section  1513 , the stored data amount DA 1  in the RB 1  decreases at the first transfer rate R EXT1 . 
     Accordingly, to prevent the stored data amount DA 1  in the RB 1  from reaching zero by the end of the periods PR T   1  and P EX1 , the lower limit RB 1   1  on the stored data amount DA 1  in the RB 1  at the end of the read period PR BLK  of data from the first shared section  1401  is expressed in equation (18), using the maximum value of the first transfer rate R EXT1 , i.e. R MAX1 =R TS 1×192/188, the size S T1  of the extended extent T 1 , and the maximum jump time T EX1  of the jump J EX1 : 
     
       
         
           
             
               
                 
                   
                     RB 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     
                       1 
                       1 
                     
                   
                   = 
                   
                     
                       
                         ( 
                         
                           
                             
                               S 
                               
                                 T 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 1 
                               
                             
                             
                               R 
                               UDEX 
                             
                           
                           + 
                           
                             T 
                             
                               EX 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               1 
                             
                           
                         
                         ) 
                       
                       × 
                       
                         R 
                         
                           MAX 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           1 
                         
                       
                     
                     = 
                     
                       
                         ( 
                         
                           
                             
                               S 
                               
                                 T 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 1 
                               
                             
                             
                               R 
                               UDEX 
                             
                           
                           + 
                           
                             T 
                             
                               EX 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               1 
                             
                           
                         
                         ) 
                       
                       × 
                       
                         R 
                         
                           TS 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           1 
                         
                       
                       × 
                       
                         
                           192 
                           188 
                         
                         . 
                       
                     
                   
                 
               
               
                 
                   ( 
                   18 
                   ) 
                 
               
             
           
         
       
     
     As further shown in  FIGS. 61A and 61C , during the period PLJ of the long jump J LJ  for skipping the layer boundary LB, during the preload period PR T   2  for the extended extent T 2  in the second extended data specific section  1421 , and during the period P EX2  of the jump J EX2  over the second stereoscopic video specific section  1523 , the stored data amount DA 1  in the RB 1  decreases at the first transfer rate R EXT1 . Accordingly, to prevent the stored data amount DA 1  in the RB 1  from reaching zero by the end of the periods PLJ, PR T   2 , and P EX2 , the lower limit RB 1   2  on the stored data amount DA 1  in the RB 1  at the start of the long jump J LJ  is expressed in equation (19), using the maximum value of the first transfer rate R EXT1 , i.e. R MAX1 =R TS 1×192/188, the maximum jump time T LJ  of the long jump J LJ , the size S T2  of the extended extent T 2 , and the maximum jump time T EX2  of the jump J EX2 : 
     
       
         
           
             
               
                 
                   
                     RB 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     
                       1 
                       2 
                     
                   
                   = 
                   
                     
                       
                         ( 
                         
                           
                             T 
                             LJ 
                           
                           + 
                           
                             
                               S 
                               
                                 T 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 2 
                               
                             
                             
                               R 
                               UDEX 
                             
                           
                           + 
                           
                             T 
                             
                               EX 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               2 
                             
                           
                         
                         ) 
                       
                       × 
                       
                         R 
                         
                           MAX 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           1 
                         
                       
                     
                     = 
                     
                       
                         ( 
                         
                           
                             T 
                             LJ 
                           
                           + 
                           
                             
                               S 
                               
                                 T 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 2 
                               
                             
                             
                               R 
                               UDEX 
                             
                           
                           + 
                           
                             T 
                             
                               EX 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               2 
                             
                           
                         
                         ) 
                       
                       × 
                       
                         R 
                         
                           TS 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           1 
                         
                       
                       × 
                       
                         
                           192 
                           188 
                         
                         . 
                       
                     
                   
                 
               
               
                 
                   ( 
                   19 
                   ) 
                 
               
             
           
         
       
     
     As further shown in  FIGS. 61A and 61C , during the preload period PR T   3  for the extended extent T 3  in the second shared section  1402 , and during the period PSJ of the jump J SJ  to skip reading of the immediately subsequent dependent-view extent D, the stored data amount DA 1  in the RB 1  decreases at the first transfer rate R EXT1 . Therefore, to prevent the stored data amount DA 1  in the RB 1  from reaching zero by the end of the periods PR T   3  and PSJ, the lower limit RB 1   3  on the stored data amount DA 1  in the RB 1  at the start of preloading of the extended extent T 3  in the second shared section  1402  is expressed in equation (20), using the maximum value of the first transfer rate R EXT1 , i.e. R MAX1 =R TS 1×192/188, the maximum jump time T SJ  of the jump J SJ , and the size S T3  of the extended extent T 3 : 
     
       
         
           
             
               
                 
                   
                     RB 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     
                       1 
                       3 
                     
                   
                   = 
                   
                     
                       
                         ( 
                         
                           
                             
                               S 
                               
                                 T 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 3 
                               
                             
                             
                               R 
                               UDEX 
                             
                           
                           + 
                           
                             T 
                             SJ 
                           
                         
                         ) 
                       
                       × 
                       
                         R 
                         
                           MAX 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           1 
                         
                       
                     
                     = 
                     
                       
                         ( 
                         
                           
                             
                               S 
                               
                                 T 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 3 
                               
                             
                             
                               R 
                               UDEX 
                             
                           
                           + 
                           
                             T 
                             SJ 
                           
                         
                         ) 
                       
                       × 
                       
                         R 
                         
                           TS 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           1 
                         
                       
                       × 
                       
                         
                           192 
                           188 
                         
                         . 
                       
                     
                   
                 
               
               
                 
                   ( 
                   20 
                   ) 
                 
               
             
           
         
       
     
     As a result, the capacity RB 1  of the RB 1  should be at least the maximum value among the lower limits RB 1   1 , RB 1   2 , and RB 1   3  expressed in equations (18)-(20):
 
 RB 1≧max( RB 1 1   , RB 1 2   , RB 1 3 ).
 
     As shown in  FIGS. 61B and 61C , during the read period PR BLK  of data from the extent block located last in the first shared section  1401 , the stored data amount DA 3  in the RB 3  decreases at the third transfer rate R EXT3 . During the preload period PR T   1  of the extended extent T 1  in the first extended data specific section  1411 , and during the period P EX1  of the jump J EX1  over the first stereoscopic video specific section  1513 , the extended extent T 1  is not read from the RB 3 . Accordingly, in order to maintain the provision of data from the RB 3  to the system target decoder until the periods PR 1  and P EX1  have elapsed, the lower limit RB 3   1  on the stored data amount DA 3  in the RB 3  at the start of the read period PR BLK  of data from the extent block is expressed in equation (21), using the number n of extent pairs D, B included in the extent block, the size S B  of the base-view extents, the maximum jump time T SJ  of the jump J SJ  to skip reading of the dependent-view extents, the size S T1  of the extended extent T 1 , the maximum jump time T EX1  of the jump J EX1  over the first stereoscopic video specific section  1513 , and the maximum value of the third transfer rate R EXT3 , i.e. R MAX3 =R TS 3×192/188: 
     
