KR101702426B1 - Video transmission method based on multi HTTP threads for reducing the viewpoint change delay in multi-view video service - Google Patents

Abstract

Disclosed is a video transmission method based on multi-HTTP threads for reducing viewpoint change delay in a multi-view video service. The method provides rapid video conversion to a user by reducing the viewpoint change delay compared to an existing multi-view video service by using a video transmission method based on the multi-HTTP thread to solve an increase of the viewpoint change delay due to an idle time generated every RTT in a single HTTP thread transmission method. The present invention comprises: a multi-view video streaming server which transmits a segment requested from a client; and a multi-view video streaming client which controls the number of HTTP threads based on a buffer occupying ratio of a client by a module for determining the number of HTTP threads.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video transmission method and a video transmission method based on multiple HTTP threads,

The present invention relates to a multi-HTTP thread-based video transmission system and method, and more particularly, to a multi-HTTP thread-based video transmission system and method for rapidly receiving segments by controlling the number of HTTP threads based on a buffer occupancy rate of a client And more particularly, to a multi-HTTP thread-based video transmission system and method for reducing a viewpoint change delay of a multi-view video service.

Various types of multimedia services are being produced and consumed due to the development of network technology and the spread of various user terminals. In addition, demand for multimedia contents is increasing as the data transmission speed is accelerated due to development of communication technologies such as 3G, 4G, and Wi-Fi. Recently, interest in interactive services such as multi-view video service as well as simple consumption type video streaming service is increasing rapidly. The multi-view video service is a video streaming service in which a user can select one of two or more cameras to provide images selected at various points of view.

Cisco predicts that by 2018, video will account for 79 percent of all IP traffic and 71 percent of domestic IP traffic. Netflix is the world's largest Internet video service provider with 33 million subscribers in 40 countries by 2013. Netflix subscribers' ratings have exceeded 80 minutes a day in 2012, and the ratings are higher than those of US cable broadcasters. The combined distribution service of broadcasters, Hulu, has secured 3 million subscribers by 2013 and generated $ 695 million in revenue in 2012. YouTube is an ad-based online video website that has received over 150 million YouTube users over 180 million users who visited online video service websites during the month of February in 2013, The average time was 362 minutes. In Korea, Fook, which provides Internet video service, has a VOD of 250,000 on 30 channels of terrestrial broadcasters and cable broadcasting based on 2013. Teabing, released by CJ HelloVision, provides over 50,000 premium high-definition VODs including MBC, KBS, SBS, and over 200 channels of live broadcasts and movies. Therefore, it is expected that the technology research and market size will be increased to improve the quality of the video streaming service, and the range of various types of multimedia services including the multi-point video service will be expanded.

The traditional video streaming protocol is the Real-time Transport Protocol (RTP) based on UDP (User Datagram Protocol). RTP provides the ability to transmit real-time data such as video or audio over the network. However, RTP has a problem that the service is limited by a firewall or a NAT (Network Address Translator). As an alternative, Hypertext Transfer Protocol (HTTP) based video streaming has emerged. HTTP-based video streaming is often used to implement video streaming services because it is free from firewall and NAT issues, is easy to implement, and has the advantage of low server load.

는 시점변경 이벤트가 발생한 후 클라이언트의 버퍼 점유율이 최소 버퍼 임계값에 도달하는 시간을 나타내며,

가 증가함에 따라 시점변경 지연이 길어지게 된다.However, since existing HTTP based video streaming uses a single HTTP thread in a multi-view video service environment, it takes a long time to change the viewpoint. HTTP-based video streaming works by downloading a segment, basically using a single HTTP thread and responding to one HTTP request with one HTTP response. As a result, the client waits until the first bit of the segment is received in response to a request for a segment in a conventional single HTTP thread transmission scheme, as shown in FIG. 1, and the idle time is a TCP / IP is equal to RTT (Round Trip Time). The longer the network delay, the longer the idle time, and thus the throughput is reduced. When the view change event occurs, the client deletes the segment of the buffered existing image, receives the segment of the new image, and plays the video after the buffer occupancy rate of the client reaches the minimum threshold value. The transmission method using a single HTTP thread takes a long time to fill the buffer because the throughput becomes low due to the idle time.

Represents the time at which the buffer occupancy rate of the client reaches the minimum buffer threshold value after the viewpoint change event occurs,

The time change delay becomes longer.

