KR20060046644A - Method for playing the real-time multimedia file using multiple file caching in mobile multimedia player - Google Patents

Abstract

The present invention checks the multimedia file play list when the multimedia file play request signal is input, divides the buffer into a predetermined number of file caches according to the structure of the file, and segments corresponding multimedia files according to the checked multimedia file play list. By buffering each of the divided caches in the order of size, the multi-file caching reduces the access of the storage module at least, multi-file caching of multiple files, and multi-file caching according to the file structure to be played. Application can help the system run smoothly.

Ring structure buffer, multiple file buffering, buffering start threshold, fragment copy

Description

Method for playing the real-time multimedia file using multiple file caching in mobile multimedia player}

1 is a configuration diagram of an embodiment of a portable multimedia player to which the present invention is applied.

2 is a diagram illustrating an embodiment of a buffer of a ring structure to which the present invention is applied.

3 is a diagram illustrating an embodiment of a relationship between a file and a file cache to which the present invention is applied.

4 is a flowchart illustrating a method of playing a real-time multimedia file using multiple file caching in a portable multimedia player according to the present invention.

5A-5C illustrate one embodiment of multiple file caching for a file to which the present invention is applied.

6 is a flowchart illustrating a method of buffering a file fragment unit to which the present invention is applied.

7A and 7B are diagrams illustrating an exemplary embodiment of a buffer in which a multimedia file to which the present invention is applied is buffered.

8 is a diagram illustrating an embodiment of copying a multimedia file fragment into a buffer to which the present invention is applied.

9 is a diagram illustrating an embodiment of a position exchange of a buffer point to which the present invention is applied.

* Explanation of symbols on the main parts of the drawing

10: storage module 11: buffer

12: multimedia playback module

The present invention is a real-time using multi-file caching in a portable multimedia player that divides the buffer into a certain number of file caches by applying a multi-file caching according to the structure of the file and buffers and reproduces the corresponding data in the order of a bufferable size in each cache A method of playing a multimedia file.

Recently, with the development of digital technology, users can use movies and music through portable multimedia players (e.g., mobile communication terminals (mobile phones, PDAs, etc.), portable MP3 players, portable video players, etc. with video / audio playback functions). You can enjoy it.

On the other hand, since multimedia files such as movie files and music files are very large, all data constituting files in a small memory cannot be cached when played in a portable multimedia player, and thus a storage module in a nonvolatile storage medium type (eg Storage in hard disk (HDD), NAND-type memory, multimedia card (MMC, compact flash memory), SD memory card, USB flash memory device (UFD) Each time it is played back, some data in the file is cached in memory.

In general, the portable multimedia player implements a buffer in the memory to reduce the playback delay caused by directly reading and playing a large multimedia file from a slower storage module than the memory and the power consumption due to repeated access to the storage module. Use buffering techniques.

Conventional portable multimedia players have abundant system resources such as computers, video / audio home appliances, etc. without considering system characteristics (e.g., low memory capacity, low speed CPU, battery powered methods, etc.) Memory, high-speed CPU, fixed external power supply, etc.) is the same buffering technique used in devices.

Meanwhile, in the portable multimedia player according to the conventional method, some buffering techniques based on a file system structure (eg, multimedia file name, storage folder specification, etc.) applied to a computer are used to facilitate the management of multimedia files scattered in various areas of the storage module. There is an attempt to apply it to a portable multimedia player.

That is, the above conventional buffering technique determines multimedia file information to be buffered through a multimedia playlist (for example, "m3u file of Winamp," etc.) and the playback order thereof. After buffering one multimedia file to play the corresponding music, the next music is played by buffering another music after a predetermined delay time between the preset music and the music.

However, the conventional buffering technique performs buffering for one multimedia file in data units, and after the playback of one multimedia file is completed, after acquiring multimedia file information to be played, the music is prepared for playback. Since buffering is performed for a predetermined delay time, there is a problem in that seamless music cannot be provided to the user.

In addition, since the conventional buffering technique deletes (clears) predetermined data that has been buffered after buffering one multimedia file in data units, it cannot immediately respond to a playback mode switch request from a user or a system. Due to the multimedia playback delay occurs.

