为了克服IP网络环境下网络扰动对流媒体连续播放的影响,从接收端的角度来解决流媒体连续播放问题,提出一种基于PI控制的实时视频流连续播放控制算法.该方法在接收端使用根轨迹法设计PI控制器,通过控制播放速率,调节缓冲区的长度,实现了媒体的连续播放.为了真实地反映网络传输对接收端播放的影响,本文构建了一种基于TFRC协议的实时视频流传输控制框架.NS2仿真实验表明该方法与其他方法相比,播放质量明显提高,缓冲区出现欠载和溢出的机率明显降低,视频帧端到端平均时延明显缩小,实时性能明显增强.
In order to eliminate the influence of network disturbance on continuous playback of streaming media.An algorithm for real-time video continuous playback based on PI controller is proposed,which deals with the problem in the sink.The playback rate is controlled by PI controller,which is applied to achieve continuous media playback by controlling the buffer level of the sink.A framework of real-rime video transmission based on TFRC is constructed to get real influence of transmission on video playback.Experiments show that compared with the existent methods it has especially better playback quality and that the probability that the buffer overflows or underflows is smaller and that the real-time capacity is great improved for end-to-end average delay of video frame is shorter.