Abstract:
A control apparatus and method for controlling an image capture apparatus having a first and a second digital interface. The apparatus and method include determining which of the first and second digital interfaces is used to connect the image capture apparatus and the control apparatus, transmitting to the image capture apparatus one of a first or a second command for changing a function of the image capture apparatus. If it is determined that the first digital interface is used to connect the image capture apparatus and the apparatus, the first command is transmitted to the image capture apparatus. If it is determined that the second digital interface is used to connect the image capture apparatus and the control apparatus, the second command is transmitted to the image capture apparatus.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a technique for externally controlling an image capture apparatus, such as a digital video camera, via a digital interface.  
         [0003]     2. Description of the Related Art  
         [0004]     Communication between a digital video camera (hereinafter referred to as a “DVCR”) and a personal computer (hereinafter referred to as a “PC”) can be established via a digital interface. If the digital interface is compliant with IEEE 1394 (see IEEE Std 1394-1995, IEEE Standard for a High Performance Serial Bus, Institute of Electrical and Electronics Engineers, Inc.; and IEEE Std 1394a-2000, IEEE Standard for a High Performance Serial Bus—Amendment 1), communication is performed on the basis of a command set defined by AV/C Digital Interface Command Set General Specification Version 4.1 (Nov. 19, 2001), or the like. If the digital interface is compliant with USB (see Universal Serial Bus Specification Revision 2.0, Apr. 27, 2000), communication is performed on the basis of a command set defined by Universal Serial Bus Device Class Definition For Video Devices.  
         [0005]     The DVCR typically has two transmission modes, camera mode and VTR mode. In the camera mode, video data captured by the DVCR is transmitted in real time to a remote PC via a network. In the VTR mode, video data already captured and recorded on a magnetic tape or memory card loaded in the DVCR is transmitted to a remote PC via a network.  
         [0006]     Switching between the camera mode and the VTR mode can be performed by a user operating a mechanical switch provided on the DVCR. However, the DVCR does not allow such switching to be performed in response to a control command transmitted from the PC.  
         [0007]     More specifically, the user cannot control switching of the transmission modes of the DVCR by operating the PC. Thus, the user needs to directly operate the mechanical switch of the DVCR for performing such switching. For example, the user may conduct video telephone session by causing the DVCR to capture a video image of the user seated before the PC and to transmit the captured video data in the camera mode. If, during this video telephone session, the user wishes to change the DVCR to the VTR mode to transmit video data of the user&#39;s child previously captured and recorded on a magnetic tape, the user must move to the location of the DVCR to operate the mechanical switch thereof. This results in an inconvenience to the user.  
         [0008]     Meanwhile, there are user requests for a DVCR having a plurality of types of digital interfaces to enhance convenience.  
       SUMMARY OF THE INVENTION  
       [0009]     An aspect of the present invention is to overcome the above-described drawbacks.  
         [0010]     Another aspect of the present invention is to enable an image capture apparatus, e.g., digital video camera or the like, having a plurality of digital interfaces to be externally controlled via each of the plurality of digital interfaces, thereby enhancing the convenience of the image capture apparatus.  
         [0011]     In another aspect of the present invention, a control apparatus for controlling an image capture apparatus having first and second digital interfaces comprises a determination unit configured to determine which of the first and second digital interfaces is used to connect the image capture apparatus and the control apparatus, and a transmission unit configured to transmit to the image capture apparatus one of a first or a second command for changing a function of the image capture apparatus. If the determination unit determines that the first digital interface is used to connect the image capture apparatus and the control apparatus, the transmission unit transmits the first command to the image capture apparatus. If the determination unit determines that the second digital interface is used to connect the image capture apparatus and the control apparatus, the transmission unit transmits the second command to the image capture apparatus.  
         [0012]     In yet another aspect of the present invention, a method for controlling an image capture apparatus having first and second digital interfaces comprises the steps of determining which of the first and second digital interfaces is used to connect the image capture apparatus and a control apparatus, and transmitting from the control apparatus to the image capture apparatus one of a first or a second command for changing a function of the image capture apparatus. The transmitting step comprises, if it is determined that the first digital interface is used to connect the image capture apparatus and the control apparatus, transmitting the first command to the image capture apparatus, and, if it is determined that the second digital interface is used to connect the image capture apparatus and the control apparatus, transmitting the second command to the image capture apparatus.  
         [0013]     Other features and advantages of the present invention will become apparent to those skilled in the art upon reading of the following detailed description of embodiments thereof when taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]     The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.  
         [0015]      FIG. 1  is a diagram showing the configuration of a communication system according to an exemplary embodiment of the invention.  
         [0016]      FIG. 2  is a block diagram showing the outline structure of a DVCR according to the embodiment.  
