JP2011186709A - Recording medium control apparatus, recording medium control method and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To set the most effectively efficient data transfer rate when there are a plurality of transfer rate modes that can be set for media. <P>SOLUTION: In a device driver 400, a transfer rate mode candidate recognition part 410 recognizes candidate transfer rate modes compatible with a medium 500. A transfer rate mode setting part 420 sequentially sets the transfer rate modes recognized as candidates. An effective transfer rate measurement part 430 measures an effective transfer rate in each candidate transfer rate modes set. A transfer rate mode determination part 440 determines the ratio of the measured effective transfer rate to a specified transfer clock frequency in each candidate transfer rate mode, and determines a maximum efficiency transfer rate mode deemed most efficient according to the value of the ratio. The transfer rate mode setting part 420 sets the maximum efficiency transfer rate mode as a data transfer rate available for file access. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a recording medium control apparatus, and more particularly to a recording medium control apparatus that controls a recording medium that can set a plurality of transfer speed modes, a method thereof, and a program that causes a computer to execute the method.

  Generally, it is preferable that the data transfer speed at the time of data writing / reading to / from a recording medium is set to be high. Therefore, for example, the following techniques are known. That is, test data is written to the recording medium while switching the data transfer rate, an error occurrence rate is obtained from the read result, a parameter value at which the error rate becomes an allowable limit value is set, and recorded on the recording medium. For example, the parameter values recorded on the recording medium are set when the storage device is activated, and data is read from and written to the recording medium (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 5-225711 (FIG. 1)

  Under the above prior art, data recording / reproduction can be executed at the highest data transfer rate that the recording medium can handle. However, at present, the data transfer rate that can be supported by the recording medium is considerably high, and there are a plurality of modes (transfer rate modes) in which different data transfer rates are defined. In such a situation, for example, it is not always efficient to perform recording and reproduction by always setting the highest transfer speed mode for the recording medium.

  As is well known, the actual transfer rate (effective transfer rate) in data transfer is usually lower than the maximum rate (theoretical value). Also, the ratio of the effective transfer rate with respect to the maximum rate varies depending on the environment and conditions at that time. From this, for example, there may be a situation in which there is no significant difference in the effective transfer rate obtained in a plurality of transfer rate modes. In addition, for example, problems such as an increase in power consumption and an increase in radiation noise appear with an increase in data transfer speed. From this point of view, it is preferable not to always set the fastest transfer rate mode but to set a more appropriate transfer rate mode according to the situation such as the effective transfer rate at that time.

  The present invention has been made in view of such a situation, and an object of the present invention is to set an optimum data transfer speed when recording / reproducing data on a recording medium.

  The present invention has been made to solve the above problems, and a first aspect thereof is a candidate recognition unit for recognizing a transfer rate mode candidate indicating a data transfer rate that can be set corresponding to a recording medium. An effective transfer rate measuring unit that measures an effective transfer rate for each transfer rate mode recognized as a candidate, and an effective for each transfer rate mode based on the effective transfer rate for each transfer rate mode recognized as a candidate. A transfer speed mode determination unit that calculates the efficiency and determines the transfer speed mode having the highest effective efficiency among the transfer speed modes recognized as the candidates as the setting target transfer speed mode; and determines as the setting target transfer speed mode A transfer speed mode setting unit configured to perform recording and reproduction with respect to the recording medium at a data transfer speed indicated by the transferred transfer speed mode; A recording medium control device provided. This brings about the effect that the optimum transfer speed mode is determined based on the effective efficiency from among a plurality of transfer speed mode candidates that can be set when transferring data for recording / reproduction to / from the recording medium.

  Also, in this first aspect, priorities for determining whether the priority when setting the transfer speed mode is effective efficiency or speed according to the device operation content accompanying recording or reproduction with respect to the recording medium. And determining a transfer rate mode with the highest effective efficiency as the setting target transfer rate mode when the priority is determined to be effective efficiency. When the priority is determined to be speed, the transfer speed mode with the highest effective transfer speed is determined as the setting target transfer speed mode instead of the transfer speed mode with the highest effective efficiency. May be. As a result, the transfer rate mode with the highest effective efficiency is set according to the device operation content that should prioritize the effective efficiency, and the transfer rate mode with the highest effective transfer rate is set according to the device operation content that should prioritize the speed. It brings about the effect of setting.

  In the first aspect, the transfer rate mode determination unit compares the minimum effective transfer rate required for recording or reproducing a file on the recording medium with the effective transfer rate, and A transfer rate mode with a lower effective transfer rate may be excluded from the candidates. As a result, the transfer speed mode is set from the transfer speed modes in which the effective transfer speed at which the file can be normally recorded and reproduced is measured.

  In the first aspect, the effective transfer rate measuring unit sequentially sets the candidate transfer rate modes, and performs device operation contents with recording or reproduction on the recording medium for each of the set transfer rate modes. When recording is performed on the recording medium, the recording corresponding measurement process for measuring the effective transfer rate is performed while data is written to the recording medium. When the device operation content is reproduction, the recording medium is recorded. You may make it perform the reproduction | regeneration corresponding | compatible measurement process which measures the said effective transfer rate, performing data reading. This brings about the effect that only one of the reproduction-corresponding measurement process or the record-corresponding measurement process is executed depending on whether the device operation content is recording or reproduction.

  In the first aspect, the effective transfer rate measurement unit may sequentially set the candidate transfer rate modes and perform data writing to the recording medium for each transfer rate mode. The recording speed measurement process for measuring the effective transfer speed of the recording medium and the reproduction compatible measurement process for measuring the effective transfer speed at the time of data reading while executing the reading to the recording medium are executed. The effective efficiency may be calculated based on the effective transfer rate which is an average value of the effective transfer rate at the time of writing and the effective transfer rate at the time of reading the data. Thus, there is an effect that the effective efficiency is calculated based on the effective transfer speed obtained by integrating the recording time and the reproducing time.

  In the first aspect, the transfer rate mode determination unit may calculate a ratio between the effective transfer rate and a transfer clock frequency defined by the transfer rate mode as the effective efficiency. As a result, the measured effective transfer rate and the transfer clock frequency are used to calculate a value corresponding to the effective efficiency.

  According to the present invention, it is possible to set an optimum data transfer speed when recording / reproducing data on / from a recording medium. For example, power consumption and noise can be reduced.

It is a block diagram which shows the structural example of the video camera 100 by which this invention is embodied. It is a figure which shows the hierarchical structural example of the media access process corresponding to embodiment of this invention. It is a figure which shows the function structural example of the device driver 400 in 1st Embodiment. It is a figure which shows the example of a process sequence of the device driver 400 in 1st Embodiment. It is a figure which shows the example of a process sequence for the maximum efficiency transfer rate mode determination in 1st Embodiment. It is a figure which shows the example of a process sequence for the evaluation value calculation corresponding to one transfer rate mode candidate in 1st Embodiment. It is a figure which shows the specific example of the content of the measurement result information. 3 is a diagram illustrating an example of a format structure of a medium 500. FIG. It is a figure which shows the function structural example of the application 200 and the device driver 400 in 2nd Embodiment. It is a figure which shows the example of the content of a priority matter table. It is a figure which shows the example of a process sequence of the application 200 in 2nd Embodiment. It is a figure which shows the example of a process sequence of the device driver 400 in 2nd Embodiment. It is a figure which shows the example of a process sequence of the fastest transfer speed mode determination in 2nd Embodiment. It is a figure which shows the function structural example of the application 200 and the device driver 400 in 3rd Embodiment. It is a figure which shows the example of a process sequence of the application 200 in 3rd Embodiment. It is a figure which shows the example of a process sequence of the device driver 400 in 3rd Embodiment. It is a figure which shows the example of a process sequence of the device driver 400 in 3rd Embodiment. It is a figure which shows the example of a process sequence of the maximum efficiency transfer rate mode determination in 3rd Embodiment. FIG. 16 is a diagram illustrating a configuration example of a personal computer 700 in which the present invention is embodied as a fourth embodiment.

