JP2010020641A - Recording apparatus and method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively use free space of a recording medium such as a memory card by suppressing a reduction in recording time even when a file system is fragmented. <P>SOLUTION: The degree of fragmentation is acquired for each AU of a memory card 109, a data writing speed depending on the degree of fragmentation is computed for each AU, and free space of a stream buffer 107 is acquired. If the free space of the buffer 107 is not less than a predetermined value, an AU of the memory card 109 having a lower write speed is selected for writing. If the free space of the buffer 107 is less than the predetermined value, an AU of the memory card 109 having a higher write speed is selected for writing. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a recording apparatus, method, and program for recording real-time data on a randomly accessible recording medium such as a memory card camcorder.

(Memory card camcorder)
In recent years, digital cameras and digital video cameras that record captured image data on a recording medium such as a memory card have become widespread. As a recording format in these devices, the FAT (File Allocation Table) method is generally used. In the FAT system, the used area and unused area of the recording medium are managed in a table system, and when there is a data write request, the unused area is specified by referring to this management table and data is written.

  However, in the FAT method, when file writing / deletion is repeated, a used area and an unused area are mixed, resulting in a situation in which a continuous free area is reduced. This is generally called fragmentation or fragmentation, and causes a problem in writing that requires real-time performance, such as moving image recording, because the recording speed is reduced. That is, in a recording medium using a flash memory such as a memory card, when writing is performed in an area where fragmentation occurs, internally, newly written data and already written data are combined into another free space. Copying to the area is performed. Therefore, there has been a problem that the writing speed is reduced by fragmentation.

  With respect to the above problems, Patent Document 1 distinguishes data to be written into data that requires real-time performance and data that does not, and data that requires real-time performance is based on the free space information of the recording medium. There is disclosed a technique in which data that does not require real-time property is recorded in a relatively high transfer rate area and is recorded in a relatively low transfer rate area.

(About SD card speed class)
Further, in recent years, there are some memory card standards that specify a minimum guaranteed recording rate that takes into account a decrease in speed due to fragmentation. For example, “Secure Digital Specifications Physical Layer Spec. Version 2.0”, which defines the standard for SD (secure digital) cards, defines what is called a speed class in order to record real-time data represented by video without failure. ing.

  The speed class will be described with reference to FIG. The speed class stipulates that the recording area on the card is divided by a unit called AU (Allocation Unit) and the degree of fragmentation is measured for each AU. Specifically, AU is an integer multiple of the cluster size in FAT, and the proportion of FAT used clusters in AU is the fragmentation rate. In accordance with the fragmentation rate of the AU, the minimum writing speed to the free cluster in the AU is defined. Then, by selectively writing to an AU that can be written at a higher speed than the bit rate of the data to be written, real-time data can be reliably recorded on the card.

  A specific example will be described. In a certain card, as shown in FIG. 11, if the rate of the free cluster in the AU is 100%, it is 6 MB / sec, if it is 75%, 4 MB / sec, if it is 50%, 2 MB / sec, 25 %, Writing at 1 MB / sec is possible. Therefore, when a stream with a bit rate of 3 MB / sec is recorded in real time, it is possible to continue recording without causing a buffer overflow by using an area where the percentage of free clusters is 100% or 75%. .

  Based on such a technical background, in Patent Document 2, in a recording apparatus that performs real-time recording on a recording medium, file system fragmentation information on the recording medium is acquired, and each area of the recording medium is used as the fragmentation information. Based on this, it is classified into multiple write speed classes, and data can be recorded in real time at a high transfer rate by preferentially writing data to the most appropriate speed class area according to the desired real-time level. What makes an area available effectively is disclosed.

JP 2000-267904 A JP 2007-49939 A

(Problems that shorten the recordable time)
By doing as described above, it is possible to perform recording with guaranteed real-time performance even on a fragmented memory card. However, the above-described conventional technique has a problem that the recordable time becomes shorter than the free space of the actual card because the area determined to be unwritable at the bit rate of the stream cannot be used.

