JP2014165693A - Recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To guarantee that a frame which can be the beginning of a record remains in a buffer at start of recording, even when, in photography using radio communication between an image pickup device and an external device, there is a gap in video between the image pickup device and the external device due to a transmission delay.SOLUTION: Provided is a recording device having a function to transfer encoded data to an external device, the recording device comprising an encoding unit for encoding inputted image data, a temporary accumulation unit for storing the encoded data generated by the encoding unit, a communication unit for transmitting/receiving data to and from the external device, and image data search means for searching the temporary accumulation unit for the position of image data by using information about displayed image data transmitted from the external device and received by the communication unit. The recording device sets, from the position in a buffer obtained by the image data search means and the position in the temporary accumulation unit into which written by the encoding unit, an area in a data accumulation unit which is disabled against overwriting.

Description

  The present invention relates to a recording apparatus, and more particularly to a recording apparatus for starting recording from an external device using a wireless communication function.

  There are digital cameras equipped with a wireless communication function capable of transmitting video captured by a camera to an external device by wireless communication, receiving a user instruction from the external device, and starting and stopping recording.

  In shooting using the wireless communication function, the user determines the recording start timing while confirming the video transmitted from the camera with the external device, and operates the external device to instruct the camera to start recording.

  When the camera receives a recording start instruction from the external device, it starts writing the encoded result on the buffer to the recording medium.

  Similar to the recording start operation, the user determines the recording stop timing while confirming the captured video of the camera with the external device, and operates the external device to instruct the camera to stop the recording. When the camera receives a recording stop instruction from the external device, the camera stops writing to the recording medium.

  When shooting with the wireless communication function described above, the video is encoded on the camera side, transmitted to the external device via wireless communication, and then displayed after being decoded by the external device. In the video displayed on the device, there is a difference in transmission time.

  For this reason, the frame that the user has instructed to start recording while checking the video of the external device refers to the past frame that has been encoded on the camera side, so which frame on the buffer is the first frame of recording start. It cannot be specified.

  There is a system that uses time information to improve operability due to a shift in transmission delay. In Patent Document 1, in a remote operation device that remotely controls a camera, stop of a user's remote operation is detected, and time information at the time of stop is transmitted to the camera. The camera executes an instructed process based on the time information.

  As described above, the time information at the time of operation is transmitted to the camera side, and the camera side searches the buffer for the time information having the time information that matches the received time information, thereby specifying the frame to start recording. Can be done.

JP 2000-350183 A

  However, in the above-described conventional technical configuration, the camera side does not know which frame on the buffer becomes the first frame of recording until time information is received from the external device, so even if the frame has already been transmitted to the external device. Although it is necessary to leave it on the buffer, the transmitted frame on the buffer may be overwritten with the code result because the buffer is limited.

  For this reason, it is conceivable that recording cannot be performed from a frame in which the user designates recording start.

The recording apparatus of the present invention
A recording device having a function of transferring encoded data to an external device,
An encoding unit that encodes input image data, a temporary storage unit that stores encoded data generated by the encoding unit, a communication unit that transmits / receives data to / from an external device, and an external device that is received by the communication unit Image data search means for searching for the position of the image data from the temporary storage unit using the information of the displayed image data sent from the position on the buffer obtained by the image data search means, and It is characterized in that an area in which overwriting of the data storage unit is disabled is set from the position written by the encoding unit in the temporary storage unit.

  According to the present invention, in shooting using wireless communication between an imaging device and an external device, even if a video shift occurs between the imaging device and the external device due to a transmission delay, a frame that can be the head of recording is recorded. It can be guaranteed that it remains on the buffer at the start.

It is a system configuration diagram of the present invention. FIG. 3 is a diagram illustrating a configuration of a temporary storage unit according to the first embodiment. It is the figure which showed the processing procedure of buffer control of this invention. FIG. 6 is a diagram illustrating a frame search processing procedure according to the first embodiment. FIG. 6 is a diagram illustrating a configuration of a temporary storage unit according to a second embodiment. FIG. 10 is a diagram illustrating a frame search processing procedure according to the second embodiment. It is the figure which showed the structure of the temporary storage part of this invention.

