KR20050010594A - Method and System for Retrieving Data - Google Patents

Abstract

PURPOSE: A data reproducing method and a system are provided to repeatedly carry out a startup mode, a read mode, a finish mode, and a standby mode based on the number of frames, and to remove an idle mode, thereby minimizing power necessary for reading data. CONSTITUTION: When a reproduction command is inputted(301), a startup mode is set(302). A data reproduction system reads data as many as the number of predetermined frames, and transmits the read data(303). The system stops reading the data(304), and maintains a standby mode by transferring to an initial state(304). The system decides whether the number of remaining frames is smaller than the number of the predetermined frames(305). If not, the system decides whether the number of accumulated frames corresponds to a certain value(306). The system repeats a process of reading 83 frames(307), and reads the remaining frames only(309).

Description

Method and System for Retrieving Data

The present invention relates to a method and a system for reproducing data from a predetermined recording medium. More particularly, the present invention relates to a start mode, a read mode, a finish mode, and a standby mode repeatedly based on a predetermined number of frames, and to an idle mode. The present invention relates to a data reproducing method and system capable of minimizing the power required to read data to be reproduced continuously and at uniform intervals, such as video or audio.

The recording medium includes magnetic media such as hard disks, floppy disks and magnetic tapes, optical media such as CD-ROMs, DVDs, and magnetic-optical media such as floptical disks. magneto-optical media, and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like, typically in a computer in the form of a desktop and reading data from the recording medium. Power is not limited in the playback.

As portable mobile devices have become popular and services supporting various functions have emerged, it has become an important issue to reduce the power used by mobile devices to solve the power problem, which is an important cause of limiting the functions of mobile devices. In the mobile device, a large amount of power is required for data transmission, and as the size of a disk such as a hard disk or an optical disk is reduced and used in a mobile device, efficient and strict management of power consumed by the mobile device is increasingly needed.

In the past years, previous research has succeeded in reducing power consumption by 10% to 25% through the disk drive scheduling method, but there is a need for a method for more efficiently managing power consumption in mobile devices.

1 is a view for explaining a conventional data reproduction method. In FIG. 1, a disk such as an optical disk, a magnetic disk, or the like will be described as an example among the above-described recording media.

The reading unit 110 reads data from the disc 100 and transfers the read data to the reproduction program 140 through the output unit 130.

There is a significant difference between the playback rate at which playback program 140 reproduces the data in real time (the playback rate should be the same as the output speed) and the maximum readable rate at which reading unit 110 reads the data. And, in general, the read speed is faster than the output speed.

The problem due to the difference between the read speed and the output speed can be solved using the buffer 120. The buffer 120 is a storage means for temporarily storing data read from the reading unit 110, and the output unit 130 regularly and stably transmits the data stored in the buffer 120 according to the reproduction speed. Thus, the data is reproduced regularly and stably in the playback program 140.

However, when the data stored in the buffer 120 is insufficient compared to the output speed, the reproduction in the reproduction program 140 is stopped while the data is filled in the buffer 120, and thus, continuous reproduction of the data is impossible. And jitter may occur. On the contrary, when the capacity of the buffer 120 is insufficient and the data read from the reading unit 110 cannot be stored in the buffer 120, the reading unit 110 stops reading.

Accordingly, the read unit 110 fills the buffer 120 at a read speed faster than the output speed, while the read operation in the read unit 110 is synchronized with the reproducing job so as to fill the buffer only so as not to exceed the storage capacity. Should be.

Conventionally, the state in which the reading unit 110 reads data is classified into a start mode, a read mode, an idle mode, a finish mode, and a standby mode. It is possible. The reading unit 110 is initially in the standby state, and switches to the start mode when receiving a data input / output request. In the case of a hard disk, spin-up, focus, and tracking are performed in the startup mode. The reading unit 110 reads the data stored in the storage device 100 in the reading mode, transmits the data to the buffer 120, and when a predetermined amount of data is accumulated in the buffer 120, the reading unit 110 reads the data. The reading mode is switched to the idle mode.

In the idle mode the head of the disc moves to its initial position and no data is read, but the disc's platter continues to rotate at the same speed as the read speed. In the state of the art, when data accumulated in the buffer 120 gradually decreases according to the output speed in this state, the data is reproduced by repeating the process of reading data from the storage device 100 and accumulating the data in the buffer 120.

