Improved Prediction Estimation Based H.264 to HEVC Intra Transcoding

High Efficiency Video Coding HEVC achieves significant coding efficiency improvement at a cost of much higher computation complexity. In this paper, we propose a prediction estimation based H.264 to HEVC intra transcoder. In HEVC intra coding, the most complexity comes from coding unit size decision. The proposed method judges the coding unit size not only by using the intra prediction mode, prediction direction and other information from H.264 decoder, but also by trying the prediction on decoding picture with the most dominant prediction directions of H.264. Both of this information is fed into the classifier. Then the Support Vector Machine SVM classifiers were trained and apply to different division level to improve the speed of coding unit size decision accuracy loss as small as possible. Experiment shows that about 1.42 times speed up over the HEVC HM 10.0 reference software at about 0.069dB rate distortion performance loss.