KR20150146353A - Playback point change method of user apparatus - Google Patents

Abstract

The present invention relates to a method for changing a playback point of a media player, in which a segment stored in a buffer of a media player is controlled by considering a change in a playback point of the media content displayed through a media player, so a segment of the media content is provided without a display delay according to a change in a playback point.

Description

{PLAYBACK POINT CHANGE METHOD OF USER APPARATUS}

The following description relates to a method of changing a playback point of a media player, and relates to a playback point-in-time changing method for minimizing a time delay due to a point-in-time change in a streaming service of an image having multiple points of view in a web environment.

In recent years, a web-based streaming service for receiving and reproducing contents desired by a user through a separate server has become popular and widely used.

The streaming service is divided into a progressive download method and a dynamic adaptive streaming over HTTP (DASH) method. Recently, the progressive download method has been replaced with the DASH method. Here, the progressive downloading method is a method in which a file is downloaded and reproduced when a user requests a video, which is simple because it is simple and requires no separate real-time encoding operation. However, when the user changes the playback time to an image at a different point in time, there is a delay in downloading the image up to that point of time, resulting in a problem of poor responsiveness.

In addition, when the progressive download method is changed to a camera image at another point of time, there is a problem that quality of service (QoS) of a service can not be guaranteed due to interruption of intermediate playback while the session is connected again.

Accordingly, the DASH scheme, which is an HTTP adaptive streaming scheme, is recently used. In the DASH method, a user receives streaming service of a video having an appropriate bit rate according to the network environment from the server.

However, in the case of the multi-view image streaming service, the DASH scheme has a problem that the reactivity of the image viewpoint change becomes poor because the next segment is reproduced after the buffered previous image is consumed.

It is possible to provide a method of changing a playback point of a media player that controls the buffer so that the screen is switched more quickly and smoothly by using the DASH scheme to improve the responsiveness to the download delay in changing the viewpoint of an image having multiple viewpoints.

It is possible to provide a method of changing the playback point of the media player that improves the QoS of the streaming service by ensuring seamless playback by controlling the segment of the video stored in the buffer so that the screen is switched smoothly.

According to another aspect of the present invention, there is provided a method of changing a playback time of a media player, the method comprising: analyzing status information of media content received from a server in response to a control request for media content; Requesting a segment of the media content to the server using the analyzed status information and the request time for the media content according to the control request; Confirming whether or not the playback time of the segment displayed through the media player is changed; And requesting the server for a segment according to the playback time of the segment to be changed using the analyzed state information and the buffer state information of the media player according to the result of the checking, The media player can transmit a segment according to a playback time or a request time of the media content to the media player.

The step of requesting the server for a segment according to a change time according to an embodiment may include: when a playback point of the media content is changed, a segment corresponding to a playback point of the requested media content among the segments stored in the buffer of the media player It is possible to delete the segments other than the segment to be reproduced at the preparation time, which is received and reproduced by the media player.

The preparation time according to an embodiment may be determined based on a request time of a first frame of a segment reproduced after a segment being reproduced through the media player, a request time of the segment being reproduced, and a buffering time for providing the media content.

A segment to be reproduced according to an embodiment may be determined based on a request time of a segment stored in the buffer of the media player and the preparation time.

The server according to an embodiment may divide and store the at least one media content in each segment in consideration of a request time according to different playback time points.

The status information of the media content according to one embodiment includes at least one of the viewpoint information of the media content, the request time information of the media content, the segment information of the media content, the resolution information of the media content, . ≪ / RTI >

 The method of changing the reproduction time of the media player can control the buffer to switch the screen more quickly and smoothly by using the DASH method in order to improve the responsiveness to the delay of the viewpoint change of the multi-viewpoint image.

The method of changing the playback point of the media player can improve the QoS of the streaming service by ensuring seamless playback by controlling the segment of the video stored in the buffer so that the screen is switched smoothly.

