一种自适应的视频流化前向纠错算法

网络视频应用经常会受到数据包丢失或错误以及网络带宽资源不足的干扰.相关研究表明:在多数情况下,动态变化的网络带宽和丢包率是影响视频流化质量的关键因素.因此,为了保证视频质量,可以采用前向纠错(forward error correction,简称FEC)编码来提高视频数据传输的可靠性;同时,为了适应网络状态的变化,发送端可以调节视频数据的发送速率,并在视频源数据与FEC数据之间合理分配网络传输带宽.首先通过对视频流结构的分析,在充分考虑帧之间的依赖关系和帧类型的基础上提出了一种帧的解码模型.在此基础上,建立了用于在视频源数据和FEC数据之间分配网络带宽资源的优化算法.实验表明,该模型可以有效地适应网络状态的变化,并通过优化分配网络带宽资源来使接收端获得最大的可播放帧率.

An Adaptive Forward Error Correction Algorithm for Streaming Video

Video applications over network are often disturbed by data packet loss or errors as well as the insufficiency of network bandwidth. Some related studies have demonstrated that in many cases, the fluctuation of network bandwidth and packet loss rate are two key factors that influence the quality of video streaming. Therefore for guaranteeing video quality, FEC (forward error correction) can be adopted to improve the reliability of video data transmission; meanwhile, according to the current network state, the sender can adjust the sending rate of video data and optimally allocate the bandwidth resource between the video source data and FEC data. This paper analyzes the structure of video stream, and presents a frame decoding model that takes into account the frame types and the dependence among frames. On this basis, an optimal algorithm is proposed to allocate the bandwidth resource between the source video data and the FEC data. Experiments show that the model can effectively adapt to the fluctuation of network state, and optimally allocate network bandwidth so as to maximize the playable frame rate on receiver.