JP4312783B2 - AV data reproducing method, AV data reproducing apparatus, program, and recording medium - Google Patents

Description

  The present invention relates to a recording method, a recording apparatus, and a recording medium for recording video data and audio data on a randomly accessible recording medium such as a hard disk, an optical disk, and a semiconductor memory.

  Video digital recording / playback apparatuses (hereinafter referred to as video disk recorders) using disk media are becoming widespread. In these cases, a technique for realizing an after recording (after-recording) function at a low cost as in the case of tape media is required. The post-recording function is a function for adding information, particularly audio, to an already recorded audio or video.

  As a conventional technique for realizing a post-recording function using a disk medium, there is Patent Document 1 by the present applicant. Hereinafter, the outline will be described with reference to FIG.

  In Patent Document 1, the stream file 3000 has a unique stream format, and an after-recording data area for synchronous playback is inserted between original stream data (initially recorded video / audio data) divided every predetermined playback time. Constitute. Taking FIG. 20A as an example, an after-recording data area 3011 for storing after-recording audio data to be synchronously reproduced is inserted immediately before the partial original stream data 3021. The relationship between 3012 and 3022 and 3013 and 3023 is the same.

  When the stream file 3000 is recorded on the optical disc 3001, as shown in FIG. 20B, the partial original stream data to be synchronously reproduced and the post-record data area are arranged in the physical vicinity to include the post-record data. The seek can be minimized at the time of reproduction, and the interruption of reproduction due to the seek is suppressed. Also, by setting the reproduction time of the partial original stream data to a value that allows real-time after-recording in consideration of seek time and the like (about several seconds), real-time after-recording is guaranteed.

Further, as a data recording method widely used in the world, Transport Stream (hereinafter referred to as MPEG-2 TS) defined in ISO / IEC 13818-1 having a configuration different from the stream configuration described in Patent Document 1 above , Program Stream (MPEG-2 PS). For example, DVD-Video is MPEG-2 PS, and the data transfer format between devices by digital broadcasting or IEEE-1394 is MPEG-2 TS. Patent Document 2 and Patent Document 3 are related to the conventional art relating to post-recording in consideration of MPEG-2 PS / TS.
JP 2001-43616 A JP 2000-306327 A Japanese Patent Laid-Open No. 11-298845

  However, when the stream configuration described in Patent Document 1 is applied to MPEG-2 PS / TS, there is a possibility that decoding cannot be performed correctly even if playback is attempted with a commonly used decoder. The reason will be described below.

  In MPEG-2 TS / PS, a standard decoder model is set, and video data and audio data are set so that the audio / video decoder buffer memory in the decoder model does not underflow or overflow. Multiplexing is stipulated. However, in the case of the stream configuration described in Patent Document 1, audio data of 1 second or longer is stored in each after-recording data area. When this stream file is reproduced by a general MPEG-2 TS / PS decoder, audio data for one second or more is sent together, and the buffer memory of the audio decoder overflows.

  The after-recording function described in Patent Document 2 multiplexes the after-recording data area in the stream in accordance with the above-mentioned MPEG-2 PS multiplexing specification. When the disc transfer rate is low, real-time after-recording is performed. There is a problem that is difficult.

  On the other hand, Patent Document 3 records the post-recording data in a separate file so that each file satisfies the MPEG-2 PS multiplexing specification. In this case, when the after-recording result is reproduced, it is necessary to repeat the seek in order to alternately read the file for recording the after-recording data and the original stream file. Therefore, when non-destructive editing is performed on the post-recording result (stream data on the disc is not moved and visual editing is performed based on the playback path information), playback may be interrupted especially between scenes. Rise. It is also disadvantageous in terms of power consumption.

  The present invention has been made in view of the above problems, and is capable of reproduction on a general MPEG-2 PS / TS decoder and real-time after-recording, and reproduction when the after-recording result is non-destructively edited. It is an object to provide a data recording method with few interruptions.

  In order to solve the above-described problems, the AV data recording method of the present invention relates to AV data in which a plurality of stream data is multiplexed on a recording medium in accordance with a predetermined multiplexing rule, and is associated with the AV data. A first step of dividing the AV data and the related data into partial AV data and partial related data at predetermined intervals; A second step of securing a first continuous area, which is a continuous area for recording partial AV data and the partial related data, and the partial AV data and the partial related data in the first continuous area. The third step of continuously recording, managing the partial AV data and the partial related data as separate files, respectively, The file system management information for managing the information for handling the minute AV data and the partial associated data as a separate file is characterized by comprising a fourth step of recording on the recording medium.

  According to the above configuration, AV data (for example, original stream) and related data (for example, post-record data) recorded on the recording medium are divided into partial AV data and partial related data by the first step, and seamlessly It is set to a recording unit that guarantees playback and real-time dubbing.

  The divided partial AV data and partial related data are recorded at positions that are physically close to each other on the recording medium by the processing of the second and third steps, with the data to be synchronized in a row.

  Furthermore, in the file system management information recorded in the fourth step, the partial AV data and the partial related data are managed as separate files, so that real-time post-recording is ensured and non-destructive editing performance is high. Playback with MPEG-2 PS decoder is possible. Further, when the reproduction of AV data and the reproduction of related data are performed in synchronization, the partial AV data and the partial related data are recorded close to each other, so the frequency of seek is reduced, and other data and In addition, there is much room for synchronous playback. For example, even if graphics data or the like other than after-recording audio is added by nondestructive editing, there is a low possibility that the reproduction is interrupted.

  Further, in the file system management information which is a separate file, the file system management information is referred to by recording information indicating the correspondence relationship between the partial AV data and the partial related data arranged in the vicinity on the recording medium on the recording medium. Thus, it is possible to know partial AV data and partial related data that are continuously recorded without any trouble, and to perform optimum data reading.

  The AV data recording method of the present invention may further include a fifth step of recording the reproduction start time of the partial AV data and the correspondence information of the position information of the first continuous area on the recording medium. Good.

  According to the above configuration, it is possible to easily specify the position of the partial related data (post-recording area) corresponding to the partial AV data to be post-recorded.

  The AV data recording method according to the present invention further comprises a sixth step of recording, on the recording medium, information for managing whether or not the partial related data is recorded in the vicinity of the corresponding partial AV data. It is good.

  If a defect is encountered when recording the partial AV data and the partial related data, the partial related data being recorded may be discarded and a new CA may be recorded in another area.

  According to the above configuration, at that time, in the information for managing the partial related data, it is made clear that there is no partial related data in the vicinity of the corresponding partial AV data. When reproducing the destructive editing result, it is possible to easily determine a section where the partial AV data and the partial related data are not continuously recorded, and to inform the user in advance that the reproduction is likely to be interrupted in the section. It becomes possible.

  According to another AV data recording method of the present invention, AV data in which a plurality of stream data is multiplexed on a recording medium according to a predetermined multiplexing rule can be recorded together with related data synchronized with the AV data. A data recording method, comprising: a seventh step of dividing the AV data into partial AV data at predetermined intervals; and the continuous AV data and the related data are recorded on the recording medium. An eighth step of securing a first continuous area which is a continuous area for recording partial reserved data for securing a recording area of partial related data divided corresponding to the partial AV data; and the partial reserved data A ninth step of continuously recording the partial AV data and the partial reserved data in the first continuous area, and generating the partial AV data And the partial reservation data are managed as separate files, and file system management information for managing information for handling the partial AV data and the partial reservation data as separate files is recorded on the recording medium. It comprises 10 steps.

  According to the above configuration, AV data (for example, an original stream) recorded on the recording medium is divided into partial AV data by the seventh step, and set to a recording unit that guarantees seamless playback and real-time after-recording. Is done.

  The divided partial AV data are physically connected to each other on the recording medium by the processes of the eighth and ninth steps as a part of the partial reservation data for securing the recording area of the partial related data synchronized therewith. Recorded at a nearby position.

  Furthermore, in the file system management information recorded in the tenth step, the partial AV data and the partial reservation data are managed as separate files, thereby guaranteeing real-time after-recording at the time of recording related data, and non-destructive editing performance. It is expensive and can be played back by a general MPEG-2 PS decoder.

  In the AV data recording method, an eleventh step of dividing the related data into partial related data at predetermined intervals when recording the related data; and A twelfth step of recording in the reserved area of the partial reservation data recorded continuously; and managing the partial related data as a separate file from the partial AV data and the partial reserved data; And a thirteenth step of recording file system management information for managing information for handling data as a separate file on the recording medium.

  According to the above configuration, when the AV data reproduction and the related data reproduction are performed in synchronization, the partial AV data and the partial related data are recorded close to each other, so the seek frequency is reduced. There is much room for further synchronized playback with other data. For example, even if graphics data or the like other than after-recording audio is added by nondestructive editing, there is a low possibility that the reproduction is interrupted.

