JP4734898B2 - Information processing apparatus, information processing method, and program - Google Patents

Description

  The present invention relates to an information processing apparatus and method for executing a predetermined data processing operation involving data writing / reading on, for example, a removable storage medium. The present invention also relates to a program executed by such an information processing apparatus.

  As a storage medium, for example, in various optical disk-shaped recording media, as one of the conditions for assuring that recording / reproduction is normally performed, the power of the laser beam irradiated on the signal recording surface during recording / reproduction (Laser power) is appropriate. For this reason, as described in Patent Documents 1 and 2 and the like, calibration for laser power is performed for each optical disc-shaped recording medium to be recorded and reproduced.

In addition, when executing a specific process (data process) that involves writing / reading data to / from a storage medium, a condition for preventing the data process from failing may include a data transfer rate of the storage medium. For example, consider playing a moving image file as data processing. In order for a moving image file to be reproduced without failure, a data transfer rate of a certain level or more is required according to the format of the moving image file. In this case, for example, even if the device serving as the storage medium host and the processing on the application side satisfy the data transfer rate, if the data transfer rate for the storage medium is lower than the data transfer rate, this is the cause. As a result, the video playback is interrupted and smooth operation cannot be obtained.
Therefore, it is often the case that a vendor that provides a device or application that hosts a storage medium designates the use of a storage medium with a data transfer rate above a certain level in order to ensure that data processing does not fail. become. Specifically, for example, a model of a storage medium whose operation is guaranteed is specified by an instruction manual (manual) of the device or application. The user sees this description and obtains and uses a storage medium in the operation guarantee range.

JP-A-8-329469 JP 2001-344753 A

However, when it is desired to use a storage medium having a data transfer rate higher than a certain level as described above, the user is burdened with the burden and burden of selecting and obtaining such a storage medium. It can be said that this is not preferable.
In addition, as a practical matter, even if the use of a storage medium having a certain data transfer rate or more is specified in the manual or the like as described above, the user always obtains and uses the storage medium of the specified model. There is a fact that it is not always true. In addition, this is noticeable for semiconductor memory devices that comply with the Compact Flash standard, but even if they are manufactured under the same standard, there is a large difference in the data transfer rate for each model, for example. May exist.
For this reason, for example, if a user obtains and uses a storage medium having a data transfer rate lower than a certain level, a certain device or application may have a low data transfer rate. There is a possibility that a normal operation cannot be obtained. For example, this may be considered that a failure has occurred unexpectedly depending on the user, which may lead to inconveniences such as a cause of impairing the reliability of the product.
Accordingly, an object of the present invention is to obtain data processing results of normal operation as much as possible even in a situation where storage devices with various data transfer rates are used.

Therefore, the present invention is configured as follows with respect to the information processing apparatus.
That is, a storage medium connection unit to which an external storage medium is connected , an acquisition unit that acquires medium identification information from the external storage medium that is connected to the storage medium connection unit, and the connection unit that is connected to the storage medium connection unit Measuring means for measuring the data transfer rate in the storage area of the external storage medium by measuring from the upper address area of the storage area and measuring from the lower address a predetermined number of times, and connected to the storage medium connecting means Data processing capable of executing predetermined data processing involving writing and / or reading of data with respect to the external storage medium connected to the storage medium connecting means, and determination means for determining a data transfer rate for the external storage medium The data processing execution means can be executed according to the execution means and the data transfer rate determined by the determination means. And a setting means for setting whether to execute for a particular data processing being a discernible medium identification information for each single said storage medium, the data transfer rate of the storage medium identified by the medium identification information Holding means for holding transfer rate information for each medium formed by associating the transfer rate information converted into the data processing level based on the processing level conversion table, and the determination means includes the transfer rate information for each medium When the medium identification information that matches the medium identification information acquired by the acquisition unit is searched, a determination is made based on the transfer rate information associated with the searched medium identification information. If the medium identification information that matches the medium identification information acquired by the acquisition means is not found, the determination is made based on the measurement result of the measurement means. In addition, when the determination means refers to the transfer rate information for each medium and the medium identification information that matches the medium identification information acquired by the acquisition means is not searched, the acquisition means The medium transfer rate information obtained by associating the acquired medium identification information with the transfer rate information obtained by converting the data transfer rate obtained based on the measurement result of the measuring means into the data processing level based on the processing level conversion table. And generating means for generating.

Also, as an information processing method, by measuring the data transfer rate in the storage area of the external storage medium connected to the storage medium connection means from the upper address area and the measurement from the lower address of the storage area a predetermined number of times Measurement procedure for measuring, acquisition procedure for acquiring the medium identification information from the external storage medium connected to the storage medium connecting means, and an external storage medium connected so as to enable communication including at least data writing / reading A determination procedure for determining a data transfer rate for the data, a data processing execution procedure capable of executing predetermined data processing involving writing and / or reading of data with respect to the connected external storage medium, and the determination procedure Depending on the data transfer rate, the specific data processing in which the above data processing execution procedure can be executed. A setting procedure for setting the executability of the identifiable medium identification information for each single said storage medium, the data processing based data transfer rate of the storage medium identified by the medium identification information to the processing level conversion table The transfer rate information converted into the level and a holding procedure for holding the transfer rate information for each medium formed in association with each other are executed, and the acquisition is performed by referring to the transfer rate information for each medium in the determination procedure. When the medium identification information that matches the medium identification information acquired by the procedure is searched, the determination is made based on the transfer rate information associated with the searched medium identification information, and the medium acquired by the acquisition procedure If medium identification information that matches the identification information is not found, a determination is made based on the measurement result of the measurement procedure and the determination is made. If the medium identification information that matches the medium identification information acquired in the acquisition procedure is not searched with reference to the medium transfer rate information in the procedure, the medium identification information acquired by the acquisition procedure, and the measurement procedure And a generation procedure for generating the medium-specific transfer rate information in association with the transfer rate information obtained by converting the data transfer rate obtained based on the measurement result to the data processing level based on the processing level conversion table. It was decided to constitute as follows.

  In addition, the program is configured by causing the information processing apparatus to execute the procedure configuring the information processing method.

  According to each of the above configurations, when the connection with the external storage medium is performed, the data transfer rate of the external storage medium is determined, and the specific data that is originally executable according to the determination result The permission / prohibition (permitted / not permitted) is set for the process. This permits processing that does not fail under the conditions of the data transfer rate of the external storage medium, and prohibits processing that fails under the conditions of the data transfer rate of the external storage medium. This means that it is possible to obtain an environment where data processing of a level and load adapted to the data transfer rate of the medium is executed.

Thus, according to the present invention, even if the data transfer rate of the external storage medium to be connected is below a certain level, for example, for a specific data process, the level at which the data transfer rate fails (processing load) However, instead, the data processing is executed at a level that can be normally executed without failure at the data transfer rate.
In other words, when an external storage medium with a data transfer rate below a certain level is used, a situation where data processing is not executed at all is avoided, and data processing at a lower level and light load is executed. As a result, data processing results of normal operation can be obtained as much as possible. Thereby, the reliability as a product improves, for example. In addition, since the user does not need to pay attention to the data transfer rate (quality) of the external storage medium, the burden on this aspect is reduced.

  Hereinafter, the best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described. In this embodiment, a case where the configuration of the information processing apparatus according to the present invention is applied to a digital video camera is taken as an example.

FIG. 1 is a block diagram illustrating a configuration example of a digital video camera 1 according to the present embodiment.
In the digital video camera 1 shown in this figure, the optical system unit 2 includes an imaging lens, a diaphragm, and the like, and forms incident light on the photoelectric conversion unit 3 as imaging light. Further, the optical system unit 2 includes a focus adjustment mechanism for focus adjustment, a diaphragm variable mechanism that varies the diaphragm according to the diaphragm value, and the like. Is performed by a drive signal output from the camera function unit 6. The camera function unit 6 is configured to output a required drive signal so as to obtain an appropriate focus state, aperture state, and the like, under the control of the CPU 10.
For example, when an optical zoom function is to be provided, a zoom mechanism for moving the zoom lens is provided in the optical system unit 2 and driving for moving the zoom mechanism in accordance with the control of the CPU 10 in the same manner as described above. What is necessary is just to provide a part. Further, the camera function unit 6 may be configured to provide a strobe light emission function after providing a strobe.

  The photoelectric conversion unit 3 includes, for example, a CCD (Charge Coupled Device) that is a photoelectric conversion element, and performs imaging conversion by photoelectrically converting imaging light incident from the optical system unit 2 and imaged on the light receiving surface. Is output to the video signal processing unit 4. At the time of shooting, for example, an instruction of a shutter speed determined according to the exposure setting result is notified from the CPU 10 to the video signal processing unit 4. The video signal processing unit 4 outputs a scanning timing signal corresponding to the notified shutter speed to the photoelectric conversion unit 3. The photoelectric conversion unit 3 performs scanning according to the scanning timing signal, executes photoelectric conversion processing, and outputs a video signal.

