Patent Publication Number: US-10334145-B2

Title: Camera supporting removable storage divided into a journaled partition and a non-journaled partition

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. patent application Ser. No. 14/093,367, entitled “Camera Supporting Removable Storage Divided into Multiple Partitions” and filed Nov. 29, 2013, the entirety of which is hereby incorporated by reference herein. 
    
    
     TECHNICAL FIELD 
     The present disclosure is directed generally at a camera that supports removable storage divided into multiple partitions. 
     BACKGROUND 
     Cameras that are able to write files to removable storage are becoming increasingly prevalent. An example type of camera is a security camera, and example types of files that can be written to removable storage are audio files, video files (including those video files that comprise an audio track), and still images. Security cameras that offer removable storage are gaining in popularity because they offer the convenience of permitting video files to be stored even when the cameras are disconnected from a network or when the network fails. Research and development accordingly continue into methods, systems, and techniques related to improving the ability of cameras to use removable storage. 
     SUMMARY 
     According to a first aspect, there is provided a camera comprising a camera body comprising an aperture to permit light to enter the camera body; an image sensor located within the camera body and positioned to receive at least some of the light entering the camera body; removable media circuitry configured to write to removable storage that is formatted to comprise: (i) a journaled partition that uses a journaling file system; and (ii) a non-journaled partition that uses a non-journaling file system supported natively by an operating system, wherein the non-journaled partition has stored thereon computer program code executable by a processor to use the operating system to access files stored on the journaled partition; and processing circuitry, communicatively coupled to the image sensor and the removable media circuitry, configured to store files to the journaled partition using the journaling file system. 
     The usable capacity of the removable storage may be allocated entirely to the journaled and non-journaled partitions. The processing circuitry optionally does not write or erase data from the non-journaled partition. The journaled partition may have a larger capacity than the non-journaled partition. The camera may be a security camera. 
     According to another aspect, there is provided a camera, comprising a camera body comprising an aperture to permit light to enter the camera body; an image sensor located within the camera body and positioned to receive at least some of the light entering the camera body; removable media circuitry, wherein the removable media circuitry is configured to write to removable storage; and processing circuitry, communicatively coupled to the image sensor and the removable media circuitry, configured to perform a method comprising: (i) partitioning the removable storage to comprise a journaled partition that uses a journaling file system and a non-journaled partition that uses a non-journaling file system supported natively by an operating system; and (ii) storing on the non-journaled partition computer program code executable by a processor to use the operating system to access files stored on the journaled partition. 
     The usable capacity of the removable storage may be allocated entirely to the journaled and non-journaled partitions. The processing circuitry optionally does not write data to or erase data from the non-journaled partition following storing the computer program code on it. The processing circuitry may be further configured, following partitioning the removable storage, to store one or more of video files derived from the light incident on the image sensor, audio files, and still images. The journaled partition may have a larger capacity than the non-journaled partition. 
     The method that the processing circuitry performs may further comprise, prior to partitioning the removable storage, any one or more of the following:
         (a) determining whether the removable storage comprises only a first initial partition that uses the non-journaling file system and whether the first initial partition is empty; and when the removable storage comprises only the first initial partition and the first initial partition is empty, erasing the first initial partition;   (b) determining whether the removable storage comprises only a first initial partition that uses the non-journaling file system and a second initial partition that uses the journaling file system; and when the removable storage does not comprise only the first and second initial partitions, prompting a user to confirm the partitioning is to proceed and commencing the partitioning after receiving user confirmation;   (c) when the removable storage comprises only the first and second initial partitions, determining the size of the first initial partition; and when the size of the first initial partition does not equal a fixed non-journaled partition size, prompting the user to confirm the partitioning is to proceed and commencing the partitioning after receiving user confirmation;   (d) when the size of the first initial partition equals the non-journaled partition size, determining whether the computer program code is present on the first initial partition; and when the computer program code is absent from the first initial partition, prompting the user to confirm the partitioning is to proceed and commencing the partitioning after receiving user confirmation; and   (e) when the computer program code is present on the first initial partition, determining whether all usable capacity of the removable storage is allocated entirely to the first and second initial partitions; and when the capacity of the removable storage is not allocated entirely to the first and second initial partitions, prompting the user to confirm the partitioning is to proceed and commencing the partitioning after receiving user confirmation.       

