KR101173552B1 - Method for recording multi image stream and its apparatus - Google Patents

Abstract

The present invention relates to a method for recording multiple video streams and a device thereof, wherein image files recorded simultaneously in consideration of cylinder information of a hard disk are arranged in a close cylinder to minimize search time of a hard disk head, and to allocate an allocation unit to a block. By performing a large segment unit, that is, recording by a plurality of contiguous blocks on the hard disk, a plurality of video streams can be recorded simultaneously by increasing write performance to make the most of the bandwidth of the hard disk. In addition, the present invention provides a method and apparatus for recording multiple video streams, so that even when recording multiple video streams at the same time, the disk bandwidth utilization is high, so that recording can be performed smoothly.

Cylinder, segment, recording, hard disk, video stream

Description

Method for recording multiple video streams and device therefor {METHOD FOR RECORDING MULTI IMAGE STREAM AND ITS APPARATUS}

The present invention relates to a method for recording multiple video streams and a device thereof, and more particularly, to a device for recording a stream of digital video onto a storage medium of a hard disk, wherein video files are simultaneously recorded in consideration of cylinder information of the hard disk. The present invention relates to a method and apparatus for minimizing the seek time of a hard disk head by arranging them in cylinders close to each other, and recording allocation units in segments larger than blocks.

The present invention is derived from the research conducted as part of the IT growth engine technology development project of the Ministry of Knowledge Economy and the Ministry of Information and Telecommunication Research and Development. [Task management number: 2007-S-051-02, Title: Digital creature production S / W development ].

As is well known, an apparatus (eg, a personal video recorder (PVR) or digital video recorder (DVR), etc.) for recording a stream of digital video onto a storage medium on a hard disk must simultaneously record several video streams.

In many fields, digital information is increasingly recorded on the hard disk due to the digitization of media information. In particular, digital image information generated by a wide variety of equipment, from home digital televisions to cinematography equipments, can be used. The stream is recorded on the hard disk.

As mentioned above, although the use of hard disks is increasing for recording streams of digital video information, the general file systems used for hard disks are not originally designed with the recording of video content in mind, but only a large number of small texts. It is designed for existing computer systems that primarily deal with files and whose sizes and contents change frequently.

In this environment, the use of hard disks is mostly random rather than sequential, and file systems are designed accordingly. Since random access is assumed for accessing a large number of small files, and the file size and contents change frequently, it is designed to allocate space in small blocks and to use it as a storage space even if there is a distance between each recorded location. It is.

That is, the file system records or stores a superblock and an inode list, which are metadata for data, in the first block of a hard disk partition to which the file system is applied. The superblock contains information such as file system size, inode block range, data block range, idle inode list, and idle data block list. The space is then used as a space for data blocks.

However, in the case of a hard disk using the conventional file system as described above, when multiple video streams are recorded simultaneously, each stream is recorded in different cylinders, especially cylinders far from each other, which causes defects. In addition, each stream must be alternately recorded and shuttled back and forth between cylinders. Even though the hard disk bandwidth is high, the seek time required for the head movement is the largest part of the disk access time. There is a problem in that the recording performance is greatly reduced since it does not use time in search time.

Accordingly, the technical problem of the present invention is to solve the above-described problems, in the hard disk-based video recording apparatus, considering the cylinder information of the hard disk, at the same time the video files recorded at the same time arranged in a close cylinder of the hard disk Minimize the seek time of the head and perform allocation unit by segment larger than block, that is, write by contiguous block unit on the hard disk, to increase write performance and make the most of the hard disk bandwidth to maximize the number of video streams Provided are a multi-image stream recording method and apparatus capable of simultaneously recording a video stream.

According to an aspect of the present invention, a method of recording multiple video streams includes selecting cylinders by priority in a hard disk when respective video streams are input, and ending the corresponding file in the cylinder according to the selected cylinder information. Selecting the last segment from the segment list in use in the cylinder when the segment adjacent to the segment is filled; and generating a recording signal when the position within the cylinder is empty and within a certain distance from the selected segment. And controlling each video stream to be recorded in units of segments on the hard disk according to the recording signal.

