JP2020005213A - Transmitter, receiver, control method of transmitter, control method of receiver, and program - Google Patents

Abstract

To provide a communication system which allows for transmission of data before completion of conversion of a video file, and which can acquire the video file simply without requiring any special processing such as reconstitution of received data on a receiving side.SOLUTION: A communication system includes: first control means (S307, S308) for controlling to estimate the size of a first header of converted video data before completion of conversion of video data (S310), and to transmit data corresponding to the estimated size of the first header to an external device; second control means (S311) for controlling to transmit the converted video data to the external device after transmitting the data according to the size of the first header; and third control means (S313, S319) for controlling to generate the first header corresponding to the converted video data after transmitting the converted video data, and to transmit the generated first header to the external device.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a transmitting device for transmitting a moving image file and a receiving device for receiving the moving image file, and more particularly to a device for converting (transcoding) a moving image file and transmitting or receiving the moving image file.

  With the spread of wireless communication, it has been proposed to transmit data such as video files between communication devices equipped with a wireless communication function in a portable terminal such as a digital camera.

  For example, in Patent Literature 1, when a moving image file is transmitted from a digital camera to an external device, a transcoding process is performed, and then the moving image file is transmitted.

JP 2017-62626 A

  In the related art disclosed in Patent Document 1, since the moving image file is transmitted after the transcoding process of the moving image file is completed, it takes time until the transmission of the moving image file is completed. On the other hand, it is also possible to start transmitting the transcoded data before completing the transcoding. However, in this case, since the header information and the like of the moving image file cannot be generated until after the transcoding of the moving image data, the header information is transmitted after the moving image data. , Or rearrangement processing of data such as rearrangement for changing the recording order of moving image data and header information.

  In view of the above, the present invention enables a transmission device to convert a moving image file and transfer it to a receiving device, thereby enabling data transmission before the conversion of the moving image file is completed, and reconstructing the received data on the receiving side. It is an object of the present invention to provide a communication system capable of easily acquiring a moving image file without performing special processing such as the above.

In order to achieve the above object, the transmitting device of the present invention is
A transmitting device for transmitting data of a moving image file to an external device, the converting device converting the moving image data of the moving image file, and performing control for transmitting the moving image file of the moving image data converted by the converting device to the external device. And control means for estimating the size of the first header of the moving image data converted by the converting means before completing the conversion of the moving image data by the converting means, and estimating the estimated first header. First control means for controlling transmission of data corresponding to the size of the first header to the external device, and transmission of the moving image data converted by the conversion means to the external device after transmission of the data corresponding to the size of the first header A second control means for controlling the processing so as to generate a first header corresponding to the converted moving image data after transmitting the converted moving image data, and removing the generated first header. And third control means for controlling to transmit device, characterized by having a.

Further, the receiving device of the present invention,
When receiving data of a moving image file transmitted from the external device in the first transmission process, the receiving device receives the data related to the header size of the moving image data. In response to this, dummy data of a size corresponding to the received data is recorded on the recording medium, and then the received moving image data is recorded in an area following the dummy data on the recording medium. First control means for controlling to overwrite and record data; and when receiving data of a moving image file transmitted from the external device in the second transmission processing, the data received from the external device is stored in a recording medium. And a second control means for controlling the recording to be performed sequentially.

  According to the present invention, data can be transmitted before the conversion of the moving image file is completed, and the moving image file can be easily obtained without performing special processing such as reconstructing the received data on the receiving side. A communication system can be provided.

FIG. 2 is a block diagram of the digital camera 100. It is a figure showing the example of composition of the communication system in this embodiment. 5 is a flowchart illustrating a moving image file transmission process in the transmission device 210. 5 is a flowchart illustrating a process of receiving a moving image file in the receiving device 220. It is a figure showing composition of a moving picture file, and composition of a 3rd header. FIG. 3 is a diagram showing a file recorded on the recording medium 109 by the receiving device 220.

(1st Embodiment)
Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Hereinafter, as an example of a communication device, an example in which the present invention is applied to an arbitrary digital camera capable of transmitting and receiving data by communication will be described. However, the present invention is not limited to a digital camera, and is applicable to any electronic device capable of transmitting and receiving data by communication. These devices may include, for example, mobile phones, game machines, tablet terminals, personal computers, and the like. In the following embodiments and the like, a communication device (transmission device) on the data transmission side is described as a digital camera, and a communication device (reception device) on the data reception side is described as a digital camera. However, the transmitting device and the receiving device may use different types of communication devices as long as data communication is possible.

(Digital camera configuration)
FIG. 1 is a diagram illustrating a configuration of a digital camera 100 according to an embodiment of the present invention. Hereinafter, the configuration of the digital camera according to the embodiment of the present invention will be described.

  The digital camera 100 includes a central processing unit (CPU) 101, a photographing lens 102, an imaging unit 103, a display unit 104, an operation unit 105, an image processing unit 106, a non-volatile memory 107, a main storage unit 108, a recording medium 109, a communication interface. 110 and an antenna 111 for wireless communication.

  The central processing unit (CPU) 101 includes one or more microprocessors or the like that execute various processes described below, reads a program from the nonvolatile memory 107, and controls each unit based on the read program. Perform various calculations. Further, based on the read program, it executes processing shown in flowcharts of FIGS.

  The imaging unit 103 includes an imaging element and the like, and converts a subject image acquired via the imaging lens 102 into image data to capture a still image or a moving image.

  The display unit 104 displays a still image or a moving image captured by the imaging unit 103, a live image being captured, a user setting screen, a live view image, and the like.

