Abstract:
Disclosed are: an information recording technology capable of shortening the termination process time when the recording ends; and an information recording technology capable of recording independently of limitations due to the maximum number of video title sets and titles, wherein information is recorded on a recording medium according to recording instructions such as a recording start instruction and a recording stop instruction. During a finalization process, management information is generated and is recorded on the recording medium. Based on this management information, the information generated by a single recording instruction is managed as one chapter. At least one chapter is managed as one title. At least one title is managed as one video title set.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a technology for recording or reproducing information from a recording medium.  
           [0003]    2. Description of Related Art  
           [0004]    Conventionally, there is known a technology for recording and processing information by using magnetic tape such as a VCR (Video Cassette Recorder).  
           [0005]    There is also known a technology for recording information on disk-shaped information recording media such as a CD-RW (Compact Disc—ReWritable) and a DVD-RAM (Digital Versatile Disc—Random Access Memory) instead of on the magnetic tape.  
           [0006]    The VCR records information sequentially on magnetic tape. Since intended information also needs to be reproduced sequentially, an information access speed is slow. By contrast, when information is recorded on disk-shaped information recording media such as CD-RW and DVD-RAM, they can provide a so-called random access to reproduce intended information immediately. The CD-RW and the DVD-RAM are characterized by a faster information access speed than the VCR.  
           [0007]    In recent years, products on the market include a DVD recorder that digitally records videos captured through TV broadcasting and line input on a write-once DVD. The DVD recorder manages a video recorded on a recording medium based on a management unit called a video title set from the beginning to the end of a single recording operation.  
           [0008]    [0008]FIG. 1 shows a data structure of a recording medium  101 . According to this data structure, video title sets increase for the number of recorded videos such as video title set # 1  ( 102 ), video title set # 2  ( 103 ), . . . , and video title set #N ( 104 ). At this time, video title set # 1  ( 102 ), video title set # 2  ( 103 ), . . . ., and video title set #N ( 104 ) correspond to title # 1  ( 105 ), title # 2  ( 106 ), . . . , and title #N ( 107 ) one to one, respectively. Further, each title is subdivided into units like chapter # 1  ( 108 ), chapter # 2  ( 109 ), . . . , and chapter #M ( 110 ) for management. For example, a chapter is increased each time the recording time exceeds five minutes, FIG. 2 shows a more detailed data structure. The data structure in FIG. 2 is configured on the recording medium  301  according to a finalization process. Information recorded on the recording medium  301  is managed by one video manager  302  and video title set # 1  ( 303 ), video title set # 2  ( 304 ), . . . , and video title set #L ( 305 ).  
           [0009]    The video manager  302  comprises video manager information  306 , a video manager menu video object set  307 , and a video manager information backup  308 . The video manager information  306  is used to manage the entire information recorded on the recording medium  301 . The video manager menu video object set  307  is used to display a menu screen for reproducing information recorded on a recording medium  301 . The video manager information backup  308  is backup information for the video manager information  306 .  
           [0010]    Each video title set comprises video title set information  309 , a video title set menu video object set  310 , a video title set video object set  311 , and a video title set information backup  312 . The video title set information  309  manages the entire of one video title set. The video title set information  309  is used to manage information in units of titles or chapters as shown in FIG. 1. The video title set menu video object set  310  provides information for reproducing a menu screen used to reproduce information within one video title set. The video title set video object set  311  is an AV stream of the recorded video, i.e., the information itself. The video title set information backup  312  is backup information of video object set information.  
           [0011]    The video manager menu video object set  307  and the video title set menu video object set  310  may or may not be configured on the recording medium.  
           [0012]    The above-mentioned recording system must create and record information about a video title set each time the recording terminates. Accordingly, a process to terminate the recording becomes time-consuming. Further, there is a limitation on the number of video title sets and titles (up to 99) that can be created on the recording medium. This also limits the number of times of recording operations. As a result, there may be a case where just a half of the recordable capacity is consumed on the recording medium even if the number of operations allowed for recording is reached. Consequently, there is a possibility of ineffectively using recording areas on the recording medium.  
