JPH10294927A - Communicating method for moving image data, recording and reproducing method for moving image data and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the communication data amount of the MPEG corresponding to the congestion level of the communication medium. SOLUTION: A packet 101a including the private data of data managing information 110 arranged at the head part of MPEG data on the packet layer of MPEG data and composed of information such as GOP reproducing time 110a, packet size 110b and bit rate 110c and a packet 101b including the private data of thinning managing information 120 arranged at the head part of the GOP and composed of information such as I picture leading offset 120a, I picture packet number 120b, audio packet offset 120c and audio packet number 120d are added and recorded. When transmitting data, the amount of data is reduced by selectively transmitting only a packet 101c corresponding to I picture and a packet 101d corresponding to AAU while using the thinning managing information 120 and on the side of reception, images and sounds are synchronously reproduced by using the data managing information 110.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for communication and recording / reproduction of moving image data and a storage medium, and more particularly to communication and distribution of encoded moving image data such as MPEG data, and further to recording / reproduction. Effective technology.

[0002]

2. Description of the Related Art Since digitalized moving image data has a large data amount, a large-capacity storage medium is required as it is when long-term data is handled, and a wideband is used when data communication is performed. Communication media. For this reason, in recent years, a standard called MPEG has been proposed as one of the methods for compressing digitized moving image data to reduce the data amount.

[0003] As for MPEG, for example, Ascii Co., Ltd., 1st edition, 6th printing issued on July 1, 1996, edited by Multimedia Study Group, "Latest MPEG Textbook"
And the like.

When transmitting and receiving MPEG data via a communication medium, a necessary bandwidth may not be secured depending on the degree of congestion of the communication medium. Further, when the performance of the information processing device used for data reproduction is low, for example, it may be impossible to reproduce and display about 30 frames / second specified by MPEG.

In such a case, in the prior art, for example, (1) a method of reducing the data amount by reducing the image size of MPEG data by scaling processing;
(2) A method of transferring / reproducing only an I picture in MPEG data can be considered.

[0006]

However, the above (1)
The measures described in (1) and (2) have a technical problem in that the size conversion takes time and overhead increases, so that the load on the system increases in the field of data communication or the like that requires real-time performance. In the first place, a reproduction system or the like having a small processing capacity cannot be adopted because the load is further increased. Further, there is also a technical problem that the size of the display screen is reduced, and the quality and convenience of moving image data are impaired.

Further, the measure (2) has a technical problem that audio information such as voice and sound is completely lost and only moving image data is reproduced, so that quality and convenience are impaired.

An object of the present invention is to provide a moving image data communication technique capable of reducing the amount of communication data according to the degree of congestion of a communication medium without increasing the system load and overhead. It is in.

Another object of the present invention is to reduce the amount of communication data in accordance with the degree of congestion of a communication medium without reducing the quality or convenience of moving image data such as reduction in display screen size or loss of audio information. An object of the present invention is to provide a moving image data communication technology capable of realizing reduction.

[0010] Another object of the present invention is to provide a playback system having a relatively low performance without reducing the quality and convenience of the moving image data such as reduction of the display screen size and loss of audio information. It is an object of the present invention to provide a moving image data reproducing technique capable of reproducing a moving image.

Another object of the present invention is to provide a technique for reproducing moving image data capable of realizing various reproduction processes such as control of presence / absence of audio information and fast-forward reproduction of audio information.

[0012]

SUMMARY OF THE INVENTION The present invention relates to a moving image data communication technique, in which video data and audio data are added to a part of a bit stream of moving image data in which video data and audio data are mixed in a desired data unit. At least one of the control data in which position information in at least a bit stream is recorded is mixed, and when moving image data is transmitted via a desired communication medium, a position obtained from the control data as necessary. The data is transmitted by thinning out at least one of the video data and the audio data based on the information.