In order to solve the above problem, the present invention solves the problem that the view change delay increases due to the idle time that occurs every RTT in a single HTTP thread transmission scheme, so that a method of transmitting video using multiple HTTP threads The present invention provides a multi-HTTP thread-based video transmission system and method for reducing a viewpoint change delay of a multi-view video service, with the object of reducing the view change delay of multi-view video service.

In order to accomplish the object of the present invention, a multi-HTTP thread-based video transmission system for reducing a viewpoint change delay of a multi-view video service changes a format by encoding a video content to enable streaming based on HTTP, A multi-view video streaming server for generating a manifest file for segmenting in units of segments and describing URL addresses for the segments, transmitting the requested manifest file from the client, and transmitting the requested segment from the client; And requesting the manifest file to the multi-view video streaming server to grasp information on the content, requesting the video content of the segment unit to the server, and generating a view change event through the camera view selection module, Module deletes segments of the existing image received in the buffer in order to rapidly switch the screen from the existing image to the new image and controls the number of HTTP threads based on the buffer occupancy rate of the client by the HTTP thread count determination module Video streaming client,

Multiple HTTP threads are used to solve the problem of increased point-to-point delay due to the idle time of each RTT in a single HTTP thread transmission method. Multiple HTTP thread-based transmission methods require multiple segments without waiting for a response The idle time to be wasted is reduced. As a result, since the time for the buffer occupancy rate to reach the minimum buffer threshold value after the viewpoint change event occurs is shortened, the viewpoint change delay is reduced.

In order to accomplish another object of the present invention, there is provided a multi-HTTP thread-based video transmission method for reducing a viewpoint change delay of a multi-view video service, comprising: (a) A manifest file for dividing the encoded content into segment units and describing a URL address for the segment, a manifest file requested from the multi-view video streaming client, and transmitting the requested segment from the client Transmitting; And (b) requesting the manifest file to the multi-view video streaming server to grasp the information about the content in the multi-view video streaming client, requesting the video content in units of segments, The buffer control module deletes the segment of the existing image received in the buffer in order to quickly switch the screen from the existing image to the new image, and the HTTP thread number determination module determines, based on the buffer occupancy rate of the client, And adjusting the number,

Multiple HTTP threads are used to solve the problem of increased point-to-point delay due to the idle time of each RTT in a single HTTP thread transmission method. Multiple HTTP thread-based transmission methods require multiple segments without waiting for a response The idle time to be wasted is reduced. As a result, since the time for the buffer occupancy rate to reach the minimum buffer threshold value after the viewpoint change event occurs is shortened, the viewpoint change delay is reduced.

The multi-HTTP thread-based video transmission method for reducing the viewpoint change delay of the multi-view video service according to the present invention solves the problem that the view change delay increases due to the idle time generated for each RTT in the single HTTP thread transmission scheme It is possible to provide a fast video switching to a user by reducing the viewpoint change delay by using a method of transmitting video using multiple HTTP threads rather than a conventional multi-view video service.

The expected effect generated by the present invention can promote the activation of the research related to the viewpoint change delay reduction technique of the multi-view video service from the technical point of view. In terms of economy and industry, it can enhance the competitiveness of the terminal industry such as TV, PC, Tablet PC, and smart phone supporting multi-point video service. On the social side, it is possible to create an opportunity to escape the existing simple consumption type video streaming service provision environment.

FIG. 1 illustrates a conventional single HTTP thread transmission scheme. Referring to FIG.
2 is a diagram illustrating a structure of a multi-HTTP thread based multi-view video service system according to the present invention.
3 is a diagram illustrating a multiple HTTP thread transmission method.
FIG. 4 is a diagram showing a competition between threads in the same HTTP Connection.
5 is a flowchart illustrating an operation procedure of a multiple HTTP thread-based transmission scheme.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a diagram illustrating a structure of a multi-HTTP thread based multi-view video service system.

3 is a diagram illustrating a multiple HTTP thread transmission method. FIG. 4 is a diagram showing a competition between threads in the same HTTP Connection.

The multi-view video streaming server 100 includes a video encoding module 101, a video segmentation module 103, a manifest file response module 105, and a segment response module 107.