For example, while the multimedia files are being played in the order of the multimedia playlist, the multimedia file backward play request signal from the current time point to the previous time point is inputted, or the specific multimedia file play request signal that was played back from the previous time point is inputted or from the current time point. If a multimedia file forward play request signal is input to a later time or a specific multimedia file play request signal to be played later, the current file must be stopped and read and buffered again after checking the multimedia file in the storage module. There is a problem in that a playback delay of multimedia and power consumption of a device are generated.

The present invention has been proposed to solve the above problems, and according to the structure of the file to be reproduced by applying a multi-file caching at least to reduce the access of the storage module, the multi-file in the portable multimedia player to help the smooth operation of the system An object of the present invention is to provide a method for playing a real-time multimedia file using caching.

In addition, the present invention is to buffer the multimedia files in order of the bufferable size according to the multimedia file play list in order to eliminate the playback delay of the multimedia due to buffering, the size of the sum of the cache of the currently buffered files is less than the threshold value In this case, an object of the present invention is to provide a real-time multimedia file reproducing method using multiple file caching in a portable multimedia player that sequentially buffers multimedia files other than the buffered multimedia files in the multimedia file play list.

The present invention for achieving the above object, mUserBP to read the point to be reproduced at the current time point in the ring structure buffer, the point to read in advance at the current time point for playback at a later time point mEndBP, the buffering start threshold is defined as mForwardTh A first step of checking a multimedia file play list when a multimedia file play request signal is input; A second step of dividing the buffer into a predetermined number of file caches according to the structure of the file, and buffering corresponding multimedia files in order of a size that can be buffered in the divided caches in pieces unit according to the checked multimedia file play list; ; And if the size mRemainSize from mUserBP to mEndBP becomes smaller than mForwardTh while playing the multimedia files buffered in the second step, multimedia other than the multimedia files buffered in the second step of the multimedia file play list. And a third step of performing the second step on the file.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, detailed descriptions of well-known functions or configurations will be omitted if it is determined that the detailed description of the present invention may unnecessarily obscure the subject matter of the present invention. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

1 is a configuration diagram of an embodiment of a portable multimedia player to which the present invention is applied.

As shown in FIG. 1, a portable multimedia player to which the present invention is applied is provided for the storage module 10 in the form of a nonvolatile storage medium in which a multimedia file (eg, a video file, an audio file, etc.) is stored and for playing a multimedia file. The multimedia file stored in the storage module 10 includes a buffer 11 in the form of a volatile memory that is copied and temporarily stored, and a multimedia playback module 12 that plays the multimedia file temporarily stored in the buffer 11.

In addition, although not shown in the drawing, the portable multimedia player is a display unit for displaying a video signal played by the multimedia play module 12, a speaker for outputting an audio signal played by the multimedia play module 12, and multimedia play. Forward playback request signal, high speed (e.g., 2x, 4x, etc.) forward playback request signal, backward playback request signal, high speed (e.g., 2x, 4x, etc.) backward playback request signal, Key input unit for inputting a specific multimedia file playback request signal that has been played, a specific multimedia file playback request signal to be played later, a battery for supplying power to each component of the portable multimedia player, and the like. It further includes the basic components.

On the other hand, in the present invention, the multimedia playback module 12 is equipped with a control function for controlling each component of the portable multimedia player, it is preferable to be implemented in the form of a chipset called a multimedia chip (Multimedia Chip).

2 is a diagram illustrating an embodiment of a buffer of a ring structure to which the present invention is applied.

A ring structure buffer 11 to which the present invention is applied is implemented in an annular structure. When data is filled up to the end region of the buffer 11, the next data is filled up again from the start region.

As shown in Fig. 2, Start is a start address of the memory constituting the buffer 11, End is a limit point address of the memory constituting the buffer 11, and mUserBP is a point played at the present time, that is, the present The file cache used in the multimedia player module 12 represents a file cache, and mEndBP represents a point read ahead at the present time point, that is, the file cache read in advance from the multimedia player module 12 for playback at a later time point, and the data to be reproduced. The remaining area (mUserBP to mEndBP; mRemainSize) 200 is used as a parameter for starting buffering and buffering is resumed when it is smaller than mForwardTh which is a preset buffering start threshold.

