CN104219540B - Distributing coding/decoding system and method - Google Patents

Abstract

A distributed encoding and decoding system includes multiple functional modules such as a transmission module, a selection module, and a calculation module. Using the above functional modules, the target file required by the client can be determined; the source server that stores the target file is selected; the priority of each source server is determined, and the encoding server is determined; the target file is divided into multiple file blocks, and Sequentially allocate the file blocks that each encoding server needs to process; generate an allocation record table and synchronize it to all encoding servers and the client, and the encoding server performs the allocation of the allocated file blocks according to the allocation record table Encoding processing. The invention also provides a distributed encoding and decoding method. By using the invention, the multimedia files can be distributedly encoded and decoded.

Description

Distributed codec system and method

technical field

The present invention relates to encoding and decoding technology, in particular to a distributed encoding and decoding system and method.

Background technique

Usually, the video signal needs to be compressed and encoded before transmission, that is, the video source is compressed and encoded, and then transmitted through the network, thereby saving transmission bandwidth and storage space, etc. With the improvement of video coding standards, the resolution is higher and higher, and the bit rate is reduced. However, the computational complexity is also increased accordingly. For example, high-efficiency video coding (HEVC, High Efficiency Video Coding) can save up to 40-50% of the bit rate, but the computational complexity may increase by 2-10 times, or even more.

Therefore, the reminder of the computational complexity will inevitably lead to an increase in the computational time for encoding and decoding video signals, which will inevitably affect the efficiency of encoding and decoding video signals.

Contents of the invention

In view of the above, it is necessary to provide a distributed encoding and decoding system and method, which can segment multimedia files, and use distributed multi-servers to encode different segmented file blocks, thereby improving encoding efficiency .

Further, it is also necessary to provide a distributed encoding and decoding system and method, which can receive encoded file blocks transmitted from multiple servers on the client side, decode them sequentially, and decode the multiple decoded file blocks Consolidation is performed to generate complete multimedia files, thereby reducing bandwidth consumption for data transfer.

A distributed encoding and decoding method, applied to a master server, the master server is connected to a plurality of slave servers and clients, the method includes: receiving client requirements, and determining the multimedia files required by the clients as target files; Select multiple slave servers that have stored the target file as the source server; determine the priority of each source server; determine multiple encoding servers from the source server according to the priority; according to the information of the target file stored in one of the encoding servers , divide the target file into multiple file blocks; according to the preset allocation method, sequentially allocate the file blocks that each encoding server needs to process, generate an allocation record table and record the file areas that each encoding server needs to process blocks; and synchronizing the allocation record table to all encoding servers and the clients, and the encoding server encodes the allocated file blocks according to the allocation record table.

A distributed encoding and decoding method applied to a client, the client is connected to a master server and a plurality of slave servers, the method includes: sending a demand to the master server, the demand includes the client required The information of the multimedia file, the multimedia file is determined as the target file; receiving the allocation record table synchronously transmitted from the main server, the allocation record table records the number and sequence of the encoding server, and the file blocks that the encoding server needs to process ; Receive the encoded file blocks returned from each encoding server, and decode the encoded file blocks according to a preset order; and determine according to the allocation record table that after all the encoded file blocks have been received When a file block is generated, the decoded file block is reassembled and a complete target file is generated.

A distributed codec system, applied to a master server, the master server is connected to multiple slave servers and clients, the system includes: a transmission module, used to receive client requirements, and determine the multimedia required by the client The file is a target file; the selection module is used to select a plurality of slave servers storing the target file as source servers; the calculation module is used to determine the priority of each source server; the determination module is used to select from the source server according to the priority Multiple encoding servers are determined in the server; the segmentation module is used to divide the target file into multiple file blocks according to the information of the target file stored in one of the encoding servers; the allocation module is used to divide the target file into multiple file blocks according to a preset allocation method, Sequentially allocate the file blocks that each encoding server needs to process, generate an allocation record table and record the file blocks that each encoding server needs to process; and a synchronization module, used to synchronize the allocation record table to all encoding servers And in the client, the encoding server encodes the allocated file blocks according to the allocation record table.

