Recording method, information processing device, and video recording system

Abstract

This recording method for video data is for recording in a first storage that can record therein the video data, that is composed of a semiconductor memory, and that includes a plurality of separated recording regions. The plurality of recording regions include a first recording region having a small number of writing times and a second recording region having a large number of writing times. The recording method includes a step for recording video data having high access frequency in the first recording region and a step for recording video data having low access frequency in the second recording region.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a recording method for recording video data in a storage constituted by a semiconductor memory, an information processing apparatus, and a video recording system for recording video data in the aforementioned storage.

BACKGROUND ART

[0002] Systems are known that receive video data output by a video output device such as a camera, and record the video data in a storage constituted by a semiconductor memory (for example, a solid state drive (SSD)). The video data recorded in this storage is used, for example, for future playback or video editing.

[0003] In a storage constituted by a semiconductor memory, there is an upper limit on the number of data write operations in the data recording area. When the number of write operations in a recording area exceeds the upper limit, data can no longer be written to that recording area. Furthermore, if the number of rewrite operations in a specific recording area exceeds the upper limit, data cannot be written to the entire storage even if the upper limit is not exceeded in other recording areas. In order to suppress the occurrence of this problem, processing called "wear leveling" is executed in storages constituted by semiconductor memories (see, for example, Patent Document 1).

[0004] Wear leveling is a process that moves data recorded in a recording area with a high number of write operations (for example, an area serving as a data erasure unit called an "erase block") to a recording area with a low number of write operations, and / or conversely, moves data recorded in a recording area with a low number of write operations to a recording area with a high number of write operations. This processing evens out the number of write operations across the entire recording area. As a result, it is possible to prevent the situation where data cannot be written to the entire storage due to the number of write operations exceeding the limit in a specific area.

PRIOR ART DOCUMENTS

PATENT DOCUMENTS

[0005] [Patent Document 1] International Publication No. 2013 / 118170 [Overview of the project] [Problems that the invention aims to solve]

[0006] In storage systems composed of semiconductor memory, the data recording area is configured as multiple recording areas that are physically, functionally, and performance-wise separated. Specifically, for each application running on the information processing device to which the storage is connected, it is determined which of the separated recording areas the video data will be recorded in. This makes it less likely for the recording and reading of video data by a particular application to be affected by the recording and reading of video data by other applications.

[0007] In conventional storage systems composed of the above-mentioned separate recording areas, the wear leveling process is performed for each individual recording area, but no wear leveling process is performed between the multiple recording areas. Therefore, in conventional storage systems, there was a possibility that the number of write cycles in a particular recording area would reach its limit, making it impossible to write video data to the entire storage system.

[0008] This disclosure aims to suppress large differences in the number of write cycles between recording areas in a storage device composed of semiconductor memory and having multiple separate recording areas. [Means for solving the problem]

[0009] The video data recording method of this disclosure is a method for recording video data to a first storage device that is capable of recording video data, is composed of semiconductor memory, and includes a plurality of separate recording areas. The plurality of recording areas include a first recording area with a low number of write cycles and a second recording area with a high number of write cycles. The recording method comprises the following steps.

[0010] A step in which frequently accessed video data is recorded in the first recording area, and less frequently accessed video data is recorded in the second recording area. [Effects of the Invention]

[0011] In the video data recording method disclosed herein, a first storage device, which is composed of semiconductor memory and has multiple separate recording areas, is configured such that video data with high access frequency is recorded in the first recording area with a low number of writes, and video data with low access frequency is recorded in the second recording area with a high number of writes. This increases the rate at which the number of writes increases in the first recording area with a low number of writes, while decreasing the rate at which the number of writes increases in the second recording area with a high number of writes. As a result, it is possible to suppress the widening of the difference in the number of writes between the multiple recording areas over time. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 shows the configuration of the video recording system. [Figure 2] Figure 2 shows the configuration of the information processing device. [Figure 3] Figure 3 shows an example of a zone write count management table. [Figure 4] Figure 4 shows the configuration of the first storage. [Figure 5] Figure 5 is a flowchart showing the operation of the information processing device in Operation Example 1. [Figure 6] Figure 6 shows the transmission and reception of signals in Operation Example 1. [Figure 7] Figure 7 is a flowchart showing the operation of the information processing device in Operation Example 2. [Figure 8] Figure 8 shows the transmission and reception of signals in Operation Example 2. [Figure 9] Figure 9 shows the configuration of the video recording system in Operation Example 3. [Figure 10] Figure 10 shows the configuration of the information processing device in Operation Example 3. [Figure 11] FIG. 11 is a diagram illustrating an example of a logical / physical conversion table. [Figure 12] FIG. 12 is a flowchart illustrating the operation of the information processing apparatus in operation example 3. [Figure 13] FIG. 13 is a diagram illustrating an example of the updated logical / physical conversion table. [Figure 14] FIG. 14 is a diagram illustrating another example of the video recording system. [Mode for Carrying Out the Invention]

[0013] Hereinafter, embodiments will be described in detail with appropriate reference to the drawings. However, unnecessarily detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and redundant descriptions of substantially identical configurations may be omitted. This is to avoid making the following description unnecessarily redundant and to facilitate understanding by those skilled in the art. The inventors provide the accompanying drawings and the following description to enable those skilled in the art to fully understand the present disclosure, and do not intend to limit the subject matter recited in the claims by these.

