應用於H.264之位元失真率導向移動預測搜尋範圍調整演算法

Rate Distortion Oriented Search Range Adjustment Algorithm for Motion Estimation in H.264

李國龍(Gwo-Long Li)

《電腦與通訊》 145期 (2012/06) Pp. 5-12

https://doi.org/10.29917/CCLTJ.201206.0002

摘要

本研究提出了搜尋範圍重新調整演算法用以解決分數點移動預測因硬體設計因素導致參考資料未被從外部記憶體下載進來所造成的編碼效能下降。透過觀察移動向量子與非重疊區域尺寸之關係，本研究提出一數學公式予以描述。經由移動向量子的大小，即可計算出非重疊區域尺寸，進而重新計算所需之搜尋範圍尺寸。此外本研究亦提出一搜尋範圍長寬比調整演算法，透過移動向量子與非重疊區域尺寸關係之數學求解，可得到較佳之非對稱式搜尋範圍長寬比。模擬結果顯示，本研究所提的搜尋範圍調整演算法可顯著的改善分數點移動預測所造成的編碼效能下降。

關鍵字

搜尋範圍調整 ； 移動估測

並列摘要

To solve the problem of coding performance drop caused by the fractional motion estimation skipping due to hardware implementation consideration, this paper proposes two search range adjustment algorithms to adjust the search range for motion estimation so that the new decided search range can cover the absent reference data as much as possible. By mathematically modeling the relationship between motion vector predictor and non-overlapping area size, the new search range can thus be adjusted. In addition, a search range aspect ratio adjustment algorithm is also proposed in this paper by means of solving the mathematical equations. Through the proposed search range adjustment algorithm, the bitrate increasing can be significantly reduced when compared to fractional motion estimation skipping mechanism. Furthermore, the proposed search range aspect ratio adjustment algorithm can achieve better rate distortion performance when compared to the exhaustive search method under the same search range area constraint.

並列關鍵字

Search Range Adjustment (SRA) ； Motion Estimation(ME)