JP2009049511A - Still image extracting device and still image extracting program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a still image extracting device for extracting a still image efficiently so as to store necessary amount of still images even when a receiver has small capacity enough to understand content of image data. <P>SOLUTION: The still image extracting device for extracting the still image using variable coding from the image data in order to create thumbnail data, comprises: a storage capacity acquiring means for acquiring information on a free space capacity of a storage means for storing the thumbnail data, a first still image extracting means for extracting the still image using a predetermined number of variable coding from the image data, an excessive image calculating means for calculating the excessive number of the still images based on the free space capacity and an average still image data capacity for one image obtained from the whole still image data capacity extracted by the first still image extracting means, and a second still image extracting means for extracting and recording the still image to be recorded by eliminating the excessive number of still images. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a still image extraction apparatus and a still image extraction program for extracting a still image from a moving image in order to create a thumbnail.

  The data of a program broadcast as a television broadcast includes video data and audio data. In addition, since the broadcast program data is included as video data, there are subtitles (introduction of program titles, casts, etc., or Japanese subtitles in overseas works) that cannot be selected by the user. May be included. In addition, the broadcast program data may include subtitle data that allows the user to select whether or not to display the program data. Such selectable subtitle data is generally called Closed Caption, and it was developed mainly for the hearing impaired, and not only the conversation of performers like Japanese subtitles in overseas works. For example, descriptions of BGM, sound effects, and the like are also included.

  For example, in NTSC (National Television System Committee) analog terrestrial broadcasting, 525 scanning lines are used for video signals. Of these 525 lines, one field is composed of two fields. The first 21 lines are allocated for an interval for starting scanning, which is called VBI (Vertical Blanking Interval). The closed caption is transmitted by multiplexing the character code in the 21st VBI of the VBIs in each field. Each field is used to transmit about 60 characters per second through two types of character sets.

  Regarding the transmission of caption information for digital television broadcasts, terrestrial digital television broadcast operation regulations / technical documents (ARIB TR-B14), BS / broadband CS digital broadcast operation regulations / technical documents (ARIB TR-B15) are domestic regulations. The subtitle information can be transmitted simultaneously with the transmission of the video information using the subtitle information transport stream. Then, in the receiver for digital television broadcasting, the code corresponding to the caption information is decoded, characters and figures constituting the caption are generated, and displayed superimposed on the video. In digital television broadcasting, the text information transmitted simultaneously with the transmission of video information using the transport stream for subtitle information is stored internally, and the text information stored internally can be displayed and viewed on a TV monitor at any time. Thus, there is a technique in which a user can utilize subtitle information without taking a note of the displayed subtitle (see, for example, Patent Document 1).

  In recent years, television broadcasts can be viewed on terminals that can be carried by users such as mobile phones and PDAs (Personal Digital Assistants). In addition, a program recorded by a recording device at home is recorded on a recording medium mounted on a portable device, and the recorded program is reproduced from the recording medium. Thus, the caption data to be broadcast has begun to be used for various services. In addition, a system is also provided in which television broadcasts themselves are received by various devices and the received programs can be browsed.

  However, a television broadcast is received by various devices, and a program broadcast by the television broadcast is recorded on a predetermined recording medium and viewed on a portable device, but the program is recorded. There is a limit to the capacity of recording media. In addition, when a condition of a recording medium that can be mounted (built in) in a portable device is added, the capacity of the usable recording medium is further limited.

  Therefore, when viewing a program on a portable device, only a short time program can be viewed (only a part of the program can be viewed), and if a high compression ratio is recorded to record a long time program, the video becomes rough and the image quality is improved. There was a problem of being lowered. For this reason, there was a problem that it did not spread. Therefore, there is a demand for a function that allows a portable device to browse a long program or a plurality of programs while preventing the image quality from being deteriorated.

