Recording medium on which a data containing navigation data is recorded, a method and apparatus for reproducing a data according to navigation data, a method and apparatus for recording a data containing navigation data on a recording

• US 5,870,523 A
• Filed: 01/30/1996
• Issued: 02/09/1999
• Est. Priority Date: 01/30/1995
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Tamada, Yuzo, Mimura, Hideki, Kikuchi, Shinichi, Taira, Kazuhiko, Kitamura, Tetsuya, Arafune, Takeo
• Primary Examiner(s): TRAN, THAI Q
• Application Number:
  US08/593,889
• Time in Patent Office: 1,106 Days
• Field of Search: 386/1, 386/33, 386/95, 386/105-106, 386/109, 386/111, 386/112, 386/125, 386/126, 386/98, 369/47-48, 369/59-60, 369/32, 369/275.3, 360/27, 360/48, 381/30, 395/144
• US Class Current: 386/241
• CPC Class Codes: G11B 19/02 Control of operating function, e.g. switching from recording to reproducing
• CPC Class Codes: G11B 19/12 by sensing distinguishing features of or on records, e.g. diameter end mark
• CPC Class Codes: G11B 20/1251 for continuous data, e.g. digitised analog information signals, pulse code modulated [PCM] data
• CPC Class Codes: G11B 2220/2562 DVDs [digital versatile discs]; Digital video discs; MMCDs; HDCDs
• CPC Class Codes: G11B 27/005 Reproducing at a different information rate from the information rate of recording for television signals H04N5/783
• CPC Class Codes: G11B 27/034 on discs G11B27/036, G11B27/038 take precedence
• CPC Class Codes: G11B 27/105 of operating discs
• CPC Class Codes: G11B 27/3027 used signal is digitally coded
• CPC Class Codes: G11B 27/329 on a disc [VTOC]
• CPC Class Codes: G11B 27/34 Indicating arrangements indicating means incorporated in magazine or cassette G11B23/046 and G11B23/0875; indicating measured values in general G01D
• CPC Class Codes: H04N 19/115 Selection of the code volume for a coding unit prior to coding
• CPC Class Codes: H04N 19/146 Data rate or code amount at the encoder output
• CPC Class Codes: H04N 19/15 by monitoring actual compressed data size at the memory before deciding storage at the transmission buffer
• CPC Class Codes: H04N 19/172 the region being a picture, frame or field
• CPC Class Codes: H04N 19/174 the region being a slice, e.g. a line of blocks or a group of blocks
• CPC Class Codes: H04N 19/192 the adaptation method, adaptation tool or adaptation type being iterative or recursive
• CPC Class Codes: H04N 19/196 being specially adapted for the computation of encoding parameters, e.g. by averaging previously computed encoding parameters processing of motion vectors H04N19/513
• CPC Class Codes: H04N 19/42 characterised by implementation details or hardware specially adapted for video compression or decompression, e.g. dedicated software implementation H04N19/635 takes precedence
• CPC Class Codes: H04N 19/46 Embedding additional information in the video signal during the compression process H04N19/517, H04N19/68, H04N19/70 take precedence
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 5/783 : Adaptations for reproducing at a rate different from the recording rate
• CPC Class Codes: H04N 5/85 : on discs or drums
• CPC Class Codes: H04N 9/8042 : involving data reduction
• CPC Class Codes: H04N 9/8063 : using time division multiplex of the PCM audio and PCM video signals
• CPC Class Codes: H04N 9/8205 : involving the multiplexing of an additional signal and the colour video signal
• CPC Class Codes: H04N 9/8216 : using time division multiplex
• CPC Class Codes: H04N 9/8227 : the additional signal being at least another television signal

Abstract

In a super density optical disk for storing video data, wherein data video is compressed to packs defined in MPEG and trains of the packs are stored in a video object unit. The video object unit includes a navigation pack which is placed at the head of the pack train. In a data cell, a plurality of video object units, each being reproduced within a predetermined period, are arranged and a cell playback information table describes a cell playback information which defines a playback order of the cells. The navigation pack has an area storing playback information for reproducing each video object unit and search information for indicating the relationship with other video object units. The data cells and the cell playback information table are stored in the optical disk.

Claims

1. A recording medium with navigation data, comprising:

a plurality of data units to be played back time-sequentially and each to be reproduced within a specific period of time, the specific time period for each data unit being substantially equal, each data unit being composed of at least one predetermined sequence of data packs, each data pack having the same pack length, the sequence of data packs including at least one of video packs, audio packs and sub-picture packs, wherein each data pack includes a header and a packet of encoded video, audio or sub-picture data and a navigation pack placed at the head of the sequence,

the navigation pack including a pack header, a first packet and a second packet,

the first packet being composed of a packet header and first control information for storing presentation control information, which includes a start time and an end time of the presentation of the data unit, and

the second packet being composed of a packet header and second control information for storing data search information, which includes a list of start addresses of a number of data units forward and backward in a playback order of the sequence, each listed start address expressed as a start address relative from the start address of the respective data unit to which the navigation data pack belongs, and a flat indicating whether or not the data unit designated by each start address contains video data.