     The camera may be a security camera. 
     According to another aspect, there is provided a method for partitioning removable storage for a camera, the method comprising determining whether the removable storage is connected to the camera; when the removable storage is connected to the camera, using the camera to: (i) partition the removable storage to comprise a journaled partition that uses a journaling file system and a non-journaled partition that uses a non-journaling file system supported natively by an operating system; and (ii) store on the non-journaled partition computer program code executable by a processor to use the operating system to access files stored on the journaled partition. 
     The usable capacity of the removable storage may be allocated entirely to the journaled and non-journaled partitions. Following partitioning the removable storage, the camera may store one or more of video files derived from the light incident on the image sensor, audio files, and still images. The journaled partition may have a larger capacity than the non-journaled partition. 
     The method may further comprise, prior to partitioning the removable storage, any one or more of the following:
         (a) using the camera to determine whether the removable storage comprises only a first initial partition that uses the non-journaling file system and whether the first initial partition is empty; and when the removable storage comprises only the first initial partition and the first initial partition is empty, erase the initial partition;   (b) using the camera to determine whether the removable storage comprises only a first initial partition that uses the non-journaling file system and a second initial partition that uses the journaling file system; and when the removable storage does not comprise only the first and second initial partitions, prompting a user to confirm the partitioning is to proceed and commencing the partitioning after receiving user confirmation;   (c) using the camera to, when the removable storage comprises only the first and second initial partitions, determine the size of the first initial partition; and when the size of the first initial partition does not equal a fixed non-journaled partition size, prompt the user to confirm the partitioning is to proceed and commencing the partitioning after receiving user confirmation;   (d) using the camera to, when the size of the first initial partition equals the non-journaled partition size, determine whether the computer program code is present on the first initial partition; and when the computer program code is absent from the first initial partition, prompt the user to confirm the partitioning is to proceed and commencing the partitioning after receiving user confirmation; and   (e) when the computer program code is present on the first initial partition, determining whether all usable capacity of the removable storage is allocated entirely to the first and second initial partitions; and when the capacity of the removable storage is not allocated entirely to the first and second initial partitions, prompting the user to confirm the partitioning is to proceed and commencing the partitioning after receiving user confirmation.       

     According to another aspect, there is provided a non-transitory computer readable medium having encoded thereon statements and instructions to cause a camera to partition removable storage for the camera by performing a method comprising determining whether the removable storage is connected to the camera; and when the removable storage is connected to the camera, using the camera to perform any aspects of the methods recited above and any suitable variations and combinations thereof. 
     This summary does not necessarily describe the entire scope of all aspects. Other aspects, features and advantages will be apparent to those of ordinary skill in the art upon review of the following description of specific embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the accompanying drawings, which illustrate one or more example embodiments: 
         FIGS. 1A and 1B  are front and rear perspective views, respectively, of a security camera that supports removable storage divided into multiple partitions, according to one embodiment. 
         FIG. 2  is a block diagram of the security camera of  FIG. 1 . 
         FIG. 3  is a memory map of the removable storage used in the security camera of  FIG. 1 . 
         FIGS. 4A and 4B  collectively depict a method for formatting the removable storage used in the security camera of  FIG. 1 , according to another embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Directional terms such as “top”, “bottom”, “upwards”, “downwards”, “vertically”, and “laterally” are used in the following description for the purpose of providing relative reference only, and are not intended to suggest any limitations on how any article is to be positioned during use, or to be mounted in an assembly or relative to an environment. Additionally, the term “couple” and variants of it such as “coupled”, “couples”, and “coupling” as used in this description is intended to include indirect and direct connections unless otherwise indicated. For example, if a first device is coupled to a second device, that coupling may be through a direct connection or through an indirect connection via other devices and connections. Similarly, if the first device is communicatively coupled to the second device, communication may be through a direct connection or through an indirect connection via other devices and connections. 