The video signal processing unit 4 performs waveform shaping on the analog video signal (captured image signal) input from the photoelectric conversion unit 3 by performing gain adjustment and sample hold processing, for example, and then performs A / D conversion. By doing so, it is converted into digital video signal data. Then, for the digital video signal obtained by this conversion process, for example, a process for generating display luminance data is performed, and a video signal process for displaying on the display unit 7 is executed. Accordingly, the video signal processing unit 4 can execute signal processing for so-called on-screen display so that a character image or the like can be displayed superimposed on the captured image under the control of the CPU 10.
The actual display device employed as the display unit 7 is not particularly limited, but currently, liquid crystal display panels are widely employed.

In addition, the video signal processing unit 4 performs, for example, compression encoding processing by a predetermined method on the digital video signal obtained by converting the analog video signal input from the photoelectric conversion unit 3 to generate compressed video data. Is possible.
The digital video camera of this embodiment also has a still camera function. That is, it is possible to generate a still image data file in a predetermined format as a photograph for the captured image signal. Such image processing is also performed by the video signal processing unit 4.

Further, the video signal processing unit 4 uses an image (video) signal input from the photoelectric conversion unit 3 or a file (AV file) of AV (Audio Video) data read from a medium described later in a predetermined format. It can be converted into an analog video signal or a digital video signal and output to an external device or the like via the image input / output unit 5.
The image input / output unit 5 can input a video signal of a predetermined system from the outside, and the input video signal can be displayed on the display unit 7 through the processing of the video signal processing unit 4. The video signal processing unit 4 converts the video signal input from the image input / output unit 5 into recording data and transfers the video signal to the media controller 13 in the same manner as the analog video signal input from the photoelectric conversion unit 3. You can also.
Correspondingly, the image input / output unit 5 includes, for example, a video (image) signal output terminal / video signal input terminal according to a predetermined method.

In addition, the digital video camera 1 according to the present embodiment includes an audio processing unit 8 and an audio input / output unit 9 so that audio signals can be input / output.
First, for voice input, a microphone or the like is provided as the voice input / output unit 9, and external voices are collected and converted into voice signals to be inputted. The audio signal input in this manner is output to the audio processing unit 8. The audio processing unit 8 performs audio signal processing such as conversion into compressed audio data encoded by an audio compression encoding method corresponding to compression encoding of a captured image.

The CPU 10 forms an AV file of a predetermined format from the compressed video data for the captured image obtained by the video signal processing unit 4 and the compressed audio data for the collected sound obtained by the audio processing unit 8. Control processing is executed. In this AV file, the playback time axis of the sound output by reproducing the compressed audio data is synchronized with the moving image output by reproducing the compressed video data. The configuration for actually forming the AV file may be a software configuration for digital signal processing obtained by the CPU 10 executing the program, or hardware for forming the AV file. In addition, the CPU 10 may be configured to control the operation of the hardware.
The data as the AV file is transferred to the media controller 13 as recording data, for example, under the control of the CPU 10. The CPU 10 can also transfer a still image data file of a predetermined format as a photographic image generated by the video signal processing unit 4 to the media controller 13 as recording data.

  The audio input / output unit 9 may be configured to include an audio signal input terminal and the like to input an audio signal from an external audio device or the like. The audio processor 8 converts the audio signal input from the audio signal input terminal into a digital audio data file in a predetermined format. The CPU 10 can also transfer data of such a digital audio data file to the media controller 13 as recording data.

  The media controller 13 is configured to be able to execute control processing related to data processing for these media in association with predetermined different types of external media (storage media) and external storage devices (storage devices) in cooperation with the CPU 10. Is done. Data processing for the media here refers to data to be stored in the media, such as media format processing and file write / read processing for file management information (file management information). Any related process.

In the present embodiment, a hard disk drive (HDD) is first connected to the media controller 13. The HDD is a storage device including a magnetic disk as a storage medium, which is called a hard disk as is well known, and currently, a large capacity of a gigabyte class can be obtained at a relatively low cost. As is well known, physical data is read / written from / to a magnetic disk as a storage medium by applying a magnetic field and detecting a magnetic field while tracing a track formed on the magnetic disk by a magnetic head. Realized.
In this case, the HDD may be fixedly incorporated in the digital video camera 1, for example, or may be removable from the digital video camera 1 (host) according to a predetermined standard. It may be said.

Further, in this figure, the media controller 13 is capable of data processing corresponding to a predetermined type of optical disk, magneto-optical disk, and a semiconductor storage device which is a storage device including a semiconductor memory element. .
In the case of corresponding to an optical disk and a magneto-optical disk, the device includes a device as a drive configured to be able to write / read data corresponding to these recording (storage) media, and these device and media controller 13 will be connected.
In the case of supporting a semiconductor memory device, the main body of the digital video camera 1 is provided with a slot in which the semiconductor memory device is inserted and removed according to the actual standard of the semiconductor memory device. When the semiconductor memory device is properly loaded in this slot, the pin terminal of the semiconductor memory device is connected to the electrode of the connector part of the slot, so that the semiconductor memory device can communicate with the media controller 13. It will be connected as possible.

  As described above, the media controller 13 sends the recording data to the media (storage medium, storage device) connected to the media controller 13 in response to the transfer of the recording data. Is further transferred to the medium selected as the target. In the medium to which the data has been transferred, the data is written and stored in the storage area in accordance with an instruction from the media controller 13 side. In this way, data stored in the medium is stored and managed as a file. Note that management of files stored on the media is performed by a predetermined file system.

For example, when playing back an AV file as playback of a file stored in a medium, the CPU 10 and the media controller 13 access and read the designated AV file. The AV file read in this way is separated into compressed video data and compressed audio data by processing of the CPU 10, for example, and the compressed video data is transferred to the video signal processing unit 4, and the compressed audio signal is processed by the audio processing unit. 8 is handed over.
In this case, the video signal processing unit 4 and the audio processing unit 8 respectively perform necessary reproduction signal processing including demodulation processing on the compressed video data and the compressed audio data transferred as described above. As a result, an image obtained by reproducing the compressed video data is displayed on the display unit 7, and the audio input / output unit 9 has an audio signal obtained by reproducing the compressed audio data in synchronization with the reproduction time of the image. Then, it can be output as audio by the speaker, or can be output from the headphone terminal.

  In addition, for example, an audio data file reproduced from a medium is output as a predetermined format audio signal and audio data to the outside via the audio input / output unit 9 after being subjected to the audio signal processing of the audio processing unit 8. It is also possible. In this case, the audio input / output unit 9 includes an audio output terminal corresponding to a format of a predetermined audio signal and audio data output from the audio processing unit 8.

A CPU (Central Processing Unit) 10 executes various control processes for the digital video camera 1 by executing a program. The ROM 11 stores various setting information used for the CPU 10 to execute processing in addition to various programs executed by the CPU 10. The RAM 12 is used as a work area when the CPU 10 executes processing according to a program, and holds data such as various arithmetic processing results.
The non-volatile memory 12a is formed of a memory element such as a flash memory that does not erase the stored contents even when the power supply is stopped, and data writing / reading is executed under the control of the CPU 10. The The data (information) to be stored in the nonvolatile memory 12a is generally setting information whose contents are appropriately changed, but is not particularly limited, and the actual specifications of the digital video camera 1 are not limited. It is sufficient to store various necessary information according to the above.

  In this case, the operation input unit 15 collectively indicates various operators provided in the digital video camera 1. For example, the operators in the operation input unit 15 include a shutter button operated at the time of taking a picture, an operator for selecting a shooting mode, an operator for increasing / decreasing parameters, and the like.

  The communication unit 16 is a part configured by mounting hardware and software for communicating with an external device by a predetermined data communication method according to the control of the CPU 10. The data communication system supported by the communication unit 16 is not particularly limited regardless of whether it is wired or wireless, and the number of corresponding data communication systems should not be limited. At present, examples of data communication methods include a network such as Ethernet (trademark), a data bus standard such as USB (Universal Serial Bus), IEEE1394, and the like. In the case of wireless, short-range wireless communication between devices such as Bluetooth (trademark) and wireless LAN (Local Area Network) standards such as IEEE802.11a / b / g can be cited.

  The power supply unit 17 supplies operating power to various hardware devices in the digital video camera 1 and includes, for example, a power supply circuit that operates by receiving power supply from a battery or a power adapter.

As described above, in the digital video camera 1 of the present embodiment, mainly the AV file obtained by imaging / sound collection is stored in the HDD, various optical disk-shaped recording media (including magneto-optical disks), and the semiconductor storage device. It can be stored in a medium (storage medium).
The file stored in the medium as described above is normally managed by a file system in a predetermined format, but in this embodiment, it is managed by a FAT (File Allocation Table) file system. It is supposed to be. As is well known, the FAT file system manages files by a tree-type directory structure, and data writing / reading is performed by a logical minimum data management unit called a cluster. It is said that. A cluster is a unit obtained by collecting a predetermined number of sectors, which are the minimum units of physical data writing / reading on a medium.

FIG. 2 shows a general system configuration of the FAT file system using a hierarchical model.
First, this hierarchical model is roughly divided into a software layer and a hardware layer as a lower layer.
In this case, the software layer corresponds to a program executed by the CPU and software processing realized by various firmware, middleware, and the like in a device that is a host (digital video camera 1 in the embodiment) with respect to the medium. It is supposed to be. As shown in the figure, the software layers in this case include the application 100, the file system 101, and the device driver 102 from the upper layer to the lower layer.
It can be considered that the physical storage area of the medium itself is located in the hardware layer.

  The application 100 has a file recording / playback function, for example, and is compatible with application software that uses media, and makes an access request at the file level to the file system 101.

The file system 101 corresponds to software that realizes a function as a file system. In this embodiment, since the FAT file system is adopted, the software that provides the functions of the file system 101 is also configured corresponding to the FAT file system.
In the file system 101, the access request at the file level from the application 100 is converted into a cluster level that is a data management unit in the FAT file system format, and an access request is made to the device driver 102.

  The device driver 102 corresponds to software for controlling a medium as a device to be controlled. An access request at a cluster level according to the FAT file system format from the file system 101 is recorded and reproduced on the medium 103. The access level to the medium 103 is requested after conversion to the sector level as a unit.

The medium 103 in this case is logically formatted (initialized) according to the FAT file system. In FIG. 1, a storage medium and a storage device connected to the media controller 13 such as an HDD, an optical disk-shaped recording medium, and a semiconductor storage device correspond to the medium 103 here. Then, in response to the sector level access request from the device driver 102, the medium 103 reads data from the designated sector address and returns it to the device driver 102. That is, an access response at the sector level is executed.
The device driver 102 receives an access response from the medium 103 at the sector level, that is, receives data in units of sectors, and treats the received data as data in units of clusters and transfers it to the file system 101 (at the cluster level). Access response).
The file system 101 transfers data received from the device driver 102 to the application 100 as file level data. The application 100 executes a required process at the application level according to, for example, an operation input by the user on the data received as a file.

  Further, the FAT file system manages storage files with a tree-type directory structure, and manages files as a cluster unit set. Such file management and data management are realized by providing directory entries and table information called FAT as is well known. The directory entry is information indicating the location of a file or directory (subdirectory) on the medium at the cluster level, and the FAT is information indicating a chain (link or link) at the cluster level that forms the directory or file.

FIG. 3 shows the format structure of the media according to the FAT standard.
Although a plurality of FAT formats are defined, here, the format structure corresponding to each of the FAT16 and FAT32 formats is shown.
First, the format structure corresponding to the FAT 16 shown on the left side of FIG. 3 will be described.
The structure shown in this figure is logical according to LBA (Logical Block Addressing). In other words, the top sector is the top sector (LBA = 0), and the block (sector) number advances downward thereafter.
Further, in the FAT file system, one physical storage area can be divided into a plurality of partitions, but here, for convenience of explanation, a format structure in the case of one partition is shown.

  First, the head sector represented as LBA = 0 is a boot area called MBR (Master Boot Recorder).

The structure of MBR is shown in FIG.
One sector has a size of 512 bytes. Therefore, the MBR is 512 bytes. In FIG. 4A, for the 512 bytes in the MBR area, the last byte position from the beginning is expressed by assigning a hexadecimal number from 0000h to 01FFh, and then arranged in units of 16 bytes. As shown. In the hexadecimal notation, h indicating the hexadecimal notation is added to the end of the numerical value, such as 0000h or 01FFh.
First, a 446-byte area from byte positions 0000h to 01BDh stores a code (boot code) for booting when used as an OS (Operating System) boot medium. It is an area.

  A 64-byte area from byte positions 01BEh to 01FDh in the MBR is used as a partition table, and stores predetermined information required for each partition at the time of startup. This partition table area is further divided into four areas in units of 16 bytes. These four divided areas are partitioned into partition 1, partition 2, partition 3, and partition 4 in order from the top. It is a corresponding area. Each area corresponding to each of these partitions is an entry area for each partition.

  Also, 55AAh is stored in the final 2-byte area in the MBR as an identifier that the current sector is the MBR.

The partition entry has a structure shown in FIG. First, the most significant byte position 00h is an area for storing a flag indicating whether or not the partition is designated as a startup drive.
In the subsequent 3-byte area at byte positions 01h to 03h, a value expressing the start sector of the partition in terms of CHS (Cylinder / Head / Sector) is stored. A 3-byte area composed of byte positions 05h to 07h stores a value representing the end sector of the partition in CHS.
In addition, a value indicating the start sector of the partition by LBA is stored in a 4-byte area at byte positions 08h to 0Bh.

  A 4-byte area consisting of byte positions 0Ch to 0Fh stores a value indicating the data size (partition size) of the partition.

  A 1-byte area indicated by the byte position 04h stores a value indicating a type of a platform, a file system, or the like corresponding to the partition, which is also called a system identifier.

Returning to FIG.
An empty area corresponding to a predetermined number of sectors is provided after the head sector as the MBR. Then, an area in units of partitions is formed by a sector area after this empty area.

An area from the first sector to a predetermined number of bytes in one partition is a system area for storing system-related information.
An area of a predetermined number of bytes starting from the head sector in this system area is a BPB (BIOS Parameter Block / Boot Parameter Block). Here, for example, a BIOS (Basic Input / Output System) on the host side is used for the current partition. As described above, necessary data to be used by the block device control program is stored. The information stored in the BPB includes information such as the number of FAT areas, the start sector of the main FAT area, and the number of sectors in the FAT area, which will be described next.

  Following BPB, FAT1 and FAT2 FAT areas are arranged in this order. Normally, one of the FAT1 and FAT2 areas is used as the main FAT area. The other FAT area is generally used as a spare area or backup area of the main FAT area, for example, as a mirror area obtained by copying the contents of the main FAT area.

These FAT areas are areas formed by arranging FAT entries in the order of cluster numbers in the data area. There is a one-to-one correspondence between a FAT entry and a cluster in the data area. In the FAT entry, as information on the cluster, for example, unused or in the corresponding file, according to the directory and file storage results. Information indicating any one of a cluster number to be chained after the current cluster, a defective cluster, EOF (End Of File: last cluster in a file), and the like is stored.
In the FAT16 format, the cluster number is represented by 2 bytes (16 bits), and accordingly, the size of each FAT entry is also 2 bytes.

  Subsequent to the FAT1 and FAT2 areas, a root directory entry of a predetermined size is arranged. The root directory entry stores directory entries for directories and files in the root directory.

  A sector area lower than the root directory is a data area. Writing / reading data to / from this data area is managed by the FAT file system. Therefore, as shown in the figure, the file system format structure is such that the data area is managed in cluster units composed of a sequence of one or more predetermined number of sectors. As described above, the FAT area is formed with the FAT entries corresponding to all the clusters forming the data area in principle.

Next, a format structure corresponding to FAT32 shown on the right side of FIG. 3 will be described.
Also in the format structure corresponding to FAT32, the MBR is arranged in the head sector represented by LBA = 0. Then, an area in units of partitions is arranged subsequent to the empty area of a predetermined number of sectors arranged after the MBR.

As a system area in the partition area of the FAT32 compatible format structure, an FSinfo area is provided after BPB.
The FSinfo is an area for storing predetermined information used to calculate the free space in the partition. The FAT areas of FAT1 and FAT2 are sequentially arranged following FSinfo.

  The FAT area in the case of the FAT32 format is also formed by arranging FAT entries corresponding to the clusters in a one-to-one order in the order of the cluster numbers. The FAT entries include predetermined entries for the corresponding clusters according to the directory and file storage results. Is stored. However, in the FAT32 format, since the cluster number is expressed by 4 bytes (32 bits), the size of each FAT entry is also divided by 4 bytes.

In the FAT32 format structure, the root directory entry area provided in the system area in the FAT16 format structure is omitted.
In the FAT32 format structure, the root directory is placed in the data area. The starting cluster number of the root directory in the data area is indicated by a value stored in a predetermined area (RootClus) in the BPB. When accessing the root directory, the cluster number recognized with reference to the RootClus is accessed. To be. The starting cluster number of the root directory indicated by RootClus is usually 2.

  In this case as well, the data area is an area in which writing / reading of data is managed in cluster units by the FAT32 file system.

Here, in the digital video camera 1 according to the present embodiment, the semiconductor storage device connected to the media controller 13 conforms to the specifications and standards of Compact Flash (registered trademark).
As a matter of fact, as a semiconductor memory device that complies with the compact flash standard, there are still various products from various manufacturers, including differences in storage capacity. In these products, for example, the data transfer rate of media for each model or individual is not uniform, and it is known that there are relatively large differences and variations.
For example, in a device as a host, some data processing that involves writing / reading of data to / from a medium such as a compact flash is executed. The data processing amount (processing load) required per unit time depends on the contents of the data processing. Will be decided. Further, according to the data processing amount per unit time, the read / write amount of data with respect to the medium per unit time, that is, the required data transfer rate is also determined.
For this reason, for example, there may be situations where the data transfer rate of the connected compact flash is lower than the value required by the data processing. In such a situation, an appropriate processing result may not be obtained due to a low media data transfer rate.
Therefore, at present, for a compact flash connected to a host device, a product that guarantees the data transfer rate required by the device is designated. In this case, if a non-designated compact flash is used, normal operation cannot be guaranteed.

However, it is considered that the user who owns the device as the host gets the designated compact flash in terms of the time and effort, and it is practically inconvenient for the user. It is naturally possible to use a compact flash that is not specified for preparation.
As described above, the use of a medium that does not have a data transfer rate sufficient for the data processing function of the host device (digital video camera 1) to be properly executed results in the data held by the host device. Situations where the processing function cannot be performed properly are treated as irrelevant. However, according to the present embodiment, even in such a situation, the user can be saved by providing an environment in which the data processing function is appropriately executed as much as possible.

  As a configuration for this, roughly, the digital video camera 1 of the present embodiment is configured such that when a medium is loaded in a slot of a semiconductor storage device and connected to be communicable, data about the connected medium is stored. The transfer rate (data processing level) is determined. The method for determining the data transfer rate will be described later. In accordance with the determined data transfer rate, settings such as restriction on predetermined data processing are performed.

Here, as the data processing, an example is an image resolution (image size) setting which is one of video signal processing for recording a moving image obtained by a captured image as an AV file, and the data transfer rate of the medium is taken as an example. A specific example of data processing change according to the above will be described with reference to FIG.
The resolution at which the digital video camera 1 of the present embodiment records a moving image as a captured image as an AV file is 1024 × 768, 800 × 600, 640 × 480, 320 × 240 in descending order of resolution. It is assumed that the mode can be selected and set in four stages.
In addition, corresponding to the four resolutions as described above, the data transfer rate tfrt of the compact flash is level 3 where tfrt ≧ a (a or more), b ≦ tfrt <a (b or more and less than a) ), Level 2 where c ≦ tfrt <b (c and less than b), and level 0 where tfrt <c (less than c). For the values a, b, and c, predetermined values are set after satisfying the relationship of a <b <c. In this case, how to specifically set the values a, b, and c should be determined in consideration of the media data transfer rate required for each of the four resolutions. become.

Then, as shown in FIG. 5, for each data transfer rate divided into four stages, it is decided whether or not the four stages of resolution can be set.
That is, when the data transfer rate of the compact flash is tfrt ≧ a (a or higher) at the highest level (level 3), the resolution from the lowest level of 320 × 240 to the highest level of 1024 × 768 is achieved. It is permitted to set all four resolutions as options.
In addition, when the data transfer rate of the compact flash is the second highest level (level 2) b ≦ tfrt <a (b or more and less than a), the highest resolution among the four resolutions is 1024 ×. The setting of 768 is prohibited, and the remaining resolutions of 800 × 600, 640 × 480, and 320 × 240 are selected as options.
In addition, when the data transfer rate of the compact flash is the third highest level (level 1) c ≦ tfrt <b (from c to less than b), the highest level and the second of the four resolutions. Setting of high resolutions of 1024 × 768 and 800 × 600 is prohibited, and the remaining two resolutions of 640 × 480 and 320 × 240 are options.
Further, when the data transfer rate of the compact flash is tfrt <c (less than c) of the lowest level (level 0), only one resolution of the lowest level of resolution 320 × 240 is selected from the four resolutions. Allowed.

The correspondence between the data transfer rate of such a compact flash and the resolution means the following.
For example, when a captured image is recorded as an AV file by the conventional digital video camera 1, a resolution of 1024 × 768, which is the highest level in FIG. 5, can always be set regardless of the data transfer rate of the compact flash. Become. Then, when the data transfer rate of the compact flash is below a certain level, the data transfer speed for transferring the data of 1024 × 768 to the compact flash and writing it normally cannot be obtained. There is a possibility that writing a file will result in an error.
On the other hand, in this embodiment, for example, when the data transfer rate of the compact flash is the second highest level b ≦ tfrt <a (b or more and less than a), 1024 × 768. Therefore, it is not possible to select and set the resolution, and select and set one of the lower resolutions 800 × 600, 640 × 480, and 320 × 240. In this case, although the highest quality image corresponding to the maximum resolution of 1024 × 768 cannot be obtained, it is guaranteed that an AV file write error due to the data transfer rate of the compact flash does not occur.

As described above, in the digital video camera 1 according to the present embodiment, data write / read with respect to the compact flash is involved, so that the processing result depends on the data transfer rate of the compact flash, the processing level and the processing level. Are changed and set according to the data transfer rate of the actual compact flash.
As a result, as described above, although the quality of the processing result such as image quality may deteriorate, the data processing itself is prevented from failing regardless of the data transfer rate of the compact flash. The In other words, for example, even if data processing is executed using a compact flash with a low data transfer rate that cannot normally be guaranteed, an environment in which the processing is normally executed without failure will be obtained. It is what

Note that the data processing in which the level, content, and the like are changed according to the data transfer rate of the connected compact flash should not be particularly limited as long as it involves data writing / reading to / from the compact flash. There are various possible. Here, some examples of data processing other than the AV file resolution setting will be described.
Apply the resolution setting described with reference to FIG. 5 to still image file recording.
When recording an AV file as a moving image / still image, the compression encoding data rate setting when compression encoding is performed according to a predetermined method is changed according to the data transfer rate of the compact flash.
-If you have a continuous shooting function with still images, change the maximum number of continuous shots per unit time according to the data transfer rate of the compact flash.
-When performing shuffle playback of AV files (moving images / still images), change the maximum number of files to be shuffled.
-Change shuffle playback units when performing shuffle playback of AV files (movies). For example, when considering that an AV file is compressed and encoded by the MPEG system, the number of GOPs as the shuffle playback unit is changed. If the number of continuous GOPs = 1, one GOP is read out from one AV file and decoded and output. If the number of continuous GOPs = 2, two GOPs are read out continuously from one AV file and decoded. Repeat the shuffle playback procedure.

Hereinafter, as described above, a configuration for realizing the operation of changing the data processing in accordance with the determination result of the data transfer rate of the connected compact flash (hereinafter also referred to as “data transfer rate compatible processing”) will be described. Let's go.
First, FIG. 6 shows a processing operation that is executed by the CPU 10 according to a program as the data transfer rate correspondence processing.
Here, first, as shown in step S101, the system waits for a new connection of a compact flash (hereinafter may be abbreviated as “CF”). Then, for example, when the media controller 13 notifies that the CF is newly loaded into the CF slot of the digital video camera 1 and connected to the media controller 13, the new CF is received in step S101. The connection is detected, and the process proceeds to step S102.

In step S102, media identification information is acquired from the media for which a new connection has been detected in step S101. FIG. 7 shows a process for acquiring the media identification information as step S102.
Here, as is well known, as an operation mode of the CF, a True ID mode and a PC Card mode (PC Card ATA mode) are defined.
In acquiring the media identification information, first, as shown as step S201 in FIG. 7, it is determined whether the operation mode is the True ID mode or the PC Card mode. For example, compact flash has different pin terminal usage assignments in True ID mode and PC Card mode. At the time of communication processing when a compact flash is newly connected, the media controller 13 determines the assignment of the usage of the pin terminal from the communication result, and thus it is either CF in the True ID mode or the PC Card mode. Can be determined. In step S201, for example, the CPU 10 makes an inquiry to the media controller 13 as to which operation mode of the newly connected CF is determined. By receiving the response in response to this inquiry, the CPU 10 can determine the operation mode.

If it is determined in step S201 that the True IDE mode is in effect, the process proceeds to step S202 and subsequent steps.
In PC Card mode, it is specified that an attribute memory space is provided on the media side.
In step S202, the CIS (Card Information Structure) is read out by accessing the attribute memory space in order to obtain the media identification information. In this CIS, information of CISTPL_VERS_1 (specified by Tuple Code = 15h) is held as media identification information. This CISTPL_VERS_1 is information indicating the model (model) name of the media. Therefore, at the stage when the process of step S202 is executed, the information for identifying the model can be acquired as the media identification information for the newly connected CF. That's right.

  In general, variation in data transfer rate in the media (CF) appears remarkably for each model, and the data transfer rate among individuals in one model is almost uniform. Therefore, in order to identify the media for the data transfer rate for processing corresponding to the data transfer rate, the level up to this model name is often sufficient in practice. However, if more accurate and highly reliable processing results corresponding to data transfer rates are expected, it is reasonable to be able to identify individual media in more detail than the model (model) level. Become. Therefore, the processing after step S203 is processing added corresponding to such individual identification.

First, in step S203, it is determined whether or not the medium identification process is set to a mode in which the level exceeds the model level and the serial number level is set. The serial number has different values for each individual even between the same model, and is unique to each individual CF (media) by the serial number alone or a combination of serial number and model number. Functions as identification information.
In step S203, if a negative determination result is obtained because the mode for identifying up to the serial number level is not set, the processing for acquiring the media identification information is terminated as it is. On the other hand, if an affirmative determination result is obtained assuming that the mode for identifying up to the serial number level is set, the processing after step S204 is executed to obtain the serial number as the media identification information. To be done.

  In step S204, a transaction by Idify Device (CF-ATA), which is one of the commands specified in CF-ATA corresponding to the PC Card mode, is newly connected to obtain the media identification information. Execute with CF. That is, as the digital video camera 1 as a host (CPU 10), an Idify Device command is transmitted to the CF of the client medium. The CF returns a response in response to receiving this command to the host, and the digital video camera 1 (CPU 10) as the host receives this response. When this response is received, as shown in the next step S205, for example, a return value stored as an operand of the response is acquired.

When it is assumed that the structure of the return value obtained in step S205 starts from the 0th word as a sequence of words in units of 2 bytes, the 10-word area from the 10th word to the 19th word includes the medium ( CF) serial number information is stored. As described above, the serial number is identification information unique to each medium (here, CF). In addition, in the 20-word area from the 27th word to the 46th word, model number information for specifying the model (model name) of the media (CF) is stored.
Then, depending on steps S206 and S207 following step S205, the serial number and model number information stored in the return value is extracted, and the newly connected CF is identified as media identification information that can be identified this time. To be held.
In this process, information for identifying the model name (CISTPL_VERS_1) is acquired as the media identification information in step S202, and the model number information is acquired in step S207, and information for identifying the model is obtained. It will be acquired twice. In this way, there is no particular problem even if a plurality of pieces of identification information about the model are acquired. However, if it is desired to avoid duplication, for example, the media identification information (CISTPL_VERS_1) previously acquired in step S202 is discarded. Thus, the model number information acquired in step S207 may be validated, or the media identification information (CISTPL_VERS_1) previously obtained in step S202 may be validated, and the process in step S207 may be omitted.

Subsequently, in the previous step S201, if it is determined that the newly connected CF is in the True IDE mode, the process proceeds to step S208 and subsequent steps.
In step S208, a transaction by IDENTIFY DEVICE (ATA / ATAPI), which is one of the commands defined in the True IDE mode, is executed with the newly connected CF in order to acquire the media identification information. . When the response returned from the CF in response to this command is received, the return value stored as the operand of this response is acquired in the next step S209.

When the structure of this return value is also assumed to start from the 0th word as a sequence of words in units of 2 bytes, the 10-word area from the 10th word to the 19th word has the serial number of the medium (CF). Stores information. The serial number is identification information unique to each medium (here, CF). In addition, in the 20-word area from the 27th word to the 46th word, model number information for specifying the model (model name) of the media (CF) is stored.
Therefore, in the subsequent steps S210 and S211, the serial number and model number information stored in the return value is extracted, and the newly connected CF is held as identifiable media identification information each time. Is done. In this case as well, the process of step S211 may be omitted if only the information up to the level specifying the model is required as the media identification information.

Returning to FIG. As shown in FIG. 7, if the process for acquiring the media identification information of the newly connected CF in step S102 is completed, the process proceeds to step S103.
In the digital video camera 1 of the present embodiment, for example, information as a media registration table (medium transfer rate information) is written and stored in the nonvolatile memory 12a. As shown in FIG. 8, this media registration table corresponds to the media identification information and the data processing level for media that have been connected once (for convenience of explanation, only CF is used here). The table information is stored in the structure.
The media identification information in the media registration table is acquired by the processing in step S102 when the media is connected for the first time. When the mode for acquiring the identification information up to the model level is set when acquiring the media identification information by the process of step S102, the media identification information in the media registration table is information for identifying the model name. It consists of only, and corresponds to each media model. On the other hand, when the mode for acquiring the identification information up to the serial number level is set, the media identification information in the media registration table is the model number (model name) only, or the model number (model name). And a serial number, corresponding to each individual media.
The data processing level indicates the level of data processing determined according to the data transfer rate of the medium. Taking FIG. 5 as an example, level 3 (tfrt ≧ a), level 2 (b ≦ tfrt <a), level 1 (c ≦ tfrt <b) set according to the data transfer rate tfrt of the compact flash, There are four levels of level 0 (tfrt <c).
Note that how the media registration table is created will be described later in the course of explaining the processing shown in FIG.
In step S103 subsequent to step S102, the media registration table is read from the nonvolatile memory 12a.

  In the next step S104, it is determined whether or not the newly connected CF is currently registered in the media registration table read in step S103. For this purpose, the media identification information stored in the media registration table at the current stage is searched for one that matches the media identification information acquired in the previous step S102. If the matched media identification information is searched as a search result, a positive determination result is obtained in step S104. On the other hand, if the matched media identification information is not searched, a negative determination result is obtained.

If a positive determination result is obtained in step S104, the process proceeds to step S105. In step S105, registration information is read from the media registration table. That is, the media registration information in this case includes the media identification information retrieved as matching with the newly connected CF by the process of step S104. Therefore, the data processing level associated with the searched media identification information is read. By executing this processing, the data processing level for the media registered in the media registration table is determined.
As described with reference to FIG. 8, the data processing level of the media registration table is determined by the level range to which the data transfer rate of the media belongs. The determination of the processing level is nothing but the determination of the data transfer rate for the CF, although it depends on the range classification.

For example, the data processing level determined in step S105 is set in a predetermined register area in step S108. As a result, subsequently, the currently activated application sets a processing mode corresponding to the set data processing level.
A specific example of the process in step S108 will be described with reference to FIG.
For example, assume that it is determined in step S105 that the data processing level is level 3 in FIG. In response to this, in step S108, for example, an application program for recording a captured image as a moving image sets a processing mode corresponding to level 3.
At this time, for example, the application program indicates whether or not it is possible to execute four levels of resolution (1024 × 768, 800 × 600, 640 × 480, and 320 × 240) with respect to the data processing level according to the structure shown in FIG. Have table information. Then, with reference to this table, the processing mode is set according to the contents of the four levels of resolution corresponding to the data processing level determined in step S105.
In this case, since the data processing level is determined to be level 3, as a result of referring to the table information as described above, the application program sets 1024 × 768 which is the highest resolution among the resolutions of four stages. As the highest mode, a processing mode in which video signal processing for AV file generation can be executed with the remaining three lower resolutions is set.
Alternatively, it is determined in step S105 that the data processing level is level 2, and this level 2 is set in step S108. Thus, a mode capable of executing video signal processing for generating an AV file having a resolution of 800 × 600 as the highest mode is set as the application processing mode.
Alternatively, it is determined that the data processing level is level 0 in step S105, and this level 0 is set in step S108. In this case, as an application processing mode, a mode capable of executing video signal processing for generating an AV file is set only with the minimum resolution of 320 × 240.

If a negative determination result is obtained in step S104, the process proceeds to step S106.
In the case of going from step S104 to step S106, the newly connected CF is not registered in the media registration table, and is therefore the first connected to the digital video camera 1. . In this case, first, it is necessary to determine the data processing level for the newly connected CF and to set an appropriate application processing mode corresponding to the CF. Also, it is necessary to newly register the CF connected for the first time in the media registration table. In order to satisfy these requirements, in step S106, a process for measuring the data transfer rate for the CF newly connected this time is executed.

A processing example of data transfer rate measurement as step S106 is shown in the flowchart of FIG. In order to measure the data transfer rate of the CF being connected, first, as shown in step S301, FAT1 formed in the partition that is the target of data writing / reading in the storage area of the connected CF. Is read out, and a process for writing the read data into the FAT2 is executed. In the present embodiment, the FAT1 area is used as the main area, but in step S301, the data stored in the FAT1 is read and written to the FAT2. In parallel with the data read / write, the data transfer rate for the data read / written is measured. That is, the amount of data per unit time for reading / writing from the CF is measured.
In the above description of FIG. 3, it has been described that when FAT1 is the main area, FAT2 is normally the mirror area and spare area of FAT1, but in this embodiment, the data transfer rate is measured. Therefore, it is used as a trial writing area for data.

  The processing in step S301 is executed in a control sequence in which 256 sectors from FAT1 are read and stored in, for example, a work RAM, and then data of 256 sectors is written to FAT2. In addition, as the process of step S301 to be executed first, the data of the first 256 sectors of FAT1 is read and the process of writing to FAT2 is executed.

Then, when the processing of the first step S301 is completed, in step S302, it is determined whether or not the remaining area size that has not yet been read by the processing of step S301 is less than 256 sectors. If a negative determination result is obtained here, the process returns to step S302 again. In the process of step S301 after the second time, the data of the next 256 sectors following the 256 sector read out by the process of the previous step S301 is read and written to FAT2, and the data transfer rate at this time is measured. Is done. Such a process is repeated until a positive determination result is obtained in step S302. If a positive determination result is obtained in step S302, data reading from FAT1 and data writing to FAT2 are performed. , And the data transfer rate measurement process ends. In other words, the processing in step S301 is repeated for the number of times represented by the integer value of the solution obtained by performing the calculation by Fatsz / 256 with the size of FAT1 as Fatsz.
For confirmation, the FAT1 area as the main FAT area is simply read out depending on the processing in step S301, and its contents do not change. Therefore, the processing in step S301 does not hinder the subsequent file management.

When it is determined that the processing in the sequence of steps S301 to S302 has been completed, the process proceeds to step S303. In this step S303, the value of the data transfer rate measured by the process of step S301 executed as described above is held here as the measured value A1.
In addition, as a specific method for obtaining the measured value A1, the following method can be cited. In other words, the amount of data read / written is integrated for each processing in step S301, and the time required for this read / write is also integrated. When a positive determination result is obtained in step S302 and the process in step S301 is completed, the data transfer rate is calculated by performing an operation based on the data amount and time.

Regarding step S106, which is the data transfer rate measurement process, as the simplest algorithm, the process up to step S303 may be executed, and the measurement value A1 may be handled as the official measurement value. However, in the present embodiment, the final measurement value is obtained by executing the processing after step S304 for the following reason.
For example, in order to make the explanation easy to understand, a storage medium such as an HDD is considered here. When the HDD is formatted by the FAT file system, for example, a format structure as shown in FIG. 3 is usually formed from the outer circumference to the inner circumference in order from the upper order to the lower order of the LBA (sector number). . For this reason, FAT1 and FAT2 which are data write / read areas in step S301 are actually located on the outer circumference side in the partition as physical positions on the magnetic disk. As is well known, the data transfer rate of data reading / writing with respect to a disk-shaped recording medium rotating at a constant angular velocity such as an HDD differs between the outer circumference and the inner circumference.
From this, the data transfer rate measured by reading / writing data to / from FAT1 and FAT2 is obtained by measuring at a position that is substantially on the outer peripheral side in the whole partition, and this alone is reliable. There may be cases where the price is not high. Therefore, by measuring the data transfer rate on the inner circumference side and using the measured values at both the outer circumference side and the inner circumference side, it is possible to obtain a more accurate and reliable measurement result. I can say that. Step S304 and the subsequent steps are originally processing for obtaining a measured value of the data transfer rate for the area on the inner circumference side of the FAT area.
However, in this embodiment, the storage medium is a compact flash. Since the compact flash performs static recording and reproduction using a semiconductor memory element called a flash memory as a storage medium, the above-described problem of the difference in data transfer rate between the outer periphery and the inner periphery does not occur. Therefore, the necessity of the processing after step S304 is not so high as in the case of an HDD or the like.
However, the processing of FIG. 9 here is based on a program configured to obtain a highly reliable measurement result even when an HDD or the like is targeted. That is, the processing procedure is designed so as to have versatility with respect to the target medium. Even in the case of a semiconductor memory device, when data is written to a physical area separated by an LBA (sector number), the possibility of a difference in data transfer rate due to some factor cannot be completely excluded. Therefore, it is considered that the processing after step S304 does not necessarily be a snake foot.

The process after step S304 is demonstrated.
In the present embodiment, as a read area and a write area for data transfer rate measurement other than FAT1 and FAT2, a predetermined area close to the end side of the LBA (sector number) is set in the partition. These areas are assumed to be in the data area, for example, and are LBA (sector numbers), which are lower than FAT1 and FAT2, and are therefore lower LBA areas for reading and writing, respectively. This is called the lower LBA area.

  Then, in step S304, the processing according to step S301 is executed with the read lower LBA area and the write lower LBA area as data read / write target areas. That is, first, 256 sectors are read from the head of the read lower LBA area, and the read data is written to the write lower LBA area. In step S305, it is determined whether or not the necessary number of times of the process of step S304 executed so far has been completed. If the required number of times is not satisfied, the process of step S304 is executed again. In the second and subsequent processing in step S304, the data of 256 sectors following the data read in the previous step S304 is executed.

  Here, it is assumed that the reading lower LBA area and the writing lower LBA area should be set to the same size as FAT1 and FAT2, respectively. As a result, the data transfer rate measurement process in step S304 is executed the same number of times as in step S301. In this way, in the present embodiment, the process itself of step S304 is also in accordance with step S301, and the number of repetitions of step S304, that is, the number of times of measurement of the data transfer rate is the same. That is, in steps S301 and S304, the data transfer rate is measured under the same conditions except for an area to be read / written for data.

The required number of times determined in step S305 is the same as the number of repetitions of the process in step S301. Then, as a result of repeating the process of step S304 a predetermined number of times, a positive determination result is obtained in step S305, the process of step S304 is terminated, and the process proceeds to step S306.
In step S306, the value of the data transfer rate measured by the process in step S304 is held as a measured value A2.

In subsequent step S307, processing for obtaining the actual measurement value A3 based on the measurement values A1 and A2 is executed. As an actual process, for example, an average value of the measured values A1 and A2 may be calculated to be the actual measured value A3. Here, the measured values A1 and A2 are compared and the lower measured value is compared. That is, the measurement value that is inferior in terms of performance of the data transfer rate is obtained as the actual measurement value A3.
The main measurement value A3 acquired in this way is handled as a measurement result of the data transfer rate measurement process in step S106.

  In the process of step S301 in FIG. 9, it is necessary to access the FAT1 and FAT2 areas in order to read / write data. The access procedure for FAT1 and FAT2 will be described with reference to the flowchart of FIG. Also, in the flow of the description of FIG. 10, reference is made to FIG. 11 as necessary. FIG. 11 shows the case of FAT32 as the format structure of the media by the FAT file system. Therefore, here, a case of a format structure based on FAT32 will be described as an example.

  In order to access the FAT1 and FAT2 areas, the MBR is first accessed as shown in step S401 in FIG. The MBR is an area located in the first sector (LBA = 0) as shown in FIG. 3, and is composed of an activation code and a partition table following this as shown in FIG. 4 (a). In step S401, the partition table of the partition (target partition) including the FAT area (FAT1, FAT2) determined as the data write / read target for the data transfer rate measurement from the accessed MBR partition table. refer.

As shown in FIG. 4B, the partition table stores information on the start sector (CHS) in CHS expression and the start sector (LBA) in LBA expression as start position information of the corresponding partition. . In step S402, information on the start sector is acquired from the partition table referred to in step S401. Here, information on the start sector (LBA) in LBA representation is acquired.
Here, if the numerical value indicated by the start sector (LBA) obtained in step S402 is A, this start sector (LBA) indicates the sector position where LBA = A, starting from LBA = 0 where the MBR is located. It will be. The sector position where LBA = A becomes the start position of the target partition as shown in FIG.

In this way, the BPB is arranged at the start position of the target partition accessed as indicated by the start sector (LBA). As described above, the BPB stores information on the FAT area in the current partition, such as the number of FAT areas, the start sector of the main FAT area, and the number of sectors in the FAT area.
Therefore, in step S403 following step S402, the BPB at the head of the target partition is accessed, the contents thereof are referred to, and a value as BPB_RsvdSecCnt is acquired from the BPB by the processing in the next step S404. This BPB_RsvdSecCnt indicates the number of reserved sectors from the partition start sector (BPB start sector) to the start position of the FAT area. Therefore, the FAT area starts from the start sector (BPB start sector) of the target partition. This is information indicating the starting sector.
In step S405, similarly, as a result of referring to BPB in step S403, a value as BPB_FATSz32 is acquired from BPB. BPB_FATSz32 indicates the size of one FAT area.

In step S406, the start position of FAT1 in the target partition is calculated using the processing results so far.
As an example of this calculation process, for example, as described above, the value of the start sector (LBA) of the target partition acquired in step S402 is set to A, and the value of BPB_RsvdSecCnt acquired in step S404 is set to B. Perform the operation.
The value as the calculation result of A + B represents the start position of FAT1 in the target partition on the medium by an absolute sector number (absolute LBA value). That is, as shown in FIG. 11, the sector having the absolute LBA value = A starting from the first sector (absolute LBA value = 0) in the medium is the first sector (also the start sector of BPB) of the target partition. Then, the relative sector position shifted by the value B of BPB_RsvdSecCnt starting from the absolute LBA value = A which is the first sector of the target partition becomes the start position of FAT1 of the same target partition. Therefore, the start position of FAT1 is represented by A + B as the absolute LBA value.

In step S407, similarly, the start position of FAT2 in the target partition is calculated using the processing results so far.
For this purpose, the value of the start sector (LBA) of the target partition acquired in step S402 is A, the value of BPB_RsvdSecCnt acquired in step S404 is B, and the BPB_FATSz32 acquired in step S405 as described above. Assuming that the value is C, the calculation of A + B + C is executed.
The value obtained by the calculation of A + B + C indicates the leading sector of FAT2 by an absolute LBA value as shown in FIG. That is, as described above, since the value obtained by A + B indicates the first sector of FAT1 of the target partition by the absolute LBA value, the value C is shifted starting from the first sector of FAT1. The sector position is the start sector of FAT2. Thus, it can be seen that A + B + C indicates the leading sector of FAT2.

Then, when reading the data of FAT1 in the first process of step S301 shown in FIG. 9, the sector having the absolute LBA value (A + B) calculated and acquired in step S406 is accessed. As a result, the first cluster of FAT1 can be accessed. When the process of step S301 is repeated from the second time onward, the sector indicated by the absolute LBA value obtained by adding 256 (sector) is accessed each time. As a result, reading from the next sector of the data read previously is performed.
Further, when data is written to FAT2 in the first processing of the same step S301, the first cluster of FAT2 can be accessed by accessing the sector having the absolute LBA value (A + B + C) calculated and obtained in step S407. . Also in this case, each time the process of step S301 is executed after the second time, the sector indicated by the absolute LBA value obtained by adding 256 (sectors) is accessed.