2. A recording medium according to claim 1, wherein said navigation pack contains address information indicating its own address.

3. A recording medium according to claim 1, wherein said navigation pack contains an end address for the data unit to which the navigation pack itself belongs.

4. A recording medium according to claim 1, wherein said navigation pack contains angle information indicating an address of the data unit related to an angle to which a current angle of the scene to be reproduced is to be switched.

5. A recording medium according to claim 4, wherein said angle information contains an item describing no data unit related to an angle to which the current angle is to be switched.

6. A recording medium according to claim 4, wherein said angle information contains information indicating addresses of the data units to be reproduced later than the data unit to which the navigation pack belongs.

7. A recording medium according to claim 4, wherein said angle information contains the addresses of the data units to be reproduced earlier than the data unit to which the navigation pack belongs.

8. A recording medium according to claim 1, wherein said navigation pack contains end address information indicating an end address of the data unit containing the navigation pack.

9. A recording medium according to claim 1, wherein, when said data unit contains the video data determined in MPEG, said navigation pack contains end address information indicating the address in the data unit in which the minimum data capable of forming an image of I picture is stored.

10. A recording medium according to claim 1, wherein, when said data unit contains video data and at least one of audio data and sub-picture data, said navigation pack contains synchronizing information on at least one of the audio data and sub-picture data reproduced in synchronization with the video data.

11. A recording medium according to claim 1, wherein said navigation pack contains reproduction information describing addresses of 15 data units to be reproduced before and addresses of 15 data units to be reproduced after a data unit to which said navigation pack belongs, and also describing addresses of 20th, 30th, 60th, 120th, and 240th data units, said data unit to which said navigation pack belongs being a 0th data unit.

12. The recording medium of claim 1, wherein:

the navigation pack contains search information consecutively indicating the addresses of a specified number of data units to be searched for consecutively before and after the address of the navigation unit, and the data units are searched for with reference to the addresses,

wherein the search information contains a flag indicating whether the data unit to be searched for contains video data, and a flag indicating whether there is video data in the data units between the address of the data unit to be searched for and the address of the navigation data.

13. A recording medium according to claim 1, wherein said recording medium contains a plurality of cell data items, where the data units to be time-sequentially made playback objects are stored in each cell data item, one data unit for one cell data item.

14. A recording medium according to claim 13, wherein said recording medium contains a table in which a playback program is written to define the playback sequence of said cell data items.

15. A recording medium according to claim 14, wherein said recording medium contains a table in which a plurality of programs are written defining the playback sequence of said cell data items and program chain information indicating a relationship between the plurality of programs and performing playback in various modes.

16. A method of reproducing playback data containing navigation data, comprising:

receiving playback data comprising a plurality of data units to be played back time-sequentially and each to be reproduced within a specified period of time, the specific time period for each data unit being substantially equal, each data unit being composed of at least packs, wherein each data pack includes, a header and a packet of encoded video, audio or sub-picture data, and a navigation pack placed at the bead of the sequence,

the navigation pack including a pack header, a first packet and a second packet

the first packet being composed of a packet header and first control information for storing presentation control information, which includes a start time and an end time of the presentation of the data unit, and

the second packet being composed of a packet header and second control information for storing data search information, which includes a list of start addresses of a number of data units forward and backward in a playback order of the sequence, each listed start address expressed as a start address relative from the start address of the respective data unit to which the navigation data pack belongs, and a flag indicating whether or not the data unit designated by each start address contains video data;

converting at least one of the data units into a playback signal with reference to the presentation control information and the data search information; and

reproducing the playback signal.

17. A method according to claim 16, wherein said navigation pack contains address information indicating its own address.

18. A method according to claim 16, wherein said navigation pack contains an end address for the data unit to which the navigation pack itself belongs.

19. A method according to claim 16, wherein said navigation pack contains angle information indicating an address of the data unit related to an angle to which a current angle of the scene to be reproduced is to be switched, where the angle is switched with the reference to the address at the time of angle change.

20. A method according to claim 19, wherein said angle information contains an item describing no data unit related to an angle to which the current angle is to be switched.

21. A method according to claim 19, wherein said angle information contains information indicating addresses of the data units to be reproduced later than the data unit to which the navigation pack belongs, where the data units are obtained with reference to the addresses and the playback signal undergoes rewind playback.

22. A method according to claim 19, wherein said angle information contains the addresses of the data units to be reproduced earlier than the data unit to which the navigation pack belongs, where the data units are obtained with reference to the addresses so that the playback signal undergoes fast-forward playback.

