JP2009277286A - Method and device for reproducing information recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To access a video file from another route even if there is a trouble in management information. <P>SOLUTION: A recording medium comprises a data region and a management region. The management region contains a file system (FS) which assigns a logical sector number and a logical block number to the information recording medium. In an area to which the logical block number is assigned, at least a video file, a management file, and route directory information thereof are managed. In the management file, logical block address information required for reproducing a packet in the video file is described. A method for reproducing information can perform reproduction by a first route wherein the video file is accessed on the basis of the logical block address information designated by the management file, and reproduction by a second route wherein the video file is accessed on the basis of a file entry and file size information contained in the route directory information. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a playback method and playback apparatus for an information recording medium, and is effective when there are a plurality of video file access systems and the management file information fails or cannot be read.

  In recent years, a digital versatile disc has been developed as an information recording medium, and a DVD on which video application content is recorded has become widespread. This information recording medium has a data area and a management area. The management area includes a file system that incorporates the universal disk format (UDF), and the file system assigns a logical sector number and a logical block number to the information recording medium. At least the video file, the management file, and the root directory information thereof are managed in the logical block number allocation area (file configuration and file descriptor area).

  In the root directory information, management information file, video file, audio file identification information and the like are described.

  In the management information file, address information (start address, end address, relative logical block number, byte number, logical block number, time information, etc.) information necessary for reproducing the video information packet in the video file is described. The

By the way, when a management information file cannot be found for some reason, there is a method of accessing a desired file according to a file entry included in the file system (for example, Patent Document 1).
JP 2004-171382 A

  As described above, the DVD (including the next-generation DVD and the next-generation high-density DVD) playback method and apparatus are based on the premise that the management information file is used as navigation information when the video file data is played back. It is said. However, in the above-mentioned Patent Document 1, a method of using a file entry of a file system is proposed when a management information file cannot be found for some reason (for example, data corruption such as a scratch).

  Therefore, in this method, when the management information file is normally found, the video file is accessed based on the management information file. However, if there is a problem in the contents of the management information file itself (for example, a shift / damage of the logical block address of the access destination), this problem cannot be avoided.

  That is, the information in the management information file is not always stable. For example, some information in the management information file may be lost due to a scratch on the disk. In particular, when information indicating the start address of a video file is damaged or when a management information file reading error occurs, it is impossible to access the video file. Further, in manufacturing, if the logical block address described in the management information file is shifted or incorrect, normal access is impossible.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an information recording medium reproducing method and apparatus capable of accessing the video file from another route even when the video file cannot be accessed due to, for example, damage to the management information file. There is to do.

  In order to solve the above problems, in an information recording medium having a data area and a management area, the management area includes a file system, and the file system has a logical sector number and a logical block number for the information recording medium. And at least a video file, a management file, and root directory information thereof are managed in the logical block number allocation area, and the management file is necessary for reproducing a packet of video information in the video file. The logical block address information is described, and the information reproducing method by the reproducing apparatus includes reproducing the video data for accessing the video file based on the logical block address information specified in the management file by the first route, Included in root directory information § yl entry, reproduction of the second route video data to be accessed directly the video files based on file size information are possible, characterized in that as is switched to reproduction by the first and the second route.

  According to the above means, even when the video file cannot be accessed due to, for example, corruption of the management file, the video file can be accessed from another route, and resources can be prevented from being wasted.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a volume space of a DVD. A data area exists between the lead-in area on the inner circumference side and the lead-out area on the outer circumference side of the disk. Physical sector numbers are assigned to the lead-in area, data area, and lead-out area. A logical sector number is assigned to the data area. In the logical sector area, a UDF bridge volume structure as a file system and an ISO9660 file structure are described. In addition, a UDF file structure, a file data structure, and the like are described. Logical block numbers are assigned to areas such as UDF file structure and file data structure.

  FIG. 2 shows an example of the UDF file structure. In the logical block numbers 0 and 1, a file set descriptor and a terminating descriptor are described. This information indicates that a root directory describing the file set hierarchically exists. The logical block number 2 describes a file entry for accessing the root directory. The logical block number 3 describes a file identifier existing in the main root directory, and the logical block number 4 describes information for accessing the root of the video title set.

  The logical block number 5 describes the identifier of each file existing in the video title set directory (subdirectory). The logical block number 6-13 describes a file entry for accessing each file in the video title set directory.

  The logical block number 14 describes a file entry for accessing the root of the audio title set. The logical block number 15 describes the identifier of each file existing in the audio title set directory (subdirectory). In the logical block number 6-13, a file entry for accessing each file in the audio title set directory is described.

  FIG. 3 shows the root directory of the video title set and the root directory of the audio title set.

  VIDEO_TS. IFO is a main video management information file (management information file), and VIDEO_TS. VOB is a video object for the video management menu. VIDEO_TS. BUP is a backup file of the video management information. VTS_01_0. IFO is a local video title set management file (management information file), VTS — 01 — 0. VOB is a video object for a local video title set menu. The main management information file includes a local management information file.