[0014] In the present disclosure, "video data" means data including moving image data and audio data, data including only moving image data, or data including still image data.

[0015] [1. Video Recording System] Hereinafter, the video recording system 100 of the present disclosure will be described with reference to the drawings. The video recording system 100 is a system for recording video data acquired by a video output device 2, which will be described later, in a storage. The video data recorded in the storage is used, for example, for future playback and editing. Editing of video data includes, for example, generating new video data by inserting a specific part of other video data into the video data.

[0016] The configuration of the video recording system 100 will be described below using Figure 1. Figure 1 is a diagram showing the configuration of the video recording system 100. The video recording system 100 comprises an information processing device 1 and a first storage device 3.

[0017] The information processing device 1 is connected to the video output device 2. The video output device 2 is a device that acquires video data and outputs it externally. The video output device 2 is, for example, a video recording device equipped with a camera that captures a predetermined image, a microphone that captures the audio of the predetermined image, etc. Alternatively, the video output device 2 may be a media server that records a large number of videos. The video output from the video output device 2 is, for example, high-definition video such as uncompressed 4K video. In the example shown in Figure 1, only one video output device 2 is provided, but this is not limited to this. The video recording system 100 may be equipped with multiple video output devices 2.

[0018] The information processing device 1 performs various information processing operations on the video data input from the video output device 2. Specifically, the information processing device 1 can, for example, perform the process of converting video data into a compressed format.

[0019] Furthermore, the information processing device 1 is connected to the operation device 4. The operation device 4 is a device that performs operations for editing video data. The operation device 4 includes, for example, an input device (e.g., keyboard, mouse, control panel, etc.) for performing operations related to editing video data, and a display device (e.g., display) for displaying video data. The information processing device 1 outputs video data to the operation device 4 for display, and also accepts operations from the operation device 4 to edit the video data. In addition, the information processing device 1 analyzes the video data to estimate the access frequency of the video data in the video recording system 100.

[0020] The information processing device 1 is connected to the first storage device 3. The information processing device 1 records video data input from the video output device 2, video data converted to a compressed format, and edited video data to the first storage device 3. The information processing device 1 also reads specific video data from the first storage device 3.

[0021] The first storage device 3 reads specified video data according to a command from the information processing device 1. The first storage device 3 also records the video data received from the information processing device 1 according to a command from the information processing device 1. The first storage device 3 is a solid-state drive (SSD) composed of semiconductor memory (flash memory 33) capable of recording video data.

[0022] [2. Information Processing Devices] The configuration of the information processing device 1 will be explained using Figure 2. Figure 2 is a diagram showing the configuration of the information processing device 1. The information processing device 1 includes a CPU 11, RAM 13, storage unit 15, interface 17, and storage interface 19.

[0023] The CPU 11 executes various processes in the information processing device 1. Specifically, the CPU 11 performs information processing such as video data compression, video data editing information processing, and video data analysis processing. The CPU 11 executes the above processes by executing instructions shown in the application AP stored in the memory unit 15. Note that some of the processing in the information processing device 1 may be implemented by hardware implemented in the CPU 11. The CPU 11 generates commands for executing various processes.

[0024] The CPU 11 estimates the access frequency of video data while executing a predetermined application AP (for example, an application AP for editing and recording video data) stored in the memory unit 15. Specifically, while executing the application AP, the CPU 11 analyzes the images and / or audio contained in the video data and estimates the access frequency based on the analysis results.

[0025] The frequency of access to video data is estimated to be high when the content of the video data is important, for example, when the video data contains a climax scene. This is because video data containing important content is likely to be used frequently in editing and other processes. On the other hand, the frequency of access to video data is estimated to be low when the video data contains unimportant content. The CPU 11 running the application AP can perform the analysis of the above video data, for example, by artificial intelligence-based image recognition or speech recognition.

[0026] CPU11 associates the frequency of access to video data with the video data as metadata for that video data. Metadata is data that records various information about the video data. In addition to the frequency of access to the video data, metadata can also record the importance of the video data and information about the video data's usage process. Usage process information includes, for example, information about the recording, editing, transmission, and / or reuse of the video data.

[0027] RAM13 is a memory area that temporarily stores commands, video data, etc., generated by the CPU11. The storage unit 15 is composed of, for example, ROM, a hard disk drive (HDD), a solid-state drive (SSD), etc. The storage unit 15 stores multiple applications AP executed by the CPU11, a zone write count management table T1, settings related to information processing executed by the information processing device 1, parameters used for said information processing, etc.

