A fast mode decision algorithm for intra prediction in AVS-M video coding

AVS-M is the latest video coding standard developed by China for mobile application, which promises improved performance close to H.264/AVC with lower complexity. AVS-M provides several predicting modes in the intra prediction. In order to achieve the best performance, the rate distortion optimization (RDO) technique should be used to choose the most suitable predicting mode. However, the computational complexity of rate distortion optimization technique is very high. As a result, it is difficult to satisfy the requirement of practical application such as real time video communication. To solve this problem, a fast mode decision algorithm for intra prediction suitable for AVS-M is presented in this paper. Based on the inherent correlation within a single frame and temporal correlation between successive frames, part of intra prediction modes are chosen to determine the best prediction mode for image block, which can decrease the calls of rate distortion function. Experimental results show that the algorithm can reduce the computational complexity of intra prediction while maintaining PSNR and bit rate almost unchanged.