According to the present invention, in a moving picture data reproducing technique, at least one of video data and audio data is added to a part of a bit stream of moving picture data in which video data and audio data are mixed in a desired data unit. A step of recording at least a control data in which position information in a bit stream is recorded on a desired storage medium, and a step of reading a bit stream from the storage medium or a communication medium to reproduce moving image data. And reproducing at least one of video data and audio data based on the position information obtained from the control data.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(Embodiment 1) FIG. 1 is a conceptual diagram showing an example of data handled by a moving image data communication method according to an embodiment of the present invention. FIGS. 2 and 3 show the present embodiment. FIG. 4 is a block diagram illustrating an example of a configuration of a system in which a moving image data communication method according to an embodiment is implemented. FIG. 4 is a concept illustrating an example of a configuration of an information network in which the moving image data communication method according to the present embodiment is implemented. FIG. FIGS. 5, 6, and 7 are flowcharts illustrating an example of the operation of the moving image data communication method according to the present embodiment.

First, as exemplified in FIG. 4, in the information network of the present embodiment, a server 200 and a plurality of clients 300 are interconnected via a desired communication medium 400 such as a LAN or a public line. And data communication is performed. In the case of the present embodiment, as an example, the server 200 needs moving image data (hereinafter, referred to as MPEG data) encoded in an MPEG format as illustrated in FIG. In response, the data is distributed to a plurality of clients 300, and each client 300 performs an operation of decoding and reproducing the received MPEG data.

As an example, as shown in FIG. 2, the server 200 includes a system bus 201, a processor 202 for performing overall control, a main memory 203 in which control programs and data of the processor 202 are stored, a hard disk drive, and the like. An operation terminal 205 comprising a secondary storage device 204 in which desired data and the like are stored, a frame memory 205a, a display 205b, a keyboard (not shown) and the like, and providing a visual interface to an operator, a network interface 206 ,
The configuration is such that an encoder device 210 for generating MPEG data and the like are connected.

The encoder device 210 includes, for example, a video source supply device 2 such as a video deck or a video camera.
20 is connected, and analog moving image data including video and audio / sound information is input.

The encoder device 210 includes an A / D converter 211 and a preprocessor 21 as a video data processing system.
2. A video encoder 213 is provided, and an A / D converter 214 and an audio encoder 215 are provided as audio data processing systems. The pre-processing unit 212 is a YUV or R
A conversion process is performed according to the difference in expression format of input video data such as GB.

As an example, the video encoder 213 has an MP
The audio encoder 215 performs encoding up to the GOP layer and data format generation processing using a predetermined encoding method defined by the EG.
Unit: audio decoding unit) and performs data format generation processing, and outputs the data to the higher-order multiplexing unit 216. The multiplexing unit 216 converts the GOP data of the video data system and the AAU into higher-order packets.
Conversion / multiplexing into packets, which are data units of layers,
Output as a bit stream of MPEG data.

The encoder device 210 may be realized by using another information processing device independent of the server 200, as shown in FIG. 4, or a so-called connected to the system bus 201. It may be implemented as hardware such as an expansion board. Also, the processor 202
Have a sufficiently large processing capacity, for example, A
The operation of each component other than the / D converters 211 and 214 may be realized by software executed by the processor 202.

In the case of the present embodiment, the processing illustrated in the flowcharts of FIGS. 5 and 6 described below executed in the server 200 executes the control program (not shown) loaded in the main memory 203 on the processor 202. It is realized by doing. That is, the control program is distributed or supplied in a state where the control program is stored in a portable storage medium 204a accessible in the secondary storage device 204, for example.
Is loaded into the secondary storage device 204 and the portable storage medium 204
a from the main memory 203
, The processes exemplified in the flowcharts of FIGS. 5 and 6 can be executed by the server 200.

