TWI408554B - File-reading method and embedded system using the same - Google Patents

Abstract

A file-reading method and an embedded method using the file-reading method are concerned. The embedded system executes thereon a multimedia application program and has a system memory. The method includes: providing a first table cache to temporarily store a first link list corresponding to a first file in response to a first file-reading command issued to a removable storage device by the multimedia application program, wherein the first table cache is located in a first block of the system memory; and providing a second table cache to temporarily store a second link list corresponding to a second file in response to a second file-reading command issued to the removable storage device by the multimedia application program, wherein the second table cache is located in a second block of the system memory.

Description

File reading method and embedded system using the same

This case is an embedded system for file reading method and application of the method.

With the rapid development of information technology, the functions of digital home appliances are becoming more and more powerful. Digital TV is an obvious example. It can directly read the multimedia files in the flash drive to play, playing the role of digital photo frame. A fairly convenient feature. As shown in the first figure, a set of universal serial bus port 埠100 is provided on the machine side of the digital television 10, and the user is provided with the flash drive 11 storing the music file and the digital photo file, and the digital television 10 is permeable. Universal serial bus to read music files and digital photo files for playback, allowing users to listen to music while viewing photos.

In order to achieve the above functions, the operating system of the digital TV will be able to let the application read the music files and digital photo files in the flash drive 11, and the most convenient way is to provide a file system application design interface (File System). Application Programming Interface (File System API) is used to let the application call to complete the reading of music files and digital photo files.

Please refer to the second figure, which is a block diagram of the software architecture function for reading and playing the files in the flash drive 11 in the digital television. When the multimedia player application 101 executed on the digital television 10 is to be in the portable disk 11, When the first file 1111 in the directory 111 is played, the file system application design interface 21 is directly called to read the first file 1111 in the first directory 111 of the flash drive 11. Since the physical address of the first file 1111 stored in the flash drive 11 is not necessarily continuous, the traditional file system application design interface 21 is provided with a table cache 211 for storing the first file 1111. A Link List, and the Table Cache 211 needs to allocate a specific area in the system memory 109 in the digital television 10 to store data. According to the link list in the table cache 211, part of the data read from the first file 1111 is temporarily stored in the first input/output cache 212, and the first input/output cache 212 is also required. Another specific area is allocated to the system memory 109 in the digital television 10 to store data.

Similarly, when the multimedia player application 101 on the digital television 10 is to simultaneously play the other files in the flash drive 11 and call the file system application design interface 21, a second input/output cache is correspondingly generated. 213 to temporarily store data. The second input/output cache 213 also needs to allocate another specific area from the system memory 109 in the digital television 10 to store the data. The first input/output cache 212 and the second input/output cache 213 have a limited capacity, so usually only part of the file data can be stored, until the fast playback is completed, the system must use the table cache 211 link table data again. Read the follow-up file data.

However, since the file system application design interface 21 provided by the operating system is conventionally capable of managing only one table cache 211, the second file 1122 to be played when the multimedia playback application 101 on the digital television 10 is to be played is located. In the second directory 112, since the first file 1111 and the second file 1122 are located in different directories, the multimedia playing application 101 cannot use the linked list data of the corresponding first directory 111 in the table cache 211, and thus needs to be cleared. The table cache 211 the original data and reloads the link table data corresponding to the second directory 112.

Since playing music and photos at the same time is a possible user requirement, if the above situation occurs, frequent switching of the Table Cache 211 will cause a great burden on the hardware system, and if it is a powerful computer system. It can also be affordable, but if the embedded system with insufficient system resources, such as digital TV, DVD player or digital photo frame, will cause the playback effect to be intermittent. How to effectively solve the lack of the above-mentioned conventional means is the main purpose of developing the case.

The present invention discloses a file reading method, which can be applied to execute a multimedia application and has an embedded system of one system memory and a removable memory device, the method comprising: responding to the removable memory in response to the multimedia application The first file read command sent by the device provides a first table cache to temporarily store the first link table data of one of the corresponding first files, and the first table cache is located in the first block of the system memory; And in response to the second file read command issued by the multimedia application to the removable memory device, providing a second table cache to temporarily store the second link table data corresponding to the second file, where the second table cache is located The second block of system memory.

The present disclosure further discloses an embedded system having a multimedia application and connected to a removable memory device, the embedded system comprising: a system memory; and an improved file system application design interface, Providing a first table cache to temporarily store a first link table data corresponding to the first file in response to the first file read command issued by the multimedia application to the removable memory device, where the first table cache is located a first block of system memory and a second file read command issued by the multimedia application for the removable memory device, providing a second table cache to temporarily store the second link table data corresponding to the second file The second table cache is located in the second block of the system memory.

