KR20180110648A - Data Mirroring System - Google Patents

Abstract

The present invention relates to a data mirroring system for a DVR, and more particularly, to a data mirroring system for a DVR, capable of performing data mirroring while minimizing the use of a CPU and a resource by blocking stream data inputted from a multi-channel camera together with an index and performing each DMA for two disks for the data.

Description

Data Mirroring System for DVR {Data Mirroring System}

The present invention relates to a data mirroring system for a DVR, and more particularly, to a data mirroring system for a DVR, in which stream data input from a multi-channel camera is blocked together with an index, and DMA control is performed on two disks, And a data mirroring system for a DVR capable of performing data mirroring while minimizing resource use.

DVR (Digital Video Recorder) system is a digital video surveillance system that replaces CCTV, which is analog video surveillance equipment. Besides the high image quality compared to CCTV, it also uses computer hard disk as a storage medium. It is a video surveillance system capable of real-time video transmission and remote surveillance over the Internet.

In general, a DVR uses a hard disk for storing data, and a hard disk (HDD) is a mechanical device that performs a read / write operation through a head of a rotating disk such as a turntable.

Since the performance of the hard disk depends on the rotational speed of the disk, the read / write performance is limited, the probability of failure is higher than that of semiconductor-based storage devices such as SSD and SD, In order to overcome the limitation of performance and stability, RAID (Redundant Array of Independent Disks) technology is used in which a plurality of HDDs are connected and read / write operations are appropriately distributed.

RAID technology is divided into several details according to the data array policy among several HDDs. Typical technologies are RAID 0 (striping), RAID 1 (mirroring), RAID 5 (striping with distributed parity) and RAID 10 (mirroring and striping) . In this case, the mirroring technique is to store data on two or more HDDs, thereby preventing data loss even when one HDD fails and continuing to provide data service through the failed HDDs.

Generally, a DVR system records or encodes stream data input from a multi-channel camera through a codec, and encodes and encodes the stream data in a storage space. The stream data is stored in an operating system Scattering where data is divided into fixed units in a driver unit, index data is mapped to the data, and gathering of the split data is completed, and then recorded in the storage space through the DMA.

Therefore, in order to perform data mirroring, the same data recording process as described above needs to be performed twice, which increases system resource usage and CPU latency.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a method and an apparatus for controlling streaming data input from a multi-channel camera, And to provide a data mirroring system for a DVR capable of performing data mirroring with a minimum amount of data.

According to another aspect of the present invention, there is provided a data mirroring system for a DVR, comprising: a buffer module for temporarily storing and temporarily storing encoded stream data; And a control driver for controlling the DMAs to perform DMA operations.

The buffer module being allocated in system memory; The stream data is divided into a plurality of blocks to store data to be stored in a hard disk, and data is allocated to virtual blocks corresponding to allocated blocks among the divided blocks.

The buffer module allocates stream data to be stored in a specific block of the hard disk through the block, and stores index data corresponding to the stream data to be stored in the block in the virtual block together.

Wherein the control driver allocates a disk area for data to be written to the hard disk, and controls DMA (Direct Memory Access) commands to the allocated disk area; And to independently DMA the blocks of data stored in the buffer module in two allocated disk areas for data mirroring.

The control driver controls to DMA the blocked data stored in the buffer module to two allocated disk areas only when data mirroring is required (for example, when motion is detected in the CCTV image or when an emergency occurs) Thereby enabling selective data mirroring.

As described above, the data mirroring system for a DVR according to the present invention blocks a stream data input from a multi-channel camera together with an index and controls a DMA command on two hard disks with respect to the buffered data, There is an excellent effect of data mirroring with minimal resource usage.

FIG. 1 is a block diagram schematically showing a DVR system according to a preferred embodiment of the present invention, and FIG. 2 is a block diagram schematically showing the data mirroring system of FIG.
3 is a flowchart schematically showing a data mirroring method according to a preferred embodiment of the present invention.
FIG. 4 is a schematic view illustrating a data mirroring process according to a preferred embodiment of the present invention.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram schematically showing a DVR system according to a preferred embodiment of the present invention, and FIG. 2 is a block diagram schematically showing the data mirroring system of FIG.

Generally, a DVR system generally includes a channel decoder 1 for decoding a channel input from a camera, a frame buffer 2 for temporarily storing stream data divided into a set frame group, A control unit 5 for determining the number of groups, indexing each frame group to control time synchronization, a codec unit 3 for encoding each frame group stored in the frame buffer, and a storage unit for storing the stream data encoded by the codec unit And a storage unit 40 that manages data.

It is obvious that the configuration of the DVR system can be variously modified according to the system specification and structure.

In the DVR system, data stored and managed in the storage unit 40 may be divided into stream data and index data.

The stream data substantially contains content to be reproduced, that is, audio and video data to be recorded or recorded, and the index data includes additional information related to the stream data.

More specifically, the index data is data in which the sequence number of the audio / video data packet in the stream data in the DVR system is mapped with the time information and includes channel information, time information, location information (address) Meta information, and the like, to support playback of stream data stored.