  The present invention has been made in view of the above situation, and in a recording apparatus that records time-series data on a recording medium such as a memory card in real time, the file system on the recording medium is increasingly fragmented. In this case, the recordable time is shortened.

The recording apparatus of the present invention includes a recording medium for recording data, a memory for temporarily storing data to be recorded on the recording medium, and the recording medium is divided into a plurality of partial areas and stored in the memory. A recording control means for reading and writing the read data, an area management means for obtaining the degree of fragmentation for each partial area of the recording medium, and for determining the writable speed of data according to the degree of fragmentation for each partial area; Free space acquisition means for acquiring the free space of the memory, and the recording control means includes a write speed of the data, a free capacity of the memory, and a writable speed of each partial area of the recording medium. Accordingly, the writing is performed by selecting a partial area of the recording medium.
Another recording apparatus of the present invention handles a recording medium for recording data, a memory capable of temporarily storing data to be recorded on the recording medium, and the recording medium divided into a plurality of partial areas. Recording control means for writing, and area management means for obtaining the degree of fragmentation for each partial area of the recording medium, and for determining the writable speed of data according to the degree of fragmentation for each partial area, The recording control means, when a partial area having a write speed higher than the data writing speed is present among the plurality of partial areas of the recording medium, selects the partial area to perform writing, and the writeable speed If there is no partial area that is faster than the data writing speed, select a partial area that is slower than the data writing speed, and And performing a writing upon temporarily stored in the memory.
The recording method of the present invention includes a recording medium for recording data, a memory for temporarily storing data to be recorded on the recording medium, and the recording medium is divided into a plurality of partial areas and stored in the memory. A recording method by a recording control means for reading and writing the acquired data, wherein the degree of fragmentation is obtained for each partial area of the recording medium, and the data writing speed according to the degree of fragmentation for each partial area And the recording control means according to the data writing speed, the memory free capacity, and the writable speed of each partial area of the recording medium. And a step of selecting and writing a partial area of the recording medium.
Another recording method of the present invention includes a recording medium for recording data, a memory capable of temporarily storing data to be recorded on the recording medium, and the recording medium is divided into a plurality of partial areas. A recording control means for writing data, a procedure for obtaining the degree of fragmentation for each partial area of the recording medium and determining the writable speed of data according to the degree of fragmentation for each partial area; The recording control means selects and writes the partial area when a partial area having a writable speed higher than the data writing speed is present among the plurality of partial areas of the recording medium. If there is no partial area whose possible speed is higher than the data writing speed, a partial area lower than the data writing speed is selected, and the data is deleted. And having a procedure for writing the data on which is temporarily stored in the memory.
The program of the present invention includes a memory that temporarily stores data to be recorded on a recording medium, a recording control unit that handles the recording medium by dividing the recording medium into a plurality of partial areas, and reads and writes the data stored in the memory; Obtaining the degree of fragmentation for each partial area of the recording medium, area management means for obtaining the writable speed of data corresponding to the degree of fragmentation for each partial area, and obtaining the free capacity for obtaining the free capacity of the memory The computer functions as means, and the recording control means determines the partial area of the recording medium according to the data writing speed, the free space of the memory, and the writable speed of each partial area of the recording medium. Selective writing is performed.
Another program of the present invention includes a memory capable of temporarily storing data to be recorded on a recording medium, a recording control unit for handling the recording medium by dividing the recording medium into a plurality of partial areas, and each of the recording medium. In addition to obtaining the degree of fragmentation for each partial area and causing the computer to function as area management means for obtaining the writable speed of data corresponding to the degree of fragmentation for each partial area, the recording control means includes a plurality of recording media. If there is a partial area whose writeable speed is higher than the data writing speed, the partial area is selected for writing, and the writeable speed is higher than the data writing speed. If there is no partial area, select a partial area that is slower than the data writing speed, and temporarily store the data in the memory. And performing a writing upon stored.

  According to the present invention, even when the file system is fragmented, it is possible to prevent the recording time from being shortened and to effectively use the free area of a recording medium such as a memory card.

