JPH10327391A - Video server, video data storage method, and recording medium storing video data - Google Patents

Abstract

(57) [Summary] [Problem] To properly read video data from a splice point. SOLUTION: A plurality of storage means 14 in which data divided at a position satisfying a condition that an image is not disturbed when reproducing compressed video data is striped and stored.
-1 to 14-5, and read means 37 from required storage means.
To read out the video data, assemble and obtain the content having the splice point at the head, and return the assembled content data read and assembled by the reading means 37 to the required client.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video server, a video data storage method, and a recording medium storing video data.

[0002]

2. Description of the Related Art In recent years, a service provided by a video server for transmitting video data of a moving image to a client via a network so that the client can enjoy a desired moving image has been provided. This video server is, for example, an MPEG (Moving Picture Experts).
Group) 2 and the like, which are stored as files in a magnetic disk device or the like in a magnetic disk device or the like, so that random access can be made in response to a request from the client, and the client can enjoy the video reproduced from a desired position. I have to.

As a conventional method for realizing random access in a video server, there is known a method using an index file 500 as shown in FIG. 10 in which a reproduction time and a file offset are set. The index file 500 uses a position called a splice point where the image is not disturbed at the time of reproduction, because the reproduced image is disturbed when the video data such as MPEG2 is reproduced from an arbitrary position. That is, the offset (unit: byte) and time (unit: second) of the data file corresponding to the splice point are registered in the index file 500 in advance. In the example of FIG. 10, the offset (0,258310, 595010,...) Is a splice point, and the reproduction time (0,496978, 993956,...) From the beginning is stored corresponding to this offset. Is what it is.

On the other hand, a storage device 510 such as a magnetic disk stores video data related to the data file without considering splice points. In this example,
The storage block 1 of the storage device 510 stores all of part A and part of part B of the content constituted by the MPEG2 data 520, and the storage block 2 stores part of part B of the content. And part C and part D are stored, and so on.

[0005] Then, a time (Time) 50 is received from the client.
When a reproduction request after the position 0000 is made, the video server refers to the index file 500 so that reproduction from 496978, which is the closest splice point before the above time (Time) 500,000 and can be performed. Is read. At this time, since the video data is stored in the storage device 500 in storage block units, the storage block 1 is read and the entire part A is discarded, and the storage block 2 is read and the part other than the part B is read out. Must be discarded. As described above, the head of the read video data does not coincide with the splice point, and there is a problem that appropriate reproduction cannot be performed as it is.

In addition, the video server prepares trick play video data contents separately from normal playback video data contents in response to trick play such as fast forward playback. Therefore, for example, it is necessary to prepare an index file 500 for MPEG2 data 520 for normal reproduction as shown in FIG. 11 and an index file 600 for MPEG2 data 620 for double speed reproduction as shown in FIG. Was.

[0007]

As described above, the video data and the index file for trick play must be prepared and stored, so that the time required to create the index file is required and the capacity of the storage device is increased. There was a problem. Also, there was a problem that trick play could not be performed except at the prepared speed.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the problems of the conventional video server described above, and an object of the present invention is to provide a video server and a video server which can appropriately read from a splice point without using an index file. An object of the present invention is to provide a data storage method and a recording medium storing video data. Another object of the present invention is to provide a video server, a video data storage method, and a recording medium storing video data, which can be handled by video data for normal playback and perform a trick play without increasing the storage capacity. .

[0009]

According to a first aspect of the present invention, there is provided a video server in which divided data is striped and stored at a position satisfying a condition that an image is not disturbed when reproducing compressed video data. A plurality of storage means and an address for obtaining an address in the plurality of storage means at which video data corresponding to the desired position is stored when a request to reproduce video data from a desired position is sent from the client; Address obtaining means for performing an obtaining process, reading means for reading data from required storage means based on the address of the storage means obtained by the address obtaining means, and data read by the reading means to the client. And returning means for returning. As a result, the divided data is stored in the storage means in a position satisfying the condition that the image is not disturbed when the video data is reproduced, and the divided data is stored. Even if any of the striped data is read, the image is stored. Reading from a position satisfying the undisturbed condition is guaranteed.

In the video server according to the present invention, when the client request is a trick play request, the address acquiring means reads data from only necessary one of the plurality of storage means. In addition, address acquisition is performed. Thus, when there is a request for a trick play, an address is obtained in accordance with the trick play, and necessary video data is sampled and can be read from a position that satisfies a condition in which an image is not disturbed.

