JP2001309301A - Video and sound recording and reproducing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording system of video and sound data capable of realizing smooth special reproduction of video and sound data and also coping with various compressing methods. SOLUTION: This system includes a TstType 103 representing types of time tables in an AV information file 101, further a 1st time search entry table 105 and a media object data unit information table 106 in the first type, further a 2nd time search entry table 108 in the second type, and a FrameTime 110, a MODUSize 111 and a NumFrame 112 in the third type.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an apparatus for recording and reproducing video and audio data.

[0002]

2. Description of the Related Art As an example of a conventional video / audio recording / reproducing apparatus, there is a DVD-RAM whose standard has already been determined. The DVD-RAM adopts a method of compressing and recording video and audio data in the MPEG2 format, and video and audio are recorded in a format defined by the MPEG2 system layer. In the system layer of MPEG2, it is specified that the transfer time and the reproduction time of data such as video and audio are set, and in the case of normal reproduction, reproduction is performed using these.

[0003] However, in order to realize special playback such as fast-forward, rewind playback, or playback at an arbitrary speed using a jog dial, it is difficult to achieve such special playback using only information specified by the system layer. For example, in Japanese Patent Application Laid-Open No. H11-155130, two time tables are prepared, and a first time table is provided for each reproduction time set at regular time intervals, with address information of a video object unit corresponding to the reproduction time. A method is disclosed in which the second time table includes the reproduction time and the data size of each video object unit in the order of the reproduction time from the beginning of the video object. According to the method disclosed in Japanese Patent Application Laid-Open No. H11-155130, a video object unit to be accessed can be specified from reproduction time information during special reproduction, and a target frame can be reproduced instantaneously. .

However, recently, MPEG4 has been standardized as a data compression method for moving pictures, and a video and audio data storage method which can be adapted to MPEG4 and solves the above-mentioned problem has been desired. For example, Japanese Patent Application Laid-Open No. H11-1551
In the method disclosed in Japanese Patent Publication No. 30, the second time table has a structure on the assumption that the video object unit starts with an I picture using intra-frame compression. It is difficult to apply when there are possible video object units that do not start with a picture.

[0005]

The present invention solves these problems by improving the time table so that it can be described by a plurality of structures according to the characteristics of AV data. An object of the present invention is to enable a recording / reproducing method applicable to data having no picture.

[0006]

A video / audio recording / reproducing method according to the present invention is a video / audio recording / reproducing method for recording video / audio data and video / audio information data relating to the video / audio data, Includes a time table type for specifying the type of the time table of the video and audio data, and a time table having a different structure depending on the value of the time table type.

Further, in the video / audio recording / reproducing method, the time table based on one of the time table types is a reproduction time corresponding to video / audio data and is set at regular time intervals. A time search entry table in which a time search entry corresponding to a playback time is configured as a table entry, and media object data unit information, which is information on media object data units set in the playback order of video and audio data, are configured as table entries. The time search entry comprises identification information for identifying the corresponding media object data unit, and a start of the media object data unit. And time difference between the time of time and time search entry contains the address information of the media object data unit, wherein the media object data unit information includes the playback time and data size of the media object data unit corresponds.

In the video / audio recording / reproducing method according to the present invention, the time table based on one of the time table types is a reproduction time corresponding to video / audio data and is set at regular time intervals. A time search entry table configured as a table entry with a time search entry corresponding to the reproduction time, wherein the time search entry includes a time difference between a start time of the corresponding media object data unit and a time of the time search entry; The address information of the media object data unit is included.

In the video / audio recording / reproducing method, the time table based on one of the time table types may include a reproduction time of one frame, a size of a media object data unit, It includes the number of frames included in the object data unit.

[0010]

(Embodiment 1) FIG. 1 shows a first structure of a data management section of a video / audio recording / reproducing apparatus according to Embodiment 1 of the present invention.

In FIG. 1, reference numeral 101 denotes an AV information file storing management information of one AV data, and 102 denotes an AV information file.
An AV data file that stores data itself.

In FIG. 1, reference numeral 103 denotes an identifier T indicating the type of a time search entry in the AV information file.
stType.

[0013] The structure of the AV information file is TstTy.
It changes according to the value of pe103 and the structure shown in FIG. 1 is obtained when the TstType 103 has a value of 1. Hereinafter, the case where the TstType 103 is 1 will be described first.

Reference numeral 104 denotes a time interval for preparing a time search entry TstInterval, and 105 denotes a TstE.
A first time search entry table composed of entry # 0 to TstEntry #m.
A media object data unit information table 107 having, as an entry, media object data unit information prepared for each media object data unit composed of I # 0 to MODUI # n
Is a media object data unit table having, as entries, a media object data unit composed of MODU # 0 to MODU # n.