According to another aspect of the present invention, a multiple video stream recording apparatus includes a cylinder selection unit for selecting cylinders by priority in a hard disk when respective video streams are input, and a corresponding file in a cylinder according to information of the selected cylinder. Segment selector that selects the last segment from the list of segments in use in the cylinder when the segment adjacent to the last segment in is filled, and generates a recording signal when the position within the cylinder is empty and within a certain distance from the selected segment. And a recording control unit for controlling each video stream to be recorded in units of segments on the hard disk according to the recording signal.

The present invention minimizes the seek time of the hard disk head by arranging video files simultaneously recorded in consideration of cylinder information of the hard disk in a close cylinder, and performs allocation unit by segment larger than the block, that is, continuous on the hard disk. By recording in multiple block units, it is possible to record multiple video streams at the same time by increasing write performance to make the most of the bandwidth of the hard disk.

In addition, the present invention provides a method and a device for recording multiple video streams, and even if a plurality of video streams are recorded at the same time, disk bandwidth utilization is high, and thus there is an advantage in that recording can be performed smoothly. For example, when the video system of a plurality of surveillance cameras is used as a file system of a hard disk, even if the number of simultaneously recorded video streams increases, disk bandwidth loss is small, so that a large number of cameras can be accommodated or image quality can be improved.

Hereinafter, with reference to the accompanying drawings will be described in detail the operating principle of the present invention. In the following description of the present invention, if it is determined that a detailed description of a known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. The following terms are defined in consideration of the functions of the present invention, and may be changed according to the intentions or customs of the user, the operator, and the like. Therefore, the definition should be based on the contents throughout this specification.

1 is a block diagram of an apparatus for recording multiple video streams according to an embodiment of the present invention, wherein the cylinder selector 10, the segment selector 20, the recording control unit 30, the hard disk 40, and the like are shown. It may include.

When the recording control scheduled signal is input from the recording control unit 30, the cylinder selector 10 selects a 'cylinder in which the last segment of the file is located', 'cylinder having more than 1 stream', and 'space usage' in the hard disk 40. The cylinders are selected in order of priority, such as a cylinder whose state is partially used, 'a cylinder having an empty state of use', and the like, and the selected cylinder information is provided to the segment selector 20.

The segment selector 20 determines whether the segment immediately adjacent to the last segment of the file in the cylinder is empty or not according to the corresponding cylinder information input from the cylinder selector 10, and if it is empty, the recording controller. If the recording signal is supplied to (30), and it is not empty, the last segment is selected from the segment list in use in the cylinder, and the position is separated by a constant (m) × (number of streams-1) based on the selected last segment. Checking whether the cylinder is out of the cylinder means that the idle space is insufficient, and thus generates a cylinder reselection signal to allow the cylinder to be re-selected and provided to the cylinder selection unit 10, and the recording control unit ( 30 to provide a recording signal.

For example, if the video streams S1-1, S1-2, ..., S1-n respectively captured by the plurality of surveillance cameras are input at the same time, the recording control unit 30 may select the hard disk 40. In order to control the recording, the control signal for providing the recording control is provided to the cylinder selector 10.

In addition, in response to the recording control scheduled signal, the recording controller 30 is 'first segment allocation' or 'append' or 'overwrite' according to the recording signal input from the segment selection unit 20. Controls to be recorded in units of segments on the hard disk 40 according to the corresponding recording classification among the three recording classifications of 'overwrite' recognition.

That is, the recording control unit 30 corresponds to a case of writing data for the first time after file generation in the case of 'first segment allocation' among three recording classifications. If there is a cylinder that meets the criteria, it is controlled to be recorded on the cylinder in the hard disk 40. On the other hand, if there is no cylinder that meets the criteria, Control to find and record in the hard disk 40.

Next, the recording controller 30 is a segment of the constant (m) of each of the video stream (S1-1, S1-2, ..., S1-n) of the three recording classifications, for example, 'ear-writ' The recording is successively recorded in the hard disk 40 by the number of times. In this case, the larger the value of the constant m, the smaller the file fragmentation, and when the different video streams are combined, the segments become consecutive segments.

Next, the recording controller 30 stores the video streams S1-1, S1-2, ..., S1-n in the hard disk 40 in the case of 'overwrite', among three recording classifications. Control to overwrite the original segment position.