In order to solve such a problem, even in a portable device, in order to be able to view a plurality of programs and long-time programs, a television broadcast program instructed by a mobile phone is recorded, and this program is recorded. There is known an information processing apparatus capable of grasping the contents of a program by converting the recorded program into thumbnail image data and text data associated with time information and displaying the data (for example, see Patent Document 2). .
JP 2003-078889 A JP 2006-253960 A

  By the way, in order to easily understand the content of video content such as broadcast programs, the content of the content is displayed by displaying subtitle data (text data) attached to the video and still images (thumbnail images) extracted from the video data. Can be browsed or searched. In this case, in order to understand the contents, it is necessary to extract a necessary amount of still images from a video without excess or deficiency, but it is not realistic to extract still images from long-time video data by hand. Also, if you use a mobile device to download and view content, it can be delivered in real time in an environment where radio waves reach, but if you want to use it in an environment where radio waves do not reach after downloading, There is a possibility that the image cannot be stored in a portable terminal with a small storage capacity. In such a case, it is necessary to limit the still image capacity, that is, the number of still images, and prepare and distribute it for download so that it can be stored in a portable terminal with a small storage capacity. This is easy for a still image using a fixed amount encoding in which the capacity of one still image is fixed, but in the case of a still image using a variable amount encoding in which the capacity of one still image is variable. Has a problem that it is difficult to obtain a predetermined amount of still image capacity.

  The present invention has been made in view of such circumstances, and it is possible to store a necessary amount of still images even in a receiving device that is not excessive or insufficient to understand the contents of video data and has a small storage capacity. It is an object of the present invention to provide a still image extraction apparatus and a still image extraction program that can efficiently extract still images so that an image can be extracted.

  The present invention is a still image extraction apparatus for extracting still images using variable amount encoding from video data to create thumbnail data, and information on the free storage capacity of a storage means for storing the thumbnail data. A storage capacity acquisition unit to acquire; a first still image extraction unit that extracts a still image using a predetermined number of variable amount encoding from the video data; and all of the images extracted by the first still image extraction unit. Based on the still image data capacity and the free storage capacity, the excess capacity calculating means for calculating the excess capacity of the still image, and extracting and recording the still image to be recorded by omitting the still images corresponding to the excess capacity And a second still image extracting means.

  The present invention is characterized in that the second still image extraction unit omits the still images corresponding to the excess capacity at a constant rate on the time axis.

  The present invention is characterized in that the second still image extracting means omits the still images corresponding to the excess capacity in ascending order of image difference between two consecutive still images.

  The present invention is characterized in that the second still image extracting means omits the still images corresponding to the excess capacity in the order of locations where the caption display interval is long.

  The present invention is a still image extraction program for extracting a still image using variable amount coding from video data by a computer in order to create thumbnail data, and having a free storage capacity of a storage means for storing the thumbnail data A storage capacity acquisition step for acquiring information, a first still image extraction step for extracting a still image using a predetermined number of variable amount encoding from the video data, and a first still image extraction step. Based on all the still image data capacity and the free storage capacity, an excess capacity calculating step for calculating the excess capacity of the still image, and extracting a still image to be recorded by omitting the still images corresponding to the excess capacity A second still image extraction step for recording is performed by a computer.

  According to the present invention, it is possible to efficiently store still images so that a necessary amount of still images can be stored even with a receiving device having a sufficient storage capacity and a sufficient storage capacity in order to understand the contents of video data. The effect that extraction can be performed is acquired.

  Hereinafter, a still image extracting apparatus according to an embodiment of the present invention will be described with reference to the drawings. First, a receiving / distributing system to which the still image extracting apparatus according to the present invention is applied will be described. FIG. 1 is a block diagram showing the configuration of the embodiment. In this figure, reference numeral 1 denotes a distribution device that distributes video, audio, text, and the like. Reference numeral 2 denotes a control unit that performs overall control of processing operations of the distribution apparatus 1. Reference numeral 3 denotes an input / output unit for inputting / outputting various data in addition to input of content data. Reference numeral 4 denotes text / thumbnail distribution / display software 9, video / audio / text distribution / display software 10, content data 11, 12, 13, distribution / display unit software management data 14, content management data 15, user management. The storage unit stores data 16, content / user additional data 17, and the like. Reference numeral 5 denotes a text / thumbnail distribution unit that distributes text and thumbnails. Reference numeral 6 denotes a video / audio / text distribution unit that distributes video, audio, and text. Reference numeral 7 denotes a content / user-added data receiving / distributing unit that receives data such as comments and evaluations given to the content by the user and distributes the aggregated data. Reference numeral 8 denotes a communication unit that performs information broadcasting or information communication.

