JP7171298B2 - Recording device, recording method, and program - Google Patents

Description

The present invention relates to a recording device, recording method, and program.

2. Description of the Related Art Recording devices such as digital cameras and digital video cameras that record moving images, still images, audio data, etc. on recording media are known. Data is managed as files by a file system such as FAT16, FAT32, exFAT, or the like.

Some recording media support multiple writing methods with different data writing speeds, and the recording device can use different writing methods according to the type of data to be recorded and the need for real-time recording. can. For example, the recording area is divided into multiple areas (allocation units: also called AUs), and high-speed writing records data continuously from the beginning of an empty AU, and normal writing writes data to an empty area within the AU. There is a recording method (Non-Patent Document 1). This takes into consideration the characteristic of the recording medium that recording in an empty area of an AU partially recorded with data takes longer than recording in an empty AU where no data is recorded. be. In other words, the device commands the recording medium in units of AUs, which contributes to achieving the maximum write speed on the recording medium.

The concept of speed class was born by applying these characteristics. This is done by making use of the characteristics of AUs, searching for empty AUs, and writing in those locations in recording units called RUs (Recording Units), which are newly divided AUs. This is the concept of realizing the minimum speed guarantee for As a result, it is possible to provide a very effective means for data control such as moving image recording, which may eventually stop moving image recording if recording cannot be executed in real time.

Also, a video speed class was proposed as a superordinate concept of the speed class. The Video Speed Class is a concept that realizes even higher performance guarantees by imposing further restrictions on the recording device side. Specifically, the maximum size of an AU is 512 MB, which is eight times the conventional size. In addition, a command called "Set Free AU" is defined, and when the device declares in advance the AU to be used in the recording medium, commands called "Suspend AU" and "Resume AU" are held in the AU. Added to use. However, if the device side complies with these restrictions, it is possible to guarantee speed for a data volume three times that of the conventional speed class.

In addition, the Video Speed Class also introduced the concept of multi-stream writing. In the conventional speed class, only single-stream data recording was subject to speed guarantee. However, in the video speed class, even if a plurality of files are recorded simultaneously on one recording medium, it is a time-sharing format, but the concept is that the recording is guaranteed.

"SD Specifications Part 1, Physical Layer, Simplified Specification, Version 5.00", [online] August 10, 2016, Technical Committee, SD Card Association, [searched February 3, 2017], Internet (URL: https: //www.sdcard.org/downloads/pls/click.php?p=part1_500.jpg&f=part1_500.pdf&e=EN_SS1)

The technique disclosed in the non-patent document mentioned above describes a technique for improving the performance of data writing speed. However, in moving image recording, there is no description of a specific method for dividing a moving image file by a predetermined time or file size. When recording a moving image file while dividing it, it is desirable to improve the writing speed by using the video speed class. An object of the present invention is to write appropriate data when dividing and recording a moving image file.

A recording apparatus according to the present invention performs control so as to record, onto a recording medium, a file including acquisition means for acquiring moving image data, and first information relating to the moving image data acquired by the acquiring means and the size of the moving image data. recording control means for recording the first information in the file in the recording medium when creating the file ; recording control means for overwriting the first information already recorded in the file with information related to the size of moving image data recorded in the file to update the first information. and the recording control means generates a split file when the size of the file reaches a predetermined size, controls to record moving image data continuous with moving image data contained in the file in the split file, and When generating a split file, in response to completion of recording of moving image data included in the file, control is performed so as not to update the first information already recorded in the file. Characterized by

According to the present invention, appropriate data can be written when dividing and recording a moving image file.

1 is a diagram showing a configuration example of an imaging device having a recording device according to an embodiment of the present invention; FIG. It is a figure which shows the functional structural example of the imaging device in this embodiment. FIG. 4 is a diagram for explaining a method of recording data on a recording medium; 4 is a diagram illustrating a configuration example of a moving image file in this embodiment; FIG. 6 is a flow chart showing an example of file division recording processing according to the present embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a configuration example of an imaging device having a recording device according to one embodiment of the present invention. In this embodiment, a lens-interchangeable single-lens reflex digital camera will be described as an example of an imaging device. As shown in FIG. 1 , the imaging apparatus according to this embodiment mainly includes a camera body 100 , an interchangeable lens type lens unit 300 , and a recording medium 200 .

The lens unit 300 will be explained. The imaging lens 310 consists of a plurality of lenses. A diaphragm 312 adjusts the amount of light incident from the lens unit 300 . A lens mount 306 mechanically couples the lens unit 300 and the camera body 100 . The lens mount 306 includes various functions for electrically connecting the lens unit 300 and the camera body 100 . Interface 320 is an interface for connecting lens unit 300 to camera body 100 in lens mount 306 .

A connector 322 electrically connects the lens unit 300 and the camera body 100 . The connector 322 exchanges control signals, status signals, data signals, etc. between the camera body 100 and the lens unit 300, and also has a function of supplying currents of various voltages. Also, the connector 322 may be configured to perform communication using not only electric communication but also optical communication, voice communication, and the like.

Based on the photometry information from the photometry control unit 46 of the camera body 100 , the aperture control unit 340 controls the aperture 312 in cooperation with the exposure control unit 40 that controls the shutter 12 of the camera body 100 . A focus control unit 342 controls focusing of the imaging lens 310 . A zoom control unit 344 controls zooming of the imaging lens 310 .

A lens system control circuit 350 controls the entire lens unit 300 . The lens system control circuit 350 has a non-volatile memory that stores constants, variables, programs, etc. for operation. Further, the lens system control circuit 350 is a non-volatile memory that holds identification information such as a unique number of the lens unit 300, management information, functional information such as the open aperture value, minimum aperture value, focal length, etc., and current and past setting values. It has a sexual memory.

