JP5100581B2 - Information transmitting apparatus, method and program, and imaging apparatus - Google Patents

Description

  The present invention relates to an information transmission apparatus, a method and a program, and an imaging apparatus that transmit management information of a file such as a moving image file in response to a request from an external apparatus.

  2. Description of the Related Art In recent years, various moving images can be taken with a digital camera, a digital camera, or the like (hereinafter, camera). In the camera, the input moving image information is encoded to generate moving image encoded information, while the input audio signal is encoded to generate audio encoded information. Some have a moving image processing apparatus that multiplexes and records audio encoded information and reproduces it. Some of these apparatuses use MPEG-4 (Moving Picture Experts Group Phase 4) compression technology for moving picture information.

  An MOV file format exists as a file format for storing an MPEG-4 stream. When the MPEG-4 stream is stored in the MOV file format, the MPEG-4 stream data can be recorded from the beginning of the file, and the moving image management information of the MOV file can be recorded behind the stream data. The MOV file can be used efficiently by recording with such an arrangement.

JP 2007-166553 A

  However, when the MPEG-4 stream is stored in the MOV file format as described above, there is a problem that playback and cueing cannot be performed until the moving image management information recorded at the end of the file is read (patent). (Refer to Literature 1).

  This problem has a great influence not only on reproduction but also on moving image transfer processing. For example, when a digital camera and a personal computer (PC) are connected, the PC requests information on still images and moving image files possessed by the digital camera. Since the still image holds its own information in the header portion, the digital camera can easily obtain the information required from the PC. However, in the case of a moving image file such as the MOV file format, when accessing the moving image management information representing the content, features, and attributes of the moving image, it takes time for disk access, parsing processing in the file, etc. There is a problem that transfer is not possible.

  There are various types of moving image file formats, and the method for storing moving image management information differs depending on the format. Therefore, it is required to efficiently acquire the moving image management information according to the moving image file format.

  The present invention has been made in view of the actual situation, and in the transmission processing of moving image management information, an information transmission device that efficiently acquires moving image management information regardless of the file format of the moving image file and realizes high-speed transmission processing The purpose is to provide.

An information transmission apparatus according to the present invention is an information transmission apparatus for transmitting management information on a plurality of files of different file formats recorded in a storage medium in response to a request, and the file of the file for which the management information is requested When the file identification means for identifying the format and the file identification means identify the first file format, the management information is requested to read the file, and when the file is identified as the second file format, A file reading unit that reads a subfile associated with the file for which the management information is requested, and a management information acquisition unit that acquires the management information from the file or subfile read by the file reading unit, To do.
The information transmission method of the present invention is an information transmission method for transmitting management information on a plurality of files of different file formats recorded in a storage medium in response to a request, wherein the file for which the management information is requested A file identification step for identifying the file format, and when the file identification step identifies the first file format, when the file requested for the management information is read and identified as the second file format A file reading step for reading a subfile associated with the file for which the management information is requested, a management information acquiring step for acquiring the management information from the file or subfile read in the file reading step, and the management information Transmitting the management information acquired in the acquisition step. The features.
The program of the present invention is a program for causing a computer to execute an information transmission method for transmitting management information on a plurality of files of different file formats recorded on a storage medium in response to a request. A file identification step for identifying a file format of a file for which information is requested; and a file for which the management information is requested when the file identification step identifies the first file format; A file reading step for reading a subfile associated with the file for which the management information is requested, and management information acquisition for acquiring the management information from the file or subfile read in the file reading step. Before the management information acquisition step Is a program for executing the steps on a computer that transmits the management information.
In addition, an imaging apparatus according to the present invention includes the information transmission device described above.

  According to the present invention, when transmission of management information such as video management information is requested, the management information can be efficiently acquired regardless of the file format of the file having the management information, and a response to the request Can be performed at high speed.

Embodiments of the present invention will be described below with reference to the drawings.
(First embodiment)
<Apparatus configuration of digital camera 100>
FIG. 1 is a diagram showing a configuration of a digital camera 100 according to the first embodiment of the present invention. In FIG. 1, reference numeral 100 denotes a digital camera. The digital camera 100 is an imaging device that can capture still images and moving images, and can be connected to an external device such as a personal computer via a network to transmit images. In the present embodiment, the information transmitting apparatus according to the present invention is configured in the digital camera 100 and transmits information in response to a request from an external apparatus. Hereinafter, components of the digital camera 100 will be described with reference to FIG.

  In the digital camera 100, 10 is a photographing lens, 12 is a shutter having a diaphragm function, 14 is an image sensor that converts an optical image into an electrical signal, and 16 is an A / D converter that converts an analog signal output from the image sensor 14 into a digital signal. It is a vessel.

  A timing generation circuit 18 supplies a clock signal and a control signal to the image sensor 14, the A / D converter 16, and the D / A converter 26. The timing generation circuit 18 is controlled by the memory control circuit 22 and the system control circuit 50.

  An image processing circuit 20 performs predetermined pixel interpolation processing and color conversion processing on the data from the A / D converter 16 or the data from the memory control circuit 22. The image processing circuit 20 performs predetermined calculation processing using the captured image data, and the system control circuit 50 controls the exposure control unit 40 and the distance measurement control unit 42 based on the obtained calculation result. I do. As a result, the digital camera 100 performs TTL (through the lens) AF (autofocus) processing, AE (automatic exposure) processing, and EF (flash pre-emission) processing. Further, the image processing circuit 20 performs predetermined arithmetic processing using captured image data, and also performs TTL AWB (auto white balance) processing based on the obtained arithmetic result.