A distributed codec system, applied to a client, the client is connected to a master server and a plurality of slave servers, characterized in that the system includes: a transmission module, used to send requirements to the master server, the The requirement includes the information of the multimedia file required by the client, and the multimedia file is determined as the target file; the transmission module is also used to receive the allocation record table synchronously transmitted from the main server, and receive the information from each encoded The coded file block returned by the server, the allocation record table records the number and order of the encoding server, and the file blocks that the encoding server needs to process; the decoding module is used to encode the encoded file according to the preset order The block is decoded; and the integration module is configured to reassemble the decoded file blocks and generate a complete target file when all encoded file blocks have been received according to the allocation record table.

Compared with the prior art, the distributed encoding and decoding system and method can segment multimedia files, and use distributed multi-servers to encode different segmented video segments (or video blocks) respectively Processing, thereby improving the encoding efficiency, and reducing the problem of overloading the server caused by encoding with a single server. In addition, in the distributed encoding and decoding system and method, the client can also receive encoded file blocks transmitted from multiple servers, decode them sequentially, and integrate multiple decoded file blocks to Generate complete multimedia files, thereby reducing bandwidth consumption for data transfer.

Description of drawings

Fig. 1 is an operating environment diagram of a preferred embodiment of the distributed codec system of the present invention.

Fig. 2 is a hardware architecture diagram of a preferred embodiment of the distributed encoding and decoding system of the present invention.

Fig. 3 is a functional block diagram of a preferred embodiment of the distributed encoding and decoding system of the present invention.

Fig. 4 is a schematic diagram of an allocation record table of the distributed codec system of the present invention.

Fig. 5 is an encoding flowchart of a preferred embodiment of the distributed encoding and decoding method of the present invention.

Fig. 6 is a decoding flowchart of a preferred embodiment of the distributed encoding and decoding method of the present invention.

Description of main component symbols

server 1 processor 11 storage device 12 client 2 processor twenty one storage device twenty two Distributed codec system 3 transfer module 30 select module 31 computing module 32 Determine the module 33 Segmentation module 34 distribution module 35 Synchronization module 36 encoding module 37 decoding module 38 Integration module 39

The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings.

detailed description

As shown in FIG. 1 , it is an operating environment diagram of a preferred embodiment of the distributed encoding and decoding system of the present invention. As shown in FIG. 2 , it is a hardware architecture diagram of a preferred embodiment of the distributed encoding and decoding system of the present invention. The following will be described in conjunction with Fig. 1 and Fig. 2 .

The distributed codec system 3 is applied to a plurality of servers 1 and clients 2, the server 1 can be a computer, a host computer and other devices, and the client 2 can be a computer, a mobile phone, a TV, a tablet Electronic devices such as computers, laptops, personal digital assistants, etc. In this preferred embodiment, the server 1 and the client 2, as well as multiple servers 1, can be connected through the Internet (Internet), intranet (Intranet) or other types of communication networks to realize data transmission .

In the first embodiment, one of the multiple servers 1 can be pre-designated as the main server (such as server A in Figure 1), and the remaining servers 1 (such as servers B, C, D, etc. in Figure 1) Can be considered as a slave server. The designation of the master server can be modified according to actual needs, for example, server B can be designated as the master server. The determination of the master server and the slave server can be performed by using the distributed codec system 3 .

Furthermore, in the second embodiment, there may be a specific master server that is independent of all other servers.

In this preferred embodiment, the distributed codec system 3 can be applied to each server 1 and the client 2 . The distributed codec system 3 is used to determine the target file required by the client 2, determine a plurality of encoding servers, divide the target file, generate a plurality of file blocks, and according to a preset distribution method The plurality of file blocks are distributed to the encoding server for distributed encoding, and then the encoded file blocks are transmitted to the client 2 according to a preset transmission method.

Further, the distributed codec system 3 is also used to receive the encoded file blocks transmitted from each encoding server at the client 2, and perform corresponding decoding processing, and convert the decoded file blocks to Integration is performed to generate a complete multimedia file.

The server 1 includes a processor 11 and a storage device 12 , and the client 2 includes a processor 21 and a storage device 22 . The processors 11 and 21 are used to execute the distributed codec system 3 and various software installed in the server 1 or the client 2, such as an operating system and the like. The storage devices 12, 22 may be hard disks, or other types of memory cards or storage devices. The storage devices 12 and 22 are used to store various types of data, such as information such as video, audio, video, and files, and to store data set and received by the distributed codec system 3 .