  The operation unit 105 includes a power button, a shutter button, a moving image shooting start / stop button, a menu button, a cross key, and the like for receiving an operation from a user, and receives an input instruction from these buttons. The central processing unit 101 performs an operation of actually photographing a still image or a moving image that executes a process corresponding to the operation in response to an operation on the operation unit 105, or a case where a desired setting is input from a user setting screen. Used for etc.

  The image processing unit 106 is a processing unit that performs image processing such as image analysis of an image captured by the imaging unit 103, image processing for displaying the image on the display unit 104, and the like. Further, various image processes such as a compression encoding process of an image for generating an image file to be recorded on the recording medium 109 and a decoding process of image data of an image file read from the recording medium 109 are executed.

  The non-volatile memory 107 is configured by a flash memory or the like, and stores information such as user setting information that should be retained even while the power of the digital camera 100 is off. The nonvolatile memory 107 also stores a program code and an operating system (OS) for controlling the digital camera 100 and performing various processes (image data compression process, data transfer process, and the like).

  The main storage unit 108 includes a RAM or the like, and is used to temporarily store data of the central processing unit 101, the imaging unit 103, and the image processing unit 106.

  The recording medium 109 is formed of, for example, a removable card-type recording medium, and stores captured still image data and moving image data.

  The communication interface 110 is an interface that connects to an external device via the wireless communication antenna 111. In the present embodiment, a case will be described in which wireless communication is performed with an external device via the wireless communication antenna 111. However, the wireless device may be connected to an external device using a local area network or USB.

  When the shutter button is operated in the shooting mode, the digital camera 100 shoots an image by the imaging unit 103 and compresses the image data subjected to image processing for a still image by the image processing unit 106 into a JPEG format. Then, under the control of the central processing unit 101, the image data in the JPEG format is recorded on the recording medium 109 as a JPEG file. In addition, when the moving image shooting start / stop button is operated, the image is continuously shot by the imaging unit 103. The image data subjected to the image processing for the moving image by the image processing unit 106 is compressed into the MPEG format. Then, under the control of the central processing unit 101, the image data in the MPEG format is recorded on the recording medium 109 as an MP4 file.

  When the operation unit 105 is operated to switch the digital camera 100 to the playback mode, the central processing unit 101 reads out the image file recorded on the recording medium 109 and displays it on the display unit 104. In accordance with an operation on the operation unit 105, the image displayed on the display unit 104 can be edited by the image processing unit 106 and recorded on the recording medium 109. The image file selected by the operation on the operation unit 105 from the plurality of image files recorded on the recording medium 109 is transmitted to the external device wirelessly connected by the communication interface 110 via the wireless communication antenna 111. Can also be sent.

(System configuration of communication system)
In the present embodiment, the digital camera on the transmitting side of the file is the transmitting device 210, and the digital camera on the receiving side of the file is the receiving device 220. The digital camera of the transmitting device 210 and the digital camera of the receiving device 220 each have the configuration shown in FIG.

  FIG. 2 illustrates an example of a communication system including a transmission device 210 and a reception device 220.

  The transmitting device 210 and the receiving device 220 participate in the formed wireless network 200 via the communication interface 11 and the wireless communication antenna 111, and establish wireless communication compliant with, for example, the IEEE 802.11 series. In this embodiment, an example in which a wireless LAN system compliant with the IEEE 802.11 series is used will be described. However, the communication mode is not limited to the wireless LAN compliant with IEEE 802.11, and another method may be used. That is, other wireless communication methods such as wireless USB, MBOA, Bluetooth (registered trademark), UWB, and ZigBee (registered trademark) may be used. Further, the present invention may be implemented in a wired communication medium such as a wired LAN. MBOA is an abbreviation for Multi Band OFDM Alliance. UWB includes wireless USB, wireless 1934, WINET, and the like.

(Video file transmission processing)
Next, FIG. 3 shows a flowchart of an operation in which the transmission device 210 transmits a moving image file to the reception device 220. In this process, the flowchart is started by the central processing unit 101 of the transmission device 210 in response to the transmission device 210 receiving a moving image file transmission start instruction. Before receiving the transmission start instruction, the user uses the display unit 104 and the operation unit 105 of the transmission device 210 to select a moving image file to be transmitted from the recording medium 109 and make transmission settings. The central processing unit 101 of the transmitting device 210 stores information of the moving image file selected as the transmission target and information of the transmission setting in the nonvolatile memory 107 of the transmitting device 210. After that, the central processing unit 101 accepts a transmission start instruction in response to the operation unit 105 of the transmission device 210 accepting the operation of starting the transmission of the moving image file. In the present embodiment, a case will be described where the transmission device 210 receives a transmission start instruction. However, the reception device 220 may receive a transmission start instruction for a moving image file recorded on the recording medium 109 of the transmission device 210. . In this case, the receiving apparatus 220 also selects the moving image file to be transmitted and sets the transmission. Then, in response to receiving the transmission start instruction, the reception device 220 transmits the information of the moving image file to be transmitted and the information of the transmission setting to the transmission device 210 together with the transmission start instruction, and the transmission device 210 transmits these. It is stored in the non-volatile memory 107 of the device 210. In the present embodiment, “Transcode transmission” for transmitting a moving image file by performing image conversion processing can be set as the transmission setting. When “Transcode transmission” is set, after performing image conversion processing for reducing the file size of the moving image file to be transmitted, the converted moving image file is transmitted from the transmitting device 210 to the receiving device 220.

