先前提出計算4×4零區塊個數作區塊模式決策之演算法效能已很好，然而其在高位元率下編碼效益並不顯著，所以在本論文中，我們提出參照8×8和4×4零區塊分佈之快速區塊模式演算法，藉此減少低量化參數、高位元率下的運算複雜度，加快編碼的時間，並且利用不同移動量向量位移取得更多8×8以及4×4零區塊個數，最後提出適應所有編碼情況的結合演算法，其擷取先前與我們所提出演算法之優點，盡可能地達到編碼加速，除此之外，我們針對畫面內區塊模式作簡化動作，減少其I4MB區塊模式決策數目，使畫面內預測複雜度降低。從實驗數據顯示，我們所提出的演算法最快可減少73％左右的編碼時間，同時維持畫面品質在一定可接受的失真範圍之內。 In the previous work we presented a zero-block mode decision algorithm. Although it reduces the computation time base upon the number of zero blocks, its performance on time saving is still limited for high bit-rate. We therefore propose some methods to reduce the computational complexity of inter/intra mode decision as possible. At first, we find the improvement by using different motion vectors to compute the number of zero-blocks (ZBs). Then, we utilize both 8×8 and 4×4 zero-blocks distribution as another zero-block mode decision algorithm. Finally, we integrate these ideals into a hybrid algorithm and SATD-based for I4MB intra mode prediction. According to the experimental results, our proposed algorithm can achieve 73% of time saving on average while maintaining coding performance.