       
         
           
             
               
                 
                   
                     RB 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     
                       3 
                       1 
                     
                   
                   = 
                   
                     
                       
                         { 
                         
                           
                             
                               ( 
                               
                                 
                                   T 
                                   SJ 
                                 
                                 + 
                                 
                                   
                                     S 
                                     B 
                                   
                                   
                                     R 
                                     UDEX 
                                   
                                 
                               
                               ) 
                             
                             × 
                             n 
                           
                           + 
                           
                             
                               S 
                               
                                 T 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 1 
                               
                             
                             
                               R 
                               UDEX 
                             
                           
                           + 
                           
                             T 
                             
                               EX 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               1 
                             
                           
                         
                         } 
                       
                       × 
                       
                         R 
                         
                           MAX 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           3 
                         
                       
                     
                     = 
                     
                       { 
                       
                         
                           ( 
                           
                             
                               T 
                               SJ 
                             
                             + 
                             
                               
                                 
                                   S 
                                   B 
                                 
                                 
                                   R 
                                   UDEX 
                                 
                               
                               × 
                               n 
                             
                             + 
                             
                               
                                 S 
                                 
                                   T 
                                   ⁢ 
                                   
                                       
                                   
                                   ⁢ 
                                   1 
                                 
                               
                               
                                 R 
                                 UDEX 
                               
                             
                             + 
                             
                               T 
                               
                                 EX 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 1 
                               
                             
                           
                           } 
                         
                         × 
                         
                           R 
                           
                             TS 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             1 
                           
                         
                         × 
                         
                           
                             192 
                             188 
                           
                           . 
                         
                       
                     
                   
                 
               
               
                 
                   ( 
                   21 
                   ) 
                 
               
             
           
         
       
     
     As further shown in  FIGS. 60B and 60C , during the jump period P EX1  over the first stereoscopic video specific section  1513 , during the read period PR B   1  of data from the first monoscopic video specific section  1512 , and during the period PLJ of the long jump J LJ  over the layer boundary LB, the stored data amount DA 3  in the RB 3  decreases at the third transfer rate R EXT3 . During the preload period PR T   2  of the extended extent T 2  in the second extended data specific section  1421 , and during the period P EX2  of the jump J EX2  over the second stereoscopic video specific section  1523 , the extended extent T 2  is not read from the RB 3 . Accordingly, in order to maintain provision of data from the RB 3  to the system target decoder until the periods P EX1 , PR B   1 , PLJ, PR T   2 , and P EX2  have elapsed, the lower limit RB 3   2  on the stored data amount DA 3  in the RB 3  at the start of the jump J EX1  is expressed in equation (22), using the size S B1  of the base-view extent in the first monoscopic video specific section  1512 , the maximum jump times T EX1 , T LJ  and T EX2  of the jumps J EX1 , J LJ , and J EX2 , the size S T2  of the extended extent T 2 , and the maximum value of the third transfer rate R EXT3 , i.e. R MAX3 =R TS 3×192/188: 
     
       
         
           
             
               
                 
                   
                     RB 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     
                       3 
                       2 
                     
                   
                   = 
                   
                     
                       
                         ( 
                         
                           
                             T 
                             
                               EX 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               1 
                             
                           
                           + 
                           
                             
                               S 
                               
                                 B 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 1 
                               
                             
                             
                               R 
                               UDEX 
                             
                           
                           + 
                           
                             T 
                             LJ 
                           
                           + 
                           
                             
                               S 
                               
                                 T 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 2 
                               
                             
                             
                               R 
                               UDEX 
                             
                           
                           + 
                           
                             T 
                             
                               EX 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               2 
                             
                           
                         
                         ) 
                       
                       × 
                       
                         R 
                         
                           MAX 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           3 
                         
                       
                     
                     = 
                     
                       
                         ( 
                         
                           
                             T 
                             
                               EX 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               1 
                             
                           
                           + 
                           
                             
                               S 
                               
                                 B 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 1 
                               
                             
                             
                               R 
                               UDEX 
                             
                           
                           + 
                           
                             T 
                             LJ 
                           
                           + 
                           
                             
                               S 
                               
                                 T 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 3 
                               
                             
                             
                               R 
                               UDEX 
                             
                           
                           + 
                           
                             T 
                             
                               EX 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               2 
                             
                           
                         
                         ) 
                       
                       × 
                       
                         R 
                         
                           TS 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           3 
                         
                       
                       × 
                       
                         
                           192 
                           188 
                         
                         . 
                       
                     
                   
                 
               
               
                 
                   ( 
                   22 
                   ) 
                 
               
             
           
         
       
     
     As further shown in  FIGS. 61B and 61C , during the period P EX2  of the jump J EX2  over the second stereoscopic video specific section  1523  and during the read period PR B   2  of data from the second monoscopic video specific section  1522 , the stored data amount DA 3  in the RB 3  decreases at the third transfer rate R EXT3 . Furthermore, during the preload period PR T   3  of the extended extent T 3  in the second shared section  1402  and during the period PSJ of the jump J SJ  to skip reading of the immediately subsequent dependent-view extent D, the extended extent T 3  is not read from the RB 3 . Accordingly, in order to maintain provision of data from the RB 3  to the system target decoder until the periods P EX2 , PR B   2 , PR T   3 , and PSJ have elapsed, the lower limit RB 3   3  on the stored data amount DA 3  in the RB 3  at the start of the jump period P EX2  is expressed in equation (23), using the maximum jump times T EX2  and T SJ  of the jumps J EX2  and J SJ , the size S B2  of the base-view extent in the second monoscopic video specific section  1522 , the size S T3  of the extended extent T 3 , and the maximum value of the third transfer rate R EXT3 , i.e. R MAX3 =R TS3 ×192/188: 
     
       
         
           
             
               
                 
                   
                     RB 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     
                       3 
                       3 
                     
                   
                   = 
                   
                     
                       
                         ( 
                         
                           
                             T 
                             
                               EX 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               2 
                             
                           
                           + 
                           
                             
                               S 
                               
                                 B 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 2 
                               
                             
                             
                               R 
                               UDEX 
                             
                           
                           + 
                           
                             
                               S 
                               
                                 T 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 3 
                               
                             
                             
                               R 
                               UDEX 
                             
                           
                           + 
                           
                             T 
                             SJ 
                           
                         
                         ) 
                       
                       × 
                       
                         R 
                         
                           MAX 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           3 
                         
                       
                     
                     = 
                     
                       
                         ( 
                         
                           
                             T 
                             
                               EX 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               2 
                             
                           
                           + 
                           
                             
                               S 
                               
                                 B 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 2 
                               
                             
                             
                               R 
                               UDEX 
                             
                           
                           + 
                           
                             
                               S 
                               
                                 T 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 3 
                               
                             
                             
                               R 
                               UDEX 
                             
                           
                           + 
                           
                             T 
                             SJ 
                           
                         
                         ) 
                       
                       × 
                       
                         R 
                         
                           TS 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           3 
                         
                       
                       × 
                       
                         
                           192 
                           188 
                         
                         . 
                       