  A memory control circuit 22 controls the A / D converter 16, the timing generation circuit 18, the image processing circuit 20, the image display memory 24, the D / A converter 26, the memory 30, and the compression / decompression circuit 32. Data output from the A / D converter 16 is written into the image display memory 24 or the memory 30 via the image processing circuit 20, the memory control circuit 22, or directly via the memory control circuit 22.

  Reference numeral 24 denotes an image display memory, 26 denotes a D / A converter, and 28 denotes an image display unit including a TFT / LCD. Display image data written in the image display memory 24 is stored in the D / A converter 26. Via the image display unit 28. If the image data captured using the image display unit 28 is sequentially displayed, the electronic viewfinder function can be realized. The image display unit 28 can arbitrarily turn on / off the display according to an instruction from the system control circuit 50. When the display is turned off, the power consumption of the digital camera 100 can be significantly reduced. it can.

  Reference numeral 30 denotes a memory for storing captured still images and moving images, and has a sufficient storage capacity to store a predetermined number of still images and a predetermined time of moving images. Thereby, even in the case of continuous shooting or panoramic shooting in which a plurality of still images are continuously shot, it is possible to write a large amount of images to the memory 30 at high speed. The memory 30 can also be used as a work area for the system control circuit 50.

  A compression / decompression circuit 32 compresses and decompresses image data by adaptive discrete cosine transform (ADCT) or the like. The compression / decompression circuit 32 reads an image stored in the memory 30, performs a compression process or an expansion process, and writes the processed data to the memory 30.

  Reference numeral 40 denotes an exposure control unit that controls the shutter 12 having an aperture function, and has a flash light control function in cooperation with the flash 48. A distance measuring control unit 42 controls focusing of the photographing lens 10. A zoom control unit 44 controls zooming of the photographing lens 10. A barrier control unit 46 controls the operation of the protection unit 103 serving as a barrier. A flash 48 has an AF auxiliary light projecting function and a flash light control function.

  The exposure control unit 40 and the distance measurement control unit 42 are controlled using the TTL method. Based on the calculation result obtained by calculating the captured image data by the image processing circuit 20, the system control circuit 50 performs the exposure control unit 40 and the distance measurement. The controller 42 is controlled.

  A system control circuit 50 controls the entire digital camera 100, and a memory 52 stores constants, variables, programs, and the like for the operation of the system control circuit 50. Reference numeral 54 denotes a display unit such as a liquid crystal display device or a speaker that displays an operation state, a message, and the like using characters, images, sounds, and the like in accordance with execution of a program in the system control circuit 50. The display unit 54 is installed at a single or a plurality of positions near the operation unit of the digital camera 100 so that the display unit 54 can be visually recognized. The display unit 54 has a part of its function installed in the optical viewfinder 104.

  Among the display contents of the display unit 54, what is displayed on the LCD or the like includes single shot / continuous shooting display, self-timer display, compression rate display, recording pixel number display, recording number display, remaining image number display, shutter speed Display, aperture value display, etc. Furthermore, exposure compensation display, flash display, red-eye reduction display, macro shooting display, buzzer setting display, clock battery level display, battery level display, error display, multi-digit number information display, external recording medium 120 There are attachment / detachment status display, communication I / F operation display, date / time display, and the like.

  Among the display contents of the display unit 54, what is displayed in the optical viewfinder 104 includes in-focus display, camera shake warning display, flash charge display, shutter speed display, aperture value display, exposure correction display, and the like.

  Reference numeral 56 denotes an electrically erasable / recordable nonvolatile memory such as an EEPROM. Reference numerals 60, 62, 64, 66, 68 and 70 are operation means for inputting various operation instructions of the system control circuit 50. These operating means are configured by a single or a combination of a switch, dial, touch panel, pointing by eye-gaze detection, a voice recognition device, and the like. Here, a specific description of these operating means will be given.

  Reference numeral 60 denotes a mode dial switch, which can switch and set various function modes such as power-off, automatic shooting mode, shooting mode, panoramic shooting mode, playback mode, multi-screen playback / erase mode, and PC connection mode.

  Reference numeral 62 denotes a shutter switch SW1, which is turned on during operation of a shutter button (not shown), and performs AF (auto focus) processing, AE (auto exposure) processing, AWB (auto white balance) processing, EF (flash pre-flash) processing, and the like. Instruct the start of operation.

  Reference numeral 64 denotes a shutter switch SW2, which is turned on upon completion of an operation of a shutter button (not shown) and instructs the start of the next operation. First, an exposure process that writes image data to the memory 30 via the A / D converter 16 and the memory control circuit 22 for the signal read from the image sensor 14, and a development process that uses operations in the image processing circuit 20 and the memory control circuit 22 Instruct. Then, the image data is read from the memory 30, compressed by the compression / decompression circuit 32, and a recording process instruction for writing the image data to the external recording medium 120 is given.

  Reference numeral 66 denotes an image display ON / OFF switch, which can set ON / OFF of the image display unit 28. With this function, when taking an image using the optical viewfinder 104, it is possible to save power by cutting off the current supply to the image display unit 28 including a TFT / LCD or the like.