         [0017]      FIG. 3  is a flow chart illustrating a communication mode switching process based on a command from a control apparatus.  
         [0018]      FIG. 4  is a diagram showing a format of a mode change command (CONNECT AV command) that is compliant with IEEE 1394.  
         [0019]      FIG. 5  is a diagram showing a format of a mode change command (Set Selector Unit Control command) that is compliant with USB. 
     
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS  
       [0020]     Embodiments of the invention will be described in detail below with reference to the drawings.  
         [0021]      FIG. 1  is a diagram showing the configuration of a communication system according to an exemplary embodiment of the present invention.  
         [0022]     In  FIG. 1 , a DVCR  101  is an image capture apparatus having a plurality of types of digital interfaces. In the present embodiment, the DVCR  101  has an IEEE 1394 interface and a USB interface. The IEEE 1394 interface is a digital interface that is compliant with IEEE 1394 (see IEEE Std 1394-1995, IEEE Standard for a High Performance Serial Bus, Institute of Electrical and Electronics Engineers, Inc.; and IEEE Std 1394a-2000, IEEE Standard for a High Performance Serial Bus—Amendment 1). The USB interface is a digital interface that is compliant with USB (see Universal Serial Bus Specification Revision 2.0, Apr. 27, 2000). The DVCR  101  is capable of being connected to a local PC  103  via a serial bus  102  that is compliant with IEEE 1394 or USB. The local PC  103  is connected to another remote PC  105  via a network  104 , such as the Internet.  
         [0023]     The DVCR  101  and the local PC  103  can transmit and receive video data, etc., according to a command defined by IEEE 1394 or USB. In this case, a command to the DVCR  101  is transmitted from an application program being executed on the local PC  103 , so that the local PC  103  can control the DVCR  101 . In addition, the local PC  103  can forward to the DVCR  101  a command that has been received from the remote PC  105  via the network  104 .  
         [0024]      FIG. 2  is a block diagram showing the outline structure of the DVCR  101 . Referring to  FIG. 2 , the DVCR  101  includes an image capture portion  201 , a control portion  202 , a display portion  203 , a communication portion  204  and a recording portion  205 . The image capture portion  201  includes an image sensor (not shown), such as a CCD (charge-coupled device) sensor, for capturing object images to generate video data. The control portion  202  controls the operation of the entire DVCR  101 . The display portion  203  displays video images and a variety of information indicative of modes, etc., of the DVCR  101 . The communication portion  204  has an IEEE 1394 interface and a USB interface. The recording portion  205  records video data supplied from the image capture portion  201  on a recording medium, such as a magnetic tape or memory card.  
         [0025]     The DVCR  101  has two communication modes, camera mode and VTR mode. In the camera mode, video data generated by the image capture portion  201  is supplied to the control portion  202 , and the control portion  202  sends the video data in real time to the display portion  203 , the communication portion  204  and the recording portion  205 . In the VTR mode, video data already recorded in the recording portion  205  is read out and supplied to the control portion  202 , and the control portion  202  sends the video data to the display portion  203  and the communication portion  204 . In addition to the camera mode and the VTR mode, the DVCR  101  has a modeless mode. In the modeless mode, the camera mode and the VTR mode can be freely switched over on the basis of a command received from a control apparatus, e.g., the local PC  103  or the remote PC  105 , via the communication portion  204 . Switching of the camera, VTR, and modeless modes is performed by a user operating a hardware switch (not shown) provided on the DVCR  101 .  
         [0026]      FIG. 3  is a flow chart illustrating a communication mode switching process based on a command from the control apparatus. The communication mode switching process is performed only when the DVCR  101  is set in the modeless mode. In addition, the processes at steps S 301  to S 306  are performed by an application program running on the local PC  103 .  
         [0027]     Referring to  FIG. 3 , at step S 301 , a mode switching command for the DVCR  101  is inputted to an application program being executed on the local PC  103 , or the local PC  103  receives a mode switching command for the DVCR  101  from the remote PC  105  via the network  104 . Then, at step S 302 , the local PC  103  checks the current communication mode of the DVCR  101  to determine if the current communication mode is identical to the mode designated by the input or received mode switching command. If the current communication mode is identical to the designated mode, the local PC  103  brings the communication mode switching process to an end.  
         [0028]     If it is determined at step S 302  that the current communication mode of the DVCR  101  is not identical to the mode designated by the input or received mode switching command the local PC  103  proceeds to step S 303 . At step S 303 , the local PC  103  determines if the digital interface used for communication between the local PC  103  and the DVCR  101  is an IEEE 1394 interface. If the digital interface used is the IEEE 1394 interface, the local PC  103  proceeds to step S 305 . At step S 305 , the local PC  103  converts the input or received mode switching command into a mode change command for the IEEE 1394 interface, e.g., a CONNECT AV command as shown in  FIG. 4 , and transmits the mode change command to the DVCR  101 .  
