中文摘要：

对H.264编码的视频流解码出现宏块丢失进行错误掩藏时,使用传统的时空域错误掩藏算法,并不能很好地恢复出原始视频帧,影响了主观观赏效果和客观视频质量.因此,分别对时空域提出了相应的改进算法.时域通过增加参考帧、运动矢量,改进匹配算法等,提高了运动矢量的搜索精确度和运动剧烈视频帧的错误恢复质量.空域通过自适应的选择加权像素平均插值和方向插值,并改进了方向插值算法,明显提高了视频帧的恢复质量,避免了错误边缘的产生.实验结果表明,改进的时空域错误掩藏算法,不仅提高了方向插值的准确性和宏块匹配的精确度,而且可以减少块效应的出现,从而有效地提高了丢失宏块的恢复质量.

英文摘要：

The traditional temporal and spatial error concealment techniques have not good performance when macroblock loss occurs in the decoding process of the H. 264 encoded video stream,which give rise to poor restoration of the original video frames,thus influence visual effect and video quality. This paper puts forward the improved algorithm in temporal and spatial domain. In temporal domain,the search accuracy of motion vector and motion video frame error recovery quality are improved by adding reference frame,the motion vector,and the improved matching algorithm. The improved error concealment algorithm of the spatial domain can adaptively select the weighted pixel average interpolation and directional interpolation,leading to the better quality of reconstructed video frame. The experiment results show that the proposed algorithms,not only improve the accuracy of direction interpolation and macro block matching,but also reduce the block effect. As a result,the quality of the recovery of lost macroblocks are improved effectively.