KR102439595B1 - Adaptive video streaming system using receiver caching - Google Patents

Abstract

An adaptive video streaming system comprising an adaptive video streaming server and a client receiving video streaming from the adaptive video streaming server is disclosed. The adaptive video streaming server and the client cache a video file, respectively, and perform streaming adaptively according to whether a video file to be streamed is cached in another client, so that the communication network can be used efficiently.

Description

Adaptive video streaming system using receiver caching {ADAPTIVE VIDEO STREAMING SYSTEM USING RECEIVER CACHING}

The following embodiments relate to an adaptive video streaming system, and more specifically, to a video streaming system that adaptively streams using information about a file stored by a client to receive a file stream.

Streaming is a process in which content consumed by the client is divided into small pieces and transmitted to the client, unlike downloading, in which the entire multimedia file is transmitted to the client before playback. Recently, not only broadcasting using public waves, but also personal broadcasting using the Internet is spreading, and most personal broadcasting is provided in a streaming method using wired/wireless Internet.

Video streaming accounts for most of Internet traffic and is rapidly increasing, so there is a great demand for an efficient streaming method.

The purpose of the following embodiments is to reduce the time required for video streaming.

The purpose of the following embodiments is to increase the efficiency of video streaming.

An adaptive video streaming server according to an exemplary embodiment receives a streaming request for a first video from a first client, and a streaming request receiving unit for receiving a streaming request for a second video from a second client. A determination unit for determining whether the first video and the second video are the same video, if the first video and the second video are different, requesting a list of videos cached by the first client, 2 A list requesting unit for requesting a list of videos cached by a client, a video list receiving unit for receiving a list of videos cached by the first client, and a list of videos cached by the second client, the first client A video list comparison unit that compares whether the second video is included in the list of videos cached by the second client, and compares whether the first video is included in the list of videos cached by the second client, and the first video according to the result of the comparison and a streaming unit configured to stream a video to the first client and stream the second video to the second client.

When the first video and the second video are the same, the adaptive video streaming server may broadcast the first video to the first client and the second client.

If the first video is not included in the list of videos cached by the second client, or the second video is not included in the list of videos cached by the first client, the adaptive video streaming server is configured to Stream video to the first client, and stream the second video to the second client.

If the first video is included in the list of videos cached by the second client, and the second video is included in the list of videos cached by the first client, the adaptive video streaming server is configured to The third video is encoded by performing an eXclusive OR (XOR) operation on the second video, the third video is broadcast to the first client and the second client, and the second video is transmitted to the first client. The third video may be used to reconstruct the first video by performing an exclusive OR operation with the second video cached in the first client.

The adaptive video streaming server may transmit information about the second video to the first client, and the exclusive OR operation may be performed on the third video based on the transmitted information.

According to an exemplary embodiment, a client receiving a video stream from an adaptive video streaming server includes a streaming request transmitter that transmits a streaming request for a first video to the adaptive video streaming server, and the streaming from the adaptive video streaming server. A list request receiving unit for receiving a request for a list of videos cached by the client in response to a request and a list of videos cached by the client in response to a request for a list of videos cached by the client in the adaptive streaming server A video list transmission unit to transmit to, the stream of the first video from the adaptive video streaming server according to a result of comparing the list of transmitted videos and the list of videos cached by the second client in the adaptive video streaming server It may include a video stream receiver for receiving.

It is determined by the adaptive video streaming server whether the first video is the same video as the second video requested by the second client from the adaptive video streaming server, and the client determines whether the video is cached by the client according to the determination result. You can receive a request for a list.

When the first video and the second video are the same, the client may receive the stream of the first video broadcast from the adaptive video streaming server.

If the first video is not included in the list of videos cached by the second client, or the second video is not included in the list of videos cached by the client, the client receiving a stream of video, and the second video may be streamed from the adaptive video streaming server to the second client.

The client further comprises a decoding unit, and when the first video is included in the list of videos cached by the second client, and the second video is included in the list of videos cached by the client, the client is configured to: The first video may be decoded by receiving a stream of the third video from the type video streaming server and performing an XOR (eXclusive OR) operation on the third video and the second video.