FIG. 2 shows the structure of a time search entry indicating each entry of the first time search entry table 105. MODU Number
r is the number of the media object data unit indicated by the time search entry, EntryFr
ameDiff is a difference time between the time pointed to by the time search entry and the start time of the media object data unit pointed to by the time search entry, MODU
Offset is a byte offset in the AV data file 102 of the media object data unit indicated by the time search entry.

FIG. 3 shows the structure of media object unit information indicating individual entries of the media object unit information table 106. E
ntrySize is the data size occupied by the I picture at the head of the media object data unit, M
ODU PbTime is the playback time of the media object data unit, and MODU Size is the data size of the media object data unit.

FIG. 4 shows a second structure of the data management unit of the video / audio recording / reproducing apparatus according to the first embodiment of the present invention.

In FIG. 4, reference numeral 101 denotes an AV information file storing management information of one AV data, and 102 denotes an AV information file.
An AV data file that stores data itself.

In FIG. 4, reference numeral 103 denotes an identifier T indicating the type of a time search entry in the AV information file.
stType, and in the second structure, the TstT
The type 103 has a value of 2.

In FIG. 4, reference numeral 104 denotes a time interval TstInterval in which a time search entry is prepared,
08 is a second time search entry table composed of TstEntry # 0 to TstEntry # m, 1
Reference numeral 09 denotes a media object data unit table having a media object data unit composed of MODU # 0 to MODU # n as an entry.

FIG. 5 shows a structure of a time search entry indicating each entry of the second time search entry table 108. EntryFrame
Diff is a difference time between the time pointed to by the time search entry and the start time of the media object data unit pointed to by the time search entry, MODU Of.
fset is the AV data file 10 of the media object data unit indicated by the time search entry.
2 is the byte offset within 2.

FIG. 6 shows a third structure of the data management unit of the video / audio recording / reproducing apparatus according to the first embodiment of the present invention.

In FIG. 6, reference numeral 101 denotes an AV information file storing management information of one AV data, and 102 denotes an AV information file.
An AV data file that stores data itself.
In FIG. 6, reference numeral 103 denotes an identifier TstType indicating the type of a time search entry in the AV information file.
In the third structure, the TstType103
Has the value 3.

In FIG. 6, reference numeral 110 denotes a FrameTime representing the reproduction time of one frame, and 111 denotes a MODU representing the byte size of the media object data unit.
Size 112 is NumFrame representing the number of frames included in one media object data unit.
Reference numerals e and 113 denote media object data unit tables each having a media object data unit as an entry.

First, specific processing in the video / audio recording / reproducing apparatus will be described. The video / audio recording / reproducing apparatus determines which of the first to third structures to use at the time of recording the video / audio, depending on the purpose and the characteristics of the video / audio to be recorded.

The video / audio data can be divided into media object data units (corresponding to GOPs in MPEG2) starting from an I picture, and the media object data unit currently being accessed is followed by media object data units before and after the currently accessed media object data unit. The first structure is used to enable easy access. The video / audio data cannot be divided into media object data units starting with I-pictures, or the media object data unit currently being accessed can be easily accessed next and subsequent media object data units. If not necessary, the second structure is used. The third structure is used when the media object data unit can be determined to have a fixed size, and the number of frames included in the unit and the reproduction time of the frame are constant.

As a specific example when the first structure of the AV information file is used, an AV file compressed in the MPEG2 format is used.
Data. AV compressed in MPEG2 format
The data includes an I picture at an appropriate timing, based on which the AV data can be divided into media object data units. Media object data unit information is created for each media object data unit, and is used as the media object data unit information table 106. In order to create a first time search entry table, the TstInte
Determine the rval value appropriately. Here, it is set to 10 seconds. Time search entries are created every 10 seconds and the first
Of the time search entry table 105 of FIG. 1
The time search entry # 1 indicating the 0th second entry includes the number of the media object data unit including the position of 10 seconds from the beginning (here, 4), the start time of the media object data unit # 4, and 10
Difference value from second, media object data unit # 4
Byte offset in the AV data file. Also, media object data unit information # 4 in the media object data unit information table
Includes the data size of the leading I-picture of the media object data unit # 4, the playback time of the media object data unit # 4, and the data size of the media object data unit # 4.

In the time search entry # 2 indicating the entry at the 20th second, the number of the media object data unit including the position of 20 seconds from the beginning (here, 9), the media object data unit # 9
Of the media object data unit # 9 in the AV data file. The media object data unit information # 9 in the media object data unit information table includes the data size of the first I picture of the media object data unit # 9, the reproduction time of the media object data unit # 9, the media object data unit # 9. Data size.

Similarly, time search entries for the 30th and 40th seconds and thereafter are subsequently created.

