JP2006294222A - Recording apparatus and method, reproduction apparatus and method, and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the following problem: although a long time recording mode can be realized by reducing a bit rate in the case of MPEG encoding such as DVD, the longer the video signal to be recorded is, the larger the amount of time map information is, and a memory size for storage has to be increased. <P>SOLUTION: An apparatus records address information of VOBUs (video object units) onto a recording medium while recording a video signal in data units (VOBU), and includes a recording mode indication means 109 for determining a recording time; and a means 110 for determining a time length of the VOBU, and long time recording is made possible without increasing a memory size 112 for storing the VOBU map by specifying a minimum time length of the VOBU according to the recording mode. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a recording apparatus, a reproducing apparatus, a recording method, a reproducing method, and a recording medium for recording an input signal such as a television signal on a recording medium.

  As a conventional recording apparatus for recording a video signal on a recording medium, an apparatus for recording a video signal in units of data units and recording time map information including any one of a recording address and reproduction time information of each data unit is disclosed. (For example, see Patent Documents 1 and 2). The video signal recorded using this time map information can be randomly accessed.

  As a method for recording a video signal on a DVD-RAM medium, there is a DVD video recording standard (hereinafter abbreviated as a DVD-VR standard). In the DVD-VR standard, video signals are recorded in units called video object units (hereinafter abbreviated as VOBU), and time map information (VOBU map information) of each VOBU is recorded. The playback time length of this VOBU is defined as 0.4 to 1.0 seconds.

  When recording a video signal on a DVD-R medium, the recording is performed in accordance with the DVD video standard. Also in the DVD video standard, VOBU is defined, and the playback time length of VOBU is defined as 0.4 seconds to 1.0 seconds like the DVD-VR standard.

  Further, it is generally used to record a video stream obtained by compressing data using an MPEG encoding method when recording a digital video signal. The MPEG encoding system performs intra-frame encoding (I picture), forward inter-frame predictive encoding (P picture), and bi-directional inter-frame predictive encoding (B picture). Here, a frame group starting from the I picture is called a group of pictures (hereinafter abbreviated as GOP). By the way, in order to randomly access and reproduce a video stream, reproduction is performed from an I picture that can be reproduced independently. That is, access can be performed in GOP units.

  On the other hand, in the DVD-VR standard, a VOBU is composed of one or more GOPs, and access can be made in units of VOBU by using VOBU map information. Although this VOBU map information is recorded on a recording medium, it is expanded on the internal memory at the time of reproduction and read from the memory at the time of random access. Considering random accessibility, the playback time length of VOBU is set to about 0.5 seconds.

By the way, the DVD recorder can record a video signal of 2 hours on a 4.7 GB DVD-RAM in the standard recording mode (hereinafter referred to as SP mode). In the long time mode (LP mode), recording can be performed for 4 hours. These recording modes are realized by controlling the compression rate (bit rate) in MPEG encoding. That is, the SP mode is about 5 Mbps, the LP mode is about 2.5 Mbps, and recording is performed for a long time by lowering the bit rate.
Japanese Patent No. 3028517 (7th to 9th pages, FIG. 9) JP 2001-103428 A (pages 13 to 15)

  However, in the case of MPEG encoding such as a DVD, a long-time recording mode can be realized by lowering the bit rate. However, as the video signal to be recorded becomes longer, the time map information increases and is stored. There has been a problem that the memory size for doing so increases.

  For example, Table 1 shows the relationship between the recording time and the data size of the time map information when the data unit is 0.5 seconds and the time information size of one data unit is 3 bytes.

For example, if 8 hours of recording is required, 200 [kbyte] of memory is sufficient, but if 16 hours of recording is performed, 345 [kbyte] of memory is required. On the contrary, when the size of the memory for storing time map information provided in the recording apparatus is 200 [kbytes], only about 8 hours of recording can be performed so that the memory does not overflow.

  Further, when playing back a recording medium on which a long-time video signal is recorded, the memory for storing time map information overflows, and there is a problem that playback cannot be performed correctly.

  Furthermore, since the recording method differs depending on the type of the recording medium, the memory size for storing the time map information may be different, and the maximum recordable time varies depending on the type of the recording medium.