     Removable storage for a camera can comprise various types of removable, non-transitory computer readable media. For example, removable storage may take the form of memory cards, external hard drives, or solid state drives (SSDs) designed to interface with ports accessible from outside the camera&#39;s housing and that can be connected to and disconnected from the camera as the user desires. Removable storage may be directly connected to the camera, such as when a memory card is inserted into a memory card reader that comprises part of the camera or when an external SSD drive is connected to the camera&#39;s USB port, or alternatively may be indirectly connected to the camera via a wide or local area network, such as an Ethernet based network, the Internet, or another Internet protocol (IP) network. 
     Regardless of what type of removable storage is used, the camera writes data to, and optionally reads data from, the storage in accordance with a file system. Many different types of file systems are known in the art. For example, a common file system used with one type of removable storage, a memory card (an example of which is labeled  128  in  FIG. 2 ), is “FAT32”. One common type of memory card is a Secure Digital (SD) memory card (SD card). One reason FAT32 is commonly used is that both the Windows™ and OS X™ operating systems natively support it. This permits the user to access video files stored on a FAT32 formatted memory card by simply taking the memory card from the camera and inserting it into a card reader connected to a desktop computer running the Windows™ or OS X™ operating systems. However, FAT32 is not particularly resilient to power loss or to removable storage being disconnected from the camera without advance notice (“sudden disconnection”). A power loss or sudden disconnection can result in the files stored using FAT32 becoming corrupt. 
     Other file systems, known as journaling filing systems, are inherently more resilient to power loss and sudden disconnection than FAT32, which is an example of a non-journaling file system. In a journaling file system, a file called a “journal” is maintained that keeps track of changes made to files stored using the file system. In the event of a power loss or sudden disconnection, the journal is accessed and is used to restore or confirm the integrity of the remainder of the file system. An example of a journaling file system is “ext4”. However, most journaling file systems, including ext4, are not natively supported by the Windows™ and OS X™ operating systems. 
     Accordingly, if ext4 or any one of several other journaling file systems is to be used for removable storage, there is a technical challenge to be overcome in order to maintain compatibility with computers running the Windows™ and OS X™ operating systems. One way to address this challenge is to require users to install third party software on their computers that provide non-native support for the journaling file system being used. However, requiring users to do this is not user friendly or convenient. Another solution is to require users to access the removable storage via an IP network through either a web interface that comprises part of the camera&#39;s firmware or through proprietary software installed on one or both of the camera and the users&#39; computers. However, using this solution requires the camera to be an IP camera that is connected to an IP network. The files stored using the removable storage are inaccessible if the network is down or if the camera becomes disconnected from the network. Additionally, accessing files via a web interface can be up to an order of magnitude slower than accessing files by directly connecting the removable storage to a computer. 
     The embodiments described herein are directed at a camera that supports removable storage that has at least two partitions. In one embodiment, the removable storage has journaled and non-journaled partitions, with the journaled partition using a journaling file system and the non-journaled partition using a non-journaling file system supported natively by an operating system such as the Windows™ and OS X™ operating systems. The journaled partition is typically much larger than the non-journaled partition and is used as the main storage area on the removable storage. Computer program code is stored on the non-journaled partition, and this program code is executable by a processor, such as a processor used in a desktop computer, to use the operating system to access files stored on the journaled partition. Various embodiments herein also describe methods and techniques describing how and when to format the removable storage to support the journaling and non-journaling file systems. By including on the non-journaled partition the computer program code that permits the operating system to access files on the journaled partition, users obtain the benefits of the journaling file system without having to separately install third party software on their computers and without having to access the camera only through an IP network. The security camera is accordingly able to use removable storage in a manner that is resilient against power loss and the removable storage&#39;s sudden disconnection. While the depicted embodiments are of a security camera, in alternative embodiments (not depicted) the camera may be another type of camera, such as a traffic camera or hand-held camera. The data the camera stores on the removable storage may be any type of data such as audio files, video files (including those video files that comprise an audio track), and still images. 