  Further, in the file system management information which is a separate file, the file system management information is referred to by recording information indicating the correspondence relationship between the partial AV data and the partial related data arranged in the vicinity on the recording medium on the recording medium. Thus, it is possible to know partial AV data and partial related data that are continuously recorded without any trouble, and to perform optimum data reading.

  In the AV data recording method of the present invention, as described above, the first step of dividing the AV data and the related data into partial AV data and partial related data at predetermined intervals, and A second step of securing a first continuous area which is a continuous area for recording the subsequent partial AV data and the partial related data; and the partial AV data and the partial related in the first continuous area In order to manage the partial AV data and the partial related data as separate files, and to manage the partial AV data and the partial related data as separate files, respectively, in the third step of continuously recording data And a fourth step of recording file system management information for managing the information on the recording medium.

  Therefore, AV data and related data recorded on the recording medium are divided into partial AV data and partial related data by the first step, and the divided partial AV data and partial related data are synchronized with each other. As a continuation, recording is performed at positions physically close to each other on the recording medium by the second and third processes. Furthermore, in the file system management information recorded in the fourth step, the partial AV data and the partial related data are managed as separate files.

  As a result, real-time after-recording is guaranteed, non-destructive editing performance is high, and reproduction by a general MPEG-2 PS decoder is possible, and reproduction of AV data and reproduction of related data are performed in synchronization. In this case, since the partial AV data and the partial related data are recorded close to each other, there is an effect that the frequency of seek is reduced.

  Further, another AV data recording method of the invention, as described above, includes AV data obtained by multiplexing a plurality of stream data on a recording medium according to a predetermined multiplexing rule, together with related data synchronized with the AV data. An AV data recording method that enables recording, a seventh step of dividing the AV data into partial AV data at predetermined intervals, a series of the partial AV data on the recording medium, and the related An eighth step of securing a first continuous area, which is a continuous area for recording partial reserved data that secures a recording area of partial related data divided corresponding to the partial AV data at the time of data recording; A ninth step of continuously recording the partial AV data and the partial reserved data in the first continuous area while creating the partial reserved data; On the recording medium, file system management information for managing the partial AV data and the partial reserved data as separate files and managing information for handling the partial AV data and the partial reserved data as separate files is provided on the recording medium. And a tenth step for recording.

  In the AV data recording method, an eleventh step of dividing the related data into partial related data at predetermined intervals when recording the related data; and A twelfth step of recording in the reserved area of the partial reservation data recorded continuously; and managing the partial related data as a separate file from the partial AV data and the partial reserved data; And a thirteenth step of recording file system management information for managing information for handling data as a separate file on the recording medium.

  Therefore, the AV data recorded on the recording medium is divided into partial AV data in a recording unit that guarantees seamless reproduction and real-time after-recording. They are recorded at positions that are physically close to each other on the recording medium. The related data is recorded by dividing the related data into partial related data and recording each partial related data in a corresponding reserved area for partial reserved data.

  As a result, when the AV data reproduction and the related data reproduction are performed in synchronization, the partial AV data and the partial related data are recorded close to each other, so that the seek frequency is reduced. .

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The description here will be made in the order of the configuration commonly used in the present invention and the contents specific to each embodiment.

<System configuration>
FIG. 2 is a basic system configuration diagram of a video disk recorder common to the embodiments described later.

  As shown in FIG. 2, the video disk recorder includes a bus 100, a host CPU 101, a RAM 102, a ROM 103, a user interface 104, a system clock 105, an optical disk 106, a pickup 107, an ECC (Error Correcting Coding) decoder 108, an ECC encoder 109, Audio reproduction buffer 110, video reproduction buffer 111, demultiplexer 112, multiplexer 113, recording buffer 114, audio decoder 115, video decoder 116, audio encoder 117, video encoder 118, audio recording buffer 119, video recording buffer 120, demultiplexer 121, post-record data reproduction buffer 122, division processing unit 123 (divides into AV data and partial related data Stage), means for securing a free area management section 125 (continuous region), the management information processing unit 126 and a camera (not shown), a microphone, a speaker, and a display or the like. The pickup 107, the ECC decoder 108, and the ECC encoder 109 constitute a drive 127 (means for continuously recording partial AV data and partial related data, means for recording file system management information on the recording medium). .

  The host CPU 101 controls the demultiplexer 112, the multiplexer 113, the pickup 107, the audio decoder 115, the video decoder 116, the audio encoder 117, and the video encoder 118 through the bus 100.

  During reproduction, data read from the optical disk 106 through the pickup 107 is error-corrected by the ECC decoder 108. The error-corrected data is subjected to file system management information processing by the management information processing unit 126 and sent to the demultiplexer 112 or the demultiplexer 121.

  In accordance with an instruction from the host CPU 101, the demultiplexer 112 distributes the read data to the audio reproduction buffer 110 and the video reproduction buffer 111 according to whether the data is audio data or video data. Similarly, the demultiplexer 121 sends the read data to the after-recording data reproduction buffer 122 in accordance with an instruction from the host CPU 101.

  The audio decoder 115 reads data from the audio reproduction buffer 110 and the after-recording data reproduction buffer 122 in accordance with an instruction from the host CPU 101 and decodes the read data. Similarly, the video decoder 116 reads data from the video playback buffer 111 in accordance with an instruction from the host CPU 101 and decodes the read data.

  On the other hand, at the time of recording, the data compression-encoded by the audio encoder 117 and the video encoder 118 are sent to the audio recording buffer 119 and the video recording buffer 120, respectively. The multiplexer 113 reads data from the audio recording buffer 119 and the video recording buffer 120 in accordance with an instruction from the host CPU 101, AV-multiplexes the read data, and sends the data to the division processing unit 123. The division processing unit 123 divides the AV multiplexed data at predetermined intervals and sends it to the recording buffer 114. At this time, the free space management unit 125 secures a continuous area for recording data, and the ECC encoder 109 adds an error correction code to the AV multiplexed data read from the recording buffer 114 and passes through the pickup 107. Recording is performed in the secured continuous area of the optical disk 106.

  MPEG-1 Layer-II specified by ISO / IEC 13818-3 is used for the encoding method of audio data, and MPEG-2 specified by ISO / IEC 13818-2 is used for the encoding method of video data. . The optical disk 106 is a rewritable optical disk such as a DVD-RAM, and 2048 bytes is one sector, and an ECC block is composed of 16 sectors for error correction.

<File system>
A UDF (Universal Disk Format), which is a file system format used in the description of the present invention, will be described with reference to FIG. FIG. 3B shows an example in which the directory / file structure shown in FIG. 3A is recorded in UDF.

  An AVDP (Anchor Volume Descriptor Pointer) 602 in the figure corresponds to an entry point for searching for UDF management information, and is usually in the 256th sector, the Nth sector, or the N-256th sector (N is the maximum logical sector number). Record. A VDS (Volume Descriptor Sequence) 601 records management information related to a volume that is an area managed by the UDF. One volume generally exists on one disk, and generally contains one partition. One FSD (File Set Descriptor) 603 exists in the partition. The position information in the partition is indicated by a logical block number corresponding to the sector number from the head of the partition. One logical block corresponds to one sector. Each partition has a table (not shown) indicating whether each logical block called Space Bitmap has already been assigned to the file or not.

  The FSD 603 includes position information of the FE 604 that is a file entry (FE) of the root directory (configured by a logical block number and a logical block number and called “extent”). The FE manages a set of extents. By rewriting, adding, or deleting extents, it is possible to change the order of the actual data that makes up a file, and to insert or delete data. It is.

  The FE 604 manages an area 605 that stores a set of file identifier descriptors (FID) that store files directly under the root directory, directory names, and the like. The FID 611 and FID 612 in the area 605 include the position information of the FE 606 and FE 608 that manage the file names of the file 621 and the file 622 and the set of extents. The FE 606 manages the areas 607 and 610 which are areas constituting the actual data of the file 621 as extents. At this time, in order to access the actual data of the file 621, the links may be followed in the order of AVDP 602, VDS 601, FSD 603, FE 604, FID 611, FE 606, area 607, and area 610.

[Embodiment 1]
A first embodiment of the present invention will be described with reference to FIGS. 1 and 4 to 18.

<File directory structure>
The file / directory structure according to the first embodiment will be described with reference to FIG. Data relating to the first embodiment is stored in five types of files as shown in FIG.

