JP2016004599A - Information processing system, storage control program and storage control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently store broadcast content in a storage device.SOLUTION: An information processing device 5 includes a reception part 5a for receiving stream data, and a control part 5b for making receiving timing of unit data 4a specifiable to store identification information 6 that can identify prescribed unit data 4a included in stream data 4 in a first storage part 5c, storing the unit data 4a in a second storage part 7, comparing the identification information 6 of unit data 4a that is previously received and stored in the first storage part 5c with identification information 6 of unit data that is later received when two or more pieces of stream data are received, discarding the unit data 4a corresponding to coincident identification information 6 when comparison results are coincident, storing the identification information 6 of the unit data 4a that is later received in the first storage part 5c, and storing the unit data 4a that is later received in the second storage part 7 when the comparison results are not coincident.

Description

  The present invention relates to an information processing system, a storage control program, and a storage control method.

2. Description of the Related Art Conventionally, a recorder that can receive broadcast content broadcast from a broadcast station and store the received broadcast content is known.
In recent years, a system capable of storing data in a storage device (network storage) provided in a server via a network instead of a storage device provided in a recorder is known.

  For example, the recorder generates stream data from broadcast content, transmits the generated stream data to a server, requests data from the server, and reproduces the broadcast content.

JP 2013-207421 A

  However, broadcast contents generally have a large data capacity, and a large number of recorders transmit the same broadcast contents to the server at the same time zone, so a large capacity resource and a high network bandwidth resource are required for the network storage.

  In one aspect, an object of the present invention is to provide an information processing system, a storage control program, and a storage control method capable of efficiently storing broadcast content in a storage device.

  In order to achieve the above object, an information processing system as shown below is provided. The information processing system includes a plurality of first information processing apparatuses and a second information processing apparatus connected to the first information processing apparatus via a network. The first information processing apparatus includes a transmission unit that transmits stream data generated from broadcast content. The second information processing apparatus includes a receiving unit and a control unit. The receiving unit receives stream data. The control unit holds identification information that can identify predetermined unit data included in the stream data in the first storage unit so that the reception timing of the unit data can be specified, and stores the unit data in the second storage unit Hold. When the control unit receives stream data from two or more first information processing apparatuses, the unit data identification information received first and held in the first storage unit, and the unit data identification information received later When the comparison results match, the unit data corresponding to the matching identification information is discarded. When the comparison results do not match, the identification information of the unit data received later is stored in the first storage unit. And the unit data received later is held in the second storage unit.

  According to the aspect, in the information processing system, the storage control program, and the storage control method, the broadcast content can be efficiently stored in the storage device.

It is a figure which shows an example of a structure of the information processing system of 1st Embodiment. It is a figure which shows an example of a structure of the broadcast content storage system of 2nd Embodiment. It is a figure which shows an example of the hardware constitutions of the server of 2nd Embodiment. It is a figure which shows an example of the flow of the data preservation | save of 2nd Embodiment. It is a figure which shows an example of the stream data of 2nd Embodiment. It is a figure which shows an example of interruption and buffering of the stream data of 2nd Embodiment. It is a figure which shows an example of the sequence of the flow of the data preservation | save of 2nd Embodiment. It is a figure which shows the flowchart of the frame transmission process of 2nd Embodiment. It is a figure which shows an example of the frame recording management information of 2nd Embodiment. It is a figure which shows the flowchart of the transmission time determination process of 2nd Embodiment. It is a figure which shows the flowchart of the frame reception process of 2nd Embodiment. It is a figure which shows the flowchart of the transmission start request reception process of 2nd Embodiment. It is a figure which shows an example of the identification information management list | wrist of 2nd Embodiment. It is a figure which shows the flowchart of the transmission start request | requirement response process of 2nd Embodiment. It is a figure which shows an example of the client management information of 2nd Embodiment. It is a figure which shows the flowchart of the single frame reception process of 2nd Embodiment. It is a figure which shows an example of the file storage format of the flame | frame of 2nd Embodiment. It is a figure which shows an example of the frame data management file of 2nd Embodiment. It is a figure which shows the flowchart of the frame preservation | save monitoring process of 2nd Embodiment. It is a figure which shows the flowchart of the bulk transmission reception process of 2nd Embodiment. It is a figure which shows the flowchart of the reproduction data output process of 2nd Embodiment.

Hereinafter, embodiments will be described in detail with reference to the drawings.
[First Embodiment]
First, the information processing system according to the first embodiment will be described with reference to FIG. FIG. 1 is a diagram illustrating an example of the configuration of the information processing system according to the first embodiment.

  The information processing system 1 includes a plurality of first information processing apparatuses 2 (2a, 2b,..., 2n), a network 9, and a second information processing apparatus 5. The first information processing device 2 and the second information processing device 5 are connected via a network 9.

  The first information processing apparatus 2 receives broadcast content and generates stream data 4 from the received broadcast content. For example, the first information processing apparatus 2 is a recorder, and transmits stream data generated from broadcast content to a server corresponding to the second information processing apparatus 5.

  The first information processing apparatus 2 includes a transmission unit 3. The transmission unit 3 generates stream data 4 from the broadcast content and transmits the stream data 4. For example, the transmission unit 3 performs processing such as encoding and packetization, and generates stream data 4 from the broadcast content.

  The stream data 4 is data processed in chronological order. For example, the stream data 4 is data that is processed in the order received without waiting for completion of reception of the entire data, and includes moving image data, audio data, and the like. The stream data 4 includes one or more unit data 4a. The unit data 4a is data divided by a predetermined unit such as a unit time or a unit data size. For example, the unit data 4a is frame unit data or packet unit data in moving image data.

  The broadcast content is content transmitted from a broadcast station by wireless or wired broadband, and is, for example, digital or analog video data or audio data.

  The second information processing device 5 includes a receiving unit 5a, a control unit 5b, a first storage unit 5c, and a second storage unit 7. The receiving unit 5a receives the stream data 4 transmitted by the first information processing apparatus 2.

  The first storage unit 5c and the second storage unit 7 are storage devices capable of storing data in a predetermined storage area. For example, the storage device is composed of a hard disk drive (HDD), a solid state drive (SSD), or a dynamic random access memory (DRAM). The second storage unit 7 is preferably a storage device such as an HDD because it stores a larger amount of data than the first storage unit 5c. Further, the second storage unit 7 may be built in the second information processing device 5 or provided outside the second information processing device 5.