23. A method according to claim 16, wherein said navigation pack contains end address information indicating an end address of the data unit containing the navigation pack, and the next data unit is acquired with reference to the end address.

24. A method according to claim 16, wherein, when said data unit contains the video data determined in MPEG, said navigation pack contains end address information indicating the address in the data unit in which the minimum data capable of forming an image of I picture is stored, and the minimum data to reproduce the I picture is acquired with reference to the address.

25. A method according to claim 16, wherein, when said data unit contains video data and at least one of audio data and sub-picture data, said navigation pack contains synchronizing information on the at least one audio data and sub-picture data to be reproduced in synchronization with the video data, and at least one of the audio data and the sub-picture data, together with the video data, is reproduced with reference to the synchronizing information.

26. A method according to claim 16, wherein said navigation pack contains reproduction information describing addresses of 15 data units to be reproduced before and addresses of 15 data units to be reproduced after a data unit to which said navigation pack belongs, and also describing addresses of 20th, 60th, 120th, and 240th data units, said data unit to which said navigation pack belongs being a 0th data unit.

27. The method of claim 16, wherein:

the navigation pack contains search information consecutively indicating the addresses of a specified number of data units to be searched for consecutively before and after the address of the navigation unit, and the data units are searched for with reference to the addresses,

wherein the search information contains a flag indicating whether the data unit to be searched for contains video data, and a flag indicating whether there is video data in the data units between the address of the data unit to be searched for and the address of the navigation data.

28. A method according to claim 16, wherein said playback data contains a plurality of cell data items, where the data units to be time-sequentially made playback objects are stored in each cell data item, one data unit for one cell data item, a program being reproduced with reference to the cell data items.

29. A method according to claim 16, wherein said playback data contains a table in which a playback program is written to define a playback sequence of said cell data items.

30. A method according to claim 16, wherein said playback data contains a table in which a plurality of programs are written defining a playback sequence of said cell data items and program chain information indicating a relationship between the plurality of programs and performing playback in various modes.

31. An apparatus for reproducing playback data containing navigation data, comprising:

means for retrieving, from a recording medium, playback data comprising a plurality of data units to be played back time-sequentially and each to be reproduced within a specific period of time, the specific time period for each data unit being substantially equal, each data unit comprising at least one predetermined sequence of data packs, each data pack having the same pack length, the sequence of data packs including at least one of video packs, audio packs and sub-picture packs, wherein each data pack includes a header and a packet of encoded video, audio or sub-picture data, and a navigation pack placed at the head of the sequence,

the navigation pack including a pack header, a first packet and a second packet,

the first packet being composed of a packet header and first control information for storing presentation control information, which includes a start time and an end time of the presentation of the data unit, and

the second packet being composed of a packet header and second control information for storing data search information, which includes a list of start addresses of a number of data units forward and backward in a playback order of the sequence, each listed start address expressed as a start address relative from the start address of the respective data unit to which the navigation data pack belongs, and a flag indicating whether or not the data unit designated by each start address contains video data; and

means for converting the data unit into a playback signal with reference to the presentation control information and the data search information in the retrieved playback data and for reproducing the playback signal.

32. An apparatus according to claim 31, wherein said navigation pack contains address information indicating its own address.

33. An apparatus according to claim 31, wherein said navigation pack contains end address for the data unit to which the navigation pack itself belongs.

34. An apparatus according to claim 31, wherein said navigation pack contains angle information indicating an address of the data unit related to an angle to which a current angle of the scene to be reproduced is switched, wherein the angle is switched with reference to the address at the time of angle change.

35. An apparatus according to claim 34, wherein said angle information contains an item descripting no data unit related to an angle to which the current angle is switched.

36. An apparatus according to claim 34, wherein said angle information contains information on the addresses of the data units to be reproduced later than the data unit to which the navigation pack belongs, where the data units are obtained with reference to the addresses so that the playback signal undergoes rewind playback.

37. An apparatus according to claim 34, wherein said angle information contains the addresses of the data units to be reproduced earlier than the data unit to which the navigation pack belongs, where the data units are obtained with reference to the addresses so that the playback signal undergoes fast-forward playback.

38. An apparatus according to claim 31, wherein said navigation pack contains end address information indicating an end address of the data unit containing the navigation pack, where a next data unit is acquired with reference to the end address.

39. An apparatus according to claim 31, wherein, when said data unit contains the video data determined in MPEG, said navigation pack contains end address information indicating the address in the data unit in which the minimum data capable of forming an image of I picture is stored.

40. An apparatus according to claim 31, wherein, when said data unit contains video data and at least one of audio data and sub-picture data, said navigation pack contains synchronizing information on at least one of the audio data and sub-picture data reproduced in synchronization with the video data, and at least either the audio data or the sub-picture data, together with the video data, is reproduced with reference to the synchronizing information.