[0028] An application AP is a program that performs various processes on video data in the information processing device 1. Examples of application APs include programs for editing video data and programs for playing back video data.

[0029] The zone write count management table T1 is a table that stores the number of times data has been written to multiple recording areas (zones Z1 to Zn) of the first storage 3. As shown in Figure 3, the zone write count management table T1 stores the identification information of a zone (for example, the identification number of the zone) in association with the number of times data has been written to that zone. Figure 3 is a diagram showing an example of the zone write count management table T1.

[0030] Interface 17 connects the information processing device 1 to other devices. As shown in Figure 2, the video output device 2 and the operating device 4 are connected to interface 17. Interface 17 is an interface for connecting video-related equipment, such as an interface conforming to the Serial Digital Interface (SDI) standard.

[0031] Interface 17 may include a network interface, such as a Gigabit Ethernet® interface. The video output device 2, the operating device 4, and / or other devices may be connected to the network interface. In this case, communication between the information processing device 1 and the other devices can use transmission according to, for example, the ST2110 standard of the SMPTE standardization organization. The network interface may also enable direct transmission and reception of data between the RAM 13 of the information processing device 1 and the RAM of the other devices via Remote Direct Memory Access (RDMA). This enables high-speed data transmission and reception between the information processing device 1 and the other devices.

[0032] The storage interface 19 connects to the first storage device 3. The storage interface 19 is, for example, a PCIe interface compliant with the PCI-SIG PCI Express standard. This allows the information processing device 1 and the first storage device 3 to send and receive data at high speed using a protocol dedicated to non-volatile memory (NVMe (Non-Volatile Memory Express)) via the PCI-Express bus. In NVMe, the controller acquires data from the NAND memory using the NAND protocol, converts it to the PCIe protocol, and then transfers it to the host. In contrast, with conventional SATA (Serial-ATA), the DMA controller that directly transfers data to the host converts data from the NAND memory to the SATA protocol, acquires it, and then converts that data to the PCIe protocol before transferring it to the host. In other words, NVMe processing directly converts from the NAND protocol to the PCIe protocol, resulting in faster data transfer speeds.

[0033] In the information processing device 1, the control unit of the information processing device 1 is comprised of a CPU 11, RAM 13, interface 17, and storage interface 19. Furthermore, the storage unit of the information processing device 1 is comprised of a storage unit 15.

[0034] [3. Storage] The configuration of the first storage 3 will be explained using Figure 4. Figure 4 is a diagram showing the configuration of the first storage 3. The first storage 3 has an access port 31, a flash memory 33, and a controller 35. The access port 31 connects the information processing device 1 and the first storage 3.

[0035] The flash memory 33 is composed of multiple NAND flash memory chips capable of recording video data. The flash memory 33 includes multiple separated recording areas (referred to as zones Z1 to Zn). In this embodiment, the flash memory 33 includes n zones Z1 to Zn. Here, "separated" includes hardware separation of the recording areas of the flash memory 33. Specifically, each zone Z1 to Zn can be composed of, for example, one or more NAND flash memory chips, a physical address of the flash memory 33, or a predetermined number of recording elements within a single NAND flash memory chip.

[0036] Furthermore, "isolated" is not limited to hardware isolation, but also includes performance isolation resulting in the formation of multiple zones, and functional isolation resulting in the formation of multiple zones. "Performance isolation" means that each zone has independent performance and does not affect the performance of other zones. "Functional isolation" means that each zone has independent functionality and does not affect the functionality of other zones. For example, even if wear leveling or garbage collection occurs in one zone, its effects do not extend to other zones. Also, even if wear leveling or garbage collection occurs in one zone, other wear leveling or garbage collection may occur in other zones. In other words, "isolated" means that each zone is independent and an operation performed on one zone does not affect other zones.

[0037] In the video recording system 100, it is preferable that the zones accessible by application APs executed on the information processing device 1 are predetermined for each application AP. This makes it less likely that the recording and reading of video data by a particular application AP will be affected by the recording and reading of video data by other application APs. However, this is not limited to this, and each application AP may have access to all zones.

[0038] Each zone Z1-Zn contains multiple erase blocks. An erase block is a unit of data erasure. In other words, data recorded in zones Z1-Zn is erased in units of erase blocks. Each erase block contains multiple pages. A page is a unit of data recording. In other words, data is written to zones Z1-Zn in units of pages.

[0039] The controller 35 performs control over the first storage 3. Specifically, the controller 35 controls the recording of data to the flash memory 33 and the reading of data from the flash memory 33 according to commands from the information processing device 1. The controller 35 also performs other processes necessary for the solid-state drive, such as garbage collection and wear leveling. Garbage collection and wear leveling are performed in units of zones Z1 to Zn.

[0040] The controller 35 executes the program stored in the memory unit 37 to perform the above process. Alternatively, the controller 35 may implement the above process using its own hardware.