The control unit 5b makes it possible to specify the timing at which the unit data 4a is received, stores the identification information 6 in the first storage unit 5c, and holds the unit data 4a in the second storage unit 7.
The control unit 5b may be able to specify the received timing by associating the unit data 4a with the information on the time when the unit data 4a is received, or in order of receiving the unit data 4a to the unit data 4a. The timing received by adding information may be specified, or may be determined by other methods.

  The identification information 6 is information that can identify a part or all of the data to be identified in the unit data 4a, and is information generated from the unit data 4a. For example, the identification information 6 is a fingerprint generated from a part or all of the data to be identified in the unit data 4a, digest information, and the like.

  When the control unit 5b receives the stream data 4 from two or more first information processing apparatuses 2, the control unit 5b receives the identification information 6 of the unit data 4a received first and held in the first storage unit 5c, and received later. The identification information 6 of the unit data 4a is compared. For example, when the identification information 6 is a fingerprint, the control unit 5b can compare the identification information 6 depending on whether or not the comparison target fingerprints match. The identification information 6 may be received from the first information processing device 2b or may be generated by the second information processing device 5. The two or more first information processing devices 2 are any two or more first information processing devices 2 among the plurality of first information processing devices 2 (2a, 2b,..., 2n). These are the first information processing apparatus 2a and the first information processing apparatus 2b.

  When the comparison results match, the control unit 5b discards the unit data 4a corresponding to the matching identification information 6. On the other hand, when the comparison result does not match, the control unit 5b holds the identification information 6 of the unit data 4a corresponding to the identification information 6 in the first storage unit 5c and stores the unit data 4a received later in the second Is stored in the storage unit 7.

  When the comparison results match, that is, when it is determined that the unit data 4a from which the identification information 6 is generated is the same, the control unit 5b discards the unit data 4a received later. As a result, the second information processing apparatus 5 can perform deduplication of data held in the second storage unit 7.

  When the comparison result does not match, that is, when it is determined that the unit data 4a from which the identification information 6 is generated is not the same, the control unit 5b holds the unit data 4a received later in the first storage unit 5c. To do. As a result, the second information processing apparatus 5 can perform deduplication of data stored in the second storage unit 7.

In this way, the information processing system 1 can efficiently save the broadcast content in the second storage unit 7 (storage device).
[Second Embodiment]
Next, the configuration of the broadcast content storage system according to the second embodiment will be described with reference to FIG. FIG. 2 is a diagram illustrating an example of a configuration of a broadcast content storage system according to the second embodiment.

  The broadcast content storage system 10 includes a plurality of clients 11 (11a, 11b,..., 11n), a network 12, a server 13, a storage device 14, a broadcast station 15, and a content distribution system 16.

  The broadcast station 15 transmits broadcast content wirelessly or by wire. The content distribution system 16 distributes various contents. Note that the broadcast station 15 and the content distribution system 16 are merely examples, and any other devices may be used as long as they can transmit or distribute broadcast content.

  The client 11 is a device having a function of receiving broadcast content and generating stream data. The client 11 is, for example, a television broadcast recorder, a computer, a portable terminal, or the like.

  The network 12 includes various networks such as a wired network connecting the client 11 and the server 13 and a wireless network. The network 12 is a network capable of bidirectional communication connecting the client 11 and the server 13. The network 12 may be a unidirectional network that performs broadcast communication from the broadcast station 15 to the client 11.

  The server 13 is a computer that receives the stream data transmitted from the client 11, executes deduplication processing on the received stream data, and stores the stream data in the storage device 14.

  The storage device 14 is a device that stores data. The storage device 14 is, for example, a RAID (Redundant Array of Independent Disks) device. The storage device 14 receives commands from the server 13 and performs data input / output control.

Next, the hardware configuration of the server according to the second embodiment will be described with reference to FIG. FIG. 3 is a diagram illustrating an example of a hardware configuration of a server used in the second embodiment.
The server 13 is entirely controlled by the processor 101. A RAM (Random Access Memory) 102 and a plurality of peripheral devices are connected to the processor 101 via a bus 107. The processor 101 may be a multiprocessor. The processor 101 is, for example, a central processing unit (CPU), a micro processing unit (MPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), or a programmable logic device (PLD). The processor 101 may be a combination of two or more elements among CPU, MPU, DSP, ASIC, and PLD.

  The RAM 102 is used as a main storage device of the server 13. The RAM 102 temporarily stores at least part of an OS (Operating System) program and application programs to be executed by the processor 101. The RAM 102 stores various data necessary for processing by the processor 101.

Peripheral devices connected to the bus 107 include an HDD 103, an input / output signal interface 104, a storage medium interface 105, and a communication interface 106.
The HDD 103 magnetically writes and reads data to and from the built-in disk. The HDD 103 is used as an auxiliary storage device of the server 13. The HDD 103 stores an OS program, application programs, and various data. Note that a semiconductor storage device such as a flash memory can also be used as the auxiliary storage device.

  An input / output device 108 is connected to the input / output signal interface 104. The input / output device 108 includes an input device and an output device. Examples of input devices include a keyboard, a mouse, and a touch panel. Examples of the output device include a monitor, a liquid crystal display, and various panel display devices.

  The input / output signal interface 104 transmits a signal sent from a keyboard or a mouse to the processor 101. Note that the mouse is an example of a pointing device, and other pointing devices can be used. Examples of other pointing devices include a touch panel, a tablet, a touch pad, and a trackball.

  The output device of the input / output device 108 displays an image on the monitor screen in accordance with a command from the processor 101. Examples of the monitor include a display device using a CRT (Cathode Ray Tube) and a liquid crystal display device.

  The storage medium interface 105 reads and writes data recorded on the storage medium 109 using magnetism, laser, or the like. The storage medium interface 105 may read data recorded in a storage medium such as a semiconductor memory. The storage medium 109 includes, for example, an optical disk, a semiconductor memory such as a flash memory, and the like. An optical disc is a portable recording medium on which data is recorded so that it can be read by reflection of light. Optical disks include DVD (Digital Versatile Disc), DVD-RAM, CD-ROM (Compact Disc Read Only Memory), CD-R (Recordable) / RW (ReWritable), and the like.

  The storage medium interface 105 can also be used as a communication interface for connecting peripheral devices to the server 13. For example, a memory device or a memory reader / writer can be connected to the storage medium interface 105. The memory device is a recording medium equipped with a communication function with the storage medium interface 105. The memory reader / writer is a device that writes data to the memory card or reads data from the memory card. A memory card is a card-type recording medium.