  The original stream file (SHRP0001.M2P) is a file created by one recording and is in the MPEG-2 PS (Program Stream) format. The after-recording data file (SHRP0001.PRE) is a file for securing an after-recording area and storing the after-recording data. The original stream management information file (SHRP0001.OMI) is a file that stores time-address correspondence information about the original stream file, attribute information, attribute information about the after-recording data file, and correspondence information with the original stream file. There is one for each file. The program information file (SHRP0001.PGM) is a file that stores information specifying which section of the stream or data is to be played back in what order. The program corresponds to one piece of content, and is a target for the user to instruct playback.

  At the time of recording, the above four files are newly created. These files share a file name extension other than the file name extension in order to show the relationship between the files. At the time of audio after-recording, the after-recording audio data is overwritten at a predetermined position in the after-recording data file, and this is reflected in the after-recording data management information file. Further, the program information file is also changed so that the added after-recording audio data is also subject to playback.

  Further, at the time of nondestructive editing, a new program information file is created, and the file name of the original stream management information file for managing the data to be reproduced and the post-record data management information file and the section to be reproduced are sequentially recorded for the section to be reproduced. The data structure of each file will be described later.

<AV stream format>
The configuration of the AV stream used in Embodiment 1 will be described with reference to FIG.

  First, the original stream file will be described with reference to FIG. The contents of the original stream file are in MPEG-2 PS format, and are composed of an integer number of continuous units (CUs) as shown in FIG. A CU is a unit for continuous recording on a disc. The length of the CU is seamless playback (the video and audio can be played back without interruption during playback) and real-time after-recording (smooth playback of the target video) While recording audio). This setting method will be described later.

  The CU is composed of an integer number of video units (VU) as shown in FIG. VU is a unit that can be played back independently, and can be an entry point during playback. As shown in FIG. 5C, the VU is composed of an integer number of audio packs (A # 1 to A # K) and video packs (V # 1 to V # L), each of which is an MPEG-2 PS format decoder. AV multiplexed so that the model does not fail. The pack size matches the sector size so that extra data does not have to be read when reading the disk. The video data to be packed is composed of 1 to 2 GOPs, and the audio data is packed to an integer number of AAUs (Audio Access Units).

  GOP is a unit of image compression in the MPEG-2 video standard, and is composed of a plurality of video frames (typically about 15 frames). AAU is a unit of audio compression in the MPEG-1 Layer-II standard, and is composed of 1152 sound wave sample points. When the sampling frequency is 48 kHz, the reproduction time per AAU is 0.024 seconds. Further, in order to enable independent reproduction in units of VU, a sequence header (SH) is placed at the head of video data in the VU.

  Note that the VU at the end of the CU is padded with a pack storing padding packets so that the CU is composed of an integer number of ECC blocks.

<Post-recording data file>
The structure of the after-recording data file will be described with reference to FIG. The after-recording data file is composed of an integer number of continuous areas (CA) as shown in FIG. One CU in the original stream file described above exists corresponding to one CA, and post-recording data relating to reproduction data in the corresponding CU is recorded in the CA. For example, post-recording audio data to be reproduced in synchronization with CU # n in the original stream file is recorded in CA # n. CA consists of an integer number of ECC blocks.

  The post-record data file is in the MPEG-2 PS format, like the original stream file, and a padding packet is recorded at the time of initial recording, and after the post-recording, the pack storing the post-recording data is overwritten. The SCR (System Clock Reference) in the pack header of the pack to be overwritten and the PTS (Presentation Time Stamp) in the packet header are matched with those of the corresponding audio pack in the original stream file. As a result, by overwriting the corresponding audio pack in the CU with the audio pack in the CA, the audio of the original stream can be easily replaced with the after-recording data.

<Distribution to disk>
The arrangement of the original stream file and the after-recording data file on the disk will be described with reference to FIG. The mutually corresponding original stream file (SHRP0001.M2P) and after-recording data file (SHRP0001.PRE) shown in FIG. 1A are recorded on the optical disk 106 so that the corresponding CA is placed immediately before the CU (FIG. 1). 1 (b)).

  As a result, the data to be synchronously reproduced (CA and CU) are placed in the vicinity of the disc, so that the movement of the pickup during reproduction is minimized, and reproduction is performed when reproducing the nondestructive editing result as described later. The possibility of interruption is reduced. In addition, it is possible to suppress the amount of buffer memory for synchronous reproduction by arranging small CAs to be read before CUs.

<CU unit determination method>
A method for determining the CU playback time will be described with reference to FIGS. This determination method assumes a standard device (reference device model) and a standard dubbing algorithm (reference dubbing algorithm) to ensure compatibility between devices, and then uses them. The CU playback time is determined so that seamless playback does not fail when post-recording is performed.

  First, the reference device model will be described with reference to FIG. The reference device model includes one pickup (not shown), an ECC encoder / decoder 501 connected thereto, a track buffer 502, a demultiplexer 503, an after-recording buffer 504, an audio encoder 509, a video buffer 505, an audio buffer 506, A video decoder 507 and an audio decoder 508 are included.

  In the reference device model, since there is one pickup, reading of reproduction data from the disk 500 and recording of post-recording data on the disk 500 are performed in a time division manner. When data for reproduction is read from the disk 500, it is read including CA. The ECC block (CA block) including the read CA is sent from the track buffer 502 to the after-recording buffer 504.

  The audio encoder 509 outputs after-recording data to the after-recording buffer 504 at an AAU period. With this output, the corresponding CA block in the after-recording buffer 504 is overwritten. After-recording data is recorded by recording the CA block in a predetermined ECC block.

  Here, the data input speed of the audio frame data to the ECC encoder 501 and the data output speed from the ECC decoder 501 are Rs. Further, Ta is the maximum period during which reading and recording are stopped by access. This period includes a seek time, a rotation waiting time, and a time until data read out from the disk first after access is output from the ECC decoder 501. In the first embodiment, Rs = 20 Mbps and Ta = 1 second.

Next, the reference after-recording algorithm will be described with reference to FIG. The numbers (1) to (6) in FIG. 8 correspond to the numbers (1) to (6) in the following description. The outline of the algorithm is as follows.
(1) Read playback data.
(2) At the same time as encoding of audio data corresponding to CA (N), which is the Nth CA, is completed, access to CA (N) is performed.
(3) Record CA (N) on the disc.
(4) Return to the original reading position.
(5) Read playback data.
(6) Access to CA (N + 1) is performed at the same time as encoding of audio data corresponding to CA (N + 1), which is the N + 1th CA, is completed.
Thereafter, the operations (3) to (6) are repeated.

  In the reference device model, when the after-recording is performed using the reference after-recording algorithm, it is guaranteed that there is no overflow of the after-recording buffer 504 and no underflow of the track buffer 502 if the following conditions are satisfied. it can.

  That is, for CU # i that is an arbitrary CU in the AV stream, the maximum playback time is Te (i), the maximum read time including a split jump is Tr (i), and the CA # i that is the CA corresponding to CU # When the maximum recording time is Tw (i), the following equation (1) may be satisfied.

  This is because the above formula (1) satisfies the following formula (2), which is a sufficient condition for seamless reproduction. Further, in the following formula (2), Ta is the maximum access time required for a round-trip access to the CA.

  Further, since the after-recording data is recorded on the disk in synchronization with the completion of the CA encoding, the data in the after-recording buffer 504 is not accumulated, and the after-recording buffer 504 does not overflow.

  Tr (i) in equation (1) satisfies the following equation (3) when the maximum bit rate of the original stream and the maximum bit rate of the after-recording audio stream are Ro and Ra, respectively. Rs indicates the input speed and output speed of audio frame data, that is, the audio bit rate.

  The first and second terms on the right side of the above equation (3) represent the VU read time and CA read time in the CU, respectively. The third term on the right side represents the access time due to the split jump accompanying reading. Since the divisional jump during the CU reading is a maximum of one time, the above equation (3), that is, Tr (i) indicates the access time for one time.

  Tw (i) satisfies the following expression (4).

  Here, the first term on the right side of the equation (4) indicates the round-trip access time to the CA. The reason why the maximum access time Ta is used for the round-trip access time to the CA is that recording is possible at an arbitrary position in units of CA, so that the CU being read is the innermost circumference of the disc and the CA to be recorded is recorded. Is considered to be the outermost circumference of the disk, and it is necessary to estimate the maximum value.

  Since the CA is continuously recorded on the disc as described above, access during CA recording does not occur. As a result, the time required for CA recording can be shortened, and as a result, the lower limit of the CU playback time can be kept low.

  By substituting Equation (3) and Equation (4) into Equation (1) and solving with Te (i), the condition of Te (i) that can guarantee real-time after-recording, that is, Equation (5) below is obtained. Rv indicates the input speed and output speed of the video frame data, that is, the video bit rate.

  In other words, the CU playback time lower limit value Temin that can be guaranteed after-recording is expressed by the following equation (6).