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. In each embodiment, a video camera functioning as a recording apparatus to which the present invention is applied will be described as an example.
(First embodiment)
FIG. 1 is a block diagram illustrating a configuration of a video camera 100 according to the first embodiment. The video camera 100 can record moving image data taken on a memory card medium. The video camera 100 includes an imaging unit 101, a video signal processing unit 102, a frame memory 103, a microphone 104, an audio signal processing unit 105, a PCM buffer 106, a stream buffer 107, a memory card I / F 108, a memory card 109, an operation unit 110, A display unit 111, a CPU (central processing unit) 112, a codec 113, a file system 114, and a write management unit 115 are provided.

  The imaging unit 101 captures a subject image and converts it into an electrical signal. The video signal processing unit 102 performs A / D conversion and appropriate image processing on the video signal obtained by the imaging unit 101. The frame memory 103 stores the video frame data generated by the video signal processing unit 102 during recording. The microphone 104 captures external sound. The audio signal processing unit 105 performs A / D conversion and appropriate signal processing on the audio signal obtained by the microphone 104. The PCM buffer 106 stores PCM data taken from the microphone 104 and AD-converted during recording. The stream buffer 107 temporarily stores (buffers) a generated stream at the time of recording, and corresponds to a memory referred to in the present invention.

  The memory card I / F 108 performs recording / reproduction with respect to the memory card 109. The memory card 109 corresponds to a recording medium referred to in the present invention. The operation unit 110 is for receiving an operation from the user and operating the video camera 100. The display unit 111 has a liquid crystal screen (not shown), and displays a video captured by the imaging unit 101 during recording and a playback video during playback. It also has a function of displaying a setting menu for the video camera 100 or information such as a recording time and a remaining battery level.

  The CPU 112 controls the operation of each unit by software. A codec (CODEC) 113 compresses and encodes the video frame data stored in the frame memory 103 and the PCM data stored in the PCM buffer 106 at the time of recording into a data format that can be recorded in the memory card 109. Convert. The file system 114 provides a function for accessing a file to the memory card 109.

  The write management unit 115 operates in cooperation with the file system 114, and calculates the writable speed for each partial area in the memory card 109 from the degree of fragmentation of the card and the performance information of the memory card 109. When there is a data write request, a write area on the memory card 109 is determined according to the data recording bit rate (write speed).

(About SD card speed class)
The video camera 100 employs an SD (secure digital) card as a type of the memory card 109, acquires information on the speed class from the card, and uses it for writing control at the time of moving image recording.

(Selection of writing area during recording)
The video camera 100 handles the memory card 109 by dividing it into a plurality of AUs and performs recording control to write data.

At the time of recording, the write management unit 115 manages the write area as follows. First, the fragmentation rate is examined for each AU, rearranged in order of the fragmentation rate, and stored as an AU information table (see FIG. 2). At this time, each AU is managed by being classified into the following three types according to the fragmentation rate. This processing is an example of processing performed by the area management means in the present invention.
Area A: Real-time writable area The writable speed specified by the speed class is equal to or higher than the stream bit rate r. Area B: The real-time writable area. The writable speed specified by the speed class is the bit of the stream. Less than rate r Area C: Area where no free cluster exists in AU Area where writing is impossible because all are used areas

  The AU information table is updated to the latest state every time data is written to the card during recording. The area A is an area that can be recorded even in the prior art. The area B is an area that cannot be recorded in the prior art. In this embodiment, a part or all of the area B is used as a writable area. When a certain AU in the area A can be written at a speed higher than the recording bit rate r of the stream, writing to this AU increases the free capacity of the stream buffer 107. Therefore, if the AU in the area A is writable at a high speed and the stream buffer 107 is sufficiently freed, even if the AU in the area B is written, the buffer overflow does not occur. It becomes possible to record.

  Hereinafter, with reference to the flowchart of FIG. 3, the procedure up to writing to the memory card 109 during recording in the first embodiment will be described. When recording is started, a recording bit rate r is first acquired (step S101).

