JP7617606B2 - Systems and programs - Google Patents

Description

The present invention relates to, for example, systems and programs.

For example, drive recorders that record vehicle status information (such as forward video, speed, and acceleration) acquired by the vehicle onto a recording medium are becoming increasingly popular, particularly in transportation vehicles such as trucks, and commercial vehicles such as taxis and buses, and are also increasingly being installed in general vehicles.

Dash cams include those that constantly record vehicle status information while the vehicle is traveling, and those that record vehicle status information at any time for a certain period of time before and after an accident or sudden braking.

The recording of vehicle status information by such drive recorders is performed on removable recording media such as memory cards, such as SD cards, which can be attached to the drive recorder. Analysis of the vehicle status information is generally performed using viewer application software (hereafter referred to as the viewer app) that runs on a PC.

When performing analysis, the recording medium is removed from the vehicle's drive recorder and inserted into a memory card reader connected to a personal computer for analysis in an office, etc. The personal computer reads the vehicle status information from the recording medium inserted into the memory card reader through processing by a viewer application, and displays the information in a visualized form on the screen (see, for example, Patent Document 1). This allows the vehicle status information to be confirmed and analyzed based on the information visualized on the screen.

JP2011-114850

However, conventional systems have had various problems.
SUMMARY OF THE PRESENT EMBODIMENTS An object of the present invention is to provide a system, program, etc. having superior characteristics to conventional systems.

The object of the present invention is not limited to this, and the applicant intends to obtain rights to configurations that aim to obtain effects from parts of the configurations disclosed in this specification and drawings, etc., through divisional applications, amendments, etc. For example, this specification discloses problems in which the phrases "can" and "is possible" are read as "the problem is". The problems are described as being independent, and the applicant intends to obtain rights to the configurations for solving each problem separately through divisional applications, amendments, etc. Even if the problems are implicitly understood from the description in the specification, the applicant intends to include part of the configurations described in this specification in the scope of the patent claims through amendments or divisional applications. The applicant has also disclosed configurations that solve problems that combine these independent problems, and the applicant intends to obtain rights to them.

(1) This system records the generated information on a recording medium accessible by this system, and when the recording medium is accessible from a personal computer, at least a portion of the information can be read by a general operating system of the personal computer, but the system records the generated information using a method different from the writing method used by the general operating system.

In this way, information recorded in the system can be read by a general operating system, and can be recorded in a method that is convenient for the system and different from the writing method in the general operating system. In this way, both can be achieved. For example, in a system that uses a writing method different from that in the general operating system, it is possible to prevent, for example, fragmentation of the contents of the recording medium, destruction of the management area due to inaccessibility caused by a sudden power outage or sudden removal of the recording medium, etc., and the number of times that periodic formatting of the recording medium is performed can be reduced, or it can be configured so that periodic formatting of the recording medium is not necessary.

The recording medium accessible by the system may be a recording medium connected to the system (e.g., an SSD, HDD, etc. connected via a USB cable, etc.), and in particular, the system may be configured to removably mount the recording medium (e.g., a configuration with a built-in SD card reader/writer, etc.), and the recording medium may be a recording medium mounted on the system (e.g., an SD card, etc.).

The personal computer may be, for example, an IBM PC/AT compatible machine. A typical operating system may be, for example, Microsoft Windows.

When the recording medium is accessible from a personal computer, it may be when the system has a wireless communication function (such as a WiFi network connection function) and the personal computer also has a wireless communication function that can be connected to the system, and the recording medium of the system can be accessed from the personal computer, but it is particularly preferable to remove a removable recording medium from the system and connect the recording medium to the personal computer.

In order to configure the recording medium so that at least a portion of it can be read by a general operating system of the personal computer when the recording medium is accessible from the personal computer, the recording medium should be in a format that is compatible with the standard format of the general operating system, for example, a format that is displayed in a GUI when a drive letter icon is right-clicked in Microsoft Windows Explorer and "Format" is selected.
The format should preferably be at least one of FAT16, FAT32, and exFAT.

When the recording medium is inserted in a personal computer, at least a part of it can be read by the general operating system of the personal computer, but the configuration for recording in a method different from the writing method in the general operating system may be such that the recording medium is provided with a partition in the same format as that used by the general operating system of the personal computer, as well as a partition in a different format (particularly, (10) below is preferable), or the recording medium is provided with a partition in the same format as that used by the general operating system of the personal computer, and the procedure for recording the partition is different from that used by the general operating system (particularly, at least one of (2) to (8) below is preferable). A combination of these may also be used.

(2) the generated information includes video data based on imaging data captured by an imaging means;
The writing method in the above general operating system is such that when data is written to a file and the file size changes from 0 to 1 or more, one unused cluster is allocated at that time, and that cluster number is set in the directory entry of the file. Thereafter, whenever the file size increases and the cluster being written overflows, a new cluster is allocated and a cluster chain is formed.
A method different from the writing method used in the general operating system may involve forming a cluster chain by pre-allocating a predetermined number of consecutively numbered unused clusters when generating a file including video data, and then writing data including the video data continuously into an area of a size calculated by multiplying the cluster size by the predetermined number to generate the file.

In this way, even if the system repeatedly writes and erases video data based on imaging data captured by the imaging means to the recording medium, file fragmentation is less likely to occur than in the past, and files containing recorded video data can be read using a typical operating system of a personal computer.

To make it possible to read at least a part of the disk with a general operating system, the disk should be formatted with a selectable cluster size when formatting with standard formatting software for the general operating system, for example, by providing a function for formatting the recording medium with a selectable cluster size (called allocation unit size by Microsoft) in Microsoft Windows. The cluster size is 4K bytes, 8K bytes, 16K bytes, 32K bytes, and 64K bytes when the format is FAT16 or FAT32. When the format is exFAT, the cluster size is 4K bytes, 32K bytes, and 128K bytes.
The predetermined number is preferably 100 or more, and more preferably 1000 or more.

The "size obtained by multiplying the cluster size by the specified number" should preferably be a size in megabytes, and more preferably a size in tens of megabytes.

For example, the "size obtained by multiplying the cluster size by the specified number" should be at least one order of magnitude larger than the cluster sizes selectable when formatting with standard formatting software for general operating systems. For example, if the cluster sizes selectable when formatting with standard formatting software for general operating systems are in kilobytes, the "size obtained by multiplying the cluster size by the specified number" should be in megabytes.

