JP2004152486A - Data recording method, data recording device, and recording media - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmitting method, a recording method, and a reproducing method of compression video and an audio signal, and a reproducing device which can easily realize retrieval by a picture group unit. <P>SOLUTION: Compression video, audio data, and a stream of independent data are packed, when they are divided into the minimum units of an intrinsic data structure for media and transmitted or recorded by media, information in which it is indicated whether boundaries of picture groups exist or not in the minimum unit is described in a sub-information part in a frame signal, and transmission or recording is performed. Video data by each prescribed unit can be retrieved at a high speed by using information added to the sub-information part at the time of reproduction and transmitted or recorded. <P>COPYRIGHT: (C)2004,JPO

Description

  The present invention relates to an apparatus for recording and reproducing compressed video and audio signals on a medium such as an optical disk.

  Non-Patent Document 1 describes the compression of video and audio signals in detail. Further, Non-Patent Document 2 describes an example of an optical disc in detail.

  Non-Patent Document 1 describes a video and audio signal compression method and a multiplexing method thereof. Non-Patent Document 2 describes a signal recording format of a CD. However, there is no mention of facilitating a search method for recording and reproducing compressed video and audio signals on a medium.

"MPEG Technology", published by Trikeps, supervised by Jun Yoneman, December 21, 1993

Edited by Kenji Hayashi, "From CD-Audio to Personal Computers", published by Corona, July 25, 1990

  When playing media such as a CD recorded with a video or audio signal compressed in a data stream format as described in "MPEG Technology", the data stream is played and the header information of packs and packets is determined. This makes it possible to determine the boundary of a picture or a group of pictures. However, when a signal is recorded on a medium, interleaving processing and error correction encoding processing unique to the medium, and framing by adding a synchronization signal and sub-information are performed to improve error resistance. . For this reason, when a picture or a picture group boundary is determined by playing back a data stream and judging the pack and packet header information, the position of a pickup or the like that is already playing back data from the media has shifted. ing. For this reason, when searching, editing, or the like is performed on a picture or picture group basis, complicated control is required to find the position on the medium of the boundary portion of the picture or picture group. There is a problem that it takes time.

  In the present invention, in order to solve the above problem, when the time-series data of the pack is divided into the minimum units of the data structure unique to the medium and transmitted or recorded by the medium, the minimum unit of the data structure unique to the medium is Achieved by describing information indicating whether there is a picture or a picture group boundary in the sub-information part of the frame signal to be transmitted or recorded when performing framing specific to media. Is done.

  When a search or editing is performed on a picture or picture group basis, the picture is included in the minimum unit of the media-specific data structure described in the sub-information portion of the media-specific frame signal reproduced from the medium. Alternatively, by reading information indicating whether there is a boundary between picture groups and making a determination, it is possible to accurately and easily detect a reproduction position on a medium for reproducing a picture or a boundary portion between picture groups. . This eliminates the need for complicated control to find the position on the medium of the boundary portion of the picture or the group of pictures, thereby enabling a high-speed search of the boundary portion of the picture or the group of pictures.

  According to the present invention, information indicating whether or not the head of data (for example, a group of pictures) of a unit of compressed video data is included in the minimum unit of the media-specific data structure is stored in the media-specific data. The transmission or recording can be performed using an area for transmitting or recording the sub-information, which is different from the area for transmitting or recording the main information in the frame signal. Further, according to the present invention, it is possible to quickly search for a data boundary of a unit of compressed video data on a medium. Further, there is an effect that it is possible to configure a reproducing apparatus capable of searching a boundary of a picture group at high speed and performing normal reproduction.