Please refer to the third figure, which is a block diagram of the software architecture function that can be implemented in the embedded system 3. The case is improved for the file system application design interface of the conventional file. Therefore, the improved version developed in this case The file system application design interface 31 is provided with a plurality of environment instances (Environment Instances) 311 to 31n, each of which has its own table cache (Table Cache) 3111 to 31n1. Preferably, the number n of environment instances (Environment Instances) 311 to 31n can be matched with the number of files that the embedded system 3 wants to support simultaneous reading. For example, when the specifications of the embedded system 3 need to support simultaneous playback of video files and music files, the improved file system application design interface 31 can be set to two environment instances in the compile phase. If the specifications of the embedded system 3 need to support simultaneous playback of video files, music files, and browsing files, in this embodiment, the improved file system application design interface 31 can be set to three in the compile phase. Environment instance.

In this way, the different needs of the application can be handled in a one-to-one manner, thereby eliminating the problem of frequent switching of table cache contents in the conventional means. The following is illustrated by the three requirements of digital TV and the application executing it.

Please refer to the fourth figure, which is a schematic diagram of the hardware and software architecture function for reading and playing the files in the flash drive inside the digital television using the technical means of the present invention. When the digital television 4 needs to be designed to allow the multimedia application 40 to simultaneously When playing video files, music files, and browsing files, three environment instances (Environment Instances) 411, 412, and 413 are provided in the improved file system application design interface 41 to provide three table caches 4110, 4120, respectively. And 4130 to store the three linked lists (Link List) corresponding to different directories. Thus, when the multimedia application 40 is to simultaneously perform the playback action of the first file 4910 (eg, video file) in the first directory 491 of the removable memory device 49, the second file 4920 in the second directory 492 (eg, the music file) During the playback action and the browsing operation of the third file 4930 in the third directory 493, the multimedia application 40 calls the first environment instance 411, the second environment instance 412, and the third in the improved file system application design interface 41, respectively. The environment instance 413 further uses the first table cache 4110 to store the link table data corresponding to the first directory 491, the second table cache 4120 to store the link table data corresponding to the second directory 492, and the third table cache. 4130 is used to store the linked list data corresponding to the third directory 493. The actual storage addresses of the three table caches 4110, 4120, and 4130 and the three input and output caches 4111, 4121, and 4131 are set in different blocks of the system memory 47.

In this embodiment, the multimedia application 40 reads the first directory 491 and the second directory 492 according to the link table data in the first table cache 4110, the second table cache 4120, and the third table cache 4130, respectively. The files in the third directory 493 are stored in the first input/output cache 4111, the second input/output cache 41121, and the third input/output cache 4131, respectively. In this embodiment, even if part of the data of the first file 4910 in the first output/output cache 4111 is exhausted, the system can directly retrieve the link table data in the first table from the first table to correspond to the removable data. In addition to the storage location of the first file 4910 in the memory device 49, the subsequent data is quickly moved into the first output/output cache 4111, which eliminates the problem of frequently emptying and loading the table cache data as in the conventional means.

Please refer to the fifth figure, which is a schematic flowchart of a preferred embodiment of the file reading method developed in the present application, which is applied to a digital television 4 and a removable memory device 49 having a multimedia application 40 and having a system memory 47. between. First, the improved file system application programming interface 41 developed in the present case can issue a first file read command to the removable memory device 49 in response to the multimedia application 40, thereby providing a first table cache 4110 for temporary storage. Corresponding to the first link table data of the first file 4910 (step 51), the data in the first table cache 4110 is actually stored in the first block of the system memory 47 (not shown). Then, when the multimedia application 40 issues a second file read command to the removable memory device 49, the improved file system application design interface 41 developed in the present case can be provided according to the second file read command. The second table cache 4120 temporarily stores the second link table data corresponding to the second file 4920 (step 52), and the data in the second table cache 4120 is actually stored in the second area of the system memory 47. Block (not shown). Further, if the multimedia application 40 issues a third file read command to the removable memory device 49, the improved file system application design interface 41 developed in the present case can be read by the third file. The third table cache 4130 is provided to temporarily store the third link table data corresponding to the third file 4930 (step 53), and the data stored in the third table cache is actually stored in one of the system memory 47. Three blocks (not shown). This will eliminate the problem of frequently emptying and loading the table cache data as in the conventional method.

The embedded system can be a multimedia player such as a digital television or a digital photo frame, and the removable memory device is a flash memory card or a universal serial bus flash drive.

In summary, the present invention effectively reduces the hardware complexity and cost of the multimedia player platform hardware, and discloses that the multimedia application interface of the open specification and the existing audio and video playback device hardware can be used to complete the system construction. It can effectively solve the lack of the above-mentioned conventional means and achieve the main purpose of developing the case. However, the present invention is modified by those skilled in the art and is not intended to be protected as claimed.