Hereinafter, modes for carrying out the present invention (hereinafter referred to as embodiments) will be described. The description will be made in the following order.
1. First embodiment (basic example of transfer transmission speed mode setting)
2. Second embodiment (transfer rate mode setting according to device operation content)
3. Third Embodiment (Transfer speed setting according to the case where the bit rate is defined in the file)
4). Fourth Embodiment (Configuration Example of Personal Computer Device to which Transfer Rate Mode Setting Configuration is Applied)

<1. First Embodiment>
[Configuration example of video camera device]
FIG. 1 is a diagram showing a configuration example of a video camera 100 as an example of a recording medium control apparatus in which an embodiment of the present invention is embodied. The video camera 100 includes an optical lens unit 101, a camera function unit 102, a photoelectric conversion unit 103, an image signal processing unit 104, an image input / output unit 105, a display unit 106, an audio processing unit 107, an audio input / output unit 108, and an operation input. Unit 109 and communication unit 110. Further, a CPU (Central Processing Unit) 111, a RAM 112 (Random Access Memory), a ROM (Read Only Memory) 113, a media drive 120, and a power supply unit 114 are provided.

  The optical lens unit 101 includes a lens group for imaging a subject, an aperture adjustment mechanism, a focus adjustment mechanism, a zoom mechanism, a shutter mechanism, a flash mechanism, a camera shake correction mechanism, and the like. The camera function unit 102 receives a control signal from the CPU 111 and generates a control signal to be supplied to the optical lens unit 101. Then, the generated control signal is supplied to the optical lens unit 101 to perform control such as zoom control, shutter control, and exposure control.

  The photoelectric conversion unit 103 is configured by an image sensor, and an image through the optical lens unit 101 is formed on an image formation surface thereof. Note that a CCD (Charge Coupled Device) sensor, a CMOS (Complementary Metal Oxide Semiconductor) sensor, or the like can be adopted as the imaging element. The photoelectric conversion unit 103 receives an image capture timing signal supplied from the CPU 111 according to, for example, a shutter operation, converts the subject image formed on the imaging surface into an image signal, and the image signal processing unit 104. To supply.

  The image signal processing unit 104 executes required signal processing for the supplied image signal based on a control signal from the CPU 111. For example, processing such as gamma adjustment, gain adjustment, and image quality adjustment is executed. Further, image compression processing by a compression method such as MPEG (Moving Picture Experts Group) is executed as necessary.

  The image signal processing unit 104 can generate an image signal of a predetermined method and output it from the image input / output unit 105 to the outside. The image input / output unit 105 can also input an image signal of a predetermined method from the outside, and can display the input image signal on the display unit 106 through processing of the image signal processing unit 104. The image signal processing unit 104 can also convert the image signal input by the image input / output unit 105 into image data for recording and supply the image signal to the media drive 120 via the CPU 111, for example.

  In addition, the video camera 100 includes an audio processing unit 107 and an audio input / output unit 108 so that audio signals can be input / output. The voice input / output unit 108 is a part where voice signals are input / output. First, the audio signal input from the audio input / output unit 108 is subjected to required audio signal processing by the audio processing unit 107. For example, compression processing using a predetermined audio compression encoding method is performed. The audio input / output unit 108 can also output an audio signal of a predetermined format supplied from the audio processing unit 107 to the outside.

  In this case, the CPU 111 can form an image / audio file in a predetermined format using the compressed image signal supplied from the image signal processing unit 104 and the compressed image signal data supplied from the audio processing unit 107. The image / audio file here is, for example, a moving image file in a format in which sound is reproduced in synchronization with a moving image.

  The data of the image / audio file is supplied to the media drive 120 as write data under the control of the CPU 111, for example. The media drive 120 is configured to be able to write and read data at, for example, the physical layer level in correspondence with a plurality of different types of media (storage media) in cooperation with the CPU 111.

  In this figure, a magnetic disk 500A, an optical disk 500B, a magneto-optical disk 500C, and a semiconductor memory 500D are shown as media 500 on which the media drive 120 writes and reads data. These media 500 may be fixedly incorporated in the video camera 100, for example. Further, the video camera 100 may be removable so as to be removable from the video camera 100 according to a predetermined standard.

  The media drive 120 performs a process of writing the recording data to the medium 500 selected as a control target in response to the recording data being transferred for file recording or the like. Note that the data recorded on the medium 500 is managed in file units by, for example, a predetermined file system method.

  For example, when reproducing an image / audio file as a reproduction of a file recorded on the medium 500, the CPU 111 and the media drive 120 access and read the medium on which the designated image / audio file is recorded. The image / audio file read out in this way is separated into compressed image signal data and compressed audio signal data by the processing of the CPU 111, for example. In addition, the compressed image signal data is transferred to the image signal processing unit 104, and the compressed audio signal is transferred to the audio processing unit 107.

  In this case, the image signal processing unit 104 and the audio processing unit 107 respectively perform necessary reproduction signal processing including demodulation processing on the compressed audio signal data and the compressed image signal data transferred as described above. Thereby, an image obtained by reproducing the compressed video data can be displayed on the display unit 106. Further, in synchronization with the reproduction time of the image, an audio signal obtained by reproducing the compressed audio signal data is output as audio by a speaker included in the audio input / output unit 108 or output from a headphone terminal. be able to.

  The CPU 111 executes various control processes for the video camera 100 by executing a program. The RAM 112 is used as a work area (work memory) when the CPU 111 executes processing according to a program. The ROM 113 is a part that stores various programs executed by the CPU 111 and various setting information used for the CPU 111 to execute processing.

  In this case, the operation input unit 109 collectively indicates various operators provided in the video camera 1. For example, as the operators in the operation input unit 109, there are a recording button operated in response to the start and stop of recording of a captured image, an operator for selecting an imaging mode, an operator for changing various parameters, and the like. included.

  The communication unit 110 is a part for communicating with an external device by a predetermined data communication method according to the control of the CPU 111. The data communication system supported by the communication unit 110 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, as a data communication system, a network such as Ethernet (registered trademark) can be cited as a wired communication system. In addition, data interface standards such as USB (Universal Serial Bus) and IEEE (Institute of Electrical and Electronic Engineers) 1394 can be listed. In the case of wireless, short-range wireless communication between devices such as Bluetooth (registered trademark) and wireless LAN (Local Area Network) standards such as IEEE802.11a / b / g can be cited.

  The power supply unit 114 supplies operation power to various hardware devices in the video camera 100, and includes a power supply circuit that operates by receiving power supply from a battery or a power adapter, for example.

[File system access level]
As described above, the video camera 100 according to the present embodiment can mainly store an image / audio file obtained by imaging and sound collection in a medium. Files stored on the media are managed by a file system based on a predetermined method. In this embodiment, it is assumed that a file allocation table (FAT) file system is used for management. This file system manages files in a tree-type directory structure as is well known. For data writing / reading, a logical data unit called a cluster is a minimum unit. The cluster is a group of sectors, which are the minimum units of physical data writing / reading with respect to the media, in a predetermined number.

  FIG. 2 shows the access level of the file system corresponding to the embodiment of the present invention. The hierarchical structure as the access level shown in this figure is roughly divided into a software layer and a hardware layer as a lower layer. The software layer is realized by a program executed by the CPU, various firmware, middleware, and the like in a device that is a host for the medium. The correspondence with FIG. 1 is realized by the CPU 111 in the video camera 100. In this case, as shown in the figure, the software layers are defined from the upper layer to the lower layer, that is, the application 200, the file system 300, and the device driver 400. Media 500 is located in the hardware layer.

  The application 200 has, for example, a file recording / playback function, and makes an access request at the file level to the file system 300.