On the other hand, the client 300 includes, for example, a processor 302 for performing overall control, a main memory 303 for storing a control program and data of the processor 302, a hard disk device, and the like on a system bus 301. Etc. are stored in the secondary storage device 304, the frame memory 305a, the display 30
5b, a user interface 305 comprising a keyboard or the like (not shown) for providing a visual interface or the like to the operator, a network interface 30
6. A decoder device 310 for decoding MPEG data and the like is connected.

The decoder 310 is, for example, an MP
A separating unit 311 for separating video data and audio data from EG data, a video decoder 312, a post-processor 313, a D / A converter 314, and a video output control device 315 for decoding and reproducing the separated video data And an audio decoder 316, a D / A converter 317, an audio amplifier 318, etc., which perform decoding and reproduction processing of the separated audio data.

In the video data processing system, the post-processor 313 and the video output control device 315 convert, for example, the decoded digital data into the RGB format as it is in accordance with the video data input format of the output display. An operation such as outputting to the memory 305a or outputting as an analog YUV format is performed.

In the audio data processing system, the decoded and analogized audio data is output to the speaker 320 via the audio amplifier 318.

The decoder device 310 may be realized by using another information processing device independent of the client 300, or may be implemented as hardware such as a so-called expansion board connected to the system bus 301. You may. When the processor 302 has a sufficiently large processing capability, for example, the D / A converter 31
The operation of the components other than 4, 317 is
May be realized by software executed by the software.

In the case of this embodiment, this client 3
The processing illustrated in the flowcharts of FIG. 7 and FIG.
02 is executed. That is,
This control program is stored in, for example, the secondary storage device 304
Is distributed or supplied in a state of being stored in a portable storage medium 304a accessible by the portable storage medium 304a.
04a is loaded in the secondary storage device 304, and the control program is read from the portable storage medium 304a and loaded into the main memory 303, so that the processes illustrated in the flowcharts of FIGS. It becomes possible.

Next, an example of MPEG data handled in the moving image data communication method according to the present embodiment will be described with reference to FIG. FIG. 1 illustrates a packet layer of MPEG data. Although a header (not shown) is attached to the head of each packet 101 described later, the details of this header are described in detail in the above-mentioned literature such as the "Latest MPEG Textbook", and therefore the description is omitted. I do.

The MPEG data output from the encoder 210 provided in the server 200 has a configuration including a plurality of packets 101 of a desired size. Each of the packets 101 includes video data, audio data, and an arbitrary user data. Any of private data for which information can be set is stored.

For example, for video data, one I picture, P picture, and B picture in the GOP layer are stored in several consecutive packets 101c, and for audio data, one packet 10c is stored.
A plurality of AAUs are stored in 1d. A plurality of I pictures,
A GOP is composed of a packet 101c corresponding to a P picture and a B picture, and a plurality of packets 101d corresponding to an AAU, and some GOPs are continuous in time series.

In the case of this embodiment, as an example, the MPE
At the beginning of the G data, as private data,
Packet 10 including data management information 110 as described below
1a, and at the head of each GOP, thinning management information 1 as described later as private data.
The packet 101b including the packet No. 20 is arranged.

The operation of adding the data management information 110 and the thinning management information 120 to the MPEG data is performed, for example, by the processor 202 using the main memory 203 as a work area as described later.

Hereinafter, an example of the operation of the moving image data communication method according to the present embodiment will be described with reference to the flowcharts of FIGS. 5, 6, and 7. In the present embodiment, as an example, MPEG data is transmitted from the server 200 to one or a plurality of clients 300 via the communication medium 400, and each client 300 side transmits the MPEG data in real time.
A case where EG data is reproduced will be described.

First, in the server 200, moving image data input from the video source supply device 220 and converted into MPEG data by the encoder device 210 is compared with the moving image data shown in FIG.
A preparatory process for storing in the secondary storage device 204 in advance with private data including the data management information 110 and the thinning management information 120 as illustrated in FIG.