In the idle mode in which data is not read as described above, the storage device 100 maintains the same device state as in the read mode (for example, in the case of a disk-based storage device, at the same speed as in the read mode). Since the spindle rotates and the drive circuit is operated, it becomes a factor of consuming unnecessary power.

FIG. 2 is a diagram showing power consumption in each of the above-described modes (FIG. 2B) and the size of data read out in the activation mode (FIG. 2A) using a hard disk as a storage device. In FIG. 2A, the horizontal axis represents time (sec), and the vertical axis represents power consumption (W), and the vertical axis of FIG. 2B represents the amount of data (KByte) read from the disk. The problem of the conventional data reproduction method is demonstrated with reference to FIG.

When the power is applied, the reading unit is in the standby mode 230. When the play command is input from the input unit (not shown), the reading unit enters the start mode 200, and the operation such as spin up, focus, and tracking is performed in the start mode 200. Is performed.

In the read mode 203, the read unit transfers the data read from the disc to the buffer 120, and switches to the idle mode 206 when the buffer is full (read mode 203 and idle mode 206 are activated modes ( 210)). As shown in Fig. 2A, data is not read in the idle mode 206, and the spindle motor continues to be driven.

In order to reduce the power consumption, the existing technology uses the technique of switching from the idle mode 206 to the standby mode 230 through the finishing mode 220 when no further playback command is input for a predetermined timeout. Also used. In the case of a hard disk, in the finishing mode 220 the platter of the disk spins down, the disk head goes to the parking position, and the rotation of the spindle motor is stopped.

That is, as shown in FIG. 2, when reading data, most power is consumed in the read mode 203 and the idle mode 206, that is, the activation mode 210. Although the power consumption is higher than the activation mode 210, such as a peak of power consumption in the start-up mode 200 and the finish mode 230, the time for which the start-up mode 200 and the finish mode 230 are maintained is the activation mode. Since it is relatively very short compared to 210, most of the power is consumed in the activation mode 210.

However, in the idle mode 206, which occupies a large portion of the activation mode 210, there is a problem that the same power is consumed as in the read mode 203 even when data is not read. In addition, as described above, the method of setting the timeout is also most likely to enter the read mode 203 again before the timeout, and thus fails in its effectiveness.

SUMMARY OF THE INVENTION The present invention has been made to improve the prior art as described above, and transmits data to a reproducing program at a stable and regular speed, and at the same time eliminates the idle mode, thereby greatly reducing the power consumed when reading data. It is an object to provide a method and system.

1 is a view for explaining a conventional data reproduction method.

Fig. 2A is a diagram showing the size of data read in the activation mode in the data reproducing method according to the prior art.

2B is a diagram showing power consumption in each mode in the data reproducing method according to the prior art.

3 is a flowchart illustrating a data reproducing method according to an embodiment of the present invention.

4 is a block diagram showing a data reproducing system according to another embodiment of the present invention;

FIG. 5 is a diagram for explaining characteristics of frames constituting data in a data reproduction method according to an embodiment of the present invention; FIG.

Fig. 6A is a diagram showing a power consumption form when reading data according to the prior art.

6B is a diagram illustrating a power consumption form when data is read according to a data reproducing method according to an embodiment of the present invention.

FIG. 7 illustrates a change in the number of frames accumulated in a buffer while performing an embodiment of the present invention. FIG.

8 is a diagram showing a change in the amount of data accumulated in the buffer at the same time.

9 is a graph comparing power consumed by a data reproducing method according to an embodiment of the present invention and a data reproducing method according to the prior art, respectively.

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

400: data playback system

401: input unit 402: reading unit

403: buffer 404: output unit

410: playback program

420: recording medium

In order to achieve the above object and to solve the problems of the prior art, the present invention provides a first step of receiving a command for reproducing data, a second step of transitioning from an initial state to a read mode in a start-up mode; A third step of reading the data from a predetermined recording medium in a read mode and transferring the data to a predetermined buffer; a fourth step of stopping the reading and performing spin down in a finishing mode when a predetermined number of frames is read; And a fifth step of maintaining the initial state in the standby mode, repeatedly performing the second to fifth steps by a predetermined number of repetitions (the second step to the fifth step in one round ( the predetermined number of frames means the number of frames to be read during the one round, and the number of repetitions is determined by the total number of frames constituting the data and the predetermined number of frames. A data reproduction method is provided.