In addition, in this configuration, the size of one file containing this video data should be set to be larger than the "size obtained by multiplying the cluster size by the specified number." For example, the recording time, bit rate, etc. of the video file should be set to create a file that is larger in size than the "size obtained by multiplying the cluster size by the specified number." Desirably, the size of one file containing this video data should be set to be several to several dozen times the "size obtained by multiplying the cluster size by the specified number."

In a typical operating system, when data is written to a file and the file size changes from 0 to 1 or more, one unused cluster is assigned at that time, and that cluster number is set in the directory entry of the file. After that, whenever the file size increases and the cluster being written overflows, a new cluster is assigned and a cluster chain is formed. This writing method allows for high usage efficiency of the recording medium when files of different sizes are repeatedly created and deleted. For example, if small and large files are mixed, the area with consecutive cluster numbers may not be secured, but since it can be used without waste, it is a good method for writing files to a computer. However, in a system, video data is a large file size. Therefore, when recording video data, if the cluster size is set in megabytes, fragmentation is less likely to occur and there is less loss of efficiency. For example, in FAT, the cluster size that can be selected when formatting is in kilobytes, so when a 50MB file is recorded, it is dispersed across approximately 5,000 cluster locations, and the drawback is that the cluster write locations gradually become fragmented as writing and erasing are repeated. However, with this method, a certain number of consecutive clusters are secured, and video data is written to those consecutive clusters, so fragmentation can be suppressed.

The system may be configured by creating and incorporating a device driver that realizes this method in a personal computer, but it is more effective to configure and include a program that realizes this method in an embedded device other than a personal computer. The system is particularly effective as a drive recorder that records video and the like in a vehicle.

The system may be configured so that, in particular, the video data continues to be generated and recorded based on the imaging data captured by the imaging means while power is being supplied to the system (this is called continuous recording).

(3) When the recording medium is inserted in a personal computer, at least a portion of it can be read by a general operating system of the personal computer, but a method that differs from the writing method in the general operating system is to reserve clusters in a fixed location for files that can be read by a file system adopted by the general operating system of the personal computer during initialization processing of the recording medium in the system, and record the video data by overwriting the file that uses the previously reserved clusters to the extent that the size of the file is not exceeded, thereby recording a file containing the video data without changing the location of the cluster of the file.

In this way, it is possible to suppress fragmentation of files caused by writing video data recorded in the system to the recording medium. It is also possible to reduce or eliminate access to the file management area, and it is possible to significantly reduce the possibility of problems occurring in conventional systems, such as video files recorded on the recording medium becoming unable to be read by a personal computer due to an unexpected power outage of the system or an unexpected removal of the recording medium while updating the file management area.
For example, the system may be provided with both the function (3) and the function (2), and the function of setting which recording to perform may be provided to perform the recording of the set function.

(4) In the initialization process of the recording medium, a plurality of files using the previously secured clusters are created in advance as fixed-length files, and the video data is at a variable bit rate, and a recording function is provided in which the size of the fixed length is set to be larger than the size of data including the video data when recorded for the specified unit of time at the maximum bit rate of the variable bit rate so that the video data for the specified unit of time is recorded in one file of the fixed length.

In this way, the video data per unit time is recorded in a pre-created fixed-length file. This almost certainly prevents file fragmentation and reduces the possibility of damage to the management area. The next unit time of video data is recorded in the next pre-created fixed-length file, and this is repeated until all video data has been recorded in all pre-created fixed-length files, at which point the video data is overwritten into the first fixed-length file recorded.

The specified unit time should preferably be in the range of 1 to 10 minutes. It is especially good to set it to 1 or 5 minutes. This is because even if the system experiences a sudden power outage or the media is removed unexpectedly while recording video data, the data that could potentially be lost will be limited to this time.

(5) In the initialization process of the recording medium, a plurality of files using the previously secured clusters are created in advance as fixed-length files, and the video data is variable bit rate. A function is provided for monitoring the capacity recorded in one fixed-length file and changing the fixed-length file to be recorded so that the video data of the variable bit rate is recorded as fully as possible in one fixed-length file.

In this way, the length of the video recorded in the fixed-length file (1) will not be constant, but it will solve the problem that occurs in the above method (4) where the video is not recorded in the entire fixed-length file, reducing the amount of video that can be recorded on the recording medium. In a method where a file is created in advance (a cluster is reserved in a fixed location) and the cluster location is overwritten without changing, the fact that the file size is determined in advance means that a file that exceeds that size can never be created. Therefore, the biggest drawback of method (4) is that the amount of free space left on the recording medium becomes extremely large. For example, if you try to record the same amount of time as (2) or (10) described below, you will have to reduce the bit rate at which the video quality is determined to about 2/3. This will result in poor quality video. However, if you use method (5), this problem can be solved.

As a configuration for recording as much as possible into the fixed-length file of one, for example, it is preferable to buffer at least the video between key frames (the frame from the key frame to the frame before the next key frame) in the system so that the next fixed-length file starts from a key frame, and if the video between the key frames still fits into the file currently being written, it is written into the file currently being written, and if it does not fit (overflows), it is controlled so that it is recorded into the next fixed-length file. For example, the video between key frames may be between I frames, and it is preferable to configure so that the content of the next fixed-length file does not start from a P frame or B frame, but starts from an I frame.
For example, both the function (5) and the function (4) may be provided, and a function for setting which recording to perform and performing the recording of the set function may be provided.

(6) The system may have a function of constantly recording the video data on the recording medium while the power is on, and in an initialization process of the recording medium, a file using the pre-allocated clusters may be created in advance as a single very large file, and the video data to be constantly recorded may be recorded within the very large file.
In this way, the process can be simplified and the possibility of fragmentation can be reduced more than before.

For example, the device may be provided with at least two of the functions (4) to (6), and may have a function for setting which recordings to make and recording the selected items.

A very large file may, for example, be one that is equal to or less than the capacity of the recording medium and has the maximum capacity of the file system that stores the file. Alternatively, a very large file may, for example, be one that has a capacity of more than half the capacity of the recording medium, and in particular, the size of this file may be more than half the capacity of the recording medium (and, for example, less than the capacity of the recording medium). It may also be desirable to have a function that allows the size to be set within this range.

