JP4203528B1 - Video data acquisition method, video data acquisition system, video reception device, and video distribution device - Google Patents

Abstract

Provided is a video data acquisition method for realizing acquisition of video content in which an optimal playback location is specified in accordance with a communication band when video content data with a playback time specified in advance is acquired in a video receiver. .
A video data acquisition method according to the present invention is a video data acquisition method by a video reception device 20 that receives video content data 60 with a playback time designated in advance and plays back the video content data 60. Based on the communication band between the video distribution device 40 that distributes the content data 60 and the video reception device 20, a reproducible point of the video content data 60 that is newly received from the video distribution device 40 is determined, and after the reproducible point The video content data 60 is acquired from the video distribution device 40.
[Selection] Figure 1

Description

  The present invention relates to a video data acquisition method, a video data acquisition system, a video reception device, and a video distribution device, and in particular, a video data acquisition method for acquiring video content data for which a reproduction time is designated in advance in the video reception device. The present invention relates to a video data acquisition system.

  In recent years, technologies and services have been diversified in the field of video distribution. Users can select various services not only by viewing existing television broadcasts but also by services realized by various communication technologies. In particular, those using IP (Internet Protocol) technology include streaming distribution, IP multicast, and storage-type broadcasting service.

  In the streaming distribution, multimedia information (video content or the like) is downloaded from a distribution server to a client terminal via a network such as the Internet and reproduced. By reducing the download waiting time, it is possible to perform reproduction with a high real-time property, so that the video content can be viewed at a timing desired by the user. In addition, since the downloaded data is not stored in the client terminal, a storage area on the client terminal side is not required so much.

  Patent Document 1 measures the transfer speed of information from a distribution server in each client terminal in order to reduce the user download waiting time in streaming distribution, and selects and distributes information of a size that matches the speed. is there. Thereby, the difference in transfer time for each network band can be reduced. However, streaming distribution is for viewing a program unit at a desired timing in an individual environment, and it is said that it is not suitable for allowing a large number of users to view the same time zone based on a broadcast schedule.

  IP multicast is a technique suitable for simultaneously distributing one piece of multimedia data to many client terminals. However, in order to realize it, it is necessary to use a dedicated router (multicast router) in the communication path, and it is difficult to use the existing network infrastructure.

In addition, the storable broadcasting service distributes video content in advance according to the broadcast schedule and stores it in the video receiving device, so that the stored video content is played back at the broadcast schedule broadcast time. Is realized. For example, the video content for the next day is delivered together in a time zone in which the network bandwidth is relatively free. Therefore, it is suitable for simultaneous broadcasting use for a large number according to the broadcasting schedule. For example, in Patent Document 2, a storage channel (video content) is transmitted from an information transmission device (video distribution device, distribution server, etc.) to a reception storage device (video reception device, client terminal, etc.) and installed in the video storage device ( Storage) to realize a storage-type broadcasting service. However, if the video storage device is viewed from the initial state or the power is not turned on for a while, the video content is not stored in the video storage device. After requesting and storing in the video storage device, viewing starts. At that time, it is necessary to reproduce the video content according to the time zone of the broadcast schedule.
JP 2003-169091 A JP 2002-77080 A

  Patent Document 2 has a problem that when video content is not stored in the video receiver in advance (unstored state), the time until the start of reproduction is not determined by the communication band. That is, Patent Document 2 does not consider the following points. In the non-accumulated state, the video receiving apparatus accumulates until the video content can be reproduced. However, although video content is transferred and stored between the video receiving device and the video distribution device, the time required to store and play the video content varies depending on the communication band, the degree of congestion due to the time zone, and the like. If the storage of video content is completed and played back as it is, there is a possibility that it will not meet the time zone of the broadcast schedule. If the broadcast time has already passed when the accumulation is completed, video content in the next time zone is acquired, and the start of reproduction is delayed. At this time, a waiting time unnecessary for the user occurs.

  The present invention provides a video data acquisition method that realizes acquisition of video content in which an optimal playback location is specified according to a communication band when video content data whose playback time is specified in advance is acquired in a video receiver. For the purpose.

  A video data acquisition method according to a first aspect of the present invention is a video data acquisition method by a video reception device that receives video content data whose playback time is designated in advance and plays back the video content data. Based on a communication band between a video distribution device that distributes content data and the video reception device, a reproducible point of the video content data that is newly received from the video distribution device is determined, and the replay point after the reproducible point is determined. Video content data is obtained from the video distribution device.

  As a result, the video receiving device can obtain the optimal video content by dynamically setting the reproducible point of the video content distributed from the video distribution device according to the communication band, and the user desires to view the content. Video content can be played back without causing unnecessary waiting time. Furthermore, even when the video receiver is installed in various environments with different communication bands, it can contribute to the effective provision of a storage-type broadcast service that broadcasts the same video in the same time zone.

  The reproducible point is preferably specified as a reproducible time of the video content data. Thereby, the video content to be acquired can be appropriately specified by time.

  In addition, the reproducible point is determined based on a predicted transfer time predicted to be required for the transfer of the video content data so that the longer the predicted transfer time is, the more future time is from the current time. Good. Thereby, the transfer time according to the communication band can be predicted, and an appropriate reproducible point can be determined for each communication environment.

  Further, the reproducible point may be calculated using the predicted transfer time and the estimated storage time estimated to be required for storage in the video reception device. As a result, it is possible to determine a more accurately reproducible point based on the accumulation processing in the video reception device.

  Furthermore, the predicted transfer time may be calculated based on a time required for transferring sample data between the video distribution device and the video reception device. Thereby, it is possible to predict the transfer time according to the current congestion state of the communication band, and it is possible to determine an appropriate reproducible point for each communication environment.

  Alternatively, the reproducible point may be determined by selecting a candidate for the predicted transfer time from a plurality of candidate times listed in advance. Thereby, it is possible to determine a transfer prediction time that is simpler and has a certain degree of validity according to the communication band.

  The determination of the reproducible point may be performed by the video reception device. Thereby, it is possible to determine an appropriate reproducible point for each communication band in the video reception device.

  Further, the acquisition of the video content data may be started based on a request for distribution of the video content data including the reproducible point from the video reception device to the video distribution device. Thereby, more appropriate video content data can be acquired.