As shown in FIG. 3 , it is a functional block diagram of a preferred embodiment of the distributed encoding and decoding system of the present invention. In this embodiment, the distributed codec system 3 includes a plurality of functional modules, which are: a transmission module 30, a selection module 31, a calculation module 32, a determination module 33, a segmentation module 34, an allocation module 35, and a synchronization module 36 , an encoding module 37 , a decoding module 38 and an integrating module 39 .

The module referred to in the present invention is a program segment that completes a specific function, and is more suitable than a program to describe the execution process of software in the client 2 . The specific functions of each module will be described below with reference to FIG. 5 and FIG. 6 .

As shown in FIG. 5 , it is an encoding flowchart of a preferred embodiment of the distributed encoding and decoding method of the present invention. In this embodiment, it is assumed that the server A is the main server. Except for the different execution modes in the different embodiments described below, the steps in this flow chart are composed of distributed Executed by each functional module in Codec 3.

Firstly, in step S2, the transmitting module 30 receives the requirement of the client, and determines the multimedia file required by the client 2 as the target file according to the requirement. For example, the target file may be a video file, an audio file, an image file or a text file.

For example, the distributed codec system 3 may provide a user interface and corresponding fields or file lists for users to input the name or other information of the required multimedia files for retrieval, or to receive video files selected by the users.

Step S4, the selection module 31 selects a plurality of servers 1 storing the target file from the plurality of servers 1 as source servers. In addition, in other implementation manners, the server 1 storing the segment of the target file can also be regarded as the source server.

Step S6, the calculation module 32 determines the priority of each source server.

The calculation module 32 can calculate the priority of each source server according to the formula "P=QoS ÷ Overhead", wherein "P" represents the priority of each source server, and "QoS" represents the relationship between each source server and the client. 2 The quality parameter of the connected network, and "Overhead" indicates the resources consumed by each source server. For example, the "QoS" refers to the number of packets transmitted by the network between each source server and client 2 (for example, each source server corresponds to the number of packets transmitted or received by the client 2 , or the number of packets transmitted or received between the client 2 and each source server, etc.), flow rate or speed, "Overhead" is the processor or memory occupancy rate (or called usage rate).

Suppose, the speed of the network connected to the client 2 of the source server A is 1.0 Gbps, and the processor occupancy rate of the source server A is 20%, then the priority of the source server A is 1.0÷20%=5. The speed of the network connected to the client 2 of the source server B is 0.9Gbps, and the processor occupancy rate of the source server B is 30%, so the priority of the source server B is 0.9÷30%=3.

In addition, in other embodiments, the calculation module 32 can also calculate the priority of each source server according to other methods, for example, according to the quality parameters of each source server and the network connected to the client 2, according to the quality parameters of each source server The current load of the server, the current job schedule according to each source server, etc. The calculation module 32 can preset and modify the way of calculating the priority of the source server according to actual needs.

Step S8, the determining module 33 determines a plurality of encoding servers from the source servers according to the priority.

The determination module 33 may sequentially select a preset number of M encoding servers according to the descending order of the priority of each source server. For example, as shown in FIG. 1 , assume that multiple source servers A, B, C, and D are selected as encoding servers, wherein, server A is the master server, and servers B, C, and D are slave servers. Each encoding server is connected to the client 2, and each slave server is connected to the master server. In addition, connections between individual slave servers are also possible.

Step S10, the segmentation module 34 divides the target file into multiple file blocks according to the information of the target file stored in one of the encoding servers. The methods for dividing the target file include: virtual division and physical division. If it is virtual segmentation, then the segmentation module 34 only determines the relevant information of multiple file blocks according to the information of a complete target file (for example, the size of the file, or the length of the playing time of the file, etc.), At this time, the split module 34 does not physically split the target file, but only determines the information of a plurality of corresponding file blocks, for example, records the size of each file block, and the corresponding file block The start time, end time, etc. of the segment (for example, video, audio, etc.) to play. Therefore, when the encoding process is involved subsequently, each encoding server determines the file chunks to be encoded according to the related information of the allocated file chunks, and then encodes the determined file chunks.

If it is physical segmentation, the segmentation module 34 can directly segment the complete target file stored in one of the encoding servers (for example, the main server A), and obtain a plurality of segmented file blocks, Corresponding information as described above for each file block is then determined.