The multi-HTTP thread-based video transmission system for reducing the viewpoint change delay of the multi-view video service of the present invention changes the format by encoding the video contents to enable streaming based on HTTP, divides the encoded contents into segments, A multi-view video streaming server 100 for generating a manifest file describing a URL address for the client, transmitting the requested manifest file from the client, and transmitting the requested segment from the client; And request the manifest file to the multi-view video streaming server 100 in order to grasp the information about the content, request the server 100 for the video content in the segment unit, The buffer control module 207 deletes the segment of the existing image received in the buffer in order to rapidly switch the screen from the existing image to the new image, and the HTTP thread number determination module 209 determines, Point video streaming client 200 that adjusts the number of HTTP threads based on the buffer occupancy rate of the multi-

Multiple HTTP threads are used to solve the problem of increased point-to-point delay due to the idle time of each RTT in a single HTTP thread transmission method. Multiple HTTP thread-based transmission methods require multiple segments without waiting for a response The idle time to be wasted is reduced. As a result, since the time for the buffer occupancy rate to reach the minimum buffer threshold value after the viewpoint change event occurs is shortened, the viewpoint change delay is reduced.

The video encoding module 101 performs a function of converting the original video content into a video format by encoding the stream to enable HTTP-based streaming.

The video segmentation module 103 divides the content encoded by the video encoding module 101 on a segment basis and generates a manifest file describing a URL (Uniform Resource Locator) address for the segment.

The manifest file response module 105, when receiving a manifest file request from the multi-view video streaming client, transmits the manifest file from the server to the client in response thereto.

The segment response module 107 performs a function of transmitting a segment from the server to the client when receiving a segment request from the client using the segment URL described in the manifest file.

The multi-view video streaming client 200 includes a manifest file request module 201, a segment request module 203, a camera view selection module 205, a buffer control module 207, and an HTTP thread count determination module 209 do.

The manifest file request module 201 requests the manifest file from the client to the server in order to grasp the URL of the segment.

The segment request module 203 functions to request segment-based video content from the client to the server.

The camera view selection module 205 performs a function of detecting a view change event from a user.

The buffer control module 207 performs a function of deleting a segment of the existing image received in the client buffer in order to rapidly switch the screen from the existing image to the new image.

The HTTP thread count determination module 209 sets a maximum threshold value for the number of HTTP threads to prevent playback interruption due to bandwidth contention among HTTP threads and sets a client buffer occupancy rate to quickly fill the client buffer while preventing a buffer overflow And adjusts the number of HTTP threads based on the buffer occupancy of the client.

In the multi-view video streaming server 100, the video encoding module 101 changes the format so that the video content can be streamed on the basis of HTTP. The video segmenting module 103 divides the encoded content into segments, Create a manifest file that describes the URL (Uniform Resource Locator) address. The manifest file response module 105 transmits the manifest file requested by the client, and the segment response module 107 transmits the requested segment from the client.

In the multi-view video streaming client 200, the manifest file request module 201 requests the manifest file to the multi-view video streaming server 100 in order to grasp the information about the content. The segment request module 203 requests the multi- And requests the video content to the multi-view video streaming server 100. When the user generates the view change event through the camera view selection module 205, the buffer control module 207 deletes the segment of the existing video received in the buffer in order to quickly switch the screen from the existing video to the new video. The thread count determination module 209 controls the number of HTTP threads based on the buffer occupancy rate of the client.

은 다중 HTTP 스레드 기반의 전송 방식에서 시점변경 이벤트가 발생한 후 클라이언트의 버퍼 점유율이 최소 버퍼 임계값에 도달하는 시간을 의미한다. 그러나, HTTP 스레드의 개수가 필요 이상으로 많아질 경우 도 4에 도시된 바와 같이 동일한 HTTP Connection에 있는 스레드끼리 대역폭을 경쟁하게 된다. 이로 인해 재생 순서가 빠른 세그먼트를 받는 데 시간이 오래 걸리게 되어 버퍼 언더플로우에 의한 재생 끊김이 발생할 수 있다. The multi-HTTP thread-based video transmission method for reducing the viewpoint change delay of the multi-view video service according to the present invention solves the problem that the view change delay increases due to the idle time generated for each RTT in the single HTTP thread transmission scheme And uses a plurality of HTTP threads as shown in FIG. Multiple HTTP thread based transports can avoid wasted idle time because multiple segments can be requested without waiting for a response. As a result, since the time at which the buffer occupancy reaches the minimum buffer threshold value after the view change event occurs is shortened, the view change delay is reduced.