  The text / thumbnail distribution / display software 9 is software for realizing text / thumbnail distribution / display processing. The video / audio / text distribution / display software 10 is software that realizes video / audio / text distribution / display processing. The content data 11 is content data composed of video, audio, text, thumbnails, and other data, and each data is distributed from the distribution device 1 via the communication unit. The content data 11 includes video data (moving image data) 18 including a collection of still images that change over time, audio data 19 that is synchronized with the video over time, video such as data obtained by converting subtitles of a television broadcast into text, or Text data 20 that is temporally linked to audio, thumbnail data 21 that is still image data obtained by reducing video, and overall information data such as the name and outline of the entire content, a scene description of part of the content, BGM, title name, etc. It is roughly divided into individual information data, and is composed of other data 22 that is temporally linked to video or audio.

  The distribution / display software management data 14 is data for managing text / thumbnail distribution / display unit software and video / audio / text distribution / display software. The content management data 15 is data for managing the content data 11 to 13. The user management data 16 is data for managing user information. The content / user additional data 17 is data such as comments and evaluations given to the content by the user.

  Reference numeral 23 denotes a receiving device that receives and displays video, audio, text, and the like distributed by the distribution device 1, and includes, for example, a mobile phone terminal. Reference numeral 24 denotes a control unit that performs overall control of processing operations of the receiving device 23. Reference numeral 25 denotes an input unit configured by a dial key, a function key, or the like, and performing a man-machine interface with the user. Reference numeral 26 denotes a display device configured with a liquid crystal display or the like in order to display content data or the like to the user. Reference numeral 27 denotes a communication unit that performs information communication with the broadcast reception and distribution device 1. Reference numeral 28 denotes a storage unit that stores text / thumbnail display software 38, video / audio / text display software 39, content data 40, 41, 42, and the like.

  Reference numeral 29 denotes a text / thumbnail display that uses text / thumbnail display software 38 to read text data and thumbnail data in the content data from the storage unit 28 via the data buffer 30 and display them on the display device 26. A text display unit 31 and a thumbnail display unit 32. The text display unit 31 displays text data in the content data on the display device 26. As the text data, data stored in the storage unit 28 or data acquired via the communication unit 27 is used, and display control such as line feed and page feed is performed in response to an operation input in the input unit 25. The thumbnail display unit 32 displays thumbnail data and other data in the content data. As the thumbnail data and other data, data stored in the storage unit 28 and data acquired via the communication unit 27 are used. Among the thumbnail data and other data, the individual information data is displayed in conjunction with the text data.

  Reference numeral 33 is a video / audio / text display software 39 that reads out video data, audio data, text data, etc. in the content data from the storage unit 28 via the data buffer 34 and displays them on the display device 26. The video / audio / text display unit includes a video display unit, an audio output unit, and a text display unit. The video display unit 35 displays video data in the content data. For video data, data stored in the storage unit 28 or data acquired via the communication unit 27 is used, and display control such as playback, stop, fast forward, and rewind is performed in response to an operation input in the input unit 25. Do. The audio output unit 36 displays audio data in the content data. As the audio data, data stored in the storage unit 28 or data acquired via the communication unit 27 is used. The audio data is output in conjunction with the video data, or the audio data is output in advance and displayed in association with the video. The text display unit 37 displays text data and other data in the content data. As text data and other data, data stored in the storage unit 28 and data acquired via the communication unit 27 are used. Among text data and other data, individual information data is displayed in conjunction with video data or audio data.