Next, the camera body 100 is described. A lens mount 106 mechanically couples the camera body 100 and the lens unit 300 . The mirrors 130 and 132 guide the light rays incident on the imaging lens 310 to the optical viewfinder 104 by a single-lens reflex system. Note that the mirror 130 may be configured as a quick return mirror or as a half mirror. The shutter 12 is a focal plane shutter.

The imaging device 14 is composed of a CCD, CMOS sensor, or the like, and photoelectrically converts an object image. An optical element such as an optical low-pass filter is arranged in front of the imaging element 14 . A light beam incident on the imaging lens 310 is guided through a diaphragm 312, lens mounts 306 and 106, a mirror 130, and a shutter 12 by a single-lens reflex system, and formed as an optical image on the imaging device 14. FIG.

An A/D converter (analog-digital converter) 16 converts an analog signal (output signal) output from the imaging element 14 into a digital signal. The timing generation circuit 18 supplies clock signals and control signals to the imaging element 14, the A/D converter 16, and the D/A converter 26, respectively. The timing generation circuit 18 is controlled by the memory control circuit 22 and the system control circuit 50, for example.

The image processing circuit 20 performs predetermined pixel interpolation processing and color conversion processing on data from the A/D converter 16 or data from the memory control circuit 22 . In addition, the image processing circuit 20 performs predetermined arithmetic processing using the image data output from the A/D converter 16 as necessary. Contrast type autofocus (AF) processing, automatic exposure (AE) processing, Flash pre-emission (EF) processing is performed. Further, the image processing circuit 20 performs predetermined arithmetic processing using the image data output from the A/D converter 16, and performs TTL auto white balance (AWB) processing based on the obtained arithmetic result. .

The memory control circuit 22 controls the A/D converter 16 , the timing generator 18 , the image processing circuit 20 , the image display memory 24 , the D/A converter 26 , the memory 30 and the compression/decompression circuit 32 . The image data output from the A/D converter 16 is written into the image display memory 24 or memory 30 via the image processing circuit 20, the memory control circuit 22, or via the memory control circuit 22 only.

The image display memory 24 stores image data and the like displayed by the image display section 28 . A D/A converter (digital-analog converter) 26 converts digital signals such as image data written in the image display memory 24 into analog signals. The image display unit 28 is composed of, for example, a TFT-type LCD or the like, and displays an image or the like. The image data for display written in the image display memory 24 is displayed by the image display section 28 via the D/A converter 26 . By sequentially displaying captured image data using the image display unit 28, an electronic viewfinder (EVF) function can be realized. In addition, the image display unit 28 can arbitrarily turn on/off the display according to an instruction from the system control circuit 50. When the display is turned off, the power consumption of the camera body 100 can be greatly reduced. can.

The memory 30 stores data of photographed still images or moving images. The memory 30 has a storage capacity sufficient to store a predetermined number of still images or a predetermined amount of moving images. This makes it possible to write a large amount of images to the memory 30 at high speed even in the case of continuous shooting or panorama shooting in which a plurality of still images are continuously shot. Also, during moving image shooting, it is used as a frame buffer for images that are continuously written at a predetermined rate. Furthermore, memory 30 can also be used as a work area for system control circuit 50 .

The image synthesizing circuit 31 synthesizes a plurality of images to create one composite photograph. The image synthesizing circuit 31 simultaneously reads a plurality of image data written in the memory 30, performs synthesizing processing within the circuit, and creates synthetic image data. The created composite image data is written in the memory 30 . The image synthesizing circuit 31 synthesizes the image data converted by the A/D converter 16 and written by the memory control circuit 22 and the image data processed by the image processing circuit 20 .

A compression/expansion circuit 32 compresses/expands image data using a known compression method. The compression/decompression circuit 32 reads the image stored in the memory 30, compresses or decompresses the image, and writes the processed data back into the memory 30. FIG. The compression/decompression circuit 32 also has a function of compression-encoding moving image data into a predetermined format, or a function of decompressing a moving image signal from predetermined compression-encoded data.

The exposure control section 40 controls the shutter 12 based on the photometry information from the photometry control section 46 in cooperation with the aperture control section 340 that controls the aperture 312 of the lens unit 300 . The distance measurement control unit 42 is a functional unit for performing AF (autofocus) processing, and measures the focus state of an image formed as an optical image. The in-focus state is measured by a single-lens reflex system, in which a light beam that has entered the imaging lens 310 in the lens unit 300 passes through an aperture 312, lens mounts 306 and 106, a mirror 130, and a sub-mirror for focus adjustment (not shown). It is done by letting

The photometry control unit 46 is a functional unit for performing AE (automatic exposure) processing, and measures the exposure state of an image formed as an optical image. The exposure state is measured by making the light rays incident on the imaging lens 310 in the lens unit 300 enter via the diaphragm 312, the lens mounts 306 and 106, the mirror 130, and the sub-mirror for photometry (not shown) in a single-lens reflex system. performed by Note that the AF control may be performed using the result of measurement by the distance measurement control section 42 and the result of calculation by the image processing circuit 20 on the image data from the A/D converter 16 . Further, exposure control may be performed using the result of measurement by the photometry control section 46 and the result of calculation by the image processing circuit 20 on the image data from the A/D converter 16 .

The system control circuit 50 incorporates a well-known CPU and the like, and controls the camera body 100 as a whole. The memory 52 stores constants, variables, programs, etc. for the operation of the system control circuit 50 .

The display unit 54 displays operating states, messages, etc. using characters, images, sounds, etc., according to the execution of the program in the system control circuit 50 . As the display unit 54, for example, a display element that performs visual display such as an LCD or an LED, or a sound generation element that performs notification by sound is used. be. In particular, in the case of a display element, it is installed in one or more easily visible areas near the operation unit 70 of the camera body 100 . A part of the functions of the display unit 54 may be realized by the optical viewfinder 104 and the image display unit 28 .