Here, the data structure used to buffer the multimedia file is called a file cache.

In addition, mForwardTh, which is a preset buffering start threshold, is preferably set to a buffering spare capacity corresponding to a data size such that music does not end.

That is, the size of mUserBP to mEndBP is an area in which data to be played remains, and if this area is smaller than mForwardTh, the portable multimedia player cleans up the already-played file cache and makes a space for a new ring buffer to cache the next file. do.

3 is a diagram illustrating an embodiment of a relationship between a file and a file cache to which the present invention is applied.

Although FIG. 3 illustrates a state in which a part of specific data constituting one file is buffered in the buffer 11, in the present invention, a plurality of files, that is, all data constituting a specific file and a part of specific data constituting another specific file, are buffered. It is preferable to buffer at (11).

In the present invention, the multimedia file is buffered based on the file system structure (aka file emulation).

In order to read the multimedia file stored in the storage module 10, information on which part of the multimedia file is to be read, namely, a file pointer and a file size and the same process as the existing file input / output related functions (file API) Should be done.

The multimedia playing module 12, in particular, the multimedia playing process (application) does not read and play specific data of the multimedia file by using the position value of the data buffered in the buffer 11 as a parameter, but from the multimedia file having a linear structure. Since specific data is read and played back, that is, a specific data is read and played back from the multimedia file using the file pointer as a parameter, the multimedia file is played as if the user handles the file without having to recognize the circular structure of the buffer 11. You can make it play.

That is, the information about the multimedia file currently being buffered is recorded in the buffer 11, and the same process as the multimedia playback module 12 reads and reproduces the multimedia file directly from the storage module 10 using the recording information. You can do it.

As shown in Fig. 3, the area A represents some future data to be reproduced later from the data of the multimedia file currently being reproduced, and the area B represents a part of the past previously reproduced from the data of the multimedia file currently being reproduced. Represents the data.

An area where the A and B areas are combined represents a part or a plurality of multimedia files of one multimedia file being buffered.

In addition, mMAXBufferSize represents the size of the buffer 11, the size of the buffer 11 is equal to the size from the start of the file pointer (StartFP) to the end of the file pointer (mEndFP), the file pointer start based on the current time It can be seen that the data from the portion to the end of the file pointer is buffered in the buffer 11.

In addition, mUserBP represents a portion currently being played, that is, a portion read (viewed) by the user, and means information mapped to a position in the buffer 11 of a file pointer on the file system, and mEndBP is currently played. It indicates the end of data to be reproduced in the future from the portion that exists, and the file area that the file cache can cover is data from mStartBP to mEndBP.

The file cache has a start and an end of the buffering area, and has a direction (Forward Direction or Backward Direction) for copying data from the storage module 10. In this case, the forward direction direction means that the multimedia file is played forward, and the reverse direction direction means that the multimedia file is played backward.

As described above with reference to FIGS. 1 to 3, mUserBP reads a point reproduced at the present time in the ring structure buffer 11, and mEndBP reads a point pre-read at the present time for replay at a later time, and a buffering start threshold. Can be defined as mForwardTh.

4 is a flowchart illustrating a method of playing a real-time multimedia file using multiple file caching in a portable multimedia player according to the present invention, and FIGS. 5A and 5B illustrate multiple file caching of a file to which the present invention is applied. 6 is a flowchart illustrating a method of buffering a file fragment unit to which the present invention is applied, and FIGS. 7A and 7B are diagrams illustrating a state of a buffer in which a multimedia file to which the present invention is applied is buffered. 8 is an explanatory diagram for copying a multimedia file fragment into a buffer to which the present invention is applied, and FIG. 9 is an explanatory diagram for exchanging a position of a buffer point to which the present invention is applied.

Referring to FIG. 4, when the multimedia file playing request signal is input by the user (S400), the portable multimedia player checks the multimedia file playing list (S401). That is, the user selects a multimedia file playlist to select a multimedia file to be listened to, selects the corresponding multimedia file, and requests playback of the multimedia file.