  Subsequently, the AU information table is updated (step S102). This is a process of acquiring information on the speed class of the card and a fragmentation rate for each AU and classifying each AU into areas A, B, and C in comparison with the recording bit rate r.

Here, if the card free space C _free exceeds a certain value C _th (Yes in step S103), the recording is continued. On the other hand, if the card free space C _free is equal to or less than a certain value C _th (No in step S103), the recording is terminated (step S113), and the stream data stored in the stream buffer 107 is written to the card (step S114). .

When the card free space C _free exceeds a certain value C _th , the following processing is performed. If stream data is not accumulated in the stream buffer 107 for the minimum writing unit for the card, the process waits until it is accumulated (step S105). In the present embodiment, the AU size is defined for each card.

At this point, the free capacity B _free of the stream buffer 107 is confirmed (acquire free capacity). If the buffer free space B _free is smaller than a certain size (predetermined value) B _th (Yes in step S106), if the area A exists (Yes in step S107), the area A is set as a write target ( In step S108, stream writing is executed (step S109). Since the area A is an area having a high writable speed, the free area of the stream buffer 107 can be increased.

On the other hand, when the buffer free capacity B _free is equal to or _larger than a certain size B _th (No in step S106), there is a sufficient free area in the stream buffer 107. Attempts to write to. First, if the region B exists (Yes in step S110), the region B is set as a write target (step S111).

Here, each AU included in the region B has various writable speeds depending on the degree of fragmentation. Therefore, it is determined whether or not there is an AU that can be written without causing a buffer overflow in the region B under the conditions of the free capacity B _free of the stream buffer 107 and the recording bit rate r (step S112). .

This determination is performed as follows. First, the free capacity of the stream buffer 107 after recording when data is recorded in one AU is estimated. Assuming that the i-th AU is denoted as AU (i), the writable speed of AU (i) is denoted as w (i), and the size of the free cluster in AU (i) is denoted as c (i). When writing to AU (i), the increment Δb (i) of the accumulation amount of the stream buffer 107 is
Δb (i) = c (i) * (r−w (i)) / w (i) (1)
It becomes.
This processing is an example of processing of the free capacity calculation means referred to in the present invention.

Therefore, _let B _{total be} the total capacity of the stream buffer 107 and α be a certain amount of margin.
B _free + Δb (i) + α <B _total (2)
If there is an AU (i) that satisfies the above condition, it is determined that a buffer overflow does not occur even if writing to AU (i) is performed (Yes in step S112), and stream writing is performed on the AU (i). Execute (Step S109).

  If there is no AU that can be written in the area B (No in step S110 or No in step S112), the process proceeds to step S107, and writing to the area A is attempted.

FIG. 4 is a characteristic diagram in which the state of write control in the present embodiment is a time-series graph. In the figure, the characteristic line A represents the generated data code amount, and the characteristic line B represents the data code amount already written in the memory card. The characteristic line C is obtained by shifting the characteristic line A by the buffer capacity B _{total in the} vertical axis direction, and the difference in the vertical axis between the characteristic line B and the characteristic line C represents the buffer free capacity B _free at that time. ing. As shown in the figure, in the present embodiment, it is possible to effectively use the region B having a low writable speed without causing a buffer overflow.

  On the other hand, FIG. 5 shows a characteristic diagram in a time-series graph of the state of write control in the prior art using only the area A as a write area. The characteristic lines A to C are the same as the characteristic lines A to C in FIG. As shown in FIGS. 4 and 5, in the present embodiment, the recordable time on a card in which fragmentation has occurred becomes longer, and convenience for the user can be improved.

  As described above, when recording stream data on the recording medium, the writing speed corresponding to the degree of fragmentation of the recording medium file system is obtained, and the bit rate of the stream data and the temporary buffer of the stream data before recording are acquired. A write target area on the recording medium is selected based on the free space. This makes it possible to effectively use the area where the writing speed has decreased due to fragmentation.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. Since the configuration of the video camera 100 of the second embodiment is the same as that of the first embodiment, description thereof is omitted. The management of the AU information table is the same as in the first embodiment.