     Referring now to  FIGS. 1A and 1B , there are shown front and rear perspective views, respectively, of a security camera  100  that supports removable storage divided into multiple partitions, according to one embodiment. The camera  100  is contained within a camera body  102 . On the top and bottom of the body  102  are camera mounts  104 , of which only the top one is visible in  FIGS. 1A and 1B . At the front of the body is an aperture  106  through which light may enter the camera body  102 , be incident on an image sensor (not shown in  FIG. 1A or 1B , but labeled  126  in  FIG. 2 ), and consequently be processed to generate video images. 
     On the rear of the camera body  102  is a control plate  122  with various inputs and outputs relevant to camera operation. On the leftmost of the control plate  122  is a power control block  108  for receiving a power plug; alternatively, in some embodiments Power over Ethernet (PoE) technology may be used to power the camera  100  in which case the power control block  108  may remain unused during camera operation. Adjacent to the power control block  108  is a network jack in the form of an RJ45 (Ethernet) jack  114 . The RJ45 jack  114  receives an RJ45 plug (not shown) that connects the camera to an IP network. At the opposing corners of the top side of the RJ45 jack  114  are a connection status LED  110  and a link LED  112  that respectively provide information on the camera&#39;s  100  status and on whether the camera  100  is connected to an active Ethernet connection. Below the RJ45 jack  114  is removable media circuitry in the form of a memory card reader and any associated host controller and similar circuitry (hereinafter, collectively “memory card reader  116 ) that accepts removable storage in the form of a memory card (not shown in  FIG. 1 , but labeled as  128  in  FIG. 2 ). Between the RJ45 jack  114  and the right edge of the control plate  122  are an audio/video connector  118  that accepts a 3.5 mm plug for connecting to a microphone or monitor, and general purpose input/output ports  120  for connecting the camera  100  to various external devices. 
     While the camera  100  of  FIG. 1  uses removable storage in the form of the memory card  128 , in alternative embodiments (not depicted) the removable storage may be any suitable type of non-transitory and removable computer readable medium. For example, the removable storage may comprise any one or more of magnetic tapes, floppy disks, zip disks, optical discs, portable external hard drives and SSDs, and flash media such as USB flash drives. Removable storage may be directly connected to the camera  100 , such as by inserting the memory card  128  into the memory card reader  116 , it may be indirectly connected to the camera  100  such as by daisy chaining several USB hard drives together, or it may be indirectly connected to the camera  100  via a network such as the Internet or a local area network. 
     Furthermore, while  FIG. 1  shows the camera  100  as being a box-body type of camera, in alternative embodiments (not depicted) the camera  100  may be a different type of camera such as a dome camera, bullet camera, pan-tilt-zoom (PTZ) camera, or multi-headed camera. 
     Referring now to  FIG. 2 , there is shown a block diagram of the security camera  100 . A lens  112  is positioned to refract light on to the image sensor  126 , which outputs a digital signal to a system on a chip  136  (SoC) in response to this incident light. The SoC  136  comprises a processor  138 , an image signal processor (ISP)  126 , a Media Access Controller (MAC)  144 , and an I2C interface  142 . The processor  138  is communicative with each of the ISP  126 , MAC  144 , and I2C interface  142 . The ISP  126  is communicative with the image sensor  126  via the MIPI™ protocol and the I2C interface  142  is communicative with the image sensor  126  using the I2C protocol. The I2C interface  142  is used to control camera parameters such as gain, exposure, and frame rate. 