According to a third aspect of the present invention, the video server divides the video data at a plurality of storage means for storing the video data and at a position which satisfies a condition that the image is not disturbed when the compressed video data is reproduced. It is characterized by comprising a dividing means and a storage means for striping the video data divided by the dividing means and storing the striped video data in the plurality of storage means. As a result, the divided video data at the position satisfying the condition that the image is not disturbed when reproducing the video data is striped and stored in the storage means, and each striped video data is stored in any storage. Reading from a position that satisfies the condition that the image is not disturbed even when reading from the means is guaranteed.

The video server according to the fourth aspect is characterized in that the video data is compressed by MPEG2. As a result, with respect to the MPEG2 video data, reading from any position that satisfies the condition that the image is not disturbed even if any of the striped data is read is guaranteed.

According to a fifth aspect of the present invention, there is provided a video data accumulating method, wherein compressed video data is divided at a position which satisfies a condition that an image is not disturbed when the video data is reproduced, and the divided video data is striped into a plurality of pieces. Is stored in the storage means. As a result, the divided data is striped and stored in the storage unit at a position that satisfies the condition that the image is not disturbed at the time of reproducing the video data, and any of the striped data is read out. Reading from a position satisfying the condition that the image is not disturbed is guaranteed.

According to a sixth aspect of the present invention, in the video data storing method, the video data is compressed by MPEG2. As a result, with respect to the MPEG2 video data, reading from any position that satisfies the condition that the image is not disturbed even if any of the striped data is read is guaranteed.

According to a seventh aspect of the present invention, in the recording medium storing video data, compressed video data divided at a position satisfying a condition that an image is not disturbed during reproduction is striped and stored. Features. As a result, reading from any position that satisfies the condition that the image is not disturbed even if any of the striped data is read is guaranteed.

[0016] In a recording medium storing video data according to claim 8, the video data is compressed by MPEG2. Thereby, MPEG2
Regarding the video data, reading from any position satisfying the condition that the image is not disturbed even if any of the striped data is read is guaranteed.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A video server, a video data storage method and a recording medium storing video data according to embodiments of the present invention will be described below with reference to the accompanying drawings. In the respective drawings, the same components are denoted by the same reference numerals, and redundant description will be omitted. FIG. 1 shows a client server system using the video server 1. The video server 1 is connected to a network 2, and clients 3 (3-1 to 3-n) are connected to the network 2. The client 3 requests desired video data from the video server 1, receives the video data, reproduces the video data, and displays a video.

The video server 1 has one or more CPUs
It is constituted by a computer centering on a central control unit 12 composed of the above. The central control unit 12 is connected to the network 2 via the communication interface 11. The communication interface 11 performs communication according to the protocol of the network 2. The central control unit 12 includes an input unit 15 including a keyboard and the like for inputting commands and data, and a display unit 1 for displaying information.
6. A video data input unit 17 constituted by a small magnetic disk device or the like for inputting video data, and a plurality of storage means 1 constituted by a magnetic disk storage device or the like
4 (14-1 to 14-5) is connected to a read / write control unit 13 for reading and writing data.

The above-mentioned storage means 14 stores striped video data at a position which satisfies the condition that the image is not disturbed when the compressed video data is reproduced. The central control unit 12 includes an address acquisition unit 31, a return unit 32, a division unit 33, and a storage address table 34. The read / write control unit 13 includes a storage unit 36 and a read unit 37. I have. Each of these means is realized, for example, by a processor executing a program.

When a request to reproduce video data from a desired position is sent from the client 3, the address acquiring means 31 stores an address in the plurality of storage means 14 in which video data corresponding to the desired position is stored. In order to obtain the address, an address obtaining process is performed. The return means 32 is a read means 37 of the read / write control unit 13.
The video data read by the client 3
Will be returned to When the compressed video data is input from the video data input unit 17, the dividing unit 33 divides the video data at a position that satisfies the condition that the image is not disturbed when the video data is reproduced. Storage address table 34
Stores the title ID and storage address of the video data stored in the storage means 14, and is referred to when the video data is read.