The client may receive the information on the second video from the adaptive video streaming server, and perform the exclusive OR operation based on the received information.

According to the following embodiments, it is possible to reduce the time required for video streaming.

According to the following embodiments, it is possible to increase the efficiency of video streaming.

1 is a diagram illustrating the concept of an adaptive video streaming server that streams to a plurality of clients using a communication network.
Fig. 2 is a flowchart illustrating step-by-step operation of the adaptive video streaming system according to an exemplary embodiment.
Fig. 3 is a block diagram showing the structure of an adaptive video streaming server according to an exemplary embodiment.
Fig. 4 is a block diagram showing the structure of a client according to an exemplary embodiment.
Fig. 5 is a diagram illustrating performance analysis of an adaptive video streaming system according to an exemplary embodiment.

Hereinafter, an embodiment will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating the concept of an adaptive video streaming server that streams to a plurality of clients using a communication network.

The adaptive video streaming server 110 transmits a stream of video to a plurality of clients 130 and 140 through the communication network 120 . According to one side, the adaptive video streaming server 110 may transmit a video stream by changing the encoding or changing the protocol according to the video requested by the clients 130 and 140 .

For example, when the first client 130 and the second client 140 request streaming for the same video, the adaptive video streaming server 110 broadcasts the video, thereby stream of the video. can be transmitted.

According to one side, the first client 130 and the second client 140 may cache some video files. In this case, the adaptive video streaming server 110 may transmit a video stream by using the information about the video file cached by the first client 130 and the second client 140, respectively.

According to one side, the second client 140 may not cache the video file requested by the first client 130 . Alternatively, the first client 130 may not cache the video file requested by the second client 140 . In this case, the adaptive video streaming server 110 directly transmits the video stream requested by the first client 130 to the first client 130, and transmits the video stream requested by the second client 140 to the second It can be transmitted directly to the client 140 .

According to one side, the second client 140 may cache the video file requested by the first client 130 , and the first client 130 may cache the video file requested by the second client 140 . In this case, the adaptive video streaming server 110 encodes the video file requested by the first client 130 and the video file requested by the second client 140 to generate one video stream, and converts the encoded video stream It can be transmitted to the first client 130 and the second client 140 . The first client 130 may restore a file requested by the first client 130 from the encoded video stream. The second client 140 may restore a file requested by the second client 140 from the encoded video stream. Even when the first client 130 and the second client 140 request different videos, the adaptive video streaming server transmits only one encoded video stream, thereby improving the efficiency of video streaming.

Fig. 2 is a flowchart illustrating step-by-step operation of the adaptive video streaming system according to an exemplary embodiment.

개의 비디오를 캐싱하고, 각 클라이언트는

개의 비디오 파일을 캐싱한다고 가정한다. 또한,

이다.2, the adaptive video streaming server 210 is

caching video, each client

Assume that you cache two video files. In addition,

to be.

In step 231 , the first client 221 transmits a streaming request for the first video to the adaptive video streaming server 210 .

In step 232 , the second client 222 sends a streaming request for the second video to the adaptive video streaming server 210 .

이라고 하고, 각 클라이언트(221, 222)들이 적응형 비디오 스트리밍 서버(210)로 요청하는 비디오 파일을

이라고 할 수 있다. 여기서, n는 클라이언트의 인덱스이다.A set of video files cached by each client (221, 222)

, and each client (221, 222) requests a video file from the adaptive video streaming server 210.

It can be said that Here, n is the index of the client.

In step 240 , the adaptive video streaming server 210 determines whether the first video and the second video are the same video.

If the first video and the second video are the same video, the adaptive video streaming server 210 transmits the video to the first client 221 and the second client 222 in steps 241 and 242. Broadcast. If each client stores a video file in a uniform distribution, the probability that the adaptive video streaming server 210 broadcasts a video to each of the clients 221 and 222 is expressed by Equation 1 below.

[Equation 1]

If the first video and the second video are different videos, the adaptive video streaming server 210 requests a list of videos cached by the first client 221 and the second client 222 in step 250 . .

In step 251 , the first client 221 receives a list request for the video cached by the first client 221 .

In step 252 , the second client 222 receives a list request for the video that the second client 222 caches.