  Reference numeral 68 denotes a quick review ON / OFF switch, which sets a quick review function for automatically reproducing image data taken immediately after photographing. In the present embodiment, in particular, a function for setting a quick review function when the image display unit 28 is turned off is provided.

  An operation unit 70 includes various buttons and a touch panel, and includes a menu button, a set button, a macro button, a multi-screen playback page break button, a flash setting button, a single shooting / continuous shooting / self-timer switching button, and the like. Furthermore, menu movement + (plus) button, menu movement-(minus) button, playback image movement + (plus) button, playback image-(minus) button, shooting image quality selection button, exposure compensation button, date / time setting button Etc.

  Reference numeral 80 denotes a power supply control unit, which includes a battery detection circuit, a DC-DC converter, a switch circuit that switches blocks to be energized, and the like. The power supply control unit 80 detects the presence / absence of a battery, the type of battery, and the remaining battery level, and controls the DC-DC converter based on the detection result and the instruction of the system control circuit 50, and requires the necessary voltage. It is supplied to each part including the recording medium for a long period.

  Reference numeral 82 denotes a connector, 84 denotes a connector, and 86 denotes a primary battery such as an alkaline battery or a lithium battery, a secondary battery such as a NiCd battery, a NiMH battery, or a Li battery, an AC adapter, or the like.

  A card controller 90 transmits and receives data to and from an external recording medium such as a memory card. 91 is an interface with an external recording medium such as a memory card, and 92 is a connector for connecting to an external recording medium such as a memory card. Reference numeral 98 denotes recording medium attachment / detachment detection means for detecting whether or not the external recording medium 120 is attached to the connector 92. Reference numeral 120 denotes an external recording medium such as a memory card. In the present embodiment, a single or a plurality of interfaces and connectors for attaching a recording medium may be provided. Moreover, it is good also as a structure provided with combining the interface and connector of a different standard. The interface and the connector may be configured using a PCMCIA card, a CF (Compact Flash (registered trademark)) card, or the like based on a standard. Furthermore, when the interface 91 and the connector 92 are configured using a standard conforming to a PCMCIA card or a CF (compact flash) card, various communication cards can be connected. Examples of the communication card include a LAN card, a modem card, a USB card, an IEEE 1394 card, a P1284 card, a SCSI card, and a PHS. By connecting such various communication cards, image data and management information attached to the image data can be transferred to and from other computers and peripheral devices such as a printer.

  Reference numeral 101 denotes a face detection unit. The face detection unit 101 analyzes the image data processed by the image processing circuit 20 and the image data stored in the image display memory 24, and detects an area considered to be a face in the image data. When the face detection unit 101 detects a region that seems to be a face, it outputs the likelihood that it is considered a human face, the position in the input image data, the size, and the like. It is also possible to output the feature amount of each feature point of the detected face.

  Reference numeral 102 denotes an image comparison unit. Image pattern matching is performed on the two images recorded in the image display memory 24 and the memory 30 based on the color information, and a difference between the images is detected.

  A protection unit 103 is a barrier that prevents the imaging unit from being soiled or damaged by covering the imaging unit including the photographing lens 10 of the digital camera 100.

  Reference numeral 104 denotes an optical viewfinder, which enables photographing using only the optical viewfinder 104 without using the electronic viewfinder function of the image display unit 28. In the optical viewfinder 104, some functions of the display unit 54, for example, a focus display, a camera shake warning display, a flash charge display, a shutter speed display, an aperture value display, an exposure correction display, and the like are installed.

A communication unit 110 has various communication functions such as RS232C, USB, IEEE1394, P1284, SCSI, modem, LAN, and wireless communication. Reference numeral 111 denotes a connector for connecting the digital camera 100 to another device by the communication unit 110 or an antenna in the case of wireless communication.
The above is the overall configuration of the digital camera 100.

<Video file format>
Next, the file format of the moving image file used by the digital camera 100 according to this embodiment will be described. In the digital camera 100, an AVI file and an MOV file can be selected and recorded as a moving image file format, and moving images of other file formats can be handled.

<AVI file>
First, an AVI file that is one of the file formats of a moving image file will be described. The AVI file is configured in a RIFF (Resource Interchange File Format) format. The RIFF format is a file format of moving image file data for making various resources into one file. That is, video data compressed by different compression methods, a plurality of audio data, and the like can be stored, and the basic structure does not change regardless of the stored data. The file format of the RIFF format is composed of blocks called chunks as one unit. All chunks are classified as RIFF chunks, LIST chunks or sub-chunks. The RIFF chunk and the LIST chunk can recursively have a LIST chunk or a sub chunk in the data area.

  FIG. 2 is a diagram showing an image of a file format in the RIFF format. In FIG. 2, 201 indicates an image of the RIFF chunk.

  In the RIFF chunk 201, 202 is a chunk ID for identifying the type of chunk. In the case of the RIFF chunk, a character string “RIFF” is set in the first 4 bytes. Note that the first chunk of the AVI file needs to be a RIFF chunk. Reference numeral 205 denotes chunk data which is a data portion of the RIFF chunk. 203 is a chunk size indicating the byte length of the chunk data 205. A form type 204 is described in the first 4 bytes of the chunk data 205. In the case of an AVI file, a character string “AVI” is described.