In the server 200, the encoder device 210
M to the packet layer coming from
The bit stream of the PEG data is stored in the main memory 203 for each GOP, for example, to generate and add data such as the data management information 110 and the thinning management information 120. It should be noted that the bit stream in GOP units held in the main memory 203 can be written to the secondary storage device 204 after the serial search from the head is completed. By using the buffer as a buffer, a search operation from the head side and a write operation to the secondary storage device 204 and a reading of a bit stream of the next GOP data into an area where the write operation has been completed are executed in parallel. The generation and addition processing of data such as the data management information 110 and the thinning management information 120 can be continuously performed at high speed.

As exemplified in FIG. 5, first, MPEG
In the processing of the GOP at the head of the data, a packet 101a including the data management information 110 as private data is generated at the head of the MPEG data (step 5).
01), and write it out to the secondary storage device 204 (step 50)
2). This data management information 110 contains the GOP playback time 1
10a, information such as a packet size 110b which is the size of each packet 101, a bit rate 110c, and the like.
These pieces of information are generated, for example, by reading information of a header portion (not shown) of each data unit in the packet layer and lower layers.

In addition, a packet 101b in which the thinning management information 120 is stored as private data is added to the head of each GOP (step 503), and the packet 101b is written to the secondary storage device 204 (step 504). (Step 50)
5).

As one example, the thinning management information 120 is, for example, an I picture head offset indicating relative position information of the head position of the packet 101c including the I picture with respect to the head of the GOP in each GOP. 120a, the number of I-picture packets 120b, which is the number of consecutive packets 101 including I-pictures, an audio packet offset 120c indicating relative position information from the start position of the GOP to the position of the packet 101d including AAU, It is composed of information such as the number of audio packets 120d indicating the number of packets 101d including the AAU. These pieces of information can be generated by searching the GOP data held in the main memory 203 from the top.

By the above-described preparation processing, the packet 101a including the data management information 110 as private data is added to the head, and the packet 101b including the thinning management information 120 as private data is added to the head of each GOP. The stored MPEG data is stored.

In FIG. 1, as an example, packet 1 containing thinning management information 120 as private data
01b is placed at the beginning of each GOP, but is not limited to this, and can be placed at any position in the bit stream of MPEG data. In this case, the decimation management information 120 of each packet 101b includes the I picture head offset 120a for managing the position information of the I picture and the AAU existing in the bit stream up to the next packet 101b based on the position of the own packet 101b. , I picture packet number 120
b, and information such as the audio packet offset 120c and the number of audio packets 120d.

Next, referring to the flowchart of FIG. 6, the MPEG data stored in the secondary storage
An example of an operation in which the server 200 transmits data to the client 300 via the communication medium 400 will be described.

First, a connection with a target client 300 is established by a predetermined protocol or the like corresponding to the communication medium 400 (step 601).

Next, from the secondary storage device 204, the target M
The PEG data is read, and first, a packet 101a containing the data management information 110 at the head as private data is transmitted (step 602).

Thereafter, the subsequent GOPs are sequentially read out (step 603), for example, the magnitude of the current load on the communication medium 400 is determined (step 604), and the bandwidth necessary for normal transmission of MPEG data is secured. If it is possible, all packets 101 of the GOP except the packet 101b including the thinning management information 120 at the beginning of the GOP are transmitted to the client 300 on the other side (step 605), while the load is large and necessary for normal transmission. If the bandwidth cannot be secured, the I picture head offset 120a and the I picture packet number 120 in the thinning management information 120 stored in the packet 101b at the head of the GOP
b, the audio packet offset 120c, the number of audio packets 120d, and the like, the positions of the I-picture corresponding packet 101c and the AAU-compatible packet 101d in the GOP are grasped from the subsequent bit stream. The operation of performing data transmission via the network interface 206 while thinning out (packets 101c corresponding to P pictures and B pictures) is performed in real time to reduce the amount of transmission data (step 606). Such a step 60
The operations from 3 to 606 are repeated until the last GOP (step 607).