When a part of the functions of the display unit 54 is realized by the optical viewfinder 104 or the image display unit 28, among the display contents of the display unit 54, the following items are displayed on the image display unit 28 such as an LCD. . First, there are displays related to shooting modes such as single shot/continuous shooting display and self-timer display. In addition, there are displays related to recording, such as a compression rate display, a recording pixel number display, a recording number display, and a remaining shootable number display. In addition, there are displays related to shooting conditions such as shutter speed display, aperture value display, exposure compensation display, exposure compensation display, external flash emission amount display, and red-eye reduction display. In addition, there are a macro photography display, a buzzer setting display, a remaining battery level display, an error display, a multi-digit information display, and a mounting/dismounting state display of the recording medium 200 . Further, display of attachment/detachment state of the lens unit 300, display of communication interface operation, date/time display, display of connection state with an external computer, and the like are also performed. Among the display contents of the display unit 54, the following items are displayed in the optical viewfinder 104, for example. In-focus display, photographing preparation completion display, camera shake warning display, flash charge display, flash charge completion display, shutter speed display, aperture value display, exposure compensation display, recording medium write operation display, and the like.

The nonvolatile memory 56 stores programs and the like, which will be described later. The nonvolatile memory 56 is an electrically erasable/recordable nonvolatile memory, and for example, an EEPROM or the like is used. A mode dial switch 60, a first shutter switch (SW1) 62, a second shutter switch (SW2) 64, and an operation unit 70 are operation members for inputting various operation instructions for the system control circuit 50. FIG. These operating members 60, 62, 64, and 70 are composed of, for example, a single switch, a dial, a touch panel, a pointing device based on line-of-sight detection, a voice recognition device, or a combination of a plurality of them.

A mode dial switch 60 is a switch for setting various shooting modes. Shooting modes include, for example, an automatic shooting mode, a program shooting mode, a shutter speed priority shooting mode, an aperture priority shooting mode, a manual shooting mode, and a depth of focus shooting mode. Other modes include portrait photography mode, landscape photography mode, close-up photography mode, sports photography mode, night scene photography mode, panorama photography mode, and the like.

A first shutter switch (SW1) 62 is turned ON while the shutter button (not shown) is being operated (for example, half-pressed), and instructs the start of operations such as AF processing, AE processing, AWB processing, and EF processing. A second shutter switch (SW2) 64 is turned ON when the operation of the shutter button (not shown) is completed (for example, full depression), and instructs the start of a series of processing operations including exposure processing, development processing, and recording processing. First, in exposure processing, a signal read from the image sensor 14 is written into the memory 30 via the A/D converter 16 and the memory control circuit 22 . Furthermore, in the developing process, the developing process using calculations in the image processing circuit 20 and the memory control circuit 22 is performed. Furthermore, in the recording process, image data is read from the memory 30 , compressed by the compression/decompression circuit 32 , and written to the recording medium 200 .

The operation unit 70 includes various buttons, a touch panel, and the like. For example, the operation unit 70 includes a live view start/stop button, video recording start/stop button, menu button, set button, multi-screen playback page break button, flash setting button, single/continuous/self-timer switching button, and the like. . Further, for example, the operation unit 70 includes a menu move + (plus) button, a menu move - (minus) button, a reproduced image move + (plus) button, a reproduced image move - (minus) button, an image quality selection button, and the like. Further, for example, the operation unit 70 includes an exposure correction button, a light control correction button, an external flash amount setting button, a date/time setting button, and the like. In addition, each function of the above-mentioned plus button and minus button becomes possible to select numerical values and functions more lightly by providing a rotary dial switch.

Further, for example, the operation unit 70 includes an image display ON/OFF switch for setting ON/OFF of the image display unit 28, a quick review ON/OFF switch for setting a quick review function for automatically reproducing image data taken immediately after shooting, and the like. including. Further, for example, the operation unit 70 includes a compression mode switch for selecting the compression rate of JPEG compression, or for selecting the RAW mode for digitizing the signal of the imaging device as it is and recording it on the recording medium. Further, for example, the operation unit 70 includes an AF mode setting switch and the like that can set the one-shot AF mode and the servo AF mode. In the one-shot AF mode, the autofocus operation is started when the first shutter switch (SW1) 62 is turned ON, and once focused, the focused state is maintained. In the servo AF mode, the autofocus operation continues while the first shutter switch (SW1) 62 is ON.

The power supply control unit 80 includes a battery detection circuit, a DC-DC converter, a switch circuit for switching blocks to be energized, and the like. The power supply control unit 80 detects whether or not a battery is installed, the type of battery, and the remaining battery level, and controls the DC-DC converter based on the detection results and instructions from the system control circuit 50 to obtain the required voltage. It is supplied to each part including the recording medium for the period. The power supply unit 86 is a power supply unit including a primary battery such as an alkaline battery or a lithium battery, a secondary battery such as a NiCd battery, a NiMH battery, a Li-ion battery or a Li polymer battery, an AC adapter, and the like. The power control section 80 and the power section 86 are connected via connectors 82 and 84 .

An interface 90 is an interface with a recording medium such as a memory card or a hard disk, or a PC. A connector 92 is a connector for connecting a recording medium such as a memory card or a hard disk, or a PC. A recording medium attachment/detachment detection circuit 98 detects whether or not the recording medium 200 is attached to the connector 92 .

The interface 90 and the connector 92 can be configured using those conforming to various storage medium standards. For example, a PCMCIA (Personal Computer Memory Card International Association) card, a CF (Compact Flash (registered trademark)) card, an SD card, or the like. When the interface 90 and the connector 92 are constructed using standards such as PCMCIA cards and CF cards, various communication cards can be connected. Communication cards include LAN cards, modem cards, USB (Universal Serial Bus) cards, IEEE (Institute of Electrical and Electronic Engineers) 1394 cards, and the like. In addition, there are P1284 card, SCSI (Small Computer System Interface) card, PHS, and the like. By connecting these various communication cards, image data and management information attached to the image data can be transferred between other computers and peripheral devices such as printers.