The data mirroring system according to the present invention is applied when the encoded stream data is stored in a storage for execution.

The data mirroring system according to the present invention may include a buffer module for storing and storing encoded stream data and a control driver for controlling dual DMA commands by allocating two disks to the block stream data.

Here, the buffer module may be provided in the system memory or in a separate memory space.

Blocking of the stream data means partitioning data to be stored in a disk into a plurality of blocks and allocating and storing data to virtual blocks corresponding to allocated blocks of the partitioned blocks.

Stream data to be stored in a specific block of the disk is allocated through the block, and index data corresponding to the stream data to be stored in the block is also stored in the virtual block.

The control driver controls direct memory access (DMA) of data to be written to the disk.

The DMA means a technique of directly transferring a series of information from the input / output device to the memory or from the memory to the input / output device without going through the CPU.

Wherein the control driver allocates a disk area to be written to the hard disk and controls data to be recorded in the allocated disk area so that the block data stored in the buffer module can be independently DMA .

Here, at least two disk spaces are required for data mirroring, and the control driver can transmit DMA commands to two hard disks, respectively.

The conventional data mirroring system must perform the same two data recording processes in order to allocate two areas of the hard disk and to record the same data in two areas.

More specifically, the conventional hard disk is a system in which stream data is recorded in a disk and index data corresponding thereto is recorded in an allocated space of the hard disk. Therefore, at least two recording processes are required while data is recorded on the hard disk There is a problem that the latency of the CPU increases and the use of system resources increases. That is, if 100% CPU for 1 record is used, 200% or more CPU performance is required to record the same 2 times.

 On the other hand, since data mirroring is possible only by controlling the control driver to DMA the block stream data to two allocated disk areas, the latency can be greatly reduced to about 110 to 120% of the CPU usage.

In addition, the control driver can control data to be DMA in two hard disk areas only when data mirroring is required.

More specifically, data mirroring is performed to prevent data from being damaged due to damage of the hard disk, and data mirroring is not required for all data.

The conventional data mirroring system is structured such that data mirroring is always performed. However, since the present invention can selectively control one or two DMAs by blocking the data before data is written, only 2 It is possible to control the same data to be recorded on the hard disks.

Hereinafter, a specific data mirroring method of the present invention will be described.

3 is a flowchart schematically showing a data mirroring method according to a preferred embodiment of the present invention.

Referring to FIG. 3, first, the encoded stream data is divided into data packet units, a block to be stored in the hard disk is allocated and designated, and the stream data is recorded in a virtual block of the buffer module .

Here, when a virtual block is filled with data in a concept corresponding to a block actually allocated to the hard disk, the virtual block is recorded in the block to which the data is actually allocated.

At this time, the stream data is stored in the virtual block, and the index data mapped to the stream data is also stored in the allocated area of the virtual block. Here, the index data includes synchronized information such as a sequence number of stream data stored in the block, channel information, time information, location information in a storage device, event information, and meta information.

When data is filled in the virtual block allocated as described above, the control driver transfers DMA commands to the two disk areas.

Here, the control driver transmits a DMA command to the first disk and the second disk when data mirroring is required, and the data of the virtual block is recorded and stored in the allocated blocks of the first disk and the second disk.

If data mirroring is not required, the control driver may select one of the first disk and the second disk to control the DMA command to be transmitted to only one disk.

FIG. 4 is a schematic view illustrating a data mirroring process according to a preferred embodiment of the present invention.

For example, when the camera is composed of four channels (CH1, CH2, CH3, and CH4), stream data is input from four channels, and stream data that is compression-encoded through a codec is allocated and stored in a virtual block of the buffer module .

Here, the index data is also stored together in the block during the stream data block process. When data is filled in the virtual block, the data filled in the virtual block is DMA-controlled to the disk through the control of the control driver.

At this time, the control driver can control the two disks (the first disk and the second disk) to be DMA only when data mirroring is required, and to control only one hard disk to DMA when data mirroring is not required.

When data is input from multiple channels, data of all channels need not be mirrored. Even if the same channel is used, time required for mirroring may be different from time to time. Therefore, only the data required for mirroring is mirrored, Can be minimized.

 While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.

1: Channel decoder 2: Frame buffer
3: codec 4: storage unit
5:

Claims (1)

A data mirroring system for a DVR,
A method of allocating data to a virtual block corresponding to a block allocated in a partitioned block and storing the encoded data in a block, temporarily storing the encoded data in a system memory, partitioning data to be stored in a disk into a plurality of blocks, A buffer module for allocating stream data to be stored in a specific block of the disk through the block and storing index data corresponding to stream data to be stored in the block in a virtual block;
Allocating a disk area for data to be written to a hard disk, and controlling a direct memory access (DMA) command to an allocated disk area; Controlling the DMA controller to independently DMA the block data stored in the buffer module in two allocated disk areas for data mirroring, and controlling the command to perform DMA by allocating two hard disks to the block stream data, And a control driver capable of performing selective data mirroring by controlling the DMA controller to DMA the block data stored in the buffer module to two allocated disk areas only when necessary.

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