         SUMMARY OF THE INVENTION  
         [0013]    It is an object of the present invention to provide an information recording technology capable of shortening the termination process time when the recording ends. Another object of the present invention is to provide an information recording technology capable of recording independently of limitations due to the maximum number of video title sets and titles.  
           [0014]    The present invention can save time for creating a video title set at the end of recording, thus shortening the recording termination time. Further, the present invention can increase the number of times for recording information signals, making it possible to effectively use recording areas on a recording medium.  
           [0015]    In order to solve the above-mentioned problems, the present invention uses the following technology in one preferred aspect.  
           [0016]    Information is recorded on a recording medium according to recording instructions such as a recording start instruction and a recording stop instruction. During a finalization process, management information is generated and is recorded on the recording medium. Based on this management information, the information generated by a single recording instruction is managed as one chapter. At least one chapter is managed as one title. All of the information comprising at least one title on the recording medium is managed as one video title set.  
           [0017]    Other and further objects, features and advantages of the invention will appear more fully from the following description.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]    [0018]FIG. 1 shows an example of a data structure comprising video title sets, titles, and chapters;  
         [0019]    [0019]FIG. 2 shows a data structure configured on a recording medium;  
         [0020]    [0020]FIG. 3 shows an example of a data structure comprising a video title set, titles, and chapters;  
         [0021]    [0021]FIG. 4 is a block diagram showing an outline of an information recording/reproducing apparatus;  
         [0022]    [0022]FIG. 5 is a block diagram showing part of the information recording/reproducing apparatus in detail;  
         [0023]    [0023]FIG. 6 is a flowchart showing operations of the information recording/reproducing apparatus after it is turned on; and  
         [0024]    [0024]FIG. 7 shows the chapter arrangement in a video title set. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0025]    An embodiment of the present invention will be described in further detail with reference to the accompanying drawings.  
         [0026]    [0026]FIG. 3 shows a data structure on a recording medium where information signals are recorded according to the embodiment of the present invention. Information is recorded so that it can be managed as one chapter from the start to the end of one recording operation. The data structure is configured to manage all the information recorded on a recording medium  201  as one video title set # 1  ( 202 ). The video title set # 1  ( 202 ) is subdivided into title # 1  ( 203 ), title # 2  ( 204 ), . . . , and title #N ( 205 ). One title is configured to bundle a plurality of chapters like chapter # 1  ( 206 ), chapter # 2  ( 207 ), . . . , and chapter #M ( 208 ). Various rules are available for bundling titles. For example, one title may comprise a plurality of chapters recorded on the same day. Alternatively, one title may comprise the specified number of chapters (e.g.  99  chapters).  
         [0027]    Recording information in this manner can save time for creating a video title set at the end of recording, thus shortening the recording termination time for the time saved. Further, it becomes possible to record information more often than the limitation of the number of video title sets or titles (up to 99).  
         [0028]    Conventionally, as mentioned above, a single recording operation from the beginning to the end (called a scene) is managed as one video title set. In addition, one video title set corresponds to one title for management. Scenes that can be recorded are restricted to the number of video title sets and titles (e.g. 99) per recording medium. According to the embodiment, however, one scene corresponds to one chapter. A title comprises a plurality of chapters. Moreover, a plurality of recorded titles is managed as one video title set as a whole. Even if there is a limitation on the number of titles as mentioned above, the number of recordable scenes per recording medium will be equivalent to the limitation on the number of titles (99) multiplied by the limitation on the number of chapters (e.g. 99). Scenes can be recorded for the number of times exceeding the number of titles.  
         [0029]    [0029]FIG. 4 shows a schematic block diagram of an information recording/reproducing apparatus  1200  according to the present invention. The information recording/reproducing apparatus  1200  is equivalent to a stationary apparatus as typified by a DVD recorder capable of recording TV programs and the like. The information recording/reproducing apparatus  1200  records information supplied from an input terminal  1229  on the recording medium  201 . The information recording/reproducing apparatus  1200  reproduces information recorded on the recording medium  201  to output it from an information signal output terminal  1128 .  