According to one aspect of the invention, the size B _i (m) of the set of frames continuously combined by the predetermined number of frames m,

Determined by

The read time T _i (m) required for reading the set of frames is

Determined by

If the maximum value of B _i (m) is B (m), the maximum value T (m) of T _i (m) is

Determined by

The predetermined frame number m is

Is determined to satisfy.

Where m is a predetermined number of frames, S _i is the size of the i-th frame, m is an integer, N is the total number of frames, R is the maximum reading speed at which the data can be read from the recording medium, and r is the transmission rate that the data is sent to the specified playback program from the buffer, T _s is a start-up time taken from the start-up mode, T _f is the finish time from the finish mode, f is the reproduction in the reproducing program This means the number of frames per second played according to the speed.

In addition, according to another aspect of the present invention, the size of the memory to be allocated to the predetermined buffer is more than the B (m).

The present invention also provides a computer readable recording medium having recorded thereon a program for executing the above method.

The present invention also provides an input unit for receiving a reproduction command, a reading unit for reading data from a predetermined recording medium when the reproduction command is input, a buffer for storing the read data, and data stored in the buffer unit. And an output unit for transmitting to a reproducing program according to a reproducing speed of the reproducing program, wherein the reading unit repeatedly performs a start mode, a read mode, a finish mode, and a standby mode.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention;

The data reproducing method and system according to the present invention can be applied to any recording medium, but for convenience of description, the case where the recording medium is a disc such as a magnetic disc or an optical disc will be described.

3 is a flowchart showing a data reproduction method according to the present embodiment. The data reproducing method according to the present embodiment may be performed by the data reproducing system 400 as shown in FIG.

One of the important requirements in reproducing data is to guarantee the number of frames to be reproduced for a predetermined time. A frame refers to a logical unit constituting arbitrary data continuously read and reproduced, such as only one image, for example, from a series of images stored or reproduced in video data.

For example, in the case of an MPEG file among video data, the MPEG file is composed of several frames having different sizes. These frames are decoded into a predetermined number of frames every second and displayed by the playback program 410 on a predetermined screen for playback.

An MPEG file consists of I, P, and B frames. The compressed data is read from the storage device, stored in the buffer 403, output from the buffer 403, and transmitted to the reproduction program 410. If the buffer 403 is not filled for the expected time, the decoding of the corresponding frame is delayed, so that the playback in the playback program 410 is also stopped. On the contrary, when data is full in the buffer 403, reading of the data is stopped.

Therefore, there is a need for a method capable of reproducing data at low power without stopping playback, and the inventors of the present invention prevent the suspension of playback by ensuring the minimum number of frames required for playback during a round as described below. After reading the minimum number of frames, power consumption is greatly reduced by maintaining a standby state instead of an idle state. (The time required to perform the one round may or may not be constant. This is only a difference depending on the implementation method, and in any case, the scope of the present invention). Thus, the term 'predetermined frame number' as used herein has a value greater than or equal to the minimum frame number to be read during the one round.

However, as shown in FIG. 5, the I, P, and B frames have different frame sizes, the I frame has a relatively large frame size, and the B frame has a relatively small frame size, and a P frame. Has a medium size. As such, it is not easy to determine a suitable number of predetermined frames based on the frames having a large amount of change in size. However, it can be seen that the values 520 composed of the average frame size obtained by dividing the frames combined by the constant frame number by the constant frame number are relatively flat compared to the original values 510 composed of the size of each frame.

Accordingly, in the present invention, the minimum number of frames required for reproduction for a predetermined period (corresponding to the time when the one round is performed) is determined by using the sum of the frames instead of each frame, and based on the read and reproduced during the one round, A predetermined number of frames is to be determined.

FIG. 6A illustrates a power consumption form when data is read according to the prior art, and FIG. 6B illustrates power when data is read according to the data reproducing method according to the present embodiment. It is a figure which shows the consumption form. As can be seen from Fig. 6, the difference between the data reproduction method in the prior art and the data reproduction method in the present invention is clear.

6 (a) and 6 (b) mean time (sec), and the vertical axis of FIG. 6 (a) indicates current value (mA) when reproducing data according to the prior art, and FIG. The vertical axis of b) is a current value (mA) in the case of reproducing data according to the present embodiment. Since the power consumption is proportional to the square of the current, the power consumption is simplified from the graphs of FIGS. 6A and 6B. Can be estimated.