  At this time, the upper limit value Temax of the CU playback time is set as in the following equation (7). Here, Tvmax is the maximum playback time of VU.

  The upper limit of the CU playback time is set in order to make it possible to estimate the maximum amount of delay memory required for synchronized playback of post-recording sound and normal sound, and to guarantee playback compatibility. In Embodiment 1, the multiplexing interval lower limit value Temin is set according to the audio bit rate Ra and the video bit rate Rv. However, a fixed lower limit value may be set regardless of the bit rate. However, the value must be based on the maximum bit rate.

  Further, the VU playback time in the stream may be fixed or variable as long as the CU playback time satisfies the above restriction.

  In the first embodiment, it is assumed that the split jump and the movement of the pickup to the past CU are performed asynchronously. The reason for this is that the condition for performing real-time after-recording is more severe than when performing asynchronously (the read data is interrupted for a longer period of time), so asynchronous real-time after-recording is possible. This is because synchronization is possible and the degree of freedom of implementation can be increased.

  Therefore, Temin may be set on the assumption that the split jump and the movement of the pickup to the past CU are performed in synchronization. In this case, the second term on the right side of Equation (3) may be removed and considered.

<Management information file format>
The management information file format according to the present invention will be described with reference to FIGS.

  First, the original stream management information file will be described. As shown in FIG. 9, the original stream management information file has o_attribute () for storing attribute information about the entire original stream file managed by this file, video_unit_table () for storing information about VU, and post-record data managed by this file. It consists of p_attribute () that stores attribute information related to the entire file, and continuous_area_table () that stores information related to CA.

  As shown in FIG. 10A, video_unit_table () is composed of number_of_video_unit indicating the number of VUs and video_unit_info () storing information on each VU.

  As shown in FIG. 10B, video_unit_info () is VU_flags indicating various attribute information related to a predetermined VU, VU_PTS storing a PTS (Presentation Time Stamp) of a head display frame of the predetermined VU, and from the head of the file. It is composed of VU_PN that stores the relative pack number. VU_PTS and VU_PN make it possible to specify the position of the VU corresponding to a specific PTS. That is, VU_PTS indicates the reproduction start time of the original stream (AV data), and VU_PN indicates position information of the first continuous area in which CA and CU are recorded, in other words, CA head position information.

  VU_flags () includes a flag first_unit_flag as shown in FIG. First_unit_flag is 1-bit information. As shown in FIG. 11B, 0b means that the VU to be managed is not the head of the CU, and 1b means that the VU to be managed is the head of the CU. Means that.

  As shown in FIG. 12A, continuous_area_table () is composed of number_of_continuous_area indicating the number of CAs and continuous_area_info () for storing information on each CA.

  As shown in FIG. 12B, continuous_area_info () is CA_flags indicating various attribute information related to a predetermined CA, CA_PTS storing a PTS (Presentation Time Stamp) of the head display frame of the corresponding CU regarding the predetermined CA, and Consists of CA_PN that stores the relative pack number from the beginning of the file. CA_PTS and CA_PN make it possible to specify the location of the CA corresponding to a specific PTS in the original stream.

  CA_flags () includes a flag placement_flag as shown in FIG. The placement_flag is 1-bit information. As shown in FIG. 13B, in the case of 0b, it means that the managed CA is not immediately before the corresponding (synchronized playback) CU, and in the case of 1b, it is managed. This means that the CA to be executed is immediately before the corresponding (synchronized playback) CU.

  By referring to this flag, it is possible to know the possibility that the reproduction is interrupted when the nondestructive editing result is reproduced. That is, if this flag is 0b, it can be seen that there is a high possibility that seek to the CA will occur and playback will be interrupted.

  A description of o_attribute () and p_attribute () is omitted.

  Finally, the program information file will be described. As shown in FIG. 14, the program information file is composed of pg_attribute () for storing attribute information of the entire program information, and scene_table () for storing information regarding each scene constituting the program.

  As shown in FIG. 15A, the scene_table () includes number_of_scene that stores the number of scenes and scene_info () that stores information on each scene. As shown in FIG. 15B, scene_info () stores the file name of the original stream management information file that manages the original stream file including the predetermined scene, and from where in the original stream the predetermined scene is reproduced. Sc_start_PTS for storing the above information and sc_duration for storing the playback time of a predetermined scene.

<Processing during recording>
Next, processing when recording is instructed by the user will be described with reference to the flowchart of FIG. The AV stream to be recorded at this time is a corresponding stream with a bit rate Ro = 12 Mbps, an audio bit rate Ra = 256 kbps, and a fixed VU playback time. It is assumed that the file system management information has already been read into the RAM.

  First, a stream configuration and a continuous region configuration are determined (S701). When 1VU is composed of 1 GOP15 frame, the conditions of Rs = 20 Mbps, Ta = 1 second, Rv = 12 Mbps, Ra = 256 kbps, and Tvmax = about 0.5 seconds are substituted into Equation (6) and Equation (7). Thus, the range of Te (i) is obtained as 3 seconds or more and 4 seconds or less. This condition is satisfied when Tvmax = about 0.5 seconds when Te (i) = 3 seconds, and a CA is inserted for every six VUs.

  The CA area size at this time is determined in consideration of the fact that a pack header and a packet header are added to audio data for 3 seconds. As described above, the process of S701 converts the original stream as AV data and the post-record data as the related data into partial AV data (CU: 6 VUs) and partial related data (CA) at predetermined intervals. This corresponds to the first step of dividing.

  An empty area capable of continuously recording six VUs and one CA is searched with reference to a space bitmap on the RAM 102. If it does not exist, the recording is stopped and the user is notified that the recording cannot be performed (S702).

  Next, the audio encoder 117 and the video encoder 118 are activated (S703). Further, it is checked whether or not data for one ECC block (32 KB) or more is stored in the recording buffer (S704), and the processing from S705 to S708 is repeated while the data is stored.

  That is, if data for one ECC block or more is stored in the recording buffer, the vacant status of the ECC block on the disk to be recorded next is checked with reference to the space bitmap on the RAM (S705). If there is a vacancy, data for one ECC block in the recording buffer 111 is recorded on the disk (S706). If there is no free space, a continuous free space in which 9 VUs and CAs can be recorded is searched (S707), the pickup is moved to the head of the free space (S708), and one ECC block in the recording buffer 111 is stored. Are recorded on the disc (S706).

  As described above, the process of S704 corresponds to a second step of securing a first continuous area that is a continuous area for recording a series of partial AV data and partial related data. The processing of S706 corresponds to a third step of continuously recording the partial AV data and the partial related data in the first continuous area.

  On the other hand, if data of one ECC block or more is not accumulated in the recording buffer 111, it is checked whether or not the recording end is instructed (S709), and if the recording is not ended, the process proceeds to S704.

  If recording end is instructed in S709, the following processing is executed. First, dummy data is added to the end of the data less than 32 KB in the recording buffer to make it 32 KB (S710). Next, the data is recorded on the disc (S711 to S714). Note that the processing of 711 to S714 is similar to the processing of S705 to S708.

  Further, the management information about the original stream and the management information about the after-recording data on the RAM 102 are recorded in the original stream management information file and the after-recording data management information file, respectively (S715). Further, file system management information is recorded on the optical disk 106 (S716). Note that the file system management information at that time is configured so that CA and CU are handled as separate files.

  As described above, the process of S716 manages the partial AV data and the partial related data as separate files, and separates the partial AV data and the partial related data from the first continuous area into separate files. This corresponds to the fourth step of recording file system management information for managing information for handling on the recording medium.

  The process of S715 corresponds to a fifth step of recording the reproduction start time of the partial AV data and the correspondence information of the position information of the first continuous area on the recording medium.

  The operations of the audio encoder 117, the video encoder 118, and the multiplexer 113 in parallel with the above processing will be described. The result encoded by each encoder is sent to the audio recording buffer 119 and the video recording buffer 120. The multiplexer 113 multiplexes these data into MPEG-2 PS and stores them in the recording buffer 114.

  If data for 1 VU is sent to the recording buffer 114 and the VU is a 9 × i-th VU (i is an integer equal to or greater than 0), the CA having the above-described size is the recording buffer 111 first. Send to.

  Further, the host CPU 101 is notified that data of 1 VU has been encoded, and the host CPU 101 relates to management information and post-record data relating to the original stream on the RAM 102 based on the top PTS of the VU, the number of packs and the number of packs constituting the CA. Update management information.

<Processing during playback>
Processing in the case where reproduction is instructed by the user to a program that has already been dubbed will be described with reference to the flowchart of FIG. Here, it is assumed that the program information file to be reproduced has already been read into the RAM 102.