         [0029]     If it is determined at step S 303  that the digital interface used is not the IEEE 1394 interface, the local PC  103  proceeds to step S 304 . At step S 304 , the local PC  103  determines if the digital interface used for communication between the local PC  103  and the DVCR  101  is a USB interface. If the digital interface used is the USB interface, the local PC  103  proceeds to step S 306 . At step S 306 , the local PC  103  converts the input or received mode switching command into a mode change command for the USB interface, e.g., a Set Selector Unit Control command as shown in  FIG. 5 , and transmits the mode change command to the DVCR  101 . If, at step S 304 , the local PC  103  determines that the digital interface used for communication between the local PC  103  and the DVCR  101  is not a USB interface, then the local PC  103  brings the communication mode switching process to an end.  
         [0030]     Determination of whether the digital interface used for communication between the local PC  103  and the DVCR  101  is an IEEE 1394 interface or a USB interface can be performed by detecting the presence or absence of a bias voltage to be applied to these interfaces. In addition to this method, any other method that would allow practice of the present invention is applicable.  
         [0031]     Returning to  FIG. 3 , at step S 307 , the control portion  202  of the DVCR  101 , which is set in the modeless mode, switches the current communication mode to the mode (camera mode or VTR mode) designated by the CONNECT AV command or the Set Selector Unit Control command received at the communication portion  204 . Then, at step S 308 , the control portion  202  of the DVCR  101  resets the connection between the local PC  103  and the DVCR  101  by dropping a bias voltage which the digital interface applies to the serial bus  102  to connect with the local PC  103  and then applying the bias voltage again. Then, the communication mode switching process comes to an end.  
         [0032]     As described above, the DVCR  101  has a dedicated mode (modeless mode) for switching communication modes (camera mode and VTR mode). Accordingly, it is possible to dynamically switch the communication modes of the DVCR  101  on the basis of a command from the local PC  103  or the remote PC  105  so that the convenience of the DVCR  101  can be enhanced. In this case, the input or received mode switching command is converted by an application program on the local PC  103  into a mode change command compliant with the format of the digital interface with the DVCR  101 . The mode change command is then transmitted to the DVCR  101 . Accordingly, even if the DVCR  101  has a plurality of types of digital interfaces, it is possible to switch the communication modes of the DVCR  101  in accordance with control from the local PC  103  or the remote PC  105  so that the convenience of the DVCR  101  can also be enhanced in this regard.  
         [0033]     It should be noted that the present invention is not limited to the above-described embodiment. For example, the present invention can be applied to cases where the digital interface is compliant with a standard other than IEEE 1394 and USB, such as Ethernet®, IEEE 802.11a, IEEE 802.11b or IEEE 802.11g.  
         [0034]     Furthermore, the present invention can also be applied to cases where an image capture apparatus other than the DVCR is controlled by a control apparatus via a digital interface. In addition, the present invention can be applied not only to control of switching of the communication modes but also to cases where various operations of an image capture apparatus are controlled by a control apparatus via a digital interface.  
         [0035]     The present invention can also be achieved by providing a system or apparatus with a storage or recording medium that stores program code of software (i.e., computer-executable process steps) for realizing the functions of the above-described embodiment, and causing a computer or a CPU (central processing unit), MPU (micro-processing unit) or the like of the system or apparatus to read the program code from the storage medium and then execute the program code.  
         [0036]     In this case, the program code itself read from the storage medium realizes the functions of the embodiment. The storage medium storing the program code constitutes the invention. Furthermore, besides the program code read by the computer being executed to realize the functions of the above-described embodiment, the present invention includes an operating system (OS) or the like running on the computer performing an actual process in whole or in part according to instructions of the program code to realize the functions of the above-described embodiment.  
         [0037]     Moreover, the present invention also includes a CPU or the like contained in a function expansion board inserted into the computer or in a function expansion unit connected to the computer, the function expansion board or the function expansion unit having a memory in which the program code read from the storage medium is written, the CPU or the like performing an actual process in whole or in part according to instructions of the program code to realize the functions of the above-described embodiment. If the present invention is applied to the above-described storage medium, program code corresponding to the above-described flow chart shown in  FIG. 3  is stored in the storage medium.  
         [0038]     The above-described embodiments are merely exemplary of the present invention, and are not to be construed to limit the scope of the present invention.  
         [0039]     The scope of the present invention is defined by the scope of the appended claims, and is not limited to only the specific descriptions in this specification. Furthermore, all modifications and changes belonging to equivalents of the claims are considered to fall within the scope of the present invention.  
         [0040]     This application claims priority from Japanese Patent Application No. 2003-417002 filed Dec. 15, 2003, which is hereby incorporated by reference herein.