The data reproducing system 400 maintains the start-up mode 610 which is in an initial state until a data reproducing command is input. If a play command is input in step 301, then in step 302 it is switched to start-up mode 620. The startup mode is a process of transitioning from the initial state to the read mode. For example, when the storage medium is a disk, the startup mode spins up the disk in the stopped state and performs operations such as focus and tracking. ) And (b) have high power consumption.

In step 303, the data reproducing system 400 reads data from a predetermined recording medium, i.e., a disc, by a predetermined number of frames and transmits the data to a predetermined buffer (read mode 630). When the predetermined number of frames of data is read, the data reproducing system 400 stops reading in step 304 and transitions to the initial state (performs SpinDown in case of a disc) (finishing mode 640 To maintain the standby mode 650.

The standby mode 650 refers to a state of the data reproducing system 400 in an initial state where power is input. That is, the data reproducing system 400 according to the present embodiment can reduce the power consumption because there is no idle mode that consumes the same power as in the read mode without reading the data.

The data reproducing system 400 determines whether the number of frames remaining to be read in step 305 is smaller than the predetermined number of frames, and if the determination result is greater than or equal to the predetermined number of frames, the buffer in step 306. It is determined whether the number of frames stacked in the buffer corresponds to a predetermined value. If the number of frames remaining in the buffer is equal to the predetermined value, the process returns to step 302. That is, as many frames as the predetermined number of frames are accumulated in the buffer, but as the frames are output to the playback program 410 through the output unit 404, the number of frames accumulated in the buffer is reduced, but steps 306 and 306 As a result, a predetermined number of frames are accumulated in the buffer.

The data reproducing system 400 repeats steps 302 to 306 sequentially until all data corresponding to the reproducing command is read unless a separate stop command is inputted. round).

The data reproducing system 400 returns to step 302 when the number of frames in the standby mode in step 306 drops below a certain value set by the operator.

In addition, if the remaining frame number is less than m as a result of the determination in step 305, the remaining frames are read. In this case, the start mode 620, the read mode 630, and the finish mode 640 are performed, but the number of frames read in the read mode 630 is smaller than the predetermined number of frames.

In order to perform the above-described data reproduction method, the predetermined number of frames must be determined, and a process of determining the predetermined number of frames will be described below.

If the predetermined number of frames is not properly determined, the reproduction of data may be stopped because the amount of data to be read is insufficient. If a predetermined number of frames is set high, data reproduction can be successful, but a large amount of main memory buffer is consumed, which may waste unnecessary system resources. Therefore, the data reproduction method according to the present embodiment solves this problem by determining the predetermined number of frames based on the minimum number of frames necessary for reproduction during a predetermined period of performing the round.

When the maximum size of a set of frames continuously combined by the predetermined number of frames is called B (m), B (m) is determined by Equation (1).

Here, m is a predetermined number of frames to be read each round, S _j is the size of the j-th frame among the data consisting of the frame, m is an integer, N is the total number of frames constituting the data.

Thus, B _i (m) is The total size of frames in reading the first frame.

For example, when the predetermined number of frames m is 83, the value obtained by sequentially adding the sizes from the first frame to the 83rd frame is called B ₁ (83), and the size from the second frame to the 84th frame. If the values obtained by adding are sequentially called B ₂ (83), and the values from the i th frame to the (83 + m-1) th frame are sequentially added as B _i (83), to be.

When B (m) is determined by Equation 1, the read time T _i (m) required to read data in the read mode is determined as in Equation 2.

Here, R is the maximum read rate at which data can be read from the disc, and r is the transfer rate at which the data is transferred from the buffer to a predetermined playback program.

Therefore, Rr means the speed at which data is accumulated in the buffer. The read time T _i (m) of Equation 2 means a time required to read a set of 83 combined frames and transmit them to the buffer.

In the prior art, when there is an empty space in the buffer, data can be read at the maximum speed R. However, once the buffer is filled, the speed of reading data from the storage device is synchronized with the working speed at which data is reproduced from the buffer, r. As in the prior art, if the reading speed is synchronized with the working speed, the power usage efficiency is reduced.

In order to solve such a problem of the prior art, in the present embodiment, when the available space of the buffer is insufficient to read at the maximum speed R, the standby mode is switched to minimize the power consumption.

