Coefficient conversion for transform domain VC-1 to H.264 transcoding

This paper discusses the problem of transcoding between VC-1 and H.264 video standards. VC-1 uses an adaptive block size integer transform, which is different from the 4x4 integer transform used by H.264. We propose an algorithm to transcode the transform coefficients from VC-1 to those for H.264, which is a fundamental step for transform domain transcoding. The paper also presents a fast computation version of the algorithm. The implementation of the proposed algorithm shows that the quality of the video remains roughly the same while the complexity is greatly reduced when compared with the reference full cascade pixel domain transcoder.