  Alternatively, the reproducible point may be determined by the video distribution device. Thereby, it is possible to determine a consistent reproducible point in the video distribution apparatus.

  Furthermore, the acquisition of the video content data may be started based on a request for distribution of the video content data including the estimated transfer time from the video reception device to the video distribution device. Thereby, more accurate video content data can be distributed.

  The distribution request may further include channel selection information in which a channel to which the video content data belongs is specified, and the video distribution device may select video content data to be distributed based on the channel selection information. Good. As a result, the amount of video content data to be acquired is reduced, and the time required to store the video content up to an amount that can be played back can be shortened.

  A video data acquisition system according to a second aspect of the present invention includes a video distribution device that distributes video content data whose playback time is specified in advance, and a video data receiver that receives and plays back the video content data. In the acquisition system, the video reception device determines a reproducible point of the video content data newly received from the video distribution device based on a communication band between the video distribution device and the video reception device. The video content data after the playable point is received from the video distribution device.

  As a result, it is possible to determine the optimal reproducible point by dynamically setting the reproducible point of the video content distributed from the video receiving device according to the communication band, and to acquire the video content. The video content can be reproduced without causing unnecessary waiting time.

  On the other hand, a video data acquisition system according to a third aspect of the present invention includes a video distribution device that distributes video content data whose playback time is specified in advance, and a video reception device that receives and plays back the video content data. In the video data acquisition system, the video distribution device determines a reproducible point of the video content data to be newly distributed to the video reception device based on a communication band between the video distribution device and the video reception device. The video content data after the playable point is determined and distributed to the video receiving device. As a result, the video distribution device can determine the optimal consistent reproducible point from the communication band, acquire the video content, and play back the video content without causing unnecessary waiting time for the user. can do.

  A video receiving apparatus according to a fourth aspect of the present invention is a video receiving apparatus that receives video content data whose playback time is specified in advance and plays back the video content data, and distributes the video content data. A reproducible point determination unit for determining a reproducible point of the video content data newly received from the video distribution device based on a communication band between the video distribution device to be performed and the video reception device; The video content data is received from the video distribution device. As a result, it is possible to determine the optimal reproducible point from the communication band in the video receiving device, to acquire the video content, and to reproduce the video content without causing unnecessary waiting time for the user. .

  The video distribution apparatus according to the fifth aspect of the present invention is a video distribution apparatus that distributes video content data for which a reproduction time is specified in advance, and the video distribution apparatus that distributes the video content data and the video content A reproducible point determining unit for determining a reproducible point of the video content data to be newly distributed to the video receiving device based on a communication band between the video receiving devices receiving data and reproducing the video content data; And a video distribution unit that distributes the video content data after the reproducible point to the video receiving device. As a result, the video distribution device can determine the optimum consistent playable point from the communication band, acquire the video content, and play the video content without causing unnecessary waiting time for the user. can do.

  According to the present invention, it is possible to provide a video data acquisition method that realizes acquisition of video content in which an optimal playback location is specified in accordance with a communication band when video content data whose playback time is specified in advance is acquired in the video receiver. . As a result, when video content data is played back, no unnecessary waiting time is generated, and the same video is broadcast in the same time zone in accordance with the broadcast schedule in various environments with different communication bands. This can contribute to the effective provision of type broadcasting services.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings. In the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted as necessary for the sake of clarity.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a configuration of a video data acquisition system 1 according to the first exemplary embodiment of the present invention. The video data acquisition system 1 includes a display device 10, a video reception device 20, a communication network 30, and a video distribution device 40. The display device 10 and the video reception device 20 are connected, and the video reception device 20 and the video distribution device 40 are connected through a communication network 30.

  The video distribution device 40 is a device for providing a broadcast service for distributing video content. The video distribution device 40 includes a video distribution unit 43 and a storage unit 44. The storage unit 44 stores a broadcast schedule 50a and video content 60a. The video distribution unit 43 has a distribution request reception function and a response transmission function. For example, various distribution requests from the video receiving device 20 are received, and the broadcast schedule 50a and the video content 60a are transmitted as a response. In addition, the video distribution unit 43 transmits sample data 45 in order to measure an accumulation completion time described later. The broadcast schedule 50a and the video content 60a will be described later with reference to FIG. The sample data 45 is a small-capacity file that is used to be transmitted to the video reception device 20 in order to measure the transfer rate.

  The communication network 30 is a network realized by IP technology. Note that the communication network 30 does not have to be IP technology, and may be another network as long as it can realize distribution of video content.

  The video receiving device 20 is a device that receives the video content distributed from the video distribution device 40, stores it, plays it back, and displays the video on the display device 10. The video receiving device 20 includes an accumulation completion time setting unit 21, a reproducible point determination unit 22, a transmission / reception unit 23, a storage unit 24, and a reproduction unit 25. The accumulation completion time setting unit 21 accumulates the video content 60a in the video reception device 20, and sets the accumulation completion time, which is the time until it can be played back. The reproducible point determination unit 22 determines the reproducible point of the video content to be reproduced from the accumulation completion time set by the accumulation completion time setting unit 21. Details of the processing of the accumulation completion time setting unit 21 and the reproducible point determination unit 22 will be described later. The transmission / reception unit 23 transmits various distribution requests to the video distribution device 40 and receives responses. The distribution request is made for the broadcast schedule 50a and the video content 60a. When the transmission / reception unit 23 receives the broadcast schedule 50a and the video content 60a as a response from the video distribution device 40, the transmission / reception unit 23 stores the broadcast schedule 50b and the video content 60b in the storage unit 24. The accumulation unit 24 is a storage unit that stores a service guide 51 in addition to the broadcast schedule 50b and the video content 60b. As the storage unit 24, a hard disk, a flash memory, or the like can be used. The service guide 51 is initial display screen data at the start of viewing, and is displayed until video content corresponding to the corresponding time zone of the broadcast schedule is displayed. The playback unit 25 decodes the video content 60b stored in the storage unit 24, plays it back as video data, sends it to the display device 10, and displays it on the screen.

  The display device 10 receives the video data sent from the video receiving device 20 and displays it on the screen. The flow from when the user desires to view and until the video content corresponding to the corresponding time zone of the broadcast schedule is displayed on the display device 10 will be described later with reference to FIG.