[Example 1]
(Example of creating a third pointer on the buffer based on time information sent from an external device)
In this embodiment, an example will be described in which a camera-side buffer is controlled based on frame information displayed on an external device in a function of performing radio communication between the camera and the external device.

<Description of block diagram>
FIG. 1 is a system configuration diagram adapted to the present embodiment.

  The image decoding apparatus in FIG. 1 includes an encoding unit 101, a control unit 102, a temporary storage unit 103, a recording medium control unit 104, a recording medium 105, and a recording medium 106. A temporary storage information management unit, a communication unit 107, and a bus 108 are provided.

  Reference numeral 101 denotes an encoding unit, which encodes the input video according to the MPEG (Moving Picture Experts Group) method and outputs the encoding result to the temporary storage unit 103.

  Reference numeral 102 denotes a control unit that controls the entire recording apparatus. The control unit 102 performs processing for searching the temporary storage unit 103 for a frame that matches the displayed frame information transmitted from the external device.

  Reference numeral 103 denotes a temporary storage unit, which is a ring buffer that temporarily stores an encoding result output from the encoding unit 101. Data stored in the temporary storage unit 103 is transmitted from the communication unit 107 to an external device by a wireless communication function. During recording, the data stored in the temporary storage unit 103 is written into the recording medium 105.

  Reference numeral 104 denotes a recording medium control unit that controls the recording medium 105. The recording medium control unit 104 receives the encoding result stored in the temporary storage unit 103 and writes the encoding result to the recording medium 105.

  Reference numeral 105 denotes a recording medium, which indicates a flash memory such as an SD card. The recording medium 105 stores the encoding result output from the recording medium control unit 104.

  Reference numeral 106 denotes a temporary storage information management unit. The temporary storage information management unit 106 holds information associated with the encoding result stored in the temporary storage unit 103. For example, it has information such as PTS, frame number, frame type, and frame size.

  Reference numeral 107 denotes a communication unit that performs wireless communication processing with an external device. The communication unit 107 performs processing for transmitting the encoding result stored in the temporary storage unit 103 to an external device. Also, it displays the displayed frame information transmitted from the external device, and notifies the control unit 102 of the received frame information.

  Reference numeral 108 denotes a bus, which exchanges data between blocks. Hereinafter, description of processing of the bus 106 when data is transferred between the blocks is omitted.

<Overall processing explanation>
Next, processing until the encoding result of the recording apparatus is transmitted to an external device will be described with reference to FIG.

  In this embodiment, the pointer W, the pointer WL, the pointer WF, and the PTSα are defined as follows.

  A pointer W indicates a position on the temporary storage unit 103 where the encoding unit 101 outputs a new encoding result.

  The pointer WL indicates a data position on the temporary storage unit 103 that is next transmitted to the external device.

  The pointer WF indicates the data position on the temporary storage unit 103 displayed on the next external device.

  PTSα indicates the PTS of the frame displayed on the external device. In this embodiment, the PTS of Frame 1 in FIG. 2A is shown.

  The encoding unit 101 encodes the input video, outputs the encoding result (FIG. 7: Frame 5) to the temporary storage unit 103, and then sets the pointer W on the temporary storage unit 103 that starts output next to the control unit. 102 is notified.

  The control unit 102 receives the pointer W output from the encoding unit 101 and information related to the encoding result (PTS, frame number, frame type, frame size, etc.) and stores them in the temporary storage information management unit 106.

  The control unit 102 converts the encoded data (FIG. 7: Frame 1-3) stored in the temporary storage unit 103 into a format that can be transmitted to the outside, and outputs the converted data to the communication unit 107. Normally, a group of frames, such as 1 GOP, is output to the communication unit 107 as a unit to be transmitted, but in this embodiment, the unit of frames to be transmitted is described as 3 frames for the sake of brevity.

  The control unit 102 sets a position indicating the head of the frame (FIG. 7: Frame 4) to be output next to the communication unit 107 as a pointer WL, and stores it in the temporarily accumulated information management unit 106.

  The communication unit 107 transmits the encoded data (FIG. 7: Frame1-3) output from the control unit 102 to any external device (not shown) existing on the network by the wireless communication function.