[0041] The storage unit 37 is provided as a memory separate from the flash memory 33, or it is part of the recording area of ​​the flash memory 33 and stores various parameters related to the control of the first storage 3. The storage unit 37 records the number of times data has been written to each zone Z1 to Zn. The number of writes to each zone Z1 to Zn may be set, for example, as the maximum number of times data has been written to the erase block included in that zone, or as the average number of writes to the erase block.

[0042] The memory unit 37 further records the number of times data has been written to each erase block contained in each zone, a table that associates an address specified by an external device (logical address) with the address of the erase block corresponding to that logical address (physical address), a threshold representing the conditions for performing wear leveling, and so on.

[0043] [4. Operation of the video recording system] [4-1. Example of Operation 1] The following describes the video data recording operation in the video recording system 100. First, we will describe example 1 of the video data recording operation. In example 1, the system determines which zone of the first storage 3 to record the video data in based on the access frequency of the video data to be recorded in the first storage 3.

[0044] The specific operation in video data recording example 1 will be explained below using Figures 5 and 6. Figure 5 is a flowchart showing the operation of the information processing device 1 in video data recording example 1. Figure 6 is a diagram showing the transmission and reception of signals in video data recording example 1.

[0045] When the video recording system 100 is started, the information processing device 1 obtains the current number of data writes for each zone in the first storage 3 (step S11 in Figure 5). Specifically, the number of writes is obtained as follows.

[0046] First, the CPU 11 of the information processing device 1 sends a command (write count transmission request) to the first storage 3 requesting it to transmit the number of data writes for each zone present in the first storage 3 (step S101 in Figure 6).

[0047] When the first storage 3 receives a request to transmit the write count, the controller 35 of the first storage 3 transmits the write count of each zone stored in the storage unit 37 of the first storage 3 to the information processing device 1 (step S102 in Figure 6). When transmitting the write count, the controller 35 transmits the zone identification information and the write count of the zone having said identification information in association.

[0048] When the information processing device 1 receives the write count for each zone, the CPU 11 of the information processing device 1 associates the received zone identification information with the write count for the zone having said identification information to generate a zone write count management table T1 as shown in Figure 3 (step S12 in Figure 5). The CPU 11 stores the generated zone write count management table T1 in the storage unit 15 of the information processing device 1. If the zone write count management table T1 is already stored in the storage unit 15, the CPU 11 updates the zone write count management table T1 stored in the storage unit 15 based on the received zone identification information and the write count for the zone having said identification information.

[0049] Subsequently, in the information processing device 1, the application AP stored in the memory unit 15 is executed by the CPU 11, and various information processing related to the video data is performed. For example, editing of video data acquired from the video output device 2, compression of video data, and playback of video data are performed by the application AP.

[0050] If the running application AP is instructed to record video data ("Yes" in step S13 of Figure 5), the CPU 11 executes the video data recording process. If the application AP is not instructed to record video data ("No" in step S13 of Figure 5), the CPU 11 waits while performing other information processing as needed.

[0051] The video data recording process is performed according to the following steps. First, the CPU 11 analyzes the content of the video data to be recorded while the application AP is running and estimates the access frequency of the video data (step S14 in Figure 5).

[0052] If the estimated access frequency is high (high in step S14 of Figure 5), the CPU 11 decides to record the video data estimated to have a high access frequency in a zone with a low number of writes (first recording area) (step S15 of Figure 5). Subsequently, the CPU 11 refers to the zone write count management table T1 stored in the storage unit 15 and decides whether to record the video data in that zone. For example, it decides to record the video data with a high access frequency in the zone with the minimum number of writes. In the case of the zone write count management table T1 shown in Figure 3, it decides to record the video data in zone Z2 which has identification information "2".

[0053] Once the CPU 11 determines the zone in which to record the video data, it sends the video data to be recorded and information about the zone in which the video data will be recorded (e.g., zone identification information, zone address, etc.) to the first storage 3 (step S103 in Figure 6).

[0054] When the first storage 3 receives frequently accessed video data and information about the zone in which the video data is recorded (zone identification information "2"), the controller 35 of the first storage 3 records the received frequently accessed video data in the zone with the fewest writes (minimum) (zone Z2) (step S104 in Figure 6).

[0055] On the other hand, if the estimated access frequency is low (low in step S14 of Figure 5), the CPU 11 of the information processing device 1 decides to record the video data, which is estimated to have a low access frequency, in a zone with a high number of writes (second recording area) (step S16 of Figure 5). Subsequently, the CPU 11 refers to the zone write count management table T1 stored in the storage unit 15 and decides which zone to record the video data in. For example, it decides to record the video data with a low access frequency in the zone with the highest number of writes. In the case of the zone write count management table T1 shown in Figure 3, it decides to record the video data in zone Z3, which has identification information "3".

[0056] Once the CPU 11 determines the zone in which to record the video data, it transmits the video data to be recorded and information about the zone in which the video data will be recorded to the first storage 3 (step S105 in Figure 6).