  The communication interface 106 is connected to the network 12. The communication interface 106 transmits / receives data to / from other computers or communication devices via the network 12. The network 12 may be a wired network or a wireless network. The communication interface 106 may be an interface capable of transmitting and receiving bidirectional digital communication, or may be an interface capable of receiving unidirectional broadcasting.

  With the hardware configuration described above, the processing functions of the second embodiment can be realized. The first information processing apparatus 2, the second information processing apparatus 5, and the client 11 shown in the second embodiment are the same hardware as the server 13 shown in FIG. Can be realized.

  The server 13 implements the processing functions of the second embodiment by executing a program recorded on a computer-readable recording medium, for example. A program describing the processing contents to be executed by the server 13 can be recorded in various recording media. For example, a program to be executed by the server 13 can be stored in the HDD 103. The processor 101 loads at least a part of the program in the HDD 103 into the RAM 102 and executes the program. The program to be executed by the server 13 can also be recorded on a portable recording medium such as an optical disk, a memory device, or a memory card. The program stored in the portable recording medium becomes executable after being installed in the HDD 103 under the control of the processor 101, for example. The processor 101 can also read and execute the program directly from the portable recording medium.

Next, the data storage flow of the second embodiment will be described with reference to FIG. FIG. 4 is a diagram illustrating an example of a data storage flow according to the second embodiment.
The plurality of clients 11 (11a, 11b,..., 11n) receive the broadcast content transmitted from the broadcast station in the same time zone, and generate stream data based on the received broadcast content. The stream data includes one or more frames 21. A plurality of clients 11 (11a, 11b,..., 11n) transmit stream data generated from broadcast content received in the same time zone to the server 13. Here, it is assumed that the client 11a transmits stream data including frames A1 and AN, and the client 11b transmits stream data including frames B1, B2, and B3.

  The server 13 receives the frame 21 from the clients 11a and 11b. The server 13 receives the stream data first from the client 11a, and then receives the stream data from the client 11b.

  The server 13 receives the stream data from the clients 11a and 11b, and determines whether or not the received stream data is the same content. For this purpose, the server 13 stores the identification information generated from the frame 21 in the identification information management list 22. The identification information management list 22 has a capacity capable of holding identification information sufficient to determine that the broadcast content is in the same time zone. The number of pieces of identification information that can be held is a number corresponding to a time sufficient to absorb the reception time lag of the same content received from each client 11, for example, a number corresponding to the number of frames for 5 seconds.

  The identification information is information that can uniquely identify the frame 21, and is, for example, fingerprint or digest information. The fingerprint is a hash value that is output as a result of calculating digital content such as frame data of a moving image with a hash function. The identification information may be generated by the client 11 and transmitted by being included in the stream data, or may be generated by the server 13 receiving the stream data.

  The server 13 determines whether the identification information received first and stored in the identification information management list 22 overlaps with the identification information of the frame 21 included in the stream data from the client 11b received later.

  When the identification information of the stream data received later matches one of the identification information held in the identification information management list 22, the server 13 determines that the stream data received later and the previously received stream data have the same content It is judged that.

  When the server 13 determines that the identification information of the stream data received later matches the identification information held in the identification information management list 22, the server 13 discards the frame 21 received later. On the other hand, the server 13 stores the frame 21 (frames A1, A2, A3,...) In the storage device 23 because the previously received stream data does not overlap with the previous stream data.

  The server 13 can reduce the load of the deduplication processing by discarding the frame 21 without performing subsequent duplication determination on the stream data that has been determined to be duplicated.

Next, stream data according to the second embodiment will be described with reference to FIG. FIG. 5 is a diagram illustrating an example of stream data according to the second embodiment.
The plurality of clients 11 (client A, client B) transmit stream data (28, 29) to the server 13, respectively. Client A transmits head frame FA1 to server 13 at timing t10, and client B transmits head frame FB1 to server 13 at timing t11.

The stream data 28 includes a plurality of frames (FA1,..., FAM,..., FAN). The stream data 29 includes a plurality of frames (FB1,..., FBP).
Stream data (28, 29) is data processed in time series. The stream data (28, 29) is defined by, for example, the MPEG-2 (Moving Picture Experts Group 2) standard or the ARIB (Association of Radio Industries and Broadcast) standard.

  Since the client A has transmitted the first frame FA1 to the server 13 before the client B, the identification information corresponding to the frame transmitted by the client A during the predetermined time width TI is recorded in the identification information management list 22. The

  Since the frames (FA1,..., FAM,..., FAN) transmitted by the client A first do not overlap with the previous stream data, they are stored in the storage device 14 by the server 13.

  The head frame FB 1 transmitted to the server 13 later is compared with the identification information recorded in the identification information management list 22. If the identification information of the first frame FB1 matches any of the identification information recorded in the identification information management list 22, the server 13 determines that the stream data 29 is the same content as the stream data 28.

The frame (FB1) transmitted by the client B is determined to overlap with any of the previously transmitted frames (FA1,..., FAM,..., FAN), and is discarded by the server 13.
The timing (t10, t11) at which the server 13 receives the first frame is managed by the server 13 as the recording start time. Also, the timing (t12, t13) at which the server 13 receives the last frame is managed by the server 13 as the recording end time.

  Next, the interruption and buffering of stream data according to the second embodiment will be described with reference to FIG. FIG. 6 is a diagram illustrating an example of interruption and buffering of stream data according to the second embodiment.

  Client A and client B transmit frames of the same content to the server. The client A transmits the frame to the server 13 before the client B.

  Client A receives a frame transmission instruction from server 13 and transmits a frame to server 13. Since client A is transmitting a frame to server 13, client B receives a frame transmission stop and buffering instruction and buffers the frame (timing t20).

  Here, when the client A interrupts the frame transmission at the timing t21 due to the failure of the communication path of the client A (timing t21), the server 13 cannot receive the frame from the client A.

  The client B receives a buffered frame transmission command (bulk transmission command) from the server 13 that cannot receive the frame from the client A. The client B that has received the bulk transmission command transmits the frame buffered between the timing t20 and the timing t22 to the server 13 (timing t22).

  The frame transmitted from the client B is received by the server 13, and the received frame is stored in the storage device 14 by the server 13. Client B transmits subsequent frames after timing t22 to server 13 on behalf of client A.