  First, sc_filename of scene_info () in the program information file is referred to, and the original stream file and the after-record data file referred to by this program are opened. At the same time, an original stream management information file for managing them is read (S901).

  Next, 0 is set to the scene number (S902), and while the scene number is smaller than number_of_scene in the scene_table () (S903), the scene described later is reproduced with reference to the contents of the scene_info corresponding to the following scene numbers. (S904) When finished, the scene number is incremented (S905).

  Next, scene reproduction processing will be described with reference to FIG. First, the video_unit_table () of the original management information corresponding to the sc_filename in the scene_info () that has already been read into the RAM 102 is referenced to search for the video_unit_info () that is not more than sc_start_PTS and has the maximum VU_PTS (S801). The process of S801 determines the VU number of the scene where playback is started. Note that the order of video_unit_info () in video_unit_table () is called a VU number.

  Next, referring to continuous_area_table (), a search is made for continuous_area_info () having a maximum CA_PTS that is less than or equal to sc_start_PTS (S802). The processing in S802 is to obtain the CA address corresponding to the scene where playback is started. Further, from the pack specified by CA_PN in the pack to the pack immediately before the pack specified by CA_PN of the next continuous_area_info () is read from the after-recording data file (S803).

  Next, the VU address is obtained by referring to the VU_PN of the video_unit_info () corresponding to the current VU number (S804), and the VU is read from the original stream file based on this (S805). Next, it is determined whether the end of the scene is reached (S806). Specifically, if the playback time of the current scene is greater than or equal to sc_duration in scene_info (), the end of the scene is set.

  If the playback of the scene has not ended, next, the VU number is incremented (S807), and by referring to first_unit_flag in video_unit_info (), whether or not the VU managed by the video_unit_info () is the head of the CU Is determined (S808).

  At this time, if first_unit_flag is 1, it is determined that the VU managed by the video_unit_info () is the head of the CU, the address of the corresponding CA is obtained by the above procedure (S809), and the CA is read from the after-recording data file. Perform (S810). On the other hand, if first_unit_flag is 0, it is determined that the VU managed by the video_unit_info () is not the head of the CU, and the processes of S804 to S808 are repeated.

  In parallel with the reading of the stream and data from the optical disk 106, the decoding process is performed as follows. First, the read VU is sent to the demultiplexer 112, the video PES packet and the audio PES packet are taken out, the video PES packet is sent to the video playback buffer 111, and the audio PES packet is sent to the audio playback buffer 110. It is done.

  The demultiplexer 112 extracts the SCR from the pack header and updates the system clock 105. The video decoder 116 and the audio decoder 115 perform decoding and output when the system clock 105 matches the time stamp attached to the PES packet header.

  In the first embodiment, since the CU storing the original stream and the CA storing the post-recording data for synchronized playback are in the physical vicinity on the disk, the scene start is from the VU near the end of the CU. Even so, the data read stop time caused by the CA to VU seek is very short.

  On the other hand, if the post-record data is not placed near the original stream to be played back synchronously, the seek time between the post-record data read at the beginning of the scene and the original stream read is from the innermost to the outermost of the worst disk. It will lead to. Therefore, there is a higher possibility that the reproduction is interrupted between scenes as compared to the present embodiment.

<Processing after dubbing>
Next, processing when a user instructs post-recording will be described. Since the post-recording process is obtained by adding several processes to the above-described playback process, only the difference will be described.

  First, in order to record after-recording data, the audio encoder 117 is activated simultaneously with the start of scene reproduction, and the result of encoding the after-recording data is sent to the audio recording buffer 119 in the form of a PES packet. The multiplexer 113 packs the PES packet and sends it to the recording buffer 114. At that time, the SCR of the pack header and the PTS of the packet header are matched with the original stream.

  When a pack having a PTS exceeding the range of the CU currently being decoded arrives at the recording buffer 114, the pack string existing in the recording buffer 114 is recorded in the after-recording data file. The position of the CA to be recorded is obtained by referring to continuous_area_table () from the PTS of the CU currently being decoded.

  If a defect is encountered during CA recording, the CA being recorded is discarded and a new CA is recorded in another area. This is because the CA recording area being recorded is reduced by the defect, and data corresponding to the reproduction time of the corresponding CU cannot be recorded in the CA. At that time, by changing the placement_flag in continuous_area_info () that manages the CA to 0, it is understood that there is no CA immediately before the corresponding CU. Of course, the discarded CA extent in the file system management information is replaced with the newly created CA extent.

  As a result, during non-destructive editing or during playback of non-destructive editing results, sections where CA and CU are not continuously recorded can be found by simply referring to the placement_flag, and there is a high possibility that playback will be interrupted in those sections. Can be communicated to the user in advance. In addition, CA and CU that are not continuously recorded can be rearranged so as to be continuously recorded later, relying on this flag.

<Modification in Embodiment 1>
In the first embodiment, the post-record data file is recorded in the MPEG-2 PS format in the same way as the original stream file. However, it is also possible to record without the elementary stream, that is, without being packed or packetized. This eliminates the trouble of extracting the AAU from the pack, replacing the AAU, and repacking when rewriting the post-record data of only a part of the CA.

  In the first embodiment, audio data is recorded in the CA, but other types of data may be recorded. For example, graphics data to be displayed superimposed on the video in the original stream may be recorded.

  In the first embodiment, one AAU can be recorded so as to span a plurality of packs, but may be limited so as not to straddle. Thus, when the after-recording data of only a part of the CA is rewritten, it is only necessary to overwrite the pack including the AAU to be rewritten.

  In the first embodiment, when a defect is detected during CA after the dubbing, the CA is discarded and recorded in another area. However, assuming that there is a defect, the size of the CA is determined in consideration of a margin for the defect during the initial recording, and if a defect is detected during the post-recording, it is recorded at the next position in the CA. Also good. As a result, CA and CU can be recorded continuously.

  In the first embodiment, since CA and CU, which are separate files, are associated with each other, the head addresses of CU and CA can be calculated from the time stamp at the beginning of the data in the CU. It goes without saying that any form of expression may be used as long as it is understood.

  In Embodiment 1, MPEG-2 PS is used, but it goes without saying that MPEG-2 TS can be similarly realized.

[Embodiment 2]
A second embodiment of the present invention will be described with reference to FIG.

  The difference between the second embodiment and the first embodiment is that the first embodiment continuously arranges a plurality of data to be synchronized and reproduced on a recording medium, and manages each data as a separate file. In contrast, the second embodiment is based on the premise that each piece of data is on the same reproduction time axis but is not reproduced at the same time but is switched and reproduced.

  Specifically, a function called a multi-angle function in DVD-Video, which can be switched during playback of videos from a plurality of angles on the same time axis, is assumed.

  In the recording operation according to the second embodiment, the relationship between the original stream to be synchronously reproduced and the after-recording data in the recording operation according to the first embodiment is represented by two kinds of original streams on the same reproduction time axis. The actual operation is the same.

<File structure>
Video / audio data is multiplexed in MPEG-2 PS format and recorded in a separate file for each angle. In the example of FIG. 19A, data from the first angle is recorded in ANGL0001.M2P, and data from the second angle is recorded in ANGL0002.M2P.

<Distribution to disk>
As shown in FIG. 19B, the data from the first angle ANGL0001.M2P is divided into partial data 2021, 2022, and 2023, and the data from the second angle ANGL0002.M2P is divided into partial data 2011, The data is divided into 2012 and 2013 and arranged alternately on the disk 2001. Note that the method for determining the division unit is the same as the arrangement of multi-angle data in DVD-Video, and thus the description thereof is omitted.

  As a result, an angle switching response similar to multi-angle switching in DVD-Video can be realized, and at the same time, each data file can be reproduced by a general MPEG-2 PS compatible decoder.

[Embodiment 3]
A third embodiment of the present invention will be described with reference to FIGS.

  The difference between the third embodiment and the first embodiment is that in the first embodiment, the after-recording area is managed by one file (that is, the after-recording data file (SHRP0001.PRE) in FIG. 4). On the other hand, in the third embodiment, a file for securing a free area and a file for recording individual AV data are separated. Since the third embodiment is similar to the first embodiment, only the differences will be described.

<File directory structure>
FIG. 21 shows a file / directory structure according to the third embodiment. In this file / directory structure, an after-recording area reservation file (SHRP0001.RSV), an after-recording data management information file (SHRP0001.PMI), and a graphics file are added to the file / directory structure in the first embodiment (see FIG. 4). (SHRP0001.PNG) has been added.