1 is a diagram illustrating a media player and a server according to an exemplary embodiment of the present invention.
2 is a flowchart illustrating a method of changing a playback time of a media player according to an embodiment.
3 is a view for explaining a segment of a media content stored in a buffer of a media player according to an exemplary embodiment of the present invention.
FIG. 4 is a detailed block diagram of a media player according to an exemplary embodiment of the present invention. Referring to FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating a media player and a server according to an exemplary embodiment of the present invention.

1, the media player 101 may include a status information analysis unit 102, a first request unit 103, a playback time confirmation unit 104, and a second request unit 105.

The status information analyzing unit 102 may analyze the status information of the media content received from the server in response to the control request for the media content. The status information of the media content may include time information of the media content, request time information of the media content, segment information of the media content, resolution information of the media content, frame rate information of the media content, and the like in a file form. For example, the status information of the media content is an MPD (Media Presentation Description) file, and may include detailed information about the media content.

The first requesting unit 103 may measure the request time for the media content according to the control request and request the server for the segment of the media content according to the measured request time. In other words, the first requesting unit 103 can measure the request time according to the current start position only once according to the initial operation for reproducing the media content.

The first requesting unit 103 may download a segment of the media content corresponding to the control request from the server 106 according to a control request of the user's media content. Here, the segment of the media content may mean a unit divided into segments suitable for the streaming service, the content of which has different bit rates according to the user's network environment.

That is, the server 106 may divide each content into segment units in order to improve the management efficiency of the bit rate content. The media player 101 can download the media content from the server 106 on a segment basis in response to a control request. The media player 101 may store a segment of the media content downloaded from the server 106 in a buffer, render a segment of the media content stored in the buffer on the screen, and provide the segment to the user.

The playback time confirmation unit 104 can confirm whether or not the playback time of the currently displayed segment is changed. Here, the playback time of the segment may mean that the playback time is shifted by the user or changed to an image at another time point.

In addition, the second requesting unit 105 may request the server for a segment according to the playback time of the segment to be changed, using the analyzed state information and buffer state information of the media player according to the result of the check. The second request unit 105 may download a segment of the media content for the changed playback point from the server 106 in response to the playback point change of the segment of the media content.

2 is a flowchart illustrating a method of changing a playback time of a media player according to an embodiment.

In step 201, the server 106 may manage a plurality of segments of media content in order to provide a segment of the media content in real time in response to the control request requested from the media player 101. [ Specifically, the server 106 may fragment the media content into a DASH format segment to provide a DASH-based multi-view streaming service, and may store the segments in a storage unit existing in the server or in a separate storage unit, .

Then, the media player 101 can transmit a control request for the media content to the server 106 in real time. At this time, the media player 101 can transmit a control request for the desired media content to the server 106 via the web site. The server 106 may transmit status information on the corresponding media content in response to the transmitted control request.

In step 202, the media player 101 may analyze the status information on the media content received from the server 106. [ The status information includes detailed information about the media content, and may include information such as a request time, playback time information, frame rate, and resolution. Then, the media player 101 can grasp the detailed configuration of the media content based on the status information.

The media player 101 can determine the storage state of the buffer storing the segment of the media content received from the server 106. [ In other words, the media player 101 can recognize the buffer storage state and perform an operation for downloading a segment of the media content from the server 106 based on the determined buffer storage state.

In step 203, the media player 101 may measure the request time for a segment of the media content. Specifically, the media player 101 may measure a request time for a segment to prevent an underflow of the buffer based on the state information and the buffer storage state of the detected media player. In addition, the media player 101 can smoothly reproduce the media content without interrupting the media content by measuring the time required for the segment.

The media player 101 may request the segment of the media content to the server 106 based on the information on the state of the segment and the buffer storage state. The server 106 may then transmit a segment of the corresponding media content to the media player 101 in response to a request from the media player 101. In one example, the media player 101 may request a segment via the HTTP protocol to the server 106 based on the request time for the segment. The server 106 may request the media player 101 for the segment in response to the HTTP request received from the media player 101. [

In step 204, the media player 101 may store a segment of the media content received from the server 106 in a buffer. And, the media player 101 can display according to the order of the segments stored in the buffer. In one example, the media player 101 may display the segment by decoding the buffered segment in the buffer and rendering it on the web browser.