(7) The file using the previously reserved clusters may be generated as an invisible file in the operating system of the personal computer during the initialization process of the recording medium, and the file to be written may be made visible when the video data is written.

In this way, when the recording medium is read by a personal computer immediately after the initialization process of the recording medium is completed, files that use the previously secured clusters and have no video data recorded on them will not be visible.

(8) The file using the pre-allocated clusters may have a function of generating a file capable of playing video on the operating system of the personal computer during initialization of the recording medium.

In this way, the image can be viewed by playing the file that is visible when the recording medium is read out on a personal computer immediately after the initialization process of the recording medium is completed. The image data of the playable file may be an image that continues to display a specific screen when played back, for example, an image completely covered with a specific color (for example, an image of a completely black screen), an image that continues to display a character string such as "This is an unrecorded file," or a file containing a specific image that has been recorded in advance inside the system may be generated by copying the file.
For example, both the function (8) and the function (7) may be provided, and a function for setting which recording to perform and performing the selected recording may be provided.

(9) The file containing the video data may be generated in a file format that can be played on a general operating system of the personal computer.

In this way, the video file recorded on the recording medium can be played back on a general operating system of the personal computer. It is particularly preferable to have the configuration of (8). In particular, in the configurations of (4) to (6), it is also preferable to generate the file created in the initialization process in a file format that can be played back on the general operating system of the personal computer.

The above format formats (2) to (9) may be the format formats adopted by the operating system of the personal computer, and in the initialization process, the format may be formatted in the format and then the initialization process described in each of items (2) to (9) may be performed.

(10) The generated information may include video data based on imaging data captured by an imaging means, and the recording medium may be configured to be at least partially readable by a general operating system of the personal computer when the recording medium is attached to the personal computer, and the recording medium may be provided with a partition of the same format as that used by the general operating system of the personal computer, and the recording medium may be provided with a function for writing to the partition, and a partition of a different format than that used by the general operating system of the personal computer may be provided as a method for writing to the partition of the different format, and the video data may be written to the recording medium sequentially without writing an index of the video data to a management area.

In this way, the concept of fragmentation is eliminated. Furthermore, video data cannot be viewed using the standard functions of a typical operating system on a personal computer. Therefore, the security element of is also high.

For example, in functions (2) to (9), if the recording medium is removed from the system while the management area is being written, depending on the timing, the contents of the recording medium may be lost. This does not happen with method (10). It is advisable to configure functions (2) to (9) so that the management area is not touched when recording video data, but there are cases where it is difficult to configure all of them in this way. In such cases, method (10) is recommended.

In the configuration of (10), a partition having the same format as that used by the general operating system of the personal computer on the recording medium may also be provided with a function for recording at least one of the video data of (2) to (9) in addition to recording the video data of (10). In this way, even if any of the partitions is destroyed, the video data can be read and played back from the undestroyed partition.

In the method (10), since the video data is variable length, it is very difficult to find the beginning of a video frame. Therefore, it is a good idea to attach chain data to each frame so that searches can be performed between frames. It is a good idea to have a system in which there is a directory entry, as in FAT, for each frame. The disadvantage is that it is not visible in a file search application such as Explorer in a general operating system of a personal computer, so a dedicated application is required. For example, when the recording medium is an SD card, writing to a continuous area is faster when accessing the SD card, but writing to discontinuous areas reduces the writing speed dramatically. However, if configured as in (10), this can be prevented, and for example, simultaneous writing of a total of four streams can be achieved, for example, for two cameras/continuous recording and events separately. Also, in a communication-type system, writing eight streams by adding dirty video (video with low capacity) is relatively easy compared to other recording methods.

(11) It is preferable that the video data is provided with a function of adding first information for going back a predetermined time in the past without using a management area, and second information for going back a predetermined frame in the past without using a management area, and cueing the video based on the first information and the second information.
(12) It is preferable that the functions of the system described in any one of (1) to (12) be realized by a computer as a program.

(13) It is preferable to provide a driver program for the general operating system of a personal computer to enable a computer to realize a function that enables the general operating system of the personal computer to reference video data of a partition in a format different from the format used by the general operating system of the personal computer, the video data being recorded by the system of (10) above.

The "personal computer" described in (1) to (13) above may be replaced with a "smartphone." Also, the "personal computer" described in (1) to (13) above may be replaced with a "tablet." In these cases, Android may be used as a general operating system.

The inventions shown in (1) to (11) above can be combined in any way. For example, the invention shown in (1) may be combined with at least a part of the configuration of at least one of the inventions from (2) onwards. In particular, the invention shown in (1) may be combined with at least a part of the configuration of at least one of the inventions from (2) onwards. Any configuration may be extracted from the inventions shown in (1) to (11) and the extracted configurations may be combined. The applicant of this application intends to acquire rights to the inventions including these configurations. Furthermore, even if there is a description such as "in the case of" or "when", this is not intended to describe the configuration as being limited to that case or time. These are examples of better configurations, and the applicant intends to acquire rights to configurations other than these cases or times. Furthermore, the parts described in order are not limited to this order. Configurations in which some parts have been deleted or the order has been changed are also disclosed, and the applicant intends to acquire rights to them.

According to the present invention, it is possible to provide a system etc. that is superior to conventional systems.
For example, it is possible to prevent fragmentation of the contents of the recording medium, or destruction of the management area due to inaccessibility caused by an abrupt power outage or abrupt removal of the recording medium, thereby reducing the number of times that recording media need to be formatted periodically, or providing a system that does not require periodic formatting of recording media.

Note that the effects of the invention of this application are not limited to these, and effects achieved from the configuration parts disclosed in this specification and drawings, etc. are also disclosed, and it is our intention to obtain rights to the configuration that achieves said effects through divisional applications, amendments, etc. For example, in this specification, statements such as "can do" and "is possible" are statements that clearly indicate the effect that is achieved, and there are also parts that show the effect even without statements such as "can do" and "is possible." Also, there are effects that can be understood from the configuration even without such statements.