  The after-recording area reservation file (SHRP0001.RSV) is a file for reserving an after-recording area. The after-recording data management information file (SHRP0001.PMI) is management information corresponding to the after-recording data file. The graphics file (SHRP0001.PNG) is a file that stores graphics data to be superimposed on the video. Further, the program information file (SHRP0001.PGM), the original stream management information file (SHRP0001.OMI), and the original stream file (SHRP0001.M2P) are the same as the files having the same names in the first embodiment.

  One after-recording area reservation file is recorded for each original stream file at the time of recording. One after-recording data management information file is created for each after-recording data file. The graphics file is a file added by nondestructive editing after recording, and stores titles and handwritten character images to be superimposed on the video. PNG (Portable Network Graphics) is used as an image storage format in the graphics file.

  Also, the post-record data file (SHRP0001.PRE) is generated only after performing post-recording, unlike the first embodiment. That is, at the time of recording, an after-recording area reservation file is recorded instead of the after-recording data file in the first embodiment.

<AV stream format>
The form of the AV stream is the same as that of the first embodiment described with reference to FIG.

<Dubbing area reservation file>
The after-recording area reservation file has the same configuration as the after-recording data file shown in FIG. 6 in the first embodiment. That is, the after-recording area reservation file is composed of an integer number of continuous areas (CA), and one CA exists corresponding to one CU in the original stream file, and an area for recording the after-recording data of the corresponding CU is secured. To do. However, the CA here is only for securing an area, and is not AV data to be played back, so the content data may be anything.

<Distribution to disk>
An arrangement form of each file on the disk in the third embodiment will be described. 22A to 22B show the file arrangement in a state where no after-recording has been performed after recording (that is, no after-recording data file has been created). The original stream file (SHRP0001.M2P) and the after-recording area reservation file (SHRP0001.RSV) corresponding to each other shown in FIG. 22A are recorded so that the corresponding CA is arranged immediately before the CU on the optical disc 106 ( FIG. 22 (b)).

  Next, the arrangement of the after-recording area reservation file, the after-recording data file, and the graphics file on the disc after additionally recording the audio and graphics will be described with reference to FIGS. 23 (a) to 23 (b). FIG. 23A shows the configuration of a graphics file (SHRP0001.PNG) and an after-recording data file (SHRP0001.PRE) to be additionally recorded. The graphics file stores graphics data IMG. The post-record data file includes post-record audio data PR # 1, PR # 2, and PR # 3 corresponding to each of CU # n-1, CU # n, and CU # n + 1 in the original stream file shown in FIG. Storing.

  The above-mentioned IMG and PR data are arranged on the optical disc 106 in the form shown in FIG. That is, in FIG. 22B, PR # 1 is assigned to the area reserved for CA # n-1, PR # 2 is assigned to the area reserved for CA # n, and PR is assigned to the area reserved for CA # n + 1. # 3 is arranged. Further, the graphics data IMG is arranged in an area secured by CA # n + 1.

  Thus, by arranging IMG and PR data in the area reserved by CA, CA # n-1, CA # n, CA # n + 1 areas constituting the after-recording area reservation file (SHRP0001.RSV) The size is reduced. This reduction is realized by changing the extent managing each CA area in the file system management information.

  In this way, by introducing an after-recording area reservation file that is a file for managing the free space in the after-recording area, it becomes easy to add a plurality of types of data later. Further, by storing the graphics data and the after-recording audio data in different files, only the graphics data can be referred to from another program, thereby increasing flexibility.

<Management information file format>
The format of the original stream management information file is the same as that in the first embodiment, and a description thereof is omitted here. The format of the after-recording data management information file is almost the same as the original stream management information file in the first embodiment, but differs in that p_attribute () and continuous_area_table () do not exist.

  Next, the structure of the program information file is shown in FIG. The program information file according to the third embodiment is different from the first embodiment in that subaudio_table () and graphics_table () for managing audio data and graphics data added after recording are added, respectively (see FIG. 14). Is different.

  As shown in FIG. 25A, the subaudio_table () is composed of number_of_subaudio indicating the number of audio data and subaudio_info () for storing information on each audio data. As shown in FIG. 25 (b), subaudio_info () includes SA_filename for storing a file name of an after-recording data management information file for managing predetermined audio data, SA_flags for managing various attributes of predetermined audio data, and a program. It is composed of SA_start_time and SA_duration respectively indicating the playback start timing and playback duration.

  On the other hand, graphics_table () is composed of number_of_graphics representing the number of graphics files and graphics_info () for storing information on each graphics file, as shown in FIG. As shown in FIG. 26 (b), graphics_info () includes gr_filename for storing a file name of a predetermined graphics file, gr_flags for managing various attributes of predetermined graphics data, reproduction start timing in the program, It consists of gr_start_time and gr_duration indicating the playback duration.

  SA_flags and gr_flags have the same configuration, and include a flag interleave_flag as shown in FIG. interleave_flag is 1-bit information. As shown in FIG. 27B, interleave_flag means that the managed audio data or graphics file is not immediately before the corresponding (synchronized playback) CU in the case of 0b. In the case of, it means that it is immediately before the corresponding (synchronized playback) CU. By referring to this flag, it is possible to know the possibility that the reproduction is interrupted when the nondestructive editing result is reproduced. That is, if this flag is 0b, it can be seen that there is a high possibility that seek to the CA will occur and playback will be interrupted.

<CU unit determination method>
The CU unit determination method is the same as the method of the first embodiment described with reference to FIGS.

<Processing during recording>
The processing at the time of recording is the same as the processing in the first embodiment described with reference to FIG.

<Processing during playback>
A process in the case where reproduction is instructed by the user to a program that has already been dubbed will be described below. Since the basic flow is the same as that described with reference to the flowchart of FIG. 17 in the first embodiment, the description of the same processing is omitted. However, in the playback process according to the third embodiment, the scene playback process is different from that of the first embodiment, and therefore only the scene playback process will be described with reference to FIG.

  First, the video_unit_table () of the original management information corresponding to the sc_filename in the scene_info () that has already been read into the RAM 102 is referenced to search for the video_unit_info () that is not more than sc_start_PTS and has the maximum VU_PTS (S801). Note that the order of video_unit_info () in video_unit_table () is called a VU number.

  Next, with reference to graphics_table () and subaudio_table () of the program information file, it is searched whether or not there is a graphics file and audio data to be synchronized with a CU including the current VU (S802 '). When such a graphics file and audio data exist, the file is read for the graphics file, and for the audio data, the audio data management information file that manages the audio data is referred to, and the corresponding audio data Is read (S803 ').

  Next, the VU address is obtained by referring to the VU_PN of the video_unit_info () corresponding to the current VU number (S804), and the VU is read from the original stream file based on this (S805). Next, it is determined whether the end of the scene is reached (S806). Specifically, if the playback time of the current scene is greater than or equal to sc_duration in scene_info (), the end of the scene is set.

  If the playback of the scene has not ended, the VU number is incremented (S807), and first_unit_flag in video_unit_info () is referred to. At this time, if first_unit_flag is 1, it is determined that the VU managed by the video_unit_info () is the head of the CU (S808), and the existence of the graphics file and audio data to be synchronized is confirmed by the above procedure ( S809 '), if it exists, it is read out by the procedure described above (S810').

<Processing after dubbing>
A process when the user instructs post-recording will be described. Since the post-recording process is obtained by adding several processes to the above-described playback process, only the difference will be described.

  First, it is confirmed whether or not there is an area for post-recording on the recording medium. Specifically, continuous_area_info () in the management information file related to the stream to be dubbed is checked to check whether the size of each area secured by the dubbing area reservation file is a size capable of recording the dubbing data. If there is a sufficient size, the after-recording data is recorded in that area, and if there is not enough size, the after-recording data is recorded in another area instead of the area reserved by the after-recording area reservation file.

  Next, the audio encoder 117 is activated simultaneously with the start of reproduction, and the encoded result is sent to the audio recording buffer 119 in the form of a PES packet. The multiplexer 113 packs the PES packet and sends it to the recording buffer 114. At that time, the SCR of the pack header and the PTS of the packet header are matched with the original stream.

  When a pack having a PTS exceeding the range of the CU currently being decoded arrives at the recording buffer 114, the pack string existing in the recording buffer 114 is recorded in the after-recording data file. The position of the CA to be recorded is obtained by referring to continuous_area_table () from the PTS of the CU currently being decoded. After-recording data is recorded in an after-recording data file in an area secured by the CA.

  When the dubbing is over, do the following: First, an after-recording data management file corresponding to the recorded after-recording data file is created. At that time, one video_unit_info () is created for each CU.

  Next, an entry is added to subaudio_table in the program information file. At this time, if after-recording data is recorded in an area reserved in the after-recording area reservation file, interleave_flag of SA_flags () is set to 1 to indicate that fact. Otherwise set 0.

