WO2007104236A1

WO2007104236A1 - Method of providing vedio-on-demand, method, server and terminal for video-on-demand

Info

Publication number: WO2007104236A1
Application number: PCT/CN2007/000722
Authority: WO
Inventors: Wei Ma; Lei Gao
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2006-03-13
Filing date: 2007-03-06
Publication date: 2007-09-20
Also published as: CN100428796C; CN1859562A; WO2007104236A8

Abstract

The present invention discloses a method for providing video-on-demand, the method comprising : after a video-on-demand server having received an on-demand request from a video-on-demand terminal, it transmitting the program data being demanded to the video-on-demanding terminal in an unicast form; building a multicast for vedio-on-demand terminals which demand the same program data as the said program data, transmitting the said program data in a multicast form, and informing the information on said multicast to the video-on-demand terminals which demand the same program data as the said program data; confirming the coincidence between the unicast program data and the multicast program data, terminating transmitting the program data to the video-on-demand terminals in the unicast form. The present invention also discloses a method ofvideo-on-demand, a server for video-on-demand and a terminal for video-on-demand.

Description

TECHNICAL FIELD The present invention relates to the field of audio and video network playback technologies, and in particular, to a method for providing video on demand, a video on demand method, a video on demand server, and a Video on demand terminal. BACKGROUND OF THE INVENTION Video on demand is one of the most important functions in the field of Internet Digital Television (IPTV), Personal Computer Television (PCTV) and the like. Video on demand allows users to choose the viewing program according to their own needs through the video on demand terminal, and then order their favorite programs for viewing at any time. The current video on demand function is mainly implemented in two ways: First, the program function is implemented by transmitting unicast between the video on demand server and the video on demand terminal for each on-demand. The second is to use a fixed time interval of multicast, allowing users to wait to join different multicast group viewing programs. Both of these methods have their own shortcomings. First, the video on demand server has a large load, the video on demand server has high network bandwidth requirements, and the second is that the response delay time is long and the user experience is poor. For convenience of description, in the present specification, the video on demand server is simply referred to as a server, and the video on demand terminal is simply referred to as a terminal.

In order to achieve true video on demand (VOD) functions, timely response to user-on-demand is usually achieved by using unicast of the IP network. However, the VOD function is implemented by means of unicast, and each connection server needs to establish a connection and send data. When a large number of on-demand broadcasts occur at the same time, the load on the server will be large, and a large number of on-demand broadcasts will result in slow response of the server and network congestion.

In view of the shortcomings of using VOD to implement the functions and network requirements of the server in the unicast mode, there is also a method of implementing the VOD function by using the multicast technology. The method of implementing VOD technology by using multicast technology is usually to initiate multiple multicasts at different times. A common method is to establish a multicast at intervals and send the number of programs to the entire network. According to. After the terminal orders the program, the server sends the next multicast address corresponding to the program to the terminal, and notifies the terminal to join the next multicast receiving program data; the terminal receives the program data sent by the server in a multicast manner according to the received multicast address.

In the prior art, a method of transmitting a program by using a multicast method to implement a VOD function has a long response time, and causes a group wipe delay to be long. Since the response time is inversely proportional to the server load, the server burden is too high in the case of a fast response. SUMMARY OF THE INVENTION In view of this, an object of the present invention is to provide a method for providing video on demand, a video on demand method, a video on demand server, and a video on demand terminal, which can solve the group existing in the prior art. The problem of prolonged broadcast and can reduce the burden on the server.

A video on demand method provided by the present invention includes the following steps:

After receiving the on-demand request from the video on demand terminal, the video on demand server sends the on-demand program data to the video on demand terminal in a unicast manner;

Establishing multicast for the video on demand terminal that plays the same program data, transmitting the program data in a multicast manner, and notifying the multicast information to the video on demand terminal of the same program on demand; confirming the unicast section S The data coincides with the multicast program data, and stops transmitting the program data to the video on demand terminal in a unicast manner.

A video on demand method provided by the present invention includes:

The video on demand terminal sends an on-demand request to the video on demand server;

Receiving the returned unicast program data and playing it;

The video on demand terminal receives the multicast information sent by the video on demand server, receives the multicast program data according to the multicast information, and stores the same; the video on demand terminal reads the received unicast program data and the stored multicast program data, and then reads The stored multicast node data is taken and played. The present invention provides a video on demand server, which includes a communication module, a decision module, and a storage module;

The communication module is configured to receive a request from the terminal for on-demand, read and transmit the corresponding program data in the storage module in a unicast manner, and transmit the on-demand request to the decision module; and send the multicast information from the decision module to the terminal And reading, according to the information initiated by the decision module from the multicast module, and transmitting the corresponding program data in a multicast manner, and stopping reading and transmitting the corresponding program data according to the suspension request from the terminal;

The decision module is configured to determine whether to add the terminal to the existing multicast according to the on-demand request from the communication module, or whether to initiate the multicast, and according to the determined information that the terminal is added to the existing multicast information or initiates the multicast information, Sending multicast information to the communication module; and storing the initiated multicast information in the storage module;

a storage module, configured to store program data and multicast information.