The corresponding information of each above-mentioned file block needs to be written into the allocation record table described in detail below, so that each encoding server can identify and determine the file block that needs to be encoded.

The segmentation module 34 can divide the target file according to the preset segmentation method and the segmentation quantity, and can also provide multiple segmentation quantities for the client 2 to choose, and then divide the target file according to the segmentation quantity selected by the client. The target file is divided into N×N document blocks. For example, the number of divisions may be 1×1, 2×2, 4×4, 16×16, and so on.

In addition, the number M of encoding servers may be determined according to the number of divisions of the target file selected by the client 2, and the number M of encoding servers is greater than or equal to N×N. For example, when the number of divisions is 2×2, the number of encoding servers M≧4.

Step S12, the allocation module 35 sequentially allocates the file blocks required to be processed (for example, encoded) by each encoding server according to a preset allocation method, generates an allocation record table and records the files required to be processed by each encoding server Information about the block. The allocation record table is first stored in the main server.

The preset allocation method is to sequentially and one by one allocate the file blocks to be processed by each encoding server according to the priority order and adopt the Round-Robin method.

The allocation record table records the size of the target file, the size and order of the divided file blocks, and the position in the target file, the number and sequence of the encoding servers arranged according to the preset order, and the number and order of each encoding server. The allocated identification codes of the file blocks to be processed and the number of file blocks allocated to each encoding server, wherein the identification codes are assigned when the target file is divided.

For example, referring to the allocation record table shown in FIG. 4, the allocation module 35 sequentially allocates file block 1 to server A (primary server), allocates file block 2 to server B, and assigns file block 3 Assign to server C, file block 4 to server D, then continue to assign file block 5 to server A, file block 6 to server B, and so on.

In addition, in other implementation manners, the source server further includes a server 1 that stores segments of the target file. When there are segments of the target file stored in one or more encoding servers, the distribution module 35 assigns the one or more encoding servers to encode the file blocks corresponding to the segments of the target files stored respectively, And according to the preset allocation method, the remaining file blocks are allocated to the remaining encoding servers for processing.

When the file blocks corresponding to the segments of the target file stored in multiple encoding servers are the same, and when the same file block is single, the allocation module 35 selects the encoding with higher priority The server encodes the same file block. Or, when there are multiple identical file blocks, the allocation module 35 allocates the multiple identical file blocks to the multiple encoding servers for encoding processing according to a preset allocation method.

Step S14, the synchronization module 36 synchronizes the distribution record table to all encoding servers and the client 2. For example, the synchronization module 36 can periodically synchronize the distribution record table stored in the master server to other encoding servers and clients 2 according to a preset synchronization period.

As illustrated above, in this embodiment, when the main server is also one of the encoding servers, the process continues to execute subsequent steps S16 to S18, and steps S16 to S18 are also executed in other encoding servers.

Step S16, the encoding module 37 performs encoding processing on the file blocks allocated to each encoding server according to the allocation record table. The encoding module 37 can encode the allocated file blocks according to a preset format or encoding method.

This step is applied to all encoding servers to implement distributed encoding of the divided and allocated file blocks.

Step S18, the transmission module 30 transmits the encoded file block to the client according to the preset transmission mode, and then ends the process.

In this preferred embodiment, the preset transmission methods may include, but are not limited to: each encoding server directly transmits the encoded file blocks to the client 2; or each encoding server according to The preset transmission schedule transmits the encoded file blocks to the client 2; or each encoding server first transmits the encoded file blocks to a designated encoding server, and uses the designated encoding server to send all The above-mentioned file block is transmitted to the client 2, and the designated encoding server is one or more of the master server or the slave server.

In other implementations, if the main server is not an encoding server, step S16 will be executed in each encoding server, and step S18 will be determined to be executed in each encoding server depending on the content of the preset transmission method (for example, the preset The transmission method is "each encoding server directly transmits the encoded file block to the client", etc.), or it is executed in the main server and each encoding server (for example, the default transmission method is " Each encoding server first transmits the encoded file block to the designated encoding server, and uses the designated encoding server to transmit the described file block to the client, and the designated encoding server is the master server") .

As shown in FIG. 6 , it is a decoding flow chart of a preferred embodiment of the distributed encoding and decoding method of the present invention, and this flow is applied to the client 2 described above.

