A novel hybrid requantization transcoding scheme for H.264/AVC

Transcoding is a fast and elegant solution for the adaptation of video content. In the case of bitrate adaptation, an important technique is requantization transcoding. In this paper, we extend our previous work, that focused on requantization of intra-coded pictures, to P and B pictures. We show that by using a combination of techniques, depending on the slice and macroblock type, improved results are obtained when compared to previously existent architectures. We also show that in the important case of transcoding to low bitrates, results of this hybrid architecture approximate the rate-distortion performance of the computationally complex decoder-encoder cascade.