KR20010073710A - method for writing/reading of digital video - Google Patents

Abstract

PURPOSE: A simultaneous recording/playing method of moving video data is provided to realize time shifting by mounting two disk of low performance to increase the capacitance of a hard disk. CONSTITUTION: If the current status of a first disk isn't at a simultaneous recording/playing step, the next record or play point is detected. If the current status of the first disk is at the simultaneous recording/playing step, the previous recorded point and a current play point are searched. Then, the searched two points are converted into physical points. Next, it is calculated whether performance is dropped when the record and play are performed using the converted physical points. Then, if the performance wasn't dropped, the next record point of the first disk is detected. If the performance was dropped, a second disk is selected and a record start point is detected.

Description

Method for simultaneously recording / playing video data {method for writing / reading of digital video}

The present invention relates to recording and playback of broadcast programs, and more particularly, to a method of simultaneously recording and playing back video data using a plurality of hard disks.

Currently, a technology for storing analog data or digital data transmitted through a TV broadcast network directly on a hard disk drive is being developed.

At present, there are companies such as Tivo and Replay TV, which have been introduced by Tivo, Replay TV, etc., and 'Personal Video Recorder (PVR)'. ) Applied the hard disk to TVs and STBs so that up to 30 hours can be recorded simultaneously in different broadcasting stations, depending on the recording quality, allowing viewers to have fun.

These companies provide a technique for receiving broadcast analog data, digitizing it to MPEG-2 and storing it on disk.

In addition, MbTV (Megabit TeleVision) is a company that provides a method of directly receiving digital broadcasting data and storing it on a hard disk.

All of these products are equipped with hard disk drives to support time-shifting, but due to the nature of consumer electronics, low cost and high capacity hard disks are required.

These hard disks, by their very nature, do not place much emphasis on disk performance.

For example, in the case of TiVo, RPM (Rotation Per Minute) has a low performance of 4000rpm.

And according to the test results, it is necessary to have a disk of 7200rpm or more in order to enable simultaneous recording and playback of 19.4Mbps, which is the current ATSC standard.

However, the simultaneous recording / reproducing method of moving picture data according to the related art described above has a problem in that performance is degraded in the system due to the low performance of the hard disk during simultaneous recording and reproducing of a disc for time shifting applications.

Accordingly, the present invention has been made to solve the above problems, and by embedding two existing low-performance disks, a file system that supports simultaneous search and playback between disks to increase the hard disk capacity and is suitable for time shifting is provided. The purpose is to provide.

1 illustrates a structure in which two different disk spaces are mapped to one logical disk space according to the present invention.

2 is a view showing a structure in which recording / playback is concentrated on one disc according to the present invention;

3 is a view showing a structure in which recording / playback is distributed to two discs according to the present invention;

4 is a flowchart of a method of simultaneously recording / playing video data according to the present invention.

* Explanation of symbols for main parts of the drawings

10: first disk 20: second disk

A feature of the simultaneous recording / playback method of moving picture data according to the present invention for achieving the above object is to detect the next recording or playback point when the current state of the first disc is not simultaneously recording and playing. Moving to a predetermined position, searching for a previously recorded point and a current playback point when the current state of the first disc is simultaneous recording and playback, and physically storing the detected previous recording point and current playback point interval. Converting to the in position, calculating whether the performance decreases when simultaneously recording and playing back using the converted physical position; and if the performance does not decrease as a result of the calculation, next to the first disc to be recorded. Detecting the recording point and moving to the detected position; And selecting a second disk not to be reused, detecting a recording start point through the selected second disk, and moving to a second disk position and a recording point to be recorded next.

Another feature of the present invention is that the first disc / second disc processes recording and playback on the first disc / second disc until the performance decreases even if the performance does not decrease even if the recording and playback points proceed simultaneously.

The operation according to the characteristics of the present invention can prevent the performance degradation that occurs during the simultaneous recording and playback of the disc for time shifting applications using a plurality of low-cost, low-performance discs.

Other objects, features and advantages of the present invention will become apparent from the following detailed description of embodiments taken in conjunction with the accompanying drawings.

A preferred embodiment of the simultaneous recording / reproducing method of moving picture data according to the present invention will be described with reference to the accompanying drawings.

1 illustrates a structure in which two different disk spaces are mapped to one logical disk space according to the present invention.

Referring to FIG. 1, the first disk 10 and the second disk 20 provide a technique of distributing and recording and simultaneously playing a file on physically different disks under the control of one file system.

In this case, the reason for dividing and storing one file into two different disks 10 and 20 is to disperse the load of the read and write operations of the disk required for applying time shifting. .

At this time, the performance value of each disk is dynamically monitored and based on the result, this is a technique to change the recording position to another location considering the data placement.

Referring to the accompanying drawings, the operation of the simultaneous video data recording / reproducing method according to the present invention configured as described above will be described in detail as follows.

First, consider a case where recording and playback are alternately performed between two different disks 10 and 20 in a simple manner.

If a time-shifted playback request is received while recording on the first disk 10, the recording on the first disk 10 is stopped and the second disk 20 is moved and recorded. Process the replay request.

Similarly, when the reproduction request from the first disc 10 is completed, the second disc 2 is moved to play.

At the same time, the recording on the second disk 20 is stopped and the recording is resumed by moving to the first disk 10.

In this way, when the playback is performed on the first disk 10, the recording is carried out exclusively by the second disk 20, and when the playback is performed on the second disk 20, the first disk 10 is dedicated to recording. It supports simultaneous search and playback.

However, this method is very simple to implement, but the disadvantage is that disk switching occurs frequently when a user requests time shifting.