On the other hand, the read means 37 provided in the read / write control section 13 reads data from the required storage means 14 based on the address obtained by the address acquisition means 31. Numeral 36 denotes striping the video data divided by the dividing means 33 and storing the striped data in the plurality of storage means 14-1 to 14-5. As a result, the storage units 14-1 to 14-1
Reference numeral 4-5 denotes a storage medium in which compressed video data divided at a position satisfying a condition that an image is not disturbed during reproduction is striped and stored.

In the video server 1 configured as described above, a magnetic disk or the like in which MPEG2 video data is stored is set in the video data input unit 17,
When a command requesting registration in the storage unit 14 is input from the input unit 15, the central control unit 12 and the read / write control unit 13 perform video data registration processing according to the program of the flowchart shown in FIG. That is, video data is read from the video data input unit 17 and divided (S1). More specifically, a splice point is detected (S1-1), and video data is divided according to the splice point (S1-2).

For example, as shown in FIG. 4, the input MPEG2 data contents 50 are A1, A2,
A3,..., Z5 can be divided into a plurality of blocks. Each block, as shown in FIG.
G including B picture and P picture starting from a picture (frame) to reaching a picture before the next I picture
The configuration is called OP (Group Of Pictures). The dividing unit 33 detects each I picture as a splice point. Specifically, since a predetermined bit string called a sequence header (SH) is arranged at the head of the GOP, this is detected. Then, the dividing means 33 determines whether each block (A1, A2, A3,..., Z
The data is divided into 5) and sent to the storage means 36 of the read / write control unit 13 together with the start address described below.

The registration in the storage address table 34 is performed in parallel with the video data division processing. In the storage address table 34, as shown in FIG. 6, the title I of the video data (content) is
D (identification information), the registration start address, and the number of divisions (the number of blocks obtained by dividing the content) are registered. The title ID is input from the input unit 15.
“00000” is registered in the entry No. 1 area as the start address of the registration, and the next entry No.
Then, a value obtained by adding the number of divisions to the head address of the previous entry is registered. In other words, the entry No. 2 is the head address “0000” of the entry No. 1 which is the previous entry.
“0867”, which is the sum of “0” and the number of divisions “8367”, is set as the start address. In the storage address table 34,
An entry No. pointer P is attached, and the entry No. to be used next is incremented after predetermined information for one entry is registered.

The storage means 36 having received the head address and the divided video data performs striping (S2), distributes the data to the respective storage means 14-1 to 14-5 (S2-1), and stores the data in the hard disk drive. Is written to each of the storage means 14-1 to 14-5 constituted by
3). The read / write control unit 13 has the address conversion circuit 70 shown in FIG. 7, and the storage unit 36 stores the transmitted start address and the number of divisions of the video data to be written (the number of the block). Gives the real address. For example, the start address “0000”
When writing from "0", first, "00000" is given to the address conversion circuit 70 as the head address and "0" is given to the division number. At this time, the storage unit 14
The real address for accessing the first storage block of -1 is output. At the timing of writing the next block of video data, the division number is incremented by “1” and the value is incremented by “1”.
Then, the real address for accessing the first storage block of the storage means 14-2 is output. Similarly, at the timing of writing the next block of video data, the number of divisions is incremented by "1" and the storage means 14-3 to 14-5 are incremented.
And obtains an address for accessing the first storage block, and executes writing of video data. Further, the number of divisions is sequentially increased by "1", and the storage means 14-1 to 14-
5, the address for accessing the storage block in the second column is obtained, the writing is continued, and the same operation is continued until the divided video data blocks disappear.
Thus, as shown in FIG.
4-5 respectively include blocks A1, A2, A3,.
・ ・ And memorized. The address conversion circuit 70
M, etc., or hardware for performing calculations.

On the other hand, when a request for reproducing video data is sent from the client 3, the central control unit 12 of the video server 1 receives the request via the communication interface 11, and the central control unit 12 and the read / write control unit Numeral 13 performs a reproduction process of video data by the program of the flowchart shown in FIG. That is, as shown in FIG.
The client 3 sends the title ID of the content of the video data and the reproduction start position information (how many seconds from the beginning), and if necessary, a trick play instruction. Therefore, the address acquisition unit 31 of the central control unit 12 performs an address acquisition process. More specifically, each block of the divided video data usually corresponds to 15 images, and data of 30 images is reproduced in one second. Is equivalent to And FIG.
, The reproduction start position information is “1263”.
(Seconds) ", multiply this by 2 to get" 2526 ". This is the number of divisions of the reproduction start position.