  The file system 300 converts a file level access request from the application 200 to the cluster level. Furthermore, an access request at the cluster level is made to the device driver 400. However, when an access request is made, the cluster number is converted into a sector address. As a result, the device driver 400 can recognize cluster unit data at the sector level. The device driver 400 makes an access request at the sector level to the medium 500 in response to the access request from the file system 300.

  In this case, the medium 500 is formatted (initialized) in accordance with the file system standard. Corresponding to FIG. 1, the magnetic disk 500A, the optical disk 500B, the magneto-optical disk 500C, and the semiconductor memory 500D are used. In response to the access request by the sector address from the device driver 400, the medium 500 reads data from the designated sector address and returns it to the device driver 400.

  The device driver 400 receives data in units of sectors in response to an access response from the medium 500. Then, the data is transferred to the file system 300 by a cluster unit in which a predetermined number of sector unit data is connected. The file system 300 converts the data in cluster units received from the device driver 400 into file level data and passes it to the application 200.

[Functional configuration example corresponding to the first embodiment]
Some media can record and play back files corresponding to a plurality of transfer speed modes. A specific example of such a transfer rate mode is the Ultra DMA (Direct Memory Access) standard. In this standard, six transfer speed modes 0 to 5 are defined, and the maximum transfer speed (theoretical value) increases as the mode number increases.

  When the media supports a plurality of transfer speed modes, until now, the device serving as a host for the media has a maximum transfer speed within a range that can be supported by the plurality of transfer speed modes. The highest one was selected and set.

  However, in practice, the fastest transfer rate mode is not always appropriate. For example, the data transfer rate (effective transfer rate) obtained by actual measurement is usually lower than the maximum transfer rate specified in the specification, and its ratio to the maximum transfer rate (hereinafter also referred to as “effective efficiency”) is also the data transfer rate. Different for each. Then, for example, even if the fastest data transfer rate is set, it is possible that there is no significant difference between the lower data transfer rate and the effective transfer rate. In addition, power consumption and radiation noise increase as the operating frequency for data transfer increases. For this reason, for example, when considering the trade-off between data transfer speed, power consumption, and radiation noise suppression, instead of always setting the fastest transfer speed mode, set the transfer speed mode with the highest effective efficiency. It is preferable to do this. Therefore, the first embodiment of the present invention is configured so that the transfer rate mode can be set as described below.

  FIG. 3 shows a configuration example for data transfer rate setting corresponding to the first embodiment of the present invention. In this figure, a device driver 400, a medium 500, and a transfer clock generation unit 121 are shown.

  As shown in FIG. 2, the device driver 400 basically executes access control to the medium 500 at the sector level. Here, the device driver 400 corresponds to the data transfer rate determination according to the embodiment of the present invention. The configuration is shown. The transfer clock generator 121 generates a transfer clock CLK having a frequency corresponding to the data transfer speed to be set. Data is written to and read from the medium 500 at a data transfer speed according to the transfer clock CLK.

  The device driver 400 shown in this figure has a transfer rate mode candidate recognition unit 410, a transfer rate mode setting unit 420, an effective transfer rate measurement processing unit 430, and a transfer rate as functions corresponding to data transfer rate determination and data transfer operation environment setting. A mode determination unit 440 is provided.

  The transfer rate mode candidate recognizing unit 410 is a part for recognizing a transfer rate mode as a candidate for determining the most appropriate transfer rate mode, that is, the maximum efficiency transfer rate mode. For this purpose, the transfer rate mode candidate recognition unit 410 reads the transfer rate mode information held in the transfer rate mode information holding unit 520 of the medium 500. The transfer rate mode information indicates predetermined contents for various specifications and the like for each transfer rate mode that the medium 500 can support. Therefore, the transfer rate mode candidate recognition unit 410 can recognize transfer rate modes that the media 500 can support by referring to the content of the transfer rate mode information. That is, all transfer rate modes that are candidates for the maximum efficiency transfer rate mode can be recognized. The transfer speed mode candidate recognition unit 410 is an example of a candidate recognition unit described in the claims.

  The transfer rate mode setting unit 420 is a functional part that actually sets the transfer rate mode. Here, “setting the transfer speed mode” means setting an operating environment in which data is recorded / reproduced with respect to the medium 500 at the data transfer speed indicated in the specification of the transfer speed mode. In order to set this operating environment, for example, the frequency of the transfer clock defined in the specification of the transfer rate mode is set. Specifically, the transfer clock generator 121 is controlled so that the transfer clock CLK is generated at a frequency defined in the specification of the transfer speed mode. This transfer clock CLK is supplied to, for example, the CPU 111 (not shown) in addition to the medium 500, so that writing and reading of data to and from the medium 500 are executed in synchronization with the transfer clock CLK. Become.

  Further, for the above operating environment setting, for example, the media 500 may have to make a setting corresponding to the corresponding transfer speed mode. In such a case, the transfer rate mode setting unit 420 designates the transfer rate mode to be set for the medium 500 for the operation environment setting. For example, the medium 500 performs an internal setting according to the designated transfer speed mode.

  The effective transfer rate measurement processing unit 430 executes test write (trial write) and test read (trial read) under settings corresponding to each candidate transfer rate mode, and supports test write and test read respectively. It is a functional part that measures the effective transfer rate. Then, the effective transfer rate measurement processing unit 430 holds measurement result information 601 indicating the effective transfer rate for each transfer rate mode candidate obtained by measurement in a predetermined storage area as information indicating the test result. Note that the area in which the data as the measurement result information 601 is actually held is, for example, a work area assigned for the device driver 400 in the register of the CPU 111 or the RAM 112 if it corresponds to the video camera 100. And so on. The transfer rate mode setting for each candidate is executed by the transfer rate mode setting unit 420. The effective transfer rate measurement processing unit 430 and the transfer rate mode setting unit 420 that sets the transfer rate mode for each candidate are examples of the execution transfer rate measuring unit described in the claims.

  The transfer rate mode determination unit 440 determines the transfer rate mode with the highest effective efficiency from among the transfer rate mode candidates based on the content of the measurement result information 601. In this case, the transfer rate mode setting unit 420 also sets a data transfer operation environment corresponding to the determined transfer rate mode. Thereby, for example, in response to the file access executed by the application 200 with respect to the medium 500, data writing and reading are executed at the most efficient data transfer rate. The transfer rate mode determination unit 440 is an example of the transfer rate mode determination unit described in the claims.

[Example of processing procedure corresponding to the first embodiment]
The flowchart in FIG. 4 shows an example of a procedure for determining the transfer speed mode and setting the operating environment according to the determination result, which is assumed to be executed by the device driver 400 corresponding to the first embodiment.

  Here, it is assumed that the transfer speed mode determination is executed in response to the corresponding medium 500 being powered on. Therefore, in this figure, first, the device driver 400 executes control for turning on the power of the medium 500 (step S901). For example, if the medium 500 is built in the host device, the power-on control is executed when the host device is turned on. If the medium 500 is a removable format, it is executed in response to the loading of the medium 500.

  Next, the transfer rate mode candidate recognizing unit 410 of the device driver 400 reads the transfer rate mode information from the transfer rate mode information holding unit 520 of the medium 500 and refers to the contents thereof to transfer as described above. A speed mode candidate is recognized (step S903). Next, it is determined whether or not there are a plurality of recognized transfer mode candidates (step S904).

  If it is determined in step S904 that there are a plurality of transfer rate mode candidates, first, 1 is substituted for the variable n corresponding to the number assigned to each transfer rate mode candidate (S905). Next, processing for setting the transfer speed mode of the nth candidate is executed in steps S906 and S907. First, in step S906, the transfer clock generation unit 121 is controlled to generate a transfer clock CLK having a frequency defined in the transfer speed mode of the nth candidate. In step S907, the nth candidate transfer rate mode is instructed to the medium 500 as necessary.

