摘要
在研究了目前主流的视频转码方案基础上,提出了一种分布式转码系统。系统采用HDFS(Hadoop Distributed File System)进行视频存储,利用MapReduce思想和FFMPEG进行分布式转码。详细讨论了视频分布式存储时的分段策略,以及分段大小对存取时间的影响。同时,定义了视频存储和转换的元数据格式。提出了基于MapReduce编程框架的分布式转码方案,即Mapper端进行转码和Reducer端进行视频合并。实验数据显示了转码时间随视频分段大小和转码机器数量不同而变化的趋势。结果表明,相比单机转码,提出的系统在采用8台机器并行转码时,可以节约80%左右的时间。
Based on study of current video transcoding solutions, we proposed a distributed transcoding system. Video resources are stored in HDFS（Hadoop Distributed File System） and transcodod by MapReduce program using FFMPEG In this paper, video segmentation strategy on distributed storage and how they affect accessing time are discussed. We also defined metadata of video formats and transcoding parameters. The distributed transcoding framework is proposed on basis of MapReduce programming model. Segmented source videos are transcoding in map tasks and merged into target video in reduce task. Experimental results show that transcoding time is dependent on segmentation size and trascoding cluster size. Compared with single PC, the proposed distributed video transcoding system implemented on 8 PCs can decrease about 80% of the transcoding time.
出处
《计算机系统应用》
2011年第11期80-85,共6页
Computer Systems & Applications
基金
国家杰出青年科学基金(60525110)
国家973计划(2007CB307100
2007CB307103)
国家自然科学基金(61072057
60902051)
中央高校基本科研业务费专项资金(BUPT2009RC0505)
国家科技重大专项(2011ZX03002-001-01
2011ZX03002-002-01)
