Reduced spatio-temporal transcoding using an intra refresh technique

This paper addresses the problem of transcoding compressed video bitstreams to reduced spatio-temporal resolutions. We propose a new technique to compensate drift error based on the principle of intra-block refresh. We also investigate other important issues related to the transcoding, such as the re-estimation of motion vectors and DCT coefficients. The rate control related to intra-refresh is also addressed. Our experimental results show that the intrarefresh method offers a good trade-off between quality and complexity in comparison to the reference method.