  In FIG. 2, 211 indicates an image of the LIST chunk. In the LIST chunk 211, reference numeral 212 denotes a chunk ID for identifying the type of chunk. In the case of a LIST chunk, a character string “LIST” is set in the first 4 bytes. Reference numeral 215 denotes chunk data which is a data portion of the LIST chunk. Reference numeral 213 denotes a chunk size indicating the byte length of the chunk data 215. 214 is a form type described in the first 4 bytes of the chunk data 215, and the meaning of the LIST chunk is defined by the described character string.

  In FIG. 2, reference numeral 221 denotes an image of a sub chunk. In the sub chunk 221, 222 is a sub chunk ID for identifying the type of the sub chunk. Reference numeral 224 denotes sub chunk data which is a data portion of the sub chunk. Reference numeral 223 denotes a sub chunk size indicating the byte length of the sub chunk data 224.

  FIG. 3 shows an image of the entire AVI file in the RIFF format. The AVI file is composed of the various chunks described above.

  In FIG. 3, reference numeral 301 denotes a RIFF chunk whose form type is “AVI”. 302, 310 and 312 are LIST chunks, and 315 is a sub-chunk. In this example, the RIFF chunk 301 includes a LIST chunk 302, a LIST chunk 310, a LIST chunk 312 and a sub chunk 315 in the chunk data area. The LIST chunk 302 has a form type “hdrl”, the LIST chunk 310 has a farm type “INFO”, the LIST chunk 312 has a form type “movi”, and the sub chunk 315 has a sub chunk ID “idx1”. .

  The LIST chunk 302 includes a sub chunk 303, a LIST chunk 304, and a LIST chunk 307. In this case, the sub chunk 303 has a sub chunk ID “avih”, and includes a main AVI header structure in the sub chunk data area. The members of the main AVI header structure include the frame interval, the maximum bit rate per second, the total number of frames, the image size, and the like.

  The LIST chunk 304 has a form type “strl”, and the LIST chunk 307 has a form type “strl”. The LIST chunk 304 includes a sub chunk 305 and a sub chunk 306.

  The sub chunk 305 has a sub chunk ID “strh” and includes an AVI stream header structure in the sub chunk data area. The members of the AVI stream header structure include the codec type, time scale, sample rate, and the like of the stream. Note that the playback time of the moving image is calculated from this time scale and the sample rate.

  The sub chunk 306 has a sub chunk ID “strf” and includes a BITMAPINFO structure in the sub chunk data area. The members of the BITMAPINFO structure include a bitmap size and the like.

  The LIST chunk 307 includes a sub-chunk 308 and a sub-chunk 309.

  The sub chunk 308 has a sub chunk ID “strh” and includes an AVI stream header structure in the sub chunk data area. The sub chunk 309 has a sub chunk ID “strf”, and includes a WAVE FORMAT structure in the sub chunk data area. The members of the WAVEFORMAT structure include the audio codec type, the number of channels, the audio sample rate, the audio bit rate, the number of bits per sample, and the like.

  Next, the LIST chunk 310 includes a sub chunk 311 having a sub chunk ID “ISFT” and having an AVI stream header structure described later in the sub chunk data area.

  Next, the LIST chunk 312 includes a sub chunk 313 having a sub chunk ID “01wb” and having audio data in the sub chunk data area, and a sub chunk ID having “00 dc” and having video data in the sub chunk data area. A chunk 314. Note that the sub-chunk having audio data and the sub-chunk having video data exist repeatedly according to the number of recorded frames. By reading and reproducing the audio data and video data of sub-chunks included in the chunk data of the LIST chunk 312 in order, reproduction of moving image data is realized by a moving image reproduction apparatus or the like. In FIG. 3, a sub chunk 313 including audio data is audio data that is read first when the AVI file is reproduced, and a sub chunk 314 including video data is image data that is read first when the AVI file is reproduced. is there.

  Next, the sub chunk 315 is an index unit for storing the offset value on the AVI file of the audio data and video data recorded in the chunk data of the LIST chunk 312 and the byte size of the audio data and video data. is there. In the sub chunk 315, 316 indicates the first entry and 317 indicates the second entry. Each of the sub chunks 313 of the LIST chunk 312 corresponds to the entry 316, and the sub chunk 314 corresponds to the entry 317 on a one-to-one basis. Each entry holds various information of the sub chunks 313 and 314, and includes an ID, a flag, an offset from the top of the chunk data of the LIST chunk 312 and the size of the sub chunk data. By using each entry such as the entries 316 and 317 for the reproduction of the AVI file, smooth access to the audio data and video data in the LIST chunk 312 is provided.

<MOV file>
Next, an MOV file that is a moving image file format different from the AVI file will be described. The MOV file is a moving image file format that can store various video and audio data, like the AVI file. MPEG-4 is a typical data to be stored.

  Images constituting MPEG-4 moving images can be classified into three types: I pictures (also called key frames), P pictures, and B pictures. The I picture is an Intra encoded image, that is, an intra-frame encoded image. A P picture is a Predictive encoded image, that is, an inter-frame forward prediction encoded image, and an image is restored using prediction from an I or P picture. The B picture is Bidirectionally Predictive coding information, that is, a bidirectional predictive encoded image, and a screen is restored from the forward interframe prediction code, the reverse interframe prediction code, and the interpolated interframe prediction code.