[0057] When the first storage 3 receives video data that is accessed infrequently and information about the zone in which the video data is recorded (zone identification information "3"), the controller 35 of the first storage 3 records the received video data that is accessed infrequently infrequently in the zone with the most frequent writes (zone Z3) (step S106 in Figure 6).

[0058] After recording the video data, the CPU 11 of the information processing device 1 notifies the application AP that commanded the recording of the video data of information about the zone where the video data will be recorded (zone identification information, zone address) (step S17 in Figure 5). This makes it easy for the information processing device 1 to determine the recording location of the video data to be read when reading the video data from the first storage 3.

[0059] As described above, by recording frequently accessed video data in zones with fewer write cycles and less frequently accessed video data in zones with more write cycles, the rate of increase in the number of writes in the first recording area with fewer write cycles can be increased, while the rate of increase in the number of writes in the second recording area with more write cycles can be decreased. In other words, the rate of increase in the number of writes in the zone with more write cycles can be made slower than the rate of increase in the number of writes in the zone with fewer write cycles. As a result, the difference in the number of writes between these zones decreases over time, thus preventing the difference in the number of writes between multiple zones from widening and becoming large over time.

[0060] [4-2. Example of Operation 2] Next, we will explain Example 2 of the video data recording operation. In Example 2, the video data is first recorded redundantly in both the zone with a high number of writes and the zone with a low number of writes. Then, based on whether or not the video data has been accessed within a predetermined time (1st hour) since the video data was recorded, it is decided which zone's recorded video data will be erased (i.e., which zone's stored video data will be retained).

[0061] The specific operation in video data recording example 2 will be explained below using Figures 7 and 8. Figure 7 is a flowchart showing the operation of the information processing device 1 in video data recording example 2. Figure 8 is a diagram showing the transmission and reception of signals in video data recording example 2.

[0062] When the video recording system 100 is started, the information processing device 1 obtains the current number of data writes for each zone in the first storage 3 and generates a zone write count management table T1 based on this (steps S21-S22 in Figure 7, steps S201-S202 in Figure 8). The operations of steps S21-S22 and S201-S202 are the same as steps S11-S12 and S101-S102 described above, respectively, so the explanation is omitted here.

[0063] When a command is issued for recording video data in a running application AP ("Yes" in step S23 of Figure 7), the CPU 11 records the video data in both the zone with a high number of writes and the zone with a low number of writes (step S24 of Figure 7). In detail, first, the CPU 11 refers to the zone write count management table T1 stored in the storage unit 15 to identify the zone with a high number of writes and the zone with a low number of writes. For example, among the zones Z1 to Zn included in the first storage 3, it identifies the zone with the maximum number of writes and the zone with the minimum number of writes. In the case of the zone write count management table T1 shown in Figure 3, zone Z3 with identification information "3" can be identified as the zone with the maximum number of writes, and zone Z2 with identification information "2" can be identified as the zone with the minimum number of writes.

[0064] Once the CPU 11 identifies a zone to record video data, it transmits the video data to be recorded and information about the zone in which the video data will be recorded to the first storage 3 (step S203 in Figure 8).

[0065] When the first storage 3 receives video data and information about the zones in which the video data is recorded (zone identification information "2" and identification information "3"), the controller 35 of the first storage 3 records the received video data redundantly in the zone with the most writes (maximum) (zone Z3) and the zone with the fewest writes (minimum) (zone Z2) (steps S204 to S205 in Figure 8).

[0066] After recording the video data, the CPU 11 of the information processing device 1 notifies the application AP that commanded the recording of the video data of information regarding the zone where the video data will be recorded.

[0067] One hour after the above video data is recorded, the CPU 11 determines whether or not the video data was accessed before the first hour had elapsed (step S25). The CPU 11 can determine whether or not the video data was accessed before the first hour had elapsed by, for example, access logs, timestamps, etc. for the target video data. In detail, for example, if the difference between the current time and the last access time to the video data is more than one hour, it can be determined that the video data was not accessed. On the other hand, if the difference between the current time and the last access time to the video data is one hour or less, it can be determined that the video data was accessed.

[0068] Access to video data within one hour of recording indicates a high frequency of access to that video data. Conversely, no access to video data within one hour of recording indicates a low frequency of access to that video data. Therefore, the first hour can be set appropriately based on criteria such as those used to determine the frequency of access.

[0069] If the video data is accessed before the first hour has elapsed, i.e., if the video data is accessed frequently (Yes in step S25), the CPU 11 decides to erase the video data recorded in the zone with the most writes (for example, zone Z3, which has the most writes) (step S26 in Figure 7). In other words, it decides to retain the video data recorded in the zone with the fewest writes (for example, zone Z2, which has the fewest writes).

[0070] Subsequently, the CPU 11 sends a command (erasure request) to the first storage 3 requesting that the video data recorded in the zone with a high number of write cycles be erased (step S206 in Figure 8).