  VTS_01_1. VOB, VTS_01_2. A VOB is a video object set for a title. VTS_01_0. BUP is local video title set (management) backup information.

  As for audio, management information files, title set files, backup files, and the like exist as in the case of video.

  FIG. 4 shows the format of the file entry. In this file entry, a plurality of allocation descriptors (L_AD) describing the positions of the corresponding files are described. The recording position of the file can be grasped one after another from the plurality of allocation descriptors. The address and extent length of some logical blocks of the corresponding file are described in bytes. Various information about the file is also described.

  FIG. 5 shows a configuration example of a reproducing apparatus to which the present invention is applied. The playback device basically includes a control block 20 and a playback block 30. The video application content recorded on the information recording medium 1 is read by the optical pickup of the disk drive unit 201 and supplied to the reproduction block 30. In the reproduction block 30, the data processor unit 300 performs demodulation processing and error correction processing of the video application content, and extracts it as an MPEG program stream. In the separation unit (DMUX) 301, the MPEG program stream is separated into video, sub-picture, and audio packs. The video pack is sent to the video decoder 302, the sub-picture pack is sent to the sub-picture decoder 303, and the audio pack is Data is transmitted to the audio decoder unit 304.

  The video decoder unit 302 decodes the elementary data in the video pack and transmits it to the video processor unit 305. The sub-picture decoder unit 303 decodes elementary data in the sub-picture pack and transmits it to the video processor unit 305. The video processor unit 305 superimposes the decoded video and sub-picture data, performs analog conversion by the D / A conversion unit 306, and outputs the result to the video output terminal. The audio decoder unit 304 decodes the elementary data in the audio pack, converts the analog data by the D / A conversion unit 306, and outputs it to the audio output terminal.

  A micro processing unit (MPU) unit 202 of the control block 20 controls the entire system including the reproduction block 30 by a program stored in a read only memory (ROM) unit 203. Also, processing such as playback / stop is executed in accordance with a user input instruction input from the key input unit 205. The memory unit 204 temporarily stores status information and the like, and stores system information in a nonvolatile memory.

  The MPU unit 202 includes therein a key input determination unit a that determines a key input unit 205 or a remote controller input. In addition, a first root reproduction control unit b that accesses a video file and reproduces video data based on logical address information specified in a management information file described later is provided. Also, a second root playback control unit c for directly accessing and playing back the video file based on the file entry, file size information, etc. included in the root directory information. Furthermore, it has the switching part d which switches the 1st and 2nd route reproduction | regeneration control parts b and c.

  FIG. 6 is a flowchart for explaining the characteristic operation of the apparatus of the present invention. When the playback device enters the playback mode and starts, the file system is read and the file entry is analyzed (SA1). Next, when there is an instruction to play a video file, management information is read based on the file entry (step SA3). Here, it is checked whether or not the management information is normal. For example, it is determined whether information in the packet can be normally determined (step SA4).

  The case where the information in the packet cannot be determined normally is, for example, the case where the read information cannot be logically determined. The judgment material includes a header, the number of bits of information, and an information delimiter. If the information is abnormal, the process proceeds to step A8 described later.

  If the management information is normal in step SA4, the menu packet is read based on this management information (step SA5). Next, in step SA6, it is determined whether or not the data is normal. Whether the data is normal is, for example, determination of whether the navigation pack, video pack, and audio pack have a normal data structure. If normal, the video object is played back based on the management information (playback control by the first route is performed).

If it is determined in step SA6 that the data is abnormal, for example, the read address may be shifted from the original position. In such a case, the process proceeds to step SA8. In step SA8, the file identifier (in logical block number 5) of the file system shown in FIG. 2 is determined, and a menu is generated (step SA8). For example,
VIDEO_TS. IFO: Video management information VIDEO_TS. VOB: Video object for video management menu,
VIDEO_TS. BUP ... backup of video management information,
VTS_01_0. IFO: Local video title set (management) information,
VTS_01_0. VOB: Video title set menu, Video object,
VTS_01_1. VOB: Title / Video object set,
VTS_01_2. VOB: Title / Video object set,
VTS_01_0. BUP ... Video title set (management) backup,
Create a menu that says At the same time, a message is displayed that the management information is abnormal.

  Next, it is determined whether or not the user has selected a desired video title set for playback. The user moves the cursor while viewing the above menu, moves the cursor to the position of the desired video object set, and presses the enter key (step SA9).

  Then, using the file entry of the designated video title set, the stream of the video title set is read (playback control of the second route is performed). Then, the packet of 2048 bytes is analyzed, and video data, sub-picture data, and audio data are decoded. The control information read from the navigation packet is temporarily stored in the memory of the control unit. When the playback of the video title set is finished, the previous menu is displayed and the next operation is waited for.

