JP5806982B2 - User pause operation time estimation apparatus, method, and program - Google Patents

Description

  The present invention relates to a user pause operation time estimation apparatus, method, and program for estimating a playback state in a terminal that receives data such as a video service, and more particularly, based on a buffer state of a terminal at a certain point in time from packet capture data. The present invention relates to a user pause operation time estimation apparatus, method, and program for estimating the time of a pause operation state (video playback pause state) by a user.

  With the progress of broadband communication networks in recent years, progressive download type content distribution systems in which large-capacity content data are downloaded and processed in parallel at the client terminal are becoming widespread. In such a content distribution mode, transmission quality degradation caused by network conditions affects content playback on the terminal side, so a playback buffer is prepared on the terminal side and a certain amount of buffering ( Conventionally, a mechanism for concealing the influence of quality degradation caused by network conditions on higher-level applications by requiring an initial buffer amount) has been widely used. However, playback may stop when the amount of data stored in the playback buffer decreases due to degradation of network conditions or the like.

  On the other hand, for content data providers who need to objectively understand the user's quality of experience and line providers who provide access lines, remote monitoring of quality, such as isolation when users report quality deterioration, etc. Therefore, it is important to understand the time series of the received byte amount of the terminal based on the given capture data, and input it to the modeled playout buffer to derive the estimated value of the playback stop state. (For example, refer nonpatent literatures 1-3.). In this method, the received byte amount time series of the terminal is grasped from the capture data, and input to the modeled playout buffer to output an estimated value of the reproduction stop state. Progressive download-type applications are known to be roughly classified into two types according to their playback methods, and the above technique can be applied to both of them. By using these techniques, the playback state of the session can be estimated based on given capture data.

Daisuke Ikegami, Yasunori Honda, Koji Yamamoto et al .: "Progressive download service stop time estimation method" IEICE Technical Report, vol. 111, no. 278, CQ2011-59, pp. 91-96, November 2011 . Yasutoshi Honda, Daisuke Ikegami, Koji Yamamoto: “A video observation state estimation method using Ack observation”, IEICE General Conference, B-11-25, March 2012. Daisuke Ikegami, Yasunori Honda, Koji Yamamoto: “Examination of playback state estimation method for chunked video distribution services”, IEICE General Conference, B-11-24, March 2012.

  However, smartphones and tablet devices that have become extremely popular have a shorter playout buffer length than PCs due to memory capacity restrictions, and the amount of unplayed data that has been downloaded has reached the upper limit of the buffer, and downloading temporarily stops. Occur frequently. In particular, the sequential progressive download type service has the feature that downloading continues even after the user performs a pause operation. Therefore, the user performs a pause operation when playback stops due to degradation of the line state, etc. In many cases, after reaching the upper limit of the buffer and becoming ready for playback, viewing is resumed after confirming whether playback is possible using a seek bar or the like on the GUI.

  As a service provider or a line provider, it is desirable to objectively grasp the quality of experience of video services provided to users from the viewpoint of maintenance. However, Non-Patent Documents 1 to 3 are techniques for estimating the video playback state based on the capture data, but the playback stop time due to the pause operation performed by the user is not included in the estimation target. For this reason, if the user performs a pause operation, the output stop time estimated value is a playback stop controlled by the relationship between the actual amount of data in the buffer on the terminal and the threshold value for playback stop and playback restart. In addition to the playback stop time controlled by the relationship with the playback restart threshold, the playback stop time due to the user's spontaneous execution of the pause operation is also included. There was a concern that the effect on the estimation accuracy of the playback state would increase.

  The present invention has been made in view of the above points, and in a terminal that receives data such as video provided via a network, such as a sequential progressive download video service, a user performs a pause operation when playback stops. It is an object of the present invention to provide a user pose operation time estimation device, method, and program capable of estimating the pose operation time occurring after resuming playback on the premise of performing.

In order to solve the above-described problem, the present invention provides a user pause operation time estimation device for estimating a user's pause operation time at the time of data reproduction in a terminal that reproduces data received via a network,
An in-buffer data amount report means for obtaining a message or a packet from capture data input at a specific time and outputting information on the amount of data in the buffer at an arbitrary time after the pause state is released;
Pause operation time estimated value calculating means for calculating an estimated value of pause operation time based on the given parameter estimated value, the buffer data amount acquired from the buffer data amount report means, and the input packet capture data When,
Have
The pause operation time estimated value calculating means is:
When the amount of data in the buffer reaches a given playback stop threshold and playback stops and the user performs a pause operation, the amount of data in the buffer resumes playback from the playback stop based on the captured data. Means for calculating a time after reaching a threshold as an estimated value of the pause operation time.