  Upon receiving the transmission start instruction, in step S301, the central processing unit 101 of the transmission device 210 determines whether the transmission setting stored in the nonvolatile memory 107 is transcode transmission, that is, normal transmission. If it is determined that the transmission is transcode transmission, the process proceeds to step S302. If it is determined that the transmission is not transcode transmission, the process proceeds to the normal transmission process of step S330.

  In step S302, the central processing unit 101 of the transmission device 210 acquires reproduction capability information of the reception device 220 that is the destination of the moving image file. Acquiring the reproduction capability information means acquiring the information acquired by the transmitting device 210 from the receiving device 220 via the wireless network 200 and held in the main storage unit 108. The reproduction capability information includes a compression format, a resolution, a bit rate, a frame rate of video data of a reproducible moving image file, a compression format of audio data, a bit rate, the number of channels, and the like.

  In step S303, the central processing unit 101 of the transmission device 210 determines the transcoding format (conversion format) of the moving image file according to the reproduction capability information of the receiving device 220 to which the moving image file is transmitted. The video file transcode format is the video data compression format, resolution, bit rate, frame rate, and audio data compression format, bit rate, number of channels, etc. when transcoding the video file. That is. In the present embodiment, the transcoding format is determined in the transmitting device according to the reproduction capability of the receiving device. However, the transcoding format may be set by the user in the transmission setting.

  In step S304, the central processing unit 101 of the transmission device 210 reads the header information of the moving image file to be transmitted recorded on the recording medium 109 into the main storage unit 108. Then, the central processing unit 101 analyzes the read header information, and determines whether or not the file is a moving image file that can be transcoded based on the analysis result. If it is determined that the moving image file can be transcoded, the process proceeds to step S305. If it is determined that the file is not a transcoding-capable moving image file, the process proceeds to a normal transmission process in step S330. Here, a description will be given of a condition for determining whether or not a moving image file can be transcoded based on the analysis result of the header information.

-For video files that do not need to be transcoded If there is a video file that does not change when transcoded, or if it is determined that the video file has already been transcoded, there is no need to perform transcoding. It is determined that the file cannot be transcoded.

In the case of a moving image file having a short playback time If the playback time of a moving image file is short, transcoding processing may not be performed.

-In the case of a moving image file recorded by another device If a moving image file is recorded by another device, it may not be possible to transcode it, so it is determined that the file cannot be transcoded.

  The above is the condition for determining whether or not the video file can be transcoded.

  In step S305, the central processing unit 101 of the transmitting device 210 acquires information on whether the receiving device 220 supports transfer while transcoding. Here, the transfer while transcoding is a function of sequentially transmitting the transcoded data. Acquisition of information as to whether or not transfer is supported while transcoding is performed when the transmitting device 210 transfers from the receiving device 220 via the wireless network 200 and transfers the transcoding while holding it in the main storage unit 108. Is to acquire information on whether or not it corresponds to Also, as a function different from transfer while transcoding, there is also a function of transcoding and then transferring data after all the moving image files have been transcoded.

  In step S306, the central processing unit 101 of the transmitting device 210 determines whether the receiving device 220 supports the transfer while transcoding. If it is determined that the transfer is supported while transcoding, the process proceeds to step S307, and the process of transmitting a moving image file while transcoding is performed in steps S307 to S319. If it is determined that the transfer is not supported while transcoding, the process proceeds to step S320. Although not described in the flowchart, the central processing unit 101 of the transmitting device 210 notifies the receiving device 220 that transmission of moving image file data is to be started before starting data transmission. At this time, when the determination is Yes in step S306, it also notifies that the moving image file is transmitted while transcoding. If No is determined in step S306, a notification indicating that the moving image file is to be transmitted while transcoding is not performed, and only the reception device 220 is notified that transmission of the moving image file data is to be started.

  In step S307, the central processing unit 101 of the transmitting device 210 reads the header information of the moving image file to be transmitted recorded on the recording medium 109 into the main storage unit 108. Then, a process of estimating the size of the first header after transcoding the moving image data is performed based on the read header information.

  Here, the file structure of the moving image file (MP4 file) will be described with reference to FIGS.

  FIG. 5A shows the file structure of the MP4 file. The MP4 file has a box structure and includes a plurality of boxes (data storage areas). The MP4 file includes an ftyp box, a moov box, and an mdat box. The ftype box describes the file type and is included only at the beginning of the MP4 file. The moov box is a container that includes meta information, and is included only once in the MP4 file. The meta information includes information on the shooting date and time of the moving image data, shooting conditions, thumbnail images, and the like. The moov box can further include a plurality of boxes, and the meta information can be stored in the moov box by dividing the box for each type of meta information. As for the mdat box, a single MP4 file can include a plurality of mdat boxes. However, in the digital camera 100 of the present embodiment, when generating an MP4 file, one mdat box is provided in one MP4 file, and compressed moving image data (video data and audio data) is stored in the mdat box. are doing.

  FIG. 5B is a diagram showing the configuration of each box. In each box, the first 8 bytes are a box header for identifying the box, the first 4 bytes indicate the size of the box, and the next 4 bytes indicate the type (entry name) of the box. In the subsequent area, data of the box is stored up to the area indicated by the box size.