Then, the portable multimedia player checks the multimedia file play list loaded by the user to determine the multimedia file name, the multimedia file size and the multimedia file properties (eg, MP3 format, WMA format, artist name, genre, etc.), and then the multimedia file. Check the playback order.

Then, the portable multimedia player divides the buffer into a predetermined number of file caches according to the structure of the corresponding file, and according to the checked multimedia file play list, the corresponding multimedia files are divided into pieces by the size that can be buffered in the divided cache. Buffer in order (S402).

For example, if the file is a single file, the portable multimedia player regards the buffer as one cache and buffers the corresponding multimedia files in pieces in accordance with the checked multimedia file playlist as shown in FIG. 5A. Buffer each in order by size.

Referring to FIG. 5A, mUserBP, which is a point played back at the current time point, when all data constituting the "1.MP3" file having the playback order 1 in the multimedia file play list is buffered in the buffer, is played back at a later time point. For this, mEndBP, the point that is read ahead at the present time, points to the same file, "1.MP3".

Since the storage capacity of the buffer is sufficient to buffer other multimedia files, as shown in the lower portion of FIG. 5A, the playback order 2, the playback sequence 3, and the playback sequence 4 according to the multimedia file playback list are displayed. 2. All the data constituting the "WMA" file, all the data constituting the "3.MP3" file, and some data constituting the "4.WMA" file are buffered in order.

If the file is a multimedia file for which index information is essential, the portable multimedia player divides the buffer into a data area cache and an index area cache, and the corresponding multimedia files are divided into pieces of a predetermined size according to the checked multimedia file play list. Each of them is buffered in order of the size that can be buffered in the divided cache.

At this time, the information of the multimedia file to be played back (played) is obtained through the multimedia playback process (application), in particular, the multimedia file play list, and the multimedia file is registered in the buffer 11 using the file cache, and then the registered multimedia is received. If files are buffered in the buffer 11 in order as much as possible, and all the data constituting the multimedia file that has started buffering are copied to the buffer 11, other multimedia files are filled until the remaining area is filled except for the file cache used by the current application. Iteratively performs the data buffering process of the file.

Thus, because the file that the user requires is already cached in the buffer, the multimedia playback module passes the data in the buffer without losing the file again from the storage module.

In this case, if the requested file exists in the buffer but requests a file that does not exist in the buffer, this is called a cache miss. It clears all the contents of the ring buffer and re-caches the file for the first time. Should be done.

In other words, in order to play multimedia data for which index information is necessary, access to an index is essential because index information behind a file is essential. However, because the size of the buffer is smaller than the total file size, a cache miss occurs when accessing multimedia data, and a cache miss occurs when accessing an index again. If the cache miss is repeated, it is difficult to expect the system to operate normally, and the playing music is broken.

For this case, multiple file caches are allocated to one file as shown in FIGS. 5B and 5C.

First, the allocation of a multi-file cache to an audio file will be described with reference to FIG. 5B.

Referring to FIG. 5B, an audio file (audio data and an index) stored in a storage module is opened twice to allocate a cache to audio data and a cache to an index.

The buffer is then currently set up with two file caches, one for caching part of the audio data and the other for caching part of the index.

That is, in buffering the audio file stored in the storage module, two caches are allocated to the buffer to store audio data in the first cache 500 and the index 512 is stored in the second cache 510. At this time, the allocated area divided into the first cache 500 and the second cache 510 constitutes a buffer independently of each other.

By allocating two caches for one file as described above, the cache miss repetition does not occur, and the storage module resource can be efficiently handled in a ring buffer smaller than the file size.

Next, the allocation of the multiple file cache to the multimedia file mixed with the audio data and the video data will be described with reference to FIG. 5C.

Referring to FIG. 5C, a multimedia file such as a video includes an index 1 for audio data and an index 2 for video data.

Therefore, since the access of the index 1 and the index 2 is essential for the portable multimedia player to play the video file, the access to the storage module is frequently expected without using the multi-file cache. Allocate more.