The determination in step 604 is not limited to the determination of the load of the communication medium 400 on the server 200 side.
For example, the data amount reduction process of step 606 may be performed in response to a data amount reduction request from the client 300 side.

In other words, if the load on the communication medium 400 is so large that a necessary band cannot be secured, the packet 101b
Packet 101c and packet 1 corresponding to an I picture and an AAU in real time using the thinning management information 120
By transmitting a bit stream of MPEG data in a state where packets 101c corresponding to P pictures and B pictures other than 01d are thinned out, the communication data amount of MPEG data is reduced.

The AAU packet 101 in the GOP
Although it is of course included in the present invention to transmit the data by thinning out d,
Since the bit rate of the AAU is smaller than that of the packet 101c corresponding to the video data, the effect of reducing the amount of communication data by thinning the AAU is small.

Next, an example of the operation of reproducing MPEG data in the client 300 on the receiving side will be described with reference to the flowchart of FIG.

First, a connection with the server 200 is established by a predetermined protocol or the like corresponding to the communication medium 400 (step 701).

Next, the data management information 11 that first arrives
Packet 101a containing 0 as private data
Is stored in a part of the main memory 303 (step 7).
02).

Thereafter, the GOP is received and the decoder 3
10 (step 703), the decoder 310
Then, the presence or absence of thinning of the packet 101 is determined (step 704). If there is thinning, that is, if each GOP is composed of only the packet 101c corresponding to the I picture and the packet 101d corresponding to the AAU, the main memory is used. Data management information 110 held in 303
, The reproduction synchronization of the audio data (AAU: packet 101d) and the video data (packet 101c) separated by the separation unit 311 is obtained (specifically, based on the GOP reproduction time 110a, I
Extend the display time of the picture to match the playback time of the AAU), the AAU converts the audio decoder 316, D /
The video data (I picture) is output to the speaker 320 via the A converter 317 and the audio amplifier 318.
Is output to a display 305b via a video decoder 312, a post-processor 313, a D / A converter 314, a video output control device 315, and a frame memory 305a.

At this time, as described above, the data management information 11
By using 0, since the video data of only the I picture in which the P picture and the B picture are thinned out and the reproduction of the corresponding audio data are synchronized, the video data being displayed and output on the display 305b, It is possible to avoid the reproduction of unnatural moving image data such as the audio data output from the speaker 320 being temporally deviated, and to realize a natural reproduction state substantially similar to the case where all the original GOP data is reproduced. Can be.

(Embodiment 2) Next, a moving image data reproducing method according to an embodiment of the present invention will be described with reference to the flowchart of FIG. As a device used in the reproducing method of the present embodiment, for example, the device having the configuration illustrated in FIG. 3 described above can be used. In this case, the secondary storage device 304 stores, for example, an arbitrary portable storage medium 3 on which a bit stream of MPEG data is recorded.
It is assumed that it has a function of reading data from 04a.

In the secondary storage device 304 or the portable storage medium 304a, for example, the aforementioned FIG.
In a device having the same function as the server illustrated in FIG. 1, a packet 101a storing the data management information 110 and a packet 101b storing the thinning management information 120 are added to a normal MPEG data bit stream. It is assumed that a bit stream in a state of being recorded is recorded.

At the time of reproduction, first, the data management information 110 stored in the packet 101a read from the secondary storage device 304 (portable storage medium 304a) first.
Is stored in the main memory 303 (step 801).

Next, the subsequent GOP data of the packet 101a is read (step 802), and it is determined whether or not the user has designated special reproduction such as, for example, stopping the output of sound (silent reproduction) or fast-forwarding the sound (step 803). If the special reproduction is specified, the processor 302, based on the thinning management information 120 of the packet 101b, which is arranged at the head of the GOP and read prior to the GOP, causes the AAU in the GOP to After decimating a part (when fast-forward reproduction is specified) or all (when silence reproduction is specified) of the packet 101d and the packet 101c of video data other than the I picture, the packet 101d is transferred to the decoder 310 (step 804).

