网络教学直播系统屏幕数据传输差错控制研究

Error control research of screen data transmission in live-cast network teaching system

针对目前网络教学直播系统中,屏幕数据量大,刷新慢的特点,采用了一种基于关键帧的图形压缩算法并提出了基于关键帧提取的选择性重传的差错控制机制。该机制根据来自接收端的反馈信息,重传在传输过程中丢失的关键帧数据来限制差错的扩散,同时在接收端屏蔽关键帧数据的丢失对回放效果的影响。实验结果表明:该机制具有降低网络资源需求,实现容易,在保证屏幕信息实时性要求的前提下,提高回放质量。

Aimed at the situation involving such problems as the screen refreshing slowly, the screen data is huge in the currently available live-cast network teaching system, an effective image compression algorithm is selected and a better error control mechanism of selective retransmission based on key flame extraction techniques is proposed. According to the feedback information from the receiver, the sender retransfers the key frame data that lost in the process to limit the diffuse of error. And the effect to the playback quality caused by the loss of key-frame is shielded at the receiver. The experimental result indicated the mechanism can reduce the request of network resources and can be implemented easily. In addition, the quality of the playback of screen data can be improved while the real-time requirement being guaranteed.