KR100621313B1 - Apparatus and method for buffering the data - Google Patents

Abstract

The present invention provides a video on demand (VOD) and audio on demand (AOD) streaming using a real-time transport protocol (RTP), a real time streaming protocol (RTSP). In particular, the present invention relates to a data buffering device and method for reducing the time required for fast forwarding by reducing the number of message exchanges with a streaming server when fast forwarding (FF) to a specific point located in a data queue. .

A data buffering method according to the present invention comprises the steps of: inputting a fast forward (FF) command during playback; Determining whether the corresponding data according to the command is in a data queue; If it is determined that the data exists, discarding the data before the data from the data currently being reproduced; Continuously buffering the data that has been stored at the last time among the data previously stored in the data queue by the discarded data amount; Reproducing corresponding data according to the command; Characterized in that it comprises a.

Real-time transport protocol (RTP), real-time streaming protocol (RTSP), buffering, data queue, server, client

Description

Apparatus and method for buffering the data}

1 is a flowchart illustrating a conventional fast forward (FF) process.

2A to 2C are diagrams showing changes in a data queue according to the conventional fast-forwarding (FF) process of FIG.

Figure 3 shows a buffering device according to the present invention.

4A to 4B are diagrams illustrating a change in a data queue due to fast-forwarding (FF) processing through buffering according to the present invention.

5 is a flowchart illustrating a fast-forwarding (FF) process using a buffering method according to the present invention.

<Explanation of symbols for the main parts of the drawings>

300: Client 302: Data transmission and reception unit 304: Data queue 306: Decoding unit 308: Control unit 310: Processing unit

312 Server

The present invention relates to a data buffering apparatus and method.

Real-time transport protocol / real-time streaming protocol (hereinafter referred to as RTP / RTSP, RTP / RTSP) is a standard protocol of streaming service. Here, the streaming refers to a technology for simultaneously playing the received data.

RTSP is a protocol that sends and receives commands for stream control through TCP / IP, and RTP is a protocol that receives actual audio / video data through UDP.

The RTSP and RTP can be used on both TCP and UPD protocols, but in most cases the RTSP is based on TCP and RTP is based on UPD. This is because the TCP is a protocol or a speed that guarantees transmission between a server and a client, and the UPD does not guarantee a transmission, but a speed is fast.

Data is exchanged between a server and a client by using the above protocol, where a server is a computer that has data information and, when a connection is made, can provide the information to the client. A client, on the other hand, is a computer that connects to a server and obtains the desired information.

Therefore, in order to stream, the user needs to setup for playback using RTSP. After the setup is completed, the RTSP message is exchanged with the server, and the audio / video data is transmitted to the client through RTP. . It then buffers and plays the transmitted audio / video data.

In the buffering, the server continuously transmits data, and the connected client continuously stores the data in a buffer of memory. If the buffer is empty, the client side no longer needs to extract data from the buffer. Waiting for a while in the paused state until the buffer is filled again.

When the client performs fast forward (FF) or rewind (REW) during streaming, the client exchanges a predetermined message with the server.

1 is a flowchart illustrating a conventional fast forward (FF) process.

Referring to FIG. 1, when a fast forward (FF) is performed on a client side, a 'PAUSE' message is transmitted to a server (S100).

After the server receives the transmitted message, the client side controller determines whether the server receives the message to receive a response (S102), and if the response is accepted, the client-side audio / video data queue ( empty the queue (S104).

The queue is a data structure like an ordered list that allocates contiguous space in a main memory in a computer so that data can be stored, retrieved and used when needed. Insertion of data occurs at one end and output at the other end. .

After step 104, the client-side control unit transmits a 'PLAY' message to the server (S106), and then determines whether the server receiving the transmitted message has accepted the response (S108).

As a result of the determination, in step 102 and step 108, if the response is not accepted in the server receiving each message, an error process is performed (S110).

In step 108, if the response is accepted, buffer the set amount of audio / video data (S112), then play the buffered audio / video data (S114) and end.

2A to 2C are diagrams illustrating a change in a data queue according to the conventional fast-forwarding (FF) process of FIG.

FIG. 2A shows an audio / video data queue being played before fast forward (FF). FIG. Referring to FIG. 2A, before the fast forward (FF) command is performed on the client side, audio / video data denoted by 'T' is sequentially allocated in a contiguous space.

Each stream data has a timestamp to be reproduced, which is displayed on the screen at a predetermined time, and after being exited by sound, is taken out of the data queue and deleted.