  In step S307, the first header for estimating the size refers to the ftyp box and the moov box. That is, the first header extends from the beginning of the moving image file to the end of the moov box. The process of estimating the size of the first header in the moving image file after transcoding (after conversion) includes the header information before conversion read into the main storage unit 108 in step S307 and the format determined in step S303 to be discarded (conversion format). Is calculated based on As the transcoding format (conversion format), at least one of a compression format, a resolution, a frame rate, a compression format, a bit rate, and the number of channels of video data of a moving image file generated by transcoding is used. Then, the first header is estimated. When estimating the first header size, calculation is performed so that the estimated size of the first header does not become smaller than the size of the first header generated after actually transcoding. In the transcoding of the present embodiment, since the file format is not changed, the size of the ftyp box does not change before transcoding (before conversion) and after transcoding (after conversion). Therefore, the size of the moov box after conversion is estimated, and the total size of the size of the ftyp box before conversion and the estimated size of the moov box is set as the size of the first header.

  Next, in step S308, the central processing unit 101 of the transmitting device 210 determines the size of the third header, and transmits the size of the third header to the receiving device 220 via the wireless network 200. Further, the size of the third header is recorded in the main storage unit 108. Here, the third header is a header including the first header and the second header as shown in FIG. The first header is an ftyp box and a moov box, as described above. The second header is a box header (box size information and box type information) of the mdat box. That is, the second header size is 8 bytes. As described above, the third header is composed of the entire ftyp box, the entire moov box, and the box header of the mdat box, as shown in FIG. 5C, from the beginning of the moving image file to the box header of the mdat box. Data. The third header can be said to be a header of a moving image file (ftyp box, moov box) and a header of moving image data (mdat box) in the moving image file. Then, the third header size is the sum of the size of the first header and the size (8 bytes) of the second header estimated in S307.

  In step S309, the central processing unit 101 of the transmission device 210 stores a part of the moving image data (video data and audio data) stored in the mdat box of the moving image file recorded on the recording medium 109 in the main storage unit 108. Read. Here, a part of the moving image data is read because the size of the moving image file recorded on the recording medium 109 may be larger than the size at which the moving image file in the main storage unit 108 can be read at one time.

  In step S310, the central processing unit 101 of the transmission device 210 performs transcoding (conversion) on the moving image data of the moving image file read into the main storage unit 108 by the image processing unit 106, and records the data in the main storage unit 108. . Then, the central processing unit 101 of the transmission device 210 records the transcode information at the time of performing the transcoding in the main storage unit 108.

  In step S311, the central processing unit 101 of the transmitting device 210 transmits the transcoded data recorded in the main storage unit 108 in step S310 to the receiving device 220 via the wireless network 200.

  In step S312, the central processing unit 101 of the transmission device 210 determines whether or not all the data of the moving image file to be transmitted recorded on the recording medium 109 has been read. If it is determined that the reading has been completed, the process proceeds to step S313. If it is determined that the reading has not been completed, the process returns to step S309.

  In step S313, the central processing unit 101 of the transmission device 210 generates a first header based on the transcode information recorded in the main storage unit 108 in step S310, and records the first header in the main storage unit 108.

  In step S314, the central processing unit 101 of the transmission device 210 generates a second header based on the transcode information recorded in the main storage unit 108 in step S310, and records the second header in the main storage unit 108.

  In step S315, the central processing unit 101 of the transmission device 210 determines the total size of the first header and the second header generated in steps S313 and S314 and the third header recorded in the main storage unit 108 in step S308. With the size of the header. That is, the size of the third header in the video file after transcoding composed of the first header and the second header generated in steps S313 and S314, and the size of the third header transmitted to the receiving device 220 Compare with size. If it is determined that the converted third header size is equal to the size of the transmitted third header, the process proceeds to step S317. It is determined that the converted third header size is not equal to the size of the transmitted third header, that is, the converted third header size is smaller than the transmitted third header size. In this case, the process proceeds to step S316. Here, the size of the third header calculated by the processing of steps S307 and S308 and transmitted to the receiving device is calculated so as not to exceed the sum of the sizes of the first header and the second header generated after transcoding. Have been. Therefore, the size of the third header transmitted to the receiving device does not fall below the sum of the sizes of the first header and the second header generated in steps S313 and S314. In step S315, the total size of the first header and the second header generated after the transcoding was compared with the size of the third header determined before the transcoding and transmitted to the receiving device. Here, the size of the third header determined before transcoding is the total size of the first header and the second header, and the size of the second header is fixed. Therefore, it is substantially the same as comparing the size of the first header generated after transcoding with the size of the first header estimated before transcoding. Therefore, in step S315, the size of the first header generated after transcoding may be compared with the size of the first header estimated before transcoding.

  In step S316, the central processing unit 101 of the transmission device 210 calculates a difference between the total of the first header size and the second header size and the size of the third header transmitted to the reception device 220. The difference is determined as the size of the padding.

  In step S317, the central processing unit 101 of the transmitting device 210 generates a third header as shown in FIG. Specifically, by adding the padding data determined in step S316 to the first header generated in step S313, the first header has the header size estimated in step S307. Then, after the first header to which the padding data has been added, the second header generated in step pS314 is concatenated, and a third header having the size transmitted in step S308 is generated and recorded in the main storage unit 108. . If the padding size has not been determined in step S316, that is, if the transmitted third header size is equal to the sum of the first and second header sizes, in step S317, the padding data is not added and FIG. A third header as shown in (d) is generated. That is, the third header is generated by concatenating the first header and the second header generated in S313 and S314. As described above, in step S317, a third header is generated from the first and second headers generated in steps S313 and S314 so as to have the third header size transmitted in step S308.