FIG. 2 is an explanatory diagram for explaining the transfer of an SD card between a drive recorder and a personal computer. FIG. 2 is an explanatory diagram illustrating an example of installation of a drive recorder in a vehicle. FIG. 2 is a block diagram illustrating an example of a schematic electrical configuration of a drive recorder. FIG. 2 is a block diagram illustrating an example of a schematic electrical configuration of a personal computer and devices connected to the personal computer. FIG. 13 is a diagram showing an example of a display on a screen when viewer software is executed on a personal computer. FIG. 13 is a diagram showing an example of a format selection screen displayed on the drive recorder.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the embodiment shown below is one embodiment of the present invention, and the contents of the present invention should not be interpreted as being limited based on the following description.
Hereinafter, as an embodiment of the present invention, the present system will be described based on an example in which the system is realized by processing a program executed by a drive recorder installed in a vehicle.

As shown in FIG. 1, the drive recorder 1 of this embodiment has a function of compressing the image data captured by the drive recorder 1 to generate video data and recording it on an SD card, which is an example of a recording medium. When the vehicle engine is turned off and the drive recorder is powered off, the SD card is removed from the drive recorder 1 and inserted into an SD card reader/writer 36 connected to a computer 35 installed in an office or the like, the drive recorder has a function of playing back and displaying the recorded video data on the screen of the viewer software shown in FIG. 5, which is executed by the computer 35. The SD card has a capacity of 32 GB. Microsoft's Windows 10 runs on the computer 35 as the operating system.

As shown in FIG. 2, the drive recorder 1 is fixed to the vehicle by attaching one side of a mounting member such as double-sided tape to a position on the passenger side adjacent to the rearview mirror 4 near the center in the left-right direction on the upper part of the vehicle's windshield 3, and attaching the other side to the windshield. The drive recorder 1 is fixed with the camera lens facing in a direction to record the image in front of the vehicle. The drive recorder 1 is connected to a cigarette lighter socket 5 and a power cable 6, and is powered from the vehicle when the vehicle's accessory power is on.

Figure 3 is a diagram showing the schematic electrical configuration of the drive recorder 1. As shown in Figure 3, the drive recorder 1 includes a controller MC, a CCD camera 13, an interface 33, a GPS receiver 24, a display unit 25 with a touch panel, an SD card reader 31, an acceleration sensor 15, a database 32, etc. The controller MC is connected to an interface 33 that is connected to the CCD camera 13 and converts a video signal from the CCD camera 13 into a digital signal that can be input to the controller MC, as well as the acceleration sensor 15, the GPS receiver 24, the display unit 25, the SD card reader 31, and the database 32.

The controller MC is composed of a microcomputer having a known CPU, memories such as ROM and RAM, a timer, other peripheral circuits, etc. The ROM of the controller MC stores various programs such as a card initialization processing program for performing initialization processing to make the SD card in a state in which video data can be written, a recording processing program for storing generated information including GPS information including position information received by the GPS receiver 24, acceleration information detected by the acceleration sensor 15, and video information captured by the CCD camera 13, programs for performing various processes described below, and a real-time OS (Operating System), and the controller MC executes these programs to realize various functions.
The controller MC executes a recording process program to perform a recording process for recording the generated information in one of eight formats, which will be described later.

The GPS receiver 24 detects the vehicle's current position information based on instructions from the controller MC. In this embodiment, the detection timing is every second. The controller MC acquires GPS information including position information every second during the recording process. The position information includes the time, vehicle position, speed, latitude, longitude, altitude, etc., determined based on signals from GPS satellites.

The acceleration sensor 15 is a three-axis type sensor that detects acceleration and tilt in each of the three axes (X, Y, Z) and constantly outputs the detected values to the controller MC. During the recording process, the controller MC generates acceleration information every 10 ms by associating this three-axis acceleration information with time information.

The SD card reader 31 reads data from the SD card inserted through the insertion slot 18 or updates the data on the SD card under the control of the controller MC. The database 32 is a non-volatile memory (e.g., an EEPROM) external to the controller MC.

The CCD camera 13 outputs constantly captured image information to the controller MC via the interface unit 33, which converts the captured image into digital form. During the recording process, the controller MC associates the image information input via the interface unit 33 with the time, compresses it, and generates video information.

The controller MC performs an SD card insertion check process immediately after power-on or when it detects that the SD card has been removed during recording processing. The SD card insertion check process checks whether an SD card is inserted in the SD card reader/writer 31, and if the insertion of the SD card is detected, it proceeds to an SD card format confirmation process. If the insertion of the SD card is not detected, it displays the text "Please insert SD card" on the display unit 25 and waits for the SD card to be inserted, and if the insertion of the SD card is detected, it erases this display and proceeds to an SD card format confirmation process.

The SD card format confirmation process reads each sector of the SD card, checks the partition and format logical structure, and determines which of the eight formats described below the card is in, then passes the resulting format type to the recording process to start the recording process. The recording process records to the SD card according to the structure of the format type passed in. If the format does not match any of the eight types, the process moves to card initialization process.

The card initialization process displays the video data recording format screen shown in FIG. 6 on the display unit 25. The video data recording format screen is a screen where one of eight formats can be selected and an instruction to initialize the card can be entered. This video data recording format screen has eight lines of text arranged vertically indicating the formatting method, radio buttons to the left of the text in each line, and a "Cancel" button and an "Initialize" button at the very bottom. When the "Initialize" button is touched, initialization is performed using the formatting method indicated by the text in the line selected by the radio button, and then the selected format type is stored in the RAM in the controller MC and the process proceeds to recording. When the "Cancel" button is touched, the process proceeds again to the SD card format confirmation process.