  Under the state where the transfer speed mode of the nth candidate is set by the above processing, the effective transfer speed measurement processing unit 430 performs the data transfer speed actually obtained while executing the test write on the medium, that is, the effective transfer. The speed is measured (step S909). Subsequently, the effective transfer rate measurement processing unit 430 measures the effective transfer rate while executing a test read on the medium (step S910). Then, the effective transfer rate measurement processing unit 430 holds the effective transfer rate measured by the test write and test read as the measurement result information 601 (step S911).

  Next, the effective transfer rate measurement processing unit 430 determines whether or not the variable n is the maximum value (step S912). If it is determined that the variable n is not the maximum value, the variable n is incremented (step S913). The process returns to S906. That is, a process for measuring the effective transfer rate corresponding to the transfer rate mode of the next candidate and holding it as test result information is started.

  A specific example of which area of the medium 500 should be subjected to the test write and test read will be described later.

  On the other hand, if it is determined in step S912 that the variable n is the maximum value, the test result information for each candidate transfer rate mode is obtained. Therefore, in this case, the transfer rate mode determination unit 440 determines one transfer rate mode from the transfer rate mode candidates based on the measurement result information 601 obtained so far (step S920). Note that the transfer speed mode determination processing in step S920 will be described later. The transfer rate mode determined in step S920 is the transfer rate mode to be set, but is treated as having the highest effective efficiency as will be understood from the description below. Because of this, hereinafter, the transfer rate mode determined in step S920 is also referred to as “maximum efficiency transfer rate mode”.

  Then, the transfer rate mode setting unit 420 sets the maximum efficiency transfer rate mode determined in step S920 as the transfer rate mode corresponding to the time of media access (step S915).

  If it is determined in step S904 that there is one transfer speed mode candidate, the transfer speed mode that can be handled by the medium 500 is originally one. Therefore, in this case, the one transfer speed mode supported by the medium 500 is set (step S916). The setting process at this time may be the same as, for example, steps S905 and S906.

[Concept of determining the maximum efficiency transfer rate mode]
First, the concept of maximum efficiency transfer rate mode determination in the embodiment of the present invention will be described. FIG. 7 shows an example of the measurement result information 601 corresponding to the first to third candidate transfer speed modes A to C obtained by the processing of steps S905 to S912 of FIG. In this case, in the first candidate transfer rate mode A, the transfer clock frequency defined in the specification is 50 MHz. The effective transfer rates at the time of test read and test write measured by setting this transfer rate mode A are 60 Mbps (bit per second) and 50 Mbps, respectively. The transfer rate mode B of the second candidate is defined as a transfer clock frequency of 25 MHz, and the effective transfer rates at the time of test read and test write are 60 Mbps and 50 Mbps, respectively. The third candidate transfer rate mode is defined as a transfer clock frequency of 12.5 MHz, and the effective transfer rates at the time of test read and test write are 25 Mbps and 20 Mbps, respectively. Note that the maximum transfer rate for each data transfer mode corresponds to, for example, the transfer clock frequency, and decreases in the order of the data transfer modes A, B, and C.

  In FIG. 7, the effective transfer rate ratio (transfer rate ratio) to the transfer clock frequency is shown in parentheses in each column of the effective transfer rate at the time of test read and test write in the transfer rate mode of each candidate. . This transfer rate ratio is obtained by (effective transfer rate (Mbps) / transfer clock frequency (MHz)). According to this, for example, the transfer rate ratio at the time of the test read is “2.0” in the case of the transfer rate modes B and C of the second candidate and the third candidate, whereas the fastest first In the case of one candidate transfer rate mode A, “1.2” is set. That is, the transfer rate ratio in the first candidate transfer rate mode is smaller than when the transfer rate modes B and C of the second candidate and the third candidate are set. The transfer rate ratio at the time of test write is “1.6” in the third candidate transfer rate mode, “1.8” in the second candidate transfer rate mode, and in the case of the first candidate transfer rate mode. Is “1.0”, which is the same as above.

  From these results, for example, even if the transfer speed mode of the first candidate having the fastest transfer clock frequency is set, the effective transfer speed at that time is significantly higher than the transfer speed mode of the second candidate. There is no such thing. Further, when the transfer rate ratios at the time of test read and test write are taken together, the second transfer rate mode is the highest. Therefore, in this case, it can be said that the second candidate transfer rate mode B has the most effective transfer rate with respect to the transfer clock frequency. That is, it can be said that it is appropriate to determine the transfer rate mode B of the second candidate as the maximum efficiency transfer rate mode.

  As described above, the effective ratio here refers to the ratio of the effective transfer rate to the maximum transfer rate. The transfer clock frequency in each transfer rate mode in the embodiment of the present invention corresponds to the maximum transfer rate defined for each transfer rate mode, for example. Therefore, the transfer rate ratio in the embodiment of the present invention may be considered to be an effective ratio substantially.

[Example of processing procedure for determining the maximum efficiency transfer rate mode]
The flowcharts of FIGS. 5 and 6 show an example of a processing procedure for determining the maximum efficiency transfer rate mode as step S920 of FIG. The process shown in these figures is one example of a procedure for determining the maximum efficiency transfer rate mode corresponding to the concept described with reference to FIG.

  First, in FIG. 5, the transfer rate mode determination unit 440 substitutes 1 for a variable n corresponding to the number assigned to each transfer rate mode candidate (step S <b> 923), and then executes the processing after step S <b> 930.

  In step S930, evaluation value calculation corresponding to the transfer speed mode of the nth candidate is executed. An example of an evaluation value calculation processing procedure as step S930 will be described later with reference to FIG. Next, the transfer rate mode determination unit 440 determines whether or not the current variable n is the maximum value (step S926). If it is determined in step S926 that the variable n is not the maximum value, the variable n is incremented to calculate an evaluation value corresponding to the remaining transfer rate mode (step S927), and the evaluation value in step S930 is determined. The calculation process is executed again. If it is determined in step S926 that the variable n is the maximum value, the transfer rate mode with the highest evaluation value among the candidates is determined as the maximum efficiency transfer rate mode (step S928).

  The flowchart in FIG. 6 shows an example of a processing procedure for calculating an evaluation value corresponding to the nth candidate transfer rate mode corresponding to step S930 in FIG. First, the transfer rate mode determination unit 440 acquires measurement result information 601 corresponding to the transfer rate mode of the nth candidate and information indicating the transfer clock frequency (step S931). Here, as the measurement result information 601, information on the effective transfer rate at the time of test read and test write corresponding to the transfer rate mode of the nth candidate is acquired. The transfer speed mode information indicates the transfer clock frequency. Therefore, the transfer clock frequency information can be acquired from the transfer rate mode candidate recognition unit 410 that interprets the content of the transfer rate mode information.

Next, the transfer rate mode determination unit 440 calculates a transfer rate ratio Rvn corresponding to the test read in the n-th candidate transfer rate mode (step S932). This transfer rate ratio Rvn can be obtained by the following equation 1, for example, where fn is the transfer clock frequency in the transfer rate mode of the nth candidate obtained in step S931 and Rrtn is the effective transfer rate at the time of test read.
Rvn = Rrtn / fn (Formula 1)

Next, the transfer rate mode determination unit 440 calculates a transfer rate ratio Wvn corresponding to the test write in the same nth candidate transfer rate mode (step S933). This transfer rate ratio Wvn can be obtained by the following equation 2 where fn is the transfer clock frequency in the transfer rate mode of the nth candidate and Wrtn is the effective transfer rate at the time of test write.
Wvn = Wrtn / fn (Formula 2)

Next, the transfer rate mode determination unit 440 calculates an evaluation value Vn corresponding to the nth candidate transfer rate mode (step S934). For this purpose, for example, the following equation 3 is used by using the transfer rate ratios Rvn and Wvn obtained in steps S931 and S932.
Vn = (Wvn + Rvn) / 2 (Formula 3)

  As can be understood from Equation 3, the evaluation value Vn in this case is an average value of the read correspondence transfer rate ratio Rvn and the write correspondence transfer rate ratio Wvn. That is, in this case, both the recording and the reproduction are evaluated comprehensively by obtaining an average value.

  In the above description, in obtaining the evaluation value Vn, the transfer rate ratios Rvn and Wvn corresponding to the test read and test write times are obtained, and the average value is obtained. The evaluation value Vn can be obtained in the same manner by calculating the average value of the effective transfer rates Rrtn and Wrtn at the time of test read and test write and calculating the ratio of the average value and the transfer clock frequency. . From this point, the following can be said in the embodiment of the present invention. That is, it can be said that the average value of the effective transfer rates Rrtn and Wrtn corresponding to each of the test write and test read is treated as a total effective transfer rate used for transfer rate mode determination.

  As described above, in the embodiment of the present invention, the transfer rate mode to be set is determined based on the evaluation value obtained using the effective transfer rate. Since the effective transfer rate of the embodiment of the present invention is obtained by actual measurement, for example, a correct determination result can be obtained corresponding to each different medium.

  Note that the transfer rate ratios Rvn and Wvn in the embodiment of the present invention correspond to the effective ratios, but as a modification, for example, instead of obtaining the transfer rate ratios Rvn and Wvn, the original effective ratio is obtained. Also good. That is, the ratios of the effective transfer rates Rrtn and Wrtn with respect to the specified maximum transfer rate are obtained. However, for example, normally, the transfer rate mode information stores information specifying the transfer clock frequency as parameter information for enabling the host to set the transfer rate mode. In other words, the embodiment of the present invention is configured such that even if the specific value of the maximum transfer rate is not known, information corresponding to the effective ratio can be acquired using the transfer clock frequency information stored in the transfer rate mode information. ing.

  Further, for example, it is conceivable that the determination result of the transfer speed mode to be set is associated with each medium and stored in, for example, a nonvolatile memory of a host device or a predetermined medium. In this case, for example, when the power of the medium is turned on, information on the determination result corresponding to the medium is read. Then, the transfer rate mode indicated by the determination result information is set. In this way, it is not necessary to execute the transfer speed mode determination process each time the medium is turned on, for example.

[Example of write area for test write and test read]
In the test write and test read executed by the effective transfer rate measurement processing unit 430 as steps S907 and S908 in FIG. 4, data is actually written to and read from the medium 500. An example of setting the areas used for writing and reading data corresponding to the test write and test read will be described.

  FIG. 8 shows an exemplary format structure for the medium 500. The format structure shown in this figure is an example corresponding to the file allocation table file system (FAT file system). The medium 500 shown in this figure is mainly composed of a main activation area 501 arranged corresponding to the head of the logical address (LBA) and an area of the partition 510. A free area 502 as a buffer area is formed between the main boot area 501 and the partition 510.

  The area of the partition 510 includes a system area 511 and a data area 512 as shown in the figure. Although detailed description is omitted here, the system area 511 is an area in which management information corresponding to the current partition such as a file allocation table (FAT) is arranged. The data area 512 is an area where data forming a file is recorded in a unit area called a cluster, for example.

  The space area 502 is actually an area that occupies a logical address range of, for example, 0x01 to 0x3E (0x indicates notation in hexadecimal notation). Then, for example, at the time of test writing and test reading, data of a predetermined size may be written and read at an arbitrary position in this area range. The data size for writing and reading is preferably, for example, one cluster. As a result, the device driver 400 can cope with the same data write and read processes as those during normal file access even during test write and test read.

<Second Embodiment>
[Functional Configuration Example Corresponding to Second Embodiment]
In the first embodiment, the maximum efficiency transfer rate mode is always set. However, for example, depending on the actual operation of the host device, it is better to execute data transfer at an effective transfer rate as fast as possible than to give priority to effective efficiency. You can also take the idea of

  As a specific example, it is assumed that, for example, the video camera 100 of FIG. 1 serving as a host device in the embodiment of the present invention and a personal computer are connected via a predetermined data interface. In such a case, it is assumed that the operation content of the host device is to read the file data recorded on the medium 500 and transfer it to the personal computer. Alternatively, it is assumed that data of a file transferred from the personal computer to the video camera 100 is recorded on the medium 500. In general, a personal computer has a higher data processing capability than a device such as the video camera 100. Therefore, there is no problem with transferring the file data in the above case at a data transfer speed as high as possible, and there is an advantage that the time required for the file transfer is shortened accordingly.

  Further, as an operation of the host device, when a still image is captured by the video camera 100 and recorded on the medium 500, for example, it is possible to shift to a state where the next still image can be captured and recorded as quickly as possible. Required. From this point of view, it is preferable that the data transfer speed be as high as possible when recording a still image file obtained by imaging on a medium.

  On the other hand, for example, when the operation of the host device is recording / playback of a moving image file obtained by imaging, the effective transfer rate that satisfies the bit rate defined according to the compression rate of the moving image file is As long as it is obtained, recording and reproduction can be performed without problems. The same applies to audio files. Further, even in the case of reproducing a still image file, it is possible to reproduce the file at a speed at which the user is not stressed, for example, at a current general data transfer rate. Therefore, in these cases, it can be said that it is preferable to set a data transfer rate giving priority to efficiency so as to be advantageous in terms of power consumption and noise.

  Therefore, in the second embodiment, a configuration in which the setting can be switched between the maximum efficiency transfer rate mode and the fastest transfer rate mode according to the operation content of the host device that accompanies file access to the medium 500 is adopted.

  FIG. 9 shows a functional configuration example corresponding to the second embodiment. In this figure, the same parts as those in FIG. The application 200 shown in this figure includes a priority determination unit 210 and a priority specification unit 220 that correspond to the above-described transfer speed mode setting switching function.

  The priority determination unit 210 is a part that determines priority according to the current device operation content. The priority determination unit 210 uses the priority table 602 and the current priority information 603 for priority determination. The priority item table 602 is read into the RAM 112 as data used by the application 200, for example, when the application 200 is expanded. The priority determination unit 210 is an example of the priority determination unit described in the claims.

  FIG. 10 shows an example of the priority item table 602. As shown in this figure, the priority table has a structure in which priority items are associated with each predetermined device operation content. Each of the device operation contents in the priority table is any one of recording and playback of a moving image file, recording and playback of a still image file, and the like as described in the above example. In addition, the file is transferred or recorded between the host device and the device connected via the data interface. Applicable priorities are indicated for each of these device operation contents. In addition, the priority items defined in the priority item table are “effective efficiency” and “speed”.

  When the priority is “effective efficiency”, it means that priority should be given to a transfer rate mode to be set that has a high effective efficiency. On the other hand, when the priority is “speed”, it means that the highest possible transfer rate should be given priority.

  In FIG. 9, the priority item determination unit 210 determines whether or not a priority item is changed in accordance with a change in device operation content, for example, as will be described later. When it is determined that the priority item is changed, the priority item is notified to the priority item designating unit 220. The priority specification unit 220 specifies the notified priority for the device driver 400. This instruction is executed so as to mediate the file system 300 as shown.

  Here, it is assumed that the transfer speed mode determination unit 440 receives the priority specification from the priority specification unit 220 in the device driver 400. First, when the designated priority is “efficiency”, the transfer rate mode determination unit 440 cooperates with the transfer rate mode candidate recognition unit 410, the effective transfer rate measurement processing unit 430, and the transfer rate mode setting unit 420. To determine the maximum efficiency transfer rate mode. Then, the determined maximum efficiency transfer rate mode is set. On the other hand, when the instructed priority is “speed”, the transfer rate mode setting unit 420 selects the fastest effective transfer from the transfer rate mode candidates recognized by the transfer rate mode candidate recognition unit 410. Set the transfer speed mode where the speed is obtained. Here, the effective transfer rate determined as the fastest is an average value of the effective transfer rates measured at the time of test write and test read.