The central control unit 12 further searches the storage address table 34 using the sent title ID “5327” of FIG. 5 to reach the entry of entry No. 2 and obtains the head address “8367”. . The division number “2526” and the head address “8367” obtained above are given to the reading means 37 of the read / write control unit 13.
The reading means 37 reads the data from the storage means 14 constituted by a hard disk or the like (S6), assembles it into video data, and sends it to the returning means 32 of the central control unit 13.

In the above, the read means 37 also uses the address conversion circuit 70 shown in FIG. That is, “8367” is given to the address conversion circuit 70 as the head address and “2526” is given as the number of divisions. Then, if the head address “8367” corresponds to the storage unit 14-1, from now on, the storage units 14-2, 14-3, and 14-
The corresponding address of the storage means 14 advanced by "2,526" in the order of 4, 14-5, 14-1,... Is output from the address conversion circuit 70 as a real address. Thereafter, the number of divisions is “1” in synchronization with the timing of reading video data.
The reading is performed sequentially from the storage means 14-1 to 14-5.

At this time, as shown in FIG.
When the blocks A1, A2, A3,... Are read out by 7A, the assembling section 37B arranges the blocks in order to create the contents 80, and returns the contents to the return section 32 of the central control section 13.
Send to The return means 32 returns the content to the client 3 which has issued the request by transmitting the title ID shown in FIG. This content 80 is divided into blocks A1 and A1 that start from a splice point.
2, A3,... Are connected, and appropriate reproduction is guaranteed.

FIG. 9 shows the processing when double speed fast forward reproduction is requested. For example, the division number “2526” and the start address “8367” obtained by the address obtaining unit 31 are provided to the reading unit 37 of the read / write control unit 13 as in the embodiment of FIG. Since data (for example, “H2”) indicating double-speed fast-forward is sent from the client 3, the address acquisition unit 31 sets the increment of the division number by “2” based on the “H2”. The instruction is given to the reading means 37.
Then, the reading unit 37A first supplies “8367” as the head address and “2526” as the number of divisions to the address conversion circuit 70 to start reading the video data. Is incremented by "2" and applied to the address conversion circuit 70. As a result, the real addresses for accessing every other unit are output to the storage units 14-1 to 14-5, and the block A
, A3, A5, B2,... Are read (S5-
1). That is, it is possible to respond to a double-speed reproduction request without preparing double-speed content in advance.

When a request for a triple speed is issued from the client, for example, blocks A1, A4, B2,.
.., The instruction to increment the division number by “3” is provided from the address acquisition unit 31 to the reading unit 37 so that the reading of the block is performed every third block. Furthermore,
In response to the request for reverse feed, an instruction to decrease the number of divisions by “1” is given from the address acquisition unit 31 to the reading unit 37. Further, in the case of N times reverse feed, the number of divisions is "N".
An instruction to decrease the value is given from the address obtaining means 31 to the reading means 37.

In the above embodiment, the divided blocks include data for 15 screens.
There is also an embodiment in which data for one screen or less or 16 screens or more is configured as one block. With this configuration, division according to the capacity of one storage block of the storage unit 14 is possible.

Further, in the above description, the video data is registered from the video data input section 17 of the video server 1,
The registration may be performed via the network 2. When performing registration via the network 2, it is convenient to go to the location of the video server 1, which is convenient. Storage means 1
A storage medium that can be set to 4 may be created by a device other than the video server 1 and set in the video server 1.

[0034]

As described above, according to the video server of the first aspect, the storage means stores the striped video data at a position satisfying the condition that the image is not disturbed when the video data is reproduced. Readout from any position that satisfies the condition that the image is not disturbed even when any of the striped video data is read out from each storage means.

As described above, according to the video server of the second aspect, when the client request is a trick play request, data is read out from only a necessary one of the plurality of storage units. As described above, since the address is obtained, there is an effect that necessary video data can be sampled and read from a position that satisfies the condition that the image is not disturbed.

As described above, according to the video server of the third aspect, the dividing means for dividing the video data at a position satisfying the condition that the image is not disturbed when reproducing the compressed video data, Storage means for striping the video data divided by the division means and storing the striped video data in the plurality of storage means. The stored video data is striped and stored, so that reading from any position that satisfies the condition that the image is not disturbed even if any of the video data stored in each storage unit is read is guaranteed.