  According to the present invention, it is possible to estimate a pause time that has occurred at the time of reproduction of received data in a terminal. For example, when the pause operation time by the user accompanying the occurrence of playback stop is included in the capture data of the video service via the network, from the state where the data amount in the buffer has reached the playback restart threshold again, By estimating the time until the pause state is released, it is possible to improve the accuracy of the reproduction state estimation.

It is a block diagram of the user pause operation time estimation apparatus in one embodiment of this invention. It is a buffer length transition image in one embodiment of the present invention. It is transition of the presumed reproduction | regeneration state by this invention and the data amount in a buffer.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a configuration diagram of a user pause time estimation apparatus according to an embodiment of the present invention.

  The user pause time estimation device 10 shown in the figure calculates an in-buffer data amount report unit 2 that reports the amount of data in the buffer at an arbitrary time after the pause state is released, and estimates of pause operation time and decode rate. The pose operation time estimated value calculating unit 3 is connected to the parameter estimated value calculating device 1 for calculating the parameter estimated value, and acquires the player parameter estimated value.

  The pause operation time estimated value calculation unit 3 calculates the estimated value based on the data amount in the buffer which is the output of the data amount report unit 2 in the buffer derived based on the given packet capture data, and the given packet capture data. calculate. In the pause operation time estimated value calculation unit 3, when the decode rate is given as a known value in advance, a pause time estimated value is calculated and output based on the decode rate. Here, the capture data is the data of the IP packet constituting the session of the application, the capture point for acquiring the capture data is an arbitrary point on the path of the server / terminal, and the capture target is All packets for the session.

  The parameter estimated value calculation device 1 uses the pause resumption threshold and decoding rate, which are the remaining amount of data in the buffer, required for the second and subsequent reproductions after the reproduction is stopped as parameter estimation values for the pause operation time estimated value calculation unit 3 Is output. In the parameter estimated value calculation apparatus 1, the player is modeled by decoding data in a finite-length buffer at a fixed rate.

The parameter estimation value calculation device 1 is connected to the user pause time estimation device 10, models a player, calculates a parameter estimation value based on the model, and outputs the parameter estimation value to the pause operation time estimation value calculation unit 3 .

The parameter estimated value calculation device 1 is a device that outputs a parameter estimated value to the pause operation time estimated value calculation unit 3 . The parameter estimated value calculation device 1 models the player, calculates a parameter estimated value based on the model, and outputs the parameter estimated value to the pause operation time estimated value calculation unit 3 . The processing in the parameter estimated value calculation apparatus 1 can be realized by various conventional techniques that can be modeled (for example, Non-Patent Documents 1 to 3).

  The parameter estimation value output by the parameter estimation value calculation apparatus 1 is shown below.

  1) Reproduction start threshold: This is the remaining amount of data in the buffer required for the first reproduction after the application is started.

  2) Playback restart threshold: This is the remaining amount of data in the buffer required for the second and subsequent playback after playback is stopped.

  3) Playback stop threshold: This is a threshold for the amount of data in the buffer that transitions from the playback state to the playback stop state.

  4) Buffer length: Playout buffer capacity. The present invention allows a finite length.

  5) The amount of data in the buffer.

  The parameter estimated value calculation apparatus 1 outputs a reproduction start threshold value, a reproduction restart threshold value, a buffer length, a decode rate, and a reproduction stop threshold value among the parameter estimated values described above. However, if the playback stop has not occurred before reaching the buffer upper limit, the playback stop threshold is not necessary.

  Below, the process of each structure of the user pause time estimation apparatus 10 is demonstrated in detail.

  As the output from the in-buffer data amount report unit 2, for example, a feedback message sent from the client terminal or a packet (TCP RST packet, Zero Window, etc.) indicating that the buffer upper limit has been reached can be considered. Here, the amount of data in the buffer at the time needs to be described in the feedback message. However, in the case of a packet (RST, FIN, Zero Window, etc.) indicating that the buffer upper limit has been reached, if the buffer length is known, the amount of data in the buffer need not be described in the packet.

  Next, the pause operation time estimated value calculation unit 3 will be described.

The pause time estimation will be described with reference to FIG. Here, after starting playback at time t1, playback stops at time t2 due to deterioration of network quality, and the user performs a pause operation. However, although the time t 5 when the time t2 is given, the t3, etc. between them have not been given. It is assumed that after the reproduction can be resumed at time t3, the user executes a pause release operation at time t4, and the data amount in the buffer at time t5 is given as the output of the data amount report unit 2 in the buffer.

  First, the output of the in-buffer data amount report unit 2 is the in-buffer data amount B at time t5 after the user pause release operation.

Here, as the reproduction restart threshold B1 given from the parameter estimated value calculation device 1, the difference is expressed as Z: = (B−B1). Then, the accumulated reception amount of bytes in from time t3 t5 seek X [byte], during which time Y: = t5-t3, the pause state after playable time to resume p: = t4-t3, decoding rate Is d [byte / sec]. At this time, the following relational expression holds:
Z = X− (Y−p) * d .... (1)
Therefore, when the decoding rate d is known, it is possible to estimate the pause operation time estimated value p after the reproduction can be resumed. Note that the decode rate d can be obtained from the parameter estimated value calculation apparatus 1 or can be obtained by the following method.