41. An apparatus according to claim 31, wherein said navigation pack contains search information consecutively indicating the addresses of a specified number of data units to be searched for consecutively before and after the address of the navigation unit, and the data units are searched for with reference to the addresses.

42. An apparatus according to claim 41, wherein said search information contains a flag indicating whether there is video data in the data units between the address of the data unit to be searched for and the address of the navigation data.

43. An apparatus according to claim 31, wherein said playback data contains a plurality of cell data items, where the data units to be time-sequentially made playback objects are stored in each cell data item, one data unit for one cell data item, a program being reproduced with reference to the cell data items.

44. An apparatus according to claim 31, wherein said playback data contains a table in which a playback program is written to define a playback sequence of said cell data items.

45. An apparatus according to claim 44, wherein said playback data contains a table in which a plurality of programs are written defining a playback sequence of said cell data items and program chain information indicating a relationship between the plurality of programs and performing a playback in various modes.

46. A method of recording playback data containing navigation data on a recording medium, comprising:

preparing at least one predetermined sequence of data packs, each data pack having the same pack length, the sequence of data packs including at least one of video packs, audio packs and sub-picture packs, wherein each data pack includes a header and a packet of encoded video audio or sub-picture data;

preparing a plurality of data units, each of which is composed of a sequence of data packs that is to be reproduced within a specific period of time, the specific time period for each data unit being substantially equal, and a navigation pack provided at the head of the sequence,

the navigation pack including a pack header, a first packet and a second packet

the first packet being composed of a packet header and first control information for storing presentation control information, which includes a start time and an end time of the presentation of the data unit, and

the second packet being composed of a packet header and second control information for storing data search information, which includes a list of start addresses of a number of data units forward and backward in a playback order of the sequence, each listed start address expressed as a start address relative from the start address of the respective data unit to which the navigation data pack belongs, and a flag indicating whether or not the data unit designated by each start address contains video data; and

recording the data units time-sequentially on a recording medium so that the data units can be reproduced.

47. A method according to claim 46, wherein said navigation pack contains address information indicating its own address.

48. A method according to claim 46, wherein said navigation pack contains an end address for the data unit to which the navigation pack itself belongs.

49. A method according to claim 46, wherein said navigation pack contains angle information indicating an address of the data unit related to an angle to which a current angle of the scene to be reproduced is to be switched.

50. A method according to claim 49, wherein said angle information contains an item describing no data unit related to an angle to which the current angle is to be switched.

51. A method according to claim 49, wherein said angle information contains information indicating addresses of the data units to be reproduced later than the data unit to which the navigation pack belongs.

52. A method according to claim 49, wherein said angle information contains the addresses of the data units to be reproduced earlier than the data unit to which the navigation pack belongs.

53. A method according to claim 46, wherein said navigation pack contains end address information indicating an end address of the data unit containing the navigation pack.

54. A method according to claim 46, wherein, when said data unit contains the video data determined in MPEG, said navigation pack contains end address information indicating the address in the data unit in which the minimum data capable of forming an image of I picture is stored.

55. A method according to claim 46, wherein, when said data unit contains video data and at least one of audio data and sub-picture data, said navigation pack contains synchronizing information on at least one of the audio data and sub-picture data reproduced in synchronization with the video data.

56. A method according to claim 46, wherein said navigation pack contains reproduction information describing addresses of 15 data units to be reproduced before and addresses of 15 data units to be reproduced after a data unit to which said navigation pack belongs, and also describing addresses of 20th, 60th, 120th, and 240th data units, said data unit to which said navigation pack belongs being a 0th data unit.

57. A method according to claim 46, wherein the step of recording data on said recording medium contains the step of recording data in units of a plurality of cell data items where the data units to be time-sequentially made playback objects are stored in each cell data item, one data unit for one cell data item.

58. A method according to claim 57, further including the step of creating a table in which a playback program is written defining a playback sequence of said cells, wherein the cell table is recorded on the recording medium in the recording step.

59. A method according to claim 57, further including the step of creating a table in which a plurality of programs are written defining a playback sequence of said cell data items, and the steps of creating program chain information indicating a relationship between the plurality of programs and performing playback in various modes, wherein the program chain information is recorded on the recording medium in the recording step.

60. An apparatus for recording on a recording medium playback data containing navigation data, comprising:

means for generating at least one predetermined sequence of data packs, each data pack having the same pack length, the sequence of data packs including at least one of video packs, audio packs and sub-picture packs, wherein each data pack includes a header and a packet of encoded video, audio or sub-picture data;

means for preparing a plurality of data units, each data unit being composed of a sequence of data packs that is to be reproduced within a specified period of time, the specific time period for each data unit being substantially equal, and a navigation pack provided at the head of the sequence,

the navigation pack including a pack header a first packet and a second packet, the first packet being composed of a packet header and first control information for storing presentation control information, which includes a start time and an end time of the presentation of the data unit, and

the second packet being composed of a packet header and second control information for storing data search information, which includes a list of start addresses of a number of data units forward and backward in a playback order of the sequence, each listed start address expressed as a start address relative from the start address of the respective data unit to which the navigation data pack belongs, and a flag indicating whether or not the data unit designated by each start address contains video data; and

means for recording said data units time-sequentially on the recording medium so that said data units can be reproduced.

