Efficient motion estimation algorithm for video transcoding
Mei‐Juan Chen, M. C. Chu, Chih-Wei Pan · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2000
In multimedia applications, it is often needed to adapt the bit-rate of the coded video bit streams to the available bandwidth of various communication channels. Because different networks may have different bandwidths, a gateway can include a transcoder to adapt the video bit-rates in order to provide video services to users on different networks. In transcoding, motion estimation is usually not performed in the transcoder because of its heavy computation complexity. To speed up the operation, a video transcoder usually reuses the decoded motion vectors from the incoming bit stream. Previously, the bilinear interpolation and forward with dominant vector selection (FDVS) methods were proposed to reuse motion vectors. In this paper, we propose a new algorithm called activity dominant vector selection (ADVS) which utilizes the quantized discrete cosine transform (DCT) coefficients of residual blocks for composing a motion vector from the incoming ones. In addition, a new motion vector refinement algorithm called variable step-size search (VSS) is presented. The performance can be improved and maintaining low computation complexity.