A video on demand terminal provided by the present invention includes a communication module, a play control module and a storage module;

The communication module is configured to receive unicast program data from the server and transmit the unicast program data to the play control module, and receive the multicast program data according to the multicast information from the server and store the data in the storage module; and The on-demand request and the abort unicast request from the play control module are sent to the server;

The play control module is configured to receive the unicast program data from the communication module and perform decoding and playing; or read the multicast program data stored in the storage module according to the determined information of the unicast program data suspension and play the program;

The storage module is used to store multicast program data.

It can be seen from the above that, after receiving the on-demand request from the video on demand terminal by the video on demand server, the video on-demand server transmits the requested program data to the terminal in a unicast manner, and reaches an instant response to the terminal on-demand request; The server establishes a multicast group for a plurality of terminals that order the same program data, and transmits the same program data to the plurality of terminals in a multicast manner, and the terminal receives the program data transmitted in a multicast manner and stores the data; of When the program data transmitted by the server in the unicast mode coincides with the program data transmitted by the server stored by the terminal in the multicast mode, the server stops transmitting the program data to the terminal in a unicast manner, thereby transmitting data to the plurality of terminals through multicast. Reduce the occupation of resources. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow chart of an embodiment of the present invention;

2 is a flowchart of interaction between a server and a terminal in a first embodiment of the method according to the present invention; FIG. 3 is a schematic diagram of a system composition of the present invention;

4 is a flowchart of internal processing of a server in an embodiment of the present invention; FIG. 5 is a flowchart of internal processing of a terminal in a first embodiment of the method according to the present invention;

6 is a schematic system diagram of a case of a first embodiment of a method according to the present invention;

FIG. 7 is a flowchart of interaction between a server and a terminal in a second embodiment of the method according to the present invention; FIG. 8 is a flowchart of interaction between a server and a terminal in a third embodiment of the method according to the present invention; FIG. 10 is a flowchart of processing inside a terminal in a fourth embodiment of the method according to the present invention; and FIG. 11 is a schematic diagram of terminal playback control. BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be further described in detail below with reference to the accompanying drawings.

According to an embodiment of the present invention, after receiving the on-demand request from the video on demand terminal, the video on demand server immediately transmits the requested program data to the terminal in a unicast manner to achieve an immediate response; thereafter, the above server is A terminal that requests the same program data to establish a multicast, and multicasts the same program data to the plurality of terminals in a multicast manner; when the unicast program data coincides with the multicast program data, the server stops unicasting The terminal transmits program data, Thereby, the data is transmitted to multiple terminals through multicast, which reduces the occupation of resources.

In another embodiment of the present invention, the video on demand terminal sends an on-demand request to the video on demand server; then receives the unicast program data returned by the server and plays the same; the video on demand terminal receives the multicast information sent by the video on demand server, according to the multicast The information receives the multicast program data and stores; after the unicast program data overlaps with the multicast program data, the video on demand terminal reads the stored multicast program data and plays the same.

The flow of an embodiment including the above two embodiments is as shown in FIG. 1, and includes the following steps:

Step 101: After receiving the request for on-demand from the terminal, the server sends the on-demand program data to the terminal in a unicast manner in response to the request, and the terminal receives the unicast program data and plays the same; - Step 102: The server is the same on-demand The terminal of the program data establishes multicast, transmits the program data in a multicast manner, and notifies the multicast information to the terminal of the same program on demand;

Step 103: The terminal that receives the multicast information receives the multicast program data according to the multicast information and stores the multicast program data.

Step 104: After the unicast program data received by the terminal overlaps with the multicast program data stored in the terminal, the server stops sending program data to the terminal in a unicast manner, and the terminal reads the stored group. Broadcast the program data and play it. ·· ·■

In order to reduce the burden on the server, when the multicast is established, the server may establish multicast according to a preset condition, which may be that the unicast of the same program reaches or exceeds the minimum unicast number N within a certain time span T. The condition may also be that there is no multicast in the time before the current unicast, but there is unicast for the same program; the condition may also be that there is no multicast for the same program.

In addition, in order to ensure that the terminal receives the multicast program data for a period of time, it can stop the connection. After receiving the unicast program data, after the multicast is established, the progress of the program data sent in the multicast mode needs to be synchronized with the progress of the earliest unicast in the unicast corresponding to the multicast or slightly faster than the progress of the unicast. .

Whether the unicast section U data received by the terminal and the multicast program data stored in the terminal overlap with each other may be performed by the terminal, and after determining that the program data overlaps according to the received program data information, the terminal needs to notify the server to stop. The unicast mode transmits program data to the terminal; or may be performed by the server, the server determines, according to the progress of the transmitted program, that the program data received by the terminal in two ways overlaps, and stops sending data to the terminal in a unicast manner.