Refers to the time when the buffer occupancy rate of the client reaches the minimum buffer threshold value after the view change event occurs in the transmission method based on multiple HTTP threads. However, if the number of HTTP threads is increased more than necessary, the bandwidths of the threads in the same HTTP connection will be competing with each other as shown in FIG. As a result, it takes a long time to receive a segment having a fast playback order, resulting in a playback interruption due to a buffer underflow.

The present invention sets a maximum threshold value for the number of threads in order to prevent playback interruption due to bandwidth contention among HTTP threads. Also, the number of threads is adjusted considering the client buffer occupancy in order to quickly fill the client buffer while preventing the buffer overflow.

The multi-HTTP thread-based video transmission method for reducing the viewpoint change delay of the multi-view video service according to the present invention includes: (a) a multi-view video streaming server 100 encodes the video contents to enable streaming based on HTTP, Generates a manifest file describing the URL address of the segment, transmits the manifest file requested by the multi-view video streaming client 200, and transmits the requested segment to the client To the client (200); And

(b) requesting the manifest file to the multi-view video streaming server 100 to grasp information about the content in the multi-view video streaming client 200, and requesting the server 100 to And generates a view change event through the camera view selection module 205, the buffer control module 207 deletes a segment of the existing image received in the buffer to quickly switch the screen from the existing video to the new video, And adjusting the number of HTTP threads based on the buffer occupancy rate of the client by the HTTP thread count determination module 209. In the existing single HTTP thread transmission scheme, the view change delay increases due to the idle time generated every RTT Multiple HTTP threads are used to solve the problem, and multiple HTTP thread-based transmission rooms Can reduce the wasted idle time because it can request multiple segments without waiting for a response and consequently the time for the buffer occupancy to reach the minimum buffer threshold after the view change event is shortened, .

In step (a), the multi-view video streaming server 100 performs a function of (a1) encoding the original video content by the video encoding module 101 so as to enable HTTP-based streaming, step; (a2) segmenting the content encoded by the video segmentation module 103 on a segment-by-segment basis and generating a manifest file describing a URL address for the segment; (a3) receiving a manifest file from the multi-view video streaming client 200 and transmitting the manifest file from the server to the client 200 by the manifest file response module 105 in response thereto; And (a4) receiving a segment request from the client using the segment URL described in the manifest file, transmitting the segment from the server to the client through the segment response module 107. [

The step (b) comprises the steps of: (b1) in the multi-view video streaming client 200, transmitting the manifest file from the client 200 to the server 100 in order to grasp the URL of the segment by the manifest file request module 201; ; (b2) requesting segment-based video content from the client (200) to the server (100) by the segment request module (203); (b3) performing a function of detecting a viewpoint change event from the user by the camera view selection module 205; (b4) deleting a segment of the existing image received in the client buffer by the buffer control module 207 to quickly switch the screen from the existing image to the new image; And (b5) setting a maximum threshold value for the number of HTTP threads in order to prevent playback interruption due to bandwidth contention between HTTP threads, and setting the maximum number of HTTP threads, considering the buffer occupancy of the client, And adjusting the number of HTTP threads based on the buffer occupancy rate of the client by the determination module 209. [

5 is a flowchart illustrating an operation procedure of the multi-HTTP thread-based transmission scheme proposed in the present invention. When the multi-view video service is started, the multi-view video streaming client obtains the URL address of the segment through the manifest file, requests the first segment to the multi-view video streaming server, and sets the number of HTTP threads to one. In order to prevent bandwidth competition between threads in the same HTTP Connection, segment downloading is completed by 1/2 or more as in Equation (1), and the number of HTTP threads does not exceed the maximum number of threads threshold value as in Equation (2) The number of HTTP threads is increased and the next segment is received when the time taken into consideration of the current buffer occupancy rate and the reproducible period of the segment being downloaded does not exceed the maximum buffer occupancy threshold as shown in Equation (3). The following formula represents a condition for increasing the number of HTTP threads.

