基于DASH的混合控制码率算法

发布时间：2018-01-20 12:35

本文关键词： 基于HTTP的动态自适应流缓存区带宽预测码率选择流媒体　出处：《计算机应用》2017年10期 　论文类型：期刊论文

【摘要】：针对平滑流(SF)算法在带宽预测时存在的"毛刺"现象以及仅依靠带宽预测而没有缓存区控制所导致的频繁播放停滞的问题,提出一种动态自适应混合控制码率算法。首先,通过使用标准差来代替原SF算法中波动参数的计算,消除了预测带宽存在的"毛刺"现象;其次,针对原SF算法存在没有考虑缓存区状态所带来的频繁播放停滞问题以及传统缓存区控制算法存在分级困难的问题,引入一种基于缓存区容量的新型缓存区控制策略;最后,将改进SF算法与新型缓存区控制策略相结合形成混合算法来选择视频码率。实验结果表明,混合算法不但消除了原SF算法在带宽预测中存在的毛刺现象,而且弥补了仅依靠单一算法选择码率的不足,使得所选码率视频既降低了播放停滞频率(恶劣网络环境下效果明显,降低43%左右)又符合实际网络情况,提高了用户的观看体验。
[Abstract]:Aiming at the problem of "burr" in bandwidth prediction of smooth streaming SFI algorithm and the problem of frequent playback stagnation caused by only relying on bandwidth prediction without buffer control. A dynamic adaptive hybrid control rate algorithm is proposed. Firstly, the "burr" phenomenon of the predicted bandwidth is eliminated by using standard deviation instead of the calculation of fluctuation parameters in the original SF algorithm. Secondly, the problem of frequent playback stagnation caused by the state of cache is not considered in the original SF algorithm, and the traditional buffer control algorithm has difficulty in grading. A new buffer control strategy based on buffer capacity is introduced. Finally, the improved SF algorithm and the new buffer control strategy are combined to form a hybrid algorithm to select the video bit rate. The hybrid algorithm not only eliminates the burr phenomenon of the original SF algorithm in bandwidth prediction, but also makes up for the lack of only relying on a single algorithm to select the bit rate. The selected bit-rate video can not only reduce the frequency of playback stagnation (the effect is obvious under the bad network environment, reduce about 43%), but also accord with the actual network situation, and improve the user's viewing experience.
【作者单位】：中北大学计算机与控制工程学院;
【基金】：国家自然科学基金资助项目(61379080)~~
【分类号】：TN919.8
【正文快照】： 0引言随着互联网以及移动智能终端的高速发展,多媒体服务在人们的日常生活中起到越来越大的作用[1]。但是随着多媒体数据流量的增加和用户要求的不断提高,当前广泛使用的基于用户数据报协议(User Datagram Protocol,UDP)的实时传输协议/实时流传输协议(Real-time Transport Pr

【相似文献】