[0071] Upon receiving the above erase request, the controller 35 of the first storage 3 executes a process to erase the video data recorded in the zone with a high number of writes (step S207 in Figure 8). The controller 35 can erase the video data that was recorded in the zone with a high number of writes by, for example, recording information (e.g., "0") indicating that no data is recorded for the pages included in the zone with a high number of writes.

[0072] The CPU 11 of the information processing device 1 notifies the application AP that commanded the recording of video data of information regarding zones where video data has been erased, or information regarding zones where video data has been retained.

[0073] On the other hand, if there is no access to the video data within the first hour, that is, if the video data is accessed infrequently (No in step S25), the CPU 11 decides to erase the video data recorded in the zone with the fewest writes (for example, zone Z2, which has the fewest writes) (step S27 in Figure 7). In other words, it decides to retain the video data recorded in the zone with the most writes (for example, zone Z3, which has the most writes).

[0074] Subsequently, the CPU 11 of the information processing device 1 sends an erase request to the first storage device 3 requesting that the video data recorded in the zone with a low number of writes be erased. Upon receiving this erase request, the controller 35 of the first storage device 3 executes a process to erase the video data recorded in the zone with a low number of writes.

[0075] The CPU 11 of the information processing device 1 notifies the application AP that commanded the recording of video data of information regarding zones where video data has been erased, or information regarding zones where video data has been retained.

[0076] In the above recording example, video data is recorded in both a zone with a high number of writes and a zone with a low number of writes, and then, after 1 hour has elapsed, the access frequency of the video data is determined. This allows the actual access frequency of the video data to be determined. In the above recording example, video data with a high actual access frequency is recorded (maintained) in the zone with a low number of writes, and video data with a low actual access frequency is recorded (maintained) in the zone with a high number of writes. In this way, by recording video data in zones determined based on the actual access frequency of the video data, it is possible to more reliably suppress the widening of the difference in write counts between multiple zones over time.

[0077] [4-3. Example of Operation 3] Next, we will explain the third example of video data recording operation. In this example, after recording video data to the first storage 3, a decision is made on whether to keep the video data in the first storage 3 or move it from the first storage 3 to another storage with lower performance (second storage 5), depending on whether or not the video data has been accessed within a predetermined time (second time).

[0078] In Operation Example 3, the video recording system further includes a second storage device 5, as shown in Figure 9. Figure 9 is a diagram showing the configuration of the video recording system 200 in Operation Example 3. As shown in Figure 10, the second storage device 5 is connected to the interface 17 of the information processing device 1. The second storage device 5 can be connected to, for example, an S-ATA interface. Figure 10 is a diagram showing the configuration of the information processing device 1 in Operation Example 3.

[0079] The second storage device 5 is a storage device with lower performance than the first storage device 3. The second storage device 5 is a storage device with slower recording and reading speeds than the first storage device 3, which is composed of flash memory 33. The second storage device 5 is, for example, a hard disk drive (HDD), an optical disc drive that writes data to and reads data from an optical disc, or a magnetic tape drive that writes data to and reads data from a magnetic tape.

[0080] Furthermore, in Operation Example 3, the information processing device 1 stores the logical / physical conversion table T2 in the storage unit 15. The logical / physical conversion table T2 is a table that stores information relating a logical zone to the corresponding physical zone (zones Z1 to Zn of the first storage 3 or the second storage 5). Specifically, as shown in Figure 11, the logical / physical conversion table T2 is a table that stores information relating a logical zone to the corresponding physical zone (for example, identification information for zones Z1 to Zn of the first storage 3, or identification information for the second storage 5), and the last access time to the corresponding physical zone. Figure 11 is a diagram showing an example of the logical / physical conversion table T2.

[0081] When accessing zones Z1-Zn of the first storage 3 or the second storage 5, the application AP uses logical zones. In other words, the "zone" in the zone write count management table T1, as explained using Figure 3, is a logical zone. Subsequently, the CPU 11 refers to the logical / physical conversion table T2 and converts the logical zone into the identification information of the actual zones Z1-Zn or the identification information of the second storage 5. Using the converted identification information, the CPU 11 can access the corresponding zones Z1-Zn of the first storage 3 or the second storage 5.

[0082] The specific operation in video data recording example 3 will be explained below using Figure 12. Figure 12 is a flowchart showing the operation of the information processing device 1 in video data recording example 3.

[0083] When the video recording system 200 is started and the application AP running on the information processing device 1 is instructed to record video data, the CPU 11 records the video data to the first storage 3 (step S31). In step S31, the recording of video data is performed according to the operation example 1 and / or operation example 2 described above. Therefore, the explanation of the video data recording operation in step S31 is omitted here.

[0084] However, as explained above, the application AP accesses zones Z1 to Zn of the first storage 3 using logical zones. Therefore, in operation example 3, when the CPU 11 running the application AP identifies the zone to record video data and records the video data in the identified zones Z1 to Zn, the CPU 11 identifies the zone to record the video data as a logical zone, and then refers to the logical / physical conversion table T2 to identify the physical zone (identification information for zones Z1 to Zn of the first storage 3) corresponding to the identified logical zone. Based on the identified physical zone, the CPU 11 decides which zone Z1 to Zn of the first storage 3 to record the video data in.