  FIG. 1 shows an embodiment of the present invention, and shows a method of transmitting or recording information. 1 indicates a packing process of compressed data, 2 indicates signal processing unique to a medium, and 3 indicates a medium for transmitting or recording information. 4 is compressed video data, 5 is compressed audio data, and 6 is independent data. 7, 8, and 9 are packetizing processes and 10 is a packing process. 11 is a process for dividing the time series data of the pack into a data structure unique to the media, 12 is a main signal process specific to the media such as addition of an error correction code and interleaving, and 13 is a process for dividing the time series data of the pack into the media unique. When the data structure is divided into data structures, information extraction processing indicating which component of the data structure includes the boundary of the picture group, framing processing 14 for generating a frame signal unique to media, and 15 Processing 16 adds sub-information to the signal, and processing 16 adds a synchronization signal to each frame of the frame signal.

  Hereinafter, a method of transmitting information or generating a recording signal according to the present invention will be described with reference to FIG.

  In the compressed data packing process 1, the compressed video data, the compressed audio data, and the independent data are packetized independently by adding a packet header indicating the head of the packet. Next, each packet is time-divided, one or more packets are collected, and a pack header indicating the head of the pack and information indicating a reference time are added to form a pack. In the media-specific signal processing 2, first, the time-series data of a pack is divided into media-specific data structures.

  At the time of the division, information extraction processing is performed to indicate which component of the data structure includes the boundary of the picture group. The time-series data of the divided packs is subjected to signal processing such as addition of an error correction code and interleaving in order to enhance error resilience in accordance with a signal processing format specific to the medium. Next, in order to transmit or record the signal-processed data, a framing process according to a frame format specific to the medium is performed. In the framing process, sub-information and a synchronization signal indicating the beginning of a frame are added to data that has undergone media-specific signal processing to generate a frame signal.

  In the present invention, information indicating which component of the media-specific data structure includes the boundary of the picture group is inserted into the sub information of the frame signal at the same time as the framing process. Further, if the frame signal has a channel code unique to the medium, channel code modulation according to the modulation rule is performed, and if not, the data is transmitted or recorded by the medium as it is.

  As described above, according to the present embodiment, the information indicating whether or not the head of the data (for example, a picture group) of a certain unit of the compressed video data is included in the minimum unit of the media-specific data structure is described above. Transmission or recording can be performed using an area for transmitting or recording the sub-information, which is different from the area for transmitting or recording the main information in the frame signal unique to the medium.

  Next, another embodiment of the present invention will be described with reference to FIG. This embodiment is an embodiment in which the present invention is applied to a CD (compact disk), CD-ROM, or a system having a data structure and a frame format equivalent to a CD-ROM.

  In the figure, reference numeral 20 denotes time series data of a pack, and a boundary between B and C indicates a boundary of a picture group. The head of the C portion indicates the head of the data of the picture group. Reference numeral 21 denotes a data structure unique to the medium, A denotes a header portion including a synchronization signal and the like, B and C denote time-series data of a pack, and apply the divided data. This is the same data as the B and C parts of the data. D part is other data including the margin part. The A, B, C, and D portions indicate the minimum unit of the data structure unique to the medium, and are defined as one block. In the present invention, the number of bytes in one block is 2352 bytes.

  Reference numeral 22 denotes a frame signal unique to the medium, SY denotes a frame synchronization signal, and SUB denotes a subcode as sub information. Reference numeral 23 denotes a main information portion in the frame signal. In the present embodiment, the main information portion has a total of 32 bytes including 24 bytes of data and 8 bytes of ECC (error correction code). It is assumed that one frame is composed of the frame synchronization signal, the subcode that is the sub information, and the main information. Numeral 24 indicates the data structure of the subcode. The subcode is composed of eight types of codes, P, Q, R, S, T, U, V, and W, each having a code length of 98 bits. It is inserted into the SUB part of the signal.

  Next, a recording method according to the present embodiment will be described. The time-series data of the pack is divided by the number of bytes corresponding to the number of bytes of the data portion of the block, which is the minimum unit of the data structure unique to the medium, and assigned to the data portion of each block. At the time of this assignment, it is detected that the boundary between the picture group B and the picture group C exists in the block. Then, a code indicating that a boundary exists is described, for example, in the Q code in the subcode. At the same time, signal processing such as addition of a media-specific error correction code and interleaving is performed on the blocked data. When the signal-processed data is framed, it is assigned to the main information portion of the frame signal.