FIG. 7 shows a specific example of an AV information file and an AV data file when certain AV data is recorded. Using this AV data, special reproduction of video and audio using the first structure will be described.

Consider a case where reproduction is performed from the middle of AV data, that is, when a time offset from the head is given, reproduction is performed from that offset. Here, considering the case where reproduction is performed from the 21st second, 21 seconds are used for the TstIn.
The quotient obtained by dividing the terval value by 10 seconds, that is, 2 is the index of the time search entry to be accessed.
Time search entry # 2 points to media object data unit # 9, and MODU Offset.
Of the media object data unit # 9 is A
Starting from the 16300000 byte offset of the V data file, the start time is EntryFrameDif
From the value of f, it can be seen that 20 seconds-0.2 seconds is 19.8 seconds. From this 19.8 seconds to the target 21 seconds, M in the media object data unit information
ODU PbTime is added. MODU PbTime of media object data unit information # 9
Is 20.8 seconds, and then MODU PbTime of the media object data unit information # 10 is 21.8 seconds.
It can be seen that the second frame corresponds to the 0.8 second of the media object data unit # 10, and the reproduction position can be specified.

Next, a description will be given of a case where fast forward reproduction is performed. In fast-forward playback, only I pictures in the media object data unit are played back in ascending order.
At some point, I of media object data unit # 9
Assuming that a picture is being played, and the next moment, the I picture of the next media object data unit # 10 is played, the offset value 16300 in the AV data file of the media object data unit # 9 is assumed.
000 to media object data unit information # 9
By adding the MODU Size of the media object data unit # 10, an offset value in the AV data file of the media object data unit # 10 can be obtained instantaneously, and by repeating this one after another, fast-forward playback can be continued while picking up only I pictures. is there.

Next, the case of performing rewind reproduction will be described. In rewind playback, only I pictures in the media object data unit are played back in descending order. Assuming that the I-picture of the media object data unit # 9 is being reproduced at one time and the I-picture of the previous media object data unit # 8 is to be reproduced at the next instant, the AV data file of the media object data unit # 9 has to be reproduced. Offset value of 16
The offset value in the AV data file of the media object data unit # 8 can be obtained instantaneously by subtracting the MODU Size of the media object data unit information # 8 from 300,000. By repeating this one after another, only the I picture is picked up. It is possible to continue rewind reproduction while doing so.

A specific example of the case where the second structure of the AV information file is used is AV data which is compressed in the MPEG4 format and all the frames are P pictures. In this case, the media object data unit is considered to be a group of frames divided in an appropriate unit (for example, one second). First, in order to create a second time search entry table, the TstInter
Determine the val value appropriately. Here, it is set to 10 seconds.
The time search entry is created every 10 seconds and forms the second time search entry table 108. The time search entry # 1 indicating the 10th second entry includes the start time of the media object data unit (here, # 4) including the position of 10 seconds from the beginning, and
Difference value from second, media object data unit # 4
Byte offset in the AV data file.

The time search entry # 2 indicating the entry at the 20th second contains a difference value between the start time of the media object data unit (here, # 9) including the position of 20 seconds from the head and 20 seconds. , The byte offset of the media object data unit # 9 in the AV data file.

Similarly, time search entries for the 30th and 40th seconds and thereafter are subsequently created.

FIG. 8 shows a specific example of an AV information file and an AV data file when certain AV data is recorded. Using the AV data, special reproduction of video and audio using the second structure will be described.

Consider a case where reproduction is performed from the middle of AV data, that is, when a time offset from the head is given, reproduction is performed from that offset. Here, considering the case where reproduction is performed from the 21st second, 21 seconds are used for the TstIn.
The quotient obtained by dividing the terval value by 10 seconds, that is, 2 is the index of the time search entry to be accessed.
It can be seen that the time search entry # 2 points to the media object data unit starting from the 16300000th byte of the AV data file (actually, this indicates the media object data unit # 9). The start time of the media object data unit is 19.8 seconds from 20 seconds to 0.2 seconds from the value of EntryFrameDiff, and the time required to reach the intended 21 seconds is 21 seconds to 19.8.
This is 1.2 seconds in seconds, and the frame corresponding to 1.2 seconds after decoding starts from the head of the media object data unit is the target frame.

As a specific example of the case where the third structure of the AV information file is used, it is conceivable to record AV data having a fixed data size of one frame, for example, DIF data. In this case, the playback time and data size of the media object data unit and the number of frames included therein are all constant, and the FrameTime, MODUSize, and NumFr of the AV information file are respectively set.
ame.