  Note that the content of the broadcast schedule 50a may be updated at an arbitrary timing. Therefore, the broadcast schedule 50a may be updated after the broadcast schedule 50a provided in the video distribution device 40 is accumulated as the broadcast schedule 50b in the video reception device 20. Therefore, in order to obtain the latest version of the broadcast schedule 50a, the video reception device 20 makes a distribution request to the video distribution device 40 periodically, when the unacquired period is long, or at the first activation.

  The broadcast schedule is data that includes a plurality of channels and defines a scheduled broadcast time zone of the program of each channel. The channel is composed of a plurality of programs, and the program is composed of a plurality of video contents (data files). Furthermore, the time (reproducible time) at which each video content is broadcast is designated. The video content is played back by the video receiving device. The video receiver controls playback according to the playback time of video content. That is, when the reproducible time has passed, the video content is not played back. In addition, the broadcast schedule should just be comprised by arbitrary units, such as a day unit and a month unit.

  FIG. 2 is a diagram illustrating a configuration example of a broadcast schedule. The broadcast schedule 50 includes a channel 6X and a channel 6Y, and defines on the time axis 700 that a program for each channel is broadcast at a specific time. The time axis 700 is data in which the time of a day on a certain date is defined, for example. Channel 6X is defined to be broadcast in the order of program 61, program 62, and program 63. For example, until time 702, the program 61 is broadcast, and then the program 62 is broadcast. Further, it is defined that the channel 6Y is scheduled to be broadcast in the order of the program 64, the program 65, and the program 66. For example, until the time 701, the program 64 is broadcast, and then the program 65 is broadcast. The time 701 and the time 702 do not need to match. Similarly, the time 705 and the time 706 that are the end times of the program 62 and the program 65 do not need to match.

  The program 62 is composed of video contents 621 to 624. A plurality of video contents actually exist between the video contents 623 to 624, but are omitted here. The same applies to the program 61, the program 63, the program 64, the program 65, and the program 66, and thus description thereof is omitted. The video content 621 is video data between time 702 and time 703, and particularly represents the start video of the program 61. Hereinafter, the video content 622 is video data between the time 703 and the time 704, and the same applies to the video content 623 or 624. In particular, the video content 624 represents the end video of the program 61.

  That is, the broadcast schedule 50 includes information that can specify the video content 621 by designating the channel 6X and the time 702.

  Hereinafter, FIGS. 3 and 4 show the solution principle of the video data acquisition method according to the first embodiment of the present invention. As the flowchart of FIG. 3 is described, processing is performed as needed in accordance with the outline of the application example of the video data acquisition method according to the first embodiment of the present invention shown in FIG.

  First, the application status of the video data acquisition method according to the first embodiment of the present invention will be described. In the video data acquisition system 1, the video receiving device 20 is in an unaccumulated state. A user who wishes to view the broadcast service of the broadcast schedule 50 turns on the video receiver 20. A service guide 51 is displayed on the screen of the display device 10. At the same time, the video receiving device 20 downloads (acquires) a plurality of video contents corresponding to programs of a plurality of channels scheduled to be broadcast until the plurality of video contents can be reproduced. During acquisition of video content, different waiting times occur depending on the communication band. After the video content is acquired, the video content corresponding to the channel that is initially set in the video receiving device 20 is reproduced. Note that the video receiving device 20 preferably acquires the latest version of the broadcast schedule from the video distribution device 40. At this time, when the broadcast schedule 50b already exists in the storage unit 24 of the video reception device 20, the newly received broadcast schedule 50a is replaced with the broadcast schedule 50b.

  FIG. 3A is a flowchart outlining the video data acquisition method according to the first embodiment of the present invention. In step S110, the video reception device 20 sets the accumulation completion time 710 (FIG. 4) in the accumulation completion time setting unit 21 when the power is turned on. At the same time, the video receiving device 20 reproduces the service guide 51 and sends a signal 721 (FIG. 4) to be displayed on the screen of the display device 10. Details of step S110 are shown in FIG. 3B as a flowchart of the accumulation completion time setting unit of the video data acquisition method according to the first embodiment of the present invention. The accumulation completion time setting process in step S110 in FIG. 3A is performed in steps S111 to S113 in FIG. In step S <b> 111, the accumulation completion time setting unit 21 of the video reception device 20 transmits a sample data transmission request 722 from the transmission / reception unit 23 to the video distribution device 40. In the information distribution device 40, the video distribution unit 43 receives the sample data transmission request 722 and transmits the sample data 45 in the storage unit 44 as the sample data transmission response 723. The sample data 45 is smaller in size than the average size of the video content data, such as a service tour, an operation method, and a part of an advertisement file. In step S <b> 112, the video reception device 20 receives the sample data transmission response 723 at the transmission / reception unit 23, and measures the transfer time 720 of the sample data 45 at the accumulation completion time setting unit 21. In S113, the accumulation completion time setting unit 21 calculates the line speed from the sample data size and the transfer time 720, and is the time required to accumulate a plurality of video contents related to a plurality of channels from the line speed to the video receiving device 20. Accumulation completion time 710 is calculated. Thereby, the accumulation completion time is set. This is because the communication network 30 that connects the video receiving device 20 and the video distribution device 40 has different line speeds, communication paths, etc. depending on the video receiving device or time zone. The accumulation completion time is set.

  Returning to FIG. In step S120, the reproducible point determination unit 22 of the video reception device 20 determines the reproducible point 712 (time 712) from the current time 711 and the accumulation completion time 710. That is, the time when the accumulation completion time 710 has elapsed from the current time 711 is determined as the reproducible point 712.

  An example of a method for concretely calculating the line speed, accumulation completion time, and reproducible point based on the communication band will be described later.

  In step S <b> 130, the video reception device 20 acquires a plurality of video contents from the reproducible point 712. Details of step S130 are shown in FIG. 3C as a flowchart of the video content acquisition process of the video data acquisition method according to the first embodiment of the present invention. The video content acquisition process in step S130 in FIG. 3A is performed in steps S131 to S135 in FIG. In step S <b> 131, the video reception device 20 transmits the reproducible point 712 as the video distribution request 724 from the transmission / reception unit 23 to the video distribution device 40. In step S132, the video distribution device 40 receives the video distribution request 724 in the video distribution unit 43, and the video content to be distributed from the broadcast schedule 50a in the storage unit 44 and the received information indicating the reproducible point 712. 622 is selected. In step S133, the video distribution device 40 transmits the video content 622 from the video distribution unit 43 to the video reception device 20 (video content distribution 725). In step S <b> 134, the video reception device 20 receives the video content 622 at the transmission / reception unit 23. In step S <b> 135, the video reception device 20 stores the video content 622 in the storage unit 24.

