JP6740110B2 - Data distribution system, communication terminal, and program - Google Patents

Description

The present invention relates to a data distribution system that distributes content data, a communication terminal that acquires content data, and a program for the communication terminal.

Adaptive streaming has been attracting attention in recent video distribution. In adaptive streaming, the distribution side encodes the video at multiple bit rates and divides it into files of several seconds unit, and the communication terminal that receives the streaming sequentially acquires the file of the bit rate that matches its own communication speed. , Plays by connecting the acquired files. Thus, even in a communication terminal whose communication speed varies, it is possible to realize moving image distribution in which reproduction is unlikely to be interrupted (for example, see Non-Patent Document 1).

However, in adaptive streaming, since each communication terminal acquires data in file units, traffic tends to be bursty, and when access from communication terminals concentrates, packet loss due to congestion in network equipment etc. easily occurs. .. Since the tendency becomes more remarkable as the distribution scale becomes larger, a technique for suppressing such bursty traffic is required.

In large-scale stream distribution to a communication terminal such as a smartphone or a PC, access from the communication terminal tends to concentrate on the network device, and the network device cannot complete processing, resulting in packet loss. As a method for suppressing this, a shaping method is known in which packets are stored in a buffer of a network device so that the communication capacity of the network device is not exceeded, and a transmission process is performed when the communication capacity becomes available (for example, See Patent Document 2).

FIG. 8 is a diagram showing the effect of shaping, FIG. 8(a) shows the communication amount without shaping, and FIG. 8(b) shows the communication amount with shaping. If shaping is not performed when a burst-like request occurs, a packet exceeding the upper limit of the distribution capacity of the distribution server will be a packet loss as shown in FIG. 8A. On the other hand, when the shaping is performed, the packet processing is delayed as shown in FIG. 8B, but the packet loss is not generated.

In addition, the communication terminal may be less than the communication speed required for streaming playback due to the congestion of the Internet, etc. It is common to acquire up to and store in a buffer, and start streaming playback when the stored data amount exceeds a set threshold value.

In addition, Patent Document 1 discloses a technique of changing the encoding rate according to the congestion situation of the distribution route.

JP, 2006-262205, A

A. Zambelli, "IIS Smooth Streaming Technical Overview", Mar.2009 Fukutomi et al., “Study of bandwidth control method in router”, IEICE Tech., NS2003-219, Dec. 2003

By performing shaping, packet loss can be reduced and distribution can be stabilized. However, the smoothing of the data receiving speed increases the data receiving time. As a result, there is a problem that it takes time to acquire the data necessary for starting the reproduction at the time of starting the viewing or the seek operation, and the time until starting the reproduction of the streaming increases.

Further, in the method described in Patent Document 1, when the access from a communication terminal instantaneously increases as in live distribution of adaptive streaming, the encoding rate is lowered more than necessary, and the quality of content data is remarkably high. There is a problem that it will decrease.

An object of the present invention made in view of such circumstances is to provide a data distribution system, a communication terminal, and a program capable of both stabilizing the viewing and listening at the communication terminal and speeding up the playback start. ..

In order to solve the above problems, a data distribution system according to the present invention is a data distribution system that distributes content data, and a first distribution server that distributes content data that is not shaped and a content that is shaped. When the second distribution server that distributes the data and the reproduction instruction of the content data are acquired, the content data is acquired from the first distribution server and the content data is stored while the storage amount of the content data is equal to or less than the threshold value. And a communication terminal that acquires content data from the second distribution server when the amount exceeds the threshold value.

Furthermore, in the data distribution system according to the present invention, the communication terminal obtains a playlist including information about a destination address of the first distribution server, a destination address of the second distribution server, and a file name of content data. Then, when the reproduction instruction of the content data is acquired, while the storage amount of the content data is equal to or less than the threshold value, the URI of the content data distributed by the first distribution server is determined based on the playlist, When a request is made to the first distribution server and the storage amount of the content data exceeds the threshold value, the URI of the content data distributed by the second distribution server is determined based on the playlist, and the second distribution is performed. It is characterized by making a request to the server.