61. An apparatus according to claim 60, wherein said navigation pack contains an end address for the data unit to which the navigation pack itself belongs.

62. An apparatus according to claim 60, wherein said navigation pack contains angle information indicating an address of the data unit related to an angle to which a current angle of the scene to be reproduced is to be switched.

63. An apparatus according to claim 62, wherein said angle information contains an item describing no data unit related to an angle to which the current angle is to be switched.

64. An apparatus according to claim 62, wherein said angle information contains information indicating addresses of the data units to be reproduced later than the data unit to which the navigation pack belongs.

65. An apparatus according to claim 62, wherein said angle information contains the addresses of the data units to be reproduced earlier than the data unit to which the navigation pack belongs.

66. An apparatus according to claim 60, wherein said navigation pack contains end address information indicating an end address of the data unit containing the navigation pack.

67. An apparatus according to claim 60, wherein, when said data unit contains the video data determined in MPEG, said navigation pack contains end address information indicating the address in the data unit in which the minimum data capable of forming an image of I picture is stored.

68. An apparatus according to claim 60, wherein, when said data unit contains video data and at least one of audio data and sub-picture data, said navigation pack contains synchronizing information on at least one of the audio data and sub-picture data reproduced in synchronization with the video data.

69. An apparatus according to claim 60, wherein said navigation pack contains reproduction information describing addresses of 15 data units to be reproduced before and addresses of 15 data units to be reproduced after a data unit to which said navigation pack belongs, and also describing addresses of 20th, 60th, 120th, and 240th data units, said data unit to which said navigation pack belongs being a 0th data unit.

70. The apparatus of claim 60, wherein;

the navigation pack contains search information consecutively indicating the addresses of a specified number of data units to be searched for consecutively before and after the address of the navigation unit, the search information containing a flag indicating whether there is video data in the data units between the address of the unit to be searched for and the address of the navigation data.

71. An apparatus according to claim 60, wherein said means for recording data on said recording medium records data in units of a plurality of cell data items, where the data units to be time-sequentially made playback objects are stored in each cell data item, one data unit for one cell data item.

72. An apparatus according to claim 71, further comprising means for creating a table in which a playback program is written defining the playback sequence of said cells, wherein the cell table is recorded by the recording means on the recording medium.

73. An apparatus according to claim 60, further comprising:

means for creating a table in which a plurality of programs are written defining the playback sequence of said cells; and

means for creating program chain information indicating the way of combining the plurality of playback programs and performing playback in various modes, wherein

the program chain information is recorded by the recording means on the recording medium.

74. A communication system for transferring playback data containing navigation data, comprising:

means for creating playback data comprising a plurality of data units to be played back time-sequentially and each to be reproduced within a specific period of time, the specific time period for each data unit being substantially equal, each data unit being composed of at least one predetermined sequence of data packs, each data pack having the same pack length, the sequence of data packs including at least one of video packs, audio packs and sub-picture packs, wherein each data pack includes a header and a packet of encoded video, audio or sub-picture data, and a navigation pack placed at the head of the sequence,

the navigation pack including a pack header, a first packet and a second packet,

the first packet being composed of a packet header and first control information for storing presentation control information, which includes a start time and an end time of the presentation of the data unit, and

the second packet being composed of a packet header and second control information for storing data search information, which includes a list of start addresses of a number of data units forward and backward in a playback order of the sequence, each listed start address expressed as a start address relative from the start address of the respective data unit to which the navigation data pack belongs, and a flag indicating whether or not the data unit designated by each start address contains video data;

means for transferring the data units;

means for converting at least one of the data units into a playback signal with reference to the presentation control information and data search information; and

means for reproducing the playback signal.

75. A communication system according to claim 74, wherein said navigation pack contains address information indicating its own address.

76. A communication system according to claim 74, wherein said navigation pack contains an end address for the data unit to which the navigation pack itself belongs.

77. A communication system according to claim 74, wherein said navigation pack contains angle information indicating an address of the data unit related to an angle to which the current angle of the scene to be reproduced is switched, where the angle is switched with reference to the address at the time of angle change.

78. A communication system according to claim 77, wherein said angle information contains a specific description indicating the existence of no data unit related to an angle to which the current angle is switched.

79. A communication system according to claim 77, wherein said angle information contains information indicating addresses of the data units to be reproduced later than the data unit to which the navigation pack belongs, so that the data units are obtained with reference to the addresses and the playback signal undergoes rewind playback.