Then, in step 205, the media player 101 can confirm whether or not the playback time of the segment is changed in real time. If it is determined in step 206 that the reproduction time is changed, the media player 101 can grasp the status information of the previously acquired media content and the storage status of the butter. At this time, the media player 101 may not calculate the request time for the segment as in step 203, in order to improve the responsiveness to the change of the playback point of the segment.

Here, the media player 101 may perform the following operations according to the result of checking whether the segment is changed according to the playback point of time.

In the case where the change to the playback point of the segment is not confirmed, the media player 101 requests the server 106 for the segment in accordance with the storage state of the buffer in consideration of preventing the buffer from underflowing in order to seamlessly provide the media content .

On the other hand, if the change to the playback point of the segment is confirmed, the media player 101 can request the segment to the server 106 more quickly in response to the playback point of the changed segment. Then, in step 207, the media player can delete the segment stored in the current buffer. However, if the media player 101 deletes all of the buffered segments in the buffer, the segmentation of the playback may occur because there is no segment currently reproducible. Accordingly, the media player 101 may leave a minimum segment without deleting the buffered segment in consideration of the preparation time to wait until the requested segment is received and displayed in the server 106. [ In other words, the media player 101 can improve the QoS service according to the change of view by leaving a part of the buffered segment in the buffer in consideration of the preparation time.

As a result, the media player 101 does not stop the display operation according to the change of the playback point of the segment of the media content. Instead, the media player 101 stores the media content that is being played back and the media content corresponding to the changed playback point, Can be controlled. Here, the preparation time taken until the segment is received and reproduced will be described in detail with reference to FIG.

The server 106 may forward the segment according to a request from the media player 101. [

In step 208, the media player 101 may store the segment received from the server 106 in a buffer, buffer the segment stored in the buffer, and render the segment, thereby displaying the segment.

3 is a view for explaining a segment of a media content stored in a buffer of a media player according to an exemplary embodiment of the present invention.

Referring to FIG. 3, the media player can be changed from the media content A to the media content B as the playback point of the media content is changed by the user. At this time, the media player can delete the segment buffered in the buffer depending on whether the segment is changed or not. However, the media player may leave a minimal segment to be displayed during the preparation time that it takes for the requested segment from the buffered segment to be received and played back to the server.

Specifically, the media player can calculate the preparation time based on Equation (1) described below.

는 세그먼트의 남은 다운로드 시간에 관한 것으로, 세그먼트가 수신되어 재생되기까지 걸리는 준비 시간을 의미하고,

는 재생 중인 세그먼트 이후에 재생되는 세그먼트의 첫 프레임 요청 시간을 의미하며,

는 재생 중인 세그먼트의 현재 시간을 의미할 수 있다. 그리고,

는 DASH 기반 스트리밍 서비스에서 목표로 하는 미디어 콘텐츠를 제공하기 위한 버퍼링 시간을 의미할 수 있다. 그리고, 미디어 플레이어는 각각의 요소들을 조합하여 세그먼트가 수신되어 재생되기까지 걸리는 준비 시간을 최종적으로 측정할 수 있다.Here, as shown in Equation (1)

Quot; refers to the remaining download time of the segment, which means the preparation time taken for the segment to be received and reproduced,

Quot; refers to the first frame request time of a segment that is played after the segment being played,

May mean the current time of the segment being played. And,

May refer to a buffering time for providing a target media content in a DASH-based streaming service. Then, the media player can finally measure the preparation time required for the segments to be received and reproduced by combining the respective elements.

Then, the media player can calculate the minimum segment through Equation (2) described below.

In Equation (2), denotes a minimum segment to be displayed during the preparation time, and " Media Segment Duration " is an abbreviation of a segment playback time.

