基于漏斗的实时VBR视频最短路径平滑算法①

针对实时VBR视频流式传输的在线平滑优化问题，提出一种基于漏斗的最短路径平滑算法——SPSF。SPSF利用滑动窗口对实时VBR视频进行分段处理，顺序读取和缓存每帧视频数据至窗口，并基于漏斗原理求解窗口内数据的最短路径。数据填满窗口后根据求得的最短路径进行传输，同时根据路径特征推进窗口滑动进行下一段数据的平滑处理及传输，以此类推完成整个视频平滑传输。实验结果表明。与传统的在线平滑算法相比，SPSF具有更优的传输比特率峰值、传输比特率谷值、及传输比特率方差；与传统的最短路径算法相比，SPSF具有更快的最短路径求解速度，提高了视频传输的实时性。

Shortest Path Smoothing Algorithm for the Real-Time VBR Video Based on Funnel

To optimize online smoothing of real-time VBR video streaming, this paper proposes a SPSF（Shortest Path Smoothing based on Funnel） algorithm. In the SPSF, the real-time VBR video is piecewise processed by sliding window. Each video frame is read and cached into the window andthe shortest path for the data transmission in the window is calculated based on funnel principle. When the window is filled with data, data start transmission according to the obtained shortest path. Window simultaneously slides according to the characteristics of the path to start smoothing and transmission of the next piece, and so complete the smooth transmission of the entire video. The experimental results show that compared with conventional online smoothing algorithm, SPSF has better bit-rate peak, valley, and variance. Compared with traditional shortest path algorithm, SPSF takes less time in computation of shortest path so as to be able to meet the real-time requirement.