The application of audio-video data transmission in distance education

Since entering the 21st century, with the rapid development of computer and network communication technology, the traditional teaching mode of education is facing great challenge. The use of Internet for online teaching and the development of Web-based courses has become an important issue in the educational technology sector and the reform trend. Audio and video transmission in the distance education has been widely used and has been a good result. Among them, such as Noah's Point reader remote education using the Anychat SDK audio and Video development application package, in the audio and video teaching to achieve a very good market share, visible audio and video network education in the future trends to be developed.

1. Streaming Media technology

For some smaller audio and video files, you can save them to your local computer by downloading them and then watch them. But for most of the files with video, the one-hour program needs to occupy hundreds of MB, or even a few gigabytes of storage space, the use of download viewing method is not convenient. In addition, for some of the more time-sensitive programs, obviously using the download method can not meet the requirements of live, therefore, it is necessary to adopt a kind of transmission mode-----stream transmission.

The use of streaming audio and video information, the need to use a dedicated streaming media server to the customer end users to send video images, sound, animation and other multimedia information, its transmission process by the streaming media server in a continuous, real-time send to the client. So that users do not have to wait for all the files to be downloaded to the local to watch, but to receive data from the streaming media server, while in the client's multimedia playback software to view the data uploaded to the local, and in the process of playback, the playback software is still continuously receiving the data sent by the server, so you can continuously see the program.

With streaming, users can see the program in real time. The real-time talk here is actually a little bit of a delay for some live shows, such as watching internet TV programs that are usually 2 minutes or so longer than the ones that are transmitted to the TV in the broadcast network. One of the reasons for the delay is the impact of network transmission speed, another important reason is that these multimedia programs need a video compression conversion process. Of course, with the development of streaming media technology, the future can be fully synchronized in full real-time.

2. Setup of Live Encoding server

Live Encoding server includes a high-performance multimedia computer, a Oserpy-210 streaming media card, a Sony DVC33 camcorder one, the specific settings are as follows:

Configuration of the live Stream encoder 1 (multimedia computer)

(1) "Start"-"program"-"Windows Meadia"-"Windows Meadia encoder";

(2) Popup "New Session" dialog box, select "Broadcast live Event" and "OK";

(3) Click "Next", Pop Up the "Broadcast Method" dialog box, select "Self-encoder pull transfer";

(4) Click "Next", Pop Up the "Broadcast Connection" dialog box, randomly find the available HTTP port, here we select "1085" port;

(5) After continuous "Next", click "Finish", pop Up "Windows Meadia Encoder" interface, click the "Start Encoding" button, the encoding begins.

At this point, audio and video live streaming encoding server completed.

3. Streaming Media server Configuration

The operating system used by this streaming media server is WindowsServer 2003, as described in the following:

(1) "Start"-"Settings"-"Control Panel"-"Administrative Tools"-double-click "Windows Mediaservices" to pop up the Windows mediaservices control interface;

(2) on the publishing point, right-click, select Add Publishing Point (Advanced), and the Add Publishing Point dialog box appears.

(3) Click "OK" to return to the Windows Media Services control interface and the streaming media server configuration is complete.

4. Client Test Live

"Start"-"Run", enter "mms://teacher/live", "OK" will automatically start the "Windows Meadia player" player, start to play "live", so far, based on the network streaming media technology audio and video live successfully.

This paper describes a method of using Windows Media Services streaming media server to implement a network-based audio and video live broadcast. In the actual use process, the audio and video obtained from the camera can be smoothly transmitted over the network to the client, achieving a more satisfactory effect. A friend who wants to develop audio and video through the development package can download the demo test on the Anychat website, which contains development documents and some source code, which is the best tool choice for personal research and business two development.

The application of audio-video data transmission in distance education