The optical viewfinder 104 guides the light rays incident on the imaging lens 310 through the diaphragm 312, the lens mounts 306 and 106, and the mirrors 130 and 132 in a single-lens reflex system, and forms and displays an optical image. . As a result, it is possible to shoot using only the optical viewfinder 104 without using the electronic viewfinder function of the image display unit 28 . Also, in the optical viewfinder 104, some functions of the display unit 54, such as focus state, camera shake warning, flash charging, shutter speed, aperture value, exposure correction, etc., are displayed.

The interface 120 connects the camera body 100 with the lens unit 300 within the lens mount 106 . The connector 122 electrically connects the camera body 100 and the lens unit 300 . Whether or not the lens unit 300 is attached to the lens mount 106 and the connector 122 is detected by a lens attachment/detachment detector (not shown). The connector 122 has a function of transmitting control signals, status signals, data signals, etc. between the camera body 100 and the lens unit 300 and supplying currents of various voltages. Also, the connector 122 may be configured to perform communication by optical communication or voice communication as well as electrical communication.

The recording medium 200 is a memory card in this embodiment. The recording medium 200 includes a recording unit 202 composed of a semiconductor memory, an interface unit 204 with the camera body 100 , and a connector 206 for connection with the camera body 100 . In this embodiment, as the recording medium 200, a memory card (SD card) conforming to the SD standard by the SD Card Association is used. It is assumed that moving images are recorded by a writing method (speed class writing) in accordance with the speed class specification in the SD standard. The speed class specification is a specification that guarantees the minimum speed when continuously recording data on a recording medium.

In speed class writing, a recording area (User Area) is managed in units of AU (Allocation Unit) having a fixed first size. One AU is composed of a plurality of RUs (Recording Units) having the second size. The RU size (second size) varies depending on the type of memory card (SDSC, SDHC, SDXC) and speed class, but is a multiple of 16 KB under the current standard, with a maximum of 512 KB. An RU has a size that is an integral multiple of a cluster, which is the minimum management unit of a recording medium. Speed class writes are performed only for empty AUs, which have no RUs with recorded data.

Note that this embodiment can also be applied to an apparatus using a recording medium of another standard that supports a writing method with a different recording area management unit. An example of such a recording medium is a CF card. For CF cards, VPG (Video Performance Guarantee) is defined as a writing method that guarantees the minimum recording speed.

FIG. 2 is a block diagram showing a functional configuration example of an imaging device having a recording device according to this embodiment. It should be noted that FIG. 2 shows only a configuration related to shooting a moving image and recording video data (moving image data) obtained by the shooting. The imaging apparatus according to this embodiment includes a control unit 210, an imaging unit 220, a signal processing unit 230, a recording processing unit 240, and a storage unit 260, as shown in FIG.

The control unit 210 controls each functional unit (the imaging unit 220, the signal processing unit 230, the recording processing unit 240, and the storage unit 260) of the imaging device. The imaging unit 220 photoelectrically converts an incident subject image and outputs an analog signal related to the subject image. The signal processing unit 230 performs predetermined signal processing on the analog signal output from the imaging unit 220, and outputs video data obtained by the signal processing.

The recording processing unit 240 performs recording processing for recording the video data output from the signal processing unit 230 on the recording medium 250 as a moving image file. The recording processing unit 240 writes video data (moving image data) to the recording medium 250 according to the moving image file structure described later. The recording processing unit 240 is an example of recording control means. The recording processing section 240 has an information generating section 241 and a determining section 242 .

The information generator 241 generates information related to video data to be recorded on the recording medium 250 . Information related to the video data generated by the information generation unit 241 is recorded in the recording medium 250 as a moving image file together with the video data. The information generator 241 generates update information including information indicating the data size of the file, for example, when dividing a file to be recorded on the recording medium 250 or when recording of the file ends. The update information generated by the information generation section 241 is recorded on the recording medium 250 or stored in the storage section 260 .

The determination unit 242 determines whether or not the file to be recorded on the recording medium 250 satisfies the division condition. In the present embodiment, the file is divided into a predetermined size or less, and video data and the like are recorded on the recording medium 250. Therefore, the determination unit 242 divides the file based on the size of the file to be recorded on the recording medium 250. determine whether or not to When the determination unit 242 determines to divide the file, the video data is recorded on the recording medium 250 as a moving image file different from the moving image file up to that point.

Here, the control unit 210 is realized by, for example, the system control circuit 50 and the memory 52 shown in FIG. 1, and the imaging unit 220 is realized by, for example, the imaging element 14 shown in FIG. Further, the signal processing unit 230 is realized by, for example, the A/D converter 16, the image processing circuit 20, the memory 30, and the compression/decompression circuit 32 shown in FIG. It is implemented by the system control circuit 50 and interface 90 shown. The recording medium 250 is implemented by, for example, the recording medium 200 shown in FIG. 1, and the storage section 260 is implemented by, for example, the memory 30 shown in FIG.

Next, recording of data in a recording medium (memory card) will be described. FIGS. 3A and 3B are diagrams schematically showing logical address maps including the concept of AU and RU of the recording section 202 of the recording medium 200. FIG. AU0 is used as a management area of the recording unit 202, and system information is recorded. Here, MBR (Master Boot Record), BPB (BIOS Parameter Block), FAT (File Allocation Table), and DE (Directory Entry) are shown as examples of system information. It should be noted that the exemplified system information is publicly known, so detailed description thereof will be omitted. Also, the system information is not limited to these.

AU1 to AUMAX are used as data areas (recording areas) for recording data. AU1 to AUMAX each consist of a plurality of RUs. FIG. 3(a) shows how to use RU in AU at the time of conventional speed class writing, and FIG. It shows how to use RU in AU when writing. 3(a) and 3(b) show the difference in usage between the two data, especially the sequence of RU usage at the time of restart of the second data, which is shown in the logical address map. are shown schematically in the form.