  At the same time, the sub-code is allocated to the SUB part by the method described above. In this way, information indicating the boundary of the picture group can be described in the subcode portion of the frame signal. The frame signal thus configured is subjected to 8-14 modulation (EFM) in which 8 bits are allocated to 14 bits and then recorded on a medium such as a CD. According to the present embodiment, the head of the group of pictures of the compressed video data is added to the CD (Compact Disk), CD-ROM, or a system having the same data structure and frame format as the CD-ROM. Information indicating whether or not the data is included in a block, which is the minimum unit of the unique data structure, can be recorded using an area for recording sub-information in a frame signal unique to the medium.

  In the present embodiment, a case has been described in which information indicating that a boundary exists is described in the subcode Q. However, the same effect can be obtained by writing any code of P, Q, R, S, T, U, V, and W, not limited to the Q code. For example, the P code describes a data start flag in a current CD. Alternatively or in part, information indicating that a boundary exists can be described. Further, by describing not only the information indicating the boundary but the serial number or address at the head of the picture group of the compressed video data, a more accurate search can be performed at the time of reproduction.

  In addition to simply indicating information indicating a boundary, a serial number or an address at the head of a group of pictures of compressed video data, a CRC code for detecting a reproduction error of these data is simultaneously added and described. Thus, the accuracy of such information to be reproduced at the time of retrieval can be improved. When the information indicating the boundary, the serial number at the head of the picture group of the compressed video data, or the address is recorded in the Q code, the part of the current CD in which PMIN, PSEC, and PFRAME are described is described. If described instead, it is possible to detect a reproduction error by the CRC code of the Q code as it is. Also, graphic information is described in R, S, T, U, V, and W in the current CD, but this part can be described in the same way as the P code described above. it can.

  Next, another embodiment of the present invention will be described with reference to FIG. FIG. 3 shows a reproducing method according to the present invention. Data reading sections indicated by 31 and 33 are periods during which the reproducing apparatus reproduces data on the medium. A portion indicating the high-speed movement of the data reading position indicated by 32 is indicated by the reproducing apparatus on the medium for high-speed search. Is a period during which the data reproduction position is moved. The playback device searches for the target position on the medium while repeating the operation of reading the data after moving the data reading position at a high speed during the high-speed search.

  In the present invention, in the data reading section, the head of data (for example, a group of pictures) of a certain unit of the compressed video data described in the sub-information in the frame signal specific to the medium is set to the head specific to the medium. It is possible to determine information indicating whether or not the data is included in the minimum unit of the data structure, and based on this information, it is possible to quickly search for a data boundary of a unit of compressed video data on a medium. . As described above, according to the present embodiment, there is an effect that a data boundary of a unit of compressed video data can be searched at high speed on a medium.

  Next, another embodiment of the present invention will be described with reference to FIG. FIG. 4 shows a reproducing method according to the present invention. This embodiment is an embodiment in which the reproducing method of the present invention is applied to a CD (compact disk), a CD-ROM, or a system having a data structure and a frame format equivalent to those of a CD-ROM. In the figure, elements having the same numbers as those in FIGS. 2 and 3 indicate the same elements.

  As in the embodiment shown in FIG. 3, the reproducing apparatus repeats the operation of moving the pickup at a high speed, moving the data reading position, and then reading the data on the disk at the time of high speed search. Search for the target position on the media. The frame signal reproduced from the disk during the data reading period is the same as the frame signal shown in FIG.