                     
                   
                 
               
               
                 
                   ( 
                   23 
                   ) 
                 
               
             
           
         
       
     
     The extended extent T 1  read from the first extended data specific section  1411  is not transferred from the RB 3  until the jump period P EX1  immediately subsequent to reading has elapsed. Accordingly, the lower limit RB 3   2  of the stored data amount DA 3  in the RB 3  at the start of the jump period P EX1  should be at least the sum of the maximum extent size maxS T1  of the extended extent T 1  and the data amount T EX1  X R MAX3  provided from the RB 3  to the system target decoder during the jump period P EX1 : 
     
       
         
           
             
               
                 
                   
                     
                       RB 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       
                         3 
                         2 
                       
                     
                     ≥ 
                     
                       
                         max 
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         
                           S 
                           
                             T 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             1 
                           
                         
                       
                       + 
                       
                         
                           T 
                           
                             EX 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             1 
                           
                         
                         × 
                         
                           R 
                           
                             MAX 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             3 
                           
                         
                       
                     
                   
                   = 
                   
                     
                       max 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       
                         S 
                         
                           T 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           1 
                         
                       
                     
                     + 
                     
                       
                         T 
                         
                           EX 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           1 
                         
                       
                       × 
                       
                         R 
                         
                           TS 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           3 
                         
                       
                       × 
                       
                         
                           192 
                           188 
                         
                         . 
                       
                     
                   
                 
               
               
                 
                   ( 
                   24 
                   ) 
                 
               
             
           
         
       
     
     The extended extent T 2  read from the second extended data specific section  1421  is not transferred from the RB 3  until the jump period P EX2  immediately subsequent to reading has elapsed. Accordingly, the lower limit RB 3   3  of the stored data amount DA 3  in the RB 3  at the start of the jump period P EX2  should be at least the sum of the maximum extent size maxS T2  of the extended extent T 2  and the data amount T EX2  X R MAX3  provided from the RB 3  to the system target decoder during the jump period P EX2 : 
     
       
         
           
             
               
                 
                   
                     
                       RB 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       
                         3 
                         3 
                       
                     
                     ≥ 
                     
                       
                         max 
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         
                           S 
                           
                             T 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             2 
                           
                         
                       
                       + 
                       
                         
                           T 
                           
                             EX 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             2 
                           
                         
                         × 
                         
                           R 
                           
                             MAX 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             3 
                           
                         
                       
                     
                   
                   = 
                   
                     
                       max 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       
                         S 
                         
                           T 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           2 
                         
                       
                     
                     + 
                     
                       
                         T 
                         
                           EX 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           2 
                         
                       
                       × 
                       
                         R 
                         
                           TS 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           3 
                         
                       
                       × 
                       
                         
                           192 
                           188 
                         
                         . 
                       
                     
                   
                 
               
               
                 
                   ( 
                   25 
                   ) 
                 
               
             
           
         
       
     
     The extended extent T 3  read from the second shared section  1402  is not transferred from the RB 3  until the jump period PSJ immediately subsequent to reading has elapsed. Accordingly, the lower limit RB 3   4  of the stored data amount DA 3  in the RB 3  at the start of the jump period PSJ must be the sum of the maximum extent size maxS T3  of the extended extent T 3  and the data amount T SJ ×R MAX3  provided from the RB 3  to the system target decoder during the jump period PSJ: 
     
       
         
           
             
               
                 
                   
                     RB 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     
                       3 
                       4 
                     
                   
                   = 
                   
                     
                       
                         max 
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         
                           S 
                           
                             T 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             3 
                           
                         
                       
                       + 
                       
                         
                           T 
                           SJ 
                         
                         × 
                         
                           R 
                           
                             MAX 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             3 
                           
                         
                       
                     
                     = 
                     
                       
                         max 
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         
                           S 
                           
                             T 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             3 
                           
                         
                       
                       + 
                       
                         
                           T 
                           SJ 
                         
                         × 
                         
                           R 
                           
                             TS 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             3 
                           
                         
                         × 
                         
                           
                             192 
                             188 
                           
                           . 
                         
                       
                     
                   
                 
               
               
                 
                   ( 
                   26 
                   ) 
                 
               
             
           
         
       
     
     As a result, the capacity RB 3  of the RB 3  should be at least the maximum value among the lower limits RB 3   1 , RB 3   2 , RB 3   3 , and RB 3   4  expressed in equations (21)-(26): 
               RB   ⁢           ⁢   3     ≥       max   ⁡     (       RB   ⁢           ⁢     3   1       ,     RB   ⁢           ⁢     3   2       ,     RB   ⁢           ⁢     3   3       ,       max   ⁢           ⁢     S     T   ⁢           ⁢   1         +       T     EX   ⁢           ⁢   1       ×     R     TS   ⁢           ⁢   3       ×     192   188         ,       max   ⁢           ⁢     S     T   ⁢           ⁢   2         +       T     EX   ⁢           ⁢   2       ×     R     TS   ⁢           ⁢   3       ×     192   188         ,       max   ⁢           ⁢     S     T   ⁢           ⁢   3         +       T   SJ     ×     R     TS   ⁢           ⁢   3       ×     192   188           )       .           
When Arrangement  1  is Used Only Immediately Before a Layer Boundary LB
 
       FIG. 62C  is a schematic diagram showing extents when an extended data specific section, a monoscopic video specific section, and a stereoscopic video specific section are designed only immediately before a layer boundary LB, as well as the playback path in extended playback mode corresponding to the extents. The extents and the playback path are equivalent to those for arrangement  1  shown in  FIG. 14  after removal of the second extended data specific section  1421 , the second monoscopic video specific section  1422 , and the second stereoscopic video specific section  1423 .  FIGS. 62A and 62B  are graphs showing changes in data amounts stored in the RB 1  and RB 3  when a playback device in extended playback mode plays back video images seamlessly from extents shown in  FIG. 62C . 
     As shown in  FIGS. 62A and 62C , during the preload period PR T   1  for the extended extent T 1  in the extended data specific section  1411 , the stored data amount DA 1  in the RB 1  decreases at the first transfer rate R EXT1 . Accordingly, to prevent the stored data amount DA 1  in the RB 1  from reaching zero by the end of the period PR T   1 , the lower limit RB 1   1  on the stored data amount DA 1  in the RB 1  at the end of the read period PR BLK  of data from the first shared section  1401  is expressed in equation (27), using the maximum value of the first transfer rate R EXT1 , i.e. R MAX1 =R TS1 ×192/188, and the size S T1  of the extended extent T 1 : 
     
       
         
           
             
               
                 
                   
                     RB 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     
                       1 
                       1 
                     
                   
                   = 
                   
                     
                       
                         
                           S 
                           
                             T 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             1 
                           
                         
                         
                           R 
                           UDEX 
                         
                       
                       × 
                       
                         R 
                         
                           MAX 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           1 
                         
                       
                     
                     = 
                     
                       
                         
                           S 
                           
                             T 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             1 
                           
                         
                         
                           R 
                           UDEX 
                         
                       
                       × 
                       
                         R 
                         
                           TS 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           1 
                         
                       
                       × 
                       
                         
                           192 
                           188 
                         
                         . 
                       