Further, in order to solve the above problems, a communication terminal according to the present invention is a communication terminal that acquires content data from a distribution server, and when a reproduction instruction of content data is acquired, the storage amount of content data is equal to or less than a threshold value. During the period, the content data is acquired from the first distribution server that distributes the content data that is not shaped, and when the storage amount of the content data exceeds the threshold, the second distribution that distributes the content data that is shaped The content data is acquired from the server.

Furthermore, in the communication terminal according to the present invention, whether or not a communication session with the first distribution server has been established is checked at regular intervals, and if the communication session has not been established, the first It is characterized by starting a communication session with the distribution server of.

Further, in the communication terminal according to the present invention, whether or not a session with the first distribution server has been established is triggered by a tap operation on the viewing screen or mouseover, and the communication session is established. If not, a communication session with the first distribution server is started.

In order to solve the above problems, the program according to the present invention causes a computer to function as the communication terminal.

According to the present invention, it is possible to achieve both stable viewing on a communication terminal and high-speed playback start and seek operation.

1 is a schematic diagram of a data distribution system according to an embodiment of the present invention. 3 is a schematic diagram of content data stored in a content distribution server in the data distribution system according to the embodiment of the present invention. FIG. It is a figure which shows an example of the playlist which the playlist server in the data distribution system which concerns on one Embodiment of this invention distributes. It is a schematic diagram showing composition of a communication terminal concerning one embodiment of the present invention. It is a figure which shows the content data memorize|stored by the communication terminal which concerns on one Embodiment of this invention from the acquisition of the reproduction instruction|indication of content data to stream reproduction. It is a flow chart which shows an example of processing of a control part in a communication terminal concerning one embodiment of the present invention. It is a figure explaining the effect by this invention. It is a figure explaining the effect by shaping.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic diagram of a data distribution system according to an embodiment of the present invention. The data distribution system 1 shown in FIG. 1 includes a playlist server 10, a first distribution server 20-1, a second distribution server 20-2, and a plurality of communication terminals 30. It is assumed that each distribution server 20 caches the same data. In the following description, the "first distribution server 20-1" and the "second distribution server 20-2" are simply referred to as "distribution server 20" unless it is necessary to distinguish them.

The data distribution system 1 distributes data by adaptive streaming. Here, continuous data (such as video or audio stream data) divided into files of a few seconds is called content data (delivery data). In adaptive streaming, each communication terminal 30 first acquires a playlist that is metadata in which the acquisition destination of the content data is described, and sequentially acquires and acquires the content data from the distribution server 20 described in the playlist. Plays together content data.

The first distribution server 20-1 is a server that distributes content data that is not shaped. The second distribution server 20-2 is a server that distributes content data that is shaped. The shaping may be performed by the second distribution server 20-2, or may be performed by a network device such as a base station or a router arranged between the second distribution server 20-2 and the communication terminal 30.

FIG. 2 is a schematic diagram of content data stored in the distribution server 20 in adaptive streaming. Content data is an independent file for each file number (sequence number).

The playlist server 10 is a server that distributes a playlist. It is also possible that the distribution server 20 also distributes the playlist so that the system does not include the playlist server 10.

FIG. 3 is a diagram showing an example of a playlist distributed by the playlist server 10. The playlist is a destination address of the first distribution server 20-1, a destination address of the second distribution server 20-2, and information indicating whether or not the distribution server distributes the content data to be shaped (for shaping). Information), and information about the file name of the content data. Although this playlist includes the presence or absence of shaping, this information may be set in advance not in the playlist but in the communication terminal 30.

In the playlist shown in FIG. 3, the distribution server whose destination address is http://aaa is the first distribution server 20-1 that distributes the content data that is not shaped, and the first distribution server 20- The URI (Uniform Resource Identifier) of the content data distributed from No. 1 is http://aaa/11, http://aaa/12, http://aaa/13... The distribution server whose destination address is http://bbb is the second distribution server 20-2 that distributes the content data to be shaped, and the content data distributed from the second distribution server 20-2. URIs of http://bbb/11, http://bbb/12, http://bbb/13...