FIG. 2B is a diagram illustrating a data queue in step 104 of FIG. 1 when the server response to the 'PAUSE' message sent in step 100 of FIG. 1 is accepted. Referring to FIG. 2B, the client side accepts the 'PAUSE' message sent to the server and empties all audio / video data.

That is, it sends a 'PAUSE' message to the server requesting to stop the transmission of the stream data currently being played, and when the response is received, the data queue is emptied.

FIG. 2C illustrates an audio / video data queue after receiving a response from the server for fast forward (FF).

Referring to FIG. 2C, the server receiving the fast forward (FF) command from the client sends a desired playback start time t 'to the server as a' PLAY 'message. Put the subsequent data on the data queue. The playback starts after buffering the amount of data before starting playback.

However, the amount of buffering of audio / video data in streaming playback is usually about 5 seconds, and fast forward (FF) operating in the order of FIG. 1 can be started from 2 seconds.

In other words, if the fast-forwarding (FF) is performed 2 seconds forward, the audio / video data buffered for 5 seconds is discarded, and the process of FIG. 1 is performed. The audio / video data of 5 seconds is buffered to start playback.

Therefore, like the RTSP and RTP protocols, if all of the audio / video data is not used and the data is retransmitted, the time required for exchanging RTSP messages, the network transmission amount, the time for receiving RTP data, and the network transmission amount become large. There is this.

In addition, if the conventional method is used, a user who waits for two seconds or more to wait two seconds or more may occur, and there is a problem in terms of user convenience.

An object of the present invention is to exchange messages with a streaming server during fast forwarding (FF), especially in streaming on demand video (VOD) and on demand music (AOD) using real time transport protocol (RTP), real time streaming protocol (RTSP). The present invention provides a data buffering apparatus and method for reducing the number of fast-forwarding times and increasing user convenience.

Data buffering apparatus according to the present invention for achieving the above object, the data transmission and reception unit for transmitting and receiving data with the server (Server); A data queue for storing stream data transmitted from the data transmission / reception unit; When connected to the data queue and executing a fast forward (FF) command, whether the data to be played back is searched for in the data queue, whether to process the fast forward (FF) command internally, or to exchange with the server. A control unit to determine whether to process through; A processing unit for processing a fast forward (FF) command internally or by exchanging with a server according to a determination of the controller; And a decoding unit for decoding the stream data from the processing unit.

In addition, the data buffering method according to the present invention comprises the steps of inputting a fast-forward (FF) command to a specific point during playback; Determining whether data to be reproduced according to the command is in a data queue; If there is data to be reproduced as a result of the determination, discarding data from the data currently being reproduced until the data to be reproduced; Continuously buffering data consecutively stored in the data stored at the latest time among the data previously stored in the data queue; Reproducing data to be reproduced according to the command; Characterized in that it comprises a.

In addition, if the data to be reproduced according to the command is not in the data queue, further comprising the step of processing through the data exchange with the server.

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

3 is a view showing a buffering apparatus according to the present invention. Referring to FIG. 3, the buffering apparatus according to the present invention includes a data transceiver 302, a data queue 304, a controller 306, a processor 308, and a decoder 310 on a client 300 side. It is configured and can exchange data with the server 312 side.

Referring to the operation of the buffering device, the data transmission and reception unit 302 exchanges various messages and data with a server (312), the data queue 304 is transmitted from the data transmission and reception unit 302 Store stream data.

In addition, the controller 306 is connected to the data queue, and if a fast forward (FF) command is input from the user, the controller 306 determines whether there is data to be reproduced in the data queue.

As a result of the determination, when there is data to be reproduced in the data queue 304, a signal is sent to the processing unit 308 to process the fast forward command internally in the system of the client 300, and if the data queue ( If there is no data to be reproduced inside 304, a signal is sent to the processing unit 308 to process the command through an exchange with the server 312.

In response to the determination of the controller 306, the processor 308 processes the fast-forward (FF) command internally or through an exchange with a server.

Then, the decoding unit 310 connected to the processing unit 308 decodes the stream data processed by the processing unit 308.

4A to 4B are diagrams illustrating a change in a data queue according to fast-forwarding (FF) processing through buffering according to the present invention.

4A is an audio / video data queue before fast forwarding according to the present invention. Referring to FIG. 4A, 't' is a time currently playing and 'Δt' is a time interval for fast forward (FF). , 't + h' is the time to continue buffering again.