                     
                   
                 
               
               
                 
                   ( 
                   27 
                   ) 
                 
               
             
           
         
       
     
     As further shown in  FIGS. 62A and 62C , during the period PLJ of the long jump J LJ  over the stereoscopic video specific section  1413 , during the preload period PR T   2  for the extended extent T 2  in the second shared section  1402 , and during the period PSJ of the jump J SJ  to skip reading of the immediately subsequent dependent-view extent D, the stored data amount DA 1  in the RB 1  decreases at the first transfer rate R EXT1 . Accordingly, to prevent the stored data amount DA 1  in the RB 1  from reaching zero by the end of the periods PLJ, PR T   2 , and PSJ, the lower limit RB 1   2  on the stored data amount DA 1  in the RB 1  at the start of the long jump J LJ  is expressed in equation (28), using the maximum value of the first transfer rate R EXT1 , i.e. R MAX1 =R TS 1×192/188, the maximum jump times T u  and T SJ  of the jumps J LJ  and J SJ , and the size S T2  of the extended extent T 2 : 
     
       
         
           
             
               
                 
                   
                     
                       
                         
                           RB 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           
                             1 
                             2 
                           
                         
                         = 
                           
                         ⁢ 
                         
                           
                             ( 
                             
                               
                                 T 
                                 LJ 
                               
                               + 
                               
                                 
                                   S 
                                   
                                     T 
                                     ⁢ 
                                     
                                         
                                     
                                     ⁢ 
                                     2 
                                   
                                 
                                 
                                   R 
                                   UDEX 
                                 
                               
                               + 
                               
                                 T 
                                 SJ 
                               
                             
                             ) 
                           
                           × 
                           
                             R 
                             
                               MAX 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               1 
                             
                           
                         
                       
                     
                   
                   
                     
                       
                         = 
                           
                         ⁢ 
                         
                           
                             ( 
                             
                               
                                 T 
                                 LJ 
                               
                               + 
                               
                                 
                                   S 
                                   
                                     T 
                                     ⁢ 
                                     
                                         
                                     
                                     ⁢ 
                                     2 
                                   
                                 
                                 
                                   R 
                                   UDEX 
                                 
                               
                               + 
                               
                                 T 
                                 SJ 
                               
                             
                             ) 
                           
                           × 
                           
                             R 
                             
                               TS 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               1 
                             
                           
                           × 
                           
                             
                               192 
                               188 
                             
                             . 
                           
                         
                       
                     
                   
                 
               
               
                 
                   ( 
                   28 
                   ) 
                 
               
             
           
         
       
     
     As a result, the capacity RB 1  of the RB 1  should be at least the larger of the lower limits RB 1   1  and RB 1   2  expressed in equations (27) and (28):
 
 RB 1≧max( RB 1 1   , RB 1 2 ).
 
     As shown in  FIGS. 62B and 62C , during the read period PR BLK  of data from the extent block located last in the first shared section  1401 , the stored data amount DA 3  in the RB 3  decreases at the third transfer rate R EXT3 . During the preload period PR T   1  of the extended extent T 1  in the extended data specific section  1411 , the extended extent T 1  is not read from the RB 3 . Accordingly, in order to maintain the provision of data from the RB 3  to the system target decoder until the periods PLJ and PR T   1  have elapsed, the lower limit RB 3   1  on the stored data amount DA 3  in the RB 3  at the start of the read period PR BLK  of data from the extent block is expressed in equation (29), using the number n of extent pairs D, B included in the extent block, the size S B  of the base-view extents, the maximum jump time T SJ  of the jump J SJ  to skip reading of the dependent-view extents, the size S T1  of the extended extent T 1 , and the maximum value of the third transfer rate R EXT3 , i.e. R MAX3 =R TS3 ×192/188: 
     
       
         
           
             
               
                 
                   
                     
                       
                         
                           RB 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           
                             3 
                             1 
                           
                         
                         = 
                           
                         ⁢ 
                         
                           
                             { 
                             
                               
                                 
                                   ( 
                                   
                                     
                                       T 
                                       SJ 
                                     
                                     + 
                                     
                                       
                                         S 
                                         B 
                                       
                                       
                                         R 
                                         UDEX 
                                       
                                     
                                   
                                   ) 
                                 
                                 × 
                                 n 
                               
                               + 
                               
                                 
                                   S 
                                   
                                     T 
                                     ⁢ 
                                     
                                         
                                     
                                     ⁢ 
                                     1 
                                   
                                 
                                 
                                   R 
                                   UDEX 
                                 
                               
                             
                             } 
                           
                           × 
                           
                             R 
                             
                               MAX 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               3 
                             
                           
                         
                       
                     
                   
                   
                     
                       
                         = 
                           
                         ⁢ 
                         
                           
                             { 
                             
                               
                                 
                                   ( 
                                   
                                     
                                       T 
                                       SJ 
                                     
                                     + 
                                     
                                       
                                         S 
                                         B 
                                       
                                       
                                         R 
                                         UDEX 
                                       
                                     
                                   
                                   ) 
                                 
                                 × 
                                 n 
                               
                               + 
                               
                                 
                                   S 
                                   
                                     T 
                                     ⁢ 
                                     
                                         
                                     
                                     ⁢ 
                                     1 
                                   
                                 
                                 
                                   R 
                                   UDEX 
                                 
                               
                             
                             } 
                           
                           × 
                           
                             R 
                             
                               TS 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               3 
                             
                           
                           × 
                           
                             
                               192 
                               188 
                             
                             . 
                           
                         
                       
                     
                   
                 
               
               
                 
                   ( 
                   29 
                   ) 
                 
               
             
           
         
       
     
     As further shown in  FIGS. 62B and 62C , during the read period PR B  of data from the monoscopic video specific section  1412  and during the period PLJ of the long jump J LJ  over the stereoscopic video specific section  1413  and the layer boundary LB, the stored data amount DA 3  in the RB 3  decreases at the third transfer rate R EXT3 . Furthermore, during the preload period PR T   2  of the extended extent T 2  in the second shared section  1402  and during the period PSJ of the jump J SJ  to skip reading of the immediately subsequent dependent-view extent D, the extended extent T 2  is not read from the RB 3 . Accordingly, in order to maintain provision of data from the RB 3  to the system target decoder until the periods PR B , PLJ, PR T   2 , and PSJ have elapsed, the lower limit RB 3   2  on the stored data amount DA 3  in the RB 3  at the start of the long jump J LJ  is expressed in equation (30), using the size S BS  of the base-view extent in the monoscopic video specific section  1412 , the maximum jump times T LJ  and T SJ  of the jumps J LJ  and J SJ , the size S T2  of the extended extent T 2 , and the maximum value of the third transfer rate R EXT3 , i.e. R MAX3 =R TS 3×192/188: 
     
       
         
           
             
               
                 
                   
                     
                       
                         