은 다운로드가 완료된 세그먼트 부분의 크기,

는 한 세그먼트의 크기이다. 수학식 2에서

는 세그먼트를 다운로드하는 HTTP 스레드의 개수,

는 HTTP 스레드 개수의 최대 임계값을 나타낸다. 수학식 3에서

는 클라이언트의 버퍼 점유율,

는 한 세그먼트가 재생 가능한 시간, 그리고

는 최대 버퍼 점유율 임계값을 의미한다. 수학식 1, 수학식 2, 그리고 수학식 3이 만족하지 못하는 경우, 기존 HTTP 스레드를 이용하여 다음 세그먼트를 수신받는다. 세그먼트 수신이 완료되면, HTTP 스레드의 개수를 감소시킨다. 이와 같은 동작은 콘텐츠의 모든 세그먼트가 수신이 완료될 때까지 반복된다. In Equation (1)

The size of the segment portion that has been downloaded,

Is the size of one segment. In Equation 2,

The number of HTTP threads downloading the segment,

Represents the maximum threshold value of the number of HTTP threads. In Equation 3,

The client's buffer occupancy,

Is the time at which one segment is playable, and

Means the maximum buffer occupancy threshold value. If Equations (1), (2), and (3) are not satisfied, the next segment is received using the existing HTTP thread. When the segment reception is completed, the number of HTTP threads is reduced. This operation is repeated until all the segments of the content have been received.

Services applicable to this technology can be used for VOD service with multi-point video streaming, news and sports relaying, and teleconferencing supporting multi-point video streaming.

In addition, the service of the present technology can be applied to a web-based live streaming service, free-view video, and free-view TV service.

As described above, the method of the present invention can be implemented as a program and recorded on a recording medium (CD-ROM, RAM, ROM, memory card, hard disk, magneto-optical disk, storage device, etc.) Lt; / RTI >

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood that various modifications and changes may be made without departing from the scope of the present invention.

100: Multi-point video streaming server
101: Video encoding module
103: Video Segmenting Module
105: manifest file response module
107: Segment response module
200: Multi Point Video Streaming Client
201: manifest file request module
203: Segment request module
205: Camera view selection module
207: Buffer control module
209: HTTP thread count determination module

Claims (8)

