视频编码中考虑模式选择的位率优化控制

本文在传统位率控制方法的基础上提出一种新算法，即基于宏块的最佳位率控制算法．主要思想是在考虑还宽，比特率和缓冲区大小的同时，考虑不同宏块模式的选择对位率的影响，文中给出了一些相关结果并将其与传统方法所得数据相比较，结果表明在多数位率条件下用本算法得到的ＰＳＮＲ比传统方法要好．

OPTIMAL RATE CONTROL FOR VIDEO CODING WITH CONSIDERING MODE SELECTION FACTORS

Rate control is very important in video coding and transmission system. Traditional rate control algorithm is restrained with bandwidth and buffer size based on frames. Nowadays prevalent video coding standard such as ITU H.261, H.263 and ISO MPEG1, MPEG2, MPEG4 all are based on macroblocks. Several kinds of macroblocks coding mode also have been given in these international video coding standards. Optimal rate distortion function is not just restrained with bandwidth, bit rate and buffer size, different macroblocks mode choice will also influence rate distortion function. This paper present a new algorithm based on traditional rate control method. Namely optimal rate control algorithm based on macroblocks. Its main contribution is that not only bandwidth, bit rate and buffer size are to be considered, but also take into account the influence of different macroblocks mode choice. Some related experimental results have been given and compared with traditional rate control method. Results show that PSNR of the proposed algorithm is better than the traditional method in various rate conditions.