                           RB 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           
                             3 
                             2 
                           
                         
                         = 
                           
                         ⁢ 
                         
                           
                             ( 
                             
                               
                                 
                                   S 
                                   
                                     B 
                                     ⁢ 
                                     
                                         
                                     
                                     ⁢ 
                                     1 
                                   
                                 
                                 
                                   R 
                                   UDEX 
                                 
                               
                               + 
                               
                                 T 
                                 LJ 
                               
                               + 
                               
                                 
                                   S 
                                   
                                     T 
                                     ⁢ 
                                     
                                         
                                     
                                     ⁢ 
                                     2 
                                   
                                 
                                 
                                   R 
                                   UDEX 
                                 
                               
                               + 
                               
                                 T 
                                 SJ 
                               
                             
                             ) 
                           
                           × 
                           
                             R 
                             
                               MAX 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               3 
                             
                           
                         
                       
                     
                   
                   
                     
                       
                         = 
                           
                         ⁢ 
                         
                           
                             ( 
                             
                               
                                 
                                   S 
                                   
                                     B 
                                     ⁢ 
                                     
                                         
                                     
                                     ⁢ 
                                     1 
                                   
                                 
                                 
                                   R 
                                   UDEX 
                                 
                               
                               + 
                               
                                 T 
                                 LJ 
                               
                               + 
                               
                                 
                                   S 
                                   
                                     T 
                                     ⁢ 
                                     
                                         
                                     
                                     ⁢ 
                                     2 
                                   
                                 
                                 
                                   R 
                                   UDEX 
                                 
                               
                               + 
                               
                                 T 
                                 SJ 
                               
                             
                             ) 
                           
                           × 
                           
                             R 
                             
                               TS 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               3 
                             
                           
                           × 
                           
                             
                               192 
                               188 
                             
                             . 
                           
                         
                       
                     
                   
                 
               
               
                 
                   ( 
                   30 
                   ) 
                 
               
             
           
         
       
     
     The extended extent T 1  read from the extended data specific section  1411  into the RB 3  is not transmitted from the RB 3  until reading of the extended extent T 1  is complete. Accordingly, the lower limit RB 3   2  on the stored data amount DA 3  in the RB 3  at the end of preloading of the extended extent T 12  should be at least the maximum extent size maxS T1  of the extended extent T 1 :
 
 RB 3 2 ≧max  S   T1 .  (31)
 
     The extended extent T 2  read from the second shared section  1402  is not transferred from the RB 3  until the jump period PSJ immediately subsequent to reading has elapsed. Accordingly, the lower limit RB 3   3  of the stored data amount DA 3  in the RB 3  at the start of the jump period PSJ is expressed as the sum of the maximum extent size maxS T2  of the extended extent T 3  and the data amount T SJ ×R MAX3  provided from the RB 3  to the system target decoder during the jump period PSJ: 
     
       
         
           
             
               
                 
                   
                     
                       
                         
                           RB 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           
                             3 
                             3 
                           
                         
                         = 
                           
                         ⁢ 
                         
                           
                             max 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             
                               S 
                               
                                 T 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 2 
                               
                             
                           
                           + 
                           
                             
                               T 
                               SJ 
                             
                             × 
                             
                               R 
                               
                                 MAX 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 3 
                               
                             
                           
                         
                       
                     
                   
                   
                     
                       
                         = 
                           
                         ⁢ 
                         
                           
                             max 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             
                               S 
                               
                                 T 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 2 
                               
                             
                           
                           + 
                           
                             
                               T 
                               SJ 
                             
                             × 
                             
                               R 
                               
                                 TS 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 3 
                               
                             
                             × 
                             
                               
                                 192 
                                 188 
                               
                               . 
                             
                           
                         
                       
                     
                   
                 
               
               
                 
                   ( 
                   32 
                   ) 
                 
               
             
           
         
       
     
     As a result, the capacity RB 3  of the RB 3  should be at least the maximum value among the lower limits RB 3   1 , RB 3   2 , and RB 3   3  expressed in equations (29)-(32): 
               RB   ⁢           ⁢   3     ≥       max   ⁡     (       RB   ⁢           ⁢     3   1       ,     RB   ⁢           ⁢     3   2       ,           ⁢     max   ⁢           ⁢     S     T   ⁢           ⁢   1         ,       max   ⁢           ⁢     S     T   ⁢           ⁢   2         +       T   SJ     ×     R     TS   ⁢           ⁢   3       ×     192   188           )       .           
When Arrangement  2  is Used Only Immediately Before a Layer Boundary LB
 
       FIG. 63C  is a schematic diagram showing extents when the locations of monoscopic and stereoscopic video specific sections are reversed compared to those shown in  FIG. 62C , as well as the playback path in extended playback mode corresponding to the extents. The extents and the playback path are equivalent to those for arrangement  2  shown in  FIG. 15  after removal of the second extended data specific section  1421 , the second monoscopic video specific section  1422 , and the second stereoscopic video specific section  1523 .  FIGS. 63A and 63B  are graphs showing changes in data amounts stored in the RB 1  and RB 3  when a playback device in extended playback mode plays back video images seamlessly from the extents shown in  FIG. 63C . 
     As shown in  FIGS. 63A and 63C , during the preload period PR T   1  for the extended extent T 1  in the extended data specific section  1411 , and during the period PEX for the jump J EX  over the stereoscopic specific section  1513 , the stored data amount DA 1  in the RB 1  decreases at the first transfer rate R EXT1 . Accordingly, to prevent the stored data amount DA 1  in the RB 1  from reaching zero by the end of the periods PR T   1  and PEX, the lower limit RB 1   1  on the stored data amount DA 1  in the RB 1  at the end of the read period PR BLK  of data from the first shared section  1401  is expressed in equation (33), using the maximum value of the first transfer rate R EXT1 , i.e. R MAX1 =R TS1 ×192/188, the size S T1  of the extended extent T 1 , and the maximum jump time T EX  of the jump J EX : 
     
       
         
           
             
               
                 
                   
                     
                       
                         
                           RB 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           
                             1 
                             1 
                           
                         
                         = 
                           
                         ⁢ 
                         
                           
                             ( 
                             
                               
                                 
                                   S 
                                   
                                     T 
                                     ⁢ 
                                     
                                         
                                     
                                     ⁢ 
                                     1 
                                   
                                 
                                 
                                   R 
                                   UDEX 
                                 
                               
                               + 
                               
                                 T 
                                 EX 
                               
                             
                             ) 
                           
                           × 
                           
                             R 
                             
                               MAX 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               1 
                             
                           
                         
                       
                     
                   
                   
                     
                       
                         = 
                           
                         ⁢ 
                         
                           
                             ( 
                             
                               
                                 
                                   S 
                                   
                                     T 
                                     ⁢ 
                                     
                                         
                                     
                                     ⁢ 
                                     1 
                                   
                                 
                                 
                                   R 
                                   UDEX 
                                 
                               
                               + 
                               
                                 T 
                                 EX 
                               
                             
                             ) 
                           
                           × 
                           
                             R 
                             
                               TS 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               1 
                             
                           
                           × 
                           
                             
                               192 
                               188 
                             
                             . 
                           