  The text / thumbnail display software 38 is software that realizes processing to display on the display device 26 using text data and thumbnail data in the content data. The text / thumbnail display software 38 is acquired from the distribution apparatus 1 via the communication unit 27 and stored in the storage unit 28. In response to a request from the user, when viewing the content data by the text / thumbnail display unit 29, this software is called and used. The text / thumbnail display software 38 is modified by upgrading, and the latest software is sequentially acquired from the distribution device 1 via the communication unit 27.

  The video / audio / text display software 39 is software that realizes processing to display on the display device 26 using video data, audio data, text data, etc. in the content data. The video / audio / text display software 39 is acquired from the distribution apparatus 1 via the communication unit 27 and stored in the storage unit 28. In response to a request from the user, when viewing the content data by the video / audio / text display unit 33, this software is called and used. The video / audio / text display unit software 39 is modified by upgrading, and the latest software is sequentially acquired from the distribution apparatus 1 via the communication unit 27.

  Next, the content browsing function in the receiving apparatus 23 shown in FIG. 1 will be described with reference to FIG. FIG. 9 is a diagram showing a content browsing function in the receiving device 23 shown in FIG. The receiving device 23 has three functions: a metadata search function, a reading mode function, and a viewing mode function.

(1) Metadata search function This is a function that allows a user to pinpoint to a desired place in a program by inputting a keyword. Metadata is created using caption data and provided as text. For example, if “deien” is entered as a search keyword, the metadata of all programs can be searched, and “Japanese garden” and scenes in the program can be reached.

(2) Reading mode function This function enables quick browsing of information by displaying text (caption data) and a still image (thumbnail) in association with each other, and can perform scrolling and page turning. Since text and still images are downloaded in advance, it can be viewed “anytime, anywhere” even when radio waves do not reach.

(3) View mode function This is a function capable of playing back a moving image from this point by clicking on a text part in the read mode, and has a fast forward / rewind / search function. The moving image reproduction has a function of reproducing video content stored in advance in the receiving device 23 and a function of reproducing by streaming via communication or broadcasting. In the case of reproduction by streaming, it is possible to reproduce a moving image for a long time, and it is possible to easily resume viewing by storing a portion where viewing is interrupted.

  The reading mode and the viewing mode can be switched in conjunction with each other, and can be used for searching for a moving image in which the reading mode is desired.

  Next, a still image extraction method for generating thumbnail data 21 among the content data 11 stored in the storage unit 4 shown in FIG. 1 will be described with reference to FIGS. The thumbnail data may be generated in the distribution device 1, but is generated in a server or the like different from the distribution device 1, input via the input / output unit 3, and stored in the storage unit 4. Also good. Here, the text / thumbnail distribution unit 5 uses the video data 18 of the content data 11 and the text data (caption data) 20 to generate thumbnail data corresponding to the storage capacity of the receiving device (mobile terminal) 23. Will be described.

  FIG. 2 is a block diagram illustrating a function of selecting a still image to be stored according to the data capacity of the still image and the free storage capacity of the receiving device 23. First, when receiving the thumbnail data 21 from the distribution device 1, the control unit 24 of the reception device 23 notifies the distribution device 1 of the free storage capacity of the storage unit 28 via the communication unit 27. In response to this, the control unit 2 of the distribution apparatus 1 stores and holds the received free storage capacity in the storage unit 4.

  Next, the still image extraction unit 51 reads the video data 18, extracts frames at regular time intervals, and sets these frames as N still images. On the other hand, the still image number calculation unit 52 reads the free storage capacity stored in the storage unit 4 and calculates the storable still image number M. The number M of still images can be obtained by dividing the free storage capacity by the data capacity of one still image. Then, the still image number calculation unit 52 outputs the calculated still image number M to the ratio selection unit 53. In response to this, the ratio selection unit 53 stops the still image at the M / N ratio so that the number of still images stored in the still image storage unit 54 among the still images extracted by the still image extraction unit 51 is M. The still image extracted by the image extraction unit 51 is selected and stored in the still image storage unit 54.