As described above, according to the video server of the fourth aspect, since the video data is compressed by MPEG2, the image is read even if any of the striped data is read from the MPEG2 video data. Reading from a position satisfying the undisturbed condition is guaranteed.

As described above, according to the video data storing method of the present invention, when the compressed video data is reproduced, the video data is divided at a position which satisfies the condition that the image is not disturbed. Since the video data is striped and stored in a plurality of storage units, the storage unit stores striped data at a position that satisfies the condition that the image is not disturbed when reproducing the video data. Even if any of the striped data is read, reading from a position that satisfies the condition that the image is not disturbed is guaranteed.

As described above, according to the video data storing method of the sixth aspect, the video data is stored in the MPEG format.
2, the reading from MPEG2 video data from a position that satisfies the condition that the image is not disturbed even when any of the striped data is read is guaranteed.

As described above, according to the recording medium storing the video data according to the seventh aspect, the compressed video data divided at the position satisfying the condition that the image is not disturbed at the time of reproduction is striped. Therefore, reading from any position satisfying the condition that the image is not disturbed even if any of the striped data is read is guaranteed.

As described above, according to the recording medium storing video data according to the eighth aspect, since the video data is compressed by MPEG2, any one of the striped data is used for the MPEG2 video data. Reading from a position that satisfies the condition that the image is not disturbed by reading is guaranteed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a video server according to an embodiment of the present invention.

FIG. 2 is a flowchart for explaining a data registration operation in the video server according to the embodiment of the present invention.

FIG. 3 is a flowchart for explaining a data read operation in the video server according to the embodiment of the present invention.

FIG. 4 is a configuration diagram for explaining a data registration operation in the video server according to the embodiment of the present invention.

FIG. 5 is a diagram showing information sent from a client.

FIG. 6 is a diagram showing a storage address table provided in the video server according to the embodiment of the present invention.

FIG. 7 is a diagram showing a main part of a read / write control unit of the video server according to the embodiment of the present invention.

FIG. 8 is a configuration diagram for explaining a data reading operation in the video server according to the embodiment of the present invention.

FIG. 9 is a configuration diagram for explaining a data reading operation at the time of double speed reproduction in the video server according to the embodiment of the present invention.

FIG. 10 is a diagram for explaining reading of video data by a conventional video server.

FIG. 11 is a view for explaining reading of video data for normal reproduction by a conventional video server.

FIG. 12 is a view for explaining reading of double-speed playback video data by a conventional video server.

[Explanation of symbols]

Reference Signs List 1 video server 2 network 3-1 to 3-n client 11 communication interface 12 central control unit 13 read / write control unit 14-1 to 14-5 storage unit 15 input unit 16 display unit 17 video data input unit 31 address acquisition unit 32 return means 33 division means 34 storage address table 36 storage means 37 reading means

Claims (8)

[Claims] 1. A plurality of storage means in which data divided at a position satisfying a condition in which an image is not disturbed when reproducing compressed video data is stored in a striped manner, and the video data is reproduced from a desired position. When a request to be sent is sent from the client, address acquisition means for performing address acquisition processing to acquire addresses in the plurality of storage means in which video data corresponding to the desired position is stored; and A video, comprising: a read unit for reading data from a required storage unit based on the obtained address of the storage unit; and a return unit for returning the data read by the read unit to the client. server. 2. The method according to claim 1, wherein when the request from the client is a request for trick play, the address is obtained so that data is read out only from a necessary storage unit out of the plurality of storage units. The video server according to claim 1, characterized in that: A plurality of storage means for storing the video data; a dividing means for dividing the video data at a position which satisfies a condition that an image is not disturbed when reproducing the compressed video data; Storage means for striping the divided video data and storing the striped video data in the plurality of storage means. 4. The video data according to claim 1, wherein the video data is compressed by MPEG2.
Video server according to paragraph. 5. The compressed video data is divided at a position that satisfies a condition that an image is not disturbed during reproduction, and the divided video data is striped and stored in a plurality of storage units. How to store video data. 6. The video data storing method according to claim 5, wherein the video data is compressed by MPEG2. 7. A recording medium storing video data, wherein compressed video data divided at a position satisfying a condition that an image is not disturbed at the time of reproduction is striped and stored. 8. The storage medium according to claim 7, wherein the video data is compressed by MPEG2.