  An external device on the network receives the encoded data (FIG. 7: Frame1-3) transmitted from the communication unit 107, performs a decoding process, and performs a display process. The external device transmits the displayed frame information to the communication unit 107 for each frame.

  The displayed frame information may be any unique information that can identify the frame. For example, there are PTS and frame number. In this embodiment, the displayed frame information is PTS.

  In the present embodiment, it is assumed that Frame 1 is displayed by an external device and Frame 1 displayed frame information (hereinafter referred to as PTSα) is transmitted to the communication unit 107.

<Description of buffer control>
Next, buffer control processing using PTSα will be described with reference to FIG.

  FIG. 3 is a diagram illustrating a processing procedure for setting an area in which overwriting of the temporary storage unit 103 is prohibited.

  Hereinafter, the processing starts when the user sets the recording apparatus to the wireless mode by a user interface (not shown).

  In step S301, the control unit 102 determines whether the setting of the recording apparatus is in the wireless mode. If the wireless mode is OFF, the process ends. If the wireless mode is ON, the process proceeds to S302.

  In step S <b> 302, the communication unit 107 receives the PTSα transmitted from the external device and notifies the control unit 102.

  In step S303, the control unit 102 refers to the PTSα notified from the communication unit 107 and executes a frame search process.

<Description of buffer control (frame search processing)>
Here, the frame search process in S303 will be described in detail with reference to FIGS.

  FIG. 4 is a diagram showing a processing procedure for performing a frame search with reference to displayed frame information.

  FIG. 2 is a diagram illustrating the temporary storage unit 103. FIG. 2A is a diagram before the frame search process. FIG. 2B is a diagram after the frame search process.

  In step S <b> 401, the control unit 102 determines whether the pointer WF is set in the temporary storage information management unit 106.

  If the pointer WF is not set, in S402, the control unit 102 sets the start position of the search process to the head of the temporary storage unit 103, and proceeds to S404.

  If the pointer WF has already been set, in S403, the control unit 102 sets the start position of the search process to the pointer WF, and proceeds to S404.

  In FIG. 2A, since WF is not set, the search process is executed from Frame 1 in FIG. 2A.

  In S404, the control unit 102 refers to the PTS of the encoded data (FIG. 2A: Frame 1-5) stored in the temporary storage information management unit 106, and searches for a frame that matches PTSα in S402 or S403. Search from the position (FIG. 2A: Frame 1).

  As a result of the search, Frame 1 in FIG. 2A matches.

  In S405, the control unit 102 ends the frame search process with the frame position (FIG. 2A: Frame 2) next to the frame searched in S404 (FIG. 2A: Frame 1) as the final result.

  This is the end of the description of the frame search process.

  Hereinafter, since the frame search is performed, FIG. 2B is referred to.

  In S304, the control unit 102 sets the search result in S303 (FIG. 2B: Frame 2) as the pointer WF and stores it in the temporary storage information management unit 106.

  In S305, the control unit 102 refers to the positions of the pointer W and the pointer WF from the temporary storage information management unit 106, and overwrites the encoding result existing between the pointer WF (FIG. 2B: Frame 2) and the pointer W (see FIG. 2B). Set as a frame (not displayed on the external device).

  The above process is repeated until the wireless mode is turned off.

  As a result of the above processing, in FIG. 2B, Frame 2, Frame 3, Frame 4, and Frame 5 are frames that may be instructed to be recorded by the user, and are therefore overwritten. Frame 1 is displayed on the external device and is not recorded, so it can be overwritten.

  As described above, in this embodiment, the frame information displayed on the external device is searched for which frame on the temporary storage unit has been displayed on the external device, and overwriting is prohibited on the temporary storage unit from the search result. By determining the area, it can be ensured that a frame that can be the head of recording remains on the buffer at the start of recording.

[Example 2]
(Example in which, when the displayed image data is a B or P picture, the frame search process returns the previous I picture as a result)
In this embodiment, when a frame displayed on an external device is encoded by inter-frame reference (P picture or B picture), a frame (I picture) that can be decoded by the immediately preceding single frame search process result. ) Position.