  Therefore, the present invention has been made in view of the above problems, and a recording apparatus, a reproducing apparatus, a recording method, a reproducing method, and a recording apparatus that realize long-time recording without overflowing the memory of time map information, and An object is to provide a recording medium.

  According to the present invention, the recording apparatus records the input signal in units of data units and records the management information of the data units on the recording medium, and determines the recording mode associated with the recording time on the recording medium. And a means for determining a time length of the data unit, and a recording apparatus configured to define a minimum time length of the data unit according to the recording mode is provided.

  A method of recording an input signal in units of data units and recording management information of the data units on a recording medium; determining a recording mode associated with a recording time on the recording medium; and the data unit A recording method configured to define a minimum time length of the data unit according to the recording mode.

  In addition, a recording medium that records an input signal in units of data and records management information of the data unit, wherein the recording medium defines a minimum time length of the data unit according to a recording mode associated with a recording time. Provided.

  An apparatus for recording an input signal in units of data units and reproducing a recording medium in which management information of the data unit is recorded, and means for reading a recording mode associated with time to the recording medium, and random access Means for determining a possible playback start time, and a random access playback is performed in units of a minimum time length of the data unit determined according to the recording mode.

  Further, the input signal is recorded in units of data units, and the recording medium in which the management information of the data units is recorded is reproduced, wherein the minimum time of the data units determined according to the recording mode associated with the recording time There is provided a playback method for performing random access playback in units of length.

  According to the present invention, the minimum time length of the data unit is defined according to the recording mode, and the minimum time length of the data unit is increased as the recording time becomes longer, so the data unit is managed. Long-time recording is possible without increasing the data size of management information.

  Hereinafter, embodiments of the present invention will be described.

(Embodiment 1)
FIG. 1 is a block diagram for explaining an example of a recording apparatus according to Embodiment 1 of the present invention. The recording apparatus includes an encoder 100 having a video encoder 101 and an audio encoder 102, a system encoder 103, a recording head 104, a frame counter 106, a VOBU configuration control unit 107, a VOBU data size measurement unit 108, a recording mode instruction unit 109, and a VOBU. The recording apparatus includes a length determination unit 110, a VOBU map creation unit 111, and a VOBU map storage memory 112, and records input audio and video signals on a recording medium 105.

  The video encoder 101 compresses and encodes an input video signal by an MPEG encoding method and outputs a video stream. Similarly, the audio encoder 102 compresses and encodes the input audio signal by the MPEG audio layer 2 encoding method and outputs an audio stream. The system encoder 103 multiplexes the video stream and the audio stream into a system stream. The frame counter 106 counts the number of frames included in one VOBU.

  The VOBU configuration control unit 107 instructs the system encoder 103 to configure the VOBU when the number of frames configuring the VOBU exceeds the minimum time length of the VOBU. In response to an instruction from the VOBU configuration control unit 107, the system encoder 103 outputs a system stream in units of VOBU. In this embodiment, since the VOBU is composed of one or more GOPs, the number of GOP frames is added, and one VOBU is composed of GOP groups having the minimum time length or more.

  The recording mode instruction unit 109 is an interface that determines a recording mode related to time in response to an instruction from the user. For example, one of five recording modes such as a 2-hour recording mode, a 4-hour recording mode, an 8-hour recording mode, a 12-hour recording mode, and a 16-hour recording mode is selected for one surface of the recording medium 105. The compression rate (bit rate) of the video encoder 101 is determined according to this recording mode. Table 2 shows an example of a correspondence table between recording modes and bit rates.

  The VOBU data size measurement unit 108 measures the data size of each VOBU and notifies the VOBU map creation unit 111 of the data size. The VOBU map creation unit 111 creates VOBU map information using the VOBU data size obtained from the VOBU data size measurement unit 108 and the VOBU time length obtained from the VOBU configuration control unit 107. The VOBU map information is information for associating the playback time and recording address of VOBU, and the VOBU map information for one VOBU is about 3 bytes. The playback time information of VOBU is generated from the playback time length of VOBU, and the recording address of VOBU is generated from the data size of VOBU. The generated VOBU map information is temporarily stored in the VOBU map storage memory 112.