                         
                       
                     
                   
                 
               
               
                 
                   ( 
                   33 
                   ) 
                 
               
             
           
         
       
     
     As further shown in  FIGS. 63A and 63C , during the period PLJ of the long jump J LJ  over the layer boundary LB, during the preload period PR T   2  for the extended extent T 2  in the second shared section  1402 , and during the period PSJ of the jump J SJ  to skip reading of the immediately subsequent dependent-view extent D, the stored data amount DA 1  in the RB 1  decreases at the first transfer rate R EXT1 . Accordingly, to prevent the stored data amount DA 1  in the RB 1  from reaching zero by the end of the periods PLJ, PR T   2 , and PSJ, the lower limit RB 1   2  on the stored data amount DA 1  in the RB 1  at the start of the long jump J LJ  is expressed in equation (34), using the maximum value of the first transfer rate R EXT1 , i.e. R MAX1 =R TS1 ×192/188, the maximum jump times T LJ  and T SJ  of the jumps J LJ  and J SJ , and the size S T2  of the extended extent T 2 : 
     
       
         
           
             
               
                 
                   
                     
                       
                         
                           RB 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           
                             1 
                             2 
                           
                         
                         = 
                           
                         ⁢ 
                         
                           
                             ( 
                             
                               
                                 T 
                                 LJ 
                               
                               + 
                               
                                 
                                   S 
                                   
                                     T 
                                     ⁢ 
                                     
                                         
                                     
                                     ⁢ 
                                     2 
                                   
                                 
                                 
                                   R 
                                   UDEX 
                                 
                               
                               + 
                               
                                 T 
                                 SJ 
                               
                             
                             ) 
                           
                           × 
                           
                             R 
                             
                               MAX 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               1 
                             
                           
                         
                       
                     
                   
                   
                     
                       
                         = 
                           
                         ⁢ 
                         
                           
                             ( 
                             
                               
                                 T 
                                 LJ 
                               
                               + 
                               
                                 
                                   S 
                                   
                                     T 
                                     ⁢ 
                                     
                                         
                                     
                                     ⁢ 
                                     2 
                                   
                                 
                                 
                                   R 
                                   UDEX 
                                 
                               
                               + 
                               
                                 T 
                                 SJ 
                               
                             
                             ) 
                           
                           × 
                           
                             R 
                             
                               TS 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               1 
                             
                           
                           × 
                           
                             
                               192 
                               188 
                             
                             . 
                           
                         
                       
                     
                   
                 
               
               
                 
                   ( 
                   34 
                   ) 
                 
               
             
           
         
       
     
     As a result, the capacity RB 1  of the RB 1  should be at least the larger of the lower limits RB 1   1  and RB 1   2  expressed in equations (33) and (34):
 
 RB 1≧max( RB 1 1   , RB 1 2 ).
 
     As shown in  FIGS. 63B and 63C , during the read period PR BLK  of data from the extent block located last in the first shared section  1401 , the stored data amount DA 3  in the RB 3  decreases at the third transfer rate R EXT3 . During the preload period PR T   1  of the extended extent T 1  in the extended data specific section  1411 , and during the period PEX of the jump J EX  over the stereoscopic video specific section  1513 , the extended extent T 1  is not read from the RB 3 . Accordingly, in order to maintain the provision of data from the RB 3  to the system target decoder until the periods PR T   1  and PEX have elapsed, the lower limit RB 3   1  on the stored data amount DA 3  in the RB 3  at the start of the read period PR BLK  of data from the extent block is expressed in equation (35), using the number n of extent pairs D, B included in the extent block, the size S B  of the base-view extents, the maximum jump time T SJ  of the jump J SJ  to skip reading of the dependent-view extents, the size S T1  of the extended extent T 1 , the maximum jump time T EX1  of the jump J EX  over the stereoscopic video specific section  1513 , and the maximum value of the third transfer rate R EXT3 , i.e. R MAX3 =R TS3 ×192/188: 
     
       
         
           
             
               
                 
                   
                     
                       
                         
                           RB 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           
                             3 
                             1 
                           
                         
                         = 
                           
                         ⁢ 
                         
                           
                             { 
                             
                               
                                 
                                   ( 
                                   
                                     
                                       T 
                                       SJ 
                                     
                                     + 
                                     
                                       
                                         S 
                                         B 
                                       
                                       
                                         R 
                                         UDEX 
                                       
                                     
                                   
                                   ) 
                                 
                                 × 
                                 n 
                               
                               + 
                               
                                 
                                   S 
                                   
                                     T 
                                     ⁢ 
                                     
                                         
                                     
                                     ⁢ 
                                     1 
                                   
                                 
                                 
                                   R 
                                   UDEX 
                                 
                               
                               + 
                               
                                 T 
                                 EX 
                               
                             
                             } 
                           
                           × 
                           
                             R 
                             
                               MAX 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               3 
                             
                           
                         
                       
                     
                   
                   
                     
                       
                         = 
                           
                         ⁢ 
                         
                           
                             { 
                             
                               
                                 
                                   ( 
                                   
                                     
                                       T 
                                       SJ 
                                     
                                     + 
                                     
                                       
                                         S 
                                         B 
                                       
                                       
                                         R 
                                         UDEX 
                                       
                                     
                                   
                                   ) 
                                 
                                 × 
                                 n 
                               
                               + 
                               
                                 
                                   S 
                                   
                                     T 
                                     ⁢ 
                                     
                                         
                                     
                                     ⁢ 
                                     1 
                                   
                                 
                                 
                                   R 
                                   UDEX 
                                 
                               
                               + 
                               
                                 T 
                                 EX 
                               
                             
                             } 
                           
                           × 
                           
                             R 
                             
                               TS 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               3 
                             
                           
                           × 
                           
                             
                               192 
                               188 
                             
                             . 
                           
                         
                       
                     
                   
                 
               
               
                 
                   ( 
                   35 
                   ) 
                 
               
             
           
         
       
     
     As further shown in  FIGS. 63B and 63C , during the jump period PEX over the stereoscopic video specific section  1513 , during the read period PR B  of data from the monoscopic video specific section  1512 , and during the period PLJ of the long jump J LJ  over the layer boundary LB, the stored data amount DA 3  in the RB 3  decreases at the third transfer rate R EXT3 . Furthermore, during the preload period PR T   2  of the extended extent T 2  in the second shared section  1402  and during the period PSJ of the jump J SJ  to skip reading of the immediately subsequent dependent-view extent D, the extended extent T 2  is not read from the RB 3 . Accordingly, in order to maintain provision of data from the RB 3  to the system target decoder until the periods PEX, PR B , PLJ, PR T   2 , and PSJ have elapsed, the lower limit RB 3   2  on the stored data amount DA 3  in the RB 3  at the start of the jump J Ex  is expressed in equation (36), using the size S B1  of the base-view extent in the monoscopic video specific section  1512 , the maximum jump times T EX , T LJ , and T SJ  of the jumps J EX , J LJ , and J SJ , the size S T2  of the extended extent T 2 , and the maximum value of the third transfer rate R EXT3 , i.e. R MAX3 =R TS3 ×192/188: 
     