  Note that the description using the flowchart of FIG. 3C and FIG. 4 described above is not only a plurality of video contents related to a plurality of channels but only one video content 622 related to one channel 6X for the sake of easy explanation. It showed about the case of getting. In order to acquire a plurality of video contents regarding a plurality of channels, the video content acquisition process of FIG. 3C may be performed sequentially or in parallel on the plurality of video contents.

  Returning to FIG. In step S140, the playback unit 25 of the video reception device 20 plays the video content of the channel selected as the playback target by the user among the plurality of video content stored in the storage unit 24. For example, if the channel selected for playback by the user is channel 6X, video content 622 is played back. At this time, the playback unit 25 compares the broadcast schedule 50b with the current time, confirms that the video content 622 is scheduled to be broadcast (played from now on and played back at time 712), and stores the video content 622. Playback and display on the display device 10 (video content playback 726). Therefore, the video content 622 is broadcast at time 712. Further, the video distribution request (not shown) for the video content 623 next to the video content 622, the response of the video content 623 (video content distribution 727), and the reproduction after accumulation (video content reproduction 728) are continued. Acquisition of video content of channels other than channel 6X is executed in the same manner. Since the reproduction time is relatively longer than the accumulation completion time, the accumulation amount increases thereafter, and after a certain amount is accumulated, the normal usage mode is obtained. That is, the video receiving device is in a state where video content is stored in the video receiving device in advance, and plays back the video content corresponding to the playable time.

  That is, in the present embodiment, the video reception device 20 calculates the time (accumulation completion time) required to acquire video content that varies depending on the communication band between the video distribution device 40 and the video reception device 20, and the accumulation completion time. The distribution request including the reproducible point calculated backward from is transmitted to the video distribution apparatus 40. In addition, the video distribution device 40 responding to the distribution request can distribute the video content after the playback start point, not the latest video content from the current time. In the example of FIG. 4, the video distribution device 40 can distribute the video content 622 instead of the first video content 621 of the program 62. Thereby, the video receiving apparatus 20 can reproduce the video content in a form according to the broadcast schedule.

The following is an example of a specific calculation method for determining the reproducible point based on the communication band. First, the line speed xV is calculated from the sample data size sZ and the sample data download time (transfer time) dT according to the equation (1). For example, when the sample data size is 1 Mbyte and the download time (transfer time) of the sample data is 8 s, the line speed is 1 Mbyte × 8 bits / 8 s = 1 Mbit / s (bit / s is hereinafter referred to as bps).
xV = sZ / dT (1)

Next, the minimum required buffer size (accumulated data amount) yS is the information speed iV of the video content data, the buffer time aT for the video receiving device 20 to start playing the video content data, the network delay time nT, and the line speed fluctuation. From the ratio fR and the line speed fluctuation duration fT, it is calculated by equation (2). For example, when the information speed of the video content data is 6 Mbps, the buffer time 2 s for the video receiver 20 to start playing the video content data, the network delay time 1 s, the line speed fluctuation ratio ± 5%, and the line speed fluctuation duration 60 s. The minimum required buffer size is 6 Mbps × (2 s + 1 s + 0.05 × 60 s) = 36 Mbit. In this example, the codec rate of the video content is H.264. H.264 is assumed, but other standards may be used.
yS = iV × (aT + nT + fR × fT) (2)

Subsequently, the time yT required for the buffer is calculated from the minimum required buffer size yS and the line speed xV by the equation (3). For example, when the minimum required buffer size is 36 Mbit and the line speed is 1 Mbps, the time required for the buffer is 36 Mbit / 1 Mbps = 36 s.
yT = yS / xV (3)

Thus, the reproducible time zT is calculated from the current time cT, the time yT required for the buffer, and the error time αT according to the equation (4). The time yT required for the buffer is the time for the video content per channel. When the video content to be acquired spans multiple channels, it is necessary to multiply the number of channels. For example, when the current time is 15:00, the buffer time is 36 s, the number of channels is 10 channels, and the error time is 30 s, the playable time is 15:00: + (36 s × 10 channels) +30 s = 15: 06 : 30. In addition, about each said value, it can implement by arbitrary things.
zT = cT + yT + αT (4)

  In the storage type broadcasting system according to the prior art such as Patent Document 2, the problem to be solved by the present invention becomes apparent in the unstored state. For example, even if the video receiving device is in the initial state or the video receiving device has not been turned on for a while and the video content at the desired viewing time is not stored (unstored), Video content or simply the entire program of the selected channel. If the video content for the next day starts to be acquired, the video content is not reproduced until the next day even if the video content is accumulated in the video receiving device. That is, the user cannot view until the next day. Also, if the entire program of the selected channel is simply started to be received, it takes time to transfer depending on the communication band. For this reason, even if the video content is stored, the reproducible time has passed, and it is necessary to wait for reception of the next video content. The video content is not played back until the video content corresponding to the playable time is stored. From the above, an unnecessary waiting time until the user viewing the broadcast reaches the viewing occurs. Therefore, in the prior art, it cannot be said that the method of acquiring the video content data is appropriate. On the other hand, according to the present embodiment, appropriate video content data is acquired according to the communication band, so that there is an effect that waiting time unnecessary for the user viewing the broadcast can be reduced.

  In the video data acquisition method according to the first embodiment of the present invention, video content data corresponding to the corresponding time zone of the broadcast schedule 50 is stored in the video reception device 20 regardless of whether the video reception device 20 is turned on. If not, accumulation completion time may be set in step S110. In step S110, it is not necessary to send a signal 721 for displaying the service guide 51 in parallel with the accumulation completion time setting. During the acquisition of the video content data, nothing may be displayed on the screen of the display device 10. The same applies to the following embodiments.