  As for the sub-codes, 98 bits of P, Q, R, S, T, U, V, and W of 98 bits are collected for each frame over the 98 frames. Is reproduced. The information indicating whether the head of the picture group of the compressed video data described in any of the subcodes is included in the block which is the minimum unit of the data structure specific to the medium is reproduced, By judging the boundaries of the picture groups, the boundaries of the picture groups can be searched at high speed. As described above, according to the present embodiment, there is an effect that a data boundary of a unit of compressed video data can be searched at high speed on a medium.

  Next, another embodiment of the present invention will be described with reference to FIG. FIG. 5 shows a reproducing apparatus according to the present invention. The present embodiment is an embodiment in which the reproducing apparatus of the present invention is applied to a CD (compact disk), a CD-ROM, or a system having a data structure and a frame format equivalent to a CD-ROM. In FIG. 5, reference numeral 51 denotes an optical disk, 52 denotes a signal processing unit unique to a medium, 53 denotes a subcode determination unit, 54 denotes a pickup control unit, 55 denotes a pickup, 56 denotes a memory, 57 denotes a memory write address generation unit, 58 Is a read address generator, 59 is an address comparator, 60 is a pack time-series data output time adjuster, 61 is a reference clock, and 62 is a media-specific clock.

  First, the operation at the time of high-speed search will be described. During a high-speed search, during a data reading section, a frame signal reproduced from the disk 51 is input to a media-specific signal processing unit 52, and a subcode and main information are separated based on a synchronization signal in the frame signal. I do. The sub-code is input to the sub-code determining unit 53, where it is determined whether or not the sub-code is a boundary of a picture group. If it is not the boundary of the picture group, the pickup is moved at high speed via the pickup control unit, and the determination based on the subcode is repeated. If it is a picture group boundary, reproduction is performed. In this way, a search can be performed in units of a picture group.

  Next, the operation at the time of reproduction after completion of the search will be described. The reproduced frame signal is input to the media-specific signal processing unit 52, where the sub-code and the main information are separated based on the synchronization signal in the frame signal, and then the main information is subjected to error correction and deinterleaving. Are performed, and data having a block structure, which is a data structure unique to the medium, is reproduced. The data having the block structure is temporarily stored in the memory 56 in accordance with a clock unique to the medium and a write address generated based on the reference clock. The data stored in the memory is read in accordance with a read address generated based on the reference clock, and is input to the output time adjusting unit 60 for the time series data of the pack.

  The write address and the read address of the memory are constantly compared by the comparator 59. When the write address value deviates from the read address value by a certain value or more, the pickup 55 is controlled via the pickup control unit 54 to pause the reproduction. . The read speed of data from the disk is always set higher than the data transmission rate of the time series data of the pack, and the above-described reproduction control is performed. It is possible to absorb the excess or deficiency of data with the sequence data decoding device.

  The data read from the memory is corrected on the time axis in the pack time-series data output time adjustment unit. Numeral 63 indicates correction on the time axis of the time series data of the pack. In the pack time-series data output time adjustment unit, the leading time interval between adjacent packs becomes equal to the difference between the reference times according to the reference time described for each pack of data read from the memory. The time axis is corrected as follows. Since the amount of data in one pack differs for each pack, the data is output at the maximum data transfer rate in the time-series data of the pack. Pack invalid data until the beginning of the pack. As described above, according to the present embodiment, there is an effect that it is possible to configure a reproducing apparatus capable of searching for the boundary of a picture group at high speed and performing normal reproduction.

FIG. 4 is a diagram showing a method of transmitting or recording information according to the present invention. FIG. 4 is a diagram showing a method for recording information according to the present invention. FIG. 4 is a diagram showing a method for reproducing information according to the present invention. FIG. 4 is a diagram showing a method for reproducing information according to the present invention. FIG. 1 is a diagram showing an information reproducing apparatus according to the present invention.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 ... Packing processing part of compressed data, 2 ... Signal processing part peculiar to media, 3 ... Media, 13 ... Extraction part of the information which shows the boundary of a picture group, 15 ... Sub-information addition part 51 ... Optical disk, 52 ... A signal processing unit unique to a medium, 53 ... Subcode discriminating unit, 54 ... Pickup control unit, 55 ... Pickup, 56 ... Memory,
60: time-series data output time adjustment unit for pack; 63: time-series data for pack