As a result, the media player can determine the minimum segment to be left in the buffer in consideration of the playback time and the preparation time of the segment through Equation (1) and Equation (2). In addition, by leaving a minimum segment in the buffer, the media player can reproduce the media content without any interruption of the media content and improve the responsiveness according to the change of the playback time point.

Accordingly, the media player does not delete all the segments of the butter for the media content A as the playback point of the media content is changed, but rather deletes the segments of the butter for the media content A in consideration of the preparation time until the media content B is displayed You can leave a segment.

FIG. 4 is a detailed block diagram of a media player according to an exemplary embodiment of the present invention. Referring to FIG.

4, the media player 401 may include a website module 402, a video element module 403, a media source module 404, and a media delivery module 405.

The web site module 402 may be an interface provided to the user through a web browser. The video element module 403 may render a segment of the media content stored in the buffer of the media player 401 on the screen of the web browser. The video element module 403 can provide a control function for controlling the media content. For example, the video element module 403 may provide control functions through APIs such as playback, pause, pause, time shift, and viewpoint change for the media content.

The media delivery module 405 may interact with the server 411 in response to a control request of the media content according to the control function of the video element module 403. [ Here, the media delivery module 405 may be located inside the media player 401 or may be included in a separate device.

In detail, the media delivery module 405 may include an MPD parser 406, a buffer status monitoring unit 407, a segment requesting unit 408, a view change unit 409, and a QoS management unit 410.

The MPD parser 406 may be matched to a status information analyzer of the media player. The MPD parser 406 may receive the MPD file from the server 411 according to the control request of the media content. The MPD file includes detailed information about media contents, and may include information such as camera viewpoint, segment information, resolution, frame rate, and the like. The MPD parser 406 parses the received MPD file to analyze the media content.

The buffer status monitoring unit 407 can monitor the storage status of the buffer. The buffer status monitoring unit 407 monitors the buffer status information in real time, thereby preventing buffer underflow.

The segment requesting unit 408 may match the first request unit of the media player. The segment request unit 408 can request a segment from the server 411 based on the status information about the media content analyzed through the MPD parser 406 and the buffer status information acquired through the buffer status monitoring unit 407 have.

The viewpoint changing unit 409 may be matched with the playback point confirmation unit of the media player. It is possible to receive an event related to the change of the playback time among the control functions by the media source module 404. That is, the view change unit 409 can confirm whether or not the playback time of the media content being played back has changed.

The QoS management unit 410 may match the second request unit of the media player. The QoS management unit 410 manages the state of the media content analyzed through the MPD parser 406, the buffer status information acquired through the buffer status monitoring unit 407, ). ≪ / RTI > At this time, the QoS management unit 410 performs an operation for preventing underflow of the buffer depending on whether the playback time is changed or performs an operation of leaving a minimum segment in the buffer in consideration of the playback time and the preparation time of the segment can do.

The server 411 may include an HTTP unit 412, a storage 413, and the like. The server 411 may provide an MPD file describing information related to the media content stored in the storage 320 according to a request from the website module 402. [

The storage 413 may store media content at various points in time in segments of the DASH format.

The methods according to embodiments of the present invention may be implemented in the form of program instructions that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions recorded on the medium may be those specially designed and configured for the present invention or may be available to those skilled in the art of computer software.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. This is possible.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the equivalents of the claims, as well as the claims.

101: Media Player
102: Status information analysis unit
103: first request unit
104:
105: second request unit
106: Server

Claims (1)

Analyzing status information of the media content received from the server in response to a control request for the media content;
Requesting a segment of the media content to the server using the analyzed status information and the request time for the media content according to the control request;
Confirming whether or not the playback time of the segment displayed through the media player is changed; And
Requesting the server for a segment according to a playback time point of the segment to be changed using the analyzed state information and the buffer state information of the media player according to the result of the checking
Lt; / RTI >
The server comprises:
And transmits a segment according to a playback time or a requested time of the requested media content to the media player.

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