As shown in Fig. 6, the eight formatting methods are, from top to bottom, "allocate a predetermined number of unused clusters with consecutive numbers in advance", "record a predetermined unit of video data in one fixed-length file (visible at initialization)", "record a predetermined unit of video data in one fixed-length file (invisible at initialization)", "record variable bit rate video data as full as possible in one fixed-length file (visible at initialization)", "record variable bit rate video data as full as possible in one fixed-length file (invisible at initialization)", "record video data to be recorded continuously in one very large file (visible at initialization)", "record video data to be recorded continuously in one very large file (invisible at initialization)", and "record in a unique format". The processing for each case is explained below in (1) to (8).
(1) In the case of "pre-allocating a predetermined number of consecutive unused clusters in the cluster chain"

When the controller MC detects that the "Initialize" button has been touched while "Pre-allocate a specified number of consecutive unused clusters in the cluster chain" is selected, it performs a normal FAT32 format in which the entire SD card is treated as one partition and that partition is formatted in FAT32 format, and then moves to the recording process. The cluster size during this formatting is the same as Windows 10: 4KB if the detected capacity of the SD card is between 512MB and 8,191MB, 8KB if it is between 8,192MB and 16,383MB, 16KB if it is between 16,384MB and 32,767MB, and 32KB if it is 32,768MB or more. In this recording process, if it is determined that the type of the format stored in the RAM is "pre-allocating a predetermined number of consecutive unused clusters in a cluster chain", the imaging information acquired from the CCD camera 13 for each frame is compressed with a predetermined codec (e.g., H.254, etc.) to generate frame information in which GPS information and acceleration information are added in text format as subtitle data to the video information, and 60 seconds of frame information is written as one container file (e.g., AVI container). The size of this container file is generally less than 70 MB. When writing this file, the writing method of Windows 10 in the personal computer 35 is a writing method in which when data is written to a file and the file size changes from 0 to 1 or more, one unused cluster is assigned at that time, the cluster number is set in the directory entry of the file, and thereafter, whenever the file size increases and the cluster being written overflows, a new cluster is assigned to form a cluster chain, but the drive recorder 35 writes using a method different from the writing method in Windows 10 running on the personal computer 35. This different method involves creating a cluster chain by allocating a predetermined number of consecutively numbered unused clusters in advance when recording a container file that records generated information including video information onto an SD card, and then writing the video information continuously into an area of a size (10 MB in this embodiment) that is the cluster size (32 KB in this embodiment) multiplied by this predetermined number (10 MB/32 KB in this embodiment) to generate a file. The next 10 MB is then secured and written in in the same manner, and the process is repeated until the container file is written onto the FAT32 file system.

Specifically, when a new container file is generated in an SD card, a range in which the predetermined number of consecutively numbered clusters can be secured is searched for on the FAT (file allocation table) formatted with FAT32, and a cluster chain is generated in this range (the first cluster stores the next cluster number, the next cluster stores the cluster number, and so on). The first cluster number is then recorded in a directory entry that records the file name, etc., of the container file. After writing out 10MB, which is the capacity of the cluster group corresponding to this cluster chain, a new cluster chain of 10MB is similarly generated, and the last cluster is chained to the beginning of the chain, repeatedly, writing out one minute's worth of container file (less than about 70MB in this embodiment), and closing the file. Each 10MB unit is treated as one huge virtual cluster, so to speak, and a container file of just under 70MB containing one minute's worth of video information can be stored in seven virtual clusters.

With this method, even if the drive recorder 1 repeatedly writes and erases generated information, including video information based on image information captured by the CCD camera 13, to the SD card, file fragmentation is less likely to occur than in the past, and the file can be read using Windows 10 on the personal computer 35.

In the writing method in Windows 10, when data is written to a file and the file size changes from 0 to 1 or more, one unused cluster at that time is assigned, and the cluster number is set in the directory entry of the file. After that, whenever the file size increases and the cluster being written overflows, a new cluster is assigned to form a cluster chain, so that the efficiency of use of the recording medium can be increased when files of different sizes are repeatedly created and deleted. For example, when small and large files are mixed, an area with consecutive cluster numbers is not necessarily secured, but it can be used without waste, so it can be said to be a good method for writing files to a personal computer. However, in the drive recorder 1, the container file that records the generated information including the video information has a large file size. Therefore, in order to record the video information, if the cluster size is set in megabytes, fragmentation is unlikely to occur and the efficiency decrease is small. For example, in FAT, the cluster size that can be selected when formatting is in kilobytes, so when a 70MB file is recorded, it is dispersed across approximately 7000 cluster locations, and the disadvantage is that the cluster write locations gradually become fragmented as writing and erasing are repeated. However, with this method, consecutive clusters of 10MB each are secured and then the container file is written to those consecutive clusters, thereby suppressing fragmentation.
(2) In the case of "recording video data of a specific unit time in one fixed-length file (visible at initialization)"

When the controller MC detects that the "Initialize" button has been touched while "Record a specific unit of video data in one fixed-length file (visible at initialization)" is selected, it performs a normal FAT32 format in which the entire SD card is treated as one partition and that partition is formatted in FAT32 format, then creates 400 70MB fixed-length AVI files (with file names from 0001.avi to 0400.avi) on the 32GB SD card and moves to recording processing. This AVI file records a completely black screen as the internal video information. In the recording process, clusters are reserved at a fixed location for files that can be read by the FAT32 file system used in Windows 10, and the recording of the AVI file containing video information is performed by overwriting each AVI file that uses the previously reserved clusters to the extent that the size of the AVI file is not exceeded. That is, frame information is generated by compressing the image information acquired from the CCD camera 13 for each frame using a predetermined codec (e.g., H.254, etc.) and adding GPS information and acceleration information as subtitle data in text format to the video information, and 60 seconds of frame information is written as one container file (e.g., AVI container) onto the file created in the initialization process. In this way, a file containing video data is recorded without changing the location of the cluster of the file. The video information is a variable bit rate, and the fixed length size (70 MB) is set to be larger than the size of the container file containing the generation information including the video information when recording one minute at the maximum bit rate of the variable bit rate (8 Mbps in this embodiment) (8 Mbps * 60 seconds / 8 bytes = 60 MB in this embodiment). One minute of generation information is overwritten and recorded into the first AVI file, and the next minute of generation information is overwritten and recorded into the second AVI file, and so on. When the overwriting of the 400th AVI file is completed, the process returns to overwriting and recording the first AVI file. By repeating this process, it is possible to continuously record to clusters that have been reserved in advance as files.

In this way, the video data per unit time is overwritten and recorded in a pre-created fixed-length file. This almost certainly prevents file fragmentation and reduces the possibility of damage to management areas such as the FAT.

In this embodiment, the unit time is one minute. In this way, even if an unexpected power outage or unexpected removal of the medium occurs while the drive recorder 1 is recording video information, the amount of data that may be lost will be within one minute.