A decoder device 310 to which a bit stream in which a packet 101d including an AAU and a packet 101c of video data other than an I picture are thinned out is input.
In the separation unit 311, audio data (AAU: packet 101 d) and video data (packet 101 c)
And by referring to the data management information 110 stored in the main memory 303,
AAU and I so that AU and video data are synchronized
The reproduction time of the picture is calculated, and the video data and the audio data are reproduced and output (step 805).

If the special reproduction is not specified, the GOP data read from the secondary storage device 304 is transferred to the decoder device 310 as it is, and normal audio data and video data are reproduced (step). 80
6).

Such steps 802 to 80
Operation 6 is repeated until the last GOP data (step 807).

As described above, according to the moving image data reproducing method of the present embodiment, when reproducing MPEG data,
Various reproduction operations such as reproduction of only video data without audio and fast-forward of audio data can be performed at any time during reproduction according to the user's specification.

In the above description, the case where the bit stream of the MPEG data is read from the local secondary storage device 304 has been described as an example.
It goes without saying that the present invention can be applied to a reproduction operation of communication data arriving via the interface 306. In this case, the thinning operation may be performed on the local processor 302 side, or the processor 30 of the transmission source server 200
2 may be instructed to do so.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the above-described embodiments, and can be variously modified without departing from the gist thereof. Needless to say, there is.

[0064]

According to the moving image data communication method of the present invention, it is possible to reduce the amount of communication data according to the degree of congestion of a communication medium without increasing system load or overhead. The effect is obtained.

Further, according to the moving image data communication method of the present invention, the degree of congestion of the communication medium is reduced without reducing the quality or convenience of the moving image data such as reduction of the display screen size or loss of audio information. Thus, the effect of reducing the amount of communication data according to the above can be achieved.

According to the moving picture data reproducing method of the present invention, the quality and convenience of moving picture data such as reduction of the display screen size and loss of audio information occur even in a reproducing system having relatively low performance. Thus, the effect that the moving image data can be reproduced can be obtained.

Further, according to the moving image data reproducing method of the present invention, there is obtained an effect that various reproduction processes such as control of presence / absence of audio information and fast forward reproduction of audio information can be realized.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing an example of data handled in a moving image data communication method according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating an example of a configuration of a system that implements a moving image data communication method according to an embodiment of the present invention.

FIG. 3 is a block diagram illustrating an example of a system configuration in which a moving image data communication method according to an embodiment of the present invention is implemented.

FIG. 4 is a conceptual diagram showing an example of a configuration of an information network in which a moving image data communication method according to an embodiment of the present invention is implemented.

FIG. 5 is a flowchart illustrating an example of an operation of a moving image data communication method according to an embodiment of the present invention.

FIG. 6 is a flowchart illustrating an example of an operation of a moving image data communication method according to an embodiment of the present invention.

FIG. 7 is a flowchart illustrating an example of an operation of a moving image data communication method according to an embodiment of the present invention.

FIG. 8 is a flowchart illustrating an example of an operation of a moving image data reproducing method according to an embodiment of the present invention.

[Explanation of symbols]

101 ... packet, 101a ... packet (control data:
Data management information), 101b ... packet (control data:
Thinning management information), 101c: packet (video data), 101d: packet (audio data), 11
0: data management information, 110a: GOP playback time, 11
0b: packet size, 110c: bit rate, 12
0: thinning management information, 120a: I picture head offset, 120b: number of I picture packets, 120c: audio packet offset, 120d: number of audio packets, 200: server, 201: system bus, 2
02: processor, 203: main memory, 204: secondary storage device, 204a: portable storage medium (storage medium),
205: operation terminal, 205a: frame memory, 205
b ... display, 206 ... network interface, 210 ... encoder device, 211 ... A / D converter, 212 ... preprocessor, 213 ... video encoder, 2
14 ... A / D converter, 215 ... Audio encoder,
216: multiplexer, 220: video source supply device, 3
00 client, 301 system bus, 302
Processor, 303: Main memory, 304: Secondary storage device, 304a: Portable storage medium (storage medium, storage medium), 305: User interface, 305a: Frame memory, 305b: Display, 306: Network interface, 310: Decoder device,
311: Separation unit, 312: Video decoder, 313: Post-processor, 314: D / A converter, 315: Video output control device, 316: Audio decoder, 317: D / A
Converter, 318: audio amplifier, 320: speaker, 400: communication medium.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H04N 7/32