  The recording head 104 records VOBU and VOBU map information on the recording medium 105. When recording of all VOBUs is completed, recording of the VOBU map information stored in the VOBU storage memory 112 is started. This is to prevent a problem that the processing time for recording the system stream data (VOBU data) is not in time if the recording medium 105 is accessed every time VOBU map information of several bytes is generated.

  Details of the recording format of the recording medium 105, the VOBU map information, and the configuration of the VOBU will be described later with reference to FIGS.

  The VOBU length determination unit 110 determines the minimum time length of the VOBU according to the recording mode. Table 3 shows an example of the relationship between the recording mode and the minimum time length of VOBU, and the data size of VOBU map information. Note that the data size of the VOBU map information is calculated with the map information corresponding to one VOBU as 3 bytes.

  By determining the minimum time length of the VOBU according to the recording mode as shown in Table 3, if the size of the memory 112 for storing the VOBU map information is 170 [kbyte] (1 kbyte = 1024 bytes), the 16-hour recording mode is also available. It becomes possible to record enough.

  When the size of the memory 112 is M, the data size of the map information corresponding to one VOBU is d, and the recording time is R, the minimum time length T of the VOBU is calculated as T = R / M × d. You can also.

  FIG. 5 is a flowchart for explaining the recording method according to the first embodiment of the present invention. As shown in the figure, when the recording process starts, the recording mode instruction unit 109 determines the recording mode according to the user's instruction (S11), and the VOBU length determination unit 110 determines the minimum VOBU according to the recording mode from the recording mode instruction unit 109. The time length T is determined (S12). Assuming that the total map information size is 200 kbytes and the data size of map information corresponding to one VOBU is 3 bytes, the minimum time length T of the VOBU can be determined as T = recording time / 200 kbytes × 3 bytes. In step S13, MPEG2 encoding of the input audio video and video data is performed by the audio encoder 102 and the video encoder 101 with the compression rate (bit rate) determined according to the recording mode from the recording mode instruction unit 109, and the encoded data. Is output. In step S14, the VOBU configuration control unit 107 controls the VOBU configuration. Specifically, the VOBU configuration control unit 107 calculates the VOBU based on the number of frames of encoded data output from the encoder 100 and the minimum time length T of the VOBU from the VOBU length determination unit 110 counted by the frame counter unit 106. The system encoder 103 is controlled to configure. Here, one VOBU is composed of a minimum number of GOPs so that the total frame length included therein is T or more. The system encoder 103 outputs a system stream that is compression-coded in accordance with instructions from the VOBU configuration control unit 107 in units of VOBUs.

  The VOBU map creation unit 111 uses the data size of each VOBU from the VOBU data size measurement unit 108 and the time length of the VOBU from the VOBU configuration control unit 107 (one frame duration × total frames included in one VOBU). VOBU map information is generated (S15) (for example, 3 bytes / VOBU), and the VOBU map information is stored in the VOBU map storage memory (112) (for example, 200 kbyte memory) (S16). Meanwhile, the system stream output in units of VOBU is recorded on the recording medium 105 by the recording head 104, and is recorded in units of VOBU until recording of all VOBUs is completed (S17, S18). When the recording of all VOBUs is completed, the VOBU map information stored in the VOBU map storage memory 112 is recorded on the recording medium 105 by the recording head 104 (S19), and all the recording processes are completed.

  2 and 3 show an example of a recording format recorded on the recording medium 105 of the present invention. The VOBU map information 301 and the system stream 302 are recorded on the recording medium 105. First, the VOBU map information 301 in FIG. 2 includes VOBU number information 401 and n VOBU maps 402-1 to 402-n. The VOBU number information 401 is information indicating the number of VOBUs constituting the system stream 302. Here, the system stream 302 is assumed to be composed of n VOBUs. Each VOBU map, for example, VOBU map (1) 402-1 includes playback time information 405 and recording address information 406. The playback time information 405 is information regarding the playback time length of the VOBU, and the recording address information 406 is information regarding the recording address on the optical disc. By reading this VOBU map information, the recording address corresponding to the temporal position of the target VOBU on the system stream is known, and random access is possible such that playback starts at a desired time. Note that information regarding the playback time position from the beginning of the system stream may be recorded as the playback time information 405.