The communication terminal 30 is a terminal such as a smartphone or a PC, and acquires a playlist from the playlist server 10. Then, when the content data reproduction instruction is acquired, while the content data storage amount is equal to or less than the threshold value, the content data is acquired from the first distribution server 20-1, and the content data storage amount exceeds the threshold value. , Starts reproducing the content data, and acquires the content data from the second distribution server 20-2.

Here, the reproduction instruction of the content data is not only an instruction to newly join the data distribution system 1 to acquire the content data, but also a seek instruction to change the reproduction start position by a seek operation to acquire the content data, It also includes a state in which the storage amount of content data is equal to or less than the threshold value and the reproduction of content data is stopped.

In FIG. 1, the communication terminal 30-4, which has acquired the content data reproduction instruction, transmits the URI (such as http://aaa/11) of the content data distributed by the first distribution server 20-1 based on the playlist. It decides and makes a request to the first distribution server 20-1 for each content data to acquire the content data. When the communication terminal 30-4 acquires the content data up to several seconds ahead of the reproduction time, the communication terminal 30-4 starts reproducing the content data and acquires the content data from the second distribution server 20-2 as indicated by a broken line. ..

In FIG. 1, the communication terminals 30-1, 30-2, 30-3 have already started reproducing the content data, and the URI of the content data distributed by the second distribution server 20-2 based on the playlist. (Http://bbb/11, etc.) is determined, a request is made to the second distribution server 20-2 for each content data, and the content data is acquired.

In this way, each communication terminal 30 selects the distribution server 20 from which the content data is acquired, according to its own viewing status. Since the content data distributed from the first distribution server 20-1 is not shaped, data distribution with less delay is possible. Further, when access from the communication terminal 30 is concentrated in the second distribution server 20-2, shaping is performed, so that the data reception speed to the communication terminal 30 is delayed, but the viewing is stabilized. It becomes possible.

FIG. 4 is a schematic diagram showing the configuration of the communication terminal 30. The communication terminal 30 includes an input unit 301, a communication unit 302, a control unit 303, a storage unit 304, and a display unit 305.

The input unit 301 is a user interface that acquires a user instruction by a user operation and outputs the user instruction to the control unit 303. The user instruction is classified into a content data reproduction instruction (including a seek instruction), a content data reproduction end instruction, and the like.

The communication unit 302 receives the playlist from the playlist server 10 and outputs it to the control unit 303. Further, it is confirmed whether or not a communication session is established with the distribution server 20 determined as the data acquisition destination, and if the communication session is not established, a new communication session is started with the distribution server 20, and the distribution server The content data is received from 20 via the network device and output to the control unit 303. It is assumed that the communication session with the distribution server 20 ends at any timing when the disconnection request from the distribution server 20 is received.

The control unit 303 controls the operation and signal flow of the communication terminal 30. The control unit 303 executes, for example, a process corresponding to a user instruction input from the input unit 301, determines the distribution server 20 from which the content data is acquired based on the playlist input from the communication unit 302, and performs communication. The content data input from the unit 302 is stored and read in the storage unit 304, and the read content data is output to the display unit 305. Further, the control unit 303 makes the display invisible (a state in which the viewing operation from the input unit 301 is not accepted) after a lapse of a certain time from the previous viewing operation, and taps an arbitrary place on the viewing screen displayed on the display unit 305. The display state (the state in which the viewing operation from the input unit 301 can be accepted) may be triggered by an operation or a mouse over on the viewing screen. Here, the viewing screen refers to a screen displayed on the display unit 305 when the viewing application for content data is activated. Further, the tap operation on the viewing screen also includes a tap operation when starting the viewing application. Details of the processing of the control unit 303 will be described later.

The storage unit 304 stores the content data received from the distribution server 20.

The display unit 305 acquires and displays the content data stored in the storage unit 304 under the control of the control unit 303.