Embodiment 2. FIG.
FIG. 5 is a block diagram showing a configuration of the video data acquisition system 2 according to the second exemplary embodiment of the present invention. Compared with the video data acquisition system 1 described above, the video data acquisition system 2 performs processing corresponding to the accumulation completion time setting unit 21 and the reproducible point determination unit 22 included in the video reception device 20 in the video distribution device 40a. And that the video reception device 20a includes the storage completion time measuring unit 26. Since the other components included in the video data acquisition system 2, the display device 10, and the communication network 30 are the same as those included in the video data acquisition system 1, detailed description thereof will be omitted.

  Similar to the video distribution device 40, the video distribution device 40a is a device for providing a broadcast service for distributing video content. The video distribution device 40 a includes an accumulation completion time setting unit 41, a reproducible point determination unit 42, a video distribution unit 43, and a storage unit 44. The accumulation completion time setting unit 41 performs the same processing as that of the accumulation completion time setting unit 21 according to the first embodiment, but does not measure the transfer time of the sample data 45, and transfers it from the video reception device 20a. Set the accumulation completion time based on the time. The reproducible point determination unit 42 is the same as the reproducible point determination unit 22 according to the first embodiment, and determines the reproducible point of the video content to be reproduced from the accumulation completion time set by the accumulation completion time setting unit 41. To do. Since the video delivery unit 43, the storage unit 44, the broadcast schedule 50a, the video content 60a, and the sample data 45 are the same as those of the video delivery device 40 of the video data acquisition system 1 according to the first embodiment of the present invention, description thereof is omitted. To do.

  Similar to the video receiving device 20, the video receiving device 20 a is a device that receives the video content distributed from the video distribution device 40 a, stores it, plays it back, and displays the video on the display device 10. The video reception device 20 a includes an accumulation completion time measurement unit 26, a transmission / reception unit 23, an accumulation unit 24, and a reproduction unit 25. The accumulation completion time measuring unit 26 does not calculate the accumulation completion time in the accumulation completion time setting unit 21 of the first embodiment, measures the transfer time of the sample data 45, and distributes the video content to the video distribution device 40a. The measured transfer time is sent with the request. Since the transmission / reception unit 23, the storage unit 24, and the reproduction unit 25 are the same as those of the video reception device 20 of the video data acquisition system 1 according to the first embodiment of the present invention, description thereof will be omitted.

  In the video data acquisition system 2, the accumulation completion time is calculated on the video distribution device 40a side. That is, the accumulation completion time, that is, the time required for accumulating the video content up to a reproducible amount is different for each video reception device 20a which is a reception client terminal, and other values, This is because the time required for storage, the time for starting reproduction processing, and the like are substantially constant regardless of the receiving client terminal. Therefore, if the transfer time portion of the sample data 45 is obtained, the calculation on the video distribution device 40a side is possible. As a result, the video distribution device 40a can select the optimal video content from the latest broadcast schedule 50a.

  The video data acquisition method in the video data acquisition system 2 according to the second exemplary embodiment of the present invention will be described as the video data acquisition method according to the second exemplary embodiment of the present invention shown in FIG. The process is followed according to the outline of the application example of the method. FIG. 6A is a flowchart of an outline of the video data acquisition method according to the second embodiment of the present invention. The processing purpose of steps S210 to S240 is the same as that of steps S110 to S140 of FIG. Hereinafter, the difference from the first embodiment will be described with reference to the flowchart of FIGS. 6B and 6C, and the process will be followed as needed in accordance with the outline of the application example of FIG.

  In step S210 in the video data acquisition system 2, the video receiving device 20a starts processing at the storage completion time measuring unit 26 when power is turned on, and the storage is completed at the storage completion time setting unit 41 of the video distribution device 40a. Time 750 (FIG. 7) is set. In parallel with this, the video receiving device 20a reproduces the service guide 51 and sends a signal 761 (FIG. 7) for displaying on the screen of the display device 10. Details of step S210 are shown in FIG. 6B as a flowchart of the accumulation completion time setting unit of the video data acquisition method according to the second embodiment of the present invention. The accumulation completion time setting process in step S210 in FIG. 6A is performed in steps S211 to S214 in FIG.

  In step S211, the accumulation completion time measurement unit 26 of the video reception device 20a transmits a sample data transmission request 762 from the transmission / reception unit 23 to the video distribution device 40a. In the video distribution unit 43, the information distribution device 40 a receives the sample data transmission request 762 and transmits the sample data 45 in the storage unit 44 as a sample data transmission response 763. In step S212, the video reception device 20a receives the sample data transmission response 763 at the transmission / reception unit 23, and measures the transfer time 760 of the sample data 45 at the accumulation completion time measurement unit 26. In S213, the video reception device 20a transmits the transfer time 760 as the video distribution request 764 from the transmission / reception unit 23 to the video distribution device 40a. This forwards the process corresponding to step S131 of FIG. 3C in the video data acquisition system 1, and further transmits the transfer time 760 measured in step S212. Further, the video distribution request 764 includes a time 751 at the time of transmission. In step S214, the video distribution device 40a receives the video distribution request 764 in the video distribution unit 43, and the accumulation completion time setting unit 41 calculates the line speed from the sample data size and the transfer time 760. A storage completion time 750, which is a time required to store a plurality of video contents related to a plurality of channels in the video receiving device 20, is calculated (set). Thereby, the accumulation completion time is set.

  Returning to FIG. In step S220, the reproducible point determination unit 42 of the video distribution device 40a determines (determines) a reproducible point 752 (time 752) from the broadcast schedule 50a, the time 751, and the accumulation completion time 750. Note that the method for determining the reproducible point based on the communication band is the same as in the first embodiment of the present invention, and thus the description thereof is omitted.

  In step S230, the video reception device 20a acquires a plurality of video contents from the reproducible point 752. Details of step S230 are shown in FIG. 6C as a flowchart of the video content acquisition process of the video data acquisition method according to the second embodiment of the present invention. The video content acquisition process in step S230 in FIG. 6A is performed in steps S232 to S235 in FIG. In step S232, the video distribution device 40a selects the video content 622 to be distributed from the broadcast schedule 50a in the storage unit 44 and the received information indicating the channel 6X and the reproducible point 752 in the video distribution unit 43. In step S233, the video distribution device 40a transmits the video content 622 from the video distribution unit 43 to the video reception device 20a (video content distribution 765). Steps S234 to 235 are the same as steps S134 to 135 in FIG.