Furthermore, in this embodiment, only the contents are overwritten and updated without writing to the file management area. This significantly reduces the possibility of problems occurring, such as when the management area of a video file recorded on a recording medium becomes unreadable by a personal computer due to an unexpected power outage of the system or an unexpected removal of the recording medium while updating the file management area, which occurred in conventional systems. This eliminates the need to perform periodic formatting of recording media, as was previously necessary, and provides a drive recorder that is superior to conventional drive recorders.

In this embodiment, the AVI file using the pre-allocated clusters has a function of generating a file capable of playing video in Windows 10, which is the operating system of the personal computer 35, during the initialization process of the SD card. Therefore, the AVI file that appears when the SD card is read by the personal computer immediately after the initialization process of the SD card is completed can be played back to view the video. The video data of the playable AVI file is an image that continues to display a black screen when played back, but it may be an image completely covered with another color (e.g., an image of a blue screen), or an image that continues to display a character string such as "This is an unrecorded file". In addition, an AVI file with the above structure that includes a predetermined video may be stored in the database 32 of the drive recorder 1 in advance, and this file may be copied from the database 32 to the SD card when a file is generated during the initialization process.
(3) In the case of "recording video data of a specific unit time in one fixed-length file (invisible at initialization)"

In the process (2) above, the process "Create 400 fixed-length AVI files of 70 MB on a 32 GB SD card and move on to recording processing" has been changed to "Create 400 fixed-length AVI files of 70 MB on a 32 GB SD card, replace the first byte of the file name of the directory entry of all files with byte data indicating deletion (0xE5 in this embodiment), and when data writing to the AVI files begins, return the first byte of the file name of the relevant file to the original byte data.

The AVI file that uses the clusters reserved in advance in this way is generated as an invisible file that is deleted in Windows 10, the operating system of the personal computer 35, during the initialization process of the SD card, and has the function of making the file to be written a visible file when writing generated information including video information to the AVI file.

This prevents files that use previously secured clusters and have no recorded video data from being seen when the recording medium is read by the computer 35 immediately after the initialization process of the SD card is completed.
(4) In the case of "recording variable bit rate video data as much as possible into one fixed length file (visible at initialization)"

In the above (3), the generation information including one minute of video information is overwritten and recorded in a fixed-length file previously generated by the initialization process, and one minute of the generation information is overwritten and recorded in the first AVI file, the next minute of the generation information is overwritten and recorded in the second AVI file, and so on. Once the 400th AVI file has been overwritten, the process returns to overwriting the first AVI file, but this is not recorded as one minute of video information, but rather recorded so that the contents of the AVI file are filled as much as possible. In other words, the capacity of one fixed-length AVI file in which the generation information has been recorded is monitored and recorded so that the variable bit rate video information is recorded as fully as possible in one fixed-length AVI file, and the fixed-length AVI file being recorded is changed to the next AVI file before the capacity is exceeded.

In this way, although the length of video recorded in the fixed-length AVI file (1) will not be constant, it solves the problem that occurs with method (3) above, where video is not recorded in the entire fixed-length AVI file, reducing the amount of video that can be recorded on the SD card. In a method in which an AVI file is created in advance (clusters are reserved in fixed locations) and the cluster locations are overwritten without changing, having a predetermined file size means that the processing will be performed so that an AVI file that exceeds that file size will never be created. Therefore, method (3) has the greatest drawback of leaving an enormous amount of free space on the SD card, especially when shooting video with a low bit rate and little change. However, method (4) can solve this problem.

In order to record as much as possible into one fixed-length AVI file, at least the video between key frames (the frame before the next key frame from the key frame) is buffered in the RAM in the controller MC of the drive recorder 1 so that the next fixed-length file starts from a key frame, and if the video between the key frames still fits into the AVI file currently being written, it is written into the AVI file currently being written, and if it does not fit (overflows), it is controlled so that it is recorded into the next fixed-length AVI file. The key frames are between I frames, and the content of the next fixed-length file does not start from a P frame or B frame, but always starts from an I frame.
(5) In the case of "Variable bit rate video data is recorded as much as possible into one fixed length file (invisible at initialization)", a process is carried out in which the process has been changed to (4) in the same manner as the process of (3) has been changed to (2) above.
(6) "Video data is recorded continuously in one very large file (visible at initialization)"

When the controller MC detects that the "Initialize" button has been touched while "Record video data to be recorded at all times in one very large file (visible at initialization)" is selected, it performs a normal FAT32 format in which the entire SD card is treated as one partition and this partition is formatted in FAT32 format, then creates seven 4GB fixed-length AVI files (file names 0001.avi to 0007.avi) on the 32GB SD card and moves to recording processing. This AVI file records a completely black screen as the internal video information. In the recording process, clusters are reserved at a fixed location for files that can be read by the FAT32 file system used in Windows 10, and the recording of the AVI file containing video information is performed by overwriting each AVI file that uses the previously reserved clusters to the extent that the size of the AVI file is not exceeded. The captured image information obtained from the CCD camera 13 for each frame is compressed with a predetermined codec (e.g., H.254, etc.) to generate frame information in which GPS information and acceleration information are added in text format as subtitle data to the video information, and the frame information is overwritten as one container file (e.g., AVI container) until the file created in the initialization process is filled. At this time, the content of the AVI file is filled as much as possible. That is, the capacity of one fixed-length AVI file in which the generated information is recorded is monitored and recorded so that the video information of the variable bit rate is filled as much as possible in one fixed-length AVI file, and the fixed-length AVI file to be recorded is changed to the next AVI file before the capacity is exceeded. In this way, a file containing video data is recorded without changing the location of the cluster of the file. In this way, the drive recorder 1 has a function for constantly recording generated information, including video information, to the SD card while the power is on, and in the initialization process of the SD card, multiple files that use pre-allocated clusters are created in advance as a single very large 4GB file, and the video information to be constantly recorded is recorded in this single very large 4GB file. In this way, the process can be simplified and the possibility of fragmentation can be reduced more than before.