80. A communication system according to claim 77, wherein said angle information contains the addresses of the data units to be reproduced earlier than the data unit to which the navigation pack belongs, where the data units are obtained with reference to the addresses and the playback signal undergoes fast-forward playback at the playback means.

81. A communication system according to claim 74, wherein said navigation pack contains end address information indicating end address of the data unit containing the navigation pack, where the next data unit is acquired with reference to the end address.

82. A communication system according to claim 74, wherein said navigation pack, when said data unit contains the video data determined in MPEG, said navigation pack contains end address information indicating the address in the data unit in which the minimum data capable of forming an image of I picture is stored, and the minimum data to reproduce the I picture is acquired with reference to the address.

83. A communication system according to claim 74, wherein, when said data unit contains video data and at least one of audio data and sub-picture data, said navigation pack contains synchronization information on the at least one audio data and sub-picture data to be reproduced in synchronization with the video data, where the at least one audio data and sub-picture data is reproduced, together with the video data, with reference to the synchronizing information.

84. A communication system according to claim 74, wherein said navigation pack contains reproduction information describing addresses of 15 data units to be reproduced before and addresses of 15 data units to be reproduced after a data unit to which said navigation pack belongs, and also describing addresses of 20th, 60th, 120th, and 240th data units, said data unit to which said navigation pack belongs being a 0th data unit.

85. the communication system of claim 74, wherein:

the navigation pack contains search information consecutively indicating the addresses of a specified number of data units to be searched for consecutively before and after the address of the navigation unit, and the data units are searched for with reference to the addresses, the search information containing a flag indicating whether there is video data in the data units between the address of the data unit to be searched for and the address of the navigation data.

86. A communication system according to claim 74, wherein said playback data contains a plurality of cell data items, where the data units to be time-sequentially made playback objects are stored in each cell data item, one data unit for one cell data item, where the transferring means transfers the cell data items, and where the reproducing means reproduces a program from the cell data items.

87. A communication system according to claim 74, wherein said playback data contains a table in which a playback program is written defining a playback sequence of said cell data items.

88. A communication system according to claim 74, wherein said playback data contains a table in which a plurality of programs are written defining a playback sequence of cell data items and program chain information indicating a relationship between the plurality of programs and performing playback in various modes.

89. A recording medium with navigation data comprising:

a plurality of data cells whose playback sequence can be specified and which are to be played back consecutively and time-sequentially, each data cell being composed of a plurality of data units, each data unit being reproduced within a specific period of time, the specific time period for each data unit being substantially equal, each data unit including at least one predetermined sequence of data packs, each data pack having the sane pack length, the sequence of data packs including at least one of video packs, audio packs and sub-picture packs, wherein each data pack includes a header and a packet of encoded video, audio or sub-picture data, and a navigation pack placed at the head of the sequence,

the navigation pack including a pack header, a first packet and a second packet,

the first packet being composed of a packet header and first control information for storing presentation control information, which includes a start time and an end time of the presentation of the data unit, and

the second packet being composed of a packet header and second control information for storing data search information, which includes a list of start addresses of a number of data units forward and backward in a playback order of the sequence, each listed start address expressed as a start address relative from the start address of the respective data unit to which the navigation data pack belongs, and a flag indicating whether or not the data unit designated by each start address Contains video data; and

a table second playback information is written concerning playback of each data cell.

90. A recording medium according to claim 89, wherein said second playback information contains an address of the first data unit in each data cell.

91. A recording medium according to claim 89, wherein second playback information contains an address of the end data unit in each data cell.

92. A recording medium according to claim 89, wherein said second playback information contains the playback time of the data cell.

93. A recording medium according to claim 89, wherein said second playback information is written on said table according the an order in which the data cells are to be reproduced.

94. A recording medium according to claim 89, wherein said data cells are assigned identification numbers.

95. A recording medium according to claim 89, wherein said navigation pack contains information on the time when the data unit containing the navigation pack is to be reproduced.

122. An apparatus according to claim 89, wherein said playback information contains an address of a first data unit in each data cell.

123. An apparatus according to claim 89, wherein said playback information contains an address of a lost data unit in each data cell.

124. An apparatus according to claim 89, wherein said playback information contains a playback time for the data cell.

126. An apparatus according to claim 89, wherein said data cells are assigned identification numbers .

127. An apparatus according to claim 89, wherein the navigation pack stores playback information on the data pack and navigation information indicating the relationship with other data units.

128. An apparatus according to claim 89, wherein said navigation pack contains information on a time when the data unit containing the navigation pack is to be reproduced.

