关键词: 视频编码, H.264/AVC, 率失真优化（RDO）, 帧内预测, 能量函数

Abstract: H.264 introduces intra-prediction coding and uses Rate-Distortion Optimization（RDO） technique to decide the best intra-coding mode.Although the intra-prediction greatly improves the intra-coding efficiency，it enormously increases the computational complexity.In order to decrease the computational complexity of the algorithm，a fast algorithm for intra-prediction mode decision based on a DCT-based energy function is proposed.Experiments show that the proposed algorithm can save about a half of the computation time stably while maintaining the PSNR-Bitrate performance of H.264/AVC.

Key words: video coding, H.264/AVC, Rate-Distortion Optimization（RDO）, intra-prediction, energy function