In this embodiment, the very large file is, for example, 32 GB or less, which is the capacity of an SD card, and 4 GB, which is the maximum capacity of a file in the file system that stores the file. However, by changing the format to exFAT, this very large file may be, for example, a file having a capacity of more than half the capacity of the SD card. In particular, the size of this file should be more than half the capacity of the SD card (and, for example, less than the capacity of the SD card). Also, within this range, a slider may be displayed on the screen of FIG. 6 displayed on the display unit 25, and a function may be provided for allowing the user to set the capacity by operating (dragging) the slider.
(7) In the case where "video data to be recorded continuously is recorded in one very large file (not visible at initialization)", a process is carried out in which the process for (6) has been changed in the same manner as the process for (2) above has been changed to (3).

In the formatting and recording methods (1) to (7) described above, the format format is FAT32, so that files can be viewed using an application such as Explorer of Windows 10 on the personal computer 35. Also, in the formatting and recording methods (1) to (7) described above, files containing video information are generated in a file format that can be played on Windows 10 on the personal computer 35, so that AVI files recorded on the SD card can be played on Windows 10 on the personal computer 35.
(8) In the case of "recording in a proprietary format"

When the controller MC detects that the "Initialize" button has been touched while "Record in unique format" is selected, it creates two partitions that are half the size of the entire SD card. One is the first partition, which is formatted in FAT32 format. The other rear partition is not formatted, and frame information is generated by compressing the image information acquired from the CCD camera 13 for each frame using a specified codec (such as H.254) to video information, to which GPS information and acceleration information are added in text format as subtitle data, and the frame information is then recorded directly and sequentially. In other words, the rear partition does not have a management area like FAT, and as a result, the index of the video information is not written to the management area, and the generated information including the video information is packed and written sequentially to the SD card.

By doing this, the concept of fragmentation is eliminated. Furthermore, the video information cannot be viewed using only the standard functions of Windows 10 on the personal computer 35. This means that the security element of the system is also high. This means that it is no longer necessary to perform periodic formatting of the recording medium, as was previously necessary, and a system that is superior to conventional systems can be provided.

For example, in functions (1) to (7), if the recording medium is removed from the system while the FAT or other management area is being written, depending on the timing, the contents of the recording medium may be lost. This does not happen with method (8). In functions (1) to (7), it is best to configure the system so that the FAT or other management area is not written to as much as possible when recording video information, but there are cases where it is difficult to configure all of them in this way. In such cases, method (8) should be selected.

In the configuration of (8), a function may be provided to perform at least one of the recording processes (1) to (7) in parallel with the recording process of (8) for partitions that have the same format as the format used by Windows 10 of the personal computer 35 for the SD card. In this way, even if any of the partitions is destroyed, the video data can be read and played back from the undestroyed partition.

In the method (8), since the video information is variable length, it is very difficult to find the beginning of a video frame. Therefore, it is a good idea to attach chain data to each frame so that it can be searched between frames. It is a good idea to have a system in which there is a directory entry, as in FAT, for each frame. The disadvantage is that it is not visible in a file search application such as Explorer in a general operating system of a personal computer, so a dedicated application is required. For example, when the recording medium is an SD card, writing to a continuous area is fast when accessing the SD card, but writing to discontinuous areas drops the writing speed at once. However, if configured as in (10), this can be prevented, and for example, simultaneous writing of a total of four streams can be achieved, for example, for two cameras/continuous recording and events separately. Also, in a communication type system, writing eight streams by adding dirty video (video with low capacity) is relatively easy compared to other recording methods.

In the recording processes (1) to (7), the video information may also be recorded with first information for going back a predetermined time without using the management area, and second information for going back a predetermined number of frames without using the management area, and the drive recorder 1 may be provided with a play button, a rewind button, and a fast-forward button for the SD card, so that playback begins when the controller MC detects that the play button has been pressed, and that processing is performed to cue the video based on the first and second information when the controller MC detects that the rewind or fast-forward button has been pressed. Also, processing to cue the video based on the first and second information may be performed on viewer software executed on the PC 35 in FIG. 5.

The functions (1) to (8) described above allow the drive recorder 1 to record generated information on an SD card that the drive recorder 1 can access, and when the SD card is accessible from the PC 35, at least a portion of the information can be read by Windows 10 on the PC 35, but the drive recorder can record generated information using a method different from the writing method used by Windows 10.

By doing this, the information recorded by the drive recorder 1 can be read by Windows 10, and recording can be performed using a method that is convenient for the drive recorder 1 and different from the writing method used by Windows 10. In this way, both can be achieved at the same time.

In this embodiment, the recording medium accessible by the drive recorder 1 is an SD card, but it may also be a recording medium connected to the drive recorder 1, such as an SSD or HDD connected via a USB cable.

In this embodiment, the SD card can be accessed from the computer 35 when the SD card is inserted into an SD card reader/writer connected to the computer 35. However, for example, the drive recorder 1 may have a wireless communication function (such as a network connection function via WiFi) and the computer 35 may also have a wireless communication function that can be connected to the drive recorder 1, and the SD card in the drive recorder 1 may be accessible from the computer 35.
The portion of the embodiment where FAT32 is used may be at least one of FAT16, FAT32, exFAT, etc. depending on the capacity of the SD card.

It is also advisable to provide the Windows 10 of the personal computer 35 with the viewer software shown in FIG. 5 that has the function of acquiring, expanding, and displaying video information from the generated information in the rear partition recorded in the process (10) above.

Alternatively, the viewer software may be configured as software that provides the generation information in the subsequent partition recorded in the process of (10) above as a file that can be referenced, as a Windows 10 device driver (a driver that processes the file system), rather than as software that performs special reading processing to read the subsequent partition of (10).

In this embodiment, the example of a personal computer 35 has been described, but the personal computer may be replaced with a "smartphone" or a "tablet." In these cases, the general operating system may be Android.

The scope of the present invention is not limited to the configurations explicitly described in the specification, but includes combinations of various aspects of the present invention disclosed in this specification. The configurations of the present invention that are sought to be patented are specified in the attached claims, but it is our intention to include configurations disclosed in this specification in the claims in the future, even if they are not currently specified in the claims.

The present invention is not limited to the configurations described in the above-mentioned embodiments. The components of each of the above-mentioned embodiments and variations may be arbitrarily selected and combined. Any components of each of the embodiments and variations may be arbitrarily combined with any components described in the means for solving the invention or any components that embody any components described in the means for solving the invention. We intend to acquire rights to these as well through amendments to this application or divisional applications, etc. Even if there is a description such as "in the case of" or "when", this is not intended to describe a configuration that is limited to that case or time. We also disclose configurations that are not in these cases or times, and we intend to acquire rights to them. Furthermore, the parts that are described in order are not limited to this order. We also disclose configurations in which some parts are deleted or the order is changed, and we intend to acquire rights to them.