  In addition, regarding the after-recording area reserved file, the area where the after-recording data is recorded is excluded from the management targets of the file. That is, the size is reduced. Further, the CA_PN of each entry in continuous_area__table () is reduced by that amount. As a result, when continuous_area_info () is referred to, it can be seen how much data can be recorded in each CA.

<Process when adding graphics data>
Processing when the user gives an instruction to add graphics data to be superimposed on the video will be described. First, it is checked whether there is an area for recording a file storing graphics data. Specifically, the graphics data can be recorded in the CA corresponding to the CU including the video frame for starting the superimposed display of the graphics data by examining the continuous_area_info () in the management information file regarding the stream to which the graphics data is to be added. Check if a region exists.

  If the graphics data can be recorded in the CA, the area is recorded in that area, and the area where the graphics data is recorded is released from the after-recording area reservation file in the same manner as at the end of the after-recording. The CA_PN of the subsequent entry in the continousou_area_info () is reduced by the amount released. Also, one entry of graphics_info () is added to graphics_table () of the program information file, and interleave_flag of gr_flags () in that entry is set to 1. In this case, since the graphics data is recorded at a position close to the video data to be reproduced at the same time on the disc, a seek for reading out the graphics data at the time of video reproduction becomes unnecessary. Therefore, it is possible to suppress interruption of video reproduction due to seek, power consumption, and the like.

  On the other hand, if graphics data cannot be recorded in the CA, the graphics data is recorded in another area. Also, one entry of graphics_info () is added to graphics_table () of the program information file, and interleave_flag of gr_flags () in that entry is set to 0. By referring to this flag at the time of reproduction, it is possible to inform the user that the interruption of the video reproduction may occur before the video reproduction.

<Modification in Embodiment 3>
In the third embodiment, the graphics file and the after-recording data file are additionally recorded after recording, but it goes without saying that they may be recorded at the time of recording. Even in such a case, the graphics file and the after-recording data file can be handled as a file independent of the video file, and the video file is a general MPEG-2 PS file, and seek is not required for synchronous playback.

  In the third embodiment, the PNG file format is used for the graphics file, but it goes without saying that other file formats such as JPEG may be used.

[Embodiment 4]
A fourth embodiment of the present invention will be described with reference to FIGS. The positioning of the fourth embodiment is a variation of the disk arrangement and CU unit determination method in the first embodiment. Therefore, since other parts are common, only the differences will be described.

<File directory structure>
Since it is the same as Embodiment 1, description is abbreviate | omitted.

<AV stream format>
The first embodiment is the same as the first embodiment except for the following points. The difference from the first embodiment is that the CU does not have to be continuously recorded in the present embodiment.

<Post-recording data file>
Since it is the same as Embodiment 1, description is abbreviate | omitted.

<Distribution to disk>
The arrangement of the original stream file and the after-recording data file on the disk will be described with reference to FIG. The mutually corresponding original stream file (SHRP0001.M2P) and post-recording data file (SHRP0001.PRE) shown in FIG. 29A correspond in principle to the optical disk 106 immediately before the CU as in the first embodiment. However, unlike the first embodiment, it is allowed to divide in the middle of the CU. Examples are CU # n-1 and CU # n in FIG. However, regarding CA, as in the first embodiment, division within one CA is not allowed. Also, the total playback time of VUs included in one continuous area must be equal to or longer than the playback time of the CU.

  As described above, by allowing the division in the middle of the CU, the possibility that the free area can be effectively used increases. For example, when the CU is 16 seconds and there is a continuous free area for 20 seconds on the optical disc 106, if the division is not allowed in the middle of the CU, only 16 seconds can be recorded in the free area, and the remaining 4 seconds are wasted. However, if it can be divided in the middle of the CU, it is possible to record for 20 seconds.

<CU unit determination method>
A method for determining the CU playback time will be described with reference to FIG. In this determination method, as in the first embodiment, a standard device (reference device model) and a standard dubbing algorithm (reference dubbing algorithm) are assumed to ensure compatibility between devices. Then, the CU playback time is determined so that seamless playback does not fail when the post-recording is performed using them.

  Since the reference device model is the same as that of the first embodiment, description thereof is omitted.

  The reference after-recording algorithm is expressed by the following (a) and (b). (A) In principle, CA recording is performed when reading of the current CU is completed. (B) However, if the end of the next CU of the CU being currently read is included in another continuous area, the CA recording is performed until the reading of the next CU of the CU being currently read is completed. put off.

  An example is shown in FIGS. 30 (a) and 30 (b). FIG. 30A is an example of the above (a). Note that numbers (1) to (8) in FIG. 30 correspond to numbers (1) to (8) in the following description.

  (1) Read CU # N which is the Nth CU. (2) Wait for the end of encoding of the CA # M after-recording data, which is the CA to be recorded next, and move the pickup to CA # M when the encoding is completed. (3) Record dubbing data in CA # M. (4) Move pickup to CU # N + 1. (5) Read CU # N + 1. (6) Wait for the end of the encoding of the post-record data of CA # M + 1, which is the CA to be recorded next, and move the pickup to CA # M + 1 when the encoding is completed. (7) Record dubbing data in CA # M. (8) Move pickup to CU # N + 2.

  FIG. 30B is an example of the above (b). (1) First, CU # N is read. At this time, since the end of CU # N + 1, which is the next CU, exists in another continuous area, CA recording is not performed immediately after reading CU # N, and CU # N + 1 exists in the same continuous area among CU # N + 1. Read up to the first half. (2) After reading CU # N + 1 to the end of the continuous area, move the pickup to CA # M, (3) record post-record data in CA # M, and (4) the remaining part of CU # N + 1 Move the pickup to.

  By using such an algorithm, even when the CU is divided in the middle, the jump between continuous areas and the jump for CA recording can be made common, and the interruption of data reading due to the jump is minimized. The area length and the unit of CU / CA can be reduced. This makes it possible to effectively use the free space on the disk.

  In the reference device model, when the after-recording is performed using the reference after-recording algorithm, it is guaranteed that there is no overflow of the after-recording buffer 504 and no underflow of the track buffer 502 if the following conditions are satisfied. it can.

  The condition is that expression (1) is established as in the first embodiment. The symbols in the fourth embodiment have the same meaning as in the first embodiment unless otherwise specified.

  Tw (i) in the formula (1) is the same as that in the formula (4) in the first embodiment, but the Tr (i) is expressed by the formula (3) in the first embodiment as shown in the formula (8). In other words, it is a form that does not include jumps.

  The reasons for not including jumps are as follows. This is because in the fourth embodiment, since the CA recording is performed at the time of the jump during the CU reading, the jump during the CU reading is handled as a jump during the CA recording. As a result, the final CU unit and continuous region unit can be reduced.

  By substituting Equation (8) and Equation (4) into Equation (1) and solving with Te (i), the condition of Te (i) that can guarantee real-time after-recording, that is, Equation (9) below is obtained.

  In other words, the CU playback time lower limit value Temin that can be guaranteed after-recording is expressed by the following equation (10).

  At this time, the upper limit value Temax of the CU playback time is set as shown in the following formula (11). Here, Tvmax is the maximum playback time of VU.

  The upper limit of the CU playback time is set in order to make it possible to estimate the maximum amount of delay memory required for synchronized playback of post-recording sound and normal sound, and to guarantee playback compatibility. In the fourth embodiment, the multiplexing interval lower limit value Temin is set according to the audio bit rate Ra and the video bit rate Rv. However, a fixed lower limit value may be set regardless of the bit rate. However, the value must be based on the maximum bit rate.

  Further, the VU playback time in the stream may be fixed or variable as long as the CU playback time satisfies the above restriction.

<Required buffer memory size>
In the present embodiment, the capacity of the track buffer 502 required for post-recording may be calculated based on the following idea. First, assuming the case where the capacity is most necessary in the fourth embodiment, it is a case where after-recording data recording to CA occurs continuously. Specifically, this is a case where the division is performed immediately before the end of the CU. In other words, the CU is divided and recorded in two continuous areas, and most of the data exists in the preceding continuous area.

  In this case, according to the above-mentioned reference after-recording algorithm, after-recording data recording to the CA is performed immediately before the end of the CU, and immediately after reading a small amount of data at the end of this CU, the after-recording data recording to the next CA is performed. And return to read CA. In order to cope with this, a capacity capable of continuing reproduction over the period of two after-recording data recordings to the CA and one CA reading period is required. Specifically, the capacity Bpb of the track buffer 502 may be secured according to the equation (12).

<Management information file format>
Since it is the same as Embodiment 1, description is abbreviate | omitted.

<Processing during recording>
The first embodiment is the same as the first embodiment except for the limitation of continuously recording CUs on the disc, and thus the description thereof is omitted.