  As described above, when the frame transmission from the client A to the server 13 is interrupted, the broadcast content storage system 10 can supplement the stream data by transmitting the frame from the client B to the server 13.

Next, a data storage sequence according to the second embodiment will be described with reference to FIG. FIG. 7 is a diagram illustrating an example of a data storage flow sequence according to the second embodiment.
Client A transmits the first frame to server 13 before client B (timing t40). Client B transmits the first frame of the same content to server 13 after client A (timing t41).

  The server 13 compares the times at which the first frame having the same content is received from a plurality of clients (clients A and B), and permits transmission of the client A that has transmitted the frame first within a predetermined time width TI. As a client.

  The server 13 transmits frame transmission permission to the client A determined as the transmission permission target (timing t42). Further, the server 13 transmits a frame buffer command to the client B (timing t43). The buffer instruction is an instruction to instruct frame buffering to the client B that is not permitted to transmit. Note that the client B may voluntarily buffer the frame even if it does not receive a buffer command and does not receive a transmission permission.

  Client B receives the buffer command from server 13 and buffers the frame. The client A receives the transmission permission from the server 13, and transmits a frame subsequent to the head frame to the server 13 (timing t44).

  Here, the client A interrupts the frame transmission due to a communication path failure or a user operation (timing t45), and the server 13 cannot receive the frame from the client A.

  The server 13 transmits a bulk transmission command to the client B after a predetermined time (frame monitoring time TW) has elapsed from the time when the frame cannot be received from the client A (timing t46). The bulk transmission command is a command for requesting transmission of a frame buffered by the client B.

  The client B that has received the bulk transmission command bulk transmits the buffered frame to the server 13 (timing t47). The server 13 receives the frame transmitted from the client B in bulk, and stores the frame received from the client B in the storage device 14.

  The server 13 transmits a subsequent frame transmission command to the client B (timing t48). Client B transmits the subsequent frame to server 13 (timing t49).

  The client A transmits a frame reproduction request to the server 13 (timing t50). The server 13 receives the frame reproduction request from the client A, and transmits reproduction data according to the frame reception status from the client A (timing t51).

  In this way, the server 13 receives frames from the client A and the client B. Further, the server 13 transmits a bulk transmission command to the client B when the frame transmission from the client A is interrupted. As a result, the server 13 can receive the frame from the client B and complement the stream data that could not be received from the client A.

Next, frame transmission processing according to the second embodiment will be described with reference to FIG. FIG. 8 is a diagram illustrating a flowchart of frame transmission processing according to the second embodiment.
The frame transmission process is a process in which the client 11 transmits a frame to the server 13. The control unit (processor) of the client 11 executes frame transmission processing when recording broadcast content received using the storage destination as the server 13.

[Step S11] The client 11 receives broadcast content and generates stream data.
[Step S12] The client 11 performs transmission time determination processing. The transmission time determination process is a process for distributing the burden on the client 11 by setting a delay time and determining the timing for issuing a transmission start request to the client 11. The transmission time determination process in step S12 will be described later with reference to FIG.

  Note that the client 11 may determine the transmission time using a method other than the transmission time determination process as long as the client 11 can issue a transmission start request to the server 13 at a different timing from the other clients 11. For example, the client 11 may receive a transmission timing instruction including a delay time different from that of the other clients 11 from the server 13.

  [Step S13] The client 11 generates identification information of the first frame. Note that when the server 13 generates identification information, the client 11 does not need to generate identification information.

[Step S14] The client 11 transmits a transmission start request to the server 13. The transmission start request includes identification information of the first frame and the first frame.
The transmission start request may include information that can identify the client 11. For example, information that can identify the client 11 can be information used by the client 11 for communication, such as a MAC (Media Access Control) address or an IP (Internet Protocol) address.

  [Step S15] The client 11 determines the type of response (response type) from the server 13 to the transmission start request. The client 11 proceeds to step S16 when the response type for the transmission start request is “single frame transmission”, and proceeds to step S17 when the response type for the transmission start request is “bulk transmission”. The client 11 proceeds to step S18 when the type of response to the transmission start request is neither “single frame transmission” nor “bulk transmission”.

  The response type “single frame transmission” is a request for transmitting a frame designated by the server 13 to the server 13. The server 13 designates a frame by the program ID. The program ID is information that can identify the content. The response type “bulk transmission” is a request for collectively transmitting frames buffered by the client 11 to the server 13.

[Step S <b> 16] When the client 11 receives a request for the response type “single frame transmission”, the client 11 transmits the frame designated by the server 13 to the server 13.
[Step S <b> 17] When the client 11 receives a request for the response type “bulk transmission”, the client 11 bulk transmits the frame corresponding to the received program ID to the server 13 from the frames stored in the buffer.

  [Step S18] The client 11 determines the response type from the server 13 to the transmission start request. The client 11 proceeds to step S19 when the response type for the transmission start request is “buffer save”, and proceeds to step S20 when the response type for the transmission start request is “buffer end”. The response type “buffer save” is a frame buffering request to the client 11. The response type “buffer end” is a frame buffering end request to the client 11.

  [Step S19] If the response type is “buffer save”, the client 11 buffers the frame. As a result, the server 13 can suppress duplicate storage of the same content and suppress communication load with the client 11.

  [Step S20] If the response type is “buffer end”, the client 11 ends frame buffering. Note that the client 11 may delete the buffered frame when the response type “bulk transmission” is not received within a predetermined time.

  [Step S21] The client 11 determines whether there is a next frame. If the client 11 determines that there is a next frame, the client 11 generates frame identification information and proceeds to step S15. If it is determined that there is no next frame, the client 11 ends the frame transmission process. Note that when the server 13 generates identification information, the client 11 does not need to generate identification information.

  As described above, the client 11 transmits a frame transmission start request to the server 13 and performs transmission or buffering of the frame according to the response type received from the server 13.

Next, frame recording management information according to the second embodiment will be described with reference to FIG. FIG. 9 is a diagram illustrating an example of frame recording management information according to the second embodiment.
The frame recording management information 60 is information used by the client 11 to manage stream data generated from broadcast content. When the client 11 records two or more broadcast contents at the same time, the frame recording management information 60 records management information of stream data for each broadcast content.