FIG. 5 is a diagram showing content data stored in the storage unit 304 from the acquisition of the content data reproduction instruction by the communication terminal 30 to the stream reproduction. When the communication terminal 30 acquires the reproduction instruction, it stores the content data in the storage unit 304, does not start the reproduction when the storage amount is less than or equal to the reproduction start threshold, and when the storage amount exceeds the reproduction start threshold (Fig. In 5, the reproduction is started after t seconds). When the reproduction instruction by the seek operation is acquired, the reproduction position is changed, new content data is stored, and the reproduction is started when a predetermined amount of content data is stored.

FIG. 6 is a flowchart showing an example of processing of the control unit 303 of the communication terminal 30. First, a playlist is acquired from the playlist server 10 via the communication unit 302 (step S101).

Next, it is confirmed whether or not a communication session with the first distribution server 20-1 is established, and if the communication session is not established, a new communication session with the first distribution server 20-1 is started. Then, the operation of the user interface is confirmed (step S102). This operation may be performed by a user's viewing operation triggered by a tap operation at an arbitrary position on the viewing screen displayed on the display unit 305 or a mouseover on the viewing screen.

Next, the user's viewing operation is confirmed (step S103). When the reproduction instruction of the content data is acquired by the input unit 301 (step S104-Yes), the acquisition destination of the content data is determined to be the first distribution server 20-1 based on the playlist (step S105). When a new reproduction instruction of the content data has not been acquired after the reproduction of the content data is started (step S104-No), the acquisition destination of the content data is determined to be the second distribution server 20-2 based on the playlist (( Step S106).

After that, it is confirmed whether or not the determined communication session with the distribution server 20 is established, and if the communication session is not established, a new communication session is started with the distribution server 20 (step S107). Then, according to the playlist, the content data is acquired from the determined distribution server 20 (step S108), and the acquired content data is stored in the storage unit 304 (step S109).

Then, when the storage amount of the content data stored in the storage unit 304 exceeds the reproduction threshold and is not reproduced (step S110-Yes), reproduction of the content data (including reproduction by a seek operation) is started. (Step S111), the acquisition source of the content data of the playlist is changed from the first distribution server 20-1 to the second distribution server 20-2 (step S112). If the storage amount of the content data is lower than the reproduction threshold value or if the content data is being reproduced (step S110-No), these processes are not performed.

Next, when it is confirmed that a communication session with the first distribution server 20-1 has been established and a certain time has elapsed (step S113-Yes), the first distribution server 20- It is confirmed whether a communication session with 1 has been established, and if the communication session has not been established, a new communication session with the first distribution server 20-1 is started (step S114). When it is determined that a certain period of time has not passed since it was confirmed whether a communication session with the first distribution server 20-1 has been established (step S113-No), this process is not performed. That is, it is confirmed whether or not a communication session with the first distribution server 20-1 has been established at regular intervals.

Next, when the reproduction of the content data ends (that is, the viewing ends) (step S115-Yes), the process ends. If the viewing has not ended (No at step S115), the process returns to the playlist acquisition flow (step S101). Note that, in FIG. 6, the playlist is acquired every time after step S115, but the playlist may be acquired only for the first time or once for several times.

FIG. 7 is a diagram for explaining the effect of the present invention. FIG. 7 shows the acquisition status of content data up to the start of distribution in the case where the present invention is applied to a certain communication terminal 30. In the example of FIG. 7, it is assumed that the communication terminal 30 starts playback after the storage unit 304 stores up to the fourth content data. FIG. 7A shows a case where the present invention is not applied. In this case, since it takes time to acquire each content data due to the delay due to shaping, it takes time to start the reproduction. On the other hand, FIG. 7B shows a case where the present invention is applied. In this case, since there is no delay due to shaping, the acquisition time of each content data is shortened, and the time until the reproduction is started is reduced. It can be shortened.

With regard to the seek operation as well, a similar time difference occurs until the playback position changes, new content data is stored, and a certain amount of content data is stored. Therefore, according to the present invention, playback is started after the seek operation. The time can be shortened.