[0085] Two hours after recording the video data to the first storage 3, the CPU 11 determines whether or not the video data has been accessed within the two hours since it was recorded (step S32). The CPU 11 can determine whether or not the video data has been accessed within the two hours by, for example, the last access time stored in the logical / physical conversion table T2, the access log for the target video data, the timestamp, etc. Specifically, for example, if the difference between the current time and the last access time to the video data exceeds two hours, it can be determined that the video data has not been accessed. On the other hand, if the difference between the current time and the last access time to the video data is two hours or less, it can be determined that the video data has been accessed.

[0086] Access to video data within two hours of recording indicates that the video data has been used to some extent. Conversely, no access to video data within two hours of recording indicates that the video data has been used very little. Therefore, the second hour can be set appropriately based on criteria such as determining when to save (archive) video data for an extended period. Furthermore, the second hour may be longer than or about the same as the first hour in the above example.

[0087] If the video data is accessed before the second hour has elapsed, that is, if the video data may have been used to some extent (Yes in step S32), the CPU 11 decides to keep the video data recorded in the first storage 3 stored in the first storage 3 as is (step S33).

[0088] On the other hand, if there is no access to the video data within the second hour, that is, if the video data may have been hardly used (No in step S32), the CPU 11 decides to move the video data recorded in the first storage 3 to the second storage 5 (step S34).

[0089] Subsequently, the CPU 11 reads the video data to be moved from zones Z1 to Zn in the first storage 3, which contain the video data to be moved, and copies the video data to the second storage 5. After that, the video data to be moved recorded in zones Z1 to Zn of the first storage 3 is erased. As a result, the video data to be moved is moved from the first storage 3 to the second storage 5.

[0090] After moving the video data, the CPU 11 updates the logical / physical conversion table T2 (step S35). Specifically, the CPU 11 rewrites the contents of the physical zone in the logical / physical conversion table T2 from the identification information of the zone in the source first storage 3 to the identification information of the destination second storage 5. For example, if the zone with identification information "2" (zone Z2) was the source of the video data, the CPU 11 rewrites the physical zone identification information "2" in the logical / physical conversion table T2 to the identification information "storage1" of the second storage 5, as shown in Figure 13. Figure 13 shows an example of the updated logical / physical conversion table T2.

[0091] By using logical zones to enable access to zones Z1-Zn of the first storage 3 or the second storage 5, and by changing the contents of the physical zone in the logical / physical conversion table T2 when video data is moved, even if video data is moved from the first storage 3 to the second storage 5, the second storage 5 can be accessed using the same logical zone that was used to access the first storage 3 before the video data was moved.

[0092] In the above recording operation example, if video data recorded in the first storage 3 is not used for a long period (2 hours), the video data is moved from the first storage 3 to the second storage 5. After the video data is moved, the zones Z1 to Zn are recorded with video data based on the above operation example 1 and / or operation example 2. This prevents the increase in the number of writes from disappearing in zones Z1 to Zn where video data that has not been used for a long period was recorded, thus preventing the difference in the number of writes between multiple zones from widening and becoming large over time.

[0093] [5. Other Embodiments] Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the invention. In particular, the multiple embodiments and modifications described herein can be arbitrarily combined as needed.

[0094] (A) The order and content of each process in the flowchart described above can be changed as appropriate without departing from the spirit of the present invention. Furthermore, the entities that execute each process (information processing device 1, first storage 3) can also be changed as appropriate without departing from the spirit of the present invention.

[0095] (B) The above examples of operation 1 to 3 may all be incorporated into the information processing device 1, or only some of them may be incorporated. Furthermore, the video recording system may be configured by user operation to execute one of the above examples of operation 1 to 3 and not the others.

[0096] (C) As shown in Figure 14, the video recording system may further include a storage control device 7 in addition to the video recording system 100 described above. Figure 14 is a diagram showing the configuration of the video recording system 300. The storage control device 7 is connected to the information processing device 1 and the first storage 3, and controls the recording of video data to the first storage 3 according to the commands of the information processing device 1. In the video recording system 300 shown in Figure 14, the information processing device 1 may perform information processing related to video data and estimate the access frequency, and the storage control device 7 may record video data based on the above operation examples 1 to 3.

[0097] The storage control device 7 can, for example, determine the access frequency of the video data by extracting metadata attached to the video data by the information processing device 1.

[0098] [6. Features of this disclosure] (1) The video data recording method of this disclosure is a method for recording video data to a first storage device which is capable of recording video data, is composed of semiconductor memory, and includes a plurality of separate recording areas. The plurality of recording areas include a first recording area with a low number of write cycles and a second recording area with a high number of write cycles. The recording method comprises the following steps.

[0099] A step in which frequently accessed video data is recorded in the first recording area, and less frequently accessed video data is recorded in the second recording area.