  Next, the system stream 302 of FIG. 3 is composed of n VOBUs 302-1 to 302-n, and each VOBU, for example, VOBU (1) 302-1 includes two GOP (1) 306 and GOP (2) 307. Become. Here, the VOBU is composed of two GOPs, but may be composed of one GOP, and is not limited to the number of GOPs. Each GOP, for example, GOP (1) 306 is composed of 12 pieces of frame data 611 to 617, for example. 4A and 4B show a configuration example of GOP (1) 306. FIG. FIG. 4A shows the display order of frames, and FIG. 4B shows the order of frame bitstreams. In the display order of FIG. 4A, 12 frames from the B frame 601 to the P frame 609 are set as one GOP (1) 306. The P frame 606 is subjected to interframe prediction encoding using the I frame 603 as a reference frame. Further, the P frame 608 is subjected to inter-frame prediction encoding using the P frame 606 as a reference frame. In addition, the B frames 604 and 605 are subjected to inter-frame prediction encoding processing using the I frame 603 and the P frame 606 as reference frames.

  The order of the display in FIG. 4A is changed in order of the bit stream as shown in FIG. 4B at the time of encoding in order to reduce memory during encoding and decoding, and the B frame 601 starts with the encoded data 613 of the I frame 603 as the head. Encoded data 611, encoded data 612 of the B frame 602, encoded data 616 of the P frame 606, and the like are encoded and recorded in this order. The minimum time length of the VOBU recorded here is defined by the recording mode associated with the recording time on the recording medium 105. As shown in Table 3, in the recording mode in which the recording time becomes longer, the minimum time length of VOBU is increased. For example, in the 16-hour recording mode, the minimum VOBU time length is 1 second, and it is sufficient to secure 170 [kbytes] as the storage capacity of VOBU map information, and the remaining recording capacity is used for recording audio and video signals. It can be used as the capacity of

  When the storage capacity of VOBU map information is C, the data size of map information corresponding to one VOBU is d, and the recording time is R, the minimum time length T of VOBU is T = R / C × d You may calculate.

(Embodiment 2)
FIG. 6 is a block diagram for explaining an example of the recording apparatus according to the second embodiment of the present invention. FIG. 6 is the same as Embodiment 1 of FIG. 1 except that the operation of the video encoder 701 in the encoder 100 ′ and the GOP configuration determining unit 702 are provided. The GOP configuration determining unit 702 determines the GOP configuration according to the VOBU minimum time length determined by the recording mode. The video encoder 701 performs an encoding process based on the determined GOP structure.

  7A and 7B show a configuration example of the GOP. FIG. 7A shows an example in which the minimum VOBU time length is 0.5 seconds. In this case, one VOBU is composed of one GOP, and the GOP is composed of 15 frames. Next, FIG. 7B is an example when the minimum VOBU time length is 0.75 seconds. In this case, one VOBU is composed of two GOPs, the first GOP is 15 frames, and the second GOP is 8 frames. That is, one VOBU is composed of 23 frames. In the case of the NTSC signal, 30 frames per second, so the playback time length of one VOBU is 0.767 seconds, and the minimum time length of 0.75 seconds can be satisfied.

  As described above, by determining the GOP configuration according to the VOBU minimum time length determined from the recording mode, it becomes possible to configure a VOBU having a playback time length that is greater than the determined VOBU minimum time length, and VOBU map information It is possible to realize long-time recording without increasing the size of the memory 112 for storing.

  In the above example, the P frame is a three-frame cycle and the two frames between them are B frames. However, the present invention is not limited to this. In FIG. 7A, a VOBU is composed of one GOP, but it may be composed of two or more GOPs. In FIG. 7B, the VOBU is composed of two GOPs. However, the VOBU may be composed of one GOP composed of 23 frames, or may be composed of three or more GOPs.