  As described above, in the case of a fixed amount encoded still image in which the data capacity of one still image is constant, the number of still images after restriction that can be stored in the storage capacity can be calculated. By selecting at a fixed rate on the time axis so that the number of still images is limited from the number of still images, it is possible to ensure that the number of still images fits in the storage capacity.

  Next, a function of selecting and extracting a still image using variable amount coding on the time axis, in which the data capacity of one still image varies depending on the content of the still image, will be described with reference to FIG. FIG. 3 is a block diagram showing a function of selecting and extracting still images using variable amount coding on the time axis, in which the data capacity of one still image varies depending on the content of the still image. First, when receiving the thumbnail data 21 from the distribution device 1, the control unit 24 of the reception device 23 notifies the distribution device 1 of the free storage capacity of the storage unit 28 via the communication unit 27. In response to this, the control unit 2 of the distribution apparatus 1 stores and holds the received free storage capacity in the storage unit 4.

  Next, the still image extraction unit 51 reads the video data 18, extracts frames at regular time intervals, and sets these frames as still images. The average encoding amount calculation unit 55 for each frame calculates the capacity of each extracted still image. The capacity calculation unit 59 calculates the data capacity of the entire still image extracted by the still image extraction unit 51, and outputs this data capacity to the excess capacity calculation unit 56. The excess capacity calculation unit 56 compares the data capacity calculated by the capacity calculation unit 59 with the free storage capacity stored in the storage unit 4 to calculate the excess capacity. When the data capacity is smaller than the free storage capacity, the determination unit 60 stores the extracted still image in the still image storage unit 54.

  On the other hand, when the data capacity is larger than the free storage capacity, the excess number calculation unit 57 calculates the excess capacity calculated by the excess capacity calculation unit 56 and the per-sheet average coding amount calculation unit 55. The excess number of still images is calculated from the still image capacity, and the excess number is output to the ratio selection unit 58. The ratio selection unit 58 is a fixed ratio based on the excess number or more so that the still images stored in the still image storage unit 54 out of the still images extracted by the still image extraction unit 51 have a free storage capacity. Starting from a small ratio, the still image extracted by the still image extraction unit 51 is selected and omitted. Then, the capacity calculation unit 59 calculates the data capacity of the entire still image after the ratio selection unit 58 omits the still image, compares the data capacity with the free storage capacity, and the excess capacity is 0 or negative. Repeat the process until the value is reached. At this time, the ratio is increased every time the ratio of the ratio selector 58 is repeated. In this manner, the still image extracted when the data capacity becomes equal to or less than the free storage capacity is stored in the still image storage unit 54.

  As described above, since still images are omitted at a constant rate on the time axis, it is possible to easily perform a process of reducing the data capacity to a free storage capacity or less.

  Next, with reference to FIG. 4, a function of selecting and extracting still images using variable amount coding in which the data capacity of one still image differs depending on the content of the still image will be described. FIG. 4 is a block diagram showing a function of selecting and extracting still images using variable amount coding in which the data capacity of one still image differs depending on the content of the still image based on the image difference. First, when receiving the thumbnail data 21 from the distribution device 1, the control unit 24 of the reception device 23 notifies the distribution device 1 of the free storage capacity of the storage unit 28 via the communication unit 27. In response to this, the control unit 2 of the distribution apparatus 1 stores and holds the received free storage capacity in the storage unit 4.

  Next, the still image extraction unit 51 reads the video data 18, extracts frames at regular time intervals, and sets these frames as still images. The average encoding amount calculation unit 55 for each frame calculates the capacity of each extracted still image. The capacity calculation unit 59 calculates the data capacity of the entire still image extracted by the still image extraction unit 51, and outputs this data capacity to the excess capacity calculation unit 56. The excess capacity calculation unit 56 compares the data capacity calculated by the capacity calculation unit 59 with the free storage capacity stored in the storage unit 4 to calculate the excess capacity. When the data capacity is smaller than the free storage capacity, the determination unit 60 stores the extracted still image in the still image storage unit 54.