Startup mode 620 and finish mode 640 are transition periods that change the state of the storage medium. If the number of frames read in one round is set smaller, the number of frames read than the required amount of frames required for playback (required for playback) including the transition period (start mode 620 and finish mode 640) is required. As it becomes small, jitter occurs.

The data reproducing method according to the present embodiment uses a buffer having a capacity of B (m) or more, which is the maximum value of B _i (m), as shown in Equation 3 to be described below, and continuously at a speed of R without causing jitter or the like. Ensure that data can be read from the disc.

Therefore, in the data reproducing method according to the present embodiment, since the read speed in the read mode is much faster than in the prior art, the read time consumed in the read mode is reduced, thereby reducing the power consumption in the read mode, and also by eliminating the idle mode. The power consumption can be further reduced.

Hereinafter, a guideline for determining the predetermined number of frames m is provided. The m is the number of frames to be reproduced for a predetermined time, and B is the maximum value of B _i (m) obtained for any m. (m) is the same as that of Equation 1 described above.

The read time T _i (m) has the longest time when the size of the frame set is B (m), and T (m) is expressed by Equation 3 below.

In addition, the predetermined period T required to perform one round is expressed by Equation (4).

In this case, T _s is a start time required in the start mode, T _r is a read time required in the read mode, T _f is a finish time required in the finish mode, and T _o is a wait time taken in the standby mode. T _s and T _f are values determined according to one data reproducing system 400, and theoretically have the same value every time. As described above, T _r is a time required to read the frame by the predetermined number of frames. to be.

Further, the predetermined number of frames should be read for a time of T _s + T _r + T _f (substantially for a time of T _r ) and should be read for a time of T _s + T _r + T _f . The number of frames is determined by the number of frames per second x (T _s + T _r + T _f ), and the maximum value of T _r is T (m), so the number of frames m to be read at once is set to satisfy Equation 5. do.

Here, f means frames per second. In general, the reproduced data is reproduced at a rate of 24 frames per second, but this varies depending on the data. Thus, Equation 5 can be used to determine m to be reproduced for one round (T time). As such, the predetermined number of frames m must satisfy at least a value of f (T _s + T (m) + T _f ).

FIG. 7 is a diagram showing a change in the number of frames accumulated in the buffer while repeating steps 302 to 306 for the understanding of the present embodiment. If the predetermined number of frames m is read and accumulated in the buffer in step 303 as described above, the reading is stopped by performing step 304 at time t1 and the data is reproduced using the already stacked frames. During this time, the number of frames accumulated in the buffer is reduced.

As described above, when the number of frames accumulated in the buffer is consumed until the predetermined value m 'as described above (step 306), the process of reading the predetermined number of frames m again at time t2 is performed. Will repeat.

8 is a diagram illustrating a change in the amount of data accumulated in the buffer at the same time (ie, the sum of the sizes of the frames stacked in the buffer). As described above with reference to FIG. 5, each frame has a different size, and thus, even when the same number of frames m are stacked in the buffer, the frames are stacked in the buffer at each time t1, time t3, and time t5. The size of the data is different from each other.

For reference, FIGS. 7 and 8 reflect the number of frames transmitted and reduced from the buffer 403 to the playback program 410 through the output unit 404.

Hereinafter, by comparing the power consumed when reproducing data according to the data reproducing method according to the present embodiment with the power consumed when reproducing data according to the prior art, the data reproducing method according to the present embodiment is low power It will be shown that it is possible to reproduce the data.

According to the data reproducing method according to the present embodiment, the total power consumed for reproducing predetermined data is determined by equation (7).

Here, N denotes the number of repetitions of repeating the round, and the number of repetitions may be obtained by dividing the total number of frames constituting the data by the predetermined number of frames. For example, when the total number of frames is 1534, from mx18 + 40 = 1534, m = 83, the data reproducing system 400 repeats reading the number of 83 frames in each round 18 times in step 307. In the 19th round (this round, which reads fewer frames than the predetermined frame number, is referred to as a 'remaining round'), only 40 frames are read. That is, N = 18.

Further, according to another embodiment of the present invention, since the remaining number of frames read in the last round is 40 frames less than the predetermined number of frames, the free capacity of the buffer is measured so that the 40 free frames are measured. If the size is larger than the corresponding data size, the 40 frames can be read by merging in the 18th round, so as not to consume power required in the start mode and the finish mode in the remaining 19th round.