Claims (5)

  The data stream of the compressed video signal, the data stream of the compressed audio signal, and the stream of independent data are each divided to form a packet including a packet header indicating the beginning of the packet and data of each of the divided streams. One or more packets are collected to form a pack consisting of a pack header indicating the start of the pack, information indicating a reference time, and packets, and the time series data of the pack is divided into the minimum units of the data structure unique to the media. And a transmission or recording and reproducing method for transmitting or recording by a frame signal subjected to media-specific framing, receiving or reproducing the transmitted or recorded data, and reproducing the time-series data of the pack. Wherein the head of the data of a certain unit of the compressed video data is a data structure specific to the medium. Information indicating whether or not it is included in the minimum unit is transmitted using an area for transmitting or recording sub-information, which is different from an area for transmitting or recording main information in the frame signal specific to the medium. Or a method of transmitting or recording information characterized by recording.   2. A method according to claim 1, wherein the unit of the compressed video data is a picture or data of a picture group consisting of several pictures.   The data stream of the compressed video signal, the data stream of the compressed audio signal, and the stream of independent data are each divided to form a packet including a packet header indicating the beginning of the packet and data of each of the divided streams. One or more packets are collected to form a pack consisting of a pack header indicating the start of the pack, information indicating a reference time, and packets, and the time series data of the pack is divided into the minimum units of the data structure unique to the media. And a transmission or recording and reproducing method for transmitting or recording by a frame signal subjected to media-specific framing, receiving or reproducing the transmitted or recorded data, and reproducing the time-series data of the pack. In the picture of the video data described in the sub-information in the frame number or several The boundary of the picture group consisting of pictures or the picture group consisting of several pictures is included using the information indicating whether the boundary of the picture group consisting of pictures is included in the minimum unit of the media-specific data structure. Retrieving a position on a medium of data of a minimum unit of a data structure unique to the medium.   The data stream of the compressed video signal, the data stream of the compressed audio signal, and the stream of independent data are each divided to form a packet including a packet header indicating the beginning of the packet and data of each of the divided streams. One or more packets are collected to form a pack consisting of a pack header indicating the start of the pack, information indicating a reference time, and packets, and the time series data of the pack is divided into the minimum units of the data structure unique to the media. And a transmission or recording and reproducing method for transmitting or recording by a frame signal subjected to media-specific framing, receiving or reproducing the transmitted or recorded data, and reproducing the time-series data of the pack. In the picture of the video data described in the sub-information in the frame number or several The boundary of the picture group consisting of pictures or the picture group consisting of several pictures is included using the information indicating whether the boundary of the picture group consisting of pictures is included in the minimum unit of the media-specific data structure. A playback apparatus for searching for a position on a medium of data of a minimum unit of a data structure unique to the medium. The data stream of the compressed video signal, the data stream of the compressed audio signal, and the stream of independent data are each divided to form a packet including a packet header indicating the beginning of the packet and data of each of the divided streams. One or more packets are collected to form a pack consisting of a pack header indicating the start of the pack, information indicating a reference time, and packets, and the time series data of the pack is divided into the minimum units of the data structure unique to the media. And a transmission or recording and reproducing method for transmitting or recording by a frame signal subjected to media-specific framing, receiving or reproducing the transmitted or recorded data, and reproducing the time-series data of the pack. Media at one rate greater than or equal to the transfer rate of the time-series data of the pack. The time series data is reproduced from the pack, and the time interval of the information indicating the reference time between adjacent packs is equal to the difference between the reference times of the adjacent packs according to the rate and the information indicating the reference time of each pack. An information reproducing method characterized by temporally rearranging time series data of a pack in pack units.

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