【摘要】 本文讨论了MPEG-2到MPEG-4视频转编码问题,提出了两种快速运动矢量重估算法,分别基于空域和时域。我们的算法利用已有运动信息和DCT变换的直流系数进行运动估计,可明显减少运算量,提高编码速度,并获得了与全搜索算法接近的图像质量,可满足网络视频传输的实时要求。更多还原

【Abstract】 The topic of heterogeneous video transcoding from MPEG-2 to MPEG-4 is discussed. Two algorithms of fast motion vector re-estimation in spatial and temporal domain are proposed respectively. Using existing motion information and direct coefficients of DCT to estimate future motion vector, computational cost can be reduced greatly by proposed algorithms. Encoding process can be speeded up and the quality of reconstructed picture is as good as by full searching. Using the proposed algorithms, real-time requirement for internet communication can be met satisfactorily.更多还原