<Processing during playback>
Since it is the same as Embodiment 1, description is abbreviate | omitted.

<Processing after dubbing>
The first embodiment is the same as the first embodiment except that the algorithm shown in FIG.

<Modification in Embodiment 4>
Although the fourth embodiment has been described as a variation of the first embodiment, it is the same as in the case of using an after-recording area reservation file as in the third embodiment or Japanese Patent Laid-Open No. 2001-43616 referred to as a conventional technique. Needless to say, it can also be applied to files. That is, the essence of the invention disclosed in the present embodiment lies in the model setting for setting the physical layout of the after-recording area and the initially recorded video data and the parameters relating to the layout.

FIG. 1A shows an embodiment of the present invention, FIG. 1A shows the data structure of an original stream file and post-record data file in Embodiment 1 of the present invention, and FIG. 1B shows the original stream file and post-record data. It is a figure which shows arrangement | positioning on the disk of a file. It is a block diagram which shows schematic structure of the video disc recorder which concerns on embodiment of this invention. FIG. 3A is a diagram showing a directory / file configuration, and FIG. 3B is a diagram showing a relationship of management information in the UDF of the directory / file configuration. It is a figure which shows the file / directory structure in Embodiment 1 of this invention. FIG. 5A to FIG. 5C are diagrams showing the configuration of the original stream file in Embodiment 1 of the present invention. It is explanatory drawing which shows the structure of the after-recording data file in Embodiment 1 of this invention. It is a figure which shows the reference device model in Embodiment 1 of this invention. It is a figure which shows the reference after-recording algorithm in Embodiment 1 of this invention. It is a figure which shows the structure of the stream management information file in Embodiment 1 of this invention. 10 (a) to 10 (b) are diagrams showing the configuration of video_unit_table in Embodiment 1 of the present invention. FIG. 11A to FIG. 11B are diagrams showing the configuration of VU_flags in Embodiment 1 of the present invention. 12 (a) to 12 (b) are diagrams showing the structure of continuous_area_table in Embodiment 1 of the present invention. FIGS. 13A to 13B are diagrams showing the configuration of CA_flags in Embodiment 1 of the present invention. It is a figure which shows the structure of the program information file in Embodiment 1 of this invention. FIG. 15A to FIG. 15B are diagrams showing the structure of the scene_table according to the first embodiment of the present invention. It is a flowchart which shows the flow of the recording process in Embodiment 1 of this invention. It is a flowchart which shows the flow of the reproduction | regeneration processing in Embodiment 1 of this invention. It is a flowchart which shows the flow of the scene reproduction | regeneration processing in Embodiment 1 of this invention. FIG. 19A shows another embodiment of the present invention. FIG. 19A shows the data structure of two types of stream files in the second embodiment, and FIG. 19B shows the arrangement of these stream files on the disk. FIG. FIG. 20 (a) shows the data structure of the stream file, and FIG. 20 (b) shows the arrangement of the stream file on the disk. It is a figure which shows the file / directory structure in Embodiment 3 of this invention. FIG. 22A shows an embodiment of the present invention, FIG. 22A shows the data structure of an original stream file and an after-recording area reservation file according to Embodiment 3 of the present invention, and FIG. 22B shows the original stream file immediately after recording. FIG. 6 is a diagram showing the arrangement of a post-record area reservation file on a disk. FIG. 23A shows the data structure of the graphics file and the after-recording data file according to the third embodiment of the present invention, and FIG. 23B shows the graphics file after-recording / non-destructive editing, the after-recording data file, the original stream file, and It is a figure which shows arrangement | positioning on the disk of an after-recording area reservation file. It is a figure which shows the structure of the program information file in Embodiment 3 of this invention. FIG. 25 (a) to FIG. 25 (b) are diagrams showing the configuration of subaudio_table in Embodiment 3 of the present invention. FIG. 26 (a) to FIG. 26 (b) are diagrams illustrating the configuration of graphics_table in Embodiment 3 of the present invention. FIGS. 27 (a) to 27 (b) are diagrams showing configurations of SA_flags and gr_flags in Embodiment 3 of the present invention. It is a flowchart which shows the flow of the scene reproduction | regeneration processing in Embodiment 3 of this invention. FIG. 29 (a) shows an embodiment of the present invention, FIG. 29 (a) shows the data structure of the original stream file and post-record data file in Embodiment 4 of the present invention, and FIG. 29 (b) shows the original stream file and post-record data. It is a figure which shows arrangement | positioning on the disk of a file. 30 (a) and 30 (b) are diagrams showing a reference after-recording algorithm according to Embodiment 4 of the present invention.

Explanation of symbols

100 bus 101 host CPU
102 RAM
103 ROM
104 User interface 105 System clock 106 Optical disc (recording medium)
107 Pickup 108 ECC Decoder 109 ECC Encoder 110 Audio Playback Buffer 111 Video Playback Buffer 112 Demultiplexer 113 Multiplexer 114 Recording Buffer 115 Audio Decoder 116 Video Decoder 117 Audio Encoder 118 Video Encoder 119 Audio Recording Buffer 120 Video Recording Buffer 121 Demultiplexer 122 After-record data playback buffer

Claims (4)

An AV data reproduction method for reproducing a recording medium on which first AV data and second AV data constituting one scene to be switched and reproduced on the same time axis are recorded ,
The first AV data and the second AV data are reproduced in a state where each is divided into a first partial AV data and a second partial AV data in a predetermined division unit and switched to each other. 1 partial AV data and the second partial AV data are recorded on the recording medium so as to be alternately arranged,
Further, the recording medium includes file system management information for managing information for handling the first AV data and the second AV data as separate files, the first AV data, and the second AV data. And a program information file for handling as a single content in association with the AV data of
In the file system management information, the position information of the first partial AV data is recorded in the order of reproduction of the first partial AV data, and the position information of the second partial AV data is recorded as the second partial AV data. Are recorded in the order of playback,
The program information file has file names of the first AV data and second AV data, and includes time information for reproducing the first AV data and second AV data,
The time information includes a time stamp indicating the start time of the scene, and each video unit that constitutes the scene and can be an entry point when playing back each of the first AV data and the second AV data. Including a time stamp indicating the start time,
A first step of acquiring the file system management information from the recording medium ;
AV data reproduction method characterized by comprising a second step of acquiring the program information file from the recording medium. An AV data reproducing device for reproducing a recording medium on which first AV data and second AV data constituting one scene to be switched and reproduced on the same time axis are recorded,
The first AV data and the second AV data are reproduced in a state where each is divided into a first partial AV data and a second partial AV data in a predetermined division unit and switched to each other. 1 partial AV data and the second partial AV data are recorded on the recording medium so as to be alternately arranged,
Further, the recording medium includes file system management information for managing information for handling the first AV data and the second AV data as individual files, the first AV data, and the second AV data. And a program information file for handling as a single content in association with the AV data of
In the file system management information, the position information of the first partial AV data is recorded in the reproduction order of the first partial AV data, and the position information of the second partial AV data is recorded as the second partial AV data. Are recorded in the order of playback,
The program information file has file names of the first AV data and second AV data, and includes time information for reproducing the first AV data and second AV data,
The time information includes a time stamp indicating the start time of the scene, and each video unit that constitutes the scene and can be an entry point when playing back each of the first AV data and the second AV data. Including a time stamp indicating the start time,
Means for obtaining the file system management information from the recording medium;
An AV data reproducing apparatus comprising: means for acquiring the program information file from the recording medium . A program for causing a computer to reproduce a recording medium on which first AV data and second AV data constituting one scene to be switched and reproduced on the same time axis are recorded,
The first AV data and the second AV data are reproduced in a state where each is divided into a first partial AV data and a second partial AV data in a predetermined division unit and switched to each other. 1 partial AV data and the second partial AV data are recorded on the recording medium so as to be alternately arranged,
Further, the recording medium includes file system management information for managing information for handling the first AV data and the second AV data as separate files, the first AV data, and the second AV data. And a program information file for handling as a single content in association with the AV data of
In the file system management information, the position information of the first partial AV data is recorded in the order of reproduction of the first partial AV data, and the position information of the second partial AV data is recorded as the second partial AV data. Are recorded in the order of playback,
The program information file has file names of the first AV data and second AV data, and includes time information for reproducing the first AV data and second AV data,
The time information includes a time stamp indicating the start time of the scene, and each video unit that constitutes the scene and can be an entry point when playing back each of the first AV data and the second AV data. Including a time stamp indicating the start time,
In the computer,
A first step of acquiring the file system management information from the recording medium;
And a second step of acquiring the program information file from the recording medium . A computer-readable recording medium storing the program according to claim 3.

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