In step 260 , the adaptive video streaming server 210 receives a list of videos cached by the first client 221 from the first client 221 , and from the second client 222 to the second client ( 222) receives a list of the videos it caches.

In step 270 , the adaptive video streaming server 210 determines whether the first client 221 caches the second video, and the second client 222 caches the first video. That is, it is determined whether the second video is included in the list of videos cached by the first client 221 , and the first video is included in the list of videos cached by the second client 222 . This can be simply interpreted as determining whether the first client 221 and the second client 222 cross-store the video.

If the first client 221 is not caching the video requested by the second client 222 or the second client 222 is not caching the video requested by the first client 221 , the adaptive The video streaming server 210 transmits the video requested by each client (221, 222) in step 271, respectively. In operation 272 , the first client 221 may receive the stream of the first video, and in operation 273 , the second client 222 may receive the stream of the second video. The first client 221 receives the stream of the first video, and the probability that the second client 222 receives the stream of the second video in step 273 is expressed by Equation 2 below.

[Equation 2]

If the first client 221 caches the video requested by the second client 222 and the second client 222 caches the video requested by the first client 221 (the first video is the second If the client 222 is included in the list of videos cached, and the second video is included in the list of videos cached by the first client 221 ), the adaptive video streaming server 210 is the first in step 280 . A third video may be generated by encoding the first video and the second video. Here, the adaptive video streaming server 210 may perform encoding using an eXclusive OR (XOR) operation.

In step 281 , the adaptive video streaming server 210 may broadcast the encoded image to the first client 221 and the second client 222 . Although the video requested by the two clients 221 and 222 is different from each other, the adaptive video streaming server 210 broadcasts only one video, so the adaptive video streaming server 210 can efficiently use radio resources. have.

The probability that each of the clients 221 and 222 receives the video encoded by the XOR operation is expressed in Equation 3 below.

[Equation 3]

In operation 282 , the first client 221 may receive the stream of the third video and reconstruct the first video from the third video.

In operation 283 , the second client 221 may receive the stream of the third video and reconstruct the second video from the third video.

는 하기 수학식 4과 같이 정의될 수 있다.Time required for streaming of a specific video file to evaluate the efficiency of streaming for three different cases

may be defined as in Equation 4 below.

[Equation 4]

은 채널이 지원 가능한 최대 전송 속도를 나타내고,

은 파일 크기가

이고, 총 재생 시간이

인 동영상을 원활히 재생하기 위하여 필요한 최소 전송속도이다.here,

represents the maximum baud rate that the channel can support,

is the file size

, and the total playing time is

This is the minimum transfer speed required for smooth video playback.

, 서로 다른 파일에 대한 스트리밍을 요구하여 각 파일을 각각 전송하는 경우(UC)의 소요시간

, 스트리밍을 요구한 파일을 각 클라이언트들이 서로 교차 저장하여, 배타적 논리합 연산을 이용하여 인코딩된 파일을 방송하는 경우(XBC)의 소요시간

는 각각 다음 수학식 5와 같이 결정될 수 있다.Time required when each client requests streaming of the same video and simply broadcasts the file (BC)

, Time required for each file transmission (UC) by requesting streaming for different files

, Time required when each client cross-stores the file requested for streaming and broadcasts the encoded file using the exclusive OR operation (XBC)

may be determined as in the following Equation 5, respectively.

[Equation 5]

는 배타적 논리합 연산을 이용하여 비디오를 인코딩, 디코딩하기 위해 필요한 처리 시간을 나타낸다.here,

represents the processing time required to encode and decode a video using an exclusive-OR operation.

As shown in FIG. 2 , the average transmission time of the adaptive video streaming method including the case of broadcasting an encoded file using an exclusive-OR operation (XBC) is as shown in Equation 6 below.

[Equation 6]

이고,

이므로, 수학식 6은 수학식 7과 같이 근사화될 수 있다.Here, generally

ego,

Therefore, Equation 6 can be approximated as Equation 7.