That is, three caches are set in the buffer, the first cache 550 stores a part of the multimedia data, the second cache 560 stores a part of the index 1, and the third cache 570 is an index. Save part of 2. That is, the ring buffer is stored in the first cache 550 in a size that can buffer the multimedia data stored in the storage module, and the index 1 corresponding to the audio data stored in the first cache 550 is stored in the second cache 560. The index 2 corresponding to the video data stored in the first cache 550 is stored in the third cache 570.

Such multi-file caching is in effective cache management to at least reduce the access of the storage module. The multi-file caching supports the smooth operation of the system by applying the multi-file caching according to the multi-file caching and the file structure to be played.

A method of buffering the continuous multimedia file in the buffer 11 in order as much as the bufferable size will be described in detail with reference to FIG. 6 again in step 402 of FIG. 4.

Referring to FIG. 6, the portable multimedia player determines whether any multimedia file is being cached (S600).

As a result of the determination in step 600, if any file is caching, the portable multimedia player copies the file to the buffer (S601), and determines whether the caching of the file is finished (S602).

If the caching of the file is terminated as a result of the determination of step 602, the portable multimedia player determines whether the entire file has been cached (S603).

If it is determined in step 603 that the entire file has been cached, it is indicated that the whole file has been cached (S604).

If it is determined in step 603 that the entire file has not been cached, it indicates that a portion of the file has been cached (S605).

That is, if all files have been copied to the buffer, it is marked as 'full', and if a part of the file is cached if the target file is too large to be contained in the buffer, 'a part of file' is displayed.

If the caching of the file is not terminated as a result of the determination of step 602, the portable multimedia player determines whether space exists in the buffer (S606).

If there is space in the buffer as a result of the determination in step 606, the portable multimedia player performs from step 601, and if there is no space in the buffer, step 605 is performed.

If it is determined in step 600 that the file is not currently being cached, the portable multimedia player determines whether space exists in the buffer (S607).

If there is space in the buffer as a result of the determination in step 607, the portable multimedia player reads file information to be cached next from the storage module (S608).

Then, the portable multimedia player determines whether the read file is a file existing in the buffer (S609).

If it is determined in step 609 that the read file exists in the buffer, the portable multimedia player performs step 608.

If it is determined in step 609 that the read file is not a file existing in the buffer, the portable multimedia player allocates space to the buffer to copy the file (S610), and starts from step 602.

As described above, when the data structure of the current cache is 'full' or 'a part of file', information about a file to be cached next is prepared and cached. However, if you consider the goal of minimizing access to slow storage devices, if you fill all the ring buffers at the first startup and the last cached file in the ring buffer is currently playing and the size of the playing file is less than the threshold, the previously buffered multimedia Leave a portion of the buffer currently playing in the file and re-buffer files other than the previously buffered file in order as much as possible.

The description of FIG. 6 will be described using the state diagram of FIG. 7A.

As shown in the upper side of FIG. 7A, in the state in which all data constituting the " 1.MP3 " file having the playback order number 1 of the multimedia file play list is buffered in the buffer 11, mUserBP, mEndBP, which is a point read ahead at the current time point for playback at a later time point, points to the same file, that is, a "1.MP3" file.

After that, since the storage capacity of the buffer 11 is sufficient to buffer other multimedia files, as shown in the lower side of FIG. 7A, the playback order 2, the playback order 3, and the playback order 4 are made according to the multimedia file play list. All data constituting the "2.WMA" file having, and all the data constituting the "3.MP3" file and some data constituting the "4.WMA" file are sequentially buffered.

Here, in the state in which some data constituting the "4.WMA" file is buffered in the buffer 11, mUserBP, which is a point played back at the present time, points to the "1.MP3" file, and the current time point for playback at a later time point is shown. MEndBP points to the "4.WMA" file.

On the other hand, since there is no capacity in the buffer 11 to store all data constituting the "4.WMA" file, only some data constituting the "4.WMA" file is buffered. That is, in FIG. 7A, "FULL" means all data constituting the multimedia file, and "A part of file" means some data constituting the multimedia file.

Meanwhile, in the buffering process in step 402 and the buffering process in step 405 to be described later, a specific part of the multimedia file indicated by a file pointer for a specific multimedia file is fragmented and buffered. Herein, a process of sequentially copying specific portions of the multimedia file will be described in detail with reference to FIG. 8.