  As described above, data recorded on a disk such as a DVD is normally designated as an LBA (logical block address) based on management information, and is read as a lump of data such as 2048 bytes. On the other hand, a moving image playback disk such as a DVD is equipped with a file system such as ISO9660 or UDF, and data indicated by its logical structure can be read out as a file. When a file is read, internal video data (MPEG standard) can be extracted by analyzing a packet structure of 2048 bytes in DVD. The packet sequence can be recognized by checking a packet header whose format is determined in advance. At this time, the data of the navigation pack (arranged at the head of each VOBU) is stored in the memory of the control unit for a certain period of time, so that functions such as fast forward and reverse feed can be obtained.

  In general, LSB-designated data access is direct, so the operation is fast and the burden on the firmware is small. On the other hand, the file system has a complicated structure because it is accessed via a file format driver, but is used in a personal computer.

  Management information recorded on a disc such as a DVD can be read directly by LBA or as a file. The management information includes information such as a search destination and is described in LBA.

  When management information recorded on a disc such as a DVD is read through a file system, the file name to be referred to is determined from the title number or chapter number and accessed.

In this way, data recorded on a disc such as a DVD can be read out by two systems.

  The method of directly specifying data with LBA is closely related to the structure of the disk. Since the logical structure and the disk address are not directly related, the LBA value may become invalid due to a disk creation error or the like. In that case, of course, it is impossible to continue playing the video.

  On the other hand, in the access method via the file system, it is possible to read the data specified by specifying the file regardless of the structure of the disk, so that a mistake in creating the disk does not easily occur. For this reason, when the method of directly designating data by LBA fails, the present invention provides a method of performing data access via the file system and reading out correct data.

  When a DVD player starts playing a video or performs a title jump or chapter jump, the player's firmware refers to the LBA address of the jump destination from the management information, and sends an ATAPI command for making a read request by designating the LBA address. Send to drive.

  The optical drive returns data in response to the ATAPI command. At this time, packet data of 20488 bytes is read out, and the head of the packet data is data called a packet header and a pack header, and the structure is analyzed to determine whether it is illegal.

  If the structure is correct, it is determined that correct data can be read, and data access is continued. If the structure is invalid, switch to access via the file system.

  First, a file name is generated from the title number and chapter number of the management information, and data is accessed using the file name. In this way, even if there is an error in the LBA description, video reproduction can be continued by accessing the data via the file system.

  In the above description, it is determined whether or not the read management information is normal, and the mode is automatically shifted to the video access mode using the file system. However, the user may switch manually.

  In the above description, the current DVD system has been described as an example. However, the present invention can be similarly applied to a high-definition DVD (so-called HD DVD) system or a Blu-ray disc system in which high-density recording is performed. Of course.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

FIG. 1 is an explanatory diagram of a volume space of a DVD. FIG. 2 is a diagram showing the description content of the UDF file structure. It is explanatory drawing which shows the root directory of a DVD system. It is a figure which shows the description content of a file entry. 1 is a configuration explanatory diagram of a playback apparatus to which the present invention is applied. FIG. It is a flowchart which shows the operation example of the apparatus of this invention.

Explanation of symbols

20... Control block, 30... Playback block, 202... MPU unit, a .. key input determination unit, b... First route playback control unit, c. Department.

Claims (4)

In an information recording medium having a data area and a management area, the management area includes a file system, and the file system assigns a logical sector number and a logical block number to the information recording medium, and the logical block At least a video file, a management information file, and a root directory thereof are managed in a number allocation area, and the management information file includes logical block address information necessary for reproducing data in a packet of video information in the video file. Has been described,
The information playback method by the playback device is as follows:
Playback of the video data for accessing the video file based on the logical block address information specified in the management information file by the first route;
The video data that directly accesses the video file based on the file entry and file size information included in the root directory can be played by the second root,
A method for reproducing an information recording medium, wherein reproduction according to the first and second routes can be switched.   2. The information recording medium according to claim 1, wherein the switching is executed in accordance with an error determination result when reproduction information by the management information file is checked in order to perform reproduction by the first route. Playback method.   2. The information recording medium reproducing method according to claim 1, wherein the switching is executed in response to a manual operation input. In an information recording medium having a data area and a management area, the management area includes a file system, and the file system assigns a logical sector number and a logical block number to the information recording medium, and the logical block At least a video file, a management information file and its root directory information are managed in a number allocation area, and the management information file describes logical address information necessary for reproducing a video information packet in the video file. And
The information playback unit by the playback device
Reproduction control means by a first route for reproducing the video data by accessing the video file based on the logical address information specified in the management information file;
Playback control means by a second route for directly accessing the video file based on a file entry included in the root directory information and playing the video file;
A reproducing apparatus for an information recording medium, comprising switching means for switching reproduction control means according to the first and second routes.

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