H.264/AVC是由ITU-T以及MPEG所共同推舉的最新一代視訊編碼標準，與其它現有的視訊標準相比，H.264提供了一些新的編碼技術，像是畫面內模式預測，其主要的目的是用來去除畫面內的冗餘。然而這項技術在編碼過程中也耗費相當多的運算時間。因此，如何對畫面內預測作複雜度降低將是本篇論文討論的方向，在此我們提出一個依據低頻交流值來對畫面內作加速編碼，其中低頻交流值是由區塊內的離散餘弦轉換係數所取得的，用來事先判斷畫面內的預測尺寸，減少進入碼率失真成本計算的候選模式。後面將秀出實驗結果，我們發現在可接受的效能失真狀況下，能讓運算複雜度大幅降低。 H.264/AVC is the latest video coding standard recommended by ITU-T and MPEG. Compared with all existing video coding standard, H.264 provides some of new coding techniques, such as intra mode prediction. It plays an important role for reducing temporal redundancy. However, it takes most computational complexity in the coding process. In this paper, we propose an efficient intra mode prediction algorithm based on AClow components. It is acquired from DCT coefficients to judging intra prediction size in advance. The experiment results show that the significant reduction of computational time with negligible video quality degradation.