[Equation 7]

는

로 정의되며, 예시적 실시예에 따른 평균 전송 시간은 근사적으로

와

의 비율인

에 의해서 결정됨을 확인할 수 있다.here,

Is

is defined as, and the average transmission time according to the exemplary embodiment is approximately

Wow

is the ratio of

It can be confirmed that it is determined by

On the other hand, only when each client requests streaming of the same video and simply broadcasts the file (BC), or requests streaming of different files and transmits each file (UC) without using the exclusive OR operation. The average transmission time in consideration of Equation 8 below.

[Equation 8]

Fig. 3 is a block diagram showing the structure of an adaptive video streaming server according to an exemplary embodiment. The adaptive video streaming server 300 according to an exemplary embodiment includes a streaming request receiving unit 310 , a determining unit 320 , a list requesting unit 330 , and a video list receiving unit 340 . It may include a video list comparison unit 350 , an encoding unit 360 , and a streaming unit 370 .

The streaming request receiving unit 310 receives a streaming request for the first video from the first client 391 and receives a streaming request for the second video from the second client 392 . According to one side, the streaming request for the first video and the streaming request for the second video may be received via the communication network 380 or the like.

The determination unit 320 determines whether the first video and the second video are the same video. If the first video and the second video are the same video, the streaming unit 370 may broadcast the corresponding video via the communication network 380 .

When the first video and the second video are different, the list request unit 330 requests a list of videos cached by the first client 391 . Also, the list request unit 330 requests a list of videos cached by the second client 392 . Here, 'caching' means that each of the clients 391 and 392 stores video in their respective storage units.

The video list receiver 340 receives a list of videos cached by the first client 391 , and receives a list of videos cached by the second client 392 .

The video list comparison unit 350 compares whether the video requested by the second client 392 is included in the list of videos cached by the first client 391, and added to the list of videos cached by the second client 392 1 Compare whether the video requested by the client 391 is included.

The streaming unit 370 may stream the first video to the first client 391 and stream the second video to the second client 392 according to the comparison result of the video list comparison unit 350 .

For example, if the first video is not included in the list of videos cached by the second client 392 or the second video is not included in the list of videos cached by the first client 391, the streaming unit 370 ) may stream the first video to the first client 391 via the communication network 380 and stream the second video to the second client 392 .

If the first video is included in the list of videos cached by the second client 392 and the second video is included in the list of videos cached by the first client 391, the encoding unit 360 is the first video and encoding the second video to generate a third video. According to one side, the encoding unit 360 may generate a third video by performing an eXclusive OR (XOR) operation on the first video and the second video. The streaming unit 370 broadcasts the encoded third video to the first client 391 and the second client 392 .

According to one side, the streaming unit may transmit information on the second video to the first client 391 and transmit information on the first video to the second client 392 .

The third video transmitted to the first client 391 is subjected to an exclusive-OR operation with the second video cached in the first client 391 , and is used to restore the first video by the first client 391 . According to one side, the first client 391 may restore the first video with reference to information on the second video received from the adaptive video streaming server 300 .

In addition, the third video transmitted to the second client 392 is subjected to an exclusive-OR operation with the first video cached in the second client 392 , and is used to restore the second video by the second client 391 . According to one side, the second client 391 may restore the second video with reference to information on the first video received from the adaptive video streaming server 300 .

According to the embodiment shown in FIG. 3 , when the first video is included in the list of videos cached by the second client 392 and the second video is included in the list of videos cached by the first client 391 In this example, the adaptive video streaming server 300 may broadcast the encoded third video, such that the first client 391 restores the first video and the second client 392 restores the second video. have. By only broadcasting one video, different videos are restored in each client 391 and 392 , thereby increasing the efficiency of the communication network 380 .

Fig. 4 is a block diagram showing the structure of a client according to an exemplary embodiment. The client 400 according to an exemplary embodiment may include a streaming request transmitter 410 , a list request receiver 420 , a video list transmitter 430 , a video stream receiver 440 , and a decoder 450 . can

The streaming request transmitter 410 transmits a streaming request for the first video to the adaptive video streaming server 470 . According to one side, the second client 480 may transmit a streaming request for the second video to the adaptive video streaming server 470 .