Also, it is checked at regular intervals whether or not a communication session with the first distribution server 20-1 that distributes content data that is not shaped is established, and if the communication session is not established, Alternatively, a new communication session with the first distribution server 20-1 may be started. This increases the possibility of establishing a session with the first distribution server 20-1 in advance when the data acquisition destination is determined to be the first distribution server 20-1, and thus further speeds up streaming reproduction. be able to.

Further, the communication terminal 30 uses the tap operation at an arbitrary position on the viewing screen displayed on the display unit 305 or the mouse over on the viewing screen as a step before the viewing operation is performed, and the first distribution is performed. It is confirmed whether a session with the server 20-1 has been established, and if a communication session has not been established, a new communication session may be started with the first distribution server 20-1. Good. Accordingly, it is possible to establish a session with the first distribution server 20-1 prior to acquiring the reproduction instruction of the content data and determining the data acquisition destination to the first distribution server 20-1, and Streaming playback can be speeded up.

A computer can be preferably used to function as the communication terminal 30 described above, and such a computer stores a program describing the processing content for realizing each function of the communication terminal 30 in the storage unit of the computer. In addition, it can be realized by reading and executing this program by the CPU of the computer. The program can be recorded on a computer-readable recording medium.

As described above, in the present invention, the first distribution server 20-1 that distributes content data that is not shaped and the second distribution server 20-2 that distributes content data that is shaped are used. The communication terminal 30 that has just participated in the distribution or the communication terminal 30 that has performed the seek operation sets the acquisition destination of the content data as the first distribution server 20-1, and the communication terminal 30 after the start of reproduction is the acquisition destination of the content data. Is the second distribution server 20-2. With this configuration, according to the present invention, it is possible to achieve both stable data distribution and high-speed streaming reproduction of the communication terminal 30.

Although the above embodiments have been described as representative examples, it will be apparent to those skilled in the art that many modifications and substitutions can be made within the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited by the above-described embodiments, and various modifications and changes can be made without departing from the scope of the claims. For example, it is possible to combine a plurality of configuration blocks described in the configuration diagram of the embodiment into one or to divide one configuration block.

1 Data Distribution System 10 Playlist Server 20-1 First Distribution Server 20-2 Second Distribution Server 30 Communication Terminal 301 Input Unit 302 Communication Unit 303 Control Unit 304 Storage Unit 305 Display Unit

Claims (6)

A data distribution system for distributing content data,
A first distribution server that distributes content data that is not shaped;
A second distribution server that distributes content data that is shaped;
When the content data reproduction instruction is acquired, the content data is acquired from the first distribution server while the content data storage amount is equal to or less than the threshold value, and when the content data storage amount exceeds the threshold value, the second content server is acquired. A communication terminal that acquires content data from the distribution server of
A data distribution system comprising: When the communication terminal acquires a playlist including information about a destination address of the first distribution server, a destination address of the second distribution server, and a file name of content data, and acquires a reproduction instruction of the content data. While the storage amount of the content data is equal to or less than the threshold value, the URI of the content data distributed by the first distribution server is determined based on the playlist, and a request is made to the first distribution server, When the storage amount of data exceeds the threshold value, the URI of the content data distributed by the second distribution server is determined based on the playlist, and a request is made to the second distribution server. The data distribution system according to item 1. A communication terminal for acquiring content data from a distribution server,
When the content data reproduction instruction is acquired, while the storage amount of the content data is equal to or less than the threshold value, the content data is acquired from the first distribution server that distributes the content data that is not shaped, and the storage amount of the content data is reduced. A communication terminal, wherein when the threshold value is exceeded, content data is acquired from a second distribution server that distributes shaped content data. Checking whether or not a communication session with the first distribution server has been established at regular intervals, and if the communication session has not been established, start a communication session with the first distribution server. The communication terminal according to claim 3, wherein: A tap operation on the viewing screen or a mouseover is used as a trigger to confirm whether or not a session with the first distribution server has been established. The communication terminal according to claim 3 or 4, which starts a communication session with the distribution server. A program for causing a computer to function as the communication terminal according to any one of claims 3 to 5.

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