(Embodiment 3)
FIG. 8 is a block diagram for explaining an example of the recording apparatus according to the third embodiment of the present invention. FIG. 8 is the same as Embodiment 1 of FIG. 1 except that it includes an operation of the VOBU length determination unit 801, a media determination unit 802, and a recording format determination unit 803, and a plurality of types of recording media 804 and recording formats. The difference is that it is possible to record. A medium determination unit 802 determines the type of a recording medium 804 loaded in the disk drive, for example, an optical disk. As a method for determining the type of the recording medium 804, identification data recorded inside the disk may be read, or may be determined based on the intensity of reflected light when a laser beam is applied. A recording format determination unit 803 selects and determines a recording format according to the type of media.

  The VOBU length determination unit 801 determines the minimum time length of the VOBU according to the recording mode and the recording format. This is because the maximum data size of the VOBU map may vary depending on the recording format defined by the type of media. The maximum data size of the VOBU map is defined by the recording format if the playback device has at least memory for the data size of the VOBU map specified by the recording format as the VOBU map storage memory. This is because it is possible to ensure that the recorded recording medium is reproduced.

  For example, in the DVD video recording recording format (DVD-VR standard) on a DVD-RAM medium, the maximum data size of a VOBU map is defined as 214 kbytes, and the data size of map information corresponding to one VOBU is 3 bytes. On the other hand, in the DVD video recording recording format (DVD + VR standard) from DVD + R / + RW media, the maximum number of VOBUs is defined as 40,959. Accordingly, if the data size of the map information corresponding to one VOBU is 4 bytes, up to 160 kbytes is allowed, and if it is 3 bytes, up to 120 kbytes are allowed. The VOBU length determination unit 801 determines the minimum time length of the VOBU from the maximum data size of the VOBU map information defined by each recording format and the recording mode. Assuming that the maximum data size of VOBU map information is D and the data size of map information of 1 VOBU is d and the recording time in the recording mode is R, the minimum time length T of VOBU can be calculated by T = R / D × d it can.

  Thus, by defining the minimum time length of VOBU according to the recording format, it is possible to realize long-time recording even in different recording formats.

(Embodiment 4)
FIG. 9 is a block diagram of a reproducing apparatus for explaining an example of a reproducing method according to the fourth embodiment of the present invention. This playback apparatus includes a video decoder 201, an audio decoder 202, a system decoder 203, a VOBU map storage memory 206, an address management unit 207, and a playback start time instruction unit 208, and is recorded on a recording medium 205 using the playback head 204. It is a device that reproduces data. The recording medium 205 is a recording medium recorded in the recording format shown in FIGS.

  The read head 204 first reads the VOBU map information from the recording medium 205 before reading the VOBU data, inputs it to the VOBU map storage memory 206, and stores it in the address specified by the address management unit 207. Read VOBU data.

  Next, the VOBU data read by the reproducing head 204 is input to the system decoder 203. The system decoder 203 separates the video stream and the audio stream from the input VOBU data, and inputs them to the video decoder 201 and the audio decoder 202, respectively. The video decoder 201 performs MPEG decoding on the video stream and outputs a video signal, and the audio decoder 202 performs MPEG audio decoding on the audio stream and outputs an audio signal.

  Next, a method for randomly accessing and reproducing a video signal recorded on the recording medium 205 will be described. The reproduction start time instruction unit 208 determines the reproduction start time from the beginning of the recorded video signal. The reproduction start time is determined by a user request, for example. The address management unit 207 obtains the recording address of the VOBU corresponding to the reproduction start time from the reproduction start time from the reproduction start time instruction unit 208 and the VOBU map information from the VOBU map storage memory 206, and instructs the reproduction head 204. The reproduction head 204 can reproduce from the designated reproduction start time by starting reading from the corresponding VOBU.

  Here, a random access unit is determined according to the recording mode recorded on the recording medium 205. This access unit is the same as the time length of the VOBU stored in the VOBU map storage memory 206. An example of the relationship between the recording mode and the VOBU minimum time length which is a random access unit is shown in Table 3.

  As described above, as the recording time becomes longer, the random access unit is lengthened, so that the data recorded for a long time can be reproduced without increasing the size of the VOBU map storage memory 206.

