降低空间分辨率视频编码转换方法  

Method for Reduced Spatial Resolution Video Transcoding

作　　者：李晓辉[1] 竺亮[2] 

机构地区：[1]安徽大学电子科学与技术学院,安徽合肥230039 [2]安徽电视台,安徽合肥230066

出　　处：《计算机技术与发展》2006年第6期29-31,共3页Computer Technology and Development

基　　金：安徽省自然科学基金资助项目(03042209)

摘　　要：根据漂移误差与帧间编码块的运动活动性的关系,提出了一种自适应帧内刷新方法。该方法根据目标比特率和实际比特率的差值,动态地调整阈值,从而有效地减少了帧内编码的比特率,保持了对差错的鲁棒性,限制了差错的时间传播。同时,根据率失真定理,在保证失真最小的情况下,为帧内不同的宏块选用最佳的量化系数。仿真结果表明:文中提出的方法有效地平滑了缓冲器的输出,同时峰值信噪比也有所提高。A self-adaptive intra-refresh scheme based on the relation between drift error and motion activity of intercoded blocks is proposed in this paper. The thresholds are dynamically adjusted according to the difference between the target bit rate and actual bit rate. This method can reduce the bit rate of intra coded frames while still maintating error robustness and limiting temporal propagation of errors. Besides, we present a new method for rate- distortion optimized coding mode selection. Using this method, we minimize distortion subject to the target rate constraint, and ohtain formulas that indicate how to choose the quantization parameters. The simulation results show that the buffer fullness tend to be stabilized and the PSNR of the reconstructed image is raised.

关 键 词：视频编码转换 降低空间分辨率 自适应帧内刷新 率失真最佳 速率控制 

分 类 号：TN919.81[电子电信—通信与信息系统]