In general, a request from a user or a system, i.e., a play mode switch request, a random multimedia file selection and play request, a power off event, etc. occur while copying all the data that can be copied to the buffer 11 at once. If the request is processed only after the current buffering process is completed, the user is returned with the delayed processing result.

In the present invention, as shown in Fig. 8, the buffering unit is a multimedia file fragment unit, and buffers data of a suitable size at a time in the buffer 11 and detects whether a specific request is generated from the user or the system at every instant of buffering, thereby processing time. Allows the request to be processed immediately without delay.

Referring back to FIG. 4, during the playback of the multimedia files buffered in the buffer 11 in step 402, no buffering is performed, and a change in the size mRemainSize from mUserBP to mEndBP is continuously detected (S403). ).

In operation S404, the portable multimedia player determines whether the size mRemainSize from mUserBP to mEndBP is smaller than mForwardTh.

As a result of the determination in step 404, when the size mRemainSize from mUserBP to mEndBP is smaller than mForwardTh, the portable multimedia player is capable of buffering multimedia files other than the multimedia files buffered in step 402 of the multimedia file playlist. The buffer 11 is sequentially buffered as much as the size (405). That is, when the size mRemainSize from mUserBP to mEndBP is smaller than mForwardTh, the portable multimedia player plays back a previously buffered multimedia file while leaving a part of a buffer currently playing in a previously buffered multimedia file. Buffer in order as much as possible. Since the buffering method has been described in detail with reference to FIG. 6, the description thereof will be omitted.

While step 405 is being performed, playback of the multimedia file is still being performed, and the multimedia file buffered in step 405 is continuously played after the previous song.

At this time, when the state of the buffer 11, that is, the change of the size (mRemainSize) from the mUserBP to the mEndBP (in particular, a change in the position of the mUserBP) is detected, and the size of the sum of the caches of the currently buffered files is less than or equal to the threshold, That is, when the size (mRemainSize) from the mUserBP to the mEndBP becomes smaller than the mForwardTh, information of a multimedia file to be played back (played) is obtained and the multimedia file is registered in the buffer 11 by using a file cache. The registered multimedia files are buffered in the buffer 11 in order as much as the bufferable size.

FIG. 7B shows the state of a buffer in which a multimedia file to be played next is buffered through a threshold comparison to which the present invention is applied.

The upper side of FIG. 7B shows the transition state of the buffer 11 in which the " 2.WMA " file is being reproduced in the state of the buffer 11 shown in FIG. 7A, and the buffer shown on the upper side of FIG. 7B in the middle side of FIG. The transition state of the buffer 11 in which the " 4.WMA " file is being reproduced after a predetermined time has elapsed in the state of (11).

As shown in the middle of FIG. 7B, mUserBP, a point played at the present time point, points to the file "4.WMA", and mEndBP, a point previously read at the present time point, for playback at a later time point is "4. WMA "file, and in this case, mUserBP and mEndBP point to the same" 4, WMA "file. When two file caches overlap, the multimedia file to be played (played) is not buffered in the future. As shown below, the multimedia file that is expected to be played next is selected according to the multimedia file play list. The data forming part of 4.WMA, all the data forming part of the 5.MP3 file, and the part of the data forming part of the "6.MP3" file. Buffer them in order.

As described above, the portable multimedia player continuously detects a change in the size (mRemainSize) from the mUserBP to the mEndBP while the file is being played. 7B, multimedia files other than previously buffered files are buffered in the buffers in order, except for the file currently being played as shown in FIG. 7B. At this time, the multimedia file is still being played, and the buffered multimedia file is continuously played after the previous song.

At this time, the state of the buffer, i.e., the change of the size (mRemainSize) from the mUserBP to the mEndBP (in particular, the position change of the mUserBP) is detected, and the sum of the caches of the currently buffered files is less than or equal to the threshold, that is, the mUserBP If the size from mEndBP to mEndBP becomes smaller than the mForwardTh, the information of the multimedia file to be played (played) is obtained, the multimedia file is registered in the buffer using the file cache, and the registered multimedia files are buffered. Buffer the buffers in order as much as possible.