  Note that the description using the flowchart of FIG. 6C and FIG. 7 described above is not only a plurality of video contents related to a plurality of channels but only one video content 622 related to one channel 6X for the sake of easy explanation. It showed about the case of getting. In order to acquire a plurality of video contents related to a plurality of channels, the video content acquisition process of FIG. 6C may be performed sequentially or in parallel on the plurality of video contents.

  In step S240, the playback unit 25 of the video reception device 20a also plays back the video content of the channel selected as the playback target by the user from among the plurality of video content stored in the storage unit 24. This is the same as the first embodiment. That is, the video content distribution 765, video content playback 766, video content distribution 767, and video content playback 768 of FIG. 7 are the same as the video content distribution 725, video content playback 726, video content distribution 727, and video content playback 728 of FIG. Therefore, the description is omitted. Also, acquisition of video content of channels other than the channel 6X is executed in the same manner.

  That is, in the video data acquisition system 2 according to the second exemplary embodiment of the present invention, the time required for the video distribution device 40a to acquire video content that varies depending on the communication band between the video distribution device 40a and the video reception device 20a (accumulation). Completion time) is calculated, and a reproducible point calculated backward from the accumulation completion time is determined. Thereby, the video distribution device 40a can distribute the video content after the reproduction start point, as in the first embodiment, instead of the latest video content from the current time. Furthermore, in the second embodiment, the optimum video content can be selected without acquiring the latest version of the broadcast schedule 50a on the video receiving device 20a side.

  In the video data acquisition system 2 according to the second embodiment of the present invention, the transfer time of the sample data 45 is measured by the storage completion time measuring unit 26 of the video reception device 20a. It may be included in the time setting unit 41. In this case, the video receiving device 20a transmits only the time required for receiving the sample data 45 to the video distributing device 40a, and the video distributing device 40a performs the calculation of the transfer time of the sample data 45 based on the time. What should I do?

Embodiment 3 FIG.
In the video data acquisition method in the video data acquisition system 3 according to the third embodiment of the present invention, in setting the accumulation completion time, the transfer time is not measured by transferring sample data, but the transfer estimated time according to the communication band. Are selected from a transfer time list enumerated in advance.

  FIG. 8 is a block diagram showing a configuration of the video data acquisition system 3 according to the third exemplary embodiment of the present invention. Compared with the video data acquisition system 1 described above, the video data acquisition system 3 replaces the video reception device 20 and the video distribution device 40 with the video reception device 20b and the video distribution device 40b. Containment is different. The other components included in the video data acquisition system 3, the display device 10, and the communication network 30 are the same as those included in the video data acquisition system 1, and thus detailed description thereof will be omitted.

  Similar to the video receiving device 20, the video receiving device 20 b is a device that receives video content distributed from the video distribution device 40 b, stores it, plays it back, and displays the video on the display device 10. The video reception device 20b includes a storage completion time setting unit 21b, a reproducible point determination unit 22, a transmission / reception unit 23, a storage unit 24, and a playback unit 25. Similar to the accumulation completion time setting unit 21, the accumulation completion time setting unit 21 b sets the accumulation completion time. However, the setting of the accumulation completion time is selected from the transfer time list 52 stored in the accumulation unit 24 without measuring the transfer time by transferring the sample data. The transfer time list 52 is a data group listing a plurality of transfer times of video content predicted in advance. Alternatively, it may be a list of accumulation completion times. For example, a corresponding transfer time or accumulation completion time can be selected according to the line speed selected by the user. The video receiver 20 of the video data acquisition system 1 according to the first embodiment of the present invention is described with reference to the reproducible point determination unit 22, the transmission / reception unit 23, the other stored in the storage unit 24, and the playback unit 25. Since it is the same as that, description is abbreviate | omitted.

  Similar to the video distribution device 40, the video distribution device 40b is a device for providing a broadcast service for distributing video content. The video distribution device 40 b includes a video distribution unit 43 and a storage unit 44. Compared to the first embodiment, the video distribution unit 43 does not transfer the sample data 45. Therefore, the storage unit 44 does not need the sample data 45 stored in the first and second embodiments. Since other functions are the same as those of the video distribution device 40 of the video data acquisition system 1 according to the first exemplary embodiment of the present invention, description thereof will be omitted.

  FIG. 9 is a flowchart of the video data acquisition method according to the third embodiment of the present invention. In addition, while explaining the flowchart of FIG. 9, processing is performed as needed in accordance with the outline of the application example of the video data acquisition method according to the third embodiment of the present invention of FIG. 10. FIG. 9A shows a schematic flowchart of a video data acquisition method according to the third embodiment of the present invention.

  In step S310, as in step S110, the video reception device 20b sets the accumulation completion time 770 (FIG. 10) in the accumulation completion time setting unit 21b when the power is turned on. At the same time, the video receiving device 20b reproduces the service guide 51 and sends a signal 781 (FIG. 10) to be displayed on the screen of the display device 10. Details of step S310 are shown in FIG. 9B as a flowchart of the accumulation completion time setting unit of the video data acquisition method according to the third embodiment of the present invention. The accumulation completion time setting process in step S310 in FIG. 9A is performed in steps S311 to S312 in FIG. 9B. In step S311, the accumulation completion time setting unit 21b selects a transfer time (not shown) from the transfer time list 52 stored in the accumulation unit 24 according to the line speed selected by the user. In step S312, the accumulation completion time setting unit 21b performs accumulation completion, which is the time required to accumulate a plurality of video contents related to a plurality of channels, based on the selected transfer time, the time required for accumulation, the time required for reproduction, and the like. Time 770 is calculated. Alternatively, an accumulation completion time list (not shown) may be selected instead of the transfer time list 52. The accumulation completion time list may be a list in which the average size of video content data, the time required for accumulation, the time required for reproduction, and the like are added to the listed transfer times in advance according to the line speed. In this case, step S311 and step S312 are processed together.