  Hereinafter, with reference to the flowchart of FIG. 6, the procedure up to writing to the memory card 109 during recording in the second embodiment will be described. When recording is started, a recording bit rate r is first acquired (step S201).

  Subsequently, the AU information table is updated (step S202). This is a process of acquiring information on the speed class of the card and a fragmentation rate for each AU and classifying each AU into areas A, B, and C in comparison with the recording bit rate r.

Here, if the card free space C _free exceeds a certain value C _th (Yes in step S203), the recording is continued. On the other hand, if the card free space C _free is equal to or less than a certain value C _th (No in step S203), the recording is terminated (step S212), and the stream data stored in the stream buffer 107 is written to the card (step S213). .

When the card free space C _free exceeds a certain value C _th , the following processing is performed. If the stream data is not accumulated in the stream buffer 107 by the minimum writing unit for the card, it waits until it is accumulated (step S205). In the present embodiment, the AU size is defined for each card.

At this time, the free capacity B _free of the stream buffer 107 is confirmed. If the buffer free space B _free is smaller than a certain size B _th (Yes in step S206), if the area A exists (Yes in step S207), the area A is set as a write target (step S208), and the stream Writing is executed (step S209). Since the area A is an area having a high writable speed, the free area of the stream buffer 107 can be increased.

On the other hand, if the buffer free capacity B _free is greater than or equal to a certain size B _th (No in step S206), there is sufficient free space in the stream buffer 107. Therefore, if the area B exists (Yes in step S210), the area B is set as a writing target (step S211), and stream writing is executed (step S209). Here, the constant size B _th is set to be large enough to be in time even when the writing speed to the region B is low.

  If there is no AU that can be written to the area B (No in step S210), the process proceeds to step S207 to try writing to the area A.

  By doing as described above, it is possible to use an area where the writing speed is low without waste while performing simple control compared to the first embodiment.

(Third embodiment)
FIG. 7 is a block diagram illustrating a configuration of a video camera 200 according to the third embodiment. Components similar to those of the video camera 100 of the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted. The video camera 200 can record moving image data taken on a memory card medium. The video camera 100 includes an imaging unit 101, a video signal processing unit 102, a frame memory 103, a microphone 104, an audio signal processing unit 105, a PCM buffer 106, a memory card I / F 108, a memory card 109, an operation unit 110, a display unit 111, A CPU (Central Processing Unit) 112, a codec 113, a file system 114, a write management unit 115, a flash memory 116, and an SDRAM 117 are provided.

  The SDRAM 117 temporarily stores (buffers) the generated stream during recording. The flash memory 116 is used not only to record video data when a memory card is not connected to the video camera 200 but also to temporarily store (buffer) the generated stream. The flash memory 116 corresponds to a memory capable of temporarily storing data to be recorded on a recording medium according to the present invention.

(About SD card speed class)
The video camera 200 employs an SD (secure digital) card as a type of the memory card 109, acquires information about the speed class from the card, and uses it for writing control at the time of moving image recording.

(Selection of writing area during recording)
The video camera 100 handles the memory card 109 by dividing it into a plurality of AUs and performs recording control to write data.

At the time of recording, the write management unit 115 manages the write area as follows. First, the fragmentation rate is examined for each AU, rearranged in order of the fragmentation rate, and stored as an AU information table (see FIG. 2). At this time, each AU is managed by being classified into the following three types according to the fragmentation rate. This processing is an example of processing performed by the area management means in the present invention.
Area A: Real-time writable area The writable speed specified by the speed class is equal to or higher than the stream bit rate r. Area B: The real-time writable area. The writable speed specified by the speed class is the bit of the stream. Less than rate r Area C: Area where no free cluster exists in AU Area where writing is impossible because all are used areas

  The AU information table is updated to the latest state every time data is written to the card during recording. The area A is an area that can be recorded even in the prior art. The area B is an area that cannot be recorded in the prior art. In this embodiment, a part or all of the area B is used as a writable area. In the writing, the area A is preferentially used, and the area B is used when the recording progresses and the area A disappears. Since writing to the area B is not in time for the recording bit rate, the stream data is temporarily held in the flash memory, and control is performed so as to buffer the data that cannot be written in time.