First, the RU use sequence at the time of conventional speed class writing shown in FIG. 3A will be described. First, an empty AU that logically does not contain any data is searched for. This is because, as mentioned above, due to the characteristics of the AU of the recording medium, it is possible to maximize the write performance of the recording medium by writing data to an empty AU where no data is recorded (an AU that is full and empty). Because it is possible.

Next, data of size in RU units is written to the searched AU. Then, when the RU in the searched AU becomes full, the next full and empty AU is searched, and data is similarly written in RU units. While repeating this, the data is recorded sequentially, and when the first file (DATA1) ends, nothing is done and the process ends. Next, when recording the second file (DATA2), a search is made for a full and empty AU in the same manner as the control for writing the data of the first file again, and data is written there in RU units. I will write. At this time, if the end position of the first file ends in AU units, there is no problem. RU is not available when writing data for the second file. Therefore, the remaining RUs in this AU cannot be used as a speed class area.

Next, the method of using RUs at the time of writing in the VSC single stream shown in FIG. 3(b) will be described. First, for the first file, as in the conventional speed class writing described above, a search is made for a fully available AU and data is written in units of RUs. However, before writing data in units of RUs, it is necessary to issue a "Set Free AU" command to declare in advance the AUs to be used to the recording medium. If data is written to a location other than the AU specified by this "Set Free AU" command, it means that the restriction of the video speed class is violated, and the minimum speed is not guaranteed.

By declaring the AU to be used by this "Set Free AU" command, even if the previous data exists in that location, the recording medium can be switched to a mode in which continuous writing is expected by invalidating it. It has the advantage of being able to Therefore, in the sense that garbage collection due to fragmentation of the recording medium is prevented, merits can be obtained from a long-term point of view. However, since the command must be issued periodically, there is a demerit that command overhead occurs and the recording apparatus cannot access the recording medium during that time.

In the video speed class, the recording medium is accessed while combining the "Set Free AU" command and the actual write command in RU units. Also, the control at the end of the first file and at the start of the second file is different from the conventional one. As a specific command, a "Suspend AU" command is issued when the first file ends, and a "Resume AU" command is issued when the second file is resumed. "Suspend AU" is a command for saving the position of an RU in the middle of an AU in a recording medium. "Resume AU" is a command for extracting from the recording medium the position of the RU in the middle of the AU saved in the recording medium. Since this information is stored in the recording medium, it is effective even when the power of the recording medium is turned off and on.

Next, the concept of multistream writing will be described. Commands related to multistream writing, that is, three commands "Update Dir", "Release Dir", and "Start Rec" will be described below. First, in the conventional speed class control method, the sector corresponding to the Directory Entry on the file system of the generated file is issued and registered on the recording medium through the command "Update Dir". This is for the purpose of minimizing the decrease in speed by performing special control when random access to the recording medium occurs and the random access destination is a pre-registered sector. After that, the recording start command "Start Rec" is called to start recording. And nothing is issued at the end.

Next, a method of controlling multistream writing for the video speed class will be described. First, the sector corresponding to the Directory Entry of the generated file is registered by the "Update Dir" command in the same way as the conventional speed class. After executing the "Set Free AU" command, etc., the "Start Rec" command is executed to start the video speed class control. Any file subsequently generated can have a video speed class applied in parallel with previously generated files. However, in order to make this possible, it is necessary to issue a new "Update Dir" command separately from the conventional "Update Dir" command to perform sector registration on the recording medium. The standard stipulates that up to eight "Update Dir" can be registered in the video speed class. When closing the additionally generated file, it is necessary to release the registered sector by issuing the "Release Dir" command, which is a paired command of the "Update Dir" command. When the number of "Release Dir" issuances becomes equal to the number of "Update Dir" issuances, the video speed class ends.

Video speed class multi-stream writing has not only restrictions on command issuance but also restrictions on where to write. Multistream writing does not guarantee a speed class for each file, but means that multiple files can perform time sharing for the minimum speed guarantee, so the write destination must be a continuous area. For example, if File 1 writes 64 MB of data to an AU of 512 MB, then File 2 does not write to the next AU, but continues to locations after 64 MB in the 512 MB of the same AU where File 1 was written. must be written to. If this restriction is not satisfied, the video speed class is not guaranteed, and the "Start Rec" command must be issued again. Furthermore, if file 1 and file 2 are recorded in the same AU, if one of them is erased, the empty capacity of the non-speed class will be increased by the erased amount, but the speed class that uses the full and empty AU will increase. There is also the problem that the amount of free space is not increased.

In this way, the conventional speed class and the video speed class perform different controls for the RU usage method and the file control method. This triples the guaranteed minimum speed in the video speed class, makes more efficient use of free space, and enables multi-stream writing. However, as a constraint for realizing these, more commands must be issued than in the past, and issuing commands causes an overhead and puts a load on the whole. Therefore, a design that minimizes command overhead and the number of command issuances is important.

<Video file structure>
Next, the structure of a moving image file handled in this embodiment will be described. FIG. 4 is a diagram showing a configuration example of a moving image file handled in this embodiment. The moving image file 400 stores various data such as moving image data and audio data. In addition, the moving image file 400 includes position information regarding the positions of moving image data and audio data, and metadata. The size of the moving image data and audio data stored in the moving image file 400 increases as the recording time increases. Information stored in the metadata includes information on moving image data and audio data. Therefore, the contents are determined after the moving image data, audio data, etc. are recorded.

The MOV file format is known as a format for recording moving image data in such a file format. In this embodiment, moving image files are recorded according to the MOV file format. A MOV file is composed of units called atoms. One atom includes an atom size, an atom type, and an atom data area. Information on the data length (size) of this atom is stored in the atom size. The atom type stores information indicating the data type stored in the atom data. Real data is stored in atom data.