  As described above, when an arbitrary moving image of an MPEG-4 moving image encoded stream composed of an I picture, a P picture, and a B picture is accessed and reproduced, a complete image may not be decoded. For example, a case in which a filed MPEG-4 moving image encoded stream is randomly accessed can be considered.

  In this case, when the user randomly accesses the file (special playback such as cue playback), if playback is started from the position of the I picture, the I picture is an intra-frame encoded image, and is a complete picture by itself. Can be reproduced without any problem. However, if playback is to be started from the position of a P picture or B picture, these are predictive coded images, so that frame information before that frame is required to restore the image, and the complete image is not restored. .

  In order to avoid such a situation, when a user tries to access a P picture or a B picture by random access, it is necessary to control to automatically start decoding from the immediately preceding I picture.

  The MOV file can cope with restoration for such random access. The MOV file multiplexes the moving image encoded stream generated by the MPEG-4 moving image compression technique and the audio encoded stream, and stores the multiplexed stream as one file in the storage medium. In the moving picture management information portion in the MOV file, the positions of all the frames are recorded with the number of bytes offset from the head of the file, and the frame numbers of I pictures are listed. With such a format, the MOV file can be played back by the random access.

  Here, the moving image management information of the MOV file refers to video and audio information in addition to information necessary for video and audio decoding, such as the two pieces of information described above (the number of bytes of offset and the frame number of I picture). It contains various information indicating contents, characteristics, and attributes. For example, same as AVI file such as frame interval, total number of frames, image size, video and audio codec type, time scale, sample rate, number of audio channels, audio sample rate, audio bit rate, number of bits per sample Contains information. On the other hand, some data is included in the AVI file, such as the maximum bit rate per second, but is not included in the MOV file. Because the file formats are different, they do not always have the same information. Therefore, processing such as calculation using other data is necessary to acquire the same information.

  When a moving image is recorded in such a MOV file format, the stream data increases with time and its size is very large. Therefore, it is necessary to write the stream data to a file even during recording. However, since the size of the movie management information portion of the MOV file format increases according to the recording time as described above, the size of the movie management information portion is unknown until recording is completed, and the stream data is written to the file. The offset position cannot be determined. Therefore, in a general moving image processing apparatus, using the flexibility of the MOV file format, the stream data (Mdat area) is arranged at the head of the file, and the moving image management information (Moov area) of the MOV file is stored in the stream data at the end of recording. Place behind and record. FIG. 4 is a diagram showing an image of the MOV file. In FIG. 4, reference numeral 400 denotes stream data (Mdat area), and 401 denotes moving image management information (located in the Moov area and footer area) recorded at the end of the file.

<Difference between AVI file and MOV file>
In the description up to here, in the AVI file format, the moving image management information such as the main AVI header structure, the AVI stream header structure, and the WAVEFORMAT structure is stored in the header area at the head of the file as described above. On the other hand, in the MOV file format, the moving picture management information in the MOV file described above is arranged and stored at the end portion (footer area) of the file. In this respect, the file structure is greatly different between the two. From this difference, the following can be said when handling AVI files and MOV files.
That is, when moving image management information is acquired from the AVI file format arranged in the header portion, there are few media accesses and the file can be easily parsed, so that it can be acquired at high speed. On the other hand, when it is arranged at the end of the file as in the MOV file format, it takes time to parse and the moving image management information cannot be easily acquired.

  Therefore, in this embodiment, in the MOV file format, a thumbnail file corresponding to a moving image file is created at the time of shooting, and moving image management information is added to the thumbnail so that the moving image management information in the MOV file can be easily acquired. To do. The details will be described below. The first file format referred to in the present invention is an example of an AVI file, and the second file format referred to in the present invention is an example of an MOV file.

<Procedure for recording information on thumbnails>
Hereinafter, a method for recording information in a thumbnail file at the time of moving image shooting in the MOV file format by the digital camera 100 according to the present embodiment will be described. FIG. 5 is a flowchart for explaining a procedure when the digital camera 100 records a moving image file and a thumbnail file at the time of moving image shooting. Note that the processing described below is performed by the system control circuit 50 reading a program from the memory 52 and executing it.

  When the moving image shooting is started, in step S501, the digital camera 100 stores the moving image audio information including the moving image reproduction time, the codec type, the maximum bit rate information of the moving image, the audio bit rate, the audio sample rate, and the number of audio channels. 52. Since the moving image playback time is obtained from the time scale and sample rate of the video, it may be the calculated playback time or two values of the time scale and sample rate. Also, regarding moving image playback time and moving image bit rate information, since moving image shooting has not yet started, an initial value (0) is stored.

  In step S502, the digital camera 100 creates a moving image file on the external recording medium 120, and the process advances to step S503.

  Next, in step S503, the digital camera 100 records the stream data in the moving image file created in step S502, and proceeds to step S504.

  Next, in step S504, the digital camera 100 updates the moving image playback time and moving image bit rate information stored in step S501, and proceeds to step S505.

  Next, in step S505, the digital camera 100 determines whether or not the moving image shooting stop button has been pressed. If it is determined that the stop button has been pressed, the process proceeds to step S506. If it is determined that the stop button has not been pressed, the process returns to step S503.

  In step S506, the digital camera 100 records the moving image playback time, codec type, and moving image audio information in the moving image file in the moving image management information area of the moving image file, and the process advances to step S507.