The invention will now be described in detail by way of specific examples.

In the first embodiment of the present invention, the server pre-sets the time span T and the minimum unicast number of establishing multicast, wherein the time span T can be determined according to the capabilities of the server, the network status, and the storage capacity of the terminal, if the server If the capacity is strong and the network status is good, the time span can be set smaller, so that the requirements for the terminal storage capacity are low. If the storage capacity of the terminal is strong, the time span can be set larger. The minimum number of unicasts N is determined according to the resource consumption of multicast and unicast. The minimum unicast quantity should satisfy the value of multicast and the cost of N unicasts are approximately equal, or multicast. The cost is slightly less than the cost of N unicasts, which can range from 10 to 100.

After determining the time span T and the minimum unicast number N of the multicast, the process of interacting between the terminal and the server in the specific embodiment of the present invention is as shown in FIG. 2, which specifically includes the following steps: Step 201: After the terminal selects the program, the terminal uses The IP network sends an on-demand request to the server. Step 202: After receiving the on-demand request, the server sends the corresponding program data to the terminal in a unicast manner in response to the request, and records the unicast information.

Here, after the terminal clicks on a program, the server can separately respond by sending different types of data content through several unicasts, for example, audio and video are respectively sent through two unicasts. To the user, you can use these unicasts as a whole. The unicast mentioned below is based on this whole; similarly, for subsequent multicast, the server can also send different multicasts through several multicasts. The type of data content, the multicast mentioned below is based on the overall of these multicasts.

In this step, the recorded unicast information includes: the ID number of the program, the time stamp of the unicast, the destination address of the unicast, and the like. The time stamp of the unicast may be the time when the unicast starts.

Step 203: The server determines whether there is a multicast of the corresponding program in the time span in which the current time is located, if yes, step 204 is performed; otherwise, step '206 is performed;

Step 204: The server sends the multicast address to the terminal, and the terminal is notified to join the multicast to receive the program data, and the unicast is identified as having joined the multicast in the recorded unicast information.

Step 205, the terminal joins the corresponding multicast receiving multicast program data according to the received multicast address, and then proceeds to step 208;

Step 206: The server determines whether multicast can be established, that is, the number of unicasts recorded in the time span in which the current time is located is not identified as having joined the multicast, and determines whether the quantity reaches a preset minimum unicast quantity. N, if it is step 207; otherwise, execute step 212; '

Step 207: The server establishes multicast transmission data, and sends the multicast address to the terminal corresponding to the unicast corresponding to the multicast time record recorded in the time span, and records the multicast information, and joins the multicast information. The multicast unicast identifier is added to the multicast, and then step 205 is performed. In this step, when the server establishes multicast, the starting point of the program data sent by the multicast needs to be sent according to the earliest unicast transmission in the multicast. The progress determination may be the same as the earliest unicast transmission progress, or may be started by the program data corresponding to the preset delay time t after the earliest currently transmitted unicast. The setting of the magnitude of the delay time t can be performed according to the network condition and the response speed, and can ensure the multicast program received by the terminal. The data is later than the unicast program data received at the same time.

In addition, the multicast information recorded in this step includes the ID number of the program, the time stamp of the multicast, and the multicast address. The time stamp of the multicast may be the start time of the earliest unicast in the multicast group.

Steps 208 to 209: After the terminal recognizes that the received unicast program data and the earliest received and stored multicast program data overlap, the terminal reads the stored corresponding progress multicast program data for playing, and sends a suspension unicast request to the server.

In this step, the terminal recognizes whether the unicast program data and the multicast program data overlap, and there are two ways, which are respectively described below.

One way is to divide the program into blocks. In this mode, the server divides the program data into a plurality of blocks, and the size of the block can be transmitted in a short time after each block, so that after the user clicks on the program, the time for waiting for the first block to be completed when watching the program is short, and the time can be timely. In response to the user's request for on-demand as a scale, each block is sequentially set in block order, and when the program data is transmitted, the block number is set at the head of the program block and transmitted together with the program block. Then, when the terminal determines that the block number of the stored multicast program block is the same as the block number of the currently received unicast program block, the terminal determines that the unicast program data and the multicast program data coincide.

Another way is to identify the time information (time_code) in the encoding of audio and video data. In this mode, when the program data is encoded in MPEG-4 or H.264, the terminal may determine whether the unicast program data and the stored multicast program data are coincident according to the time code information in the video object group (GOP) header; When the program data is encoded in MPEG-2 or AVS, the terminal can determine whether the unicast program data and the stored multicast program data coincide according to the time code information in the header group. Specifically, when the terminal determines that the time-code of the time-code of the currently received unicast program exists in the stored multicast program, it is determined that the unicast program data and the multicast program data coincide.

