1 Adaptive Variable Block-Size Early Motion Estimation Termination Algorithm for H.264/AVC Video Coding Standard Mohammed Golam Sarwer and Q. M. Jonathan Wu, Senior Member, IEEE IEEE TRANSACTIONS on CIRCUITS and SYSTEMS for VIDEO TECHNOLOGY, Vol. 19, No. 8, AUGUST 2009 報告者：廖子勳

2 Outline 1. Introduction 2. Algorithm of Proposed Early Termination 3. Statistical Analysis of Rd Cost Function 4. Threshold Selection 5. Region-based Search Order For Full Search ME 6. Search Point Reduction In Multihexagon Grid Search 7. Simulation Results 8. Conclusion

3 1. Introduction 在 H.264 架構下，對 Rate distortion(RD) cost 進行門檻值比對，來中斷不必要的 搜尋。

4 2. Algorithm of Proposed Early Termination SAD ：絕對誤差和 Ft ：目前影像 Ft-1 ：參考影像 N ： MB 大小 (u,v): 搜尋中的座標

5 2. Algorithm of Proposed Early Termination mv: 目前的 MV : Lagrangian multiplier SAD: 絕對誤差和 pmv: 預測的 MV R: 編碼後所需的位元量 Rate distortion (RD) costs

6 2. Algorithm of Proposed Early Termination

7 3. Statistical Analysis of Rd Cost Function

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9 4. Threshold Selection J t-1 :Frame t-1’s RD cost J t-2 :Frame t-2’s RD cost

10 4. Threshold Selection m=2 、 3 、 4 m=5 、 6 、 7 S m =2 for m=2 、 3 、 5 、 6 S m =4 for m=4 、 7

11 4. Threshold Selection =500 A=50 B=1/8 D=45

12 5.Region-based Search Order For Full Search ME(Motion Vector)

13 5.Region-based Search Order For Full Search ME(Motion Vector)

14 5.Region-based Search Order For Full Search ME(Motion Vector) R=1 、 2 、 … 16 但是 不等於最佳區域

15 5.Region-based Search Order For Full Search ME(Motion Vector)

16 6. Search Point Reduction In Multihexagon Grid Search

17 7. Simulation Results

18 7. Simulation Results

19 7. Simulation Results

20 8. Conclusion 此方法節省了相對於全域搜尋 & 快速搜尋 演算法，節省了 63~93% 的搜尋點