An atom type is a fixed length data area of 32 bits. Atom data is an area of variable length. The atom size is usually a 32-bit area, and the size of one atom is usually 0xFFFFFFFF bytes or less (4 gigabytes or less). Also, the atom size can be extended to 64 bits. Therefore, as described later, when the size of the moving image stored in the mdat atom exceeds 4 gigabytes, the atom size of the mdat atom is recorded as 64-bit data.

The moving image file 400 is composed of three atoms: a file type compatible atom (ftyp) 410 , a movie data atom (mdat) 420 and a movie atom (moov) 430 . The atoms ftyp (410), mdat (420), and moov (430) are the highest hierarchy.

ftyp (410) is an atom whose atom type is ftyp and stores information about file compatibility. Based on the atom data described in ftyp (410), it is possible to discriminate the encoding method of the moving image data and audio data stored in the MOV file. mdat (420) is an atom whose atom type is mdat and stores each sample of moving image data and audio data. Encoded video data and audio data are divided into units called chunks and stored. In this embodiment, one chunk of video data is video data of 1 GOP (Group Of Picture) composed of a group of frames, and one chunk of audio data is audio data of the number of frames corresponding to this 1 GOP.

moov (430) is an atom whose atom type is moov and stores metadata about moving image data, audio data, and annotation data. The atom data of the moov (430) stores information such as a chunk offset indicating the offset from the head of the file of a chunk of video data or audio data, the number of samples of each chunk, the sample size, metadata, and the like. moov (430) contains one or more traks (431). A trak (431) is information defining one or more tracks such as video and audio. In the example shown in FIG. 4, for the sake of explanation, trak (431) is described as trak1 (431-1) and trak2 (431-2), which are audio and video tracks, respectively.

trak (431) contains mdia (432). The mdia (430) stores information describing the media type of each track. For example, the mdia chunk information includes information for determining whether the trak contains video information or audio information. mdia (432) includes mdhd (433) and stbl (434). The mdhd (433) stores information for calculating the frame rate for reproducing moving image data. The stbl (434) stores information such as a chunk offset indicating an offset from the head of the file of a chunk of video data or audio data, the number of samples of each chunk, the display time of the sample, the sample size, and the like.

Here, one sample of moving image data corresponds to a frame, and one sample of audio data corresponds to an audio frame. stco and co64 (435) are atoms that store information indicating the position (offset position) from the file head of each chunk of the moving image data and audio data stored in mdat (420), respectively. These pieces of position information are information necessary for reproducing the moving image data and audio data stored in this moving image file. Note that co64 is an atom capable of storing position information that can represent 64-bit position information. Also, moov (430) includes udta, meta (437). udta, meta (470) are atoms in which arbitrary metadata is stored.

In this way, the moving image file structure includes audio data and video data, and stores information necessary for displaying video on a playback device or the like. Since the atom size is recorded in each atom, the playback device can analyze the atom structure by acquiring the stored information. During moving image recording, moving image data is added as atom data of mdat (420). Therefore, when the atom size of mdat (420) is not determined, a dummy value is written in the atom size, and the following contents of mdat (atom data) are written. Then, when the moving image file is divided (hereinafter referred to as file division) or when the moving image recording ends, the atom size is determined, so the dummy value written in advance is overwritten with the determined value for correction.

<File division recording process>
Next, file division recording processing in this embodiment will be described. FIG. 5 is a flowchart showing an example of file division recording processing in this embodiment. This flowchart is executed by the system control circuit 50 controlling each unit and performing various processes based on a program read from the nonvolatile memory. Moving image recording, in which video data obtained by imaging is recorded on a recording medium, is continued after being divided by predetermined time and file size. In this embodiment, FAT32 is used as the file system of the recording medium 200 as an example. Since FAT32 has an upper limit of 4 gigabytes in file size, a moving image file is divided when it reaches 4 gigabytes.

When the user presses the moving image recording start/end button of the operation unit 70, the system control circuit 50 starts recording moving images and starts the flow of FIG. First, in step S<b>501 , the system control circuit 50 (recording processing unit 240 ) creates a file for recording moving image data (captured video data and audio data) in the recording medium 200 . Then, in step S502, the system control circuit 50 (recording processing unit 240) records dummy data as the atom size of mdat of the file generated in step S501. Since the dummy data recorded here needs to be updated to the actual data size of mdat later, the position on the recording medium 200 where the dummy data is recorded as the atom size of mdat is stored in the memory 30 (storage unit 260 ). Subsequently, in step S503, the system control circuit 50 (recording processing unit 240) records moving image data (video data and audio data captured by the imaging unit 220 and signal-processed by the signal processing unit 230) on the recording medium 200. It writes out sequentially to the file that becomes.

In step S<b>504 , the system control circuit 50 (determination unit 242 ) determines the file size of the moving image file currently being recorded on the recording medium 200 . In FAT32, the upper limit of the file size is 4 gigabytes, so the system control circuit 50 determines whether the moving image file being recorded is approaching 4 gigabytes. For example, if the current file size exceeds 3.9 gigabytes, it is determined that 4 gigabytes is imminent. If it is determined in step S505 that the moving image file being recorded is approaching 4 gigabytes, which is the file division condition, the system control circuit 50 determines to divide the file, and proceeds to step S510. On the other hand, if it is determined in step S505 that the moving image file being recorded is not approaching the file division condition of 4 gigabytes, the system control circuit 50 determines not to divide the file, and proceeds to step S506.

In step S506, system control circuit 50 determines whether the user has pressed the moving image recording start/end button of operation unit 70 or not. If the system control circuit 50 determines that the moving image recording start/end button of the operation unit 70 has been pressed, the system control circuit 50 proceeds to step S507 to perform recording end processing. repeat.