  On the other hand, when the data capacity is larger than the free storage capacity, the video difference adjustment unit 62 determines the excess capacity calculated by the excess capacity calculation unit 56 and the per-frame average coding amount calculation unit 55. The excess number of still images is calculated from the still image capacity, and the corresponding video difference amount is output to the difference selection unit 61. The difference selection unit 61 omits a still image according to the image difference amount between two consecutive still images among the still images extracted by the still image extraction unit 51. Then, the capacity calculation unit 59 calculates the data capacity of the entire still image after the difference selection unit 61 omits the still image, and compares this data capacity with the free storage capacity, and the excess capacity is 0 or negative. Repeat the process until the value is reached. At this time, the video difference amount of the video difference adjustment unit is increased every time it is repeated. In this manner, the still image extracted when the data capacity becomes equal to or less than the free storage capacity is stored in the still image storage unit 54.

  As described above, since the still images having the fewest image differences are omitted in order, the data capacity can be reduced to the free storage capacity while increasing the possibility of leaving an important video scene.

  Next, a function for selecting and extracting still images using variable amount encoding in which the data capacity of one still image differs depending on the content of the still image will be described with reference to FIG. FIG. 5 is a block diagram showing a function of selecting and extracting still images using variable amount coding whose data capacity of one still image differs depending on the content of the still image at intervals of subtitle display. First, when receiving the thumbnail data 21 from the distribution device 1, the control unit 24 of the reception device 23 notifies the distribution device 1 of the free storage capacity of the storage unit 28 via the communication unit 27. In response to this, the control unit 2 of the distribution apparatus 1 stores and holds the received free storage capacity in the storage unit 4.

  Next, the still image extraction unit 51 reads the video data 18, extracts frames at regular time intervals, and sets these frames as still images. The average encoding amount calculation unit 55 for each frame calculates the capacity of each extracted still image. The capacity calculation unit 59 calculates the data capacity of the entire still image extracted by the still image extraction unit 51, and outputs this data capacity to the excess capacity calculation unit 56. The excess capacity calculation unit 56 compares the data capacity calculated by the capacity calculation unit 59 with the free storage capacity stored in the storage unit 4 to calculate the excess capacity. When the data capacity is smaller than the free storage capacity, the determination unit 60 stores the extracted still image in the still image storage unit 54.

  On the other hand, when the data capacity is larger than the free storage capacity, the caption page number adjustment unit 65 calculates the caption page between the still image extracted by the still image extraction unit 51 and the still image calculated by the caption page number calculation unit 63. The number of still images is calculated from the excess capacity calculated by the excess capacity calculation unit 56 and the still image capacity per frame calculated by the average encoding amount calculation unit 55 per frame. At the same time, the number of subtitle pages (number of subtitle updates) corresponding thereto is output to the subtitle page number selection unit 64. The subtitle page number selection unit 64 omits the still image extracted by the still image extraction unit 51 according to the subtitle display interval. Then, the capacity calculation unit 59 calculates the data capacity of the entire still picture after the subtitle page number selection part 64 omits the still picture, and compares this data capacity with the free storage capacity, and the excess capacity is 0 or Repeat the process until the value is negative. At this time, the number of subtitle pages (number of subtitle updates) of the subtitle page number adjustment unit 65 is increased each time it is repeated. In this manner, the still image extracted when the data capacity becomes equal to or less than the free storage capacity is stored in the still image storage unit 54.

  As described above, since the caption display intervals are omitted in the order of long intervals, it is possible to reduce the data capacity below the free storage capacity while increasing the possibility of leaving a still image associated with the caption.