  Hereinafter, with reference to the flowchart of FIG. 8, a procedure until writing to the memory card 109 at the time of recording in the third embodiment will be described. When recording is started, a recording bit rate r is first acquired (step S301).

  Subsequently, the AU information table is updated (step S302). This is a process of acquiring information on the speed class of the card and a fragmentation rate for each AU and classifying each AU into areas A, B, and C in comparison with the recording bit rate r.

  When the area A exists in the updated AU information table (Yes in step S303), the stream data storage destination is set in the SDRAM 117 (step S304). Then, after waiting for a certain amount of stream data to be accumulated (step S305), the stream data is written into the area A (step S306). Thereafter, the process returns to step S302, the AU information table relating to the AU in which writing has been performed is updated, and the same processing is repeated thereafter.

  On the other hand, if the area A does not exist, that is, if the area A has been used up (No in step S303), the stream data storage destination is set in the flash memory 116 (step S307). As a result, the encoded / multiplexed stream data is buffered on the flash memory 116. On the flash memory 116, the stream data is managed as a ring buffer, and the stream data can be written faster than the bit rate without causing fragmentation.

  Here, the AU information table is updated (step S308), and it is checked whether or not the region B exists (step S309). The presence of the area B means that there is an empty area on the card. Therefore, after waiting for a certain amount of streams to be accumulated (step S310), the stream is written to the area B (step S311). Then, it is confirmed whether or not an empty area remains in the flash memory 116 (step S312). If an empty area remains, the process returns to step S308 to continue recording. If there is no free space remaining on the card (No in step S309) or if no free space remains in the flash memory 116 (No in step S312), recording is stopped (step S313).

(Calculation of recordable time)
The calculation of the time during which data can be continuously recorded in the memory card 109 in the recording mode is performed as follows. This processing is an example of processing by the recordable time calculating means referred to in the present invention.
(1) Region A
If the size of the free cluster in the area is Sa and the recording bit rate of the stream is r,
Recording time = Sa / r (3)
Is required.

(2) Region B
Assuming that the i-th AU is denoted as AU (i), the writable speed of AU (i) is denoted as w (i), and the size of the free cluster in AU (i) is denoted as c (i). When writing to AU (i), the increment Δb (i) of the accumulation amount of the flash memory 116 is
Δb (i) = c (i) * (r−w (i)) / w (i) (4)
It becomes.

  In order to extend the recordable time, it is desirable to write from a writable area at high speed. Therefore, the increment of the storage amount Δb (i) obtained by the above equation (4) is added in order from the AU that has a low fragmentation rate and can be written at a relatively high speed, and the free capacity of the flash memory 116 is increased. Up to the point where the maximum value is reached in a range that does not exceed is set as the recordable area.

If the free area size of the recordable area set in this way is Sb,
Recording time = Sb / r (5)
It becomes.

  Therefore, the recordable time for the entire card is calculated as the sum (Sa + Sb) / r of the recording times obtained by the above formulas (3) and (5), including the portion corresponding to the recording in the area B, and is displayed on the display unit 111. Is displayed.

  When encoded as a variable bit rate stream, since the recording bit rate changes depending on the subject, the actual recordable time is not always as estimated. Therefore, whether or not to actually stop recording is determined from the amount of free space in the flash memory 116.

FIG. 9 is a characteristic diagram showing a time-series graph of the state of write control in this embodiment. In the figure, the characteristic line A represents the generated data code amount, and the characteristic line B represents the data code amount already written in the memory card. In the range Y ₁ in the figure, recording is performed in the area A, but in the range Y ₂ after the area A disappears, recording is performed in the area B.