In step S507, the system control circuit 50 (information generation unit 241) generates moov to record the metadata of the moving image data in the file currently being recorded. Then, in step S508, the system control circuit 50 (recording processing unit 240) records the moov generated in step S507 in the file currently being recorded on the recording medium 200. FIG.

In step S509, the system control circuit 50 (recording processing unit 240, information generating unit 241) updates the atom size of mdat of the file on the recording medium 200 that is currently being recorded. Since dummy data is recorded as the atom size of mdat, the size of the moving image data actually recorded in mdat is overwritten to update the atom size. In the overwrite (update) process, since the location of the atom size on the recording medium is held in the memory 30 (storage unit 260), the atom size is recorded at the location on the recording medium 200 specified by that information. Here, in the present embodiment, moving images are recorded on the recording medium 200 in the video speed class. Therefore, by recording moov in a continuous area after recording of moving image data is completed, recording in the video speed class is continued even during moov recording. Since updating the atom size is writing to the previously recorded area, recording is not performed in a continuous area, and video speed class recording is not possible. Therefore, by recording the atom size of mdat after the recording of mdat and moov, that is, the recording of file data is completed, the recording of mdat and moov can be recorded in a continuous area at high speed in the video speed class. become able to.

At step S523, the system control circuit 50 (control unit 210) determines whether the atom size information is temporarily stored in the memory 30 (storage unit 260). to run. If file division has not been performed, the atom size is not stored, so the process of step S524 is not performed, and the moving image recording process ends. The processing of step S524 will be described later.
In this way, when file division is not performed, the processing of steps S501 to S509 is executed.

Next, the processing for file division will be described. If it is determined in step S505 that the file is to be divided, the processing from step S510 is executed.
In step S510, the system control circuit 50 (information generating unit 241) starts generating moov of the moving image file currently being recorded, as in step S507. Next, in step S511, the system control circuit 50 determines whether the generation of moov has been completed. If it is determined in step S511 that moov generation has not been completed, the system control circuit 50 advances to step S516 to determine whether moving image data to be recorded in mdat of the file after division has been accumulated. That is, the system control circuit 50 already has moving image data to be written in the next moving image file, which is the divided moving image file, and determines whether or not the next moving image data can be recorded. If the mdat is determined to be accumulated, the system control circuit 50 proceeds to step S517. If it is determined that the mdat is not accumulated, the system control circuit 50 returns to step S511 and repeats the determinations of steps S511 and S516. That is, Yes in step S511 is when the moving image data to be recorded in the mdat of the divided file is accumulated, that is, when moov generation is completed before the next moving image data can be recorded. becomes.

If Yes in step S511, in step S512, the system control circuit 50 (recording processing unit 240) stores the generated moov in the file currently being recorded on the recording medium 200, as in step S508. Record. Then, in step S513, similarly to step S509, the system control circuit 50 (recording processing unit 240, information generating unit 241) updates the atom size of mdat of the file on the recording medium 200 that is currently being recorded. . With this processing, all recording processing of the file before division is completed. Even if the file is split, if the completion of moov generation is faster than the accumulation of the mdat video data of the file after the next split, the recording of the file before splitting is the same as when the file is not split. is performed on

When the recording of the file before division is completed, in step S514, the system control circuit 50 (recording processing unit 240) creates a new file on the recording medium 200 and sets it as a file to be recorded. Then, the process advances to step S515 to record dummy data in the atom size of the mdat of the divided file generated in step S514 as in step S502, and the process advances to step S503. After that, with the divided file generated in S514 as a file to be recorded, the recording process from step S503 onward is executed again.

If Yes in step S516, in step S517, the system control circuit 50 (recording processing unit 240) stores the mdat atom size of the undivided file currently being recorded in the memory 30 (storage unit 260). is temporarily stored. It may be stored in association with the previously stored mdat atom size recording position on the recording medium 200 .

Next, in step S518, the system control circuit 50 generates split files as in step S514. Then, in step S519, the system control circuit 50 records dummy data in the atom size of mdat of the split file generated in step S518, similarly to step S515. After that, in step S520, the system control circuit 50 records the accumulated moving image data in the mdat of the split file generated in step S518. In step S521, the system control circuit 50 determines whether the moov generation of the file before division, which started in step S510, is completed, and repeats step S520 until it is determined that the moov generation is completed. If it is determined in step S521 that the moov has been generated, the process proceeds to step S522. In step S522, the system control circuit 50 records the moov of the file before division on the recording medium 200. FIG. After that, the recording process from step S503 onwards is executed with the divided file generated in step S519 as the file to be recorded.

In the file splitting process, when the processes of steps S517 to S522 are executed, in the recording medium 200, dummy data remains recorded in the atom size of mdat of the file before splitting.
Therefore, after the recording of the last file is completed in step S509, the system control circuit 50 determines whether the atom size of mdat is temporarily stored in the memory 30 in step S523. The fact that the atom size of mdat is temporarily stored in the memory 30 means that the dummy data remains recorded in the mdat of the file recorded on the recording medium 200 . Therefore, if it is determined in step S523 that the atom size is temporarily stored, in step S524 the system control circuit 50 replaces the dummy data of the file before division with the atom size of mdat temporarily stored in the memory 30. update to Since the position on the recording medium where the dummy data is recorded as the atom size is held in the memory 30, the atom size temporarily stored in the memory 30 is changed to the position on the recording medium 200 specified by the information. Record.

As described above, in the present embodiment, it is determined which of moov and mdat can be prepared earlier at the time of file division. If the moov generation is completed before the preparation for writing mdat, the atom size is written to the recording medium 200 in step S513. Since this mdat atom size write is 32 bits, which is different from the RU size, the speed class is violated and the speed class is canceled. Therefore, it is necessary to re-enter the speed class when generating the split files, but since mdat is not ready yet, there is time to re-enter the speed class. On the other hand, when preparation for writing mdat is completed first, the atom size is temporarily stored in the memory 30 so as not to cancel the speed class, and the data of the split file is first recorded on the recording medium 200 . In the present embodiment, when moov generation is completed prior to mdat write preparation, split files are generated after updating the mdat atom size. However, when dividing a file, the mdat atom size is always temporarily stored in the memory 30, and after the recording of the divided file is completed, the mdat atom size of all the files before and after the division is updated. good too.