The streaming request for the first video and the streaming request for the second video may be compared in the adaptive video streaming server 470 . If the first video and the second video are the same, the video stream receiver 440 may receive a stream of the first video broadcast from the adaptive video streaming server 470 .

The list request receiving unit 420 receives a request for a list of videos cached by the client 400 in response to the streaming request from the adaptive video streaming server 470 . According to one side, it is determined in the adaptive video streaming server 470 whether the first video is the same video as the second video, and when the first video and the second video are different, the list request receiving unit 420 determines the result Accordingly, the client 400 may receive a request for a list of videos cached.

The video list transmitter 430 transmits a list of videos cached by the client 400 to the adaptive streaming server 470 in response to a request for a list of videos cached by the client 440 . The second client 480 may also transmit a list of videos cached by the second client 480 to the adaptive streaming server 470 .

Whether the first video requested by the client 400 is included in the list of videos cached by the second client 480, and the second video requested by the second client 480 is a list of videos cached by the client 400 Whether included in the adaptive streaming server 470 may be determined.

The video stream receiving unit 440 is provided from the adaptive video streaming server 470 according to a result of comparing the list of transmitted videos and the list of videos cached by the second client 480 in the adaptive video streaming server 470 . 1 A video stream can be received.

If the first video is not included in the list of videos cached by the second client 480 or the second video is not included in the list of videos cached by the client 400, the video stream receiving unit 440 is an adaptive video A stream of the first video may be received from the streaming server 470 . Also, the second video may be streamed from the adaptive video streaming server 470 to the second client 480 .

When the first video is included in the list of videos cached by the second client 480 and the second video is included in the list of videos cached by the client 400, the video stream receiving unit 440 is an adaptive video streaming server A stream of the third video may be received from 470 . The third video may be generated by performing an XOR operation on the first video and the second video. In this case, the video stream receiving unit 400 receives the information on the second video from the adaptive video streaming server 470, and the decoding unit 450 based on the information on the second video, the third video and the second video. The first video may be decoded by performing an exclusive OR operation on the two videos.

는 500MB이고, 비디오 파일의 총재생시간

는 초이다. 또한, 적응형 비디오 서버가 캐싱하는 비디오 파일의 개수

는 50개인 환경을 가정한다. 도 5에 도시된 그래프는 각 클라이언트들이 캐싱하는 비디오 파일의 개수

가 20, 30, 40으로 변경되는 경우의 성능을 나타낸다.Fig. 5 is a diagram illustrating performance analysis of an adaptive video streaming system according to an exemplary embodiment. In FIG. 5 , the horizontal axis indicates the transmission rate, and the vertical axis indicates the average transmission time. 5, the size of the video file being streamed

is 500MB, and the total playing time of the video file

is seconds Also, the number of video files that the adaptive video server caches.

assumes a 50-person environment. The graph shown in Fig. 5 shows the number of video files cached by each client.

It shows the performance when is changed to 20, 30, 40.

Referring to FIG. 5 , when the adaptive video streaming server broadcasts a video or when the video is directly transmitted to each client, adaptive streaming according to an exemplary embodiment has an average lower transmission time. can be seen to indicate

가 40인 경우를 나타내고, 제2 그래프(520)는 각 클라이언트들이 캐싱하는 비디오 파일의 개수

가 30인 경우를 나타내고, 제3 그래프(530)는 각 클라이언트들이 캐싱하는 비디오 파일의 개수

가 20인 경우를 나타낸다.In FIG. 5 , the first graph 510 shows the number of video files cached by each client.

is 40, and the second graph 520 shows the number of video files cached by each client.

is 30, and the third graph 530 shows the number of video files cached by each client.

is 20.

가 증가함에 따라 배타적 논리합을 이용하여 브로드캐스트될 확률이 높으므로 전체적인 평균 전송시간이 감소함을 확인할 수 있다.Referring to FIG. 5 , the number of video files cached by each client

It can be seen that the overall average transmission time decreases because the probability of broadcasting using exclusive OR increases as α increases.

The adaptive video streaming server described in FIGS. 2 to 5 can stream video to multiple clients in a similar manner. However, in order to improve streaming efficiency, the adaptive video streaming server compares the list of videos owned by each client with the list of videos included in the streaming request, and classifies each client into a plurality of groups to which different streaming techniques are applied. , a streaming method corresponding to each group may be applied to each group.