[Example of processing procedure corresponding to the second embodiment]
The flowchart of FIG. 11 shows an example of a processing procedure executed by the application 200 corresponding to the second embodiment. First, the priority determination unit 210 determines whether or not the device operation content is changed from this (step S941). For example, in response to a user operation on the host device or an instruction from another device connected to the host device, the application 200 executes processing for switching the operation mode of the device. The priority determination unit 210 determines that the device operation content is changed based on the processing result of the application 200, for example.

  Next, the priority determination unit 210 refers to the priority table held in the priority table 602 to determine what the priority corresponding to the changed device operation content is (step S942). . Next, the priority indicated by the current priority information 603 is compared with the priority corresponding to the changed device operation content determined in step S942 (step S943), and the comparison results match. It is determined whether or not (step S944).

  The current priority information 603 indicates the priority that has been set corresponding to the device operation content so far. Therefore, if it is determined in step S944 that the comparison results do not match, the priority item is also changed according to the change in the device operation content. In this case, the priority determined by the priority specification unit 220 is specified to the device driver 400 (step S948). Note that the designation of priority in step S948 is substantially a data transfer rate setting execution request after the designation of priority. In addition, the priority item determination unit 210 indicates the priority item determined in step S942 as the content of the current priority item information 603 when it is determined in step S944 that the comparison results do not match. (Step S949).

  On the other hand, if it is determined in step S944 that the comparison results match, the priority item is not changed regardless of the change in the device operation content. In this case, the priority designation unit 220 ends the process without executing the priority designation process in step S948. Further, the priority determination unit 210 does not update the current priority information 603 in step S946.

  For example, it is also conceivable that the device driver 400 performs the transfer speed mode determination by designating the determined priority item every time the device operation content is changed. However, as described above, the device driver 400 designates the priority only when it is determined in step S944 that the comparison results do not match, so that the device driver 400 changes the transfer speed mode each time the device operation content is changed. There is no need to perform a judgment. Thereby, for example, the processing load can be reduced.

  FIG. 12 shows an example of a processing procedure executed by the device driver 400 corresponding to the second embodiment. Note that, in the steps shown in this figure, the same reference numerals are given to the same processing as in FIG. For example, the transfer rate mode determination unit 440 receives a priority item designation transmitted from the priority item designation unit 220 (step S901A).

  The subsequent processes in steps S903 to S913 and step S916 are the same as those described with reference to FIG. 4, and thus description thereof is omitted here.

  In FIG. 12, when it is determined in step S912 that the variable n is the maximum value, it is determined which of the effective efficiency and the speed is specified as the priority specification received in the previous step S901A. (Step S914). If it is determined in step S914 that the priority is effective efficiency, the maximum efficiency transfer rate mode is determined from the transfer rate mode candidates as the transfer rate mode to be set (step S920). On the other hand, when it is determined that the priority is speed, the fastest efficient transfer speed mode is determined from the transfer speed mode candidates as the transfer speed mode to be set (step S950). The maximum efficiency transfer rate mode determination process as step S920 may be the same process as described above with reference to FIGS. The fastest efficient transfer rate mode determination process as step S950 will be described later.

  In this case, when the maximum efficiency transfer rate mode is determined in step S920, the transfer mode setting unit 420 sets an operating environment corresponding to the transfer rate mode determined as the maximum efficiency transfer rate mode. If the fastest transfer speed mode is determined in step S950, an operating environment corresponding to the transfer speed mode determined as the fastest transfer speed mode is set.

  The flowchart of FIG. 13 shows an example of the processing procedure for determining the fastest transfer speed mode as step S950. The transfer rate mode determination unit 440 substitutes 1 for the variable n (step S951). Next, the transfer rate mode determination unit 440 acquires the effective transfer rate corresponding to each of the read time and the write time as measurement result information corresponding to the second candidate transfer rate mode (step S952). Then, the evaluation value Vn is obtained by calculating or adding the obtained effective transfer rate at the time of reading and the effective transfer rate at the time of writing (step S953). The processes in steps S952 and S953 are repeatedly executed after incrementing the variable n until it is determined that the variable n is the maximum value (steps S954 and S955). If it is determined that the variable n has reached the maximum value, for example, the evaluation value Vn for each transfer rate mode is compared, and the maximum value is determined as the fastest transfer rate mode (step S956).

  For example, it is assumed that the execution transfer rate measured in one transfer rate mode candidate is not likely to be equal to or higher than the effective transfer rate measured in a transfer rate mode candidate having a higher transfer rate clock frequency. . In this case, even if the effective transfer rate is not measured, the fastest transfer rate mode is the transfer rate mode having the highest transfer clock frequency. Therefore, on the assumption of this, the following modifications can be considered. That is, when the priority is speed, the transfer speed mode having the highest transfer clock frequency is determined as the fastest transfer speed mode without being based on the effective transfer speed. In this case, depending on the priority being speed, for example, the test write and test read in steps S909 and S910 can be omitted to reduce the processing load.

<Third Embodiment>
[Outline of Third Embodiment]
For example, as described in the second embodiment, a bit rate is defined for a content file such as a moving image or audio according to its compression rate. That is, the data processing amount required for recording / reproduction per unit time is defined. Corresponding to this bit rate, the minimum required effective transfer rate (essential effective transfer rate) is also determined. If the required effective transfer rate is exceeded, the file read from the medium can be reproduced and the file can be recorded on the medium normally. In this respect, it is effective to set a data transfer rate giving priority to efficiency. However, when data transfer is performed at an effective transfer rate lower than the required effective transfer rate, there is a possibility that a normal recording / reproducing result cannot be obtained. From this, for example, when determining the maximum efficient transfer rate mode based on the device operation content of recording and reproducing a file of a format in which the data rate is defined, the following must be taken into consideration. In other words, it is necessary to prevent a transfer rate mode having an effective transfer rate below the required effective transfer rate from being determined.

  As an example, it is assumed that the device operation content is to record a moving image file having a bit rate of 24 Mbps. In this case, it is assumed that the essential effective transfer rate determined according to the bit rate of 24 Mbps is 32 Mbps. This is based on the assumption that the essential effective transfer speed is 4/3 times the bit rate of the file, for example, as a characteristic of the medium for recording the moving image file. Assume that the measurement result shown in FIG. 7 is obtained in the process of determining the maximum efficiency transfer rate mode corresponding to the recording of the moving image file. When comparing the effective transfer rate at the time of test write in FIG. 7 with the required effective transfer rate of 32 Mbps, the effective transfer rate at the time of test write is 20 Mbps in the third candidate transfer rate mode, which is higher than the required effective transfer rate. Low. On the other hand, the effective transfer rates during the test write in the transfer rate mode of the first candidate and the second candidate are 45 Mbps and 50 Mbps, respectively, which are higher than the essential effective transfer rate. Therefore, at this stage, it is necessary to exclude the third candidate transfer rate mode from the determination target.

  Further, the device operation contents can be distinguished from the viewpoint of file recording and reproduction. In this case, if the maximum efficient transfer rate mode is determined only for file recording, it can be said that there is no problem with the determination using only the effective transfer rate at the time of test writing. That is, there is no need to execute a test lead. Similarly, when it is limited to the reproduction of a file, it is sufficient to make a determination using only the effective transfer rate at the time of test read, and there is no need to execute test write.

  Therefore, in the third embodiment, first, the following processing is executed in response to the device operation content of recording / playback of a file in which the bit rate is defined. . That is, a transfer rate mode that does not satisfy the required effective transfer rate according to the bit rate defined in the file is excluded from candidates and the maximum efficiency transfer rate mode determination is performed. As a result, it is possible to set the maximum efficient transfer rate mode while preventing troubles in file recording and reproduction.

  The other is configured to execute only one of the test write and the test read in the maximum efficiency transfer rate mode determination depending on whether the device operation content is file recording or playback. To do. Thereby, for example, the load of the maximum efficiency transfer rate mode determination process can be reduced. In addition, since the frequency of access to the medium is lowered, the life of the medium is extended in the case of a flash memory, for example.