  In step S318, the central processing unit 101 of the transmitting device 210 transmits a header overwriting instruction to the receiving device 220 via the wireless network 200.

  In step S319, the central processing unit 101 of the transmission device 210 transmits the third header generated in step S317 and recorded in the main storage unit 108 to the reception device 220 via the wireless network 200. Then, the transcode transmitting process for transmitting the moving image file while performing the transcoding is ended.

  If transcode transmission is set and the receiving device 220 does not support transfer while transcoding, in step S320, the central processing unit 101 of the transmitting device 210 checks whether the recording medium 109 has sufficient free space. Determine whether or not. If it is determined that there is sufficient free space, the process proceeds to step S321, and the process of transcoding and transmitting in steps S321 to S329 is executed. If it is determined that there is not enough free space, the process proceeds to a normal transmission process in step S330. Here, the sufficient free space refers to a free space that can temporarily store a moving image file generated by transcoding a moving image file to be transmitted recorded on the recording medium 109. The size of a moving image file generated by transcoding can be estimated based on information such as the compression format, resolution, and frame rate of video data, the compression format of audio data, the bit rate, and the number of channels.

  In step S321, the central processing unit 101 of the transmission device 210 reads a part of the moving image data (video data and audio data) of the moving image file recorded on the recording medium 109 into the main storage unit 108. Here, a part of the moving image data is read because the size of the moving image file recorded on the recording medium 109 may be larger than the size at which the moving image file in the main storage unit 108 can be read at one time.

  In step S322, the central processing unit 101 of the transmission device 210 transcodes the moving image data of the moving image file read into the main storage unit 108 by the image processing unit 106, and records the transcoded moving image data in the main storage unit 108. Further, the central processing unit 101 of the transmission device 210 records the transcode information at the time of performing the transcoding in the main storage unit 108.

  In step S323, the central processing unit 101 of the transmission device 210 records the transcoded moving image data recorded in the main storage unit 108 in step S322 on the recording medium 109.

  In step S324, the central processing unit 101 of the transmission device 210 determines whether all the data of the moving image file to be transmitted recorded on the recording medium 109 has been read. If it is determined that the reading has been completed, the process proceeds to step S315. If it is determined that the reading has not been completed, the process returns to step S324.

  In step S325, the central processing unit 101 of the transmitting device 210 uses the first header (ftyp box, moov box) and the second header (mdat box) based on the transcode information recorded in the main storage unit 108 in step S322. Is generated and recorded in the main storage unit 108.

  In step S326, the central processing unit 101 of the transmitting device 210 transmits the first header (ftyp box, moov box) recorded in the main storage unit 108 in step S325 to the receiving device 220 via the wireless network 200.

  In step S327, the central processing unit 101 of the transmission device 210 reads a part of the transcoded data (mdat box) recorded on the recording medium 109 in step S323 into the main storage unit 108. Here, the reason why a part of the data is read is that the size of the transcoded data recorded on the recording medium 109 may be larger than the size at which the moving image file in the main storage unit 108 can be read at one time. is there.

  In step S328, the central processing unit 101 of the transmitting device 210 transmits the transcoded data read into the main storage unit 108 in step S327 to the receiving device 220 via the wireless network 200. In steps S327 and S328, a process of transmitting the entire mdat box including the header (second header) of the mdat box as transcoded data to the receiving device 220 is performed.

  In step S329, the central processing unit 101 of the transmission device 210 determines whether or not reading of all the transcoded moving image data recorded on the recording medium 109 has been completed. If it is determined that the reading has been completed, the transcode transmission process for transmitting the data of the moving image file is completed after the transcoding of the moving image file is completed. If it is determined that the reading has not been completed, the process returns to step S327, and the processes of steps S327 and S328 are repeated until reading and transmission of all moving image data are completed.

  Next, a description will be given of a normal transmission process for transmitting a moving image file without transcoding, instead of transcoding transmission.

  In step S330, the central processing unit 101 of the transmission device 210 reads the header (ftyp box, moov box) of the moving image file recorded on the recording medium 109 into the main storage unit 108.

  In step S331, the central processing unit 101 of the transmitting device 210 transmits the header read into the main storage unit 108 in step S330 to the receiving device 220 via the wireless network 200.

  In step S332, the central processing unit 101 of the transmission device 210 reads a part of the moving image data (mdat box) of the moving image file recorded on the recording medium 109 into the main storage unit 108. Here, part of the data is read because the size of the moving image file recorded on the recording medium 109 may be larger than the size at which the moving image file in the main storage unit 108 can be read at one time.

  In step S333, the central processing unit 101 of the transmitting device 210 transmits the data read into the main storage unit 108 in step S332 to the receiving device 220 via the wireless network 200.

  In step S334, the central processing unit 101 of the transmission device 210 determines whether all the data of the moving image file to be transmitted recorded on the recording medium 109 has been read. If it is determined that the reading has been completed, the normal transmission process ends. If it is determined that the reading has not been completed, the process returns to step S332.

(Video file reception processing)
Next, the receiving process of the receiving device 220 when receiving the data of the moving image file transmitted from the transmitting device 210 as in the flowchart of FIG. 3 will be described. FIG. 4 shows a flowchart of a receiving process in which the receiving device 220 receives a moving image file from the transmitting device 210.