Step S20, the transmission module 30 sends the request of the client 2 to the main server. The requirement includes information about a multimedia file required by the client, and the multimedia file is determined as a target file.

In step S22, the transmission module 30 receives the allocation record table synchronously transmitted from the main server, and receives the encoded file blocks transmitted back from each encoding server.

The allocation record table records the size of the target file, the size and order of the divided file blocks, and the position in the target file, the number and sequence of the encoding servers arranged according to the preset order, and the number and order of each encoding server. The allocated identification codes of the file blocks to be processed and the number of file blocks allocated to each encoding server, wherein the identification codes are assigned when the target file is divided.

Step S24, the decoding module 38 decodes the encoded file blocks according to a preset order.

The preset order may be the receiving order in which the client 2 receives each encoded file block, or the preset arrangement order of each encoding server, or the arrangement order of the encoded file blocks ( For example, according to the order determined by the identification code of the file block).

Step S26, the integration module 39 judges whether the client 2 has received all the encoded file blocks according to the allocation record table. If the client 2 has not received all the encoded file blocks, the process returns to step S24. If the client 2 has received all encoded file blocks, step S28 is executed.

Step S28, when the client has received all encoded file blocks, the integration module 39 reorganizes the decoded file blocks according to the allocation record table and generates a complete target file, and then, End this process.

In addition, in other implementation manners, the integration module 39 may further invoke playing software to play the complete target file.

The above embodiments are only used to illustrate the technical solutions of the present invention without limitation. Although the present invention has been described in detail with reference to the above preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced All should not deviate from the spirit and scope of the technical solution of the present invention.

Claims (21)