  On the other hand, FIG. 10 shows a characteristic diagram in which the state of write control in the prior art using only the area A as a write area is a time-series graph. As shown in FIGS. 9 and 10, in the present embodiment, the recordable time on the card in which fragmentation has occurred becomes longer, and the convenience for the user can be improved.

  In the case of a memory card using a flash such as an SD card, the reading speed is higher than that of writing, and the speed reduction due to fragmentation is smaller than that at the time of writing. Therefore, even in the case where the stream data recorded in the area B is reproduced in the present embodiment, the reading is fast with respect to the bit rate of the stream, and smooth reproduction without interruption is possible.

  In the present embodiment, the flash memory 116 can be replaced with a hard disk.

  As described above, when recording stream data on a recording medium, if the file system is fragmented and cannot be written in real time, recording can be continued while temporarily buffering to another medium. It is possible to extend the recordable time.

  The object of the present invention can also be achieved by supplying a storage medium storing software program codes for realizing the functions of the above-described embodiments to a system or apparatus. In this case, the computer (or CPU or MPU) of the system or apparatus reads and executes the program code stored in the storage medium.

  In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the program code itself and the storage medium storing the program code constitute the present invention.

  As a storage medium for supplying the program code, for example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

  Further, the functions of the above-described embodiments are not limited to being realized by executing the program code read by the computer. For example, an OS (basic system or operating system) running on the computer performs part or all of the actual processing based on an instruction of the program code, and the functions of the above-described embodiments are realized by the processing. May be.

  Further, the program code read from the storage medium may be written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer. In this case, after being written in the memory, the CPU of the function expansion board or function expansion unit performs part or all of the actual processing based on the instruction of the program code, and the function of the above-described embodiment is performed by the processing. Is realized.

It is a figure which shows the structure of the video camera of 1st Embodiment. It is a figure showing an AU information table. 4 is a flowchart for explaining a procedure until writing to a memory card at the time of recording in the first embodiment. It is a characteristic view which shows the relationship between the generated code amount at the time of recording and the code amount already written in the memory card in time series in the first embodiment. FIG. 10 is a characteristic diagram showing, in a time series, a relationship between a generated code amount at the time of recording and a code amount written to a memory card in the related art. It is a flowchart for demonstrating the procedure until writing to the memory card at the time of recording in 2nd Embodiment. It is a figure which shows the structure of the video camera of 3rd Embodiment. 10 is a flowchart for explaining a procedure until writing to a memory card at the time of recording in the third embodiment. It is a characteristic view which shows the relationship between the generated code amount at the time of recording and the code amount written in the memory card in time series in the third embodiment. FIG. 10 is a characteristic diagram showing, in a time series, a relationship between a generated code amount at the time of recording and a code amount written to a memory card in the related art. It is a figure for demonstrating the concept of the speed class in an SD card.

Explanation of symbols

100, 200: Video camera 101: Imaging unit 102: Video signal processing unit 103: Frame memory 104: Microphone 105: Audio signal processing unit 106: PCM buffer 107: Stream buffer 108: Memory card I / F
109: Memory card 110: Operation unit 111: Display unit 112: CPU (Central processing unit)
113: Codec 114: File system 115: Write management unit 116: Flash memory 117: SDRAM

Claims (12)