In this step, the multicast program data corresponding to the progress is read, which may be after the coincidence is recognized. That is, reading the coincident multicast program data to start playing; or after reading the current program block, or the video object group, or the group of pictures, reading the next corresponding program block in the stored multicast program data, Or the video object group or the group of pictures is played, and then the stored multicast program data is sequentially played.

In addition, if the terminal recognizes that the user stops playing midway before this step, the unicast program data is stopped, the server is notified to stop unicast, and the multicast is exited. After receiving the stop unicast notification, the server stops sending program data to the terminal in unicast mode.

Step 210: After receiving the suspension unicast request from the terminal, the server stops sending unicast program data to the terminal, and deletes the unicast information, and then performs step 213.

Step 211: After the terminal stops playing or completes the playback of the on-demand program, the terminal exits the multicast.

Step 212: After the terminal stops playing or completes the playback of the on-demand program data, the terminal notifies the server to stop the unicast, and after receiving the notification, the server stops sending the unicast program data to the terminal, and deletes the unicast information. Then end the process.

Step 213: After completing the playing of the multicast program data, the server deletes the multicast information. The above is the flow of interaction between the terminal and the server in this embodiment, and the internal components of the server and the terminal that interact through the process are as shown in FIG. 3. In FIG. 3, the server 31 and the terminal 32 are connected through the IP network 33. The server 31 specifically includes a communication module 311, a decision module 312, and a storage module 313. The terminal 32 specifically includes a communication module 321 and a playback control module 322. The storage module 323 and the determination module 324.

The process of interaction between modules in the server is as shown in FIG. 4, and includes the following steps:

Step 401: After receiving the on-demand request from the terminal, the communication module of the server transmits the request to the decision module.

Step 402: The decision module responds to the request, and sends a corresponding to the terminal in a unicast manner. Program data, and record the unicast information in the storage module.

Step 403: The decision module queries whether the multicast in the storage module is stored in the preset time span T of the current time, if the step 404 is performed; otherwise, step 405 is performed.

Step 404: The decision module sends a message to the terminal through the communication module to notify the terminal to join the multicast, and marks the unicast information stored in the storage module as having joined the multicast, and then performs step 408.

Step 405: The decision module queries the unicast information recorded in the storage module that is not marked as being joined to the multicast, and determines whether the number of the unicasts meets or exceeds a preset minimum unicast number N. If yes, Step 406 is performed; otherwise, step 408 is performed.

Step 406: The decision module establishes a multicast, and sends the multicast address to the terminal corresponding to the unicast information that is not marked as joined by the communication module, notifies the joining of the multicast receiving program data, and marks the unicast information. It has been added to multicast.

Step 407: The decision module stores the multicast information in the storage module.

Step 408: After receiving the information of the suspended unicast sent by the terminal, the communication module forwards the information to the decision module.

Step 409: The decision module stops sending the unicast program data to the corresponding terminal according to the received information of the suspended unicast, and deletes the unicast information from the storage module.

Step 410: After determining that the unicast or multicast program data is sent, the decision module stops sending unicast or multicast program data to the corresponding terminal, and deletes the corresponding unicast or multicast information from the storage module.

The processing flow inside the terminal is shown in Figure 5, which specifically includes the following steps:

Step 501: The determining module of the terminal sends an on-demand request to the communication module after receiving the request of the user. '

Step 502: The communication module sends the on-demand request to the server through the IP network. Step 503: After receiving the program data sent by the server in the form of unicast, the communication module transmits the received program data to the play control module.

Step 504: The play control module plays according to the received program data in a unicast form. Step 505: After receiving the notification of joining the multicast from the server, the communication module adds the corresponding multicast receiving program data, and stores the received multicast program data into the storage module.

Step 506: The judging module judges whether the program data received in the unicast form and the program data received in the multicast form overlap, if the step 507 is overlapped; otherwise, step 512 is performed.

Step 507: The judging module sends a suspend request to the server through the communication module, and sends the superposed information to the play control module.

Step 508: The play control module reads the stored multicast program data and sequentially plays the data. Step 509: The play control module determines whether the user's suspension play request is received. If yes, step 511 is executed to exit the multicast, and then the process ends. Otherwise, step 510 is executed to determine whether the program is completed. Go back to step 511; otherwise, go back to step 509.

Step 512: The determining module determines whether the user's suspension play request is received. If the step 513 is performed, the communication module sends a suspension unicast request to the server, and notifies the play control module to stop playing the program data, and then ends the process; 514. Determine whether the play of the program is completed. If yes, go back to step 513; otherwise, go back to step 512.

The present embodiment will be further described below by applying a case of the embodiment. As shown in FIG. 6, the system on which a case of the present embodiment is based includes a server 31, an IP network 33, and terminals 3201, 3202, ..., 320n. Among them, the server includes a CPU, a hard disk, a network card, a memory, and an on-demand software server. The terminal includes a CPU, a hard disk, a network card, a memory and an on-demand software client, a display card, and the like. The server's network card is a communication module, hard The disk is a storage module, and the server on-demand software is a decision module; the CPU and the memory are environments required for operation. The network card of the terminal is used as the communication module, the on-demand software client is the judgment module, the hard disk is the storage module, and the display device such as the display card is used as the play control module.

Suppose a program is 100 minutes long, the preset time span T is 10 minutes, and the minimum number of unicasts N is 10. The terminal 1 first performs program on demand at 10:00, the server transmits unicast program data thereto, and stores the unicast information. The terminal 1 has a waiting time of 0 without considering the delay. Thereafter, there are 8 terminals respectively joining the same program on demand, and their processing is the same as that of the terminal 1. The terminal 10 broadcasts the program again at 10:03, and the server immediately sends the unicast data to it and stores the unicast information, so as to respond immediately on demand. Then, the on-demand software client determines that the number of on-demand programs in the previous 10 minutes has been 10, so the multicast transmission data is established, and the unicast information corresponding to these on-demand terminals is marked as joined multicast. It is found that the earliest terminal 1 of the ten programs has been played for 3 minutes. Since the network delay is considered, the multicast data is transmitted from the content of the fourth minute program, and the multicast information is recorded, and the multicast time is marked as 10: 00 is the originating time of the first unicast, and notifies all terminals to join the multicast receiving data. Considering the delay of processing, it is assumed that the multicast data received by the terminal 1 is program data starting from 4 minutes and 10 seconds, and the terminal 1 simultaneously receives multicast and unicast data, and stores the received multicast data in the hard disk. When the terminal reaches 10:04:10, the terminal finds that the received unicast program data and the stored multicast program data have coincided, notifying the server that the unicast program data is no longer sent, and the server stops the unicast data of the network terminal 1 and this The unicast information is deleted from the storage module; and the terminal 1 starts reading the stored multicast program data from the hard disk for playback. At 10:07:10, the unicast sent by the server to all terminals 1 to 10 is aborted, and all on-demand programs are sent through one multicast. When there is a terminal 11 on-demand program at 10:09, the server first sends data to the terminal 11 by unicast and stores the unicast information, and the server notifies the terminal to join the multicast to receive the multicast data, '"put the unicast information. It is set to join the multicast, and the terminal 11 joins the received multicast data and stores the received multicast data to the hard disk. When it reaches 10:13:10, the terminal 11 finds that the point unicast data coincides with the multicast content, notifies the server to suspend the unicast transmission data and deletes the unicast information, and then the terminal 11 starts to read the stored multicast from the hard disk. Data, and play. When the 10:11 terminal 12 initiates an on-demand request, the server immediately responds to send the program data to the terminal 12 in a unicast manner, and simultaneously finds whether there is a multicast within 10 minutes, determines that there is no, and searches for 10 minutes without being marked as joined multicast. The unicast information is not present at this time, so the server will not notify the terminal 12 to join the multicast until the condition for establishing a new multicast is reached and the terminal satisfies the condition for joining the new multicast.

Table 1

Table 1 illustrates the beneficial effects of the present invention by comparing the above-described scenarios in which the present invention is applied with various performance analysis of unicast, multicast, and sliced multicast in the prior art.

It can be seen from Table 1 that the traditional multicast method requires a long response time. If it is reduced to two seconds, it needs 1800 times of single play speed multicast or 420 times play speed multicast, and even more terrible. The receiving bandwidth of the terminal is required to be 420 times the program playing speed, that is, the MPEG-4 program of 1 Mbps has a bandwidth of 420 Mbps. The traditional unicast approach requires too much performance and bandwidth for the server when multi-terminal on-demand. By adopting the method of the invention, the instant response of the unicast is realized, and the requirement for the server to be too high by the traditional unicast VOD is overcome, and at the same time, The traditional multicast mode also requires a large amount of bandwidth and slow response when unattended. The foregoing is a description of the first embodiment of the method of the present invention. In the first embodiment, the condition for initiating multicast is that the number of unicasts reaches or exceeds the minimum unicast quantity within a certain time span T.

N, and the terminal decides whether the received unicast program data and the multicast program data coincide. In the present invention, the condition for initiating multicast may also be that there is no multicast for the same program within the time of establishing the multicast time threshold before the current unicast, but there is unicast for the same program, and the following is performed by the second embodiment. This situation is explained.

In the second embodiment of the present invention, the value of establishing the multicast time threshold ΤΓ is set in the server in advance, and the value may be determined according to the length of the program, for example, may be a value between 1/20 and 1/5 of the length of the program. Or, it may be a predetermined value, for example, a value between 5 and 20.

In this embodiment, the flow of interaction between the server and the terminal is as shown in FIG. 7. The flow is basically the same as the flow of the server and the terminal in the first embodiment, and the difference is only: In step 703, the server is based on the stored multicast. The information determines whether there is a multicast for transmitting the program data in the time period before the current time, if it is step 704; otherwise, step 706 is performed. In step 706, the server determines, based on the stored unicast information, whether there is another unicast for the same program data as the current unicast, if step 707 is performed; otherwise, step 712 is performed. In step 707, the server sends the multicast address to the terminal corresponding to the other unicast recorded in the current unicast and server and the same as the current unicast program data.

The flow of internal processing of the server is basically the same as that in the first embodiment, except that the judgment content mentioned in the above-mentioned server-terminal interaction flow is different. The process of the internal processing of the terminal is the same as that of the first embodiment in this embodiment, and will not be described in detail herein.

In the present invention, the condition for initiating multicast may also be that there is no multicast for the same program before the current unicast, and this case will be described below by the third embodiment.

In this embodiment, the flow of the interaction between the server and the terminal is as shown in FIG. 8. The flow of the interaction between the server and the terminal in the first embodiment is basically the same, and the difference is only in the step 802. The unicast information may not be recorded; in step 803, the server determines whether there is already a multicast for the same program. If the step 804 is performed, since the unicast information may not be recorded in step 802, the unicast information may also be recorded in step 804. The step of marking the unicast information is not performed; otherwise, step 806 is directly performed. In step 806, the server establishes multicast, sends the multicast address to the terminal, and records the multicast information, and then performs step 805, which is the same as step 205. Subsequent steps 807 to 812 are substantially the same as steps 208 to 213, with the difference that the unicast information may not be deleted in steps 809 and 811.

In this embodiment, the process of the internal processing of the server is basically the same as that in the first embodiment, except that the judgment content mentioned in the above-mentioned server and terminal interaction flow is different. The flow of the internal processing of the terminal is the same as that of the first embodiment in this embodiment, and will not be described in detail herein. ,

In the present invention, when the terminal that receives the same program in both unicast and multicast modes stops receiving unicast program data, it can also be implemented by server control. The details will be described below by the fourth embodiment.

The fourth embodiment of the present invention may be based on any one of the foregoing first to third embodiments, except that, in the flow of the above three embodiments, when the terminal is notified to join the multicast, that is, the above steps 204 and 207 In 704, 707, 804 and step 806, the server further reads the time Tg at which the multicast starts, the time at which the multicast starts is the earliest start time of all unicasts, and reads each terminal that joins the multicast. The unicast start time Ts, the server calculates for each terminal to stop sending the unicast program data time Tstop, Tstop = Ts - Tg. Then, the terminal side does not perform the step of determining whether the unicast program data and the multicast program data overlap, but only receives and stores the program data according to the information from the server side, and reads the first received multicast after the unicast program data is stopped. Program data is played. On the server side, according to the Tstop calculated for the terminal, after the time arrives, the transmission of the unicast program data to the terminal is stopped.

The processing flow inside the server in this embodiment is shown in FIG. 9, where step 901 and step Step 902 is the same as step 501 and step 502. In step 903, the decision module determines whether there is a multicast that the terminal can join, if it is step 904. Otherwise, step 905 is performed.

Step 904: The decision module sends a message to the terminal through the communication module to notify the terminal to join the multicast, and calculates Tstop according to the start time of the multicast and the start time of the terminal unicast, and then step 908 is performed.

Step 905. The decision module determines whether multicast can be established. If yes, step 906 is performed; otherwise, step 907 is performed.

Step 906: The decision module establishes multicast, stores the multicast information in the storage module, sends the multicast program data through the communication module, and notifies the corresponding terminal to join the multicast receiving program data, and then calculates Tstop for the terminals respectively.

Step 907: After the decision module reaches the time Tstop calculated for the terminal or after receiving the suspension unicast request from the terminal through the communication module, stop sending the unicast program data to the terminal, and delete the unicast information.

Step 908: After determining that the unicast or multicast program data is sent, the decision module stops sending unicast or multicast program data to the corresponding terminal, and deletes the corresponding unicast or multicast information from the storage module.

The processing flow inside the terminal is as shown in FIG. 10, wherein steps 1001 to 1005 are the same as steps 501 to 505 in FIG. The difference is that after step 1005, execution 1006: the play control module determines whether the user's stop-on-demand request is received, and if step 1007 is performed, the communication module sends a stop-on-demand request to the server, and stops playing, and then ends the process; Otherwise, in step 1008, the play control module sequentially reads the multicast program data stored in the storage module for playing after recognizing that the unicast program data has been received and the program is not played.

In this embodiment, since the server directly decides to stop sending the unicast program data to the terminal, the interaction between the terminal and the server is reduced, the network resources are saved, and the network resource is reduced. The burden of the terminal.

The above is a detailed description of specific embodiments of the method of the present invention. The components and connections of the system, server and terminal of the present invention will be described in detail below.

Figure 3 has shown an embodiment of the system of the present invention, mainly comprising a server 31 and a terminal 32, which may be carried out over the IP network 33 during the communication between the server 31 and the terminal 32.

The server 31 is configured to send corresponding program data to the unicast form according to the on-demand request from the terminal 32; and according to the determined presence information of the multicast that the terminal 32 can join, or according to the determined unicast Establishing corresponding multicast information, transmitting the corresponding multicast address to the terminal 32; and transmitting the multicast program data according to the determined multicast establishment information; and according to the suspended unicast information from the terminal 32, or according to the determined simultaneous reception The unicast program data and the information superimposed on the data received by the terminal 32 of the multicast program data stop transmitting the unicast program data to the terminal 32.

The terminal 32 is configured to send an on-demand request to the server 3.1 according to the user's request for on-demand, receive and play the program data sent by the server 31 in a unicast manner, and transmit in a multicast manner according to the multicast address receiving and storing server 31 from the server 31. Program data; and transmitting the suspended unicast information to the server 31 according to the user's suspended play request or the determined program data received in a unicast manner and the program data received in a multicast manner; or further determined according to the determined The program data received in the unicast mode and the program data superimposed in the multicast mode are superimposed, and the stored multicast program data is sequentially played.

The server 31 may specifically include a communication module 311, a decision module 312, and a storage module 313.

The communication module 311 is configured to connect the decision module 312, the storage module 3, and the IP network 33 in the server, and transmit the information received through the IP network 33 to the corresponding decision module 312 or the storage module 313, and from the server 31. The information of the decision module 312 and the storage module 313 is sent to the terminal 32 through the IP network. Specifically, the method includes: receiving terminal 32 passes The on-demand request sent by the IP network 33, in response to the request, reads the corresponding program data in the storage module 313 in a unicast manner, records the unicast information into the storage module 313, and transmits the on-demand request to the decision module 312; Transmitting the multicast information from the decision module 312 to the terminal 32 through the IP network 33, and reading the corresponding program data from the storage module 313 according to the information for initiating multicast from the decision module 312, and transmitting the data in a multicast manner, and The reading and transmitting of the corresponding program data is stopped based on the suspension request from the terminal 32 or the stop request from the decision module 312.

The decision module 312 is configured to determine whether to add the terminal 32 to the existing multicast according to the on-demand request from the communication module 311, or whether to initiate the multicast, and add the terminal 32 to the existing multicast information or the initiation group according to the determined. Broadcast information, the multicast information is sent to the communication module 311; and the information of the multicast generated is stored in the storage module 313; or further used to determine the stop according to the unicast and multicast time information sent to each user Unicast, and the determined stop request to stop unicast is sent to the communication module 321.

The storage module 313 is configured to store program data, unicast information, and multicast information.

The terminal 32 mainly includes a communication module 321, a play control module 322, a storage module 323, and a judging module 324.

The communication module 321 is configured to receive the unicast program data from the server 31 and transmit the unicast program data to the play control module 322, and receive the multicast program data according to the multicast information from the server 31 and store the data in the storage module 323; The user-initiated request for on-demand is sent to the server 31; the abort unicast request is sent to the server 31 according to the user-initiated suspension request or based on the information of the received unicast program data and the multicast program data from the judging module 324; The abort request from the user stops receiving multicast data.

The play control module 322 is configured to receive the unicast program data from the communication module 321 and perform decoding and playing; stop playing the unicast program data according to the information of the unicast program data from the judging module 324 and the multicast program data, and read Multicast program stored in the storage module The data is decoded and played, or the multicast program data stored in the storage module is read and played according to the determined information of the unicast program data suspension.

The storage module 323 is mainly used to store multicast program data.

The determining module 324 is configured to determine whether the received unicast program data and the multicast program data stored in the storage module are coincident, and send the determined information of the unicast program data and the multicast program data to the playback control module. And communication modules. In the case where it is determined by the server to stop transmitting unicast program data to the terminal, the judging module 424 may not be included in the terminal.

As shown in FIG. 11, a schematic diagram of playing control in the terminal embodiment, wherein when the switch 111 is in the current position, the playback control module 322 decodes and plays the unicast program data, and receives the received multicast. The program data is stored in the storage module 323. When the switch shown in the figure is connected to the storage module 323 and the playback control module 322, it indicates that the playback control module 322 stops receiving the unicast program data, and reads the multicast program data stored in the storage module 323 and decodes the playback.

The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., which are included in the spirit and scope of the present invention, should be included in the present invention. Within the scope of protection. '

Claims

Claim

A method for providing video on demand, the method comprising: the video on demand server receiving the on-demand request from the video on demand terminal, and transmitting the on-demand program data to the video on demand terminal in a unicast manner;

Establishing multicast for the video on demand terminal that plays the same program data, transmitting the program data in a multicast manner, and notifying the multicast information to the video on demand terminal of the same program on demand;

It is confirmed that the unicast program data coincides with the multicast program data, and the transmission of the program data to the video-on-demand terminal is stopped in a unicast manner.

2. The method according to claim 1, wherein the video on demand server determines whether there is currently a multicast for transmitting the program data before establishing the multicast, and if yes, directly notifying the multicast information to the A video on demand terminal that broadcasts the same program.

The method according to claim 2, wherein the video on demand server stores the multicast information after the multicast is established, and performs the determining according to the stored multicast information whether the program data is currently sent. Multicast.

The method according to claim 3, wherein the stored multicast information includes an identifier of the program, a time stamp of the multicast, and a multicast address; and the multicast information included in the notification to the video on demand terminal includes Multicast address.

The method according to claim 4, wherein the time stamp of the multicast is: a start time of the first unicast started in the unicast corresponding to the multicast; or: corresponding to the multicast The time at which the delay time is preset after the start time of the earliest unicast in unicast.

The method according to any one of claims 2 to 5, further comprising: before the multicasting of the video on demand terminal for ordering the same program data, the video point The broadcast server determines whether multicast can be established.

The method according to claim 6, wherein the determining whether there is currently a multicast for transmitting the program data is: determining whether the program is sent within a preset time before the moment Multicasting of the data; determining whether the multicast can be established as: determining whether there is a unicast for the program data before a predetermined time before the moment, and if so, the video-on-demand terminal corresponding to the multicast And including the video on demand terminal and the existing unicast corresponding video on demand terminal for the program data.

The method according to claim 6, wherein the determining whether there is currently a multicast for transmitting the program data is: determining whether the sending is performed within a preset time span in which the time is located Multicasting of the same program data; determining whether the multicast can be established as: determining whether the unicast quantity of the program data reaches or exceeds a preset minimum within a preset time span in which the time is located The number of unicasts, if yes, the video on demand terminal corresponding to the multicast is the video on demand terminal and the video on demand terminal corresponding to the unicast for the program data.

The method according to claim 6, further comprising: recording, by the video on demand server, unicast information; and determining whether the multicast can be established according to the recorded unicast information.

10. The method according to claim 1, wherein the confirming the unicast program data and the multicast program data overlap is:

The unicast program data is coincident with the multicast program data according to the time when the data is transmitted to the unicast-frequency terminal in unicast mode and multicast form; or:

The abort unicast request sent by the video on demand terminal is received.

11. A video on demand method, the method comprising:

Receiving the returned unicast program data and playing it; The video on demand terminal receives the multicast information sent by the video on demand server, receives the multicast program data according to the multicast information, and stores the data;

After determining that the received unicast program data coincides with the stored multicast program data, the video on demand terminal reads the stored multicast program data and plays it.

The method according to claim 11, wherein the video on demand terminal determines that the received unicast program data and the stored multicast program data are coincident, and further includes: sending a suspension to the video on demand server Unicast request.

The method according to claim 11, wherein the determining that the received unicast program data and the stored multicast program data coincide is:

Recognizing that the stored multicast program data is the same as the block number of the currently received unicast program data; or: the identifying that the stored multicast program data exists in the same time as the currently received unicast program data information.

14. A video on demand server, the server comprising a communication module, a decision module, and a storage module;

The communication module is configured to receive a request from the terminal for on-demand, read and send the corresponding program data in the storage module in a unicast manner in response to the request, and transmit the on-demand request to the decision module; and send the multicast information from the decision module to Ending, reading, and transmitting corresponding program data in a multicast manner according to the information of the originating multicast from the decision module, and stopping reading and transmitting the corresponding program data according to the suspension request from the terminal;

a storage module, configured to store program data and multicast information.

15. The video on demand server according to claim 14, wherein: The decision module is further configured to determine whether the unicast program data received by the terminal and the data received by the video on demand terminal of the multicast program data are coincident according to the time of transmitting the unicast program data to the same video on demand terminal and the time of the multicast program data. And sending the determined coincidence information to the communication module;

The communication module is further configured to receive the coincidence information from the decision module, and stop transmitting the corresponding program data in the storage module in a unicast manner according to the coincident information.

A video on demand terminal, wherein the terminal comprises a communication module, a play control module, and a storage module;

The storage module is used to store multicast program data.

The video-on-demand terminal according to claim 16, wherein the terminal further comprises: a determining module, configured to determine whether the received unicast program data and the multicast program data stored in the storage module are coincident And sending the determined information of the unicast program data and the multicast program data to the playback control module and the communication module;

The play control module is further configured to stop playing the unicast program data according to the coincident information from the judging module, and read the stored multimedia program data in the storage module and play the same;

The communication module is further configured to: according to the overlapping information from the determining module The video on demand server sends abort unicast request.