  In step S507, the digital camera 100 closes the moving image file created in step S502, and proceeds to step S508.

  In step S508, the digital camera 100 creates a thumbnail file on the external recording medium 120, and the process advances to step S509. Here, the file name of the thumbnail is the same as the moving image file name created in step S502 except for the extension. For example, the file name of the thumbnail corresponding to the moving image file name “MVI — 0001.MOV” is “MVI — 0001.THM”. Thereby, a moving image and a thumbnail can be associated.

  In step S509, the digital camera 100 reads the first frame from the moving image file once closed in step S507. In step S510, a thumbnail image is created from the first frame of the moving image file read in step S509, and the process proceeds to step S511.

  In step S511, the digital camera 100 records the information stored in steps S501 and S504 in a thumbnail file. At this time, data for confirming the association between the moving image and the thumbnail may be recorded together. As data for confirming the association, for example, a hash value or a file size created from the contents of the moving image file can be considered.

  In step S512, the digital camera 100 closes the thumbnail file and ends the moving image shooting process.

  The above is the information recording procedure to the thumbnail file when the digital camera 100 captures a moving image in the MOV file format. In the above-described processing, the moving image bit rate information is stored only in the thumbnail file. This is because the area for storing the moving picture bit rate information is not defined in the MOV file. For this reason, when obtaining the moving image bit rate information from the MOV file itself, it is necessary to newly calculate from the stream data of the MOV file. The processing described here corresponds to an example of processing by the file generation means referred to in the present invention, and the thumbnail file is an example of a subfile referred to in the present invention.

<Connection / Transfer Processing Between Digital Camera 100 and External Device (PC 600)>
Next, connection / transfer processing between the digital camera 100 and an external device will be described. First, FIG. 6 shows a configuration of a personal computer (PC) 600 that is an example of an external device that performs connection / transfer processing with the digital camera 100.

<Device configuration of external device>
In FIG. 6, 600 is a PC. Reference numeral 601 denotes a CPU that controls the entire apparatus. Reference numeral 602 denotes a display unit that displays an image or the like. Reference numeral 603 denotes a storage unit such as a hard disk for storing data such as images. A ROM (Read Only Memory) 604 stores control programs, various application programs (driver software, etc.), data, and the like. Reference numeral 605 denotes a RAM (random access memory) that is a work area used when the CPU 601 performs processing. Reference numeral 606 denotes an input unit such as a keyboard and a mouse.

<Object management method>
Next, an object management method of the digital camera 100 and the PC 600 according to the present embodiment will be described. In this embodiment, the information shown in FIG. 7 is recognized as attribute information of one object (moving image file in this embodiment), and the object is managed. The attribute information is roughly classified into two categories (category 1 and category 2).

  First, as classification 1 (simple information 701), information that can be acquired from file system information managed by the file system in the digital camera 100 is handled. These are pieces of information that can be easily obtained from the file system and take relatively little time to obtain. The simple information 701 includes FileName, FileSize, FileStamp, and the like.

  As classification 2 (complete information 702), information that cannot be acquired without decoding the contents of each file is handled. In other words, those that take time to obtain are classified as category 2. The complete information 702 includes the thumbnail data size, the number of vertical and horizontal pixels of the image, actual thumbnail data, various image properties, and the like. These various image properties include the playback time of the moving image file, codec type, bit rate, moving image audio information, and the like.

  These pieces of attribute information are basically used when the driver software operating on the PC 600 manages the object tree. However, even in the digital camera 100, in order to speed up the response to the second and subsequent acquisition requests for the same information, the information is held as a management table on the memory 52 such as an internal DRAM.

<Connection / transfer processing procedure>
Next, a procedure for connection / transfer processing between the digital camera 100 and the PC 600 will be described with reference to FIG. FIG. 8 is a flowchart for explaining a connection / transfer process procedure between the digital camera 100 and the PC 600. In the processing described below, the CPU 601 reads and executes the driver software from the ROM 604 in the operation performed by the PC 600, and the system control circuit 50 reads and executes the program from the memory 52 in the operation performed by the digital camera 100.

  First, in step S <b> 801, when the PC 600 is connected to the digital camera 100 through the connector 111, the PC 600 acquires device information such as a camera model name, a vendor name, supported operations, and event types from the digital camera 100. Then, preparation for communication with the digital camera 100 is made.

  In step S <b> 802, the PC 600 requests the digital camera 100 to search for a DCF-compliant folder in a subfolder existing under the DCIM folder in the recording medium provided in the digital camera 100. The digital camera 100 transmits the folder information to the PC 600, and the received PC 600 forms an object tree as a folder object. It is assumed that digital camera 100 according to the present embodiment conforms to DCF (Design Rule for Camera File system).

  Next, in steps S <b> 803 and S <b> 804, the PC 600 repeatedly acquires a part of each piece of object attribute information corresponding to the above-described classification 1 that does not take time to acquire all objects in the digital camera 100. Then, the object attribute information is stored in the previously created object tree. At the time of acquisition, the PC 600 requests the digital camera 100 for information to be stored in the object tree created in step S802.

  If the PC 600 determines in step S803 that information has been stored in the object tree, the process advances to step S805. When the storage of the object attribute information for all objects is completed, the operation of the driver software at the time of connection is completed.