Here, the description returns to FIG.
As described above, assuming that the measurement result of the data transfer rate for the newly connected CF as step S106 is obtained as the actual measurement value A3, the process of step S107 is subsequently executed.

In step S107, a process for registering the CF newly connected this time in the media registration table is executed.
For this purpose, first, as shown in step S501 in FIG. 12, the transfer rate-level conversion table is referred to. This transfer rate-level conversion table is table information for converting the data transfer rate measurement value (main measurement value A3) obtained in step S106 into a data processing level. For example, the non-volatile memory 12a or the ROM 11 It is memorized.

The structural concept of the transfer rate-level conversion table in this case is shown in FIG. As shown in this figure, the transfer rate-level conversion table divides the measured value of the data transfer rate obtained in step S106 (this measured value A3) within a predetermined range, and sets different data processing levels for each of the categories. It is formed so as to correspond.
In this case, in order to make the explanation easy to understand, the measured value of the data transfer level is a specific numerical value. In this case, the data transfer rate measurement values are divided into four ranges from [40 Mbps or more], [20 Mbps or more to less than 40 Mbps], [10 Mbps or more to less than 20 Mbps], and [less than 10 Mbps] from the best. ing. Then, the highest level 3 as the data processing level is associated with the category of [40 Mbps or more]. Thereafter, the second level 2 is associated with the [20 Mbps to less than 40 Mbps] category, the level 1 is associated with the [10 Mbps to less than 20 Mbps] category, and the level 0 is associated with the [less than 10 Mbps] category. Let

  In step S501, the transfer rate-level conversion table is accessed, read, and referenced to perform data processing corresponding to the measurement value (main measurement value A3) of the data transfer rate obtained in step S106. Recognize the level. For example, if the measured value of the data transfer rate (main measured value A3) is 27 Mbps, the data transfer rate classification including this value is [20 Mbps to less than 40 Mbps], and level 2 corresponds. Therefore, it is recognized that the data processing level is level 2. In this way, the process of converting the measurement value of the data transfer rate to the data processing level as the process of step S501 is executed.

In the next step S502, processing for registering the CF newly connected this time in the media registration table is executed. For this purpose, information as a table item in which the media identification information acquired by the processing in the previous step S102 and the data processing level acquired in step S501 are associated with each other is added to the media registration table. Update process is executed.
In this way, the new registration process to the media registration table as step S107 in FIG. 6 is executed.

  When the processing in step S107 is performed, the data processing level obtained in, for example, step S501 in FIG. 12 is set as the processing mode setting of the application in the next step S108. Therefore, if the connected CF is the first one connected to the digital video camera 1 (not registered in the media registration table) and a negative result is obtained in step S104, This determination of the data processing level for the connected CF is realized as a process of converting the measured value of the data transfer rate in step S501 into the data processing level. Also in this case, the determination of the data processing level is performed based on the measured value of the data transfer rate obtained in step S106. Therefore, also in this case, the determination of the data processing level is as follows: It can be regarded as synonymous with the determination of the data transfer rate.

  For reference, in the file system hierarchical model shown in FIG. 2, a configuration example showing the details of the internal functions of the file system 101 and the application 100 is shown in FIG. Also in this figure, as in FIG. 2, the entire system hierarchy model including the application 100, the file system 101, the device driver 102, and the medium 103 is shown.

  As shown in this figure, when the processing executed by software as the file system 101 is viewed as a functional block, it can be considered that the file system 101 includes the recording control unit 200 and the media control unit 210.

  The recording control unit 200 executes various control processes related to recording (writing) and reading of data with respect to a medium, and includes a directory entry control unit 201, a FAT control unit 202, and a cluster control unit 203. Further, the media control unit 210 includes a position calculation unit 211 as a functional part capable of exchanging data with the device driver 102 in order for the file system to control the media.

The directory entry control unit 201 in the recording control unit 200 performs various necessary control processes for the directory entry, such as creating, deleting, and updating the directory entry in accordance with the data processing results such as writing and erasing files on the medium. Execute. The FAT control unit 202 executes various necessary control processes for the FAT area, such as rewriting a predetermined FAT entry in the FAT area in accordance with the file data processing result for the medium. The cluster control unit 203 executes various control processes for allowing processes in the file system to be executed at the cluster level.
For example, if data to be written to the medium is transferred from the application 100 as file-based processing, the cluster control unit 203 converts the file level data into data at the cluster level. Then, it instructs the position calculation unit 211 of the media control unit 210 to write the data at the cluster level to the media.
The position calculation unit 211 calculates the position (cluster number) of the cluster to which the file data is to be written from the unused area of the media recognized by referring to the contents of the FAT area managed by the FAT control unit 202. To do. Then, the cluster unit data to be written is transferred to the device driver 102 and the cluster number to which this data is to be written is instructed. The device driver 102 finally converts the instructed cluster number into an address of a physical sector in a storage area on the medium, and executes data writing to the medium at the sector level.

At the same time, the file system rewrites (updates) the directory entry and the FAT area so that the file written and stored in the medium as described above is properly managed on the FAT file system. .
For example, first, the directory entry control unit 201 creates a directory entry for the file to be recorded this time. At this time, in cooperation with the FAT control unit 202, a cluster in which a file is to be recorded is determined from the free area in the FAT area. Along with this, the value stored in the starting cluster in the directory entry is also determined. Further, in response to the determination of the cluster on which the file is to be recorded, the FAT control unit 202 sets the FAT entry of the required cluster number so that the contents such as the cluster chain for the file are indicated in the FAT area. Rewrite the value.
Then, the directory entry created in this way and the rewritten contents of the FAT area are processed by the cluster control unit 203 and the media control unit 210 (position calculation unit 211) in the same manner as described above, so that the predetermined area of the media Write to and store.

  Also, as an example only, for example, the application 100 having a program configuration corresponding to the data transfer rate compatible processing of the present embodiment is an application program for recording a captured image as a file in a moving image format. The program 100a, the moving image reproduction program 100b that is an application program for reproducing the moving image file recorded on the medium, the still image recording program 100c for recording the captured image as a still image, and the still image file recorded on the medium It is conceivable to install an application program related to recording / playback of a file, such as the still image playback program 100d. In the present embodiment, the processing mode setting program 100e, which is a program for executing the setting of the data processing level for these file recording / reproducing programs according to the processing procedure shown in FIG. 6, is also implemented. . Furthermore, here, a user interface program 100f that manages the user interface is also implemented.

By the way, as described in FIG. 9, in the measurement of the data transfer rate according to the present embodiment, not only the FAT1 and FAT2, but also the lower LBA area for reading and the lower LBA area for writing which are lower sector positions. Also, it can be used as an area for reading / writing data.
At this time, when a medium (CF) formatted with a plurality of partitions is targeted, a partition including FAT1 and FAT2 from which data is read / written, a lower LBA area for reading, and a lower LBA area for writing are Although it is necessary to consider whether or not the partition to be included should be the same, the present embodiment may be the same or different.
If the two partitions are different from each other, for example, if the partition of the highest sector area is divided into the partition of the lowest sector area, the measured value of the data transfer rate of the entire medium. Since a value close to the best and a value close to the minimum can be obtained, it is possible to obtain a measurement result with a reasonably high reliability.
On the other hand, even if multiple partitions are formed, for example, in a usage environment where only one specific partition is used at all times, the partition that includes both is used as the partition that is always used. By making them the same, the measurement result of the data transfer rate is rather highly reliable. Also, in an environment where the partition to be used is not specified, for example, by providing an information structure that can be identified up to the partition level as the media identification information in the media registration table, the data transfer rate for each partition can be determined. The data processing level can be set.
Further, the use of the FAT area (the FAT1 and FAT2 areas) as the data reading / writing area for measuring the data transfer rate means that the size of the FAT area is the data required for the data transfer rate measurement. This is extremely appropriate because it is appropriate in consideration of the amount of reading / writing, and because it is easy to access in a position close to the head sector in the partition and media. However, as a concept of the present invention, it is not always necessary to use the FAT area. For example, another area may be used as long as there is no problem in recording and reproducing the file.

In this embodiment, the FAT1 is used as a main FAT area, and the FAT2 area is used as a data trial writing area for data transfer rate measurement. As described above, The FAT2 may be used as a spare area or backup area for the FAT1 as a copy of the same contents as the FAT1. Therefore, when FAT2 is used as a test writing area for measuring the data transfer rate as described above, FAT2 does not function as a spare area or a backup area.
There are several possible ways to solve this problem, but here are two examples.
For example, trial writing of data to FAT2 is frequently performed when the medium (CF) is connected to one host for the first time and is executed only once to measure the data transfer rate. It is not a thing. In addition, the content of FAT2 at the stage where the measurement of the data transfer rate has been completed is merely that trial-written data has been written, and does not make any particular sense. Even if the contents are changed, there is no problem in the operation of the file system.
Therefore, at the predetermined timing when the data transfer rate measurement is completed, for FAT2, the contents of FAT1 are completely copied or initialized to the predetermined data contents to form contents adapted to the actual application. You just have to do it.
Alternatively, for the FAT area, in addition to FAT1 as the main area and FAT2 as the trial writing area for data transfer rate measurement, three or more FAT areas having a required number of FAT areas as backup, spare areas, etc. Adopt the format to be formed. In the BPB, information indicating the number of FAT areas called BPB_NumFATs is stored. Therefore, by setting a required value of 3 or more according to the number of FAT areas actually required for BPB_NumFATs and executing the media format, a structure in which 3 or more FAT areas are formed can be obtained.