  In the above description, the example in which the still image extraction unit 51 illustrated in FIGS. 2 to 5 performs extraction at regular time intervals has been described. However, on the time axis, still image extraction based on image difference and caption display is performed. You may do it.

  As described above, in the case of a variable amount encoded still image, the number of still images after restriction is calculated by calculating the average encoding amount of one still image from the capacity of all the still images extracted in advance. However, there is a possibility that it will not fit in the storage capacity even if the process of omitting still images is performed based on the limited number of pictures as in the case of fixed amount encoding, but if it exceeds the storage capacity, the capacity will be exceeded. Since the number of corresponding still images is calculated based on the average encoding amount and is further omitted, it is possible to ensure that the number of still images fits in the free storage capacity.

  A program for realizing the functions of the processing units in FIGS. 2 to 7 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into the computer system and executed to execute a still image. An extraction process may be performed. Here, the “computer system” includes an OS and hardware such as peripheral devices. The “computer system” includes a WWW system having a homepage providing environment (or display environment). The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Further, the “computer-readable recording medium” refers to a volatile memory (RAM) in a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, those holding programs for a certain period of time are also included.

  The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, what is called a difference file (difference program) may be sufficient.

It is a block diagram which shows the structure of one Embodiment of this invention. It is a block diagram which shows the function of the still image extraction in the text / thumbnail delivery part 5 shown in FIG. It is a block diagram which shows the function of the still image extraction in the text / thumbnail delivery part 5 shown in FIG. It is a block diagram which shows the function of the still image extraction in the text / thumbnail delivery part 5 shown in FIG. It is a block diagram which shows the function of the still image extraction in the text / thumbnail delivery part 5 shown in FIG. It is explanatory drawing which shows the function of the receiver 23 shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Distribution apparatus, 23 ... Receiving device, 4 ... Memory | storage part, 5 ... Text / thumbnail distribution part, 51, 55, 56 ... Frame extraction part, 52 ... Number of still images Calculation unit, 53, 58... Ratio selection unit, 54... Still image storage unit, 55... Average coding amount calculation unit per sheet, 56. Number calculation unit, 59 ... Capacity calculation unit, 60 ... Determination unit, 61 ... Difference selection unit, 62 ... Video difference adjustment unit, 63 ... Subtitle number calculation unit, 64 ... Subtitle Number selection unit, 65 ... subtitle number adjustment unit

Claims (5)

A still image extraction device that extracts a still image using variable amount coding from video data to create thumbnail data,
Storage capacity acquisition means for acquiring information on free storage capacity of storage means for storing the thumbnail data;
First still image extraction means for extracting a still image using a predetermined number of variable amount encoding from the video data;
Excess capacity calculating means for calculating an excess capacity of the still picture based on all the still picture data capacity extracted by the first still picture extracting means and the free storage capacity;
A still image extraction apparatus comprising: a second still image extracting unit that extracts and records a still image to be recorded without the excess capacity still image.   The still image extraction device according to claim 1, wherein the second still image extraction unit omits still images corresponding to the excess capacity at a constant rate on a time axis.   2. The still image extraction apparatus according to claim 1, wherein the second still image extraction unit omits still images corresponding to the excess capacity in ascending order of image difference between two consecutive still images.   The still image extraction apparatus according to claim 1, wherein the second still image extraction unit omits the still images corresponding to the excess capacity in the order of locations where the interval between caption display is long. A still image extraction program for extracting a still image using variable amount encoding from video data by a computer in order to create thumbnail data,
A storage capacity acquisition step of acquiring information on the free storage capacity of the storage means for storing the thumbnail data;
A first still image extraction step of extracting a still image using a predetermined number of variable amount encoding from the video data;
An excess capacity calculating step of calculating an excess capacity of the still image based on all the still image data capacity extracted by the first still image extraction step and the free storage capacity;
A still image extraction program for causing a computer to perform a second still image extraction step of extracting and recording a still image to be recorded by omitting the excess capacity of still images.

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