A Fast Skip Mode Selection and Intra Mode Skip Decision Algorithm for H 264/AVC Video Coding

[[abstract]]H.264/AVC視訊壓縮標準為了要增加壓縮效能，採用RDO (rate-distortion optimization)技術來選擇區塊的最佳編碼模式，但是同時也會大大提升運算複雜度。在本論文裡我們提出一個加速模式選擇的演算法，這個演算法包含使用適應性門檻值來提早偵測skip模式和利用畫面間預測模式所選出最佳模式的RD cost來判斷畫面內預測模式是否該執行或省略，主要的想法來自於統計上skip模式在區塊編碼中常被採用，但畫面內模式較少採用的緣故。實驗結果顯示，我們的方法對於靜態影像的編碼時間有大幅地縮短，平均比JM14.2編碼模型約減少80%的編碼時間，視訊編解碼的品質及編碼位元率方面，仍然保有比JM14.2略為降低的效能表現。[[abstract]]In order to improve compression performance, H.264/AVC video coding standard employs the rate-distortion optimization (RDO) technique to choose the beat prediction mode for each variable-sized block. But it requires a significant increase in the computational complexity. It this paper, we propose a fast mode decision algorithm based on RD cost of reference frames. The proposed algorithm uses an adaptive threshold for early skip mode decision and the information of RD cost of inter mode selection for intra mode skip decision. The main idea is based on the skip mode with high probability and the intra mode with low probability in statistics for video sequence. The experimental results show that the proposed method can reduce substantially the encoding time about 80% for static sequence with negligible performance degradation, compared to JM14.2 reference software