As shown in FIG. 2, the hard disk 40 has one segment list of the superblock and one segment list of the inode, one cylinder for each cylinder. Each ellipse shown represents one cylinder, and metadata for each cylinder is independent. Indicates that you are recording or storing. That is, the above-described superblock is recorded or stored in the first block of each cylinder, and the inode is recorded or stored from the next block of the superblock. Of course, each superblock and inode only contains information about that cylinder.

Here, the recording controller 30 loads the superblock information stored in each cylinder of the hard disk 40 into the memory, and adds information of 'stream number' and 'space usage state' to the loaded superblock information for each cylinder. 'Number of streams' refers to the number of files currently being written to the cylinder, and 'Space usage' means 'empty', 'some use', 'no idle space' Is classified into one of three states. These two added data fields do not need to be stored on the hard disk but only need to be present in the superblock information loaded into the memory.

Therefore, the present invention minimizes the seek time of the hard disk head by arranging video files simultaneously recorded in consideration of cylinder information of the hard disk in a close cylinder, and performs an allocation unit by a segment unit larger than a block, that is, on a hard disk. By recording in a plurality of contiguous block units, it is possible to record multiple video streams simultaneously by increasing write performance to make the most of the bandwidth of the hard disk.

Next, a multi-video stream recording process in an embodiment of the present invention having the above-described configuration will be described.

3 is a flowchart sequentially illustrating a method of recording multiple video streams according to an embodiment of the present invention.

First, the recording controller 30 simultaneously inputs each of the video streams S1-1, S1-2, ..., S1-n respectively captured by a plurality of surveillance cameras (not shown) (S301). If so, to provide a recording control signal to the cylinder selector 10 to control the recording on the hard disk 40 (S303).

Then, when the recording control scheduled signal is input from the recording control unit 30, the cylinder selection unit 10, in the hard disk 40, 'cylinder in which the last segment of the file is located', 'cylinder with one or more streams',' The cylinders are selected in a priority order, such as 'cylinders with partial use of space', 'cylinders with empty space use', and the like (S305).

Next, the cylinder selection unit 10 provides the selected cylinder information to the segment selection unit 20 (S307). Here, when a cylinder is selected by the cylinder selection unit 10, when there are a plurality of cylinders satisfying the condition, the cylinder having more idle space is selected by comparing the idle segment list of the selected cylinders.

The segment selector 20 determines whether the segment immediately adjacent to the last segment of the file in the cylinder is empty according to the cylinder information input from the cylinder selector 10 (S309).

As a result of the determination (S309), if an adjacent segment is empty, the recording control unit 30 provides a recording signal (S311).

On the other hand, if the adjacent segment is not empty as a result of the determination (S309), the last segment is selected from the segment list in use in the cylinder (S313), and the constant (m) × (number of streams based on the selected last segment). -1) It is checked whether the position separated by the number leaves the cylinder (S315).

As a result of the check (S315), when leaving the cylinder, it means a state in which the idle space is insufficient, and generates a cylinder reselection signal for reselecting the cylinder and provides the cylinder selection unit 10 (S317).

On the other hand, as a result of the check (S315), if the empty without leaving the cylinder, the recording control unit 30 provides a recording signal (S319).

The recording controller 30 records three types of recording, 'first segment allocation', 'append', or 'overwrite' according to the recording signal input from the segment selector 20. The control is performed so that the hard disk 40 is recorded in units of segments in accordance with the corresponding recording classification during the classification (S321).

That is, the recording control unit 30 corresponds to a case of writing data for the first time after creating a file in the case of 'first segment allocation' among the three recording classifications. If there is a cylinder that meets the criteria and finds a cylinder with 1 or more first, it is controlled to record in the cylinder in the hard disk 40. On the other hand, if there is no cylinder that meets the criteria, The cylinder, which is a part of use, is found in the hard disk 40 and controlled to be recorded.

Next, the recording controller 30 is a segment of the constant (m) of each of the video stream (S1-1, S1-2, ..., S1-n) of the three recording classifications, for example, 'ear-writ' The recording is successively recorded in the hard disk 40 by the number of times. In this case, the larger the value of the constant m, the smaller the file fragmentation, and when the different video streams are combined, the segments become consecutive segments.