The method comprising: generating a manifest file that encodes the video content to enable streaming based on HTTP to divide the encoded content into segment units and describe the URL address of the segments, transmits the manifest file requested by the client, A multi-view video streaming server for transmitting the requested segment from the client; And
Requesting the manifest file to the multi-view video streaming server to grasp the information about the content, requesting the server for the video content in units of segments, and generating a view change event through the camera view selection module, Which deletes a segment of the existing image received in the buffer in order to quickly switch from the existing image to the new image and controls the number of HTTP threads based on the buffer occupancy rate of the client by the HTTP thread count determination module, A streaming client,
Multiple HTTP threads are used to solve the problem of increased point-to-point delay due to the idle time of each RTT in a single HTTP thread transmission method. Multiple HTTP thread-based transmission methods request multiple segments without waiting for a response The time change delay is reduced since the time required for the buffer occupancy rate to reach the minimum buffer threshold is shortened after the viewpoint change event has occurred and thus the viewpoint change time point of the multi-view video service Multiple HTTP thread based video transmission system to reduce delay. The method according to claim 1,
The multi-view video streaming server
A video encoding module that encodes the original video content to enable HTTP-based streaming to convert the video format;
A video segmentation module for segmenting the content encoded by the video encoding module on a segment basis and generating a manifest file describing a URL address for the segment;
A manifest file response module for receiving a manifest file from the multi-view video streaming client and transmitting the manifest file from the server to the client in response thereto; And
A segment response module for transmitting a segment from the server to the client when a segment is requested from the client using the segment URL described in the manifest file;
A multi-HTTP thread-based video transmission system for reducing the viewpoint change delay of a multi-view video service. The method according to claim 1,
The multi-view video streaming client
A manifest file request module for requesting a manifest file from the client to the server to identify a URL of the segment;
A segment request module for requesting segment-based video contents from a client to a server;
A camera viewpoint selection module that performs a function of detecting a viewpoint change event from a user;
A buffer control module for deleting a segment of an existing image received in a client buffer to switch a screen from a previous image to a new image rapidly; And
In order to prevent playback interruption due to bandwidth contention between HTTP threads, we set a maximum threshold value for the number of HTTP threads, and based on the buffer occupancy of the client, considering the client buffer occupancy rate to quickly fill the client buffer while preventing buffer overflow An HTTP thread count determination module for controlling the number of HTTP threads;
A multi-HTTP thread-based video transmission system for reducing the viewpoint change delay of a multi-view video service. (a) a multi-view video streaming server encodes the video content to enable streaming based on HTTP to change the format, divides the encoded content into segment units, generates a manifest file describing URL addresses for segments, and Transmitting a manifest file requested from a point video streaming client, and transmitting the requested segment from the client; And
(b) requesting the manifest file to the multi-view video streaming server to grasp information about the content in the multi-view video streaming client, requesting the server for the video content in units of segments, and When generating the view change event, the buffer control module deletes the segment of the existing image received in the buffer in order to rapidly switch the screen from the existing image to the new image. Based on the buffer occupancy rate of the client by the HTTP thread count determination module Adjusting the number of HTTP threads,
Multiple HTTP threads are used to solve the problem of increased point-to-point delay due to the idle time of each RTT in a single HTTP thread transmission method. Multiple HTTP thread-based transmission methods require multiple segments without waiting for a response The time change delay is reduced since the time required for the buffer occupancy rate to reach the minimum buffer threshold is shortened after the viewpoint change event has occurred and thus the viewpoint change time point of the multi-view video service Multih HTTP thread based video transmission method for reducing delay. 5. The method of claim 4,
Wherein the step (a) comprises, in the multi-view video streaming server,
(a1) performing a function of converting a video format by encoding the original video content by a video encoding module so as to enable HTTP-based streaming;
(a2) segmenting the content encoded by the video segmentation module on a segment-by-segment basis and generating a manifest file describing a URL address for the segment;
(a3) receiving a manifest file from the multi-view video streaming client and transmitting the manifest file from the server to the client in response to the manifest file response module; And
(a4) receiving a segment request from the client using the segment URL described in the manifest file, and transmitting the segment from the server to the client through the segment response module;
A multi-HTTP thread-based video transmission method for reducing a viewpoint change delay of a multi-view video service, 5. The method of claim 4,
Wherein the step (b) comprises, in the multi-view video streaming client,
(b1) requesting the manifest file from the client to the server to identify the URL of the segment by the manifest file request module;
(b2) requesting segment-based video content from the client to the server by a segment request module;
(b3) performing a function of detecting a viewpoint change event from a user by a camera viewpoint selection module;
(b4) deleting a segment of the existing image received in the client buffer by the buffer control module to quickly switch the screen from the existing image to the new image; And
(b5) adjusting the number of HTTP threads based on the buffer occupancy rate of the client by the HTTP thread count determination module;
A multi-HTTP thread-based video transmission method for reducing a viewpoint change delay of a multi-view video service, The method according to claim 6,
If the number of HTTP threads is increased more than necessary, the bandwidths of the threads in the same HTTP connection will be competing with each other. As a result, it takes a long time to receive segments having fast playback order, resulting in playback interruption due to buffer underflow.
A maximum threshold value for the number of threads is set by the HTTP thread number determination module in order to prevent playback interruption due to bandwidth competition between HTTP threads. In order to quickly fill a client buffer while preventing a buffer overflow, Wherein the number of HTTP threads is adjusted in order to reduce the time delay of the multi-view video service. 5. The method of claim 4,
When the multi-view video service is started, the multi-view video streaming client obtains the URL address of the segment through the manifest file, requests the first segment to the multi-view video streaming server, sets the number of HTTP threads to 1, To prevent bandwidth contention between threads in an HTTP Connection

If the understanding segment downloading is completed by 1/2 or more in [Equation 1]

Equation (2) shows that the number of HTTP threads does not exceed the maximum number of threads threshold, and to prevent buffer overflow

The number of HTTP threads is increased and the next segment is received when the current buffer occupancy rate and the time in consideration of the reproducible period of the segment being downloaded do not exceed the maximum buffer occupancy rate threshold by Equation (3)
In Equation (1)

The size of the segment portion that has been downloaded,

Is the size of one segment, and in Equation 2

The number of HTTP threads downloading the segment,

Represents the maximum threshold value of the number of HTTP threads, and in Equation 3

The client's buffer occupancy,

Is the time at which one segment is playable, and

If Equation (1), Equation (2), and Equation (3) are not satisfied, the next segment is received using the existing HTTP thread, and when the segment reception is completed, the number of HTTP threads And repeating this operation until all the segments of the content have been received. A method of transmitting multiple video streams based on multiple HTTP threads to reduce the view change delay of a multi-view video service.

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