         [0030]    A signal detected by an optical pickup  1118  is sent to a servo signal generation circuit  1119  and an information signal reproduction circuit  1120 . The servo signal generation circuit  1119  generates a focusing control signal and a tracking control signal appropriate to an optical disk  201  from these detected signals. Based on these signals, an actuator drive circuit  1121  drives an objective lens actuator in the optical pickup  1118  to control objective lens positions. The information signal reproduction circuit  1120  reproduces information recorded on the optical disk  201  from the detected signal. The reproduced information is output to the information signal output terminal  1128 . Part of signals obtained from the servo signal generation circuit  1119  and the information signal reproduction circuit  1120  is sent to a system control circuit  1122 .  
         [0031]    A recording information signal conversion circuit  1124  converts information supplied from the input terminal  1229  to an AV stream. The AV stream is sent to the system control circuit  1122  and is converted to a laser drive recording signal. The laser drive recording signal drives a laser beam source lighting circuit  1123  to control the laser intensity and records information on an optical disk  201  via the optical pickup  1118 .  
         [0032]    The system control circuit  1122  connects with an access control circuit  1125  and a spindle motor drive circuit  1126  which respectively control access direction positions of the optical pickup  1118  and rotations of a spindle motor  1127  of the optical disk  201 . The information recording/reproducing apparatus  1200  is supplied with power from a power supply circuit  1250  that processes power supplied from a commercial power source.  
         [0033]    A user input processing unit  1151  can be used to issue instructions for recording and reproduction. A display processing unit  1152  can display information reproduced from the recording medium  201  or supplied from the input terminal  1229 .  
         [0034]    There may be a case where the information recording/reproducing apparatus  1200  is a portable apparatus as typified by a DVD camera. In such case, after an image is picked up optically, a camera signal processing circuit (not shown) converts an information signal to an electrical signal. The converted signal is supplied to the recording information signal conversion circuit  1124 . Power is supplied from a battery instead of the power supply circuit  1250 .  
         [0035]    The information recording/reproducing apparatus  1200  itself can reproduce information recorded on the recording medium even if a so-called finalization process is not performed.  
         [0036]    [0036]FIG. 5 is a block diagram showing part of the information recording/reproducing apparatus  1200  in detail.  
         [0037]    In FIG. 5, an AV stream processing unit  402  corresponds to the recording information signal conversion circuit  1124 . A management information processing unit  403  and a control unit  407  constitute part of the system control circuit  1122  in FIG. 4. A recording medium drive processing unit  404  corresponds to the optical pickup  1118 , the laser beam source lighting circuit  1123 , the servo signal generation circuit  1119 , the information signal reproduction circuit  1120 , the access control circuit  1125 , the spindle motor drive circuit  1126 , the system control circuit  1122 , etc. in FIG. 4. An operation unit  408  corresponds to the user input processing unit  1151 .  
         [0038]    The AV stream processing unit  402  encodes information output from the input terminal  1229 . The recording medium drive processing unit  404  writes the coded information as an AV stream to the recording medium  201 . On a movie apparatus or a stationary video recorder, an AV stream is written to the recording medium  201  during the beginning to the end of recording. This AV stream is written once. A segment from the beginning to the end of a single recording session is defined as one chapter.  
         [0039]    During recording, the AV stream processing unit  402  transmits information to the management information processing unit  403 . At the end of recording, the management information processing unit  403  creates intermediate management information. The recording medium drive processing unit  404  writes the intermediate management information to the recording medium  201 .  
         [0040]    This intermediate management information is written once each time the recording terminates. The operation unit  408  sends information about the beginning or end of recording to the control unit  407 . The control unit  407  centrally controls each block in a portion  406  enclosed in a dotted line in FIG. 5.  
         [0041]    [0041]FIG. 6 is a flowchart showing operations of the information recording/reproducing apparatus  1200  after it is turned on. The following description assumes that the operations according to the flowchart are performed under control of the system control circuit  1122  (especially the control unit  407 ).  
         [0042]    After the power is turned on, it is determined whether or not the recording medium drive processing unit  404  initializes the recording medium  201  (step S 501 ). If the recording medium  201  is not initialized, the display processing unit  1152  displays a prompt to determine whether to perform the initialization (step S 502 ). If the user input processing unit  1151  chooses not to perform the initialization, no information signal can be recorded on the recording medium  201 . All the subsequent processes terminate (step S 503 ). If the user input processing unit  1151  chooses to perform the initialization, the display processing unit  1152  displays a message indicating that no information can be recorded on the other apparatuses after the initialization (step S 504 ). After the recording medium  201  is initialized (step S 505 ), control returns to step S 501 .  