Next, the recording controller 30 stores the video streams S1-1, S1-2, ..., S1-n in the hard disk 40 in the case of 'overwrite', among three recording classifications. Control to overwrite the original segment position.

As described above, the present invention provides a method for recording multiple video streams and an apparatus thereof, so that even when simultaneously recording a plurality of video streams, the disk bandwidth utilization is high, so that recording can be performed smoothly.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the scope of the appended claims, and equivalents thereof.

1 is a block diagram of an apparatus for recording multiple video streams according to an embodiment of the present invention;

FIG. 2 is a detailed view of the hard disk shown in FIG. 1;

3 is a flowchart sequentially illustrating a method of recording multiple video streams according to an embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

10: cylinder selection unit 20: segment selection unit

30: recording control unit 40: hard disk

Claims (11)

A multiple video stream recording method using a multiple video stream recording apparatus, Identifying a segment list, an idle segment list, a number of streams, and a space usage state of data storage space for each of the cylinders for a hard disk including a plurality of cylinders; Discerning which of the first segment allocation and subsequent writes corresponds to a write request for a video stream; Selecting one cylinder from among the plurality of cylinders based on the result of the grasp and the result of the classification; Selecting a segment for recording based on the segment list of the selected cylinder and the idle segment list, and controlling the video stream to be recorded in units of segments Multiple video stream recording method comprising a. The method of claim 1, Selecting the cylinder, When the result of the classification is classified as the rewriting, the cylinder in which the last segment of the previously recorded file is located is selected first, the cylinder in which the number of streams is one or more is selected second, and the space usage state is partially Selecting the cylinder as the third using the cylinder, and selecting the cylinder according to the priority of selecting the fourth cylinder with the empty space in use; Selecting the cylinder based on a priority including the first through the fourth when the result of the classification is classified into the first segment allocation. How to record multiple video streams. The method of claim 2, The controlling step, If the result of the classification is classified as the subsequent writing, if the segment adjacent to the last segment of the previously recorded file is filled in the first selected cylinder, the last segment is selected, based on the selected last segment. To control the video stream to be recorded if the position away by a certain distance is within the first selected cylinder and is empty. How to record multiple video streams. The method of claim 3, wherein And the specific distance is a position separated by a constant m × (the number of streams-1) based on the last segment. The method of claim 3, wherein The controlling step, The video stream is controlled to be recorded when the adjacent segments are empty. How to record multiple video streams. The method of claim 3, wherein The multiple video stream recording method, Reselecting the cylinder by a second of the priorities if the position away from the first selected cylinder by a distance relative to the last segment Multiple video stream recording method further comprising. For the hard disk including a plurality of cylinders, the segment list for each of the cylinders, the idle segment list, the number of streams and the space usage status of the data storage space are identified, and the first segment for the write request for the video stream. A recording controller for classifying which category corresponds to allocation and rewriting; A cylinder selection unit that selects one cylinder from among the plurality of cylinders based on the result of the grasp and the classification result; Selecting a segment for recording based on the segment list of the selected cylinder and the idle segment list, and providing a recording signal for the selected segment for recording to the recording controller so that the recording controller Segment selector to control recording to the camera Multiple video stream recording device comprising a. The method of claim 7, wherein The hard disk may store metadata including the segment list and the idle segment list. Multiple video stream recording device. The method of claim 7, wherein The cylinder selector, When the result of the classification is classified as the rewriting, the cylinder in which the last segment of the previously recorded file is located is selected first, the cylinder in which the number of streams is one or more is selected second, and the space usage state is partially Selecting the cylinder as the third using the cylinder, and selecting the cylinder according to the priority of selecting the fourth cylinder with the empty space in use; Selecting the cylinder based on a priority including the first through the fourth when the result of the classification is classified into the first segment allocation. Multiple video stream recording device. The method of claim 9, The segment selector, If the result of the classification is classified as the subsequent writing, if the segment adjacent to the last segment of the previously recorded file is filled in the first selected cylinder, the last segment is selected, based on the selected last segment. Providing a recording signal to the recording control unit when the position separated by a specific distance is within the first selected cylinder and is empty. Multiple video stream recording device. 11. The method of claim 10, And the specific distance is a position separated by a constant m × (the number of streams-1) based on the last segment.

Images