As shown in the lower part of FIG. 7B, in the state of the buffer after being buffered, mUserBP points to the "4.WMA" file, and the buffer includes the remaining file "4.WMA" (A part of "4.WMA"). file) ", 5.MP3, 6.MP3 files are buffered sequentially.

Therefore, mEndBP, which is a point read ahead at the current time point for playback at a later time point, points to a "6.MP3" file.

That is, the 4.WMA file cache is copied from start again because the same file is a ring buffer. New files are cached in the area of previously played files, and the resizing of the 4.WMA (A part of file) relinquishes the previously played part and fills up the data to be played back.

In this case, the data is not read from the storage module while the cached data remains, because the slow storage module reads the data once cached. This cache operation is advantageously performed as background task processing using the OS and improves the overall execution time by allocating more CPU resources to play back using the OS scheduler function when the storage module is not in use.

Meanwhile, in the present invention, the multimedia file backward playback request signal from the current time point to the previous time point is inputted while the multimedia file is being buffered in the buffer 11 according to the order of the multimedia play list. When a specific multimedia file play request signal, which has been played at a previous time, is input or a multimedia file forward play request signal is input from a current time point to a later time, or a specific multimedia file play request signal to be played at a later time is input, the mUserBP is applied to the corresponding multimedia. By setting the file to a buffered buffer point (switching the position of the buffer point) and starting playback, it is not necessary to read and copy the multimedia file from the storage module 10, thereby reducing the number of buffering accesses.

That is, as shown in the upper side of Fig. 9, the mUserBP, which is the point played back at the present time in the buffer 11, points to the "3.MP3" file, and the point read in advance at the present time point for playback at a later time point. If there is a request to play the "1.MP3" file previously played by the user while the mEndBP is pointing to the "4.WMA" file, as shown in the lower side of FIG. Does not need to perform a separate buffering process because only after exchanging the position to "1.MP3", playback starts from this "1.MP3" file.

Meanwhile, in the process of setting the mUserBP as a buffer point buffered with the corresponding multimedia file, if the corresponding multimedia file is not buffered in the buffer 11, after initializing the buffer 11, the corresponding multimedia file is buffered. It is preferable.

While the content of the present invention has been described by way of examples, the embodiments of the present invention are merely illustrative of the present invention and should not be construed as limiting the scope of the present invention. Those skilled in the art to which the present invention pertains may modify or alter the present invention in various forms within the principles and scope described in the claims herein.

According to the present invention as described above, since a specific piece of the multimedia file is read and copied using the file pointer, the user can play the multimedia file as easily as the file is handled without the user having to recognize the circular structure of the ring structure buffer. A portable multimedia player can provide a real-time multimedia file playback method using multiple file caching.

In addition, according to the present invention, by applying multiple file caching to reduce the access of the storage module at least, the portable multimedia player to help the smooth operation of the system by applying multiple file caching according to the file structure to be multi-file caching of multiple files and to play Can provide a real-time multimedia file playback method using multi-file caching.

In addition, according to the present invention, multiple file caching prevents system replay delay due to frequent access of a slow storage module through efficient cache management, and responds quickly because data required by a user is copied to a fast memory in advance. A fast portable multimedia player can provide a real-time multimedia file playback method using multiple file caching.

In addition, according to the present invention, since a device that consumes a lot of power to drive a storage device such as an HDD prevents frequent driving, a real-time multimedia file playing method using multiple file caching in a portable multimedia player that can reduce current consumption. Can be provided.

In addition, according to the present invention, caching a single file or a part of data in a large memory is wasteful, so it is advantageous to cache several files, so that multi-file caching is effective in a portable multimedia player effective for controlling a large memory as a cache. It is possible to provide a real-time multimedia file playback method.