  In the embodiment, the FAT file system is adopted as a file system for managing the recording data of the medium. However, other file systems such as HSF (Hierarchical File System) are used. The file system standard is not particularly limited.

Further, in the present invention, as shown in FIG. 14, a moving image recording program 100a, a moving image reproduction program 100b, a still image recording program 100c, a still image reproduction program 100d, and the like are shown. There may be a plurality of application programs that can change and set the data processing mode in accordance with the transfer rate. Further, in one application program, it should be possible to change the setting of the processing mode according to the data processing level for each of a plurality of different data processes.
Further, the number of stages of the data processing level and the range classification of the data transfer rate corresponding to each data processing level should be appropriately changed according to the actual data processing content.
Therefore, when the processing mode change according to the data processing level is executed for a plurality of application programs or a plurality of data processing in one application program as described above, the processing mode is changed according to the contents of each data processing. Thus, the correspondence between the number of steps of the data processing level and the range classification of the data transfer rate may be changed, and it is more preferable.

  In the description of the embodiments so far, the compact flash (CF) is exemplified as a medium (storage medium, storage device) whose data processing level is changed according to the data transfer rate. For example, as suggested by considering the versatility of the media in the process shown in FIG. 9, the present invention should not be particularly limited with respect to the target media, and may be other semiconductor memory devices. May be. 1 may be media other than the semiconductor storage device connected to the media controller 13, and various media other than those connected to the media controller 13 in FIG. In addition to media connected using physical connection means such as cables and connectors, it is also possible to target media connected wirelessly to the host via Bluetooth, wireless LAN (Local Area Network), etc. .

  In the above embodiment, the information processing apparatus of the present invention should not be limited to the digital video camera described in the embodiment. For example, a digital still camera, a reserved recording device for a television broadcast program, Furthermore, the present invention can be applied to any apparatus capable of data processing such as data writing / reading corresponding to an external medium (external storage medium) such as a personal computer and various information processing apparatuses conforming thereto.

It is a block diagram which shows the structural example of the digital video camera of embodiment of this invention. It is a figure which shows the system configuration | structure of a FAT file system by a hierarchical model. It is a figure which shows the format structure of the medium in a FAT file system. It is a figure which shows the structure of MBR in a FAT file system. It is a figure which shows the specific example of a corresponding | compatible setting with the data transfer rate (data processing level) of a medium, and data processing (resolution setting). It is a flowchart which shows the process for the data processing setting of an application when a medium (compact flash) is newly connected. It is a flowchart which shows the process for media identification information acquisition. It is a figure which shows the structural example of a media registration table. It is a flowchart which shows the process for the data transfer rate measurement of a medium. It is a flowchart which shows the process for access to FAT1 and FAT2. It is a figure which shows typically the access procedure to FAT1 and FAT2 corresponding to the process of FIG. It is a flowchart which shows the process for the new registration to a media registration table. It is a figure which shows the structural example of a transfer rate-level conversion table. It is a figure which shows the processing function in a file system hierarchical structure corresponding to embodiment.

Explanation of symbols

  1 digital video camera, 2 optical system unit, 3 photoelectric conversion unit, 4 video signal processing unit, 5 image input / output unit, 6 camera function unit, 7 display unit, 8 audio processing unit, 9 audio input / output unit, 10 CPU, 11 ROM, 12 RAM, 13 media controller, 15 operation input unit, 16 communication unit, 100 application, 100a moving image recording program, 100b moving image reproduction program, 100c still image recording program, 100d still image reproduction program, 100e processing mode setting program, 100f user interface program, 101 file system, 102 device driver, 200 recording control unit, 201 directory entry, 202 FAT control unit, 203 cluster control unit, 210 media control unit, 211 position calculation unit

Claims (3)

Storage medium connection means to which an external storage medium is connected;
Acquisition means for acquiring medium identification information from the external storage medium connected to the storage medium connection means;
Measuring means for measuring the data transfer rate in the storage area of the external storage medium connected to the storage medium connecting means by measuring from the upper address area of the storage area and measuring from the lower address a predetermined number of times; ,
Determining means for determining a data transfer rate for the external storage medium connected to the storage medium connecting means;
Data processing execution means capable of executing predetermined data processing involving writing and / or reading of data with respect to the external storage medium connected to the storage medium connection means;
Setting means for setting whether or not to execute specific data processing that can be executed by the data processing execution means according to the data transfer rate determined by the determination means;
Corresponding medium identification information capable of identifying the storage medium for each unit and transfer rate information obtained by converting the data transfer rate of the storage medium identified by the medium identification information into a data processing level based on the processing level conversion table Holding means for holding transfer rate information for each medium formed by
Equipped with a,
When the medium identification information matching the medium identification information acquired by the acquisition means is searched with reference to the medium transfer rate information, the determination means is associated with the searched medium identification information. If the medium identification information that matches the medium identification information acquired by the acquisition means is not found, the determination is made based on the measurement result of the measurement means. And
When the determination means refers to the medium-specific transfer rate information and the medium identification information that matches the medium identification information acquired by the acquisition means is not searched, the medium identification information acquired by the acquisition means, Generation means for generating the transfer rate information for each medium by associating the transfer rate information obtained by converting the data transfer rate obtained based on the measurement result of the measurement unit with the data processing level based on the processing level conversion table; Prepare
Information processing device. A measurement procedure for measuring the data transfer rate in the storage area of the external storage medium connected to the storage medium connecting means by measuring from the upper address area of the storage area and measuring from the lower address a predetermined number of times;
An acquisition procedure for acquiring the medium identification information from the external storage medium connected to the storage medium connection means;
A determination procedure for determining a data transfer rate for an external storage medium connected so that communication including at least data writing / reading is possible;
A data processing execution procedure capable of executing predetermined data processing involving writing and / or reading of data with respect to the connected external storage medium;
A setting procedure for setting whether or not to execute the specific data processing in which the data processing execution procedure is executable according to the data transfer rate determined by the determination procedure;
Corresponding medium identification information capable of identifying the storage medium for each unit and transfer rate information obtained by converting the data transfer rate of the storage medium identified by the medium identification information into a data processing level based on the processing level conversion table Holding procedure for holding transfer rate information for each medium formed by
The execution,
In the determination procedure, when medium identification information that matches the medium identification information acquired by the acquisition procedure is searched with reference to the medium-specific transfer rate information, the medium identification information is associated with the searched medium identification information. When the medium identification information that matches the medium identification information acquired by the acquisition procedure is not searched, the determination is made based on the measurement result of the measurement procedure, and
When the medium identification information matching the medium identification information acquired in the acquisition procedure is not searched with reference to the medium transfer rate information in the determination procedure, the medium identification information acquired in the acquisition procedure, A generation procedure for generating the transfer rate information for each medium by associating the transfer rate information obtained by converting the data transfer rate obtained based on the measurement result of the measurement procedure into the data processing level based on the processing level conversion table; Execute,
Information processing method. A measurement procedure for measuring the data transfer rate in the storage area of the external storage medium connected to the storage medium connecting means by measuring from the upper address area of the storage area and measuring from the lower address a predetermined number of times;
An acquisition procedure for acquiring the medium identification information from the external storage medium connected to the storage medium connection means;
A determination procedure for determining a data transfer rate for an external storage medium connected so that communication including at least data writing / reading is possible;
A data processing execution procedure capable of executing predetermined data processing involving writing and / or reading of data with respect to the connected external storage medium;
A setting procedure for setting whether or not to execute the specific data processing in which the data processing execution procedure is executable according to the data transfer rate determined by the determination procedure;
Corresponding medium identification information capable of identifying the storage medium for each unit and transfer rate information obtained by converting the data transfer rate of the storage medium identified by the medium identification information into a data processing level based on the processing level conversion table Holding procedure for holding transfer rate information for each medium formed by
It was executed in the information processing apparatus,
In the determination procedure, when medium identification information that matches the medium identification information acquired by the acquisition procedure is searched with reference to the medium-specific transfer rate information, the medium identification information is associated with the searched medium identification information. When the medium identification information that matches the medium identification information acquired by the acquisition procedure is not searched, the determination is made based on the measurement result of the measurement procedure, and
When the medium identification information matching the medium identification information acquired in the acquisition procedure is not searched with reference to the medium transfer rate information in the determination procedure, the medium identification information acquired in the acquisition procedure, A generation procedure for generating the transfer rate information for each medium by associating the transfer rate information obtained by converting the data transfer rate obtained based on the measurement result of the measurement procedure into the data processing level based on the processing level conversion table; The program to be executed .

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