  In step S805, the PC 600 determines whether there is a request from the application. If there is a request, the process proceeds to step S806; otherwise, the process ends.

  If a request from the application is generated in step S806, in step S806, the PC 600 determines whether it can respond with object attribute information corresponding to classification 1 (simple information) that has already been constructed as an object tree. If the response is possible, the process proceeds to step S807. If the response is impossible, the process proceeds to step S808.

  In step S807, the PC 600 does not access the digital camera 100, but returns object attribute information (simple information) corresponding to the classification 1 to the application.

  In step S808 when the request from the application cannot be answered with the object attribute information belonging to category 1, the PC 600 determines whether or not the object attribute information of category 2 exists. Here, it is necessary to acquire the object attribute information of category 2, but if the target object has a history acquired previously, it is already stored because it is stored in the object tree managed by the driver software. Check if it is. If the object attribute information is already held, in step S810, the PC 600 does not access the digital camera 100, and returns information to the application based on the held information (complete information).

  If the object attribute information is not held in the object tree, in step S809, the PC 600 requests the digital camera 100 to acquire the classification 2 (complete information) object attribute information that takes time. The digital camera 100 switches the file for acquiring the information in accordance with the requested information file format (AVI file or MOV file), acquires the classification 2 object attribute information, and transmits it to the PC 600. To do. Details of the information acquisition process of the digital camera 100 will be described later with reference to FIG. Then, class 2 object attribute information is acquired from the digital camera 100 and stored in the object tree. In step S810, the PC 600 returns the information acquired in step S809 to the application.

<Procedure for Information Acquisition Processing of Digital Camera 100>
FIG. 9 is a flowchart for explaining the details of the process in which the digital camera 100 repeatedly acquires part of each piece of object attribute information corresponding to the classification 2 requested from the PC 600.

  First, in step S901, the digital camera 100 selects a moving image file having object attribute information corresponding to the classification 2 requested from the PC 600, and proceeds to step S902.

  In step S902, the digital camera 100 determines whether the moving image file selected in step S901 is an AVI file format or a MOV file format. Here, the determination may be made simply from the extension of the file name of the target file, or may be made by reading the beginning of the file and simply checking the file. If it is the AVI file format, the process proceeds to step S903, and if it is the MOV file format, the process proceeds to step S904. Note that the processing in step S902 corresponds to a processing example of the file identification means in the present invention.

  In step S903, the digital camera 100 reads the header of the AVI file, while in step S904, reads the thumbnail file corresponding to the MOV file. Note that the processing in step S903 corresponds to a processing example of the file reading means in the present invention.

In step S905, if the digital camera 100 is an AVI file, the digital camera 100 acquires the reproduction time, codec type, bit rate, and moving image audio information of the moving image file from the AVI main header structure or WAVEFORMAT structure of the read AVI file. On the other hand, in the case of an MOV file, the reproduction time, codec type, bit rate, and moving image audio information of the moving image file saved in advance are acquired from the read thumbnail, and the processing ends. Thereafter, the digital camera 100 transmits these pieces of information to the PC 600. Note that the acquired playback time may be two values, a time scale and a sample rate. The processing in step S905 corresponds to a processing example of management information acquisition means in the present invention.
The above is the description of the first embodiment of the present invention.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. The difference between the second embodiment and the first embodiment lies in the process of repeatedly acquiring a part of each object attribute information corresponding to the above-described classification 2 by the digital camera 100. Since other hardware and system configuration are the same, description thereof will be omitted.

  FIG. 10 is a flowchart for explaining details of processing of the digital camera 100 according to the present embodiment.

  In step S1001, the digital camera 100 selects a moving image file having object attribute information corresponding to classification 2 requested from the PC 600, and proceeds to step S1002.

  In step S1002, the digital camera 100 determines whether the moving image file selected in step S1001 is an AVI file format or a MOV file format. Here, the determination may be made simply from the extension of the file name of the target file, or may be made by reading the beginning of the file and simply checking the file. If it is the AVI file format, the process proceeds to step S1003, and if it is the MOV file format, the process proceeds to step S1004.

  In step S1003, the digital camera 100 reads the header of the AVI file. On the other hand, in step S904, the digital camera 100 confirms the consistency between the MOV file and the thumbnail file associated therewith. Since the MOV file and the thumbnail file are separate files, the contents of the thumbnail file may not reflect the contents of the corresponding MOV file simply by associating with the file name according to the user's usage method or image management method. obtain. Therefore, in the present embodiment, for example, consistency is confirmed using values such as a hash value created from the data of the MOV file embedded in the thumbnail file and the file size of the MOV file.

  If the consistency is confirmed in step S1005, the digital camera 100 proceeds to step S1006 and reads a thumbnail file. If the consistency cannot be confirmed, a process for reading the footer of the MOV file is performed in step S1007 although it takes time.

Finally, in step S1008, the digital camera 100 acquires the reproduction time, codec type, bit rate, and moving image audio information of the moving image file from the AVI main header structure or WAVEFORMAT structure of the read AVI file if it is an AVI file. If the MOV file is consistent, the playback time, codec type, bit rate, and video / audio information of the moving image file are acquired from the read thumbnail, and if the consistency is not achieved, the footer. And the process here is complete | finished. Thereafter, the digital camera 100 transmits these pieces of information to the PC 600.
The above is the description of the second embodiment of the present invention.