  In step S401, the central processing unit 101 of the receiving device 220 determines whether or not data of a moving image file is transmitted from the transmitting device 210 by a transmission process of transmitting data while transcoding the moving image file. Specifically, the central processing unit 101 of the receiving device 220 determines whether there has been a notification that the transmission of the moving image file is transmitted from the transmitting device 210 via the wireless network 200 and a notification that the moving image file is transmitted while being transcoded. I do. If it is determined that the data of the moving image file is transmitted by the transmission process of transmitting while transcoding, the process proceeds to step S402. If it is determined that the data of the moving image file is transmitted by a transmission process other than the transmission process of transmitting while transcoding, the process proceeds to step S410. In addition, regarding the transmission processing that is not the transmission processing that is transmitted while transcoding, the transmission processing (S321 to S329) in which the transcoded video file is transmitted after transcoding is completed, and the video file is transmitted without transcoding Normal transmission processing (S330 to S334).

  In step S402, the central processing unit 101 of the receiving device 220 receives the size of the third header transmitted from the transmitting device 210 in the process of step S308.

  In step S403, the central processing unit 101 of the receiving device 220 records the dummy data for the size of the third header received in step S403 on the recording medium 109 of the receiving device 220, as shown in FIG. . FIG. 6A shows a file that the central processing unit 101 of the receiving device 220 records on the recording medium 109 in step S404. The size of the dummy data matches the size of the third header received in step S403.

  In step S404, the central processing unit 101 of the receiving device 220 receives the transcoded moving image data transmitted from the transmitting device 210 by the process of step S311 and records the data in the main storage unit 108 of the receiving device 220.

  In step S405, the central processing unit 101 of the receiving device 220 transmits the transcoded moving image data received from the transmitting device 210 in step S404 and recorded in the main storage unit 108 of the receiving device 220 to the recording medium 109 of the receiving device 220. To record. At the time of recording, as shown in FIG. 6B, the received transcoded moving image data is recorded following the dummy data recorded on the recording medium 109 in step S403. FIG. 6B illustrates a file that the central processing unit 101 of the receiving device 220 records on the recording medium 109 in step S405. The transcoded moving image data_1 is recorded in an area following the dummy data.

  In step S406, the central processing unit 101 of the receiving device 220 determines whether or not the header overwriting instruction transmitted from the transmitting device 210 by the process of step S318 has been received. If it is determined that it has been received, the process proceeds to step S408. If it is determined that it has not been received, the process returns to step S405, and the processes of steps S404 and S405 are repeated until a header overwrite instruction is received, that is, until all transcoded moving image data is received. FIG. 6C shows a file that the central processing unit 101 of the receiving device 220 records on the recording medium 109 by repeating the processing of steps S404 and S405. The received transcoded moving image data is recorded subsequent to the data recorded on the recording medium 109. When the reception of all the transcoded moving image data is completed, the dummy data and all the transcoded moving image data are sequentially recorded as shown in FIG. At this point, since the dummy data is recorded instead of the first header and the second header, data that cannot be read as a file is recorded.

  In step S407, the central processing unit 101 of the receiving device 220 receives the third header transmitted from the transmitting device 210 by the process of step S319, and records the third header in the main storage unit 108 of the receiving device 220.

  In step S408, the central processing unit 101 of the reception device 220 records the third header received from the transmission device 210 in step S408 and recorded in the main storage unit 108 of the reception device 220 in the recording medium 109 of the reception device 220. I do. When the received third header is recorded on the recording medium 109, as shown in FIGS. 5D-1 and 5D-2, the third header is overwritten and recorded on the position of the dummy data recorded in step S403.

  FIGS. 5D-1 and 5D-2 show files recorded on the recording medium 109 by the central processing unit 101 of the receiving device 220 in step S408. The area which was the dummy data in FIG. 5C is overwritten by the received third header in FIGS. 5D-1 and 5D-2. FIG. 5D-1 shows a file recorded when a third header not containing padding data is received. FIG. 5D-2 shows a file recorded with the third header containing padding data. This shows a file recorded when received. The third header includes an ftyp box and a moov box that are the first header, and a header of the mdat box that is the second header. Therefore, by overwriting the dummy data with the third header, the file recorded on the recording medium 109 becomes an MP4 format moving image file having an ftyp box, a moov box, and an mdat box as shown in FIG. Structure.

  In order to have the structure of the MP4 format moving image file, it is necessary to record the transcoded moving image data following the second header (header of the mdat box). Records coded video data. Further, when the dummy data is overwritten by the third header, the third header is generated in step S317 so that the second header (header of the mdat box) and the transcoded moving image data are continuous. I have. That is, instead of adding padding data after the second header, the central processing unit 101 of the transmitting device 210 adds padding data to the first header, and adds the first header to which the padding data has been added to the first header. The second header is combined to generate a third header.

  Next, a case will be described in which a moving image file transmitted from the transmission device 210 is received in a transmission process other than the transmission process transmitted while transcoding.

  In step S410, the central processing unit 101 of the reception device 220 receives the header (ftyp box, moov box) of the moving image file transmitted from the transmission device 210 by the processing of step S326 or S331, and the main storage unit of the reception device 220. Record at 108.

  In step S411, the central processing unit 101 of the receiving device 220 records the header of the moving image file received from the transmitting device 210 in step S410 and recorded in the main storage unit 108 of the receiving device 220 on the recording medium 109 of the receiving device 220. I do.

  In step S412, the central processing unit 101 of the receiving device 220 receives the data (mdat box) transmitted from the transmitting device 210 by the processing of step S328 or S333, and records the data in the main storage unit 108 of the receiving device 220.

  In step S413, the central processing unit 101 of the reception device 220 records the data received from the transmission device 210 in step S412 and recorded in the main storage unit 108 of the reception device 220 on the recording medium 109 of the reception device 220. The received data is recorded following the header recorded in step S411.