[Functional Configuration Example Corresponding to Third Embodiment]
FIG. 14 shows a functional configuration example corresponding to the third embodiment. The structure of the functional site shown in this figure is the same as that in FIG. However, the transfer rate mode determination unit 440 uses the bit rate information 605 in addition to the measurement result information 601 when executing the determination process. Another difference is that the effective transfer rate measurement processing unit 430 uses the recording / playback identification information 604.

[Example of processing procedure corresponding to the third embodiment]
The flowchart of FIG. 15 shows an example of a processing procedure executed by the application 200 corresponding to the third embodiment. In this figure, the same steps as those in FIG. 11 are denoted by the same reference numerals.

  In this figure, the processing in steps S941 to S944 is the same as that in FIG. In this case, if it is determined in step S944 that the priority indicated by the current priority information 603 does not match the priority corresponding to the changed device operation content determined in step S942. The process is executed as follows. That is, the recording / playback identification information 604 indicating either recording or playback is generated in accordance with whether the changed device operation content determined corresponding to step S941 is recording or playback on the medium 500. (Step S945). Note that the application 200 can recognize whether the device operation content is recording or reproduction based on the execution result of its own processing. Next, it is determined whether or not the file to be recorded or reproduced on the medium based on the device operation content after the change is a file with a prescribed bit rate (step S946).

  For example, if it is determined in step S946 that the bit rate is specified in accordance with the video file or the audio file, the bit rate information 605 indicating the value of the specified bit rate is generated. (Step S947). The bit rate value can be recognized as one of the attributes of the target file by the application 200, for example. On the other hand, if it is determined in step S946 that the file is not a file with a prescribed bit rate, step S947 is skipped. Next, the priority specification unit 220 specifies the priority determined for the device driver 400 (step S948A). This is the same as step S948 in FIG. 11, but in step S948A, the recording / playback identification information 604 generated in step S945 is also transmitted together with the designation of the above-mentioned priority items. If bit rate information 605 has been generated in step S947, this bit rate information 605 is also transmitted.

  The flowcharts of FIGS. 16 and 17 show an example of a processing procedure executed by the device driver 400 corresponding to the third embodiment. In the steps shown in these drawings, the same processes as those in FIG.

  In FIG. 16, in response to receiving the priority designation in step S901A, for example, the transfer rate mode determination unit 440 holds the recording / playback identification information 604 transmitted together with the priority designation in, for example, a register. Further, when the bit rate information 605 is transmitted together with the recording / reproducing identification information 604, the bit rate information 605 is also held.

  In this case, the transfer rate mode determination unit 440 executes, for example, the process of setting the nth candidate transfer rate mode in steps S906 and S907, and then in step S908, whether the recording / playback identification information 604 indicates recording. It is going to be judged about.

  If it is determined in step S908 that the recording / playback identification information 604 indicates recording, the device operation content is recording. Therefore, in this case, the effective transfer rate by the test write is measured (step 909), and the measurement result information is held (step S911). That is, the effective transfer rate is not measured by the test read in step S910.

  On the other hand, when it is determined that the recording / playback identification information 604 does not indicate recording, the device operation content is playback. In this case, without measuring the effective transfer rate by the test write in step S909, the effective transfer rate by the test read is measured (S910), and the measurement result information is held (step S911). Thus, in the third embodiment, the test read process is not executed if the device operation content is recorded, and the test write process is not executed if the device operation content is playback. Configured.

  The flowchart in FIG. 18 shows an example of the processing procedure for determining the maximum efficiency transfer rate mode as step S920A shown in FIG. In the steps shown in this figure, the same reference numerals are given to the same processing as in FIG. In this case, the transfer rate mode determination unit 440 first acquires the bit rate value indicated in the bit rate information 605 (step S921). However, as can be understood from the above description, the bit rate information 605 is not held when the file to be recorded / reproduced is a still image or a document, for example. When there is no bit rate information 605 in this way, in step S921, a bit rate value of 0 is set instead of acquiring the bit rate value. By setting the bit rate value to 0 in this way, as will be understood from the following description, it is possible to produce the same result as when the processing of steps S924 and S925 described later is invalidated.

  Next, the transfer rate mode determination unit 440 calculates an essential effective transfer rate (step S922). As a specific example of the calculation, for example, the bit rate value acquired in step S921 is multiplied by the count k. The coefficient k is set in advance as follows. That is, the ratio of the required transfer rate to the bit rate is determined by the specifications of the host device, the processing capability, and the like. As a specific example, it is assumed that the required effective transfer rate needs to be 4/3 times (about 1.3 times) the bit rate due to the performance of the host device. In this case, the coefficient k is 4/3. Here, it is assumed that a bit rate of 24 Mbps, 16 Mbps, or 9 Mbps is defined for a certain type of moving image file in accordance with the compression rate or the like. As a result, a required effective transfer rate of 32 Mbps is required corresponding to a bit rate value of 24 Mbps. In addition, a required effective transfer rate of 22 Mbps is required for a bit rate value of 16 Mbps. Corresponding to a bit rate value of 9 Mbps, an essential effective transfer rate of 12 Mbps is required. Further, when the bit rate value is set to 0 corresponding to the case where there is no bit rate information 605, the required effective transfer rate is always 0.

  Next, after substituting 1 for the variable n in step S923, the effective transfer rate corresponding to the transfer rate mode of the nth candidate acquired from the measurement result information 601 and the required effective transfer rate obtained in step S922 are calculated. Compare (step S924). In the description of FIG. 18, the effective transfer rate corresponding to the n-th candidate transfer rate mode acquired from the measurement result information 601 is referred to as a measured effective transfer rate and distinguished from the essential execution transfer rate. Then, as a comparison result, it is determined whether or not the measured effective transfer rate is higher than the required effective transfer rate (step S925).

  If it is determined in step S925 that the measured effective transfer rate is higher, the evaluation value calculation process in step S930 is executed, but if the measured effective transfer rate is lower, step S930 is skipped. Thus, by skipping step S930, the evaluation value for the nth candidate cannot be obtained. As a result, it is excluded from the determination target in step S928. That is, the transfer rate mode in which the effective transfer rate is lower than the required effective transfer rate can be excluded from the determination candidates.

  If a bit rate value of 0 is set assuming that there is no bit rate information 605, it is determined in step S925 that the measured effective transfer rate is always higher, and the evaluation value calculation in step S930 is executed. That is, the same result as that obtained when step S930 is executed without executing the processing of steps S924 and S925 is obtained.

  In this case, the evaluation value calculation process corresponding to the nth candidate in step S930 is, for example, as follows. In the third embodiment, by the processing of S908 to S910 in FIG. 16, the measurement result information 601 has only effective transfer rate information corresponding to either test write or test read. Therefore, as the evaluation value calculation processing, the transfer rate ratio may be calculated based on the effective transfer rate and the transfer clock frequency fn only during either the test write or the test read acquired from the measurement result information 601. That is, either one of steps S932 and S933 in FIG. 6 may be executed. The transfer rate ratio thus obtained is set as an evaluation value Vn.

  Further, even in the processing of the fastest transfer rate mode determination in step S950 in FIG. 17, the information on the effective transfer rate for only one of the test write and the test read obtained corresponding to the nth candidate is evaluated as it is. The value Vn may be used. As described above, when only one of the test write and the test read is executed, the effective transfer rate measured by the test write or the test read is directly used for the transfer rate mode determination.

  As a modification, both the test read and test write are executed, and only the effective transfer rate at the time of test read or test write depends on whether the device operation content is recording or playback. A configuration in which an evaluation value is calculated by using can be considered. For example, in practice, the time required for the test read and test write can be as short as about 1 ms. Therefore, even if both are executed, for example, the operation delay of the device as experienced by the user does not occur. There is no problem at this point.

<Fourth embodiment>
[Configuration example of personal computer]
In the description of the embodiments so far, the video camera 100 has been described as an apparatus in which the embodiment of the present invention is embodied. However, for example, the embodiment of the present invention may be embodied by a personal computer. Is possible. The block diagram of FIG. 19 shows a configuration example of such a personal computer 700.