  The frame recording management information 60 includes a program ID, a flag, a recording start time, a recording end time, and a pointer. The program ID is identification information that can identify broadcast content, that is, a program. For example, the program ID is “SN123 — 13895”. The flag is information indicating a transmission state of the stream data corresponding to the broadcast content to the server 13. For example, the flag includes “S” indicating a state of “single frame transmission”, “B” indicating a state of “buffer saving”, and the like. The recording start time is the time when the storage (recording) of the broadcast content is started. For example, the recording start time is time “13: 20: 25.08”. The recording end time is the time when the storage (recording) of the broadcast content is ended. For example, the recording end time is the time “14: 17: 02.19”. The pointer is a pointer that indicates the storage destination of the frame corresponding to the program ID. For example, the pointer indicates the storage destination of the frames A1, A2, A3,... And the storage destination of the frames N1, N2,. The storage destination of each frame is a storage area of the HDD provided in the client 11.

Thereby, the client 11 can request the server 13 to record two or more broadcast contents.
Next, the flowchart of the transmission time determination process of 2nd Embodiment is demonstrated using FIG. FIG. 10 is a diagram illustrating a flowchart of a transmission time determination process according to the second embodiment.

  When a large number of clients 11 receive broadcast contents at the same time and transmit them simultaneously to the server 13, the processing load on the server 13 increases. In order to avoid this, the client 11 receives a frame transmission permission from the server 13 and transmits the frame. If the server 13 grants frame transmission permission to the client 11 that has arrived first, there is a risk that the burden on the specific client 11 may be concentrated depending on environmental conditions such as the network configuration. The transmission time determination process is a process for distributing the burden on the client 11 by setting a delay time and determining the timing for issuing a transmission start request to the client 11. The transmission time determination process is a process executed by the client 11 in step S12 of the frame transmission process.

  [Step S31] The client 11 determines the validity of the time width TI and RTT (Round Trip Time) held in advance. The client 11 proceeds to step S34 when the held time width TI and RTT are valid, and proceeds to step S32 when invalid. The client 11 can determine the validity of the time width TI and the RTT by checking with a preset valid period (for example, one day). The time width TI is a holding period of frame identification information, that is, a fingerprint, and is a period that the server 13 regards as the same time when receiving transmission start requests from a plurality of clients 11. For example, the time width TI is 5 seconds.

  [Step S32] The client 11 acquires the time width TI from the server 13, and transmits an Internet Control Message Protocol (ICMP) packet to the server 13 to acquire the RTT.

[Step S33] The client 11 updates the time widths TI and RTT held in advance with the acquired time widths TI and RTT.
[Step S34] The client 11 determines an individual transmission time width. For example, the client 11 extracts a random value from the uniformly distributed pseudorandom number F in the range of the time width TI, and determines the difference between the extracted random value and the RTT as the individual transmission time width.

  [Step S35] The client 11 determines the transmission time of the transmission start request (start request transmission time). The start request transmission time is a time delayed by an individual transmission time width from the time when the client 11 receives the broadcast content.

  Thus, the broadcast content storage system 10 first changes the client 11 that transmits a frame to the server 13, cancels the bias of the client 11 that transmits the frame to the server 13, and performs arbitration control of the client 11 that transmits the frame. be able to.

  Next, the flowchart of the frame reception process of 2nd Embodiment is demonstrated using FIG. FIG. 11 is a diagram illustrating a flowchart of frame reception processing according to the second embodiment. The frame reception process is a process in which the server 13 receives a frame from the client 11. The control unit (processor 101) of the server 13 executes frame reception processing after the server 13 is started.

  [Step S41] The server 13 determines whether a transmission start request is received from the client 11. The server 13 proceeds to step S42 when the transmission start request is received from the client 11, and proceeds to step S43 when the transmission start request is not received.

  [Step S42] The server 13 executes a transmission start request reception process and proceeds to step S41. The transmission start request reception process is a process in which the server 13 receives a request to start frame transmission from the client 11. Details of the transmission start request reception process will be described later with reference to FIG.

  [Step S43] The server 13 determines whether or not a bulk transmission has been received. The server 13 proceeds to step S44 when the bulk transmission is not received, and proceeds to step S45 when the bulk transmission is received.

  [Step S44] The server 13 executes a single frame reception process and proceeds to step S41. The single frame reception process is a process of receiving a frame designated by the server 13 from the client 11. Details of the single frame reception process will be described later with reference to FIG.

  [Step S45] The server 13 executes bulk transmission / reception processing, and proceeds to step S41. The bulk transmission reception process is a process in which the server 13 receives frames accumulated in the buffer from the client 11 that has requested bulk transmission. Details of the bulk transmission reception process will be described later with reference to FIG.

  Next, the flowchart of the transmission start request reception process of 2nd Embodiment is demonstrated using FIG. FIG. 12 is a diagram illustrating a flowchart of a transmission start request reception process according to the second embodiment.

  The transmission start request reception process is a process in which the server 13 receives a transmission start request from the client 11. The transmission start request is a process of transmitting a frame first when the client 11 requests the server 13 to store (record) a frame. When the server 13 receives a transmission start request from the client, the server 13 executes a transmission start request reception process.

  [Step S51] The server 13 generates identification information and a program ID based on the received first frame. If the server 13 receives the identification information from the client 11 together with the transmission start request, the server 13 does not generate the identification information.

  The server 13 generates a program ID based on the identification information of the first frame and the time when the transmission start request is received. The server 13 may generate a program ID based on information (for example, an IP address) for identifying the client 11 that has transmitted the transmission start request and the recording start time, or may be generated by another method. Good. Further, the server 13 may generate a program ID at regular time intervals (for example, every 30 minutes) when frames are continuously received from the client 11 for a long time.

  [Step S52] The server 13 registers identification information, a program ID, and the like as information managed by the server 13 in association with time information. The server 13 also registers information (IP address, recorder identification information, etc.) for identifying the client 11 that has transmitted the transmission start request.

  [Step S53] The server 13 compares the identification information of the first frame received during the time span TI with the identification information group registered in the server 13. As a result of comparing the identification information, if the received identification information is the same identification information as one of the registered identification information groups, the server 13 determines that the received frames are duplicated. It is determined that the frames do not overlap. If the server 13 determines that the frames do not overlap, the server 13 proceeds to step S54. If the server 13 determines that the frames overlap, the server 13 discards the received frames and proceeds to step S55.

  [Step S54] The server 13 newly stores the received frame. The server 13 stores the received frame in the directory with the program ID and records the frame time information and the like in the management file.