  From the captured data, the cumulative received byte amount A1 during the period from the restart of download when the received data is confirmed again in the capture data to the buffer upper limit reaching time is calculated from the captured data. The buffer upper limit arrival time is obtained by detecting a specific packet such as a TCP RST packet, a FIN packet, and a Dup Ack packet in the capture data. For example, when the buffer limit is reached due to continuous data storage in the playout buffer, the terminal closes the session by sending a TCP RST packet or FIN packet, or sets the receive window size to 0 (TCP Zero Window). Prevents buffer overflow. When the TCP session is closed, it is distinguished from session close due to timeout because there are no packets indicating transfer quality degradation such as Dup Ack and retransmission in N packets before and after the capture data.

From buffer upper limit arrival time a1, playback resume time estimate a2, pause state time p, cumulative received byte amount A1
d = A1 / (a1-a2-p)
Thus, the decoding rate d can be obtained. Note that the reproduction restart time estimated value a2 is calculated from the last transmission time of a packet having an RST / Zero Window or the like indicating that the buffer upper limit has been reached in the packet capture data.

  FIG. 3 shows the estimation results of the playback state and buffer state according to the present invention. In the prior art, since the reproduction stop time due to the user's pause operation is not an estimation target, the length of the pause operation time causes a decrease in the accuracy of the stop time estimated value. According to the present invention, FIG. As shown in FIG. 5, it can be confirmed that the time during which the user has continued the pause operation after the state where the buffer data amount has reached the threshold value at which reproduction can be resumed in a single trial can be estimated with high accuracy.

  In the present invention, the operation of each component of the user pause operation time estimation device in FIG. 1 is constructed as a program and installed in a computer used as the user pause operation time estimation device to be executed, or a network It is possible to circulate through.

  The present invention is not limited to the above-described embodiments, and various modifications and applications are possible within the scope of the claims.

DESCRIPTION OF SYMBOLS 1 Parameter estimated value calculation apparatus 2 Buffer amount of data report part 3 Pause operation time estimated value calculation part 10 User pause time estimation apparatus

Claims (5)

In a terminal for reproducing data received via a network, a user pause operation time estimation device for estimating a time during which reproduction is stopped by a user's pause operation during data reproduction,
An in-buffer data amount report means for obtaining a message or a packet from capture data input at a specific time and outputting information on the amount of data in the buffer at an arbitrary time after the pause state is released;
The amount in the data buffer to be output by the buffer data amount report means reaches a given reproduction stop threshold, when the user stops playback is performed pause operation, based on the input capture data, said buffer <br/> the amount inner data and a pause operation time estimation value calculating means for calculating a time after reaching a given reproduction resuming threshold as an estimate of time reproduced by the pause operation is stopped An apparatus for estimating a user pause operation time. The pause operation time estimated value calculating means is:
The difference Z of the buffer data amount B and the playback resume threshold B1, the time from said specific point in time until resuming reproduction of the captured data Y, time playback by the pause operation after resuming the reproduction is stopped p , X is the cumulative number of received bytes from the resumption of playback to the specific point in time, and d is the given decoding rate.
Z = X− (Yp) * d
The apparatus for estimating a user pause operation time according to claim 1, further comprising means for calculating an estimated value of a time during which reproduction is stopped by the pause operation. In a terminal that reproduces data received via a network, a computer that estimates a time during which reproduction is stopped by a user's pause operation during data reproduction,
A buffer data amount report step for obtaining a message or packet from capture data input at a specific time and extracting information on the data amount in the buffer at an arbitrary time after the pause state is released;
The amount in the data buffer to be output in the buffer data amount report step reaches the given playback stop threshold, when the user stops playback is performed pause operation, based on the input capture data, said buffer <br/> amount inner data to execute a pause operation time estimate calculation step of reproducing by the pause operation time after reaching a given reproduction resuming threshold is calculated as an estimate of the time that has been stopped A method for estimating a user pause operation time. In the pause operation time estimated value calculating step,
The difference Z of the buffer data amount B and the playback resume threshold B1, the time from said specific point in time until resuming reproduction of the captured data Y, time playback by the pause operation after resuming the reproduction is stopped p , X is the cumulative number of received bytes from the resumption of playback to the specific point in time, and d is the given decoding rate.
Z = X− (Yp) * d
4. The user pause operation time estimation method according to claim 3, wherein an estimated value of a time during which reproduction is stopped by the pause operation is calculated. Computer
A user pose operation time estimation program for functioning as each means of the user pose operation time estimation device according to claim 1.

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