Claims (11)

In the method of buffering data in a ring structure buffer, With mUserBP defining a point to be reproduced at the present time in the buffer of the ring structure, mEndBP as a point to read in advance at the present time for reproducing at a later time, and a buffering start threshold value as mForwardTh, A first step of checking a multimedia file play list when a multimedia file play request signal is input; A second step of dividing the buffer into a predetermined number of file caches according to the structure of the file, and buffering corresponding multimedia files in order of a size that can be buffered in the divided caches in pieces unit according to the checked multimedia file play list; ; And If the size mRemainSize from mUserBP to mEndBP becomes smaller than mForwardTh while playing the multimedia files buffered in the second step, multimedia files other than the multimedia files buffered in the second step of the multimedia file play list. A third step of performing the second step with respect to Real-time multimedia file playback method using multiple file caching in a portable multimedia player comprising a. The method of claim 1, Dividing the buffer into a predetermined number of file caches according to the structure of the file may include assigning one cache to the buffer if the file is a single file that does not require index information, and if the file is a multimedia file for which index information is essential. And dividing the buffer into a data area cache and an index area cache. The method of claim 2, When the multimedia file for which the index information is essential is an audio file, the buffer is divided into an audio data cache and an index cache. When the file is a file in which audio data and video data are combined, the multimedia data cache and an index cache corresponding to the audio data are included. And real-time multimedia file playing method using multi-file caching in a portable multimedia player, characterized in that divided into index cache corresponding to the video data. The method according to claim 2 or 3, The divided cache comprises a ring buffer independently from each other, Real-time multimedia file playback method using multiple file caching in a portable multimedia player. The method of claim 1, Buffering the data in the cache in order as much as the bufferable size If the first file is being cached, copying the file to the buffer, and if caching of the file is terminated, determining whether the entire file is cached; And if the entirety of the file is cached as a result of the determination, indicating that the entirety of the file is cached, and if the entirety of the file is not cached, indicating that the portion of the file is cached. Real-time multimedia file playback using multi-file caching in the player. The method of claim 5, If the first file is not caching, determining if space exists in the buffer; If there is a space in the buffer as a result of the determination, reading file information to be cached next and copying it to the buffer, and when caching of the file is terminated, determining whether the entire file is cached; And if the entirety of the file is cached as a result of the determination, indicating that the entirety of the file is cached, and if the entirety of the file is not cached, indicating that the portion of the file is cached. Real-time multimedia file playback using multi-file caching in the player. The method according to claim 5 or 6,  Copying the file to the buffer is performed by multi-file caching in the portable multimedia player, characterized in that by reading a specific piece of the multimedia file stored in the storage module using a file pointer (File Pointer) for the multimedia file. Real-time multimedia file playback using. The method according to any one of claims 1 to 7, And copying and buffering the multimedia file into a buffer of the ring structure in units of file fragments, and detecting whether a specific request is generated from a user or a system at every buffering. The method according to any one of claims 1 to 8, The second step and the third step, During playback of the buffered multimedia files in the order of the multimedia play list, a multimedia file backward play request signal is input from the current time point to the previous time point or a specific multimedia file play request signal that has been played at the previous time point is inputted from or after the current time point. When the multimedia file forward play request signal is input to the viewpoint or a specific multimedia file play request signal to be played later is input, the mUserBP is set as a buffer point at which the corresponding multimedia file is buffered. Buffering method. The method of claim 9, In the second step and the third step, In the process of setting the mUserBP as a buffer point in which the corresponding multimedia file is buffered, if the corresponding multimedia file is not buffered, the multimedia file is buffered after initializing the buffer. Way. In a portable multimedia player with a processor, With mUserBP defining a point to be reproduced at the present time in the buffer of the ring structure, mEndBP as a point to read in advance at the present time for reproducing at a later time, and a buffering start threshold value as mForwardTh, A first step of checking a multimedia file play list when a multimedia file play request signal is input; A second step of dividing the buffer into a predetermined number of file caches according to the structure of the file, and buffering corresponding multimedia files in order of a size that can be buffered in the divided caches in pieces unit according to the checked multimedia file play list; ; And If the size mRemainSize from mUserBP to mEndBP becomes smaller than mForwardTh while playing the multimedia files buffered in the second step, multimedia files other than the multimedia files buffered in the second step of the multimedia file play list. A third step of performing the second step with respect to A computer-readable recording medium having recorded thereon a program for realizing this.

Images