  [Step S55] The server 13 executes a transmission start request response process, and ends the transmission start request reception process. The transmission start request response process is a process in which the server 13 responds to the transmission start request received from the client 11. Details of the transmission start request response process will be described later with reference to FIG.

  As a result, the server 13 can efficiently deduplicate broadcast content even when receiving a large number of content storage requests from the multiple clients 11 during the same time period.

Next, the identification information management list of the second embodiment will be described with reference to FIG. FIG. 13 is a diagram illustrating an example of an identification information management list according to the second embodiment.
The identification information management list 61 includes information for determining duplication of identification information in the time width TI. The identification information management list 61 has a capacity capable of storing identification information corresponding to the time width TI. The identification information management list 61 is not limited to the list format, and may be a circular pointer table and information held in the time width TI. For example, the server 13 re-uses the list of information associated with the identification information by shifting the pointer indicating the current time every second and overwriting and saving the current information on the information after a certain time has passed. May be.

  The identification information management list 61 includes identification information, a program ID, frame data, time information, and the number of clients. The identification information is information that can specify a frame, and is, for example, “d0e9fdba65”. The program ID is identification information of the program to which the frame belongs, and is “SN123 — 1395”, for example. The frame data is frame data, for example, “0x128519...”. The time information is the time when the server 13 receives a frame from the client 11. The number of clients is the number of clients 11 that accept frame transmissions belonging to the same program ID. When receiving stream data of the same content from a plurality of clients 11, the server 13 can maintain the redundancy of the frame data stored in the storage device 14.

  The server 13 can use the identification information management list 22 to manage frames received from the client 11 during the time span TI, to assign a program ID, and to determine duplication of identification information.

  The identification information is a digest for identifying unit data such as frame data of a moving image or a fingerprint. The client 11 or the server 13 can generate identification information using a known method such as SHA-1 (Secure Hash Algorithm 1) defined by RFC (Request For Comment) 3174. The client 11 may generate identification information, and the client 11 may transmit the frame and the identification information to the server 13. The server 13 may receive a frame from the client 11 and generate identification information from the received frame. The time information may manage the time when the client 11 receives the broadcast content.

  Next, the flowchart of the transmission start request response process of 2nd Embodiment is demonstrated using FIG. FIG. 14 is a diagram illustrating a flowchart of a transmission start request response process according to the second embodiment.

  The transmission start request response process is a process in which the server 13 responds to the transmission start request received from the client 11. The transmission start request response process is a process executed by the server 13 in step S55 of the transmission start request reception process.

  [Step S61] The server 13 determines whether or not the same program ID as the program ID related to the received transmission start request exists in the client management information. The server 13 proceeds to step S62 when the same program ID exists, and proceeds to step S63 when the same program ID does not exist. The client management information will be described later with reference to FIG.

  [Step S62] The server 13 determines whether or not the number of clients that transmit the frame of the program ID is less than a threshold value (client number threshold value). The server 13 proceeds to step S63 when the number of clients 11 is less than the threshold, and proceeds to step S65 when the number of clients is equal to or greater than the client number threshold. The server 13 sets a client number threshold in advance. Note that the server 13 may determine the client number threshold according to the number of received transmission start requests, or may determine the client number threshold by another method.

[Step S63] The server 13 transmits a frame transmission command and a program ID to the client 11.
[Step S64] The server 13 registers the client 11 that has transmitted the frame transmission command in the client management information as a single frame transmission target. The server 13 associates an identifier meaning single frame transmission with the information of the client and registers it in the client management information.

[Step S65] The server 13 transmits a buffer storage command and a program ID to the client 11.
[Step S66] The server 13 registers the client 11 that has transmitted the buffer save command in the client management information as a buffer save target.

  The transmission start request response process is an example of the process of the server 13. The server 13 may transmit a buffer storage command to the client 11 as necessary, for example, when the capacity of the storage device 14 has reached the upper limit. The server 13 sends a buffer save command to the client 11 and stops receiving stream data from the client 11 that sent the buffer save command.

Next, client management information according to the second embodiment will be described with reference to FIG. FIG. 15 is a diagram illustrating an example of client management information according to the second embodiment.
The client management information 62 is information used by the server 13 for managing the client 11 for each program ID. The client management information 62 is used for managing the frame transmission status and the like. The client management information 62 includes a program ID, a client ID, head frame identification information, a flag, a start time, and an end time.

  The program ID is the same as the program ID included in the identification information management list. The client ID is identification information for identifying the client 11. For example, the client ID may be an IP address or a MAC address as a client ID, or may be a recorder manufacturing number, a product serial number, or the like. The client ID may be information used by the server 13 to send a frame transmission command to the client 11. The client ID may be information used by the server 13 to transmit a bulk transmission command to the client.

  The first frame identification information is identification information of the first frame. The flag is information indicating the frame transmission state of the client 11. The flag includes, for example, “S” indicating a frame transmission state and “B” indicating a frame buffering state.

  The start time is a time when the client 11 starts transmitting a frame (recording start time). The start time may be information on the time at which the server 13 received the start frame from the client 11 together with the start request. The start time is the buffering start time when the client 11 is buffering.

  The end time is the time when the client 11 has finished transmitting the frame (recording end time). The end time may be information on the time at which the server 13 receives the last frame from the client 11. The end time is the buffering end time when the client 11 is buffering.

  Next, a flowchart of the single frame reception process of the second embodiment will be described with reference to FIG. FIG. 16 is a diagram illustrating a flowchart of the single frame reception process according to the second embodiment.

  The single frame reception process is a process in which the server 13 receives a single frame from the client 11. The server 13 transmits a frame transmission command to the client 11 as a response to the start request, and then executes a single frame reception process when receiving a subsequent frame from the client 11. Further, the server 13 performs a single frame reception process when receiving a subsequent frame after receiving the bulk-transmitted data.

  [Step S71] The server 13 determines the storage location of the received frame. The server 13 receives the program ID from the client 11 together with the subsequent single frame. The server 13 determines the directory to which the program ID is attached as the storage destination of the received frame. When the server 13 does not receive the program ID from the client 11, the server 13 can specify the program ID based on the information for identifying the client 11 and determine the frame storage destination.

  [Step S72] The server 13 additionally stores the received frame in the directory. The server 13 stores the received frame in a folder assigned with a program ID corresponding to the received frame. The server 13 records the file name, start time, and end time of the frame data in a file that manages the frame data.