If there are multiple clients, it can be assumed that either the first client or the second client are multiple.

According to one side, the video list comparison unit 350 of the adaptive video streaming server 300 may compare a list of videos that each client caches with a list of videos that each client tries to play.

In the first step, the client classification unit (not shown) receives the video cached by each client without streaming from the adaptive video streaming server 300 to the client if the video that the client wants to play is stored in the client's cache. It can be categorized into local playgroups that are playing.

If several clients try to play the same video and each client cannot cache the video, the client classifier (not shown) can classify the clients into a multicast group that streams and plays the same video with other clients. have.

According to one side, the client classifier (not shown) may classify clients that are not classified into the local play group and the multicast group into the remaining groups.

In the second step, the client classifier (not shown) receives and plays different videos from the clients included in the remaining group together with other clients using a streaming technique using an exclusive-OR operation, and each client can be classified into unicast groups that transmit individual videos.

The streaming unit 370 may stream by applying a streaming method corresponding to each group to clients included in each group.

The method according to the embodiment 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, etc. alone or in combination. The program instructions recorded on the medium may be specially designed and configured for the embodiment, or may be known and available to those skilled in the art of computer software. Examples of the computer-readable recording medium include magnetic media such as hard disks, floppy disks and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic such as floppy disks. - includes magneto-optical media, and hardware devices specially configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine language codes such as those generated by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

As described above, although the embodiments have been described with reference to the limited embodiments and drawings, various modifications and variations are possible by those skilled in the art from the above description. For example, the described techniques are performed in a different order than the described method, and/or the described components of the system, structure, apparatus, circuit, etc. are combined or combined in a different form than the described method, or other components Or substituted or substituted by equivalents may achieve an appropriate result.

Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.

110: adaptive video streaming server
120: communication network
130, 140: client

Claims (13)

A streaming request receiving unit for receiving a video streaming request for a video to be played from a plurality of clients,
A video list receiver for receiving the video list being cached from the plurality of clients,
By comparing the video to be played from the plurality of clients and the list of videos being cached, the plurality of clients are first divided into a local play group, a multicast group, and the remaining group, and the clients included in the remaining group are separated into an exclusive-OR streaming group and a client classifier for classifying into unicast groups, and
A streaming unit for streaming video by applying a streaming method corresponding to a group to which each of the plurality of clients belongs to the plurality of clients
including,
Among the plurality of clients, a client caching a video to be played is classified into the local play group,
While trying to play the same video, the clients that are not caching the video are classified into the multicast group, and the video requested for streaming is streamed in a multicast method,
Clients that are alternately caching the first video and the second video that the other party wants to play are classified into the exclusive-OR streaming group, and an eXclusive OR (XOR) operation is performed on the first video and the second video. Stream the encoded third-party video,
An adaptive video streaming server that classifies a client that does not belong to the exclusive OR streaming group among the clients belonging to the remaining group into the unicast group, and streams the streaming-requested video in a unicast manner. Receiving a video streaming request to be played from a plurality of clients and a list of videos being cached;
By comparing the video to be played back and the caching video list in the plurality of clients, the plurality of clients are first divided into a local play group, a multicast group, and the remaining group, and the clients included in the remaining group are separated into an exclusive-OR streaming group and classifying into unicast groups; and
For the plurality of clients, applying a streaming method corresponding to a group to which each of the plurality of clients belongs, performing video streaming
including,
Among the plurality of clients, a client caching a video to be played is classified into the local play group,
While trying to play the same video, clients not caching the video are classified into the multicast group, and the video requested for streaming is streamed in a multicast method,
Clients that are alternately caching the first video and the second video that the other party wants to play are classified into the exclusive-OR streaming group, and an eXclusive OR (XOR) operation is performed on the first video and the second video. Stream the encoded third-party video,
An adaptive video streaming method for classifying a client that does not belong to the exclusive OR streaming group among clients belonging to the remaining group into the unicast group, and streams the streaming-requested video in a unicast manner. delete delete delete delete delete delete delete delete delete delete delete

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