       
         
           
             
               
                 
                   
                     
                       
                         
                           RB 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           
                             3 
                             2 
                           
                         
                         = 
                           
                         ⁢ 
                         
                           
                             ( 
                             
                               
                                 T 
                                 EX 
                               
                               + 
                               
                                 
                                   S 
                                   
                                     B 
                                     ⁢ 
                                     
                                         
                                     
                                     ⁢ 
                                     1 
                                   
                                 
                                 
                                   R 
                                   UDEX 
                                 
                               
                               + 
                               
                                 T 
                                 LJ 
                               
                               + 
                               
                                 
                                   S 
                                   
                                     T 
                                     ⁢ 
                                     
                                         
                                     
                                     ⁢ 
                                     2 
                                   
                                 
                                 
                                   R 
                                   UDEX 
                                 
                               
                               + 
                               
                                 T 
                                 SJ 
                               
                             
                             ) 
                           
                           × 
                           
                             R 
                             
                               MAX 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               3 
                             
                           
                         
                       
                     
                   
                   
                     
                       
                         = 
                           
                         ⁢ 
                         
                           
                             ( 
                             
                               
                                 T 
                                 EX 
                               
                               + 
                               
                                 
                                   S 
                                   
                                     B 
                                     ⁢ 
                                     
                                         
                                     
                                     ⁢ 
                                     1 
                                   
                                 
                                 
                                   R 
                                   UDEX 
                                 
                               
                               + 
                               
                                 T 
                                 LJ 
                               
                               + 
                               
                                 
                                   S 
                                   
                                     T 
                                     ⁢ 
                                     
                                         
                                     
                                     ⁢ 
                                     2 
                                   
                                 
                                 
                                   R 
                                   UDEX 
                                 
                               
                               + 
                               
                                 T 
                                 SJ 
                               
                             
                             ) 
                           
                           × 
                           
                             R 
                             
                               TS 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               3 
                             
                           
                           × 
                           
                             
                               192 
                               188 
                             
                             . 
                           
                         
                       
                     
                   
                 
               
               
                 
                   ( 
                   36 
                   ) 
                 
               
             
           
         
       
     
     The extended extent T 1  read from the extended data specific section  1411  is not transferred from the RB 3  until the jump period PEX immediately subsequent to reading has elapsed. Accordingly, the lower limit RB 3   2  of the stored data amount DA 3  in the RB 3  at the start of the jump period PEX should be at least the sum of the maximum extent size maxS T1  of the extended extent T 1  and the data amount T EX ×R MAX3  provided from the RB 3  to the system target decoder during the jump period PEX: 
     
       
         
           
             
               
                 
                   
                     
                       
                         
                           RB 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           
                             3 
                             2 
                           
                         
                         ≥ 
                           
                         ⁢ 
                         
                           
                             max 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             
                               S 
                               
                                 T 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 1 
                               
                             
                           
                           + 
                           
                             
                               T 
                               EX 
                             
                             × 
                             
                               R 
                               
                                 MAX 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 3 
                               
                             
                           
                         
                       
                     
                   
                   
                     
                       
                         = 
                           
                         ⁢ 
                         
                           
                             max 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             
                               S 
                               
                                 T 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 1 
                               
                             
                           
                           + 
                           
                             
                               T 
                               EX 
                             
                             × 
                             
                               R 
                               
                                 TS 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 3 
                               
                             
                             × 
                             
                               
                                 192 
                                 188 
                               
                               . 
                             
                           
                         
                       
                     
                   
                 
               
               
                 
                   ( 
                   37 
                   ) 
                 
               
             
           
         
       
     
     The extended extent T 2  read from the second shared section  1402  is not transferred from the RB 3  until the jump period PSJ immediately subsequent to reading has elapsed. Accordingly, the lower limit RB 3   3  of the stored data amount DA 3  in the RB 3  at the start of the jump period PSJ must be the sum of the maximum extent size maxS T2  of the extended extent T 2  and the data amount T SJ ×R MAX3  provided from the RB 3  to the system target decoder during the jump period PSJ: 
     
       
         
           
             
               
                 
                   
                     
                       
                         
                           RB 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           
                             3 
                             3 
                           
                         
                         = 
                           
                         ⁢ 
                         
                           
                             max 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             
                               S 
                               
                                 T 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 2 
                               
                             
                           
                           + 
                           
                             
                               T 
                               SJ 
                             
                             × 
                             
                               R 
                               
                                 MAX 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 3 
                               
                             
                           
                         
                       
                     
                   
                   
                     
                       
                         = 
                           
                         ⁢ 
                         
                           
                             max 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             
                               S 
                               
                                 T 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 2 
                               
                             
                           
                           + 
                           
                             
                               T 
                               SJ 
                             
                             × 
                             
                               R 
                               
                                 TS 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 3 
                               
                             
                             × 
                             
                               
                                 192 
                                 188 
                               
                               . 
                             
                           
                         
                       
                     
                   
                 
               
               
                 
                   ( 
                   38 
                   ) 
                 
               
             
           
         
       
     
     As a result, the capacity RB 3  of the RB 3  should be at least the maximum value among the lower limits RB 3   1 , RB 3   2 , and RB 3   3  expressed in equations (35)-(38): 
               RB   ⁢           ⁢   3     ≥       max   ⁡     (       RB   ⁢           ⁢     3   1       ,     RB   ⁢           ⁢     3   2       ,           ⁢       max   ⁢           ⁢     S     T   ⁢           ⁢   1         +       T   EX     ×     R     TS   ⁢           ⁢   3       ×     192   188         ,       max   ⁢           ⁢     S     T   ⁢           ⁢   2         +       T   SJ     ×     R     TS   ⁢           ⁢   3       ×     192   188           )       .           
Other Characterizations of the Present Invention
 
