MPEG-2到H．264下采样转码快速算法

A Fast Algorithm for Transcoding in Transform Domain and Downsampling from MPEG-2 to H.264

提出了一种从MPEG-2中的DCT系数到H.264中的HT系数转换并同时进行下采样的算法。提出的方法可同时进行DCT-HT系数转换和下采样两个过程,并根据变换矩阵的稀疏性和初始MPEG-2系数矩阵的特征,引入了快速算法,可减少大约82%甚者99%的运算量,而对于图像质量几乎没有降低。

The paper proposes an algorithm for converting MPEG-2 8-tap discrete cosine transform （DCT） coefficients to H.264/ AVC 4-tap integer Transform （IT） coefficients while downsampling at the same time. These are the indispensable operations for transcoding from MPEG-2 to H.264 in the transform domain. According to the characteristic of the transform matrix,we propose a fast algorithm, which can reduce up to about 82% or even 99% of computing time with negligible degradation in quality.