[0100] In the recording method disclosed herein, in a first storage device composed of semiconductor memory and having multiple separate recording areas, it is decided that frequently accessed video data is recorded in the first recording area with a low number of writes, and less frequently accessed video data is recorded in the second recording area with a high number of writes. This increases the rate at which the number of writes increases in the first recording area with a low number of writes, while decreasing the rate at which the number of writes increases in the second recording area with a high number of writes. As a result, it is possible to suppress the widening of the difference in the number of writes between the multiple recording areas over time.

[0101] (2) In the recording method described in (1) above, the recording step may include the following steps:

[0102] A step of recording video data in the first recording area and the second recording area.

[0103] If video data recorded in both the first and second recording areas is accessed within one hour of recording, the video data recorded in the second recording area is deleted.

[0104] If video data recorded in both the first and second recording areas is not accessed within one hour of recording, the video data recorded in the first recording area is deleted.

[0105] This allows video data to be recorded in a recording area determined based on the actual access frequency of the video data, thus more effectively suppressing the widening of the difference in the number of writes between multiple recording areas over time.

[0106] (3) In the recording method described in (1) or (2) above, the recording step may include the step of moving video data recorded in the first storage that has not been accessed up to two hours after it was recorded to a second storage which has lower performance than the first storage.

[0107] This prevents the increase in write cycles from disappearing in recording areas where video data that has not been used for a long period of time has been recorded, thus preventing the difference in write cycles between multiple recording areas from widening and becoming large over time.

[0108] (4) The recording method described in (3) above may further include a step of storing a logical / physical conversion table. The logical / physical conversion table is a table that associates logical zones for accessing the first or second storage with the corresponding zones in the first or second storage. This allows, for example, even if video data is moved from the first storage to the second storage, the second storage can be accessed using the same logical zone that was used to access the first storage before the video data was moved.

[0109] (5) The information processing device of the present disclosure comprises an interface and a control unit. The interface communicates with a first storage device which is composed of a semiconductor memory capable of recording video data. The control unit controls the recording of video data. The first storage device includes a plurality of separate recording areas, the plurality of recording areas including a first recording area with a low number of writes and a second recording area with a high number of writes. In this case, the control unit records video data with a high access frequency in the first recording area and video data with a low access frequency in the second recording area.

[0110] In the above-described information processing device, the first storage device, which is composed of semiconductor memory and has multiple separate recording areas, is configured to record frequently accessed video data in the first recording area with fewer writes, and less frequently accessed video data in the second recording area with more writes. This increases the rate at which the number of writes increases in the first recording area with fewer writes, while decreasing the rate at which the number of writes increases in the second recording area with more writes. As a result, it is possible to suppress the widening of the difference in the number of writes between the multiple recording areas over time.

[0111] (6) The video recording system of the present disclosure comprises an information processing device and a first storage device. The information processing device performs processing on video data. The first storage device is composed of a semiconductor memory capable of recording video data. The first storage device includes a plurality of separate recording areas, the plurality of recording areas including a first recording area with a low number of writes and a second recording area with a high number of writes. The information processing device records video data with a high access frequency in the first recording area and video data with a low access frequency in the second recording area.

[0112] In the video recording system described above, the first storage device, which is composed of semiconductor memory and has multiple separate recording areas, is configured to record frequently accessed video data in the first recording area with fewer writes, and less frequently accessed video data in the second recording area with more writes. This increases the rate at which the number of writes increases in the first recording area with fewer writes, while decreasing the rate at which the number of writes increases in the second recording area with more writes. As a result, it is possible to suppress the widening of the difference in the number of writes between the multiple recording areas over time. [Industrial applicability]

[0113] This disclosure is broadly applicable to video recording systems, information processing devices, and recording methods for recording video data in storage composed of semiconductor memory. [Explanation of Symbols]

[0114] 100, 200, 300: Video recording system 1: Information Processing Device 11: CPU 13: RAM 15: Storage section 17: Interface 19: Storage Interface 2: Video output device 3: First Storage 31: Access Port 33: Flash memory 35: Controller 37: Storage section 4: Operating device 5: Second Storage 7: Storage control unit AP: Application T1: Zone write count management table T2: Logical / Physical Conversion Table Z1~Zn: Zone

Claims

[Claim 1] A method for recording video data to a first storage device that is capable of recording video data, is composed of semiconductor memory, and includes a plurality of separate recording areas, wherein the plurality of recording areas include a first recording area with a low number of write cycles and a second recording area with a high number of write cycles. The system includes the step of recording frequently accessed video data in the first recording area and infrequently accessed video data in the second recording area. The aforementioned recording step is, A step of recording video data overlapping in the first recording area and the second recording area, If the video data recorded overlapping in the first recording area and the second recording area is accessed within one hour after recording, the video data recorded in the second recording area is deleted. If there is no access to the video data recorded overlapping in the first recording area and the second recording area within one hour after recording, the video data recorded in the first recording area is deleted. A recording method that includes this.

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