     The SoC  136  comprises part of the camera&#39;s  100  processing circuitry. The SoC  136  is communicative with a variety of different components that comprise the camera  100 . The SoC  136 , and more particularly the processor  138 , is communicative with removable media circuitry in the form of the memory card reader  116 . The SoC  136  is also communicative with a physical layer integrated circuit (PHY)  146  that is communicative with the MAC  144 ; flash memory  148 , which is an example non-transitory computer readable medium that is non-volatile and that stores statements and instructions to cause the SoC  136  to perform tasks such as image processing; RAM  150 , which is another example non-transitory computer readable medium, but which is volatile and which the SoC  136  uses to temporarily store information and for working space while performing tasks; the connection status and link LEDs  110 , 112 ; the audio/video connector  118  and the general purpose input/output ports  120 . 
     While in the depicted embodiment the removable media circuitry comprises the memory card reader  116 , in alternative embodiments (not depicted) the removable media circuitry may be any suitable type of circuitry that permits the SoC  136  to communicate with removable media. For example, the removable media circuitry may alternatively comprise a USB port and controller that permit the SoC  136  to communicate with an external and portable SSD or via other forms of removable media via eSATA, FireWire™, ThunderBolt™ or proprietary connections. 
     Also comprising part of the camera  100  are Ethernet magnetics  152 , which are communicative with the RJ45 jack  114  and the PHY  146 , and the power control block  108 , which supplies power to the various electrical components comprising the camera  100 . While in the depicted embodiment the power control block  108  accepts DC power as input, in alternative embodiments (not depicted) the camera  100  may be powered using, for example, an AC adapter, with batteries, or using PoE technology as mentioned above in respect of  FIG. 1 . 
     While  FIG. 1  shows the camera  100  as being contained within a single housing that is the camera body  102 , in alternative embodiments (not depicted) the camera  100  may be divided between multiple housings and collectively comprise several components that are communicative with each other. For example, the camera circuitry may be split across several printed circuit boards placed in different housings and connected via cables in order to miniaturize various camera components, as described in PCT patent application PCT/CA2013/050334. 
     Additionally, while  FIGS. 1 and 2  show the lens  112  as comprising part of the camera  100 , in alternative embodiments (not depicted) the camera  100  may be a lensless camera. 
     Referring now to  FIG. 3 , there is shown a memory map  300  of the memory card  128  after it has been formatted into a journaled partition  302 , which uses the ext4 file system, and a non journaled partition  304 , which uses the FAT32 file system. At the beginning of the address space of the memory card  128  is a partition table  314  that describes, among other things, the location and nature of the journaled and non journaled partitions  302 , 304 . The partition table  314  may be, for example, a master boot record or a GUID Partition Table. The journaled partition  302  comprises a journal  306 , which ext4 uses to log changes made to files in the file system; camera metadata  313 , which comprises information about the camera  100  such as its MAC, serial number, name, and location, which off-camera software applications can use when categorizing and processing data the camera  100  stores to the journaled partition  302 ; and storage space that the processor  138  can write data to and read data from. As shown in the memory map  300 , a portion of this storage space is filled with video files  312 , while the remainder of it is empty and available to the processor  138  as required. 
     The non-journaled partition  304  comprises a file allocation table  308 , which is an index table identifying the clusters comprising the non-journaled partition  304 ; instructional files  311 , which comprise files such as a readme file or help file to explain to users how to use the ext4 access files  310 ; and the ext4 access files  310 , which comprise computer program code executable by a processor, such as the processor in a desktop computer, to use an operating system, such as the Windows™ and OS X™ operating systems, to access files stored on the journaled partition  302  (this processor is hereinafter the “client processor”, and the operating system the client processor runs is hereinafter the “client OS”). In one embodiment this computer program code comprises Ext2Read, available from http://sourceforge.net/projects/ext2read/, but in alternative embodiments (not depicted) the program code may vary depending on, for example, the type of file system used in the journaled partition  302 . While in the depicted embodiment this computer program code comprises multiple files, in alternative embodiments (not depicted) this computer program code may be only a single file. 