Therefore, by mapping two different disk spaces into one single disk space, in terms of file system management, the two disk spaces can be distinguished only by the address number.

Therefore, it is easy to add the disk switch function to the allocation algorithm used in the existing file system and use the block addressing configuration as it is.

Let's take a closer look.

First, a plurality of disks may be assumed, but for the sake of simplicity, two different disks, the first disk 10 and the second disk 20 will be described.

First, the data selected by the user's recording request is sequentially recorded on the first disk 10.

At this time, if the user's request for playback is input due to the nature of the time shifting application, playback starts from an arbitrary point of the disk among data currently being recorded or data already recorded.

In this case, as shown in FIG. 2, recording and playback on one disc occur simultaneously.

At this time, if the position of the disc under recording and the position of the disc to be played are physically separated, the disc of low performance does not satisfy the performance of recording and reproducing.

Accordingly, by analyzing the physical position difference between the current recording point and the playback point, it is calculated whether the time shifting performance will not be satisfied and based on the calculated value, the second disc 20 which does not currently use the recording position is calculated. Move to.

3 is a diagram illustrating a case where a position to record on the second disk 20 is moved.

Therefore, playback is performed on the first disk 10 and recording on the second disk 20.

At this time, playback is continued on the first disc 10 and the second disc 20 is recorded from the current recording point 30a according to the first disc 10 to the recording point 30b according to the second disc 20. When is reached, the current playback position is moved to the second disc 20.

At this moment, if there is a conflict between the recording on the second disc 20 and the disc request to change the position of the playback disc from the first disc 10 to the second disc 20, i.e., a performance degradation occurs, the second The physical position difference between the recording point in progress on the disc 20 and the playback point to be resumed on the second disc 20 is analyzed to determine whether to move the ongoing recording point on the second disc 20 to the first disc 10. do.

At this time, even if the recording and playback points are simultaneously performed on one disc (the first disc 10 or the second disc 20), if the performance is not degraded, the recording and playback are processed on the same disc until the moment when the performance is reduced.

In this case, in order to separate a program to be recorded and played back, program index information must be provided, which is called a file system.

And a file system must be able to manage one disk or two or more disks at the same time.

Here, in order to manage two disks at the same time and ensure the performance of the time-shifting application, the disk to store the data is determined according to the algorithm policy as shown in FIG.

4 is a flow chart for determining where to store data currently input to a routine that is called whenever a data writing request is received according to the present invention.

4, first, it is searched whether the current state of the first disk 10 is being recorded and played back at the same time (S10).

When the simultaneous recording and reproducing of the search result (S10) is not performed, the next recording or reproducing point is detected (S60), and the detected position is moved (S90).

In the case where the search result (S10) indicates that the current state is simultaneous recording and playback, the previously recorded point and the current playback point are searched for (S20).

Subsequently, the space between the searched previous recording point and the current playback point is converted into a physical location (S30).

Subsequently, when the recording request and the playback request are simultaneously processed by substituting the converted physical location, it is calculated whether the performance is deteriorated (S40).

The performance here refers to the usage of the disk capacity, the data processing time, the system load, and the like.

As a result of the calculation (S50), if the performance is not deteriorated, the next recording point of the first disc currently recorded is searched (S60).

After the search result is detected, the apparatus moves to the position to be recorded (S90).

When the next recording point search result (S50) decreases in performance, a second disc that is not currently used is selected (S70).

Then, the recording start point is detected through the selected second disk (S80).

Subsequently, as a result of the detection of the recording start point, it moves to the second disc position to be recorded and the recording point (S90).

To distinguish two different disks from above, two variables, the current disk number and the sector number in the disk, designate the location to store the data.

When a viewer requests a time-shifting application, recording and playback are performed on one disc until the requesting application can be accommodated, as shown in FIG.

In addition, when recording and playback cannot be handled by one disc performance, the recording disc and the playing disc are separated, and are shown in FIG.

At this time, it was found out that the high quality hard disk can be used to record high quality video data (recording rate of 19.4Mbps) and play back simultaneously.

However, since this is expected to be a high cost for TVs targeting the consumer market, the present invention provides two disks which are inexpensive and have some disk performance (5,400 rpm or less). Using more or more ensures time-shifting of the disk completely.

Simultaneous recording / playback method of moving picture data according to the present invention as described above has the following advantages.

First, it is possible to record and play back high-quality video data using a low-cost, low-performance hard disk by using a dynamic disk position changing method.

Second, by using a large number of inexpensive, but with some disk performance, the time-shifting performance of the disk can be guaranteed.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the embodiments, but should be defined by the claims.

Claims (3)

If the current state of the first disc is not simultaneously recording and playing, detecting a next recording or playing point and moving to the detected position; Searching for a previously recorded point and a current playback point when the current state of the first disc is simultaneous recording and playback; Converting the retrieved previous recording point and the current playback point interval into a physical location; Calculating whether performance decreases when simultaneously recording and playing back the data using the converted physical location; If the performance does not decrease as a result of the calculation, detecting a next recording point of the first disc to be recorded and moving to the detected position; Selecting a second disc that is not currently used when the performance decreases as a result of the calculation, detecting a recording start point through the selected second disc, and moving to a second disc position and a recording point to be recorded next; Simultaneous recording / playback method of moving picture data. The method of claim 1, A method of simultaneously recording / playing moving picture data, characterized in that the division of a location for storing data on the first and second discs is designated by a current disc number and a sector number within the disc. The method of claim 1, If the performance of the first disc / second disc does not decrease even when the recording and playback points are simultaneously performed, the video data can be recorded and played back on the first disc / second disc until the performance decreases. How to record / play back.