That is, the controller 306 of the buffering apparatus according to the present invention determines whether there is data to be found in the already-buffered stream data range when the controller 306 moves forward by 'Δt' with fast forward (FF) and finds the data to be found. If there is, it does not send a message to the server, but discards only the data before '△ t' and buffers the stream data from 't + h'.

FIG. 4B is an audio / video data queue after fast forwarding to a specific point located in the data queue according to the present invention. Referring to FIG. 4B, a user fast forwards (FF) in the data queue 304 state of FIG. 4A. Once done, the previous time's data is discarded.

Therefore, the data queue 304 into which a predetermined amount of data enters is started from 't + Δt', which is the time when the fast forward (FF) to the specific point located in the data queue 304 is finished, and 't' From + h ', the continuous data stream is continuously buffered and playback starts until the amount of data corresponding to the discarded' Δt 'is filled in the data queue 304.

At this time, if the video data is encoded in Mpeg4, H.263, H.264, etc., if the time data of the stream data to be played (timestamp) is less than 't + Δt', it is played unconditionally. Problems can arise.

This is because, in this case, data of one frame may be only a change of the previous frame. In this case, after finding a frame (I-frame) encoding a complete frame, a new 'Δt' is obtained and the previous data is found. Should be discarded.

Therefore, when processing the fast forward (FF) to a specific point located in the data queue 304 by the buffering method according to the present invention, while reproducing while buffering the data of 5 seconds, fast forward (FF) 2 seconds forward When you do this, you only need to buffer two seconds of data, so you can wait for about two seconds to play smooth images.

5 is a flowchart illustrating a fast forward (FF) process using a buffering method according to the present invention.

Referring to FIG. 5, when a fast-forward (FF) command is input by the user (S500), the controller 306 in the buffering apparatus according to the present invention first quickly enters the data currently buffered in the data queue 304. It is determined whether there is audio / video data to be reproduced by winding (FF) (S502).

As a result of the determination, if there is audio / video data to be reproduced by fast forwarding (FF) in the data currently buffered in the data queue 304, the fast forwarding (FF) in the data queue 304 in which continuous data is stored. In step S504, data for the amount of time is discarded.

Then, the data is buffered for the amount of time discarded in succession to the data stored at the later time in the data queue 304 (S506).

After step 506, when enough data is collected in the data queue 304 to start playback, playback starts (S508) and ends when all of the data is played back.

On the other hand, if there is no audio / video data to be played by fast forward (FF) in the data currently buffered in the data queue 304 in step 502, the process is performed according to the conventional fast forward (FF) operation of FIG. ).

The above buffering method has the effect of reducing the time required for fast forwarding by reducing the number of message exchanges with the streaming server when fast forwarding (FF), and applied to all areas of streaming, a technology for simultaneously playing the received data. It is possible.

Although the present invention has been described with reference to the embodiments illustrated in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible.

Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

The present invention relates to streaming video on demand video (VOD) and streaming music on demand (AOD) using real time transport protocol (RTP), real time streaming protocol (RTSP), especially with fast forwarding (FF) message with streaming server (Server). By reducing the number of exchanges, the time taken to fast forward is reduced.

Claims (6)

Data transmission and reception unit for sending and receiving data with the server (Server); A data queue for storing stream data transmitted from the data transmission / reception unit; When connected to the data queue and executing a fast forward (FF) command, whether the data to be played back is searched for in the data queue, whether to process the fast forward (FF) command internally, or to exchange with the server. A control unit to determine whether to process through; A processing unit for processing a fast forward (FF) command internally or by exchanging with a server according to a determination of the controller; A decoding unit for decoding the stream data from the processing unit; Data buffering device comprising a. Inputting a fast forward (FF) command to a specific point during playback; Determining whether data to be reproduced according to the command is in a data queue; If there is data to be reproduced as a result of the determination, discarding data from the data currently being reproduced until the data to be reproduced; Continuously buffering data consecutively stored in the data stored at the latest time among the data previously stored in the data queue; Reproducing data to be reproduced according to the command; Data buffering method comprising a. The method of claim 2, If the data to be reproduced according to the command is not in a data queue, processing the data through a data exchange with a server. The method of claim 2, And the specific point is a point located in data previously stored in a data queue. The method of claim 2, In the step of discarding the data, If the video data is encoded in the format including Mpeg4, H.263, or H.264, the time required to fast forward again after finding the frame (I-frame) that encodes a complete frame. Obtaining and discarding the old data. The method according to any one of claims 2 to 5, The data comprises audio and video data.

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