In Equation 6, P _s is the power consumed in the start-up, P _f is the power consumed in the finishing mode, Is the power consumption rate per hour in the read mode, S _j is the size of the j-th frame.

As shown in FIG. 6, the power consumed during one round is the sum of the power P _s consumed in the start-up mode, the power P _f consumed in the finish mode, and the power P _r consumed in the read mode (shown in FIG. 6). As the standby mode consumes little power, the power consumption in the standby mode is assumed to be 0), and P _r is the power consumption rate per hour. And time spent in reading mode Can be calculated as the product of Corresponds to T _i (m) in each round as described above.

When each round is repeated N times (N = 18 in the above example), the power consumption is obtained as the sum of the power consumption in each round as in the first half of the right side of Equation 6.

The second half of the right side of Equation 6 represents power consumed in the remaining rounds. P _s and P _f are the same in the remaining rounds, but since fewer frames are read than the predetermined number of frames, P _r is obtained differently from the power consumption calculation method in the first to eighteenth rounds. That is, the time spent in the read mode of the remaining rounds is the sum of the sizes of the frames read in the remaining rounds, D _r (which is the sum of the total number of frames minus mx N) divided by the maximum read rate R. .

FIG. 9 shows power consumption according to the data reproducing method according to the present embodiment and the data reproducing method according to the prior art for three pieces of data (data identifiers of each data are 'jun', 'benz' and 'dunkman', respectively). Is a graph comparing each.

Since the size of each frame and the corresponding frame is enormous, the detailed data values are not described herein. However, in the data reproducing system 400 used to obtain the graph of FIG. 9, R = 5324.8 [kBps], r = 166.487 [kBps], T _s = 1 [sec], T _f = 0.7 [sec], and T (m ) = 0.039 [sec], P _s = 0.858 [W], P _f = 0.7 [W], = 0.924 [W / sec], m = 83, = 0.05 [W / sec].

As shown in Fig. 9, the power consumption in the case of using the data reproducing method according to the present embodiment was only 57%, 56% and 52% of the power consumption in the case of reading data by the prior art.

As described above, the data reproducing method according to the present embodiment reads the predetermined number of frames during a predetermined period and excludes the time spent in the start mode, the read mode, and the finish mode during the period (corresponding to the standby mode). In time), the power consumption is significantly reduced compared to the prior art by returning to the initial state and preventing idling of the disk.

The present invention also provides a computer readable recording medium having recorded thereon a program for executing the above-described data reproduction method.

Hereinafter, a data reproducing system 400 according to an embodiment of the present invention will be described. As shown in FIG. 4, the data reproducing system 400 includes an input unit 401, a reader 402, a buffer 403, and an output unit 404.

The input unit 401 receives a reproducing command (or a read command according to the reproducing command) from a predetermined reproducing program, and the reading unit 402 receives a predetermined recording medium (e.g., an optical disc, a magnetic field) when the reproducing command is input. Data is read from a disc, such as a disc.

The read unit 402 performs a transition operation from the initial state to the read mode (for example, spin up, focus, and track in the case of a disc) in the startup mode 620, and the disc in the read mode 630. Reads the data from the frame, and when a frame of a predetermined number of frames is read, the transition mode from the finishing mode 640 to the initial state (for example, spin down in the case of a disk, etc.) is performed, and the standby mode ( In 610, the initial state is maintained.

The predetermined number of frames refers to the number of frames to be read in the read mode 620, and the reading unit 402 reads data based on the number of frames constituting the data, not the size of the data. Therefore, the time taken in each read mode 620 for reading the predetermined number of frames may be different from each other.

The data read by the reading unit 402 is temporarily stored in the buffer 403 before being transferred from the output unit 404 to the reproduction program 410. As described in the above-described data reproducing method, by using the buffer 403 having a capacity of B (m) or more, the data can be accumulated in the buffer 403 at a rate of R-r.

The output unit 404 outputs data from the buffer 403 to the playback program 410 at a predetermined output speed (same as the playback speed) r, and the playback program 410 receives the data at the playback speed r. By reproducing the data, the data is provided to the users of the reproducing program 410 both visually and audibly.

As described above, the present invention has been described based on a logical unit constituting data called a frame. The term 'frame' is a concept including each frame in video data, each voice sample in voice data, and the like. A logical unit constituting arbitrary data to be reproduced.