  A personal computer 700 shown in FIG. 19 includes a CPU 701, a RAM 702, a ROM 703, a bus 704, an input / output interface 705, an input unit 710, an output unit 720, a communication unit 730, and a storage unit 740.

  The CPU 701 executes processing according to a program stored in the ROM 703 or a program loaded into the RAM 702 from a predetermined recording medium in the storage unit 740. In addition to the above programs, the ROM 703 also stores predetermined setting data required when the CPU 701 executes processing. The RAM 703 is also used as a work area in which the program loaded as described above is expanded and, for example, data obtained by the operation of the CPU 701 is appropriately stored.

  The CPU 701, RAM 702, and ROM 703 are connected to each other via a bus 704. An input / output interface 705 is also connected to the bus 704.

  An input unit 710, an output unit 720, a communication unit 730, and a storage unit 740 are connected to the input / output interface 705. The input unit 710 is a device or device that inputs signals and data to the personal computer 700, and specifically includes a keyboard, a mouse, a scanner, a microphone, and the like. The output unit 720 is a part for outputting data, signals, and the like processed by the personal computer 700 in a predetermined manner, and specifically includes a display device, a speaker, a printer, a plotter, and the like. The communication unit 730 is a functional part for communicating with an external device via a network or a predetermined data interface. Specifically, it is a part configured corresponding to a wired data interface such as a LAN (Local Area Network), a USB (Universal Serial Bus), and IEEE1394. In addition, it is a part configured to support wireless communication such as Bluetooth (registered trademark) or wireless LAN standard.

  The storage unit 740 has one or more auxiliary storage devices, and is a part where data of a file used by the personal computer 700 is recorded and reproduced under the control of the CPU 701, for example. Here, a magnetic disk 741A, an optical disk 741B, a magneto-optical disk 741C, and a semiconductor memory 741D are shown as recording media corresponding to the auxiliary storage device.

  For example, in the configuration shown in FIG. 19, the operations of the application 200, the file system 300, and the device driver 400 described so far are realized by the CPU 701 executing a program. The function corresponding to the transfer clock generation unit 121 may be configured such that, for example, in the input / output interface 705, hardware that actually exchanges data with the storage unit 710 has the function.

  The embodiment of the present invention shows an example for embodying the present invention. As clearly shown in the embodiment of the present invention, the matters in the embodiment of the present invention and the claims Each invention-specific matter in the scope has a corresponding relationship. Similarly, the matters specifying the invention in the claims and the matters in the embodiment of the present invention having the same names as the claims have a corresponding relationship. However, the present invention is not limited to the embodiments, and can be embodied by making various modifications to the embodiments without departing from the gist of the present invention.

  The processing procedure described in the embodiment of the present invention may be regarded as a method having a series of these procedures, and a program for causing a computer to execute the series of procedures or a recording medium storing the program May be taken as As this recording medium, for example, a CD (Compact Disc), an MD (MiniDisc), a DVD (Digital Versatile Disk), a memory card, a Blu-ray Disc (registered trademark), or the like can be used.

DESCRIPTION OF SYMBOLS 100 Video camera 120 Media drive 121 Transfer clock generation part 200 Application 210 Priority determination part 220 Priority specification part 400 Device driver 410 Transfer speed mode candidate recognition part 420 Transfer speed mode setting part 430 Effective transfer speed measurement process part 440 Transfer speed mode Determination unit 500 Media 501 Main boot area 502 Free area 520 Transfer rate mode information holding unit 601 Measurement result information 602 Priority item table 603 Current priority item information 604 Recording / playback identification information 605 Bit rate information 700 Personal computer

Claims (8)

A candidate recognition unit for recognizing a transfer rate mode candidate indicating a data transfer rate that can be set in correspondence with the recording medium;
An effective transfer rate measuring unit that measures an effective transfer rate for each transfer rate mode recognized as the candidate;
An effective efficiency for each transfer rate mode is calculated based on the effective transfer rate for each transfer rate mode recognized as the candidate, and the transfer rate with the highest effective efficiency among the transfer rate modes recognized as the candidates is calculated. A transfer rate mode determining unit that determines the mode as a setting target transfer rate mode;
A recording medium control apparatus comprising: a transfer speed mode setting unit configured to perform recording and reproduction with respect to the recording medium at a data transfer speed indicated by the transfer speed mode determined as the setting target transfer speed mode. A priority determination unit that determines whether the priority when setting the transfer speed mode is effective efficiency or speed according to the device operation content accompanied by recording or reproduction with respect to the recording medium;
When it is determined that the priority is effective efficiency, the transfer rate mode determination unit determines the transfer rate mode having the highest effective efficiency as the setting target transfer rate mode, and the priority is the speed. 2. The recording medium control apparatus according to claim 1, wherein if it is determined that there is, the transfer speed mode with the highest effective transfer speed is determined as the setting target transfer speed mode instead of the transfer speed mode with the highest effective efficiency. .   The transfer rate mode determination unit compares the effective transfer rate with a minimum required effective transfer rate necessary for recording or reproducing a file on the recording medium, and the transfer rate mode having a lower effective transfer rate. The recording medium control apparatus according to claim 1, wherein: is excluded from the candidates. The effective transfer rate measuring unit sequentially sets the candidate transfer rate modes and, for each of the set transfer rate modes, according to the case where the device operation content accompanied by recording or reproduction with respect to the recording medium is recording. Executes a recording-corresponding measurement process for measuring the effective transfer rate while executing data writing to the recording medium, and executes the effective transfer while executing data reading to the recording medium when the device operation content is reproduction. The recording medium control apparatus according to claim 1, wherein a reproduction-compatible measurement process for measuring speed is executed. The effective transfer rate measuring unit sequentially sets the candidate transfer rate modes and measures the effective transfer rate at the time of data writing while executing data writing to the recording medium for each transfer rate mode. Execute the measurement process and the playback-compatible measurement process that measures the effective transfer rate when reading data while executing reading to the recording medium,
2. The transfer rate mode determination unit calculates the effective efficiency based on the effective transfer rate that is an average value of an effective transfer rate at the time of data writing and an effective transfer rate at the time of data reading. Recording medium control device. The recording medium control apparatus according to claim 1, wherein the transfer rate mode determination unit calculates a ratio between the effective transfer rate and a transfer clock frequency defined by the transfer rate mode as the effective efficiency.
A candidate recognition procedure for recognizing transfer speed mode candidates indicating data transfer speeds that can be set according to the recording medium;
An effective transfer rate measurement procedure for measuring an effective transfer rate for each transfer rate mode recognized as the candidate;
An effective efficiency for each transfer rate mode is calculated based on the effective transfer rate for each transfer rate mode recognized as the candidate, and the transfer rate with the highest effective efficiency among the transfer rate modes recognized as the candidates is calculated. Transfer speed mode determination procedure for determining the mode as the setting target transfer speed mode,
A recording medium control method comprising: a transfer speed mode setting procedure for setting the recording medium to be recorded / reproduced at a data transfer speed indicated by the transfer speed mode determined as the setting target transfer speed mode. A candidate recognition procedure for recognizing transfer speed mode candidates indicating data transfer speeds that can be set according to the recording medium;
An effective transfer rate measurement procedure for measuring an effective transfer rate for each transfer rate mode recognized as the candidate;
An effective efficiency for each transfer rate mode is calculated based on the effective transfer rate for each transfer rate mode recognized as the candidate, and the transfer rate with the highest effective efficiency among the transfer rate modes recognized as the candidates is calculated. Transfer speed mode determination procedure for determining the mode as the setting target transfer speed mode,
A program for causing a computer to execute a transfer speed mode setting procedure for setting so that recording and reproduction with respect to the recording medium are performed at a data transfer speed indicated by the transfer speed mode determined as the setting target transfer speed mode.

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