  [Step S73] The server 13 determines whether the received frame is the last frame. The server 13 proceeds to step S74 when the frame is the end frame, and ends the single frame reception process when it is not the end frame.

  [Step S74] The server 13 registers the reception time of the last frame as the end time in the client management information. Note that the server 13 may transmit a “buffer end” notification to the client 11 when the client 11 is buffering without receiving the end frame from the client 11 after a certain period of time has elapsed.

Next, a frame file storage format according to the second embodiment will be described with reference to FIG. FIG. 17 is a diagram illustrating an example of a frame file storage format according to the second embodiment.
The frame file storage format is a format in which the server 13 stores the frame data received from the client 11 as a file. The server 13 provides a directory (time information directory) with time information. For example, the directory “2014041014” is a time information directory. The time information directory provides a directory (program directory) with one or more program IDs in the directory. For example, the directory “SN1234 — 1395” is a program directory. The server 13 stores one program (broadcast content) in one directory. That is, the server 13 provides a time information directory for each predetermined time period (for example, 30 minutes), and provides one or more program directories for the same time period in the time information directory.

  The program directory includes one frame data management file and one or more frame data files. For example, “Fileable” is a frame data management file, and “File — 0” and “File — 1” are file names of frame data files. The frame data management file is a file for managing frame data stored in the same program directory. The server 13 attaches a file name to the received frame, generates a frame data file, and stores it in the program directory. The server 13 may give the received frame a file name according to the reception order, or may add other information necessary for reproducing the stream data.

  Accordingly, the server 13 can specify the program ID of the stream data to which the received frame belongs based on the client ID and the client management information. Further, the server 13 can specify the directory to which the program ID is assigned as the frame storage destination.

Next, a frame data management file according to the second embodiment will be described with reference to FIG. FIG. 18 is a diagram illustrating an example of a frame data management file according to the second embodiment.
The frame data management file 66 includes frame data management information. The frame data management information includes a frame data file name, a leading edge time, and a terminal time. Frame data management information is managed by the server 13. The file name is a file name given to each frame data. For example, the file name is “File_0”. The leading edge time is the earliest time of the broadcast content included in each frame. The end time is the last time of the broadcast content included in each frame.

  Next, a flowchart of the frame storage monitoring process according to the second embodiment will be described with reference to FIG. FIG. 19 is a diagram illustrating a flowchart of the frame storage monitoring process according to the second embodiment.

  The frame storage monitoring process is a process in which the server 13 monitors the storage state of a frame received from the client 11. The control unit (processor 101) of the server 13 executes frame storage monitoring processing after the server 13 is started.

  [Step S81] The server 13 determines whether reception of a frame from the client 11 is interrupted. The server 13 proceeds to step S82 when the frame reception is interrupted, and proceeds to step S81 when the frame reception is not interrupted.

  The server 13 determines that the frame transmission from the client 11 is interrupted when it does not receive the last frame even after the predetermined frame monitoring time TW has elapsed. The server 13 may determine that the reception of the frame is interrupted when the data of the last frame is not stored in the directory to which the program ID is attached. The server 13 may determine that the frame transmission is interrupted when it is determined that the frame data management file has not been updated from the update time of the frame data management file at the frame monitoring time TW.

  [Step S82] The server 13 determines whether or not there are a plurality of clients 11 (the number of clients) that transmit frames. The server 13 proceeds to step S83 when the number of clients is not plural, and proceeds to step S81 when the number of clients is plural. The server 13 can acquire the number of clients from the client management information.

  [Step S83] The server 13 determines whether or not there is a client 11 being stored in the buffer. The server 13 proceeds to step S84 when there is a client 11 that is storing a buffer, and proceeds to step S81 when there is no client 11 that is storing a buffer. The server 13 can acquire the presence / absence of the client 11 being stored in the buffer from the client management information.

[Step S84] The server 13 issues a bulk transmission command to the client 11 that is saving the buffer.
Next, the flowchart of the bulk transmission reception process of 2nd Embodiment is demonstrated using FIG. FIG. 20 is a diagram illustrating a flowchart of bulk transmission reception processing according to the second embodiment.

  The bulk transmission reception process is a process when the server 13 receives a bulk transmission of a buffered frame from the client 11. The server 13 executes a bulk transmission reception process when the client 11 receives a bulk transmission of the buffered data.

  [Step S91] The server 13 determines a bulk transmission frame storage destination. Based on the program ID received from the client 11, the server 13 determines a directory for storing frames received by bulk transmission.

  [Step S92] The server 13 newly stores the received bulk transmission frame. The server 13 stores the received frame in the directory with the program ID and adds the received information to the frame data management file 66. If there is a frame already saved in the directory of the program ID, the server 13 may avoid overwriting and save it with a new file name, or create another directory name. May be saved.

  [Step S93] The server 13 changes the client 11 from a bulk transmission target to a single frame transmission target. The server 13 changes the flag of the client management information 62 corresponding to the client 11 that has performed the bulk transmission from the bulk transmission target flag “B” to the single frame transmission target flag “S”.

  [Step S94] The server 13 issues a subsequent frame transmission command to the client 11. In this way, the server 13 receives and stores the bulk transmission frame. In addition, the server 13 changes the client 11 that is the target of bulk transmission to the client 11 that is the target of single frame transmission.

  Next, a flowchart of reproduction data output processing according to the second embodiment will be described with reference to FIG. FIG. 21 is a flowchart illustrating the reproduction data output process according to the second embodiment.

  The reproduction data output process is a process in which the server 13 determines time information of a reproduction request received from the client 11, reads frame data to be reproduced from the storage device 14, and transmits the frame data to the client 11. When the server 13 receives a content playback request from the client 11, the server 13 executes playback data output processing.

[Step S <b> 101] The server 13 receives a reproduction request for content from the client 11, information on the reproduction start time and end time, and information on the program ID.
[Step S102] The server 13 acquires management information from a frame data management file existing in the directory corresponding to the program ID.

[Step S103] The server 13 sorts the frame data stored in the directory corresponding to the received program ID in ascending order based on the management information.
[Step S104] The server 13 reads the frame data stored in the directory corresponding to the program ID according to the sort result.