     As the memory map  300  shows, in the depicted embodiment all usable capacity of the memory card  128  is allocated entirely to the journaled and non-journaled partitions  302 , 304 . Furthermore, the non-journaled partition  304  has less capacity than the journaled partition  302 , since the purpose of the non-journaled partition  304  is to store the ext4 access files  310  while the purpose of the journaled partition  304  is to store the video files  312 , which are typically much larger. 
     When the memory card  128  is inserted into a memory card reader connected to the client processor, the client processor reads the partition table  314  using the client OS. Assuming the client OS is the Windows™ or OS X™ operating systems, the user will be able to natively access the non-journaled partition  304  but not the journaled partition  302 . The user can consequently use the client processor to run the ext4 access files  310 , which will give the user access to the journaled partition  302  and, consequently, to the video files  312 . In an alternative embodiment (not depicted), the non-journaled partition  304  may also store in its root directory an autorun.inf file configured to cause the Windows™ operating system to automatically run the ext4 access files shortly after the client processor gains access to the memory card  128 . 
       FIGS. 4A and 4B  collectively show a method  400  for formatting the removable storage used in the security camera  100 , according to another embodiment. In particular, the method  400  is directed at embodiments in which the removable storage comprises the memory card  128  and in which formatting of the memory card  128  is consequently done by the user as opposed to the camera&#39;s  100  manufacturer. While the depicted embodiment of the method  400  contemplates the use of FAT32 as the non-journaling file system and ext4 as the journaling file system, in alternative embodiments (not depicted) different journaling and non-journaling file systems may be used. For example, alternative journaling file systems include ext2, ext3, NTFS, JFS, and exFAT, while alternative non-journaling file systems include FAT16, FAT32, CDFS, and UDF. Similarly, while the method  400  is directed at removable storage in the form of the memory card  128 , in alternative embodiments (not depicted) removable storage comprising other types of computer readable media may be used. 
     Various use cases embodied by the method  400  are described below. 
     No Formatting Required 
     In one example, the memory card  128  is already properly formatted into the journaled and non-journaled partitions  302 , 304 , and upon determining this the processor  138  does not again format the memory card  128  (this example is the “no formatting example”). 
     In this example, the processor  138  begins performing the method at block  402  and proceeds to block  404  where it determines whether the memory card  128  is connected to the camera  100  by entering a loop waiting for the user to connect the memory card  128  to the removable media circuitry. When the user connects the memory card  128  to the removable media circuitry, the processor  138  proceeds to block  406  where it reads the partition table  314  on the memory card  128 . Assuming the memory card  128  has already been formatted and comprises at least one partition (“first initial partition”), the processor  138  then determines at block  408  whether the first initial partition comprises the only partition on the memory card  128  and uses FAT32. If no, then the processor  138  proceeds to block  410  where it determines whether the memory card  128  includes another partition (“second initial partition”), whether the first and second initial partitions comprise the only partitions on the memory card  128 , and whether the first and second initial partitions are FAT32 and ext4 partitions, respectively. If yes, then depending on the sizes of these partitions it may be that the memory card  128  has already been properly formatted and is ready for use. The initial partition that uses FAT32 is hereinafter the “FAT32 partition” and the other initial partition that uses ext4 is hereinafter the “ext4 partition”. As mentioned above, however, in alternative embodiments (not depicted) a different journaling file system, a different non-journaling file system, or both, may be used. 
     The processor  138  accordingly proceeds to block  412  where it reads the size of the FAT32 partition, which is hereinafter “FAT32SIZE”. Once the processor  138  has FAT32SIZE, the processor  138  proceeds to block  414  where it determines whether FAT32SIZE equals P1SIZE, which is the name of a constant that represents a fixed non-journaled partition size. If FAT32SIZE equals P1SIZE, the non-journaled partition  304  then proceeds to block  416  where it determines whether all the ext4 access files  310  are already on the FAT32 partition. If all the ext4 access files  310  are present, the processor  138  reads the total capacity of the memory card  128  at block  418 , reads the size of the ext4 partition at block  420 , which is hereinafter “EXT4SIZE”, and determines at block  422  whether all usable capacity of the memory card  128  is allocated entirely to the FAT32 and EXT4 partitions. If yes, then the processor  138  concludes that the memory card  128  has been properly formatted into the journaled and non-journaled partitions  302 , 304 , treats the ext4 partition as the journaled partition  302 , and consequently begins writing data to the ext4 partition as block  424 . The processor  138  remains in this state at block  426  until the memory card  128  is removed, following which the processor  138  returns to the start  402  of the method  400 . 