In addition, by converting to a design registration application, it is intended to obtain rights to the overall design or partial design. The drawings show the entire device in solid lines, but they include not only the overall design but also partial designs claimed for a portion of the device. For example, it is not only a drawing that includes a portion of the device as a partial design, but also a drawing that includes a portion of the device as a partial design regardless of the portion. A portion of the device may be a portion of the device, or a portion of that portion. It is intended to obtain rights to not only the overall design, but also partial designs in which any portion of the solid line portion of the drawing is shown as a broken line portion. In addition, the modules, materials, parts, etc. inside the device's casing, all of which are shown in the drawings, are subject to trade independently, and it is intended to obtain rights to them by converting to a design registration application in the same way.

1... drive recorder, 2... main body case, 15... acceleration sensor, 24... GPS receiver, 31... SD card reader/writer, 32... database, 35... personal computer, 36... SD card reader/writer, 45... monitor, MC... controller.

Claims (6)

A system having a function of recording generated information on a recording medium,
a function of recording the generated information in a manner that is readable by a general operating system of a personal computer when the recording medium is accessible from the personal computer, but that is different from a writing method used by the general operating system;
When the recording medium is inserted in a personal computer, at least a part of the recording medium can be read by a general operating system of the personal computer, but the method differs from the writing method in the general operating system in that, in the initialization process of the recording medium of the system, clusters are reserved at a fixed location for files that can be read by a file system adopted in the general operating system of the personal computer, and the generated information is recorded by overwriting a file that uses the clusters reserved in the initialization process to the extent that does not exceed the size of the file, thereby recording a file containing video data without changing the location of the cluster of the file,
In the initialization process of the recording medium, a plurality of files using the clusters secured in the initialization process are created in advance as fixed-length files;
The video data is variable bit rate, and the system has a recording function that sets the size of the fixed length to be larger than the size of data including the video data when recorded for the specified unit time at the maximum bit rate of the variable bit rate, so that video data for the specified unit time is recorded in one fixed length file. A system having a function of recording generated information on a recording medium,
a function of recording the generated information in a manner that is readable by a general operating system of a personal computer when the recording medium is accessible from the personal computer, but that is different from a writing method used by the general operating system;
When the recording medium is inserted in a personal computer, at least a part of the recording medium can be read by a general operating system of the personal computer, but the method differs from the writing method in the general operating system in that, in the initialization process of the recording medium of the system, clusters are reserved at a fixed location for files that can be read by a file system adopted in the general operating system of the personal computer, and the generated information is recorded by overwriting a file that uses the clusters reserved in the initialization process to the extent that does not exceed the size of the file, thereby recording a file containing video data without changing the location of the cluster of the file,
In the initialization process of the recording medium, a plurality of files using the clusters secured in the initialization process are created in advance as fixed-length files;
The video data is variable bit rate, and the system has a function of monitoring the capacity recorded in one fixed-length file and changing the fixed-length file to be recorded so that the variable bit rate video data is recorded in one fixed-length file. A system having a function of recording generated information on a recording medium,
a function of recording the generated information in a manner that is readable by a general operating system of a personal computer when the recording medium is accessible from the personal computer, but that is different from a writing method used by the general operating system;
When the recording medium is inserted in a personal computer, at least a part of the recording medium can be read by a general operating system of the personal computer, but the method differs from the writing method in the general operating system in that, in the initialization process of the recording medium of the system, clusters are reserved at a fixed location for files that can be read by a file system adopted in the general operating system of the personal computer, and the generated information is recorded by overwriting a file that uses the clusters reserved in the initialization process to the extent that does not exceed the size of the file, thereby recording a file containing video data without changing the location of the cluster of the file,
the system has a function of constantly recording the video data on the recording medium while the power is on;
In the initialization process of the recording medium, a file using the clusters secured in the initialization process is created in advance as a very large single file,
The system is characterized by having a function for recording the constantly recorded video data in the very large file. A system having a function of recording generated information on a recording medium,
a function of recording the generated information in a manner that is readable by a general operating system of a personal computer when the recording medium is accessible from the personal computer, but that is different from a writing method used by the general operating system;
When the recording medium is inserted in a personal computer, at least a part of the recording medium can be read by a general operating system of the personal computer, but the method differs from the writing method in the general operating system in that, in the initialization process of the recording medium of the system, clusters are reserved at a fixed location for files that can be read by a file system adopted in the general operating system of the personal computer, and the generated information is recorded by overwriting a file that uses the clusters reserved in the initialization process to the extent that does not exceed the size of the file, thereby recording a file containing video data without changing the location of the cluster of the file,
The system is characterized by having a function of generating a file that uses the secured cluster as an invisible file that is a file that has been deleted in the operating system of the personal computer during the initialization process of the recording medium, and converting the file to be written when writing the video data into a visible file that is an undeleted file. A system having a function of recording generated information on a recording medium,
a function of recording video data based on imaging data captured by an imaging means as the generated information in a manner readable by a general operating system of the personal computer when the recording medium is accessible from the personal computer but different from a writing method in the general operating system;
The writing method in the above general operating system is such that when data is written to a file and the file size changes from 0 to 1 or more, one unused cluster is allocated at that time, and that cluster number is set in the directory entry of the file. Thereafter, whenever the file size increases and the cluster being written overflows, a new cluster is allocated and a cluster chain is formed.
The method different from the writing method in the general operating system includes a configuration in which, when generating a file including video data, a cluster chain is formed by pre-allocating a predetermined number of unused clusters with consecutive numbers, and data including the video data is continuously written in an area having a size obtained by multiplying the cluster size by the predetermined number to generate the file,
The system is characterized by having a function of adding to the video data first information for going back a predetermined time in the past without using a management area with a directory entry present on the recording medium, and second information for going back a predetermined frame in the past without using a management area with a directory entry present on the recording medium , and cueing the video based on the first information and second information. A program for causing a computer to realize all the functions of the system according to any one of claims 1 to 5.

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