A recording medium for recording data;
A memory for temporarily storing data to be recorded on the recording medium;
Recording control means for handling the recording medium divided into a plurality of partial areas, and reading and writing data stored in the memory;
An area management means for obtaining the degree of fragmentation for each partial area of the recording medium, and obtaining a writable speed of data according to the degree of fragmentation for each partial area;
Free space acquisition means for acquiring the free space of the memory,
The recording control means selects and writes a partial area of the recording medium according to the data writing speed, the free space of the memory, and the writable speed of each partial area of the recording medium. A recording apparatus. The recording control means includes
If the free space of the memory is equal to or greater than a predetermined value, write a partial area with a low writable speed among the partial areas of the recording medium,
2. The recording apparatus according to claim 1, wherein when the free space of the memory is lower than the predetermined value, writing is performed by selecting a partial area having a high writable speed from among the partial areas of the recording medium. . Free space calculating means for estimating the free space of the memory after recording when data is recorded in one of the partial areas of the recording medium,
The write control means selects and writes one of the partial areas of the recording medium based on the estimate calculated by the free capacity calculation means so that the free capacity of the memory is not lost. The recording apparatus according to claim 1. A recording medium for recording data;
A memory capable of temporarily storing data to be recorded on the recording medium;
Recording control means for handling the recording medium divided into a plurality of partial areas and writing data;
An area management unit that obtains the degree of fragmentation for each partial area of the recording medium and obtains the writable speed of data according to the degree of fragmentation for each partial area, and
The recording control means includes
Of the plurality of partial areas of the recording medium, if there is a partial area whose writable speed is higher than the data writing speed, select the partial area and perform writing.
If there is no partial area whose writing speed is faster than the data writing speed, select a partial area that is slower than the data writing speed, and write the data after temporarily storing the data in the memory. A recording apparatus characterized by performing.   The recording apparatus according to claim 4, wherein the memory is a flash memory.   The recording apparatus according to claim 4, wherein the memory is a hard disk. A recordable time calculating means for calculating a time during which data can be continuously recorded on the recording medium;
The recordable time calculation means includes, in the calculation of the recordable time, a portion corresponding to recording in a partial area where the writable speed is lower than the data writing speed among the plurality of partial areas of the recording medium. The recording apparatus according to claim 4, wherein the recording apparatus is a recording apparatus. It has an imaging unit that captures the subject image,
The recording apparatus according to claim 1, wherein the data is moving image data acquired by the imaging unit. A recording medium for recording data, a memory for temporarily storing data to be recorded on the recording medium, a recording medium in which the recording medium is divided into a plurality of partial areas, and data stored in the memory is read and written A recording method by a control means,
A procedure for obtaining the degree of fragmentation for each partial area of the recording medium and obtaining a writable speed of data according to the degree of fragmentation for each partial area;
Obtaining the free space of the memory;
A procedure in which the recording control means selects and writes a partial area of the recording medium according to the data writing speed, the free space of the memory, and the writable speed of each partial area of the recording medium. And a recording method. Recording method for recording data, a memory capable of temporarily storing data to be recorded on the recording medium, and a recording control means for handling the recording medium divided into a plurality of partial areas and writing the data Because
A procedure for obtaining the degree of fragmentation for each partial area of the recording medium and obtaining a writable speed of data according to the degree of fragmentation for each partial area;
When the recording control unit has a partial area whose writable speed is higher than the data writing speed among the plurality of partial areas of the recording medium, the partial control area can be selected to perform writing. When there is no partial area whose speed is higher than the data writing speed, a partial area whose speed is lower than the data writing speed is selected, and the data is temporarily stored in the memory and then written. And a recording method. A memory for temporarily storing data to be recorded on the recording medium;
Recording control means for handling the recording medium divided into a plurality of partial areas, and reading and writing data stored in the memory;
An area management means for obtaining the degree of fragmentation for each partial area of the recording medium, and obtaining a writable speed of data according to the degree of fragmentation for each partial area;
Causing the computer to function as free space acquisition means for acquiring the free space of the memory;
The recording control means selects and writes a partial area of the recording medium according to the data writing speed, the free space of the memory, and the writable speed of each partial area of the recording medium. A program characterized by A memory capable of temporarily storing data to be recorded on the recording medium;
Recording control means for handling the recording medium divided into a plurality of partial areas and writing data;
Acquiring the degree of fragmentation for each partial area of the recording medium, and causing the computer to function as area management means for obtaining the writable speed of data according to the degree of fragmentation for each partial area,
The recording control means includes
Of the plurality of partial areas of the recording medium, if there is a partial area whose writable speed is higher than the data writing speed, select the partial area and perform writing.
If there is no partial area whose writing speed is faster than the data writing speed, select a partial area that is slower than the data writing speed, and write the data after temporarily storing the data in the memory. A program characterized by being performed.

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