  In step S414, the central processing unit 101 of the receiving device 220 determines whether reception of all data has been completed. If it is determined that reception of all data has been completed, the process ends. If it is determined that the reception of all data has not been completed, the process returns to the step, and the processing of S411 and S412 is repeated until the reception of all data is completed.

  As described above, in the transmission processing of transmitting the transcoded moving image file or the processing of steps S410 to S414 in the case of the normal transmission processing, the header of the received moving image file and the moving image data are transmitted to the receiving device 220 in the order received. The information is recorded on the recording medium 109. In the case of the transmission process of transmitting the transcoded video file, the header of the video file of the transcoded video data and the transcoded video data are sequentially received, and the recording medium 109 of the receiving device 220 is received in the received order. Recording is sequentially performed in a continuous area. In the case of the normal transmission processing, the header of the transmission target moving image file and the moving image data of the transmission target moving image file are sequentially received, and are recorded in a continuous area of the recording medium 109 of the receiving device 220 in the order of reception.

  As described above, according to the present embodiment, in the transcode transmission process of transmitting a moving image file while performing transcoding, the data of the moving image file is transmitted before the transcoding process of the moving image file is completed in the transmitting device. Start sending. The first header and the second header are stored before the moving image data in the moving image file, but if the transcoding process of the moving image data is not completed, the first header and the second header after the transcoding are generated. Can not do it. Thus, in the present embodiment, the header size of the third header composed of the first header and the second header is estimated and transmitted to the receiving device 220, and after transcoding, the third header is transmitted. I have. As a result, the receiving apparatus 220 secures a recording area for the third header, records the transcoded moving image data following the secured area, and then records the third header in the secured area. A moving image file can be recorded without performing the combining process.

  In the above embodiment, the transmitting device 210 transmits the size of the third header in step S308, and the receiving device 220 records a dummy header corresponding to the received size on the recording medium 109 of the receiving device 220 in step S403. And However, in step S308, the transmitting apparatus 210 transmits the third header size dummy data without transmitting the third header size, and the receiving apparatus 220 may record the received dummy data. Good. The third header includes a first header and a second header, but the size of the second header is fixed. Therefore, the estimated first header size is transmitted instead of the third header size, and the receiving device adds the second header size to the received first header size to reduce the size of the third header. You may ask for it.

  In the above-described embodiment, the transmission device 210 transmits the third header size in step S308 before starting the transcoding process of the moving image data. However, the transcoding process of the moving image data may be started before transmitting the third header size. However, the transmission processing of the third header size is performed before the completion of the transcoding processing of the moving image data and before the transmission of the transcoded moving image data to the receiving device is started.

  In the above-described embodiment, the first header is composed of the ftyp box and the moov box. However, since the ftyp box can be generated even before the completion of the transcoding process of the moving image data, the first header may be only the moov box. In this case, the transmitting device 210 transmits the ftyp box to the receiving device 220, and after transmitting the ftyp box, transmits the size of the third header including the first header and the second header. Then, the receiving device records the received ftyp box on the recording medium 109 of the receiving device 220, and thereafter records the received dummy data having the same size as the third header size in the ftyp box. Then, after transcoding the moving image data, the transmitting device 210 generates a first header and a second header and transmits the first header and the second header to the receiving device 220 as a third header, and the receiving device 220 Over the area where the dummy data is recorded.

  In the above embodiment, the moving image file has an ftype box, a moov box, and an mdat box. However, the present invention is also applicable to a case where an additional box other than the moving image data, for example, for storing various detection results when the moving image data is captured, is provided after the mdat box. When performing a transmission process while transcoding a moving image file having an additional box, the additional box is transmitted after the moving image data stored in the mdat box is transcoded and transmitted from the transmitting device 210 to the receiving device 220. To do. The data in the additional box is transmitted without transcoding. Then, it is preferable to perform the generation and transmission processing of the header after S313. In the receiving device 220, after the transcoded moving image data is recorded on the recording medium 109 as the data of the mdat box, the additional box received thereafter is recorded in the area of the recording medium 109 following the mdat box. After that, when a header overwrite instruction is received in S406, the processing in S407 and thereafter is performed.

  In the above-described embodiment, the structure of each box in the moving image file is such that the first 4 bytes store the size of the box, the next 4 bytes store the type of the box, and the box data thereafter. However, in this case, the size data must be described in 4 bytes, so that the size of the box can be expressed only up to 4 Gbytes. On the other hand, the mdat box for storing moving image data may exceed 4 Gbytes. In order to store data of 4 GB or more in the mdat box, the extension flag is stored in the first 4 Bytes of the mdat box, the type is stored in the subsequent 4 Bytes, the size of the box is stored in the subsequent 8 Bytes, and then the data in the mdat box is stored. There is a way to store. For the moving image file generated by this method, the first 16 bytes of the mdat box, that is, the size storage area (4 bytes) for storing the extension flag, the type storage area (4 bytes), and the extension for storing the actual size of the box The size storage area (8 bytes) in the function is used as a second header.

(Other embodiments)
As described above, the present invention has been described in detail based on the preferred embodiments. However, the present invention is not limited to these specific embodiments, and various forms that do not depart from the gist of the present invention are also included in the present invention. included. A part of the above-described embodiments may be appropriately combined.