  The server 13 reads out the frame data within the range of the frame data requested by the client 11 that requested the reproduction from the frame data from the start time to the end time received by the reproduction request. As a result, the server allows the client 11 to reproduce the frame data only for the frame data stored by the client 11. For example, when the client 11 is recording only a part of the broadcast content, the client 11 can reproduce the frame data only for a part of the recorded program. Note that the recording time by the client 11 includes the time when the client 11 is buffering the frame data in addition to the time when the frame data is transmitted from the client 11 to the server 13.

  [Step S105] The server 13 determines whether or not the frame data read in step S104 is frame data at the recording end time. The server 13 proceeds to step S106 when the read frame data is frame data at the recording end time, and proceeds to step S104 when it is not frame data at the recording end time.

  [Step S106] The server 13 transmits the frame data read in step S104 to the client 11. The server 13 can identify a plurality of clients 11 that store the same broadcast content based on the client management information. The server 13 can transmit the same broadcast content to the identified client 11.

  As described above, the server 13 can efficiently perform de-duplication by using the identification information management list when storing a large amount of broadcast contents having the same contents in the same time zone. In addition, the server 13 can reduce overlapping frames and reduce the storage capacity of the storage device.

  In addition, when there are a plurality of clients 11 requesting transmission start of the same broadcast content frame, the server 13 transmits a command to transmit a frame to some clients 11, and transmits to another client 11. Send an instruction to buffer. In this way, the server 13 can reduce the number of frames received from the client 11 and reduce the network bandwidth for communicating a large amount of data.

  The above processing functions can be realized by a computer. In that case, a program describing the processing contents of the functions that the first information processing apparatus 2, the second information processing apparatus 5, the client 11, and the server 13 should have is provided. By executing the program on a computer, the above processing functions are realized on the computer. The program describing the processing contents can be recorded on a computer-readable recording medium. Examples of the computer-readable recording medium include a magnetic storage device, an optical disk, a magneto-optical recording medium, and a semiconductor memory. Examples of the magnetic storage device include a hard disk device (HDD), a flexible disk (FD), and a magnetic tape. Optical discs include DVD, DVD-RAM, CD-ROM / RW, and the like. Magneto-optical recording media include MO (Magneto-Optical disk).

  When distributing the program, for example, portable recording media such as a DVD and a CD-ROM in which the program is recorded are sold. It is also possible to store the program in a storage device of a server computer and transfer the program from the server computer to another computer via a network.

  The computer that executes the program stores, for example, the program recorded on the portable recording medium or the program transferred from the server computer in its own storage device. Then, the computer reads the program from its own storage device and executes processing according to the program. The computer can also read the program directly from the portable recording medium and execute processing according to the program. In addition, each time a program is transferred from a server computer connected via a network, the computer can sequentially execute processing according to the received program.

  In addition, at least a part of the processing functions described above can be realized by an electronic circuit such as a DSP, ASIC, or PLD.

DESCRIPTION OF SYMBOLS 1 Information processing system 2, 2a, 2b, 2n 1st information processing apparatus 3 Transmission part 4 Stream data 4a Unit data 5 2nd information processing apparatus 5a Reception part 5b Control part 5c 1st memory | storage part 6 Identification information 7 1st 2 storage units 9, 12 network 10 broadcast content storage system 11, 11a, 11b, 11n client 13 server 14 storage device 15 broadcast station 16 content distribution system 101 processor 102 RAM
103 HDD
104 I / O signal interface 105 Storage medium interface 106 Communication interface 107 Bus 108 Input / output device 109 Storage medium

Claims (7)

In an information processing system having a plurality of first information processing devices and a second information processing device connected to the first information processing device via a network,
The first information processing apparatus includes a transmission unit that transmits stream data generated from broadcast content,
The second information processing apparatus
A receiving unit for receiving the stream data;
Identification information that can identify predetermined unit data included in the stream data is held in the first storage unit so that the reception timing of the unit data can be specified, and the unit data is held in the second storage unit And
When the stream data is received from two or more first information processing apparatuses, the identification information of the unit data received first and held in the first storage unit, and the unit data received later When the comparison result matches the identification information, the unit data corresponding to the matched identification information is discarded, and when the comparison result does not match, the identification of the unit data received later A control unit for holding information in the first storage unit and holding the unit data received later in the second storage unit;
An information processing system comprising:   The information processing system according to claim 1, wherein the control unit associates the identification information received in a predetermined time width with information indicating a reception time of the unit data and holds the information in the first storage unit. The control unit instructs one of the first information processing devices that transmitted unit data having the same comparison result to store the stream data in a buffer included in the first information processing device. Sending a buffer save command and stopping receiving the stream data from the first information processing apparatus that sent the buffer save command;
The information processing system according to claim 1. The control unit instructs the first information processing apparatus to transmit the stream data including a delay time different from that of the other first information processing apparatus.
The information processing system according to claim 1. The control unit requests the first information processing apparatus that stores the stream data in the buffer to perform bulk transmission of the stream data stored in the buffer;
The information processing system according to claim 3. A storage control program executed by the second information processing apparatus in an information processing system having a plurality of first information processing apparatuses and a second information processing apparatus connected to the first information processing apparatus via a network Because
In the second information processing apparatus,
Receiving stream data generated from broadcast content from the first information processing apparatus;
The identification information that can identify the predetermined unit data included in the received stream data is held in the first storage unit so that the reception timing of the unit data can be specified, and the unit data is stored in the second storage unit Hold on
When the stream data is received from two or more first information processing apparatuses, the identification information of the unit data received first and held in the first storage unit, and the unit data received later When the comparison result matches the identification information, the unit data corresponding to the matching identification information is discarded, and when the comparison result does not match, the identification information of the unit data received later is Holding in the first storage unit and holding the unit data received later in the second storage unit;
A storage control program for executing processing. A control method in an information processing system having a plurality of first information processing apparatuses and a second information processing apparatus connected to the first information processing apparatus via a network,
The first information processing apparatus transmits stream data generated from broadcast content,
The second information processing apparatus
Receiving the stream data;
Identification information that can identify predetermined unit data included in the stream data is held in the first storage unit so that the reception timing of the unit data can be specified, and the unit data is held in the second storage unit And
When the stream data is received from two or more first information processing apparatuses, the identification information of the unit data received first and held in the first storage unit, and the unit data received later When the comparison result matches the identification information, the unit data corresponding to the matched identification information is discarded, and when the comparison result does not match, the identification of the unit data received later Holding the information in the first storage unit and holding the unit data received later in the second storage unit;
Memory control method.

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