  Further, subsequent steps S320 to S340 are the same as steps S120 to S140 in FIG. 3A of the first embodiment, and thus the description thereof is omitted. That is, in step S320, the reproducible point determination unit 22 determines the reproducible point 772 from the time 771 and the accumulation completion time 770 in FIG. Also, the video content distribution 785, the video content playback 786, the video content distribution 787, and the video content playback 788 in FIG. 10 are the same as the video content distribution 725, the video content playback 726, the video content distribution 727, and the video content playback 728 in FIG. Therefore, the description is omitted.

  In the third embodiment, as in the first embodiment, for ease of explanation in the description of FIG. 4, instead of a plurality of video contents related to a plurality of channels, one video content 622 related to one channel 6X. Shown only about getting. As in the first embodiment, in order to acquire a plurality of video contents related to a plurality of channels, the video content acquisition process of FIG. 3C may be performed sequentially or in parallel for the plurality of video contents. is there.

  From the above, the video data acquisition system 3 according to the third exemplary embodiment of the present invention can set the accumulation completion time more easily than the first exemplary embodiment but with a certain degree of validity. .

Note that, unlike the video data acquisition system 3 according to the third embodiment of the present invention, the transfer time is not measured by transferring sample data, but is selected from a transfer time list determined in advance according to the communication band. it can be changed even realized for the second embodiment. For this purpose, a transfer time list 52 is stored instead of the sample data 45 in the storage unit 44 of the video distribution device 40a of FIG. In addition, the processing of step S211 and step S212 in FIG. 6B is not performed, and in step S213, information on the line speed is transmitted together with the distribution request (764), and in step S214, the video distribution device 40a side This can be realized by performing the processing corresponding to steps S311 and S312.

Other embodiments.
Note that the video reception devices 20, 20a, and 20b according to the first to third embodiments of the present invention may be devices such as STB (Set Top Box). Alternatively, the video reception devices 20 to 20b may be devices integrated with the display device 10. Furthermore, the video receiving devices 20 to 20b may be mobile phone terminals. In that case, the communication network 30 may be a communication network including a base station capable of wireless communication with a mobile phone terminal.

  The communication network 30 is a communication form such as satellite communication, terrestrial, cable television, and the Internet, and the line may be ADSL, optical fiber, or the like. In other words, various communication forms can be combined in the target broadcast, and the existing network infrastructure can be diverted to reduce the cost for implementation.

  In the video data acquisition method according to the first to third embodiments of the present invention, the video reception devices 20, 20a, and 20b do not have to acquire the latest version of the broadcast schedule 50b in an unstored state. This is because the video distribution apparatuses 40, 40a, and 40b always have the latest version of the broadcast schedule 50a and can be referred to when selecting video content.

  Furthermore, in the video data acquisition method according to the first to third embodiments of the present invention, the channel selection information is included on the video distribution device side, including the channel selection information indicating the channel selected in the broadcast schedule in the distribution request from the video reception device. The video content may be selected from the reproducible points. The case where the above-described modification is added to the first embodiment of the present invention is as follows. Here, it is assumed that the channel 6X is selected as the channel selection information. In step S <b> 131, the video reception device 20 transmits the channel 6 </ b> X as channel selection information as the video distribution request 724 in addition to the reproducible point 712 from the transmission / reception unit 23 to the video distribution device 40. In step S132, the video content 622 to be distributed is selected from the broadcast schedule 50a in the storage unit 44 and the received information indicating the channel 6X and the reproducible point 712. Note that there may be a plurality of channel selection information. Alternatively, it may be selected by the user immediately after the video receiver 20 is turned on.

  Moreover, when adding the said change to Embodiment 2 of this invention, it is as follows. In step S213, the video reception device 20a transmits the channel 6X, which is channel selection information, as the video distribution request 764 in addition to the transfer time 760 from the transmission / reception unit 23 to the video distribution device 40a. In step S232, the video distribution device 40a selects the video content 622 to be distributed from the broadcast schedule 50a in the storage unit 44 and the received information indicating the channel 6X and the reproducible point 752 in the video distribution unit 43. To do. In order to add the above-described modification to the third embodiment of the present invention, it may be performed in the same manner as in the first embodiment of the present invention, and thus description thereof is omitted.

  As described above, since the video receiving device acquires video content data by specifying a channel, the amount of data to be acquired is relatively small compared to the case of acquiring video content data of all channels. It is possible to shorten the time required for accumulating up to an amount that can be reproduced. For example, in the non-accumulated state, it is possible to shorten the playback start time by acquiring video content data using only the channels initially set in the video receiver as channel selection information. Then, if video content data of all channels including the remaining channels is acquired after the start of reproduction, the normal accumulation state can be reached during reproduction. From the above, the user can be provided with a shorter waiting time when viewing the video content.

  Note that the reproducible points according to the first to third embodiments of the present invention are expressed by time, but may be expressed by information (file name or the like) specifying video content in the broadcast schedule. For example, the determination process in the reproducible point determination unit 22 according to Embodiment 1 of the present invention may be determined by further adding information on the broadcast schedule 50b in addition to the current time 711 and the accumulation completion time 710. That is, the current time 711 is checked against the time schedule corresponding to the broadcast schedule 50 b, and information specifying the video content at the time when the accumulation completion time 710 has elapsed is determined as the reproducible point 712. Furthermore, the above channel selection information may be included.

  In the first to third embodiments of the present invention, the estimated time for transfer is based on the time from the video content transmission request to the reception of the video content distribution in the video reception device. For example, in the first embodiment of the present invention, the time from when the video reception device 20 transmits the sample data transmission request 722 until the sample data transmission response 723 from the video distribution device 40 is received is used as a reference. However, the time until the sample data transmission response 723 from the video distribution device 40 is received by the video reception device 20 may be used as a reference. This is because the time required for the distribution response is actually longer than the time required for the transmission request.

  In the video data acquisition method according to the first to third embodiments of the present invention, the accumulation completion time is set every time, but this may be performed only at an arbitrary timing. For example, the accumulation completion time is set only at the first time when the video reception device 20 according to the first embodiment of the present invention is installed. In that case, the set accumulation completion time 710 is stored in a storage means such as the accumulation unit 24, and when the video data is acquired next time, the accumulation completion time 710 in the accumulation unit 24 is read and the reproducible point is stored. A determination may be made.

  Furthermore, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention described above.