     Based on the above embodiments, the present invention may be characterized as follows. 
     In a recording medium according to an aspect of the present invention, the monoscopic video specific section may be located immediately after the stereoscopic video specific section. In this case, the playback device in 3D playback mode can skip access to only the extended data specific section by performing a jump immediately after finishing reading of data from the shared section. Accordingly, the extent blocks arranged at the end of the shared section should include two or more extent pairs, like the other extent blocks. 
     In a recording medium according to an aspect of the present invention, a first combination of the stereoscopic video specific section, the monoscopic video specific section, and the extended data specific section may be located immediately before a location at which a long jump is necessary, and a second combination thereof may be immediately after the location. In this case, in the playback path in each mode, the start point and end point of the long jump may be designed to be in different positions. Accordingly, in the playback path in any mode, the distance of the long jump can reliably be kept within an acceptable range. 
     A recording device according to an aspect of the present invention is for recording a main-view stream, a sub-view stream, and an extended stream on a recording medium and comprises an encoding unit, a multiplexing unit, and a write unit. The encoding unit encodes main views of stereoscopic video images into a main-view video stream, sub-views of the stereoscopic video images into a sub-view video stream, and extended data to be used in combination with the main-view video stream. The multiplexing unit multiplexes the main-view video stream into the main-view stream, the sub-view video stream into the sub-view stream, and the extended data into the extended stream. The multiplexing unit also divides the main-view stream into a plurality of main-view extents, the sub-view stream into a plurality of sub-view extents, and the extended stream into a plurality of extended extents, and determines an arrangement of extents on the recording medium. The write unit writes the plurality of main-view extents, the plurality of sub-view extents, and the plurality of extended extents onto the recording medium in accordance with the arrangement of extents determined by the multiplexing unit. The multiplexing unit designs a shared section, a stereoscopic video specific section, a monoscopic video specific section, and an extended data specific section on the recording medium. The shared section includes a continuous, interleaved arrangement of extents having one each of the plurality of main-view extents, the plurality of sub-view extents, and the plurality of extended extents. The stereoscopic video specific section includes a continuous, interleaved arrangement of extents having one each of the plurality of main-view extents and the plurality of sub-view extents. The monoscopic video specific section is located adjacent to the stereoscopic video specific section and includes a continuous arrangement of a copy of the main-view extent arranged in the stereoscopic video specific section. The extended data specific section is located immediately before a continuous arrangement of the stereoscopic video specific section and the monoscopic video specific section and includes one of the plurality of extended extents that is to be used in combination with the copy of the main-view extent arranged in the monoscopic video specific section. The design of the shared, stereoscopic video specific, monoscopic video specific, and extended data specific sections causes a playback device to perform access as follows. First, the playback device is caused to access the shared section when playing back the stereoscopic video images, when playing back the main views as monoscopic video images, and when using the extended stream in combination with the main-view stream. Next, the playback device is caused to access the stereoscopic video specific section during playback of the stereoscopic video images, next to the shared section immediately before start of a long jump, or ahead of the shared section immediately after completion of a long jump. Furthermore, the playback device is caused to access the monoscopic video specific section during playback of the monoscopic video images, next to the shared section immediately before start of a long jump, or ahead of the shared section immediately after completion of a long jump. Finally, the playback device is caused to access the extended data specific section and the monoscopic video specific section when reading the extended stream along with the main-view stream, next to the shared section immediately before start of a long jump, or ahead of the shared section immediately after completion of a long jump. 
     A recording method according to an aspect of the present invention is for recording a main-view stream, a sub-view stream, and an extended stream on a recording medium and comprises the following steps. First, main views of stereoscopic video images are encoded into a main-view video stream, sub-views of the stereoscopic video images are encoded into a sub-view video stream, and extended data to be used in combination with the main-view video stream is encoded. Next, the main-view video stream is multiplexed into the main-view stream, the sub-view video stream into the sub-view stream, and the extended data into the extended stream. The main-view stream is then divided into a plurality of main-view extents, the sub-view stream into a plurality of sub-view extents, and the extended stream into a plurality of extended extents, and an arrangement of extents on the recording medium is determined. The plurality of main-view extents, the plurality of sub-view extents, and the plurality of extended extents are then written onto the recording medium in accordance with the determined arrangement of extents. In the step to determine the arrangement of extents, a shared section, a stereoscopic video specific section, a monoscopic video specific section, and an extended data specific section are designed on the recording medium. The shared section includes a continuous, interleaved arrangement of extents having one each of the plurality of main-view extents, the plurality of sub-view extents, and the plurality of extended extents. The stereoscopic video specific section includes a continuous, interleaved arrangement of extents having one each of the plurality of main-view extents and the plurality of sub-view extents. The monoscopic video specific section is located adjacent to the stereoscopic video specific section and includes a continuous arrangement of a copy of the main-view extent arranged in the stereoscopic video specific section. The extended data specific section is located immediately before a continuous arrangement of the stereoscopic video specific section and the monoscopic video specific section and includes one of the plurality of extended extents that is to be used in combination with the copy of the main-view extent arranged in the monoscopic video specific section. The design of the shared, stereoscopic video specific, monoscopic video specific, and extended data specific sections on the recording medium causes a playback device to perform access as follows. The playback device is caused to access the shared section when playing back the stereoscopic video images, when playing back the main views as monoscopic video images, and when using the extended stream in combination with the main-view stream. The playback device is caused to access the stereoscopic video specific section during playback of the stereoscopic video images, next to the shared section immediately before start of a long jump, or ahead of the shared section immediately after completion of a long jump. The playback device is caused to access the monoscopic video specific section during playback of the monoscopic video images, next to the shared section immediately before start of a long jump, or ahead of the shared section immediately after completion of a long jump. The playback device is caused to access the extended data specific section and the monoscopic video specific section when reading the extended stream along with the main-view stream, next to the shared section immediately before start of a long jump, or ahead of the shared section immediately after completion of a long jump. 
     When reading data recorded on a recording medium by the recording device and the method according to the above aspect of the present invention, a playback device accesses different areas immediately before and immediately after performing a long jump during playback of the stereoscopic video images, playback of the monoscopic video images, and use of the extended stream in combination with the main-view stream. Therefore, the above recording device and method may set the conditions to be satisfied by the size of extents in order to prevent buffer underflow during the long jump separately for each area. This technology therefore makes seamless playback of both stereoscopic video images and monoscopic video images compatible with a further reduction in the buffer capacity within the playback device. Furthermore, the same monoscopic video specific section is accessed both during playback of the monoscopic video images and during use of the extended stream in combination with the main-view stream. As a result, the data amount of the main-view extents to be redundantly recorded on one recording medium is reduced to a minimum. Accordingly, during playback of stereoscopic video images, playback of monoscopic video images, and use of the extended stream in combination with the main-view stream, the distance of the long jump can be kept within an acceptable range. The above recording device and method can thus record a combination of 3D video content and extended data on a recording medium so as to allow the playback device to maintain good playback performance. 
     INDUSTRIAL APPLICABILITY 
     The present invention relates to a technology for recording and playback of stereoscopic video images, and as described above, arranges three types of sections immediately before or immediately after locations on a recording medium where a long jump is necessary. The present invention thus clearly has industrial applicability. 
     REFERENCE SIGNS LIST 
       1401  first shared section 
       1411  first extended data specific section 
       1412  first monoscopic video specific section 
       1413  first stereoscopic video specific section 
       1402  second shared section 
       1421  second extended data specific section 
       1422  second monoscopic video specific section 
       1423  second stereoscopic video specific section 
     L 0  first recording layer 
     L 1  second recording layer 
     LB layer boundary 
     T extended extent 
     D dependent-view extent 
     B base-view extent 
     B 2D  2D-playback-only block 
     B 3D  3D-playback-only block 
     EXT 2 D[m] Extent in file  2 D 
     EXTSS[m] Extent in file SS 
     EXT 3 [m] Extent in extended stream file 
     J LY  long jump 
     J 2D  jump in 2D playback mode 
     J 3D  jump in 3D playback mode 
     J EX  jump in extended playback mode