The components included in the diagram of this case are listed as follows:

10. . . Digital TV

100. . . Universal serial bus connection埠

11. . . Flash drive

101. . . Multimedia player application

111. . . First directory

1111. . . First file

twenty one. . . File system application design interface

211. . . Table cache

212. . . First input and output cache

213. . . Second output and cache

109. . . System memory

112. . . Second directory

1122. . . Second file

3. . . Embedded Systems

311~31n. . . Environment instance

31. . . Improved file system application design interface

3111~31n1. . . Table cache

3112~31n2. . . Output and cache

4. . . Digital TV

40. . . Multimedia application

41. . . Improved file system application design interface

411. . . First environment instance

412. . . Second environment instance

413. . . Third environment instance

4110. . . First table cache

4120. . . Second table cache

4130. . . Third table cache

49. . . Removable memory device

491. . . First directory

4910. . . First file

492. . . Second directory

4920. . . Second file

493. . . Third directory

4930. . . Third file

47. . . System memory

4111. . . First input and output cache

4121. . . Second output and cache

4131. . . Third output into the cache

This case can be obtained through a more in-depth understanding of the following diagrams and descriptions:

The first figure shows the system architecture of a conventional digital TV.

The second figure shows a block diagram of the software architecture function used to read and play the files in the flash drive inside the digital TV.

The third figure shows the block diagram of the software architecture function that can be implemented in the embedded system.

The fourth figure shows a schematic diagram of the function of the software and hardware architecture for reading and playing the files in the flash drive inside the digital television using the technical means of the present invention.

The fifth figure shows a flow chart of a preferred embodiment of the present invention.

3. . . Embedded Systems

31. . . Improved file system application design interface

311~31n. . . Environment instance

3111~31n1. . . Table cache

3112~31n2. . . Output and cache

Claims (16)

A file reading method is applicable to an embedded system having a multimedia application and having a system memory and a removable memory device, wherein the file reading method comprises: Removing the memory device to issue one of the first file read commands, providing a first table cache to temporarily store the first link table data corresponding to one of the first files; and removing the corresponding data from the multimedia application The memory device issues a second file read command to provide a second table cache to temporarily store the second link table data corresponding to one of the second files. The file reading method of claim 1, wherein the first table cache is located in a first block of the system memory and the second table cache is located in a second area of the system memory. Piece. The file reading method of claim 2, wherein the first block and the second block in the system memory do not overlap each other. The method for reading a file according to claim 1, wherein the embedded system is a digital television or a digital photo frame, and the removable memory device is a flash memory card or A universal serial bus with a flash drive. The file reading method of claim 1, further comprising providing a first input/output cache to temporarily store the first file read command issued by the multimedia application for the removable memory device. Corresponding to part of the first file. The file reading method of claim 1, further comprising providing a second input/output cache to temporarily store the second file read command issued by the multimedia application for the removable memory device. Relatively part of the second file. The file reading method of claim 1, wherein the first file and the second file are respectively stored in a first directory and a second directory of the removable memory device. The file reading method of claim 1, further comprising: providing a third file read command to the removable memory device according to the multimedia application, providing a third table cache to temporarily store Corresponding to a third link table data of a third file, the third table cache is located in a third block of the system memory. An embedded system having a multimedia application and coupled to a removable memory device, the embedded system comprising: a system memory; and an improved file system application design interface for The multimedia application should issue a first file read command to the removable memory device, provide a first table cache to temporarily store the first link table data corresponding to one of the first files, and The application issues a second file read command to the removable memory device, and provides a second table cache to temporarily store the second link table data corresponding to one of the second files. The embedded system of claim 9, wherein the first table cache is located in a first block of the system memory and the second table cache is located in a second block of the system memory. . The embedded system of claim 10, wherein the first block and the second block in the system memory do not overlap each other. The embedded system of claim 9 is a digital television or a digital photo frame, and the removable memory device is a flash memory card or a universal serial bus. The embedded system of claim 9, wherein the improved file system application design interface further provides a first file read command issued by the multimedia application to the removable memory device. The first output is cached to temporarily store part of the data corresponding to the first file. The embedded system of claim 9, wherein the improved file system application design interface further provides a second file read command issued by the multimedia application to the removable memory device. The second output is cached to temporarily store part of the data corresponding to the second file. The embedded system of claim 9, wherein the first file and the second file are respectively stored in a first directory and a second directory of the removable memory device. The embedded system of claim 9, wherein the improved file system application design interface further provides a third file read command for the removable memory device by the multimedia application. The third table caches the third link table data corresponding to one of the third files, and the third table cache is located in the third block of the system memory.