Claims (7)

[Claims] At least one of the video data and the audio data has at least one of position information in the bit stream in a part of a bit stream of moving image data in which video data and audio data are mixed in a desired data unit. When the recorded control data is mixed and the moving image data is transmitted via a desired communication medium, the video data and the audio are based on the position information obtained from the control data as necessary. A moving image data communication method, characterized in that at least one of the data is thinned out and transmitted. 2. The method of claim 1, wherein the moving image data is MPEG data.
The video data is composed of an I picture which is an intra-coded image, a P picture which is an inter-frame forward predicted image, and a B picture which is a bi-directional predicted coded image, and the audio data can be reproduced independently. AAU, which is an audio decoding unit, is recorded as the position information in the control data, the position in the bit stream of the data unit including each of the I picture and the AAU, and the I picture and the AAU are recorded. And transmitting the video data other than the video data. 3. The moving image data communication method according to claim 1, wherein prior to the transmission of the bit stream, a reproduction time of a desired data unit in the bit stream, a size of the data unit, a bit rate, and the like. On the side that transmits control data in which the data management information is stored and receives the bit stream via the communication medium, receives the bit stream in which at least one of the video data and the audio data is thinned out. Wherein the video data and the audio data are reproduced and synchronized based on the data management information. 4. A part of a bit stream of video data in which video data and audio data are mixed in a desired data unit, at least one of the video data and the audio data has at least one position information in the bit stream. Mixing the recorded control data on a desired storage medium, and reading the bit stream from the storage medium or a desired communication medium to reproduce the moving image data. Recording and reproducing moving image data, comprising: thinning out and reproducing at least one of the video data and the audio data based on the position information obtained from the video data. 5. The method of recording and reproducing moving image data according to claim 4, wherein said moving image data is MPEG data, and said video data is an I picture which is an intra-frame coded image, and an inter-frame forward prediction. P which is an image
Picture, and a B picture that is a bidirectionally coded image, and the audio data is composed of AAU that is an audio decoding unit that can be reproduced independently, and the I picture and the AAU are used as the position information in the control data. The position of the data unit including each in the bit stream is recorded, and the AAU
A method for recording and reproducing moving image data, wherein at least a part of the image data is reproduced. 6. The moving image data recording / reproducing method according to claim 4, wherein a reproduction time of a desired data unit in the bit stream, a size of the data unit, a bit rate, and the like are provided at a head portion of the bit stream. When the control data in which the data management information is stored is recorded and the moving image data is reproduced by reading the bit stream from the storage medium, at least a part of the audio data is decimated and reproduced as necessary. In this case, the video data and the audio data are reproduced and synchronized based on the data management information. 7. A part of a bit stream of moving image data in which video data and audio data are mixed in a desired data unit, and at least one of the video data and the audio data has position information in at least the bit stream. A process of mixing the recorded control data and recording it on a desired storage medium; reading the bit stream from the storage medium and transmitting the bit stream to a desired communication medium, the position information obtained from the control data as necessary A process of thinning out and transmitting at least one of the video data and the audio data on the basis of, when reproducing the moving image data by reading the bit stream from the storage medium or the communication medium, if necessary, from the control data Based on the obtained location information, Storage medium characterized by processing of reproducing by thinning at least one of Odeta and audio data, a control program for performing at least one process is stored.