JP2005174479A - Control unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the overwriting of data when a REC instruction is made by user's erroneous operation in a state that a mode is other than REC or RECPAUSE. <P>SOLUTION: This control unit is provided with a interface for inputting/outputting digital data, and the function of connecting a network by using the digital interface. The device is further provided with the function of transmitting a control signal and an inquiry signal to an external data recording/reproducing device connected to the digital interface, and the function of receiving a response signal with respect to the signal. A state inquiry signal is sent to the external data recording/reproducing device, and a control signal for requesting data recording is sent only when the response signal of the inquiry signal is in a specific state. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a control apparatus for controlling a digital data recording / reproducing apparatus having a digital interface.

  Currently, there are devices that record and reproduce digital video data having a high-speed serial interface, and digital video using tape as a recording medium and IEEE1394 as a serial interface is widely used (Non-Patent Document 1 and 2). The digital video is equipped with a command set of AV / C Tape Recorder / Player subunit defined by the 1394 Trade Association, which is a standard organization of the IEEE 1394 interface standard, and performs recording / playback operation according to the control command received via IEEE 1394. Can be done.

  The transmission / reception of this command is defined as FCP (Function Control Protocol) in IEC61883 (see Non-Patent Document 3), and the controller writes control data to the specific address of the target device using a write transaction. This is realized when the target that has received the data of the write transaction writes the response data with a write transaction to a specific address of the controller. In the AV / C protocol, a CTS (Command Transaction Set) is defined for each AV / C subunit, and FIG. 8 shows a command frame format used in the CTS.

  The ctype field indicates the type of command and specifies the command type shown in FIG. The subunit_type and subunit ID fields are fields indicating which unit in the specified node is the command. The opcode and operand fields are fields for specifying the actual command contents.

  FIG. 9 shows a response frame format used in CTS. The response field indicates the type of response, and specifies the response type shown in FIG. The subunit_type and subunit ID fields are fields indicating from which unit in the node the response is received. The opcode and operand fields are fields for specifying response data.

  For example, a command frame for instructing recording to the Tape Recorder / Player subunit and a response frame when the command is received are data shown in FIG.

  A camera-integrated digital video generally has two modes: a camera mode for shooting and a video mode for playback. The camera mode can perform recording operations and the video mode can perform recording and playback operations. It can be done.

In the camera mode, when a tape is set, a recording standby state is automatically entered, and each time a recording start / recording stop trigger button is pressed, a recording state and a recording standby state are switched. In the camera mode, it accepts the RECORD command that requests to enter the recording state and the RECORD PAUSE command that requests to enter the recording standby state. In the video mode, it also accepts other playback request commands. Commands such as rewind, fast forward, etc. are also accepted. The digital video camera in the camera mode can be controlled by issuing RECORD and RECORD PAUSE commands.
IEEE Std 1394-1995, IEEE Standard for a High Performance Serial Bus, Institute of Electrical and Electronics Engineers, Inc. IEEE Std 1394a-2000, IEEE Standard for a High Performance Serial Bus-Amendment 1 IEC 61883-1, Consumer audio / video equipment-Digital interface-Part 1: General

  When a RECORD command is issued to the digital video camera, a recording state occurs when a recordable tape is set in either the camera mode or the video mode. For example, if the user accidentally issues a RECORD command, there is a problem that even if the tape is being played back in the video mode, the data is overwritten from the place where it is being played back.

  In the present invention, in order to solve the above problem, before issuing the RECORD command and the RECORD PAUSE command, a command for inquiring about the state of the device is issued in advance to the target to which the command is transmitted. Issue the RECORD and RECORD PAUSE commands only at times.

  A control device having an interface for digital data input / output and having a function of connecting to a network using the digital interface, and sending a control signal and an inquiry signal to an external data recording / reproducing device connected to the digital interface It has a function to transmit and a function to receive a response signal to the signal, and transmits a status inquiry signal to an external data recording / reproducing device. A control device that transmits a control signal to be performed.

  The specific state can be a recording standby state. A specific state can be a recording state.

  Before issuing RECORD, RECORD PAUSE CONTROL Command, by checking the target status with TRANSPORT STATE STATUS Command and issuing the command according to the result, necessary data can be prevented from being overwritten by user's misoperation. .

  This embodiment will be described below. FIG. 1 shows a sequence for issuing the RECORD command of the present invention. First, the user makes a recording request by operating a button or the like included in the controller, and the controller that receives the request issues a TRANSPORT STATE STATUS Command to the digital video camera (hereinafter referred to as a target). This command inquires about the target status.

  FIG. 2 shows command frame data of TRANSPORT STATE STATUS Command and response frame data returned by the target in the recording standby state.

  When the controller receives the response data and finds that the target is in a recording standby state, it subsequently issues a RECORD command to the target and the target enters a recording state. If the response to the TRANSPORT STATE STATUS Command indicates a recording state, the controller does not need to issue it because the target state does not change even if the RECORD command is issued.

  When the controller receives a recording standby request from the user, the controller issues a command in the sequence shown in FIG. First, the controller that has received the request issues a TRANSPORT STATE STATUS Command to the target. FIG. 4 shows the TRANSPORT STATE STATUS Command command frame data and the response frame data returned by the recording state target.

  When the controller receives the response data and finds that the target is in a recording state, it subsequently issues a RECORD PAUSE command shown in FIG. 5 to the target, and the target transmits a response to the controller and enters a recording standby state. If the response to the TRANSPORT STATE STATUS Command indicates a recording standby state, the controller does not need to issue a RECORD PAUSE command because the target state does not change.

  Regardless of the RECORD CONTROL Command or RECORD PAUSE CONTROL Command command, if the response to the TRANSPORT STATE STATUS Command is not in the recording state or recording standby state, the CONTROL Command is not issued. The operation of this embodiment is shown in flowcharts in FIGS.

  As described above, before issuing RECORD, RECORD PAUSE CONTROL Command, by checking the target status with TRANSPORT STATE STATUS Command and issuing the command according to the result, necessary data is overwritten by user's mistaken operation. Can be prevented.

The figure which shows the sequence which issues the RECORD control command of a present Example. The figure which shows the command frame data of a TRANSPORT STATE STATUS command, and the data of the response frame which a digital video camera of a recording standby state returns. The figure which shows the sequence which issues the RECORD PAUSE control command of a present Example. The figure which shows the command frame data of a TRANSPORT STATE STATUS command, and the data of the response frame which a digital video camera of a recording state returns. The figure which shows the data of the command frame and response frame of a RECORD PAUSE control command. The flowchart which shows operation | movement of the control apparatus of an Example. The flowchart which shows operation | movement of the control apparatus of an Example. The figure which shows the command frame format used by CTS. The figure which shows the response frame format used by CTS. The figure which shows the data of the command frame and response frame of a RECORD control command. The table | surface which shows the value of the ctype field set to the command frame of CTS. The table | surface which shows the value of the response field set to the response frame of CTS.

Claims (3)

  A control device having an interface for digital data input / output and having a function of connecting to a network using the digital interface, the control signal and inquiry to an external data recording / reproducing device connected to the digital interface A function of transmitting a signal and a function of receiving a response signal to the signal, transmitting an inquiry signal of a state to the external data recording / reproducing apparatus, and when the response signal of the inquiry signal is in a specific state A control device for transmitting a control signal for requesting data recording only.   The control device according to claim 1, wherein the specific state is a recording standby state. The control device according to claim 1, wherein the specific state is a recording state.

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