OpTrans:一个率失真优化的MC-EZBC转换编码算法

OpTrans:a Rate-distortion Optimized MC-EZBC Video Transcoding Algorithm

可伸缩性视频转换编码算法是大型分层视频组播系统层次化代理自适应机制的核心技术.好的转换编码算法不仅要满足拥塞速率控制的要求,而且要使分层视频组播流中的增强层数据以率失真优化的方式进行截断,以提高接收者的接收效能.本文对可伸缩三维小波编码算法MC-EZBC视频转换编码的联合率失真目标函数和优化算法进行了深入研究,提出了率失真优化的MC-EZBC转换编码算法及其分层速率控制方法.对比实验结果表明,采用了联合率失真优化后的转换编码码率控制方法比原有的按顺序截断方法可提高平均视频质量PSNR0.3-0.5dB,进而可优化大型分层视频组播系统的整体效能.

Scalable video transcoding is the key technology of a adaptive mechanism for hierarchical agents in a large-scale layered video multicast. An ideal transcoding scheme can not only meet the requirement for congestion control, but also optimize truncating bits of enhancement layers according to rate-distortion theory for maximizing receiving utility. This paper focus on the joint rate-distortion target model and optimized algorithm of MC-EZBC, a scalable 3D wavelet codec, and then propose a rate-distortion optimized transcoding algorithm and its layered rate control method. Experimental results show that our method can improve the average video quality PSNR by 0. 3-0. 5dB in comparison with the existing ordered truncating method, and can further optimize the total utility of a large-scale layered video multicast system.