         [0043]    If it is determined at step S 501  that the recording medium is initialized, control proceeds to step S 506 . It is determined whether or not the user input processing unit  1151  issues a recording start instruction. If the recording start instruction is issued, the recording medium drive processing unit  404  records an AV stream (information) encoded in the AV stream processing unit  402  on the recording medium  201  (step S 507 ) until the user input processing unit  1151  issues a recording stop instruction. When the recording stop (end) instruction is issued (step S 508 ), the recording medium drive processing unit  404  stops recording information. The management information processing unit  403  generates intermediate management information for managing recorded AV streams. The recording medium drive processing unit  404  records this intermediate management information on the recording medium  201  (step S 509 ), then returns control to step S 501 . The recording is performed so that information recorded from a recording start instruction to a recording stop instruction can be managed as one chapter.  
         [0044]    [0044]FIG. 7 shows the chapter arrangement on the recording medium  201 . In this example, recording start/stop instructions are issued to record the information three times to record three chapters. The information is recorded so that no gap occurs between chapter # 1  ( 1001 ) and chapter # 2  ( 1002 ). Likewise, information is recorded so that no gap occurs between chapter # 2  ( 1002 ) and chapter # 3  ( 1003 ). In order to leave no gap between chapters, they need to be recorded in alignment with each other so that the size of each chapter becomes an integral multiple of a specified unit for recording on the recording medium. On an optical disk, for example, dummy information is recorded so that the chapters can be aligned in units of ECC blocks (32 kilobytes). The size of each chapter is adjusted to an integral multiple of the specified recording unit to generate no gap between the chapters. When the information is recorded so as to leave no gap between chapters, it can be normally reproduced also on a read-only apparatus.  
         [0045]    If it is determined that the recording start instruction is issued at step S 506 , control proceeds to step S 510 . It is determined whether or not the user input processing unit  1151  issues a source picture resolution change instruction. If the source picture resolution change instruction is issued, the recording medium drive processing unit  404  determines whether or not the recording medium  201  already records information (step S 511 ). If no information is recorded, the system control circuit  1122  changes the resolution to a source picture resolution specified from the user input processing unit  1151  (step S 512 ), and then returns control to step S 501 . If information is recorded, the display processing unit  1152  displays a message indicating that the source picture resolution cannot be changed (step S 513 ), and then returns control to step S 501 . This is because one video title set cannot manage information signals with different source picture resolutions.  
         [0046]    If it is determined that the source picture resolution change instruction is not issued at step S 510 , control proceeds to step S 514 . It is determined whether or not the user input processing unit  1151  issues a finalization process instruction. If no finalization process instruction is issued, control returns to step S 501 . If the finalization process instruction is issued, a finalization process is performed by executing steps S 515  through S 517  (step S 515 ). The subsequent operations are terminated (step S 516 ).  
         [0047]    Performing the finalization process at step S 515  constructs the data structure as shown in FIG. 2. Specifically, the process generates management information and menu screen information for reproduction, and then records these pieces of information on the recording medium  201 . As mentioned above, it is obvious that the embodiment generates only one video title set.  
         [0048]    The management information is equivalent to the video manager information  306 , the backup for video manager information  308 , the video title set information  309 , and the video title set information backup  312  in FIG. 2. The menu screen information for reproduction is equivalent to the video manager menu video object set  307  and the video title set menu video object set  310  in FIG. 2.  
         [0049]    The management information is created based on the intermediate management information recorded on the recording medium at the end of recording. As shown in FIG. 3, the recorded AV stream is configured to be one video title set # 1  ( 202 ). One scene from the beginning to the end of the recording is allocated to a chapter. Chapters are foldered according to the same date to form a title. When the number of chapters on the same date reaches a specified value, e.g. 99, these chapters are united to a title.  
         [0050]    The foregoing invention has been described in terms of preferred embodiments. However, those skilled, in the art will recognize that many variations of such embodiments exist. Such variations are intended to be within the scope of the present invention and the appended claims.