96. A method of reproducing playback data containing navigation data, comprising:

acquiring contents of a table that includes first playback information indicating playback information for data cells; and

playing back the data cells based on contents of the table and converting information from the data cells into playback signals, the data cells being played back consecutively and time-sequentially, each data cell being composed of a plurality of data units to be reproduced within a specified period of time, the specific time period for each data unit being substantially equal, each data unit including at least one predetermined sequence of data packs, each data pack having the same pack length, the sequence of data packs including at least one of video packs, audio packs and sub-picture packs, wherein each data pack includes a header and a packet of encoded video, audio or sub-picture data, and a navigation pack placed at the head of the sequence,

the navigation pack including a pack header, a first packet and a second packet,

the first packet being composed of a packet header and first control information for storing presentation control information, which includes a start time and an end time of the presentation of the data unit, and

the second packet being composed of a packet header and second control information for storing data search information, which includes a list of start addresses of a number of data units forward and backward in playback order of the sequence, each listed start address expressed as a start address relative from the start address of the respective data unit to which the navigation data pack belongs, and a flag indicating whether or not the data unit designated by each start address contains video data.

97. A method according to claim 96, wherein said first playback information contains an address of a first data unit in each data cell.

98. A method according to claim 96, wherein said first playback information contains the address of a last data unit in each data cell.

99. A method according to claim 96, wherein said playback information contains the playback time of the data cell.

100. A method according to claim 96, wherein said acquiring step contains the step of transferring the data cell to be reproduced after a certain time has elapsed with reference to said playback time.

101. A method according to claim 96, wherein said first playback information is written on said table according to an order in which the data cells are to be reproduced.

102. A method according to claim 96, wherein said data cells are assigned identification numbers.

103. A method according to claim 96, wherein said navigation pack contains information indicating a time when the data unit containing the navigation pack is to be reproduced, and said acquiring step contains the step of transferring the data cell to be reproduced after a certain time has elapsed with reference to the playback time of said data cell and the time information on the data unit.

104. A method according to claim 103, wherein said acquiring step includes a step of indicating a playback time and determining an address of a data unit which is to be reproduced at the indicated time.

105. An apparatus for reproducing data from a recording medium with navigation data, comprising:

means for receiving playback information from said recording medium and for storing second playback information, where the recording medium contains;

a plurality of data cells whose playback sequence can be specified and which are to be played back consecutively and time-sequentially, each data cell being composed of a plurality of data units, each data unit being reproduced within a specific period of time, the specific time period for each data unit being substantially equal, each data unit including at least one predetermined sequence of data packs, each data pack having the same pack length, the sequence of data packs including at least one of video packs, audio packs and sub-picture packs, wherein each data pack includes a header and a packet of encoded video, audio or sub-picture data, and a navigation pack placed at the head of the sequence

the navigation pack including a pack header, a first packet and a second packet,

the first packet being composed of a packet header and first control information for storing presentation control information, which includes a start time and an end time of the presentation of the data unit, and

the second packet being composed of a packet header and second control information for storing data search information, which includes a list of start addresses of a number of data units forward and backward in a playback order of the sequence, each listed start address expressed as a start address relative from the start address of the respective data unit to which the navigation data pack belongs, and a flag indicating whether or not the data unit designated by each start address contains video data, and

a table in which the second playback information is written concerning playback of each data cell;

means for converting the playback information from the data cell into playback signals; and

means for transferring the playback information from the data cells to the converting means with reference to the stored playback information.

106. An apparatus according to claim 105, wherein said playback information contains an address of a first data unit in each data cell.

107. An apparatus according to claim 105, wherein said second playback information contains an address of a last data unit in each data cell.

108. An apparatus according to claim 105, wherein said second playback information contains a playback time of the data cell.

109. An apparatus according to claim 105, wherein said transferring means transfers the data cell to be reproduced to the converting means after a certain time has elapsed with reference to said playback time.

110. An apparatus according to claim 105, wherein said second playback information is written on said table according to an order in which the data cells are to be reproduced.

111. An apparatus according to claim 105, wherein said data cells are assigned identification numbers.

112. An apparatus according to claim 105, wherein said playback information contains the playback time of the data cell, said navigation pack contains information indicating a time when the data unit containing the navigation pack is to be reproduced, and said transferring means transfers the data cell to be reproduced to the converting means after a specific time has elapsed with reference to the playback time of said cell and the time information on the data unit.

113. A method according to claim 105, wherein said acquiring step includes a step of indicating a playback time and determining an address of a data unite which is playbacks at the indicated time.