  Heretofore, the first embodiment and the second embodiment of the present invention have been described. In the digital camera 100 according to the present embodiment, when the moving image management information of the moving image file is requested from the external device, the location (file where the moving image management information requested from the external device is acquired according to the format of the moving image format) ). With such a configuration, digital camera 100 according to the present embodiment can efficiently acquire moving image management information regardless of the format of the moving image format, and can perform high-speed information transmission to an external device. It becomes.

  In order to realize the present invention, a computer-readable storage medium that records a program code (computer program) of software that implements the functions of the above-described embodiments may be used. In this case, the object of the present invention is achieved by supplying the storage medium to the system or apparatus, and the computer (or CPU or MPU) of the system or apparatus reads and executes the program code stored in the storage medium.

  In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the program code itself and the storage medium storing the program code constitute the present invention.

  As a storage medium for supplying the program code, for example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

  Needless to say, the OS (basic system or operating system) running on the computer performs part or all of the actual processing based on the instruction of the program code.

  Furthermore, the program code read from the storage medium may be written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer. In this case, based on the instruction of the written program code, the CPU or the like provided in the function expansion board or function expansion unit may perform part or all of the actual processing.

It is a figure which shows the structure of the digital camera which concerns on the 1st Embodiment of this invention. It is a figure which shows the image of the file format of a RIFF format. It is a figure which shows the image of the whole AVI file of a RIFF format. It is a figure which shows the image of a MOV file. It is a flowchart explaining the procedure at the time of recording the moving image file and thumbnail file at the time of the video recording with the digital camera concerning the 1st Embodiment of this invention. It is a figure which shows the structure of the personal computer (PC) which is an example of the external device which performs a connection / transfer process with the digital camera which concerns on the 1st Embodiment of this invention. It is a figure explaining the attribute information which a digital camera and PC classify | categorize and handle in the 1st Embodiment of this invention. It is a flowchart explaining the procedure of the connection / transfer process of the digital camera and PC concerning the 1st Embodiment of this invention. It is a flowchart explaining the detail of the process which the digital camera which concerns on the 1st Embodiment of this invention repeatedly acquires a part of each object attribute information corresponded to the classification 2 requested | required from PC. It is a flowchart explaining the detail of the process which the digital camera which concerns on the 2nd Embodiment of this invention repeatedly acquires a part of each object attribute information corresponded to the classification 2 requested | required from PC.

Explanation of symbols

14 Image sensor 20 Image processing circuit 50 System control circuit 52 Memory 100 Digital camera 110 Communication unit 120 External recording medium 600 PC
601 CPU
604 ROM
605 RAM

Claims (12)

An information transmission device that transmits management information about a plurality of files of different file formats recorded in a storage medium in response to a request,
File identification means for identifying the file format of the file for which the management information is requested;
When the first file format is identified by the file identification means, the file requested for the management information is read. When the second file format is identified, the management information is converted into the requested file. A file reading means for reading the associated subfile;
An information transmission apparatus comprising: management information acquisition means for acquiring the management information from a file or subfile read by the file reading means.   The first file format is a format for recording the management information in a header area of the file, and the second file format is a format for recording the management information in a footer area of the file. The information transmission device according to claim 1. In the case where it is identified as the second file format, it further comprises confirmation means for confirming consistency between the file for which the management information is requested and the subfile associated therewith,
The information transmission apparatus according to claim 1, wherein the file reading unit reads the sub file when consistency is confirmed by the confirmation unit.   4. The information transmitting apparatus according to claim 3, wherein the file reading unit reads the file identified as the second file format by the file identifying unit when consistency is not confirmed by the confirmation unit. .   The information transmission apparatus according to claim 1, wherein the file is a moving image file.   6. The information transmission apparatus according to claim 5, wherein the sub file is a thumbnail file.   The information transmission apparatus according to claim 5 or 6, wherein the first file format is an AVI file, and the second file format is a MOV file.   8. The management information includes at least one of a reproduction time or time scale of a moving image file, a sample rate, a codec type, a bit rate, and moving image audio information. The information transmission apparatus according to item 1.   9. The apparatus according to claim 1, further comprising a file generation unit configured to generate a file in the second file format and generate a subfile including management information about the file. Information transmission device. An information transmission method for transmitting management information about a plurality of files of different file formats recorded on a storage medium in response to a request,
A file identification step for identifying a file format of the file for which the management information is requested;
When the file identification step identifies the first file format, the management information is read into the requested file. When the second file format is identified, the management information is converted into the requested file. A file reading step that reads the associated subfile;
A management information acquisition step for acquiring the management information from the file or subfile read in the file reading step;
And a step of transmitting the management information acquired in the management information acquisition step. A program for causing a computer to execute an information transmission method for transmitting management information about a plurality of files of different file formats recorded in a storage medium in response to a request,
A file identification step for identifying a file format of the file for which the management information is requested;
When the file identification step identifies the first file format, the management information is read into the requested file. When the second file format is identified, the management information is converted into the requested file. A file reading step that reads the associated subfile;
A management information acquisition step for acquiring the management information from the file or subfile read in the file reading step;
A program for causing a computer to execute the step of transmitting the management information acquired in the management information acquisition step.   An imaging apparatus comprising the information transmission apparatus according to claim 1.

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