- 會議論文
- OpenAccess
H.265/HECV 畫面間預測之提早終止Merge 預測模式決策法
摘要
H.265/HEVC 視訊壓縮標準在進行畫面間預測時，會針對每個模式進行成本函數的計算與比較，從中挑選出最佳的模式當作當前區塊的編碼模式。因為每個模式都必須運算一次，因此在模式選擇時所花費的計算複雜度是非常高的，且必須在失真度與位元率之間去做取捨。因此本篇論文著重於降低模式選擇的計算複雜度，利用編碼組態所使用的QP 值與計算Merge 模式中的SKIP模式的成本函數設定門檻值，使編碼能提前結束模式選擇，達到減少編碼時間的目的。實驗結果顯示，我們所提出的提早終止模式選擇演算法與H.265/HEVC 參考軟體HM16.9原本的模式選擇演算法相比，平均能節省43%~49%左右的編碼時間，但只有少量的位元率增加與視訊品質損失。
並列摘要
When the H.265/HEVC standard processes the mode decision in the inter-frame prediction, it computes the RD cost of each mode and gives the comparison among entire cost functions to obtain the optimal inter-frame prediction mode. Hence, the computational complexity of the inter-frame prediction in H.265/HEVC standard is very high. In this thesis, we propose an early termination algorithm for the procedure of the inter-frame prediction using two thresholds. A predefined threshold corresponding to the QP value is used to determine whether the inter-frame prediction is skipped after the merge mode if the RD cost function of optimal merge mode is less than the threshold value. And, a threshold calculated from the average of RD costs of five SKIP modes in merge mode is used to determine whether the next inter-frame prediction modes are skipped if the cost function of the current inter-frame prediction mode is less than the threshold value. The experimental results show that the proposed algorithm can save 43%~49% of total encoding time on average compared to the original mode decision in H.265/HEVC reference software HM16.9 with negligible performance degradation in the bit rate and the quality of reconstructed video.