幀內預測是H.264采用的一種編碼新技術。與以前的編碼標準相比，H.264編碼性能有了很大的提高，但同時編碼復雜度和計算量也明顯增加。該文研究了提高H.264編碼速度的途徑，著重分析了幀內預測模式快速選擇的問題。經過分析發現，4X4亮度塊的參考像素亮度值通常具有相似性，對應地，,4X4亮度塊的9種預測模式所得的預測結果也是相近的。根據4X4亮度塊參考像素的這一特征，該文提出了一種基于4X4亮度塊參考像素特征的快速幀內預測模式選擇算法。實驗結果說明了該文算法的有效性，與H.264編碼器JM92相比，該算法的計算量減少了46%，而編碼質量、PSNR和輸出碼率保持基本不變。

Intra-prediction is one of the new techniques adopted by H.264. Compared with the previous video coding standards, H.264 improves coding performance greatly. However, the computation load of H.264 video coding increases drastically. This paper investigates improvement of encoding speed for H.264 with special focus on fast intra prediction mode selection. Some experimental analyses indicate that the luminance values of the reference pixels for each 4 x 4 luminanceb locka rec ommonlys imilar,an din th atca se,th ep redictionb lockso fth en inep redictionm odesa rea lsos imilar. According to this feature of 4 x 4 luminance block, a fast mode selection algorithm for intra prediction is proposed. Experimentalre sultssh owt hep roposeds chemeis v ery efective.C omparedw ithJ M92in H .264e ncoder,it re duces4 6%encoding time while maintaining the PSNR and bit rate