That is, the present invention reads and reproduces the data based on a logical unit constituting the data rather than the size of the data when reading and reproducing the data so that the data can be regularly reproduced while ensuring continuity. .

According to the present invention, there is provided a data reproducing method and system capable of reducing the power consumed in reading data by eliminating the idle mode that consumes the same power as in the read mode without reading the data.

Further, according to the present invention, since the minimum frame number is set on the basis of the number of frames required for reproduction for a predetermined period and the data is read out based on the minimum frame number, the data is reproduced stably and regularly in the reproduction program. Provided are methods and systems for reproducing data.

In addition, according to the present invention, by using a buffer having a capacity larger than the maximum of the sum of the frame size of the minimum number of frames, the data reproduction method that can read data at a high speed while preventing the overflow of the buffer in the read mode and A system is provided. Therefore, the time required in the read mode is shortened, and the power consumed at the time of reading is reduced.

As described above, the present invention has been described by way of limited embodiments and drawings, but the present invention is not limited to the above-described embodiments, which can be variously modified and modified by those skilled in the art to which the present invention pertains. Modifications are possible. Accordingly, the spirit of the present invention should be understood only by the claims set forth below, and all equivalent or equivalent modifications thereof will belong to the scope of the present invention.

Claims (7)

In the data reproduction method, A first step of receiving a reproduction command of data; A second step of transitioning from an initial state to a read mode in the startup mode; A third step of reading the data from the recording medium in the read mode and transferring the data to a predetermined buffer; A fourth step of stopping the reading in the finishing mode and transitioning to the initial state when the data is read by a predetermined number of frames m; And A fifth step of maintaining the initial state in a standby mode Including, Repeatedly performing the second to fifth steps by a predetermined number of repetitions, and defining the second to fifth steps as one round. The predetermined frame number m means the number of frames to be read while the one round is performed, The repetition number is determined by the total number of frames constituting the data and the predetermined number of frames m. The method of claim 1, The size B _i (m) of the set of frames continuously combined by the predetermined number of frames m is Determined by The read time T _i (m) required for reading the set of frames is Determined by If the maximum value of B _i (m) is B (m), the maximum value T (m) of T _i (m) is Determined by The predetermined frame number m is It is determined to satisfy the data reproduction method. Where m is a predetermined number of frames, S _i is the size of the i-th frame, m is an integer, N is the total number of frames, R is the maximum reading rate at which the data can be read from the recording medium, wherein r is the transmission rate that the data is sent to the specified playback program from the buffer, T _s is a start-up time taken from the start-up mode, T _f is the finish time from the finish mode, f is in the reproducing program The number of frames played per second depending on the playback speed. The method of claim 2, And a size of a memory to be allocated to the predetermined buffer is greater than or equal to B (m). A computer-readable recording medium having recorded thereon a program for executing the method of any one of claims 1 to 3. In a data reproduction system, An input unit for receiving a play command; A reading unit for reading data from a predetermined recording medium when the reproduction command is input; A buffer for storing the read data; And An output unit for transmitting data stored in the buffer unit to a reproduction program at a predetermined reproduction speed Including, The reading unit, A data reproducing method characterized by repeatedly performing a start mode, a read mode, a finish mode and a standby mode. The method of claim 5, The reading unit transitions from an initial state to a reading mode in the start-up mode, In the read mode, the data is read from the recording medium, When the data is read out by a predetermined number of frames, the finishing mode stops the reading and transitions to the initial state, Maintain the initial state in the standby mode, The predetermined number of frames means the number of frames to be read during each read mode, And the repetition number is determined by the total number of frames constituting the data and the predetermined number of frames. The method of claim 4, wherein The size B _i (m) of the set of frames continuously combined by the predetermined number of frames m is Determined by The read time T _i (m) required for reading the set of frames is Determined by If the maximum value of B _i (m) is B (m), the maximum value T (m) of T _i (m) is Determined by The predetermined frame number m is The data reproduction system, characterized in that it is determined to satisfy. Where m is a predetermined number of frames, S _j is the size of the jth frame, m is an integer, N is the total number of frames, R is the maximum reading speed at which the data can be read from the recording medium, wherein r is the transmission rate that the data is sent to the specified playback program from the buffer, T _s is a start-up time taken from the start-up mode, T _f is the finish time from the finish mode, f is in the reproducing program The number of frames played per second depending on the playback speed.