[0040]

According to the video / audio recording / reproducing method according to the present invention, the video / audio recording / reproducing method for recording video / audio data and video / audio information data related to the video / audio data, wherein the video / audio information data is It includes a timetable type for specifying the type of the timetable of the video and audio data, and includes a timetable having a different structure depending on the value of the timetable type. There is an effect that the structure of the time table can be changed in consideration of the method of using the time table.

According to the present invention, in the video / audio recording / reproducing method, the time table based on one of the time table types is a reproduction time corresponding to the video / audio data and is provided at regular time intervals. A time search entry table configured as a table entry with a time search entry corresponding to the reproduction time set in the table, and media object data unit information that is information on the media object data units set in the reproduction order of the video and audio data. The time search entry includes identification information for identifying the corresponding media object data unit, and the media object data unit. The media object data unit includes a time difference between a start time and a time of a time search entry, and address information of the media object data unit, and the media object data unit information includes a reproduction time and a data size of the corresponding media object data unit. Therefore, there is an effect that a time table such as MPEG2 that can easily perform special reproduction of video / audio data including an I picture periodically can be configured.

According to the invention, in the video / audio recording / reproducing method, the time table based on one of the time table types is a reproduction time corresponding to the video / audio data and is provided at regular time intervals. The time search entry corresponding to the reproduction time set in the above is configured from a time search entry table configured as a table entry, the time search entry,
Since the time difference between the start time of the corresponding media object data unit and the time of the time search entry is included, and the address information of the media object data unit is included, MPEG4 that does not include an I picture is included.
Even in the case of compressed video / audio data, there is an effect that a time table can be configured while saving memory.

According to the invention, in the video / audio recording / reproducing method, the time table based on one of the time table types includes a reproduction time of one frame, a size of a media object data unit, Since the number of frames included in the media object data unit is included, there is an effect that a time table can be formed even for video / audio data having a fixed data size of one frame.

[Brief description of the drawings]

FIG. 1 is a diagram showing the structure of an AV information file and an AV data file in the case of type 1 according to the first embodiment of the present invention.

FIG. 2 is a diagram showing a structure of a time search entry in the case of type 1 according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a structure of media object data information in the case of type 1 according to the first embodiment of the present invention.

FIG. 4 is a diagram showing structures of an AV information file and an AV data file in the case of type 2 according to the first embodiment of the present invention.

FIG. 5 is a diagram showing a structure of a time search entry in the case of type 2 according to the first embodiment of the present invention.

FIG. 6 is a diagram showing structures of an AV information file and an AV data file in the case of type 3 according to the first embodiment of the present invention.

FIG. 7 is a diagram for explaining specific data in case of type 1 according to the first embodiment of the present invention.

FIG. 8 is a diagram illustrating specific data in the case of type 2 according to the first embodiment of the present invention.

[Explanation of symbols]

101 AV information file 102 AV data file 103 TstType 104 TstInterval 105 First time search entry table 106 Media object data unit information table 107 Media object data unit table 108 Second time search entry table 109 Media object data unit table 110 FrameTime 111 MODUSize 112 NumFrame 113 Media Object Data Unit Table

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 5/93 H04N 5/93 Z F-term (Reference) 5C052 AA02 AC01 CC06 CC20 DD07 5C053 FA03 FA25 GB06 GB08 GB11 GB37 GB38 HA24 HA25 HA27 HA29 JA05 JA22 JA24 5D044 AB05 AB07 BC06 CC04 DE14 DE23 DE39 GK08 5D045 DA20

Claims (4)

[Claims] 1. A video / audio recording / reproducing method for recording video / audio data and video / audio information data related to the video / audio data, wherein the video / audio information data is used to specify a type of a time table of the video / audio data. A video / audio recording / reproducing method comprising a time table type and a time table having a different structure depending on the value of the time table type. 2. The time table based on one of the time table types includes a time search entry corresponding to a reproduction time corresponding to video / audio data and a reproduction time at regular time intervals. A time search entry table, and a media object data unit information table configured as media table data unit information, which is information on media object data units set in the order of reproduction of video and audio data, The time search entry includes identification information for identifying the corresponding media object data unit, a time difference between a start time of the media object data unit and a time of the time search entry, It contains address information of the media object data unit, wherein the media object data unit information, characterized in that it comprises a playback time and data size of the media object data unit corresponding, video and audio recording and reproducing system according to claim 1, wherein. 3. The time table based on one of the time table types includes a time search entry corresponding to a playback time corresponding to video / audio data and a playback time at regular time intervals. The time search entry includes a time difference between the start time of the corresponding media object data unit and the time of the time search entry, and address information of the media object data unit. 2. The video / audio recording / reproducing method according to claim 1, wherein: 4. The time table based on one of the time table types includes a playback time of one frame, a size of a media object data unit, and a number of frames included in the media object data unit. 2. The video / audio recording / reproducing method according to claim 1, wherein: