Abstract:
A method for supporting multi audio tracks in wireless communication field, which uses multi stream media servers to share the assignment for supporting multi audio tracks. One stream media server receives one video data and multi audio data, but outputs only one determinate audio data; or one stream media server receives one video data and one audio data from multi audio data. User can select the required language by using portal website, and then connect to the stream media server for obtaining one video data and one audio data. The invention also provides a stream media server and a system for supporting multi audio tracks.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of International Patent Application No. PCT/CN2007/001714, filed May 28, 2007, which claims priority to Chinese Patent Application No. 200610111991.6, filed Aug. 30, 2006, both of which are hereby incorporated by reference in their entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to the field of communications, and in particular to a method, a system and a stream media server designed to support multiple audio tracks contents in the field of wireless multimedia. 
       BACKGROUND OF THE INVENTION 
       [0003]    With the development of technologies, mobile station devices have evolved to include some functions of computers, such as wireless network access and online receiving of stream media contents including TV programs, movies, etc. However, at present, an analog signal data stream only contains one channel of audio data and one channel of video data, that is, one channel of audio data only corresponds to a single audio track (one kind of language). If different users want to receive audio contents in different languages, multiple live broadcast encoders must be adopted to receive respective channels of audio information and video information; thus, two languages need at least two live broadcast encoders. The corresponding Session Description Protocol (SDP) file only contains the definition for one channel of audio data and one channel of video data, an instance of which is shown as follows: 
         [0000]    
       
         
               
             
               
               
             
               
             
           
               
                   
               
             
             
               
                 v=0 
               
               
                 o=− 2631350701 1507213 IN IP4 192.168.18.101 
               
               
                 s=b3 14 
               
               
                 c=IN IP4 236.130.128.182/1 
               
               
                 b=RR:0 
               
               
                 t=0 0 
               
               
                 m=video 8686 RTP/AVP 96 
               
               
                 b=AS:1920 
               
               
                 a=rtpmap:96 H264/90000 
               
               
                 a=fmtp:96 
               
               
                 profile-level-id=4D4015; 
               
               
                 sprop-parameter-sets= 
               
               
                     Z01AFZZWCwJNgyRAAAD6AAAYahgwADgnADqargAK, 
               
               
                     aO88gA==; packetization-mode=1 
               
               
                 a=cliprect:0,0,576,352 
               
               
                 a=framerate:25. 
               
               
                 a=mpeg4-esid:21 
               
               
                 a=x-envivio-verid:0002229A 
               
               
                 m=audio 8688 RTP/AVP 97 
               
               
                 b=AS:32 
               
               
                 a=rtpmap:97 mpeg4-generic/16000/2 
               
             
          
           
               
                 a=fmtp:97 
                  profile-level-id=15;  conFIG=1410;  streamtype=5; 
               
               
                   
                 ObjectType=64; mode=AAC-hbr; SizeLength=13; 
               
               
                   
                 IndexLength=3; IndexDeltaLength=3 
               
             
          
           
               
                 a=mpeg4-esid:101 
               
               
                 a=lang:eng 
               
               
                 a=x-envivio-verid:0002229 a   
               
               
                   
               
             
          
         
       
     
         [0004]    With the development of mobile terminal technologies and the increase of user demands, the above technical solution has not been adapted to the current demands. The users expect to watch a variety of TV programs in different languages. A conventional solution is to replicate one channel of video into multiple channels of video by means of a video replicator, match the multiple channels of video with multiple channels of audio, and then send the matched multiple channels of audio and video to multiple live broadcast encoders for encoding. With reference to  FIG. 1 , each solid arrow line denotes one channel of video, and each dotted arrow line denotes one channel of audio data. The three dotted arrow lines denote three channels of audio, i.e., three different languages. The video replicator needs to replicate the one channel of video to obtain another two channels of video, match the three channels of video with the three channels of audio respectively, and send each of the three channels of audio, together with one channel of video matching with this channel of audio, to a corresponding live broadcast encoder. Three live broadcast encoders are needed for the three channels of audio, and each of the live broadcast encoders sends information via two ports (one video port and one audio port) to a stream media server, and the stream media server forwards the information to a terminal device through a wireless network. Thus, requirements for live broadcast encoders and video replicators are increased, however, the live broadcast encoders are at present very high in price, and therefore the running cost will be increased significantly, and additionally subsequent maintenances will cause great inconveniences. 
       SUMMARY OF THE INVENTION 
       [0005]    An embodiment of the present invention provides a method, a system, and a stream media server for supporting multiple audio tracks, in order to solve the problems in the prior art, such as the problem of insufficient support for multiple audio tracks, higher cost, and maintenance difficulties. 
         [0006]    A method of supporting multiple audio tracks is provided, which includes (1) sending one channel of video data and multiple channels of audio data having being processed to multiple stream media servers by a live broadcast encoder, wherein, the number of the stream media servers is not less than the number of channels of audio data; and (2) replicating the one channel of video data and one channel of the multiple channels of audio data and sending the replicated video data and audio data to a user&#39;s terminal by the stream media servers at the user&#39;s request, wherein, each of the stream media servers outputs one channel of the multiple channels of audio data. 
         [0007]    A stream media server is provided, which includes (1) a receiving unit, adapted to receive one channel of video data and multiple channels of audio data from a live broadcast encoder; (2) a replicating unit, adapted to replicate the one channel of video data and one channel of the multiple channels of audio data; and (3) a sending unit, adapted to send the one channel of video data and the one channel of audio data replicated by the replicating unit to a terminal. 
         [0008]    A stream media server is provided, which includes (1) a receiving unit, adapted to receive one channel of video data and one channel of multiple channels of audio data output from a live broadcast encoder; (2) a replicating unit, adapted to replicate the one channel of video data and the one channel of audio data received by the receiving unit; and (3) a sending unit, adapted to send one channel of video data and one channel of audio data replicated by the replicating unit to the terminal. 
         [0009]    A system for supporting multiple audio tracks, which includes a live broadcast encoder and multiple stream media servers connected to the live broadcast encoder. The live broadcast encoder is adapted to perform an A/D conversion on one channel of analog video signal and multiple channels of analog audio signals received, and send the one channel of video data and multiple channels of audio data having being processed to the multiple stream media servers, wherein, the number of the stream media servers is not less than the number of the channels of video data. Each of the stream media server is adapted to replicate the one channel of video data and one channel of the multiple channels of audio data and send them to a user&#39;s terminal at the user&#39;s request, wherein, each of the stream media servers outputs one channel of audio data of the multiple channels of audio data. 
         [0010]    According to an embodiment of the present invention, multiple stream media servers are used to support multiple audio tracks in a shared manner, in which each stream media server receives one channel of video signals and multiple channels of audio signals but outputs one channel of multiple channels of audio signals; or each stream media server receives one channel of video signals and one channel of multiple channels of audio signals. The stream media servers work together to support output of multiple channels of audio signals, so there is no need for video replicators or too much live broadcast encoders. The users&#39; requirement for multiple languages can be met with reduced cost and network resources and easier maintenance. In addition, the technical solution of the present invention is applicable for a variety of wireless network systems. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a structural diagram of a network of supporting multiple audio tracks according to the conventional art; 
           [0012]      FIG. 2A  is a structural diagram of a network in which a user receives stream media contents according to an embodiment of the present invention; 
           [0013]      FIG. 2B  is a general flowchart of multiple servers supporting multiple audio tracks according to an embodiment of the present invention; 
           [0014]      FIG. 3A  is a structural diagram of a network in which a server receives multiple audio according to an embodiment of the present invention; 
           [0015]      FIG. 3B  is a structural diagram of a server which receives multiple audio according to an embodiment of the present invention; 
           [0016]      FIG. 4  is a specific flowchart of a server receiving multiple audios according to an embodiment of the present invention; and 
           [0017]      FIG. 5  is a specific flowchart of a server receiving a single audio according to an embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0018]    In an embodiment of the present invention, a live broadcast encoder and multiple stream media servers are used to support information broadcasts of multiple audio tracks; each of the stream media servers can output one channel of audio signal while outputting one channel of video signal. A user can log onto a portal website to choose a required language and obtain a link to a corresponding stream media server. 
         [0019]    With reference to  FIG. 2A , according to an embodiment, a basic network structure, by means of which a user receives stream media contents, includes a live broadcast encoder  21 , a stream media server  22 , a Wireless Application Protocol (WAP)/WEB portal website  23 , a wireless network  24 , and a terminal  25 . 
         [0020]    The live broadcast encoder  21  is adapted to receive analog TV signals of video and audio; convert the analog TV signals into digital signals and compress the digital signals; and then send the compressed signals to the stream media server  22 . 
         [0021]    The stream media server  22  is adapted to receive the compressed signals from the live broadcast encoder  21 , and replicate and send required signals to a user according to the request of the terminal  25 . 
         [0022]    The WAP/WEB portal website  23  is adapted to provide the user with a network service interface and provide links to relevant services. 
         [0023]    The wireless network  24  is adapted to provide a platform for interaction between the terminal  25  and the stream media server  22 , and interaction between the terminal  25  and the WAP/WEB portal website  23  in the network. 
         [0024]    The terminal  25  is adapted to connect to the stream media server  22  based on RTSP/RTP protocols via the wireless network  24 , and connect to the WAP/WEB portal website  23  based on WAP/HTTP protocols via the wireless network  24 ; the user can watch stream media contents using the terminal. The terminal  25  may be a mobile telephone, a personal digital assistant (PDA), or any device that can access the network in wireless manner. 
         [0025]    The user logs onto the WAP/WEB portal website  23  via the wireless network  24  using the terminal  25 , chooses a desired program and language, obtains a corresponding route link, URL (Uniform Resource Locator), and establishes a connection to the stream media server  22  by means of the route link. After receiving the URL requested from the terminal  25 , the stream media server  22  parses a corresponding SDP file to obtain a data transmission port of the live broadcast encoder  21 . By listening in the corresponding port, the stream media server  22  obtains audio signals and video signals sent from the live broadcast encoder  21 , replicates the audio signals and video signals, and then sends the replicated audio signals and video signals to the terminal  25  via the wireless network  24 . The terminal  25  then decodes and displays the received audio signals and video signals. 
         [0026]    The link information provided by the WAP/WEB portal website  23  is shown as follows: 
         [0000]    
       
         
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 Sex and the City (English) 
                 RTSP://IP1/TV.SDP 
               
               
                   
                 Sex and the City (Chinese) 
                 RTSP://IP2/TV.SDP 
               
               
                   
                 Sex and the City (Cantonese) 
                 RTSP://IP3/TV.SDP 
               
               
                   
                   
               
             
          
         
       
     
         [0027]    The user chooses a language therefrom and obtains a link to a corresponding audio track. 
         [0028]    The corresponding relationship between language and audio track needs to be specified in advance in either of the following two ways. 
         [0029]    1. The sequence of the audio tracks in different languages needs to be specified through the interface when the live broadcast encoder encodes the audio data, for example, the first audio track is in English, the second audio track is in Chinese, and the third audio track is in Cantonese, etc. The operational manuals of the corresponding live broadcast encoder may be referred to for details. 
         [0030]    2. The encoder adds a tag to each audio track when encoding the audio data. In this way, different languages can be identified with different tags, for example, the name of the tag may be Chinese, English, French, and German—the name of a tag may not necessarily represent the corresponding language, but can be used to represent any other language as required. For example, if Japanese is required, the tag name “German” may be used to represent Japanese. 
         [0031]    With reference to  FIG. 2B , in this embodiment, the main flow of supporting multiple audio tracks by multiple stream media servers is as follows. 
         [0032]    Step  201 : After converting received analog signals, which include one channel of analog video signals and multiple channels of analog audio signals, into digital signals and compressing the digital signals, the live broadcast encoder  21  sends the compressed signals to the multiple stream media servers  22 . The number of the stream media servers  22  is not less than the number of the channels of audio signals. 
         [0033]    Step  202 : The multiple stream media servers  22  receive the one channel of video signals, and, the multiple channels of audio signals or one channel of the multiple channels of audio signals. 
         [0034]    Step  203 : A user accesses the WAP/WEB portal website  23  with the terminal  25 , chooses a language, and obtains a route link to a stream media server  22 . 
         [0035]    Step  204 : The user sends a request to the stream media server  22 . 
         [0036]    Step  205 : The stream media server  22  locally replicates the one channel of video signals and a specified channel of audio signals and sends the replicated video and audio signals to the terminal  25  according to the user&#39;s request. 
         [0037]    According to this embodiment, each stream media server receives one channel of video signals and multiple channels of audio signals, and the multiple stream media servers support multiple audio tracks. In configuration files, an audio track is specified by an audio track number or an audio track tag, indicating the audio track corresponding to the audio signals that can be output by a server along with one channel of video signals; or, each stream media server receives one channel of video signals and one channel of the multiple channels of audio signals, and the multiple stream media servers support output of all audio signals, the number of the stream media servers is not less than the number of the channels of audio signals. In case of traffic congestion in the network, the multiple stream media servers can output the same channel of audio signals when they output the same channel of video signals. 
         [0038]    With reference to  FIG. 3A , according to an embodiment, a network of supporting multiple audio tracks includes a live broadcast encoder  21 , two stream media servers  22 , two wireless networks  24 , and two terminals  25 . The network further includes a WAP/WEB portal website  23  (not shown). Although the embodiment is illustrated by the example of two stream media servers, the number of stream media servers may be set as required. 
         [0039]    The live broadcast encoder  21  is adapted to receive analog TV signals including one channel of video signals and two channels of audio signals, convert them into digital signals and compress the digital signals, generate an SDP file, and then send the compressed digital signals including one channel of video signals and two channels of audio signals to the two stream media servers  22 , respectively. 
         [0040]    The two stream media servers  22  are adapted to receive the digital signals including one channel of video signals and two channels of audio signals sent from the live broadcast encoder  21 . The contents received by the two stream media servers are identical. The stream media servers  22  each replicate one channel of audio signals and one specified channel of audio signals according to parameter settings in a local configuration file, and then send the replicated signals to the wireless network  24 . The configuration file in the stream media servers  22  specifies different audio signals on different audio tracks. Another approach is: each of the two stream media servers receives one channel of video signals and one channel of the two channels of audio signals sent from the live broadcast encoder  21 , i.e., the two stream media servers receive different channels of audio signals corresponding to the same channel of video signals. In that case, no parameter information of audio tracks is added in the local configuration file. 
         [0041]    The multiple stream media servers may have the same configuration file, i.e., they can output the same audio signals when they output the same video signals, and the wireless network  24  indicates to which stream media server the terminal  25  is connected. 
         [0042]    The two wireless networks  24  are adapted to provide a platform for interaction between the stream media server  22  and the terminal  25 , and interaction between the terminal  25  and the WAP/WEB portal website  23 . 
         [0043]    The two terminals  25  are adapted to connect to the WAP/WEB portal website  23  through the wireless network  24  and receive stream media signals forwarded via the wireless network  24 . Users may watch the stream media contents with the terminals and release contents that have been played. If the multiple terminals  25  request the same channel of audio signals corresponding to the same channel of video signals, the wireless network  24  may send the stream media data stream to the terminals  25  in multicast mode. If one terminal  25  makes a request, the wireless network  24  may send in unicast mode. 
         [0044]    The wireless networks  24  subsequently connected to the two stream media servers  22  are not required to be connected in a fixed way, but they may be cross-connected, or they may be the same wireless network. Likewise, either of the two terminals  25  may be subsequently connected to the wireless network  24 , depending on actual situations. 
         [0045]    With reference to  FIG. 3B , the stream media server  22  includes a receiving unit  221 , a replicating unit  222 , and a sending unit  223 . The receiving unit  221  receives the stream media data stream containing one channel of video signals and multiple channels of audio signals output from the live broadcast encoder. The replicating unit  222 , according to the request of the terminal  25 , reads the local configuration file which specifies one channel of the multiple channels of audio signals, and replicates the one channel of video signals and the specified channel of audio signals. The sending unit  223  sends the one channel of video signals and the channel of audio signals replicated by the replicating unit  222  to the terminal  25 . 
         [0046]    According to another embodiment, as shown in  FIG. 3B , the stream media server  22  includes a receiving unit  221 , a replicating unit  222 , and a sending unit  223 ; in which the receiving unit  221  receives the stream media data stream containing one channel of video signals and one channel of the multiple channels of audio signals output from the live broadcast encoder, according to parameter information and port numbers in the local SDP file. The replicating unit  222  replicates the one channel of video signals and the one channel of audio signals according to the request of the terminal  25 . The sending unit  223  sends the one channel of video signals and the one channel of audio signals replicated by the replicating unit  222  to the terminal  25 . 
         [0047]    With reference to  FIG. 4 , according to an embodiment, multiple audio tracks are supported by multiple stream media servers, each of which receives the same one channel of video signals and multiple channels of audio signals. The procedure of receiving the same one channel of video signals and multiple channels of audio signals is as follows. 
         [0048]    Step  401 : The live broadcast encoder  21  generates an SDP file, and sends the SDP file to the two stream media servers  22 . The live broadcast encoder  21  defines that the first audio track is in English and the second audio track is in Chinese, in which the audio track can be identified by a number or tag. The SDP file contains parameter information of two channels of audio and one channel of video, wherein, each channel of the signals is specified to be sent via a specific port. An example of the SDP file is shown as follows. 
         [0000]    
       
         
               
             
           
               
                   
               
             
             
               
                 v=0 
               
               
                 o=− 2631350701 1507213 IN IP2 192.168.18.101  //The name of the user at the 
               
               
                     session initiating end is “-”, the session ID is 2631350701, the session 
               
               
                     version is 1507213, the network type is Internet, the address type is ipv4, 
               
               
                     and the address is 192.168.18.101 
               
               
                 s=b3 14 
               
               
                 c=IN IP2 236.130.128.182/1  //Description of connection data: the network type is 
               
               
                     Internet, the address type is ipv4, and the address is 236.130.128.182 
               
               
                 b=RR:0 
               
               
                 t=0 0 
               
               
                 m=video 8686 RTP/AVP 96  //Start the description of the video media information; 
               
               
                     the video media data will be sent to port 8686, based on UDP-based RTP 
               
               
                     protocol, in format “96”(dynamic RTP load type) 
               
               
                 b=AS:1920  //Description of bandwidth, bandwidth=15kbps 
               
               
                 a=rtpmap:96 H264/90000  //Description of load type “96”:  in the format of H264 
               
               
                     code, at a sampling clock rate of 90000Hz 
               
               
                 a=fmtp:96             profile-level-id=4D4015; 
               
               
                     sprop-parameter-sets=Z01AFZZWCwJNgyRAAAD6AAAYahgwADgnA 
               
               
                     DqargAK, 
               
               
                 aO88gA==; packetization-mode=1  //Further provide parameters of load type “96” 
               
               
                 a=cliprect:0,0,576,352 
               
               
                 a=framerate:25.   //Frame rate:  15fps 
               
               
                 a=mpeg4-esid:21   //Correspond to stream ID 201 (the video file may contain 
               
               
                     multiple video streams and audio streams, each of which is allocated an ID. 
               
               
                     In this example, the ID of the video stream is 201) 
               
               
                 a=x-envivio-verid:0002229A 
               
               
                 m=audio 8688 RTP/AVP 97   //Start the description of the first channel audio media 
               
               
                     information.  The audio media data will be sent to port 8688, in 
               
               
                     UDP-based RTP protocol, in format “97” (dynamic RTP load type) 
               
               
                 b=AS:32 
               
               
                 a=rtpmap:97 mpeg4-generic/16000/2 
               
               
                 a=fmtp:97  profile-level-id=15;  conFIG=1410;  streamtype=5;  ObjectType=64; 
               
               
                     mode=AAC-hbr; SizeLength=13; IndexLength=3; IndexDeltaLength=3 
               
               
                 a=mpeg4-esid:101 
               
               
                 a=lang:eng  //ID of each audio track; used to differentiate different audio tracks, but 
               
               
                     not necessarily represent it must be this language 
               
               
                 a=x-envivio-verid:0002229A 
               
               
                 m=audio 8690 RTP/AVP 14  //Start the description of the second channel audio 
               
               
                     media information 
               
               
                 b=AS:48 
               
               
                 a=rtpmap:14 MPA/48000/2 
               
               
                 a=mpeg4-esid:102 
               
               
                 a=lang:chi 
               
               
                 a=x-envivio-verid:0002229A 
               
               
                   
               
             
          
         
       
     
         [0049]    Step  402 : The live broadcast encoder  21  receives one channel of analog video signals and two channels of analog audio signals. 
         [0050]    Step  403 : At the live broadcast encoder  21 , the analog signals are converted into digital signals through A/D conversion, and the digital signals are compressed. 
         [0051]    Step  404 : The two stream media servers  22  receive the stream media data stream (one channel of video signals and two channels of audio signals) sent from the live broadcast encoder  21  in real time by listening to the port specified in the received SDP file. 
         [0052]    Step  405 : The two stream media servers  22  receive the stream media data stream, and add relevant information in a local configuration file to specify one channel of audio. The configuration files in the two stream media servers  22  are different from each other, and different audio channels are specified corresponding to the same one video. For example, take the stream media server  22  as an example, if the second audio track is specified in the configuration file, the corresponding language is Chinese. Examples of such a configuration file are shown as follows. 
         [0000]    
       
         
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 Audio_channel_id=2(1,2,3) 
               
               
                   
                 or 
               
               
                   
                 Audio_language= Chinese (English, Chinese, Cantonese) 
               
               
                   
                   
               
             
          
         
       
     
         [0053]    Step  406 : The terminal  25  accesses the WAP/WEB portal website  23  through the wireless network  24  and chooses a language; for example, select “Chinese.” Accordingly, read the route address “RTSP://IP2/TV.SDP” of the audio track, which corresponds to the audio track “Sex and the City” defined by the live broadcast encoder  21 ; then the corresponding stream media server  22  can be located through IP2, and the specific channels of video and audio signals in the stream media server  22  can be located according to the TV.SDP file. The terminal  25  establishes a connection to the stream media server  22 , in which the language of audio corresponding to the specific video is Chinese, and sends a request to the stream media server  22 . 
         [0054]    Step  407 : When receiving the request from the terminal  25 , the connected stream media server  22  reads the configuration file, which specifies that the stream media server  22  can send audio signals in Chinese or support the second audio track corresponding to one channel of video signals selected by the user. 
         [0055]    Step  408 : The connected stream media server  22  locally searches for one channel of video signals and one channel of audio signals in Chinese that can be output corresponding to the channel of video, replicates them, and sends the one channel of video signals and one channel of audio signals to the terminal  25  through the wireless network  24 . 
         [0056]    Step  409 : The terminal  25  decodes the one channel of video signals and the one channel of audio signals in Chinese after it receives them and plays them to the user. 
         [0057]    With reference to  FIG. 5 , according to an embodiment, multiple audio tracks are supported by multiple stream media servers, each of which receives one channel of video signals and one channel of the multiple channels of audio signals. The procedure is as follows: 
         [0058]    Step  501 : The live broadcast encoder  21  generates an SDP file containing parameter information of one channel of video signals and multiple channels of audio signals, and corresponding port numbers, and defines that the first audio track is in English and the second audio track is in Chinese, which may be identified by a number or tag. Then, the SDP file containing all the information is split manually or automatically into two SDP files each containing one channel of audio signals, and the two SDP files are sent to the two stream media servers  22  respectively. The two SDP files specify the parameter information of the same channel video signals and different channels of audio signals and corresponding port numbers. The SDP file in a stream media server  22  contains the parameter information of one channel of video signals and one channel of the two channels of audio signals, wherein, the one channel of video signals and the one channel of audio signals are specified to be sent via a specific port. Take one of the stream media servers  22  as an example, the stream media server  22  supports a first audio track, and the corresponding language is “English.” An example of the SDP file is shown as follows. 
         [0000]    
       
         
               
             
           
               
                   
               
             
             
               
                 v=0 
               
               
                 o=− 2631350701 1507213 IN IP4 192.168.18.101 
               
               
                 s=b3 14 
               
               
                 c=IN IP4 236.130.128.182/1 
               
               
                 b=RR:0 
               
               
                 t=0 0 
               
               
                 m=video 8686 RTP/AVP 96 
               
               
                 b=AS:1920 
               
               
                 a=rtpmap:96 H264/90000 
               
               
                 a=fmtp:96         profile-level-id=4D4015; 
               
               
                      sprop-parameter-sets= 
               
               
                      Z01AFZZWCwJNgyRAAAD6AAAYahgwADgnA DqargAK, 
               
               
                 aO88gA==; packetization-mode=1 
               
               
                 a=cliprect:0,0,576,352 
               
               
                 a=framerate:25. 
               
               
                 a=mpeg4-esid:21 
               
               
                 a=x-envivio-verid:0002229A 
               
               
                 m=audio 8688 RTP/AVP 97 
               
               
                 b=AS:32 
               
               
                 a=rtpmap:97 mpeg4-generic/16000/2 
               
               
                 a=fmtp:97  profile-level-id=15;  conFIG=1410;  streamtype=5; 
               
               
                      ObjectType=64; mode=AAC-hbr; SizeLength=13; 
               
               
                      IndexLength=3; IndexDeltaLength=3 
               
               
                 a=mpeg4-esid:101 
               
               
                 a=lang:eng 
               
               
                 a=x-envivio-verid:0002229A 
               
               
                   
               
             
          
         
       
     
         [0059]    Wherein, the port of the audio track is m=audio 8688 RTP/AVP 97, and the corresponding audio channel is a=lang:eng. 
         [0060]    The SDP file in the other stream media server  22  contains the parameter information for one channel of video signals and one channel of audio signals, wherein, this channel of video signals and this channel of audio signals are specified to be sent via a specific port. The stream media server  22  supports a second audio track, and the corresponding language is “Chinese.” An example of the SDP file is shown as follows. 
         [0000]    
       
         
               
             
           
               
                   
               
             
             
               
                 v=0 
               
               
                 o=− 2631350701 1507213 IN IP4 192.168.18.101 
               
               
                 s=b3 14 
               
               
                 c=IN IP4 236.130.128.182/1 
               
               
                 b=RR:0 
               
               
                 t=0 0 
               
               
                 m=video 8686 RTP/AVP 96 
               
               
                 b=AS:1920 
               
               
                 a=rtpmap:96 H264/90000 
               
               
                 a=fmtp:96            profile-level-id=4D4015; 
               
               
                      sprop-parameter-sets= 
               
               
                      Z01AFZZWCwJNgyRAAAD6AAAYahgwADgnA DqargAK, 
               
               
                 aO88gA==; packetization-mode=1 
               
               
                 a=cliprect:0,0,576,352 
               
               
                 a=framerate:25. 
               
               
                 a=mpeg4-esid:21 
               
               
                 a=x-envivio-verid:0002229A 
               
               
                 m=audio 8690 RTP/AVP 14 
               
               
                 b=AS:48 
               
               
                 a=rtpmap:14 MPA/48000/2 
               
               
                 a=mpeg4-esid:102 
               
               
                 a=lang:chi 
               
               
                 a=x-envivio-verid:0002229A 
               
               
                   
               
             
          
         
       
     
         [0061]    Wherein, the port for the audio track is m=audio 8690 RTP/AVP 14, and the corresponding audio track is a=lang:chi. 
         [0062]    Step  502 : The live broadcast encoder  21  receives one channel of analog video signals and two channels of analog audio signals, wherein, the first audio channel is in English, and the second audio channel is in Chinese. 
         [0063]    Step  503 : At the live broadcast encoder  21  the analog signals are converted into digital signals, and the digital signals are compressed. 
         [0064]    Step  504 : The stream media server  22  receives the stream media data stream (one channel of video signals and one channel of audio signals in English among the multiple channels of audio signals) sent from the live broadcast encoder  21  in real time, by listening to the port specified in the received SDP file. 
         [0065]    Step  505 : The terminal  25  accesses the WAP/WEB portal website  23  through the wireless network  24 . The user chooses a language with the terminal  25 , for example, select “English,” and accordingly, the terminal reads the route address “RTSP://IP1/TV.SDP” of the audio track, which corresponds to the audio track “Sex and the City” in the live broadcast encoder  21 , and establishes a connection to the stream media server  22  that is specified by the route address and receives this channel of audio signals in English corresponding to this channel of video signals. 
         [0066]    Step  506 : After receiving a request from the terminal  25 , the connected stream media server  22  locally replicates the one channel of video signals and the one channel of audio signals in English, and sends the one channel of video signals and one channel of audio signals in English to the terminal  25  through the wireless network  24 . 
         [0067]    Step  507 : When receiving the one channel of video signals and the one channel of audio signals in English, the terminal  25  decodes them and plays them to the user. 
         [0068]    In the embodiments of the present invention, multiple stream media servers are used to support multiple audio tracks tasks in a shared way, wherein, one stream media server receives one channel of video signals and multiple channels of audio signals but outputs one channel of audio signals among the multiple channels of audio signals; or one stream media server receives one channel of video signals and one channel of the multiple channels of audio signals. The stream media servers work together to support output of the multiple channels of audio signals, and therefore can meet the users&#39; demands for multiple languages and save network resources, without the need for video replicators or too much live broadcast encoders, thereby decreasing the cost and facilitating maintenance. In addition, the technical solution of the present invention can be applied to a variety of wireless networks, such as GPRS (General Packet Radio Service), EDGE (Enhanced Data Rate for GSM Evolution), WCDMA (Wideband Code Division Multiple-Access), CDMA 2000 (Code Division Multiple-Access 2000), TD-SCDMA (Time Division—Synchronous Code Division Multiple Access), DVB-H (Digital Video Broadcast-Handheld), DMB (Digital Multimedia Broadcasting), and ISDB-T (Integrated Service Digital Broadcasting-Terrestrial), etc. In a mobile network, the terminals can use the interaction technique in a point-to-point manner (unicast technique) or use the technique through DVB-H, DMB, MBMS (Multimedia Broadcast Multicast Service), or Broadcast and Multicast Services (BCMCS) manner in multicast manner. 
         [0069]    Apparently, those skilled in the art could make various variations and modifications without departing from the spirit and the scope of the present invention. The present invention is intended to include all these variations and modifications if they fall within the scope of the appended claims and equivalents thereof.