     Automatic Formatting Performed 
     In another example, the processor  138  determines that the memory card  128  has not been properly formatted into the journaled and non-journaled partitions  302 , 304 , and automatically reformats the memory card  128  (this example is the “automatic formatting example”). 
     In this example, the processor  138  begins performing the method  400  as in the no formatting example until the processor  138  determines whether the FAT32 partition is the only partition on the memory card  128  at block  408 . Unlike in the no formatting example, in the automatic formatting example the FAT32 partition is the only partition on the memory card  128  and the processor  138  proceeds to block  444  where it determines whether the FAT32 partition is empty. If yes, the processor  138  determines it can safely reformat the memory card  128  without erasing any data the user may want to protect and proceeds to block  436  where it erases the FAT32 partition. Once the FAT32 partition has been erased, the processor  138  proceeds to block  438  where it creates a new FAT32 partition of size P1SIZE, which is the non-journaled partition  304 . The processor  138  then proceeds to block  440  where it creates a new ext4 partition encompassing the remaining usable capacity of the memory card  128 ; this new partition is the journaled partition  302 . After creating the journaled partition  302  the processor  138  proceeds to block  442  where it copies the ext4 access files  310  to the non-journaled partition  304 , and the processor  138  then begins writing data such as the video files  312  to the journaled partition  302  at block  424 . As in the no formatting example, the processor  138  remains in this state at block  426  until the memory card  128  is removed, following which the processor  138  returns to the start  402  of the method  400 . 
     User Confirmation Obtained Prior to Formatting 
     In another example, the processor  138  determines that the memory card  128  has not been properly formatted into the journaled and non-journaled partitions  302 , 304 , but does not automatically format the memory card  128  because there is a chance that by doing so data on the memory card  128  may be inadvertently erased (this example is the “user confirmation example”). In this user confirmation example, the processor  138  seeks user confirmation prior to formatting the memory card  128  into the journaled and non-journaled partitions  302 , 304 . 
     In the user confirmation example, the processor  138  waits for any one of several triggering events before prompting the user to confirm he or she wishes to reformat the memory card  128 . In the embodiment of  FIG. 4 , these events comprise the processor  138  determining any one or more of the following:
         (i) the memory card  128  comprises only a single, FAT32 partition, but this partition is not empty (block  444 );   (ii) the memory card  128  does not comprise only a single, FAT32 partition, nor does it comprise only one FAT32 partition and one ext4 partition (block  410 ); and   (iii) the memory card  128  comprises only one FAT32 partition and one ext4 partition, but:
           (1) FAT32SIZE does not equal P1SIZE (block  414 );   (2) the ext4 access files  310  are not present on the FAT32 partition (block  416 ); or   (3) all usable capacity of the memory card  128  is not allocated entirely to the FAT32 and ext4 partitions (block  422 ).   