  The object of the present invention is also achieved by executing the following processing. That is, a software program for realizing the functions of the above-described embodiments is supplied to a system or an apparatus having one or more computers capable of executing the program directly from a non-volatile recording medium or using communication, and the program is executed. The present invention includes the case of executing. In addition, since the functions of the present invention are implemented by computer, the program code supplied and installed in the computer also implements the present invention.

Reference Signs List 101 Central processing unit 102 Imaging lens 103 Imaging unit 104 Display unit 105 Operation unit 106 Image processing unit 107 Non-volatile memory 108 Main storage unit 109 Recording medium 110 Communication interface 111 Wireless communication antenna

Claims (19)

A transmission device for transmitting data of a video file to an external device,
Conversion means for converting the video data of the video file;
Control means for performing control for transmitting a moving image file of the moving image data converted by the converting means to the external device,
The control means includes:
Before the conversion of the moving image data by the conversion unit is completed, the size of the first header of the moving image data converted by the conversion unit is estimated, and data corresponding to the estimated first header size is converted to the data. First control means for controlling transmission to an external device;
A second control unit that controls transmission of the moving image data converted by the conversion unit to the external device after transmission of data according to the size of the first header;
After transmitting the converted moving image data, a third control unit that generates a first header corresponding to the converted moving image data and controls the generated first header to be transmitted to the external device. When,
A transmission device comprising:   The transmitting apparatus according to claim 1, wherein the first control means controls to transmit information of a header size corresponding to the estimated first header size to the external device.   The transmitting apparatus according to claim 1, wherein the first control means controls to transmit dummy data corresponding to the estimated size of the first header to the external device.   The third control means generates the first header and the second header corresponding to the converted moving image data, and sends the generated first header and the second header to the external device. The transmitting device according to claim 1, wherein the transmitting device is controlled to transmit.   2. The control device according to claim 1, wherein the third control unit controls the external device to transmit a third header obtained by connecting the second header after the generated first header. 3. The transmitting device according to claim 1.   5. The apparatus according to claim 4, wherein the first control unit controls to transmit data corresponding to a header size including the first header and the second header to the external device. 6. Transmission device.   The first control unit estimates the size of the first header according to a conversion format when converting the moving image data by the conversion unit and a size of the moving image data before conversion. The transmission device according to claim 1.   The transmission device according to claim 1, wherein the conversion unit converts at least one of a compression format, a resolution, a bit rate, and a frame rate of the moving image data included in the moving image file.   When the size of the first header estimated by the first control means is larger than the size of the first header generated by the third control means, the third control means The transmitting apparatus according to claim 1, wherein padding data is added to the first header to control transmission to the external apparatus.   The third control means controls so as to transmit to the external device a third header obtained by connecting the first header to which the padding data is added and the second header. Item 10. The transmitting device according to any one of Items 4 and 9. The first header is a video file header,
The transmission device according to claim 4, wherein the second header is a header of moving image data. The moving image file includes an ftype box, a moov box for storing meta information, and an mdat box for storing moving image data.
The first header is an ftyp box and a moov box, or a moov box;
The transmission device according to claim 4, wherein the second header is a header of an mdat box. After converting the moving image data converted by the converting unit, a fourth control unit controls the header corresponding to the converted moving image data and the converted moving image data to be transmitted to the external device. And
When transmitting the moving image file by the first transmission processing, the data of the moving image file is transmitted to the external device under the control of the first control means, the second control means, and the third control means. And transmitting the moving image file by the second transmission process, wherein the control of the fourth control means controls to transmit the data of the moving image file to the external device. The transmission device according to claim 1.   2. The transmitting apparatus according to claim 1, wherein the second control unit starts transmission of a part of the moving image data converted by the converting unit before conversion of all the moving image data is completed. . A receiving device that records data received from an external device on a recording medium,
When receiving data of a moving image file transmitted from the external device in the first transmission processing, in response to receiving data relating to a header size of the moving image data, a dummy corresponding to the size of the received data is received. Recording data on the recording medium, thereafter recording the received moving image data in an area following the dummy data on the recording medium, and then controlling to overwrite and record the received header over the dummy data. 1 control means;
When receiving data of a moving image file transmitted from the external device in the second transmission process, a second control unit that controls the data received from the external device to be sequentially recorded on the recording medium,
A receiving device comprising: A control method of a transmission device for transmitting a moving image file of moving image data converted by the conversion unit to an external device,
Before the conversion of the moving image data by the conversion unit is completed, the size of the first header of the moving image data converted by the conversion unit is estimated, and data corresponding to the estimated first header size is converted to the data. A first control step of controlling transmission to an external device;
A second control step of controlling to transmit the moving image data converted by the conversion unit to the external device after transmitting the data according to the size of the first header;
A third control step of generating a first header corresponding to the converted moving image data after transmitting the converted moving image data, and controlling transmission of the generated first header to the external device; When,
A transmission device control method, comprising: A method for controlling a receiving device that receives a moving image file from an external device,
When receiving data of a moving image file transmitted from the external device in the first transmission processing, in response to receiving data relating to a header size of the moving image data, a dummy corresponding to the size of the received data is received. Recording data on the recording medium, thereafter recording the received moving image data in an area following the dummy data on the recording medium, and then controlling to overwrite and record the received header over the dummy data. 1 control process;
When receiving data of a moving image file transmitted from the external device in the second transmission process, a second control step of controlling to sequentially record the data received from the external device on the recording medium,
A method for controlling a receiving device, comprising:   A program for causing a computer to function as each unit of the transmission device according to any one of claims 1 to 14.   A program for causing a computer to function as each unit of the receiving device according to claim 15.

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