114. A method of recording playback data containing navigation data on a recording medium, comprising:

preparing at least one predetermined sequence of data packs, each data pack having the same pack length, the sequence of data packs including at least one of video packs, audio packs and sub-picture packs, wherein each data pack includes a header and a packet of encoded video, audio or sub-picture data, a navigation pack being placed at the head of each predetermined sequence

the navigation pack including a pack header, a first packet and a second packet,

the first packet being composed of a packet header and first control information for storing presentation control information, which includes a start time and an end time of the presentation of the data unit, and

the second packet being composed of a packet header and second control information for storing data search information, which includes a list of start addresses of a number of data units forward and backward in a playback order of the sequence, each listed start address expressed as a start address relative from the start address of the respective data unit to which the navigation data pack belongs, and a flag indicating whether or not the data unit designated by each start address contains video data;

preparing a plurality of data units, each of which is composed of at least one data pack train, each data unit to be reproduced within a certain period of time;

collecting the plurality of data units to be reproduced time-sequentially and creating a plurality of data cells whose playback sequence can be specified;

creating a table in which second playback information is written concerning playback of each data cell; and

recording on the recording medium the plurality of data cells and the table, the data cells being recorded immediately after the table.

115. A method according to claim 114, wherein said second playback information contains an address of a first data unit in each data cell.

116. A method according to claim 114, wherein said second playback information contains an address of a last data unit in each data cell.

117. A method according to claim 114, wherein said second playback information contains a playback time of the data cell.

118. A method according to claim 114, wherein said second playback information is written on said table according to an order in which the data cells are to be reproduced.

119. A method according to claim 114, wherein said data cells are assigned identification numbers.

120. A method according to claim 114, wherein said navigation pack contains information on a time when the data unit containing the navigation pack is reproduced, and said transferring means transfers the data cell to be reproduced to the converting means after a specific time has elapsed with reference to the playback time.

121. An apparatus for recording playback data containing navigation data on a recording medium, comprising:

means for creating at least one predetermined sequence of data packs, each data pack having the same pack length, the sequence of data packs including at least one of video packs, audio packs and sub-picture packs, wherein each data pack includes a header and a packet of encoded video audio or sub-picture data;

means for preparing a plurality of data units, each data unit being composed of a sequence of data packs and a navigation pack, each data unit to be reproduced within a certain period of time, the navigation pack located at a head of the sequence,

the navigation pack including a pack header, a first packet and a second packet,

the first packet being composed of a packet header and first control information for storing presentation control information, which includes a start time and an end time of the presentation of the data unit, and

the second packet being composed of a packet header and second control information for storing data search information, which includes a list of start addresses of a number of data units forward and backward in a playback order of the sequence, each listed start address expressed as a start address relative from the start address of the respective data unit to which the navigation data pack belongs, and a flag indicating whether or not the data unit designated by each start address contains video data;

means for collecting the plurality of data units so that they may be reproduced time-sequentially and for creating a plurality of data cells whose playback sequence can be specified;

means for creating a table in which second playback information is written concerning playback of each data cell; and

means for recording the plurality of data cells and the table, the data cells being recorded immediately after the table.

125. An apparatus according to claim 121, wherein said second playback information is written on said table based on an order in which the cells are to be reproduced.

129. A communication system for transferring playback data containing navigation data, comprising:

means for creating a plurality of data cells whose playback sequence can be specified and which are played back consecutively and time-sequentially, each data cell being composed of a plurality of data units to be reproduced within a specific period of time, each data unit including at least one predetermined sequence of data packs, each data pack having the same pack length, the sequence of data packs including at least one of video packs, audio packs and sub-picture packs, wherein each data pack includes, a header and a packet of encoded video, audio or sub-picture data, and a navigation pack placed at the head of the sequence

the navigation pack including a pack header, a first packet and a second packet,

the first packet being composed of a packet header and first control information for storing presentation control information, which includes a start time and an end time of the presentation of the data unit, and

the second packet being composed of a packet header and second control information for storing data search information, which includes a list of start addresses of a number of data units forward and backward in playback order of the sequence, each listed start address expressed as a start address relative from the start address of the respective data unit to which the navigation data pack belongs, and a flat indicating whether or not the data unit designated by each start address contains video data;

a table in which second playback information is written concerning the playback of each data cell; and

means for transferring the table with reference to the table after transferring the data units including the navigation pack.

130. A communication system according to claim 129, wherein said playback information contains an address of a first data unit in each data cell.

131. A communication system according to claim 129, wherein said playback information contains an address for date data unit in each data cell.

132. A communication system according to claim 129, wherein said playback information contains the playback time of the cell.

133. A communication system according to claim 129, wherein said acquiring step contains the step of transferring the data cell to be reproduced with reference to said playback time after a certain time has elapsed.

134. A communication system according to claim 129, wherein said second playback information is written on said table according to an order in which the data cells are to be reproduced.

135. A communication system according to claim 129, wherein said data cells are assigned identification numbers.

136. A communication system according to claim 129, wherein said navigation pack contains information on the time when the data unit containing the navigation pack is to be reproduced.

137. A communication system according to claim 129, further comprising, converting at least one of means for converting the data units into a playback signal with reference to the navigation information in the transferred playback data.

138. A communication system according to claim 137, wherein said converting means receives the data cells with reference to said navigation pack.