               

     If any one or more of the above listed conditions occurs, the processor  138  proceeds to block  430  where it prompts the user for confirmation that the memory card  128  is to be reformatted and checks to see if the user has provided this confirmation at block  432 . Until the processor  138  receives this confirmation or until the memory card  128  is removed, the processor  138  loops between blocks  432  and  434  while waiting for user confirmation or for the user to remove the memory card  128 . If the user removes the memory card  128  (block  434 ), the processor  138  proceeds to block  446  and returns to the beginning of the method  400 . If the user provides confirmation that the memory card  128  is to be reformatted (block  432 ), the processor  138  proceeds to block  436  and proceeds as it does in the automatic formatting example. That is, the processor  138  erases all partitions on the memory card  128  (block  436 ), creates the journaled and non-journaled partitions  302 , 304  (blocks  438  and  440 ), copies the ext4 access files  310  to the non-journaled partition  304  (block  442 ), and starts and continues using the journaled partition  302  (block  424 ) until the user removes the memory card  128  (block  426 ) in which case the processor  138  returns to the beginning of the method (block  428 ). 
     In the method  400  of  FIGS. 4A and 4B , the processor  138  does not write data to or erase data from the non-journaled partition  304  after having created it and copied the ext4 access files  310  to it. In alternative embodiments, however, the processor  138  may subsequently modify the non-journaled partition  304  even after having completed formatting the memory card  128  by performing the method  400 . 
     Additionally, in the method  400  of  FIGS. 4A and 4B  the processor  138  ensures that the memory card  128  is formatted to comprise the journaled and non-journaled partitions  302 , 304 , and that these partitions  302 , 304  collectively utilize all the memory card&#39;s  128  usable capacity. In alternative embodiments (not depicted), the processor  138  may permit usage of a differently formatted memory card  128 . For example, the processor  138  may permit usage of a memory card  128  having three or more partitions so long as two of those partitions are the journaled and non-journaled partitions  302 , 304 , even though the journaled and non-journaled partitions  302 , 304  do not collectively utilize all the memory card&#39;s  128  usable capacity. Alternatively or additionally, the processor  138  may not require FAT32SIZE to equal P1SIZE, and instead may allow the memory card  128  to be used so long as the FAT32 partition is large enough to store the ext4 access files  310 . Alternatively or additionally, if the ext4 access files  310  are not present on the FAT32 partition, instead of reformatting the entire memory card  128  the processor  138  may simply copy the ext4 access files  310  to the FAT32 partition and, presuming the FAT32 partition is large enough to store those files  310  and the memory card  128  also comprises the ext4 partition, begin storing files on the ext4 partition. 
     In another alternative embodiment (not depicted), the processor  138  may automatically reformat the memory card  128  without waiting for user confirmation if the memory card  128  is not partitioned into the journaled and non-journaled partitions  302 , 304  that collectively utilize all the memory card&#39;s  128  usable capacity. 
     As an example of another alternative embodiment that is not depicted, the processor  138  may automatically partition the memory card  128  when it detects that the memory card  128  has been connected to the memory card reader  116 . This embodiment can be used, for example, when each time the memory card  128  is removed its entire contents is presumed to be transferred to a desktop computer or server. 
     In the depicted embodiments, the removable storage is partitioned via formatting. In alternative embodiments (not depicted), partitioning may be done without formatting. 
     While the SoC  136  is used in the foregoing embodiments, in alternative embodiments (not depicted) the SoC  136  may instead be, for example, a microprocessor, processor, microcontroller, controller, programmable logic controller, field programmable gate array, or an application-specific integrated circuit. Examples of computer readable media are non-transitory and include disc-based media such as CD-ROMs and DVDs, magnetic media such as hard drives and other forms of magnetic disk storage, and semiconductor based media such as flash media, SSDs, random access memory, and read only memory. 
     It is contemplated that any part of any aspect or embodiment discussed in this specification can be implemented or combined with any part of any other aspect or embodiment discussed in this specification. 
     For the sake of convenience, the example embodiments above are described as various interconnected functional blocks. This is not necessary, however, and there may be cases where these functional blocks are equivalently aggregated into a single logic device, program or operation with unclear boundaries. In any event, the functional blocks can be implemented by themselves, or in combination with other pieces of hardware or software. 
     While particular embodiments have been described in the foregoing, it is to be understood that other embodiments are possible and are intended to be included herein. It will be clear to any person skilled in the art that modifications of and adjustments to the foregoing embodiments, not shown, are possible.