1. A distributed encoding and decoding method is applied to a master server, and the master server is connected with a plurality of slave servers and clients, it is characterized in that the method comprises: Receive client requirements, and determine the multimedia files required by the client as target files; Select multiple slave servers that store the target file as the source server; Determine the priority of each origin server; determining multiple encoding servers from the source servers according to priority; Splitting the target file into a plurality of file blocks according to the information of the target file stored in one of the encoding servers; According to the preset allocation method, sequentially allocate the file blocks required to be processed by each encoding server, generate an allocation record table and record the file blocks required to be processed by each encoding server; and The allocation record table is synchronized to all encoding servers and the clients, and the encoding server performs encoding processing on the allocated file blocks according to the allocation record table. 2. The decentralized encoding and decoding method according to claim 1, wherein the method further comprises: According to the allocation record table, each encoding server encodes the allocated file blocks; and The encoded file blocks are transmitted to the client according to a preset transmission mode. 3. The decentralized encoding and decoding method according to claim 2, wherein the preset transmission method comprises: Each encoding server directly transmits the encoded file blocks to the client respectively; or Each encoding server transmits the encoded file blocks to the client according to a preset transmission schedule; or Each encoding server first transmits the encoded file block to a designated encoding server, and uses the designated encoding server to transmit the described file block to the client, and the designated encoding server is a master server or a slave server. 4. The distributed encoding and decoding method according to claim 1, wherein the priority of each source server is calculated according to the formula P=QoS÷Overhead, wherein "P" represents the priority of each source server "QoS" indicates the quality parameters of the network that each source server is connected to the client, and "Overhead" indicates the resources consumed by each source server. 5. The distributed encoding and decoding method according to claim 4, wherein the "QoS" refers to the number of packets, traffic or speed transmitted by the network between each source server and the client, and "Overhead ” is the utilization of processor or memory in each origin server. 6. The decentralized encoding and decoding method according to any one of claims 1 to 5, wherein the method further comprises: providing multiple split quantities for the client to choose to split the target file; and The target file is divided into N×N file blocks according to the number of divisions selected by the client, wherein the value of N is a positive integer. 7. The distributed encoding and decoding method according to claim 6, wherein the number of the encoding servers is determined according to the number of divisions of the target file selected by the client, and the number of the encoding servers The quantity is greater than or equal to N×N. 8. The decentralized encoding and decoding method according to any one of claims 1 to 5, wherein the preset allocation method is based on the order of priority and adopts a round-robin method, sequentially and one by one Allocate file chunks to be processed by each encoding server. 9. The distributed encoding and decoding method according to any one of claims 1 to 5, wherein the allocation record table records the size of the target file, the size and order of the divided file blocks, and The position in the target file, the number and order of the encoding servers arranged according to the preset order, the identification codes of the file blocks to be processed allocated to each encoding server, and the IDs of the file blocks allocated to each encoding server quantity, wherein the identification code is assigned when the target file is divided. 10. The distributed encoding and decoding method according to any one of claims 1 to 5, wherein the source server further includes a server storing segments of the target file. 11. The decentralized encoding and decoding method according to claim 10, characterized in that the method further comprises: When there are segments of the target file stored in one or more encoding servers, the one or more encoding servers are assigned to encode the file blocks corresponding to the segments of the target file stored respectively, and according to the preset allocation method distributes the remaining file chunks to the remaining encoding servers for processing. 12. The distributed encoding and decoding method according to claim 11, wherein when the file blocks corresponding to the fragments of the target file stored in a plurality of encoding servers are the same, the method also includes: When the same file block is single, select an encoding server with a higher priority to encode the same file block; or When there are multiple identical file blocks, the multiple identical file blocks are allocated to the multiple encoding servers for encoding processing according to a preset allocation method. 13. The distributed encoding and decoding method according to any one of claims 1 to 5, wherein the target file is a video file, an audio file or an image file. 14. The distributed encoding and decoding method according to any one of claims 1 to 5, wherein the encoding server includes one or more of the master server and/or slave server. 15. A distributed encoding and decoding method applied to a client, wherein the client is connected to a master server and a plurality of slave servers, it is characterized in that the method comprises: Sending a request to the main server, the request includes the information of the multimedia file required by the client, and the multimedia file is determined as the target file; receiving the allocation record table synchronously transmitted from the main server, the allocation record table records the serial number and sequence of the encoding server, and the file blocks to be processed by the encoding server; receiving the encoded file blocks returned from each encoding server, and decoding the encoded file blocks according to a preset sequence; and When it is determined according to the allocation record table that all encoded file blocks have been received, the decoded file blocks are reassembled to generate a complete target file. 16. The distributed encoding and decoding method according to claim 15, wherein the allocation record table records the size of the target file, the size and order of the file blocks after division, and the location, the identification code of the file block to be processed allocated to each encoding server, and the number of file blocks allocated to each encoding server, wherein the identification code is given when the target file is divided. 17. The distributed encoding and decoding method according to claim 15, wherein the preset order is the receiving order of each encoded file block received by the client, or the preset order of each encoding server Arrangement order, or the arrangement order of the encoded file blocks. 18. The decentralized encoding and decoding method according to any one of claims 15 to 17, wherein the method further comprises: The corresponding playing software is invoked to play the complete target file. 19. A distributed codec system, applied to a master server, the master server is connected to multiple slave servers and clients, characterized in that the system comprises: The transmission module is used to receive client requirements, and determine that the multimedia files required by the client are target files; The selection module is used to select multiple slave servers storing the target file as the source server; a calculation module, configured to determine the priority of each source server; A determining module, configured to determine multiple encoding servers from the source servers according to priority; A segmentation module, configured to divide the target file into multiple file blocks according to the information of the target file stored in one of the encoding servers; The allocation module is used to sequentially allocate the file blocks to be processed by each encoding server according to a preset allocation method, generate an allocation record table and record the file blocks to be processed by each encoding server; and A synchronization module, configured to synchronize the allocation record table to all encoding servers and the clients, and the encoding server performs encoding processing on allocated file blocks according to the allocation record table. 20. The decentralized codec system according to claim 19, wherein the system further comprises: An encoding module, configured to encode the file block allocated to each encoding server according to the allocation record table; and The transmission module is further configured to transmit the encoded file block to the client according to a preset transmission method. 21. A distributed codec system, applied to a client, the client is connected to a master server and a plurality of slave servers, it is characterized in that the system includes: A transmission module, configured to send a demand to the main server, the demand includes information about the multimedia file required by the client, and the multimedia file is determined as the target file; The transmission module is also used to receive the allocation record table synchronously transmitted from the main server, and receive the encoded file blocks returned from each encoding server, and the allocation record table records the number of the encoding server and sequence, and file blocks that the encoding server needs to process; a decoding module, configured to decode the encoded file blocks according to a preset order; and The integration module is configured to reassemble the decoded file blocks and generate a complete target file when it is determined according to the allocation record table that all encoded file blocks have been received.