    If the size of the VOBU map storage memory 206 is m, the data size of map information corresponding to one VOBU is d, and the recording time is R, the random access unit T is calculated as T = R / m × d. May be.

  FIG. 10 is a flowchart showing a random access playback process of a video signal according to a playback method using a random access unit T (= R / M × d). When the reproduction process of the data recorded on the recording medium 205 starts, the reproducing head 204 reads the VOBU map information (S21) and stores it in the VOBU map storage memory 206 (S22). Further, after reading the recording mode recorded on the recording medium 205 (S23), a time unit T that can be randomly accessed is determined (S24). If the VOBU map storage memory is 200 kbytes and the data size of map information corresponding to one VOBU is 3 bytes, the random access unit T can be determined as T = recording mode time / 200 kbytes × 3 bytes. The reproduction time instruction unit 208 receives the reproduction disclosure time S from the user (S25), and obtains the random access reproduction disclosure time S '(S26). The accessible playback disclosure time S ′ can be obtained by S ′ = INT (S / T) × T (INT () is an integer). Thereafter, the address management unit 207 determines the address of the VOBU closest to the playback disclosure time S ′ that can be randomly accessed from the VOBU map storage memory 206 (S27), and the playback head (204) corresponds to this address from the recording medium 205. By starting reading from the VOBU (S28), the VOBU data of the corresponding VOBU is decoded by the system decoder 203, the video decoder 201, and the audio decoder 202, and a reproduction signal subjected to the MPEG2 decoding process is output. (S29).

  As described above, in the recording apparatus and the reproducing apparatus according to the present invention, the video signal may be encoded by the MPEG encoding method, but the present invention is not limited to this, and other encoding methods may be used.

  As an audio signal encoding method, an MPEG audio layer 2 encoding method, a Dolby AC3 encoding method, an AAC encoding method, an MP3 encoding method, or the like may be used. A conversion method may be used. An uncompressed method such as linear PCM may be used.

  Note that, as a system encoder, an MPEG2 multiplexing method may be used, but the present invention is not limited to this, and other multiplexing methods may be used.

  The input signal of the recording apparatus of the present invention may be an encoded stream that is compressed. In this case, the number of frames is detected by reading only the header information of the encoded data of each frame, and the data unit is determined based on the GOP based on the minimum time length of the data unit determined in advance and the detected number of frames. Next, the data size of the determined data unit is measured, and time map information may be generated from reproduction time information determined from the number of frames (GOP number) and address information determined from the data size. The method for determining the minimum time length of the data unit according to the recording mode to the recording medium is as described above.

  In addition, since the VOBU of this embodiment is composed of one or more GOPs, the number of GOP frames is added, and one VOBU is configured as the minimum number of GOPs that is equal to or greater than the minimum time length of the VOBU. However, the VOBU may be configured such that the length of each VOBU is not equal to or greater than the minimum time length and the average length of the VOBU is equal to or greater than the minimum time. For example, if one GOP is 12 frames, one GOP is 0.4 seconds. If the minimum time length of a VOBU is 1 second, one VOBU must be composed of three GOPs, and the length of one VOBU playback time is 1.2 seconds. However, when the average time length of a VOBU is 1 second, it is possible to configure the adjacent VOBUs to be composed of three and two GOPs alternately, and the average length of playback time of one VOBU is 1 second. Therefore, there is an effect that the random access unit or the memory can be shortened without overflowing the memory for storing the VOBU map information.

  In addition, although the video signal and the audio signal are used as the input signal, either one or a continuous data string may be used.

  Note that the recording mode is not limited to the above-described example, and any recording mode may be used. For example, the recording mode may be determined in units of seconds.

  The recording medium may be an optical disk such as DVD-RAM, DVD-RW, DVD-R, DVD + RW, DVD + R, and is not limited to a type such as a magnetic disk or a semiconductor memory.

  Each unit of the recording device and the playback device may be realized by software. The embodiment in this case is realized as a program, and each means may be constituted by a software module or the like.

  Although VOBU is taken as an example of the data unit that is a recording unit, the present invention is not limited to this, and any unit may be used as long as it is defined by time.

