H.264為最新的影像壓縮編碼標準，它擁有眾多有線或無線傳輸上的工業應用。然由於H.264要達到各高的壓縮率或是更為精細的品質，因此H.264它需要更為複雜的計算，以至於需要耗費大量的時間以供運算。

本篇論文我們將改進H.264中的P frame inter prediction計算複雜度，試著找出一個快速而卻不嚴重影響預測品質的演算法。我們的方法是，首先我們主要利用鄰近區塊的特性來決定是否為skip mode，由於若是鄰近區塊及前一區塊皆利用skip mode編碼的區塊很可能它也是skip mode，反之若是週遭皆為細碎區塊則表示此區塊需要利用較小區塊編碼的可能性很大，因此判定為非skip mode。然後利用本身區塊的平滑程度來計算並提供他提早收歛條件，若是平滑區塊則要求他提早收歛，若非平滑區塊才一一嘗試找出最適合的區塊。由於可限定一區塊可選擇的模式，也因此能夠提升他計算的速度精簡它所須計算。

H. 264 is the latest coding standard for video compression. It has a lot of industry applications for wired or wireless transmission. However, the H.264 requires complex computation for motion estimation because it tries to find the best subdivision for each 16 x 16 block.

We will improve the computational time of the inter prediction for P frames in H.264 video. Our proposed method first categorise macroblocks into two types, “skipped” and “not skipped”. Then, our method tries to find the most appropriate sub-block for motion estimation. Because our method does not involve computation for 16 x 16 blocks, 16 x 8 or 8 x 16 blocks for motion estimation it can reduce the computation time.

Abstract (in Chinese)---------1

Abstract (in English)---------2

Acknowledgements--------------3

Contents---------------------4

List of Figures---------------5

List of Tables----------------6

1.Introduction----------------7

2.Related work----------------9

3.The Proposed Method---------11
Block Base-----------12
Pixel Base-----------15

4.Discussions and Experimental Results------18

5.Conclusion------------------------23

Reference:--------------------------24

References：
[1]. Hongtao Yu, Zhiping Lin and Feng Pan, “Applications and improvement of H.264 in medical video compression” IEEE Trans. IEEE Transactions on Circuits and Systems Part I: Regular Papers Volume 52, Issue 12, Dec. 2005 Page(s):2707 – 2716
[2]. Ming Yin and Hong-yuan Wang, “An improvement fast INTER mode selection for H.264 joint with spatio-temporal correlation” Wireless Communications, Networking and Mobile Computing, 2005. Proceedings. 2005 International Conference on Volume 2, 23-26 Sept. 2005 Page(s):1237 – 1240
[3]. Wu, D., Wu, S., Lim, K.P., Pan, F., Li, Z.G. and Lin, X. “Block INTER mode decision for fast encoding of H.264” Acoustics, Speech, and Signal Processing, 2004. Proceedings. (ICASSP '04). IEEE International Conference on. Volume 3, 17-21 May 2004 Page(s):iii - 181-4 vol.3
[4]. Yu, A.C.” Efficient block-size selection algorithm for inter-frame coding in H.264/MPEG-4 AVC” Acoustics, Speech, and Signal Processing, 2004. Proceedings. (ICASSP '04). IEEE International Conference on Volume 3, 17-21 May 2004 Page(s):iii - 169-72 vol.3
[5]. “Fast Mode Decision for Inter Frames in H.264/AVC” Communications and Information Technology, 2005. ISCIT 2005. IEEE International Symposium on Volume 1, 12-14 Oct. 2005 Page(s):433 - 436
[6]. Jeyun Lee and Byeungwoo Jeon “Fast mode decision for H.264” Multimedia and Expo, 2004. ICME '04. 2004 IEEE International Conference on Volume 2, 27-30 June 2004 Page(s):1131 - 1134 Vol.2
[7]. Zhao, Y.and Richardson, I.E.G., ” Macroblock skip-mode prediction for complexity control of video encoders” Visual Information Engineering, 2003. VIE 2003. International Conference on 7-9 July 2003 Page(s):5 - 8
[8]. Jing, X.and Chau, L.-P., “Fast approach for H.264 inter mode decision” IEEE Electronics Letters Volume 40, Issue 17, 19 Aug. 2004 Page(s):1050 - 1052
[9]. F. Pan, X. Lin, R. Susanto, K. P. Lim, Z. G. Li, G. N. Feng,D. J. Wu, and S. Wu, “Fast Mode Decision Algorithm for Intra Prediction in JVT”, JVT-G013, 7th JVT meeting, Pattaya, March 2003.
[10]. Ralf Schafer, Thomas Wiegand and Heiko “The emerging H.264/AVC standard” EBU TECHNICAL REVIEW – January 2003