  The configuration of this embodiment is the same as that of FIG.

  Further, the buffer control process is the same as the process of FIG. 3 used in the first embodiment, and a description thereof will be omitted.

  In this embodiment, the pointer W, pointer WL, pointer WF, and PTSβ are defined as follows.

  The pointer W and the pointer WL have the same meaning as in the first embodiment.

  The pointer WF indicates the position of the I picture immediately before the frame displayed by the external device.

  PTSβ indicates the PTS of the frame displayed on the external device. In this embodiment, the PTS of Frame 2 in FIG. 5A is shown.

  The frame search process according to the present embodiment will be described with reference to FIGS.

  FIG. 5 is a diagram showing the temporary storage unit 103. FIG. 5A is a diagram before the frame search process. FIG. 5B is a diagram after the frame search process.

  FIG. 6 is a diagram showing a processing procedure for searching the temporary storage unit 103 for the immediately preceding I picture that is a reference destination when the frame type included in the displayed frame information is a P picture or a B picture. Since S401 to S404 are the same as those in the first embodiment, the description thereof is omitted.

  In this embodiment, the displayed frame information received from the external device in S302 is assumed to be PTSβ of Frame 2 and the frame type in FIG. 5A.

<Explanation of frame search processing>
In S404, the control unit 102 refers to the PTS of the encoded data (FIG. 5A: Frame 1-5) stored in the temporary storage information management unit 106, and searches for a frame that matches PTSβ in S402 or S403 Search from the position (FIG. 5A: Frame 1).

  In step S601, the control unit 102 determines whether the frame type received from the external device in step S302 is P or B.

  In the case of P or B, in S602, the control unit 102 uses the I frame (FIG. 5A: Frame 1) immediately before the frame position (FIG. 5A: Frame 2) coinciding with PTSβ as the search result.

  If it is not P or B, the frame position (FIG. 5A: Frame 2) matching PTSβ is taken as the search result in S603.

  This is the end of the frame search process.

  Hereinafter, since the frame search is performed, FIG. 5B is referred to.

  In S304, the control unit 102 sets the search result in S303 (FIG. 2B: Frame 1) as the pointer WF and stores it in the temporary storage information management unit 106.

  In S305, the control unit 102 refers to the positions of the pointer W and the pointer WF from the temporary storage information management unit 106, and overwrites the encoding result existing between the pointer WF (FIG. 2B: Frame 1) and the pointer W (see FIG. 2). Set to a frame that is not displayed on the external device.

As a result of the above processing, in FIG. 5B, Frame3, Frame4, and Frame5 are frames that may be instructed to be recorded by the user, and thus overwriting is prohibited.
Since Frame1 and Frame2 are frames necessary for decoding Frame3, overwriting is prohibited.

  As described above, in this embodiment, when a frame that matches the frame information displayed on the external device is encoded by inter-frame reference, the frame that can be decoded by the immediately preceding single frame search result. The position is taken as a search result, and in the case of a frame that can be decoded alone, the matched frame position is taken as a search result. By determining the area where overwriting is prohibited on the temporary storage unit from the search result, it can be ensured that a frame that may be instructed to remain is left on the buffer at the start of recording.

101 Encoding unit 102 Control unit 103 Temporary storage unit 104 Recording medium control unit 105 Recording medium unit 106 Temporary storage information management unit 107 Communication unit 108 Bus

Claims (2)

A recording device having a function of transferring encoded data to an external device,
An encoding unit that encodes input image data, a temporary storage unit that stores encoded data generated by the encoding unit, a communication unit that transmits / receives data to / from an external device, and an external device that is received by the communication unit Image data search means for searching for the position of the image data from the temporary storage unit using the information of the displayed image data sent from the position on the buffer obtained by the image data search means, and A recording apparatus, wherein an area in which overwriting of a data storage unit is disabled is set from a position written by the encoding unit in the temporary storage unit. When the displayed image data is image data decoded with reference to other image data,
The position of the image data determined by the image data search means is
The recording apparatus according to claim 1, wherein the position is set as a position of image data that can be decoded without a previous reference.