  The unit of the data unit may be about 0.5 seconds to about 1 second, but is not limited to this.

  In addition, VOBU is exemplified as being composed of GOP units composed of frames. However, GOPs can be composed of picture units including fields instead of frames, and encoding and decoding can be performed in units of pictures (frames). Field or a mixture of frames and fields).

  The recording apparatus, reproducing apparatus, recording method, reproducing method, and recording medium according to the present invention require random accessibility during reproduction by determining the recording data unit length according to the recording mode, and long-time recording is possible. It can also be applied to essential uses.

1 is a block diagram for explaining a recording apparatus according to a first embodiment of the invention. The figure which showed the VOBU map information of the recording format of the recording medium of this invention The figure which showed the system stream structure of the recording format of the recording medium of this invention Diagram showing an example of GOP configuration Flowchart for explaining a recording method according to the first embodiment of the present invention. Block diagram for explaining a recording apparatus according to a second embodiment of the present invention The figure which showed an example of the VOBU structure in the recording device by Embodiment 2 of this invention Block diagram for explaining a recording apparatus according to a third embodiment of the present invention. Block diagram for explaining a playback apparatus according to Embodiment 4 of the present invention The flowchart for demonstrating the reproducing | regenerating method by Embodiment 4 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Encoder 101,701 Video encoder 102 Audio encoder 103 System encoder 104 Recording head 105,205,804 Recording medium 106 Frame counter 107 VOBU structure control part 108 VOBU data size measurement part 109 Recording mode instruction part 110,801 VOBU length determination part 111 VOBU map creation unit 112,206 VOBU map storage memory 201 Video decoder 202 Audio decoder 203 System decoder 204 Playback head 207 Address management unit 208 Playback start time instruction unit 802 Media determination unit 803 Recording format determination unit

Claims (12)

A recording apparatus for recording an input signal in units of data and recording management information of the data unit on a recording medium, a unit for determining a recording mode associated with a recording time on the recording medium, and Means for determining a time length, and defining a minimum time length of the data unit according to the recording mode. 2. The recording apparatus according to claim 1, further comprising a memory for storing the management information including information relating to any one of a reproduction time and a recording address of the data unit as the management information of the data unit. Coding means for coding at least one picture among the means constituting the data unit and at least one of the subunits composed of at least one picture and inter-picture coding the remaining pictures, wherein the data unit is at least 1 The recording apparatus according to claim 1, wherein the recording apparatus includes one of the subunits, and the subunit includes a plurality of pictures. 4. The recording apparatus according to claim 3, wherein the number of pictures of the subunit is determined according to a recording mode or a minimum time length of a data unit. 2. A recording apparatus according to claim 1, further comprising means for determining the type of the recording medium, wherein the minimum time length of the data unit is defined according to the type of the recording medium and the recording mode. The recording apparatus according to claim 3, wherein the subunit is a GOP. The recording apparatus according to claim 3, wherein the picture includes a frame and / or a field. The minimum time length is a theoretical minimum time length defined according to a recording mode, the data unit has two or more different time lengths, and the average time length of the data unit is the theoretical minimum time length. The recording apparatus according to claim 1, wherein the recording apparatus is longer than a time length. A method of recording an input signal in units of data units and recording management information of the data units on a recording medium, determining a recording mode associated with a recording time on the recording medium, and a time of the data unit Determining a length, and defining a minimum time length of the data unit according to the recording mode. A recording medium for recording an input signal in units of data units and recording management information of the data units, wherein the minimum time length of the data units is defined according to a recording mode associated with a recording time. Recording media. An apparatus for recording an input signal in units of data and reproducing a recording medium on which management information of the data unit is recorded, and means for reading a recording mode associated with time to the recording medium, and randomly accessible Means for determining a reproduction start time, and performing random access reproduction in units of a minimum time length of the data unit determined according to the recording mode. A method of recording an input signal in units of data units and reproducing a recording medium in which management information of the data units is recorded, wherein the minimum time length of the data units determined according to a recording mode associated with a recording time is determined. A reproduction method comprising random access reproduction as a unit.

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