It is a block diagram which shows the structure of the video data acquisition system 1 concerning Embodiment 1 of this invention. It is a figure which shows the structural example of a broadcast schedule. It is a flowchart figure of the video data acquisition method concerning Embodiment 1 of this invention. It is a schematic diagram of the example of application of the video data acquisition method concerning Embodiment 1 of the present invention. It is a block diagram which shows the structure of the video data acquisition system 2 concerning Embodiment 2 of this invention. It is a flowchart figure of the video data acquisition method in the video data acquisition system 2 concerning Embodiment 2 of this invention. It is a schematic diagram of the example of application of the video data acquisition method concerning Embodiment 2 of the present invention. It is a block diagram which shows the structure of the video data acquisition system 3 concerning Embodiment 3 of this invention. It is a flowchart figure of the video data acquisition method in the video data acquisition system 3 concerning Embodiment 3 of this invention. It is a schematic diagram of the example of application of the video data acquisition method concerning Embodiment 3 of the present invention.

Explanation of symbols

1-3 Video Data Acquisition System 6X Channel 6Y Channel 10 Display Devices 20, 20a, and 20b Video Receiver 21 Storage Completion Time Setting Unit 22 Reproducible Point Determination Unit 23 Transceiver 24 Storage Unit 25 Playback Unit 26 Storage Completion Time Measurement Unit 30 Communication networks 40, 40a and 40b Video distribution apparatus 41 Accumulation completion time setting unit 42 Reproducible point determination unit 43 Video distribution unit 44 Storage unit 45 Sample data 50-50b Broadcast schedule 51 Service guide 52 Transfer time list 60a-60b Video content 61 -66 program 621-624 video content

Claims (14)

A video data acquisition method by a video receiving device that receives video content data for which a playback time is specified in advance based on a broadcast schedule from a video distribution device via a network and plays back the video content data at the playback time ,
When it is assumed that the transfer of the video content data from the video distribution device to the video reception device is started via the network, the reception of the data necessary for starting the playback of the video content data is completed and The estimated time required for the video content data to be reproduced is determined based on the communication bandwidth of the network,
Determining a reproducible point that is a future time after the time obtained by adding the predicted time to the current time or a data position of video content data corresponding to the future time ;
A video data acquisition method for acquiring the video content data after the playable point from the video distribution device. Claims the predicted time, a transfer estimated time that is expected to require the transfer of the video content data, is calculated using the accumulated prediction time predicted to be required for the accumulation of the video content data to the video receiving device Item 2. The video data acquisition method according to Item 1 . The video data acquisition method according to claim 2 , wherein the estimated transfer time is calculated based on a time required for transferring sample data between the video distribution device and the video reception device. The video data acquisition method according to claim 2 , wherein the reproducible point is determined by selecting a candidate for the predicted transfer time from a plurality of candidate times listed in advance. The determination of the reproducible point is performed when the video content data in which a playback time corresponding to the current time is designated is not stored in the video reception device. Video data acquisition method. The determination of renewable point, the video data acquisition method according to any one of claims 1 to 5, characterized in that is carried out by the video receiving apparatus. The acquisition of the video content data according to claim 6 , wherein the acquisition of the video content data is started based on a request for distribution of the video content data including the reproducible point from the video reception device to the video distribution device. Method. The determination of renewable point, the video data acquisition method according to any one of claims 1 to 5, characterized in that performed in the video distribution device. The acquisition of the video content data, in any one of claims 2 to 5 is started based on that the delivery request of the video content data, including the transfer estimated time to the video distribution device from said video receiving device 9. The video data acquisition method according to claim 8, which is dependent . The distribution request further includes channel selection information in which a channel to which the video content data belongs is specified,
The video data acquisition method according to claim 7 or 9 , wherein the video distribution device selects video content data to be distributed based on the channel selection information. A video data acquisition system comprising: a video distribution device that distributes video content data whose playback time is specified in advance based on a broadcast schedule; and a video reception device that receives the video content data via a network and plays back the video content data. Because
The video receiver is
When it is assumed that the transfer of the video content data from the video distribution device to the video reception device is started via the network, the reception of the data necessary for starting the playback of the video content data is completed and The estimated time required for the video content data to be reproduced is determined based on the communication bandwidth of the network,
Determining a reproducible point that is a future time after the time obtained by adding the predicted time to the current time or a data position of video content data corresponding to the future time ;
A video data acquisition system for receiving the video content data after the playable point from the video distribution device. A video data acquisition system comprising: a video distribution device that distributes video content data whose playback time is specified in advance based on a broadcast schedule; and a video reception device that receives the video content data via a network and plays back the video content data. Because
The video distribution device includes:
When it is assumed that the transfer of the video content data from the video distribution device to the video reception device is started via the network, the reception of the data necessary for starting the playback of the video content data is completed and The estimated time required for the video content data to be reproduced is determined based on the communication bandwidth of the network,
Determining a reproducible point that is a future time after the time obtained by adding the predicted time to the current time or a data position of video content data corresponding to the future time ;
A video data acquisition system that distributes the video content data after the playable point to the video receiver. A video receiving device that receives video content data whose playback time is designated in advance based on a broadcast schedule via a network, and plays back the video content data at the playback time ,
When it is assumed that transfer of the video content data has started from the video distribution device that distributes the video content data to the video reception device via the network, data necessary for starting the reproduction of the video content data An estimated time determining unit that determines an estimated time required for reception of the video content data after reception is complete based on a communication band of the network;
A reproducible point determination unit that determines a reproducible point that is a future time after the time obtained by adding the predicted time to the current time or a data position of video content data corresponding to the future time ;
A video receiving apparatus comprising: a receiving unit configured to receive the video content data after the playable point from the video distribution apparatus. A video distribution device that distributes video content data whose reproduction time is designated in advance based on a broadcast schedule via a network ,
When it is assumed that the transfer of the video content data is started to the video reception device that receives the video content data from the video distribution device via the network and reproduces the video content data at the playback time. A predicted time determination unit that determines a predicted time required from the completion of reception of data necessary to start playback of video content data until the video content data can be played back based on a communication band of the network;
A reproducible point determination unit that determines a reproducible point that is a future time after the time obtained by adding the predicted time to the current time or a data position of video content data corresponding to the future time ;
A video distribution apparatus comprising a video distribution unit that distributes the video content data after the playable point to the video reception apparatus.

Images