According to this embodiment, when the file division condition is satisfied during the imaging operation, the atom size of the moving image file before division is not updated, and the atom size is stored in the memory 30 to continue the imaging operation. do. In this way, when a moving image file is divided and recorded, the atom size is not rewritten at the time of file division. decline can be suppressed. In other words, it is possible to suppress the occurrence of buffer overflow (recording stop due to buffer full) due to write speed reduction. In addition, the writing timing of the atom size is changed depending on which of moov generation and mdat accumulation is earlier. By rewriting the atom size when the moov generation is completed before preparing to write mdat, the movie file 200 is completed, so the playback device can analyze the atom structure of the movie file 200. become. This makes it possible to generate a moving image file that can be played back on a playback device even if an unexpected event occurs, such as a sudden power cut while recording a moving image.

(Another embodiment of the present invention)
The present invention supplies a program that implements one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and one or more processors in the computer of the system or apparatus reads and executes the program. It can also be realized by processing to It can also be implemented by a circuit (for example, ASIC) that implements one or more functions.

It should be noted that the above-described embodiments are merely examples of specific implementations of the present invention, and the technical scope of the present invention should not be construed to be limited by these. That is, the present invention can be embodied in various forms without departing from its technical concept or main features.

100: camera body 200: recording medium 300: lens unit 14: image sensor 20: image processing circuit 30: memory 32: compression/expansion circuit 50: system control circuit 90, 204: interface 202: recording unit 210: control unit 220: Imaging unit 230: Signal processing unit 240: Recording processing unit 241: Information generating unit 242: Judging unit 250: Recording medium 260: Storage unit

Claims (12)

Acquisition means for acquiring video data;
recording control means for controlling recording of a file containing moving image data acquired by said acquiring means and first information relating to a size of said moving image data on a recording medium , wherein said first information is recorded in the file in the recording medium, and in response to completion of recording of moving image data included in the file, the first information already recorded in the file is recorded in the file recording control means for controlling to update the first information by overwriting with information related to the size of the moving image data,
The recording control means is
generating a split file when the size of the file reaches a predetermined size, and controlling to record moving image data continuous with moving image data contained in the file in the split file;
When generating the split file, controlling so as not to update the first information already recorded in the file in response to completion of recording of moving image data included in the file;
A recording device characterized by: When generating the split file, the recording control means does not update the first information already recorded in the file in response to completion of recording of moving image data included in the file. 2. The recording apparatus according to claim 1, wherein said first information already recorded in said file is updated after recording of said divided file is completed. If the recording of the moving image data to be recorded in the split file becomes possible before the recording of the moving image data included in the file is completed, the recording control means records the moving image data included in the file. is completed, the first information already recorded in the file is not updated, and the moving image contained in the file is controlled before recording of the moving image data to be recorded in the divided file becomes possible. The first information already recorded in the file is controlled to be updated in response to the completion of the recording of moving image data included in the file when data recording is completed. 2. A recording apparatus according to claim 1. The recording control means records dummy data in the file as the first information before starting recording of moving image data of the file, and records dummy data in the file when recording of the moving image data included in the file is completed. to overwrite the dummy data already recorded in the file as the first information with information related to the size of moving image data recorded in the file, thereby updating the first information. 2. The recording apparatus according to claim 1, wherein: 2. The recording apparatus according to claim 1, wherein said recording control means performs control so that second information relating to said moving image data is recorded in said file after recording of said moving image data of said file is completed. 6. The recording apparatus according to claim 5 , wherein said recording control means performs control so that said second information is recorded in an area following said moving image data. 6. A recording apparatus according to claim 5 , wherein said recording control means performs control so as to update said first information in response to completion of recording of said second information. 2. A recording apparatus according to claim 1, wherein said recording control means performs control to record moving image data in video speed class. 6. The recording apparatus according to claim 5 , wherein said recording control means performs control to record said moving image data and said second information in video speed class. having imaging means,
2. A recording apparatus according to claim 1, wherein said acquiring means acquires moving image data obtained by photographing by said imaging means. an acquisition step of acquiring video data;
A recording control step for controlling to record a file containing the moving image data obtained in the obtaining step and first information relating to the size of the moving image data on a recording medium, wherein when the file is created, the 1 information is recorded in the file in the recording medium, and in response to completion of recording of moving image data included in the file, the first information already recorded in the file is recorded in the file . a recording control step of controlling to update the first information by overwriting with information related to the size of the recorded moving image data;
In the recording control step,
generating a split file when the size of the file reaches a predetermined size, and controlling to record moving image data continuous with moving image data included in the file in the split file;
When generating the split file, controlling so as not to update the first information already recorded in the file in response to completion of recording of moving image data included in the file;
A recording method characterized by: an acquisition step for acquiring video data;
A recording control step for controlling to record a file containing the moving image data obtained in the obtaining step and first information relating to the size of the moving image data on a recording medium, wherein when the file is created, the 1 information is recorded in the file in the recording medium, and in response to completion of recording of moving image data included in the file, the first information already recorded in the file is recorded in the file . causing a computer to execute a recording control step of controlling to update the first information by overwriting with information related to the size of the recorded moving image data;
In the recording control step,
generating a split file when the size of the file reaches a predetermined size, and controlling to record moving image data continuous with moving image data contained in the file in the split file;
In the case of generating the split files, a process of controlling not to update the first information already recorded in the file in response to completion of recording of moving image data included in the file. A program that makes a computer run.

Images